Applications in Musculoskeletal Disorders - part 5 ppt

Fig. 4.8 Semiquantitative radiological grading of bone growth 5 weeks after SWA. 0: Osteolysis; 1: Unchanged; 2: Positive reaction; 3: Complete bridging; N.S.: Not significant. Fig. 4.9 Semiautomated image analysis of the histo- logical sections. N.S.: Not significant. Table 4.1 Radiological evaluation of osseous reaction after creating a defect following ESWT Subgroups Grade a 1 b 2 c 3 Bridging 3 0 3 0 Positive bony reaction 2 4 13 0 No reaction 1 12 40 13 Osteolysis 0 4 0 7 Mean grade 4 0.9 2.0 0.7 Standard deviation 0.7 0.6 0.5 1 3000 impulses of 0.08 mJ/mm 2 2 3000 impulses of 0.28 mJ/mm 2 3 (Control group) received no SWT 4 Comparison of Group I and Group II showed p 0.05. Comparison of Group I and Group III showed no significant difference. Comparison of Group II and Group III showed p 0.01. Discussion At the beginning of the 1990s, first reports on the use of ESWT were published that went beyond the already established disintegration of kidney stones and gallstones. Valchanou and Michailov (1991), and Schleberger and Senge (1992) introduced shock waves to the treat- ment of delayed union and nonunion of frac- tures describing phenomena of local decortica- tion. Noncontrolled, nonrandomized clinical studiesreportedsuccessratesbetween52% and 91% (Russo et al. 1995, Vogel et al. 1997). Unlike in pulsed ultrasound, where excellent prospective clinical studies have demonstrated an acceleration of bone healing in fresh frac- tures and pseudarthrosis (Frankel et al 1996, Heckman et al. 1994, Kristiansen 1990, Xavier and Duarte 1987), the published examinations on shock wave therapy (SWT) did not meet this quality standard. Accordingly, the results of SWT must be viewed with caution. Whereas in pulsed ultrasound the osteoge- netic effect was clearly related to a piezoelec- Discussion 29 Table 4.2 Experimental data on ESWA on bone Author Species Effect Graff Rabbit Damage to osteocytes, bone marrow necrosis Yeaman Rat Epiphyseal dysplasia Seemann Rat Delay in bone healing Augat Sheep Reduction in mechanical stability Forriol Sheep Delay in fracture healing tric effect and a low-level mechanical force to the fracture area, resulting in an increase in vascularization, in development of soft callus, and faster enchondral ossification (Pilla et al. 1990), the mechanism of shock waves on bone is not yet understood. Histological studies did produce evidence forstimulationofosteogenesis,butnoquanti- tative analysis has been presented so far (Delius et al. 1995, Forriol et al. 1994, Graff et al. 1988, McCormack et al. 1996, Seemann et al. 1992). Most disconcerting were reports on disturbance of bone healing after SWT of experimentally produced defects (Augat et al. 1995, Ikeda et al. 1999, Yeaman et al. 1989) (Table 4.2). Recently, Schmitz (2001) reported on cellular and molecular investigations after SWA to the noninjured, intact, distal rabbit femur. 1500 impulses of 0.1, 0.35, 0.5, 0.9, and 1.2 mJ/mm 2 were applied. After fluochrome labeling, periosteal bone growth was observed regularly after application of energy flux densities of 0.5 mJ/mm 2 and more, the amount of periosteal reaction increasing with higher energy flux densities. No endosteal bone growth was observed; no cortical dam- age was found. However, while there were only minor signs of collateral damage to the adjacent quadriceps tendon up to 0.5 mJ/mm 2 , asignificantdamagetothetendonwasfound after application of 1500 impulses of an energy flux density of 0.9 or 1.2 mJ/mm 2 . The inconsistency of results related to stim- ulation of bone growth may be attributed to thefactthatthelithotriptermachines employed cannot be compared. Ideally, shock wave generators should be classified by means of acoustic measurements. Theoreti- callytheycanbedefinedbytherisetime, peak positive and negative pressure, duration of impulse, spectrum of frequencies, size of focal area, and acoustic energy of every impulse. At present there are no standardized hydrophones availabe to produce reliable measurements of these parameters. Another reason for the large variation in results is the use of different animal models (dog, sheep, rabbit) with various kinds of osteotomies and subsequent fixation. In the current study, a defect of 5 mm was created in the middle to proximal third of the fibular shaft. We did not observe any bridging of the gap in the control group radiologically. On the contrary, on the radiographs we not only saw no tendency towards bony bridging, but rather further osteolysis in 30%. After the application of 3000 impulses of a low energy density (0.08 mJ/mm 2 )wesawapositivebony reaction in 20%. This rate quadrupled to 80% after 3000 high-energy shock