1 MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE MILITARY MEDICAL UNIVERSITY DUONG HOANG LUONG SURGICAL PROCEDURE OF HUMERUS SURGICAL CLOSED NECK FRACTURE WITH METAIZEAU NAIL Major Surgery Num[.]
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE MILITARY MEDICAL UNIVERSITY DUONG HOANG LUONG SURGICAL PROCEDURE OF HUMERUS SURGICAL CLOSED NECK FRACTURE WITH METAIZEAU NAIL Major: Surgery Number code: 72 01 04 SUMMARY OF MEDICAL DOCTORAL THESIS HA NOI - 2023 STUDY COMPLETED AT VIET NAM MILITARY MEDICAL UNIVERSITY Supervisor: Assoc., Prof PhD Tran Dinh Chien Assoc., Prof PhD Nguyen Thai Son Reviewer 1: Assoc., Prof PhD Vo Thanh Toan Reviewer 2: Assoc., Prof PhD Luu Hong Hai Reviewer 3: Assoc., Prof PhD Pham Dang Ninh This thesis has been defended at Institute-level Thesis Evaluation Council at Thesis can be found at: • National Library • Library of Viet Nam Military Medical University INTRODUCTION The topicality of the thesis Surgical neck fractures of humerus can be commonly seen at all ages, especially among the elderly and the adolescents This type usually occurs close to the shoulder joint whose reduction and fixation are technically difficult. Poor treatment can leave severe sequeals affecting shoulder joint For undisplaced or minimally displaced fractures, most of injuries are treated conservatively by immobilizing the injured arm in a cast or in a Desault shirt Immobilisation by a cast is, however, lengthy which greatly affects the glenohumeral joint The widely employed surgical treatment for the osteosynthesis of proximal humerus fractures in health facilities is open reduction and internal fixation using screw/plate, locking intramedullary nails, Kirschner wires and shoulder arthroplasty Open fractures have many disadvantages including a skin incision 6–15 cm in length, more damage to the surrounding soft tissue, the periosteum, axillary nerve and rotator cuff, infection, delayed bone healing, long scar and prolonged hospital stay With a view to overcoming these disadvantages, some authors advocate minimally invasive surgery and fracture fixation with intramedullary nails such as Rush nails, Ender’s nails, Metaizeau nails based on basic principle of three-point fixation provided by symmetrical bracing action of two elastic nails, which facilitates the healing process The advantage of this method is to avoid direct exposure of fracture site, less injuried soft tissue; reduced blood loss; restricted antibiotic use, short treatment, stable fixation under C-arm image intensifier control, faster bone healing and early functional recovery There have been various reports on surgical procedures and techniques of surgical neck fractures of humerus using titanium elastic nail (TEN) without exposing the fracture Nevertheless, no consensus on surgical procedures applicable to all patients have achieved Each techniques has their pros and cons, especially some procedures have no clear guidelines in selection of intramedullary nails, techniques of fracture correction and nail insertion into fracture site; techniques of stabilizing the nail in the metaphyseal part In recent years, treatment of the surgical neck fractures of the humerus with TEN has been implemented in health facilities thoughout Vietnam Nonetheless, the number of these facilities is relatively small and no consensus procedures has yet been reached on the technique of fracture fixation, C-arm image intensifier control, nail insertion for prevention of nail jamming, broken nail extractor From these above-mentioned reasons, we conducted the study: “Technical procedure of humerus surgical closed neck fracture with Metaizeau nail” Two objectives To evaluate the surgical procedure of humerus surgical closed neck fracture with Metaizeau nail To evaluate the surgical outcome of humerus surgical closed neck fracture with Metaizeau nail Practical importance of the thesis - and new contribution of the thesis The thesis has made significant contribution to the field of medical science Besides its clinical practice, the thesis topic has also met the requirements of the urgency and topicality Foreign researches by S.W.Wachtl, B.C.Marti; Naoshi Ogiwara; Wiselaw Pospula; Jin Soo Park have reported the procedure for treating surgical neck fractures of humerus with elastic nails but there are no domestic studies on this issue In Vietnam, there have been a number of reports on the application of this procedure However, there exists debates on this issue This present study might be the first to address the surgical procedure and outcome of humerus surgical closed neck fracture with Metaizeau nail in a systematic way Organization of the thesis The thesis is comprised of 127 pages, of which there are 02 pages for Introduction, 33 pages for Overview, 27 pages for Subjects and Methods, 31 pages for Results, 31 pages for Discussion; 02 pages for Conclusion; 01 page for Recommendations; 01 page for Lists of published