Pathological External Rotation Research Articles

Research progress on pathological mechanism and clinical correlation between medial meniscus posterior root tear and tibial rotation

To summarize the current research progress on the concept, clinical presentation, diagnosis, biomechanical changes, and pathological mechanisms of the medial meniscus posterior root tear (MMPRT), and its clinical correlations with tibial rotation. The research literature on MMPRT and its relationship with tibial rotation at home and abroad in recent years was extensively consulted and summarized. MMPRT is a specific and common type of medial meniscus injury of the knee joint. The occurrence of posterior medial pumping pain events following low-energy trauma in patients provides important clues for the diagnosis of this injury, with MRI being the preferred imaging modality. The biomechanical effects generated by MMPRT are similar to those caused by total removal of the medial meniscus. And this injury is usually associated with tibial rotation. MMPRT induces pathological external rotation of the tibia, which can be restored by timely medial meniscus posterior root repair. Furthermore, changes in tibial rotation are related to the healing status after medial meniscus posterior root repair. MMPRT is closely related to tibial rotation. Understanding the biomechanics, pathological mechanisms, and clinical correlations between the two is of great significance for improving the diagnosis and treatment strategies.

Medial meniscus posterior root repair influences sagittal length and coronal inclination of the anterior cruciate ligament: a retrospective study.

Medial meniscus (MM) posterior root tears (PRTs) lead to abnormal kinematic changes in the knee and may induce pathological external rotation of the tibia during knee flexion. This study aimed to investigate changes in the length and inclination of the anterior cruciate ligament (ACL) after MM posterior root repair using magnetic resonance imaging (MRI). This retrospective study included 44 patients who underwent MM posterior root repair between 2016 and 2019. Clinical outcomes were evaluated before and after surgery. MRI examinations were performed at 10°/90° of knee flexion preoperatively and 3months postoperatively. The ACL length, proximal angle, and distal angle were determined using the sagittal view. MM extrusion and ACL inclination angle were determined using the coronal view. Clinical outcomes significantly improved 1year after surgery. The postoperative ACL length (29.7 ± 2.4mm) and proximal angle (47.0 ± 7.4°) at 90° of knee flexion decreased relative to the preoperative values (31.5 ± 2.3mm and 51.8 ± 8.7°, P < 0.01). The postoperative ACL inclination (64.9 ± 5.6°) at 10° of knee flexion decreased relative to the preoperative value (69.7 ± 5.6°, P < 0.01). Pathologically-stretched linear ACL at 90° of knee flexion and a steep ACL inclination at 10° of knee flexion could be reduced after MM posterior root repair. This suggests that pullout repair could restore MM function as a secondary stabilizer, thereby preventing meniscal and cartilage degeneration.

An Arthroscopic Technique for Release of the Middle Glenohumeral Ligament and the Effect on External Rotation of the Shoulder

The middle glenohumeral ligament (MGHL) is well recognized as a primary stabilizer of the shoulder. Its role in shoulder pathologies such as adhesive capsulitis, subscapularis tendon tear, and glenohumeral arthritis is less understood. Biomechanically, the MGHL plays an important role in range of motion, specifically involving normal and pathologic external rotation in less than 45° of abduction. In this Technical Note, we present a technique for arthroscopic release of the MGHL in the setting of a stable shoulder with preoperative loss of external rotation and a patient at risk for postoperative restriction of external rotation.

The effect of proximal tibiofibular joint dislocation on knee mechanics: reduction and fixation matters.

Proximal tibiofibular joint (PTFJ) dislocations are under-investigated injuries. There is scant basic science or clinical evidence to direct management. The purpose of this study was twofold; first to investigate the pathomechanics of PTFJ dislocation on knee mechanics. The second purpose was to evaluate knee mechanics following reduction and fixation. Six cadaveric legs were tested on a mechanical platform. A 5Nm external rotation force was applied to each knee and the external rotation and fibular translation was measured for several study conditions at 0°, 30°, and 90° of flexion. Conditions included: the native state, transection of the posterior PTFJ ligament, transection of the anterior and posterior ligaments, screw fixation, and suspensory fixation. Screw fixation was performed using a single quadricortical 3.5mm screw. Suspensory fixation was performed using an Arthrex TightRope device RESULTS: Transection of the anterior and posterior ligaments increased external rotation by 4.3°, 5.9°, and 5.6°, at 0°, 30°, and 90° (p ≤ 0.001), respectively. Screw and suspensory fixation returned external rotation to a near native state with mild overconstraint. Complete transection of anterior and posterior ligaments resulted in pathologic anterior fibular translation of 1.51mm (p = 0.001), 1mm, (p = 0.02) and 0.44mm (p = 0.69) for 0°, 30°, 90° of knee flexion. Screw and suspensory fixation restored native translation at all points with a small degree of overconstraint. Disruption of the PTFJ causes pathologic external rotation and anterior fibular translation. Fixation restores near native motion with minor overconstraint. Surgeons should consider reduction and fixation of PTFJ injuries to restore native knee mechanics.

