We used dual-energy x-ray absorptiometry (DEXA) to evaluate the extent of periprosthetic bone remodelling around a prosthesis for distal femoral reconstruction, the Kotz modular femoral tibial replacement (KMFTR; Howmedica, Rutherford, New Jersey). A total of 23 patients was entered into the study which had four parts: 1) 17 patients were scanned three times on both the implant and contralateral legs to determine whether the precision of DEXA measurements was adequate to estimate bone loss surrounding the anchorage piece of the KMFTR; 2) in 23 patients the bone mineral density (BMD) in different regions of interest surrounding the diaphyseal anchorage was compared with that of the contralateral femur at the same location to test whether there was consistent evidence of loss of BMD adjacent to the prosthetic stem; 3) in 12 patients sequential studies were performed about one year apart to compare bone loss; and 4) bone loss was compared in ten patients with implants fixed by three screws and in 13 without screws. The mean coefficients of variation (SD/mean) for the 17 sets of repeated scans ranged from 2.9% to 7.8% at different regions of interest in the KMFTR leg and from 1.4% to 2.5% in the contralateral leg. BMD was decreased in the KMFTR leg relative to the contralateral limb and the percentage of BMD loss in general increased as the region of interest moved distally in the femur. Studies done after one year showed no consistent pattern of progressive bone loss between the two measurements. The ten patients with implants fixed by screws were found to have a mean loss of BMD of 42% in the most distal part of the femur, while the 13 without screw fixation had a mean loss of 11%. DEXA was shown to have adequate precision to evaluate loss of BMD around the KMFTR. This was evident relative to the contralateral leg in all patients and generally increased in the most distal part of the femur. In general, it stabilised between two measurements taken one year apart and was greater surrounding implants fixed by cross-locking screws

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Although knee osteoarthritis (OA) is diagnosed and monitored radiologically, actual full-thickness cartilage loss (FTCL) has rarely been correlated with radiological classification. This study aims to analyze which classification system correlates best with FTCL and to assess their reliability.

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The aim of this study was to identify modifiable risk factors associated with mortality in patients requiring revision total hip arthroplasty (THA) for periprosthetic hip fracture.

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The early mortality in patients with hip fractures from bony metastases is unknown. The objectives of this study were to quantify 30- and 90-day mortality in patients with proximal femoral metastases, and to create a mortality prediction tool based on biomarkers associated with early death.

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To examine the relationship of sex steroid hormones with osteopenia in a nationally representative sample of men in the USA.

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Commonly performed unicompartmental knee arthroplasty (UKA) is not designed for the lateral compartment. Additionally, the anatomical medial and lateral tibial plateaus have asymmetrical geometries, with a slightly dished medial plateau and a convex lateral plateau. Therefore, this study aims to investigate the native knee kinematics with respect to the tibial insert design corresponding to the lateral femoral component.

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There has been a significant reduction in unicompartmental knee arthroplasty (UKA) procedures recorded in Australia. This follows several national joint registry studies documenting high UKA revision rates when compared to total knee arthroplasty (TKA). With the recent introduction of robotically assisted UKA procedures, it is hoped that outcomes improve. This study examines the cumulative revision rate of UKA procedures implanted with a newly introduced robotic system and compares the results to one of the best performing non-robotically assisted UKA prostheses, as well as all other non-robotically assisted UKA procedures.

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Our retrospective analysis reports the outcome of patients operated for slipped capital femoral epiphysis using the modified Dunn procedure. Results, complications, and the need for revision surgery are compared with the recent literature.

Restoration of leg length and offset is an important goal in total hip replacement. This paper reports a calliper-based technique to help achieve these goals by restoring the location of the centre of the femoral head. This was validated first by using a co-ordinate measuring machine to see how closely the calliper technique could record and restore the centre of the femoral head when simulating hip replacement on Sawbone femur, and secondly by using CT in patients undergoing hip replacement. Results from the co-ordinate measuring machine showed that the centre of the femoral head was predicted by the calliper to within 4.3 mm for offset (mean 1.6 (95% confidence interval (CI) 0.4 to 2.8)) and 2.4 mm for vertical height (mean -0.6 (95% CI -1.4 to 0.2)). The CT scans showed that offset and vertical height were restored to within 8 mm (mean -1 (95% CI -2.1 to 0.6)) and -14 mm (mean 4 (95% CI 1.8 to 4.3)), respectively. Accurate assessment and restoration of the centre of the femoral head is feasible with a calliper. It is quick, inexpensive, simple to use and can be applied to any design of femoral component

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Options for the treatment of intra-articular ligament injuries are limited, and insufficient ligament reconstruction can cause painful joint instability, loss of function, and progressive development of degenerative arthritis. This study aimed to assess the capability of a biologically enhanced matrix material for ligament reconstruction to withstand tensile forces within the joint and enhance ligament regeneration needed to regain joint function.

