- Discussion:
- as with ulnar injuries, a mid subtance tear is rare;
- Treatment Acute Tears:
- if there is no instability and no sign of volar subluxation, the thumb is immobilized for 3 to 4 weeks;
- Surgical Treatment:
- after curved incision and mobilization of skin flaps, longitudinal incision is made in the abductor aponeurosis volar to EPB tendon, leaving a
rim of tissue on the tendon for later closure;
- aponeurosis is reflected dorsally and volarly, exposing the dorsal capsule and radial collateral ligament, respectively;
- ruptured ligament is then resutured into either the proximal phalanx or metacarpal, depending on the bone from which it ruptured;
- any volar subluxation of the phalanx must be reduced and the dorsal capsule and the EPB repaired;
- generally in these situations, the joint is transfixed with a K wire for several weeks;
- Chronic Radial Collateral Ligament Tear:
- phalanx in a chronic radial collateral ligament injury rotates into pronation;
- correcting the rotational deformity is important, and this can only be accomplished by repairing the ligament;
- w/ chronic radial collateral ligament injuries the ligament will be deficient in 33% of cases and will require free tendon graft;
(as compared to game keepers thumb in which 66% of patients require free tendon grafts);
- after reconstruction, additional stability is obtained by tightening conjoined tendon of insertion of the abductor pollicis brevis & the radial
head of the FPB