Clinical Scorecard: Evaluating Thumb Palmar and Radial Abduction in Individuals with Carpometacarpal Osteoarthritis Using Intermetacarpal Distance Techniques: A Study of Validity, Reliability, and Accuracy

At a Glance

Key Highlights

• CMC1 OA is a common and symptomatic hand osteoarthritis, with higher prevalence in older adults and females.
• Thumb adduction contracture reduces thumb web space and range of motion, impacting daily activities.
• Intermetacarpal distance (IMD) measurement methods, including tape and caliper, are evaluated for reliability and validity in assessing thumb palmar and radial abduction.

Guideline-Based Recommendations

Diagnosis

• Use radiographic confirmation to diagnose CMC1 osteoarthritis.
• Exclude other conditions such as carpal tunnel syndrome, neurological disorders, tenosynovitis, rheumatological diseases, and prior CMC1 surgery.

Management

• Consider restoring thumb web space to improve function and reduce symptoms.
• Use reliable measurement methods to assess thumb abduction for treatment planning.

Monitoring & Follow-up

• Employ test–retest reliability assessments of IMD measurements to monitor patient prognosis and treatment efficacy.
• Use the mean of two or three trials rather than a single trial to improve measurement reliability.

Risks

• Measurement errors may occur due to MCP joint enlargement and inflammation affecting tape placement.
• Poor reliability of goniometry for palmar abduction assessment suggests alternative measurement methods are preferred.

Patient & Prescribing Data

Individuals with radiographically confirmed CMC1 osteoarthritis, mainly older adults and postmenopausal women.

Reliable measurement of thumb abduction using IMD methods can guide treatment efficacy and functional improvement strategies.

Clinical Best Practices

• Use intermetacarpal distance methods (tape or caliper) to measure thumb palmar and radial abduction in CMC1 OA patients.
• Perform multiple trials (two or three) and use their mean to enhance measurement reliability.
• Avoid sole reliance on goniometry for palmar abduction due to poor reliability.
• Consider anatomical changes such as MCP joint enlargement when placing measurement tools to reduce error.

References

• Prevalence and risk factors of CMC1 OA
• Measurement methods of thumb abduction
• Reliability of intermetacarpal distance methods
• COSMIN guidelines for measurement instruments
• STROBE guidelines for observational studies