Part 2 book “Key notes on plastic surgery” has contents: The upper limb, the lower limb, the trunk and urogenital, burns, aesthetic surgery, ethics, the law and statistics.Invite to reference.
CHAPTER The Upper Limb CHAPTER CONTENTS Embryology, 309 Congenital deformities, 311 Hand trauma, 329 Hand infections, 351 Complex regional pain syndrome (CRPS), 355 Nerve compression, 357 Traumatic brachial plexus injury, 371 Obstetric brachial plexus palsy, 382 Tendon transfers, 384 Dupuytren’s disease, 388 Tumours, 396 Arthritis, 401 Miscellaneous tendinopathy, 417 Further reading, 419 Embryology Developmental anatomy • Upper limb bud appears in the flank of the embryo on day 26 • Consists of a core of lateral plate mesoderm covered by ectoderm ∘ This mesoderm will differentiate into bone, cartilage and tendon • Ectoderm thickens at the tip of the bud in the anteroposterior (AP) axis to form the apical ectodermal ridge (AER) ∘ In the embryo, the AP axis is analogous to the radio-ulnar axis • The limb bud is initially supplied by a capillary network • This coalesces into a main stem artery that drains into a marginal vein ∘ Artery becomes the subclavian-axillary-brachial axis ∘ Vein becomes the basilic-axillary-subclavian axis • The brachial artery branches into interosseous and median arteries ∘ The median artery provides the main blood supply to the hand ∘ It is usually replaced by ulnar and radial arteries around day 44 ∘ Regresses to provide the blood supply of the median nerve • By day 33 a paddle-shaped hand is present Key Notes on Plastic Surgery, Second Edition Adrian Richards and Hywel Dafydd © 2015 John Wiley & Sons, Ltd Published 2015 by John Wiley & Sons, Ltd 309 310 Chapter • Prechondrogenic condensations of mesenchyme appear where skeletal elements will form • Around day 36, nerve trunks enter the arm • Somitic mesoderm invades the limb and aggregates into dorsal and ventral masses ∘ These differentiate into myoblasts that become muscle • By day 42, digital rays are present and the hand assumes a webbed appearance • During the 7th week, upper limbs rotate 90∘ laterally to bring the palm anteriorly • At the same time, the elbow begins to flex • During this period, ossification begins and digital separation occurs ∘ This occurs by the apoptosis of tissue between finger rays • By the 8th week, the upper extremity resembles a miniature adult upper limb Mechanisms of development • Our understanding comes largely from transplanting tissue within chick embryos • Discrete cell signalling pathways establish the three axes of limb development: Proximodistal axis • Controls how the limb differentiates into a shoulder proximally but fingers distally • The critical area is the AER ∘ Resection of the AER results in a truncated limb ∘ Earlier resection results in more proximal limb truncation ∘ Grafting of the AER elongates limbs of chick embryos • AER produces fibroblast growth factors (FGFs), most importantly FGF 2, and Anteroposterior axis • Controls how an ulna and little finger develop on one side but a radius and thumb on the other • The critical area is the zone of polarising activity (ZPA) ∘ ZPA is a cluster of mesenchymal cells in the posterior limb bud margin ∘ Grafting of ZPA cells to the anterior limb margin induces mirror image duplication • The ZPA produces Sonic hedgehog (Shh) ∘ Higher concentrations of Shh result in more posterior (ulnar) digits being formed • Cells of the AER and ZPA are interdependent: ∘ FGFs from the AER are required for Shh expression ∘ Shh signal is required to maintain AER integrity • This may explain why loss of elements often occurs in both AP and proximodistal axes Dorsoventral axis • Controls how the limb differentiates into a dorsal and palmar surface • The critical area is non-AER ectoderm ∘ Removing and replacing ectoderm from a chick limb bud, having reversed its dorsoventral polarity, will produce a reversal in the polarity of the underlying mesoderm • Wnt-7a is a protein encoded by the WNT7A gene ∘ WNT7A is expressed specifically by dorsal limb ectoderm and determines dorsal limb identity, e.g fingernails ∘ Wnt-7a activates expression of LIM homeodomain factor Lmx1 The Upper Limb 311 • In contrast, ventral ectoderm expresses engrailed-1 (en-1), which inhibits Wnt-7a and restricts its actions to the dorsal ectoderm • Failure of these systems produces duplicated palms or circumferential fingernails Congenital deformities Classification • Swanson’s classification is widely accepted • The following account does not include the full hierarchy of the classification: I Failure of formation of parts (arrest of development) A Transverse arrest • Shoulder, arm, elbow, forearm, wrist, carpal, metacarpal, phalanx B Longitudinal arrest • Radial ray • Ulnar ray • Central ray (cleft hand) • Intersegmental (intercalated) type of longitudinal arrest II Failure of differentiation (separation) of parts A Soft tissue involvement • Arthrogryposis • Cutaneous syndactyly • Camptodactyly • Thumb-in-palm deformity B Skeletal involvement • Clinodactyly • Osseous syndactyly • Symphalangia • Elbow, forearm and carpal synostosis C Congenital tumorous conditions III Duplication • Whole limb, humerus, radius, ulna • Mirror hand • Radial polydactyly (preaxial polydactyly) • Central polydactyly • Ulnar polydactyly (postaxial polydactyly) IV Overgrowth • Whole limb • Macrodactyly 312 Chapter V Undergrowth • Whole limb, whole hand • Brachymetacarpia • Brachysyndactyly, with or without absence of pectoral muscle • Brachydactyly VI Congenital constriction band syndrome • Constriction band either with or without lymphoedema • Acrosyndactyly • Intrauterine amputation VII Generalised skeletal abnormalities • Chromosomal abnormalities • Other generalised abnormalities • This classification is based on work published in the 1960s and 1970s • As understanding of the pathogenesis has progressed, the shortcomings of the classification have become evident • Differentiating between transverse arrest, brachysyndactyly and symbrachydactyly (previously termed atypical cleft hand) can be difficult: ∘ Some consider brachysyndactyly and symbrachydactyly to be the same entity, on a continuum with transverse arrest, rather than classified as undergrowth ∘ Buck-Gramcko wrote in 1999: ‘The Congenital Committee of the IFSSH has recognized the problem of symbrachydactyly classification since 1995 but has not come to any conclusions and recommendations’ ∘ Swanson himself noted: ‘Brachysyndactyly could be placed in either Category I or II because of some of its features … Its most obvious failure clinically, however, is hypoplasia or undergrowth, and for that reason it is placed in Category V’ Failure of formation Transverse arrest • Can occur at any level • Most common at the junction of proximal and middle thirds of the forearm • Treatment is usually non-surgical with a prosthesis from months ∘ Children with unilateral deformities tend to discard the prosthesis • When there are metacarpal remnants, these may be amenable to: ∘ Distraction lengthening ∘ Free phalangeal or toe transfer Longitudinal arrest Radial deficiency • A spectrum of abnormalities affecting the radial side of the forearm • Radius, radial carpus, thumb, tendons, ligaments, muscles, nerves and blood vessels can all be involved • Most common type of longitudinal failure of formation, affecting one in 55,000 live births The Upper Limb 313 • Usually manifests as hypoplastic or absent radius with radial deviation of the hand – formerly known as ‘radial club hand’ Associated abnormalities • Up to 40% of unilateral and 77% of bilateral cases are syndromal • All require assessment by a paediatrician and geneticist • Associated conditions include: ∘ Holt–Oram syndrome – Cardiac septal defects and various upper limb malformations – Autosomal dominant inheritance ∘ VACTERL association – Vertebral anomalies, Anal atresia, Cardiac defects, Tracheal anomalies (including tracheo-oesophageal fistula), Esophageal atresia, Renal and radial abnormalities, other Limb abnormalities ∘ TAR syndrome – Thrombocytopaenia-Absent Radius; autosomal recessive inheritance – The thumb is usually present in TAR ∘ Fanconi’s anaemia – Rare autosomal recessive cause of bone marrow failure – Radial deficiency affects 40%; aplastic anaemia develops around years – Fatal without bone marrow transplantation Clinical features • Short forearm, bowed on the radial side • Complete or partial absence of the radius, which may be replaced by a fibrous anlage ∘ [In German, Anlage (pronounced ann-lager), means ‘foundation’ or ‘plan’] • Radially deviated hand with reduced passive wrist motion • Radial skin deficiency