The study protocol was composed according to the most recent CONSORT 2010 recommendations for transparent reporting of RCTs [12, 13]. The study protocol according to the CONSORT recommendations has been published previously .
Ethics and Trial Registration
This RCT was approved in May 22, 2009 by the ethics institutional review board at Hannover Medical School, Germany, under the German title “Stosswellentherapie und Krafttraining zur Therapie der Cellulite—eine randomsiert-kontrollierte Studie” (Nr. 5206). The study is internationally registered at ClinicalTrials.gov with ClinicalTrials.gov identifier: NCT00947414.
All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000 and 2008. Informed consent was obtained from all patients for being included in the study and for the publication of patient photographs.
This was a single-center, double-blinded, RCT with a 1:1 parallel group randomization.
The mean age of the enrolled participants was 41.4 years in the intervention group and 45.0 years in the control group. BMI (mean ± SE) was 24.2 ± 3.2 kg/m2 in the intervention group and 25.3 ± 4.5 kg/m2 in the control group.
Eligible patients were females aged between 18 and 65 years with documented cellulite 0° to 3° according to the Nürnberger Müller score . Exclusion criteria were the following: suspected or evident pregnancy, no cellulite, no informed consent, and age under 18 years or above 65 years. Patients were recruited by advertisements in local regional newspapers and via the Internet. The patient enrollment flow chart according to the CONSORT statement is outlined in Fig. 1.
In CelluShock-2009 patients were randomly assigned with a 1:1 ratio to either ESWT with 0.35 mJ/mm2 in the intervention group or 0.01 mJ/mm2 in the SHAM-ESWT group. Both groups additionally participated in a home-based, daily gluteal thigh exercise program.
The intervention group received six sessions of ESWT (every 1–2 weeks) with focused shock waves (2,000 impulses, 0.35 mJ/mm2, Fig. 2) plus home-based, daily gluteal strength exercises (Figs. 3, 4). The control group received six sessions of SHAM-ESWT (2,000 impulses, 0.01 mJ/mm2, every 1–2 weeks) plus home-based, daily gluteal strength exercises. Extracorporeal shock wave therapy was applied using a STORZ focused Duolith machine (Taegerwilen, Suisse) as acoustic wave treatment.
In order to increase the motivation of the participating females, especially in terms of follow-up, we added a daily, home-based gluteal strength exercise program. Twice a day (in the morning and the evening), two different exercises focusing on the gluteal muscles involving the piriformis, the gemelli, and the gluteal muscles were performed with 15 repetitions for each leg (Figs. 1, 2). The compliance to the daily gluteal workout program was noted in a exercise log to improve and supervise participants’ compliance, respectively.
Primary and Secondary Outcome Measures
The primary endpoint, with respect to efficacy of the combined ESWT and gluteal strength exercises versus SHAM-ESWT and the same gluteal strength exercise program, was the change on digital photographs 3 months after the last ESWT treatment assessed by the validated CSS . This provided reliable, comprehensive, and reproducible results. Cellulite severity may be classified according to the result of this assessment in the CSS in three degrees, as described in Table 2.
The classification was performed based on standardized photographs taken by a professional medical photographer at baseline and 12 weeks after the last ESWT treatment in both groups. The assessment of the anonymous digital images was carried out by two blinded assessors who were not aware of either the study arm or the fact that it is a baseline or a follow-up photograph taken 12 weeks after the last ESWT treatment in both groups.
In order to overcome the problems of interpretation associated with multiplicity of analyses we decided to choose the aforementioned clinical endpoint which is a visual one as the primary endpoint and results as secondary endpoints in CelluShock.
Secondary endpoints of the CelluShock RCT were as follows: change of circumference of the thigh (cm), skin elasticity using the Cutometer® (Cutometer MPA 580, Kosmetik Konzept KOKO GmbH & Co KG, Leichlingen, Germany) [16–19], and self-assessment of the success on a visual analogue scale 0–10 (0 = no change, 10 = fully satisfied).
All patients were measured at baseline and after 12 weeks regarding the primary and all secondary endpoints.
To detect at least a change of two points in the CSS of cellulite, with a two-sided, 5% significance with an 80% power, a sample size of 26 participants with an estimated drop-out rate of 15% was calculated. This was done prior to the start of trial.
Randomization and Allocation Sequence
For allocation of participants, a 1:1 ratio randomization was performed using opaque envelopes for the concealment of allocation. The allocation sequence was concealed from the researcher (BJ) enrolling and assessing participants in sequentially numbered, opaque, sealed envelopes .
Blinding was achieved for all participants enrolled in the trial, the photographer taking the digital images for the primary outcome measure, the two assessors of the outcome measures, all additional health care providers, and for the analyst from the biometrical department. Only one researcher (BJ) was aware of the group assignment performing the randomization and the ESWT.
The assessment of the primary and secondary outcomes was performed by blinded assessors independently from each other, unaware whether the digital image displayed was before or after therapy or with group (intervention or control group) was randomized.
The primary endpoint was change of CSS assessed on digital, standardized photographs by two independent expert examiners. Student’s t test was applied for parametric data, the Wilcoxon test for non-parametric data, and a level of P < 0.05 was reported as significant. An intention-to-treat analysis was applied. SPSS (IBM Corp., New York, USA) was used to carry out the analysis.
CONSORT Flow Chart
Figure 1 highlights the patient flow throughout the CelluShock-2009 RCT (Fig. 1).