Intermediate-term outcome of primary digit amputations in patients with diabetes mellitus who have forefoot sepsis requiring hospitalization and presumed adequate circulatory status.

PURPOSE: The intermediate success and outcome of primary forefoot amputations in patients with diabetes mellitus who have sepsis limited to the forefoot and presumed adequate forefoot perfusion, as determined by means of noninvasive methods, was studied.

METHODS: Cases of a university hospital-based practice from January 1984 to April 1998 were retrospectively reviewed. Patients included had diabetes mellitus with forefoot sepsis requiring immediate hospitalization for digit amputations who had adequate arterial circulation for healing based on noninvasive and clinical assessment: palpable pedal pulses (29%), "compressible" ankle pressure of 70 mm Hg or higher (48%), pulsatile metatarsal waveforms (67%), and/or toe pressure higher than 55 mm Hg (36%). All patients underwent a primary single- or multiple-digit amputation (through the interphalangeal joint, metatarsal head, or metatarsal shaft). Additional forefoot procedures (debridement, digit amputation) were performed during the follow-up period as needed for persistent or recurrent infection. The main outcome variables were recurrent or persistent foot infection (defined as requiring rehospitalization for antibiotics, wound care, and/or reoperation), the number of repeat operations and hospitalizations for salvage of limbs with recurrent or persistent infections, and time to complete forefoot healing or foot amputation.

RESULTS: Ninety-two patients who had diabetes mellitus with 97 forefoot infections comprised the study group. Ninety-seven primary digit amputations (34 through interphalangeal joints, 28 through metatarsal heads, 35 through metatarsal shafts) were performed. The median length of hospital stay was 10 days. There were no operative deaths. The mean follow-up period was 21 months (range, 3 days to 105 months). The primary amputation healed (without persistent infection) in only 38 limbs (39%), at a mean time of 13 +/- 10 weeks. Twenty-three limbs (24%) had not healed the primary amputation without evidence of persistent infection at last follow-up (mean, 12 weeks). Infection persisted in 35 limbs (36%), and infection recurred in 15 of 38 (40%) healed limbs. An average of 1.0 reoperations (range, 0 to 3) and 1.6 rehospitalizations (range, 1 to 4) were involved in salvage attempts in these recurrent/persistent infections. Five persistent and five recurrent infections ultimately healed (mean, 53 weeks). Complete healing was achieved in only 33 of 97 limbs (34%). Twenty-two foot amputations (20 transtibial, two Syme's) were performed (mean, 49 +/- 74 weeks; 20 for persistent infection). Eighteen persistent/recurrent infections remained unhealed at the last follow-up examination (mean, 105 weeks).

CONCLUSION: Patients with diabetes mellitus who have sepsis limited to the forefoot requiring acute hospitalization and undergoing primary digit amputations have a high incidence of intermediate-term, persistent, and recurrent infection, leading to a modest rate of limb loss, despite having apparently salvageable lesions and noninvasive evidence of presumed adequate forefoot perfusion.