Repeated luxations, periprosthetic fractures, infections, and nerve palsies are the most frequent complications of hip alloarthroplasty. Paresis acquired during elective implantation entails considerable restrictions in the quality of life. The risk of sustaining a nerve injury depends upon the initial clinical situation, cases of planned leg lengthening in patients with hip dysplasia and high luxations being particularly at risk.
A Medline search was conducted using the query "nerve palsies during hip prosthesis implantation", yielding 126 publications, of which 18 were used to predict the risk of nerve palsies in cases with simultaneous leg lengthening during total hip arthroplasties according to different preconditions.
The risk for an acquired nerve lesion during hip alloarthroplasty in arthritis was 0.5 %. In cases of hip dysplasia (with no or moderate leg lengthening during the procedure), the risk was increased to 2.3 %. An even higher risk of 3.5 % was found in cases of revision surgery. According to the literature, the risk of nerve palsies in cases of continuous leg lengthening before THA is raised to 5.9 % with a linear correlation between the amount of leg lengthening and rate of nerve palsies.
Neural lesions during single-stage leg lengthening of less than 3 cm in hip alloarthroplasty are uncommon. More extensive lengthening can be achieved with continuous procedures, which should be conducted under clinical monitoring of the peripheral nerves to avert possible nerve injury.