Comparison of two hydroxyapatite-coated femoral stems: clinical, functional, and bone densitometry evaluation of patients randomized to a regular or modified hydroxyapatite-coated stem aimed at proximal fixation.

Clinical function, bone mineral density (BMD), and radiographs of 80 randomly allocated, hydroxyapatite-coated femoral stems of two differing lengths were studied for 2 years. The short stem was optimized for proximal fixation. The predictive value of bone densitometry was also studied. After 2 years, significantly more bone apposition and a higher BMD percentage were observed in Gruen zone 7 of the short stem. We conclude that stem design can be enhanced to achieve more proximal fixation. However, we found a higher incidence of pain with the short stem, indicating a trade-off between increased proximal fixation and diminished overall mechanical stability. No strong correlations between clinical function and radiographic evaluation of remodeling were found with BMD, suggesting that dual-energy x-ray absorptiometry has no predictive value for short-term clinical outcome.

The "Oxford Heup Score": the translation and validation of a questionnaire into Dutch to evaluate the results of total hip arthroplasty.

BACKGROUND: The evaluation of a total hip prosthesis would be most complete if the opinion of the patient, surgeon and the radiographs are combined. Disease specific patient outcome questionnaires are scarce, especially in Dutch. METHODS: The disease-specific 12-item questionnaire on the perception of patients with total hip replacement was translated into Dutch. We also investigated the extra value of two specific hip items, "the need for walking aids" and "sexual problems because of the hip", four general items on overall satisfaction and one question about patient classification. The 14 hip-specific items were each scored from 1 (least difficulties) to 5 (most difficulties). The Dutch translation, the "Oxford Heup Score" (OHS) was tested on psychometric quality in a multicenter prospective study. RESULTS: The psychometric results of the OHS proved to be adequate. In the first postoperative year the score was very sensitive to changes, whereas in the second year it did not change significantly. The two added hip-specific questions were both filled out positively by more than 50% of the patients and thus fit perfectly into a hip-specific patient outcome questionnaire such as the OHS. INTERPRETATION: The OHS proves to be an appropriate instrument for assessment of the outcome of total hip replacement from the patient's perspective. Together with the judgement of the surgeon, it provides useful insights into the question of whether this operation has been a success or not.