Suprascapular neuropathy in massive rotator cuff tears with severe fatty degeneration in the infraspinatus muscle

Quantitative assessment of rotator cuff injuries using synthetic MRI and IDEAL-IQ imaging techniques

Purpose

To evaluate synthetic magnetic resonance imaging (SyMRI) and iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL-IQ) imaging for a comprehensive evaluation of rotator cuff injuries (RCI).

Methods

Ninety-seven patients with RCI were classified into four groups based on the arthroscopic results: (grade II), partial tear (grade III), complete tear (grade IV), and controls (grade I). T1 (Transverse Relaxation Time 1), T2 (Transverse Relaxation Time 2), proton density (PD), and fat fraction (FF) were evaluated using SyMRI and IDEAL-IQ. Measurement reliability was assessed using intraclass correlation coefficients (ICC). The diagnostic potential for grading RCI was evaluated using ordinal regression and ROC analyses.

Results

A high measurement reliability (ICC > 0.7) was observed across subregions. T1 and T2 significantly varied across grades, particularly T2 in the lateral subregion between grades III and IV (P < 0.001) and the central subregion between grades II and III (P < 0.001). ROC analyses yielded valuable diagnostic accuracy, including T2 in the lateral subregion with an AUC of 0.891, distinguishing grade I from grade IV. Positive correlations were found between T2 values in specific shoulder subregions and injury grade (r = 0.615 for lateral, r = 0.542 for medial, both P < 0.001). In grade IV, FF was notably increased in the supraspinatus, infraspinatus, and subscapularis muscles compared with grades I-III. There were no significant FF variations in the teres minor muscle among grades.

Conclusions

Quantitative MRI parameters from SyMRI and IDEAL-IQ, especially T2 and FF, may classify and assess RCI severity. The results could help improve the accuracy of diagnosing different grades of RCI, offering clinicians additional tools for improving patient outcomes through personalized medicine.

A rare presentation of a large suprascapular fossa lipoma causing suprascapular nerve traction injury leading to massive rotator cuff tear, treated arthroscopically - case report

Suprascapular fossa lipoma extending to the suprascapular notch causing traction injury to the suprascapular nerve is a rare presentation. We report a 47-year-old male with progressive weakness of the right shoulder joint of 8 months duration, with a palpable mass over the spine of the scapula was noticed 2 months earlier and developed a sudden drop in arm following a moderate strain. A magnetic resonance imaging (MRI) scan revealed a rotator cuff tear involving the supraspinatus and infraspinatus muscles with a tumor like lesion in the suprascapular fossa, displacing the suprascapular muscle mass and extending into the suprascapular notch. Electromyography and nerve conduction velocity studies revealed suprascapular neuropathy. After histopathologic confirmation, an arthroscopic excision of the mass with decompression of the suprascapular notch was performed along with repair of the rotator cuff. Six months after the procedure, the patient had improved considerably in terms of function and postoperative MRI revealed a complete excision of the mass, and further follow-up of 2 years showed no recurrence. Suprascapular nerve entrapment can be caused by a lipoma in the shoulder, leading to weakness, atrophy, and consequent tear of the rotator cuff tendons. Arthroscopic management, after histopathological confirmation, gives good results in this situation. LEVEL OF EVIDENCE: Level IV.

Outcomes After Rotator Cuff Repair With Transverse Scapular Ligament Release in Patients With Severe Fatty Degeneration of the Infraspinatus

BACKGROUND

In some large to massive rotator cuff tears (RCTs), fatty degeneration (FD) is more severe in the infraspinatus than the supraspinatus muscle, and in such cases, suprascapular neuropathy is highly suspected. Nerve release at the suprascapular notch might alleviate this problem.

PURPOSE

To evaluate the effects of the transverse scapular ligament (TSL) release in patients with large to massive RCTs with more severe FD of the infraspinatus than the supraspinatus.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between September 2017 and January 2022, arthroscopic TSL release with rotator cuff repair was performed in patients with large to massive RCTs and more severe FD of the infraspinatus muscle than the supraspinatus muscle (TSL group). Cuff integrity, FD, and atrophy of cuff muscles were evaluated using preoperative and 1-year postoperative magnetic resonance imaging. In addition, results were compared with those of patients who did not undergo TSL release during arthroscopic large to massive rotator cuff repair (NTSL group).

