Outcomes of extra-articular, intra-epiphyseal drilling for OCD lesions of the knee with intact articular cartilage Eric W Edmonds, MD Jay Albright, MD Scott J Mubarak, MD Tracey Bastrom, MA Henry G Chambers, MD

Introduction Juvenile Osteochondritis dissecans (JOCD) –Subchondral lesion with degrees of osseous resorption, collapse, and sequestrum formation, possible delamination of articular cartilage in the skeletally immature

Guhl Classification

Management Non-operative management: –Activity modification, PT, casting –50% heal in 10 to 18 months (Cahill, 1989) Operative techniques: –Intra-articular drilling –Four outcome studies: 82% to 95% successful union

Outcomes of Intra-articular Drilling Multiple perforations in the previously intact cartilage.

Outcomes of Intra-articular Drilling Less perpendicular perforations in the sclerotic rim of the lesion.

Purpose Evaluate: –Extra-articular, intra-epiphyseal drilling –Does not damage intact articular cartilage –Increased fenestration of sclerotic rim

Methods Retrospective review Years 1997 to children, 75 knees (76 OCD lesions) Inclusion criteria –Open growth plates, failed six months conservative management, arthroscopically confirmed intact articular cartilage Exclusion criteria –Arthroscopic drilling through cartilage, detached cartilage, or closed growth plates.

Technique 1. Diagnostic arthroscopy to confirm Guhl grade 2. A inch K-wire, percutaneous, intra-epiphyseal to center of lesion

Technique 1.This center-center “ guide ” wire is then preserved as a guide for further wire placement.

Technique A parallel wire guide is used to direct a subsequent “ drilling ” K-wire 15 to 20 holes are drilled through the sclerotic rim

Outcome Determination Radiographic outcomes –Success: complete resolution of OCD lesion Clincial outcomes –Failure: further intervention

Results 59 lesions with complete data –17 lateral condyles and 42 medial condyles Mean age 13.4 years (8 to 18.6) 15 girls and 36 boys

Results 52 lesions with successful healing (87%) 7 lesions requiring further intervention (13%) Pre-drilling Post-drilling

Results Mean duration to healing: –11.8 months (1.3 to 47.3) Mean follow-up: –23.7 months (1.3 to 72) Each Lesion in Study Duration to Complete Healing Time (months)

Failures 2nd operation, mean 18 months after index operation: –4 required repeat drillings –2 required repeat drilling with bone graft –1 required trans-articular drilling with osteochondral tack

Failures 3rd operation: requiring matchstick bone graft and chondroplasty – 39 months after the index procedure (15 months after the second procedure of repeat drilling)

Complications No other complications resulted from this procedure

Comparing Our Results Our rate of 87% complete radiographic healing represents comparable outcomes to previous intra-articular drilling reports of 82% to 95% successful union

Discussion Extra-articular, intra-epiphyseal drilling of OCD lesions –Similar rate of healing compared to intra- articular drilling –Improved fenestration of subchondral rim –Nullifies damage to the overlying articular cartilage

Conclusion Less iatrogenic damage A safe and effective technique

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