research results of thesis The thesis also includes 39 tables, 36 figures, with a total of 111 references numbering 14 ones in Vietnamese, 02 in French and 95 in Enlgish CHAPTER 1: OVERVIEW 1.1 ANATOMICAL AND PHYSIOLOGICAL FEATURES OF PROXIMAL HUMERUS 1.1.1 Proximal humerus The proximal humerus consists of the humeral head, anatomical neck, greater and lesser tuberosity and surgical neck The surgical neck is the part between the tuberosities and the humeral shaft 1.1.2 Blood supply to proximal humerus Proximal humerus is supplied by anterior and posterior humeral circumflex artery and the arteries of the humeral head 1.1.3 Shoulder range of motion Function of humerus is chiefly assessed via range of motion for elbow and glenohumeral joints Shoulder joints has a greater range of movement than any other body joint 1.2 CLASSIFICATION OF HUMERUS SURGICAL NECK FRACTURE 1.2.1 Anatomical features of the proximal humerus fractures (PHFs) 1.2.1.1 Features of fracture line 1.2.1.2 Features of the displaced fractures of the proximal humerus 1.2.1.3 Soft tissue injury 1.2.2 Classification of the PHFs 1.2.1 According to AO This system divides PHFs into three main types (A, B, C) according to extent of injury and risk of developing osteonecrosis of the humeral head 1.2.2 According to Neer et al This classification system is based on conventional anteroposterior and lateral radiographs aiming to identify the extent of displacement of each segment (humeral head, anatomical neck, greater and lesser tuberosity and surgical neck) The Neer classification is considered to be of great valuein assessing the extent of displacement and predicting the risk of osteonecrosis of the humeral head due to vascular damage 1.3 TREATMENT OF HUMERUS SURGICAL NECK FRACTURE 1.3.1 Conservative treatment Surgical neck fractures of humerus is treated conservatively with over 90% of bone healing, especially for undisplaced and minimally displaced fractures 1.3.2 Surgical treatment 1.3.2.1 AO internal fixation with screws and plates This procedure is widely employed in dosmetic health facilities in treatment of humerus surgical neck fracture because it allows anatomically good fracture reduction and direct visualization of blood vessels In other words, besides stabilization of fracture fragments, some splints have compression effect in the fractured faces offering the chances of fast healing and early function rehabilitation 1.3.3.2 Osteosynthesis using locking plates Locking plate fixation was first described in 1995 and used initially for humeral shaft and then for humeral head Two types of locking plate fixation exist, namely one with conventional incision such as screw and plates and the other with minimal incision Locking plate has anatomical structure appropriate for humeral head and the screw head threads are fixed to the plate with a specific angle Locking plate behaves like an external fixator when placed in a supracutaneous fashion 1.3.3.3 Intramedullary osteosynthesis of humerus Methods of locking intramedullary nails for humeral surgical neck fractures include Ender nail, locking screws, locked intramedullary nailing, closed reduction with Schanz screws for two- and three- part fractures, closed percutaneous Kirschner wire fixation with the Kapandji technique, open reduction and internal fixation of three- and four-part proximal humeral fractures by intrafocal distraction 1.3.3.4 Shoulder replacement surgery Arthroplasty replacement is indicated for the surgical treatment of proximal humeral fractures with complex fracture patter Nevertheless, its complications consist of loosening implant, malunion, ectopic ossification, deep wound infection, injury to nerves and blood vessels 1.4 OSTEOSYNTHESIS WITH METAZEAU 1.4.1 Biomechanical properties of Metaizeau tip - Properties of Metaizeau + Material: Metaizeau nails were more stable than stainless steel nails Metaizeaus of 4-mm diameter were used Titanium has elastic characteristics + Shape: Generally, Metaizeaus have a conical-shaped point on one end and a curved tip on the other A good understanding of this feature is required The curved tip is intended for cortical orientation opposite the entry hole, facilitating advancement of the nail within the medullary canal Radius of curvature of nails can be slightly reduced or increased to match the anatomy of the patient The length of the curved tip should not exceed the length of the orthogonal projection of the isthmus of the medullary canal, otherwise the nail will get stuck in the bone - Advantage of Metaizeau Metaizeau nails have a bow shape with the nail tip in the form of C-shaped manner The projected length of the curved tip is about 2.2 times greater than the diameter of the nail Sharp nail tip can penetrate through the opposite cortical bone whereas too long the curved tip may distract fracture during nail insertion Benefits of nail tip: Allows easy nail insertion and sliding along the medullary