Purpose of the study: PEEK (polyetheretherketone)is increasingly used for spinal fusion since its elasticity modulus is close to that of cancellous bone. This favors harmonious force distribution within and around the implant and thus stimulates bone healing by remodeling. The purpose of this work was to report the mid-term radiographic outcome with this material used for sagittal correction.

Material and methods: Fifty-seven patients aged 54.6 years on average were reviewed 4 to 8 years after isolated intervertebral fusion for degenerative disease. Levels varied from L2L3 to L5S1. Posterior instrumentation used a rigid or semi-rigid pedicle screw-plate configuration associated with an anterior approach to install a lordozing intersomatic PEEK cage and a cancellous autograft. Six patients were overweight. Regional lordosis was unchanged postoperatively for 47 patients but increased 8.2° on average for ten. The clinical outcome and radiographic fusion were noted using the Brantigan classification. Multivariate analysis was used to search for correlation between regional sagittal correction at last follow-up and the following variables: age, body weight, level, quantity of intersomatic autograft as assessed by CT, rigidity of the posterior instrumentation, posterior regional correction and size of the cage.

Results: The clinical outcome was excellent for 24 patients, good for 25, fair for 6 and poor for 2. Mean sagittal correction was decreased in 13 (5.6° on average). Multivariate analysis demonstrated a significant correlation (p< 0.01, R2=0.590) between loss of correction and the following variables: degree of initial correction, rigidity of the posterior instrumentation, age, lower level, size of the cage.

Discussion and conclusion: Despite the excellent rate of fusion, sagittal correction of the regional lordosis did not persist over time and tended to return to the initial state irrespective of the patient’s weight or the quality of the initial graft. A rigid posterior instrumentation should be considered in parallel with the effect of the PEEK for explaining its role in the loss of correction.

Purpose of the study: Misalignment after insufficient treatment of unstable fracture of the pelvis is often poorly tolerated, compromising quality-of-life due to limping, leg length discrepancy, posterior pain, uncomfortable sitting position and/or sexual disorders due to mechanical problems. Secondary surgical treatment can be proposed despite its invasive nature (generally three phase surgery). The purpose of this work was to present the technique and the results of standardized correction of pelvis misalignment using a two-phase procedure.

Material and methods: Eight consecutive patients (May 2002–May 2004) with sequelae of Tile C fractures were treated on average eight years after the initial trauma. A double-approach was used. The series included four men and four women, aged 18–43 years. The first posterior approach in the ventral supine position was used for osteotomy of the sacroiliac callus and systematic debridement by section of the sacroiliac ligaments. The secondary ilioinguinal approach was performed in the dorsal supine position to achieve osteotomy of the symphyseal callus, reduction of the iliac wing, and symphyseal synthesis using a sacroiliac plate anteriorly and percutaneous screws.

Results: The mean operative time was four hours 30 minutes. Blood loss required transfusion of 3.5 packed red cell units on average. Anatomic reduction was achieved in six cases, partial reduction in two. Despite one nosocomial infection and two partial popliteal external sciatic deficits, all patients wer satisfied with the operation at mean eight months follow-up. Bone healing was achieve din all cases.

Discussion: Standard two-phase surgery is possible for a wide range of cases. The anatomic result is reliable with good clinical outcome. The duration of the operation and blood loss are reduced compared with classical techniques.

Conclusion: Despite the advantage of this original operative strategy, surgery for correction of pelvis misalignment remains a difficult surgical procedure for selected and motivated patients informed of the operative risks.

Purpose of the study: The mean rotation center (MRC) characterizes the movement of two solids in relation to each other. This parameter has been proposed for the cervical spine to describe the motion of vertebral segments. Two lateral views (flexion and extension) are required to draw the necessary lines and establish the centers of rotation. The process is rigorous but time-consuming. We validated a computerized analysis system for automatic determination of the cervical MRC and study the localizations observed in healthy subjects.

Material and methods: Validation of the computerized system. Accurate angle measurements: nine cervical spines were harvested from anatomic specimens. A K-wire was inserted sagittally into each vertebra. Lateral images were obtain in flexion and extension. The measurements of mobility made by the software were compared with manual measurements. Reproducibility tests (intra- and interobserver): six pairs of flexion and extension views in healthy subjects. Two different observers made fifteen successive measurements of each MRC for each spinal segment. Frequently encountered positions of the MRC in healthy subjects: stress films were obtained in 51 healthy subjects aged 18–40 years. For each spinal segment, the MCR was determined with the computerized system.

