Risk factors for heterotopic ossification and spur formation after total knee arthroplasty.

INTRODUCTION: The present study investigated the incidence and risk factors of heterotopic ossification (HO) after implantation of knee prosthesis. MATERIALS AND METHODS: We undertook a retrospective cohort study in 434 cases (363 patients) treated with a total knee replant using a Press-Fit-Condylar (P.F.C.(®)Sigma(®)) prosthesis. The occurrence of HO in radiograph after a follow-up period of 11.2 ± 2.4 months was correlated in a regression model with a variety of influencing factors. RESULTS: 21 patients (4.8 %) developed heterotopic ossifications, all located in the area of the distal femur. The only risk factor found concerning the development of HO was osteoarthritis when compared to rheumatoid arthritis (OR = 4.07, 95 % CI 1.18-14.05; p = 0.0201) and postoperative wound healing problems (OR = 11.32, 95 % CI 3.26-39.33; p = 0.0001). Notching (OR = 2.22, 95 % CI 0.92-5.36; p = 0.0765) and osteophyte forming (hypertrophic) arthrosis (OR = 2.40, 95 % CI 0.97-5.95; p = 0.0596), however, were associated with the development of a bony spur in the contact area of the femoral component of the prosthesis. CONCLUSIONS: Our study has revealed that patients with rheumatoid arthritis are at lower risk of HO than patients with osteoarthritis. An impairment of wound healing would appear to promote the development of a HO. Notching and hypertrophic arthrosis are highly likely to be associated with the development of a bony spur in the ventral contact area of the prosthesis.

Application of local anesthesia inhibits effects of low-energy extracorporeal shock wave treatment (ESWT) on nociceptors.

OBJECTIVE: Clinical studies of extracorporeal shock wave therapy (ESWT) provided conflicting results depending on the use of local anesthesia (LA). DESIGN: The present study investigated whether the biological effects of ESWT differ between application with and without LA. SETTING AND PATIENTS: In 20 healthy subjects, ESWT was applied to the ventral surface of forearm skin, either after topical lidocaine pretreatment or without on the corresponding contralateral side. MEASURES: During and after ESWT ongoing pain, axon-reflex vasodilation (laser Doppler imaging), thresholds for pinprick, and blunt pressure were recorded. RESULTS: The results indicate that increasing ESWT energy flux density led to increasing pain (P < 0.001). LA reduced ESWT-related pain (P < 0.02) and in parallel inhibited local axon-reflex vasodilation (P < 0.001). In addition, LA prevented ESWT-related drop in pressure pain threshold (P < 0.001). CONCLUSION: This study provided evidence that ESWT dose-dependently activates and sensitizes primary afferent nociceptive C-fibers, and that both activation and sensitization were prevented if LA was applied locally. These results suggest that LA substantially alters the biological responses of ESWT.

Cell viability, osteoblast differentiation, and gene expression are altered in human osteoblasts from hypertrophic fracture non-unions.

Recent studies have provided evidence that the number and proliferation capacity of bone marrow-derived mesenchymal stem cells, as well as the number of osteoprogenitor cells are reduced in patients with fracture non-unions. For fracture non-unions that do not heal after appropriate surgical intervention, the question arises as to what extent systemic cellular dysfunctions should be considered as being pathogenetic factors. For this purpose, we have examined the hypothesis that the cell function of osteoblasts isolated from patients with fracture non-unions may differ from those of normal control individuals in an identical and controlled in vitro situation. We analyzed the osteoblast cell viability, formation of alkaline phosphatase-positive (CFU-ALP) and mineralization-positive (CFU-M) colony forming units, as well as global differences of gene expression in osteoblasts from patients with fracture non-unions and from control individuals. We found that cell viability and CFU-M-formation were significantly reduced in non-union osteoblasts. This was accompanied by significant differences in osteoblast gene expression as revealed by Affymetrix-microarray analysis and RT-PCR. We identified a set of significantly down-regulated factors in non-union osteoblasts that are involved in regulation of osteoblast proliferation and differentiation processes (canonical Wnt-, IGF-, TGF-beta-, and FGF-signaling pathways). The results of the present study strongly support the hypothesis that cell viability, differentiation, and gene expression of osteoblasts may be altered in patients who develop recurrent and recalcitrant fracture non-unions. Proteins involved in Wnt-, IGF, TGF-beta-, and FGF-signaling pathways may be of particular interest and may unveil new potential therapies.

