Introduction

Current artificial discs include 1 or 2 bearing surfaces, providing 3 or 5 degrees of freedom. The ESP® is a one-piece e implant made of silicon and polycarbonate -urethane securely fixed to titanium endplates. It allows limited rotation and translation with elastic return. This cushion without fixed rotation center achieves 6 degrees of freedom including shock absorption. This objective of this study was to evaluate the safety and efficacy of the concept in a prospective nonrandomized trial.

Purpose of the study: Progressive cervical myelopathy secondary to cervical stenosis is generally treated surgically. Results of surgical decompression are generally good, but the progression and the type of neurological recovery have not been studied. We followed a cohort of patients who underwent cervical decompression in order to study the kinetics and the mode of the neurological recovery after surgery.

Material and methods: This was a prospective mono-centric observation study conducted in a routine clinical setting. The cohort included 60 patients (mean age 65.7 years) who underwent surgery around 2006. Inclusion criteria were an association of stenosis documented on the imaging and clinical signs of medullary compression. One surgeon performed all interventions (80% posterior approach, 15% anterior and 5% mixed). Preoperative evaluation used complete cervical imaging and three validated function tests: the global JOA score, the Crockard walking test, and the nine-hold plug test of manual dexterity (9HPT) for both hands. Patients were reviewed postoperatively at 1, 3, 6, 12, 18 and 24 months. Two populations were distinguished: group 1 with mild to moderate compression: mean preoperative JOA > 10; group 2 with severe compression: mean pre-operative JOA ≤10.

Results: The mean preoperative JOA was 11.7/17 (5; 15), the mean Crockard 34.5s (24; 140), and the mean time for the 9HPT 23s for both hands. Analysed by group according to the JOA showed that cervical myelopathy is mainly expressed by sensorial disorders. The JOA score, the walking test and the hand dexterity test for the dominant hand described the same pattern of recovery with a clear improvement for the first three postoperative months then a neurological stabilisation of the acquired improvement on a plateau that persisted till the end of follow-up. There was no improvement in the non-dominant hand. The same pattern was observed in both groups: the severe group presented a better improvement, reaching a final JOA score equivalent to that in the “mild-to-moderate” group.

Discussion: The pattern of recovery of cervical neurological deficits occurs rapidly during the first three months following surgical decompression, then stabilises on a plateau, irrespective of the severity of the initial condition. The benefit is certain for initially severe compression.

Current total disc prostheses are 2- or 3-pieces devices, including 1 or 2 bearing surfaces, and providing 3 or 5 degrees of freedom but with no, or very little, resistance. The ESP^® is a one-piece deformable implant made of silicon and polycarbonate polyurethane elastomer securely fixed to titanium endplates. It allows limited rotation and translation with elastic return. This cushion without fixed rotation center achieves 6 degrees of freedom including shock absorption. An earlier attempt to use elastomers (Acroflex^®) failed clinically due to the polymer. This highlights the need for accurate in-vitro fatigue testing and clinical evaluations.

In-vitro fatigue testing with more than 40 millions cycles were performed on different samples for compression, flexion-extension bending, lateral bending, torsion and shear. A prospective trial was initiated in 2004 for L3L4, L4L5 and L5S1 levels. Total disc replacements have been performed in 153 lumbar levels through extra-peritoneal mini-invasive anterior approach.

After in-vitro testing, microscopic examination showed that the polymer core remained unchanged without evidence of cracking or other degradation. Gravimetric analysis revealed insignificant changes in weight. The geometrical characteristics and the cohesion of the implants remained stable. After 3 years clinical experience, there was no device related complication, except one early revision for a post-traumatic implant migration. VAS and ODI scores improvements were equivalent to other published series.

In-vitro fatigue testing and short term results of the innovative ESP^® prosthesis demonstrate the reliability of the concept. The results are equivalent to other series with conventional implants.

Purpose: Orthopaedic treatment of Achilles tendon tears was detailed by Rodineau. Equine immobilisation for eight to twelve weeks without weight bearing is necessary. The rate of recurrent tears varies from 10 to 20%. Conventional surgery provides very low re-tear rates but can lead to cutaneous complications in 10 to 20% of cases. In 2001, Moller et al. conducted a prospective comparison between surgical and functional treatment in 112 patients followed for two years. The rates of recurrent tears were 1.7% for surgery versus 20.8% for functional treatment. The percutaneous suture with Tenolig(r) has not totally eliminated these problems and raises a cost issue. The Achillon procedure is presented as a minimally invasive technique which does not appear to be extremely easy to perform. Several other techniques have been proposed using an external fixator (Nada, 1985), subcutaneous arthroscopy (Aldam, 1989), or a transverse miniincision (Thermann, 2001). The oldest truly percutaneous method was published by Ma and Griffith in 1977. In 2001, Lim et al. conducted a prospective comparison between conventional surgery and percutaneous treatment using the Ma and Griffith method on 66 patients reviewed at six months. Average immobilisation was 12.4 weeks. There were seven infections (21%) in the surgery cohort versus three cases of painful nodules (9%) in the percutaneous cohort in addition to one case of sural nerve paraesthesia.