Results: Accuracy of the angle measurements: the precision was 1.4° for a 95% interval of confidence. Reproducibility: variability of the position in X and Y for the MRC (expressed in percent of the size of the vertebral body) was: 19.6 and 24.5 for C2–C3; 112 and 15.3 for C3–C4; 7.7 and 9.4 for C4–C5; 9.1 and 9.4 for C5–C6; 13.1 and 11.8 for C6–C7. Positions frequently encountered in healthy subjects: the most frequent position of the MRC varied from one segment to another. There was a frequent position for each segment. These frequent positions were situated in the posterosuperior quadrant of the subjacent vertebra for C2–C3, C3–C4, C4–C5, and C5–C6. For C6–C7, the frequent positions for MRC were at the level of the intervertebral space, behind the center of the disc.

Discussion: The software tested here appeared to provide good measurements for cervical spine from C3 to C7. At these levels, the measures were accurate and reproducible, as were the coordinates for the MCR of each segment. The frequent positions of the MRC found in this study are the same as reported by other authors. This method is easy to apply in routine practice.

Purpose of the study: Pelvic fractures disrupting the pelvic girdle often create a serious challenge for reduction and fixation. Type C fractures of the Tile classification provoke vertical instability. Percutaneous screw fixation under fluoroscopic control in patients positioned in dorsal decubitus enables an extension of early indications for fixation to patients with abdominal or thoracic injuries. The reduction is obtained by progressive transcondylar traction on an orthopedic table. The purpose of this study was to assess functional mid-term outcome and to analyze causes of failure.

Material and methods: From 1995 through 2003, we used the percutaneous sacroiliac screw fixation method for type C fractures in 25 patients; clinical assessment at 45 months mean follow-up was available for 22 patients. Six patients presented a bilateral lesion (C2), seven a vertical sacral fracture (C1-3), and nine sacroiliac disjunction (C1-2). One screw was inserted for ten patients, two screws for twelve. Complementary anterior osteosynthesis was performed for eight patients.

Results: The functional outcome was assessed with the Mageed score. The mean score was 801%. All patients presente satisfactory postoperative reduction (less than 10 mm residual vertical displacement). Early displacement was noted one day 10 in one patient who underwent a revision procedure. There were two late secondary displacements (one with mobilization and one with material fracture) which heal in a misaligned position. There were no iatrogenic complications (neurologic, vascular, infectious) and no cases of nonunion.

Discussion: The long-term functional results were directly related to the quality of the reduction, as previously demonstrated by Matta. In our series, the quality of the postoperative reduction was significantly correlated with time from trauma to surgery. This delay must be as short as possible (less than five days for Routt). The main complication was secondary displacement which was observed in this study among cases with a single posterior screw.

Conclusion: Percutaneous sacroiliac screw fixation provides good functional results and appears to be a safe technique if the initial reduction is satisfactory. Two posterior screws are needed to avoid secondary displacement.

This preliminary study concerns the results of THR using a minimally invasive computer assisted technique: We use the Siguier and Judet procedure. The patient is in supine position and we use an orthopedic table. The skin incision is 6 to 8 cm long and we dont cut any muscle during the approach.

The first 30 cases are studied: The navigation system is scanner free and allows different controls: cup inclination and anteversion, center of rotation, laterality, lengh of the lower limb.

The acetabular implant is a cementless impacted cup and the femoral implant is either cemented or cementless.

The first results are rapported and the technical modifications are descreibed.

A randomized study of 50 patients with CAS and 50 without CAS is now begining to determine if the risk of bad positionning the implants in MIS decreases when we use computer assisted surgery.

Purpose: Serum cobalt and chromium levels after metal-on-metal implantations are not well known. There has been little data on the correlation with clinical and radiological surveillance. This prospective analysis followed the changes in serum cobalt, chromium, and titanium levels in order to ascertain the behaviour of the femoral implant and the bearing.

Material and methods: The series included 292 patients followed for 27–72 months who were free of kidney failure, were not given vitamin B12 supplementation, and did not have occupational exposure. The same cemented implants were used in all patients: titanium femoral stem, Metasuly heads (28 mm). Serum samples were drawn preoperatively and at three, six and twelve months then annually (systematic activity questionnaire). The limit for detection of serum cobalt and chromium was 1 nmol/l (0.05μg/l); for titanium it was 30 nmol/l (1.4m/l).

