Purpose of the study: The purpose of this prospective study was to compare insert wear radiographically at minimum three years comparing crosslinked (Duration, Howmedia) versus regular (Stratec Medical) polyethylene.

Material and methods: We used two types of UHMWPE for a series of 140 total hip arthroplasties (THA) (February 1999 – August 2000). Duration polyethylene (Howmedica) was used for 63 implants. This UHMWPE undergoes gamma ray treatment under nitrogen which leads to a stabilization phase under temperature and time conditions enabling preferential formation of cross links between the molecular chains. Vecteur Orthopedic polyethylene implants exposed to gamma radiation under air were used for 62 implants. Eighty-seven patients were reviewed at minimum three years radiological follow-up. This series included 60 women and 27 men, mean age 64 years (range 32–93 years). The trans-trochanteric approach was used in all cases for insertion of a Charnley-Kerboull cemented femoral stem. All cups were cemented (abnormal implant position was an exclusion criterion). Cups were assigned randomly with a permutation table. Wear measurements were made by graphic construction comparing the immediate postoperative and last follow-up anteroposterior pelvis x-rays.

Results: Follow-up was at least 36 months for 87 patients. Mean follow-up for these 87 patients was 49.9 months. Mean wear was 0.32 mm for crosslinked poly-ethylene and 0.35 mm for regular polyethylene. Five patients presented wear ≥ 1 cm for crosslinked poly-ethylene and there were nine patients with ≥ 1 cm for regular polyethylene.

Discussion: In vitro, crosslinked polyethylene exhibits significantly improved mechanical qualities for wear resistance. Several factors can account for differences in polyethylene wear: the size and composition of the prosthetic head, and patient gender, age, activity level and BMI. These factors were comparable in our two groups. It does however appear that even with crosslinked poly-ethylene, after four years implantation, wear is limited, close to the detection level of the measurement method.

Conclusion: The measurement method used in this prospective randomized study of polyethylene wear comparing crosslinked versus regular polyethylene showed no difference between the two groups at four years follow-up.

Purpose: Periprosthetic ossification is a frequent complication of total hip arthroplasty and can have a major functional impact. Non-steroidal anti-inflammatory drugs (NSAID) can provide effective prevention but with a risk of morbidity. The purpose of this work was to evaluate the efficacy of an anti-Cox2 agent, cele-coxib, for this indication.

Material and methods: Total hip arthroplasty was performed in 42 patients with a relative (gastrointestinal) contraindication for the use of NSAID. These patients were given celecoxib (Celebrxy(r)) 200 mg bid starting the day before the operation and continuing for at least five days. A control group of 42 age- (±3 yr) and sex-matched patients who underwent surgery for the same indication performed by a surgeon with equivalent experience was also established. The control patients were given ketoprofen (Profénidy(r)) 50 mg qid for two days then 150 mg bid for five days. The approach, implant, and other adjuvant treatments were equivalent between the two groups. Ossifications were analysed on the follow-up films taken at least three months after surgery. The Brooker classification was used. The exact Fisher test was used for the statistical analysis.

Results: The two groups each included 31 women and eleven men, mean age being the same in the two groups (67.12 yrs). Mean follow-up was very similar (8.44 vs 8.6 months). Aetiologies were: primary degenerative hip (n=30), degenerative hip disease after dysplasia (n=9), sequela of infantile arthritis (n=1), revision total hip prosthesis (n=2). Two patients in each group interrupted their treatment between day 2 and 4 because of intolerance. There were no cases of significant haematoma in either group. No ossification > grade 2 was observed. The overall rate of ossification was 42.5% in the control group versus 48.6% in the celecoxib group. The rate of grade 2 ossifications was 8% in the cele-coxib group versus 12% in the control group. These rates were not significantly different (Fisher’s exact test= 0.6).

Discussion: In this study, celecoxib and ketoprofen were found to have equivalent efficacy for the prevention periprosthetic ossification. This is an interesting perspective in the probable hypothesis of less morbidity with anti-Cox 2 antiinflammatory drugs used in combination with an antalgesia protocol.

Purpose of the study: Extensive loss of femoral bone subsequent to implant loosening raises an unsolved problem. The purpose of this work was to examine mid-term results of 18 iterative total hip arthroplasties with femoral reconstruction using massive allografts performed between 1986 and 1997.

Materials and methods: Using the Vives classification, the femoral bone lesions were grade 3 (n = 2) and grade 4 (n = 16). The reconstruction was achieved with radiated massive allografts measuring 11 to 35 cm implanted in a split host femur. Charnley-Kerboull implants with a long stem were cemented in the reconstructed femurs.

Results: Mean follow-up was 4 years 10 months (range 2 to 9 years). Nine complications in 7 hips were observed: 6 trochanter nonunions, two recurrent prosthesis dislocations and 1 femoral fracture. At last follow-up, the functional result was excellent or very good in 12 hips (Merle d’Aubigné classification). A stable fixation persisted for 15 implants and 3 had loosened. Graft-host femur consolidation was achieved in all cases except 1. There were 3 cases with extensive resorption of the graft including 2 associated with loosening of the femoral component.

Discussion: Reconstruction of the femur after extensive bone loss using a massive allograft appears to be a useful method for restoring bone tissue and providing immediate mechanical support for the femur.