The influence of bone allograft processing on osteoblast attachment and function.

In order to assess the influence of eight different sterilisation and disinfection methods for bone allografts on adhesion, proliferation, and differentiation of human bone marrow stromal cells (BMSC), cells were grown in culture and then plated onto pieces of human bone allografts. Following processing methods were tested: autoclavation (AUT), low-temperature-plasma sterilisation of demineralised allografts (D-LTP), ethylene oxide sterilisation (EtO), fresh frozen bone (FFB), 80 degrees C-thermodisinfection (80 degrees C), gamma-irradiation (Gamma), chemical solvent disinfection (CSD), and Barrycidal-disinfection (BAR). The seeding efficiency was determined after one hour to detect the number of attached cells before mitosis started. The cell viability was determined after 3, 7, and 21 days. Tests to confirm the osteoblastic differentiation included histochemical alkaline phosphatase staining and RT-PCR for osteocalcin. Human BMSC showed greatest attachment affinities for D-LTP-, 80 degrees C-, and CSD-allografts, whereas less cells were found attached to AUT-, EtO-, FFB-, Gamma-, and BAR-probes. Cell viability assays at day 3 revealed highest proliferation rates within the FFB- and 80 degrees C-groups, whereas after 21 days most viable cells were found in D-LTP-, 80 degrees C-, CSD-, and Gamma-groups. BAR-treatment showed a considerably toxic effect and therefore was excluded from all further experiments. Highest AP-activity and gene expression of osteocalcin were detected in the D-LTP-group in comparison with all other groups. In summary, our results demonstrate that cell adhesion, final population, and function of BMSC are influenced by different disinfection and sterilisation methods. Therefore, processing-related alterations of BMSC-function may be important for the success of bone grafting. The experimental setup used in the present work may be useful for further optimisation of bone allograft processing.

Health-related quality of life and somatization in patients with long-term low back pain: a prospective study with 109 patients.

STUDY DESIGN: For this study, a prospective cohort of 109 patients was recruited consecutively at an orthopedic inpatient unit of a university hospital. Three self-report instruments were administered to patients with sciatica believed to be caused by a herniated lumbar disc to examine their quality of life and psychic stress at baseline and at the 1-year follow-up visit. OBJECTIVES: To investigate whether patients who have undergone a previous discectomy experience greater psychic stress than patients with no surgery, and to determine whether the groups differed regarding their health-related quality of life at the follow-up visit. SUMMARY OF BACKGROUND DATA: Previous studies have described psychic abnormalities in patients with long-term back pain, particularly patients with severe chronicity (i.e., history of surgeries and persistent problems) or those who underwent a previous discectomy. Additionally, a series of studies has shown that psychic and psychosocial parameters exert a significantly greater influence on the success of treatment than do clinical and imaging findings or the extent of disc abnormality. METHODS: The Short Form Health Survey 36, the Symptom Checklist 90, and Screening for Somatoform Disorders were administered to 109 patients consecutively treated in the authors' orthopedic university clinic, at baseline and at the 1-year follow-up visit. RESULTS: In all the patients examined, the physical and mental quality of life improved regardless of their group classification. The psychological distress, according to the Symptom Checklist 90, was clearly reduced in both groups at the follow-up visit, with the exception of somatization, as indicated by Symptom Checklist 90 and Screening for Somatoform Disorders. Whereas the patients who had undergone surgery remained nearly unchanged with regard to their somatization, the patients with no previous surgery improved significantly, as indicated by Screening for Somatoform Disorders and Symptom Checklist 90. Somatization, particularly that surveyed by the comprehensive Screening for Somatoform Disorders, proved to be quite a stabile factor over time in both groups. The extent of the physical impairment before treatment was nearly the same in both groups, as indicated by Short Form Health Survey 36. Despite a markedly higher chronicity of reported problems, patients who had undergone surgery were hardly more greatly impaired in terms of their mental quality of life and psychological distress, as indicated by Symptom Checklist 90, than those without a history of surgery. At the follow-up visit, the differences tended to be minimal as well. As compared with those who had no previous surgeries, the patients who had undergone surgery were significantly more heavily impaired in their physical quality of life despite significant improvements. CONCLUSIONS: Patients with sciatica demonstrated less abnormality in terms of the psychopathologic markers investigated than described in previous studies. Nevertheless, the predisposition to somatize influences health-related quality of life to a high degree.

