Radiofrequency Energy on Cortical Bone and Soft Tissue: A Pilot Study

BACKGROUND: Radiofrequency-generating energy devices have been used clinically in musculoskeletal procedures to provide hemostasis and capsular shrinkage (thermal capsulorrhaphy). However, the dose-effects are not well known. QUESTIONS/PURPOSES: We therefore determined dosage effects of radiofrequency energy on bone, skin incisions, and joint capsule in sheep. METHODS: Five mature sheep had six 2.5-cm(2) tibial periosteal defects and six 1.0-cm skin incisions assigned to six treatments varying by watts and fluence (f = watts · seconds/cm(2)): (1) untreated control, (2) 50 W for 9.5 seconds (190f; n = 5), (3) 110 W for 4.3 seconds (190f; n = 5), (4) 170 W for 2.8 seconds (190f; n = 5), (5) 170 W for 5.6 seconds (380f; n = 5), or (6) 170 W for 8.4 seconds (570f; n = 5). Outcomes included hemostasis, contraction, healing, and histomorphometry for inflammation and necrosis at 2 weeks. RESULTS: Radiofrequency energy application on skin at 190f or greater had more than 80% hemostasis and dose-dependent contraction, inflammation, and necrosis. Radiofrequency energy application on bone had good (70%) hemostasis at 190f and complete (> 95%) hemostasis at 380f and 570f, without histologic or clinically detectable necrosis. CONCLUSIONS: Hemostasis can be achieved with radiofrequency energy at 190f in skin and bone. Bone necrosis was not detected at up to 570f. Using fluence greater than 190f in skin achieved dose-dependent necrosis and incisional contraction. CLINICAL RELEVANCE: Radiofrequency energy can be used on bone and skin for hemostasis, but potential incisional complications, such as necrosis and an atypical firm and desiccated surface, should be expected.