Results: The main problems encountered were two impingements and two femoral loosenings. Four patterns were identified in the time courses of serum cobalt and chromium. In decreasing order, they were: type 1, low initial level (< 50 nmol/l) then no change; type 2, high initial level (> 50 nmol/l) then decrease; type 3 low initial level then progression; type 4, high initial level then further elevation. Bilateral prostheses showed a particular pattern with elevation after the second implantation. The serum levels rapidly returned to normal after revision in the two impingement cases. The titanium levels were correlated with femoral problems which were not initially detected on the x-rays.

Discussion: Correlation between serum cobalt level and wear is difficult to establish. There was no specific pattern after dislocation. The kinetics showed certain patterns with possible prognostic significance: groups 1 (metallic silence) and 2 (breaking-in) would correspond to favourable evolution; type 3 would be difficult to interpret (missed impingement, foreign body, articular decoaptation or major change in activity level); type 4 is highly suggestive of premature wear or a biological problem (excepting bilateral implants). It is important to monitor serum cobalt and titanium simultaneously to detect an interface problem and or femoral loosening.

Purpose: Transverse fractures of the upper part of the sacrum are exceptional (3–5% of sacral fractures). The neurological implications are serious: loss of the anatomic relation between the pelvic girdle and spine.

Material and methods: We reviewed the cases of 50 patients treated between 1997 and 2001 (31 women, 19 men, mean age 31 years). Most of the patients had fallen from windows (n=46) and many had multiple injuries (n=38). There were 31 associated spinal fractures (18 L1 fractures). The Roy Camille classification was: type I (n=6), type II (n=34),and type III (n=20) with involvement of the pelvic girdle in 30, especially for type II and III (3 Tile A, 10 Tile B, 17 Tile C). Neurological lesions were observed in 42 patients: ten patients had paraplegia (seven total, three partial), 38 had L5 and/or S1 radicular pain, and 36 presented perineal involvement. Functional treatment was given in 11 patients (including five with neurological involvement and serious cutaneous lesions). Surgery was performed early in 25 patients (three with no deficit, 22 with neurological deficit), and late (one month) after callus formation in 14 (13 with neurological deficit, 1 for a cutaneous indication).

Results: Mean follow-up was nine years. The gravity of the pelvic injury corresponded with the degree of associated neurological deficit. Incomplete functional recovery was observed in three patients given functional treatment. For patients undergoing early surgery, ten achieved functional recovery (six total and four partial) with no case of aggravation. Surgery after formation of a callus was followed by total functional recovery in three and partial recovery in six. Surgical complications included infection (n=9) and cerebrospinal fluid fistula (n=2) which resolved after re-operation. Progress in surgical techniques (subtraction osteotomy, better stabilisation) has improved the mechanical results.

Discussion and conclusion : Analysis of these fractures must consider the frontal and sagittal planes to determine the degree of pelvic girdle involvement. The final outcome depends on the time to surgical treatment (particularly for type II and III fractures) and reconstitution of the sagittal alignment of the spine with the pelvis.

Purpose: Uncertain position of the acetabular implant has been the cause of dysfunction in certain cases of total hip arthroplasty (THA). Classical computed tomographic analysis of anteversion has certain limitations. Integrated reconstruction of positions at risk allows a better diagnostic approach.

Material and methods: We studied 46 THA because of posterior malposition (n=17, anterior subluxation in the standing position in twelve, and true dislocation in five) and anterior malposition (n=29, posterior subluxation in sixteen and true dislocation in thirteen). Two groups of 70 naïve hips and a group of 56 THA with no functional problem served as controls. The position of the acetabulum was studied on optimised computed tomography slices reconstructing the planes of analysis for the standing, sitting and reclining positions. The reference planes for the slices was given by the sacral tilt angle measured on the lateral views of the patient in the corresponding positions. The optimised computed tomographic measurements of anteversion were compared with the classical measures. None of the patients had abnormal femoral anteversion and/or an oblique pelvis and/or leg length discrepancy greater than 10 mm. The frontal inclination of the acetabular implants was 40°–50°.

Results: In the naïve hips, acetabular anteversion varied: 19.2 with the conventional method, 15.7 in the standing position and 31 in the sitting position. In the THA controls, anteversion measurements differed: 21.3 with the conventional method, 21.4 in the standing position and 35.8 in the sitting position. In the THA with a posterior malposition, 18/29 could not be explained by the conventional measurement, but the optimised measurement enabled an understanding in 17 hips (defective anteversion in the sitting position).

Discussion: Changes in pelvis orientation between the sitting and standing positions modifies real anteversion of the cup. In particular, subjects with THA tend to have a spontaneous posterior tilt of the pelvis related to trunk ageing. This element should be taken into account for the analysis of both major and minor THA dysfunction.

