Introduction: Dislocation following total hip arthroplasty is a recognised complication and is attributable to several factors. The posterior approach to the hip is associated with higher dislocation rates than anterior or lateral approaches. We retrospectively reviewed the incidence of dislocation following total hip arthroplasty, in our institution, over a period of 5 years (from January 2000 to December 2004).

Results: We found 97 instances (in 49 patients) of dislocation following total hip arthroplasty. Of the 49 patients, 35 had the total hip arthroplasty done through the posterior approach. The Stacathro approach was performed on one patient, antero-lateral approach in 7 patients, and the transtrochanteric approach on 6 patients. Eleven patients had undergone revision arthroplasty prior to sustaining a dislocation and 16 had undergone primary arthroplasty. 16 patients had multiple dislocations. 8 of the 16 with multiple dislocations had a primary arthroplasty and rest had revision procedures done. A number of authors have reported decreased dislocation rates after using various techniques for enhancing the closure of the posterior soft tissues following total hip arthroplasties using the posterior approach. We reviewed 256 patient records that had undergone total hip arthroplasty in this period by the senior author through the posterior approach. The Savory technique was used to repair the posterior soft tissue layer. 160 patients had undergone primary arthroplasty and 96 had revision surgery. There were 3 cases of dislocation among the primary arthroplasty cases and 7 among the revision group.

Conclusion: This review showed that posterior approach to the hip continues to be associated with higher dislocation rates than other approaches. Using the Savory technique can reduce the dislocation rate following total hip arthroplasty.

Metal on metal hip resurfacing was introduced in 1992 by Derek McMinn initially using an all cementless device and then an all cemented device. A hybrid resurfacing with a cemented femoral component and a cementless acetabular component was introduced in 1994. The manufacturer of the hybrid hip resurfacing was changed in 1996. Since 1997 the Birmingham hip resurfacing has been in continuous use.

The device is approved by NICE (National Institute for Clinical Excellence) for use within the NHS in patients with Osteoarthritis of the hip. The device is not yet approved for use in patients with Rheumatoid Arthritis and other types of inflammatory arthritis. There are concerns regarding bone quality in rheumatoid patients, which may result in a high incidence of component loosening or femoral neck fracture. Conventional total hip replacement is a successful procedure in inflammatory arthritis however with modern treatments producing increased activity levels there are concerns about polyethylene wear.

The author has performed metal on metal hip resurfacing in patients with inflammatory arthritis over the past 12 years. A total of 170 patients have been operated on with 198 resurfacings. 33% of patients have a diagnosis of some type of inflammatory arthritis. The outcomes have been assessed using Oxford hip scores and long term clinical and radiological review. Our results indicate that there is a minimal risk of femoral neck fracture and a minimal risk of component loosening when the device is used with this approach in patients with inflammatory arthritis.

Inadequate cementation remains a prime cause of aseptic loosening in Hip Arthroplasties. While good progress has been made in preparation of femoral canal and cement, with newer techniques there are problems with ensuring adequate cement mantle. A distal centraliser available with some prosthesis does aid in better alignment and distal centralisation, but proximal centralisation remains a problem especially with some approaches.

We have recently used a new prosthesis CPS (Endoplus) which has a smooth polished double tapered design and also comes with a proximal and distal centraliser. We undertook a study to evaluate the effect of these on cement mantle, stem alignment, centralisation and supero-medial cement thickness. We defined adequate mantle as a thickness of at least 2mm. 75 consecutive cases were included in the study. All cases were done either by or under direct supervision of the senior author using the antero-lateral approach.

We found 88% of stem’s aligned within 2 deg. of anatomical axis of the femur. Distal tip of the prosthesis was within 2mm of centre of the medullary canal in 92% in the lateral view and in 95% in AP view. Deficiencies in cement mantle were noted in very few cases, zones 6 & 13 had the highest incidence but even here only 9% of cases had inadequate cementation.

We find the centralisers a useful adjunct in cemented hip arthroplasty.

We examined soft tissue biopsies from 26 patients with symptomatic nerve root fibrosis and arachnoiditis after a previous laminectomy. Dense fibrous connective tissue was found about the nerve roots and in 14 cases (55%) fibrillar foreign material was seen within it. This material had the histochemical characteristics of cotton fibres from swabs and neurosurgical patties. In two other cases nerve root fibrosis was associated with residual radiopaque lipid thought to derive from earlier myelography. Our findings suggest that risks may be associated with the introduction of foreign material into the vertebral canal, and that microscopic fragments of surgical swabs and patties may have a role in the pathogenesis of postoperative periradicular fibrosis.

The technique and results of microsurgical techniques for lumbar disc protrusions in 60 patients are presented. All patients were followed up for a minimum of 2.5 years, and 91% had good or excellent results. The only patient with a recurrent disc sequestration had a good result after a second operation.