Previously Funded Research

Over the years, through different charitable vehicles, the British Orthopaedic Association has granted in excess of £5.7 million to support orthopaedic research. As a charity, it relies on voluntary donations from members of the orthopaedic community and members of the general public alike. Support has been given for basic, clinical and health services research. Grants have ranged from small one-off pump priming grants, to support for major three year projects and beyond. Both departments and individuals have been supported throughout the UK.

The results of the research from many projects have been published in leading medical journals and several projects have led directly to improved treatment methods for patients. The following examples indicate the range of work undertaken.

Improved Methods for the Treatment of Wrist Fractures

Mrgaret McQueen, Edinburgh

Serious fractures of the distal radius are difficult to treat, and often result in permanent disability. A prospective, randomised clinical trial comparing methods of treatment used for serious, unstable fractures of the distal radius was designed, and undertaken. The investigators studied the important features within fracture patterns which could be used to predict whether the fracture would show itself to be unstable; such instability usually leads to poor fracture position, and hence disability. The merit of different methods of treatment, including the use of bone graft was defined.

Results: Better results were achieved when potential instability was identified, and treated initially with non-bridging external fixators. These results have led to a change in the way that these common fractures are treated throughout the UK, and elsewhere in the world.

The Value of Questionnaires in the Assessment of the Outcome of Knee and Shoulder Arthroplasties

Andrew Carr and Ray Fitzpatrick, Oxford

In the field of joint replacement surgery it has become increasingly important to be able to assess the results of operations in a reliable manner, so that treatment methods can be evaluated, and compared. There is a great need for simple methods that can be used for large numbers of patients.

Results: These studies demonstrated that the use of questionnaires was valid for the measurement of the level of success achieved, from both the point of view of the patient, and the doctors, for both shoulder and knee joint replacements. These simple questionnaires can be completed by patients, and have also been shown to be a very effective way of assessing patient progress. The questionnaires have been accepted widely by the profession.

Relationship of Muscle Architecture to Function in children with Cerebral Palsy

Martin Gough and Adam Shortland, London

One child in every 350 is born with cerebral palsy, many of whom develop a spastic form in which their muscles are overactive, weak and difficult to control. As the child grows, the affected muscles shorten, causing the joints in the limb to lose their range of movement, which adds to the problem. Previously, it was believed that shortness of muscle fibres was responsible for contracture of the whole muscle. In this study the detailed architecture of muscles was studied directly, during, and after soft tissue surgery in patients with cerebral palsy. A non-invasive, new technique, based on the use of ultrasound, was also developed which could demonstrate muscle architecture in 3D. Long views of the muscles were constructed, and the overall architecture of the muscle was defined.

Results: This study showed surprisingly, that muscle fibres in children with spastic cerebral palsy are of similar length to those seen in unaffected children. Another mechanism to explain the loss of function is therefore needed. It was also found that many operations performed on muscles in these patients led to an unfavourable decrease in muscle fibre length. Surgical intervention puts the joint in a more normal position, but the operation may diminish the performance of the muscle.
The 3D studies showed the quite marked loss of volume, and abnormal architecture seen in calf muscles in all patients with cerebral palsy.
The investigators conclude that the shortening of the muscles is probably due to muscle fibre atrophy, and future treatments need to concentrate on preventing this by non-operative means. It is hoped that the ultrasound assessment will become a routine clinical service for the evaluation of muscle abnormality.

Cellular Responses to Wear Particles

Nicholas Athanasou, Oxford

A small percentage of joint replacements become loose over the years that follow the initial operation, and this problem usually leads to a painful joint. There are various causes for such loosening, and this research group investigated the mechanism of loosening at a cellular level.

Results: For the first time it was to shown that specialised cells, called macrophages, ingest the microscopic particles that are produced by the wear that occurs due to normal, day to day, repeated use of the prosthesis. These cells then differentiate, and change into osteoclasts. These osteoclast cells, in turn, are known to be capable of resorbing bone. This resorption damages, and weakens the interface where the bone is bonded to the prosthesis. It was also found that the amount of bone resorption seen around a failed implant, was very dependent on the type of material from which particles were produced. The results of this project have clarified our understanding of the cellular mechanisms that cause bone loss, and the loosening that follows. The future lies in developing prostheses, designed to produce fewer wear particles, and of more suitable materials.

The Effects of Tibial Lengthening on Articular Cartilage, and Muscles

Michael Saleh, Sheffield

The surgical operation of lengthening a segment of a bone is now used widely for the correction of short limbs, and for bridging large defects in long bones. Defects can be caused by traffic accidents, or by having to remove diseased bone. At an initial operation the bone is cut, and the fragments are then stretched progressively over a period of weeks. During this lengthening a great deal of tension may develop in the surrounding soft tissues, possibly leading to damage in these tissues. In this study a new method was developed in which the forces acting on joint cartilage, and through calf muscles, could be measured during leg lengthening.

Results: It was found that very high forces developed in the soft tissues during procedures when large lengthenings were undertaken. The forces that act across the two surfaces of the joints adjacent to the lengthened segment were also raised to unphysiological levels. In some instances damage to articular cartilage was seen, as well as to leg muscles. These results show that the rates at which limbs are lengthened should be adapted accurately to the condition of the soft tissues for each individual. Lengthening will then be performed without the risk of troublesome complications.