Introduction Infection of posterior instrumentation supposes a severe failure in long arthrodeses with a demineralized skeleton.

Materials and methods From 1998 to 2002, ten patients of 19 to 76 years (mean 56 years) have been grafted with anterior Peek cages filled with autograft.

Four cases of scoliosis were operated as an average 5 times by posterior approach (3 – 9 times), all of them suffered fistulised non-unions recidivating after every one of the previous operations. 4 times the germ xas a Staph. Aureus Met. resist (1 associated with a streptococcus and 2 of them with an enterococcus). Three patients presented severe radicular pain.

Six posttraumatic cases underwent a surgical extraction of the posterior instrumentation. All of them presented a non-union with total loss of the initial angular correction. In one case the septic destabilisation affected the level proximal to the fixation. The germ responsible was every time a Staph. Aureus Met. Res. with an enterococcus associated in one of the cases.

Two inveterate fistulae were operated before. The grafts were performed on 1 to 4 levels without a new posterior fixation but in one case (5 thoracolumar approaches, 5 on lumbosacral fusions, external support by a 3 points corset between 4–6 months). The postoperative antibiotherapy has been maintained for 4 months in average (3–12 mos). The fusion was appreciated by the graft aspect on CT scan with a mean follow-up of 22 months (12 months minimum).

Results: No anterior infection has been observed, but in one post-traumatic case with a violation of the discal space by a screw. (Flare-up of the infection without anterior collection, treated by a new posterior approach with definitive kyphotic fusion as a result). All the nine others fused with clinical improvement (sevrance of the rigid corset and decreasing analgesic doses in a mean time of six months) and without significant correction loss. Three cases of radicular pain improved too. As a complication, one female patient previously operated three times by an anterior approach, was operated a new by a minimal left approach without incidents. She suffered in the postoperative period an ureteral necrosis needing a secondary nephrectomy.

Conclusion This strategy of intersomatic graft is a recovering solution in the mechanical failures of severe and reccurrent infections, often germs association. With these severe deformities on aged patients this technique is more difficult. The positive culture of disc material is a bad prognostic factor. In case of previous anterior approach, it is a good procedure the catheterisation of the ureteral duct to prevent a possible necrosis. The intersomatic cage has been a safe procedure assuring a primary and late stability in those patients with a deficient bone-stock. The cages did not induced any additionnal septic problems.

Purpose: Choronic tendinopathy of the Achilles tendon is frequent. Conservative treatment is long and difficult. Surgical treatment is indicated when response to medical treatment is unsatisfactory. The purpose of this study was to assess at different times and according to the type of tendinopathy treated, the results of our open surgical technique.

Material and methods: We performed a retrospective analysis of 154 cases of Achilles tendonopathiy in 136 patients (104 men and 32 women) operated between March 1985 and October 1997. Mean age was 35.5 years (range 16–70). The majority of the patients (n=146) practised sports regularly (120 at a competition level). These patients had not responded to prolonged medical treatment (mean duration of prior treatment 33.4 months, range 3 months – 15 years) and had invalidating conditions according to the Blazina scale (72 grade III-A and 82 grade III-B). We had 78 cases of insertion tendionpathy (59 without desinsertion, 19 with partial des-insertion), 49 cases of body tendinopathy (32 nodular, 17 non-nodular), 16 partial tears, and 11 cases of isolated peritendinitis. The standard surgical technique consisted in resection of the peritendinous sheath and tendon combing. Depending on the injuries observed, we associated resection of nodules, tendon reinforcement, resection of the calcaneum, or bursectomy.

Results: The overall results were classed excellent (renewed sports activity at former level without pain), good (renewed sports activity at a slightly lower level), or poor (no improvement). Results of 110 cases with more than 43 months follow-up were evaluated at one year, three years, and last follow-up (7.1 years, range 43 months–147 months). Overall results were unchanged for the different assessment times and were, at last follow-up: excellent 70%, good 18.2%, poor 11.8%. Early local complications were observed in 40/154 cases (late healing in 18, haematomas in 12, skin necrosis in 6, and infection in four).

Discussion: The overall results were satisfactory and persisted over time. The final prognosis depends basically on the type of tendinopathy with better results being obtained for isolated peritendinitis and body tendinopathy.

Purpose: Infection of a posterior fixation can lead to a therapeutic dilemma, particularly if the extensive fixation involves a demineralised spine.

