Contribution of biomechanics, orthopaedics and rehabilitation: the past present and future.

Biomechanics is a field that has a very long history. From its beginnings in ancient Chinese and Greek literature, the field of orthopaedic biomechanics has grown in the areas of biomechanics of bone, articular cartilage, soft tissues, upper extremities, spine and so on. Bioengineers in collaboration with orthopaedic surgeons have applied biomechanical principles to study clinically relevant problems, improving patient treatment and outcome. In the past 30 years, my colleagues and I have focused our research on the biomechanics of musculoskeletal soft tissues, ligaments and tendons in particular. Therefore, in this review article, the function of the knee ligaments and the associated homeostatic responses secondary to immobilisation and exercise will be described. Research on healing of the medial collateral ligament (MCL) of the knee and possible future approaches in improving the healing of the knee ligaments will be presented. Finally, improvement of the understanding of ligament reconstruction, specifically of the anterior cruciate ligament (ACL), through the use of robotics technology will be included. Throughout the manuscript, specific scientific findings that have guided or changed the clinical management of injury to these soft tissues will be emphasised.

[Biomechanical tests for type II SLAP lesions of the shoulder joint before and after arthroscopic repair]. / Biomechanische Untersuchungen zur Typ-2-SLAP-Läsion am Schultergelenk vor und nach arthroskopischen Repair.

Superior labral anterior-to-posterior (SLAP) lesions can cause shoulder pain partly by causing glenohumeral instability. The purpose of this study was to examine the effect of a simulated type II SLAP lesion and subsequent repair on glenohumeral translation of the vented shoulder. In eight cadaver joints, a robotic/UFS testing system was used to measure joint translation by applying an anterior, posterior, or inferior load of 50 N to each shoulder. The "apprehension tests" for anterior and posterior instability were simulated by applying an anterior load of 50 N with an external rotation torque of 3 Nm or a posterior load of 50 N with an internal rotation torque of 3 Nm. Each loading condition was applied at 30 degrees and 60 degrees of glenohumeral abduction with a constant joint compressive load (44 N) to the intact, simulated SLAP lesion, and repaired shoulder. Repair of the type II SLAP was then performed by placing a Suretac through the labrum both anterior and posterior to the biceps anchor and testing was repeated. ANOVA was used to compare translation of the intact joint, the joint after the type II SLAP lesion had been simulated, and after repair. At 30 degrees of abduction, anterior translation of the intact vented shoulder joint from anterior loading was 18.7+/-8.5 mm and increased to 26.2+/-6.5 mm after simulation of the type II SLAP lesion ( p< or =0.05). The arthroscopic repair did not restore anterior translation (23.9+/-8.6 mm) to the same degree as the intact joint ( p> or =0.05). At 60 degrees of abduction, anterior translation of 16.6+/-9.6mm in the intact joint was not significantly increased at 19.4+/-10.1 after simulation of the type II SLAP lesion ( p=0.0527). AP loading also resulted in inferior translation. At 30 degrees of abduction it was 3.8+/-4.0 mm in the intact joint and increased to 8.5+/-5.4 mm after the type II SLAP lesion ( p< or =0.05. After repair the inferior translation decreased significantly to 6.7+/-5.3 mm ( p< or =0.05). Although inferior translations were less at 60 degrees of abduction, results were similar to those at 30 degrees after repair. There were no significant increases in translation after SI/AP combined external rotation torque or posterior-anterior combined internal rotation torque loading. In this study the repair of a type II SLAP lesion only partially restored translations to the same degree as an intact vented shoulder joint. Therefore, improved repair techniques or an anteroinferior capsulolabral procedure in addition to the type II SLAP lesion repair might be needed to restore normal joint function.