Dr. Kevin Yip

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

Featured on Channel NewsAsia

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 rotation may be an expected outcome, and this should be conveyed to patients preoperatively. While loss of 10 degrees of external rotation may have little functional consequence for most individuals, it may be devastating for an overhead athlete.

This is an important point that should be considered when selecting the procedure and when selectively shifting the capsule. Over-tightening should be avoided, as the over-constrained joint develops abnormal kinematics with shear across the articular cartilage, altered joint reactive forces, and premature degenerative arthrosis.

Harryman et al.They have shown that passive motion of the glenohumeral joint is coupled reproducibly to translation of the humeral head on the glenoid. When the anterior capsule is overly tight, the humeral head has excessive posterior translation with external rotation. This posterior translation creates shearing forces on the posterior glenoid rim that may result in cartilage erosion and early osteoarthrosis.

This phenomenon has been called “capsulorrhaphy arthropathy” or “arthritis of dislocation” and results from loss of motion with subsequent cartilage deterioration and joint arthrosis. Unfortunately, there is no clear threshold beyond which these biomechanical consequences become realized.

A loss of external rotation of greater than 30%, as compared with the controlateral shoulder, increases the risk of capsulorrhaphy arthropathy and is a reasonable indication for a capsular release with or without a subscapularis lengthening.

Motion loss is best prevented at the time of surgical repair by physiologically tensioning the capsule while the arm is in abduction and external rotation. A rule of thumb is 30 degrees of external rotation and 30 degrees of abduction.

This avoids over-constraint. Furthermore, proper rehabilitation postoperatively can prevent the development of excessive stiffness. When refractory motion loss persists, formal capsular release may be considered.

Comments are closed.