Material and methods: The percutaneous technique we used was derived from the Ma and Griffith technique. The purpose of this percutaneous technique is to obtain rapidly and easily a solid suture which can be achieved under local anaesthesia at little cost. We developed a special needle with an eye which accepts the type of thread desired. Early in our experience, we used a non-resorbable thread (Ethicon(r) N1) but because of painful nodules we changed to a resorbable thread (Vincryl n2) used for a double suture. The suture is performed under local anaesthesia, the patient in the ventral supine position. An equine plaster boot is worn for three weeks followed by a 90° boot with a walking heal for another three weeks during which weight bearing is allowed. From 1999 to 2002, we have used this technique for 43 patients (28 men and 15 women), mean age 51 years.

Results: The only complications were one case of superficial infection, one painful subcutaneous nodule, and one sural thrombophlebitis. There were no cases of recurrent tear or sural neurinoma.

Discussion: The contraindications for this technique are old tears, recurrent tears, and tears too close to the cal-caneal insertion.

Conclusion: This technique is easy to perform and low-cost. The suture is solid allowing rapid recovery without cutaneous complications.

Purpose: Patients with advanced Blount disease present severe metaphyseal varus associated with an oblique medial tibial plateau. Prior to 1987, we used tibial wedge osteotomy to correct the varus deformation and in certain situations also raised the medial plateau with the wedge. From 1987, we performed both procedures during the same operation. The purpose of this work was to describe our technique and evaluate the results of the dual technique.

Material and methods: Between 1987 and 2000, we performed 31 dual procedures. Fifteen patients who had advanced-stage Blount disease were seen late (eight before complete fusion of the growth cartilage and seven as adults). Thirteen children presented recurrent varus deformation after osteotomy during childhood. One patient presented tibia vara during adolescence and three others had poly-epiphyseal dysplasia. Mean age at osteotomy was 17 years (range 10–40). For all patients, the operative technique consisted in lateral closed wedge osteotomy associated with a second access for an oblique osteotomy directed towards the tibial spikes to insert the lateral wedge medially and raise the medial plateau. A mid-third fibular osteotomy was also performed together with stapling for tibial epiphysiodesis superior and lateral when the growth cartilage was still active. We recorded pre- and postoperatively: mechanical femoro-tibial angle, the tibial and femoral mechanical angles to determine intra-osseous deformation, the slope of the medial plateau, and the length of the lower limbs at the end of growth.

Results: Mean follow-up was eight years. Fusion was achieved in all patients. The mechanical femoro-tibial angle was 148.5 (mean) preoperatively giving 31.5° (20–42) varus and 178° postoperatively. The mean femoral mechanical angle was 94°, giving 4° valgus (range 88–102°) preoperatively, with no change postoperatively. The mean mechanical tibial angle was 71° preoperatively (intra-osseous varus of 19°) and 89° postoperatively. The medial tibial plateau slope was 45° preoperatively and 22° postoperatively. Leg length discrepancy was 2.2 cm at last follow-up (range 0.5–5 cm).

Discussion: Different techniques have been described for correcting two deformation components during the same operation. Here, we used the metaphyso-epiphyseal oblique osteotomy technique. This technique assumes that the medial part of the cartilage has already fused and requires fusion of the lateral part when it is active. Currently, we use chondrodiastasis with a special external fixator when the cartilage is still active. This corrects the alignment and raises the plateau, treating the length discrepancy by lengthening. The dual osteotomy technique is reserved for patients with total physis fusion. A long-term analysis after dual osteotomy in comparison with chondrodiastasis will be needed to determine the relative merits of the two techniques and the frequency of secondary osteoarthritis. This work is being conducted at the orthopaedic surgery department of the Fort-de-France University Hospital in Martinique.

Purpose: Treatment of major bone loss still raises difficult reconstruction problems. For bone tumours, massive resection prostheses allow rapid reconstruction of the architecture and satisfactory function. Several publications have reported the use of autoclave-sterilised cortical autografts for the treatment of bone tumours but only two old publications (1961) have used this method for the treatment of major bone loss in limb traumatology.

