[Influence of local anesthesia and energy level on the clinical outcome of extracorporeal shock wave-treatment of chronic plantar fasciitis].
BACKGROUND
The efficacy of low energy extracorporeal shock wave treatment (ESWT) for chronic plantar fasciitis is discussed controversially. It is unclear whether the simultaneous application of local anesthesia (LA) interferes with clinical outcome.


METHODS
60 patients with a chronic plantar fasciitis were enrolled in a triple-arm (20 patients per group), prospective randomized and observer-blinded pilot trial. The patients were randomly assigned to receive either active ESWT without LA (;3 x 1 500 shocks, total energy flux density [EFD] per shock 0.09 mJ/mm(2) [Group A]), ESWT with LA (3 x 1 500 shocks, EFD 0.18 mJ/mm(2) per shock [Group B]) or ESWT with LA (3 x 1 500 shocks, EFD 0.09 mJ/mm(2) [Group C]). Main outcome measures were: pain during first stepps in the morning (measured on a 0-10 point visual analogue scale) and number of patients with > 50 % reduction of pain and no further therapy needed, measured at 6 weeks after the last ESWT.


RESULTS
Group A improved in the VAS from 6.4 (SD: 1.7) to 2.2 (SD: 2.6) points, group B from 6.7 (SD: 1.5) to 4.1 (SD: 2.4) points, group C from 6.2 (SD: 1.6) to 3.8 (SD: 2.5) points. A reduction of pain of at least 50 % was achieved in 60 % of group A, in 36 % of group B and in 30 % of group C. Group A without LA showed a significantly higher improvement in the VAS and subjective evaluation than groups B (p = 0.007) and C (p = 0.016).


CONCLUSIONS
At 6 weeks success rates after low-energy ESWT with local anesthesia were significantly lower than after identical low-energy ESWT without local anesthesia. Higher energy levels could not balance the disadvantage of this effect. LA significantly influenced the clinical results after low energy ESWT in a negative way. Blinding patients by LA in ESWT studies must therefore be considered a systematic error in study design.
Labek
G
G
Orthopädische Abteilung, Allgemeines Krankenhaus Linz, Osterreich. gerold.labek@akh.linz.at
Auersperg
V
V
Ziernhöld
M
M
Poulios
N
N
Böhler
N
N
D000328:Adult; D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D036981:Fasciitis, Plantar / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D010865:Pilot Projects; D011829:Radiation Dosage; D016037:Single-Blind Method; D016896:Treatment Outcome