Preoperative estimation of screw fixation strength in vertebral bodies.

STUDY DESIGN: Bone mineral density and bone cross-sectional area of human cadaveric vertebral bodies were investigated radiologically and histologically, respectively. After ventral instrumentation with ventral derotation spondylodesis screws, axial pullout force was measured and compared with radiologic and histologic data. OBJECTIVES: To elucidate how well ventral derotation spondylodesis screw fixation strength can be estimated before surgery by specified applications of dual-energy x-ray absorptiometry, quantitative computed tomography, T2*-relaxation time in magnetic resonance imaging, and histomorphometry. SUMMARY OF BACKGROUND DATA: It is postulated that bone quality plays a crucial role in initial strength of the instrumented spine. Bone quality is even more important in anterior fixation because of the prevalence of spongy bone in the vertebral body. METHODS: Bone mineral density of human cadaveric lumbar-vertebral bodies was assessed by dual-energy x-ray absorptiometry and quantitative computed tomography (cancellous and cortical bone separately). Cancellous bone was also characterized by T2*-relaxation time, measured by magnetic resonance imaging and histomorphometric study. Vertebral bodies were instrumented ventrally with VDS screws, and screw axial pullout force was measured and correlated with each of the nonmechanical measures. Patients with manifest osteoporosis, osteomalacia and tumors were excluded. For statistical analysis, the Mann-Whitney rank sum test was used with a significance value of P < 0.05. RESULTS: The highest correlation with pullout force was for density of cancellous bone determined by quantitative computed tomography (r = 0.72; P < 0.001), immediately followed that determined by dual-energy x-ray absorptiometry (r = 0.70; P < 0.001). Results of measurement of T2*-relaxation time and those of histomorphometric study correlated moderately (r = 0.55; r = 0.50), whereas cortical bone density determined by quantitative computed tomography showed negligible correlation (r = 0.2). CONCLUSIONS: The absorptiometric techniques, quantitative computed tomographic scan of cancellous bone and dual-energy x-ray absorptiometric study, provide more accurate readings for preoperative estimation of initial VDS screw fixation strength than do the other methods studied.

[MRI in chronic epicondylitis humeri radialis using 1.0 T equipment--contrast medium administration necessary?]. / MRT bei chronischer Epicondylitis humeri radialis an einem 1.0 T-Gerät--Kontrastmittelgabe notwendig?

PURPOSE: Evaluation of the diagnostic value and confidence of contrast-enhanced MR imaging in patients with lateral epicondylitis in comparison to clinical diagnosis. MATERIAL AND METHODS: 42 consecutive patients with clinically proven chronic lateral epicondylitis and 10 elbow joints of healthy controls have been examined on a 1.0 T MR-unit. Criteria for inclusion in the prospective study were: persistent pain and a failed conservative therapy. The MR protocol included STIR sequence, a native, T2-weighted, fat-suppressed TSE sequence, and a Flash-2-D sequence. Also, fat-suppressed, T1-weighted SE sequences before and after administration of Gd-DTPA contrast media have been recorded. RESULTS: In 39/42 patients the STIR sequence showed an increased SI of the common extensor tendon. Increased MR signal of the lateral collateral ligament combined with a thickening and a partial rupture or a full thickness tear have been observed in 15/42 cases. A bone marrow edema at the lateral epicondilus was noticed in 6 of the studied patients and a joint effusion in 18/42 patients. After administration of contrast media we noticed an average increase of SI by about 150%. However, enhanced MR imaging did not provide additional information. CONCLUSION: In MR imaging of chronic epicondylitis administration of gadolinium-DTPA does not provide additional information.

Analgesic effect of extracorporeal shock-wave therapy on chronic tennis elbow.

We report a controlled, prospective study to investigate the effect of treatment by low-energy extracorporeal shock waves on pain in tennis elbow. We assigned at random 100 patients who had had symptoms for more than 12 months to two groups to receive low-energy shock-wave therapy. Group I received a total of 3000 impulses of 0.08 mJ/mm2 and group II, the control group, 30 impulses. The patients were reviewed after 3, 6 and 24 weeks. There was significant alleviation of pain and improvement of function after treatment in group I in which there was a good or excellent outcome in 48% and an acceptable result in 42% at the final review, compared with 6% and 24%, respectively, in group II.

