Aim: The aim of the study was to analyze the results of hybrid alumina prothesis using a pressþt metal backed socket and a cemented stem in young and active patients. Methods: From 1990 to 1992, 71 hybrid alumina-onalumina hip replacements were performed in 62 consecutive patients under age 55, with a mean age of 46 years at surgery. There were 56 primary procedures and 15 revision procedures. The prostheses included a cemented Ti alloy stem, a 32-mm alumina head, and a press-þt metal backed socket with an alumina insert. Results: 3 patients (4 hips) died from unrelated causes. 4 hips had revision surgery for deep infection, unexplained persistant pain, fracture of alumina head, and socket aseptic loosening. The 9-year survival rate was 93.7% if revision for any cause was the end point, and 98.4% if revision for aseptic loosening was the end point. Results in surviving patients with a minimal 5-year followup and an average followup of 8 years (57 hips) were excellent in 47 hips (82.5%), very good in 8 hips (14%), good in 1 hip and fair in one hip. 38% of the sockets had a thin and partial lucent line and 1 socket had a complete lucency less than 1mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. Conclusion: Hybrid alumina prosthesis gave satisfactory results at mid term in active patients. Press-þt metal backed socket appeared as a reliable method of acetabular þxation in alumina-alumina hip replacement. Excellent results of cemented stem þxation may be related to low wear debris production.

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point.

The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis.

This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris.

Aims: Mid and long term results of a continuous series, including learning curve, of 500 TKR cruciate sparing implanted between September 1992 and February 1995 by different surgeons of GUEPAR (staff members and residents) Material: Patients average age70.3 years (26–93). Etiology: Primary OA 74%, post traumatic 6%, RA 6%, associated aetiology in 14% (osteonecrosis, microcristalline arthropathy...). No previous surgery in 325 knees. 175 knees operated before (tibial osteotomy: 37, femoral osteotomy: 4, patella:13, other knee surgery: 74% knee arthroplasty mainly unicompartmental: 19.) Operation procedureby medial approach, except 16 lateral (3.2%) and 6 tibial osteotomy (1.2%). Lateral retinacular release in 19.6% aligned patella and 29.2% subluxed or luxed patella. Per operative complications: PCL weakness (24), tibial plateau fissure (16), condylar fracture (1), patellar fracture (3) without consequence on weight bearing. Although anatomic shape of Wallaby 1 trochl, 86.5% inlay and 11.1% resurfacing patellar component have been done. Very few patella (2%) are not resurfaced at the beginning of our experience. Postoperative complications: No specific earliest complications related to the prosthesis. Latest compliations are: 2 infections in the first month treated by lavage debridement with total recovery and 6 latest infections (> 5th month) with prosthesis removed. 1 bipolar aseptic loosening, 1 patellar loosening without fracture and only 2 of 21 patellar fractures have been fixed by wires. 3 reoperations for persistent pain: 2 patella resurfacing and 1 patellar lateral retinacular release, 3 periprosthetic femoral fractures, 2 fixed by plate, 1 treated by conservative treatment with good results.1 medial collateral ligament rupture after trauma revised with another prosthesis. 5 Sudeck syndrome. Results: Femoro tibial alignment is good (between 3° valgus and 2° varus) in 71.1% and reach 90% if between 5° valgus and 5° varus in%. 38 patients (38 knees: 7.6%) are deceased or lost for follow-up before 1 year (without any revision); 462 knees (92.4%) are follow-up between 1 to 5 years and 381 (76.%) more then 5 years. According to International Knee Score results on these 381 knees are: 104∞ of average flexion (pre op. 109∞), 90.6% had any or mild pain. IKS Knee score 90,6 (45–100) (pre op. 25) IKS function score: 59,7 (0–100) (pre op. 28,5) Survival rates at 8 years: 98.2%(confidence interval of 95%: 99.4–96.9) for removed prosthesis whatever the reasons, and 99.2% (confidence interval of 95% 100–98.4)for revision for mechanical failure only. Conclusions: Encouraging results with a true condylar divergent device encourage us to continue Alignment has to be improved, perhaps with navigation tools.

