Acetabular dysplasia was produced in 24 immature white rabbits. A rotational acetabular osteotomy was then carried out and radiological and histological studies of the articular cartilage were made.

In the hips which did not undergo osteotomy, radiographs at 26 weeks showed that residual subluxation remained and arthritic changes such as narrowing of the joint space or dislocation were still seen. However, in the operated group there was a remarkable increase in cover, but arthritic changes were not observed. After 24 weeks, the Mankin grading score in the operated group was significantly lower than that in the non-operated group. The latter hips showed an irregular surface of the cartilage, exfoliation and proliferation of synovial tissue. In those undergoing osteotomy, primary cloning of chondrocytes or hypercellularity was seen and at 24 weeks after operation and metaplasia of the cartilage in the fibrous tissue was observed in the boundary between the medial area of the acetabulum and the acetabular fossa.

We reviewed 142 consecutive primary total hip replacements implanted into 123 patients between 1988 and 1993 using the Exeter Universal femoral stem. A total of 74 patients (88 hips) had survived for ten years or more and were reviewed at a mean of 12.7 years (10 to 17). There was no loss to follow-up.

The rate of revision of the femoral component for aseptic loosening and osteolysis was 1.1% (1 stem), that for revision for any cause was 2.2% (2 stems), and for re-operation for any cause was 21.6% (19 hips). Re-operation was because of failure of the acetabular component in all but two hips.

All but one femoral component subsided within the cement mantle to a mean of 1.52 mm (0 to 8.3) at the final follow-up. One further stem had subsided excessively (8 mm) and had lucent lines at the cement-stem and cement-bone interfaces. This was classified as a radiological failure and is awaiting revision. One stem was revised for deep infection and one for excessive peri-articular osteolysis. Defects of the cement mantle (Barrack grade C and D) were found in 28% of stems (25 hips), associated with increased subsidence (p = 0.01), but were not associated with endosteal lysis or failure.

Peri-articular osteolysis was significantly related to the degree of polyethylene wear (p < 0.001), which was in turn associated with a younger age (p = 0.01) and male gender (p < 0.001).

The use of the Exeter metal-backed acetabular component was a notable failure with 12 of 32 hips (37.5%) revised for loosening. The Harris-Galante components failed with excessive wear, osteolysis and dislocation with 15% revised (5 of 33 hips). Only one of 23 hips with a cemented Elite component (4%) was revised for loosening and osteolysis.

Our findings show that the Exeter Universal stem implanted outside the originating centre has excellent medium-term results.

This review describes the development of arthroscopy of the hip over the past 15 years with reference to patient assessment and selection, the technique, the conditions for which it is likely to prove useful, the contraindications and complications related to the procedure and, finally, to discuss possible developments in the future.

We performed 114 consecutive primary total hip arthroplasties with a cementless expansion acetabular component in 101 patients for advanced osteonecrosis of the femoral head. The mean age of the patients at surgery was 51 years (36 to 62) and the mean length of follow-up was 110 months (84 to 129).

The mean pre-operative Harris hip score of 47 points improved to 93 points at final follow-up. The polyethylene liner was exchanged in two hips during this period and one broken acetabular component was revised. The mean linear wear rate of polyethylene was 0.07 mm/year and peri-acetabular osteolysis was seen in two hips (1.9%). Kaplan-Meier analysis indicated that the survival of the acetabular component without revision was 97.8% (95% confidence interval 0.956 to 1.000) at ten years.

Our study has shown that the results of THA with a cementless expansion acetabular component and an alumina-polyethylene bearing surface are good.

We have undertaken a prospective clinical and radiological analysis of 124 shoulder arthroplasties (113 patients) carried out for osteoarthritis. The clinical results showed improvement in the absolute Constant score and the American Shoulder and Elbow Surgeons score of 22 and 43, respectively. Both were statistically significant (p < 0.001). There was no significant difference in the scores after hemiarthroplasty and total arthroplasty in those patients with an intact rotator cuff.

When revision was used as the end-point for survival at ten years, survival of 86%, or 90% if glenoid components made of Hylamer sterilised in air were omitted, was obtained in primary osteoarthritis. The most common cause for revision in the hemiarthroplasty group was glenoid pain at a mean of 1.5 years; in the total arthroplasty group it was loosening of the glenoid at a mean of 4.5 years. Analysis of pre-operative factors showed that the risk of gross loosening of the glenoid increased threefold when there was evidence of erosion of the glenoid at operation. Shoulder arthroplasty should not be delayed once symptomatic osteoarthritis has been established and should be undertaken before failure of the cuff or erosion of the glenoid are present.

We describe a method of reconstruction using tumour-bearing autograft treated by liquid nitrogen in 28 patients. The operative technique consisted of en bloc excision of the tumour, removal of soft tissue, curettage of the tumour, drilling and preparation for internal fixation or prosthetic replacement before incubation for 20 minutes in liquid nitrogen, thawing at room temperature for 15 minutes, thawing in distilled water for ten minutes, and internal fixation with an intramedullary nail, plate or composite use of prosthetic replacement. Bone graft or cement was used to augment bone strength when necessary.

The limb function was rated as excellent in 20 patients (71.4%), good in three (10.7%), fair in three (10.7%), and poor in two (7.1%). At the final follow-up six patients had died at a mean of 19.8 months after the operation, while 21 remained free from disease with a mean follow-up of 28.1 months (10 to 54). One patient is alive with disease. Bony union was seen at a mean of 6.7 months after the operation in 26 patients. Complications were encountered in seven patients, including three deep infections, two fractures, and two local recurrences. All were managed successfully. Our results suggest that this is a simple and effective method of biological reconstruction.

