Purpose of the study: The analysis of hip prostheses often remains limited to standard x-rays taken in the upright position or a CT scan taken in the supine position. The EOS^® system enables imaging the entire body for head to foot in a lateral and anteroposterior views, in an upright or sitting position. The purpose of this work was to compare the standard radiographic work-up with the EOS system for the analysis of postural elements in patients with hip arthroplasty.

Material and method: This prospective study included 50 patients free of complications. The standard radiographic work-up included AP and lateral views in the upright and sitting positions. The standard then EOS imaging protocols were performed in two different locations. Images were acquired with the patients in a comfortable position: for the sitting position, the knees were flexed 90°. Two operators took measurements to be able to analyse reproducibility of the morphological parameters (incidence, sacroacetabular angle, and the positional parameters (version, sacral slope, Lewinnek angle, sagittal and frontal cup inclinations, pelvifemoral angle and orientation of the prosthetic neck on the lateral standing then AP sitting position). Pelvic rotation was determined on the AP view by comparative measurement of the projected width of the iliac wings in each pelvis. Hip extension reserve was calculated on the hyperextension lateral view.

Results: Reproducibility of position was excellent for different times and locations. Twelve hip (24%) presented significant reproducible rotation in the AP view; for eight of these hips (16%), the phenomenon disappeared in the sitting position. Four hips (8%) had pelvic rotation in the sitting position on the AP view. On the AP pelvic view in the sitting position, three patients had a femoral neck in functional retroversion while the anatomic femoral anteversion was normal on the scanner. The pelvic parameters were equivalent to those already described. The reproducibility of the measures was excellent between the standard x-rays and the EOS images with the exception of measurements involving the centre of the femoral head (incidence, pelvifemoral angle). It was easier to align the femoral axis on the EOS lateral images, particularly for additional calculation of extension reserve. The Lewinnek angle could not be measured in the sitting position in 32 hips (60%) because of insufficient resolution.

Conclusion: The overall evaluation of the pelvis and the subpelvic sector provides new information concerning the respective positions of the cup and the femur in functional situations.

Introduction: In patients with gonarthrosis secondary to a femoral or a tibial mal union, the technical problems are different according to the localization and the importance of the deformity, the presence of boneless, the cutaneous and ligamenteous status and the degree of preoperative motion.

Material and Methods: Between 1995 and 2003, 34 TKR have been performed in patients with mal unions either post trauma (26 cases) either secondary to surgery (osteotomy with hypercorrection). There were 21 males and 13 females. The average age was 63 years (38 to 77) The mal union was localized to the femur (9 cases) or the tibia (23 cases) or to the both femur and tibia (2 cases). The deformity was variable : varus, valgus, flessum, recurvatum or rotationnal mal union. IKS scoring, HKA, MFA and MTA angles were evaluated pre and post operatively. 11 cases of intra articular mal unions, secondary to epiphyseal fractures were operated : a TKR posterostabilized (9 cases) or constrained (2 cases) was performed.

In the extra articular mal unions (23) the technique depended on the degre of intraosseous deformity : medial or lateral release or osteotomy performed when the intra osseous deformity was more than 10°. TKR was associated with an osteotomy in one time surgery in 5 femoral mal unions and 12 tibial deformities.

Results: The average follow up was 8 years (4 to 13 years). Complications consisted in 5 phlebitis, 2 superficial skin necrosis, 4 stiff knees (flexion less than 80°). There was no infection in this short serie. The average IKS score was 65 before and 163 after operation. The average flexion was 83° preoperatively and 98° after surgery. Average HKA angle was 167° pre and 182° post operatively in the varus deformities. In the valgus deformity it was 191° pre and 181° post surgery.

Discussion: Average IKS scoring is less good in post traumatic mal unions than in the habitual TKR specially because of the motion : the knee is often stiff preoperatively and remain often stiff postoperatively. A quadriceps release is sometimes indicated either during the TKR either in a second time. Constrained implants (constrained condylar knee or rotating hinge) are necessary in some cases of medial or lateral insuffisency of the collateral ligament.

Introduction: In patients with gonarthrosis secondary to a femoral or a tibial mal union, the technical problems are different according to the localization and the importance of the deformity, the presence of boneless, the cutaneous and ligamenteous status and the degree of preoperative motion.

