Drs. Jones, Bürger, Bishop, and Shin offer a carefully-performed study of an innovative method for managing a difficult problem, and the results that they have achieved are impressive. They retrospectively compared the results of two series of similar patients, in which all patients had a scaphoid waist nonunion that was associated with an avascular proximal pole and carpal collapse. One group of patients had been treated with a distal radial graft based on a 1,2 intercompartmental supraretinacular artery pedicle, and the other group had been treated with a free osseous graft taken from the medial femoral condyle on a branch of the superior medial geniculate artery. In comparing these groups, the authors found a significantly higher rate of union (p = 0.005) among those with the medial femoral condyle flap and also a significantly shorter time to union (p < 0.001).
This is an important result and offers insight into the management of this difficult surgical problem. In evaluating this paper however, it is helpful to consider two factors. One is the historical context of previous innovations designed to treat scaphoid nonunion, and the other is the substantial jump in complexity of the free-flap operation compared with a pedicled graft taken locally.
It is particularly instructive to consider the 1,2 intercompartmental supraretinacular artery graft, as experience with it has evolved. The first report of this technique was by Zaidemberg et al. in 1991, who reported union in all eleven of the patients in their series1. Early results from other authors were similarly spectacular. For example, within a group of recalcitrant nonunions that had been treated with a variety of techniques, Smith and Cooney reported 100% union in the four patients treated with a 1,2 intercompartmental supraretinacular artery graft2. In subsequent reports, however, the success rate reported by various groups was lower. Boyer et al. reported a 60% union rate with this technique in 1998, finding that failure was correlated with a previous failed attempt at repairing the nonunion3.
Several authors of the current paper recently reported on a large group of patients who underwent 1,2 intercompartmental supraretinacular artery grafting, and they found an overall rate of union of only 71%4. They suggested a mechanical hypothesis for this failure after noting that most of the nonunions occurred in patients with uncorrected humpback deformity.
It will be interesting to see whether the early good results with the medial femoral condyle graft deteriorate over time in the same way that the 1,2 intercompartmental supraretinacular artery graft results did.
A second important caveat for the general orthopaedic surgeon is obvious but bears pointing out. A pedicled local vascular graft from the distal part of the radius is a relatively straightforward operation: no special technique beyond careful handling of the tissues is required, and the donor and recipient sites are located within the same operative field. In contrast, a free osseous flap taken at a distance is a technically demanding procedure that involves microscopic vascular anastomosis and produces donor-site morbidity in an otherwise uninjured limb.
The authors of this study are internationally recognized for their skill in microsurgery. Other surgeons may not be technically able to achieve the results reported here, so these results should be interpreted with that in mind.
*The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.
1. Zaidemberg C, Siebert JW, Angrigiani C. A new vascularized bone graft for scaphoid nonunion. J Hand Surg [Am]. 1991;16:474-8.
2. Smith BS, Cooney WP. Revision of failed bone grafting for nonunion of the scaphoid. Treatment options and results. Clin Orthop Relat Res. 1996;327:98-109.
3. Boyer MI, von Schroeder HP, Axelrod TS. Scaphoid nonunion with avascular necrosis of the proximal pole. Treatment with a vascularized bone graft from the dorsum of the distal radius. J Hand Surg [Br]. 1998;23:686-90.
4. Chang MA, Bishop AT, Moran SL, Shin AY. The outcomes and complications of 1,2-intercompartmental supraretinacular artery pedicled vascularized bone grafting of scaphoid nonunions. J Hand Surg [Am]. 2006;31:387-96.