1. A method is described for measuring blood flow to the head of the femur after fracture of the femoral neck, by estimation of the rate of uptake of radioactive phosphorus. 2. Of one hundred cases investigated the readings in fifteen were incomplete, and in seventeen were unreliable. Reasons are given for discarding the latter seventeen cases. After two years seven patients had died, leaving sixty-one available for analysis. 3. The results in sixty-one surviving patients with a follow-up of not less than two years are analysed. In twenty of these radioactivity was measured by bone sampling and in forty-one by direct readings with a needle counter. 4. The twenty-one intertrochanteric fractures studied were used as controls. In these the P. 32. ratio varied from 0·4 to 3·0. Union occurred in all patients and none developed avascular necrosis. 5. Of the forty patients with displaced fractures of the femoral neck twenty-eight showed a low P. 32. ratio. In twenty-three of these (82 per cent) the fracture united. 6. Twelve patients with fractures of the femoral neck showed a borderline or abnormal P. 32. ratio. In ten of these there was subsequent avascular necrosis or non-union. 7. The possible reasons for the discrepancy between expected and actual results are discussed. 8. Almost 40 per cent of the cases investigated had to be abandoned because of technical faults and in one-fifth of the remaining cases the expected results failed to agree with the clinical results. The method of investigation is therefore not of much practical value at the present time. Improvements in apparatus and technique might make the method more reliable and more useful

Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques.

The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

Extracorporeal shock-wave (ESW) treatment hasbeen shown to be effective in promoting the healing of fractures. We aimed to determine whether ESW could enhance the growth of bone-marrow osteoprogenitor cells. We applied ESW to the left femur of rats 10 mm above the knee at 0.16 mJ/mm. 2. in a range of between 250 and 2000 impulses. Bone-marrow cells were harvested after ESW for one day and subjected to assessment of colony-forming unit (CFU) granulocytes, monocytes, erythocytes, megakaryocytes (CFU-Mix), CFU-stromal cells (CFU-S) and CFU-osteoprogenitors (CFU-O). We found that the mean value for the CFU-O colonies after treatment with 500 impulses of ESW was 168.2 CFU-O/well (. sem. 11.3) compared with 88.2 CFU-O/well (. sem. 7.2) in the control group. By contrast, ESW treatment did not affect haematopoiesis as shown by the CFU-Mix (p = 0.557). Treatment with 250 and 500 impulses promoted CFU-O, but not CFU-Mix formations whereas treatment with more than 750 impulses had an inhibiting effect. Treatment with 500 impulses also enhanced the activity of bone alkaline phosphatase in the subculture of CFU-O (p< 0.01), indicating a selective promotion of growth of osteoprogenitor cells. Similarly, formation of bone nodules in the long-term culture of bone-marrow osteoprogenitor cells was also significantly enhanced by ESW treatment with 500 impulses. The mean production of TGF-β1 was 610 pg/ml (. sem. 84.6) in culture supernatants from ESW-treated rats compared with 283 pg/ml (. sem. 36.8) in the control group. Our findings suggest that optimal treatment with ESW could enhance rat bone-marrow stromal growth and differentiation towards osteoprogenitors presumably by induction of TGF-β1

We describe the development and early clinical application of a ported, proximally-cemented titanium stem for cemented total hip arthroplasty. PMMA bone cement is delivered to the proximal femur under pressure after the stem has been positioned within the femoral canal. A mid-stem cement occluder contains the cement to the proximal stem only. A tapered body is incorporated in the design of the stem to reduce the structural stiffness and hence the degree of stress shielding within the reconstructed joint. We performed preclinical studies to measure the reduction in porosity and the pressurisation achieved. The porosity, as measured by the void percentage within the cured cement mantle, was reduced by more than 50% and there was an almost threefold increase in the mean pressure. Mechanical testing of the stem, using a three-point bend test, showed that the addition of cement injection ports on the anterior and posterior sides of the body of the proximal stem did not reduce its strength. Finite-element analysis indicated that, compared with a fully-cemented conventional stem, there was no change in the stresses within the cement mantle. In a series of 40 proximally-cemented stems followed for up to six years (mean 51 months) the mean Harris hip score was 91, and 85% of patients had good or excellent results. There was excellent pain relief, an increased level of activity and good patient satisfaction. One mechanical failure of the stem required revision at three years after implantation. The early results indicate that the clinical performance was equal to that achieved with other modern cemented stems. Radiological evaluation showed excellent results with no evidence of stress shielding. Further follow-up will determine if long-term stress shielding is reduced and if revision is made easier by the absence of a distal cement mantle

Aims

The purpose of this retrospective study was to differentiate between the MRI features of normal post-operative change and those of residual or recurrent disease after intralesional treatment of an atypical cartilage tumour (ACT)/grade I chondrosarcoma.

Objectives

Osteoporosis is a chronic disease. The aim of this study was to identify key genes in osteoporosis.

