Aims

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA.

Mechanical irritation or impingement of the iliopsoas tendon accounts for 2–6% of persistent postoperative pain cases after total hip arthroplasty (THA). The most common trigger is anterior cup overhang. CT-scan can be used to identify and measure this overhang; however, no threshold exists for symptomatic anterior iliopsoas impingement. We conducted a case–control study in which CT-scan was used to define a threshold that differentiates patients with iliopsoas impingement from asymptomatic patients after THA.

We analyzed the CT-scans of 622 patients (758 CT-scans) between 2011 and 2020. Out of this population we identified 136 patients with symptoms suggestive of iliopsoas impingement. Among them, 6 were subsequently excluded: three because the diagnosis was reestablished intra-operatively (one metallosis, two anterior instability related to posterior prosthetic impingement) and three because they had another obvious cause of impingement (one protruding screw, one protruding cement plug, one stem collar), leaving 130 patients in the study (impingement) group. They were matched to a control group of 138 patients who were asymptomatic after THA. The anterior cup overhang (anterior margin of cup not covered by anterior wall) was measured by an observer (without knowledge of the clinical status) on an axial CT slice based on anatomical landmarks (orthogonal to pelvic axis).

The impingement group had a median overhang of 8 mm [IQR: 5 to 11] versus 0 mm [IQR: 0 to 4] for the control group (p<.001). Using ROC curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%, PPV = 75%, NPV = 85%).

Pain after THA related to iliopsoas impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of iliopsoas irritation or another reason for the pain after THA before concluding impingement is present.

The hip-shelf procedure is less often indicated since the introduction of peri-acetabular osteotomy (PAO). Although this procedure does not modify pelvic shape, its influence on subsequent total hip arthroplasty (THA) is not known. We performed a case-control study comparing THA after hip-shelf surgery and THA in dysplastic hips to determine: 1) its influence on THA survival, 2) technical issues and complications related to the former procedure.

We performed a retrospective case-control study comparing 61 THA cases done after hip-shelf versus 63 THA in case-matched dysplastic hips (control group). The control group was matched according to sex, age, BMI, ASA and Charnley score, and bearing type. We compared survival and function (Harris, Oxford-12), complications at surgery, rate of bone graft at cup insertion, and post-operative complications.

The 13-year survival rates for any reason did not differ: 89% ± 3.2% in THA after hip shelf versus 83% ± 4.5% in the controls (p = 0.56). Functional scores were better in the control group (Harris 90 ± 10, Oxford 41/48) than in the hip-shelf group (Harris 84.7 ± 14.7, Oxford 39/48) (p = 0.01 and p = 0.04). Operative time, bleeding and rate of acetabular bone grafting (1.6 hip-shelf versus 9.5 control) were not different (p > 0.05). Postoperative complication rates did not differ: one transient fibular nerve palsy and two dislocations (3.2%) in the hip-shelf group versus four dislocations in the control group (6.3%).

The hip-shelf procedure does not compromise the results of a subsequent THA in dysplastic hips. This procedure is simple and may keep its indications versus PAO in severely subluxed hips or in case of severe femoral head deformity.

Cementless distally locked stems were introduced in revision hip arthroplasty (RTHA) in the late 1980s to deal with severe femoral bone loss. These implants have not been assessed over the long-term, particularly the influence of the design and porous coating. Therefore we performed a retrospective case-control study at a minimum 10-years' follow-up comparing the straight Ultime™ stem with 1/3 porous coating versus the anatomical Linea™ stem with 2/3 proximal coating with hydroxyapatite.

We performed a single-center case-control study measuring survival, function based the Harris and Oxford-12 scores, and rate of thigh pain. X-rays were done at regular intervals and at follow-up. No femoral bone graft was used at insertion.

The two groups were comparable in terms of age, sex and follow-up (mean 12.2 years in Ultime and 10.8 years in Linea cohorts); however they differed in the severity of bone loss therefore the results were adjusted according to this variable. Ten-year survival considering revision for any reason was 63.5% ± 5.4 for Ultime and 91.6% ± 2.7 for Linea (p < 0.001). Merle d'Aubigné scores and Oxford-12 were higher in the Linea group 82.9 ± 12.4 and 26.3/48, respectively, versus 69.5 ± 16 and 21/48 in the Ultime group (p < 0.001). Thigh pain was observed in 30% of Ultime cases versus 3% of Linea cases. Bone reconstruction measured via cortical thickness was better in the Linea group and correlated to metaphyseal filling at insertion.

This study confirms the benefits of using of locked stems in RTHA with severe bone loss. Better metaphyseal filling and optimized porous coating help to minimize thigh pain and the revision rate.

Aim

The treatment of a chronic prosthetic joint infection (PJI) is a combination of the bacteria's identification, a «carcinological» surgery and an appropriate antibiotherapy. In case of gram positive cocci infection, rifampicin is often used.

The aim of this study is to determine which factors are responsible for the development of resistance to rifampicine.

There is currently no consensus on the use of suppressive antibiotic therapy (SAT) in prosthetic joint infections (PJI) (1). We describe herein the experience of a French Reference Centre for Complex Osteo-Articular Infections on use of oral cyclines (doxycline and minocycline) for SAT.

A retrospective analysis was performed on consecutive patients with PJI who received oral cyclines (doxycycline or minocycline) for SAT between January 2006 and June 2014. All patients had surgical management, followed by systemic antibiotic treatment and SAT instauration thereafter. Remission was defined as an asymptomatic patient with a functioning prosthesis.

Seventy-nine patients with a mean age of 63.8 ± 16.8 years were included. Sixteen patients (20%) had neoplasia, 9 (11%) diabetes mellitus, 10 (13%) rheumatoid arthritis, and 6 patients (8%) were receiving corticosteroids or chemotherapy.

There were 37 knee (47%), 36 hip (46%), 4 elbow (5%), and 2 shoulder (3%) infections, with a mean delay from implantation of 7.37 ± 6.94 months (range 1–27). Surgical management consisted in debridement and implant retention for 60 patients (76%), or in implant exchange for 19 patients (24%).

Main pathogens were coagulase-negative staphylococci (37%) and Staphylococcus aureus (41%); 23 patients had polymicrobial infection (29%).

The most frequent initial antibiotic regimens debuted before SAT were rifampicin combinations (70%). Mean duration of curative antibiotic therapy was 103 ± 75 days.

Indications of SAT were (i) patients unsuitable for or refusing further surgery (n=23), suboptimal (ii) surgery (n=26) or (iii) curative antibiotic therapy (n=11), (iv) complex orthopaedic surgery (n=11), and (v) immunosuppressive status (n=8). Seventy-three patients received doxycycline and 6 patients received minocycline as SAT (n=48). Mean SAT duration was 625± 536 days (range 30–2900), with a mean follow-up of 765 ± 572 days.

Adverse events were reported in 13 patients (16%), leading to SAT discontinuation in 5 (6%).

During follow-up, 59 patients were considered in remission (75%), and 20 failed including 13 relapses (16%) and 7 reinfections (9%). Among failure patients, 10 pathogens resistant to doxy/minocycline were identified, including 5 with acquisition of cycline resistance.

In our study, SAT with cyclines is associated to a 75% remission rate, with an acceptable tolerability.

Further studies are warranted to determine ideal regimens and optimal duration of SAT.

We would like to thank Dron Hospital and Lille University Hospital medical teams.

The authors declare that there are no conflicts of interest.

Introduction

In valgus knees, ligament balance remain difficult when implanting a total knee arthroplasty (TKA), this leads some authors to systematically propose the use of constrained devices. Others prefer reserving higher constraints to cases where it is not possible to obtain final satisfactory balance: less than 5 of residual frontal laxity in extension in each compartment, and a tibiofemoral gap difference not in excess to 3mm between flexion and extension. The goal of the study was to assess if is possible to establish preoperative criteria that can predict a constrained design prosthetic implantation at surgery.

Introduction

The same cup orientation is classically applied to all cases of hip replacement (45° abduction, 20° anteversion). We hypothesize that this orientation must be adapted to the patient's hip range of motion. We tested this hypothesis by means of an experimental study with respect to hip range of motion, comparing the classical orientation (45° and 20°), and the orientation obtained with computer-assisted navigation.

Introduction

The prosthetic impingement occurs if the range of motion of the hip exceeds implant mobility or in case of component malorientation. This retrieval study was designed to assess the frequency and the risk factors of this phenomenon.

Purpose of the study: Factors affecting the course of Staphylococcus aureus (SA) infected total hip arthroplasty (THA) and total knee arthroplasty (TKA) are poorly understood.

Material and methods: The microbiology laboratory database on patients hospitalised from June 2001 to June 2006 for medical and surgical treatment of an SA infected THA or TKA were reviewed. Data collected were: clinical, radiological, and biological (CRP) status known at least two years after the end of the antibiotic treatment. Success was defined as normal findings in all three domains at last follow-up and failure for any other situation.

Results: The series included 87 patients (43 male and 54 female, mean age 66.5 years, 62 THA, 35 TKA). Material was removed in 51 patients (52.6%). The infection was related to met-R SA in 14 patients (14.4%) and polymicrobial infection in 24 patients (24.7%). Mean duration of intravenous treatment was 7.3±9.4 days and total duration of antibiotic treatment was 115.472.2 d. At mean follow-up of 54.1±19.4 d, the overall success was 62/97 (63.9%). The only parameters significantly associated with failure were delay to management after first signs revealing longer infection (67.9 days vs 144.8 days) and an antibiotic therapy not adapted bacteriological results to immediately after surgery. (28.6% vs 3/28; 4.8%). In this series, met-R SA was not a risk factor of failure.

Conclusion: This work suggests that delayed surgical management and quality of antibiotic treatment for the first revision are factors affecting the prognosis of SA infected THA and TKA. These results are in favour of a multidisciplinary approach to care for these patients.

