We have reviewed 20 cases of parosteal osteosarcoma treated by wide local resection and prosthetic replacement and followed up for six to 17 years. Limb function was excellent in 85%. One patient with grade III histological disease developed pulmonary metastases. Four patients had local recurrences, which were related to repeated preliminary biopsies, inappropriate siting of biopsy and vascular encroachment by the tumour. After this mode of treatment, the outcome was not related to medullary invasion by the tumour.

We have reviewed 25 cases of focal femoral osteolysis in radiographically stable, cemented femoral implants. In three hips retrieved at post-mortem from two patients, we have been able to make a detailed biomechanical and histological analysis. The interval between arthroplasty and the appearance of focal osteolysis on clinical radiographs ranged from 40 to 168 months, and in over 70% of the cases this did not appear until after five or more years. Few had significant pain and there was no relation to age, sex or original diagnosis. The most common site for osteolysis were Gruen zones 2 and 3 on the anteroposterior radiograph and zones 5 and 6 on the lateral radiograph. In 15 cases (60%), the area of osteolysis corresponded to either a defect in the cement mantle or an area of very thin cement. The rate of progression of these lesions was variable, but to date only one has progressed to gross loosening of the femoral component. The back-scatter scanning electron microscopic examination of serial sections and biomechanical testing of the post-mortem specimens demonstrated focal cement fracture around implants that were otherwise rigidly fixed. In eight cases from which tissue was available, histology showed a histiocytic reaction with evidence of particulate polymethylmethacrylate. We consider that this local fragmentation was the stimulus for local osteolysis in an otherwise stable cemented femoral component.

Four cases are described of localised endosteal bone lysis in the femur occurring in association with cemented femoral components that were not obviously 'loose' radiologically. In each, the area of lysis was shown at operation to be related directly to a region in which there was a local defect in the cement mantle surrounding the stem. Via the space between the stem and cement, such defects provide a route through which the contents of the joint cavity may reach the endosteal surface of the femur, subsequently leading to localised bone lysis, and later to frank loosening.

We describe six patients with aggressive granulomatous lesions around cementless total hip prostheses. Two patients previously had a cemented prosthesis in the same hip. The Lord prosthesis was used in five patients, the PCA in one. Both prostheses were made of chrome-cobalt alloy. Pain on weight-bearing occurred on average 3.2 years after the cementless arthroplasty, and at that time radiography revealed aggressive granulomatosis around the proximal femoral stem and the acetabular component in five of the patients; one had a large solitary granuloma in the proximal femur. Revision was performed on average 4.8 years after the cementless arthroplasty. At that time all granulomas had grown large in size; while waiting for revision operation, two femoral stem components fractured. All the granulomas showed a uniform histopathology, which included histiocytosis; the cause for these lesions was thought to be plastic debris from the acetabular socket.

We assessed wound, air and operative field contamination at 50 total hip operations, performed in a zonal ventilation system. Theatre staff wore either a specially designed polypropylene non-woven coverall or conventional cotton shirt and trousers. The surgeons wore partially impermeable operating gowns. The polypropylene coverall was associated with significantly lower air and wound counts. The coverall was warmer than cotton but judged to be acceptable. The combined use of zonal ventilation and the coverall achieved ultra-clean air conditions.

We investigated in vitro a mechanism by which particulate debris may induce bone resorption and cause implant loosening. We first studied two standard particles: latex, which is considered to be inert, and zymosan, which is inflammatory. Macrophages that phagocytosed either particle became activated, and stimulated 15 times as much bone resorption as did control macrophages. For activation to occur, 100 times more latex than zymosan had to be phagocytosed. We also found that bone cement and polyethylene particles activated macrophages in a similar manner, and that the necessary amounts of these were intermediate between those of latex and zymosan. None of the particles were toxic. It was concluded that implant loosening may result from bone resorption stimulated by mediators released by macrophages that have phagocytosed particles of bone cement or polyethylene.

There is no firm published evidence to support the use of closed suction drains. Over 20 years ago, large studies by the Public Health Laboratory Service and the National Research Council found that drains were risk factors for wound infection. A prospective randomised study of the use of closed suction drains after surgery for fractured neck of femur in 70 patients failed to show that drains improved wound healing. Drained cases had more complications.

We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years). Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular cup. The cup orientation and containment were interrelated; all vertically oriented cups were completely contained, whereas 25% of more horizontal cups were only partially contained. Completely contained cups had significantly lower incidences of complete cement-bone radiolucency (p = 0.02) and of wear (p = 0.09). Vertically oriented cups had a lower incidence of continuous radiolucency than neutrally oriented cups, but this was not statistically significant (p = 0.25). Our results confirm the importance of complete bony containment, and also indicate that it is better to accept vertical orientation and obtain full bony coverage than to have a more horizontal orientation with partial containment.