La réparation en «pull out» transtibial des lésions de la racine postérieure du ménisque médial restaure la rotation physiologique du ménisque médial sur un genou fléchi

BackgroundMedial meniscus posterior root tear (MMPRT) results in joint overloading and degenerative changes in the knee. Favorable clinical outcomes have been reported after transtibial pullout repair of MMPRT. To date, however, in vivo tibial rotational changes before and after root repair remain poorly understood. The purpose of this study was to investigate postoperative changes in tibial rotation following MMPRT pullout repair. HypothesisPathological external rotation in the knee-flexed position is caused by MMPRT and is reduced after transtibial pullout repair. Patients and methodsFifteen patients who underwent MMPRT pullout repair and 7 healthy volunteers were included. Magnetic resonance imaging examinations were performed in the 10° and 90° knee-flexed positions. The angles between the surgical epicondylar axis and a line between the medial border of the patellar tendon and the apex of the medial tibial spine were measured. Baseline was defined as a line lying at a right angle to the other, and a value was positive and negative when the tibia rotated internally and externally, respectively. ResultsIn the volunteer's normal knees, tibial internal rotation was +1.00°±3.27° at 10° flexion and +4.14°±3.46° at 90° flexion. In the MMPRT preoperative knees, tibial internal rotation was +1.07°±3.01° at 10° flexion and +1.27°±2.96° at 90° flexion. In the postoperative knees, tibial internal rotation was +1.60°±2.85° at 10° flexion and +4.33°±2.89° at 90° flexion. DiscussionThis study demonstrates discontinuity of the MM posterior root may induce a pathological external rotation of the tibia during knee flexion and that MMPRT pullout repair reduces the pathological external rotation of the tibia in the knee-flexed position. Level of evidenceIII, comparative retrospective study.

Transtibial pullout repair of medial meniscus posterior root tear restores physiological rotation of the tibia in the knee-flexed position

BackgroundMedial meniscus posterior root tear (MMPRT) results in joint overloading and degenerative changes in the knee. Favorable clinical outcomes have been reported after transtibial pullout repair of MMPRT. To date, however, in vivo tibial rotational changes before and after root repair remain poorly understood. The purpose of this study was to investigate postoperative changes in tibial rotation following MMPRT pullout repair. HypothesisPathological external rotation of the tibia in the knee-flexed position is caused by MMPRT and is reduced after transtibial pullout repair. Patients and methodsFifteen patients who underwent MMPRT pullout repair and 7 healthy volunteers were included. Magnetic resonance imaging examinations were performed in the 10° and 90° knee-flexed positions. The angles between the surgical epicondylar axis and a line between the medial border of the patellar tendon and the apex of the medial tibial spine were measured. Baseline was defined as a line lying at a right angle to the other, and a value was positive and negative when the tibia rotated internally and externally, respectively. ResultsIn the volunteer's normal knees, tibial internal rotation was +1.00°±3.27° at 10° flexion and +4.14°±3.46° at 90° flexion. In the MMPRT preoperative knees, tibial internal rotation was +1.07°±3.01° at 10° flexion and +1.27°±2.96° at 90° flexion. In the postoperative knees, tibial internal rotation was +1.60°±2.85° at 10° flexion and +4.33°±2.89° at 90° flexion. DiscussionThis study demonstrates discontinuity of the MM posterior root may induce a pathological external rotation of the tibia during knee flexion and that MMPRT pullout repair reduces the pathological external rotation of the tibia in the knee-flexed position. Level of evidenceIII, comparative retrospective study.

Long-Term Retrospective Study of Patients with Idiopathic Clubfoot Treated with Posterior Medial-Lateral Release

It has been demonstrated that an important component of clubfoot deformity is related to pathologic external rotation of the talus with respect to the remainder of the foot. The purpose of the present study was to review the long-term results for a cohort of patients with idiopathic clubfoot who were managed by a single surgeon with a uniform surgical protocol consisting of extensive posterior medial-lateral release in addition to the use of a temporary Kirschner wire to derotate the talus prior to fixation. Eighty patients (120 clubfeet) with idiopathic clubfoot without previous surgery were managed with posterior medial-lateral release. At an average of twenty-one years postoperatively, patients underwent a detailed physical examination and completed four quality-of-life surveys (the Short Form-36, the Laaveg and Ponseti scale, the Foot Function Index, and the modified Atar scale). Thirty-two clubfeet (27%) had required additional procedures at the time of follow-up, with only one patient requiring complete revision posterior medial-lateral release and none requiring subtalar or triple arthrodesis. In patients with unilateral clubfoot, clinical examination demonstrated a significant decrease in the range of motion (p < 0.001), foot length (p = 0.045), and calf circumference (p = 0.008) on the affected side as compared with the unaffected, contralateral side. The results on all four quality-of-life scales remained durable, with no decline in relation to the time from the index procedure (p ≥ 0.48). Significantly worse scores were found for patients who required additional surgical procedures (p ≤ 0.03). Previous studies have demonstrated inconsistent long-term results following the treatment of clubfoot with extensive soft-tissue releases. With our technique, thirty-two clubfeet (27%) required additional procedures and only one clubfoot required revision posterior medial-lateral release. We demonstrate that our technique, which involves aggressive posterior medial-lateral soft-tissue release in addition to manual derotation of the talus with a Kirschner wire to correct pathologic external rotation, produces acceptable results.