Muscle hypoxia in rheumatoid hands: does it play a role in ulnar drift?

A new assessment tool for ulnar drift in patients with rheumatoid arthritis using pathophysiological parameters of the metacarpophalangeal joint

OBJECTIVES

To establish a new assessment tool for ulnar drift (UD) in rheumatoid arthritis (RA).

METHODS

We established an observational cohort of 67 patients (134 rheumatoid hands) beginning in 2004. Fifty-two patients (100 hands) had follow-up in 2009 and 37 patients (63 hands) completed follow-up in 2015. UD was evaluated with the Fearnley classification and our scoring method, which assesses four parameters of the metacarpophalangeal joint. Cluster analysis using UD parameters divided hands into groups. Changes in UD over time, correlation of the Fearnley stage and cluster with a functional assessment, and reliability of the parameters were analyzed.

RESULTS

UD increased and worsened over time according to the trend test. A dendrogram indicated five clusters would be appropriate. Both the Fearnley classification and cluster were associated with function; however, our method related to function more linearly (R-squared: 0.42). We found one type of hand in which bone destruction precedes the joint dislocation and one type in which joint dislocation progresses with little deviation during UD progression.

CONCLUSION

Our UD evaluation appeared to be simple and related to function. Additionally, it enables dividing UD hands into five stages. Thus, our assessment should be beneficial compared to the Fearnley classification in considering treatments of UD.

Intrinsic contracture of the hand: diagnosis and management

Intrinsic contracture of the hand may result from trauma, spasticity, ischemia, rheumatologic disorders, or iatrogenic causes. In severe cases, the hand assumes a posture with hyperflexed metacarpophalangeal joints and hyperextended proximal interphalangeal joints as the contracted interossei and lumbrical muscles deform the natural cascade of the fingers. Considerable disability may result because weakness in grip strength, difficulty with grasping larger objects, and troubles with maintenance of hygiene commonly encumber patients. Generally, the diagnosis is made via history and physical examination, but adjunctive imaging, rheumatologic testing, and electromyography may aid in determining the underlying cause or assessing the severity. Nonsurgical management may be appropriate in mild cases and consists of occupational therapy, orthoses, and botulinum toxin injections. The options for surgical management are diverse and dictated by the cause and severity of contracture.

Intrinsic contractures of the thumb

A wide range of conditions can lead to intrinsic contractures of the thumb. A thorough understanding of the normal and pathologic anatomy as well as the disease processes and their effect on thumb function is essential in understanding and treating these contractures. Because intrinsic contractures of the thumb rarely present in isolation, a patient-specific approach based on functional needs is required. Prevention of iatrogenic contractures and progression of predictable contractures regardless of etiology is the health care provider's primary responsibility.