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Aim: We wanted to improve MRI visualization of early hip pathology invisible on plain radiographs., Method: An MR arthrography of the hip with radial sequences is described. The standard MR technique is improved by 1) using a small flexible surface coil to show selectively the hip joint to be examined, 2) application of gadolinium intra-articularly and 3) by radial imaging sequences perpendicular to the true plane of the acetabulum., Conclusion: By this technique it is possible to achieve an undistorted image of each aspect of the acetabular rim. Regions of special interest can be defined and their pathologies possibly related to morphologies of the proximal end of the femur.

Aim: The study was undertaken to determine the value of standard radiographs in the early stages of osteoarthritis., Methods: Standard radiographs and arthro-MRI's from thirty hips operated on for early arthrosis (age 25-57 years) were independently analyzed by two orthopaedic surgeons and one radiologist blinded from the intra-operative findings. The radiographs were read on two occasions two months apart. The radiographic findings were then compared to the intra-operative findings., Results: Intra-operatively, all cases had a labral lesion and, in all but three of the cases, there was a major acetabular cartilage lesion. Each investigator diagnosed all of the labral and/or cartilage lesions on the arthro-MRI. However, on average, the investigators judged 20% (10-35%) of the hips to be normal on the standard radiographs. The probability of detecting an abnormal hip joint was statistically significantly better with arthro-MRI in four of six readings (p < 0.05) and there was a trend in favor of the arthro-MRI in the other two readings (p < 0.1). Intra-observer agreement when using the Tönnis classification of arthrosis on standard radiographs was 0.26 (-0.1-0.62), 0.69 (0.42-0.96) and 0.83 (0.53-1) [kappa-statistic, (95% confidence interval)]. The interobserver agreement was 0.24 (-0.07-0.55)., Conclusion: Plain radiographs in the early stages of osteoarthrosis of the hip are neither reliable nor valid to diagnose the onset of disease. Therefore, in the case of a normal radiograph and clinical suspicion of arthrosis, a "normal" radiograph does not exclude the diagnosis and an artho-MRI should be obtained for further evaluation.

We performed a prospective randomized study to determine blood loss differences between supine or lateral patient position, during surgery in elective total hip replacement. Between January and October 1996, 64 consecutive cases of total hip replacements were randomly scheduled for a procedure either in the supine or in the lateral position. Of the 56 cases evaluated, 29 were operated in the supine position (SP) and 27 in the lateral position (LP). The standardized implantations were performed without cement and the blood loss was measured. The calculated loss of Hb on the day of operation was 235 g Hb +/- 17 (mean +/- s.e.) in the SP group and 177 g Hb +/- 14 in the LP group, respectively, (unpaired t-test p = 0.01). The calculated loss of Hb after five postoperative days was 227 g Hb +/- 24 (mean +/- s.e.) in the SP group and 179 g Hb +/- 24 in the LP group, respectively, p < 0.2. The net loss of Hb after five postoperative days was calculated by subtracting all perioperative blood substitutions (Cellsaver, autologous and homologous blood) resulting in 340 g Hb +/- 21 (mean +/- s.e.) in the SP group and 272 g Hb +/- 21 in the LP group, respectively, p = 0.02. The blood loss in primary cementless total hip replacement surgery can be significantly reduced by performing the procedure in the lateral position compared to that in the supine position. The blood loss is limited to the day of operation, as indicated by the stable Hb-levels thereafter.