Matériel et méthodes: Between 1995 and 2003, 34 TKR have been performed in patients with mal unions either post trauma (26 cases) either secondary to surgery (osteotomy with hypercorrection).

There were 21 males and 13 females. The average age was 63 years (38 to 77)

The mal union was localized to the femur (9 cases) or the tibia (23 cases) or to the both femur and tibia (2 cases). The deformity was variable : varus, valgus, flessum, recurvatum or rotationnal mal union. IKS scoring, HKA, MFA and MTA angles were evaluated pre and post operatively. 11 cases of intra articular mal unions, secondary to epiphyseal fractures were operated : a TKR posterostabilized (9 cases) or constrained (2 cases) was performed.

In the extra articular mal unions (23) the technique depended on the degre of intraosseous deformity : medial or lateral release or osteotomy performed when the intra osseous deformity was more than 10°. TKR was associated with an osteotomy in one time surgery in 5 femoral mal unions and 12 tibial deformities.

Results: The average follow up was 8 years (4 to 13 years). Complications consisted in 5 phlebitis, 2 superficial skin necrosis, 4 stiff knees (flexion less than 80°). There was no infection in this short serie. The average IKS score was 65 before and 163 after operation. The average flexion was 83° preoperatively and 98° after surgery. Average HKA angle was 167° pre and 182° post operatively in the varus deformities. In the valgus deformity it was 191° pre and 181° post surgery.

Discussion: Average IKS scoring is less good in post traumatic mal unions than in the habitual TKR specially because of the motion : the knee is often stiff preoperatively and remain often stiff postoperatively. A quadriceps release is sometimes indicated either during the TKR either in a second time. Constrained implants (constrained condylar knee or rotating hinge) are necessary in some cases of medial or lateral insufficiency of the collateral ligament.

Introduction: Hip dislocation remains a relevant complication of total hip arthroplasty.The implants position plays a major role, especially cup anteversion.It has been demonstrated that anteversion measured on CTscan depends on the pelvic position in a lying patient. This prospective study evaluates the influence of pelvic tilt according to standing and sitting positions.

Material and Methods: The radiological records of 328 consecutive asymptomatic patients with THP were analyzed. These were routine radiological controls of non cemented THP with metal back acetabular implants. All patients had AP and lateral radiographs in standing and sitting position and a “low-dose” CT scan of the pelvis in lying position.Patients were checked for the absence lower limb length discrepancy and lumbosacral junction abnormality.

All the measurements were done by two independent observers and averaged. From the standard radiographs, the sacral slope (SS), the acetabular frontal inclination (AFI), and the acetabular sagittal inclination (ASI) were measured in standing, sitting, and lying positions.

From the CT scan sections, the anatomical ante-version (AA) was measured in lying position on axial images according to Murray. The results were compared to a previously described protocol replicating standing and sitting positions: CTscan sections were oriented according to sacral slope.

Results: We confirmed that the anatomical anteversion (AA), the frontal inclination (FI), and the sagittal inclination (SI) were functional parameter which significantly varied between standing, sitting, and lying positions according to sacral slope variations.The acetabular parameters in lying position highly correlated to the one in standing position, while poorly correlated with sitting position. The difference between the lying and the sitting positions was about 10°, 25°, and 15° for the AA, the AFI, and the ASI respectively.Mean lying anteversion angle was 24.2° (SD6,9°).Posterior pelvic tilt in sitting position, (sacral slope decrease) was linked to anteversion increase (mean value 38,8° - SD 5,4°). Anterior pelvic tilt in standing position (sacral slope increase) was linked to lower anteversion (mean value 31,7° - SD5,6°).

Discussion and Conclusions: Our study confirms the interest CTscan sections oriented according to sacral slope.The strong correlation between lying and standing measurements suggests that classical CTscan protocol is relevant for standing anteversion. According to the poor correlation between lying and sitting positions, it is less contributive for the investigation of dislocations in sitting position.

