High Tibial Osteotomy – Complications
Undercorrection – the most common complication
– basically, anything less than 7 degrees of valgus is undercorrected. Must get them to 8-10 degrees of valgus (representing an overcorrection of 3-5 degrees from normal valgus)
Overcorrection – second most common complication
– going too far is bad also; > 15 degrees of valgus is poorly tolerated and can cause patellofemoral tracking problems
Deep Peroneal Nerve Injury – third most common, but most dreaded complication
– caused by tight post-op bandages, tight casts, transient anterior compartment syndrome, and direct injury
– in general, it is not recommended to go expose it – just keep the knee flexed during the procedure; exposing it and even gentle handling of it can cause a neuropraxia.
– 0-40 mm from tip is where the motor branch to tibialis anterior arises
– 68-153 mm from tip is where motor branch to EHL arises – EHL weakness postop is frequently seen because of failure to recognize this. The safe zone is 160 mm from tip of fibula.
Vascular Injury & Compartment Syndrome
– do prophylactic fasciotomy and use drain if necessary
– preserve the medial osseoperiosteal hinge! It is critical to stability of the osteotomy.
– osteotomy proximal to the tibial tubercle has a lower rate of nonunion than distal