Cartilage Injury in the Knee: Assessment and Treatment Options

Aaron J. Krych, MD; Daniel B. F. Saris, MD, PhD; Michael J. Stuart, MD; Brittney Hacken, MD

Disclosures

J Am Acad Orthop Surg. 2020;28(22):914-922. 

In This Article

Fixation of Unstable Osteochondral Fragment or Loose Body

Unstable osteochondral fragments and loose bodies are commonly observed in the setting of patellofemoral instability or osteochondritis dissecans. If these fragments have viable cartilage and bone, typically 3 mm or greater on the progeny fragment, then consideration should be given to repair the fragment in the donor location. The presence of bone is ideal, but case series have shown that large chondral fragments without observable bone may do well with fixation in select cases in skeletally immature patients.[11] Skeletally mature and immature patients can benefit from fixation of unstable osteochondral fragments with healing rates not dependent on epiphyseal plate status.[12]

Fixation of these fragments is ideal because it uses native cartilage, can be performed in a single stage, and is relatively inexpensive. Unfortunately, a long-standing loose body may have poor quality cartilage, may resorb, or may hypertrophy, making it difficult to fix in the donor site.[13] We prefer to repair osteochondral fragments with viable bone and cartilage by thoroughly cleaning the fibrous tissue from the defect and fragment, adding an autologous bone graft if needed, and contouring and fixing the fragment.

The method of fixation varies and is largely dependent on fragment size and surgeon preference. Osteochondral defect progeny fragments can be fixed with headless compression screws, countersunk headed compression screws, or various bioabsorbable chondral darts and nails (Figure 2). The goal is to fix the osteochondral or chondral fragment to a healthy bleeding bone surface with good compression to allow for healing within the intra-articular environment of the knee.[11,14]

Figure 2.

Photographs showing the fixation of osteochondral loose body secondary to osteochondritis dissecans. A, Shows loose body retrieval during knee arthroscopy. Care is taken to not damage the cartilage while grasping fragment. B, After preparation of the donor site to good bleeding subchondral bone surface, fixation with multiple headless compression screws that are sunk below the cartilage surface is achieved.

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