Shoulder Stiffness Clinical Trial
Official title:
Can Vitamin C Reduce the Risk of Postoperative Shoulder Stiffness? A Multi-center, Double-blinded, Randomized and Placebo-controlled Study
Postoperative shoulder stiffness is a common complication after shoulder surgery (incidence 10-15%). The symptoms consist primarily in a painful impairment of the mobility of the glenohumeral joint, usually after initially good course. Cause and origin are not clear. Vitamin C is known as an inactivator of free radicals and plays a key role in building collagen tissue. Vitamin C thus has a modulating role in inflammatory reactions. Injured and ill people have been shown to have significantly increased vitamin C needs, which underlines this role. Evidence was also found that vitamin C has a positive influence on similar diseases such as the complex regional pain syndrome (CRPS, Morbus Sudeck) on the wrist and postoperative arthrofibrosis on the knee joint. The Investigators want to investigate whether vitamin C intake can positively influence the incidence and / or severity of postoperative shoulder stiffness after shoulder surgery. The primary objective of this study is to investigate the effect of vitamin C on the external rotational ability of the operated shoulder in the glenohumeral joint compared to the opposite side at 12 weeks post surgery. Secondary objectives of this study are to investigate other shoulder mobility tests, patient-reported outcomes (level of pain, ability/return to work, smoking habits), patient-reported questionnaires (Constant Score, Oxford shoulder score, DASH score) and the incidence of a frozen shoulder at 6, 12, 26, and 52 weeks post surgery. Total duration of study: 2.5 years.
Participants will be randomly allocated to the two treatment arms, vitamin C or placebo, in a 1:1 ratio Study participants in the verum group receive one capsule of Burgerstein Vitamin C retard 500mg b.i.d. with treatment starting in the evening on the day of the operation for a total of 50 days. The placebo group receives one placebo capsule b.i.d. with treatment starting in the evening on the day of the operation for a total of 50 days. Vitamin C will be administered orally. Burgerstein Vitamin C Retard Capsules 500 mg (Pharmacode: 6739189) will be used for this study. Active substance: Ascorbic acid (Vitamin C, E 300). Since a known drug should be tested for a new indication, the exclusion of a bias by a placebo effect, the administration of a placebo to the control group is necessary. To exclude a detection bias and a performance bias, the study is performed double-blind. A randomization protects against a selection bias. The determination of the sample size is based on the following considerations. The primary endpoint is not expected to be normally distributed. Therefore the sample size determination is based on a Mann-Whitney test for the comparison of the two groups (placebo and treatment) assuming a logistic distribution. Based on a few data of comparable measurements the Investigators think that the standard deviation of the primary endpoint is 10(=SD) in each group. The treatment effect is expected to be Delta=10, a medically reasonable effect. To achieve a power of at least 80% for the 4 tested comparisons in the final analysis of the primary endpoint, a minimal sample size of 42 in each of the 4 patient groups (strata) is required. In expectation of a drop-out rate of 20%, the target sample size will be 50 patients in each stratum and 200 patients in total, with 100 in the placebo group and 100 in the treatment group. ;