The management of osteoarthritis of the knee associated with patellar instability secondary to external tibial torsion > 45° is challenging. Patellofemoral biomechanics in these patients cannot be achieved by intra-articular correction using standard techniques of total knee replacement. We reviewed seven patients (eight knees) with recurrent patellar dislocation and one with bilateral irreducible lateral dislocation who had undergone simultaneous total knee replacement and internal tibial derotational osteotomy. All had osteoarthritis and severe external tibial torsion. The mean follow-up was for 47.2 months (24 to 120). The mean objective and functional Knee Society scores improved significantly (p = 0.0001) from 29.7 and 41.5 pre-operatively to 71.4 and 73.5 post-operatively, respectively. In all patients the osteotomies healed and patellar stability was restored. Excessive external tibial torsion should be identified and corrected in patients with osteoarthritis and patellar instability. Simultaneous internal rotation osteotomy of the tibia and total knee replacement is a technically demanding but effective treatment for such patients

Objectives

The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration.

Aims

The aim of this study was to present the long-term surgical outcomes, complications, implant survival, and causes of implant failure in patients treated with the modified Harrington procedure using antegrade large diameter pins.

Aims

Arthroplasty skills need to be acquired safely during training, yet operative experience is increasingly hard to acquire by trainees. Virtual reality (VR) training using headsets and motion-tracked controllers can simulate complex open procedures in a fully immersive operating theatre. The present study aimed to determine if trainees trained using VR perform better than those using conventional preparation for performing total hip arthroplasty (THA).

Mechanical and biomechanical testing of a new bone cement suggests that improved load transfer to the proximal femur could be achieved with the combination of a cement having a lower modulus, a greater ductility and a lower creep resistance than polymethylmethacrylate and a suitably shaped femoral component

We reviewed ten patients with metastatic carcinoma and impending pathological fractures of the subtrochanteric region of the femur who had prophylactic insertion of the Russell-Taylor reconstruction nail. There were no operative complications or long-term mechanical failures. This reconstruction nail has some technical and biomechanical advantages over other implants and is ideal for the management of such cases

Aim

Mesenchymal stem cells (MSCs) have several properties that may support their use as an early treatment option for osteoarthritis (OA). This study investigated the role of multiple injections of allogeneic bone marrow-derived stem cells (BMSCs) to alleviate the progression of osteoarthritic changes in the various structures of the mature rabbit knee in an anterior cruciate ligament (ACL)-deficient OA model.

There are various methods of measuring proprioception at the knee. Beard et al (1993) have described a delay in reflex hamstring contraction in anterior cruciate deficient knees. We have repeated their experiment and were unable to detect any significant difference in reflex hamstring contraction between the injured and uninjured legs. We discuss possible neurophysiological and biomechanical causes for the conflicting results and conclude that this method may not be a valid measure of proprioception

The effects of synovectomy and excision of the radial head in 40 elbows affected by rheumatoid arthritis have been assessed. In contrast with many reports indicating minimal side-effects of this procedure, a common pattern of deterioration from what was often a satisfactory initial result has been demonstrated. A biomechanical theory of one of the factors responsible for failure has been put forward and the importance of conserving or replacing the radial head emphasised

Aims

The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA).

Children with flail feet who have control of their hips and knees are able to walk but are unable to stand still and find it difficult to walk slowly. These problems have been overcome in fifty-three children with flail feet due to myelomeningocele by fitting them with below-knee orthoses which provide maximum stability and yet allow normal walking. The biomechanical principles and the development of the orthoses are discussed

We matched 78 patients with a loose cemented Charnley Elite Plus total hip replacement (THR) by age, gender, race, prosthesis and time from surgery with 49 patients with a well-fixed stable hip replacement, to determine if poor bone quality predisposes to loosening. Clinical, radiological, biomechanical and bone mineral density indicators of bone quality were assessed. Patients with loose replacements had more pain, were more likely to have presented with atrophic arthritis and to have a history of fragility fracture, narrower femoral cortices and lower peri-prosthetic or lumbar spine bone mineral density (all t-test, p < 0.01). They also tended to be smokers (chi-squared test, p = 0.08). Vitamin-D deficiency was common, but not significantly different between the two groups (t-test, p = 0.31). In this series of cemented hip replacements performed between 1994 and 1998, aseptic loosening was associated with poor bone quality. Patients with a THR should be screened for osteoporosis and have regular radiological surveillance

This paper describes a procedure of activating osteogenesis by the use of the "petal" technique. The osteogenetic effect of these "petals" has been established in experimentally produced fractures and pseudarthroses in rats by radiographical, biomechanical, mechanical and histological examinations. The conventional concept of the osteogenetic activity of bone transplants is discussed. The authors feel that this method will find its clinical application in the operative treatment of pseudarthroses and, in selected cases, of fractures that are known for their tendency to unite slowly

Aims

The aim of this study was to analyze the results of two radiocapitellar prostheses in a large case series followed prospectively, with medium-term follow-up.

The development of genu valgum in a child after a fracture of the upper metaphysis of the tibia with a medial gap is due to the interposition of a flap of fibrous tissue consisting of pes anserinus and periosteum avulsed from the lower fragment. The ensuing biomechanical disturbance induces bowing of the shaft and asymmetrical growth at both ends of the bone. Four cases of established deformity are reported, together with two cases of fresh fracture successfully treated by surgical clearance of the fibrous tissue from the gap

We have assessed the biomechanical properties of a 'double-bundle' prosthetic ligament replacing the anterior cruciate in cadaver knees. We compared the results with those of single bundle 'over-the-top' and 'through-the-condyle' techniques, performing anterior drawer tests at 20 degrees and 90 degrees knee flexion. The over-the-top reconstruction gave better anteroposterior stability at 20 degrees, while the through-the-condyle repair was more stable at 90 degrees. The double-bundle reconstruction gave practically normal anterior stability at both 20 degrees and 90 degrees