• Aim: To investigate the effect of arthroscopic Bankart repair on shoulder biomechanics and proprioception, and increase understanding of traumatic anterior shoulder instability.~• Main research questions: A (biomechanics): Does arthroscopic Bankart repair have a stabilising effect on the anterior-posterior glenohumeral translation in patients with traumatic anterior shoulder instability? B (proprioception): Does arthroscopic Bankart repair improve neuromuscular control in patients with traumatic anterior shoulder instability?~• Objectives and hypotheses research question A: In patients with symptomatic traumatic anterior shoulder instability treated with arthroscopic Bankart repair in combination with a standardized rehabilitation protocol, to: Primary: Investigate if Bankart repair affects anterior-posterior glenohumeral translation, measured during dynamic and isometric exercises 6 months after surgery. Further, whether the effect remains 12 months after surgery. Hypothesis: The treatment results in a ≥2.5 mm decrease in anterior-posterior glenohumeral translation, remaining both 6 and 12 months after surgery.~Secondary: Investigate if the treatment reduces anterior-posterior glenohumeral translation to the same range as the healthy opposite shoulder (±2.5 mm). Hypothesis: The treatment reduces anterior-posterior glenohumeral translation to the same range as measured in the healthy opposite shoulder (±2.5 mm).~Secondary: Investigate if other kinematic measures (superior-inferior glenohumeral translation and scapular rotations and tilt) are affected 6 months after surgery. Hypothesis: The treatment reduces superior-inferior glenohumeral translation while scapular rotations and tilt remain unchanged 6 months after surgery.~Secondary: Investigate if there is a correlation between the range of anterior-posterior glenohumeral translation and 1) patient-reported outcome measures (PROM) and 2) range of motion (ROM). Hypotheses: There is a positive correlation between smaller range of anterior-posterior translation and better PROM. There is a positive correlation between smaller range of anterior-posterior translation and reduced ROM.~• Objectives and hypotheses research question B: In patients with symptomatic traumatic anterior shoulder instability, treated with arthroscopic Bankart repair in combination with a standardized rehabilitation protocol, to: Primary: Investigate if the treatment improves neuromuscular control, measured using the Copenhagen Assessment of Neuromuscular Control in the Unstable Shoulder (CANCUS) test series 6 months after surgery, and whether the improvement remains 12 months after surgery. Hypothesis: The treatment improves neuromuscular control, remaining both 6 and 12 months after surgery.~Secondary: Investigate if the treatment improves neuromuscular control to the same range as the healthy opposite shoulder. Hypothesis: The treatment improves neuromuscular control to the same range as the healthy opposite shoulder.~Secondary: To investigate if there is a correlation between the degree of improvement of neuromuscular control and 1) PROM and 2) ROM. Hypotheses: There is a positive correlation between the degree of improvement of neuromuscular control and better PROM. There is a positive correlation between the degree of improvement of neuromuscular control and larger ROM.~• Type of study: Multi-clinical prospective cohort study including 55 patients. Patients' contralateral shoulders will be used as controls.~• Time schedule: Recruitment and inclusion is planned to begin 1 March 2022 and is expected to last for twelve months. With a one-year follow-up the complete study period is expected to last two years.~• Set-up: Five sports orthopaedics clinics in the Capital Region of Denmark will recruit patients for the study. While the responsibility for treatment remains at the recruiting center, all study-related activities will take place at the Copenhagen University Hospital Hvidovre. Patients who have signed an informed consent form will undergo examinations prior to, as well as six and twelve months after surgery. All examinations will include biomechanical and proprioceptive testing, accompanied by a clinical shoulder examination and two validated electronic questionnaires regarding shoulder-related function and quality of life. A pre-interventional 3D computed tomography scan will be performed to evaluate bone loss. Study participation will not influence the treatment course.
The purpose of the study is to investigate biomechanical and proprioceptive conditions in patients with symptomatic traumatic anterior shoulder instability undergoing arthroscopic Bankart repair. To determine these, non-invasive and non-irradiating examination methods that have been proven valid and reliable will be used in a combination that has not been reported before. The objective is to determine whether the anatomical reconstruction affects biomechanical and proprioceptive measures in the traumatic unstable shoulder. The study will also investigate the correlations between biomechanics and proprioception and patients' functional outcomes and range of motion.~The hypotheses are that the intervention improves biomechanical and proprioceptive conditions to the near-normal state, as measured after both 6 and 12 months. Further, hypotheses are that there are positive correlations between improved biomechanical and proprioceptive measures and both patients' functional outcomes and range of motion.