canal; allows a central orientation in relation to the medullary canal; good reduction of fracture fragments; stabilize the nail in the metaphyseal part to prevent rotation and displacement 1.4.2 Biomechanical principle of Metaizeau According to Piere Lascombes, goal of fixation with Metaizeau was originally similar to rigid fixation, namely restore limb function Nonetheless, the major differences between elastic fixation and rigid fixation include: - For elastic fixation, a rapid recovery of limb function is attributed to faster healing through maximum growth of peripheral ossification whereas in rigid fixation, fracture fixation devices are determinants for fast restoration of extremity function For elastic internal fixation, fracture fragment mobility enhances formation of peripheral ossification which provides the strongest mechanical fixation during callus formation - Solid fixation is an important contributor to primary bone healing without the production of callus but peripheral calcification growth is not possible + The second goal of fixation with Metaizeau: To reduce risks of deep wound infection, osteomyelitis, prosthetic joint infection, mini-invasive incision, blood transfusion; to minimize excessive growth of bone after a fracture; to restore quickly limb function; no requirement for additional fixation and short healing time 1.4.3 The biomechanical principle of fracture fixation with Metaizeau Osteosynthesis with Metaizeau is based on the principle of three-point fixation and a balanced force produced by insertion of two opposite nails into the metaphysis and spreading of these two tips over a wide range in the horizontal plane when stabilized in the metaphysis Insertion of single nail may generate a force causing angular displacement but slightly at the fracture site thanks to contraction of muscles The placement of the second nail offering three contacts into the bone opposite to the first nail produces a perfectly balanced construct and symmetrical bracing action of two elastic nails These two nails hold fracture fragments stable, of which shear force disappears but compression and traction force remain at the fractured segments The former occurs on the concave side and the latter on convex side of the bone Both forces work together at fracture site to stimulate healing process The principle of 3-point fixation has created a solid fixation system, preserving the axial alignment, preventing displacement and rotation 1.5 RESEARCHES AND APPLICATION OF ELASTIC NAILS 1.5.1 Foreign studies There have been numerous studies published on the application of elastic nails in fracture fixation 1.5.2 Domestic studies Surgical treatment of humerus surgical closed neck fracture with TEN has been employed since 2003 in some major hospitals in Ha Noi, Ho Chi Minh and provincial cities with satisfactory results CHAPTER 2: SUBJECTS AND METHODOLOGY 2.1 RESEARCH SUBJECTS The study enrolled the medical records of 55 patients with displaced humeral surgical neck fractures aged 19-79 years who were operatively treated with Metaizeaus without opening the fracture site under C-arm image intensifier control between April, 2015 to December, 2018 at Orthopedics and Trauma Department, Saint Paul Hospital, Hanoi * Selection criteria - Patients with displaced humeral surgical neck fractures received no previous treatment or underwent unsuccessful conservative treatment - Patients were eligible for surgery - Time from trauma to operation did not exceed 14 days - Fracture morphology: According to Neer classification, Neer III, Neer IV fracture and three-part fracture was selected * Exclusion criteria - None of the fractures was pathological including bone cysts, bone tumors, osteogenesis imperfecta; There were no associated neurovascular injuries in the arms; Bone marrow due to congenital anomalies or previous fractured humerus; The injured arm with prior sequeal affecting the shoulder and elbow joints Patients refused to participate in the study 2.2 METHODOLOGY 2.2.1 Study design This is a prospective, cross-sectional descriptive and noncontrolled study The study made a reference to literature review on establishment of surgical procedure for proximal humeral fractures by foreign and domestic authors such as the technique of reduction, nail insertion, number of nails, exercise following surgery Patients with Neer III, IV fracture and three-part fracture were administered for osteosynthesis with Metaizeau nail without opening the fracture site under the guidance of C-arm 2.2.2 Preoperative planning + Full physical examination was performed on every patients + Patients were scheduled for treatment and indicated for conventional laboratory-based testing: Three-dimensional computer tomography (3D CT) + Neer classification for proximal humeral fractures; Indications for surgery; Selection of reduction and fixation technique; Proper choice of surgical timing; Measurement of diameter