Vascularized bone grafts and their applications in the treatment of carpal pathology

Abstract

Vascularized bone grafts (VBGs) are techniques in the management of certain types of carpal pathology. VBGs have traditionally been advocated for conditions including delayed and nonunion of fractures and avascular necrosis. The most common indications for VBG have been for scaphoid nonunion, lunatomalacia (Kienböck's disease), and osteonecrosis of the scaphoid (Preiser's disease). Advantages over NVBG have been established. VBGs provide improved blood flow, osteocyte preservation, and accelerated healing rates. Local pedicled VBGs are the most commonly used methods. They are technically less demanding than are free VBGs and are associated with less morbidity. Commonly used donor grafts arise from the dorsal vasculature of the wrist and include the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA), the 2,3 ICSRA, the fourth extensor compartment artery (fourth ECA), and the fifth ECA. A 4 + 5 ECA combination graft has been described to provide a longer pedicle. In managing osteonecrosis, most surgeons would agree that VBG should be reserved for carpal bones with an intact cartilaginous shell and no collapse. In treating scaphoid pathology, indications for VBG include fractures/nonunions with proximal pole avascular necrosis and/or small proximal pole fragments.

Keywords: Vascular bone grafting; nonunion; osteonecrosis.

Figure 1

Schematic of the primary dorsal distal radius blood supply and possible VBG donor sites. (From Sheetz KK, Bishop AT, Berger RA. The arterial blood supply of the distal radius and the ulna and its potential use in vascularized pedicled bone grafts. J Hand Surg [Am] 1995;20:906, Fig. 4c. Figure used with permission.)

Figure 2

The volar blood supply of the distal radius. The radial and ulnar vessels communicate to form a metaphyseal arch. rPCA, radial half of the palmar arch; uPCa, ulnar half of the palmar arch; pMeta, palmar metaphyseal arch; RA, radial artery; UA, ulnar artery; Ant Int A, anterior interosseous artery. (From Sheetz KK, Bishop AT, Berger RA. The arterial blood supply of the distal radius and the ulna and its potential use in vascularized pedicled bone grafts. J Hand Surg [Am] 1995;20:906, Fig. 4b. Figure used with permission.)

Figure 3

Schematic demonstrates the technique of dorsal distal radius VBG for scaphoid nonunion. (A) A curvilinear incision is made in line with the scaphoid on the radial side of the wrist. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 7. Figure used with permission. (B) The 1,2 ICSRA is identified between the first and second dorsal compartments. The superficial branch of the radial nerve (SBRN) is safely retracted. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 8. Figure used with permission.) (C) The first and second dorsal compartments are opened at the level of the bone graft site to create a cuff or retinaculum that contains the 1,2 ICSRA. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 9. Figure used with permission.) (D) The fracture or nonunion site is visualized after dorsal capsulotomy. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 10. Figure used with permission.) (E) The nonunion site is debrided and bone ends prepared. A burr can be used to create a slot in preparation of the donor graft. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 11. Figure used with permission.) (F) The bone graft is elevated after a series of osteotomies with the nutrient artery centered in graft. After completing a proximal osteotomy, the radial and ulnar osteotomies can be performed. Then the distal edge can be gently levered to prevent risk of injury to the pedicle. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 12. Figure used with permission.) (G) Schematic illustrates the bone graft placement in the slot. It is then secured with supplemental fixation. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 13. Figure used with permission.) (H) Schematic demonstrated how the VBG can be used as a wedge graft in cases of humpback deformity. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 19. Figure used with permission.)

Figure 4

Vascular bone grafting procedure with 4 + 5 ECA vessels. (A) After a longitudinal incision centered over the lunate and distal radius, the interval between the fourth and fifth compartments is used. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 21. Figure used with permission.) (B) The fifth extensor compartment artery (ECA) is identified and traced proximally to its origin from the anterior interosseous artery. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 22. Figure used with permission.) (C) A ligament sparing capsulotomy is performed to expose the carpus. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 23. Figure used with permission.) (D) This schematic demonstrates the technique of preparing the lunate for VBG. Necrotic bone is removed using a burr or curette while leaving the shell intact. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 24. Figure used with permission.) (E) The appropriately sized bone graft is then raised and set into the lunate bone defect. The cortical strut is oriented in a proximal to distal direction to help prevent collapse. (From Shin AY, Bishop AT, Berger RA. Vascularized pedicled bone grafts for disorders of the carpus. Tech Hand Upper Extrem Surg 1998;2:94–109, Fig. 25. Figure used with permission.)