It has been suggested that a supramalleolar osteotomy can return the load distribution in the ankle joint to normal. However, due to the lack of biomechanical data, this supposition remains empirical. The purpose of this biomechanical study was to determine the effect of simulated supramalleolar varus and valgus alignment on the tibiotalar joint pressure, in order to investigate its relationship to the development of osteoarthritis. We also wished to establish the rationale behind corrective osteotomy of the distal tibia.

We studied 17 cadaveric lower legs and quantified the changes in pressure and force transfer across the tibiotalar joint for various degrees of varus and valgus deformity in the supramalleolar area. We assumed that a supramalleolar osteotomy which created a varus deformity of the ankle would result in medial overload of the tibiotalar joint. Similarly, we thought that creating a supramalleolar valgus deformity would cause a shift in contact towards the lateral side of the tibiotalar joint. The opposite was observed. The restricting role of the fibula was revealed by carrying out an osteotomy directly above the syndesmosis. In end-stage ankle osteoarthritis with either a valgus or varus deformity, the role of the fibula should be appreciated and its effect addressed where appropriate.

Aseptic loosening of the acetabular component continues to be the most common indication for revision of total hip replacements in younger patients. Early in the evolution of the cemented hip, arthroplasty surgeons switched from removal to retention of the acetabular subchondral bone plate, theorising that unfavourable mechanical forces were the cause of loosening at the bone-cement interface.

It is now known that the cause of aseptic loosening is probably biological rather than mechanical and removing the subchondral bone plate may enhance biological fixation of cement to bone. With this in mind, perhaps it is time to revive removal of the subchondral bone as a standard part of acetabular preparation.

The low contact stress patellofemoral replacement consists of a trochlear component and a modular patellar component which has a metal-backed mobile polyethylene bearing. We present the early results of the use of this prosthesis for established isolated patellofemoral arthritis in 51 consecutive patellofemoral replacements in 35 patients. The mean follow-up was 25 months (5 to 60). The estimated survival rate at three years was 63% (95% confidence interval 47 to 80) with revision as the endpoint and 46% (95% confidence interval 30 to 63) with revision and ongoing moderate or severe pain as the endpoint.

The early results of the use of the low contact stress patellofemoral replacement are disappointing with a high rate of revision. We cannot therefore recommend its use.

A suspected fracture of the scaphoid remains difficult to manage despite advances in knowledge and imaging methods. Immobilisation and restriction of activities in a young and active patient must be balanced against the risks of nonunion associated with an undiagnosed and undertreated fracture of the scaphoid.

The assessment of diagnostic tests for a suspected fracture of the scaphoid must take into account two important factors. First, the prevalence of true fractures among suspected fractures is low, which greatly reduces the probability that a positive test will correspond with a true fracture, as false positives are nearly as common as true positives. This situation is accounted for by Bayesian statistics. Secondly, there is no agreed reference standard for a true fracture, which necessitates the need for an alternative method of calculating diagnostic performance characteristics, based upon a statistical method which identifies clinical factors tending to associate (latent classes) in patients with a high probability of fracture.

The most successful diagnostic test to date is MRI, but in low-prevalence situations the positive predictive value of MRI is only 88%, and new data have documented the potential for false positive scans. The best strategy for improving the diagnosis of true fractures among suspected fractures of the scaphoid may well be to develop a clinical prediction rule incorporating a set of demographic and clinical factors which together increase the pre-test probability of a fracture of the scaphoid, in addition to developing increasingly sophisticated radiological tests.

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21.

The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis.

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 studied the effects of hyperbaric oxygen (HBO) and zoledronic acid (ZA) on posterior lumbar fusion using a validated animal model. A total of 40 New Zealand white rabbits underwent posterior lumbar fusion at L5–6 with autogenous iliac bone grafting. They were divided randomly into four groups as follows: group 1, control; group 2, HBO (2.4 atm for two hours daily); group 3, local ZA (20 μg of ZA mixed with bone graft); and group 4, combined HBO and local ZA. All the animals were killed six weeks after surgery and the fusion segments were subjected to radiological analysis, manual palpation, biomechanical testing and histological examination.

Five rabbits died within two weeks of operation. Thus, 35 rabbits (eight in group 1 and nine in groups 2, 3 and 4) completed the study. The rates of fusion in groups 3 and 4 (p = 0.015) were higher than in group 1 (p < 0.001) in terms of radiological analysis and in group 4 was higher than in group 1 with regard to manual palpation (p = 0.015). We found a statistically significant difference in the biomechanical analysis between groups 1 and 4 (p = 0.024). Histological examination also showed a statistically significant difference between groups 1 and 4 (p = 0.036).

Our results suggest that local ZA combined with HBO may improve the success rate in posterior lumbar spinal fusion.