Purpose of the study: The objectives of this work were to assess the stability of outcome achieved after Duquennoy procedure to tighten the lateral capsule-ligament structures of the ankle joint. To do this, we reviewed the same series of patients at 3 and 25 years follow-up to analyse the very long-term stability, laxity, and stiffness of the ankle joint and any osteoarthritic degradation.

Material and methods: From 1975 to 1986, we performed 75 Duquennoy procedures on the lateral capsule and ligament structures of the ankle joint. At mean 25 years follow-up (2007) we were able to review 28 ankles (27 patients) with the same method as applied in 1980 (3 years follow-up). The function outcome was assessed with the Good, Karlsson, Duquennoy and Tegner scores. Clinically, other than joint range of motion, were noted varus laxity or anterior drawer. Static x-rays were obtained to search for signs of osteoarthritis and stress images to measure talocrural laxity, in comparison with the preoperative figures and the 1980 data.

Results: There were two early technique failures (one persistent talocrural instability, one subtalar instability). Good and Karlsson scores were good or excellent in 92% of cases. Patients were very satisfied with the operation and the VAS was 8.9/10. Pain and occasional instability were reported by 27% of patients. There was no talocrural no subtalar stiffness at last follow-up. Radiographic laxity declined significantly between the preoperative value and the last review. Only one patient presented a narrow talocrural space (less than 50% narrowing). Eight patients had osteophytes whose presence was not correlated with poor functional outcome. These osteophytes were also present on the controlateral side. Importantly, there was no significant difference in the mean function scores between 3 and 25 years follow-up (Duquennoy score). Similarly joint range of motion and radiographic laxity remained stable over time.

Discussion: The Duquennoy procedure to tighten the lateral capsule and ligament structures is a simple technique with rare complications which provides excellent results both in terms of ligament stability and in terms of preservation from degenerative osteoarthritis. These results remain stable over time. Conversely, the technique has no action on the subtalar joint and should not be proposed as treatment for associated subtalar laxity, if diagnosed.

Purpose of the study: For young active patients, implantation of metal backed socket with a metal-on-metal bearing is an attractive tribological alternative when a standard prosthesis cannot be implanted. Metal ion assays have not been reported in this type of population. The purpose of this work was to present the clinical, radiographic and metal ion results.

Material and methods: Between 1998 and 2003 23 total hip arthroplasties (THA) (six primary and 17 revision) were implanted with a cemented Metasul™ bearing in a Muller inlay. Mean follow-up was 6.1 years (5–10). None of the patients was lost to follow-up. The Harris and PMA scores were noted as were signs of implant loosening or migration. Metal ions were assayed in total blood (Cr and Co) by mass spectrometry and atomic emission spectrometry (Ti).

Results: At follow-up, the mean Harris and PMA scores were significantly increased, from 62.2 to 95.2 (p = 0.01) and from 12.9 to 17.4 (p = 0.02) respectively. No revisions were required for aseptic loosening or failure of fixation. The radiographs did not reveal any signs of osteolysis or lucency. The mean levels of Cr, Co and Ti were 1.85μg/l (0.8–3.2). 1.24μg/l (0.5–1.86) and 9.62μg/l (5–18) respectively. Ti > 10μg/l was noted in six patients; Ti > 10 μg/l and Cr > 2μg/l in five patients. There was no correlation of metal ion levels with size of the implants, activity level, gender, clinical scores or cup inclination.

Discussion: The mean Co and Cr levels observed in this series were similar to those reported in the literature for standard THA (cementless press fit cups). Ti levels have only been reported in rare studies so that comparison with other series is hazardous. The Ti level observed here appeared to depend on the femoral stem resurfacing (in our series, the porous surface of the stem was coated with a Ti-6Al-7nB alloy).

Conclusion: Cementing the metal-on-metal bearing in the supporting inlay appears to be a reliable and attractive technique for this young and active population. Levels of Cr and Co in blood were the same as reported for standard implants. These levels of metal ions should be followed to confirm the long-term results.

Purpose of the study: Locked implants have yielded favourable results for femoral bone reconstruction for revision total hip arthroplasty, but defective integration has also been reported due to insufficient bioactive coating. The purpose of this work was to evaluate a locked pivot with a two-third proximal hydroxyapatite coating.

Material and methods: From 1996 to 2007, 158 femoral implants (Linea™) were implanted for hip arthroplasty revision. The 143 cases with more than one year follow-up were reviewed (14 deaths, 1 lost to follow-up); 83 revisions for aseptic loosening, 41 periprosthetic fractures, 19 revisions in an infected context. Patients were reviewed retrospectively by a non-operator observer. These were older patients (mean age 68 years, range 31–93) and 36 patients had complex situations requiring at least two prior prostheses; 25% had severe grade 3 or 4 (SOFCOT) bone lesions and 59% diaphyseal damage.

Results: Clinical improvement was significant, the Postel Merle d’Aubigné score improved from 7.7 + 4.3 (0–17) to 15.6 + 2.2 (8–18) at mean 50 months (14–131) (p< 0.001). At last follow-up, 14 patients (10%) reported thigh pain and only seven pivots (5%) had not achieved Engh osteointegration (five with thigh pain two without). There were no fractures. There was on non-union of the femorotomy. According to the Hoffman index, femoral bone regeneration was significant at the metaphyseal and diaphyseal levels. Eighteen of the 19 infections cured, all periprosthetic fractures healed. The implant survival was 88.9% at 91 months (65–96.7%). There were five pivot replacements for non integration and/or thigh pain which resolved in all cases; there were no other pivot replacements. The quality of the metaphyseal and diaphyseal filling was predictive of the quality of the bone fixation of the pivot (p< 0.01).

Discussion: Compared with older models of locked pivots, this implant reduced the rate of thigh pain while allowing constantly satisfactory bone reconstruction. The metaphyseal and diaphyseal filling index is the main factor predictive of clinical and radiological success by favouring osteointegration. Maximal filling, obtained with a full range of implant diameters and lengths, contributes to this good result.

Purpose of the study: Hip resurfacing (HR) is becoming popular again with the advent the the metal-on-metal bearing. This type of surgery is proposed for young, often very active, patients for whom restoration of optimal hip joint range of motion constitutes and important objective. The purpose of this work was to analyse anterior translation of the femoral component to optimise joint range of motion (particularly flexion).

Material and method: From September 2007 to May 2008, 68 hip resurfacing prostheses were implanted in 66 patients aged on average 45 years (range 19–61). All procedures were performed by the same operator using a posterorlateral approach and the same surgical technique. Anterior head-neck offset was a constant objective. The Postel-Merle-d’Aubigné and Harris scores as well as the Devane classification and the WOMAC and the SF-12 were noted. Joint range of motion was noted preoperatively and at last follow-up by and independent operator. Anterior head-neck offset was measured radiographically on the Dunn view using an original technique and calibrated by the Imagika software according to the known diameter of the implants.

Results: All clinical scores as well as the activity level and the subjective scores improved significantly. There were no revisions. The mean anterior head-neck offset was 4.5 mm (range 2–9). Significant correction was observed for gain in postoperative flexion and increased offset (p< 0.005). The group of patients who had an anterior offset considered to be significant (> 4 mm) exhibited significantly better flexion than the group of patients with a small anterior offset.

Discussion: Hip resurfacing has a poor head-neck ratio, depending on the patient’s anatomy, which compares unfavourable with conventional hip prostheses (THA). Nevertheless, the joint range of motion after resurfacing, as observed in our study and in the literature, does not show any decline compared with THA. The greater gain in flexion is an important factor to take into consideration, especially in a young active athletic subject. Each millimetre of gain in anterior offset produces a significant increase in flexion. This offset can be improved by the surgical technique (implanting the femoral component tangentially to the posterior cortical), but also by the design of the resurfacing prosthesis (thick femoral component, increased cement sheath). After hip resurfacing, anterior offset appears to be an essential biomechanical factor for restoration of joint motion.

Purpose of the study: Drilling along yields disappointing results for osteonecrosis of the femoral head due to the high failure rate despite prolonged rest and also because of the risk of fracture. To prevent these problems, we have developed a new drilling technique which was evaluated prospectively.

Material and methods: The procedure performed percutaneously uses a lateral cortical orifice measuring 5mm, non-concentrated autologous bone marrow was injected after drilling. Osteoinductive protein (BMP7) was associated in random fashion (groups BMP+ and BMP−). Ficat stage 1 and 2 necrosis was included. Outcome was the rate or revision for prosthesis.

Results: Forty hips (36 patients) were included and assessed at mean four years (range 2–6). The necrosis was related to: alcoholism (n=5), cortisone (n=25), barotraumas (n=2), metabolic disease (n=4), idiopathic condition (n=4). Group BMP- (drilling+bone marrow) included 24 hips and group BMP+ (drilling+bone marrow+BMP7) 16 hips. The groups were comparable regarding necrosis stage (15% stage 3, 65% stage 2, 20% stage 1) and mean Koo index (27 BMP+ vs 34 BMP-; NS). There were no infections and no fractures despite immediate and complete weight-bearing. The revision rate for prosthesis was higher in the BMP- group (67%) than in the BMP+ group (43%) but the difference did not reach significance (p=0.10). The failure rate was not affected by the severity of the necrosis in the BMP+ group: all stage 3 hips were revised in the BMP- group versus none in the BMP+ group. The only variable predictive of revision for prosthesis was the Koo index (p=0.02).

Discussion: Adjunction of BMP did not improve significantly the success rate of drilling with bone marrow adjunction but adding BMP appeared to limit the unfavourable impact of server necrosis observed in the BMP- group. To reach a statistical power of 80%, 40 cases would be needed in each arm. This threshold has not yet been reached. It can be noted however that the proposed method does ensures early weight bearing without the risk of complications. Similarly, since it is a percutaneous procedure, later arthroplasty is not compromised. The principle confounding factor, the richness of the bone marrow, was not assessed, motivating a new randomized trial with measurement of CFU-F.

