Clinical outcomes of suprascapular nerve decompression

Suprascapular nerve release does not provide additional benefits in arthroscopic rotator cuff repair surgery: a systematic review and meta-analysis

PURPOSE

To investigate the effect of suprascapular nerve release in arthroscopic rotator cuff repair surgery.

METHODS

This systematic review was performed to include randomized controlled trials (RCTs) and non-RCTs that compared the outcomes of patients who did and did not receive suprascapular nerve release (SSNR) during arthroscopic rotator cuff repair surgery. MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for relevant studies. Methodological Index for Non-randomized Studies (MINORS) was used for cohort study assessment. The Cochrane risk of bias assessment tool (version 1.0) was used to assess the risk of bias in randomized trials. The primary outcomes were pain and shoulder function. The secondary outcome was the re-tear rate.

RESULTS

Two RCTs and three non-RCTs with a total of 187 patients (90 patients received SSNR and 97 patients did not receive SSNR) were included in this systematic review. The meta-analysis revealed that the SSNR group did not had a more pain reduction, assessed by visual analogue scale, compared to the non-SSNR group. Also, the SSNR group did not have a significantly more improvement in the UCLA score, compared to the non-SSNR group. In addition, there was no significant difference between the two groups in terms of Constant score and re-tear rate.

CONCLUSIONS

The result of this study showed that additional suprascapular nerve release did not provide additional benefit in arthroscopic rotator cuff repair surgery. Routine arthroscopic SSNR is not recommended when treating patients with rotator cuff tear.

LEVEL OF EVIDENCE

Level III.

Eхperience of endoscopic decompression of the suprascapular nerve

Background: Suprascapular nerve neuropathy is a commonly spread pathology, caused by a traction force trauma or compression in the scapular notch area. In the case of a conservative treatment failure, a standard surgical procedure is neurolysis (decompression) of the suprascapular nerve in the scapular notch. This procedure can be done in an open manner or endoscopically. Aims: to evaluate the results of endoscopic decompression of the suprascapular nerve in the scapular notch area at a 6 months follow-up. Methods: We operated 10 patients with the clinical picture of posttraumatic suprascapular nerve neuropathy in the period from 2015 to 2021. The mean age of patients was 52.311.8. All the patients underwent the shoulder joint and subacromial space arthroscopy, and decompression of the suprascapular nerve in the scapular notch area. Results: According to the VAS-scale, the severity of pain syndrome before the surgery was 6 cm, while in 6 months after the surgery it decreased to 2 cm. According to the DASH scale, the dysfunction of the of shoulder joint before the surgery was 70 points, in 6 months after the surgery it decreased to 10 points. The range of motion in the shoulder joint before the surgery was: flexion 15514,4, abduction 14042, external rotation 125,6; 6 months after the surgery we observed: flexion 17415,6, abduction 17514,4, external rotation 489. Conclusion: The obtained results let us characterize the method of endoscopic decompression of the suprascapular nerve as a low-traumatic and effective technique, which promotes restoration of the function of the suprascapular nerve and shoulder joint, and elimination of pain syndrome from the shoulder area.

Does the Suprascapular Nerve Move within the Suprascapular Notch? Biomechanical Perspective Using the Finite Element Method

PURPOSE

We aimed to analyze changes in suprascapular nerve (SSN) position within the suprascapular notch during in vivo shoulder abduction.

MATERIALS AND METHODS

Three-dimensional models of the shoulder complex were constructed based on magnetic resonance imaging of the brachial plexus (BP-MR) in a patient diagnosed with SSN dysfunction but normal scapular movement. Using BP-MR in neutral position and computed tomography data on shoulder abduction, shoulder abduction was simulated as the transition between two positions of the shoulder complex with overlapping of a neutral and abducted scapula. SSN movement during abduction was evaluated using the finite element method. Contact stress on the SSN was measured in the presence and absence of the transverse scapular ligament (TSL).

RESULTS

In the neutral position, the SSN ran almost parallel to the front of the TSL until entering the suprascapular notch and slightly contacted the anterior-inferior border of the TSL. As shoulder abduction progressed, contact stress decreased due to gradual loss of contact with the TSL. In the TSL-free scapula, there was no contact stress on the SSN in the neutral position. Towards the end of shoulder abduction, contact stress increased again as the SSN began to contact the base of the suprascapular notch in both TSL conditions.

CONCLUSION

We identified changes in the position of the SSN path within the suprascapular notch during shoulder abduction. The SSN starts in contact with the TSL and moves toward the base of the suprascapular notch with secondary contact. These findings may provide rationale for TSL release in SSN entrapment.

