Rarely, the extent of a malignant bone tumour may necessitate resection of the complete humerus to achieve adequate oncological clearance. We present our experience with reconstruction in such cases using a total humeral endoprosthesis (THER) in 20 patients (12 male and eight female) with a mean age of 22 years (6 to 59). We assessed the complications, the oncological and functional outcomes and implant survival. Surgery was performed between June 2001 and October 2009. The diagnosis included osteosarcoma in nine, Ewing’s sarcoma in eight and chondrosarcoma in three. One patient was lost to follow-up. The mean follow-up was 41 months (10 to 120) for all patients and 56 months (25 to 120) in survivors. There were five local recurrences (26.3%) and 11 patients were alive at time of last follow-up, with overall survival for all patients being 52% (95% confidence interval (CI) 23.8 to 74) at five years. The mean Musculoskeletal Tumor Society score for the survivors was 22 (73%; 16 to 23). The implant survival was 95% (95% CI 69.5 to 99.3) at five years.

The use of a THER in the treatment of malignant tumours of bone is oncologically safe; it gives consistent and predictable results with low rates of complication.

Aims

To compare changes in gait kinematics and walking speed 24 months after conventional (C-MLS) and minimally invasive (MI-MLS) multilevel surgery for children with diplegic cerebral palsy (CP).

Aims

We aimed to address the question on whether there is a place for shoulder stabilization surgery in patients who had voluntary posterior instability starting in childhood and adolescence, and later becoming involuntary and uncontrollable.

Aims

Vitamin E-infused highly crosslinked polyethylene (VEPE) has been introduced into total hip arthroplasty (THA) with the aim of further improving the wear characteristics of moderately and highly crosslinked polyethylenes (ModXLPE and HXLPE). There are few studies analyzing the outcomes of vitamin E-infused components in cemented arthroplasty, though early acetabular component migration has been reported. The aim of this study was to measure five-year polyethylene wear and acetabular component stability of a cemented VEPE acetabular component compared with a ModXLPE cemented acetabular component.

Soaking bone grafts in a bisphosphonate solution before implantation can prevent their resorption and increase the local bone density in rats and humans. However, recent studies suggest that pre-treatment of allografts with bisphosphonate can prevent bone ingrowth into impaction grafts. We tested the hypothesis that excessive amounts of bisphosphonate would also cause a negative response in less dense grafts. We used a model where non-impacted metaphyseal bone grafts were randomised into three groups with either no bisphosphonate, alendronate followed by rinsing, and alendronate without subsequent rinsing, and inserted into bone chambers in rats. The specimens were evaluated histologically at one week, and by histomorphometry and radiology at four weeks. At four weeks, both bisphosphonate groups showed an increase in the total bone content, increased newly formed bone, and higher radiodensity than the controls. In spite of being implanted in a chamber with a limited opportunity to diffuse, even an excessive amount of bisphosphonate improved the outcome. We suggest that the negative results seen by others could be due to the combination of densely compacted bone and a bisphosphonate. We suggest that bisphosphonates are likely to have a negative influence where resorption is a prerequisite to create space for new bone ingrowth

We subjected the proximal tibial growth plates of six-week-old rabbits to either compression or distraction of 1 kg on both legs. On one side the proximal tibial periosteum was divided circumferentially and stripped for 1 cm. After six weeks, growth was measured at both proximal and distal growth plates. Compression inhibited total tibial growth and distraction enhanced it. The compressed growth plate grew less and the distracted growth plate grew more, but there was a reciprocal change at the other end of the bone. Periosteal division enhanced growth at the adjacent growth plate but inhibited it distally; the effect of distraction was enhanced and that of compression reduced. We found reciprocal growth rates at the proximal and distal growth plates. Relatively small amounts of compression or distraction did affect total bone growth. Periosteal division appeared to induce overgrowth at least partly by a mechanical effect; it may be useful as an adjunct to other methods of leg lengthening, though not to epiphyseolysis