Introduction: The prosthetic impingement occurs if the range of motion of the hip exceeds implant mobility or in case of component malorientation. This phenomenon is rarely studied in the literature and most data have come from sporadic cases. This study was designed to assess the frequency and the risk factors of this phenomenon.

Material: The frequency and the severity of the impingement were calculated from a continuous series of 413 cups retrievals. These cups were examined macroscopically twice by two independent observers. The cam effect was noted as: absent, grade 1 (visible at gross inspection but measuring < 1 mm), grade 2 (notch measuring 1–3 mm), grade 3 (notch measuring > 3 mm). The risk factors were analyzed for 298 retrievals that had complete clinical charts.

Results: Among the 413 cups explants, the frequency of impingement was 51.3 percent (grade 3 in 12% and grade 2 in 24%). The impingement was the reason for removal in only 1.7 percent (only for hard bearings), meaning that impingement was mainly an unexpected event (98.3 percent). The impingement was more frequent when revisions were performed because of instability (80 percent; odd-ratio 4.2 (1.1–16.2)) than for loosening (52%) osteolysis (59%) or infection (38%) (p =.002). Likewise, impingement was more frequent when the sum of hip motion exceeded 200 degrees (sum of motion in the 6 degrees of freedom of the hip) (66% versus 45% if the sum was below 200°). The other risk factors were: use of heads with skirts (78% versus 55%), liner with an elevated rim (73% versus 55%), and head-neck ratio below 2.

Discusssion and conclusion: This study underlines the impingement is common when assessing cup retrievals (over 50 percent). One should be aware of impingement when performing hip replacement in patients having a high range of motion. This situation may require prostheses with a high head-neck ratio, as well as use of computer-assisted surgery. One should avoid liners with elevated rim as well as heads with skirts to prevent dislocation, particularly when other risk factors are detected.

Introduction: Cementless revision hip arthroplasties require a stable initial fixation that does not compromise a subsequent bone reconstruction. In case of severe femoral bone loss, stems usually requires distal fixation that may induce stress shielding and finally reduce the spontaneous bone reconstruction. We introduced the use of distally locked revision stems in 1993 hoping strong fixation and bone reconstruction. The goal of the current study was to assess if these components fulfill these two objectives.

Materials and Methods: 101 cementless femoral revision stems with distal locking by screws (Ultime™ Wright-Cremascoli) were inserted from 1993 to 2001. These stems were smooth distally and porous coated with or without HA 1/3 proximally. The indication to use these components was severe bone loss (Paprosky grade IIC and III in 51%) when press fit distal fixation could not be obtained. The use of bone graft was limited to segmental defects or to treat trochanteric non-union. An extended trochanteric osteotomy was performed in 89%. The revision was performed because of aseptic loosening in 43,4%, periprosthetic fracture in 24,2% and infected loosening in 25,2%. The results were assessed after a mean follow-up of 6 years (5–12).

Results: 13 patients deceased and 2 were lost for follow-up. All the extended trochanteric osteotomies healed. Merle d’Aubigné hip score increased from 8.3 to 13.4, but thigh pain was observed in 44%. Bone reconstruction was significant according to Hoffman index at 3 levels of assessment. The 5-year survivorship was 87% considering aseptic revision for any reason. Seventeen repeated femoral procedures were performed: 9 related to thigh pain (because there was no proximal osteointegration) that were revised for short primary stems, 8 because of stem fractures (all occurred at the level of the proximal hole with the same stem size because there was no proximal fixation as long as the stems were smooth or without HA-coating.

Discussion: This serie has the longest follow-up using locked revision stems. Despite severe pre-operative bone loss, primary fixation and significant bone reconstruction were obtained for all the cases without extensive bone grafting. The major weakness, thigh pain and stem break, were related to unadequate femoral coating for these cementless stems that did not achieved osteointegration. Conversly, the reoperations were simple, allowing the use of short primary designs as bone reconstruction was achieved in all cases without extensive bone grafting. These locked stems allow a strong primary distal fixation that does not compromise bone regeneration. An improvement of femoral coating (extension to 2/3 and use of hydroxyapatite) may reduce the rate of thigh pain and reoperation.

Purpose of the study: The incidence of revision hip arthroplasty is increasing. In order to overcome certain problems related to loss of femoral bone stock, an original technique was developed combining fragmented allograft material and a metallic mesh with a non filling stem cemented distally in a healthy zone to ensure stability.

Materials and Methods: The clinical data (Postel-Merle-d’Aubigné, PMA score) and radiographic findings (implant migration, loss of bone stock using the SOFCOT and PAPROSKY classification, quality of cementing, filling, and graft aspect, graft lysis, periprosthetic lucency, final aspect of the graft) were collected retrospectively. The operation and the technical difficulties and intraoperative complications were noted.

Results: We report a series of 32 hips treated with this technique and having a mean follow-up of 12.5 years (range 8–20 years). The population studied had particularly significant bone loss (78.2% SOFCOT stage 3 and4). These hips underwent revision for aseptic loosening. The implantation technique required a femoral window in 39.1%. Preventive cerclage was often used (39.1%) but did not prevent fracture or missinsertion in 30.4%. The PMA score improved significantly from 10.6 (7–18) preoperatively to 17 (12–18) at last follow-up. Radiologically, femoral bone regeneration at last follow-up had an aspect of corticalisation in 63.6% of hips, and of cancellous trabeculation in 36.4%. Femoral implant survival was 100% at eight years, and 92.8±6.88% at mean follow-up of 12.5 years. There was only one revision at eleven years for secondary osteolysis related to polyethylene wear in a very active subject implanted before the age of 50 years.

Discussion: The clinical and radiographic results are very satisfactory for this series of femoral revisions using an impacted fragmented graft material and with the longest follow-up reported in the literature. Distal fixation limited migration observed when the stem is entirely cemented in the graft, but did not affect reconstruction which demonstrated long-term stability. This technique, initiated in 1986 without a specific instrument set, had now demonstrated its long-term reliability. The only problem is the length of the operation and the complications related to femoral preparation.

Implantation of a large-diameter femoral head prosthesis with a metal-on-metal bearing surface reduces the risk of dislocation, increases the range of movement, minimises the risk of impingement and, in theory, results in little wear.

Between February 2004 and March 2007 we implanted 100 consecutive total hip replacements with a metal-on-metal bearing and a large femoral head into 92 patients. There were 51 men and 41 women with a mean age of 50 years (18 to 70) at the time of surgery.

Outcome was assessed using the Western Ontario McMaster University osteoarthritis index and the Harris hip score as well as the Devane activity score. These all improved significantly (p < 0.0001). At the last follow-up there were no cases of dislocation, no impingement, a good range of movement and no osteolysis, but seven revisions, two for infection and five for aseptic loosening. The probability of groin pain increased if the other acetabular component inclination exceeded 50° (p = 0.0007). At 4.8 years of follow-up, the projected survival of the Durom acetabular component, with revision for any reason, was 92.4% (sd 2.8) (95% confidence interval 89.6 to 95.2).

The design of the component made it difficult both to orientate and seat, which when combined with a poor porous coating, produced unpredictable fixation and a low survival at five years.

Purpose of the study: Theoretically, long-term functional and radiographic degradation is predictable after ankle fusion, but sound evidence from consecutive analysis of the same cohort is lacking. The purpose of this study was to evaluate the same cohort of patients who underwent ankle fusion.

Material and Methods: The cohort included 52 ankle fusions which had been analyzed in 1984 at seven years (2–22 years) of follow-up then again in 2000 using the same evaluation criteria. Among the 52 patients, six were lost to follow-up, 20 had died and one had undergone leg amputation. The second analysis thus included 25 patients (18 men and 7 women), mean age 62±12.6 years (40–94) at the 2000 assessment performed 23±4.5 years (19–36 years) after the fusion. Functional outcome was assessed with the 100-point Duquennoy scale. Osteoarthritis of the subtalar and mediotarsal joints were assessed preoperatively and at follow-up using the same scale.

Results: The functional outcome did not deteriorate significantly between 1984 and 2000. The mean score was 65.8±22.6 (19–92) in 1984 and 64.7±18.3 (34–90) in 2000 (p=0.67). Fifteen patients (60%) had a good or very good outcome at seven years, and 14 (56%) at 23 years. Between 1984 and 2000, ten patients improved their score (on average 10.4 points, range 1–21 points), two had an unchanged score and thirteen a lower score (on average 10 points, range −1 to −24). Ten of these thirteen patients developed severe intercurrent conditions explaining the degradation. At last follow-up, sixteen ankles were pain free or nearly pain free. Twelve patients considered their ankle as a forgotten problem and had no regrets concerning the operation. The evolution of the subtalar joint in 16 cases (nine fusions including five at the same time as the ankle fusion and four performed within four years) showed that all developed early osteoarthrtic degradation with aggravation between 1984 and 2000, leading in the majority of cases to severe degenerative disease. This osteoarthritis was painful in less than one-third of the cases (including the four secondary subtalar fusions and the four sub-talar fusions which were painful at mobilization). The mediotarsal joints degradation was later and less severe than for the subtalar joint with a majority of moderate osteoarthritis. Ten ankles exhibited compensatory hypermobility of the forefoot measured at more than 15° without pain.

Discussion: This long-term follow-up with two successive assessments using the same evaluation criteria did not demonstrated late degradation of function expected after ankle fusion. It did show however the presence of radiographic degradation of the subtalar joint but with little clinical expression at a minimal follow-up of 19 years. There was no need for complementary fusion between 4 and 23 years follow-up.

Introduction: The anterior pelvic plane (APP), described by Lewinnek, is defined by the following points : anterior iliac spines, pubic symphysis. This plan is mostly considered as vertical in weight bearing and is currently used as the reference to guide cup insertion by means of imageless computer assistance (CAS). However, to our knowledge, there is no data that strongly confirm APP is vertical in weight bearing and how much his orientation is modified with regards operative position, or THA insertion. This study assessed these data by means of a radiological analysis.