Twenty-five patients with 30 chondral lesions of the knee were treated with an autogenous strip of costal perichondrium. The graft was fixed to the subchondral bone with Tissucol (Immuno, Vienna), a human fibrin glue. The leg was then immobilised for two weeks followed by two weeks of continuous passive motion. Weight-bearing was permitted after three months. The mean knee score (Ranawat, Insall and Shine 1976) changed from 73 before operation to 90 one year after; in 14 patients evaluated after two years there was no decrease. In 28 cases the defect was completely filled with tissue resembling articular cartilage. We conclude that in most cases perichondral arthroplasty of cartilage defects of the knee gives excellent results.

One hundred hips in patients who had had primary uncemented replacements were followed up for one or two years, and assessed by five different methods. All produced different results. The Hospital for Special Surgery rating produced the most optimistic assessment and the Merle d'Aubigne rating the most pessimistic. The functional class of the patients, as defined by Charnley in 1979, significantly affected the ratings, and these should clearly be included in all rating systems. Moreover, if systems are to be compared, they should all use descriptive words, such as limp or pain, in precisely the same way.

We have reviewed 368 osteotomies carried out for osteoarthritis of the hip at the Nuffield Orthopaedic Centre. Survivorship analysis showed that 10 years after osteotomy 47% had required no further surgery, and even after 20 years 23% had still not had a hip replacement. Hips with moderate arthritic change showed significantly better results than those with more severe degeneration. Osteotomies with varus angulation as well as medial displacement showed longer survival.

We report the 12 to 74 month results of our mark I saddle prosthesis after its use as a salvage device for gross loss of pelvic bone stock in 76 patients with failed hip arthroplasties. The implant transmits load between iliac bone and bare polish chrome-cobalt. Our clinical and radiological results indicate that a useful and stable articulation can be achieved in most cases, provided that continued deep infection can be avoided. The appearance of radiological sclerosis at the bearing site in successful cases seems to indicate that significant late migration will not occur. Based on our experience with the mark I prosthesis we have designed and developed a mark II model which has freedom of axial rotation of the saddle. Our early results in 40 cases show a significant improvement over the results which could have been predicted for the mark I device.

The intra-osseous pressure, PO2, and PCO2 were measured in 32 hips (21 patients) which were painful but showed no severe degenerative changes. Pre-operative scintigraphy and radiography was performed in all patients. Thirteen hips showed early osteoarthritis, eight had early osteonecrosis, and 11 had no changes. Core biopsies were performed and the bone was examined histologically and graded for necrosis. Histologically, necrosis was present in 27 specimens. Scintigraphic findings did not correlate with the histological results but were more closely related to the radiographic findings. The intra-osseous pressure in hips with histological necrosis (mean 47 mmHg) was significantly higher than in hips without necrosis (mean 26 mmHg). The PO2 was lower in bone with histological necrosis (mean 44 mmHg) than in bone without (mean 71 mmHg). PO2 increased and intra-osseous pressure decreased after decompression. The results confirm that ischaemia plays a central role in the development of necrotic changes in bone. Histological necrosis was found in hips with radiographic signs of osteonecrosis and in those with osteoarthritis. Radiography, and scintigraphy are shown to be insensitive methods for differentiating between those disorders.

We studied the healing and torsional strength of non-vascularised (28) and vascularised (28) sections of tibial diaphyses in 56 cats. Both types of graft achieved fracture union in the same period of time, and at 12 and 16 weeks the non-vascularised grafts were as strong as the vascularised grafts.

Sterilisation of demineralised bone matrix with ethylene oxide has been claimed to destroy the ability of bone matrix to induce new bone formation on intramuscular implantation. Other workers have routinely used ethylene oxide sterilised bone matrix for assays in rodents without detrimental effects. We studied the effects of various lengths of exposure to ethylene oxide gas, and found that bone induction properties are destroyed in a dose-dependent manner. After a short exposure, bone induction properties were moderately diminished. However, this short ethylene oxide treatment did not kill Bacillus subtilis spores. A sterilisation procedure that killed these spores rendered the implants incapable of bone-induction.

We have assessed the biomechanical properties of a 'double-bundle' prosthetic ligament replacing the anterior cruciate in cadaver knees. We compared the results with those of single bundle 'over-the-top' and 'through-the-condyle' techniques, performing anterior drawer tests at 20 degrees and 90 degrees knee flexion. The over-the-top reconstruction gave better anteroposterior stability at 20 degrees, while the through-the-condyle repair was more stable at 90 degrees. The double-bundle reconstruction gave practically normal anterior stability at both 20 degrees and 90 degrees.