Introduction: Leg length and offset restoration are known to improve function after total hip arthroplasty, and to minimize the risk of dislocation and limp. Anatomic data of the hip are needed to determine specifications for prosthesis design that restore patient hip anatomy more closely. Furthermore, femoral off-set values calculated on X-Rays may be inaccurate in case of external rotational contracture or high femoral ante-version. The goal of this study was to determine three-dimensional morphological data of the hip in case of primary osteoarthritis, especially for femoral off-set.

Material and Method: 223 hips with primary osteoarthritis have been analysed using a CT-scan and a specific software (HIP-PLAN^®) that allows image post-processing for re-orienting the pelvis or the femur to a standardized orientation. Femoral and acetabular anteversions were measured. The planar (2D) and three-dimensional (3D) values of femoral offset were determined. 3D values were measured as the distance between the femoral head centre and the diaphyseal femur axis; 2D values were calculated as the projection of this distance on the frontal plan.

Results: Measurements precision was good with correlation scores ranging between 0.91 and 0.99. Mean acetabular anteversion angle was 26° +/−6.6° when measured in the Anterior Pelvic Plane and 21.9° +/−6.6° in the frontal plane according to the method of Murray. Mean femoral anteversion was 21.9° +/−9.4 according to the method of Murphy. The Sum of acetabular and femoral anteversion was found to be out of the safe zone regarding dislocation risk in 47% of patients. Mean 3D femoral off-set was found to be 42.2 mm+/− 5, significantly increased by 3.5 mm +/− 2.5 when compared to the 2D femoral off-set values. Femoral off-set was above 45mm in 31% of cases and higher than 50 mm in 12% of cases. The tip of the great trochanter was located higher than the femoral head centre, at a mean distance of about 9 mm.

Discussion: When measured on X-rays, femoral off-set may be significantly under-estimated. This error is probably due to the external rotational contracture of the hip induced by osteoarthritis. If the implants are positioned using the anatomical preoperative anteversion angles, 47% of patients would not be in the safe zone regarding posterior dislocation risk.

Conclusions: Planar measurement using X-Rays underestimates significantly the femoral off-set. Neck and head modularity may be useful to achieve simultaneous restoration of femoral off-set and leg length in 12 to 31% of cases.

Introduction: The goal of the study was to determine the precision of a three-dimensional pre-operative planning tool using a specific software (HIP-PLAN^®) and an anatomic cementless neck-modular stem.

Method: 223 patients who underwent a primary total hip replacement had a CT Scan before and after surgery. A pre-operative three-dimensional planning based on the CT-scan was performed. A cementless cup and a neck-modular stem were used. A computational matching of the pre-operative and the post-operative CT-scans was performed in order to compare the values of the planned anteversions and the planned displacement of the hip rotation center to the post-operative values.

Results: The implanted component was the same as the one planned in 89% for the cup and 94% for the stem. For the mean femoral anteversion, there was no significant difference between the planned value (26.1° +/−11.8) and the post-operative value (26.9° +/−14.1). There was a poor correlation between the planned values and the actual ones for the acetabular cup anteversion (coefficient 0.17). The hip rotation center was restored with a precision of 0.73 mm +/3.5 horizontally and 1.2 mm +/−2 laterally. Limb length was restored with a precision of 0.3 mm +/−3.3 and the femoral off-set with a precision of 0.8 mm +/−3.1. There was no significant modification of the femoral off-set (0.07 p=0.7) which was restored or slightly increased in 93% of cases. Almost all the surgical difficulties were predicted

Conclusion: HIP-PLAN^® software is a reliable three-dimensional pre-operative planning tool which allows acurate prediction of components and hip anatomy.

Introduction: The goal of the study was to analyse the modification of the sagittal lombo-pelvic equilibrium after total hip replacement for osteoarthritis.

Materials and Methods: The sagittal lombo-pelvic equilibrium was analysed among 89 patients who underwent total hip replacement for osteoarthritis, using lateral X-rays of the whole spine including the hips performed pre-operatively and at one year post-operatively. Reference values were calculated by carrying out the same analysis among 100 asymptomatic healthy volunteers. The studied parameters were: the sacral tilt (ST), the pelvic version (PV) and the sacral incidence (SI).