Material and methods: From 1998 to 2001, seven patients aged 19 to 76 years (mean 58) were treated with an interbody cage and an autologous graft. Four patients with scoliosis had had prior posterior surgery (mean five operations, range 3 – 9 operations). All had exhibited non-union with repeated fistulisation at each prior anterior approach, in four cases with meti-R Staphylococcus associated once with a Streptococcus and twice with an Enterococcus. Three patients suffered severe radicular pain. Three of the post-trauma patients had undergone revision procedures to remove the posterior implants. All had developed nonunion with total loss of the initial correction in two cases, one with septic instability concerning the level above the fixation. Both infections were caused by meti-R Staphylococcus, associated with an Enterococcus in one case. Two persistent posterior fistulae had been reoperated earlier. The grafts involved one to four levels with no new posterior fixation except for one patient (two accesses to the thoracolumbar junction, five lumbosacral fusions, immobilisation for four to six months with a corset). Mean duration of postoperative antibiotics was four months (3–12 months). Fusion was confirmed by the radiological aspect of the grafts on the scan obtained at a mean 22 months follow-up (minimum follow-up 12 months).

Results: There were no cases of anterior infection except for one post-trauma patient where a posterior screw touched the disc (reactivation of infection without anterior abscess, posterior approach for revision and final fusion in kyphosis). There was no appreciable improvement in correction, but the six other patients fused with a clear clinical improvement (removal of rigid corset, reduction of antalgesics, mean time 6 months). Improvement was observed in the three patients with radicular pain. One patient who had undergone three prior anterior operations underwent the minimally invasive posterior revision with no particular intraoperative problem but later presented ureteral necrosis (secondary nephrectomy).

Discussion: This interbody grafting strategy is a possible solution to salvage mechanical failures subsequent to recurrent severe infection often due to multiple germs. The technique is more difficult in older patients with complex malformations. A positive disc sample is a factor of less satisfactory outcome. In the event of prior anterior revision, an ureteral catheter is advisable to limit the risk of necrosis. Use of intersomatic cages is not a problem and has allowed us to achieve primary and secondary stability in these patients with poor bone stock and this without supplementary infection problems.

Purpose: We analysed the radiographic course of anterior lumbar interbody fusion achieved via a minimal anterior extraperitoneal approach.

Material and methods: From January 1996 to December 2001, we operated 198 patients with this technique. Twenty-one patients were excluded from the analysis (two deaths, three tumours, 16 follow-ups less than 12 months). Mean age of the 177 patients retained for study was 53 years (range 22–78). Mean follow-up was 2.7 years. The 55 post-trauma cases involved essentially thoracolumbar junction. The 122 cases of degenerative lumbar spine included 14 cases of scoliosis, 26 cases of spondylolisthesis, 72 cases of unstable spines after primary posterior surgery, and 10 isolated degenerative discs. Only eight patients did not have posterior fixation. Fusion (globally 360 levels) concerned one disc in 89 patients, two discs in 71, three discs in 17. Cancellous autologous grafts were used with cages. Tricortical grafts were implanted after corporectomy (n=23). Radiological fusion was confirmed by the absence of a mobility chamber around the pedicular screws, the cages or the tricortical grafts, and by searching for loss of sagittal angles (digitalized scans and x-ray, Auto Cad L.T.2000).

Results: 1) Early postoperative status. For the post-trauma cases (65 fused levels, 55 patients), a simple callus was observed in 28. For the others, mean correction was 4° per level. 2) Angle loss. For the trauma cases, mean angle loss was 3.9° in 36 cases (29 grafts on a single level). There were two partial expulsions of the tricortical grafts implanted in osteoporotic patients; revision was not attempted. Mean angle loss for the 65 grafted levels was 2°. For the degenerative cases, mean angle loss was 3.7° for 172 fused levels (112 patients). Cage expulsion on a grade 3 spondylolisthesis did not warrant revision. Two cage impactions did not cause significant loss of angle. 3) Anatomic status of the grafts. Fusion was achieved at all levels without cage or tri-cortical graft rupture. We observed a partial but stable lucent line around the case in five cases.

Discussion: The rate of fusion reported after anterior lumbar interbody fusion has varied from 55 to 100% in the literature. This technique is an original approach for trauma victims avoiding the need for extensive posterior assemblies and/or the damage caused by a wide anterior approach. For the degenerative spine, the mediocre quality of the bone and the frequency of several level fusions is not a particular problem.

Conclusion: Anterior lumbar interbody fusion is an interesting method for reinforcing posterior fixation with a real efficacy in terms of effective fusion.