of canal isthmus using three-dimensional computed tomography (CT) images at middle and lower third humerus to facilitate the selection of the most suitable Metaizeau When two or three nails are used, they should have the diameter about mm smaller than the diameter of the isthmus in order to allow the nail to slide along the medullary canal smoothly without getting stuck Patients were explained about benefits of TENs, complication and accidents that might arise intra-and/or post-operation There should be a collaboration between physicians and patient’s family before, during, and after surgery + Monitoring and evaluation of surgical outcome; postoperative care Post-operative radiographs were taken to evaluate the results of reduction and fixation technique; results of bone healing, rehabilitation and complications Data were processed using SPSS.20.0 software 2.2.3 Selection of convenience sampling Selection of non-probability sampling involving convenience sampling, corresponding to medical records of 79 patients aged 19-79 years who were operatively treated with Metaizeau nail without opening the fracture site These patients were categorized into groups of Neer III, IV and threepart fracture and selected from study time until adequate sampling size 2.2.4 Materials and medical instruments Surgical arm tables The C-arm machine is used during reduction and fixation of fractures Metaizeau nails were made from titanium alloy raw materials with dimensions of 3mm and 3.5mm in diameter; and 440mm - 450mm in length by GPC Medical Ltd TENing System manufacturing company from India TEN Instruments Set: Bone Awl (3-4mm); Locking Pliers; Cutter for Nail; Hammer Fiber Handle, pince; Drill Bit Plane 3-4m 2.3 PROCEDURE FOR RESEARCH 2.3.1 Indications for fracture fixation using Metaizeau nail Displaced humeral surgical neck fractures according to the Neer classification (Neer III, IV fracture and three-part fracture) 2.3.2 Surgical procedure for humeral surgical neck fractures with Metaizeau nail * Step 1: Patient selection by age (19-79 years of age); location of fractured bone (humeral surgical neck fractures); fracture type (Neer III, IV fracture and three-part fracture) * Step 2: Instrument preparation: Surgical arm tables The C-arm machine is used during reduction and fixation of fractures Metaizeau nails had diameter of 3mm and 3.5mm and its length ranged from 440mm – 450mm Selection of the most suitable Metaizeau nail was based on the diameter of the canal; Surgical lead apron * Step 3: Surgical technique: Tiến hành phẫu thuật: Patients were performed endotracheal anesthesia or brachial plexus anesthesia; Closed reduction and Metaizeau nailing was done under Under C-arm image intensifier control 18 Isthmus dimeter of mm was observed in 18 cases (32.7%) undergoing fixation with 3.0 mm nail whereas 8-mm isthmus dimeter was present in 19 cases (34.5%), 18 of which mostly utilized a nail diameter of 3.0 mm and only one case using 3.5 mm nail There were patients with 9-mm isthmus dimeter, of which were stabilized using 3.5mm nail and three remaining cases using a nail diameter of 3.0 mm There were 11 patients with 10-mm isthmus dimeter, of which were stabilized using 3.5mm nail and cases using a nail diameter of 3.0 mm The isthmus has minimum diameter of 7mm and maximum of 10 mm, median 8.1 mm There was an association between canal and nail diameter However, statistically significant association was not yet found (p < 0.05) 3.2.6 Association of nail technique and age group In the current study, Metaizeaus of equal diameter were used Metaizeaus with different sizes should not be employed for osteosynthesis due to high force impact at the fragment leading to angulation Of 55 patients, nail diameter of 3.0 mm was employed in 48 patients (87.3%) Of them, 28 patietns were 61 years and older; 16 cases in 41-60 years of age and cases in 19-40 years old Nail diameter of 3.5 mm was applied in patients (12.7%) Of them, patient was in age group of 41-60 years and patients aged over 61 years 3.2.7 Association between fixation and fracture type classified by Neer et al Table 3.12 Nailing technique and fracture type Metaizeau Total Number of TENs Fracture Number type Two Three Percent of cases nails nails age (%) (n) Neer III 17 19 34,5 Neer IV 27 36 65,5 Total 44 11 55 100 Percentage 80,0 20,0 (%) ... lateral view or angular displacement still exists in the AP view or lateral view at an angle - 15 0, its outcome is satisfactory + If displacement had angulation more than150 in both AP and lateral... medullary canal; allows a central orientation in relation to the medullary canal; good reduction of fracture fragments; stabilize the nail in the metaphyseal part to prevent rotation and displacement... third posterior incision above the olecranon fossa; split bilateral tendon of medial and lateral epicondyle for lateral incision Use a regular retractor for spliting so that one end of retractor