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Summary: Extracorporeal shockwave therapy showed a pronounced effect on bone mass in previous animal studies. We showed in this pilot study that a single treatment with unfocused shockwave therapy in unselected patients does not show side effects. Although our study did not show any effect of shockwave on BMD, the limited sample size does not definitively exclude this and a study with 174 subjects per group would be needed to show an effect size of 0.3 with a power of 80%. Purpose: Unfocused extracorporeal shockwave therapy might stimulate bone formation to reduce the fracture risk. In this study, we assessed the safety of unfocused extracorporeal shockwave therapy and its effects on bone mass. Methods: A clinical pilot study with twelve female patients free of bone disease undergoing elective surgery of the lower extremity or elective spinal surgery under general anesthesia received 3.000 electrohydraulic-generated unfocused extracorporeal shockwaves (energy flux density 0.3 mJ/mm2) to one distal forearm. The contralateral forearm served as a control. We examined the effect on bone mass with the use of repeated dual energy X-ray absorptiometry measurements and we measured patient discomfort around the therapy. Results: No difference in bone mineral content and density was measured 6 and 12 weeks after therapy. shockwave therapy occasionally caused transient erythema or mild hematoma, but no discomfort in daily life or (late) adverse events. Conclusions: Unfocused extracorporeal shockwave therapy is a safe treatment, but no increase in bone mass on the forearm was found at 0.3 mJ/mm2 energy flux density. In this study, we were not able to demonstrate that a single treatment with unfocused shockwave therapy in unselected patients had any effect in terms of bone mineral density (BMD) or bone mineral content (BMC). A power analysis indicated that 174 patients per group are required to show an effect size of 0.3 with a power of 80%., Biomaterials & Tissue Biomechanics

Background: Predictive models permitting individualized prognostication for patients with fracture nonunion are lacking. The objective of this study was to train, test, and cross-validate a native Bayesian classifier for predicting fracture-nonunion healing in a population treated with extracorporeal shock wave therapy. Methods: Prospectively collected data from 349 patients with delayed fracture union or a nonunion were utilized to develop a naive Bayesian belief network model to estimate site-specific fracture-nonunion healing in patients treated with extracorporeal shock wave therapy. Receiver operating characteristic curve analysis and tenfold cross-validation of the model were used to determine the clinical utility of the approach. Results: Predictors of fracture-healing at six months following shock wave treatment were the time between the fracture and the first shock wave treatment, the time between the fracture and the surgery, intramedullary stabilization, the number of bone-grafting procedures, the number of extracorporeal shock wave therapy treatments, work-related injury, and the bone involved (p < 0.05 for all comparisons). These variables were all included in the naive Bayesian belief network model. Conclusions: A clinically relevant Bayesian classifier was developed to predict the outcome after extracorporeal shock wave therapy for fracture nonunions. The time to treatment and the anatomic site of the fracture nonunion significantly impacted healing outcomes. Although this study population was restricted to patients treated with shock wave therapy, Bayesian-derived predictive models may be developed for application to other fracture populations at risk for nonunion., Investigation performed at the AUVA-Trauma Center, Meidling, Vienna, Austria; DecisionQ Corporation, Washington, DC; Walter Reed Army Medical Center, Washington, DC; and National Naval Medical Center, Bethesda, Maryland.. The original document contains color images. Published in Journal of Bone and Joint Surgery, v93 A p187-194, 19 Jan 2011.

Objectives: Delayed and nonunion of the tibia are not uncommon in orthopaedic practice. Multiple methods of treatment have been developed with variable results. The objective of this study was to define disease-specific and treatment-related factors of prognostic significance in patients undergoing shock wave therapy for tibia nonunion. Design: Retrospective analysis. Patients: One hundred ninety-two patients treated with extracorporeal shock wave therapy (ESWT) at a single referral trauma center, AUVA-Trauma Center Meidling, a large single-referral trauma center located in Vienna, Austria, in an attempt to determine the feasibility and factors associated with the use of ESWT in the treatment for tibia nonunion. Intervention: ESWT coupled with posttreatment immobilization, external fixation, or ESWT alone. Main Outcome Measures: Fracture healing, overall healing percent, and factors associated with ESWT success or failure. Results: At the time of last follow up, 138 of 172 ( 80.2%) patients have demonstrated complete fracture healing. Mean time from first shock wave therapy to complete healing of the tibia nonunion was 4.8 + or - 4.0 months. Number of orthopaedic operations (P = 0.003). shock wave treatments (P = 0.002), and pulses delivered (P = 0.04) were significantly associated with complete bone healing. Patients requiring multiple (more than one) shock wave treatments versus a single treatment had a significantly lower likelihood of fracture healing (P = 0.003). This may be attributable to the finding that a significantly greater proportion of patients with multiple rather than single ESWT treatments had three or more prior orthopaedic procedures (more than one ESWT, 63.9% versus one ESWT. 23.5%; p 0.001). Conclusions: ESWT is a feasible treatment modality for tibia nonunion., Published in Journal of Orthopaedic Trauma, v24 n3 p133-141, Mar 2010.