Purpose of the study: Tibial osteotomy to correct for varus deformity is a well defined procedure. Survival has reached 80% at ten years. Nevertheless, a number of early failures are related to inadequate initial correction. Computer assisted surgery has demonstrated its efficacy for knee arthroplasty. We hypothesised that it could also improve the reliability of correction for tibial osteotomy.

Material and method: From 2007, in a prospective case-control study, 34 tibial wedge osteotomies were performed, 17 were computer assisted (Navitrack, Orthosoft) with plate fixation (Tomofix, Synthès) without wedge insertion; the objective was valgus measuring 2 to 5°.

Results: The two series were comparable for age (54.2±6 and 55.7±4.5), body mass index (28.9±6.2 and 28.7±5.7), and varus deformity (7.2±3 and 6.2±6) respectively in the standard and navigated groups. Osteoarthritis was more severe in the navigated group, with five patients stage 2 and 12 stage 2 versus one stage 1, 12 stage 2 and 4 stage 3 in the standard group (p=0.0152). The duration of the operation was not longer in the navigation group (p)0.2779). Comparisons were made for alignment at three months, between the groups and in relation to the preoperative data. There was no significant difference between the intraoperative navigation alignment and the alignment measured at 3 months: 3.6±6 and 2.5±3 at 3 months (p=0.2187). At 3 months, there was no significant difference in alignment between the two groups with 3.22 and 2.5±1.6 valgus in the standard and navigation groups respectively (p=0.2136). The objective was achieved in 25 patients: 12 in the standard group and 13 in the navigated group. In the navigation group, there were four failures, no cases of over correction, two cases of insufficient valgus at 1.5, one neutral alignment, and one recurrent varus. In the standard group, there were five failures with two over corrections at 7 and 8, two under corrections at 0 and 1, and 1 recurrent varus at 4.

Discussion: We were unable to prove that navigation improves the reliability of the correction but it did appear to avoid important errors, particularly over correction. Few series have compared standard varus navigated osteotomies, and all published series have been small. Our study has the advantage of being monocentric with two comparable series of patients. The sample size nevertheless remains small and the follow-up short.

Purpose of the study: The survival of a total hip arthroplasty (THA) depends mainly on the choice of the implant and the quality of the implantation. Mini-incisions have been criticised because of the increased risk of complications and the uncertainty concerning implant position. The main objective of this work was to assess this later feature.

Material and method: This was a prospective series of consecutive patients attending different centres from January 2008 to January 2009 comparing 100 THA implanted via the reduced Watson-Jones approach (2 centres) and 520 THA implanted in a third centre via the anterior hemimyotomy. Objective assessment (PMA, Harris) and early functional outcome (WOMAC, SF12), biological aggression (myoglobinaemia, CPK, blood loss), complications, and scanographic position of the implants were analysed.

Results: For the mini-Watson-Jones arthroplasties, there was a longer operative time (p< 0.0001), smaller scar, less consumption of analgesics the first postoperative day (p=0.003), and better objective and functional recovery at six weeks (PMA: p < 0.0001; Harris: p = 0.004; WOMAC: p < 0.0001; SF12: p = 0.007). Conversely, there was no significant difference for intraoperative or postoperative blood loss, intraoperative and early postoperative complications, elevation of serum muscle markers, or duration of hospital stay. Regarding implant position, significantly greater acetabular and cumulated anteversion was observed with the mini-incision (p=0.03 and p=0.002 respectively). Nevertheless, the proportion of well positioned implants (Lewinnek criteria) was not significantly different.

Discussion: This series confirms the contribution of the mini-incision to more rapid recovery. We did not find any difference in implant malposition related to approach. The first analyses did however show that the position of the implants is more reproducible with the conventional approach.

Purpose of the study: The purpose of this study was to assess traumatic damage to muscles using biological markers. Two approaches were evaluated: a modified Hardinge approach (anterior hemimyotomy) and a reduced anterolateral approach (Rottinger).

Material and method: This was a multicentric prospective study conducted in three centres in 2008. The first 50 patients in each centre were included. Total creatinine phosphokinase (CPK) and serum myoglobulin levels were used to evaluate muscle damage. Blood samples were taken ten hours after surgery for myoglobulaeia and at one and two postoperative days for CPK. Student’s t test was used for the statistical analysis.

Results: There was no statistically significant difference in serum myoglobulin levels 10 hours postoperatively (p=0.25) or for CPK level at day 1 (p=0.098) and day 2 (p=0.105). Objective clinical recovery (Postel-Merle-d’Aubigné, Harris) and function (WOMAC and SF-12) were better at six weeks with the reduced anterolateral approach.

