A special combined proximal tibial osteotomy (CPTO) was designed to correct varus osteoarthritis of the knee with severe intra-articular pathologies, which could not be fully corrected by opening-wedge high tibial osteotomy (OWHTO).

A new study published in Knee evaluated and compared the biomechanical strength of the CPTO bone-implant construct with those of existing osteotomy methods.

In this study, three variations of osteotomy were performed – OWHTO, tibial condylar valgus osteotomy (TCVO)s and CPTO, on synthetic bones with locking plate and screws. Wedge stiffness, wedge displacement and load failure were measured by biomechanical tests.

The results revealed that wedge stiffness, wedge displacement and failure load of the CPTO construct were very close to those of the OWHTO construct. Additionally, the numerical results of wedge stiffness and displacement showed good conformity to previous biomechanical results. The stress distribution at lateral hinge, plate corner and holes of the CPTO construct were equivalent those of the OWHTO counterpart. On the other hand, the stress distribution at the inter-condylar eminence of tibia and at the middle region of the screws was similar to those of the TCVO counterpart.

Hence, it was inferred that the CPTO construct can provide comparable strength for early mobilization and rehabilitation to that of the OWHTO construct.

Source: Knee. 2020 Feb 8. pii: S0968-0160(20)30005-3. doi: 10.1016/j.knee.2020.01.006.