In order to determine whether an allogeneic tendon could be used to replace an extra-articular ligament, the right medial collateral ligament from 11 adult dogs was replaced with a fresh-frozen allogeneic patellar tendon. At each of 3, 6, 15, 30 and 52 weeks postoperatively, one dog was killed for micro-angiographical and histological studies; at 52 weeks the remaining six dogs were killed for tensile testing. Micro-angiograms showed that the allogeneic tendon was revascularised with infiltration of the mesenchymal cells from the surrounding tissues and both ends of the graft. Histologically, the alignment of the fibroblasts and collagen bundles became more regular over time, without any immunological rejection. A biomechanical study performed at 52 weeks found no significant difference in stiffness or ultimate load between normal and reconstructed ligaments. Fresh-frozen allogeneic tendons are therefore considered useful for extra-articular ligament reconstruction.

Open reduction and internal fixation was employed in the treatment of 25 severely displaced fractures and fracture-dislocations of the proximal humerus. Our aims were accurate reduction and stable fixation to allow early mobilisation and to achieve full functional recovery. In 15 fractures an AO T-plate was used and in 10 a bent semitubular plate was employed as a blade plate. Excellent or satisfactory results were obtained in all six patients with two-part fractures involving the surgical neck; in four of the five patients with three-part fractures involving the surgical neck and tuberosities; in nine of the 11 patients with fracture-dislocation; and in two of the three patients with split fractures of the humeral head. Overall results were good or satisfactory in 21 of the 25 cases. Unsatisfactory results were associated with rotator cuff damage.

Serum 1.25 dihydroxyvitamin D concentrations were reduced in elderly patients with femoral neck fractures, irrespective of the presence of osteomalacia. This reduction was not attributable to a decrease in vitamin D binding protein. The low rate of bone turnover in these elderly patients might reduce the requirement for vitamin D and protect against the development of osteomalacia. Serum vitamin D metabolite concentration cannot be used as a screening test for osteomalacia in these patients.

From 1962 to 1986, 117,256 neonates were screened for congenital dislocation of the hip (CDH). When the primary physical examination was performed by the junior paediatric staff there was a persistent late diagnosis rate of 0.5 per 1000 live births. When the primary examination was undertaken by experienced orthopaedic personnel (1982 to 1984) the late diagnosis rate fell and fewer infants were splinted.

We have determined the natural history of hip development in 42 patients with multiple epiphyseal dysplasia (MED). Premature osteoarthritis was a frequent outcome and was almost inevitable before the age of 30 years in those with incongruent hips. There were two types of immature hips: type I, the more severe form, had a fragmented and flattened ossific nucleus and acetabular dysplasia, was misshapen at skeletal maturity and osteoarthritic by 30 years of age; the milder type II hip had a small, rounded, uniformly ossified nucleus and a more normal acetabulum. Type II hips were well formed at maturity and were less prone to premature osteoarthritis. Considerable variations were noted in the manifestations of MED between families but not within families. The prognosis of a child's hip could be predicted; in sporadic cases from the type of immature hip, and in familial cases by also taking into account the outcome of affected relatives.

Above-knee amputation has been the traditional treatment for osteosarcoma of the proximal tibia. Recent advances in chemotherapy have encouraged the development of limb-salvage techniques. Van Nes rotationplasty for malignant lesions of the distal femur has increased in popularity as a reconstructive technique, but no similar procedure has been described for lesions of the proximal tibia. We have developed a modified rotationplasty for this lesion and have performed it in four children. The surgical technique, postoperative management and results of the procedure are described. Two patients had delayed wound healing. No other complications have developed and our patients were disease-free at follow-up, while the appearance of the leg was well accepted by the patients and their parents. This procedure is a useful addition to the armamentarium of the tumour surgeon for the treatment of malignant lesions of the proximal tibia.

We evaluated 67 shoulders in 65 patients who had pain and dysfunction for more than two years after an initial acromioplasty for impingement syndrome without a rotator cuff tear. In addition to a thorough history, physical examination, local anaesthesia injection and any other necessary investigations all patients had arthroscopic evaluation of the shoulder. In 27 shoulders there had been diagnostic errors, and in 28 operative errors; only in 12 had the diagnosis and the operative procedure both been correct. Subsequent operative intervention in patients not receiving worker's compensation benefit had a 75% success rate, whereas in those receiving such benefits the success rate was only 46%.

Five patients with Boyd type II congenital pseudarthrosis of the tibia underwent excision of the pseudarthrosis and double onlay bone grafting. Stability was maintained by extending intramedullary rods. Clinical union was achieved in all cases at a mean of 8.6 months (range six to 11). The rods extended by 15.7% (range 2% to 31.4%) as growth occurred. One rod was removed because of infection and a vascularised free fibular graft was subsequently performed. The extending rods provided stability while union occurred and did not require revision as the legs grew. The rods can be removed easily and have not jeopardized further surgical options.