Influence of extracorporeal shock waves on human bone marrow cell culture

Introduction: Extracorporeal shockwave therapy (ESWT) is a new method of tr eating insertion tendopathy and pseudo-arthrosis, the clinical importance o f which cannot yet be definitively assessed, and the underlying mechanisms of which are still unclear. Aim: To develop an experimental set-up enabling the standardised applicatio n of ESWT to human bone marrow cell culture and the determination of the ef fect of ESWT. Material and methods: After 14 days incubation, human bone marrow cell cult ures were subjected to ESWT using 200/500 pulses at an energy flux densitie s ED + of 0.03, 0.04, 0.07, 0.11 and 0.25 millijoule/mm(2). Samples were ob tained for LDH measurement 15 minutes, 4 h and 18 h after ESWT. Transmissio n light microscopy was carried out before and after ESWT to determine cell numbers and for morphological analysis. Results: Gaps in the cellular tissue first appear at an energy of 0.01 mill ijoule/mm(2). At energies of 0.25 millijoule/mm(2), morphologically altered cells thinned out cellular tissue with a cell-free focal zone are found. A t low energy levels, defects ha;ie been repaired ca. 1 week after ESWT. No significant increase in LDH was detected at any of the energy levels applie d. Conclusion: Increasing energy and higher pulse frequency is associated with an increase in the size and number of holes in cellular tissue and in cell separation. Regeneration capability (regrowth, sprouting, normal cell form ) decreases as the energy level increases. Changes can be detected even at the lowest energy flux densities, which up until now had been assumed to ha ve no effect on cell morphology or number. The standardised application of ESWT to human bone marrow cell cultures provides reproducible results that can be controlled by a placebo ESWT application.