1. Isografts of articular cartilage of young rats, with mucoproteins labelled with . 35. S, extracellular fibrous proteins labelled with . 3. H-glycine, and nuclei labelled with . 3. H-thymidine, were transplanted into the anterior chamber of the eye. 2. Thin split-thickness transplants of the cells of the gliding surface of immature articular cartilage induced the formation of fibrous tissue. 3. Thick transplants and subsurface slices of immature articular cartilage, containing germinal cells of the epiphysial cartilage, induced the formation of new bone consistently within 4 weeks. 4. Full-thickness transplants in articular cartilage from senile rats induced only the formation of fibrous tissue. 5. Slices of growing cartilage, devitalised by cryolysis, or extraction of acid-soluble proteins, produced scanty deposits of bone or cartilage, or both, but only infrequently and generally after a lag phase extending from six to twelve weeks. 6. Reduction in the amount of mucoprotein in the cartilage matrix by papain, and suppression of the resynthesis of tissue proteins by cortisone, retarded but did not prevent bone induction. 7. Bone induction is the product of a series of interactions between inducing cells and responding cells by intracellular and intercellular reactions too complex to characterise in physico-chemical terms at this time

1. A simple method of internal fixation of adult forearm fractures which gives consistent good results is necessary because the closed method of treatment is of limited application. 2. Open reduction of fractures without rigid internal fixation gives a high proportion of non-union and poor results. 3. Rigid internal fixation with standard plates and screws has been shown to give a low incidence of non-union in this series. 4. A three and a half inch long plate with six screws is suitable for most fractures, but if there is moderate or severe comminution, or if there is a segmental fracture, longer plates and more screws should be used to provide sound fixation. 5. Severely comminuted fractures with large avascular bone fragments should have the addition of a bone graft at the time of the plating operation in order that union may be assured. Thin strips of iliac bone are preferred. 6. Rigid plating is considered to be the most satisfactory treatment for open fractures. 7. Immobilisation of the limb after operation is not necessary and is undesirable if the fixation is rigid. 8. The functional results of this treatment are good and seemingly better than those achieved by other methods. 9. Serious complications of the plating operation are few and avoidable

1. The radiological features of skeletal hydatid disease are discussed. Osseous lesions occur in about 1 to 2 per cent of cases, bone being involved only after the embryos have passed the filters provided firstly by the liver and secondly by the lungs. At first, ill defined areas of translucency appear which are not diagnostic. In developed lesions, clear-cut destructive areas, with a surrounding sclerotic reaction, become visible. The cysts thin and expand the cortex and tend to spread throughout an affected bone. In advanced stages the cortex is ruptured, and exuberant hydatid cyst growth takes place in the adjacent soft tissue. Around this an ectocyst forms, which may later calcify, indicating death of the parasite. The progress of the disease is very slow. 2. Three cases of affection of the thoracic spine are described, and the differential diagnosis is considered, particularly from plasmacytoma and neurofibroma. Each case presented with cord pressure symptoms. Operative decompression relieved these totally in one case, incompletely in another, and not at all in the third and most advanced case. 3. With rapid and easy travel in the modern world hydatid disease is liable to be seen in areas where it is not endemic

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) died from unrelated causes. Four hips had revision surgery for either deep infection, unexplained persistent pain, fracture of the alumina head, or aseptic loosening of the socket. The nine-year survival rate was 93.7% with revision for any cause as the end-point and 98.4% with revision for aseptic loosening as the end-point. The outcome in the surviving patients (50 patients, 57 hips) with a minimum five-year follow-up (mean eight years) was excellent in 47 hips (82.5%), very good in eight (14%), good in one and fair in one. A thin, partial, lucent line, mainly in zone III was present in 38% of the sockets and one socket had a complete lucency less than 1 mm thick. One stem had isolated femoral osteolysis. There was no detectable component migration nor acetabular osteolysis. This hybrid arthroplasty gave satisfactory medium-term results in active patients. The press-fit metal-backed socket appeared to have reliable fixation in alumina-on-alumina hip arthroplasty. The excellent results using cemented fixation of the stem may be related to the low production of wear debris

Aims

The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach.