Objectives. Because of the contradictory body of evidence related to the potential benefits of helical blades in trochanteric fracture fixation, we studied the effect of bone compaction resulting from the insertion of a proximal femoral nail anti-rotation (PFNA). . Methods. We developed a subject-specific computational model of a trochanteric fracture (31-A2 in the AO classification) with lack of medial support and varied the bone density to account for variability in bone properties among hip fracture patients. Results. We show that for a bone density corresponding to 100% of the bone density of the cadaveric femur, there does not seem to be any advantage in using a PFNA with respect to the risk of blade cut-out. On the other hand, in a more osteoporotic femoral head characterised by a density corresponding to 75% of the initial bone density, local bone compaction around the helical blade provides additional bone purchase, thereby decreasing the risk of cut-out, as quantified by the volume of bone susceptible to yielding. Conclusions. Our findings indicate benefits of using a PFNA over an intramedullary nail with a conventional lag screw and suggest that any clinical trial reporting surgical outcomes regarding the use of helical blades should include a measure of the femoral head bone density as a covariable

1. A case is described of three giant-cell tumours, the first in 1966 in the lower left femur, the second in 1968 in the upper right femur, the third later in 1968 in the upper left femur. 2. None of the tumours could be described as frankly malignant. 3. Despite a lapse of four years it is still not possible to decide whether the first tumour had metastasised or whether all three arose independently by multifocal origin

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When the present study was initiated, we changed the treatment for late-detected developmental dislocation of the hip (DDH) from several weeks of skin traction to markedly shorter traction time. The aim of this prospective study was to evaluate this change, with special emphasis on the rate of stable closed reduction according to patient age, the development of the acetabulum, and the outcome at skeletal maturity.

The August 2012 Oncology Roundup. 360. looks at: prolonged symptom duration; peri-operative mortality and above-knee amputation; giant cell tumour of the spine; surgical resection for Ewing’s sarcoma; intercalary allograft reconstruction of the femur for tumour defects; and an induced membrane technique for large bone defects

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Induction heating is a noninvasive, nonantibiotic treatment modality that can potentially be used to cause thermal damage to the bacterial biofilm on the metal implant surface. The purpose of this study was to determine the effectiveness of induction heating on killing Staphylococcus epidermidis from biofilm and to determine the possible synergistic effect of induction heating and antibiotics.

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The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA).

Objectives. Orthopaedic surgeons use stems in revision knee surgery to obtain stability when metaphyseal bone is missing. No consensus exists regarding stem size or method of fixation. This in vitro study investigated the influence of stem length and method of fixation on the pattern and level of relative motion at the bone–implant interface at a range of functional flexion angles. Methods. A custom test rig using differential variable reluctance transducers (DVRTs) was developed to record all translational and rotational motions at the bone–implant interface. Composite femurs were used. These were secured to permit variation in flexion angle from 0° to 90°. Cyclic loads were applied through a tibial component based on three peaks corresponding to 0°, 10° and 20° flexion from a normal walking cycle. Three different femoral components were investigated in this study for cementless and cemented interface conditions. Results. Relative motions were found to increase with flexion angle. Stemmed implants reduced relative motions in comparison to stemless implants for uncemented constructs. Relative motions for cemented implants were reduced to one-third of their equivalent uncemented constructs. Conclusions. Stems are not necessary for cemented implants when the metaphyseal bone is intact. Short cemented femoral stems confer as much stability as long uncemented stems

We analysed retrospectively the risk factors leading to femoral overgrowth after flexible intramedullary nailing in 43 children (mean age 7.1 years (3.6 to 12.0)) with fractures of the shaft of the femur. We reviewed their demographic data, mechanism of injury, associated injuries, the type and location of the fractures, the nail–canal diameter (NCD) ratios and femoral overgrowth at a mean follow-up of 40.7 months (25.2 to 92.7). At that time, the children were divided into two groups, those with femoral overgrowth of < 1 cm (Group 1), and those with overgrowth of ≥ 1 cm (Group 2). The mean femoral overgrowth of all patients was 0.6 cm at final follow-up. Overgrowth of ≥ 1 cm was noted in 11 children (25.6%). The NCD ratio was significantly lower in Group 2 than in Group 1, with an odds ratio of 30.0 (p = 0.003). We believe that a low NCD ratio is an indicator of an unstable configuration with flexible intramedullary nailing, and have identified an association between a low NCD ratio and femoral overgrowth resulting in leg-length discrepancy after flexible intramedullary nailing in paediatric femoral shaft fractures. Cite this article: Bone Joint J 2013;95-B:254–8