Results: The mean pre-operative value of STangle was significantly lower in the osteoarthritis group (20.6° +/−6) compared to the reference group (39.4 +/6, p< 0,00001). The mean pre-operative value of VP angle was significanlty higher in the osteoarthritis group (31°+/−8) compared to the reference group (13.5 +/−6 p < 0,00001). There was no significant difference between the two groups for the sacral incidence (p=0,3). At one year post-operatively, the sacral tilt has significantly increased by 5.5° (p< 0.00001).

Discussion: Compared to asymptomatic healthy volunteers, patients affected by osteoarthritis had a pelvic retroversion that has decreased post-operatively but still remained lower than the norm.

Conclusion: The lombo-pelvic equilibrium is different in case of osteoarthritis. After total hip replacement the pelvis remained retroverted. This phenomenon should be taken into account for the planning of total hip arthroplasty.

Hip-spine relationships should be better investigated in THP as lumbo-sacral orientation in the sagittal plane plays a critical role in the function of the hip joints. Lateral X-rays showing spine and hips together in standing, sitting or squatting positions characterize the adaptations of the sagittal balance and the functionnal interactions between hips and spine.

Acetabular cup implantation has to be planned for frontal inclination, axial anteversion, and sagittal orientation. The later refers to the sacro-acetabular angle, key-point in the spine – hip relationships, and that is redefined by the surgeon at the time of implantation.

Usual standard CT-sections are biased for evaluating acetabular anteversion. The conventional CT procedure does not refer to the pelvic bony frame and. the measured anteversion is a projected angle on a transverse plane, depending on the pelvic adaptation in lying position. This measured angle is often considered as anatomical anteversion, leading to some confusion. Therefore this angle is only a “functional” supine anteversion, reflecting the anterior opening angle of the acetabulum in a specific position. According to the sagittal orientation of the pelvis, the true functional acetabular orientation can virtually be assessed in various postures from adjusted CT-scan sections.

The EOS^™ low irradiation 2D-3D X-ray scanner is an innovative technology already used for global evaluation of the spine. This technology allows simultaneously “full body” frontal and lateral X-rays with the patient in standing, sitting or squatting positions; a tridimensionnal patient specific bone recontruction can be performed and the cup anteversion can be directly assessed according to the position.

We investigated the lumbo-pelvic parameters influencing the tridimensionnal orientation of the acetabulum. We compared the data obtained for real postural situations using the EOS^™ system and the measures from plane X Rays and classical CT scan cuts replicating standing, and sitting positions.368 patients with cementless THP were involved in a prospective follow-up protocol. Sacral slope and pelvic tilt, incidence angle, acetabular frontal and sagittal inclination were evaluated on AP and lateral standard XRays. Functionnal anteversion of the cup has been measured using a previously described protocol with CTscan cuts oriented according to standing and sitting sacral slope. The mean difference between CTscan and EOS^™ system was 4,4° with comparable accuracy and reproductibility.

Sacral slope decrease in sitting position was linked to anteversion increase (38,8° SD 5,4°). Sacral slope increase in standing position was linked to lower ante-version (31,7° SD 5,6°). The anatomical acetabular anteversion, the frontal inclination, and the sagittal inclination were functional parameter which significantly varied between the standing, sitting, and lying positions. We noticed that the acetabular parameters in lying position highly correlated to the one in standing position, while poorly correlated with the one in sitting position. The difference between the lying and the sitting positions was about 10°, 25°, and 15° for the cup anteversion (CA) and the frontal and sagittal inclinations (FI,SI) respectively. The poor correlation between the lying and sitting positions suggests that the usual CT scan protocol is biased and not fully appropriate for investigating the cases of posterior THP dislocation and subluxation, which happen in sitting position. On the contrary, a strong correlation was observed between lying and standing measurements with all the acetabular parameters (CA,FI, SI), suggesting that the classical CT assessment of the cup anteversion remains an interesting source of information in case of anterior THP

Each patient is characterized by a morphological parameter, the incidence angle. High incidence angle is linked to low acetabular anteversion, increasing the instability risk and anterior impingement in sitting and squatting position; higher anteversion angles are observed in low incidence angle patients, leading to more internal rotation of the hip in any position.

