Introduction

Excellent long-term survival rates associated with the absence of stem subsidence have been achieved with total hip arthroplasty (THA) using femoral components cemented line-to-line (“French Paradox”). Recently, short stems have been introduced in order to preserve diaphyseal bone and to accommodate to minimal invasive THA and a variety of clinical situations. The aim of the current study was to quantify the rotational and tilting stability of a Kerboull stem of varying length after line-to-line cementation using a validated in-vitro model.

Introduction

The wear performances of polyethylene in THA are influenced at a great extent by the manufacturing process. During the past decade, highly cross-linked materials have been developed with encouraging results in terms of wear, whereas another body of the literature has indicated potential catastrophic failures related to reduced fatigue properties and oxidation due to lipids adsorption and fatigue mechanism. Also, each of the materials available on the market has its own processing characteristics. Therefore, a specific evaluation is necessary for each of them. The aim of this retrospective study was to evaluate the wear properties of metal-back sockets using a first generation highly cross-linked PE in a consecutive series of primary THAs.

Introduction

Total hip replacement (THR) is one of the most widely used and most successful orthopedic procedures performed in developed countries. The burden of revision surgery, however, has become a major issue in terms of both volume and cost. Technical errors at the time of the index operation are known to be associated with an increased rate of revision.

Statistical methods, such as the CUSUM test, which have been developed for the manufacturing industry to monitor the quality of products, have come to the attention of health-care workers as a result of centers with protracted periods of inadequate performance. In orthopedics, these methods have been used to monitor the quality of total hip replacement in a tertiary care department using conventional imaging techniques.

Biplane low-dose X-ray imaging (EOS) may allow an easy, patient-friendly, way to retrieve data on the position of implants immediately postoperatively. Therefore real-time feedback is provided to surgeons and performance adjusted accordingly

Purpose: The purpose of this retrospective study was to evaluate at minimal 5 years follow-up outcome in a consecutive series of total hip arthroplasties implanted for fracture of the acetabulum.

Material and methods: The series included 53 arthroplasties implanted between January 1980 and December 1995 in 53 patients, 16 women and 37 men, mean age 53.1 years (24–84). The initial fracture involved the acetabular wall in 18 patients, one column in seven and two columns in six. It was a complex fracture in eleven cases and classification was unknown in the eleven other hips. Orthopaedic treatment was used for 23 patients and surgery for 30. Mean time between fracture and arthroplasty was 16.4±10.8 years. Cemented Charnley-Kerboull implants with a metal-polyethylene bearing were used. The Postel-Merle-d’Aubigné (PMA) score was used to assess functional outcome. The actuarial survival was determined.

Results: At five years minimum follow-up, 33 patients were alive and had not undergone revision at mean follow-up of 12.4±3.8 years (7–21). Six patients had had revision of the acetabular and/or femoral element, five patients had died, and seven were lost to follow-up. Revisions were required for cup wear associated with periacetabular osteolysis. The mean preoperative functional score was 10.6±2.5 versus 16.2±2.8 (8–18) at last follow-up (Wilcoxon rank test, p< 0.0001). Cumulative survival, taking revision as failure, was 90.3±6.5% at 15 years (95%CI 77.6–100%) for hips treated orthopaedically versus 66.5±14.5 (95%CI 38.1–94.9%) for hips treated surgically. The difference for the analyzable hips was not significant (logrank, p=0.69).

Discussion: The results of this series confirm that the long-term risk of mechanical failure of total hip arthroplasty for fracture of the acetabulum is high.

Aims: The purpose of this retrospective study was to report on the treatment of migrated ununited greater trochanter following total hip arthroplasty. Methods: Between January 1986 and December 1999, 72 non-unions of the greater trochanter in 71 patients were treated using a trochanteric claw plate. The mean age of the patients was 66 ± 11 years. The average time to re-operation was 8 months. Fixation of the non-united greater trochanter was performed using a claw plate only in 47 hips, and the association of frontal wires with a claw plate in the remaining 25 hips. The main criterion for evaluation was the consolidation of the greater trochanter judged as follows: bony consolidation (no pain, no Trendelenboug gait, radiologic fusion); fibrous consolidation (moderate pain, no Trendelenboug gait, radiologic fusion difficult to assess); and non-union (Trendelenboug gait and/or absence of radiologic fusion). Results: The average follow-up of the series was 4 years (1 to 14 years). The mean d’Aubigné score significantly increased from 13.5 preoperatively to 15.9 at last follow-up (paired signs test, p < 0.0001). Bony consolidation was obtained in 51 hips, fibrous in 9, whereas repeat non-union occurred in 12. The only predictive factor for union was the use frontal wires in association with a claw plate that provided 87.5% of unions and no failure (Chi square test, p = 0.006). Conclusions: This study indicated that non-union of the greater trochanter following total hip arthroplasty can be successfully treated with frontal wires in conjunction with a trochanteric claw plate.

