Morphology of First Extensor Compartment Tendons and their Association with First Carpometacarpal Joint Arthritis
Rituraj Majumder, Gomathi Ramakrishnan, Suman VermaContext:
Variations in abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendon slips and intertendinous septation within the first dorsal compartment may increase friction, predisposing to De Quervain’s disease and first carpometacarpal joint (CMC) arthritis.
Aim:
This study evaluated variations in APL and EPB tendons and the intertendinous septum, and their association with first CMC arthritis.
Settings and Design:
This was a descriptive and analytical cross-sectional morphological study.
Materials and Methods:
A total of 58 formalin-embalmed upper limbs (16 upper limbs from 8 bilaterally dissected cadavers and 42 disarticulated upper limbs) from Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, were utilized. Specimens with damaged tendons, deformities, or prior surgeries were excluded. APL and EPB tendon slip counts and insertion sites were recorded. The first CMC joint was examined macroscopically for degenerative changes and graded.
Statistical Analysis Used:
Frequency distributions, Chi-square, and Fisher’s exact tests were used. Odds ratios (OR) with 95% confidence intervals (CIs) were calculated (
Results:
Two APL slips were most common (48%), with up to six variations. Among 127 APL insertion sites, the first metacarpal base was frequent (64.6%). EPB was absent in 3.4% of limbs. A septum was present in 48.3% of limbs, mostly incomplete. Fisher’s exact test showed a significant association between septum and first CMC arthritis (
Conclusion:
A septum in the first dorsal compartment is significantly associated with first CMC joint arthritis. Awareness of these variations aids diagnosis and surgical management.