Evaluation and treatment of rotator cuff tears

Effects of Release of TSG-6 from Heparin Hydrogels on Supraspinatus Muscle Regeneration

Muscle degeneration after rotator cuff tendon tear is a significant clinical problem. In these experiments, we developed a poly(ethylene glycol)-based injectable granular hydrogel containing two heparin derivatives (fully sulfated (Hep) and fully desulfated (Hep-)) as well as a matrix metalloproteinase-sensitive peptide to promote sustained release of Tumor Necrosis Factor Stimulated Gene 6 (TSG-6) over 14+ days in vivo in a rat model of rotator cuff muscle injury. The hydrogel formulations demonstrated similar release profiles in vivo , thus facilitating comparisons between delivery from heparin derivatives on level of tissue repair in two different areas of muscle (near the myotendious junction (MTJ) and in the muscle belly (MB)) that have been shown previously to have differing responses to rotator cuff tendon injury. We hypothesized that sustained delivery of TSG-6 would enhance the anti-inflammatory response following rotator cuff injury through macrophage polarization, and that release from a fully sulfated heparin derivative (Hep) would potentiate this effect throughout the muscle. Inflammatory/immune cells, satellite cells, and fibroadipogenic progenitor cells, were analyzed by flow cytometery 3 and 7 days after injury and hydrogel injection, while metrics of muscle healing were examined via immunohistochemistry up to Day 14. Results showed controlled delivery of TSG-6 from Hep caused heightened macrophage response (Day 14 macrophages, 4.00 ± 1.85% single cells, M2a, 3.27 ± 1.95% single cells) and increased markers of early muscle regeneration (embryonic heavy chain staining) by Day 7, particularly in the MTJ region of the muscle, compared to release from desulfated heparin hydrogels. This work provides a novel strategy for localized, controlled delivery of TSG-6 to enhance muscle healing after rotator cuff tear.

IMPACT STATEMENT

Rotator cuff tear is a significant problem that can cause muscle degeneration. In this study, a hydrogel particle system was developed for sustained release of an anti-inflammatory protein, Tumor Necrosis Factor Stimulated Gene 6 (TSG-6), to injured muscle. Release of the protein from a fully sulfated heparin hydrogel-based carrier demonstrated greater changes in amount inflammatory cells and more early regenerative effects than a less-sulfated carrier. Thus, this work provides a novel strategy for localized, controlled delivery of an anti-inflammatory protein to enhance muscle healing after rotator cuff tear.

Single-Plane 3-Dimensional Isotropic Spin-Echo Magnetic Resonance Imaging Reconstructions of Shoulder Exhibit Superior Correlation to Surgical Findings Than 2-Dimensional Dixon Multiplanar Magnetic Resonance Imaging

OBJECTIVE

The aim of the study is to evaluate concordance of multiplanar 2-dimensional magnetic resonance imaging (2D-MRI) versus 3D isotropic MRI for rotator cuff and labral tears with the reference standard of arthroscopic surgical findings.

METHODS

It was an institutional review board-approved retrospective single-center study of consecutive preoperative patients with isotropic 3D-MRI on 3-Tesla scanners, multiplanar 2D-MRI, and shoulder arthroscopy. Scapular plane-oriented contiguous multiplanar reconstructions of 3D-images were evaluated by 2 experienced fellowship-trained musculoskeletal radiologists. Variables included the following: labral tear presence and rotator-cuff tear Ellman grade, thickness, and width. Sensitivities (Sen) and specificities (Spe) were calculated for binary variables. Mean squared errors (MSE) were calculated for ordinal variables. Lower MSE indicated higher concordance.

RESULTS

Seventy-two patients (43 female) with a mean age of 50.75 ± 9.76 years were evaluated. For infraspinatus-tear presence, 3D-MRI showed higher sensitivity (0.96) and specificity (0.68) than 2D-MRI (Sen = 0.85, Spe = 0.32) ( Psen = 0.005, Pspe = 0.002). For subscapularis-tear presence, 3D-MRI showed higher sensitivity (0.94) and specificity (0.73) compared with 2D-MRI (Sen = 0.83, Spe = 0.56) ( Psen = 0.02, Pspe = 0.04). For supraspinatus-tear presence, there was no significant difference between 3D-MRI (Sen =0.96, Spe = 0.67) compared with 2D-MRI (Sen = 0.98, Spe = 0.83) ( Psen = 0.43, Pspe = 0.63). For infraspinatus-tear thickness, 3D-MRI showed lower MSE (0.35) compared with 2D-MRI MSE (0.82) ( P = 0.01). For subscapularis-tear thickness, 3D-MRI had lower MSE (0.31) compared with 2D-MRI MSE (0.51) ( P = 0.007). However, no difference noted for supraspinatus-tear thickness when comparing 3D-MRI MSE (0.39) and 2D-MRI MSE (0.51) ( P = 0.49). For labral-tear presence, 3D-MRI had a lower MSE (0.20) compared with 2D-MRI MSE (0.57) ( P < 0.001).