Case report: A 17-year-old male patient was transported from a neighbouring island after a motorcycle accident. The patient presented Cauchoix stage 2 fracture of the lower end of the femur with bone lose measuring 11 cm. The complete diaphysometaphyseal segment was recovered on the road and was brought in a sack. Emergency debridement was performed followed by complete skin closure and transcalcaneal traction. The femoral cortical fragment was cleaned and sterilised in the autoclave with one cycle at 121°C for 20 minutes at 1.3 bars. Twenty days later, osteosynthesis was performed using a large 95° Muller plate via a lateral approach. The cortical segment was put in position enabling complete recovery of length, alignment and rotation. Rehabilitation was initiated postoperatively. Total weight bearing began at three months and nautical sports (wind surf, surfing) at six months. Complete recovery of motion was achieved (heal-buttocks). Extension was normal and symmetrical both actively and passively with no recurvatum.

Results: Successive postoperative x-rays taken at 1.5 and 4 months and 1, 2, 3, 4, 6, and 7 years showed excellent graft incorporation. Healing of the metaphyseal and diaphyseal interfaces was complete at two years. Biopsy of the metaphyseal zone showed a normal bone structure.

Discussion: This exceptional case illustrates the capacity of this method to allow total recovery of function, an outcome rarely achieved after such important bone loss.

Purpose: Ossification (YLO) and calcification (YLC) of the yellow ligaments constitute an exceptional pathological situation described almost exclusively in Japan. We report a retrospective series of 19 patients from the French West Indies followed between 1996 and 2003.

Material and methods: The series included six men and thirteen women, mean age 67.8 years (31–79). A neurological examination was performed in all patients. Positive diagnosis was based on computed tomography results. MRI was performed in fifteen patients. Twelve patients underwent surgery (eight for laminectomy and four for laminoplasty). Operative specimens were analysed. The Rankin score was used to assess treatment efficacy.

Results: The patients generally consulted for progressive aggravation of gait disorders. Physical examination disclosed spastic tetra- or paraparesia associated with a pyramidal reflex syndrome and sphincter disorders. Computed tomography provided the positive and differential diagnosis. YLO was seen as a linear hyperdensity underlining the laminae, generally at the lower thoracic level (T9–T12 in six of ten patients). YLC was found at the lower cervical level in nine of the nine patients and appeared as round bilateral hyperdensities independent of the laminae. MRI revealed cord involvement seen as a high intensity signal on T2 sequences. The fifteen operated patients improved 1 to 3 points on the Rankin scale. Prognosis was better for YLC. Pathology examination revealed cartilaginous metaplasia of the yellow ligament leading to laminar bone for the YLO and microcrystal deposits (calcium pyrophosphate and/or hydroxyapatite) for he YLC.

Discussion: YLO and YLC are exceptional pathologies. More than 90% of the cases have been described in Japan and only one case in a black patient has been reported. YLO generally affects men in the fifth decade, YLC more often women after the age of 65 years. Positive and differential diagnosis are provided by CT scan. MRI visualises cord involvement. Treatment is based on posterior decompression. Prudence is particularly important for YLO due to dural adherences and the risk of dural breaches.

Conclusion: The frequency of YLO and YLC appears to be underestimated in the black population. These conditions can lead to severe myelopathy. Treatment is based on posterior decompression, best performed before appearance of a high intensity signal on the MRI.

Purpose: We report results obtained after surgical treatment of cervical myelopathy in 42 patients.

Material and methods: This prospective study included 42 consecutive patients who underwent surgical treatment performed by the same operator between 1999 and 2002. Inclusion criteria were clinical expression of cervical cord suffering and radiological evidence (high-intensity intramedullary signal on the T2-weighted MRI). Anterior (corporectomy associated with autologous graft and plate-screw fixation) or posterior (laminoplasty or laminectomy) decompression was performed. The approach was chosen according to the number of levels requiring decompression and static disorders. The Japanese Orthopaedic Association (JAO) score was determined prepoperatively and at six months.

Results: Forty-two patients (25 men and 17 women), mean age 65.7 years (38–80) were included, 18 anterior approaches and 24 posterior approaches. There were no neurological or infectious complications. One suffocating haematoma required early revision after an anterior decompression. Metameric hyperpathy occurred in two patients after segmentary laminectomy. The mean pre-operative JOA score was 8.3/17 (2–15); the postoperative score was 13.4 (5–17). There was no significant difference in the JOA score for anterior and posterior decompression.

