Subsidence after Trapeziometacarpal Arthroplasty

Area of Science:

• Orthopedic surgery
• Radiographic analysis
• Biomechanical assessment

Background:

• Trapeziometacarpal (TMC) arthroplasty is a common procedure for arthritis.
• Surgeons sometimes attribute poor patient outcomes to trapezium subsidence.
• Subsidence, or reduced trapezial space height (TSH), is a radiographic concern.

Purpose of the Study:

• To determine the relationship between subsidence and functional outcomes after TMC arthroplasty.
• To identify study factors associated with subsidence and TSH.
• To quantify the mean subsidence over time.

Main Methods:

• Systematic review of PubMed, Cochrane, and Web of Science databases (from 1986 onwards).
• Inclusion criteria: TMC arthroplasty (various types) with subsidence measurement.
• Analysis of 91 identified studies.

Main Results:

• Few studies reported correlations between subsidence and pinch strength (7/31), incapability (5/21), grip strength (1/16), or pain (2/20).
• No studies found a correlation between subsidence and patient satisfaction (0/10).
• Mean TSH change was 5.0 mm (<1 year) and 5.5 mm (1-3.5 years).

Conclusions:

• Most studies show no association between radiographic subsidence and patient outcomes (strength, capability, comfort, satisfaction).
• Limiting subsidence may not be a primary benefit for TMC arthroplasty.
• Revision arthroplasty should not be based solely on radiographic subsidence measurements.