Material and Methods: The orientation of the APP was measured with regards to the vertical plane on weight-bearing profile X-rays of the pelvis in 106 subjects including:

1) 82 patients with THA (40 who had at least one dislocation, and 42 matched patients without instability randomly selected, 19 of these 42 underwent a profile X-ray of the pelvis before and after THA insertion)

Results: Thirty-eight percent of the subjects in weight-bearing had an orientation of the APP different of more than ± 5° from vertical plane and 13% were out of the interval ±10°. The orientation of the APP was not significantly different between the groups (standard and THA) nor between the groups who had stable or unstable THA. The orientation of the APP was significantly modified between lying and weight-bearing posture, from a mean of 1,2° lying to −2,25° upright. Under these conditions, 12 subjects presented a variation of more than 7°. Insertion of a THA did not significantly modify the orientation of the APP in weight-bearing among the 19 subjects (variations were small (−1° ± 7° [from – 21° to 8°]), but were more than 5° for 7 of the 19 subjects).

Discussion and Conclusion: Most of the surgeons use the APP as a reference to guide navigation for cup insertion, considering it is vertical in weight-bearing. However, it is not true for 38% with a margin of 10°, which is equivalent to approximately half of the anatomical anteversion of the acetabulum. Standing up produced a significant variation of the orientation of the APP with regards to lying position. These errors that are not integrated by most of the CAS without preoperative CT scans, may produce cam effect or dislocation when the patient is moving to sited position. The variations of APP orientation with regards to vertical plane suggest it is not adequate to guide the CAS insertion of the cup. There is no reliable reference, easily identifiable during surgery that integrates the variations of position of the pelvis. This leads us to promote a new CAS for THA insertion free of reference plane, based on kinematics.

Purpose of the study: Most systems used for computer-assisted total hip arthroplasty require preparatory computed tomography acquisition or use of multiple bone markers fixed on the pelvis. In order to overcome these problems, we developed a novel system for CT-free computer assisted hip surgery based on a functional approach to the hip joint. The concept is to orient the cup within a cone describing hip motion. The purpose of the present study was to analyze preliminary results obtained with this new system.

Material and methods: This new system was used to implant 18 primary total hip arthroplasties in 16 women and 2 men (mean age 68±7.8 years, age range 54–83 years) with degenerative disease. Two optoelectronic captors were fixed percutaneously on the pelvis and the distal femur. The acetabulum was reamed, then the femur prepared with instruments of increasing caliber. The last reamer positioned in the shaft carried an upper head which matched the size of the prepared acetabulum. Hip joint motion was recorded to determine the cone of maximal hip mobility. The system then oriented the cup so that this cone was completely included the cone described by the prosthesis.

Results: There was one traumatic posterior dislocation (fall in stairs) at three weeks, without recurrence. The Postel Merle d’Aubigné score improved from 8±2.9 (3–12) preoperatively to 17±0.8 (16–18) at last follow-up. None of the patients complained about the sites where the percutaneous markers were inserted and ther were no cases of hematoma or fracture. Mean leg length discrepancy was 5.6±7.5 mm (range 0–25 mm) before surgery and 0.6±3 mm (range −5 to 10 mm) at last follow-up. Mean anteversion of the femoral implant was 22.3±6.7° (14–31). Anatomic anteversion of the cup (measured from a marker linked to the pelvis and thus independently of the position of the pelvis) was 25.9±10.4° (12–40). The sum of the femoral and acetabular anteversions was 48.2±14.6° (range 27–71°).

Conclusion: This method can be used in routine practice without lengthening operative time excessively. It provides a safe way to control the length of the limb and helps position the cup. This study demonstrated that there is no ideal position for the cup that can be applied for all patients. Because of the wide spread of the inclination and anteversion figures, half of the cases were outside the safety range recommended by Lewinnek.

Purpose of the study: Because of its specific properties, linezolid (LZD) is an alternative to glycopeptides for the treatment of BJI causes by resistant Gram-positive cocci. The efficacy and tolerance of long-term (> 28d) administration remain to be determined with precision.

Material and methods: This was a retrospective analysis of the files of patients who received long-term LZD for BJI with a post-treatment follow-up of at least twelve months.

Results: Between January 2001 and December 2003, 68 patients (mean age 54.6 years) received LZD (600 mg/12h) intravenously then orally for a mean duration of 14.6 weeks on average (range 6–36 weeks). The orthopedic implants were infected in 31 patients (45.6%, 27 prostheses and 4 external fixators). A fistulization was diagnosed in 29 patients (42.6%). Medical and surgical treatment was undertaken in 51 patients (75%). Germs isolated from deep samples were staphylococci (n=57, 51 meti-R), and strepotococci (n=11). A polymicrobial infection was recorded in six patients (8.8%). Clinical success was achieved in 52 patients (76.5%) at the end of treatment, a result which was sustained for 48 of them to mean follow-up of 16.8 months (range 12–48). Sixty-three episodes of side effects were noted: anemia (n=29), peripheral neuropathy (n=9), nausea (n=14), headache (n=2), neutropenia (n=2), and thrombopenia (n=1), leading to discontinuation of LZD in 23 patients (33.8%) on average 11.9 weeks (range 6–36) after onset of treatment. Fifteen patients (22.1%) required transfusion.

Discussion: Among the patients in this series with BJI, most caused by a multiresistant germ, the rate of success was satisfactory (48/68, 70.6%) with LZD. Treatment was associated with a high frequency of serious adverse effects leading to discontinuation in one-third of patients.

Conclusion: Long-term treatment of BJI with LZD appears to be effective, including in patients with infected orthopedic material. Conversely, tolerance problems can limit is use to infections caused by mul-tiresistant Gram-positive cocci unresponsive to other compounds.

Purpose of the study: In order to evaluate the influence of prosthesis design and resurfacing on the outcome of total hip arthroplasty (THA) implanted without cement, we reviewed the orthopedic literature from 1980 to 2004.

Material and methods: The PubMed database was screened from 1980 to 2004 for publications reporting cementless THA with a follow-up analysis. The same criteria were used to screen three registries. In all, the publications retained had studied 50,162 cementless THA (mean patient age 48.9 years, mean follow-up 6.5 years) where were studied according to rate of revision, presence of osteolysis, and presence of operative fractures. Eleven families of components grouped together the majority of prostheses: five acetabular families [screw fixation without resurfacing (n=2997), screw fixation with hydroxyapatite (HA) resurfacing (n=3618), screw fixation with corindon resurfacing (2360), press-fit mac-roporous (15691), press-fit HA (6094)]; and six families of femoral pivots [straight macroprous (n=7502), straight HA (n=3255), straight corindon (n=6136), anatomic HA (n=3468), anatomic macroporous (n=1215), anatomic corindon (n=1041)].

Results: The rates of revision and of osteolysis were higher for screw fixed cups without resurfacing. For screw fixed or press-fit cups, HA resurfacing did not reduce the rate of revision compared with corindon coated or macroporous implants. For anatomic pivots, adjunction of HA resurfacing reduced the rate of revision but at the shortest follow-up and without reducing the rate of osteolysis. Corindon-coated pivots gave comparable results for straight or anatomic implants. Conversely, HA-coated pivots gave better results with an anatomic design. The shape of the pivot had les effect than resurfacing on osteolysis and revision, but had a greater influence on operative fractures (2.9% for straight implants versus 4.6% for anatomic versions).

Conclusion: In all:

uncoated implants should be abandoned;

Delayed sciatic nerve palsy is uncommon after primary hip replacement. Two kinds of sciatic palsy have been reported with regard to the time of onset: early palsy related to wound haematoma or lumbosacral nerve elongation which occurs between surgery and 18 days, is more frequent than delayed palsy, occurring between 10 and 32 months, which is usually caused by cement extrusion or heat produced by cement polymerisation.

We present two cases of delayed, transient sciatic nerve palsy arising at three weeks and four months after primary cementless arthroplasty, respectively, without haematoma and with a normal lumbar spine. These palsies were possibly caused by excessive tension from minor limb lengthening of 2 cm to 4 cm required to achieve leg-length equality. As the initial symptoms were limited to calf pain and mild numbness in the foot, surgeons should be aware of this mode of onset, particularly when it is delayed after hip replacement. Both patients recovered fully by 12 months after surgery so we did not undertake surgical exploration of the nerve in either patient.

Thirty-nine cementless hip replacements using metal-on-metal articulation were consecutively implanted in thirty patients less than fifty years of age and compared with a matched control group of cementless replacements using ceramic-on-polyethylene articulation. The Harris hip score at follow-up (minimum five years) for the metal-on-metal was 94.9 (range, 74–100). After the same follow-up, the results of the ceramic-on-polyethylene were significantly worse: nine osteolyses and seven surgical revisions related to wear. Five-year survival rates were 97% +/− 2% for the ceramic-on-polyethylene and 100% for the metal-on-metal. The metal-on-metal may be recommended to prevent wear problems in younger and more active patients.

The aim of the current study was to assess the results of metal-on-metal articulating components inserted as a primary hip replacement in patients under the age of fifty, comparated with a matched control group using ceramic-on-polyethylene.

Patients and methods

The inclusion of patients was: under fifty years of age and a diagnosis of arthrosis or necrosis of the femoral head.

Femoral stem and cup migration was detected. A variation over five millimeters between the follow-up radiographs was considered as migration.

At the follow-up in 2003, the cobalt concentrations in the whole blood were assessed in the metal-on-metal cohort. The detection limit of cobalt in the whole blood was 0.06 μg/L.

None of the components had migration.

At a mean follow-up of sixty-nine months, the median concentration of cobalt in the whole blood was 0.62μg/L. Only eight patients had cobalt levels greater than 1 μg/L.