Endoscopic/arthroscopic decompression of the suprascapular nerve at the spinoglenoid notch: indications and surgical technique

Suprascapular nerve compression at the spinoglenoid notch can lead to posterior shoulder pain, muscle weakness, and longstanding muscle atrophy of the infraspinatus. Although rare, it is most commonly seen in overhead athletes and laborers who perform repetitive overhead activities. Early diagnosis requires a thorough history and physical examination including imaging, diagnostic injections, and electromyography to avoid a missed diagnosis. While a course of nonoperative treatment is most often prescribed, early surgical intervention may be prudent to avoid irreversible damage especially if a space occupying lesion is present. This article will describe the history, physical examination findings, diagnostic workup, and our surgical technique for arthroscopic decompression of the suprascapular nerve at the spinoglenoid notch through a simple posterior approach avoiding the subacromial space.

Outcomes of Arthroscopic Nerve Release in Patients Treated for Large or Massive Rotator Cuff Tears and Associated Suprascapular Neuropathy: A Prospective, Randomized, Double-Blinded Clinical Trial

BACKGROUND

Suprascapular neuropathy has been observed in the setting of rotator cuff tears (RCTs), but its association with these tears and their treatment are unclear.

HYPOTHESIS

Arthroscopic suprascapular nerve release during rotator cuff repair will not alter the outcomes of neuropathy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 42 patients with large/massive reparable RCTs and suprascapular neuropathy were recruited and followed up at 6 and 12 months. Electrophysiological results as well as Disabilities of the Arm, Shoulder and Hand (DASH), American Shoulder and Elbow Surgeons (ASES), and Constant scores were evaluated at selected time periods. Patients were randomly assigned to 2 groups. Patients in the control group underwent arthroscopic repair of the rotator cuff without combined arthroscopic release of the superior transverse scapular ligament; in the second group, the superior transverse ligament was released. The primary outcome was to examine full suprascapular nerve recovery through electrophysiological changes between groups. The secondary/tertiary outcomes were analysis of clinical outcomes and assessment of the relation between RCT size and the degree of suprascapular nerve recovery. Patients, clinical staff members, and the neurologist were blinded to the type of surgical procedure.

RESULTS

Of 42 patients, 37 completed the follow-up at 12 months (median age, 64 years [range, 50-75 years]). Overall, 17 of 19 (89.5%) patients in the control group and 15 of 18 (83.3%) patients in the nerve release group had full nerve recovery, with no significant difference between the 2 groups. Clinically, all patients in both groups showed a significant improvement (P < .001), but no significant difference was observed between the 2 groups in terms of 12-month postoperative scores (control group: DASH: median, 5 [range, 0-21]; ASES: median, 88 [range, 83-98]; Constant: median, 86 [range, 70-98]) (nerve release group: DASH: median, 6 [range, 0-25]; ASES: median, 90 [range, 83-98]; Constant: median, 88 [range, 75-98]). Also, no significant difference was found between the 2 groups regarding other secondary and tertiary outcomes.

CONCLUSION

Combined arthroscopic release of the superior transverse scapular ligament and rotator cuff repair in patients with large/massive RCTs and suprascapular neuropathy did not produce statistically significant improved outcomes compared with repair of the rotator cuff alone.

REGISTRATION

NCT02318381 (ClinicalTrials.gov identifier).

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.

Clinical Outcomes of Arthroscopic Suprascapular Nerve Decompression for Suprascapular Neuropathy

PURPOSE

To report clinical outcomes following arthroscopic suprascapular nerve (SSN) decompression for suprascapular neuropathy at the suprascapular and/or spinoglenoid notch in the absence of major concomitant pathology.

METHODS

We retrospectively reviewed prospectively collected data of 19 patients who underwent SSN release at the suprascapular and/or spinoglenoid notch between April 2006 and August 2017 with ≥2 years of follow-up. Patients who underwent concomitant rotator cuff or labral repairs or had severe osteoarthritis were excluded. Pre- and postoperative strength and patient-reported outcomes were collected, including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numerical Evaluation (SANE), Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), 12-item Short Form (SF-12), and satisfaction. Complications and revisions were recorded.

RESULTS

At a mean final follow-up of 4.8 years, pre- to postoperative ASES (64.9 ± 18.7 versus 83.5 ± 23.1; P = .018), QuickDASH (28.7 ± 17.2 versus 12.7 ± 17.1; P = .028), SANE (64.3 ± 16.4 versus 80.8 ± 22.3; P = .034), and SF-12 PCS (41.1 ± 10.8 versus 52.3 ± 5.8; P = .007) scores all significantly improved. Median strength for external rotation improved significantly (4 [range 2 to 5] versus 5 [range 3 to 5]; P = .014). There was no statistically significant improvement in median strength for abduction (4 [range 3 to 5] versus 5 [5]; P = .059). Median postoperative satisfaction was 9 (range 1 to 10), with 8 patients (50%) rating satisfaction ≥9. No complications were observed, and no patients went on to revision surgery.

