OBJECTIVE To review some of the important biomechanical factors that provide glenohumeral stability, along with the pathologic mechanisms involved in glenohumeral instability of the shoulder. DATA SOURCES Current English medical literature concerning the multiple pathologic factors involved in glenohumeral instability was reviewed. DATA SYNTHESIS Multiple dynamic and static factors control ...

This paper develops optimal tests for model selection between two nested models in the presence of underlying parameter instability. These are joint tests for both parameter instability and a null hypothesis on a subset of the parameters. They modify the existing tests for parameter instability to allow the parameter vector to be unknown. These tests statistics are useful if one is interested i...

Atraumatic shoulder instability (ASI) which is almost always multidirectional, results due to minimal trauma. The redundant capsule leads to an increased glenohumeral joint volume resulting in the instability. The multifactorial etiology has hindered a universally accepted breakthrough in the management plan for such cases. The initial treatment is recommended to be conservative with surgery ad...

Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of mo...

This is a retrospective analysis of the clinical and radiological outcome in 24 patients with acute or chronic posttraumatic elbow instability, who were treated with open reduction, internal fixation and a hinged external fixator. The instability was acute after elbow fracture dislocation in 11 cases; the other 13 had chronic posttraumatic instability of the elbow. Concentric stability and a su...

Initial assessment of severity of injury to the lateral ligament of the ankle is by clinical examination. If it is thought that there is a possibility of either lateral or anterior instability, patients are investigated radiologically by anterior and inversion stress films. If instability is demonstrated a peroneal tenogram is carried out to exclude damage to the calcaneo-fibular ligament. Trea...

To our knowledge, proximal tibiofibular joint instability has never been reported in a patient with a total knee arthroplasty (TKA). We present the case of a patient with anterolateral proximal tibiofibular joint instability associated with a complex primary TKA. In 2010, a male patient of 47 years was referred for TKA after posttraumatic osteoarthritis. The patient's history includes a fractur...

We often see painful ankle joint destruction with painful hindfoot valgus deformity in rheumatoid arthritis. Our policy in such cases has been to first correct the hindfoot deformity in the subtalar joint with fusion, but then ankle joint pain has been observed. Two women with rheumatoid arthritis underwent correction and fusion surgery for hindfoot valgus deformity. They had been using wheelch...

Of eithty-six patients with collateral ligament instability of the metacarpophalangeal joint of the thumb, sixty-six (77 per cent) had ulnar and twenty (23 per cent) had radial instability, while in addition twenty-four had fractures and twenty-nine had volar subluxation of the proximal phalanx. Of the sixty-nine patients operated on, sixty-five had an abnormality of the ulnar or radial collate...