RESULTS

A total of 103 patients-20 in the TSL group and 83 in the NTSL group-were included. Group preoperative characteristics, including tear size and supraspinatus FD, were not significantly different, but infraspinatus FD (TSL vs NTSL; grade, 0-4, 0/0/5/10/5 vs 1/33/42/4/3) and atrophy (grade, 1-3. 3/9/8 vs 56/20/7) differed significantly (P < .001). Healing failure occurred in 13 of 20 (65%) patients in the TSL group and 30 of 83 (36%) patients in the NTSL group, which was a statistically significant difference (P = .019). Postoperatively, infraspinatus FD and atrophy were more severe in the TSL group than in the NTSL group (P < .001), and supraspinatus FD was more severe in the TSL group (P = .029). Seven patients in the TSL group achieved healing, but FD and atrophy of the supraspinatus and the infraspinatus showed no improvement in this group (all, P > .05).

CONCLUSION

In patients with more FD in the infraspinatus than the supraspinatus muscle, TSL release appeared to have no benefit for cuff healing or FD reversal in cuff muscles. The possibility of suprascapular nerve entrapment remains in patients with more FD in the infraspinatus than the supraspinatus, and this potential nerve problem is not properly addressed by TSL release alone.

Does suprascapular nerve release provide additional benefits for rotator cuff repair: a systematic review and meta-analysis

BACKGROUND

There is still a lack of consensus regarding whether suprascapular nerve decompression should be routinely performed with rotator cuff repair. Therefore, this meta-analysis aimed to evaluate whether additional suprascapular nerve release (SSNR) could improve shoulder functional outcomes and pain relief more than rotator cuff repair alone.

MATERIALS AND METHODS

We performed a literature review of electronic databases for noncomparative and comparative studies investigating the effect of SSNR in patients undergoing rotator cuff repair. The primary outcome was the change in shoulder function scores from the preoperative status, and the secondary outcome was the change in the visual analog scale (VAS) score of pain after surgery. A subgroup analysis was conducted based on the study design (noncomparative studies vs. comparative studies).

RESULTS

Nine studies comprising 279 participants were included. Our analysis demonstrated that the group that underwent SSNR had a better shoulder functional score after surgery than at preoperative assessment (standardized mean difference [SMD], 1.333, 95% confidence interval [CI], 0.708-1.959). No significant differences were identified in shoulder function improvement between those with and without SSNR, with an SMD of 0.163 (95% CI, -0.091 to 0.418). Likewise, the group with SSNR showed a decreased VAS score after surgery compared to their preoperative status (SMD, 0.910; 95% CI, 0.560-1.260). However, there was no significant difference in VAS change between those with and without SSNR, with an SMD of 0.431 (95% CI, -0.095 to 0.956).

CONCLUSION

The present meta-analysis revealed that SSNR might not be routinely needed in rotator cuff tendon repair as no additional benefits in functional improvement or pain relief were identified compared to rotator cuff tendon repair alone.

Safety and Efficacy of Autologous Dermal Fibroblast Injection to Enhance Healing After Full-Thickness Rotator Cuff Repair: First-in-Human Pilot Study

Background:

There is growing interest in various biological supplements to improve tendon healing in patients after arthroscopic rotator cuff repair. The ideal biological supplement to strengthen rotator cuff remains unknown.

Purpose:

To assess the safety and efficacy of autologous cultured dermal fibroblast (ADF) injection on tendon-to-bone healing in patients after arthroscopic rotator cuff repair.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 6 patients who underwent arthroscopic rotator cuff repair between June 2018 and March 2020; all patients had a full-thickness rotator cuff tear (>2 cm) involving the supraspinatus and infraspinatus tendons. The patients were injected with ADF between the repaired tendon and footprint during arthroscopic rotator cuff repair using the suture bridge technique. The safety of ADFs and the procedure was evaluated at 5 weeks postoperatively, and the anatomical healing of the repaired tendon was accessed at 6 months postoperatively using magnetic resonance imaging and at 12 months using ultrasonography. Outcomes including shoulder range of motion (ROM), visual analog scale (VAS) for pain, and functional scores were measured at 6 and 12 months postoperatively.