waves (0.28mJ/ mm 2 ). In histopathology, we did not discover any signs for deletary effects of the shock waves, but found significant development of soft callus and enchondral ossification. In his- tomorphometry, bone coverage related to the defect area was significantly higher after the application of high-energy shock waves. Of course, the timing of the shock wave application is critical (Forriol et al. 1994). We chose the fourteenth postoperative day for the beginning of treatment because we feared that earlier treatment would disrupt hema- toma formation and that later treatment mighthavenoeffectonnewlyformedbone. We cannot rule out that an earlier date for treatment might result in a more propitious effect on bone healing. Thesameappliestothenumberofimpulses and amount of energy flux density adminis- tered. From clinical studies, however, we had strong hints for the effectiveness of the cho- sen parameters. Vogel et al. (1997) performed only one treatment session because of the anesthesia required. Since bone repair occurs by cellular proliferation and differentiation over a period of several weeks, repeated 4 Dose-Dependent Effects of Extracorporeal Shock Waves in a Fibular-Defect Model in Rabbits30 applications over the course of a few weeks might have a beneficial effect that we do not yet know about. The timing of follow-ups will also influence the results. Bony healing of an osteotomized rabbit fibula can be expected after 4 weeks (Pienkowski et al. 1994). Of course, this will not be the case after producing a 5 mm defect. For reasons of sequential labeling and to allow comparison of the osteotomy and of the defect group, we chose an identical posttreat- ment follow-up of 5 weeks, expecting a bony reaction in the area of the fibular defect. The aim of the current study was not to evaluate mechanical stability and possible acceleration of bone healing. This would have required sacrificing the animals at various periods after the SWT, the latest at the six- teenth postoperative day when a rabbit fibu- lar fracture is most responsive to stimulation and stiffness is greatest (Friedenberg et al. 1971). This would, of course, have interfered with the desired evaluation of sequential labeling. In our study mechanical testing was useless 7 weeks after the operation as only three out of 30 fibulae with a defect osteo- tomy showed consolidation at this point and would have been usable for mechanical exam- ination. The current results cannot be compared with pulsed ultrasound in a comparable ani- mal model (Pienkowski et al. 1994, Pilla et al. 1990, Wang et al. 1994). In these studies non- displaced osteotomies or fractures were treated beginning only a few days after opera- tion. In this ideal situation an impressive stimulation of bone growth and fracture heal- ing, as measured with biomechanical testing, was described. The current study produced no information on the biomechanical aspect of the healing of bone but addressed the issue of a bony reac- tion to shock waves. Although radiographic and histological results correlated well, there was no correlation made with the biomaterial properties of the healing defects. Further studieswillhavetorelatethefindings observed on radiographs and those occurring in the tissues to the acquisition of load bear- ing properties, which, of course, is the most important outcome of fracture or bone defect union. Discussion 31 Page intentionally left blank 5 Shock Wave Application for Plantar Fasciitis Introduction Plantar fasciitis is one of the most common painful foot conditions (Atkins et al. 1999, Crawford et al. 2000, Leach et al. 1983, Young et al. 2001). The specific pathological features of this clinical entity are not well understood (Leach et al. 1983, Ogden et al. 2001). The pain classically is present when the patient first stands on his/her feet after awakening; it per- sistsorisworsenedbyeverydayactivities. The use of conservative methods will alleviate the condition in most patients (Pfeffer et al. 1999, Probe et al. 1999, Schepsis et al. 1991, Sobel et al. 1999, Wagner and Sharkey 1991). Heel elevation to achieve reduction of loading of the plantar fascia is being controversially discussed (Kogler et al. 2001). Steroid injec- tions into the painful area also have been used (Martin et al. 1998), but are associated with a significant risk of subsequent rupture of the plantar fascia (Leach et al. 1983). Plantar fasciotomy is not without signifi- cant risk and may be associated with pro- longed healing and postoperative rehabilita- tion (Barrett and Day 1991, Benton-Weil et al. 1998, Blanco et al. 2001, Henricson and West- lin 1984, Tomczak and Haverslock 1995, Ward and Clippinger 1987). Since 1996 several