Introduction:

The sealing function of the acetabular labrum is central to the stability of the hip and the health of the joint. Disruption of the labrum has been shown to reduce intra-articular pressure and increase the rate of cartilage consolidation during static loading. Functional activities require movement of the hip through wide ranges of joint motion which disrupt joint congruency, and thus may alter the seal. This study was performed to test the hypothesis that the sealing function of the labrum varies with the position of the hip during functional activities.

Objectives:

Experimental disruption of the labrum has been shown to compromise its sealing function and alter cartilage lubrication. However, it is not known whether pathological changes to the labrum secondary to femoro-acetabular impingement (FAI) have a similar impact on labral function. This study was performed to determine the effect of natural labral damage secondary to abnormal femoral morphology on the labral seal.

Purpose: Synovial chondromatosis is a cartilaginous metaplasia that can result in multiple intracapsular and extracapsular loose bodies. Open arthrotomy has been the conventional treatment for this condition in the hip, but is associated with neurovascular embarrassment and femoral head osteonecrosis. Hip arthroscopy avoids these problems, and is a minimally invasive approach to diagnosis and treatment. Our aim was to evaluate the role of arthroscopy in the management of synovial chondromatosis of the hip at the early-to-intermediate stages of disease.

Method: Twenty-nine patients had arthroscopic treatment for synovial chondromatosis of the hip. All lesions were intracapsular and smaller than 10mm. Radiographs of the painful hip, computed tomography, and gadolinium-enhanced magnetic resonance imaging were obtained pre-operatively. During arthroscopy, loose bodies were removed via a cannula, and partial synovectomy, partial labrectomy, chondroplasty, and microfracture were done as needed.

Results: Fourteen patients were women and 15 were men; mean age was 41 years old; mean duration of symptoms was 52 months. All patients had hip pain. Mechanical hip symptoms were reported by 63% of patients. Twenty-three patients had a follow-up of at least 12 months (12 to 184 months of follow-up). Loose bodies could be seen in the imaging studies of 58% (15 of 29) of patients: 8 on radiographs and 7 with computed tomography or gadolinium-enhanced magnetic resonance imaging. At surgery, 23 of the 29 patients had torn or frayed labra. There was an average of 35 loose bodies per patient. Twenty-three of the 29 patients had femoral head changes, four of which had Grade III or IV lesions. Twenty-five of the 29 had acetabular chondral findings, ten of which had Grade III or IV lesions. Five of the 29 patients eventually underwent total hip reconstruction surgery at an average of 52 months follow-up; four of these 5 patients had at least a Grade III lesion at the time of arthroscopy. Eleven of the 23 patients who had a minimum of 12 months follow-up (12 to 184 months) had good to excellent outcomes at an average of 60 months follow-up. Complications included a case of perineal numbness and another with tingling of the foot.

Conclusion: Our patients with synovial chondromatosis of the hip benefited from hip arthroscopy. Imaging studies alone, including gadolinium-enhanced MRI, failed to establish the diagnosis in half of the patients. Diagnosis was eventually made by direct visualization of the loose bodies via arthroscopy. None of our patients had subsequent femoral head osteonecrosis or infection. For patients who had Grade I or II cartilage lesions, early diagnosis and treatment via arthroscopy helped prevent or delay the onset of secondary osteoarthritis. Arthros-copy also avoided an open surgical exposure with its associated prolonged rehabilitation. It is a valid and effective treatment for early-to-intermediate stages of synovial chondromatosis.

Introduction and Aims: A recently reported study and reports in the German lay press have indicated that there may be an increased incidence of limp following Robodoc THR. This paper presents the detailed functional aspects from the first randomised US FDA multicentre trial.

Method: The controlled randomised trial was conducted from 1994–98, with 136 hip replacements performed on 119 patients at three centres. The implants were either AML (Depuy) or Osteoloc (Howmedica). Twenty-eight patients were lost to follow-up at two years. Twenty-four month Harris hip score surveys for the remaining 108 patients – 53 Robodoc and 55 Control – were reviewed and relevant scores were tabulated for limp and use of support aids.

Results: In the Robodoc group, 45 patients had no limp and eight patients had slight to moderate limp. In the control group, 44 patients had no limp, and 11 patients had slight to moderate limp. The average Harris limp score was 10.49 for the Robodoc group and 10.24 for the control group (NS). In the use of supportive aids and canes, at 24 months, there was essentially no difference between the average of the scores. In the Robodoc group,47 patients required no aids, and six required the use of a cane. In the control group, 49 patients required no supportive aids, and six patients required the use of a cane.

Conclusions: In this randomised controlled study no statistically significant difference was found between the Robodoc and the manual method in the incidence of limp and use of supportive aids, following primary Total Hip Arthroplasty. This data is also consistent with other published studies using Robodoc and is in contrast to a recent study from one centre.