An experimental study is reported of fracture healing in the femora of 36 Beagle dogs, comparing the results of using stainless steel plates with those of using less rigid titanium alloy plates. The alloy plates led to the appearance of a small amount of periosteal callus without any histological evidence of fracture instability, thus allowing the radiological assessment of fracture union. This also produced less bone loss during the remodelling phase. Radiological measurements 24 weeks after osteotomy showed cortical thickness to be reduced by six per cent under titanium alloy and by 19 per cent under stainless steel, while histological measurements showed a total bone loss of 3.7 per cent under titanium alloy and of 11 per cent under stainless steel plates. Removal of the titanium alloy plates after eight weeks followed by a recovery period of 16 weeks produced an increase of cortical thickness of 69 per cent and a gain in total bone mass of 30 per cent. Titanium alloy plates also produced less soft-tissue reaction than stainless steel plates. It is concluded that this alloy is a promising material for internal fixation devices

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

1. Individuals who are normal and not osteoporotic seem to show retention of cortical bone at successive decades of life in proportion to the total lean body-mass. In patients with osteoporosis the weight of the skeleton decreases at a rate exceeding the physiological rate of atrophy of muscle, tendon and bone tissue that occurs with the time-dependent process of ageing. 2. Six patients representing the typical forms of osteoporosis commonly found in orthopaedic practice were investigated intensively over a period of three years and compared with individuals in whom there was no osteoporosis by studies of metabolic balance, Sr85 osteograms, and tetracycline deposition. 3. Studies of metabolic balance in patients with osteoporosis showed normal or negative calcium balances, but an equilibrium for the metabolism of nitrogen and phosphorus. Increased intake of calcium in the diet produced retention of calcium but not sufficient phosphorus, nitrogen or gain in weight to prove that the patient had made new bone and healed the osteoporosis. 4. Radio-isotope osteograms showed high, normal or low rates of change of uptake of Sr85 and the accretion rate was calculated to be normal or low in individuals with osteoporosis. High uptake of tetracycline by a small mass of bone tissue and by a relatively small percentage of the total number of osteons suggested that in an adult human being the calcium reserve in the skeleton is enormous. Thirty to 50 per cent of the total bone mass was sufficient to turn over 0·5 to 1·0 gramme, the amount of calcium utilised in twenty-four hours by the human adult. This was accomplished by structural or old bone throughout the entire skeleton, and by labile or newer bone located in approximately 10 per cent of the total number of Haversian cylinders or osteons. 5. Some of the unclosed or half-closed osteons were hyperactive in osteoporotic bones. In the process of remodelling of cortical bone a significant quantity of bone tissue was incompletely restored and there were, presumably as a result, intermittently large or small negative calcium balances. Osteoporosis may have been the cause, rather than the result, of the negative calcium balance. 6. The experimental and clinical literature of the past ten years, and studies on patients described in this critical review, were interpreted to indicate that prolonged calcium deficiency, castration, hyperadrenal corticoidism or a sedentary life may precipitate, accentuate and accelerate osteoporosis in individuals who are genetically predisposed to develop it. Sometimes high calcium intake or sex hormones, or both, may have slowed the rate of resorption but did not replace the deficit in cortical bone. 7. Further research is necessary to find the chief etiological factor and to produce the cure for this increasingly common disorder of the skeleton

The last decade has seen a considerable increase in the use of in total ankle arthroplasty (TAA) to treat patients with end-stage arthritis of the ankle. However, the longevity of the implants is still far from that of total knee and hip arthroplasties.

The aim of this review is to outline a diagnostic and treatment algorithm for the painful TAA to be used when considering revision surgery.

Cite this article: Bone Joint J 2017;99-B:5–11.

