Session XI - Reconstruction
Sun., 10/10/04 Reconstruction, Paper #64, 9:45 am
Use of Calcium-Based Demineralized Bone Matrix (DBM) Allograft Product for Nonunions and Posttraumatic Reconstruction of the Appendicular Skeleton: Preliminary Results and Complications
Purpose: We evaluated the preliminary experience of use of a surgical-grade calcium sulfate allograft demineralized bone matrix (DBM) product for the treatment of atrophic fracture nonunions.
Methods: All fracture nonunions in adults treated at two level I trauma centers were considered. Atrophic and oligotrophic nonunions that were deemed not to have biologic potential were included in the study. Previously infected nonunions were included only after a staged protocol that included a tumor type resection and staged evaluation to determine eradication of the infection. Exclusion criteria included acute infections, pathologic fractures, skeletal immaturity, and hypertrophic nonunions. All treatments were performed or supervised by senior fellowship-trained trauma surgeons. Allomatrix (Wright Medical Technologies) was used as the primary inductive and conductive agent. The amount of graft was determined by the tissue bed available and at the discretion of surgeon. Data were collected prospectively and analyzed retrospectively. In addition to routine demographic data, fracture pattern and location, the amount of graft, healing and any complications were recorded. Healing was determined clinically and radiographically by the senior surgeons and radiologists, who were blinded to the study. Statistical analysis was performed with use of chi-square. Primary outcome measures were wound complications, postoperative infections, and healing.
Results: Evaluated were 41 nonunions in 19 (46.3%) men and 22 (53.7%) women with a mean age of 42.5 years. There were two clavicle, one calcaneus, seven femur, two humerus, three pelvis, two pilon, four radius/ulna, and 20 tibia fractures. Of these, nine had previously been infected and undergone staged treatment. Twenty-one patients (51.2%) experienced postoperative drainage within 2 weeks of the index surgery. Of these, 13 required surgical debridement, and the remaining eight patients responded to local wound care and a short course of antibiotics. Fourteen of 41 (34.1%) patients developed a deep infection. Of these, three patients required amputation and two have ongoing infection. The remaining nine infections resolved with subsequent treatment. Nineteen of 41 (46.3%) patients had fractures that did not heal and required revision surgery. Twelve of these patients were those that were infected. The remaining seven patients were treated with various modalities, and their fractures healed. Postoperative infection correlated with the history of preoperative infection (P = 0.007) and postoperative wound drainage (P = 0.001). The need for revision surgery correlated (P = 0.001) with postoperative infection.
Discussion: This preliminary evaluation of a calcium sulfate-based DBM identified significant problems with use in nonunions. Although the study had numerous variables and was heterogeneous, the high rate of drainage, infections, and failure of healing warrant further critical analysis. Wound drainage and preexisting infection are independent risk factors for subsequent infection and treatment failure. High rates of postoperative drainage have been anecdotally reported previously for CaSO4-based products. In atrophic nonunions, the osmolarity and increased fluid shift engendered by these grafts may be especially challenging to the tenuous soft tissue sleeve and compromised local vasculature. The subsequent high rate of local wound drainage predicted failure in our series. The failure of the graft to promote union may be related to the drainage phenomenon, particularly when there is resultant deep infection.
Conclusion: Calcium sulfate DBM allograft (Allomatrix) used in atrophic and previously infected nonunions resulted in high rates of wound drainage, subsequent deep infection, and treatment failure. We do not recommend use in this clinical setting.