Purpose: Fracture of alumina implants is a rare cause of total hip arthroplasty (THA) failure. Over the last twenty years, improvement in the design of ceramic implants has helped reduce this risk. We observed five cases of alumina implant fracture over the last year. The purpose of this work was to analyse these recent events and to examine our experience to search for an explanation.

Material and methods: Between 1976 and 2002, eleven patients, five women and six men, mean age 57 years (range 32–87 years) required revision surgery for fracture of an alumina component. The time interval from primary surgery to revision was 36.5 months (range 7 – 106 months). An alumina-alumina couple was involved in nine cases and an alumina-PE couple in two. The primary THA used a press-fit metal backed alumina cup for five hips, a cemented alumina cup for three hips and a massive press-fit alumina cup for one. The alumina head measured 32 mm for ten hips, 22.2 mm for one. The femoral stems were cemented in seven cases, and hydroxyapatite surfaced in four. The acetabular component was involved in four cases and the femoral head in seven.

Results: Identified causes of ceramic implant fracture were: high-power trauma (insert) (n=1), insufficient head diameter (n=1), and defective head match (n=1). For the eight other fractures, involving three insets and five heads, no triggering factor could be identified. The three insert fractures involved two 50-mm cups and one 52-mm cup. Insert design had been changed before these fractures. Mean time from insertion to fracture was 12 months (range 8.5–15 months) in these cases.

Discussion: To our knowledge, all reported cases of ceramic implant fracture have concerned the prosthetic head. The present series demonstrates a recent development, fracture of acetabular implants. It is hypothesised that these fractures could be explained by an insufficient cup diameter associated with a recent change in the design of the metal-backed flush ceramic insert. These inserts have been modified and now have an “overhang” design associated with a thicker layer of ceramic for the smaller cup diameters. These accidents remain rare but justify careful surveillance, particularly during the first postoperative year.

Purpose: During revision of alumina-on-alumina prostheses, reimplantation of a ceramic head on the former stem raises the risk of head fracture. Furthermore, serious deformation of the metal head has been reported after failure of ceramic-on-ceramic prostheses. The purpose of this retrospective study was to evaluate the incidence of these complications and analyse clinical and radiological results of revision for alumina-on-alumina total hip arthroplasties.

Material and methods: This consectutive series included 107 patients (74 women and 33 men, mean age 65 years, age range 32–91 years) who underwent 118 revision arthroplasties from 1976 to 1997. The cause in the majority of the cases was isolated non-infected cup loosening (80%) or ceramic implant fracture (4%). There were 72 cemented alumina cups, 38 screwed cups, six press-fit metal-backed cups, and two massive alumina impacted cups. Cavitary acetabular osteolysis was present in 67% of the cases. The cup was replaced alone in 94 cases (80%). The implanted cup was a polyethylene cup in 93 cases and an alumina cup in 25. When the femoral stem was left in place, a new ceramic head was implanted in 49 cases (39 alumina, 10 zircone). The alumina head was replaced by a metal head in 18 cases.

Results: Four early dislocations and two infections were noted. Mean follow-up after revision surgery was 67 months. Fourteen patients were lost to follow-up. Sixteen patients required revision surgery, ten of them for repeated cup loosening. At last follow-up (mean 61 months), there were no failures among the 49 ceramic heads implanted on a stem left in place. No revisions were required for polyethylene cup wear or metal head wear. In all, 72 hips were evaluated at a minimum two years follow-up. The functional score at last follow-up was 15.2±3.5. Seven-year actuarial survival was 95.5% taking revision of non-infected revision as the endpoint.

Discussion and conclusion: Analysis of the results shows that acetabular loosening is the main cause of revision of alumina-on-alumina total hip arthroplasties. The femoral stem was loosened in only nine cases and could be preserved in 80% of the cases. Replacement of an alumina-on-alumina couple with a metal-on-polyethylene couple does not appear to be a contraindication in this series.

In order to avoid the consequences of polyethylene wear in a high-risk population, 128 alumina-alumina total hip arthroplasty were implanted in 116 consecutive patients of 40 years old or less. Osteonecrosis and sequellae of congenital hip dislocation were the main etiologies representing 71% of the hips. The same titanium alloy cemented stem was implanted in all hips. Four alumina acetabular component fixations were used: cemented plain alumina socket (41 hips), screw-in ring with an alumina insert (22 hips), a press-fit plain alumina socket (32 hips) and a press-fit titanium metal back with an alumina insert (33 hips).