This retrospective study describes the long-term results of core decompression and placement of a non-vascularised bone graft in the management of avascular necrosis of the femoral head. We treated 80 hips in 65 patients, 18 by a cortical tibial autograft and 62 by a fibular allograft. The mean age of the patients was 36 years (sd 13.2). A total of 78 hips were available for evaluation of which pre-operatively six were Ficat-Arlet stage 0, three stage I, 31 stage IIA, 16 stage IIB, 13 stage III and nine stage IV.

A total of 34 hips (44%) were revised at a mean of four years (sd 3.8). Survivorship analysis using a clinical end-point showed a survival rate of 59% five years after surgery. We found a significant difference (p = 0.002) in survivorship, when using a clinical and radiological end-point, between the two grafts, in favour of the tibial autograft. We considered this difference to be the result of the better quality and increased volume of tibial bone compared with that from the trochanteric region used with the fibular allograft.

This is a relatively simple, extra-articular and reproducible procedure. In our view core decompression, removal of the necrotic tissue and packing of the cancellous grafts into the core track are vital parts of the procedure.

We describe five adolescent patients aged between 13 and 16 years with bipartite ossification of the posteromedial aspect of the talus. All presented without a history of trauma.

All the ankles had a similar radiological appearance. Clinically, some restriction of movement was noted in three ankles and two subtalar joints, In addition, pain was noted over the posteromedial aspect of the ankle in three patients. In each patient the bipartite fragment was excised through a posteromedial approach to the ankle. Complete resolution was achieved at six months in three patients, with the remaining two describing exercise-induced symptoms. In one of these this precluded participation in sport.

Despite numerous anatomical variations within the tarsus, a case series of a bipartite talus has not previously been reported. This anatomical variation should be recognised to avoid misinterpretation as post-traumatic or other pathological processes. In the presence of recalcitrant symptoms excision is an option, but this is not universally successful in abolishing symptoms.

We identified a series of 128 patients who had unilateral open reconstruction of the anterior cruciate ligament (ACL) by a single surgeon between 1993 and 2000. In all, 79 patients were reviewed clinically and radiologically eight to 15 years after surgery. Assessment included measurement of the Lysholm and Tegner scores, the ACL quality-of-life score and the Short Form-12 score, as well as the International Knee Documentation Committee clinical assessment, measurement of laxity by the KT-1000 arthrometer, a single-leg hop test and standardised radiography of both knees using the uninjured knee as a control.

Of the injured knees, 46 (57%) had definite radiological evidence of osteoarthritis (Kellgren-Lawrence grade 2 or 3), with a mean difference between the injured and non-injured knees of 1.2 grades. The median ACL quality-of-life score was 80 (interquartile range (IQR) 60 to 90), the Lysholm score 84 (IQR 74 to 95), the Short Form-12 physical component score 54 (IQR 49 to 56) and the mean Hop Index 0.94 (0.52 to 1.52). In total 58 patients were graded as normal, 20 as nearly normal and one as abnormal on the KT-1000 assessment and pivot-shift testing. Taking the worst-case scenario of assuming all non-attenders (n = 48), two septic failures and one identified unstable knee found at review to be failures, the failure rate was 40%. Only two of the patients reviewed stated that they would not have similar surgery again.

Open reconstruction of the ACL gives good, durable functional results, but with a high rate of radiologically evident osteoarthritis.

Guiding growth by harnessing the ability of growing bone to undergo plastic deformation is one of the oldest orthopaedic principles. Correction of deformity remains a major part of the workload for paediatric orthopaedic surgeons and recently, along with developments in limb reconstruction and computer-directed frame correction, there has been renewed interest in surgical methods of physeal manipulation or ‘guided growth’. Manipulating natural bone growth to correct a deformity is appealing, as it allows gradual correction by non- or minimally invasive methods.

This paper reviews the techniques employed for guided growth in current orthopaedic practice, including the basic science and recent advances underlying mechanical physeal manipulation of both healthy and pathological physes.

Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An in vivo micro-CT scanner was used to monitor healing within the bone tunnel at four, eight and 12 weeks postoperatively. At week 12, the animals were killed for histological and biomechanical analysis.

In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone.

We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.

The aim of this study was to establish a classification system for the acromioclavicular joint using cadaveric dissection and radiological analyses of both reformatted computed tomographic scans and conventional radiographs centred on the joint. This classification should be useful for planning arthroscopic procedures or introducing a needle and in prospective studies of biomechanical stresses across the joint which may be associated with the development of joint pathology.

We have demonstrated three main three-dimensional morphological groups namely flat, oblique and curved, on both cadaveric examination and radiological assessment. These groups were recognised in both the coronal and axial planes and were independent of age.

Most injuries to the medial collateral ligament (MCL) heal well after conservative treatment. We have identified a subgroup of injuries to the deep portion of the MCL which is refractory to conservative treatment and causes persistant symptoms. They usually occur in high-level football players and may require surgical repair.

