Seven hips with protrusio acetabuli which showed complete or partial resolution of the protrusion after replacement with Ring's prosthesis are reported. It is suggested that this prosthesis offers a simple and effective method of treating painful protrusion into the pelvis; it allows healing of the medial wall of the acetabulum while avoiding many of the hazards of other methods of treatment

Aims

The removal of the cruciate ligaments in total knee arthroplasty (TKA) has been suggested as a potential contributing factor to patient dissatisfaction, due to alteration of the in vivo biomechanics of the knee. Bicruciate retaining (BCR) TKA allows the preservation of the cruciate ligaments, thus offering the potential to reproduce healthy kinematics. The aim of this study was to compare in vivo kinematics between the operated and contralateral knee in patients who have undergone TKA with a contemporary BCR design.

A primary hydatid cyst in the pelvis is rare, and usually presents with pressure symptoms affecting the adjacent abdominal organs. We describe such a cyst which protruded through the sciatic notch and presented as a gluteal swelling with a foot drop due to compression of the lumbosacral nerve roots. Surgical excision and postoperative treatment with albendazole for six weeks were effective in controlling the disease and preventing recurrence

1. A case is reported which shows the typical features of osteopathia striata in all the long bones and probably in the pelvis, with the features of osteopetrosis in the skull and ribs. 2. The occurrence of longitudinal striation in osteopoikilosis and osteopetrosis is described, and the possible relationship between these two diseases and osteopathia striata is discussed. 3. The differential diagnosis is indicated

Seven patients with Ewing's sarcoma of the pelvis were treated by chemotherapy followed by wide resection of the primary tumour. Although good function after operation is possible, survival in this series reflects the poor prognosis associated with the disease; two patients died, two are alive with local recurrence and metastases and three patients are alive with no evidence of disease

Objectives

The paradoxical migration of the femoral neck element (FNE) superomedially against gravity, with respect to the intramedullary component of the cephalomedullary device, is a poorly understood phenomenon increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. The aim of this study was to investigate the role of bidirectional loading on the medial migration phenomenon, based on unique wear patterns seen on scanning electron microscopy of retrieved implants suggestive of FNE toggling.

A 15-year-old girl presented with a very large desmoid tumour in her buttock; it extended into the pelvis and thigh and would have required hindquarter amputation for its removal. This was not performed and the tumour underwent spontaneous regression. Fourteen years later the patient is alive and well. The suggestion is made that in some cases a more expectant approach to treatment might be justified for what is essentially a non-malignant condition

We report six caucasian patients who had acute pain in the hip and marked limitation of all movements of the joint. Plain radiographs and CT of the pelvis showed calcification within the reflected head of rectus femoris. All six responded to accurate CT-controlled injections of corticosteroid and local anaesthetic with dramatic and prolonged pain relief, although one required a second injection for recurrence of symptoms after two months

1. Nine cases of stress fracture of the pelvis after total hip replacement are reported, five after Ring replacement and four after a McKee. In none of the cases did the fractures unite. 2. In three cases infection was probably an important cause of the fracture. In six cases there was no infection. Only one presented a history of injury. 3. The combination of the various factors that might have caused the stress fractures is discussed

We reviewed the long-term results at ten to 12 years of 118 total hip replacements in 109 patients using a second-generation hemispherical cementless acetabular component (Reflection) designed to address the problem of backside wear. Five patients (five hips) died and six patients (seven hips) were lost to follow-up. The remaining 98 patients (106 hips) had a mean age of 62.9 years (34.0 to 86.2) A rate of revision for aseptic loosening of 0.9%, and predictable results were found with respect to radiological evidence of fixation, lack of pain, walking ability, range of movement and function. One component was revised for aseptic loosening, and of the 101 hips (95.2%) that did not have a revision, minor osteolytic lesions of the pelvis were seen in six (5.9%). Kaplan-Meier survival analysis for the total cohort of 118 hips revealed a 96.4% survival at both ten (95% confidence interval 90 to 98) and 12 years (95% confidence interval 86 to 98)

One-hundred newborn children at high risk of hip instability were prospectively assessed clinically and by ultrasound. The decision to treat was based only on the clinical examination. At the age of three months all the children were evaluated clinically and with an anteroposterior radiograph of the pelvis. None of the standard ultrasound measurements of acetabular depth and femoral head cover correlated with the outcome at three months. Dynamic assessment of stability was the only ultrasound technique that had a significant relation with outcome

Ten cases are described of catastrophic failure of the polyethylene liner of three different designs of uncemented acetabular component. Failure occurred as a result of either 'wearthrough' to the metal backing, liner fracture or a combination of both, at a mean of 4.6 years after implantation (2 to 7.6). At revision there was metallosis in all hips and osteolysis of the femur or the pelvis in six. Catastrophic failure was seen only in cups with a minimum polyethylene thickness of less than 5 mm

1 . The incidence of hydatid disease in bone is discussed and the relevant literature reviewed. 2. The parasitology and methods of control are described. 3. The pathology of hydatid disease affecting bone is described. 4. An analysis of fifty-three cases is made showing that the disease commonly occurs in the spine, the long bones, the ribs and scapula, and the pelvis and hip. The treatment and prognosis of each group is discussed. 5. Three cases of hydatid disease of bone occurring in animals are described

Aims

The aim of the current study was to assess the reliability of the Ottawa classification for symptomatic acetabular dysplasia.

Discrepancy in leg length after total hip replacement has been associated with patient dissatisfaction. We prospectively studied 200 consecutive patients undergoing unilateral Charnley hip replacements to identify whether there is a demonstrable association between such disparity and postoperative function. Radiological measurements between defined points on the pelvis and femur of the operated hip were compared with the same points on the contralateral joint. A lengthening index was derived and statistical analysis used to compare this with validated functional outcome scores (Harris hip score and the SF36 Health Survey) and patient satisfaction. Our results showed no statistical association between leg-length discrepancy after hip arthroplasty and functional outcome or patient satisfaction

1. A case of essential osteolysis, progressing for thirteen years and involving the right femur and pelvis of a boy who was thirteen years old at the time of onset, is presented. 2. The histological appearance of fragments of bone and soft tissue removed from the affected thigh is described. 3. No evidence that might throw light on the etiology of the disease was obtained from biochemical investigations or from the histological studies. 4. None of the many lines of treatment that were tried had any effect upon the progress of the disease

1. Details of clinical, radiological, biochemical and histological investigations of a case of metaphysial dysostosis are presented. 2. The patient was a boy of seven years, and showed widespread lesions (involving long bones of limbs, small bones of hands and feet, pelvis, clavicles, and ribs) characterised by retardation of growth and ossification with masses of partly calcified tissue in the metaphyses. 3. No radiological, clinical or histological evidence of renal osteodystrophy was found in the case described. 4. Metaphysial dysostosis is discussed in relation to other chondrodystrophies