Many authors have recommended undercorrection of the deformity when carrying out unicompartmental knee arthroplasty (UKA). The isolated effect of alignment of the knee on the outcome of UKA has, however, received little attention. We reviewed 185 UKAs at a minimum of five years after surgery. They had been carried out by a single surgeon using metal-backed tibial components in the management of arthritis of the medial compartment. We measured the tibiofemoral angle (TFA) before and at four months after operation and at the most recent assessment. The amount of correction of the TFA and any subsequent loss were recorded. While adjusting for the effects of age, weight and gender of the patients and the type and thickness of the implants, the mean correction was significantly less for those with a Marmor rating of failure (6.8°) than for those rated excellent (9.2°). The mean correction was also significantly less for patients with a Marmor rating of failure (6.8°) than for those rated poor (11.1°). The mean correction for the UKAs which were revised (6.6°) was significantly less than for those not revised (9.1°). Additionally, revised UKAs had a significantly higher percentage (63%) of thinner tibial implants (< 8 mm) than the surviving UKAs (27%). These findings suggest that undercorrection of the TFA in UKA of the medial compartment should be avoided, particularly if a thin tibial polyethylene insert is used

We studied 16 femora retrieved at post-mortem from symptomless patients who had a satisfactory cemented total hip arthroplasty from two weeks to 17 years earlier, with the aim of delineating the initial mechanisms involved in loosening. Only one specimen showed radiographic evidence of loosening; the other 15 were stable to mechanical testing at 17.0 Nm of torque. In all 16 specimens, the cement-bone interface was intact with little fibrous tissue formation. By contrast, separation at the cement-prosthesis interface and fractures in the cement mantle were frequent. The most common early feature was debonding of the cement from the metal, seen at the proximal and distal ends of the prosthesis. Specimens which had been in place for longer also showed circumferential fractures in the cement, near the cement-metal interface, and radial fractures extending from this interface into the cement and sometimes to the bony interface. The most extensive cement fractures appeared to have started at or near sharp corners in the metal, or where the cement mantle was thin or incomplete. Fractures were also related to voids in the cement. The time relationship in this series suggested that long-term failure of the fixation of cemented femoral components was primarily mechanical, starting with debonding at the interface between the cement and the prosthesis, and continuing as slowly developing fractures in the cement mantle

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

We reviewed the radiological and clinical long-term results after the nailing in situ of slipped upper femoral epiphysis in 59 hips in 43 patients. The displacement of the epiphysis had been measured as the ‘slipping angle’ before operation and related to the results at follow-up at a mean of 30.9 years (27 to 34). The mean age at follow-up was 44.2 years (39 to 50). Radiographic re-examination of 41 hips with slipping angles of ≤30° at the time of operation showed that eight (20%) had developed mild osteoarthritis and one had severe changes. For 18 hips with slipping angles ranging from 31 to 50° at surgery six (33%) had mild osteoarthritis and three had severe changes. The differences did not quite achieve statistical significance (p = 0.09). Clinical re-examination of the 41 hips with slipping angles of ≤30° showed fair or poor results (Harris hip score < 90) in three (7%). In the 18 hips with slipping of 31 to 50°, four had fair or poor results (22%) (p= 0.13). We conclude that nailing in situ for slipping of ≤30°, using one thin nail, can give excellent long-term results. At present we recommend that hips with slips ranging from 31 to 50° should also be nailed in situ, but further long-term studies are required, especially on the choice between nailing in situ and corrective osteotomy for slips in excess of 50°

Aims

Complex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips.

1. A study is reported of 190 femora in 174 patients in whom self-curing acrylic cement had been present in the medullary cavity of the upper end of the femur for the fixation of an endoprosthesis for an average period of four years. 2. The bone remained radiologically normal in 81 per cent of cases. 3. Improvement in the thickness of the cortex from pre-existing atrophy was noted in 2·6 per cent. 4. In 4·7 per cent the bone showed some atrophy after insertion of the cement. This exceeded 10 per cent in only two cases. All were originally osteoporotic from polyarthritis; all were satisfactory as regards the arthroplasty itself, and the atrophy could usually be explained by disuse resulting from the state of the opposite lower extremity, or the knee on the same side. 5. In 9·4 per cent there was fusiform hypertrophy of the femoral cortex, the bony texture remaining normal. This appearance was considered physiological and benign. 6. In 2·2 per cent there were changes for which the most likely explanation is chronic non-suppurative osteitis, though no collateral evidence of infection was found. 7. In 44·8 per cent there was a thin line of condensation in the cancellous bone demarcating the outer limits of the cement. This is considered to be physiological and not to indicate failure of immobilisation. 8. In 37·2 per cent there was slight resorption of the cut surface of the calcar femorale. This is considered to be physiological and to confirm the efficacy of weight transmission by cement lower down in the medullary cavity