CONCLUSION

Arthroscopic SSN decompression for suprascapular neuropathy at the suprascapular and/or spinoglenoid notch in the absence of major concomitant glenohumeral pathology results in good functional outcomes with significant improvements from before to after surgery.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Arthroscopic release of proximal supra-scapular nerve entrapment: Medium-term results

OBJECTIVE

To evaluate the clinical and electrophysiological results in the medium term of the arthroscopic release of the proximal entrapment of the suprascapular nerve.

MATERIAL AND METHOD

It is a retrospective study that includes 75 patients with idiopathic entrapment of the suprascapular nerve in the suprascapular notch in whom conservative treatment has failed. All patients underwent electrophysiological tests (EMG) as well as clinical test (Constant and DASH test) preoperatively and during follow-up.

RESULTS

75 patients (53 women and 22 men) with a mean age of 44.1 ± 10.7 years met study criteria with a mean follow-up of 63.7 ± 29.1 months. Preoperatively the DASH value was 78,6 ± 10,2, the Constant test value was 37.1 ±8.8 and the EVA value was 8.8 ± 1.1 while the values in the last revision were 19.4 ± 15.8 for DASH, 80.2 ± 9.6 (for the CS and 2 ±1.3 for the EVA scale; the differences were significant in all cases (P<.001). Regarding the results of the electrophysiological test, preoperatively there were 21 very severe grades (28%), 32 severe (42.6%), 17 moderate (22.6%) and 5 mild (6.6%). While in the last review there were 3 severe degrees (4%), 6 moderate (8%), 40 mild (53.3%) and 26 normal (34.6%). There was no very severe grade (0%); 3 patients (4%) had to be reoperated due to persistent symptons.

CONCLUSIONS

The arthroscopic release of idiopathic entrapment of the suprascapular nerve in the superior scapular notch achieved good clinical and electrophysiological results in the medium term.

LEVEL OF EVIDENCE

iv; case series; treatment study.

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.

Shoulder Double Crush Syndrome: A Retrospective Study of Patients With Concomitant Suprascapular Neuropathy and Cervical Radiculopathy

Purpose

While the double crush phenomena (compression along two points on a nerve) has been established between median neuropathy and cervical radiculopathy, combined suprascapular neuropathy (SSN) and cervical C5/C6 radiculopathy-so-called shoulder double crush syndrome-has not been well examined. We aim to identify the incidence of shoulder double crush syndrome in patients undergoing arthroscopic suprascapular nerve release for SSN.

Methods

One hundred consecutive patients >18 years of age who were positive for SSN on electromyography and motor nerve conduction studies (EMG/NCS) and underwent a suprascapular nerve release were included. Patients with evidence of shoulder double crush syndrome were identified based on x ray, cervical spine magnetic resonance imaging (MRI) and examination findings. Demographics, electrodiagnostics results, treatment courses, and clinical outcomes (visual analog scores and rotator cuff strength) following arthroscopic suprascapular nerve release were compared between patients with double crush syndrome versus isolated SSN.

Results

Thirty one percent of patients had evidence of shoulder crush syndrome. Two significant electrophysiologic differences were noted in shoulder double crush patients compared to isolated SSN patients. Patients with double crush had an increased incidence of median neuropathy (51% vs 30%, P = .04). Double crush patients had less supraspinatus motor amplitude difference between the affected side and non-affected side compared to isolated SSN patients (2.62 mV vs 3.44 mV, P = .03). In general, most double crush patients were treated conservatively with regard to their cervical spine pathology.

Conclusion

A significant percentage of patients with SSN have evidence of shoulder double crush syndrome. Patients with SSN and concomitant median neuropathy should have a detailed neck examination performed.

Motor Recovery of the Suprascapular Nerve after Arthroscopic Decompression in the Scapular Notch - a Systematic Review

BACKGROUND

The suprascapular nerve can be compromised as a result of a compression syndrome in different locations. A (proximal) compression within the scapular notch can lead to dorsal shoulder pain and simultaneous weakness of the infraspinatus and supraspinatus muscles. By transection of the lig. transversum this compression syndrome can be treated. By means of a systematic review, the present work analyzes the motor recovery potential after arthroscopic decompression.

