2015 ISAKOS Biennial Congress Paper #0

Subchondral Changes are Linked to Age and Clinical Outcome in Patients with Osteochondral Fractures in the Knee: Analysis of Postoperative Magnetic Resonance Imaging at 1 to 10 Years

Jakob Ackermann, MD, Zurich SWITZERLAND
Manuel Waltenspül, MD, Zürich SWITZERLAND
Gergo B Merkely, MD, PhD, Boston, MA UNITED STATES
Christoph Germann, MD, Zurich SWITZERLAND
Christoph Alexander Aufdenblatten, MD, MBA, Zürich, Zürich SWITZERLAND
Sandro Fucentese, Prof MD, Zuerich, CH SWITZERLAND
Balgrist University Hospital, Zurich, SWITZERLAND

FDA Status Not Applicable

Summary: Fixation of OCF yields acceptable clinical and imaging outcome regardless of surgical timing, yet postoperative subchondral changes were significantly associated with clinical outcome and linked to patient age at the time of surgery.

Abstract:

Background

Surgical fixation of osteochondral fractures (OCF) in the knee yields good clinical outcomes, yet predictive factors influencing outcome, particularly time between injury and surgery, have not been determined yet.
Purpose/Hypothesis: To report imaging and clinical outcomes after OCF fixation and to assess associations between patient demographics, lesion morphology, MR appearance and clinical scores.
Study Design: Case series; Level of evidence, 4.

Methods

This study assessed the radiographic and clinical outcomes of 19 patients following screw fixation of an OCF in the knee at a minimum follow-up of 1 year. Patient demographics, lesion morphology and time from trauma to surgery were reviewed for each patient. At final follow-up, patients completed the VAS, Tegner activity scale, KOOS, and a patient satisfaction survey. Postoperative MRI was assessed for the MOCART 2.0 score, the OCAMRISS, and bone marrow edema (BME) size.

Results

The mean age at the time of surgery was 21.3 +/- 11.4 years with time from trauma to surgery ranging from 0 to 143 days (median 10 days). The refixed OCF fragment failed in one patient (5.3%) on the lateral condyle at 15 months postoperatively. Patients with an intact OCF fragment were evaluated at a mean follow-up of 4.7 +/- 3.2 years. Patients reported a mean VAS of 9.5 +/- 17.9, Tegner score of 4.3 +/- 2.4, KOOS Pain of 85.9 +/- 17.6, KOOS Symptoms of 76.4 +/- 16.1, KOOS Activities of Daily Living (ADL) of 90.3 +/- 19.0, KOOS Sport of 74.4 +/- 25.4 and KOOS Quality of Life (QOL) of 55.9 +/- 24.7, and patient satisfaction of 84.2%. Patient age was significantly associated with KOOS subscales and subchondral imaging parameters including BME and subchondral cysts, which in turn were the only imaging variables linked to clinical outcome (p < 0.05). Time from injury to surgery did not correlate with clinical or imaging outcome (n.s.).

Conclusion

Fixation of OCF yields acceptable clinical and imaging outcome at a mean follow-up of approximately 5 years with seemingly little influence of delayed surgical treatment. Yet, postoperative subchondral changes were significantly associated with clinical outcome and linked to patient age at the time of surgery.