Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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A Patient’s Guide to Osteonecrosis of the Humeral Head

Osteonecrosis Humeral Head

Osteonecrosis Humeral Head

Introduction

Osteonecrosis of the humeral head is a condition where a portion of the bone of the humeral head (the top of the humerus or upper arm bone) loses its blood supply, dies and collapses. Another term used for osteonecrosis is avascular necrosis. The term avascular means that a loss […]

Anatomy and Biomechanics of the Glenohumeral Capsule

The shoulder is an inherently loose articulation permitting a wide range of motion. The glenohumeral capsule remains lax throughout mid-range motion where stability is conferred by the dynamic action of the rotator cuff and the conforming articulation of the humeral head and the glenolabral surface. The capsuloligamentous structures about the glenohumeral joint act as passive […]

Pectoralis Major Tendon Ruptures

Key Points

The pectoralis major muscle demonstrates two distinctively different parts—the clavicular head and the sternal head. The clavicular head arises from the medial clavicle and upper sternum. It is supplied by the pectoral nerve off of the lateral cord and the deltoid branch of the thoraco-acromial artery. The sternal head arises from the sternum, […]

Early Osteoarthritis

Separate consideration should be given to the arthroscopic management of the early osteoarthritic shoulder. The disease in young patients is a challenging clinical problem. Non-surgical treatment options include physical therapy, therapeutic modalities, intra-articular corticosteroid injections, activity modification, and nonsteroidal anti-inflammatory medications .

There is a substantial amount of literature to support the use of the […]

Cartilage

Key Points

Full-thickness articular cartilage defects have a limited capacity to heal. Thus, articular cartilage lesions and osteochondral defects in any joint present a challenging problem. Cartilage lesions are less likely to be seen in the glenohumeral joint than in the knee, therefore there has not been extensive research on shoulder cartilage repair. Making the […]

Biomechanics

Few would dispute the critical role of the biceps brachii at the elbow joint and its function has been well documented at this position. It is with the LHB’s role at the shoulder where the arguments intensify. Many authors have suggested that the LHB has a role in humeral head depression—particularly with shoulder external rotation […]

Impingement: Secondary

Individuals with shoulder instability or other underlying pathology can develop significant abnormal mechanics that can lead to rotator cuff functional disability, eventual fatigue and loss of humeral head containment. When this occurs, rather than the coracoacromial arch moving toward the cuff, the cuff migrates cephalad as containment is compromised.

In addition to articular-sided internal impingement-type […]

Function

The rotator cuff muscles centralize the humeral head and permit a single center of rotation while providing stability and strength. During active shoulder elevation, the rotator cuff muscles depress the humeral head, allowing efficient elevation of the extremity while the head remains reduced in the glenoid.

Studies have been performed evaluating the individual rotator cuff […]

Stiffness

Stiffness after surgery for open anterior instability is infrequently noted in literature and the incidence of this complication is probably under-reported. Certain repairs were designed to limit external rotation and hence the risk of recurrence, so loss of motion was not considered a complication.

In some settings (e.g., capsular reconstruction or revision surgery), limited external […]

Subscapularis Tears

Rupture of the subscapularis in association with primary anterior shoulder instability is more common after a prior open instability repair and should be suspected in those who have had prior anterior stabilization procedures in which the subscapularis was released for exposure.

Failure to recognize and treat a subscapularis tear in a proper and timely fashion […]