MATERIAL AND METHODS

A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The search words used were "suprascapular" and "arthroscopic"; "suprascapular" and "arthroscopy". Based on the evaluated literature, articles in English with at least a partial arthroscopic case series from 4 cases on and a compression syndrome of the suprascapular nerve treated with arthroscopic decompression in the scapular notch were identified. Motor recovery was described by means of EMG, clinical strength and MRI.

RESULTS

Primarily 408 hits were generated. Six articles met the inclusion criteria and were further analyzed. The number of arthroscopic cases was between 4 and a maximum of 27. The level of evidence was between III and IV. The majority of the reported clinical results were good. Motor recovery as measured by EMG was observed, recovery of full strength was not achieved in the majority of reported cases (60%), neither was regression of structural (fatty) degeneration of the muscle bellies.

CONCLUSION

Arthroscopic decompression of the suprascapular nerve in the scapular notch provides good clinical results and considerable pain relief. However, in the majority of cases it does not lead to a complete recovery of the strength of the supra- and infraspinatus muscles. Patients should be informed about this. An early decompression after diagnosis in the event of proximal compression within the suprascapular notch combined with beginning EMG or MRI changes appears reasonable. These beginning changes should be further defined. Future studies should develop prognostic criteria for motor recovery. Awareness regarding the diagnosis needs to be improved due to the probably time-dependent irreversibility of resulting muscular weakness.

Nerve and Muscle Abnormalities

Muscle atrophy in shoulders with rotator cuff tendon tears is a negative prognosticator, associated with decreased function, decreased reparability, increased retears after repair, and poorer outcomes after surgery. Muscle edema or atrophy within a neurologic distribution characterizes denervation. Because most nerve entrapments around the shoulder are not caused by mass lesions and show no nerve findings on routine MR imaging sequences, pattern of muscle denervation is often the best clue to predicting location of nerve dysfunction, which narrows the differential diagnosis and guides clinical management. The exception is suprascapular nerve compression in the spinoglenoid notch caused by a compressing cyst.

MRI diagnosis of suprascapular neuropathy using spinoglenoid notch distension

PURPOSE

To assess the use of a spinoglenoid notch distension measurement as a radiographic marker on MRI to aid the diagnosis of suprascapular neuropathy.

METHODS

Spinoglenoid notch distension was compared on MRI by blinded independent observers for two patient cohorts: one group with an electromyography/nerve conduction study confirmed diagnosis of suprascapular neuropathy who underwent arthroscopic suprascapular nerve decompression, and a control group of patients aged 18-30 years with a normal shoulder MRI.

RESULTS

Sixty suprascapular nerve patients (average age 52 years) were compared to 47 control patients (average age 24 years). Intra-rater and inter-rater reliability showed excellent agreement between reviewers for all measurements. There was a significant difference in the mean spinoglenoid notch distension for the SSN group (m = 8.36, SD = 2.42) compared to the control group (m = 5.7, SD = 1.56); [t(212) = 9.40, p < 0.0001].

CONCLUSION

The spinoglenoid notch distension is significantly increased in patients with suprascapular neuropathy. We hypothesize that hypertrophy of the transverse scapular ligament creates a venous obstruction resulting in varicosities of the suprascapular vein which runs with the nerve under the ligament. This distends the spinoglenoid notch and can be enlarged in cases of suprascapular neuropathy which is evident on MRI.

Electrodiagnostic evidence of suprascapular nerve recovery after decompression

INTRODUCTION

The purpose of this study was to determine whether surgical arthroscopic decompression or ultrasound-guided aspiration of a paralabral cyst would result in suprascapular nerve recovery from axonal regeneration based on electrodiagnostic testing.

METHODS

Nine patients with preoperative electromyography (EMG) evidence of suprascapular neuropathy due to paralabral cysts at the suprascapular or spinoglenoid notch were prospectively studied. Eight patients underwent arthroscopic surgical decompression, and 1 patient underwent ultrasound-guided aspiration. Postoperative EMG was performed in all patients to evaluate nerve regeneration.

RESULTS

Three (33%) patients had cysts at the suprascapular notch, whereas 6 (67%) patients had cysts at the spinoglenoid notch. All patients showed complete electrophysiological recovery after decompression.

DISCUSSION

Decompression of paralabral cysts at the suprascapular or spinoglenoid notch resulted in postoperative EMG evidence of nerve recovery. Long-term studies with a greater number of patients are required to elucidate time to recovery. Muscle Nerve 59:247-249, 2019.

Shoulder Arthroscopy With Versus Without Suprascapular Nerve Release: Clinical Outcomes and Return to Sport Rate in Elite Overhead Athletes

PURPOSE

To compare the clinical outcomes and return to sport rate between elite overhead athletes who underwent shoulder arthroscopy and decompression of the suprascapular nerve (SSN) versus overhead athletes who underwent shoulder arthroscopy without SSN release.