Considering a reoperation with the exchange of one of the components as end point, the five year survival rates were 100% for the metal-on-metal group and 97% + 2 for the ceramic-on-polyethylene group. Our study suggests that the metal-on-metal articulation gives a significant improvement in terms of resistance to wear when compared with these conventional bearing components. Our results suggest the metal-on-metal articulation with cementless components can be recommended in the young and active patient to prevent the occurrence of wear and osteolysis. A careful assessment of patients with high levels of whole-blood cobalt should be performed.

Funding: Aucun

Purpose: In young active subjects, total hip arthroplasty (THA) raises the risk of early polyethylene wear eventually warranting the use of alternative bearings. The purpose of this study was to analyze outcome in subjects aged less than 50 years implanted with a primary metal-on-metal prosthesis.

Material and methods: Between 1995 and 1998, thirty-nine THA with a metal-on-metal bearing were implanted without cement in 30 consecutive patients aged less than 50 years, mean age 23–50). There were nine bilateral implantations. The cementless implants had surface treatment without hydroxyapatite and 28 mm heads. The indication for THA was necrosis in twenty cases, osteoarthritis in nineteen, most in patients with hip dysplasia. The Devane classification placed 84% of the patients in levels 4 or 5, indicating heavy work and/or sports activities. Inclusion criteria were: 1) age less than 50 years, 2) significant activity (occupation and/or sports), 3) osteoarthritis or necrosis. Patients were included and followed prospectively. Serum cobalt level was measured at last follow-up. None of the patients were lost to follow-up.

Results: The Postel-Merle-d’Aubigné score (PMA) improved from 12.8±2.2 (7–15) before surgery to 17.2±1 (14–18) at 5.1 years (5–6.3). None of the patients complained of hip pain. Two patients has moderate inguinal pain related to a cupiliopsoas conflict. All patients achieved complete weight bearing on the fourth postoperative day excepting three who resumed weight bearing at six weeks due to an acetabular augmentation graft. There were no cases of implant migration and all implants exhibited signs of osteointegration on the radiograms. There were no postoperative dislocations and no cases of osteolysis could be identified, particularly in the eight patients who had increased serum cobalt (four bilateral implants) and who had no other statistically significant favouring factor.

Conclusion: The results at five years suggest that the second-generation metal-on-metal bearing is a reliable alternative when THA is proposed for young active subjects. Long-term follow-up of this cohort of subjects at high risk of wear is necessary to confirm these encouraging results.

Purpose: Femoral revision can be difficult when associated with important loss of bone stock and femoral deformation, particularly when the deformation prevents using a long prosthesis despite major loss where it would be useful. We describe a novel technique allowing a simultaneous solution to these two problems and report preliminary results in five patients.

Material and methods: The technique was applied in five patients. Briefly, one or several osteotomies at different levels were performed to correct the deformation in one or more planes, and fixed with a locked femoral implant. Femorotomy was associated in four patients to facilitate removal of prior implants and constituted one of the correction osteotomies. In one patient, non-union of the greater trochanter was treated with a plated autograft. The series included three men and one woman, mean age 72 years (65–83). According to the SOFCOT score, femoral bone loss was grade II in four patients and grade III in one. All femurs had varus deformation (mean 21°, range 16°–40°), and two femurs exhibited permanent flexion (40° and 45°). One shaft osteotomy was used in four patients and two osteotomies in one. The locked femoral implant measured 250 mm in three and 300 mm in two.

Results: Mean follow-up was 3.5 years (0.5–5). One patient committed suicide at six months. The mean Postel Merle d’Aubigné score improved from 9.4 (7–11) to 16.4 (15–18). The trochanter non-union and all osteotomies head at three to four months except one case of shaft non-union which was well tolerated (PMA=16, in a patient without femorotomy who did not require recalibration of the proximal femur). In these healed cases, remodelling and/or spontaneous reconstruction of the femur was observed without grafting for the shaft. There was no stress shielding aspect in the patients with the longest follow-up although they had non-cemented stems with distal locking and no surface treatment.

Conclusion: The technique proposed for this specific indication enables resolution of the double problem of fixation and correction of deformation while allowing spontaneous reconstruction around the non-cemented locked implant. Use of femorotomy is recommended to allow recalibration and stabilisation of the proximal femur around the stem. Longer follow-up is needed to ascertain longevity of the spontaneous reconstruction. Nevertheless, these non-reintegrated implants behave like locked centromedullary nailing.

Purpose: The purpose of this retrospective study was to detail factors influencing outcome of corticocancellous grafts for the treatment of scaphocarpal non-union and to determine ideal indications.

Material and methods: Between 1984 and 1999, this grafting technique was used for 103 patients; we retained for analysis 57 wrists (58 nonunions). Mean follow-up was 106 months. Mean age was 36 years. For 45 patients, non-union occurred because of misdiagnosis. According to the Schernberg classification, eleven nonunions were in zone II, 40 in zone III, and seven in zone IV. Time from fracture to treatment was 35 months on average. The Alno classification of non-union was: stage I=13, stage IIA=20, stage IIA=22, stage IIIA=2, stage IIIB=1. The graft was harvested from the pelvis in 50 cases. Osteosynthesis was associated with a graft in 33 of the 58 cases. Postoperative immobilisation was maintained for 2.7 months on average. Bone healing was achieved within thee months.

Results: Thirty-six patients were very satisfied. Twenty-seven had significant pain on the pelvic harvesting site (50 harvestings). Wrist motion was 56.2° flexion, 56° extension, 83° supination, 83° pronation, and 11° radial and 32.7° ulnar inclination. Thumb opposition was noted 9.4/10 and average contraopposition was 4. Mean index of carpal height was 0.547. The mean radiolunate angle was 4.8°. A DISI deformation was observed for 20 wrists. Thirty-six patients (62%) developed little or no osteoarthritis. The rate of bone healing was 81% but eleven nonunions did not heal, including seven cases of necrosis of the proximal pole. The absence of DISI deformation correction at the time of grafting favoured development of radiocarpal osteoarthritis. The presence of necrosis favoured persistent non-union. Concomitant osteosynthesis did not improve the healing rate.

Discussion: Treatment of scaphoid non-union with a corticocancellous graft remains the choice alternative, providing 81% healing. Grafts consolidation must occur at the radial epiphysis in order to limit painful sequelae. This procedure can be performed for patients with a DISI deformation, but vascularised grafts should be preferred in the event of necrosis of the proximal pole of the scaphoid.

Aims: Rosenow’s broth is an enriched liquid medium used at laboratory for culture of anaerobes. It has never been tested for transport and culture of bacteria, particularly those that are frequently involved in chronic prosthetic infections. This prospective study assessed these data. Methods: 154 intraoperative specimens and joint aspirations were harvested between 1998 and 2000 in 80 patients that had infected knee (24) or hip (56) prostheses. For each of the 154 specimens there was a standard and a Rosenow recipient. Culture obtained on agar medium was called “direct culture” (DC) and culture from any liquid medium was called after “enrichment” (AE). The similitude between bacteria isolated from different specimens was assessed. Results: A bacteria was isolated from DC in 59 specimens (38%) and after AE in 95 specimens (62%). Among the 59 positive DC there was agreement between standard and Rosenow in 87%, and no agreement in 13% [ Staphylococcus sp. (6), Pseudomonas sp.(1) Enterobacteriacae (1)]. Among the 95 cultures AE, Rosenow and standard cultures were in agreement in 41 (43,1%), only standard was positive in 13 (13,6%), but only Rosenow’s broth was positive in 41 (43,1%) with negative standard cultures [16 Staphylococcus sp(13 S. epidermidis), 5 Streptococcus sp., 2 Enterococcus sp., 1 Corynebacterium sp, 3 Enterobacteriacaeand 14 anaerobes]. Sensibility and predictive positive value of Rosenow were respectively 0.86 and 0.86. Conclusion: This study suggest the accuracy of the Rosenow’s broth for transport and culture as agreement was observed in 87% with the DC that is considered as the “gold standard”. When only cultures AE were positive, the Rosenow’s broth corrected the diagnosis in 43%, particularly for infections related to S. epidermidis-and anaerobes.

Aims: The goal was to determine if young patients respect the instructions for medical supervision control instructions after a total hip arthroplasty (THA). Methods:We performed 50 THA (Harris cups and ABG I stems) in 39 patients, mean age 38 years ± 11 (15–58). There were thirty-eight 28mm femoral heads (30 zirconia, 8 chromium-cobalt) and 12 chromium-cobalt heads in 22mm. Each patient was told how necessary a regular medical supervision was with the following schedule: controls at 2 months, 1 year then every two years. In 2000, all the patients were evaluated (no lost for follow-up). Wear was measured according to Livermore with a digitizer. Results: At 72 ± 14 months of follow-up (5–9 years), 51% of the patients (20/39) did not come back for the intermediate controls. No factor could be accounted for that, except being a male (p=0.04). Wear was rather severe (average 0.23 mm/year). 37% of the patients with a severe wear (> 0.2 mm/year) did not come back for intermediate controls and were all free of symptoms. There were 3 revisions because of wear (> 2 mm) and 3 others hips are awaiting revision because of wear. Three of these 6 patients did not come back for intermediate examination. The 28mm heads induced more wear than the 22mm heads (p=0.008). No other factor was related to how severe wear was (age, sex, activity or thickness of polyethylene inserts). Moreover the zirconia did not reduce wear. Conclusion: In spite of the recommendations, half of the patients did not respect the medical supervision schedule and that was unpredictable. We recommend a careful follow-up of young patients after a THA in order to detect wear (usually free of symptoms). Moreover our study underlined that the zirconia wasn’t so efficient to prevent wear phenomena.