with relative excess on the ulnar side • Hypoplastic or absent thumb • Flexion contracture and stiffness of the radial digits • Elbow stiffness, which may be due to bony fusion (synostosis) • Proximal muscles of the arm and shoulder can also be affected • Bilateral and unilateral involvement are equally common ∘ Involvement of the contralateral limb may be subtle and asymmetric Classification • Classified into four types by Bayne and Klug: ∘ Type I: Short distal radius ∘ Type II: Hypoplastic radius ∘ Type III: Partial absence of the radius ∘ Type IV: Total absence of the radius Treatment • Based on age, severity and degree of functional deficit 314 Chapter Manipulation • Physiotherapy to elbow and wrist prevents progressive stiffness and maintains range of motion ∘ Parents should this at least twice a day • Mildest deformities can be treated with physiotherapy alone • Splintage is difficult to apply and adds little benefit • External fixators are widely used to distract radial soft tissues prior to surgery Surgery • Performed around 12 months, but this varies • The following abnormalities may be found: ∘ Variable deficiencies of the radial forearm structures ∘ Aberrant radial wrist extensors and extrinsic thumb muscles ∘ Absence of the radial artery ∘ Absence of the radial nerve below the elbow ∘ Median nerve is always present – often the most radial structure of the wrist • Centralisation ∘ Carpus is repositioned over the ulna and stabilised with a pin through the third metacarpal and carpus into the ulna – Usually requires extensive soft tissue release ∘ Radial wrist extensors are transposed onto extensor carpi ulnaris (ECU) to counter the radial deforming force ∘ Some recommend transposing redundant skin from the ulnar wrist to release the radial contracture • Radialisation ∘ Scaphoid is placed over the ulna and secured with a pin through the second metacarpal ∘ Transfer of flexor carpi radialis (FCR) and flexor carpi ulnaris (FCU) to the ulnar carpus or fifth metacarpal decreases the radial deforming force • Microvascular joint transfer ∘ Centralisation and radialisation are associated with high recurrence rates ∘ They also have the potential to injure the distal ulnar physis, causing growth arrest ∘ Vilkki described vascularised transfer of the second MTPJ to avoid these problems ∘ It is technically demanding and not widely practised • Pollicisation of the index finger ∘ Indicated for cases with a severe hypoplastic thumb ∘ Aims to reproduce thumb function by shortening and rotating the index finger A radial palmar incision is made, creating skin flaps at the base of the index finger • Allows subsequent creation of a first webspace Ulnar digital nerve is mobilised by interfascicular dissection of the common digital nerve to the index-middle finger web Radial digital artery to the middle finger is ligated and divided Interossei are elevated from the index finger metacarpal Index metacarpal is removed, except for its head, which forms the new trapezium • The epiphysis is resected to prevent subsequent growth The Upper Limb 315 Metacarpal head is rotated 160∘ – this will subsequently relax to 120∘ , ideal for opposition • Secured with K wires in 40∘ of palmar abduction with metacarpophalangeal joint (MCPJ) hyperextended The length of metacarpal removed is measured and a similar length of flexor and extensor tendon is excised • Some not remove tendon because they are said to shorten over time Rebalancing the intrinsics is essential: • First dorsal interosseous is sutured to the radial lateral band to become abductor pollicis brevis (APB) • First palmar interosseous is sutured to the ulnar lateral band to become adductor pollicis • Extensor indicis proprius (EIP) acts as extensor pollicis longus (EPL) • Extensor digitorum communis (EDC) to the index finger acts as the abductor pollicis longus (APL) • Many children require opponensplasty between and years Ulnar deficiency • One-tenth as common as radial deficiency • Spectrum of abnormalities, from hypoplasia of ulnar digits to absence of ulna • Hand and carpus are always affected: missing digits, syndactyly, thumb abnormalities • It differs from radial deficiency: ∘ The wrist is stable but elbow unstable ∘ Associated more with musculoskeletal abnormalities than cardiovascular ∘ Total absence is most common for the radius; partial absence is most common for the ulna ∘ Less likely to occur as part of a syndrome Classification • Classified by Bayne into four types: ∘ Type I: hypoplasia of the ulna (both proximal and distal epiphyses present) ∘ Type II: partial aplasia of the ulna (absence of the distal or middle third) ∘ Type III: total aplasia of the ulna ∘ Type IV: radiohumeral synostosis Treatment • Depends on the nature and severity of the deformity; there is no consensus view • Release of the fibrous anlage with realignment of the carpus and forearm ∘ The anlage, present in types II and IV, is claimed to increase ulnar deviation of the hand and ulnar bowing of the radius as the child grows • Hand function is improved as required by: ∘ Separating any syndactyly ∘ Deepening the first webspace ∘ Thumb reconstruction: opponensplasty, rotation osteotomy or pollicisation • Rotation osteotomy of the humerus improves hand position for some cases of radiohumeral synostosis 316 Chapter Central deficiency • Also known as cleft hand • Historically, cleft hand was divided into typical and atypical types Typical cleft hand • V-shaped cleft in the centre of the hand; one or more digits may be absent • Often bilateral; frequently involves both the hands and feet • Family history is common – inheritance is autosomal dominant • May form part of a syndrome, e.g split-hand/split-foot, EEC (ectrodactyly, ectodermal dysplasia, facial clefts) • First webspace often narrowed • ‘Transverse metacarpals’ can further widen the cleft over time • Phalanges may have longitudinally bracketed epiphyses or duplications Classification of typical cleft hand • The Manske and Halikis classification focuses on the first webspace: ∘ Type I: normal web ∘ Type IIA: mildly narrowed web ∘ Type IIB: severely narrowed web ∘ Type III: syndactylised web (first webspace is obliterated) ∘ Type IV: merged web (index ray suppressed; first webspace merged with the cleft) ∘ Type V: absent web (thumb elements suppressed; first webspace not present) Treatment of typical cleft hand • Patients usually have good hand function • Labelled ‘a functional triumph, but a social disaster’ • Early surgery may be required to prevent progressive deformity: To separate syndactyly between unequal digits, especially thumb-index To remove transverse bones that would worsen the cleft with growth • Other surgery can be postponed until between and years: Release or reconstruction of the first webspace Closure of the cleft – Snow-Littler technique: palmar-based flap from the cleft is transposed to the first web – Miura and Komada method: simpler – palmar and dorsal flaps are redraped – 2nd metacarpal is transferred to the 3rd metacarpal base and secured with K wires • Transposing the 2nd metacarpal at the level of its neck may preserve the adductor pollicis origin from the 3rd metacarpal – Deep transverse metacarpal ligament is reconstructed using adjacent A1 pulleys, unfolded towards one another Creation of a thumb for cases where it is absent – Pollicisation or, if no radial ray available, free toe transfer Addressing the foot deformity – Only indicated when there are difficulties fitting footwear The Upper Limb 317 – The fibular ray is the most important for weight bearing and gait – The tibial toe can usually be transferred to the hand if required Atypical cleft hand • Now known as symbrachydactyly • Characterised by short vestigial digits, like small nubbins ∘ Often have vestigial nails • May occur with Poland’s syndrome • Symbrachydactyly, in contrast to central ray deficiency: ∘ Is usually unilateral ∘ Seldom involves the feet ∘ Is not usually associated with a family history • Its place within Swanson’s classification is controversial ∘ Probably not a longitudinal central ray deficiency Classification of symbrachydactyly • Blauth and Gekeler classify symbrachydactyly into four types: ∘ Short finger type – a thumb and four short stiff digits ∘ Oligodactylic type – central aplasia – the classic ‘atypical cleft hand’ ∘ Monodactylic type – a thumb and four nubbins ∘ Peromelic type – complete absence of fingers and thumb Treatment of symbrachydactyly • Short finger type usually have excellent function ∘ Some may require syndactyly release or free phalangeal bone transfer • Oligodactylic type achieve pincer grip with thumb and little