[Assessment of the vulnerability of the proximal tibiofibular joint to injury during osteotomies].

Objectives: We evaluated the dimensions and anatomic localization of the proximal tibiofibular joint (PTFJ) in human cadaver and amputated knees. In addition, we assessed the relation between the osteotomy line and the PTFJ and its vulnerability to injury on radiographs of patients after proximal tibial medial open wedge osteotomy (PT-MOWO).

Methods: In the first phase, dimensions of the tibial part of the PTFJ lying between the lateral tibial condyle and the fibular head were measured by digital calipers in six human cadaver and six fresh amputed tibiae (4 females, 8 males; mean age 57 years) to evaluate the relation between the tibial surface of the PTFJ and the posterior part of the lateral tibial plateau. In the second phase, anteroposterior, lateral, and medial oblique radiographs were assessed with respect to the relation of the osteotomies with the PTFJ following PT-MOWO in 46 knees of 44 consecutive patients (38 females, 6 males; mean age 51 years).

Results: On cadaver and fresh amputation materials, the mean long and short axis dimensions of the ellipsoidal articular surface of the PTFJ in the posterolateral aspect of the tibial plateau measured 18.8 mm (range 13 mm to 20 mm) and 14.9 mm (13 mm-17 mm), respectively. The upper articular border lied at a mean of 6.3 mm (2 mm to 11 mm) distal to the posterior border of the articular surface of the lateral tibial plateau. Medial oblique radiographs showed that the osteotomy line extended to the PTFJ in cases in which it was proximally located, particularly in three cases (6.5%) where lateral cortex continuity was interrupted.

Conclusion: The osteotomy line may encroach upon the PTFJ unless preoperative oblique radiographs are evaluated and a parallel course to the tibial slope of the lateral tibial plateau is followed. In addition, insufficient evaluation of PT-MOWO candidates may result in damage to the lateral cortex, which increases the risk for injury to the PTFJ.