Practical approach to modern cartilage repair combined with realignment osteotomy of the knee joint

Background: Realignment osteotomies are established procedures for treating unicompartmental knee osteoarthritis and focal cartilage injuries. However, persistent mechanical malalignment frequently compromises the success of cartilage restoration. Addressing the load-bearing axis is essential when treating deep-seated defects to prevent graft overload and subsequent failure.

Objective: This article reviews the clinical indications, surgical planning, and technical execution of combining various cartilage repair techniques with realignment osteotomies in patients presenting with concomitant bony deformities.

Key Points: Preoperative assessment requires comprehensive radiographic deformity analysis, including weight-bearing long-leg films to evaluate the mechanical axis. For defects smaller than 1.5 cm², microfracture or osteochondral transfer are viable options. Matrix-augmented bone marrow stimulation (M-BMS) serves as a single-stage alternative for medium-sized defects. Matrix-associated autologous chondrocyte transplantation (M-ACT) remains the gold standard for defects exceeding 2.5 cm², although it necessitates a two-stage approach and higher costs. Emerging techniques like autologous minced cartilage offer single-stage biological restoration but require further comparative evidence. Surgical sequencing typically involves performing the osteotomy first to ensure a stable mechanical environment before graft implantation. Postoperative protocols generally mandate six weeks of restricted weight-bearing to protect the regenerative tissue.

Conclusion: Integrating realignment osteotomy with cartilage repair provides a comprehensive approach to unicompartmental pathology. Success depends on precise axis correction—typically indicated for malalignment exceeding 3°—and selecting a restoration procedure tailored to the specific ICRS grade and defect dimensions.