Eight patients (11 hips) died during the follow-up period. Sixteen revisions were documented, 12 for ace-tabular aseptic loosening, 3 for bipolar loosening (2 were septic), and 1 for unexplained pain. Eighty-nine hips were followed radiologically for two to twenty years. No femoral nor acetabular osteolysis were observed with an average follow-up of 8.4 years. Wear was unmeasurable. Four additional sockets showed definite migration. The respective survival rate at 7 years were 91.4% for the cemented cup, 88.8% for the screw-in ring, 95.1% for cementless press-fit plain alumina socket and 94.3% for the metal-back press-fit component.

The ten-year survival rate was 88.0% for the cemented socket and 88.8% for the screw-in ring. The fifteen-year survival rate was 76.7% for the cemented socket. The occurrence of a graft was the only prognostic factor with a 62.6% survival rate at ten years for the grafted hips and a 90.1% for the non-grafted hips (p=0.004).

The alumina-alumina bearing surfaces for young patients appeared as a valuable alternative to standard metal-polyethylene system. There is a need to improve socket fixation if we want to have a survival of the arthroplasty as long as the life expectancy of this increasing and demanding population. The last design with a fully coated HA titanium shell and an alumina liner seems to fulfill the requirements.

Introduction: The achievement of a well aligned limb is one of the main factor that probably affect the long term survival of total knee arthroplasty. Despite many improvements in ancillary device design, a significant number of total knee arthroplasty remain in excessive varus or valgus. Computer assisted systems may improve the control on implant positioning. The goal of this paper is to present the rationale and the early experience with a recently developed system (Navitrack®).

Material and methods: A CT-scan allows acquisition of patient anatomy. The 3D reconstruction is obtained with specially developed software. Location of the instruments and bone during surgery is obtained either with a magnetic or an optical system. After captor placement, navigation allows real-time control of the ancillary device in order to perform the necessary cuts. The main landmarks given by the system during surgery are the femoral and tibial mechanical axis, cuts location, rotational positioning of the femoral implant can also be controlled using the transepicondylar axis, the posterior aspects of the femoral condyles, or the patellar groove. Rotational positioning of the tibial component can also be evaluated in order to allow a adequate orientation of the tibial slope.

Results: Four implantations failed for technical reasons including failure of captor fixation on bone during surgery, and failure of the electronic control of the captors. However, most attempted implantations were successful with an accurate placement of the implants evaluated on long leg radiographs.

Discussion: Implantation of a TKA with an anatomic-based system is possible. But, this first encouraging experience needs to be confirmed and improvements are in progress.

We have carried out a prospective, randomised study designed to compare the long-term stability of the stem of cementless femoral implants with differing surface configurations. A total of 50 hips (46 patients) was randomised into two groups, according to whether the medullary stem had been grit blasted (GB) or coated with hydroxyapatite (HA). Both femoral prostheses were of the same geometrical design. We used Ein Bild Roentgen Analyse femoral component analysis (EBRA-FCA) to assess the stability of the stem. The mean follow-up was for 8.66 years.

The mean migration of the stem was 1.26 mm in the HA group compared with 2.57 mm in the GB group (Mann-Whitney U test, p = 0.04). A mixed model ANOVA showed that the development of subsidence was statistically different in the two groups during the first 24 months. After this subsidence increased in both groups with no difference between them. Our results indicate that, with the same design of stem, HA coating enhanced the stability of the femoral stem when compared with GB stems.

We report 17 patients who had grafting of the common peroneal nerve after traction injuries. Sixteen were reviewed at a median follow-up of 36 months. The nerve gap ranged from 7 to 20 cm. A functionally satisfactory result was achieved in six patients (37.5%), a fair result in six and a poor result in four. Seven patients had, in addition, a posterior tibialis tendon transfer; this improved the result in five. Grafting produced some satisfactory results even when the nerve gap was as long as 20 cm.