1. The hypothesis is put forward that the cartilage of a developing epiphysis consists of two separate moieties. There is a superficial zone which from the first is destined to become articular cartilage and is incapable of ossification, whereas the deeper layers are concerned with the actual growth of the epiphysis and will eventually be converted totally to bone. 2. The results of an experiment which support this theory are described. A piece of developing joint cartilage was excised and replaced in its bed upside down. It was found that although the cartilage continued to proliferate at its normal rate, ossification of the original articular layer did not occur, so that there was a considerable increase in the thickness of the excised cartilage. 3. The supporting evidence for the hypothesis is discussed

Aims

The aim of this study was to establish what happens to patients in the long term after endoprosthetic replacement for a primary malignant tumour of bone.

Previous classification systems of failure of limb salvage focused primarily on endoprosthetic failures and lacked sufficient depth for the effective study of the causes of failure. In order to address these inadequacies, the International Society of Limb Salvage (ISOLS) formed a committee to recommend revisions of the previous systems. The purpose of this study was to report on their recommendations. The modifications were prepared using an earlier, evidence-based model with subclassification based on the existing medical literature. Subclassification for all five primary types of failure of limb salvage following endoprosthetic reconstruction were formulated and a complementary system was derived for the failure of biological reconstruction. An additional classification of failure in paediatric patients was also described.

Limb salvage surgery presents a complex array of potential mechanisms of failure, and a complete and precise classification of types of failure is required. Earlier classification systems lacked specificity, and the evidence-based system outlined here is designed to correct these weaknesses and to provide a means of reporting failures of limb salvage in order to allow the interpretation of outcome following reconstructive surgery.

Cite this article: Bone Joint J 2014;96-B:1436–40.

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

Impaction allograft is an established method of securing initial stability of an implant in arthroplasty. Subsequent bone integration can be prolonged, and the volume of allograft may not be maintained. Intermittent administration of parathyroid hormone has an anabolic effect on bone and may therefore improve integration of an implant.

Using a canine implant model we tested the hypothesis that administration of parathyroid hormone may improve osseointegration of implants surrounded by bone graft. In 20 dogs a cylindrical porous-coated titanium alloy implant was inserted into normal cancellous bone in the proximal humerus and surrounded by a circumferential gap of 2.5 mm. Morsellised allograft was impacted around the implant. Half of the animals were given daily injections of human parathyroid hormone (1–34) 5 μg/kg for four weeks and half received control injections. The two groups were compared by mechanical testing and histomorphometry. We observed a significant increase in new bone formation within the bone graft in the parathyroid hormone group. There were no significant differences in the volume of allograft, bone-implant contact or in the mechanical parameters.

These findings suggest that parathyroid hormone improves new bone formation in impacted morsellised allograft around an implant and retains the graft volume without significant resorption. Fixation of the implant was neither improved nor compromised at the final follow-up of four weeks.

Previously, we showed that case-specific non-linear finite element (FE) models are better at predicting the load to failure of metastatic femora than experienced clinicians. In this study we improved our FE modelling and increased the number of femora and characteristics of the lesions. We retested the robustness of the FE predictions and assessed why clinicians have difficulty in estimating the load to failure of metastatic femora. A total of 20 femora with and without artificial metastases were mechanically loaded until failure. These experiments were simulated using case-specific FE models. Six clinicians ranked the femora on load to failure and reported their ranking strategies. The experimental load to failure for intact and metastatic femora was well predicted by the FE models (R² = 0.90 and R² = 0.93, respectively). Ranking metastatic femora on load to failure was well performed by the FE models (τ = 0.87), but not by the clinicians (0.11 < τ < 0.42). Both the FE models and the clinicians allowed for the characteristics of the lesions, but only the FE models incorporated the initial bone strength, which is essential for accurately predicting the risk of fracture. Accurate prediction of the risk of fracture should be made possible for clinicians by further developing FE models.

We have investigated the effectiveness of the transplantation of bone-marrow-derived mononuclear cells (BMMNCs) with interconnected porous calcium hydroxyapatite (IP-CHA) on early bone repair for osteonecrosis of the femoral head. We studied 22 patients (30 hips) who had osteonecrosis with a minimum follow-up of one year after implantation of BMMNCs. The mean age at surgery was 41 years (18 to 64) and the mean period of follow-up was 29 months (19 to 48). In a control group, cell-free IP-CHA was implanted into a further eight patients (9 hips) with osteonecrosis of the femoral head and the outcomes were compared.