Discussion: The JOA score is one of the rare scores which has been validated for cervical myelopathy. This easy to use scale does not however estimate the importance of manipulation disorders and heaviness in the hands. Most of the items are based on history taking. Recently described scores with measurable parameters appear to be essential to achieve better assessment of these patients. Severe myelopathy (three patients in our series) is considered a poor indication for surgical management although prognosis does not appear to be so bad for active disease or when the objective is limited decompression. Choice of the anterior or posterior approach is based on the predicted position of the cord after surgery. This position depends on static parameters of the cervical spine measured on the lateral view and has not been studied extensively.

Conclusion: Proper study of cervical myelopathy requires the development of objective scores using measurable and reproducible items. Study of the cervical spine statics on the lateral view should provide better criteria for choosing the surgical approach.

An extra articular correction may be necessary in osteoarthritis with an important post traumatic or congenital deformity. In the last 5 years we performed 11 TKR associated with a tibial (9 cases) or a femoral Osteotomy (2 cases), in one time surgery. The average intra osseous deformity was 14°. The technical problems are different in varus and valgus knees.

1- Which type of osteotomy ? In varus knees with a tibial deformity (6 cases) we use a hight tibial valgus osteotomy with opening wedge. Pre operative planning with long standing X rays allows precise determination of the amount of correction needed. A rigide wire, driven up to the fibular head, is placed. A provisional wedge of the desired size (degree of correction) is maintened temporarily by a staple, which will be removed later. Once the correction has been performed and maintened, the standard instrumentation to implant the prosthesis is used. In valgus knees with a tibial deformity (2 cases) a hight tibial closing wedge osteotomy, and in valgus knees with a femoral deformity (2 cases), a low femoral closing wedge osteotomy, are used. In all cases a medial approach without any release and without fibular osteotomy is performed.

2- Which kind of prosthesis?

Two degrees of constraint are possible in fonction of particular needs.

Most of the time, a non-constrained PS articular implants will be used and when more constraint will be needed (in lateral instability), CCK-type articular surfaces will be choised.

In all cases, a stem will have to be, associated with the osteotomy (tibial or femoral). Different diameters will allow a good press-fit and if necessary, an offset stem will be used.

3- Associated osteosynthesis or not? Stability provided by the press-fit stem may allow not to use an osteosynthesis in most than 50% of cases. If a doubt remains about stability, a small plate can bee added on the medial tibial side of the tibia.

4- Which immediate post-op follow-up?

Full weight bearing will be immediate. A splint will be used only for walking during six weeks. A standard rehabilitation protocole will be followed. In our 11 patients with a short follow up (1 to 5 years) complications consisted in one hematom and one phlebitis. Post-operative alpha angle was 96° and beta angle 91°. TKR with an associated osteotomy seems to be a possible alternative when osteoarthritis is associated with an important extra articular deformity.

Purpose: Most series on revision total knee arthroplasty (TKA) have cited femorotibial instability as a frequent cause of failure, after loosening and patellar complications. The purpose of this study was to analyse TKA failure due to femorotibial instability and to search whether an initial defect in technique or indication was the cause of stability and thus to draw therapeutic conclusions for revision surgery.

Material and methods: Between 1989 and 2000, 43 aseptic TKA required revision with implant replacement (tibial, femoral or both). During the same period 1013 first-intention TKA were implanted. Among the failures, implant loosening (femoral, tibial or both) was noted as the cause in 22 cases, isolated femorotibial instability in 15. Among the 22 loosenings, there were seven cases of femorotibial instability not related to implant migration or wear. We retained the 22 cases of femorol instability related to ligaments (15 cases of isolated instability and 7 cases associated with loosening) for study. Clinical data recorded were: initial diagnosis, patient age and sex, manifestations of instability, time to revision after first intervention. Radiological data recorded were: type of prosthesis implanted, implant position (alpha and beta angles), pre- and postoperative mechanical femorotibial alignment, tibial slope, tibial and femoral mechanical angles (searching for extra-articular deformation).

Results: The 22 revisions conserned 17 women and five men. Signs were pain and sensation of instability. Mean time to revision was two years eight months for isolated instability and six and one half years for instability associated with loosening. Prostheses were implanted in different units and thus varied: all were semi-constrained implants. Among the 22 instabilities leading to revision, we found 13 frontal instabilities, three sagittal instabilities, and six global instabilities. Analysis of the patient files demonstrated that failure could be explained in 19 cases by several defects, sometimes associated: insufficient release during initial intervention (medial or lateral release), excessive release (n=1), varus or valgus frontal or tibial cut, excessive tibial slope, internal rotation of the femoral or tibial implant, extra-articular deformation corrected intra-articularly (n=4), insufficient medial collateral ligament with major genu valgum (n=3). Certain failures were particular for certain implants, posterior laxity after implant with preservation and insufficiency of the posterior cruciate ligament, dislocaton of a posterior stabilised implant (n=1).