An increasing number of patients are treated by autologous chondrocyte implantation (ACI). This study tests the hypothesis that culture within a defined chondrogenic medium containing TGF-β enhances the reexpression of a chondrocytic phenotype and the subsequent production of cartilaginous extracellular matrix by human chondrocytes used in ACI. Chondrocytes surplus to clinical requirements for ACI from 24 patients were pelleted and cultured in either DMEM (Dulbecco’s modified eagles medium)/ITS+Premix/TGF-β1 or DMEM/10%FCS (fetal calf serum) and were subsequently analysed biochemically and morphologically.

Pellets cultured in DMEM/ITS+/TGF-β1 stained positively for type-II collagen, while those maintained in DMEM/10%FCS expressed type-I collagen. The pellets cultured in DMEM/ITS+/TGF-β1 were larger and contained significantly greater amounts of DNA and glycosaminoglycans. This study suggests that the use of a defined medium containing TGF-β is necessary to induce the re-expression of a differentiated chondrocytic phenotype and the subsequent stimulation of glycosaminoglycan and type-II collagen production by human monolayer expanded chondrocytes.

We have investigated whether control of balance is improved during stance and gait and sit-to-stand tasks after unilateral total hip replacement undertaken for osteoarthritis of the hip.

We examined 25 patients with a mean age of 67 years (sd 6.2) before and at four and 12 months after surgery and compared the findings with those of 50 healthy age-matched control subjects. For all tasks, balance was quantified using angular measurements of movement of the trunk.

Before surgery, control of balance during gait and sit-to-stand tasks was abnormal in patients with severe osteoarthritis of the hip, while balance during stance was similar to that of the healthy control group. After total hip replacement, there was a progressive improvement at four and 12 months for most gait and sit-to-stand tasks and in the time needed to complete them. By 12 months, the values approached those of the control group. However, trunk pitch (forwards-backwards) and roll (side-to-side) velocities were less stable (greater than the control) when walking over barriers as was roll for the sit-to-stand task, indicative of a residual deficit of balance.

Our data suggest that patients with symptomatic osteoarthritis of the hip have marked deficits of balance in gait tasks, which may explain the increased risk of falling which has been reported in some epidemiological studies. However, total hip replacement may help these patients to regain almost normal control of balance for some gait tasks, as we found in this study. Despite the improvement in most components of balance, however, the deficit in the control of trunk velocity during gait suggests that a cautious follow-up is required after total hip replacement regarding the risk of a fall, especially in the elderly.

Our aim in this prospective study was to determine the best diagnostic method for discriminating between patients with and without osteochondral lesions of the talus, with special relevance to the value of MRI compared with the new technique of multidetector helical CT. We compared the diagnostic value of history, physical examination and standard radiography, a 4 cm heel-rise view, helical CT, MRI, and diagnostic arthroscopy for simultaneous detection or exclusion of osteochondral lesions of the talus. A consecutive series of 103 patients (104 ankles) with chronic ankle pain was included in this study. Of these, 29 with 35 osteochondral lesions were identified. Twenty-seven lesions were located in the talus.

Our findings showed that helical CT, MRI and diagnostic arthroscopy were significantly better than history, physical examination and standard radiography for detecting or excluding an osteochondral lesion. Also, MRI and diagnostic arthroscopy performed better than a mortise view with a 4 cm heel-rise. We did not find a statistically significant difference between helical CT and MRI. Diagnostic arthroscopy did not perform better than helical CT and MRI for detecting or excluding an osteochondral lesion.

We produced large full-thickness articular cartilage defects in 33 rabbits in order to evaluate the effect of joint distraction and autologous culture-expanded bone-marrow-derived mesenchymal cell transplantation (ACBMT) at 12 weeks. After fixing the knee on a hinged external fixator, we resected the entire surface of the tibial plateau. We studied three groups: 1) with and without joint distraction; 2) with joint distraction and collagen gel, and 3) with joint distraction and ACBMT and collagen gel.

The histological scores were significantly higher in the groups with ACBMT collagen gel (p < 0.05). The area of regenerated soft tissue was smaller in the group allowed to bear weight (p < 0.05). These findings suggest that the repair of large defects of cartilage can be enhanced by joint distraction, collagen gel and ACBMT.

We studied 60 patients with an acute displaced fracture of the femoral neck and with a mean age of 84 years. They were randomly allocated to treatment by either internal fixation with cannulated screws or hemiarthroplasty using an uncemented Austin Moore prosthesis. All patients had severe cognitive impairment, but all were able to walk independently before the fracture. They were reviewed at four, 12 and 24 months after surgery. Outcome assessments included complications, revision surgery, the status of activities of daily living (ADL), hip function according to the Charnley score and the health-related quality of life (HRQOL) according to the Euroqol (EQ-5D) (proxy report).

General complications and the rate of mortality at two years (42%) did not differ between the groups. The rate of hip complications was 30% in the internal fixation group and 23% in the hemiarthroplasty group; this was not significant. There was a trend towards an increased number of re-operated patients in the internal fixation group compared with the hemiarthroplasty group, 33% and 13%, respectively (p = 0.067), but the total number of surgical procedures which were required did not differ between the groups. Of the survivors at two years, 54% were totally dependent in ADL functions and 60% were bedridden or wheelchair-bound regardless of the surgical procedure. There was a trend towards decreased mobility in the hemiarthroplasty group (p = 0.066). All patients had a very low HRQOL even before the fracture. The EQ-5D_index score was significantly worse in the hemiarthroplasty group compared with the internal fixation group at the final follow-up (p < 0.001).

In our opinion, there is little to recommend hemiarthroplasty with an uncemented Austin Moore prosthesis compared with internal fixation, in patients with severe cognitive dysfunction.