Purpose: The purpose of this work was to determine the role of orthopaedic treatment as a function of initial criteria of instability and potential risk of secondary restabilisation after healing of the common anterior vertebal ligament in patients with bipediculated C2 fractures and to compare the results of surgical treatment using CE pediatric fixation of C1-C3 fractures associated with C1-C3 graft to those with C2-C3 arthrodesis using posterior screw plate fixation with a pedicular screw in C2.

Material and methods: This was a retrospective analysis conducted in patients treated over a ten year period. There were 57 patients treated by two different orthopaedic surgery teams. There were 33 women and 24 mean, mean age 37 years with a maximum follow-up of 12 months. Clinical and radiographic findings were the same before treatment and at last follow-up. The surgical indication was for rupture of the common posterior vertebral ligament as assessed differently by two different surgical teams.

Results: Orthopaedic treatment was given to 65% of the patients (72% and 62% for the two teams). Clinical outcome in these patients was good or excellent in 69% and 79% resepectively for the two teams. Surgical treatment was given in 35% of the cases. Cervical CD fixation produced 100% fair clinical results and 40% very good and good radiographic results with the other 60% being acceptable. For the C2-C3 plate with a pedicular screw in C2, the clinical outcome was good or very good in 53% with 34% fair and poor results and 73% good and very good and 27% poor radiographic results.

Discusssion: This work demonstrated that indications or orthopaedic treatment can be extended, following the work by Roy-Cammille on the instability of these lesions introducting thus the notion of spontaneous anterior restabilisation due to healing of the common anterior vertebral ligament. For the choice of the technique, arthrodesis by cervical CD fixation remains a safe and sure technique despite the logical loss of C2-C3 rotation. Plate screw fixation with a C2 pedicular screw is more attractive but remains technically difficult.

Purpose: This work was not designed to re-examine the different surgical techniques and their indications, but to verify the long-term stability of outcome in patients having undergone the same surgical technique performed by the same surgeon (82% of the cases). The purpose of this work was to assess elbow function at more than ten years after surgery in a series of 28 elbows with a mean follow-up of 13 years.

Material and method: Between 1985 and 1990, 31 patients underwent elbow surgery in our unit for epicondylitis after failure of well-conducted medical treatment. No selection was made, all operated patients were included in the analysis. Twenty-five patients (28 elbows) could be re-evaluated. All patients included in the analysis responded to a phone interview and completed a questionnaire at a mean 13 years follow-up. The surgical technique was the same in all cases: systematic complete dissection of the common epicondyle muscles, with very superficial partial epicondylectomy with a chisel was needed.

Results: All patients in the series were reviewed at three and nine months after surgery then were included in this study at ten to fifteen years. At last follow-up, outcome was excellent in 21 elbows, good in five, and acceptable in two. There were no elbows with a poor outcome (based on the roles and Maudsley classification).

Discussion: For some, surgical treatment with muscular release would hinder muscle force and increase the risk of destabilised elbow (the epicondylar muscles being considered to actively stabilise the joint). The present analysis was unable to identify any signs suggestive of sequelae related to instability nor patient complaints related to decreased muscle force.

Conclusion: It would appear that the good results remain stable in the long term. The only case exhibiting a worse situation was in a patient with predictable problems due to cartilage injury. The good initial results were definitive, inciting us to propose this surgical procedure for patients who do not respond to medical treatment. This procedure allows renewed sports activities at the former level in the great majority of the cases after a simple standardised intervention.

A 55-year-old man developed a pseudoaneurysm of the popliteal artery after tibial valgization osteotomy performed for degenerative genu varum. A tourniquet was used for the procedure. A wedge osteotomy was performed two centimeters under the joint line; the correction angle was ten degrees. Immediately after the end of the procedure, the distal pulses disappeared for ten minutes. Doppler exploration of the arterial network did not demonstrate any anomaly. Ten days postoperatively, the patient complained of sudden onset pain in the knee and tension in the popliteal fossa. Arteriography demonstrated a pseudo-aneurysm of the popliteal artery. The lesion caused an interruption of arterial flow and was successfully treated by emergency resection and suture.

Purpose: The aim of this work was to evaluate the short- and long-term biocompatibility, tolerance and tissue response after implantation of an intersomatic bioresorbabled lumbar cage (Phusiline®).

