Abstract
Background
Leg length discrepancy real or perceived remains an important source of patient dissatisfaction after a total hip replacement. Pre-operative templating and intra-operative measurement has to be used to ensure an accurate restoration of the normal centre of rotation of the hip as well as equal leg lengths. Theoretically more bone has to be resected from the femur to maintain the centre of the femoral head in the same location. This is due to a smaller size of the prosthetic femoral head compared to the native femoral head. It was postulated that this was an accurate predictor of leg length after a total hip replacement.
Methods
56 consecutive patients who underwent a total hip replacement (cemented, uncemented or hybrid) had intra-operative measurements documented of their femoral head-neck resection distance. This was compared with the measurement of the femoral prosthesis that was inserted. A telephonic survey of the patients perceived leg equality as well as a radiological measurement of their actual leg lengths on a standing AP X-ray at 6 weeks post-operatively was done.
Results
Forty eight of the 56 patients (85%) reported subjectively equal leg lengths. Eight patients reported unequal leg lengths, 5 longer and 3 shorter. Of the 5 cases that reported longer leg lengths 4 had more prosthesis inserted than bone resected. The 3 shorter reported legs also had more prosthesis inserted than bone resected in 2 cases. Of the 8 patients who reported unequal leg lengths only 3 were unequal on X-ray measurement (2 longer and 1 shorter). There was good correlation between the amount of bone resected versus prosthesis inserted and the patient's subjective evaluation of leg length discrepancy, but poor correlation between subjective leg length discrepancy and objective radiological evaluation.
NO DISCLOSURES