METHODS

From 2007 to 2014, high-level overhead athletes diagnosed with a rotator cuff tear and/or a glenoid labral lesion and SSN entrapment were included in the study if their symptoms did not improve with nonoperative treatment and if they agreed to undergo surgery and participate. Their preoperative University of California at Los Angeles (UCLA) shoulder score, bilateral postoperative Constant scores, postoperative UCLA score, and return to sport rate were evaluated and compared with those of a group of elite athletes who had a similar diagnosis but refused to undergo SSN decompression during shoulder arthroscopy.

RESULTS

Thirty-five athletes (25 male, 10 female) were included in the SSN decompression group (group 1), and 21 athletes were included in the non-SSN decompression group (group 2). The mean age was 27 years (range: 19-34) and 24 years (range: 21-32) in group 1 and group 2, respectively (P = .56). The mean follow-up time was 38.4 months (24-50 months) in group 1 and 42.2 months (26-53 months) in group 2 (P = .09). Both groups had significantly improved UCLA scores after surgery (P < .05). The postoperative UCLA (P = .01) and Constant scores (P < .001) were significantly higher in the SSN decompression group. The mean difference in Constant score between the affected and the unaffected side was 4 points (range: 2-12) in the SSN decompression group and 8 points (range: 4-14) in the non-SSN decompression group postoperatively (P = .0002). In both groups, 100% of patients reached the patient acceptable symptom state value for Constant score at follow-up. For the UCLA score, patients who underwent SSN decompression had significantly higher pre- to postoperative improvement than the nondecompression group (P = .016). The return to sport rate was 97% in group 1 and 84% in group 2. The mean length of career was 2.1 years (range: 1.5-2.4 years) and 2.3 years (range: 1.2-3.2 years) in group 1 and group 2, respectively.

CONCLUSIONS

In elite overhead athletes with shoulder pathology and SSN entrapment, combined shoulder arthroscopy and SSN release yield superior clinical outcomes, greater improvement in UCLA score, and a higher return to sport rate than shoulder arthroscopy without SSN decompression. Regardless of SSN treatment, both groups achieved the patient acceptable symptom state after shoulder arthroscopy.

LEVEL OF EVIDENCE

Level III, comparative case series.

Hourglass-like constriction of the suprascapular nerve: a contraindication for minimally invasive surgery

BACKGROUND

Suprascapular nerve (SSN) entrapment is usually ascribed to static or dynamic compression. When no cause of compression is found, SSN entrapment is defined as idiopathic. Focal hourglass-like constriction (H-LC) of the SSN that results in muscle paralysis represents an unusual condition that may be misinterpreted and erroneously diagnosed as SSN entrapment or as neuralgic amyotrophy.

METHODS

With the aim of finding clinical and surgical clues that could differentiate the traditional form of idiopathic SSN entrapment from the rare H-LC, a series of 6 cases of SSN palsy caused by H-LC is presented.

RESULTS

All but 1 supraspinatus muscle recovered M5 muscle strength. The Constant shoulder score was excellent in 3 patients, good in 1, fair in 1, and poor in 1.

DISCUSSION

If a diagnosis is not made in time, H-LC may evolve from mild to severe nerve torsion that may require a shift in surgical procedure from epineurotomy and external neurolysis to focal resection and suture. If an incorrect therapy is chosen, the chance of recovery might be definitively compromised with the persistence of muscle palsy. Conversely, when SSN palsy persists despite notch decompression, especially when it is performed with a limited open approach or arthroscopically, concerns about the real etiology and location of nerve compression responsible for the nerve palsy may arise.

CONCLUSION

When approaching SSN pathology, H-LC should be considered as a potential cause of nerve palsy, as it may represent a contraindication for a limited open approach or arthroscopic decompression.

Clinical outcomes of suprascapular nerve decompression: a systematic review

BACKGROUND

Suprascapular neuropathy is an uncommon clinical diagnosis. Although there have been a number of case series reporting on this pathologic process, to date there has been no systematic review of these studies. This study aimed to synthesize the literature on suprascapular neuropathy with regard to clinical outcomes. The secondary objective was to detail the diagnosis and treatment of suprascapular neuropathy and any associated complications.

METHODS

A systematic review was performed to identify studies that reported the results or clinical outcomes of suprascapular nerve decompression. The searches were performed using MEDLINE through PubMed and Cochrane Database of Systematic Reviews.

