Long term results of the Corin C-Fit uncemented total hip arthroplasty in young patients

Hemiarthroplasties in young patients with osteonecrosis or a tumour of the proximal femur; an observational cohort study

Background

The failure scenario in total hip arthroplasty (THA), in younger patients, is dependent on the fixation and wear of the acetabular component. In selected cases, where endoprosthetic replacement of the femoral head is unavoidable for limb salvage or functional recovery, hemiarthroplasty can be chosen as an alternative. The purpose of this study is to evaluate hemiarthroplasty as treatment strategy for young patients with osteonecrosis or a tumour of the proximal femur.

Methods

Between 1985 and 2008, 42 hemiarthroplasties (unipolar and bipolar) were performed in patients younger than 65 years with osteonecrosis (n=13) or a tumour of the proximal femur (n=29). All patients were seen at yearly follow-up examination and evaluated. Revision or conversion to a THA was regarded as a failure of the implant. A Kaplan Meier analysis was performed. To determine significant differences between categorical groups, the Pearson chi-square test was used. In numerical groups the independent T-test and One-way ANOVA were used.

Results

After a mean follow-up of 7.1 years, failure of the hemiarthroplasty occurred 6 times. The Kaplan Meier survival analysis with conversion to THA or revision as endpoint of the bipolar hemiarthroplasties (n=38) shows a 96% survival at 15, and 60% at 20 years. In the unipolar type (n=4) we found a conversion rate of 50% within 3 years.

Conclusions

Bipolar hemiarthroplasty is a reasonable alternative in a young patient with osteonecrosis or a tumour of the proximal femur as indication. Because of the high conversion rate after unipolar hemiarthroplasties, we would not recommend this type of prosthesis in the young patient.

Neck-preserving femoral stems

BACKGROUND

Surgeons undertaking total hip arthroplasty (THA) routinely perform a distal femoral neck resection. It has been argued that retaining the femoral neck during THA can provide mechanical and biological advantages.

PURPOSES

The objectives of this study were to review: (1) the current evidence on the advantages of femoral neck preservation during THA and (2) the clinical and radiological outcome of neck-preserving femoral stems.

METHODS

A search of the English-language literature on neck-preserving THA and on the individual neck-preserving implants was performed using PubMed, Ovid SP and Science Direct.

RESULTS

Studies have indicated that neck preservation offers superior tri-planar implant stability and allows more accurate restoration of the hip geometry and biomechanics. The trend towards tissue sparing surgery has contributed to the development of bone-conserving short-stem implants that offer variable levels of neck preservation. Despite an initial learning curve, these implants have generated promising early clinical results, with low revision rates and high outcome scores. However, radiological evaluation of some neck-preserving implants has detected a characteristic pattern of proximal femoral bone loss with distal cortical hypertrophy. The long-term implications of this finding are not yet known.

CONCLUSIONS

Preserving the femoral neck during THA has biomechanical advantages. However, long-term outcome data are needed on neck-preserving femoral stems to evaluate on-going bone remodelling and assess implant performance and survival.

Mid- to long-term outcome of cementless total hip arthroplasty in younger patients

PURPOSE

To assess mid- to long-term outcomes of cementless primary total hip arthroplasty (THA) in younger patients.

METHODS

Records of 28 women and 34 men (75 hips) aged 18 to 55 (mean, 38) years who underwent primary THA using a hydroxyapatite-coated stem and a threaded cup and had been followed up for a mean of 10 (6-15) years were reviewed. 13 of the patients had bilateral THAs. Clinical and radiographic outcomes were evaluated.

RESULTS

After a minimum follow-up of 7 (range, 7-14) years, 12 (16%) of the hips were revised, of which 8 (11%) were for the cup. The causes for revision were late deep infections (n=2), aseptic loosening of the cup (n=4), and polyethylene wear (n=6). No stem was revised for aseptic loosening. Osteolysis was noted in 24 (38%) hips. Of the 63 unrevised hips, the mean Harris Hip Score was 92 (range, 45-100) and the mean D'Aubigne and Postel score was 17 (range, 9-18). The survival of the threaded cup was 88% at 10 years, using revision surgery as the end point. 27 (41%) of the hips showed signs of polyethylene wear; 15 were >2 mm.

CONCLUSION

In younger patients undergoing THA, rates of polyethylene wear and pelvic osteolysis are high, and thus long-term follow-up is crucial.