Authors: Conway J, Specht S, Mansour J, Kotze K.
Sinai Hospital, International Center for Limb Lengthening Baltimore, MD
Title: Antibiotic Cement-Coated Nails: An Effective Treatment of Infected Nonunions, Fusions, and Bone Defects
Background: Stabilizing fusions and nonunions with infections is a challenging orthopaedic dilemma. Traditionally, the infection is treated surgically with debridement and local antibiotic delivery. Stability is then achieved with a cast or external fixator, which is not ideal especially in obese patients or those requiring wound care.
Antibiotic cement coated intramedullary nails (ACC nail) provides bone stability and local antibiotic delivery. This technique avoids the problems associated with external fixation, and avoids joint stiffness associated with cast immobilization.
Hypothesis/Purpose: Are ACC nails effective for treating infected nonunions, fusions and bone defects?
Methods: From 2003-2012, 155 patients received an ACC nail. 100 male and 55 female patients with an average age of 50 (15-92 years) were included. According to the Cierny-Mader classification, 32 (20.5%) were A host, and 123 (79.5%) were B host patients. 100 patients presented with an infected non-union or fusion, 42 with an infected joint, 7 with a bone defect and 6 with a fracture. Nails were made with a concentration of 1 gram of vancomycin and 3.6 grams of tobramycin per 40 grams of cement. Nail type included 50 knee arthrodesis, 38 hindfoot fusion, 38 tibial, and 29 femoral. 62 patients had bone defects averaging 6.7cm (1-35cm). The majority of patients cultured MRSA.
Results: 102 (66%) of patients did not require additional procedures to treat the non-union or infection. 53 patients had at least one additional procedure to treat infection (12-23%), nonunion (14-26%), or both(27-51%). 5(3%) patients required an amputation making the overall limb salvage rate 97%. The average length of follow up was 20 months (0-112 months).
At latest follow up 114/139(82%) of the patients had bone union. Infection was controlled at latest follow up in 83% (125/150).
Of the 55 nails removed, 16 had either full or partial debonding of the cement mantle. There were 18 nail related complications for a complication rate of 12%.
Discussion: Our treatment method provides bone stability while delivering antibiotics to the infected area. Infections require a stable environment to minimize micromotion at the nonunion site as well as the soft tissue shearing which promotes necrosis.
Conclusion: The ACC nail is effective for treating complex orthopaedic infections with a limb salvage rate of 97%. 66% of patients required only the index surgical procedure.