RESULTS

Twenty-one studies comprising 275 patients and 276 shoulders met inclusion criteria. The mean age was 41.9 years, and mean follow-up was 32.5 months. The most common symptom was deep, posterior shoulder pain (97.8%), with a mean duration of symptoms before decompression of 19.0 months; 94% of patients underwent electrodiagnostic testing before decompression, and 85% of patients had results consistent with suprascapular neuropathy. The most common outcome reported was the visual analog scale score, followed by the Constant-Murley score. The mean postoperative Constant-Murley score obtained was 89% of ideal maximum. Ninety-two percent of athletes were able to return to sport. Only 2 (0.74%) complications were reported in the included studies.

CONCLUSIONS

Surgical decompression in the setting of suprascapular neuropathy leads to satisfactory outcomes as evidenced by the patient-reported outcomes and return to sport rate. Furthermore, the rate of complications appears to be low.

Arthroscopic management of suprascapular neuropathy of the shoulder improves pain and functional outcomes with minimal complication rates

PURPOSE

The purpose of this study was to systematically assess the arthroscopic management of suprascapular neuropathy, including the aetiology, surgical decision-making, clinical outcomes, and complications associated with the procedure.

METHODS

Three databases [PubMed, Ovid (Medline), and Embase] were searched. Systematic literature screening and data abstraction was performed in duplicate to present a review of studies reporting on arthroscopic management of suprascapular neuropathy. The quality of the included studies was assessed using level of evidence and the MINORS (Methodological Index for Nonrandomized Studies) checklist.

RESULTS

In total, 40 studies (17 case reports, 20 case series, 2 retrospective comparative studies, and 1 prospective comparative study) were identified, including 259 patients (261 shoulders) treated arthroscopically for suprascapular neuropathy. The most common aetiology of suprascapular neuropathy was suprascapular nerve compression by a cyst at the spinoglenoid notch (42%), and the decision to pursue arthroscopic surgery was most commonly based on the results of clinical findings and investigations (47%). Overall, 97% of patients reported significant improvement in or complete resolution of their pre-operative symptoms (including pain, strength, and subjective function of the shoulder) over a mean follow-up period of 23.7 months. Further, there was a low overall complication rate (4%) associated with the arthroscopic procedures.

CONCLUSION

While most studies evaluating arthroscopic management of suprascapular neuropathy are uncontrolled studies with lower levels of evidence, results indicate that such management provides patients with significant improvements in pain, strength, and subjective function of the shoulder, and has a low incidence of complications. Patients managed arthroscopically for suprascapular neuropathy may expect significant improvements in pain, strength, and subjective function of the shoulder.

LEVEL OF EVIDENCE

Level IV, systematic review of level II to IV studies.

Perivascular Stem Cells Diminish Muscle Atrophy Following Massive Rotator Cuff Tears in a Small Animal Model

BACKGROUND

Rotator cuff tears are a common cause of shoulder pain and often necessitate operative repair. Muscle atrophy, fibrosis, and fatty infiltration can develop after rotator cuff tears, which may compromise surgical outcomes. This study investigated the regenerative potential of 2 human adipose-derived progenitor cell lineages in a murine model of massive rotator cuff tears.

METHODS

Ninety immunodeficient mice were used (15 groups of 6 mice). Mice were assigned to 1 of 3 surgical procedures: sham, supraspinatus and infraspinatus tendon transection (TT), or TT and denervation via suprascapular nerve transection (TT + DN). Perivascular stem cells (PSCs) were harvested from human lipoaspirate and sorted using fluorescence-activated cell sorting into pericytes (CD146 CD34 CD45 CD31) and adventitial cells (CD146 CD34 CD45 CD31). Mice received no injection, injection with saline solution, or injection with pericytes or adventitial cells either at the time of the index procedure ("prophylactic") or at 2 weeks following the index surgery ("therapeutic"). Muscles were harvested 6 weeks following the index procedure. Wet muscle weight, muscle fiber cross-sectional area, fibrosis, and fatty infiltration were analyzed.

RESULTS

PSC treatment after TT (prophylactic or therapeutic injections) and after TT + DN (therapeutic injections) resulted in less muscle weight loss and greater muscle fiber cross-sectional area than was demonstrated for controls (p < 0.05). The TT + DN groups treated with pericytes at either time point or with adventitial cells at 2 weeks postoperatively had less fibrosis than the TT + DN controls. There was less fatty infiltration in the TT groups treated with pericytes at either time point or with adventitial cells at the time of surgery compared with controls.

CONCLUSIONS

Our findings demonstrated significantly less muscle atrophy in the groups treated with PSCs compared with controls. This suggests that the use of PSCs may have a role in the prevention of muscle atrophy without leading to increased fibrosis or fatty infiltration.