1. With the object of perfecting the design of footwear for feet anaesthetic from leprosy, pressures on the soles of feet during walking were measured with transducers sufficiently thin to be worn inside ordinary shoes. 2. It was found that anaesthetic feet without deformity or muscle imbalance did not produce significantly higher pressures than normal feet during barefoot walking on a flat surface. The pressure distribution under drop feet with active posterior tibial muscles differed from normal, with increased pressure under the lateral forefoot and decreased pressures elsewhere. 3. Loss of toes or function of the toes results in high, sharp pressure peaks under the anterior end of the foot during push-off. In deformed feet these pressures are usually concentrated at one or two small areas. 4. In anaesthetic feet the prevention of trophic ulceration largely depends on the even distribution of pressure over the sole of the foot. 5. Moulding by carefully placed arch supports or metatarsal bars effectively redistributes plantar pressure. 6. A shoe with a rigid sole pivoting on a rocker near the centre of the foot most effectively reduces pressures under the forefoot of shortened, deformed feet. 7. We recommend the use of insoles made of microcellular rubber (approximately 1 5 degrees shore). 8. The importance of studying each deformed foot for areas of high pressure before fitting shoes is stressed; a pressure-indicating footprint is satisfactory for this purpose

Aims

The efficacy and safety of intrawound vancomycin for preventing surgical site infection in primary hip and knee arthroplasty is uncertain.

Aims

The aticularis genu (AG) is the least substantial and deepest muscle of the anterior compartment of the thigh and of uncertain significance. The aim of the study was to describe the anatomy of AG in cadaveric specimens, to characterize the relevance of AG in pathological distal femur specimens, and to correlate the anatomy and pathology with preoperative magnetic resonance imaging (MRI) of AG.

The pathogenesis of aseptic loosening of total joint prostheses is not clearly understood. Two features are associated with loosened prostheses, namely, particulate debris and movement of the implant. While numerous studies have evaluated the cellular response to particulate biomaterials, few have investigated the influence of movement of the implant on the biological response to particles. Our aim was therefore to test the hypothesis that excessive mechanical stimulation of the periprosthetic tissues induces an inflammatory response and that the addition of particulate biomaterials intensifies this. We allocated 66 adult Beagle dogs to four groups as follows: stable implants with (I) and without (II) particulate polymethylmethacrylate (PMMA) and moving implants with (III) and without (IV) particulate PMMA. They were then evaluated at 2, 4, 6, 12 and 24 weeks. The stable implants were well tolerated and a thin, fibrous membrane of connective tissue was observed. There was evidence of positive staining in some cells for interleukin-6 (IL-6). Addition of particulate PMMA around the stable implants resulted in an increase in the fibroblastic response and positive staining for IL-6 and tumour necrosis factor-alpha (TNF-α). By contrast, movement of the implant resulted in an immediate inflammatory response characterised by large numbers of histiocytes and cytokine staining for IL-1ß, TNF-α and IL-6. Introduction of particulate PMMA aggravated this response. Animals with particulate PMMA and movement of the implant have an intense inflammatory response associated with accelerated bone loss. Our results indicate that the initiation of the inflammatory response to biomaterial particles was much slower than that to gross mechanical instability. Furthermore, when there was both particulate debris and movement, there was an amplification of the adverse tissue response as evidenced by the presence of osteolysis and increases in the presence of inflammatory cells and their associated cytokines

Aims

The aim of this study was to systematically compare the safety and accuracy of robot-assisted (RA) technique with conventional freehand with/without fluoroscopy-assisted (CT) pedicle screw insertion for spine disease.

Aims

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.