Posttraumatic osteonecrosis and nonunion of distal pole of scaphoid
A 30 year old male presented to the outpatient department in January 2010 with complaints of increasing pain and stiffness in the left wrist for the last 2 years following a fall on outstretched hand. He took treatment in form of massage for two and half months and no radiological investigations were done for his injury. He returned to stitching clothes, his profession, after two and a half months. His wrist pain increased progressively along with restriction of movements to such an extent that he had to discontinue his job. On examination his left wrist (non-dominant) showed gross restriction of motion with just 10 degrees of dorsiflexion and 15 degrees of palmar flexion. There was mild tenderness on radial side of wrist, which was more marked in the anatomical snuffbox. Radiographs showed a nonunion of scaphoid with avascular necrosis of distal pole with no evidence of radiocarpal arthritis []. The lateral intrascaphoid angle as observed in the lateral view was 60° indicating a mild humpback deformity; however, luno-capitate angle was 0°, indicating absence of carpal instability. There was no loss of carpal height. The carpal height ratio was 50% (45-60%), ruling out a carpal collapse. Computed tomographic (CT) scan of right wrist showed the distinct fracture line in the scaphoid with cystic changes in the adjacent region of bony fragments and a sclerotic distal fragment [].\nAn open reduction and internal fixation of the nonunion with k-wires supplemented with a pronator quadratus muscle pedicle bone graft was planned. The scaphoid was exposed through a standard palmar approach after extending the incision beyond the distal palmer crease by 2 cm []. Nonunion was exposed and fractured surfaces cleared of fibrous tissue. The distal fragment was retrieved, which was approximately 1 × 0.5 cm in size. No bleeding could be observed in the distal fragment on curettage of its fractured surface, confirming avascular distal fragment as preoperative MRI was not done in this patient for assessing avascularity. The nonunion was reduced and a 2.0 mm k-wire was passed across the fracture site from distal to proximal fragment, under fluoroscopic guidance. We had planned fixation with Herbert's screw, however, because of the fear of crushing the small sized distal fragment, we preferred k-wire. The pronator quadratus muscle pedicle bone graft was harvested and transposed to the nonunion site. A second k-wire was now introduced, which held the graft in position and supplemented the fixation of the fracture []. The wound was closed in layers with a suction drain in place. The wrist was immobilized in a below elbow plaster of paris cast in neutral flexion The postoperative radiographs showed a reduction in the lateral intrascaphoid angle to 46° from a preoperative 60° []. The pop cast was continued for 12 weeks followed by gradual mobilization and range of motion exercises. At 6 months, sound union at the fracture site was observed radiographically and was confirmed by CT scan [Figure and ]. He returned to (stitching clothes) job at 4 months and resumed his part time farming activities after k-wire removal at 6 months, postoperatively. At 2 years followup, he was able to perform all activities of daily living and had attained his pre-injury functional level. He still experiences mild pain after heavy work and has restriction of terminal 10° of palmar flexion []. His Disabilities of the arm, Shoulder and Hand (DASH) Score was 4.25, which is consistent with good hand function. The magnetic resonance imaging (MRI) scan of the left wrist showed evidence of revascularization 2 years post-injury suggesting successful incorporation of pronator quadratus muscle pedicle bone graft [].