Arthroscopic rotator cuff tear reconstruction. The shoulder arthroscopy is performed according to internal and international standard procedure with patients positioned in beach-chair position under general anesthesia.

One of five surgical techniques can be used in this study, as routinely performed by each surgeon:

1. RISA with FCR-Ligament (flexor carpi radialis ligament) modified according to Epping
2. RISA with FCR-Ligament modified according to Weilby
3. RISA with APL-Ligament (abductor pollicis longus ligament)
4. RISA with Graftjacket modified according to Weilby
5. Resection arthroplasty

TSA preOP:

• Status of the rotator cuff (intact / partial rupture)
• Supraspinatus muscle atrophy
• Amount of fatty infiltration in the rotator cuff muscles
• Acromiohumeral distance
• Severity of arthrosis

TSA postOP:

• Head position with respect to glenoid
• Occurrence of osteolysis and migration
• Cortical bone resorption (when a shaft is implanted)
• Status of the Tuberculum Majus

RCR preOP:

• Location and extent of the injury of the rotator cuff (partial / complete rupture)
• Amount of fatty infiltration in the rotator cuff muscles
• Extend of tendon retraction
• Signs of tendon degeneration

RCR postOP:

• Position of the anchors
• Postoperative tissue growth

TMC OA preOP:

• Stage of Osteoarthritis
• Occurrence of articular chondrocalcinosis
• Involvement of the scapho-trapezio-trapezoidal (STT) joint
• Distance between the scaphoid and the metacarpal

The Constant (Murley) score is possibly the most commonly used tool for assessment of shoulder function. The physician asks and documents answers to Quality of life questions (pain and activity of daily living, ability to work, sleep, sports and leisure) and certain clinical parameters (active range of motion, abduction strength). The different scales will be summed and normalized to 0 = worst to 100 = best. A German version is available for clinical use.

With the CS we can assess the change and gain in functional shoulder outcome.

Additional to th Constant score we assess the

• passive abduction
• passive elevation
• active and passive external rotation by 0°
• active and passive external-internal rotation by 90°

The ability to oppose the thumb of both hands will be quantified using the Kapandji index. The flexion/extension of the metacarpo-phalangeal (MCP) and inter-phalangeal (IP) joint of the affected and contralateral thumb will be measured with an electrical Goniometer (ELINK, Biometrics Ltd., Gwent, UK).

Grip strength as well as key pinch strength of both hands will be measured with the help of an electrical dynamometer and pinch gauge (ELINK, Biometrics Ltd., Gwent, UK). Three records will be taken and the mean value will be taken for analyses. The standardized testing position as recommended by the American Society of Hand Therapists will be used.

The Shoulder Pain and Disability Index (SPADI) is a short, self-administered questionnaire that provides an item scoring by a visual analogue scale (VAS) from 0 (no pain/no difficulty, i.e. best) to 11 (worst pain imaginable/so difficult required help, i.e. worst). Five items assess pain and 8 items disability of the arm (function). The unweighted means of the 5 pain and the 8 function items will be transformed into the scale from 0 (=worst) to 100 (=best) for both scales and are used to determine pain and function scores. The average of these two scores then gives the total SPADI score. A validated German version is available.

The OSS is a condition-specific questionnaire developed for patients with a degenerative or inflammatory state of the shoulder. It contains 12 items to be answered by the patient independently, which deal with pain (degree, time point) and possible handicaps in private and professional life. There are five categories of response for every question, corresponding to a score ranging from 0 to 4. Scores are combined to give a single score, with a range from 0 (worst outcome) to 48 (best outcome). The score can also be standardized from 0 to 100 (best) for comparison with other outcome instruments. A German version of this questionnaire is available and it is suitable for patient-based outcome after rotator cuff repair.

The Michigan Hand Outcomes Questionnaire MHQ was specifically designed to measure health state domains important to patients with hand disorders. In contrast to the widely applied DASH, the MHQ seems to be more sensitive to functional changes in hand patients. Compared to the DASH and Patient Evaluation Measure, the MHQ shows the highest correlation in finger patients with grip strength and range of motion.

In this study we will use a short version of the MHQ that includes only 12 questions for patients with acute or chronic disorders of the hand. The answers are rated on a 5-point Likert scale and scores are normalized on a scale of 0 to 100. The brief MHQ demonstrated an excellent test-retest reliability.

The Disability of the Arm, Shoulder and Hand questionnaire (DASH) is a comprehensive self-administered questionnaire about symptoms and functioning of the entire upper extremity. The DASH enquires about the ability to perform simple and complex activities of daily living (ADL) that are commonly performed with either one or both arms. The total score is derived from the unweighted mean of 30 items, of which at least 27 have to be answered. The QuickDASH is a more efficient version of the DASH outcome measure that appears to retain its measurement properties. It contains eleven items and is similar with regard to scores and properties to the full DASH. A validated full-length German version is available that can be used in the shortened version.

The Subjective Shoulder Value (SSV) is based on a single question that is answered subjectively by the patients. The formulation of this question is: "What is the overall percent value of your shoulder if a completely normal shoulder represents 100%?" It is an easily administered measure of shoulder function.

The outcome measure "general health" is a composite of these three questions:

• patients will be asked to report their general health status on a visual analog scale from 0 (worst possible health) to 100 (best possible health) using the EQ-5D-5L instrument.
• In addition, patients will be asked to assess their current state of health related to the operated shoulder or hand at follow-up compared to the state before surgery. This so-called 'transition' question has the possible answers 'much worse', 'slightly worse', 'equal', 'slightly better', and 'much better'.
• A similar question will be asked regarding their perceived change in quality of life at follow-up compared to the state before surgery.

The outcome measure "level of satisfaction" is a composite of these two questions:

• Patients are asked to rate their level of satisfaction, with the help of a numeric rating scale (NRS: 0-10), in terms of how the outcome met up to their preoperative expectations.
• Finally, they will be asked whether - with their current knowledge of the outcome - they would again choose the operation if they found themselves in similar circumstances to those which prevailed preoperatively.