Please assess the completion status of the following clinical trial:

Trial Title: Can Vitamin C Reduce the Risk of Postoperative Shoulder Stiffness?

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: TRIPLE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Informed Consent as documented by signature~* 18 years or older at the time of informed consent signature~* Complication-free rotator cuff\* or shoulder arthroscopy\*\* with or without resection of the acromioclavicular joint at the orthopedics Sonnenhof. The rotator cuff operations are basically open or in mini-open technique, usually with additional tenotomy / tenodesis of the long biceps tendon.~  \* rotator cuff surgery can include tenotomy/tenodesis of long biceps tendon, intra-articular debridement with or without resection of the coracoacromial ligament and/or acromioplasty, biopsies, diagnostic arthroscopy~  \*\* Arthroscopic procedures include subacromial debridement (including partial resection of the coracoacromial ligament \& acromioplasty), diagnostic arthroscopy, tenotomy of the long biceps tendon, intra-articular debridement, resection of calcium depots for treatment of tendinitis calcarea, biopsies, stabilizations (only without postoperative immobilization)~* Sufficient knowledge of German to understand the patient information and informed consent, follow instructions by study personnel, and complete patient questionnaires \& diary~Exclusion Criteria:~* Contraindications to ascorbic acid or one of the excipients, e.g. known hypersensitivity or allergy to the investigational product~* Planned single or multiple intake of vitamin supplements during the study period, which results in an additional daily intake of \> 50 mg ascorbic acid~* Known pregnancy or breast feeding~* Known or suspected non-compliance, for example drug or alcohol abuse~* Inability to follow the procedures of the study, e.g. due to psychological disorders, dementia, etc.~* Participation in another interventional study within the 30 days preceding and during the present study~* Previous enrollment into the current study~* Enrollment of the investigator, his / her family members, employees and other dependent persons~* Current or previous frozen shoulder (no matter on which side)~* Pre-surgery on the affected shoulder joint (preoperative procedures include all procedures examined in this study, including all other procedures involving the glenohumeral joint and / or acromioclavicular joint. In addition, all interventions, which as a result, negatively influence the mobility of the shoulder with great likelihood up to the current time)~* Known current unstable medical problem on the not-affected shoulder joint according to the judgment of the investigator~* Taking a cortisone preparation or an immunomodulatory drug (for example methotrexate or similar)~* Alcoholism (defined as intake of more than 12g (women) or 24g (men) alcohol per day)~* Regular hemodialysis~* Known diabetes mellitus~* Known Addison's disease~* Known not correctly adjusted thyroid metabolism~* Known Parkinson's disease and similar CNS disorders (Diffuse Lewy Body Disease, Corticobasal Degeneration, Multisystem Atrophy, Progressive Supranuclear Paralysis, Essential Tumor, Huntington's Disease, Multiple Sclerosis)~* Known diseases / injuries of the peripheral nerves (Isaac's Syndrome, Stiff-Person Syndrome, Guillain-Barré Syndrome, Chronic Inflammatory Demyelinating Polyneuropathy, Hereditary Neuropathies, Amyotrophic Lateral Sclerosis, Hereditary Motor Neuropathies Prone to Pressure Paralysis, Motor Neurone Diseases, Myasthenia Gravis, Spinal Muscular Atrophies, Thoracic Outlet Syndromes)~* Known infection in the shoulder joint to be operated~* Known Hyperlipidemia~* Known Uremia~* Known Thalassemia~* Known iron storage diseases~* Known Glucose-6-phosphate dehydrogenase (G6PD) deficiency~* Planned further operation of any kind within the next 50 days after shoulder surgery

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Vitamin C (Type: EXPERIMENTAL): Patients who are assigned to the experimental treatment group will be given extended release capsules with 500 mg of ascorbic acid orally two times daily, packed in PET/PP-bottles identical as used for the licenced product.
- Placebo (Type: PLACEBO_COMPARATOR): The control intervention of this study consists of treatment with no active substance (placebo) but in the same schedule as the experimental treatment (verum).

Based on this trial design, predict the completion outcome and termination type (if applicable).