Posterolateral rotatory instability of the knee after arthroscopic subtotal lateral meniscectomy: a case report.

A 33-year-old Caucasian woman came to our attention complaining of lateral knee pain on the left side, severe external instability associated with varus malalignment, and difficulties in weight-bearing activities. The symptoms had appeared following two lateral meniscectomies on her discoid meniscus, performed elsewhere. The patient was initially submitted to an allograft meniscus transplantation exploiting the unloaded condition of lateral compartment and obtained pain relief. The posterolateral corner was reconstructed in combination with a valgus osteotomy to address the posterolateral rotatory instability. The follow-up assessment at two years after the last surgery showed no symptoms, maintenance of limb alignment and no evidence of joint degeneration.