Dose-related effects of shock waves on rabbit tendo Achillis. A sonographic and histological study.

We aimed to determine whether extracorporeal shock waves of varying intensity would damage the intact tendo Achillis and paratenon in a rabbit model. We used 42 female New Zealand white rabbits randomly divided into four groups as follows: group a received 1000 shock-wave impulses of an energy flux density of 0.08 mJ/mm2, group b 1000 impulses of 0.28 mJ/mm2, group c 1000 impulses of 0.60 mJ/mm2, and group d was a control group. Sonographic and histological evaluation showed no changes in group a, and transient swelling of the tendon with a minor inflammatory reaction in group b. Group c had formation of paratendinous fluid with a significant increase in the anteroposterior diameter of the tendon. In this group there were marked histological changes with increased eosin staining, fibrinoid necrosis, fibrosis in the paratenon and infiltration of inflammatory cells. We conclude that there are dose-dependent changes in the tendon and paratenon after extracorporeal shock-wave therapy and that energy flux densities of over 0.28 mJ/mm should not be used clinically in the treatment of tendon disorders.

[Ultrasound follow-up of experimental muscle injuries]. / Sonographische Verlaufskontrolle von experimentellen Muskelverletzungen.

Experimental muscle lesions were produced in 28 rabbits by stab incision, thus creating a lesion of known extent and site. The changes in the course of healing were followed up and documented at short intervals for a period of two months via sonography. The changes take place in regular course and can be explained by fine tissue changes, taking into consideration the fundamentals of theoretical ultrasound physics. Sonography renders both valuable assistance in diagnosing muscular lesions and in following up the healing process--the latter, however, with some reservations due to the clinical terminology defining the extent of muscular lesions.

Clinical application of shock wave therapy (SWT) in musculoskeletal disorders.

Currently the application of shock wave therapy (SWT) in musculoskeletal disorders has been primarily used in the treatment of tendinopathies (proximal plantar fasciopathy, lateral elbow tendinopathy, calcific tendinopathy of the shoulder, and patellar tendinopathy, etc.) and bone defects (delayed- and non-union of bone fractures, avascular necrosis of femoral head, etc.). Although the mechanism of their therapeutic effects are still unknown, the majority of published papers have shown positive and beneficial effects of using SWT as a treatment for musculoskeletal disorders, with a success rate ranging from 65% to 91%, while the complications are low or negligible. The purpose of this paper is to inform the reader about the published data on the clinical application of SWT in the treatment of musculoskeletal disorders. In this paper, with the help of a literature review, indications and success rates for SWT in the treatment of musculoskeletal disorders are outlined, while adequate SWT parameters (e.g., rate of impulses, energy flux density, etc.) are defined according to the present state of knowledge.

[Epidural injection shows no advantages over oral medication and physiotherapy in the treatment of sciatica, irrespective of the duration of symptoms]. / Kein Vorteil der epiduralen Injektion vs. oraler Medikation und Physiotherapie bei Ischialgie, unabhängig von der Beschwerdedauer.

BACKGROUND: The study presented here investigated the short-term effectiveness of one-off lumbar caudal epidural injection (EI) in sciatica in relationship to the reported duration of pain. MATERIALS AND METHODS: This retrospective analysis involved 106 consecutive in-patients who received either conservative treatment (Group I) or an additional EI on the first day of their treatment (Group II). Both groups were divided according to the duration of symptoms at the time of admission (less than three months, or more than six months). Propensity score matching was performed for the whole collective and the resulting subgroups. This incorporated gender, age and pain intensity at the time of admission. The target parameter were changes on a visual analogue scale (VAS) of pain intensity on days D1, D3, and D10 depending on the respective treatment. A routine evaluation of the mental variables anxiety, depression and somatisation was performed as part of the examination upon admission and their relationship to the success of treatment was later assessed. RESULTS: The mean age of the patients was 61.7 (± 11.6) in Group I and 63.6 (± 13.6) in Group II. 59 % of the patients were female (n = 63). The Lasègue sign was prevalent in 45 % of Group I and 51 % of Group II. The intensity of pain on the day of admission was similar in both groups (7.0 ± 1.0 for Group I, 6.7 ± 1.8 for Group II). The length of stay on the ward was also similar in both groups (10.2 ± 3.9 and 9.4 ± 3.7 d, respectively). It was found that, independent of the duration of symptoms, injection treatment was significantly more effective than conservative treatment only in the early stages (D1 and D3, p < 0.001). No differences could be found in the expression of these mental variables between treatment groups, as these factors showed no influence on the results of therapy. CONCLUSIONS: In the context of acute treatment a once only lumbar caudal epidural injection represents at most a short-term effectiveness for the therapy of sciatica. The results presented here indicate that neither the duration of symptoms nor the measured psychometric variables show any effect on the success of therapy.