Lumbo-sacral orientation in the sagittal plane influences the tridimensionnal orientation of the acetabulum, especially for anteversion. Aging of the hip-spine complex is linked to progressive pelvic posterior extension. Impingement phenomenons, orientation of stripe wear zones and some instability situations can be interpreted according to those data.

This study points out the opportunity to adjust the CT scan sections to the sacral slope in functional position for properly investigating the orientation of the acetabular cup, mainly in case of posterior dislocation.

In addition, the mobility of the lumbo-sacral junction could be a crucial parameter in the mechanical functioning and the stability of a THP due to its impact on sacral slope and pelvic tilt. Therefore we also recommend doing dynamic lateral radiographs of the lumbo sacral junction in standing and sitting position for planning a THP implantation in order to detect stiff lumbosacral junction or sagittal pelvic malposition.

Anterior approaches have been suggested for THP revision in order to reduce dislocation rate. However, the exposure is considered to be more strenuous. The goal of the study was to evaluate if anterior approach in lateral position may improve the exposure.

From 2005 to 2007, 47 patients underwent THP revision, 34 times on the acetabular side, 2 times on the femoral side and 11 patients had a bipolar revision. Mean age was 64 years and mean BMI was 23. Patients were positioned on the lateral side and had an antero-lateral approach. During the femoral procedure, the leg was placed in a sterile bag stuck on the lateral side in order to optimize the exposure by positioning the femur in adduction and posterior translation.

Acetabular and femoral exposures were achieved correctly in all the cases allowing to perform all the revisions using this technique and no additional approach was needed in any patient. Antero-posterior femorotomies were performed in 7 patients for stem replacement and cement extraction, without any specific complication. Early post-operative anterior dislocations occurred in 2 patients who underwent monopolar cup revision. Dislocation was explained by an excessive anteversion of the remaining stems. 2 patients had an incomplete and transitory sciatic deficiency due to excessive posterior translation of the femoral head in the sciatic notch.

Using this technique, THP revision seems to be achievable even in complicated cases requiring stem revision and femorotomy. Dislocation rate was low; however a larger cohort is needed to confirm these preliminary results.

The new technology using femoral heads with sleeves allows conservative procedures for revision hip arthroplasty. The implantation of classical ceramic heads on a previously used femoral taper is not recommanded. When there is no loosening of the femoral implant, the use of sleeves is a good solution for using an alumine on alumine couple, specially in young and active patients.

Material and methods: 25 hips in 25 patients were included. In 12 cases the cause of revision was an acetabular osteolysis with or without loosening in metal on metal cimented THR.

In 13 patients the revision was performed for a loosening and a wear of the PHE cup with osteolysis (4 zyrcon and 9 chrome-cobalt heads). The mean age was 49 years for the metal on metal revisions (36 to 75) and 54 years for the prosthesis using a polyethylen socket.

Cementless cups were implanted using XLW delta alumina inserts. The 32 mm delta alumina sleeved heads were adjusted on the existing femoral 12–14 tapers. Patients were evaluated preoperatively and followed-up with clinical and radiological examinations.

Results: At 2 years mean follow-up, average Harris Hip Score was significantly improved (97 vs 54, p< 0.05). We did not observe ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities.

Concerning the metal on metal revisions, the aseptic loosening of the socket was combined with high rates of cobalt and chromium serum levels. Mean delay before revision was 4 years (2 to 11). Unipolar acetabular revisions were only decided after a carefull inspection of the remaining stems to detect any taper alteration or impingement lesions.

Postoperative cobalt and chromium serum levels significantly decreased postoperatively.

Concerning the metal on PHE and the zyrcon on PHE revisions, the mean delay before revison was 11 years (4 to 21).

At this short follow up, we did not notice any parasitic impingement due to the additional sleeve or any ceramic fracture or squeaking. The radiographic results did not demonstrate acetabular loosening, osteolysis, or femoral abnormalities.

Discussion: Failures of metal-on-metal or metal on PHE hip arthroplasties raise new technical problems. Conversion to ceramic on ceramic has been suggested in case of hypersensibility reactions or high rate of serum metal ions, and in case of osteolysis in young population. This prospective study evaluates a revision strategy using ceramic cups and delta ceramic heads with titanium adapter sleeves when a femoral revision is not required. Despite the limitation due to short follow-up, this technical option should be considered when wear surfaces exchange is decided.