Results:

Adverse reactions to ADF injection were not observed at 6 months after surgery. VAS and functional scores at 6 and 12 months postoperatively were significantly improved compared with preoperative scores (all P < .05). However, there was no significant difference on any ROM variable between preoperative and postoperative measurements at 6 and 12 months (all P > .05). No healing failure was found at 6 and 12 months postoperatively.

Conclusion:

There was no adverse reaction to ADF injection, and all patients had successful healing after rotator cuff repair. A simple and easily accessible ADF injection may be a novel treatment option for increasing the healing capacity of torn rotator cuff tendons. Further clinical research is needed to verify the study results.

Fatty degeneration of the rotator cuff: pathogenesis, clinical implications, and future treatment

Chronic rotator cuff pathology is often complicated by fatty degeneration of the rotator cuff (FDRC) muscles, an insidious process associated with poor prognosis with or without surgical intervention. Currently there is no treatment for FDRC, and many studies have described a natural course for this disease almost always resulting in further degeneration and morbidity. Recapitulating FDRC using animal injury models, and using imaging-based studies of human FDRC, the pathophysiology of this disease continues to be further characterized. Researchers studying mesenchymal stem cell-derived progenitor cells and known fibrogenic and adipogenic signaling pathways implicated in FDRC seek to clarify the underlying processes driving these changes. While new cell- and molecular-based therapies are being developed, currently the strongest available avenue for improved management of FDRC is the use of novel imaging techniques which allow for more accurate and personalized staging of fatty degeneration. This narrative review summarizes the evidence on the molecular and pathophysiologic mechanisms of FDRC and provides a clinical update on the diagnosis and management of this condition based on the existing knowledge. We also sought to examine the role of newer biologic therapies in the management of RC fatty degeneration and to identify areas of future research.

Comparison of clinical outcome of decompression of suprascapular nerve at spinoglenoid notch for patients with posterosuperior massive rotator cuff tears and suprascapular neuropathy

PURPOSE

In the present study, we aimed to determine whether decompression of suprascapular nerve (SSN) at the spinoglenoid notch could lead to a better functional outcome for the patients who underwent repairment of rotator cuff due to posterosupeior massive rotator cuff tear (MRCT) and suprascapular neuropathy.

METHODS

A total of 20 patients with posterosuperior MRCT and suprascapular neuropathy were analyzed in the present work. The preoperative magnetic resonance imaging (MRI) showed rotator cuff tear in supraspinatus and infraspinatus. All patients underwent arthroscopic rotator cuff repair. Patients were divided into two groups (group A: non-releasing, group B: releasing) according to whether the SSN at the spinoglenoid notch was decompressed. The modified University of California at Los Angeles shoulder rating scale (UCLA) and visual analog scale (VAS) questionnaire were adopted to assess the function of the affected shoulder preoperatively and 12 months after the operation. Electromyography (EMG) and nerve conduction study (NCS) were used to evaluate the nerve condition. Patients underwent MRI and EMG/NCS at 6 months after operation and last follow-up.

RESULTS

All patients were satisfied with the treatment. MRI showed that it was well-healed in 19 patients at 6 months after the operation. However, the fatty infiltration of supraspinatus and infraspinatus was not reversed. Only one patient in the non-releasing group showed the retear. The retear rate of group A and group B were 30% (3/10) and 20% (2/10) respectively at 12 months after the operation. One patient undergoing SSN decompression complained of discomfort in the infraspinatus area. His follow-up EMG after 6 months showed fibrillation potentials (1+) and positive sharp waves (1+) in the infraspinatus. The other patients' EMG results showed no abnormality. The postoperative UCLA and VAS scores were improved in both groups, and there was no significant difference in the follow-up outcomes between the two groups.

CONCLUSIONS

Patients with postersuperior MRCT and suprascapular neuropathy, decompression of suprascapular nerve at spinoglenoid notch didn't lead to a better functional outcome with the repairment of rotator cuff. Arthroscopic rotator cuff repair could reverse the suprascapular neuropathy.

LEVEL OF EVIDENCE

Level III.

