A flexible hyperextension deformity of the metacarpophalangeal joint of
the thumb in eleven patients was repaired by tendon reinforcement of the
volar capsule of the joint using the tendon of the extensor pollicis
brevis. This tendon, which was regarded as a deforming factor, was left
attached at its insertion on the proximal phalanx and was divided at the
musculotendinous junction proximally. The mobilized tendon was pulled out
distally and then passed proximally and volarly, first superficial to the
sheath of the long flexor tendon and then back through a hole in the neck
of the metacarpal, and finally in a distal direction to form a criss-cross
pattern and be sutured to the tendon of the adductor pollicis. The
procedure gave reliable results after an average follow-up of 6.5 years in
these eleven patients who had rheumatoid, paralytic, and traumatic
lesions.