publications have exhib- ited promising results following extracorpo- real shock wave application (ESWA) (Chen et al. 2001, Krischek et al. 1998, Maier et al. 2000a, Ogden et al. 2001, Perlick et al. 1998, Rompe et al. 1996b). Randomized, controlled studies and observational trials reported com- parable treatment effects in 50–60 % of patients for various entities (Benson and Hartz2000,Concatoetal.2000).Thethera- peutic mechanism involved remains specula- tive (Heller and Niethard 1998, Loew et al. 1999). Ogden et al. (2001) described shock waves directed at controlled internal fascial tissue microdisruption that initiates a more appropriate healing response within the fas- cia and a better long-term capacity to adapt to biological and biomechanical demands. The clinical study described in the following evaluated effects of extracorporeal shock waves on the chronic painful heel in runners. Materials and Methods The study was planned as a placebo- controlled trial to determine the effectiveness of three applications of 2100 impulses of low- energy shock waves to long-distance runners with intractable plantar fasciitis. Runners covering distances of more than 30 miles per week and suffering from chronic plantar fasciitis for more than 12 months were screenedandrandomizedintooneoftwo treatment groups: Group I Active treatment: energy flux den- sity 0.16 mJ/mm 2 , 2100 impulses, three times at weekly intervals. Fig. 5.1 Radiologically proven heel spur. Fig. 5.2 Infection at the insertion of the plantar fascia after repeated corticosteroid injections (a Bone scin- tigraphy; b MRI). a b Group II Placebo treatment: sham treat- ment using a sound reflecting pad, energy flux density 0.16 mJ/mm 2 ,2100impulses, three times at weekly intervals. Inclusion Criteria For the current study, chronic heel pain was definedassymptomsofmoderatetosevere heel pain in the involved foot at the origin of the proximal plantar fascia on the medial cal- caneal tuberosity (Fig. 5.1). The pain had to have persisted for at least 12 months before enrolling in the study, in patients covering a running distance of at least 30 miles per week before symptoms occurred. All patients had failed to respond to at least three attempts at conservative treat- ment, including at least two prior courses of intervention with physical therapy, the use of orthotics, and at least one prior course of pharmacological treatment, over a period of more than 6 months. Exclusion Criteria Exclusion criteria were: dysfunction in the knee or ankle, local arthritis, generalized poly- arthritis, rheumatoid arthritis, ankylosing spondylitis, Reiter syndrome, neurological abnormalities, nerve entrapment syndrome, history of previous plantar fascial surgery, age under18years,pregnancy,infections(Fig.5.2) or tumors, history of spontaneous or steroid- induced rupture of the plantar fascia, bilateral heel pain, participation in a workman’s com- pensation program, receiving systemic thera- peutic anticoagulants, and receiving nonste- roidal antiinflammatory drugs (NSAIDs) for any chronic conditions. Group I Group I, receiving a total of 6300 impulses of an energy flux density of 0.16 mJ/mm 2 ,con- sisted of 10 women and 12 men, with a mean age of 50 years and a mean duration of pain of 20 months. Group II Group II, receiving sham treatment, consisted of 13 women, and 10 men, with a mean age of 50 years and a mean duration of pain of 18 months. 5 Shock Wave Application for Plantar Fasciitis34 Table 5.1 Laser-hydrophone data on the shock wave device 1 Physical Value Unit Energy level 1 Energy level 2 Energy level 3 (Treatment level) Peak positive pressure P + MPa 5.5 7.9 11 –6 dB focal extend in x,y,z direction f x(−6dB) f y(−6dB) f z(−6dB) mm mm mm 6.0 6.0 58 5.7 5.7 57 5.5 5.5 56 5MPafocalextent,lateral f x(5 MPa) f y(5 MPa) mm mm 2.2 2.2 3 3 5 5 Positive energy flux density ED + mJ/mm 2 0.016 0.04 0.07 Total energy flux density ED mJ/mm 2 0.04 0.09 0.16 Positive energy of –6 dB focus E +(−6 dB) mJ 0.38 0.7 1.1 Total energy of –6 dB focus E (−6 dB) mJ 1.1 2 3 Positive energy of 5 MPa focus E +(5 MPa) mJ 0.5 0.7 1 Total energy of 5 MPa focus E (5 MPa) mJ 1.8 2 3 Positive energy of 5 mm focal area E +(5 mm) mJ 0.24 0.5 0.9 Total energy of 5 mm focal area E (5 mm) mJ 0.63 1.3 2 1 Sonocur Plus provides eight user-selectable energy levels. The physical data listed in the table are typical values for the energy levels used in this study. All measurements were made using a laser hydrophone. Method of Treatment The extracorporeal shock wave therapy (ESWT) was applied using a mobile therapy unit especially designed for orthopedic use (Sonocur Plus, Siemens AG, Erlangen, Ger- many), with the shock wave head suspended by an articulating