finger ∘ Metacarpal rotation osteotomy can improve the position of these digits • Some oligodactylic and monodactylic types may be suitable for toe-to-hand transfers if metacarpals and extrinsic tendons are present • Peromelic type is difficult to reconstruct due to lack of proximal structures Intersegmental deficiency • ‘Phocomelia’ is the historical term for intercalated deficiency of the upper limb ∘ Phocomelia derives from the Greek, meaning ‘seal limb’, i.e a flipper • The hand is always present • Prevalent in the 1960s due to the use of thalidomide for hyperemesis gravidarum ∘ Worldwide, thalidomide is still used as an anti-angiogenic drug to treat leprosy and myeloma • Frantz and O’Rahilly classify phocomelia into three types: ∘ Type I: complete – the hand is directly attached to the trunk ∘ Type II: proximal – the forearm and hand are attached to the trunk ∘ Type III: distal – the hand is attached to the humerus at the elbow • A prosthesis may be required if the hand cannot reach the mouth • Surgery, usually to stabilise the limb, is rarely indicated 318 Chapter Failure of differentiation Soft tissue failures of differentiation Syndactyly • Derived from the Greek, ‘syn’ – ‘together’ and ‘dactylos’ – ‘digit’ • May result from failure of apoptosis in interdigital tissue • Occurs once every 2000 live births • One of the two most common upper limb malformations, the other being polydactyly • 20% have a family history (autosomal dominant); 50% are bilateral • Twice as common in males • Most common in Caucasian races • May be associated with other deformities such as Apert’s and Poland’s Classification • Complete – digits fused to the level of the tips • Incomplete – fusion does not extend to the tips • Simple – only soft tissue connections between the digits • Complex – soft tissue and bony connections between the digits • Complex complicated – associated accessory digits or phalanges within the syndactyly • Acrosyndactyly – characterised by fused distal parts of the fingers ∘ Small spaces (fenestrations) are always present between the digits proximally ∘ Pathogenesis of acrosyndactyly is different from other forms of syndactyly: – Distal parts of the digits are thought to re-fuse due to constriction ring syndrome Clinical features • Middle-ring finger web is most commonly affected – 58% of cases ∘ 27% ring-little finger web ∘ 14% middle-index web ∘ 1% thumb-index web • Nail fusion (synonychia) with loss of the paronychial fold suggests synostosis of the distal phalanges • Associated limb, chest wall and foot abnormalities • Radiographs may show synostosis, synpolydactyly or other anomalies • More complex syndactyly is associated with tendon, nerve and vessel anomalies • Variable vascular anatomy and distal bifurcation of common digital vessels can lead to vascular compromise following separation Indications for surgical correction • Not usually performed before year of age • Aim to have separation completed by school age • Indications for earlier surgery, as soon as the child is deemed fit, include: ∘ Syndactyly of thumb-index or little-ring fingers – Released early because length discrepancy can cause deformity with growth 612 Index fasciectomy, 355, 390, 392–5 dermofasciectomy, 394 limited (partial) fasciectomy, 394 segmental fasciectomy, 394 total (radical) fasciectomy, 394 fasciotomy, 394 fast imaging employing steady-state acquisition (FIESTA), 377 fat injection, 569–72 adipose tissue, 570 graft survival theories, 570 history, 569–70 possible complications, 571–2 standard technique, 570–571 FDS opponensplasty, 387 felon, 353 Female Genital Mutilation Act 2003, 602 Ferguson–Smith syndrome, 81–2 fetal wound healing, 29 fibrocartilage, 35 fibrous dysplasia, 156 fibula flap, 204 fifth metacarpal neck fractures, 342 fillet of thigh, 457 fine needle aspiration cytology (FNAC), 195 fingertip amputation, 335 fingertip injuries, 334–6 fingertip amputation, 335 nail bed injury, 334 first branchial arch, 134 five-flap plasty, See jumping man flap flaps, classification, 9–13 fleur-de-lis, 577 flexor digitorum superficialis (FDS), 319–20, 327, 330, 333, 343, 346–7, 351, 360–2, 386–90, 412–14, 418 flexor sheath infections, 354 flexor tendon reconstruction, 350 flexor tendon repair, 346–7 flexor tendon sheath, 346–7 outcomes, 348–9 rehabilitation following, 348 skin incision, 346 flexor tendon rupture, 413 flexor tendon sheath, 346–7 flexor tendons, 41 flexor tenosynovitis, 412–13 fluid resuscitation, 497–500 complications of, 500 crystalloid sparing strategies, 498 factors specific to children, 499 Muir and Barclay, 498–9 Parkland, 498 fluorocarbons, 51 5-fluorouracil, 96, 520 forced duction test, 223 fossa-fascia sutures, 261 four-flap plasty, 15 Fox’s method, 240 ‘Fraser competence’, 595 fractures, 338–46, See also frontal sinus fractures; intra-articular fractures; Le Fort fractures; lower limb trauma; mandibular fractures; maxillary fractures; metacarpal fractures assessment, 339 complications of fractures, 340 intra-articular fractures, 342–3 investigation, 339 management, 339–340 MCPJ UCL avulsion, 344–5 metacarpal fractures, 341 nasal fractures, 225 open surgical approaches to hand fractures, 340–341 orbital fractures, 222–5 paediatric hand fractures, 345 phalangeal fractures, 342 phalangeal neck fractures, 345 Rolando fracture, 344 Seymour fracture, 345 thumb fractures, 344 treatment, 339 zygomatic (malar) fractures, 218–19 Franceschetti syndrome, See Treacher Collins syndrome free functioning muscle transfer (FFMT), 381 free nipple graft technique, 266 free radial forearm flap (Chinese method), 487 free tissue transfer, 305 freezing injury, 525–6 frostbite, 525–6 frostnip, 525 ‘French bikini pattern’, 575 French trial, 112 frontal sinus endoscopy, 228 frontal sinus fractures, 226–8 classification, 227 cranialisation, 228 frontal sinus endoscopy, 228 management, 227 obliteration, 227–8 observation, 227 ORIF, 227 panfacial fractures, 228 frontalis, 548 frontonasal process, 134–5 frost sutures, See lid traction sutures frostbite, 525–6 frostnip, 525 full thickness skin grafts, 30, 298, 510 ‘Furlad’ technique, 176 Furlow technique, 176 Furnas sutures, 260 galea aponeurotica, 549 Galveston formula, 501 gamekeeper’s thumb’, 344 ganglia, 397–400, See also dorsal wrist ganglia; volar wrist ganglia differential diagnosis, 398 of flexor tendon sheath, 399 location, 397–8 mucous cysts, 399 pathogenesis, 397 signs and symptoms, 398 Gardner syndrome, 85 generalised skeletal abnormalities, 312 Geneva declaration, 591 genioplasty, 563–5 assessment of the patient, 563–4 complications, 565 techniques of, 564–5 giant cell tumour of the tendon sheath, 400 Gillick competence, 595 Gillies’ fan flap, 199 Gillies’ lift, 219 gingivoperiosteoplasty, 170 glabellar incision, 222 glans, 475 Glasgow seven-point checklist, 103 glomus tumours, 400 glucocorticoids, 409–10 glycoprotein IIb/IIIa antagonists, 77 glycosaminoglycans (GAGs), gold, 50 Gore-Tex®, 51, 304 Gorlin’s syndrome, See basal cell naevus syndrome Gorlin–Goltz syndrome, See basal cell naevus syndrome gout, 417 graft survival theories, 570 Granuflex®, 54 GranuGel®, 54 Great Ormond Street Speech Assessment (GOS.SP.ASS), 178 ground substance, Guérin’s fracture, See Le Fort fractures: Le Fort I gynaecological invasive malignancy, treatment of, 466 vagina, 466–7 vulva, 466 gynaecomastia, 278–90 aetiology, 278 Index classification, 279, 281–5 pre-operative assessment, 279 surgical correction, 279–80 haematoma, 30, 32 haemostasis, 23, 74–7, See also anticoagulants; coagulation cascade hair follicles, 3–4 Hall-Findlay technique, 267 halo naevi, 89–90 hamartomatous polyps, 83 hand infections, 351–5, See also bite wounds; palm infections acute paronychia, 353 chronic paronychia, 353 clenched fist injuries, 352 dorsal hand infections, 355 felon, 353 flexor sheath infections, 354 herpetic whitlow, 354 hand trauma, 329–51, See also dislocations; fingertip injuries; fractures; tendon injury; thumb reconstruction; toe-to-hand transplantation assessment, 329–31 examination, 330 history, 329–30 position of safe immobilisation (POSI), 331 replantation and revascularisation, 332–4 tourniquets in hand surgery, 331–2 hard palate, 175 healing, 22–31, See also bone healing; cartilage: healing; tendon healing; wound healing nerve healing, 36–41 Health and Social Care Act 2001, 599 health records, patient access to, 600 Helsinki declaration, 591 hemifacial microsomia, 149, 246 classification, 150 OMENS classification, 150 treatment, 151 hemihypertrophy, 326 ‘hemirhinoplasty’, 169 heparin, 70, 76 herpes zoster oticus, 247 herpetic whitlow, 354 hidradenitis suppurativa, hidrocystoma, 84 high lateral