Lateral to medial fibro-adipogenic degeneration are greater in infraspinatus than supraspinatus following nerve and tendon injury of murine rotator cuff

Small animal models of massive tears of the rotator cuff (RC) were introduced a decade ago and have been extensively used to study the pathophysiology of chronically injured RC. Transection of rodent suprascapular nerve and RC tendon results in progressive muscle atrophy, fibrosis and fat accumulation and affect the infraspinatus and supraspinatus muscles similarly to that seen in the setting of massive RC tears in humans. The purpose of this study was to perform a comprehensive and detailed analysis of the kinetics of fibrotic scar and adipose tissue development comparing phenotypic differences between chronically injured infraspinatus and supraspinatus. Automatic mosaic imaging was used to create large image of whole infraspinatus or supraspinatus sectioned area for quantification of spatial heterogeneity of muscle damage. Pathologic changes advanced from the lateral site of transection to the medial region far from the transection site. A prominent, accelerated muscle fibrosis and fat accumulation was measured in injured infraspinatus compared to supraspinatus. Furthermore, adipose tissue occupied significantly larger area than that of fibrotic tissue in both muscles but was greater in infraspinatus within 6 weeks post induction of injury. Our findings confirm that infraspinatus is more susceptible to accelerated chronic degeneration and can be used to identify the physiological functions that distinguish between the response of infraspinatus and supraspinatus in the setting of massive tears. Whether these pathologic differences observed in mice are reflected in humans is one key aspect that awaits clarification.

Rotator cuff tear degeneration and the role of fibro-adipogenic progenitors

The high prevalence of rotator cuff tears poses challenges to individual patients and the healthcare system at large. This orthopedic injury is complicated further by high rates of retear after surgical repair. Outcomes following repair are highly dependent upon the quality of the injured rotator cuff muscles, and it is, therefore, crucial that the pathophysiology of rotator cuff degeneration continues to be explored. Fibro-adipogenic progenitors, a major population of resident muscle stem cells, have emerged as the main source of intramuscular fibrosis and fatty infiltration, both of which are key features of rotator cuff muscle degeneration. Improvements to rotator cuff repair outcomes will likely require addressing the muscle pathology produced by these cells. The aim of this review is to summarize the current rotator cuff degeneration assessment tools, the effects of poor muscle quality on patient outcomes, the role of fibro-adipogenic progenitors in mediating muscle pathology, and how these cells could be leveraged for potential therapeutics to augment current rotator cuff surgical and rehabilitative strategies.

Suprascapular Neuropathy around the Shoulder: A Current Concept Review

Suprascapular neuropathy is an uncommon but increasingly recognized cause of shoulder pain and dysfunction due to nerve entrapment. The aim of this review is to summarize some important aspects of this shoulder pathology. An extensive research was performed on PubMed and Clinical Key. The goal was to collect all the anatomical, biomechanical and clinical studies to conduct an extensive overview of the issue. Attention was focused on researching the state of art of the diagnosis and treatment. A total of 59 studies were found suitable and included. This condition is more frequently diagnosed in over-head athletes or patients with massive rotator cuff tears. Diagnosis may be complex, whereas its treatment is safe, and it has a great success rate. Prompt diagnosis is crucial as chronic conditions have worse outcomes compared to acute lesions. Proper instrumental evaluation and imaging are essential. Dynamic compression must initially be treated non-operatively. If there is no improvement, surgical release should be considered. On the other hand, soft tissue lesions may first be treated non-operatively. However, surgical treatment by arthroscopic means is advisable when possible as it represents the gold standard therapy. Other concomitant shoulder lesions must be recognized and treated accordingly.

Factors Influencing the Reparability and Healing Rates of Rotator Cuff Tears

PURPOSE OF THE REVIEW

To discuss tear- and patient-related factors that influence the healing potential of rotator cuff tears and to clarify the terminology surrounding this topic.