CONCLUSIONS

Three-dimensional MRI of the shoulder is time efficient with a shorter acquisition time and exhibits comparable with superior correlation to surgical findings than 2D-MRI for detection of labral tears and some rotator cuff tears. Three-dimensional MRI may be used in place of traditional 2D-MRI in detection of soft-tissue shoulder injury in centers equipped to do so.

Algorithmic assessment of shoulder function using smartphone video capture and machine learning

Tears within the stabilizing muscles of the shoulder, known as the rotator cuff (RC), are the most common cause of shoulder pain-often presenting in older patients and requiring expensive advanced imaging for diagnosis. Despite the high prevalence of RC tears within the elderly population, there is no previously published work examining shoulder kinematics using markerless motion capture in the context of shoulder injury. Here we show that a simple string pulling behavior task, where subjects pull a string using hand-over-hand motions, provides a reliable readout of shoulder mobility across animals and humans. We find that both mice and humans with RC tears exhibit decreased movement amplitude, prolonged movement time, and quantitative changes in waveform shape during string pulling task performance. In rodents, we further note the degradation of low dimensional, temporally coordinated movements after injury. Furthermore, a logistic regression model built on our biomarker ensemble succeeds in classifying human patients as having a RC tear with > 90% accuracy. Our results demonstrate how a combined framework bridging animal models, motion capture, convolutional neural networks, and algorithmic assessment of movement quality enables future research into the development of smartphone-based, at-home diagnostic tests for shoulder injury.

Magnetic resonance imaging could precisely define the mean value of tendon thickness in partial rotator cuff tears

PURPOSE

Rotator Cuff (RC) lesions are classified in full-thickness and partial-thickness tears (PTRCTs). To our knowledge, no studies investigated the mean size of shoulder tendons in healthy and PTRCT patients using MRI scans. The aim of the study was to provide data to obtain and compare the mean value of tendon sizes in healthy and PTRCTs groups.

METHODS

From 2014 to 2020, 500 were included in the study. They were divided into two groups: Group 1 (100 subjects) was composed of people positive for partial-thickness rotator cuff tears (PTRCTs), while the 400 subjects in Group 2 were negative for PTRCTs.

RESULTS

Overall, of the patients included in the study, 231 were females and 269 were males. The mean age of the patients was 49 ± 12.7 years. The mean thickness of the supraspinatus tendon (SSP) was 5.7 ± 0.6 mm in Group 1, 5.9 ± 0.6 mm in Group 2 (p < 0.001). The mean length of the ISP tendon was 27.4 ± 3.2 mm in Group 1, 28.3 ± 3.8 mm in Group 2 (p = 0.004). The mean width of the SSP tendon was 17 ± 1.6 mm in Group 1, 17.6 ± 2 mm in Group 2 (p = 0.004). The mean width of the infraspinatus tendon (ISP) tendon was 17.7 ± 1.4 mm in Group 1, 18.3 ± 2.1 mm in Group 2 (p = 0.02).

CONCLUSION

The anatomical data present in this paper may serve as a tool for surgeons to properly manage PTRCTs. The findings of the present study aimed to set the first step towards reaching unanimity to establish international cut-off values to perform surgery. Additionally, they could widely increase diagnostic accuracy, improving both conservative and surgical approaches. Lastly, further clinical trials using more accurate diagnostic MRI tools are required to better define the anatomical differences between PTRCT and healthy patients.

LEVEL OF EVIDENCE

Level II, Retrospective Comparative Trial.

