Treatment of Multiple Digit Amputation in an Infant Using an Abdominal Pocket Combined with Composite Grafts of the Amputated Distal Phalanxes and Nails.

Retention of the distal phalanxes is important in the treatment of multiple digit amputations in infants to preserve the digit length and nail for functional and cosmetic reasons. We report the case of a 22-month-old boy with multiple digit amputations of his left index, middle, and ring fingers, which were severely mangled and not suitable for replantation. We propose the usefulness of the abdominal pocket method combined with composite grafts of the amputated phalanxes and nails and report the outcome of our case, with 2-year follow-up.

Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis

OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a subcutaneous abdominal pocket was devised. To maintain animal mobility and longevity, the femur was harvested from syngeneic donors. Two technetium-99m-labeled tracers targeting angiogenesis and bone matrix were selected. METHODS: Medronic acid and a homodimer peptide conjugated with RGDfK were radiolabeled with technetium-99m, and biodistribution was evaluated in Swiss mice. The grafted and control femurs were evaluated after 15, 30 and 60 days, including computed tomography (CT) and histological analysis. RESULTS: Radiolabeling achieved high (>95%) radiochemical purity. The biodistribution confirmed good blood clearance 1 hour after administration. For 99mTc-hydrazinonicotinic acid (HYNIC)-E-[c(RGDfK)2, remarkable renal excretion was observed compared to 99mTc-methylene diphosphonate (MDP), but the latter, as expected, revealed higher bone uptake. The results obtained in the control femur were equal at all time points. In the implanted femur, 99mTc-HYNIC-E-[c(RGDfK)2 uptake was highest after 15 days, consistent with early angiogenesis. Regarding 99mTc-MDP in the implant, similar uptake was documented at all time points, consistent with sustained bone viability; however, the uptake was lower than that detected in the control femur, as confirmed by histology. CONCLUSIONS: 1) Graft viability was successfully diagnosed using radiotracers in severely ischemic bone at all time points. 2) Analogously, indirect information about angiogenesis could be gathered using 999mTc-HYNIC-E-[c(RGDfK)2. 3) These techniques appear promising and warrant further studies to determine their potential clinical applications.

Abdominal Pocket Method as a Salvage Procedure for Vascular Insufficiency After Distal Digital Replantation.

PURPOSE: To assess the utility of abdominal pocketing of a deepithelialized reattached digit to allow for neovascularization as a salvage procedure for circulatory insufficiency after digital replantation. We performed this method in Tamai zone II cases in which microsurgical vascular anastomosis was expected to be difficult based on the findings at the initial operation. MATERIALS AND METHODS: From 2008 to 2014, 5 injured digits from 5 patients (mean age, 34 years; range: 25-54 years) underwent the abdominal pocket method as a salvage procedure for postoperative circulatory insufficiency. We evaluated the survival incidence, the timing between operations, and the duration of the second operation. During this study period, 7 amputated digits from 7 patients underwent vascular reanastomosis. We also evaluated the survival incidence for these cases. RESULTS: Four out of 5 replanted digital tips survived. The mean time between the initial operation and the onset of vascular problems was 82 hours, and the mean duration of the second operation was 48 minutes. The survival incidence for reanastomosed cases was 6 out of 7. CONCLUSIONS: The abdominal pocket method is useful for treating circulatory insufficiency after digital replantation in Tamai zone II cases in which microsurgical vascular reanastomosis was expected to be difficult based on the findings at the initial operation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.