[Shock wave treatment for tennis elbow]. / Stosswellentherapie bei Tennisellenbogen Literaturüberblick.

Randomized controlled trials were evaluated to assess the effectiveness of extracorporeal shock wave treatment in the management of tennis elbow. Five trials had a mediocre methodology and four trials had a high-quality design. Well-designed randomized control trials have provided evidence of the effectiveness of shock wave intervention for tennis elbow.

Osteoid osteoma of the axis.

A 15-year-old boy suffering from osteoid osteoma of the right lamina of the axis presented with torticollis and local pain without neurological deficits. The tumour was treated by en-bloc resection and laminoplasty with autogenous iliac crest. The follow-up at 14 months showed complete pain relief and a perfect incorporation of the transplanted bone.

Application of extracorporeal shock-waves in the treatment of pseudarthrosis of the lower extremity. Preliminary results.

Between January 1991 and January 1996, pseudarthroses of the legs were treated prospectively in 48 patients by application of high-energy extracorporeal shock waves with an experimental device. The mean duration of pseudarthrosis was 12 months. On average, 2.4 surgical interventions had previously been performed. A total of 3000 impulses with an energy density of 0.6 mJ/mm2 was applied to the pseudarthrosis. Bony union was achieved in 60.4% of our patients after an average of 3.4 months. Failures were found especially in the atrophic types of pseudarthrosis as well as in congenital bone disorders like fibrous dysplasia or osteogenesis imperfecta. No serious complications were observed. Even after numerous surgical interventions high-energy extracorporeal shock-wave therapy showed a fair success rate. A higher success rate of this non-invasive method for the treatment of bony non-unions may be expected by applying strict selection criteria.

[Fractures after total knee joint endoprosthesis. Results of treatment with various stabilizing methods]. / Frakturen nach Kniegelenkstotalendoprothese. Behandlungsergebnisse bei verschiedenen Stabilisationsverfahren.

In 20 patients with a fracture of femur or tibia 5.2 years after arthroplasty of knee the results of the operative treatment are presented. The results show that especially bone damaging diseases as rheumatoid arthritis, osteoporosis and the loosening of the endoprosthesis are favorable for the fracture during the follow-up. The conclusion of the investigation shows that in younger patients the external fixation by plates and screws is the preferential treatment, in elderly people or comminuted fracture an internal fixation, also in combination with an additional osteosynthesis, allows a fast mobilization. The number of observed complications is higher than in primary knee arthroplasty, the full weight bearing 1st delayed. The rate of further operations and unsatisfactory results is also higher being affected by the high mean age of the operated patients (73.4 years). The possible use of a total femur implant must be discussed critically because only an individual production can avoid further damage of the parts of the joint that were not concerned by the fracture.

[Significance of dorsal decompression and instrumentation in the treatment of spinal malignancies]. / Der Stellenwert der dorsalen Dekompression und Instrumentation im Behandlungskonzept von Wirbelsäulenmalignomen.

