Posterolateral aspect and stability of the knee joint. I. Anatomy and function of the popliteus muscle-tendon unit: an anatomical and biomechanical study. | LitMetric
This study examined ten human adult cadaveric knees to dissect the popliteus muscle-tendon unit (PMTU), including its numerous attachments to other posterior and posterolateral structures, and to determine the effect of tensioning the PMTU on the internal and external rotation, total rotational arcs, and neutral tibial rotation in full extension and 30 degrees, 60 degrees, and 90 degrees of knee flexion. The junction between the popliteus tendon and the fibular head commonly described as the popliteofibular ligament became lax in internal and tense in external tibial rotation. The internal and external rotational arcs increased gradually between extension and 90 degrees of flexion. Tensioning the PMTU resulted in a statistically highly significant internal tibial rotation with decreased internal and increased rotational arcs. The anatomical findings and functional data indicate that the PMTU is an important structure maintaining dorsolateral stability, stabilizing the lateral meniscus, and balancing the neutral tibial rotation.
Background: Anterior tibial laxity is considered to be a risk factor for knee injuries, including anterior cruciate ligament ruptures. The anterior cruciate ligament reconstruction also aims to restore anterior tibial laxity. While anterior tibial laxity is considered to be linked to dynamic knee stability, the mechanisms connecting anterior tibial laxity to these stability issues are not fully understood.
Background: Supination external rotation (SER) fibula fractures with abnormal medial clear space (MCS) on stress radiographs that normalizes with weightbearing radiographs, termed SER4a ankle fractures, pose a challenge in treatment decision making. This study aims to quantify differences in joint contact area, tibiotalar rotation, and translation using weightbearing computed tomography (CT) scans in SER4a ankle fractures.
Methods: Between November 2022 and September 2023, patients presenting with isolated Weber B fibula fractures were evaluated for inclusion.
Purpose: The efficacy of medial pivot total knee arthroplasty (MP TKA) in treating valgus knees that may cause medial instability is unknown. The purpose of this study was to investigate the in vivo kinematics of MP TKA for the valgus knees and compare them to those for the varus knees.
Methods: The kinematics of 19 valgus knees and 19 varus knees operated in the MP TKA were investigated under fluoroscopy during squatting using a two- to three-dimensional registration technique.
Background: The diagnosis of syndesmotic instability is challenging, and chronically unstable injuries can potentially lead to ankle arthritic degeneration. The objective of this cadaveric study was to utilize a 3-dimensional (3D) weight-bearing computed tomography (WBCT) distance mapping algorithm for the detection of subtle syndesmotic instability, induced by complete syndesmotic ligament sectioning and stressed by isolated axial load. We hypothesized that this algorithm would accurately detect subtle syndesmotic instability.
Objective: To investigate ideal screw implant angle in reconstruction of tibiofibular syndesmosis injury by using a biomechanical test.
Methods: A total of 24 ankle specimens from adult cadavers were used as the tibiofibular syndesmosis injury model. According to the angle of screw placement, the tibiofibular syndesmosis injury models were randomly divided into groups A (0°), B (10°-15°), C (20°-25°), and D (30°-35°), and the screws were placed at a level 2 cm proximal to the ankle joint.