Discussion: This analysis of factors contributing to failure by femorotibial instability demonstrated that the majority of the cases have a technical explanation: 1) defective cuts and ligament imbalance are frequent; the cut or ligament release should be revised when changing the prosthesis. 2) Ligament insufficiency generally involving the medial collateral ligament in knees with major genu valgum; a more constrained prosthesis should be used or, as advocated by some, ligamentoplasty. 3) Extra-articular deformations are generally observed in knees with major genu varum; osteotomy may be needed if the extra-articular deformation exceeds 10°.

Conclusion: Femorotibial instability is a frequent cause of early failure of TKA. Greater precision in prosthesis implantation and correct ligament balance as well as proper choice of the degree of constraint should allow reduction of this frequency.

Purpose: Necrosis of the navicular bone, described by Müller then Weiss in 1927, is an uncommon finding, unlike talonavicular degeneration which is a rather frequent complication of talipes planovalgus. Between 1985 and 2000, we cared for 25 patients with this condition. The purpose of this retrospective analysis was to describe the clinical and radiological presentation and attempt to reconstruct its natural history with the aim of determining therapeutic indications.

Material and methods: We analysed 25 cases of navicular bone necrosis observed in 14 women and 3 men (eight bilateral cases). Mean age of the patients was 39 years (range 16–59). The diagnosis of necrosis was established on the basis of structural alterations (densification, bone defects) and in the more advanced cases, flattening and “expulsion” of the navicular bone. We looked for clinical signs and described the radiological aspect of the necrotic zone. A computed tomography was available in 14 cases and magnetic resonance imaging in the five most recent cases.

Results: Pain was the major sign in all cases. One-third of the cases occurred in a foot with prior planovalgus. History taking revealed elements suggestive of an aetiology in three cases: probable Köhler-Mouchet disease in a 16-year-old boy, sickle cell disease in a 35-year-old man, and prolonged walking with signs suggesting stress fracture in a 40-year-old woman. In the other 19 cases (11 women and 1 man, 7 bilateral cases), necrosis was considered idiopathic. Radiologically, we used the Ficat classification (described for hips): stage 0 with normal x-ray and strong uptake on scintigram (n=1), stage 1 with a normally shaped navicular bone but condensation or bone defect, stage 2 with modification of the shape of the bone without signs of degeneration, stage 3 where changes in the shape of the bone are associated with narrowing of the talonavicular then cuneonavicular space. Computed tomography included frontal and horizontal slices as well as lateral reconstructions indispensable to assess the posterior part of the interarticular spaces. Treatment was surgical in 12 cases and medical in 13. Well tolerated forms were treated with plantar ortheses with regular surveillance. Surgical procedures included triple arthrodesis (early in our experience), mediotarsal arthrodesis (n=2), talonavicular arthrodesis (n=7) and talocuneate arthrodesis with replacement of the scaphoid by an iliac graft (n=2). The natural course of necrosis was studied in the cases without surgery. The first sign was medial mediotarsal pain. At this stage scin-tigraphy or MRI was required for positive diagnosis. At stage 0 condensation of the navicular bone, confirmed by computed tomography, preceded bone flattening then expulsion upwardly and medially, sometimes with fragmentation and onset of talonavicular degeneration. Cuneonavicular degeneration appeared to occur later (except in one case). Long-term results of surgery were good with pain relief and renewed activity.

Discussion: The clinical presentation initially described as Müller-Weiss disease or scaphoiditis, which concerns a bilateral condition generally occurring after trauma and sometimes with a favouring factor (alcoholism, osteoporosis), appears somewhat different from our description. Mechanical factors predominated in our patients and the aetiologies were quite similar to those observed in Kienböck syndrome. Excessive pressure on the navicular bone, which leads to avascular necrosis, flattening, and expulsion, is undoubtedly the essential cause of this condition. It is well tolerated in some individuals and can lead to spontaneous fusion. In this situation, treatment can be limited to surveillance or orthopaedic care. If the functional impact is important, surgical treatment can be proposed, generally limited to talonavicular arthrodesis. If the navicular bone is sclerosed and flat, the remaining fragment can be replaced by an iliac graft to achieve talocuneate fusion.

Conclusion: Necrosis of the navicular bone appears to be less uncommon than in the classical description, particularly in black women aged 25–50 years. A more precise study of favouring anatomic factors (length of the medial ray, size of the talar neck, depression of the medial arch) could provide further information concerning the aetiology which appears to be similar to that of Kienböck disease.