Material and methods: Eighteen sheep were operated on in 1999; three animals were sacrificed for study at three, six, nine and twelve months after implantation. The cage was placed between two lumbar vertebrae and filled and covered with cancellous bone. Cerebrospinal fluid, lateroaortic lymph nodes, liver, spleen and kidney samples were taken after sacrifice. The spinal segment from L1 to S1 was removed with the surrounding ligaments and muscles for radiography, MRI, and CT scan. Histology sections were stained with Paragon. The pathology examination included: bone and cell density, degree of tissue differentiation in contact with the implant, remodeling and consolidation of the fusion, implant resorption and associated reactions. An epifluorescence study was performed to assess bone apposition. Reaction of tissue in contact with the implant or far from the implant (laterovertebral muscles, paravetebral lymph nodes, liver, kidney, spleen) were qualified histologically.

Results: At three months, there was no evidence of implant resorption; there was active formation of new bone around the implant. Implant resorption and osteointegration had started at six months and bone remodeling around the implant was increased. There were signs of bone fusion within and around the cage. Spondylodesis was effective at nine months with bone apposition. Implant resorption continued. Spondylodesis was confirmed. After nine and twelve months implantation, there was no sign of local or general intolerance. Degradation of the implants was visible after one month and appeared to be most marked at 12 months. Approximately 30% of the initial surfaced area of the implants had been resorbed at 12 months.

Conclusion: One year after implantation, the implant had not induced any sign of local intolerance (no sign of inflammation, necrosis, osteolysis). Fusion occurred within and around the case. This study will be pursued (two groups of three animals will be sacrificed at 24 and 36 months) and should confirm the long-term effectiveness of this technique.

Purpose: External fixators are widely used for limb lengthening procedures. More recently the femoral nail has been introduced combining the advantages of progressive lengthening obtained with external fixation and of the percutaneous approach of internal fixation. This retrospective analysis of 14 patients treated with the progressive femur lengthening nail (ECMP) Albizzia®, was conducted to analyse results in terms of limb length correction, bone healing and complications.

Material and methods: The fourteen patients, nine men and five women, mean age 27.3 years had leg length discrepancies = 20 cm. All were treated with the ECMAP nail (Albizzia®)in January or February 2000. There were nine right legs and five left legs. The patients had discrepancy subsequent to trauma (64.3%), hip dysplasia (21.4%) or neurological (7.15%) or infantile (7.15%) conditions. Mean leg length discrepancy was 41.5mm (20–150 mm); 57.1% of the patients wore a raised heal and 14.2% used crutches. The nail was inserted with reaming and locked on both ends. The corticotomy was made with an endomedullary saw in a closed procedure for 78.5% of the patients and with an open procedure for 21.5%. Angular correction was associated in 32.7% of the cases. Outcome was analysed on the basis of operative time, blood loss, rhythm and amount of limb lengthening, delay to healing and complications.

Results: Mean follow-up was 25 months. Mean operative time was 2 hr 28 min. The lengthening procedure began 4.1 days after nailing with, on the average, 20 ratchet clicks per day. Mean duration of the lengthening procedure was 32.5 days. Mean lengthening was 32.15 mm, i.e. 0.99 mm/day. Ten patients had a general anaesthesia at least twice to manipulate the nail ratchet. There were five cases with mechanical complications and one case of regressive nerve injury. There were no infections, no cases of joint stiffness and no axis defects. Bone healing was achieved a mean 2.7 days. There was one nonunion. Mean haemoglobin loss was four points, three patients required transfusion. Limb length was equivalent in six patients, with < 5 mm discrepancy in three, 6–10 mm discrepancy in one, 11 mm discrepancy in two and 64 mm discrepancy in one. One lengthening procedure had to be interrupted before term.

Discussion: ECMAP is unable to avoid the complications inherent in lengthening procedures but does offer undeniable advantages over external fixation. The risk of infection is very low and skin scars are minimal. Patient comfort is greatly improved (elimination of the cumbersome external fixator). Delay to bone healing is satisfactory and axial rotation defects can easily be corrected. This technique appears to be an excellent means for lengthening the femur in trauma patients.

Purpose: A significant increase in serum cobalt level has been reported after metal-on-metal total hip arthroplasty with wide individual variability related to activity level, mechanical conditions of the implant, and urinary elimination of cobalt. We studied serum cobalt levels over time to further analyse these factors.

Material and methods: The Metazul® prosthesis was implanted in 119 patients (72 men and 47 women, 12 bilateral implantations) (131 implants). We selected 50 patients (27 men and 23 women, mean age 53 years) who had two blood samples after the procedure allowing an assessment of the serum cobalt kinetics. Other chromium-cobalt implants, vitamin B12 intake, renal failure, or haematological disorders were recorded. An activity questionnaire was filled out by the patients at the time of the blood sample. Samples were drawn with a special kit to avoid metal contamination. The detection limit was 1 nmol/L (0.06 μg/L) with direct electrothermic atomic spectrometric absorption.

