SLR - March 2010 - Ameneh Aminian
Reference:
Choi, W. J; Park, K.K; Kim, B.S; Lee, J. W. (2009). Osteochondral Lesion of the Talus: Is There a Critical Defect Size for Poor Outcome? The American Journal of Sports Medicine, 37 (10), August, 2009.
Scientific Literature Reviews
Reviewed by: Ameneh Aminian, DPM
Residency Program: Massachusetts General Hospital, Boston, MA
Podiatric Relevance:
Osteochondral lesions of the talus are a common cause of ankle pain and disability. Many studies have demonstrated that focal chondral and osteochondral defects progress to osteoarthritis, but analysis of clinical findings (and their predictive value) including age, sex, duration of symptoms, location, and size of the cartilage defect have been inconsistent and unsatisfactory. The dual purpose of this study was (1) to determine the prognostic significance of defect size as treated by arthroscopic marrow stimulation techniques and (2) to identify the cutoff point of defect size at which poor outcomes can be identified with maximum specificity and sensitivity.
Methods:
This cohort study was a retrospective analysis, including 117 patients (120 ankles) who received arthroscopic treatment from January 2001 to June 2006. Microfractures were performed on 64 ankles, and abrasion arthroplasties were performed on 56 ankles. Average patient age was 34.6 years (range 13-66), including 80 men and 37 women. The mean duration of symptoms was 27.7 months (range 6-120) and the average follow up was 44.5 months (range 12-81). All patients included in this study had MRI-confirmed, localized defects of the talar dome, with ankle pain or functional limitation for minimum of 6 months. Patients with diffuse arthritic changes and ankle fractures were excluded from the study. Postoperative outcomes were assessed according to the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score, stepwise multivariate linear regression was used to assess the association between preoperative MRI variables and clinical outcomes, and the Kaplan-Meier method was used to estimate probabilities of clinical failure, including cutoff point of the defect size.
Results:
In this study, eight (6.7%) ankles required osteochondral transplantation, and twenty-two (18.4%) ankles were considered failures due to AOFAS scores less than 80. Lesion area was the strongest MRI predictor of clinical outcome, while length (coronal & sagittal) was moderately strong, and depth of lesion was the weakest. A critical defect area larger than 150 mm2 correlated with a poor clinical outcome, and was considered the cutoff point for clinical failure. Patient age, duration of symptoms, location of lesion, trauma or associated lesions did not demonstrate a significant correlation with clinical outcome.
Conclusions:
The initial size of an osteochondral lesion of the talus (OLT) is easily determined by MRI, is an important prognostic indicator of clinical outcome, and may also provide a guide for preoperative surgical decision-making.