OCD Lesions of the Knee - An Updated Review on a Poorly Understood Entity

Abstract

Osteochondritis dissecans (OCD) of the knee is a condition that has continued to perplex the orthopaedic community in its origin, despite clear advances in identification and treatment. The incidence of this potentially disabling condition has remained relatively steady, but with a shifting distribution towards young, athletic males as the primarily affected demographic. The condition commonly presents insidiously as vague knee pain but may advance to overt mechanical symptoms due to loose body formation in the joint. OCD lesions are typically classified with magnetic resonance imaging (MRI) as either stable or unstable based on the mechanical integrity of the fragment and the state of the underlying subchondral bone. The purpose of this paper is to review the current understanding of pediatric OCD of the knee, contemporary treatment principles, including methods to promote OCD lesion healing, fixation methods, and salvage techniques. Key Points: • High-intensity T2-signal behind the progeny fragment of the OCD lesion is suggestive of instability. • Retroarticular or transarticular drilling of a non-healing, stable OCD lesion in the pediatric knee results in increased healing rates. • Unstable or ex situ OCD lesions with intact subchondral bone can adequately be fixated using metallic screws, absorbable screws, or other biological device constructs. • Unsalvageable OCD lesions pose a challenge to the surgeon. However, new developments with osteochondral autograft, allograft, and autologous cell techniques have increased the surgeon's ability to manage these challenging lesions.