RECENT FINDINGS

Over the last few years, further insight has been gained regarding rotator cuff tear features that are associated with poor healing rates after rotator cuff repair. Some of these features have been incorporated in prediction models developed to accurately predict rotator cuff healing rates utilizing preoperative risk factors weighted by importance. Rotator cuff tears may be considered functionally irreparable based on their size, chronicity, absence of adequate tendon length, atrophy, and fatty infiltration. Furthermore, advanced age, use of tobacco products, diabetes, and other patient-related factors may impair tendon healing. Careful analysis and discussion of all these factors with patients is essential to determine if surgical repair of a rotator cuff tear should be recommended, or if it is best to proceed with one of the several salvage procedures reviewed in this topical collection, including augmentation of the repair, superior capsular reconstruction, tendon transfers, and other.

Beige FAPs Transplantation Improves Muscle Quality and Shoulder Function After Massive Rotator Cuff Tears

Rotator cuff (RC) tears are a common cause of upper extremity disability. Any tear size can result in subsequent muscle atrophy and fatty infiltration (FI). Preoperative muscle degeneration can predict repair and postoperative functional outcomes. Muscle residential fibro-adipogenic progenitors (FAPs) are found to be capable of differentiating into beige adipocytes that release factors to promote muscle growth. This study evaluated the regenerative potential of local cell transplantation of beige FAPs to mitigate muscle degeneration in a murine massive RC tear model. Beige FAPs were isolated from muscle in UCP-1 reporter mice by flow cytometry as UCP-1⁺ /Sca1⁺ /PDGFR⁺ /CD31^- /CD45^- /integrin α7^- . C57/BL6J mice undergoing supraspinatus tendon tear with suprascapular nerve transection (TT + DN) received either no additional treatment, phosphate-buffered saline injection, or beige FAP injection 2 weeks after the initial injury. Forelimb gait analysis was used to assess shoulder function with DigiGait. Mice were sacrificed 6 weeks after cell transplantation. FI, fibrosis, fiber size, vascularity were analyzed and quantified via ImageJ. Our results showed that beige FAP transplantation significantly decreased fibrosis, FI, and atrophy, enhanced vascularization compared with saline injection and non-treatment groups. Beige FAP transplantation also significantly improved shoulder function as measured by gait analysis. This study suggests that beige-differentiated FAPs may serve as a treatment option for RC muscle atrophy and FI, thus improving shoulder function in patients with massive RC tendon tears. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1159-1166, 2020.

Suprascapular nerve injury affects rotator cuff healing: A paired controlled study in a rat model

Purpose

We designed a paired controlled study to investigate the role of the suprascapular nerve (SSN) in rotator cuff healing using a rat tear model, and we hypothesised that rotator cuff healing is impaired in the absence of a healthy SSN.

Methods

Bilateral supraspinatus tenotomy from the great tuberosity was performed for 36 Wistar rats, which was then repaired immediately. A defect on the SSN was made on the right side, and a sham surgery was performed on the SSN at the left side. Twelve rats were sacrificed for biomechanical (six rats) and histological (six rats) testing, evaluated at 3, 6, and 9 weeks after surgery.

Results

The bone–tendon junction on the nerve-intact side showed significantly better biomechanical characteristics than the nerve-injured side in terms of maximum load, maximum stress over time, stiffness at 9 weeks, and Young's modulus at 3 and 9 weeks. On the nerve-injured side, significantly smaller fibrocartilage layers and muscle fibres could be obtained over time. In addition, on the nerve-injured side, inferior bone–tendon interface formation was obtained in terms of cell maturity, cell alignment, collagen orientation, and the occurrence of tidemark and Sharpey's fibres through 9 weeks. In addition, neuropeptide Y was secreted in the nerve-intact group at 6 and 9 weeks.

Conclusion

This study showed the inferior healing of the bone–tendon junction on the nerve-injured side compared with the nerve-intact side, which indicates that the SSN plays an important role in rotator cuff healing. Surgeons should pay more attention to SSN injury when treating patients with rotator cuff tear.

Efficacy of suprascapular nerve block compared with subacromial injection: a randomized controlled trial in patients with rotator cuff tears

HYPOTHESIS

We aimed to compare the clinical efficacy of a suprascapular nerve block (SSNB) versus subacromial injection (SA) for outpatient treatment of patients with symptomatic rotator cuff tears in a double-blinded, randomized controlled trial using sealed-envelope randomization.

