Summary

Patients with osteochondral defects of the knee joint treated with autologous chondrocyte implantation with spheroids combined with simultaneous autologous bone grafting showed a significant improvement in all analyzed scores and a high patient satisfaction. However, altered knee biomechanics in 3D-instrumented gait analysis were observed.

Abstract

Introduction

Osteochondral defects of the knee joint require complex treatment. In recent years, the combination of autologous chondrocyte implantation with simultaneous autologous bone grafting has become established as a therapeutic procedure. However, there are few data on the functional outcome of this therapeutic procedure. The aim of this study is a systematic analysis of the functional midterm outcomes using a 3D-instrumented motion analysis and validated clinical scores.

Methods

37 patients (22m, 15f; mean age: 31.5 years, range: 18-55 years, mean follow-up: 3.7 ± 1.96 years, range: 1-7.25 years) have been included. The mean chondral lesion size was 4.5 cm2 ± 2.8. 3D-instrumented gait analysis (Motion Capture System, Vicon Nexus) was used to assess lower extremity kinematics and kinetics. The functional outcome was assessed with the IKDC score, the Lysholm score, the PROMIS 29 profile v2.0 score and a patient satisfaction survey.

Results

All clinical scores showed statistically significant improvement compared to the preoperative condition (IKDC: 56.5 ± 17.0 vs. 73.6 ± 10.3, p<0.01; Lysholm: 64.6 ± 17.6 vs. 75.2 ± 14.3, p<0.01). The PROMIS 29 profile v2.0 score showed significant improvement in the categories pain intensity (4.9 ± 2.5 vs. 2.6 ± 2.0, p<0.01), physical function (45.3 ± 6.8 vs. 50.6 ± 5.9, p<0.01), pain interference (55.0 ± 6.7 vs. 49.5 ± 6.7, p<0.01) and social roles and activities (50.2 ± 8.4 vs. 54.7 ± 6.6, p=<0.01). The patients reported a high satisfaction rate (94.6%). Kinetics, kinematics and ROM of hip and ankle were not statistically significantly different to the contralateral limb, nor were significant differences in step length, step width, stance time and swing time observed. We found a significant smaller knee flexion (9.58° ±7.33 vs. 13.65° ±6.67, p=0.02) and a significant lower knee extension moment (0.08Nm/kg ±0.25 vs. 0.22Nm/kg ±0.19, p=0.01) during loading response phase compared to the contralateral knee joints. There were no significant differences in the knee adduction moment during initial contact, loading response and toe off, compared to the contralateral side. The joint-power of the operated knees was significantly reduced during initial contact (0.15W/kg ± 0.22 vs. 0.26W/kg ± 0.2) compared to the contralateral knee joints.

Discussion And Conclusion

The combination of autologous chondrocyte implantation with spheroids and simultaneous bone grafting showed significant improvements in all analyzed scores and a high patient satisfaction at midterm follow-up in patients with osteochondral defects of the knee joint. 3D-instrumented gait analysis showed significant differences in kinematics and kinetics of the operated knees compared to the contralateral side. The operated knees showed as a smaller knee flexion and a lower knee extension moment during loading response phase compared to the contralateral side. No affection in the adjacent joints was found in 3D-instrumented gait analysis.