We have reviewed, retrospectively, all children with a lower limb deformity who underwent an acute correction and lengthening with a monolateral fixator between 1987 and 1996. The patients were all under the age of 19 years and had a minimum follow-up of eight months after removal of the fixator. A total of 41 children had 57 corrections and lengthening. Their mean age was 11.3 years (3.2 to 18.7) and there were 23 girls and 18 boys. The mean maximum correction in any one plane was 23° (7 to 45). In 41 bony segments (either femur or tibia) a uniplanar correction was made while various combinations were carried out in 16. The site of the osteotomy was predominantly diaphyseal, at a mean of 47% (17% to 73%) of the total bone length and the mean length gained was 6.4 cm (1.0 to 17.0). Univariate analysis identified a moderately strong relationship between the bone healing index (BHI), length gained, maximum correction and grade-II to grade-III complications. For logistic regression analysis the patients were binary coded into two groups; those with a good outcome (BHI ≤ 45 days/cm) and those with a poor outcome (BHI > 45 days/cm). Various factors which may influence the outcome were then analysed by calculating odds ratios with 95% confidence intervals. This analysis suggested a dose response between increasing angular correction and poor BHI which only reached statistical significance for corrections of larger magnitude. Longer lengthenings were associated with a better BHI while age and the actual bone lengthened had little effect. Those patients with a maximum angulatory correction of less than 30° in any one plane had an acceptable consolidation time with few major complications. The technique is suitable for femoral deformity and shortening, but should be used with care in the tibia since the risk of a compartment syndrome or neurapraxia is much greater

Aims

The aim of this study was to compare the post-operative radiographic and clinical outcomes between kinematically and mechanically aligned total knee arthroplasties (TKAs).

Objectives

Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments.

Objectives

The injured anterior cruciate ligament (ACL) is thought to exhibit an impaired healing response, and attempts at surgical repair have not been successful. Connective tissue growth factor (CTGF) is reported to be associated with wound healing, probably through transforming growth factor beta 1 (TGF-β1).

Aims

We report on the outcome of the Synergy cementless femoral stem with a minimum follow-up of 15 years (15 to 17).

Objectives

Malalignment of the tibial component could influence the long-term survival of a total knee arthroplasty (TKA). The object of this study was to investigate the biomechanical effect of varus and valgus malalignment on the tibial component under stance-phase gait cycle loading conditions.

1. The effect of implanting heterogenous anorganic bone, homogenous organic bone, autogenous compact bone from the iliac crest, and autogenous bony callus into circumscribed defects in the femur of albino rats of the Wistar strain is described. 2. Neither heterogenous anorganic bone nor homogenous organic bone appeared to induce new bone formation in a healing defect. 3. Some of the osteogenic cells of autogenous callus implants survived transplantation to a bone defect and gave rise to new bone formation. This did not occur when compact bone from autogenous iliac crest was implanted. 4. Implants of autogenous callus, autogenous compact bone, homogenous organic bone and heterogenous anorganic bone all impeded the normal development of host bone trabeculae in a healing bone defect, seemingly because they acted as physical barriers to the proliferating host callus. None of the implant materials appeared to suppress the healing reaction ofthe host. 5. Implanted homogenous organic bone was removed and replaced by host bone more quickly than was implanted heterogenous anorganic bone, and it appears to be the better material for grafting into bone defects. 6. Autogenous callus or autogenous cancellous bone is a superior implant material to autogenous compact bone and is the bone graft material of choice. 7. The absorption of all the implant materials used in this investigation was associated with the presence of multinucleated giant cells. 8. The activity of multinucleated giant cells may be influenced by the organic matrix of the material which is to be absorbed. 9. Except when fresh autogenous callus was implanted into the defects, the rate of healing in the grafted defects was slower than that in the control defects. In the defects grafted with fresh autogenous callus the healing rates of the control and grafted defects were the same

Aims

To assess the long-term effect of distal trochanteric transfer (DTT) on the clinical and radiographic outcomes of patients with Legg-Calvé-Perthes’ disease (LCPD) following a varus derotational osteotomy (VDRO).

Objectives

To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone.

Aims

Our aim was to examine the clinical and radiographic outcomes in 257 consecutive Oxford unicompartmental knee arthroplasties (OUKAs) (238 patients), five years post-operatively.

The successful management of femoral neck fractures is obviously based upon many factors. The forces acting upon the proximal end of the femur are believed to be mainly compressive in nature, and the low-angle nail by stabilising the fully reduced fracture in the line of these forces is held to allow weight bearing to take place. Low-angle nailing is believed to offer many advantages over conventional methods of treatment but only in the presence of stability. Stable reduction is the essential preliminary to any form of treatment, and low-angle fixation with early weight bearing in the absence of stability is regarded as futile. It is suggested that those subcapital separations which follow trivial injury may originate as stress fractures accompanying the process of bone remodelling in the aged, and that many of these fractures may remain unrecognised and heal spontaneously. With rare exceptions, subcapital fractures are regarded as being of the same essential pattern, and their varying radiological appearance is considered to be due to the different degrees of displacement to which they have been subjected. A new classification based on this premise has been suggested. In a series of eighty subcapital fractures the incidence of avascular necrosis was not adversely affected by early weight bearing, but reduction in the extreme valgus position was invariably followed by this disaster. This is probably also true of any malposition in extreme rotation which must stretch and obliterate the vessels in the ligamentum teres. A rough alignment index of reduction was found to provide an almost infallible guide to the prognosis both in regard to union and to avascular change. It may therefore be possible to base prognosis on the quality of reduction before the fixation appliance has been inserted. The unsatisfactory results in those cases apparently destined to non-union or avascular necrosis may then be avoided by alternative means of treatment at an early stage. Whether this will prove to be true must depend upon a much longer experience of low-angle fixation, and, in common with almost every communication on this subject, premature publication must largely offset the value of the present findings

Aims

To present our experience of using a combination of intra-articular osteotomy and external fixation to treat different deformities of the knee.

Aims

Femoral impaction bone grafting was first developed in 1987 using morselised cancellous bone graft impacted into the femoral canal in combination with a cemented, tapered, polished stem. We describe the evolution of this technique and instrumentation since that time.