A new study is investigating the potential of stem cell therapy to enhance rotator cuff regeneration after surgical repair. The prospective, single-center trial is being conducted to evaluate the effectiveness of stem cell treatment in improving shoulder function and healing. The study focuses on patients with confirmed rotator cuff lesions verified by MRI and aims to provide evidence for a novel approach to accelerate recovery and improve long-term outcomes.
Trial Design and Objectives
The trial's primary objective is to assess patient-reported shoulder function using the Oxford Shoulder Score (OSS) questionnaire 12 months after surgery. The OSS comprises 12 items, with each item rated on a 5-point Likert scale, where 0 indicates the worst outcome, and 4 indicates the best. The scores from these 12 items are summed to produce a total score ranging from 0 to 48. Secondary objectives include evaluating improvements in the OSS at 3 and 6 months post-surgery compared to baseline, as well as assessing the EuroQol-5 Dimension (EQ-5D-5L) questionnaire results at 3, 6, and 12 months.
Measuring Clinical and Radiological Healing
Clinical healing will be measured by assessing pain, function, and strength. Pain will be documented on a scale from 0 to 10, and pain-free movement above shoulder level will be recorded. Strength tests will be performed using ISOBEX 4.0, with the median of three tests recorded in newtons. Radiological healing will be defined as the closure of the gap between the tendon and the greater tuberosity, assessed by MRI. MRI will also provide information on muscle atrophy and fatty infiltration, which are important prognostic factors in rotator cuff tear.
Assessing Supraspinatus Muscle Function
Improvement of muscle strain in the supraspinatus muscle will be recorded by speckle tracking ultrasonography (STU). STU patterns will be used to quantify changes in muscle contractility for direct recording of muscle recovery. The maximum voluntary contractions will be reported in newtons, and the median of five measures of muscle strain of 20%, 40%, and 60% will be documented.
Recruitment and Data Collection
Patients with a confirmed rotator cuff lesion verified by an MRI will have an appointment at the outpatient clinic, where a physician will perform a clinical examination and screening for the study. Patients who fulfill the inclusion and exclusion criteria will receive written and oral information about the study. All data will be collected through patient interviews, and demographic data will include patients’ age, gender, social status, occupation, and education. Lifestyle variables comprise smoking history, alcohol consumption, and physical activity. Clinical data reported will include lesion age in days, how the patient got injured, and sick leave. Pain will be reported on a scale from 0 to 10 at each clinical examination. Medicine information comprises if patients have an intake of statins, any painkillers, or have multipharmacy (> 5 medications). Adverse events will be registered with a date and a description.
Statistical Analysis
To calculate the sample size, Monte Carlo simulation was used. The simulation was based on a linear regression. The p value was based on the difference at 12 months, where adjustments were made for multiple testing through Bonferroni correction. Under these assumptions, 30 patients in total (15 in each arm) are needed to achieve a power of 94% at an alpha level of 0.05. Descriptive statistics will be applied to check for exchangeability between the two groups according to the variables measured at baseline and to assess the reproducibility of the sample with previous studies within this field. The final manuscript will report 95% confidence intervals and two-sided p values. A p value below 0.05 will be considered statistically significant, and multiple testing will be handled by using Hochberg’s sequential procedure.
Safety Measures
The liposuction procedure is safe with a very low risk of complications (less than 1%), such as bleeding, infections, and scarring. Harvest of 0.1–0.2 g muscle biopsies from the supraspinatus muscle is performed under direct vision from the arthroscope and has been performed without complications in 42 patients in a former protocol. MRI and ultrasonography have no reported risks or adverse effects. The responsible surgeon or physician will report adverse events in the study database at the time they occur. All adverse events occurring during surgery, post-surgery, and up to the final follow-up at 1 year will be documented.