tension abdominoplasty, 577 hip joint infection, 457 Hippocratic oath, 591 holocrine glands, Holt–Oram syndrome, 313 Homans procedure, 450 horizontal maxillary fracture, See Le Fort fractures: Le Fort I hormonal therapy, 289 Horner’s syndrome, 238, 374, 377, 383 host replacement theory, 570 Huber transfer, 387 human amnion, 508 human bite wounds, 352 human epidermal growth factor receptor (HER2/neu), 284 human leukocyte antigens (HLAs), 43 Human Tissue Act 2004, 602 Hunstadt’s solution, 568 hyaline cartilage, 35 hyaluronic acid, 50, 277 hydraulic theory, 222 hydrocephalus, 135 hydrocolloids, 54 Hydrofiber® dressings, 54 hydrofluoric acid, 521 hydrogels, 54 Hynes pharyngoplasty, 179–80 Hynes–Giddins device, 343 hyperacute rejection, 44 hyperadrenergic state, hyperkeratosis, hypermetabolic response, 500–504 environment control, 502 medication and hormone manipulation, 502 modulation of, 500 nutrition, 501 nutritional supplementation, composition of, 501 prevention of sepsis, 503 route of feeding, 502 hypernasality, 178 hypernatraemia, 512 hypertelorism, 141 hypertrophic scars, 24 hyponasality, 178 hypopharyngeal cancer, SND for, 185 hypospadias, 471–81 aetiology, 472 in child, assessment, 475–6 classification, 472 complications of surgery, 480–481 embryology, 472–4 epidemiology, 471–2 surgical correction, 476–80 hypothenar aponeurosis, 390 Imiquimod (Aldara®), 96 immunosuppression, 45 biological agents, 45 613 drugs, 45 immunological tolerance, 45 non-specific techniques, 45 radiation, 45 specific techniques, 45 immunotherapy, 111 impedance monitoring, 73 implants or expanders, 291 combined with flap reconstruction, 292 Mentor Siltex® Becker expander/implant, 291–2 Natrelle® Style 133V series expander, 292 incision biopsy, 104 inclusion cysts, 84 incomplete CL, 162 Independent Review Group (IRG), 272 indirect AVAs, indirect lymphangiography, 447 indocyanine green (ICG) lymphography, 447–8 infantile haemangioma, 115 aetiology, 115 associations, 116 classification, 115 complications, 116–17 laser, 119 pathogenesis, 116 pharmacological agents, 118 surgery, 119 treatment, 117 inferior gluteal artery perforator (IGAP) flap, 296 inferior pedicle technique, 266–7 inferior turbinate hypertrophy, 562 inflammation, 23, 32 in arthritis, 368, 402 bone healing, 32, 42 in rheumatoid arthritis, 405–6 in secondary lymphoedema, 445 informed consent, 594 infracartilaginous incision, 558 inframammary incision, 271 inhalation injury, 495–7 carbon monoxide (CO) poisoning, 496 classification of, 495 complications of, 497 diagnosis, 495 factors suggestive of, 495 tracheostomy, 496–7 injectable fillers, 583–4, See also alloplastic implantation Institute of Medicine of the National Academy of Science (IMNAS), 273 Integra®, 510 614 Index interconnecting vessels, intercostal artery perforator (ICAP) flaps, 294 interdomal suture, 561 interflap shunting hypothesis, Intergroup Melanoma Surgical Trial, 112 interleukin-2, 111–12 intermaxillary fixation (IMF), 216 internal nasal valve, 562 internal nerve topography, 39 intersegmental deficiency, 317 intra-articular fractures, 342–3 intradermal naevi, 89 intraepithelial neoplasia, treatment of, 466 intralesional corticosteroid injection, 519 intramembranous ossification, 31 in-transit metastases, 105 intra-operative expansion, 60 Intrasite™, 54 intravelar veloplasty, 176 intravenous fluorescein infusion, 73 intrinsic tendon healing, 42 intrinsic-plus position, See position of safe immobilisation (POSI) inverted ‘V’ deformity, 563 inverted T, 266 inverted T scar technique, 268 involutional ectropion, 241 ipilimumab, 111, 113 ischial pressure ulcers, 456 isografts, 43 isolated CP, 161 Jackson’s burn wound model, 491 Jelonet®, 64 jumping man flap, 15, 243 junctional naevi, 89 justice, 592 juvenile melanoma, 89 Kaplan’s cardinal line, 359 Karapandzic flap, 198 Kasabach–Merritt phenomenon, 120 Keen’s transoral approach, 219 keloid scars, 24 keratin horn, 81 keratinisation, keratinocytes, keratoacanthoma (KA), 81 Kernahan’s striped ‘Y’, 162 keystone flaps, 18–19 Klein’s solution, 568 Klippel–Trénaunay syndrome (KTS), 123 Kuhnt-Szymanowski procedure, 241 lacrimal system, 231–2 lagophthalmos, 544 Langerhans cells, ‘laparostomy’, 459 laser Doppler, 73 laser lipolysis, 569 lasers, 61–9, 520, 582–3 ablative lasers, 583 clinical applications of, 64 cooling, 63 interaction with tissue, 62–3 laser physics, 61 laser variables, 63–4 nonablative lasers, 583 properties of laser light, 62 Q-switching, 62 safety, 64–5 structure of basic laser, 61–2 thermal effects, 63 lateral antebrachial cutaneous nerve, 40 lateral approach to hand fractures, 341 lateral canthal support, 547 lateral intercostal artery perforator (LICAP), 294 lateral wall pharyngoplasties, 179 Hynes pharyngoplasty, 179–80 latissimus dorsi, 305 latissimus dorsi miniflap (LDMF), 293 law, 593–601 advance decisions, 596 advance directives, 596 advance statements, 596 Bolam test, 597 Bolitho case, 597 breach of duty, 597 Caldicott Guardians, 600–1 capacity to give consent, 594 causation, 598 confidentiality, 598–601 consent for minors, 594 consent, 593–5 disclosure with patient consent, 599 disclosure without patient consent, 599 disclosure, 599 duty of care, 597 Gillick competence, 595 informed consent, 594 liability, 596 medical photography, 601 negligence, 596–8 parental responsibility, 595 patient access to health records, 600 refusal, 595 valid consent, 593 voluntary consent, 593 Le Fort fractures, 220 Le Fort I, 220 Le Fort II, 220 Le Fort III, 221 management, 221 Le Fort I osteotomy, 149 Le Fort III osteotomy, 148 leech therapy, 74 leg ulcers, 422–6 aetiology, 422–3 arterial ulcer disease, 425–6 examination, 423 investigation, 423 medical history, 423 venous ulcer disease, 424–5 lentigo, 90 lentigo maligna (LM), 106 lentigo maligna melanoma (LMM), 106 Leri–Weill dyschondrosteosis, 328 leukoplakia, 200 levator aponeurosis repair, 239–40 levator function, 238–9 levator palpebrae superioris muscle, 230–231 levator resection, 240 levator veli palatini, 172 levobupivacaine, 67 liability, 596 lichen sclerosus et atrophicus, 481 ‘Lichtenberg figures’, 524 lid traction sutures, 243 lidocaine, 66 Li–Fraumeni syndrome, 201 limb salvage versus primary amputation, 438 limited (partial) fasciectomy, 394 lines of maximum extensibility (LME), 13 lipoabdominoplasty, 576 lipofibromatosis, 326 lipofilling, 276–7 lipomodelling, 296 liposuction, 279, 450, 565–9 abdomen, 565 anatomy, 565–6 assessment of patient, 566 complications, 567 hips and flanks, 566 lower leg, 566 neck, 565 operative technique, 568–9 preoperative counseling, 566–7 techniques, 567 wetting solutions, 568 live-unrelated allograft, 508 LMX 4®, 67 Index lobular in situ neoplasia (LISN), 282 local anaesthesia, 65–9 Ametop, 67 bupivacaine, 66 classification, 65 CNS toxicity, 68 common local anaesthetics, 66 CVS toxicity, 68 dose calculation, 67–8 EMLA, 67 epinephrine, 66 levobupivacaine, 67 lidocaine, 66 LMX 4, 67 pharmacokinetics, 65–6 prilocaine, 67 topical anaesthesia, 67 toxicity, 68 management, 68–9 local flaps, 12, 13–22, 297 advancement flaps, 16–19 bilobed flap, 22 geometry of, 13–22, See also plasty techniques interpolation flaps, 21 pivot flaps, 16, 20–21 rotation flaps, 21–2 local muscle transposition, in facial palsy, 253 locally aggressive or borderline vascular tumour, 114 locoregional recurrent melanoma, 111 longitudinal arrest, 311–12 lotus petal, 468–9 lower back lift, 578 lower limb trauma, 426–38, See also acute compartment syndrome; amputation epidemiology, 426 initial management of, 429–30 open fractures, classification of, 426–8 Bastion classification, 428 Gustilo and Anderson, 427 limb ischaemia, 428 MESS, 428 NISSSA, 428 skeletal/soft tissue injury, 428 segmental bone defects, management, 434 surgical management, 430–434 lower limb, 422–57, See also leg ulcers; lymphoedema; osteomyelitis (OM); pressure ulcers low-molecular-weight heparins (LMWH), 76 L-shaped scar technique, 269 Lund and Browder charts, 494 lymphatic malformations (LMs), 122 lymphatic system, 441–3 anatomy, 442 embryology, 442 lymph nodes, 443 lymphatic vessels, 442–3 lymphaticolymphatic anastomosis, 450–451 lymphaticovenous shunts, 450 lymphoedema congenita, 444 lymphoedema praecox, 445 lymphoedema tarda, 445 lymphoedema, 441–51 classification, 444–5 clinical diagnosis, 446–8 investigation, 447–8 non-surgical management, 448–9 pathogenesis, 443–4 primary lymphoedema, 444 secondary lymphoedema, 445 staging, 445–6 surgical management, 449–51 Charles procedure, 449 excisional techniques, 449 Homans procedure, 450 liposuction, 450 lymphaticolymphatic anastomosis, 450–451 lymphaticovenous shunts, 450 physiological