Proximal Tibiofibular Joint Surgery: Preoperative Planning With MRI Scan to Determine Intraoperative Safe Zones

The proximal tibiofibular joint (PTFJ) is a less-understood aspect of the knee, which has significance in knee injuries. However, current literature has shown that there is a lack of a gold standard in PTFJ fixation. Our study aims to characterize the PTFJ and describe safe zones for intraoperative instrumentation and implant fixation for PTFJ stabilization.

Magnetic resonance imaging (MRI) knee images from 49 patients in a large public institution were reviewed retrospectively and analysed. Morphological parameters of PTFJ were measured, such as the PTFJ angle, width, shape, and safe zones for instrumentation. Descriptive statistics of parameters were reported as mean ± standard deviation (SD), with 95% confidence intervals (CI), and the Mann-Whitney U-test was used to examine if there were differences in PTFJ parameters between male and female patients.

The PTFJ angle had a mean of 28.2 ± 6.5° on the coronal view, 29.5 ± 6.6° on the sagittal view, and 34.2 ± 6.8° on the axial view. PTFJ width had a mean of 15.4 ± 1.8mm on the coronal view, 18.3 ± 2.2mm on the sagittal view, and 17.0 ± 1.7mm on the axial view. Male patients were found to have a wider PTFJ width on the coronal (P = 0.015), sagittal (P = 0.002), and axial (P = 0.008) planes when compared to female patients. The superior, anterior, and posterior safe zones for PTFJ instrumentation were 14.3° ± 2.5, 36.3° ± 6.1, and 6.8° ± 6.6, respectively. Male patients were found to have a longer distance from the fibula head to the entry point on both the coronal (P = 0.001) and sagittal (P = 0.004) planes. The mean distance from the neurovascular bundle was 12.6 ± 1.9mm.  Conclusions: In our study, we defined safe zones for PTFJ stabilization and described our intraoperative technique for instrumentation and implant fixation of the PTFJ joint to minimize complications. We also described morphological parameters of the PTFJ for our study population. The study will hopefully contribute to further understanding of the PTFJ and describe intraoperative safe zones for the stabilization of PTFJ injuries.