A Tool for Low-Cost, Quantitative Assessment of Shoulder Function Using Machine Learning

Tears within the stabilizing muscles of the shoulder, known as the rotator cuff (RC), are the most common cause of shoulder pain-often presenting in older patients and requiring expensive, advanced imaging for diagnosis1-4. Despite the high prevalence of RC tears within the elderly population, there are no accessible and low-cost methods to assess shoulder function which can eschew the barrier of an in-person physical exam or imaging study. Here we show that a simple string pulling behavior task, where subjects pull a string using hand-over-hand motions, provides a reliable readout of shoulder health across animals and humans. We find that both mice and humans with RC tears exhibit decreased movement amplitude, prolonged movement time, and quantitative changes in waveform shape during string pulling task performance. In rodents, we further note the degradation of low dimensional, temporally coordinated movements after injury. Furthermore, a predictive model built on our biomarker ensemble succeeds in classifying human patients as having a RC tear with >90% accuracy. Our results demonstrate how a combined framework bridging task kinematics, machine learning, and algorithmic assessment of movement quality enables future development of smartphone-based, at-home diagnostic tests for shoulder injury.

Injection of Micronized Human Amnion/Chorion Membrane Results in Increased Early Supraspinatus Muscle Regeneration in a Chronic Model of Rotator Cuff Tear

Surgical repair of severe rotator cuff tear often results in retear due to unaddressed muscle degeneration. The objective of this study was to test the regenerative potential of micronized dehydrated Human Amnion/Chorion Membrane (dHACM), in a clinically relevant delayed reattachment model of rotator cuff repair. Micronized dHACM was injected into rat supraspinatus muscle during tendon re-attachment surgery, three weeks after original tendon injury. One week after material injection, inflammatory and mesenchymal stem cell infiltration into supraspinatus muscles was assessed via flow cytometry. Histological methods were utilized to assess structural and regenerative changes in muscle one and three weeks after material injection. Micronized dHACM injection resulted in increased M1-like macrophages (17.1 [Formula: see text] fold change over contralateral controls) and regenerating muscle fibers (4.3% vs 1.7% in saline treated muscles) one week after injection compared to saline treated muscles. Tendon reattachment itself exhibited intrinsic healing in this model, demonstrated by a general return of muscle weight and reduced fibrosis. Our results indicate that injection of micronized dHACM may initiate an inflammatory response in degenerated muscle that promotes early muscle regeneration, and that our animal model may be a suitable platform for studying treatments in muscle at early timepoints, before intrinsic healing occurs.

Post-surgery rehabilitation following rotator cuff repair. A survey of current (2020) Italian clinical practice

AIMS

To analyse the clinical practice of Italian physiotherapists within the framework of postoperative rehabilitation of rotator cuff (RC) surgery patients, and to compare it with similar studies carried out in other countries.

METHODS

A web-based, voluntary, cross-sectional survey with 27 closed multiple-choice questions was developed and submitted to Italian-based physiotherapists in order to assess their clinical practice.

RESULTS

Data from 1160 questionnaires were then analysed. Thirty-five percent of respondents (n = 413/1160) reported that they commence passive range of motion from the first postoperative week, while 49.2% (n = 571/1160) start during the second or third week. The majority of respondents (n = 603/1160, 52.0%) introduce active mobilisation between the fourth and the sixth week after surgery and 41.1% (n = 477/1160) introduce overhead movements between the fourth and the sixth week after surgery.

DISCUSSION AND CONCLUSIONS

When managing the postoperative rehabilitation of RC surgery patients, Italian physiotherapists' practice is congruent with the guidelines published by American Society of Shoulder and Elbow Therapists (ASSET) and also with other UK surveys. However, while Italian physiotherapists manage immobilisation periods, active and passive mobilisation and the return to sport activities, according to evidence-based best practice guidelines, there is less consistency with respect to physical exercise, patient follow-up and referral.IMPLICATIONS FOR REHABILITATIONItalian physiotherapists' practice with patients following rotator cuff (RC) repair complies with evidence-based practice guidelines regarding immobilisation periods, passive and active mobilisation, and return to sport activities.There is less consistency between reported/declared practice and available evidence concerning physical exercise, patient follow-up, and referral.Physiotherapist with Orthopaedic Manipulative Physical Therapy (OMPT) training is more aligned with the current literature compared to physiotherapists without specific training, in terms of managing rehabilitation programmes, period of immobilisation and therapeutic exercise.More careful adherence to the international guidelines is recommended, in order to manage patients following RC repair in accordance with the evidence and to achieve the best possible outcomes.