techniques, 450 Thompson procedure, 450 vascularised lymph node transfer, 451 lymphoma, 273 lymphoscintigraphy, 447 macrocystic lymphatic malformations, 122 macrodactyly, 326 macrometastases, 105 macrophage, 26 macroreplantation, 332 Madelung’s deformity, 328 Maffucci’s syndrome, 401 magnetic resonance imaging (MRI), 191 magnetic resonance lymphography, 448 major histocompatibility complex (MHC), 43 malar fat pad, management of, 540 malformation, 136 malignant fibrous histiocytoma (MFH), 129 malignant melanoma (MM), 101–13 assessment, 103–4 epidemiology, 101 615 lymph node basins management, 108–11 clinically node-negative patients, 108 clinically or radiologically suspicious lymph nodes, 109 confirmed lymph node metastasis, treatment, 109 elective lymph node dissection, 108 sentinel lymph node biopsy (SLNB), 108 metastatic disease management, 111–12 minimum data set, 107 pathogenesis, 102–3 premalignant lesions, 102 primary lesion, definitive treatment of, 107–8 primary treatment, 104 prognostic factors, 106–7 risk factors, 101–2 TNM staging, 104–5 malignant mixed tumour, 194 malignant nonpigmented skin lesions, 91–101, See also basal cell carcinoma (BCC); cutaneous squamous cell carcinoma; Merkel cell carcinoma (MCC) aetiology, 91–2 sebaceous carcinoma, 101 malocclusion, 137 Manchester repair, 171 Manchester scar scale, 517 mandibular arch, 134 mandibular branch, 533–4 mandibular fractures, 215–18 in children, 218 classification, 215 condylar fractures, management, 217–18 external fixation, 217 fixation, 217 management, 216 conservative management, 216 intermaxillary fixation (IMF), 216 open reduction and internal fixation (ORIF), 217 surgical approaches, 217 extraoral, 217 intraoral, 217 mandibulofacial dysostosis, See Treacher Collins syndrome mandibulomaxillary fixation (MMF), 216 Marcus Gunn pupil, 212 margin-reflex distance, 238 616 Index Marinacci communication, 366 Marlex® polypropylene mesh, 52, 304 Martin–Gruber anastomosis, 365 masculinised female, 482 masseter muscle, 253 mastectomy, 286 masticator space, 533 mastopexy, 267–9 classification, 267–8, See also ptosis complications of, 269 Mathieu perimeatal-based flap technique, 479 Matriderm®, 510 maxillary fractures, 220–222 Le Fort fractures, 220 maxillofacial trauma, 209–28 assessment, 211 examination, 211 history, 211 imaging, 213 management principles, 210–14 zygomatic (malar) fractures, 218–19 maxillonasal dysplasia, See Binder’s syndrome Mayer–Rokitansky–Küster–Hauser syndrome (MRKH), 485 McComb technique, 169 McCune–Albright syndrome, 90 McGregor cheek flap, 234 meatal advancement and glanuloplasty, 479 medial antebrachial cutaneous nerve, 40 medial canthopexy, 142 medial canthoplasty, 250 medial crural fixation suture, 561 medial pedicle technique, 267 median nerve palsy, 386–7 medical ethics, 592 medical photography, 601 Medical Research Council (MRC) grading of nerve function, 37 medium peels, 582 Medpor, 51 megameatus intact prepuce (MIP), 471 melanin, 86 melanocytes, 3, 86 melanocytic lesions, 86 classification, 87 melanocytic naevi, 87 melanoma, See malignant melanoma (MM) Melkersson-Rosenthal syndrome, 248 melolin, 54 membranous urethra, 475 meningoceles, 142 meningoencephaloceles, 142 Mental Capacity Act (MCA), 594 Mentor MemoryGel®, 274 Mentor Siltex® Becker expander/implant, 291–2 Mepitel®, 54 Merkel cell carcinoma (MCC), 99–100 Merkel cells, Mersilene®, 304 mesh implants, 303 meshed split thickness skin graft, 509 mesodermal penetration theory, 138 mesonephric duct, 472–3 metacarpal fractures, 341–2 metacarpophalangeal joints, 413–14 metaidoioplasty, 487 methylmethacrylate, 52 Meyer-Bahlburg, 485 microcephaly, 135 microcirculation, microcystic lymphatic malformations, 122 micrometastases, 105 microreplantation, 332 microscopic satellites, 105 microsurgery, 69–74 drugs that limit thrombus formation, 70 equipment, 71 history, 69 leech therapy, 74 non-flowing anastomosis, management, 73–4 no-reflow phenomenon, 71 pathophysiology of vessel healing, 69 post-operative management, 72 post-operative monitoring, 72–3 reperfusion injury, 70 technique, 71–2 thrombus formation, 69–70 microtia, 256–7 milia, 85 Millard repair, 171 Millard rotation–advancement technique, 167 mini abdominoplasty, 576 Minimal Access Cranial Suspension (MACS), 540 minors, consent for, 594 3-minute elevated arm stress test (EAST), 370 mirror hand, 325–6 Miura and Komada method, 316 mixed cystic lymphatic malformations, 122 mixed gonadal dysgenesis, 483 Möbius syndrome, 246, 254 modified radical mastectomy, 287 modified radical neck dissection (MRND), 184 Mohs micrographic surgery, 94 Mongolian blue spot, 91 motor deficits, 387–8 motor evoked potentials (MEPs), 379 mucocutaneous lesions, 83 mucoepidermoid carcinoma, 193 mucous cysts, 399 Muenke’s syndrome, 147 Muir and Barclay, 498–9 Muir–Torre syndrome, 82 Müller’s muscle, 231, 239 Multicenter Selective Lymphadenectomy Trial (MSLT-1), 113 multiple enchondromatosis, 401 Multistatic Array Processing for Radiowave Image Acquisition (MARIA), 286 muscle flaps, 156, 254, 305, 433 in autologous reconstruction, 463 external oblique, 305 latissimus dorsi, 305 for lower leg coverage, 433 pectoralis major, 305 proponents of, 433 rectus abdominis, 305 muscle only flaps, 12 muscle sparing TRAM flap, 295 musculocutaneous flaps, 10, 12 musculocutaneous vessels, Mustardé lower lid switch flap, 236 Mustardé cheek rotation flap, 234 Mustardé sutures, 261 myeloceles, 143 myofibroblast, 26 NA Ultra®, 54 naevus cell naevi, 87 naevus cells, 86 naevus of Ito, 91 naevus of Ota, 91 naevus simplex, 121 Nager’s syndrome, 153 nail bed injury, 334 Narakas’ rule of ‘seven seventies’, 372 nasal airway, 562 nasal cavity, tumours of, 205–9 benign tumours, 205 epithelial tumours, 205 excision, 206 lining, 209 management, 206 primary tumours, 205 Index reconstruction, 206–7 sarcomas, 205 nasal dermoid cysts, 159 nasal fractures, 225 nasendoscopy, 179 nasogastric (NG) feeding, 154 nasolabial transposition, 199 nasoorbitoethmoidal (NOE) fractures, 225–6 nasopharyngeal airway (NPA), 154 National Pressure Ulcer Advisory Panel (NPUAP), 453 Natrelle® Style 133V series expander, 292 near-infrared spectroscopy, 73 neck, 536–7, 540 management of, 540 neck dissection, complications of, 187–8 negative pressure wound therapy (NPWT), 55, 302 negative vector relationship, 542 negligence, 596–8 Bolam test, 597 Bolitho case, 597 causation, 598 confidentiality, 598–601 duty of care, 597 neoplasia–hyperplasia, 156–9, See also fibrous dysplasia neurofibromatosis, 157 unclassified craniofacial abnormalities, 159 nerve anatomy, 36–7 function, 36–7 healing, 36–41 injury, 38–9 repair, 39 nerve action potentials (NAPs), 379 nerve compression, 357–71, See also anterior interosseous syndrome; carpal tunnel syndrome; pronator syndrome; radial nerve and its branches; ulnar nerve classification, 358 common communicating branches, 365–6 Berrettini branch, 366 Marinacci communication, 366 Martin–Gruber anastomosis, 365 Riche–Cannieu anastomosis, 366 median nerve and its branches, 358–63 thoracic outlet syndrome (TOS), 369–71 nerve grafts, 40–41 nerve territory-oriented macrodactyly, 326 neural crest, 135–6 neurapraxia, 38 neurilemmoma, 84 neurofibroma, 84 plexiform neurofibroma, 84 neurofibromatosis, 157, 326 classification, 157 neurofibromatosis type (NF 1), 157 neurofibromatosis type (NF 2), 157 orbitopalpebral neurofibromas, 158 plexiform neurofibromas of facial soft tissues, 158 neurofibromatosis type (NF 1), 157 neurofibromatosis type (NF 2), 157 neurolysis, 384 neurotmesis, 38 neurotrophism, 38 neurotropism, 38 niche theory, 570 nipple reconstruction, 297 cartilage grafts, 297 external nipple prosthesis, 297 local flaps, 297 nipple sharing, 297 nipple sharing, 297 nipple sparing mastectomy (NSM), 287–8 nodular melanoma, 106 nonablative lasers, 583 non-accidental injury (NAI), 513–14 non-animal stabilised hyaluronic acid (NASHA), 277 non-flowing anastomosis, management, 73–4 non-freezing injury, 526 nonmaleficence, 592 Nonne-Milroy syndrome, 445 nonoperative facial rejuvenation, 581–7, See also botulinum toxin; resurfacing injectable fillers, 583–4 nonparametric tests, 603 non-steroidal anti-inflammatory drugs (NSAIDs), 77 no-reflow phenomenon, 71 ‘no touch’ technique, 571 Nuss repair, 299 obstetric brachial plexus palsy, 382–4 assessment, 383 classification, 383 examination, 383 history, 383 617 investigations, 383 management, 383–4 risk factors, 382 surgical technique, 384 oculoplastic surgery, 228–44, See also ectropion; entropion; eyelid reconstruction; ptosis distichiasis, 242–3 enucleation, 244 epicanthic folds, 243 evisceration, 243–4 exenteration, 244 lid traction sutures, 