Aims: The purpose of this prospective randomized study was to report on the minimal 10-year follow-up results of a consecutive series of cemented total hip arthroplasty according to the surface finish of the femoral implant. Methods: Between January 1988 and December 1989, 311 total hip arthroplasties were performed in 286 patients. Implants were of Charnley Kerboull design combining a 22.2-mm femoral head and an all-polyethylene socket. The cemented femoral implant was available in two configurations: polished (Ra = 0.4 μm) and matte (Ra = 3 μm). The polished stem (MK III, Stryker Howmedica) was implanted in 166 hips, and the matte stem (CMK 3, Vecteur Orthopedic) in the remaining 145. The mean age of the patients was 63.6 years. Results: At the minimum 10-year follow-up evaluation, 187 patients (204 hips) were still alive and had not been revised at a mean of 11.7 years (10–14 years), 15 patients (15 hips) had been revised, 54 patients (58 hips) had died from unrelated causes, and 30 patients (34 hips) were lost to follow-up. The mean d’Aubigné hip score was 17.7 ± 0.3 at the latest follow-up. The survival rate at 13 years, using radiologic loosening as the end-point, was 97.3 ± 2.6% (95% confidence interval, 92.2 to 100%) for polished stems, versus 78.9 ± 5.8% (95% confidence interval, 67.6 to 90.3%) for matte stems (log-rank test, p = 0.0001). Conclusions: This study demonstrated that cemented fixation of femoral stems was significantly more reliable in the long-term with a polished surface.

Aims: The aim of this open prospective study was to evaluate the minimum 2-year follow-up outcome of a consecutive series of low friction total hip arthroplasties combining zirconia on polyethylene. Methods: Between January 1997 and June 1999 fifty-five total hip arthroplasties were performed in 51 patients. The mean age was 52.2 ± 12 years. The 22.2-mm femoral head made of zirconia ceramic was secured to the femoral component through a Morse taper that had an angle of 11°25 for 27 hips and 5°40 for 33 hips. All prostheses were of Charnley-Kerboull design. Clinical results were evaluated according to the Merle d’Aubigné hip score. Wear of the acetabular component and periprosthetic osteolysis was measured on serial radiographs of the pelvis. Results: The mean follow-up of the series was 32 months (24 to 48 months). No patient was lost to follow-up. The mean functional hip score significantly increased from 12.2 ± 2.6 preoperatively to 17.8 ± 0.2 at the latest follow-up (paired Student’s t test, p < 0.0001). None of the acetabular or femoral component had migrated. Wear of the socket was always undetectable on plain radiographs. However, lytic endosteal lesions of the calcar were observed in 19 of the 55 arthroplasties (34.5%). These lytic lesions appeared between the first and second postoperative year. Conclusions: Early calcar osteolysis observed in this study can be related to either run-in wear or to preliminary severe wear. The authors do not recommend further use of zirconia ceramic until long-term follow-up studies are available.

Purpose: The purpose of this retrospective study was to assess long-term clinical and radiological outcome in a continuous series of alumine-alumine total hip arthroplasties.

Material and methods: This series included 118 total hip arthroplasties performed in 106 patients (70 men and 36 women), mean age 62.2 ± 11.9 years (32–89). Primary degenerative hip disease was the main aetiology. All the arthroplasties were performed by the same operator. In all cases, the femoral piece was a titanium alloy with a Morse cone for fixation of the femoral head; an “all alumine” cup was used for all. The implants were fixed with cement for 85 hips, without cemented for 29, and with a hybrid technique for four. The Merle d’Aubigné score was used to assess clinical outcome. Classical landmarks on the AP pelvis views were used to assess implant migration. Cup wear was measured using the Livermore method. Actuarial survival curves were plotted.

Results: At mean follow-up of 20 years, 45 patients (51 hips) were still living and had not required revision. Twenty-five patients (25 hips) had undergone revision for replacement of the acetabular component and/or the femoral component. Twenty-seven patients (30 hips) had died and nine patients (12 hips) were lost to follow-up. The mean functional score was 16.2 ± 1.8 at last follow-up. Cumulated survival at 20 years was 85.6% (95%CI 72.2–99.0) for cups without cement compared with 61.2% (95%CI 46.8–75.6) for stems without cement (log rank test p = 0.0162). Cumulated survival at 20 years was 84.9% (95%CI 71.1–98.8) for stems without cement compared with 87.3% (95%CI 77.4–97.1) for cemented stems (log rank, p < 0.05). Wear was unmeasurable. Osteolytic lesions required reconstruction with an allograft in three of the 25 revisions. There were no cases with fracture of the alumine head or cup.

Discussion: The limited number of cases with osteolysis at 20 years is probably related to minimal wear of the prosthetic components. Fixation of alumine cups could still be improved.