The results of hip and knee replacement surgery are generally regarded as positive for patients. Nonetheless, they are both major operations and have recognised complications. We present a review of relevant claims made to the National Health Service Litigation Authority. Between 1995 and 2010 there were 1004 claims to a value of £41.5 million following hip replacement surgery and 523 claims to a value of £21 million for knee replacement. The most common complaint after hip surgery was related to residual neurological deficit, whereas after knee replacement it was related to infection. Vascular complications resulted in the highest costs per case in each group.

Although there has been a large increase in the number of operations performed, there has not been a corresponding relative increase in litigation. The reasons for litigation have remained largely unchanged over time after hip replacement. In the case of knee replacement, although there has been a reduction in claims for infection, there has been an increase in claims for technical errors. There has also been a rise in claims for non-specified dissatisfaction. This information is of value to surgeons and can be used to minimise the potential mismatch between patient expectation, informed consent and outcome.

Cite this article: Bone Joint J 2013;95-B:122–6.

We present a case of superior dislocation of the patella trapped by interlocked osteophytes. Unlike previous reports, in which the mechanism resulted from a blow to the inferior pole, it is postulated that increased load on the extensor mechanism, combined with patella alta and patellofemoral osteophytes, caused locking of the knee in extension.

After total knee replacement a 57-year-old woman developed increasing pain in her left calf on exercise. This was due to erosion of the popliteal artery by a spur of cement. Removal of the spur with resection and Dacron grafting of the damaged section of the vessel cured her symptoms.