243 symblepharon, 243 temporary central tarsorrhaphy sutures, 243 temporary lateral tarsorrhaphy sutures, 243 trichiasis, 242–4 oestrogen receptor (ER), 284 Ollier’s disease, 401 omental flap, 295, 303 Omiderm®, 54 oncoplastic techniques, 290 onlay preputial flap, 479 open abdomen, 459–64 anatomy, 459–60 classification, 461 management of, 461–4 pathogenesis, 461 open fractures of lower limb, 426–8 open injury, 375 opponensplasty, 327 Opsite®, 54 oral cavity, tumours of, 200–202 orbicularis myocutaneous advancement flap, 237 orbicularis oculi muscle, 230 orbital apex syndrome, 213 orbital fat, management, 546 orbital fractures, 222–5 management, 223 orbital septum, 230 orbitopalpebral neurofibromas, 158 oropharyngeal cancer, SND for, 185 orthognathic surgery (OGS), 176–7 Orticochoea sphincter pharyngoplasty, 180 Jackson’s modification of, 180 Oslo technique, 165 osseocartilaginous framework, 553 osseoconduction, 34 osseous genioplasty, 564 osteoarthritis, 402–5 clinical features, 402 epidemiology, 402 pathogenesis, 402 treatment, 404 osteoblasts, 32 618 Index osteochondroma, 401 osteoclasts, 32 osteocytes, 32 osteogenesis, 34 osteoid, 33 osteoid osteoma, 401 osteomyelitis (OM), 438–41 acute OM, 439–40 chronic OM, 440–441 classification, 438–9 mechanism of infection, 439 Osteoset®, 53 osteotomy, 378, 404–5, 559–60 box osteotomy, 142 Le Fort I osteotomy, 149 Le Fort III osteotomy, 148 rotation osteotomy, 315, 323 wedge osteotomy, 322, 328 otoplasty, 259–60 concha-mastoid sutures, 260 excisional techniques, 261 fossa-fascia sutures, 261 Furnas sutures, 260 Mustardé sutures, 261 suture techniques, 260 overgrowth, 326, See also macrodactyly paediatric hand fractures, 345 pagetoid, palliative local therapy, 112 palm infections, 354–5 hypothenar space, 355 midpalmar space, 354–5 thenar space, 354 palmar aponeurosis, 390 palmar fascia, 389–91 anatomy, 389–91 digital fascia, 391 hypothenar aponeurosis, 390 palmar aponeurosis, 390 pathological anatomy, 391 thenar aponeurosis, 390–391 panendoscopy, 190 panfacial fractures, 228 panniculectomy, 577 papillomatosis, parakeratosis, paralytic ectropion, 241 paramesonephric duct, 473 parametric tests, 603 paranasal sinuses, tumours of, 205–9, See also nasal cavity, tumours of paratenon, 41 Parkes–Weber syndrome, 123 parotid duct (Stensen’s duct), 215 parotidectomy complications of, 196 superficial parotidectomy, 195 total parotidectomy, 196 Parry–Romberg syndrome, 155 passive appliances, 165 patient access to health records, 600 pectoralis major flap, 11, 109, 188, 202, 204, 271–2, 287, 291–2, 300, 302, 305, 322, 373–4, 376, 381 pectus carinatum, 300 pectus deformities, 298–300 pectus excavatum, 299 pedicled distant flaps, 12 pedicled flaps, 188, 244, 294, 304–5, 425, 433, 457, 463, 468, 487, 518 penile reconstruction, 486–7 ambiguous genitalia, 486 free radial forearm flap (Chinese method), 487 metaidoioplasty, 487 total penile reconstruction, 487 penile urethra, 475 penis, anatomy of, 474–5 body, 474–5 glans, 475 membranous urethra, 475 penile urethra, 475 prostatic urethra, 475 root, 474 urethra, 475 pentoxifylline, 426 percutaneous needle fasciotomy, 393 perialar crescentic flap, 198 periareolar incision, 271 periareolar technique, 268 perineal reconstruction, 464–71 anal triangle, 465 anatomy, 464–5 anorectal invasive malignancy, treatment of, 467 defect assessment, 467–8 flap options, 468 pathology, 465–7 perineal body, 465 perineal skin, 465 principles of, 468–71 reconstructive strategy, 470 regional arterial anatomy, 465 perineal skin, 465 Permacol®, 304 permanent lateral tarsorrhaphy, 250 Pfeiffer’s syndrome, 147 phalangeal fractures, 342 distal phalanx, 342 phalangeal shaft, 342 phalangeal neck fractures, 345 Phalen’s test, 360, 362 pharyngeal wall augmentation, 179 pharyngoplasty, 179 Hynes pharyngoplasty, 179–80 lateral wall pharyngoplasties, 179 Orticochoea sphincter pharyngoplasty, 180 posterior wall pharyngoplasties, 179 phenylephrine test, 239 phocomelia, 317 phosphorus burns, 522 photodynamic therapy (PDT), 96 Pierre Robin sequence (PRS), 136, 150, 154–5, 174–5 treatment, 154 pilar cysts, 85 pilomatrixoma, 83 pilon fractures, 342 pivot flaps, 16, 20 transposition flaps, 20 transposition flaps with direct closure of donor site, 20–21 plasty techniques, 13–16 five-flap plasty, 15 four-flap plasty, 15 W-plasty, 15–16 Z-plasty, 13 platelet activating factor (PAF), 23 platelet-derived growth factor (PDGF), 23 platelets, 76 pleomorphic adenoma, 192–3 plethysmography, 73 plexiform neurofibroma, 84 plexiform neurofibromas of facial soft tissues, 158 Poland’s syndrome, 300–301 clinical features, 300 surgical treatment, 301 Police and Criminal Evidence Act 1984, 599 poliglecaprone 25, 56 polly-beak deformity, 563 Poly Implant Prothèse (PIP) silicone implants, 274–5 polydioxanone sulphate (PDS), 56 polyester, 52 polyethylene, 51 polyglactin 910, 56 polyglycolic acid, 56 polymethylmethacrylate (PMMA), 52 polymorphonuclear neutrophils (PMNs), 23 polypropylene, 52 polytetrafluoroethylene (PTFE), 51 Index polyurethane, 50 porcine xenograft, 509 poroma, 83 position of safe immobilisation (POSI), 331 positional plagiocephaly, 145 positron emission tomography (PET), 191–2 positive vector relationship, 542 post-burn contractures, surgical management of, 518–19 posterior cranial vault reconstruction, 148 posterior interosseous nerve graft, 40 posterior interosseous nerve syndrome, 367–8 posterior lamella, alternatives for, 233 posterior trunk reconstruction, 305–6 posterior wall pharyngoplasties, 179 power-assisted liposuction (PAL), 569 prefascial plexus, premalignant lesions, 89, 97, 101–4 AIN, 466 atypical naevi, 102 BXO, 481 congenital melanocytic naevi, 102 oral cavity, 200 VAIN, 466 VIN, 466 pressure ulcers, 451–7 anatomical distribution, 451–2 classification, 453 pathogenesis, 452–3 prevention, 454–5 risk assessment, 453–4 treatment, 455–7 presurgical orthodontics, 165 prezygomatic space, 533 prickle cell layer, prilocaine, 67 primary bone healing, 33 primary nasal surgery, 169–70 alveolar bone grafting, 170 Anderl technique, 170 McComb technique, 169 Tajima technique, 170 procerus, 549 progeria, 27 progesterone receptor (PR), 284 progressive hemifacial atrophy (PHA), 155 clinical features, 155 radiation-induced atrophy–hypoplasia, 156 treatment, 155–6 progressive macrodactyly, 326 prolabium, 171 Prolene®, 304 proliferation, 23 prominent ears, 259–61, See also otoplasty cartilage moulding techniques, 261–2 pronator syndrome, 362 symptoms and signs, 362 treatment, 362 Proplast, 51 propranolol, 118 prostatic urethra, 475 Proteus syndrome, 326 proximal hypospadias, urethroplasty for, 479 tubularised preputial flap, 480 two-stage repair, 480 proximal interphalangeal joint (PIPJ), 319, 414–15 proximal thigh lift, 579 proximodistal axis, 310 prudent patient test, 594 pseudoptosis, 237, 268 pseudotelecanthus, 141 pseudoxanthoma elasticum, 27 psoriatic arthropathy, 416 ptosis, 237–40, 267, 544, See also breast ptosis; eyelid ptosis brow, 536, 541–3, 548, 553, 587 chin, 564 lip, 564 pudendal-thigh flap, 469–70 pulse oximetry, 73 pyogenic granuloma, 120 pyramidal maxillary fracture, See Le Fort fractures: Le Fort II Q-switching, 62 quadrantectomy, 286 quadripod flap, 297 radial club hand, 313 radial forearm flap, 204 radial nerve and its branches, 366–9, See also posterior interosseous nerve syndrome; radial tunnel syndrome Wartenberg’s syndrome, 368 radial nerve palsy, 386 classic transfer, 386 motor deficits, 386 superficialis transfer, 386 tendon transfers, 386 radial polydactyly, 324 radial tunnel syndrome, 366–7 symptoms and signs, 367 treatment, 367 619 radical mastectomy, 287 radical neck dissection (RND), 184, 186–7 radical radiotherapy, 189 Radiesse®, 53 radiofrequency assisted liposuction (RFAL), 569 radiology for head and neck cancer, 191–2 radiotherapy, 188–9, 289, 520 random flaps, rapid expansion, 60 Ravitch procedure, 299 rectus abdominis flap, 303, 305 refinement, 571 refusal, 595 regional arterial anatomy, 465 regional flaps, 12 relaxed skin tension lines (RSTLs), 13 remodelling, 23–4, 32 reperfusion injury, 70 replantation, 332–4, See also under hand trauma restrictive procedures, 572 with malabsorption, 572 resurfacing, 581–3 ablative lasers, 583 chemical peels, 581 deep peels, 582 dermabrasion, 583 lasers, 582 medium peels, 582 nonablative lasers, 583 superficial peels, 581–2 retaining ligaments, 532 retrobulbar haematoma, 212 retro-orbicularis oculi fat (ROOF), 545 revascularisation, 332–334, See also under hand trauma reverse abdominoplasty, 577 reverse Phalen’s test, 360 rheumatoid arthritis (RA), 405–16 aetiology, 406 autoantibodies, 406 classification, 407 clinical