Extracorporal shock wave treatment of the achilles tendinitis: Experimental and preliminary clinical results

Objective: Various studies have shown the benefit of etracorporal shock wave therapy (ESWT) in the treatment of soft tissue pathologies. The aim of this prospective study was to compare the results of ESWT with the operative treatment for achilleus tendopathy. Furthermore mechanical effects of the shock waves on the achilleus tendon were analysed by an in-vitro model. Method: The achilleus tendons of common pigs treated with 1500 impulses twice using an energy varying from 0.23 - 0.54 mJ/mm(2) were histologically examined. The clinical results of two patient groups of which the first (n = 28) was treated with 2000 impulses (0.23 mJ/mm(2)) once and the second (n = 26) underwent surgery for achilleus tendopathy were compared. Results: The in-vitro model demonstrated that an EFD of 0.42 and 0.54 mJ/mm(2) can lead to tendon lesions. One year follow-up showed good and excellent results in 69% and satisfactory results in 15% of the operated group and good and excellent results in 29% and satisfactory results in 43% of the ESWT group. We could show a time-dependent effect of the shock wave treatment on the clinical outcome. Conclusions: Follow-ups show acceptable results with little side effects when an energy flow density (EFD) under 0.23 mJ/mm(2) is used. ESWT offers a non-invasive therapeutic concept that can seriously be contemplated before operative treament, but lower success rates in comparison to the operative results can be expected.