The use of two-dimensional plain X-rays for preoperative planning in total hip arthroplasty is unreliable. For example, in the presence of rotational hip contracture the lateral femoral off set can be significantly under-estimated. Pre-operative planning is of particular importance when using uncemented prostheses. The aim of this study was to determine the precision of a novel 3D CT-based preoperative planning methodology with the use of a cementless modular-neck femoral stem.

Pre-operative computerised 3D planning was performed using HIP-PLAN® software for 223 patients undergoing THA with a cement-less cup and cement-less modular-neck stem. Components were chosen that best restored leg length and lateral off set. Postoperative anatomy was assessed by CT-scan and compared to the pre-operative plan.

The implanted component was the same as the planned one in 86% of cases for the cup and 94% for the stem. There was no significant difference between the mean planned femoral anteversion (26.1° +/− 11.8) and the mean postoperative anteversion (26.9° +/− 14.1) (p=0.18), with good correlation between the two (coefficient 0.8). There was poor correlation, however, between the planned values and the actual post-operative values of acetabular cup anteversion (coefficient 0.17). The rotational centre of the hip was restored with a precision of 0.73mm +/3.5 horizontally and 1.2mm +/− 2 laterally. Limb length was restored with a precision of 0.3mm +/− 3.3 and femoral off set with a precision of 0.8mm +/− 3.1. There was no significant alteration in femoral off set (0.07mm, p=0.4) which was restored in 98% of cases. Almost all of the operative difficulties encountered were predicted pre-operatively.

The precision of the three-dimensional pre-operative planning methodology investigated in this study is higher than that reported in the literature using two-dimensional X-ray templating. Cup navigation may be a useful adjunct to increase the accuracy of cup positioning.

Purpose of the study: The major functional impairment which results from femoral head necrosis in patients with sickle-cell anemia leads to implantation of a total hip arthroplasty (THA) in many of these often young patients. Intra- and postoperative complications are frequent.

Material and methods: In order to better understand the causes of these complications, and to search for ways of preventing them, we analyzed the cases of 35 sickle-cell anemia patients with 38 THA. Mean patient age was 36.4 years for these 22 women and 13 men. Twenty-eight patients had SS hemoglobin, five AS hemoglobin, and two presented sickle-cell-thalassemia (S-ß-hemoglobin). Mean follow-up was 7.6 years (range 2–29 years).

Results: Fifteen patients underwent revision surgery (39%) on average 4.8 years after primary implantation for loosening (n=13) or infection (n=2). Five other prostheses presented peripheral lucent lines (13%). The overall complication rate was 64% (shaft fractures, sickle cell crisis, dislocation or loosening, infection). One patient developed an early superficial infection which resolved. One other patient required revision for severe pain and prosthesis misalignment (flexion-external rotation) but with normal cell counts and a simply inflammatory synovial fluid. The presence of slowly progressive degenerative disease in a patient with severe pain should be carefuly identified before undertaking THA. Systematic samples are necessary. The femor-related complications in this series were: two intraoperative shaft fractures, one fracture below the stem during the first six months, and intraoperative shaft reaming in two. Femoral shaft morphological anomales must be identified preoperatively to enable a proper surgical plan. Small-size femoral stems should be available and zones of sclerosis in the canal must be identified. Cup-related complications are more difficult to analyze. The bony structure of the acetabulum was often remodeled, with very weak cancellous bone. Avivement of the acetabulum must be performed prudently manually or with a well controlled motor.

Discussion: Series report few cases in the literature, on average 22 cases (8–36). Mean follow-up was 5.1 years (range 4.6–9.5). The overall rate of complications was 42% (33–59) except for one series with only 2.8%. The rate of deep infection was 14.8% on average (0–36.4).

Conclusion: The decision to implant a THA in these young patients must be made conjointly with the patient. Multidisciplinary management before surgery is essential. Precise planning must take into consideration all the potential pitfalls. Special attention must be given to hemodynamic balance, intra- and postoperative oxygenation and the hemoglobin level.