Aims: Three methods of mobilization are currently performed: arthroscopic release (AR), manipulation under general anesthesia (MUGA), open surgical release (OSR). This study assessed the accurate indications of these 3 procedures to treat stiff knee arthroplasties. Methods: Sixty-two of these procedures were performed between 1989 and 2001 and followed at least 1 year: 34 MUGA, 18 AR and 10 OSR. The 3 groups were comparable excepted for the delay between the prosthetic insertion and the mobilization procedure: 17 weeks for MUGA, 46 weeks for AR, 97 weeks for OSR. All the patients had the same postoperative analgesia and rehabilitation program. Results: For the 62 procedures there was an improvement in range of ßexion from preop-erative (mean 58.4¡) to follow-up (mean 94.6¡) and a decrease in ßessum deformity from 7.6¡ to 2.5¡ (p= 0.001). From surgery to 1 year of follow-up, there was a decrease in ßexion (104.6¡ to 94.6¡) and an increase in ßessum deformity (1.3¡ to 2.5¡) (NS). The worst postoperative ranges of motion were observed at 6 weeks after the procedure, and then an improvement was observed up to 6 months but was non-signiþcant. Flexion did not improved beyond 6 months after the procedure. The results of the 3 techniques were not signiþcantly different. However, failures were more frequent when MUGA were performed beyond 8 weeks after prosthetic insertion, and when AR were performed beyond 6 months after prosthetic insertion (p< 0.01). Conclusions: We recommend to treat stiff total knee prostheses by MUGA until 8 weeks after insertion, by AR between 8 weeks and 6 months, and by OSR later on. This protocol addresses stiff prostheses without infection and without component malposition. The deþnitive ranges of motions were obtained at 6 months after mobilization.

Aims: This study compared in vivo kinematics of a posterior stabilized TKA inserted either with a fixed (FBC) or with a mobile bearing component (MBC). Methods: Ten patients with unilateral previously defined TKA were selected among 150 TKA performed in 2000 by a single surgeon according to the following criteria: primary TKA because of osteoarthritis, controlateral knee free of clinical symptoms, patient < 80, TKA flexion > 90°, knee IKS score > 80/100. Ten TKA (10 patients) were selected differing only by the adjunction of the mobile bearing (5 MBC and 5 FBC). The range of the 3 knee rotations (flexion, axial rotation, varus-valgus) were assessed by means of a 6-degree freedom electromagnetic goniometer during: level walking, rising from a chair, non weight-bearing flexion. Non-parametric tests compared motions between TKA and contro-lateral knee and between MBC and FBC. Results: FBC had a better mobility that MBC in valgus-varus, which was related to a larger frontal laxity. According to the increase in frontal laxity, FBC demonstrated better axial rotations that MBC in non-weight-bearing (NS). However, better ranges of axial rotation were recorded in MBC in weight-bearing (p< 0.05) (MBC axial rotation exceeded by 10° the motions of FBC). In patients with MBC, there was no difference in range of motion between the TKA and the controlateral healthy knee. In the FBC group the range of axial rotation was lower in the TKA by comparing with the controlateral knee (p< 0.05). Conclusion: With a unique prosthetic design our study suggests the role of MBC to reproduce a physiological range of axial rotation in weight-bearing. The MBC better reproduced knee kinematics Shoulder instability

Aims: Henri Dejour promoted a mechanism involving a third femoral condyle to achieve Posterior Stabilization (PS) in total knee arthroplasty (TKA) introducing the HLS II prosthesis. This retrospective study was conducted to assess the behavior of such PS mechanism. Methods: Between 1992 and 1993, 105 HLS II prostheses (94 patients) were consecutively inserted (78% arthrosis, 19% rheumatoid arthritis). No patient was lost for follow-up but 14 had died, 6 were unable to walk (severe neurological disorder), 4 were contacted by phone. Consequently, 70 patients (77 TKA) mean aged 66 years (22–79) were assessed after a mean follow-up of 7 years (6–8). All the components were fixed with cement and patellar resurfacing was always performed. Results: The knee IKS score increased from de 27 points [0–63] before surgery to 81 [21–100] at follow-up and functional IKS from 35 points [0–75] to 64 [0–100] (p< 0,0001). Similarly range of motion improved from 114° [60°–140°] to 116° [80°–135°] (NS). At follow-up, 86% of the patients were able to practice stairs (13% without support and 28% in alternative manner) against 52% before surgery (1% without support and 1% in alternative manner) (p=0,001). Tibial bone-cement radiolucencies were observed without loosening in 30% (all < 1 mm and non- progressive) mainly related to severe preoperative varus deformation (p = 0.01). One late infection required reoperation. Ninety months survival was 97% ± 1.3% with reoperation related to infection or mechanical disorder as end-point. Conclusion: The posterior stabilization, by means of a third condyle, allowed a satisfactory range of flexion and improved ability to practice stairs. Mid-term follow-up did not identified adverse effects of this PS mechanism on component fixation or knee stability.

Purpose: The distal tibiofibular joint is implicated in ankle movement but has been the topic of less work than the talotibial joint. Its mobility within the talo-crural complex has not been described in detail as precisely as its static role. The purpose of this work was to develop a simple noninvasive method for characterising in vivo the mobility of the fibula at the ankle level between is positions in dorsal and plantar flexion.

Material and methods: We used 32 computed tomo-graphic studies of the ankle in 16 healthy volunteers (men and women), one study in each position of ankle flexion. We identified one cross-sectional slice through the syndesmosis in each of the two positions. A medio-lateral reference line was drawn tangent to the posterior cortical of the tibial metaphysis. The displacement of the fibula in relation to the tibia when moving between the two positions of ankle flexion was calculated using a remarkable landmark on the tibia, the anterior rim of the posterior tibial incisure, and the polar co-ordinates of the ends of the anteroposterior axis of the fibula.The repeatability and reproducibility of this method were tested.

Results: Repeatability was satisfactory for translation movements. Reproducibility was fair except for the reference line where it was good. When the ankle moved from dorsal flexion to plantar flexion, the fibula moved medially 1.25 mm (0.03–2.58 mm) (p< 0.0001) without correlation with the amplitude of the ankle flexion. Mean anterioposterior displacement was 0.46 mm (NS) with a wide range from −1.58 to +7.2 mm. It was correlated with lesser amplitude of ankle flexion.

Discussion: This dynamic method confirms published data concerning active mediolateral tibiofibular approach during plantar flexion. The results point out the variability of the anteroposterior movement of the fibula, the influence of the amplitude and the flexion position of the ankle, and the possible antepulsion effect of fibular tendons. The three-dimensional movement of the ankle joint merits further study including its tibio-fibular and talofibular components in view of potential prosthetic repair of the ankle.

Conclusion: Distal tibiofibular mobility is undeniable. We call for more work to achieve a better understanding of the lateral component of the talocrural complex.

Purpose: The Rosenow enriched medium (RW) enables culture of anaerobic germs as well as slow-growing germs sometimes causing chronic infections on implanted material. The purpose of this work was to determine the usefulness of RW for the bacteriological diagnosis of infections on total hip arthroplasty (THA) and total knee arthroplasty (TKA°.

Material and methods: One hundred fifty-four pre- or intraoperative standard and RW samples were obtained in a prospective study of 80 consecutive patients (mean age 67.6 years) with an infected THA (n=56) or TKA (n=24) between January 1998 and June 2000. A bacteria was considered “infecting” if it grew on direct culture on at least two samples after enrichment. A single positive sample after enrichment was considered a contamination except for strict anaerobes for which direct culture could not be achieved. For these germs, growth after enrichment was thus considered significant.

Results: Among the 154 samples, 59 (38%) gave positive direct cultures and 95 (62%) positive enriched cultures. Among the 59 positive direct cultures, the RW culture was concordant in 87% of the cases. For the 13% of discordant cultures, the germs did not grow on standard medium: Staphylococcus (n=6), Pseudomonas (n=1), and enterobacteria (n=1). For the 95 positive enriched cultures, 41 (43.1%) of the RW cultures were condordant with the standard culture; the standard was positive in 13 (13.6%) and the RW negative (11 Staphylococcus including five aureus, one Pseudomonas, and one Corynebacterium), but in 41 cases, the RW was positive while the standard was negative (16 Staphylococcus, including 13 coagulase negative, five Streptococcus, two Entero-coccus, one Corynebacterium, three enterobacteria, and fourteen anaerobes). The infecting nature of the aerobic bacteria was retained because earlier or later samples were positive. The sensitivity and predictive value of a positive RW culture were 86% and 86% respectively.

Discussion: Using RW medium and standard samples is useful if germs grow after enrichment in order to confirm the infecting nature of the isolated germ (double culture). The reliability of RW medium was confirmed since it was concordant in 87% of the cases with a positive “gold standard” culture. For positive cultures after enrichment with a negative standard culture, RW allows correcting the diagnosis of infection in 43% of the cases. Its usefulness lies basically in the isolation of coagulase negative Staphylococcus and anaerobes (especially Propionibacterium spp. and Peptostreptococcus spp.).

Purpose: Use of a mobile tibial plateau for total knee arthroplasty (TKA) is designed to reduce wear and improve prosthetic kinetics. The purposes of this study were: 1) to compare the kinetics of a posterior stabilised TKA implanted with a fixed plateau (FP) or a mobile plateau (MP) and, 2) to determine whether the mobile plateau improves axial rotation.

Material and methods: Ten patients with a unilateral TKA (HLS) with a fixed or mobile plateau were selected for this study according to the following criteria: arthroplasty for degenerative knee disease, healthy contralateral knee, age < 80 years, pain-free prosthesis, IKS > 80/100, flexion > 90°, follow-up > 1 year. There were five patients with a fixed plateau and five patients with the same prosthesis except with a mobile plateau. Knee movement (flexion-extension, axial rotation, valgus-varus) were measured with an electromagnetic goniometer on the implanted and healthy sides. Four movements were recorded: walking, standing up sitting down, flexion-extension without loading. Amplitudes were compared with non-parameteric statistical tests between the healthy side and the implanted side and between the two types of implants

Results: The FP knees were more mobile in valgus-varus due to greater residual frontal laxity than the MP knees. This extra laxity generated excessive axial rotation on the FP during non-loaded movements. Conversely, when loaded, axial rotation of the MP knees was 10° greater (mean, p < 0.05) than for the FP knees, giving better stability in the frontal plane. This study did not demonstrate any difference in flexion between FP and MP. Patients with an MP prosthesis did not have significantly different amplitudes of the three movements for the healthy versus implanted knee. For the patients with a FP prosthesis, axial rotation and frontal plane movement was lower in the implanted knee than in the healthy knee (p< à.05).

