Successful Rehabilitation Following Stem Cell Therapy for Large Knee Osteochondritis Dissecans in an Adolescent Wrestler.

Context: Detailed rehabilitation protocols after stem cell treatment are lacking. This case highlights the rehabilitation of a patient treated with human umbilical cord blood-derived mesenchymal stem cell implantation for a large osteochondritis dissecans lesion of the knee.

Case presentation: A 17-year-old male adolescent wrestler experienced persistent left knee pain for 1 year, unresponsive to 6 months of conservative treatment. MRI revealed a large osteochondritis dissecans lesion (38 × 18 mm) in the lateral femoral condyle, which was treated with human umbilical cord blood-derived mesenchymal stem cell implantation.

Management and outcomes: Rehabilitation was conducted in 4 phases. The protection phase (1-8 wk) emphasized weight-bearing restrictions, continuous passive motion, and early gait training. The gait recovery phase (9-12 wk) incorporated stationary cycling and open kinetic chain exercises. During the maturation phase (13-24 wk), maximal strength and proprioception exercises were introduced with antigravity treadmill running. The final recovery phase (24-52 wk) focused on plyometric drills and sport-specific activities. Team training resumed at 32 weeks, and return to full competitive training occurred at 52 weeks. The limb symmetry index for isokinetic knee-extensor strength and single-leg hop test reached 95.2% and 97.9%, respectively, by 12 months, indicating near-complete functional recovery. The modified MRI of cartilage repair tissue score improved from 40 to 60 points between 1 and 3 years postsurgery. Second-look arthroscopy revealed an International Cartilage Repair Society grade 1 at 35 months. International Knee Documentation Committee scores increased from 17.2 preoperatively to 98.9 at 2 years, while visual analog scale scores decreased from 10 to 2 over 3 years.

Conclusions: Accelerated weight bearing, early gait training, and phased strength exercises facilitated substantial improvements in function and cartilage healing in an adolescent wrestler with a large osteochondritis dissecans lesion. Further studies with larger cohorts are recommended to confirm these findings.