From 1986 to 1990 50 patients with increasing spinal instability due to pathologic fractures of one or more vertebrae were operated in the Orthopedic Department of Mainz University Hospital. In the course of 57 operations anterior decompression and stabilization were performed 3 times, whereas dorsal spondylodesis was done with Cotrel-Dubousset's instrumentation (CDI) 32 times, with Luque's 7 times and with Harrington's 1 time; a combination of CDI and Luque was chosen in 2 cases, a combination of Harrington and Luque in 1 case. 3 times a single-stage combination and 4 times a two-stage combination of ventral and dorsal stabilization was used. The application of the CDI required no postoperative external support. 35 patients suffered from major neurologic deficits preoperatively--among them 11 from a complete and 6 from an incomplete paraparesis--which made spinal cord decompression necessary in advance of the dorsal stabilization. Of these, 16 improved significantly; however, deterioration of the neurologic status occurred in 4 cases with a paraparesis in 3 of them. Survival time postoperatively was approximately 13 months in 27 patients. 9 of these died within half a year after the operative intervention. Failure of fixation as a result of tumor lesion was found in 2 cases of CDI procedure and in 1 case of the Harrington instrumentation. All required a revisional operation. 3 patients developed a radiologic lysis of methylmethacrylate implants fixed by an anterior procedure. Posterior decompression and stabilization render possible resolution of spine pain as well as restoration of mobility until a few days before exitus letalis without restricting adjuvant radio- or chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Individual bone cement spacers (IBCS) for septic hip revision-preliminary report.

BACKGROUND: Two-stage septic hip revision with intermediate resection arthroplasty leads to temporary poor function and difficult reimplantation. Antibiotic-loaded cement spacers improve patient mobility and maintain stability of the joint as well as length of the limb. Prefabricated spacers are readily available but lack adaptability. We developed modular moulds separately for stem and head to create more individual spacers with optimised femoral press-fit and smooth head surface. METHODS: Moulds are fabricated preoperatively by forming 4 mm polyethylene over trial stems and cups under vacuum (MS 30, Centerpulse, Switzerland). After gas sterilization, Refobacin Palacos (Merck, Darmstadt, Germany) is poured into stem and head moulds of appropriate size. A double K-wire is inserted as a rod. Fluoroscopy is used to check for air inclusions, which might impair resistance. For mechanical resistance testing trials, 5 spacers were resin-fixed with 80% stem insertion and loaded in a craniocaudal direction at 20 N/s (universal testing machine, Zwick, Germany) until failure. RESULTS: The static testing showed an average failure load of 1550 N (range 1350-2000 N). The K-wires prevented complete dislocation of the fragments. CONCLUSION: Partial weight-bearing is possible with this system, but a fall might lead to an acute fracture. New materials for the core can be tested with our biomechanical model. Following the presented craniocaudal static testing, torsion testing and dynamic testing in Ringer's solution are planned.

[Effect of design and implantation technique on risk of progressive sintering of various cervical vertebrae cages]. / Einfluss von Design und Implantationstechnik auf das Risiko der progredienten Sinterung verschiedener HWS-Cages.

The aim of this study was to compare the subsidence of differently designed cervical interbody fusion devices under defined conditions. Forty-five bovine vertebral bodies were dissected from soft tissue and cartilage. The bony end plate was then taken off by 0, 1, and 2 mm. Five vertebral bodies of each abrasion depth were prepared for the uptake of a fusion device. Thus, three different fusion devices of comparable size underwent biomechanic testing in a Zwick testing machine with 4000 cycles of axial compression between 50 and 1000 N. Every 1000 cycles, the subsidence into the vertebral body was measured. Abrasion of the end plate resulted in an increased subsidence. The cage with rectangular shape and the cage with cylindric body and lateral wings showed better resistance to axial compression as long as the end plate remained intact. When the end plate was taken off, the subsidence was as high as in the cylindric cage, of which the subsidence did not correlate to the end plate abrasion. During preparation of the implant bed, the cortical bone of the end plate must be treated carefully. In cases of intact end plate, rectangular supporting areas can decrease the risk of subsidence.

[Indications and results of surgical treatment of neuromuscular scoliosis]. / Indikation und Ergebnisse der operativen Behandlung neuromuskulärer Skoliosen.

The results of the operative treatment of 44 patients suffering from a neuromuscular scoliosis are presented. Only multisegmental procedures - also in combination with anterior methods - should be used to avoid a postoperative care with cast or brace. By means of the operation an average correction of the curves of 50.7% was achieved. The preoperative mean angle was 75.1 degrees, postoperatively a mean angle of 37.0 degrees (mean correction of 38.1 degrees) was determined. The preoperative angle, the duration of the operations, the blood loss and the quantity of the complications are higher than in idiopathic scolioses. As a result of the known tendency of deterioration in neuromuscular scolioses, the members of the Arbeitskreis Skoliose of the German Orthopaedic Society (DGOT) recommend an early operation (in progressing curves over 20 degrees) in patients suffering from a muscular dystrophy Duchenne.