CLINICAL RELEVANCE

Improved muscle quality in the setting of rotator cuff tears may increase the success rates of surgical repair and lead to superior clinical outcomes.

Suprascapular neuropathy in the setting of rotator cuff tears: study protocol for a double-blinded randomized controlled trial

Background

It has been indicated that rotator cuff tears, especially large or massive ones, can cause suprascapular neuropathy. When such a diagnosis has been established, it is still unknown whether an arthroscopic release of the superior transverse scapular ligament during cuff repair can change the course of this neuropathy.

Methods/design

This is a single-center, double-blinded randomized controlled trial for which 42 patients with large or massive repairable rotator cuff tears and suprascapular neuropathy will be recruited and followed up at 6 and 12 months. Nerve function will be measured by nerve conduction and electromyography studies preoperatively and at the selected follow-up periods. Patients will be randomly divided into equally numbered groups, the first one being the control group. Patients of this group will undergo arthroscopic repair of the rotator cuff without combined arthroscopic release of the superior transverse scapular ligament; in the second group the ligament will be released. The primary objective is to test the null hypothesis that arthroscopic repair of large/massive rotator cuff tears in patients with combined suprascapular neuropathy provides equivalent outcomes to one-stage arthroscopic cuff repair where the superior suprascapular ligament is additionally released. The secondary objective is to search for a relation between rotator cuff tear size and degree of suprascapular nerve recovery. The tertiary objective is to demonstrate any relation between rotator cuff muscle fatty infiltration grade and degree of suprascapular nerve function. Patients, clinicians during follow-up clinics and the neurologist will be blinded to the type of surgery performed.

Discussion

To the best of our knowledge, we are unaware of any prospective, randomized double-blinded studies with similar objectives. So far, the evidence suggests a positive correlation between massive rotator cuff tears and suprascapular neuropathy. However, there is mixed evidence suggesting that neuropathy can be effectively treated with rotator cuff repair with or without release of the superior transverse scapular ligament.

Trial registration

ClinicalTrials.gov registration number NCT02318381; date of initial release: 5 December 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1672-y) contains supplementary material, which is available to authorized users.

Anatomic landmarks for arthroscopic suprascapular nerve decompression

PURPOSE

Arthroscopic suprascapular nerve (SSN) decompression has become a more frequently utilized procedure in the treatment of SSN entrapment and has gained popularity over recent years. Despite increasing technical notes and outcomes information regarding this technique, there remains a paucity of data with respect to clear anatomic guidelines for teaching this procedure. The purpose of this study was to provide guidelines that are visible arthroscopically and palpable externally to allow safer and more efficient surgery for arthroscopic decompression by analysing the superior scapular anatomy with respect to local landmarks.

METHODS

A cadaveric study was used to examine neurovascular structural measurements obtained in twelve cadavera with 23 usable shoulders. Arthroscopic dissection of the pertinent anatomy as determined by previously described approaches was followed by meticulous open regional dissection and measurements of the local landmarks.

RESULTS

Measurements of the pertinent arthroscopic anatomy with respect to local landmarks of the superior shoulder were recorded in 23 shoulders and are included herein. Measurements taken arthroscopically on 22 shoulders revealed that the lateral insertion of the transverse suprascapular ligament to the acromioclavicular joint was 3.6 cm (SD 0.5 cm). One of the anatomic measurements on open dissection had a significant correlation with our subject's demographics and was found between cadaveric height and the linear distance from the lateral acromion to the suprascapular notch (mean distance = 66.53 ± 5.30 mm; Pearson's correlation = 0.739; p = 0.006).

CONCLUSIONS

This cadaveric study describes meaningful landmarks and their measurements, which are identifiable arthroscopically and enable safer surgery in this area. Using these numbers, surgeons can know that it is safe to bluntly dissect to 2.5 cm medial to the acromioclavicular joint (and 5 cm medial to the palpable lateral acromion) before dissection is likely to encounter the SSN or artery. This knowledge will allow surgeons to learn this surgical technique, and for surgical educators to safely teach dissection and release in this uncommonly accessed anatomic region.

Suprascapular nerve injury: A cause to consider in shoulder pain and dysfunction

Suprascapular nerve injury is increasingly being recognized as an important cause of shoulder dysfunction. The non-specific clinical features of suprascapular nerve injury can make diagnosis difficult. However, it is essential for clinicians to consider it as part of the differential diagnoses in patients with vague pain or sensory disturbances over the posterosuperior part of their shoulder or have unexplained atrophy and weakness of their supraspinatus or infraspinatus muscle. Electrodiagnostic studies are useful in confirming and localising the nerve injury, while MRIs can be employed to determine the cause of nerve injury and assess the integrity of the rotator cuff muscles. Isolated suprascapular nerve injury can be managed with a trial of conservative management for at least 6 months. Subsequently, decompression of the nerve through open or arthroscopic techniques can be considered - both are associated with high rates of pain relief and functional improvement.