Discussion: These findings show that muscle aggression after mini-incision is to the same order as with the standard approach. The damage is however different: section for the Hardinge type approaches, stretching and contusion for the mini-incisions.

Conclusion: Use of biological markers specific for muscle tissue appears to be a simple way of quantifying muscle damage. However, adjunction of an imaging technique (MRI) might provide a more precise assessment of muscle injury.

Purpose of the study: Survival of a total hip arthroplasty (THA) mainly depends on the choice of the implant and the quality of the implantation. Use of minimally invasive approaches remains a subject of controversy due to the uncertain implant position and questions concerning increased perioperative complications. The purpose of this work was to assess these two elements in a consecutive series of patients who underwent THA implanted via the minimally invasive anterolateral approach described by Rottinger.

Materials and Methods: This was a consecutive series of 130 patients (84 female, 46 male, mean age 69 years, age range 46–91) operated by the same surgeon. Mean follow-up was twelve months (range 6 – 24 months). The clinical parameters studied were: the pre–and post-operative Postel-Merle-d’Aubigné (PMA) score, mean operative time, presence of perioperative surgical complications. Radiographic parameters studied were lucent lines (De Lee and Gruen), homogeneous cementing of the femoral piece, axial position of the femoral implant, angle of acetabular inclination, acetabular anteversion (Hassan), and any leg length discrepancy.

Results: Intraoperative complications were: one intraoperative mobilisation of a press-fit cup, one trochanter fracture. Postoperatively, the rate of dislocation was 2.3%. In 3.8% of the patients developed skin lesions or a local haematoma but none with infection. Mean operative time was 107 minutes (range 80–210). Mean postoperative PMA score was 17.4 versus 12.4 preoperatively. Patients were able to walk without limping 3.3 months postoperatively (range 0.5–12 months). Mean cup inclination and anteversion were 46.1° (28–60°) and 12.3° (0–35°) respectively. Leg length discrepancy was +4.8mm on average (operated side). Femoral alignment was ±3° relative to the femoral axis in 83% of hips. Homogeneous cementing of the femoral stem was noted in 84%. There was a learning curve with an 11% complication rate for the first twenty hips versus 4% for the remainder of the hips in this series.

Discussion: In our hands, the minimally invasive anterolateral approach described by Rottinger enables proper reproducible THA implantation. The rate of intraoperative complications is low. There is a learning curve which was an estimated twenty cases in our series. This method has become our first-intention option for implantation of THA.

Purpose: The purpose of this work was to present clinical and radiographic results of our experience with the Exeter technique for femoral reconstruction during revision total hip arthroplasty.

Material and methods: Eighteen patients (18 hips) underwent surgery between 1994 and 2001 and were reviewed a mean 3.5 years (1–7.5). Mean age was 67.2 years (27–78). These patients had aseptic loosening (17 hips) or septic loosening (1 hip). The femoral loosening was stage II in six hips and stage III in twelve according to the SOFCOT classification. The mean preoperative Postel Merle d’Aubigné (PMA) score was 13.6 [pain 3.4 (2–5), motion (5.9, function 3.8 (2–6)]. Postoperative assessment noted complications, the PMA score and radiographically, search for lucent lines, graft aspect, and cortical classification (Gie). Prosthesis migration was measured with the EBRAFCA method. The alpha risk was set at 5% for statistical analysis.

Results: Five complications were noted: three greater trochanter fractures, one sernsorimotor ischiatic deficit, one infraprosthetic fracture at 4.5 months. The overall mean PMA score at last follow-up was 17 [pain 5.4 (3–6), motion 6, function 5.6 (4–6)]. Radiographically thirteen hips exhibited cortical thickening with incorporation of the graft, with one case of isolated cortical thickening. One case could not be analysed (metal mesh). The EBRA analysis was used in 14 hips. After the stage II lesions, median descent was 2.8 mm (1.55–6.25) versus respectively 6.5 mm (2.1–8.7) in stage III (p=0.35)].

Discussion: The Exeter technique is one solution for femoral bone stock loss during revision THA. This technique has provided good clinical outcome (overall final PMA 17 versus 13). Radiographically, in the majority of the cases, graft integration was satisfactory with no sign of loosening. Prosthetic descent (EBRA analysis) was slightly greater than published results but there was no correlation with the initial lesion or the clinical outcome.

Conclusion: The Exeter technique is reliable and effective. It provides a less aggressive solution compared with other techniques for femoral bone loss.