Narrow Results

We report a rare case of irreducible chronic palmar dislocation of the distal radioulnar joint (DRUJ). This case showed that the dislocated ulnar head was impacted to the palmar cortex of the radius probably due to the dynamic force of the pronator quadratus muscle. Re-attachment of the ulnar styloid and partial resection of the ulnar head were necessary to make the reduction of the DRUJ possible. The continuity of the radioulnar ligament to the ulnar head was restored and the stability of DRUJ was maintained after reduction.

Irreducible volar subluxation should be considered when assessing a patient with flexion deformity of the proximal interphalangeal finger joint (PIPJ). Primary assessment requires careful examination of the collateral ligaments and extensor tendon. Preoperative imaging such as ultrasound and MRI can help identify the interposed structures and plan the subsequent operation. Although rare, irreducible volar subluxation due to radial collateral ligament interposition is an important entity to be aware of. Prompt and appropriate management can prevent joint stiffness and loss of function.

We describe 4 cases of irreducible volar rotatory subluxation of the proximal interphalangeal (PIP) joint of the finger that required open reduction. All of the patients had radiographically proven (in lateral-view radiographs) volar rotatory subluxation of the PIP joint, without fracture. The causes of irreducibility were interposition of the lateral band about the condyle of the middle phalanx in 2 cases, interposition of the collateral ligament in 1 case, and scarring of the injured central slip in 1 case. Rupture of the collateral ligament of one side was found in all cases. Acceptable results were provided with all cases after restoration of the collateral ligaments and the damaged parts. Accurate early diagnosis by careful physical examination and obtaining true lateral radiographs of the PIP joint is important.