A reduction in the size of the osteonecrotic lesion was observed subsequent to hypertrophy of the bone in the transition zone in the BMMNC group. In three patients in the treatment group progression to extensive collapse was detected. In the control group subtle bone hypertrophy was observed, but severe collapse of the femoral head occurred in six of eight hips.

In this limited study the implantation of BMMNCs and IP-CHA appears to confer benefit in the repair of osteonecrosis and in the prevention of collapse.

The cortical strains on the femoral neck and proximal femur were measured before and after implantation of a resurfacing femoral component in 13 femurs from human cadavers. These were loaded into a hip simulator for single-leg stance and stair-climbing. After resurfacing, the mean tensile strain increased by 15% (95% confidence interval (CI) 6 to 24, p = 0.003) on the lateral femoral neck and the mean compressive strain increased by 11% (95% CI 5 to 17, p = 0.002) on the medial femoral neck during stimulation of single-leg stance. On the proximal femur the deformation pattern remained similar to that of the unoperated femurs.

The small increase of strains in the neck area alone would probably not be sufficient to cause fracture of the neck However, with patient-related and surgical factors these strain changes may contribute to the risk of early periprosthetic fracture.

Juvenile idiopathic arthritis (JIA) is a chronic disease of childhood; it causes joint damage which may require surgical intervention, often in the young adult. The aim of this study was to describe the long-term outcome and survival of hip replacement in a group of adult patients with JIA and to determine predictors of survival for the prosthesis. In this retrospective comparative study patients were identified from the database of a regional specialist adult JIA clinic. This documented a series of 47 hip replacements performed in 25 adult patients with JIA. Surgery was performed at a mean age of 27 years (11 to 47), with a mean follow-up of 19 years (2 to 36). The mean Western Ontario and McMaster Universities osteoarthritis index questionnaire (WOMAC) score at the last follow-up was 53 (19 to 96) and the mean Health Assessment Questionnaire score was 2.25 (0 to 3). The mean pain component of the WOMAC score (60 (20 to 100)) was significantly higher than the mean functional component score (46 (0 to 97)) (p = 0.02). Kaplan-Meier survival analysis revealed a survival probability of 46.6% (95% confidence interval 37.5 to 55.7) at 19 years, with a trend towards enhanced survival with the use of a cemented acetabular component and a cementless femoral component. This was not, however, statistically significant (acetabular component, p = 0.76, femoral component, p = 0.45). Cox’s proportional hazards regression analysis showed an implant survival rate of 54.9% at 19 years at the mean of covariates.

Survival of the prosthesis was significantly poorer (p = 0.001) in patients who had been taking long-term corticosteroids and significantly better (p = 0.02) in patients on methotrexate.

We have developed an animal model to examine the formation of heterotopic ossification using standardised muscular damage and implantation of a beta-tricalcium phosphate block into a hip capsulotomy wound in Wistar rats. The aim was to investigate how cells originating from drilled femoral canals and damaged muscles influence the formation of heterotopic bone. The femoral canal was either drilled or left untouched and a tricalcium phosphate block, immersed either in saline or a rhBMP-2 solution, was implanted. These implants were removed at three and 21 days after the operation and examined histologically, histomorphometrically and immunohistochemically.

Bone formation was seen in all implants in rhBMP-2-immersed, whereas in those immersed in saline the process was minimal, irrespective of drilling of the femoral canals. Bone mineralisation was somewhat greater in the absence of drilling with a mean mineralised volume to mean total volume of 18.2% (sd 4.5) versus 12.7% (sd 2.9, p < 0.019), respectively.

Our findings suggest that osteoinductive signalling is an early event in the formation of ectopic bone. If applicable to man the results indicate that careful tissue handling is more important than the prevention of the dissemination of bone cells in order to avoid heterotopic ossification.