Fixation Methods, Complications, and Outcomes After Primary Fixation of Isolated Chondral Fragments in the Knee: A Systematic Review

Background: Knee injuries resulting in purely cartilaginous defects are rare, and controversy remains regarding the reliability of chondral-only fixation. Purpose: To systematically review the literature for fixation methods and outcomes after primary fixation of chondral-only defects within the knee. Study Design: Systematic review; Level of evidence, 5. Methods: A literature search was conducted following the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using keywords and Boolean phrases in PubMed, Embase, Cochrane, and Scopus on October 10, 2023. Human studies reporting fixation methods and outcomes after primary fixation of chondral-only defects within the knee were included in this systematic review. Studies reporting subchondral bone involvement were excluded. Study quality was assessed using the Joanna Briggs Institute critical appraisal tool. Postoperative outcomes, reoperations, and return to sport/activity were evaluated. Failure was defined as chondral fragment dislodgement or failure of healing postoperatively. Results: A total of 18 studies (N = 93 patients) were identified. The mean patient age was 16 years (mean range, 11-32 years), with a mean final follow-up of 42.4 months (mean range, 5-61.2 months). Men comprised 81% (n = 59/73) of patients. Bioabsorbable implants (n = 13 studies) were the most commonly reported fixation method. Complications related to fixation of the chondral fragment occurred in 10.8% of patients (n = 10/93), with all other complications occurring in 9.8% (n = 9/93) of patients. Revision surgery directly associated with the chondral fragment was reported in 10.8% (n = 10/93) of patients. Successful return to sport/activity was observed in 90% (n = 60/67) of patients. Intact fixation was reported in 85% (n = 75/88) of patients undergoing postoperative magnetic resonance imaging, computed tomography, or second-look arthroscopy. Conclusion: Primary fixation of chondral-only defects can lead to low rates of failure and revision surgery with a high return to sport/activity in young patients, even with relatively large lesions. Bioabsorbable implants and absorbable sutures were the most common fixation methods, primarily performed via open arthrotomy after diagnostic arthroscopy. Failure of fixation and implant irritation were the most commonly reported complications related to fixation, with reoperations directly related to fragment fixation performed in 10.8% of patients. Healing of the chondral fragment as evaluated using postoperative magnetic resonance imaging, computed tomography, or second-look arthroscopy was reported in 85% of patients.