A cross-sectional study to assess variability in knee frontal plane movement during single leg squat in patients with anterior cruciate ligament injury.

BACKGROUND: Single leg squat (SLS) tests help predict anterior cruciate ligament injuries. However, the variability in joint movement during this test has not been fully investigated. The aim of this study was to examine the knee frontal plane movement variability during SLS in patients with anterior cruciate ligament (ACL) injury. METHODS: In this cross-sectional study, we enrolled 56 patients with ACL injury (28 males; 28 females) and 46 healthy subjects (23 males; 23 females). All participants underwent SLS tests. All kinematic variables were joint angle of trunk, pelvis and lower limb, center of gravity (COG), center of pressure (COP). These data were obtained at the frontal plane and the coefficient of variation (CV) were calculated. Multiple comparisons were performed between healthy subjects and the injured leg and uninjured leg of patients with ACL injury. The correlation of the CV in knee varus/valgus range of motion (ROM) with the CV in other kinematic variables were investigated in patients with ACL injury. RESULTS: Compared with healthy subjects, patients with ACL injury exhibited significantly larger the CV in knee varus/valgus ROM. A positive correlation was observed between the CV in knee varus/valgus ROM and the CV in pelvic lateral inclination ROM in patients with ACL injury. CONCLUSIONS: Knee frontal plane movement variability during SLS may help evaluate the risk of ACL injury/re-injury. In addition, pelvic lateral inclination variability during SLS may need to be evaluated in conjunction with knee frontal plane movement variability.

Joint movement variability during landing in patients with anterior cruciate ligament reconstruction.

BACKGROUND: Rapid knee valgus and knee internal rotation motions in the initial phase of landing are the known mechanisms for anterior cruciate ligament injury, and many studies have been investigated on knee joint peak angle during landing. However, the variability in joint movement during landing has not been fully investigated. This study aimed to compare the coefficient of variation of lower extremity range of motion in patients with anterior cruciate ligament reconstruction and healthy subjects during landing. METHODS: In this cross-sectional study, 54 patients with anterior cruciate ligament reconstruction and 44 healthy subjects were enrolled. All participants underwent six trials of single-leg hop landing for maximum safe horizontal distance. The kinematic variables were the coefficient of variation during two discrete (0.05 after initial contact and maximum knee flexion) time points for selected three-dimensional hip and knee joint range of motion. Comparisons were performed between the two groups. RESULTS: Compared with healthy subjects, patients with anterior cruciate ligament reconstruction had greater the coefficient of variation in hip internal/external rotation range of motion (patients with anterior cruciate ligament reconstruction had 41.9%, healthy subjects had 25.5%; P=0.0018; effect size: 0.32) and knee internal/external rotation range of motion (patients with anterior cruciate ligament reconstruction had 68.4%; healthy subjects had 48.1%; P=0.0014; effect size: 0.32) for periods that spanned 0.05 s from the initial contact. CONCLUSIONS: Patients with anterior cruciate ligament reconstruction could be disadvantageous in ability to control and adapt hip and knee joint rotations when controlling landings.

Morphological changes in the tibiofibular joint following open wedge high tibial osteotomy.

BACKGROUND: To investigate the morphological changes in the tibiofibular joint following open wedge high tibial osteotomy (OWHTO). METHODS: We studied 397 joints in 341 patients. Standing femorotibial angle (FTA), %mechanical axis (%MA), corrected tibial angle, distance (D) to tibial joint surface (T) and fibular head (F) and angle (A; proximal, distal), proximal tibiofibular joint (PTFJ) osteoarthritis (OA) onset, and tibiofibular joint-related complications were the parameters assessed. RESULTS: FTA improved from 181.1° to 168.8° and %MA from 28.7 to 68.7, whereas the mean tibia corrected angle was 10.4°. Proximal TFD changed from 9.4 mm preoperatively to 7.8 mm during the investigation. The fibular head was displaced 1.6 mm upwards, and proximal tibial femoral angle (TFA) moved approximately 10° in the valgus direction from 82.5° to 92.4°. However, no significant changes were noted for the distal TFD or TFA. PTFJ OA was observed in 57 cases (14.7%), and lateroposterior knee pain in 11 cases (2.8%). Additional resection of the fibula was performed in cases with marked pain. CONCLUSIONS: With OWHTO, increased load is placed on the PTFJ postoperatively. In rare cases, this can cause pain and is therefore a complication that physicians should be aware of.