presentation, 408 dorsal tenosynovitis, 411 environment, 406 epidemiology, 406 extensor tendon rupture, 412 extra-articular disease, 407 flexor tendon rupture, 413 flexor tenosynovitis, 412–13 inflammation, 406 investigation, 409 620 Index rheumatoid arthritis (RA), (continued) metacarpophalangeal joints, 413–14 non-operative treatment, 409 operative treatment, 410 pathophysiology, 406 proximal interphalangeal joints, 414–15 symptom control, 410 wrist, 411 rhinoplasty, 553–63 anatomy, 553–5 assessment of the patient, 556–7 cartilage grafts, 561 complications, 562–3 correction of nasal tip, 560 depressor septi nasi division, 561–2 descriptive terms, 555–6 dorsal augmentation, 560 incision types, 558 nasal airway, 557, 562 nasofacial analysis, 556 osseocartilaginous framework, 553 osteotomies, 559 sensory nerve supply, 555 septum, 554–5 suture techniques, 561 techniques of, 558–62 vascular supply, 555 rhytidectomy, See facelift ribcage, reconstruction, 299 Nuss repair, 299 Ravitch procedure, 299 sternal turnover operation, 299 Riche–Cannieu anastomosis, 366 ring avulsions, 333 rocker deformity, 563 Rolando fracture, 344 Roos’ test, 370 round-block technique, 268 rotation flaps, 21–2 Royle-Thompson technique, 387 Rubens flap, 296 rugger jersey finger, 346 sacral pressure ulcers, 456 Saethre–Chotzen syndrome, 147 sagittal strip craniectomy, 148 salivary gland tumours, 192–6 acinic cell carcinoma, 194 adenoid cystic carcinoma, 194 adenolymphoma, 193 assessment and staging, 194 benign tumours, 192 malignant mixed tumour, 194 malignant tumours, 193 mucoepidermoid carcinoma, 193 pleomorphic adenoma, 192–3 superficial parotidectomy, 195 total parotidectomy, 196 sarcoma, 124–9, See also bone sarcomas; cutaneous sarcomas aetiology, 125 biopsy, 126 chemosensitive tumours, 129 classification, 126 clinical assessment, 125 clinical presentation, 125 cutaneous sarcomas, 129–30 diagnostic pathway, 125–6 epidemiology, 125 planning, 126 prognosis, 129 radiological assessment, 126 surgical management, 127 satellite lesions, 105 Sauvé–Kapandji procedure, 328 scaphotrapezium-trapezoid (STT) joint, 399 scapular flap, 204 Schirmer’s test, 238 schwannoma, 84 Schweckendiek technique, 165 Sculptra®, 52 sebaceous adenomas, 83 sebaceous carcinoma, 101 sebaceous gland hyperplasia, 83 sebaceous glands, seborrhoeic keratosis, 80 secondary bone healing, 33 sedimentation, 571 segmental bone defects, management, 434 segmental fasciectomy, 394 selective neck dissection (SND), 184 self-inflating expanders, 60 sensory nerve action potentials (SNAPs), 377 sentinel lymph node biopsy (SLNB), 108 sentinel vein, 550 sepsis, 511 septal deviation, 562 Seymour fracture, 345 Shprintzen’s syndrome, 174 signal transduction inhibitors, 112 silicone, 49 silicone controversy, 272–3 silicone expander capsule, 58 silver sulfadiazine (SSD), 503–4 simple (total) mastectomy, 287 simple (unicameral) bone cysts, 401 simple flaps, 16 simple vascular malformations, 114 single incision fasciotomy, 437 sirolimus, 45 skate flap, 297 skeletal failures of differentiation, 322 clinodactyly, 322 symphalangism, 322 synostosis, 323 skier’s thumb, 344 skin, 1–5, See also dermis; epidermis blood supply to, 5–9, See also individual entry embryology, 1–5 epidermis, function of, 1–5 histological terms, 4–5 structure, 1–5 skin appendages, 3–4 apocrine glands, eccrine glands, hair follicles, 3–4 sebaceous glands, secretion from glands, types of, skin grafts, 30–31 adherence, 30 failure, reasons for, 30 full-thickness skin grafts, 30 mechanisms, 30 remodelling, 30 revascularisation, 30 serum imbibitions, 30 split-skin grafts, 30 skin lesions, 80–131, See also benign nonpigmented skin lesions; benign pigmented skin lesions skin sparing (subcutaneous) mastectomy, 287 skin tag, 81 Skoog’s procedure, 540 SNAP principle, 462 Snodgrass repair, 478 Snow-Littler technique, 316 soft palate, 176 soft tissue failures of differentiation, 318–23 arthrogryposis, 321 camptodactyly, 319–20 clasped thumb, 320–321 syndactyly, 318 trigger thumb, 320 soft tissue tumours, 124–30, See also sarcoma; skin lesions somatosensory evoked potentials (SSEPs), 379 special naevus cell naevi, 89–90 atypical naevi, 89 halo naevi, 89–90 Spitz naevi, 89 Spitz naevi, 89 split-skin grafts, 30 spreader grafts, 561 squamous papilloma, 81 Index Stahl ear, 261 stainless steel, 50 standard of disclosure, 594 staphylococcal scalded skin syndrome (SSSS), 528 star flap, 297 static macrodactyly, 326 statistics, 602–3 nonparametric tests, 603 parametric tests, 603 sensitivity, specificity and predictive value, 603 Stener lesion, 345 sternal turnover operation, 299 sternal wound infection, 301–3 classification, 301–2 treatment, 302 steroid injection, 393 Stevens–Johnson syndrome (SJS), 526 Stewart–Treves syndrome, 447 Stickler’s syndrome, 174–5 Stiles–Bunnell procedure, 388 stockings, 424 Strattice®, 304 stratum corneum, stratum germinativum, stratum granulosum, stratum lucidum, stratum spinosum, streak gonad, 483 subcutaneous plexus, subcutaneous tissue, 5–6 subdermal plexus, subepidermal plexus, subfascial endoscopic perforating vein surgery (SEPS), 425 subfascial plexus, subfascial pocket, 271 subglandular pocket, 271 subglottic inhalation injury, 495–6 submuscular pocket, 272 subpectoral pocket, 271 suction-assisted liposuction (SAL), 568 superficial circumflex iliac artery (SCIA), superficial inferior epigastric artery (SIEA) flap, 295 superficial muscular aponeurotic system (SMAS), 531 superficial parotidectomy, 195 superficial peels, 581–2 superficial spreading melanoma, 106 superficial temporal fascia, 549–550 superior gluteal artery perforator (SGAP) flap, 295–6 superior orbital fissure syndrome, 213 superwet liposuction (1:1), 567 supraglottic inhalation injury, 495 supraorbital nerve, 550 supratrochlear nerve, 550 sural nerve, 40 surgical methods of weight loss, 572–3 Surgimend®, 304 Surgisis®, 304 sutures and suturing, 55–69 swan neck deformity, 414 Swedish and Danish trial, 112 Swedish trial, 112 swinging flashlight test, 212 symblepharon, 243 symbrachydactyly, 317 sympathectomy vasodilatation theory, symphalangism, 322 syndactyly, 318 syndromal synostosis, 146 synostosis, 143–9, 323 aetiology, 143 Apert’s syndrome, 146 bicoronal synostosis, 144 Carpenter’s syndrome, 147 classification, 143–4 clinical features, 144 complications, 149 Crouzon’s syndrome, 147 Le Fort I osteotomy, 149 Le Fort III osteotomy, 148 Muenke’s syndrome, 147 Pfeiffer’s syndrome, 147 positional plagiocephaly, 145 posterior cranial vault reconstruction, 148 postoperative care, 149 radiological features, 145 Saethre–Chotzen syndrome, 147 sagittal strip craniectomy, 148 skeletal distraction, 149 syndromal synostosis, 146 synovitis, 49 synthetic foams, 54–5 synthetic non-absorbable suture, 57 syringocystadenoma papilliferum (SCAP), 83, 84 syringoma, 84 systemic inflammatory response syndrome (SIRS), 511 systemic inhalation injury, 496 systemic lupus erythematosus (SLE), 416–17 tacrolimus, 45 Tagliacozzi’s nasal reconstruction, Tajima technique, 170 Tamoxifen, 289 621 tangential burn excision, 506 TAR syndrome, 313 tardy ulnar nerve palsy, 363 tarsal plates, 230 tattooing, 297 Teflon®, 51 Tegaderm™, 54 telangiectasia, 121 telecanthus, 141 teledermoscopy, 103 telephone deformity, 261 Telfa™, 54 temperature measurement, 73 temporal branch, 533 temporalis muscle, 253 temporary abdominal closure, 461–2 temporary central tarsorrhaphy sutures, 243 temporary lateral tarsorrhaphy sutures, 243 temporary tarsorrhaphy, 250, 547 tendon healing, 41–2 anatomy, 41 extensor tendon, 41 extrinsic healing, 41–2 flexor tendons, 41 intrinsic healing, 42 mechanisms of, 41–2 paratenon, 41 phases of, 42 tendon injury, 346–51, See also extensor tendons flexor tendon repair, 346–7 flexor tendons, 346 management options, 350–351 methods of securing tendon grafts, 351 primary tendon graft, 350 pulley reconstruction, 351 tendon repair, 347–8 two-stage tendon graft, 350 tendon transfers, 384–8, See also ulnar nerve palsy Bunnell technique, 387 Camitz transfer, 387 extensor indicis transfer, 387 FDS opponensplasty, 387 general principles, 384–6 for high median nerve lesions, 387 Huber transfer, 387 median nerve palsy, 386–7 radial nerve palsy, 386 Royle-Thompson technique, 387 surgical principles, 386 Tennison–Randall technique, 167–8 tensor veli palatini, 172 Tessier 6, 7, cleft, See Treacher Collins syndrome 622 Index thenar aponeurosis, 390–391 therapeutic mammaplasty, 291 thermal burns, 491–516, See also inhalation injury assessment, 492–4 burn depth, estimating, 493 history, 493 initial management, 492 Jackson’s burn wound model, 491 pathophysiology of, 491–2 surface area of