Combined Cartilage Procedures After High Tibial Osteotomy: Cartilage Status, Early Functional Recovery, and Short-term Clinical Outcomes

Abstract

Background: The clinical benefit of performing cartilage procedures concurrently with high tibial osteotomy (HTO) remains uncertain. While these procedures aim to enhance cartilage regeneration, concerns persist regarding increased early postoperative pain and delayed functional recovery. Purpose: To evaluate whether adding cartilage procedures increases pain or delays functional improvement during early recovery after HTO.Study Design: Cohort study; Level of evidence, 3.Methods: Patients who underwent HTO between March 2015 and December 2022 were included if patient-reported outcomes (PROs) were available at 6, 12, and 24 months postoperatively. Patients were categorized into 3 groups: isolated HTO (group I), HTO with microdrilling (group M), and HTO with umbilical cord blood-derived mesenchymal stem cell implantation (group C). PROs were retrospectively reviewed. Factors such as osteoarthritis severity, cartilage defect size, kissing lesions, and postoperative alignment were analyzed. For patients with 1-year postoperative magnetic resonance imaging (MRI) studies, subchondral edema severity and depth were assessed. Postoperative cartilage status was evaluated using second-look arthroscopy. Results: Among 234 knees, 93 were included: 38 in group I, 32 in group M, and 23 in group C. Baseline characteristics were comparable, although group M had smaller medial femoral condyle cartilage defects (group I: 6.5 +/- 2.6 cm(2) vs group M: 4.4 +/- 2.4 cm(2 )vs group C: 7.4 +/- 2.1 cm2; P < .001). At 6 months, group C demonstrated significantly less improvement in Lysholm (5.3 +/- 20.1 vs 20.8 +/- 21.5; P = .018) and International Knee Documentation Committee Function (0.0 +/- 2.7 vs 2.3 +/- 3.3; P = .014) scores compared with group I. Minimal clinically important difference achievement rates at 6 months were lower in groups M and C than in group I (Lysholm score: P = .041; Knee injury and Osteoarthritis Outcome Score Activities of Daily Living: P = .020). These differences were no longer significant at 12 and 24 months. No baseline factor correlated significantly with PROs. MRI showed that subchondral edema correlated with greater pain and poorer function (r = 0.250-0.380; P < .05). Although second-look arthroscopy indicated improved cartilage status in the cartilage procedure groups, these findings did not correlate with PROs. Conclusion: Combined cartilage procedures involving subchondral drilling after HTO are associated with increased early postoperative pain and delayed functional recovery during the first 6 months. Although second-look arthroscopy demonstrated improved cartilage status in the cartilage procedure groups, clinical outcomes at 12 and 24 months were comparable to those observed after isolated HTO.