Corticosteroid Injections May Increase Retear and Revision Rates of Rotator Cuff Repair: A Systematic Review

PURPOSE

To synthesize the clinical outcome data of preoperative and postoperative corticosteroid injections (CIs) and their effect on rotator cuff repairs (RCRs).

METHODS

A systematic review was performed to identify studies that reported the results or clinical outcomes of RCRs in patients receiving either preoperative or postoperative CIs. The searches were performed using MEDLINE, Google Scholar, and Embase, and studies were chosen following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines.

RESULTS

A total of 11 studies were included with data for 176,352 shoulders: 6 studies involving 175,256 shoulders with data regarding preoperative CIs, 4 studies involving 1,096 shoulders with data regarding postoperative CIs, and 1 study with 212 shoulders containing preoperative and postoperative data. Preoperative CIs were found in 3 studies to increase the risk of revision surgery when administered within 6 months (odds ratio [OR], 1.38-1.82) and up to 1 year (OR, 1.12-1.52) prior to RCR, with revision rates in 2 studies being highest when patients received 2 or more injections (OR, 2.12-3.26) in the prior year. Postoperative CIs reduced pain and improved functional outcomes in 5 studies without increasing the retear rates (5.7%-19% for CI and 14%-18.4% for control) in most studies.

CONCLUSIONS

CIs provide benefit by relieving pain and improving functional outcome scores. However, repeated preoperative CIs may increase retear rates and the likelihood of revision surgery. A lower frequency of CI and longer preoperative waiting period after CI should be considered to decrease such risks. Postoperative CIs several weeks after RCR do not appear to increase retear rates.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV studies.

Rehabilitation Management of Rotator Cuff Injuries in the Master Athlete

Rotator cuff (RTC) injuries are common in master athletes, especially overhead athletes. Risk factors include aging and degeneration as nonmodifiable and volume of activity, muscle weakness, and loss of motion as modifiable. The clinical presentation involves limited range of motion (ROM), pain at rest and at night. Injury classification into traumatic versus nontraumatic and tendinopathy, partial or full-thickness tears helps to establish a treatment plan. RTC injury rehabilitation protocols are criteria-based, multimodal, and divided into four phases. The acute phase addresses pain, inflammation, ROM, and RTC protection. The recovery phase addresses kinetic chain abnormalities, flexibility, and strength, and the functional phase involves exercises directed toward specific sport activities. Return to sports is based on clinical recovery, kinetic chain principles, and adequate sports technique. Nonsurgical management is recommended in most cases, and surgical management is considered if symptoms progress, especially for full-thickness tears.

Reporting rotator cuff tears on magnetic resonance arthrography using the Snyder's arthroscopic classification

AIM

To determine diagnostic performance of magnetic resonance arthrography (MRA) in evaluating rotator cuff tears (RCTs) using Snyder's classification for reporting.

METHODS

One hundred and twenty-six patients (64 males, 62 females; median age 55 years) underwent shoulder MRA and arthroscopy, which represented our reference standard. Surgical arthroscopic reports were reviewed and the reported Snyder's classification was recorded. MRA examinations were evaluated by two independent radiologists (14 and 5 years' experience) using Snyder's classification system, blinded to arthroscopy. Agreement between arthroscopy and MRA on partial- and full-thickness tears was calculated, first regardless of their extent. Then, analysis took into account also the extent of the tear. Interobserver agreement was also calculated the quadratically-weighted Cohen kappa statistics.

RESULTS

On arthroscopy, 71/126 patients (56%) had a full-thickness RCT. The remaining 55/126 patients (44%) had a partial-thickness RCT. Regardless of tear extent, out of 71 patients with arthroscopically-confirmed full-thickness RCTs, 66 (93%) were correctly scored by both readers. All 55 patients with arthroscopic diagnosis of partial-thickness RCT were correctly assigned as having a partial-thickness RCT at MRA by both readers. Interobserver reproducibility analysis showed total agreement between the two readers in distinguishing partial-thickness from full-thickness RCTs, regardless of tear extent (k = 1.000). With regard to tear extent, in patients in whom a complete tear was correctly diagnosed, correct tear extent was detected in 61/66 cases (92%); in the remaining 5/66 cases (8%), tear extent was underestimated. Agreement was k = 0.955. Interobserver agreement was total (k = 1.000).

CONCLUSION

MRA shows high diagnostic accuracy and reproducibility in evaluating RCTs using the Snyder's classification for reporting. Snyder's classification may be adopted for routine reporting of MRA.