burn, estimating, 493 surgical decompression, 494 systemic effects, 492 thigh lift, 579–80 extended (vertical) thigh lift, 579–80 proximal thigh lift, 579 third-degree nerve injury, 38 Thompson procedure, 450 thoracic outlet syndrome (TOS), 369–71 thoracoabdominal advancement flap, 294 thoracodorsal artery perforator (TDAP) flap, 293–4 thrombosis, 74–7 thrombus formation, 69–70 thumb fractures, 344 Bennett’s fracture-subluxation, 344 Rolando fracture, 344 thumb hypoplasia, 327–8 Blauth’s classification, 327 surgical correction, 327 thumb reconstruction, 336–7 Tinel’s sign, 360 tip grafts, 561 tissue engineering, 47–8 tissue expansion, 57–61 changes, 57–8 complications, 60–61 contraindications, 59 conventional expansion, 60 design of expanders, 59–60 insertion and placement of expanders, 58–9 intra-operative expansion, 60 length of, 60 mechanisms, 57 microscopic appearance of expander capsule, 58 rapid expansion, 60 self-inflating expanders, 60 timing of, 60 titanium, 50 TNM staging, 104–5 breast, 282–4 head and neck, 179–82 melanoma, 104–5 cutaneous SCC, 98–9 toe-to-hand transplantation, 337–8 anatomy, 337 variants of toe transfer, 337 tongue blade test, 213 tonofibrils, tonsillectomy, 191 topical anaesthesia, 67 total (radical) fasciectomy, 394 total parotidectomy, 196 total penile reconstruction, 487 tourniquets in hand surgery, 331–2 towel-processing, 571 toxic epidermal necrolysis (TEN), 526–7 toxic shock syndrome (TSS), 511 tracheostomy, 496–7 traction, 374 transcartilaginous incision, 558 transcolumellar incision, 558 transconjunctival approach, 546 preseptal, 546 retroseptal, 546 transcutaneous approach, 546 TransCyte®, 509 transdomal suture, 561 transfixion incision, 559 transforming growth factor-β (TGF-β), 23, 26–7 transpalpebral technique, 553 transplant immunology, 43–5 acute rejection, 44 chronic rejection, 45 history, 43 hyperacute rejection, 44 transplantation, 42–7, See also vascularised composite allotransplantation (VCA) transverse arrest, 311–12 transverse rectus abdominis myocutaneous (TRAM) flap, 6, 294 free TRAM flap, 294 muscle sparing TRAM flap, 295 transverse upper gracilis (TUG) flap, 296 trauma, chest wall reconstruction following, 303–5 traumatic brachial plexus injury, 371–82 anatomy, 372–374 assessment, 375–7 classification, 375 examination, 376 history, 375 imaging, 376 management, 377–82 mechanisms of injury, 374–5 Narakas’ rule of ‘seven seventies’, 372 secondary procedures, 381 surgical strategies, 379 surgical techniques, 380–381 Treacher Collins syndrome, 139, 151 clinical features, 151 treatment, 152 trefoil flaps, 293 trench foot, 526 tricalcium phosphate, 53 trichiasis, 242–4 trichilemmal cysts, 85 trichilemmoma, 82 trichoblastoma, 82 trichoepithelioma, 82 trichofolliculoma, 82 trigger finger, 417–18 trigger thumb, 320 triphalangeal thumb polydactyly, 325 triple negative breast cancer, 284 trochanteric pressure ulcers, 457 trunk, 459–87 tuberous breast, 277–8 deformity, classification, 277 surgical correction, 277 tubularised incised plate (TIP), 478–80 tubularised preputial flap, 480 tug test, 431 tumescent liposuction (3:1), 567 tumour ablation, chest wall reconstruction following, 303–5 tumours of hand, 396–400, See also ganglia aneurysmal bone cyst, 401 bone and cartilage tumours, 400–401 bone and cartilage, 397 enchondroma, 400 fat, 396 fibrous tissue, 396 giant cell tumour of the tendon sheath, 400 glomus tumours, 400 joint, 397 muscle, 396 neural tissue, 396 osteochondroma, 401 osteoid osteoma, 401 Index simple (unicameral) bone cysts, 401 skin, 396 tendon sheath, 397 vascular tissue, 396 ‘Turkish delight’ technique, 560 Tutopatch®, 304 typical cleft hand, 316 ulnar deficiency, 315 ulnar nerve, 363–5 compression of, in Guyon’s canal, 364 cubital tunnel syndrome, 363 ulnar nerve palsy, 387–8 tendon transfers, 388 ulnar paradox, 388 ulnar polydactyly, 323 ultrasound (US), 192 ultrasound-assisted liposuction (UAL), 569 umbilical incision, 271 unclassified craniofacial abnormalities, 159 undergrowth, 327–8, See also thumb hypoplasia brachydactyly, 328 Madelung’s deformity, 328 unicondylar fractures, 342 unifying theory, unilateral CL nasal deformity, 162 United Nations Convention on the Rights of the Child 1989, 601 unknown primary, 189–91 examination, 190 history, 189 investigations, 190 tonsillectomy, 191 upper back lift, 577–8 upper eyelid, 235–6 alternative reconstructions, 236 blepharoplasty for, 541–2 defects between 1∕3 and 2∕3 of the horizontal width, 235 defects greater than 2∕3 of the horizontal width, 236 defects less than 1∕3 of the horizontal width, 235 upper limb, 309–419, See also congenital deformities; Dupuytren’s disease; hand trauma; nerve compression; obstetric brachial plexus palsy; tendon transfers; traumatic brachial plexus injury; tumours of hand De Quervain’s disease, 418–19 development mechanisms, 310–311 developmental anatomy, 309–10 embryology, 309–11 trigger finger, 417–18 upper Z-plasties, 166 urethra, 475 urethral advancement, 479 urogenital system, 459–87, See also ambiguous genitalia; bladder exstrophy-epispadias complex; hypospadias; penile reconstruction; perineal reconstruction; vaginal agenesis urogenital triangle, 464–5 utilitarianism, 592 VACTERL association, 313 vagina, 466–7 vaginal agenesis, 485–6 dilatation, 486 reconstruction with a split-skin graft, 486 reconstruction, 485–6 vaginal reconstruction, 471 Vancouver scar scale, 517 vascular anomalies, 113–23, See also congenital haemangioma; infantile haemangioma arteriovenous malformations (AVMs), 122–3 classification, 113–15 Kasabach–Merritt phenomenon, 120 lymphatic malformations (LMs), 122 pyogenic granuloma, 120 simple malformations, 120–123, See also capillary malformations (CMs); venous malformations (VMs) vascular malformations, 114, 120–123 vascular tumours, 114, 115–20 vascular injury, 432 vascular plexus, vascular plexuses of fascia, 5–6 vascularised composite allotransplantation (VCA), 46–7 vascularised lymph node transfer, 451 Vaughan–Jackson syndrome, 412 Veau-Wardill-Kilner repair, 175 velocardiofacial syndrome, 174 velopharyngeal insufficiency (VPI), 177–80 speech assessment, 178 623 treatment of, 179 velopharyngeal assessment, 178–9 velum, 172 vemurafenib, 112, 113 venous axial flap, 11 venous characteristics, venous malformations (VMs), 121 blue rubber bleb naevus (BRBN) syndrome, 122 common VMs, 121 multiple cutaneous and mucosal venous malformations, 122 venous ulcer disease, 424–5 ventral curvature, correction, 477–8 Veritas®, 304 Versiva®, 54 vertical rectus abdominis myocutaneous (VRAM) flap, 303, 305, 468, 470–1 vertical scar technique, 268 vessel healing, 69 Vibration Amplification of Sound Energy at Resonance (VASER®), 569 Vicryl®, 304 VII–VII cross facial nerve grafting (CFNG), 252–3 viral wart, 81 Vismodegib (Erivedge®), 96 Vistabel®, 584 visual analog scale, 517 vitallium, 50 volar approach to hand fractures, 341 volar retinacular ganglia, 399 volar wrist ganglia, 399 voluntary consent, 593 Von Langenbeck repair, 175 von Recklinghausen’s disease, See neurofibromatosis type (NF 1) von Willebrand factor (vWF), 23, 76 vulva, 466 V-Y flaps, 17–18 Wallace rule of nines, 494 warfarin, 76 Wartenberg’s syndrome, 368 Waterlow score, 453–4 Weber–Ferguson approach, 159 Webster-Bernard flap, 199 Wee flap, 469–70 weight loss, surgical methods of, 572–3 Werner syndrome, 27 wet liposuction, 567 wetting solutions, 568 wide local excision (WLE), 286 624 Index World Health Organisation (WHO) Melanoma Cooperative Group Trial, 112 wound dressings, 53–5 wound healing, 22–31 abnormal scars, 24–5 epithelial repair, 25–6 factors affecting healing, 27–9 local factors affecting, 28 phases of wound healing, 23–4 systemic factors affecting, acquired, 28 systemic factors affecting, congenital, 27 TGF-β, 26–7 W-plasty, 15–16 xanthelasma, 85 xenografts, 36, 43, 304 Xeomin®, 584 Zancolli lasso technique, 388 zone of polarising activity (ZPA), 310 z-plasty, 13 Zyderm® and 2, 49 zygomatic (malar) fractures, 218–19 classification, 218 fixation, 219 management, 219 surgical approaches, 219 Zyplast®, 49 ... range of motion exercises 322 Chapter • Surgical intervention is controversial; indicated for specific functional problems: Recalcitrant elbow contracture release Restoration of elbow flexion with... completely excised Thumb reconstruction • Thumb reconstruction should address: Sensation – To allow interaction with the environment – Protection – Freedom from pain Opposition – Length – Stability... stabilised: • Chondrodesis (joint fusion), or • Tendon graft to augment the vestigial UCL, or • UCL reconstruction incorporated into an FDS opponensplasty Opponensplasty to augment hypoplastic thenar