Purpose of the study: Three-bone arthrodesis, described in 1997, is designed for radiocarpal osteoarthritis with mediocarpal extension. The procedure consists in a capitolunohamate fusion after resection of the scaphoid and the triquetrum. It is associated with carpal shortening proportional to the degree of preoperative wrist stiffness. The objective is to achieve less stiffness than with four-bone fusion.

Material and methods: To verify our hypothesis, the first 24 patients (25 wrists) were reviewed with mean 5.2 years (2–8.5 years) follow-up. All wrists were painful and stiff, and presented radiocarpal and mediocarpal osteoarthritis. There were twelve SLAC III, nine SNAC III and four SCAC III. Mean age was 59 years (range 37–79 years). Mean preoperative range of motion was 50.5° flexion-extension (range 10–105°), mean force was 17 kg (range 10–35 kg). Radiological assessment was performed preoperatively and at last follow-up to determine the Youm index (carpal height) and the Bouman index (carpal translation) and to study the radiolunate joint space.

Results: At last follow-up, all patients had improved but one. Ten wrists were pain free twelve caused some pain at forced wrist movements, and two caused pain daily but at a level below the preoperative level. One patient still suffered from severe pain and required revision for total radiocarpal arthrodesis. The final mean flexion-extension range of motion was 67.8°, for a 13.3° gain in extension and a 3.8° gain in flexion. Ulnar inclination was improved 14° on average. Mean force was 24 kg (73% of healthy side), for a 40% improvement over the pre-operative force. RAdiographically, there was one case of capitolunate nonunion. The radiolunate space remained unchanged. Carpal height decreased 15% on average and the Bouman index increased from 0.90 to 0.93 with no significant ulnar misalignment on the carpus.

Discussion: For pain and force, these results are similar to those achieved with four-bone fusion. The overall results for range of motion are however better for flexion-extension and unlar inclination. In our practice, we have decided to replace the four-bone technique by three-bone fusion because the outcome is a less stiff wrist with a simpler surgical technique. Better results are obtained for stiffer wrists which achieve a significant improvement in motion due to carpal shortening.

Purpose of the study: Analyze failures (recurrent anterior instability) and other complications (pain, stiffness) compromising the overall outcome after arthroscopic anterior shoulder stabilization.

Material and methods: We studied failures and complications in a consecutive inaugural series of 43 patients undergoing an arthroscopic Bankart procedure for chronic anterior shoulder instability. The procedure was performed with knitted resorbable threads on metallic anchors. Outcome was reviewed at mean 26 months (range 6–63 months). There were 19 recurrent dislocations, 12 recurrent subluxations, 4 cases of recurrent subluxation and dislocation and 6 cases of painful unstable shoulder. Mean patient age was 35.6 years (range 19–59 years). Thirty-two patients practiced sports, including 21 who practiced high-risk sports.

Results: One patient, a competition basketball player, presented recurrent traumatic dislocation due to a violent shock after premature resumption of sports activities five months after surgery. There were no recurrent dislocations among the subluxation cases. Pain persisted in three of the six painful unstable shoulders. Sixteen patients presented persistent apprehension but none complained of instability. Nine patients had a positive relocation test. Limited external rotation of less than 30% as observed in five patients and of 30–50% in two. Residual pain was observed in 14 patients (33%) (when carrying a heavy load with the arm hanging along the body, with fatigue, and for forced movements without warm-up in the morning). For four patients, pain occurred in the armed position. Seventeen patients (43%) interrupted their sports activity. The Duplay score showed 13 (30%) fair and poor objective overall results. Subjectively, only seven patients (15%) were only partially satisfied or dissatisfied.

Discussion: Analysis of failures and complications disclosed a discordance between the low rate of failure using the classical definition (recurrent dislocation or subluxation) and the high rate of fair or poor overall outcomes. Residual pain and non-resumption of sports activities appeared to be the major problems. These two factors were analyzed in detail to compare this series with data in the literature. It was found that non-resumption of sports activities is not always related to shoulder instability or apprehension and that pain is often related to associated injury (SLAP, cuff). Conversely, pain associated with a positive relocation test should be considered as a true recurrence, especially in a subject who was unable to resume sports activities.

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: 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.

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.