Arthroscopic Cartilage Lesion Preparation in the Human Cadaveric Knee Using a Curette Technique Demonstrates Clinically Relevant Histologic Variation.

PURPOSE

To examine the quality of arthroscopic cartilage debridement using a curette technique by comparing regional and morphologic variations within cartilage lesions prepared in human cadaveric knee specimens for the purpose of cartilage repair procedures. A secondary aim was to compare the histologic properties of cartilage lesions prepared by surgeons of varying experience.

METHODS

Standardized cartilage lesions (8 mm × 15 mm), located to the medial/lateral condyle and medial/lateral trochlea were created within 12 human cadaver knees by 40 orthopaedic surgeons. Participants were instructed to create full-thickness cartilage defects within the marked area, shouldered by uninjured vertical walls of cartilage, and to remove the calcified cartilage layer, without violating the subchondral plate. Histologic specimens were prepared to examine the verticality of surrounding cartilage walls at the front and rear aspects of the lesions, and to characterize the properties of the surrounding cartilage, the cartilage wall profile, the debrided lesion depth, bone sinusoid access, and the bone surface profile. Comparative analysis of cartilage wall verticality measured as deviation from perpendicular was performed, and Spearman's rank correlation analysis was used to examine associations between debrided wall verticality and surgeon experience.

RESULTS

Mean cartilage wall verticality relative to the base of the lesion was superior at the rear aspect of the lesion compared to the front aspect (12.9° vs 29.2°, P < .001). Variability was identified in the morphology of the surrounding cartilage (P < .001), cartilage wall profile (P = .016), debrided lesion depth (P = .028), bone surface profile (P = .040), and bone sinusoid access (P = .009), with sinusoid access identified in 42% of cases. There was no significant association of cartilage lesion wall verticality and surgeon years in practice (r = 0.161, P = .065) or arthroscopic caseload (r = -0.071, P = .419).

CONCLUSIONS

Arthroscopic cartilage lesion preparation using standard curette technique in a human cadaveric knee model results in inferior perpendicularity of the surrounding cartilage walls at the front aspect of the defect, compared to the rear aspect. This technique has shown significant variability in the depth of debridement, with debridement depths identified as either too superficial or too deep to the calcified cartilage layer in more than 60% of cases in this study. Surgeon experience does not appear to impact the morphologic properties of cartilage lesions prepared arthroscopically using ring curettes. CLINICAL RELEVANCE: To optimize restoration of hyaline-like cartilage tissue, careful attention to prepared cartilage lesion morphology is advised when arthroscopically performing cartilage repair, given the tendency for standard curette technique to create inferior verticality of cartilage walls at the front of the lesion, and the variable depth of debridement achieved.