Discussion: This study devoted to the design of a single prosthesis demonstrated the usefulness of the mobile plateau for axial rotation during loaded movement. The kinetics of MP prostheses is similar to that of the healthy knee. Better axial rotation with MP prostheses during loaded movements suggests the persistence of the plateau mobility which should be confirmed with a cinematographic study.

Purpose: Management of extensive tibial loss raises the question of indications for vascularised grafts. These techniques depend on the number of functional vascular trunks available. We developed a modified technique which allows using this type of graft without sacrificing the tibial pedicle, making it usable when only one trunk remains functional. We use the fibular arterial supply to bridge the remaining axis. The purpose of this work was to detail the modalities of this technique and provide early results.

Material and method: Since 2000, we have reserved this technique for infected nonunion with loss of tibial tissue extending over 5 cm in patients who decline amputation. Four patients (four men, mean age 30 years) underwent the procedure. The initial trauma resulted from a motorcycle (n=3) or firearm (n=1) accident. The patients were referred to our unit within three months on the average. Prior treatments (cancellous graft in an open or intrafocal procedure) had failed in all patients who presented persistent infection. Antibiotics were administered until bone healing in all patients. Mean length of the gap was 10 cm (7 – 15 cm). The composite graft (skin and fibula with a vascularised fibular bundle) was raised from the contralateral limb and cross-leg anastomosed proximally and distally on the receiver anterior tibial bundle (all four cases).

Results: All fractures consolidated between six and twelve months after initiating management of this technique. Bone and soft tissue losses healed without shortening. There were not repeated fractures after mean follow-up of twelve months (range eight months to two years). No complementary bone graft was necessary. Infection resolved in all patients.

Discussion and conclusion: As for classical vascularised fibula grafts, this technique enables controlling bone and soft tissue problems together (composite graft). The graft is vascularised favouring antibiotic diffusion. The mechanical quality is better than with a pure cancellous graft but longer follow-up would be required to determine the rate of repeated fractures. This technique broadens indications for vascularised fibula grafts which can be used in unfavourable vascular contexts where only one or two leg trunks persist.

Purpose: Posterior stabilisation with a third condyle was introduced by Henri Dejour with the HLSI prosthesis. While the posterior stabilisation process has been validated, this implant still raises some problems with the tibial fixation in patients with advanced joint degeneration, leading to the development of the HLSII model. The purpose of the present retrospective work was to evaluate functional outcome and persistance of the HLSII prosthesis fixation.

Material and methods: Between January 1992 and December 1993, 105 total knee arthroplasties (TKA) were performed in 94 consecutive patients using posterior stabilised HLSII prostheses. Indications were joint degeneration (40% stage 4) in 78% and polyarthritis in 19%. None of the patients were lost to follow-up but 14 patients died, six were bedridden (stroke sequela) and four were contacted by phone only. In all, 70 patients (77 TKA), mean age 66 years (22–79) were retained for clinical and radiological assessment at mean follow-up of seven years (range 6–8 years). All implants were cemented and the patella was resurfaced in all cases. Eight operators participated in this series. Junior surgeons (n=5) implanted one-third of the prostheses.

Results: The mean IKS knee score rose from 27±18 points (0–63) preoperatively to 81±18 (21–100) at last follow-up, function score from 35±20 (0–75) to 64±24 (0–100) (P< 0.0001). Motion changed from 114° (60–140°) to 116° (40–135°) (NS).Eighty-six percent of the patients used stairs (13% without handrail and 28% with alternate steps) versus 52% before the intervention (1% without handrail and 1% with alternate steps). (P=0.001). Knee alignment was normal ±5° in 87% of the cases versus 27% before surgery (P< 0.0001). Seventy-nine percent of the knees had a slope ±2° (desired slope 0°). The patellar retinaculum was sectioned in one quarter of the knees which led to four of the five postoperative haematomas (no revision). Five patellar fractures were noted, including two with patellar loosening (revised) and one clunk (cured after arthroscopic release). Lucent lines observed under the medial tibial plateau in 30% of the cases (all < 1 mm) were more frequent in patients with more severe joint degeneration and genu varus preoperatively (P =0.01). There was no case of aseptic femorotibial loosening. One case of late infection (30 months) was followed by replacement arthroplasty. Survival rate, taking mechanical and/or infectious failure as the endpoint, was 97± 1.3% at 90 months.

Discussion: Good axial control emphasises the reliability of the instrumentation since one-third of the prostheses were implanted by junior surgeons. Improvements in tibial fixation with the HLSII appear to be effective, particularly for stage 4 degeneration. Long-term surveillance is however necessary. The femoropatellar joint can give rise to non-infectious complications and should be improved. The concept of posterior stabilisation with a third condyle authorises good flexion amplitude and favours use of stairs.

Purpose: The few reports of long-term outcome of Kien-böck disease are helpful in establishing therapeutic indications.

Material and methods: Between 1970 and 1995, radius shortening procedures were performed in 44 patients. Among these 31 patients (eight women and 23 men), mean age 32 years (18–48) at surgery, with 33 operated wrists (18 right, 11 left, 2 bilateral, 19 dominant hands) were reviewed clinically (25 patients by an independent observer, three by their family physician) and radiologically (26 patients) or responded to a phone interview (five patients) at a mean 12 years follow-up (4–19 years). Four patients had died, nine were lost to follow-up. Before surgery the pain was intense (Michon scale): 32 grade I, one grade II. According to Lichtman, there were three grade I, seven grade II, eighteen grade IIIa and five grade IIIb. There was one case of haematoma and one reflex dystrophy, five late consolidations and five nonunions (three diaphyseal out of eight and two metaphyseal out of 25).

Results: The Michon pain score was variable, 11 grade IV, six grade III, nine grade II, but also seven grade I and four secondary arthrodeses. Postoperative amplitudes ere: flexion 50°, extension 53°, abduction 20°, adduction 29°, pronation 83°, supination 74°. Mean amplitudes increased for flexion (+12°), extension (+13°), abduction (+6°), and adduction (+11°), but decreased for pronation (−3°) and supination (−13°). The postoperative wrist fore (Jamar) was 32 kg (80° of other side). Eighteen patients were able to resume an occupational activity, requiring equivalent (14 patients, including 12 manual labourers) or greater (two patients) wrist force. At last follow-up the Lichtman classification was one grade I, four grade II, eight grade III1, three grade IIIb, and seven grade IV. The pre- to postoperative radiography comparison (26 wrists) showed two improvements, seven stabilisations, 14 aggravations, and three arthrodeses. There were also three cases of ulnocarpal impingement (one reoperated). Discussion: the factors predictive of good outcome were minimally advanced disease (Lichtman), little reduction in lunatum height (Stahl), absence of carpal collapse (McMurtry), absence of complication.

Conclusion: Shortening of the radius is an excellent procedure to Lichtman grade IIIa. Results are less satisfactory for grade IIIb but still acceptable compared with resections of the first row or intracarpal arthrodesis. To avoid the risk of ulnocarpal impingement, it would be preferable to reorient the glenoid or shorten the capitatum rather than shorten the radius in patients with a normal radioulnar index.

Purpose of the study: There are few reports onlong-term outcome after Bankart procedure. The purpose of this study was to determine the rate of recurrent dislocation, the clinical results and the incidence of glenohumeral osteoarthritis after a minimum 10-year follow-up.

Material and methods: Ninety-seven Bankart procedures were performed in 97 patients between 1972 and 1986 for treatment of anterior shoulder instability with recurrent dislocations. We retrospectively reviewed 74 patients and obtained 64 complete radioclinical evaluations for an average follow-up of 16 years. Clinical evaluation was based on the G. Walch and the Duplay group score but for easier comparisons, we also calculated the Rowe et al. score. Radiographical evaluation was established on the Samilson and Prieto classification but real glenohumeral osteoarthritis with joint narrowing was noted independently as grade four. We also studied the contralateral shoulder.

Results: At last follow-up, 7 shoulders (9.5%) had recurrent dislocation, but two of them occurred subsequent to severe trauma over 18 months. Most patients (95%) were satisfied or very satisfied. Six patients (8.1%) had persistent apprehension but in some it was not due to anterior apprehension. According to the Duplay score (or the Rowe score), 25 shoulders (44.6%) had an excellent result (35/61.4%) 16 (28.6%) a good result (7/12.3%), 11 (19.7%) a fair result (11.19.3) and 4 (5.4%) a poor result (4/7%). Operated shoulders were pain free for 75% and painful for forced movements only for 25%. External rotation at 90° of abduction was reduced by 8.7 ± 15.7°. There was no limitation of internal rotation. Patients returned to preoperative sports activities at the same level for 70.9% and at a lower level for 12.7%. According to the Samilson classification, 7 (13%) of the shoulders had grade 2 and 2 (3.7%) had grade 3 glenohumeral osteoarthritis. We found 4 cases (7.4%) of real glenohumeral osteoarthritis (grade four) and 2 of these patients had contralateral osteoarthritis of a non unstable shoulder. There was no perioperative complication.

Discussion: In our hands the Bankart procedure is appeared as a safe procedure with a low rate of glenohumeral osteoarthritis and a high rate of patient satisfaction.

Purpose: The aims of this work were to assess very long-term outcome and to assess functional course of talocrural arthrodesis as well as to determine the clinical and radiological impact on adjacent joints.