METHODS

A total of 42 participants with symptomatic partial- and full-thickness rotator cuff tears quantified by ultrasound or magnetic resonance imaging received either an ultrasound-guided SSNB or SA. The primary outcome measure was shoulder function measured by the modified Constant-Murley (CM) score and the secondary outcome was the pain score measured by a visual analog scale at 2, 6, and 12 weeks after injection.

RESULTS

We analyzed 43 shoulders (27 in male patients, 62.2%). The mean age was 65.2 years (standard deviation [SD], 11.9 years). Of the shoulders, 22 (51.2%) underwent SAs and 21 (48.8%) underwent SSNBs. Continuous variables were analyzed by an independent t test (2 tailed), and nominal data were analyzed by the Fisher exact test (1 sided). At 6 weeks, the mean change from the baseline CM score was significantly higher in the SSNB group than in the SA group (14.3 [SD, 18.1] vs 3.0 [SD, 12.8]; P = .048). At 12 weeks' follow-up, the SSNB group had a significantly higher CM score than the SA group (57.6 [SD, 10] vs 44.6 [SD, 16]; P = .023) and greater improvement from the baseline CM score (23.4 [SD, 17.5] vs 7.8 [SD, 16.5]; P = .014). At 12 weeks, the visual analog scale score was significantly better in the SSNB group than in the SA cohort (9.9 [SD, 3.3] vs 7.3 [SD, 4.3]; P = .03).

CONCLUSIONS

This study demonstrates that an SSNB resulted in better pain and functional results than an SA at 6 and 12 weeks for symptomatic rotator cuff tears.

Irreparable rotator cuff tears: challenges and solutions

Irreparable rotator cuff tears are common conditions seen by shoulder surgeons, characterized by a torn and retracted tendon associated with muscle atrophy and impaired mobility. Direct fixation of the torn tendon is not possible due to the retracted tendon and lack of healing potential which result in poor outcome. Several treatment options are viable but correct indication is mandatory for a good result, pain improvement, and restoration of shoulder function. Patient can be treated either with a conservative program or surgically when necessary, by different available modalities like arthroscopic debridement, partial reconstruction, subacromial spacer, tendon transfer, and shoulder replacement with reverse prosthesis. The aim of this study was to review literature to give an overview of the available possible solutions, with indications and expected outcomes.

Teres major tendon transfer in the treatment of irreparable posterosuperior rotator cuff tears: long-term improvement of shoulder function and pain reduction at eight to 12 years’ follow-up

Aims

Since long-term outcome of teres major tendon transfer surgery for irreparable posterosuperior rotator cuff (RC) tears is largely unknown, the primary aim of this study was to evaluate the long-term outcome of the teres major transfer. We also aimed to report on the results of a cohort of patients with a similar indication for surgery that underwent a latissimus dorsi tendon transfer.

Patients and Methods

Patients and Methods In this prospective cohort study, we reported on the long-term results of 20 consecutive patients with a teres major tendon transfer for irreparable massive posterosuperior RC tears. Additionally, we reported on the results of the latissimus dorsi tendon transfer (n = 19). The mean age was 60 years (47 to 77). Outcomes included the Constant score (CS), and pain at rest and during movement using the Visual Analogue Scale (VAS).

Results

At a mean of ten years (8 to 12) following teres major transfer, the CS was still 23 points (95% confidence interval (CI) 14.6 to 30.9, p < 0.001) higher than preoperatively. VAS for pain at rest (21 mm, 95% CI 4.0 to 38.9, p = 0.016) and movement (31 mm, 95% CI 16.0 to 45.1, p < 0.001) were lower than preoperatively. We also found an increase in CS (32 points, 95% CI 23.4 to 40.2, p < 0.001) and reduction of pain (26 mm, 95% CI 9.9 to 41.8, p = 0.001) six years after latissimus dorsi transfer.

Conclusion

Teres major tendon transfer is a treatment option to gain shoulder function and reduce pain in patients with an irreparable posterosuperior RC tear at a mean follow-up of ten years. The teres major tendon might be a valuable alternative to the commonly performed latissimus dorsi tendon transfer in the treatment of irreparable posterosuperior RC tears. Cite this article: Bone Joint J 2018;100-B:309-17.