arm for flexible movement of the head in three planes. The shock wave head was equipped with an electromagnetic shock wave emitter. Shock wave focus guid- ance was established by inline integration of an ultrasound probe—a 7.5 MHz sector scanner—in the shock head. The physical out- put parameters of the device, measured using a laser hydrophone, are listed in Table 5.1. Both groups were treated under the same conditions and the patients were treated sin- gly to avoid them influencing one another. Each study subject assigned to active treat- ment underwent shock wave application (SWA) for a total of 6300 shocks in three treat- ment sessions, with a one-week interval in between, at an energy flux density of 0.16 mJ/ mm 2 and at a frequency of 4 Hz, without local anesthesia. Ultrasound coupling gel was used between the treatment head and the heel. The shock tube head was applied under inline ultrasound control, fine adjustment to the most tender region was performed by palpa- tion and interaction with the patient. For those patients assigned to placebo therapy a sound reflecting polyethylene pad was inter- posed between the coupling membrane of the treatment head and the heel to absorb the shockwavesbythepresenceofmultipleair cavities. Method of Treatment 35 Method of Evaluation Follow-ups were done 3 months after the last application of the ESWT by an independent, treatment-blinded observer. The actual study procedure was done by a second physician who was aware of the treatment. Results Follow-up Twenty-two and 23 patients were random- ized consecutively to either group. At 3 months, one patient in each of the two groups denied further cooperation because shock wave therapy (SWT) had not improved their condition, leaving 21 patients in Group I and 22 patients in Group II. Improvementfromthebaselineat3months posttreatment in the American Orthopaedic Foot and Ankle Society’s (AOFAS) Ankle–- Hindfoot Scale was evaluated. This strictly clinical score has a maximum of 100 possible points (pain: 40 points; function: 50 points; alignment: 10 points). Regarding the AOFAS Ankle–Hindfoot Scale, an increase was observed in both groups (from 52.7 81.7 points in Group I, and from 49.8 to 62.7 points in Group II). While the pre- treatment difference was not significant between Group I and Group II, it was signifi- cant after 3 months (p = 0.0039). Before the ESWT started all patients rated their pain condition themselves as “four” in a subjective four-step scale (1 = excellent; 2 = good; 3 = fair; 4 = poor). There was no differ- ence between the groups at this point in time. On the four-step scale an improvement was seen in both groups from 4.0 to 2.3 points in Group I, and from 4.0 to 3.0 points in Group II (p = 0.0179). Complications Low-energy ESWT was felt as unpleasant by all patients, though not as unpleasant as the local infiltration all patients had received dur- ing the various and unsuccessful treatment regimes prior to the current study. No patient discontinued the shock wave procedure because of severe pain. No side effects were seen at any follow-ups. There were no hema- tomas, infections or abnormal neurological findings. Discussion In patients with chronic heel pain, magnetic resonance imaging (MRI) regularly shows involvement of the calcaneal insertion of the plantar aponeurosis (Berkowitz et al. 1991, Grasel et al. 1999, Steinborn et al. 1999). The diagnosis of plantar fasciitis is straightfor- ward,evenmoresowhenaninferiorcalca- neal spur has been detected. However, the spur may be an incidental finding (Lapidus and Guidotti 1965). Clinically, the field is wide open for discussion (Pfeffer et al. 1999, Probe et al. 1999). Atkins et al. (1999) and Crawford et al. (2000) found only 11 randomized con- trolled trials with low methodological assess- ment scores carried out since 1966. There was limited evidence for the effectiveness of topi- cal corticosteroids administered by iontopho- resis; there was limited evidence for the effec- 5 Shock Wave Application for Plantar Fasciitis36 Table 5.2 Overview of prospective studies on use of ESW for the treatment of plantar fasciitis Author Journal n EFD 1 Anesthesia RCT 2 FU 3 (Mo) Success (%) Rompe JD Arch Orthop Trauma Surg 1996 36 L 4 No Yes 6 + 6 Krischek O Z Orthop Ihre Grenzgeb 1998 50 L No Yes 12 58 Perlick L Unfallchirurg 1998 83 H 5 Yes No 12 61 Maier M J Rheumatol 2000 48 L No No 19 75 Wang C J Formos Med Assoc 2000 41 H Yes No 3 81 Hammer DS Arch Orthop Trauma Surg 2000 44 L No No 6 70 Ogden JA Clin Orthop 2001 235 H Yes Yes 3 47 Chen HS Clin Orthop 2001 80 H Yes No Buch M Lecture 2001 150 H Yes Yes 3 70 Rompe JD J Bone Joint Surg [Am] in press 112 L No Yes 6 57 1 Energy flux density 2 Randomized controlled