The morphometry of soft tissue insertions on the tibial plateau: Data acquisition and statistical shape analysis

This study characterized the soft tissue insertion morphometrics on the tibial plateau and their inter-relationships as well as variabilities. The outlines of the cruciate ligament and meniscal root insertions along with the medial and lateral cartilage on 20 cadaveric tibias (10 left and 10 right knees) were digitized and co-registered with corresponding CT-based 3D bone models. Generalized Procrustes Analysis was employed in conjunction with Principal Components Analysis to first create a geometric consensus based on tibial cartilage and then determine the means and variations of insertion morphometrics including shape, size, location, and inter-relationship measures. Step-wise regression analysis was conducted in search of parsimonious models relating the morphometric measures to the tibial plateau width and depth, and basic anthropometric and gender factors. The analyses resulted in statistical morphometric representations for Procrustes-superimposed cruciate ligament and meniscus insertions, and identified only a few moderate correlations (R 2: 0.37-0.49). The study provided evidence challenging the isometric scaling based on a single dimension frequently employed in related morphometric studies, and data for evaluating cruciate ligament reconstruction strategies in terms of re-creating the native anatomy and minimizing the risk of iatrogenic injury. It paved the way for future development of computer-aided personalized orthopaedic surgery applications improving the quality of care and patient safety, and biomechanical models with a better population or average representation

Changes in joint position sense after surgically treated chronic lateral ankle instability

Background: A search of the literature shows that the effect of surgery on ankle proprioception has been hardly investigated. Objective: To examine the effect of anatomical reconstruction of the anterolateral capsuloligamentous complex on ankle joint position sense. Methods: A prospective study using the "slope box" test. Ten consecutive patients were included in the study, and 10 healthy athletes represented the control group. Results: Similar test-retest reliability rates (overall reliability 0.92; p = 0.0013) were obtained to those of the original designers of the method. There were no significant differences with respect to side dominance (p = 0.9216). Investigation of the characteristics of mean absolute estimate errors showed that the controls tested became error prone in the range of slope altitudes 7.5–25° in every direction, compared with the range 0–5° (range of p values 0.00003–0.00072). The results of the intervention group showed that, for the two main directions of interest (anterior and lateral), preoperative differences in mean absolute estimate errors between injured (anterior 3.91 (2.81)°; lateral 4.06 (2.85)°) and healthy (anterior 2.94 (2.21)°, lateral 3.19 (2.64)°) sides (anterior, p = 0.0124; lateral, p = 0.0250) had disappeared (postoperative differences: anterior, p = 0.6906; lateral, p = 0.4491). The afflicted ankle had improved significantly after surgery in both important directions (anterior, p<0.0001; lateral, p = 0.0023). Conclusions: The study shows that differences in joint position sense between healthy and injured ankles disappeared as the result of surgery. Preoperative data show that proprioceptive malfunction is a cause of functional instability. If treatment is by means of surgery, the retensioning of the original anterolateral structures is inevitable, even if other grafting or surgical techniques are used