Based upon the clinical course and imaging findings, this patient was diagnosed with a proximal pole scaphoid nonunion with fragmentation of the proximal pole.

The treatment of proximal pole scaphoid nonunions is a challenging problem that does not always yield favorable results. Both vascularized and nonvascularized bone grafting have been advocated for scaphoid nonunions. Iliac–crest bone grafting with compression screw placement is considered a first-line treatment for scaphoid nonunions [1, 2, 3]. However, when avascular necrosis of the proximal pole is present, vascularized bone grafting has demonstrated superior union rates [1, 2]. In a retrospective study reviewing patients with scaphoid nonunions treated with 1,2-intercompartmental supraretinacular arterial vascularized bone grafting, 18 of 25 patients (72 %) with a nonunion at the proximal pole achieved union. However, in those patients with proximal scaphoid nonunion with avascular necrosis, only 8 of 14 (57 %) achieved union.

When a proximal pole scaphoid fracture with avascular necrosis leads to fragmentation of the proximal pole, treatment options become more limited. In the rare condition that the fragmented proximal pole is small enough to leave the scapholunate interosseous ligament primarily repairable to the remaining distal scaphoid, the fragment may be excised [4]. However, should excision of a larger proximal pole be necessary, replacement of this necrotic bone should be performed. Interposition of several different materials has been proposed to replace larger proximal pole fragments including silicone implants, fascial interpositions, and pyrocarbon implants. Given complications with silicone synovitis, silicone implants have fallen out of favor [5]. Fascial interposition unfortunately results in loss of scaphoid height and may lead to carpal instability [6]. Pyrocarbon implants have been advocated, but long-term results are still unclear and short-term complications of implant dislocation and need for reoperation have been reported [7].

Other options for replacement of an excised fragmented proximal pole include allograft and autograft reconstruction. Cadaveric scaphoid allografts, though, have the downsides of potential disease transmission, host rejection, and failure of integration [8, 9]. Autograft options include the vascularized medial femoral osteochondral flap and the osteochondral rib autograft. The medial femoral osteochondral flap is a free tissue transfer supplied by periosteal branches of the descending geniculate artery. This flap relies upon the similar contours of the proximal scaphoid and medial femoral trochlear articular surfaces. Early reports demonstrate a high rate of union for this technically demanding procedure [10]. Osteochondral rib autograft is a nonvascularized option that provides a cartilaginous surface to substitute as an articular surface and a bony surface that allows for primary bone healing to the distal pole of the scaphoid .

This patient was treated with an osteochondral rib autograft. The patient was placed supine on the operating table, and an endotracheal tube was placed after the successful induction of general anesthesia. The patient’s operative extremity and his contralateral hemithorax was prepped and draped past the midline (Fig. 19.3). A dorsal approach to the scaphoid was utilized to confirm an unsalvageable proximal pole nonunion, and the distal pole was debrided until bleeding bone was identified. The interspace between the seventh and eighth ribs was identified by palpation, and an incision inferior to and following the interspace was made. The osteochondral junction of the ribs is readily identifiable by a sharply demarcated color change. The seventh rib was circumferentially subperiosteally dissected, elevated off the pleura, and carefully excised (Figs. 19.4 and 19.5). After graft harvest, the wound is flooded with saline and the anesthesiologist delivers a positive inspiration (simulated Valsalva maneuver) to the patient to confirm no air leak. On the back table, the graft is fashioned using a sharp blade to reapproximate the proximal articular surface of the scaphoid while leaving a 2-mm rim of bone to heal to the distal pole (Fig. 19.6). We err on the side of “overstuffing” the graft to help maintain carpal alignment. The graft is inserted and secured with two 0.062 Kirschner wires that are bent and cut at the level of the scaphoid (Fig. 19.7).