We describe a consecutive series of 17 men with a mean age of 29 years (18 to 44) who were all engaged in high levels of sport. Following a minor injury to the MCL there was persistent tenderness at the site of the proximal attachment of the deep MCL. It could be precipitated by rapid external rotation at the knee by clinical testing or during sport. The mean time from injury to presentation was 23.6 weeks (10 to 79) and none of the patients had responded to conservative treatment. The surgical finding was a failure of healing of a tear of the deep MCL at its femoral origin which could be repaired. After a period of postoperative protective bracing and subsequent rehabilitation the outcome was good. All the patients returned to their sports and remained asymptomatic at a mean of 48 weeks (28 to 60) post-operatively.

Recognition of this subgroup is important since the clinical features, the course of recovery and surgical requirement differ from those of most injuries to the MCL.

Coccydynia is a painful disorder characterised by coccygeal pain which is typically exaggerated by pressure. It remains an unsolved mystery because of the perceived unpredictability of the origin of the pain, some psychological traits that may be associated with the disorder, the presence of diverse treatment options, and varied outcomes. A more detailed classification based on the aetiology and pathoanatomy of coccydynia helps to identify patients who may benefit from conservative and surgical management.

This review focuses on the pathoanatomy, aetiology, clinical features, radiology, treatment and outcome of coccydynia.

Various chemicals are commonly used as adjuvant treatment to surgery for giant-cell tumour (GCT) of bone. The comparative effect of these solutions on the cells of GCT is not known. In this study we evaluated the cytotoxic effect of sterile water, 95% ethanol, 5% phenol, 3% hydrogen peroxide (H₂O₂) and 50% zinc chloride (ZnCI₂) on GCT monolayer tumour cultures which were established from six patients. The DNA content, the metabolic activity and the viability of the cultured samples of tumour cells were assessed at various times up to 120 hours after their exposure to these solutions.

Equal cytotoxicity to the GCT monolayer culture was observed for 95% ethanol, 5% phenol, 3% H₂O₂ and 50% ZnCI₂. The treated samples showed significant reductions in DNA content and metabolic activity 24 hours after treatment and this was sustained for up to 120 hours. The samples treated with sterile water showed an initial decline in DNA content and viability 24 hours after treatment, but the surviving cells were viable and had proliferated. No multinucleated cell formation was seen in these cultures.

These results suggest that the use of chemical adjuvants other than water could help improve local control in the treatment of GCT of bone.

Short intense electrical pulses transiently increase the permeability of the cell membrane, an effect known as electroporation. This can be combined with antiblastic drugs for ablation of tumours of the skin and subcutaneous tissue. The aim of this study was to test the efficacy of electroporation when applied to bone and to understand whether the presence of mineralised trabeculae would affect the capability of the electric field to porate the membrane of bone cells.

Different levels of electrical field were applied to the femoral bone of rabbits. The field distribution and modelling were simulated by computer. Specimens of bone from treated and control rabbits were obtained for histology, histomorphometry and biomechanical testing.

After seven days, the area of ablation had increased in line with the number of pulses and/or with the amplitude of the electrical field applied. The osteogenic activity in the ablated area had recovered by 30 days. Biomechanical testing showed structural integrity of the bone at both times.

Electroporation using the appropriate combination of voltage and pulses induced ablation of bone cells without affecting the recovery of osteogenic activity. It can be an effective treatment in bone and when used in combination with drugs, an option for the treatment of metastases.

The β-angle is a radiological tool for measuring the distance between the pathological head-neck junction and the acetabular rim with the hip in 90° of flexion in patients with femoroacetabular impingement. Initially it was measured using an open-chamber MRI. We have developed a technique to measure this angle on plain radiographs. Correlation analysis was undertaken to determine the relationship between the range of movement and the β-angle in 50 patients with femoroacetabular impingement and 50 asymptomatic control subjects. Inter- and intra-observer reliability of the β-angle was also evaluated.

Patients with femoroacetabular impingement had a significantly smaller (p < 0.001) mean β-angle (15.6°, 95% confidence interval (CI) 13.3 to 17.7) compared with the asymptomatic group (38.7°, 95% CI 36.5 to 41.0). Correlation between internal rotation and the β-angle was high in the impingement group and moderate in the asymptomatic group. The β-angle had excellent inter- and intra-observer reliability in both groups.

Our findings suggest that the measurement of the β-angle on plain radiography may represent a valid, reproducible and cost-effective alternative to open MRI in the assessment of the pathological bony anatomy in patients with cam, pincer and mixed femoroacetabular impingement.

We implanted titanium and carbon fibre-reinforced plastic (CFRP) femoral prostheses of the same dimensions into five prosthetic femora. An abductor jig was attached and a 1 kN load applied. This was repeated with five control femora. Digital image correlation was used to give a detailed two-dimensional strain map of the medial cortex of the proximal femur. Both implants caused stress shielding around the calcar. Distally, the titanium implant showed stress shielding, whereas the CFRP prosthesis did not produce a strain pattern which was statistically different from the controls. There was a reduction in strain beyond the tip of both the implants.

This investigation indicates that use of the CFRP stem should avoid stress shielding in total hip replacement.