Purpose of the study. Release of tight lateral structures is an integral part of balancing the valgus knee during knee replacement surgery. The posterolateral capsule is released through an inside-out technique. The common peroneal nerve is in close proximity to the capsule during this step. This study was undertaken to determine the distance of the nerve and the safe level for the posterolateral release. Methods. MR scans of the knee of 100 patients were evaluated. The age range of selected patients was 50 to 70 years. The distance of the nerve was measured to the closest point on the posterolateral capsule. Two separate measurements were taken - one 9mm above the joint line indicating the distal femoral resection level and the other 9mm distal to the joint line indicating the level of tibial resection. A third point was at the joint line level. The position of the nerve was also recorded in relation to the cross section of the femur/tibia on a ‘clock-like’ reference. Results. The mean distance of the nerve from the capsule was 13.4mm at level of distal femoral resection, 12.4mm at the level of the joint line and 10.9mm at the level of tibial resection. The minimum distance was 8.2mm at the proximal level, 6.7mm at the level of joint line and 4.7mm at the distal level. Conclusions. The common peroneal nerve is in close proximity to the
The cause of dissatisfaction following total
knee arthroplasty (TKA) remains elusive. Much attention has been
focused on static mechanical alignment as a basis for surgical success and
optimising outcomes. More recently, research on both normal and
osteoarthritic knees, as well as kinematically aligned TKAs, has
suggested that other specific and dynamic factors may be more important
than a generic target of 0 ± 3º of a neutral axis. Consideration
of these other variables is necessary to understand ideal targets
and move beyond generic results. Cite this article: