Can Vitamin C Reduce the Risk of Postoperative Shoulder Stiffness?

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.