Results: In the overall series, serum cobalt level was 44 nmol/L for a physiological level in a control population of 4.28 nmol/L. The difference was significant (p < 0.0001) between the levels observed before surgery and after 18 months implantation. There was no significant correlation with the indication for arthroplasty, presence of dislocation or subdislocation, functional outcome or radiographic findings. Activity level the week before sampling did not influence the results. For the 50 cases evaluated longitudinally, four groups of patients could be identified. The first group (29 patients) had a serum cobalt level below 50 nmol/L over the entire study period. The second group (nine patients) had a level greater than 50 nmol/L followed by a decline ending with a final level below 50 nmol/L. In the third group (six patients) serum cobalt was greater than 50 nmol/L with no trend to a decline. In the fourth group (six patients) the cobalt levels were very high (greater than 150 nmol/L).

Discussion: The six patients in the fourth group were very particular. There were three patients with secondary bilateral implants with a late peak in serum cobalt, one with an impingement on the acetabular rim, one with renal failure, and one who had a very high level of physical activity. The first group had what appears to be a favourable course, similar to the second group where a stabilisation phenomenon could be operating. An explanation in the third group is difficult but could involve a third segment abrasion phenomenon.

Conclusion: Longitudinal analysis of serum cobalt levels provides more information than point measures in patients with metal-on-metal arthroplasties. Intercurrent mechanical phenomena can be detected; unexpected behaviour of the metal-on-metal junction can be suspected in certain patients.

Purpose: Nonunion of the tibia is a therapeutic challenge requiring a good understanding of bone healing, bone substance loss and skin trophicity disorders. The fibula pro tibia Huntington procedure consists in transposing the homolateral fibula onto the injured tibia. This allows bridging the bone defect, realignement and stabilisation of the nonunion segment.

Material and methods: This retrospective series included eleven patients (ten men and one woman), mean age 32 years (16–62). The cause of the injury was a traffic accident in six cases, defenestration in one, adamatinoma in one and osteomyelitis in one. The skin was broken in nine patients with septic nonunion in seven. Mean follow-up was 13 years (1–21).

Results: Mean delay to healing was 10.5 months (8.5 for post-traumatic nonunions) and was achieved in eight cases. A higher tibial nonunion persisted after resection of an adamantinoma measuring 22 cm and two patients had to be amputated in a context of acute suppuration. Walking without crutches was possible for eight patients whose tibia had healed and the mean pain score was 2 / 10.

Discussion: Several solutions can be proposed for patients with a tibial nonunion. The inter-tibiofibular graft requires a large bone graft in patients who have already had several operations. Th Papineau method only provides cancellous bone which is mechanically weak. The Ilizarov method can allow bone transfer and dynamisation of the nonunion with compression distraction. Microanastomosis transfers using a free fibula require a trained team with the risk of potential infection of the anastomoses in these infected patients. The Huntington method has the advantage of providing osteosynthesis without the inconvenients of inert material. The fibular acts like a biological plate with good vascularisation and stability to realign and lengthen the tibial segment.

Conclusion: This surgical technique is a supplementary therapeutic means for treating (septic) nonunion of the tibia. It is easy to perform and may be the last salvage method. The advantages are: a solid compact graft fixed in the mechanical axis of the tibia, possibility of bridging bone loss of more than 28 cm, short operative time without risk of complications related to graft harvesting, shorter hospital stay.

There is ambiguity concerning the nomenclature and classification of fractures of the ring of the second cervical vertebra (C2). Disruption of the pars interarticularis which defines true traumatic spondylolisthesis of C2, is often wrongly called a pedicle fracture. Our aim in this study was to assess the influence of asymmetry on the anatomical and functional outcome and to evaluate the criteria of instability established by Roy-Camille et al. We studied the plain radiographs and CT scans of 24 patients: 13 were judged to be asymmetrical, ten were considered unstable and 14 stable.

Treatment was with a Minerva jacket in 15 fractures and by operation in nine. Surgery was undertaken in patients with severe C2 to C3 sprains. One patient with an unstable lesion refused operation and was treated conservatively with a poor radiological result.

Our study showed that asymmetry of the fracture did not affect the outcomes of treatment and should not therefore influence decisions in treatment. The criteria of Roy-Camille seem to be reliable and useful. We prefer the posterior approach to the cervical spine, which allows both stabilisation of the fracture and correction of a local kyphosis.