Material and method: Fifty-two talocrural arthrodeses performed in 52 patients between 1963 and 1981 served as the reference population for this study. Clinical and radiological assessment of this series of patients was conducted in 1983, then again in 1999. Twenty-five talocrural arthrodeses in 25 patients were reviewed at a mean 23 years (19 to 36 years) (six patients were lost to follow-up, 20 had died, one had had leg amputation. The arthrodesis had been performed for advanced degenerative joint disease or to correct for post-traumatic deformity, or in two cases, for neurological varus equinus. Functional outcome was evaluated on the Duquennoy and Stahl score (100 points) that was also used for the intermediary assessment. Radiographic assessment included the position of the arthrodesis, the status of the adjacent joints (subtalar and mediotarsal), and residual motion of the forefoot.

Results: At 23 years follow-up, 13 patients (52%) had good (five patients) or very good (eight patients) function and 12 (48%) had fair function, according to the 100 point scale. There were no patients with poor function. Patients without intercurrent conditions (neurological or heart disease, obesity) had good or very good function in 80% of the cases. Patients were very satisfied in 48% of the cases, having “forgotten” their ankle. At the seven-year follow-up analysis, 15 patients (60%) had a very good (ten patients) or good (five patients) result, seven had a fair result, and three had a poor result. Comparing the 7-year and 23-year assessments did not disclose any significant degradation of the result (p = 0.07). Intercurrent conditions explained the two functional degradations, but there were also three functional improvements over the same period. Talocrural arthrodesis induced stiffness in the subtalar joint in all cases, associated with severe osteoarthritis with little clinical expression. There was a slow degradation of the mediotarsal joint but hypermobility useful for good function was maintained in 45% of the cases (mean 24°). Fair results were related to development of subtalar osteoarthritis, malposition of the arthrodesis in the frontal plane (rear foot varus) and presence of intercurrent conditions (cardiovascular, neurological disease).

Conclusion: Talocrural arthrodesis is a safe and reliable procedure for the treatment of destroyed joints. This palliative surgery can restore satisfactory function which persists in the long term.

Purpose: The synovectomy-reaxation-stabilisation (SRS) procedure classically involves tenosynovectomy of the extensors, articulr synovectomy, partial deinnervation of the wrist, and tendon transfer. The purpose of this study was to: 1) evaluate functional and radiographic results, 2) search for possible correlations between results and the extent of articular synovectomy or type of tendon transfer.

Material and methods: Between 1984 and 1998, an SRS procedure was performed in 75 patients, 14 were excluded: seven had died, five were lost to folow-u and two had had wrist arthrodesis. A total of 73 wrists were analysed in 61 patients. Mean follow-up was 70 months and mean patient age was 53 years. Functional assessment was based on the Gschwend pain scale.

Results: Before surgery, 94% of the patients had grade III or IV pain. At last follow-up, 93% of them grade 0 or I. The gain in pain was greatest for patients with severe carpitis. At last follow-up, the wrist was stiff; stiffness basically involved flexion with 43° pre and 27° postoperatively, radial inclination 13° pre and 9° postoperatively, and pronation in patients with advanced Larsen grade preoperatively. Extension, ulnar inclination, and supination were improved 5° to 10°. Extension of the synovectomy to carpal joints had a stiffening effect. Before the operation, 25 wrists were in Larsen grades 0, 1 and 2 and 48 wrists were in Larsen grades 3 or 4. At last follow-up, there were nine wrists in Larsen grades 0, 1, or 2 and 64 in Larsen grades 3 or 4. Carpitis thus continued to evolve and the height of the carpus declined. Ulnar translation of the carpus progressed a mean 2 mm. Spontaneous radial inclination of the wrist was aggravated by a mean 3°. The frontal position of the wrist was better after transfer of the long radial extensor of the carpus on the short radial extensor of the carpus than for transfer on the ulnar extensor of the carpus or without transfer.

Discussion: Our pain results are in agreement with data in the literature but we did not observe preserved or improved mobility. Extended synovectomy appeared to have a stiffening effect. Progression of the ulnar translation of the carpus was less pronounced with simple resection of the head of the ulna. It was better to transfer the long radial extensor of the carpus on the short radial extensor of the carpus to correct for frontal deviation of the carpus.

Purpose: A new radiographic classification of the femoral trochlea was proposed by David Dejour in 1998 to quantify the severity of bony dysplasia. The purpose of this work was to evaluate the reproducibility of this classification system and to determine its contribution to the identification of trochlea with a high-risk of femoropatellar instability.

Material and methods: Nine independent observers (one resident, four junior surgeons, four senior surgeons) with no knowledge of the patient’s history read 68 strict lateral views of knees with femoropatellar instability (53 objective instabilities (OI) and 15 potential instabilities (PI)). The classification system includes four types determined with three signs: crossing (defining the dysplasia and present in all four types), supratrochlear spike, double contour. The four types are: type A crossing alone, type B crossing and spike, type C crossing and double contour, type D crossing, spike and double contour. The kappa test was used to assess reproducibility and chi square test to analyse data by category.

Results: Twenty-one radiographs were excluded by one or several observers due to insufficient quality or the impossibility to identify the signs of the new classification. Interob-server reproducibility assess on 47 radiographs was fair (kappa = 0.48). The crossing sign was identified by the nine observers on the 47 radiographs. Reproducibility of identification of the spike was good (κ= 0.62), but was fair for the double contour (κ = 0.51). there was no difference in reproducibility by level of experience of the observers. The new classification system was not correlated with severity of femoropatellar instability: presence of spike 80% OI, absence of spike 67% OI; presence of double contour 74% OI, absence of double contour 75% OI.

Discussion, conclusion: This new classification system is more reproducibly than the former 3-type system proposed by Henri Dejour. The crossing sign and the spike are the most reproducible signs. There presence is however insufficient to quantify the dysplasia and predict the severity of the femoropatellar instability. A quantitative measure of the depth of the trochlea, which shows excellent reproducibility (interclass coefficient 0.65) could be added to better quantify the morphological anomaly and determine the most adapted treatment.

Purpose: Changes in the lever arm of the abductors is not always perfectly controlled during implantation of total hip arthroplasties. Its possible effect on the development of prothesis dislocation is not known. The purpose of this study was to evaluate the influence of the lever arm and its modifications on the development of prosthetic instability.

Material and methods: We analysed prospectively 73 total hip arthroplasties implanted via the posterolateral approach. The study group was composed of a consecutive series of 45 dislocated prostheses and a control group of 28 stable prostheses selected at random. The following measurements were made on the anteroposterior x-ray: 1) lever arm of the abductors, 2) femoral offset. These measures were compared with the healthy contralateral hip and when this hip was diseased or had a prosthesis, with the pre-implantation x-rays.

Results: None of the studied parameters was statistically different between the dislocated and stable prostheses. However, in the dislocated prostheses, the lever arm of the abductors before insertion of the prosthesis was shorter than in the control group (p = 0.04) suggesting the presence of a group of hips “at risk”. There was a correlation between the offset values and the lever arm values for the stable prostheses and for the healthy contralateral hips in both groups. Conversely, this balance was not found in the dislocated hips. The lever arm/offset ratio was calculated to determine if the ideal ratio influenced hip stability. This ratio was not directly related to the development of dislocation, but it was decreased for dislocated hips. This ratio was ideal for 75% of the stable prostheses and for only 53% of the dislocated prostheses.

Conclusions: We concluded that: 1) hips “at risk” of dislocation would have a shorter lever arm, 2) the lever arm or the femoral offset do not have a direct effect on dislocation, and 3) stable hip prostheses have a balance similar to that in healthy hips identified by a correlation between the lever arm and the femoral offset. We thus emphasise the importance of respecting these parameters although they are probably not the only factors influencing prosthesis stability. Allowable variations are small, demanding careful and precise operation planning.

Purpose: The aim of this study was to follow a prospective cohort of young subjects with total hip arthroplasties (THA) in order to determine 1) how they complied with instructions concerning the surveillance of their implant, and 2) determine factors affecting non-compliance and the potential consequences in terms of wear.

Material and methods: We implanted fifty Harris I cups with the ABG I stem in 15 young men and 24 young women (11 bilateral implantations) between 1991 and 1995. These patients were a non-consecutive prospective series of patients under 60 years of age (mean age at implantation was 38 ± 11 years, range 15–58 years). The ABG I stem was implanted when the femoral canal was cylindrical, other implants were chosen for other morphologies. 28-mm femoral heads were used in 38 cases (30 zircone, 8 chromium-cobalt, polyethylene thickness 8.6 mm, range 8.3–12.4). The patients were informed of the need for regular surveillance with controls at two months, and one year and then every two years. We re-evaluated all the patients again in 2000. Radiographic wear was assessed according to Livermore using a numeric table (OrthoGraphics).

Results: At mean follow-up of 72 ± 14 months (5–9 years), 20 of the 39 patients (25/50 implants) had not attended the intermediary consultations, but all were seen again for the systematic review made in 2000. There was no particular factor related to non-attendance other than male gender (p = 0.04). Wear was rather severe. Mean values were: linear wear 1.32 mm, 0.23 mm/an. Thirty-seven percent of the patients who had severe annual linear wear (> 0.2 mm) had not attended consultations, all were asymptomatic. The 28 mm head produced more volumetric wear than the 22 mm heads (p = 0.008). There was no other factor correlated with severity of wear (age, sex, activity, polyethylene thickness). This systematic revision led to: three replacements due to excessive wear > 2 mm and replacements planned for three others with > 2 mm wear. These six patients were asymptomatic and three of the six had never attended the planned visits.

Conclusion: Despite our recommendations, half of the patients did not comply with the planned surveillance protocol. Non-compliance being inevitable, we recommend regular systematic recalls to detect severe wear early, even in asymptomatic patients. In addition, our study demonstrated that zircone heads contribute little and confirmed the interest of 22 mm heads to limit wear phenomena.