trial 3 Follow up 4 Low 5 High 6 Improvement compared with control group. No specific percentage mentioned in publication tiveness of dorsiflexion night splints; and there was limited evidence for the effective- ness of low-energy ESWT. A previous study from the presenting author had shown comparable short-term results for patients with plantar fasciitis and heel spur (Rompe et al. 1996b). In the meantime, this positive outcome has been confirmed in vari- ous clinical studies (Krischek et al. 1998, Per- lick et al. 1998, Sistermann and Katthagen 1998). Maier et al. (2000) obtained good or excellent results according to the Roles and Maudsley score in 75 % of 48 heels 29 months after applying low-energy shock waves with- out local anesthesia three times at weekly intervals. The clinical outcome was not influ- enced by the length of follow-up periods. No negative side effects were reported. Wang et al. (2000) reported 33 patients out of 41 patients to be either free of complaint or sig- nificantly better at 12 weeks after SWT. Ogden et al. (2001) published a randomized placebo- controlled study with 119 patients in the treat- ment group and 116 patients in the placebo group. Twelve weeks after a single application of 1500 high-energy shock waves under local anesthesia success was observed in 47% of the patients. After sham treatment the success rate was only 30 %. Buch et al. (2001) reports early results of a randomized placebo- controlled study involving 150 patients. Ther- apy was applied once, with 3800 high-energy impulses under local anesthesia. After 3 months 70% of the patients in the treatment group fulfilled the success criteria, as did 40 % of the placebo group. Most recently, Rompe et al. (in press) reported a randomized controlled trial on 112 patients. Group I received 1000 impulses of a low energy flux density three times; Group II received 10 impulses on three occasions over a period of 2 weeks. Comparing the rates of good and excellent outcome in a four-step score in the two groups, there was a signifi- cant difference of 47 % in favor of Group I treatment at 6 months. At 6 months pressure pain had dropped for patients in Group I from 77 points to 19 points on a Visual Analogue Scale (VAS). In Group II the ratings were sig- nificantly worse: from 79 points to 77 points. In Group I walking became completely free from pain in 25 out of 50 patients, compared with 0 out of 48 patients of Group II. By 5 years, comparing the rates of good or excel- lent outcomes in the four-step score, the dif- ferenceofonly11%infavorofGroupIwasno longer significant; pressure pain was down to 9 points in Group I, and to 29 points in Group II. Meanwhile, 5 out of 38 patients (13%) had undergone an operation of the heel in Group I, compared with 23 of 40 patients (58 %) in Group II (Table 5.2). Discussion 37 In the current study better results were observed 3 months after low-energy SWA of 2100 impulses compared with placebo treat- ment. Cointerventions remained on a compa- rable, low level in both groups. No side effects have so far been noticed with low-energy ESWA compared with calcification after ste- roid injections or postsurgical development of wound infections, hypertrophic sensitive scars or calcaneal fractures (Conti and Shinder 1991, Schepsis et al. 1991). Our clinical experi- ence is in accordance with histological and MRI-based studies (Maier et al. 2000, Rompe et al. 1998a). High-energy shock waves, also in use for the treatment of heel pain (Perlick et al. 1998, Sistermann and Katthagen 1998), on the other hand may produce side effects such as periosteal detachments and small fractures of the inner surface of the cortex (Ikeda et al. 1990). Although the Food and Drug Administration of the United States Department of Health and Human Services (FDA) recently approved a shockwavedevicefortherapyofheelpain (Henney 2000), as long as the therapeutic mechanism involved remains speculative (Heller and Niethard 1998, Loew et al. 1999) further studies should verify the results of the studies available. 5 Shock Wave Application for Plantar Fasciitis38 . P + MPa 5. 5 7.9 11 –6 dB focal extend in x,y,z direction f x(−6dB) f y(−6dB) f z(−6dB) mm mm mm 6.0 6.0 58 5. 7 5. 7 57 5. 5 5. 5 56 5MPafocalextent,lateral f x (5 MPa) f y (5 MPa) mm mm 2.2 2.2 3 3 5 5 Positive. strictly clinical score has a maximum of 100 possible points (pain: 40 points; function: 50 points; alignment: 10 points). Regarding the AOFAS Ankle–Hindfoot Scale, an increase was observed in both. energy of 5 MPa focus E + (5 MPa) mJ 0 .5 0.7 1 Total energy of 5 MPa focus E (5 MPa) mJ 1.8 2 3 Positive energy of 5 mm focal area E + (5 mm) mJ 0.24 0 .5 0.9 Total energy of 5 mm focal area E (5 mm) mJ