Since January 1993 we have carried out MR arthrography on 23 patients with clinical symptoms and signs of abnormality of the acetabular labrum. Most of the patients were young adults. Such symptoms are known precursors of osteoarthritis, and therefore early and accurate evaluation is required. We assessed the value of MR arthrography of the hip as a minimally-invasive diagnostic technique, in a prospective study and compared the findings with those at subsequent operations. All the patients complained of groin pain; 22 had a positive acetabular impingement test and 15 had radiological evidence of hip dysplasia. In 21 of the patients, MR arthrography suggested either degeneration or a tear of the labrum or both. These findings were confirmed at operation in 18 patients, but there was no abnormality of the labrum in the other three. In two of the patients, MR arthrography erroneously suggested an intact labrum. Both MR arthrography and intraoperative inspection located lesions of the superior labrum most often, and these appeared slightly larger on arthrography than at operation. We consider that MR arthrography is a promising diagnostic technique for the evaluation of abnormalities of the acetabular labrum.

Since January 1993 we have carried out MR arthrography on 23 patients with clinical symptoms and signs of abnormality of the acetabular labrum. Most of the patients were young adults. Such symptoms are known precursors of osteoarthritis, and therefore early and accurate evaluation is required.We assessed the value of MR arthrography of the hip as a minimally-invasive diagnostic technique, in a prospective study and compared the findings with those at subsequent operations. All the patients complained of groin pain; 22 had a positive acetabular impingement test and 15 had radiological evidence of hip dysplasia.In 21 of the patients, MR arthrography suggested either degeneration or a tear of the labrum or both. These findings were confirmed at operation in 18 patients, but there was no abnormality of the labrum in the other three. In two of the patients, MR arthrography erroneously suggested an intact labrum. Both MR arthrography and intraoperative inspection located lesions of the superior labrum most often, and these appeared slightly larger on arthrography than at operation.We consider that MR arthrography is a promising diagnostic technique for the evaluation of abnormalities of the acetabular labrum. have given enhanced visualisation of labral integrity 8 allowing better management. We have compared our assessment of the labrum in patients with ARS using MR arthrography with subsequent intraoperative findings. PATIENTS AND METHODSWe reviewed 23 patients with ARS in whom there was uncertainty as to the exact location and extent of the abnormality. After clinical assessment and plain radiography MR arthrography was undertaken. Clinical and radiological findings. The patients were young adults with a mean age of 40 ± 2 years. There were 14 women and 9 men. They all had a history of intermittent groin pain for up to 15 years (mean 3.5 years), mostly elicited by rotational movement without a significant initiating event. Six had night pain. A full range of joint movement was present but six described episodes of locking. All but one had discomfort and a sensation of apprehension when performing an impingement provocation test. This involves flexion, adduction and internal rotation for the anterosuperior acetabular rim (21/23), and hyperextension, abduction and external rotation for the posteroinferior rim (5/23). 1 Acetabular dysplasia was present in 15 of the patients assessed by plain radiography.

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Adult human bone cells isolated from jaw bone biopsies were cultured either on Thermanox ' coverslips or on polished or plasma-sprayed surfaces of titanium or hydroxylapatite and the levels of their various metabolic functions were compared after 2 and 5 days of staying in culture. Thus, jaw bone cells grown on hydroxylapatite proliferated very little, while expressing discrete levels of alkaline phosphatase activity and of osteocalcin secretion into the growth medium. On the other hand, bone cells seeded onto titanium surfaces proliferated much more intensely than those on Thermanox ~', besides expressing alkaline phosphatase (very intensely after 5 days) and secreting osteocalcin. Thus, both kinds of titanium surfaces greatly enlarged the size of both populations of preosteoblastic precursors and of pre-osteoblasts in vitro, but plasma-sprayed titanium surfaces elicited, between day 2 and 5 in culture, greater increases in bone cell numbers markedly enhancing their proliferative and alkaline phosphatase activities, along with their osteocalcin secretion into the growth medium, and thus favouring the expression of the mature osteoblastic phenotype. These preliminary findings show that studies correlating the physical surface features of various biomaterials with the corresponding expression of specific differentiation markers by the bone cells cultured on these same surfaces can provide information relevant to the clinical application of biomaterials.