We describe a previously unpublished and possibly unrecognised association between injuries to the posterior cruciate ligament and Osgood-Schlatter disease.

Over a two-year period the authors have treated thirty patients with isolated or combined injuries to the posterior cruciate ligament, confirmed with MR1 or examination under anaesthetic/arthroscopy. Five of these had previously suffered from Osgood-Schlatter disease as adolescents, leaving them with prominent tibial tuberosities.

We feel there may be a significant association between these two conditions and the importance of this association is twofold: – firstly, at the time of injury the prominent tibial tuberosity impacts first and results in increased posterior translation of the tibia rendering the posterior cruciate ligament more prone to injury – secondly, during examination of the injured knee, the prominence of the tibial tubercle may make a posterior sag sign less obvious thus obscuring the diagnosis unless one is diligent.

We believe that patients who have previously suffered with Osgood-Schlatter disease are vulnerable to posterior cruciate ligament injury and this should be borne in mind whilst examining them following knee injuries.