MRI appearance of the superior transverse scapular ligament

OBJECTIVE

The superior transverse scapular ligament (STSL) forms the roof of the suprascapular notch, which is the most common location of entrapment of the suprascapular nerve, a cause of shoulder pain and weakness. The purpose of this study is to determine the frequency of visualization of the STSL on routine shoulder MRIs, to identify the sequences and imaging planes on which it is visualized most frequently, and to describe its typical MRI appearance, none of which have been previously addressed in the radiologic literature.

MATERIALS AND METHODS

One hundred twenty-one consecutive shoulder MRIs were reviewed for the presence or absence of the STSL, including the imaging plane and sequence that best depicted the ligament. Dimensions of the ligament were recorded.

RESULTS

Fifty four of 121 shoulder MRIs were technically adequate for visualization of the STSL, and it was identified on 51 of these studies (94%). There was no statistically significant difference between 1.5-T and 3-T systems. The best individual sequence for visualizing the STSL was the sagittal T1-weighted sequence, in which the STSL was visible on 75/80 technically adequate sequences (94%). The sagittal plane was the best plane for visualizing the STSL, in which it was visible on 65/69 technically adequate studies (94%). The STSL on average measured 12.8 ± 1.5 mm in transverse dimension.

CONCLUSIONS

The STSL can be visualized on the majority of shoulder MRIs and is best seen on sagittal T1-weighted images on our imaging protocol. Evaluation of the STSL can potentially help in identifying pathologic conditions affecting the suprascapular nerve.

Anatomic observation of the running space of the suprascapular nerve at the suprascapular notch in the same direction as the nerve

PURPOSE

The configuration of suprascapular notch was previously analysed from the anteroposterior viewing. However, the approach direction of the suprascapular nerve (SSN) to the inlet of the suprascapular notch is consistently craniocaudal and mediolateral. We propose a new method to observe the suprascapular notch according to the running course of the SSN. We reviewed the anatomic characteristics of the suprascapular notch in relation to the nerve.

METHODS

In 30 formalin-fixed cadaveric shoulders, the morphology of the suprascapular notch and the attachments of the superior transverse scapular ligament (STSL) were examined from both the anteroposterior and the nerve approach direction. The dimensions of the opening of the SSN passage were measured.

RESULTS

By observing from the nerve approach direction, the inlet of the suprascapular notch was recognized to be a space-bordered by the medial wall of the coracoid process, the deep fascia of subscapularis, and the STSL. The STSL formed a sheet-like structure, which ran parallel to the nerve and also to the deep fascia of subscapularis. The attachment of the ligament to the coracoid process was located at the posteromedial corner rather than the medial side.

CONCLUSION

Based on the present study, the space between the STSL and deep fascia of the subscapularis formed the space for the nerve to run through. As a clinical implication, this new method to assess the suprascapular notch in the nerve approach direction might develop the imaging techniques for evaluation of SSN entrapment.

Determinants of nerve conduction recovery after nerve injuries: Compression duration and nerve fiber types

INTRODUCTION

The aims of this study were to determine the influences of: (1) timing of nerve decompression; and (2) nerve fiber types on the patterns of nerve conduction studies (NCS) after nerve injury.

METHODS

Nerve conduction studies (NCS) were performed on 3 models of nerve injury: (1) crush injury due to transient nerve compression (crush group); (2) chronic constriction injury (CCI), or permanent compression (CCI group); and (3) CCI with removal of ligatures, or delayed nerve decompression (De-CCI group).

RESULTS

There were distinct patterns of NCS recovery. The crush and De-CCI groups achieved similar motor nerve recovery, better than that of the CCI group. In contrast, recovery of sensory nerves was limited in the CCI and De-CCI groups and was lower than in the crush group.

CONCLUSIONS

Immediate relief of compression resulted in the best recovery of motor and sensory nerve conduction. In contrast, delayed decompression restored only motor nerve conduction.

An alternative endoscopic portal for suprascapular nerve approach: an anatomic study

PURPOSE

Arthroscopic approaches have been less preferred than open techniques for treating suprascapular nerve entrapment, possibly because current arthroscopic portals are based on distances to reference points, resulting in discrepancies from differing shoulder sizes. This study reports a portal placement based on proportions rather than absolute length.

METHODS

Open dissection (12 left shoulders) and arthroscopy (12 contralateral shoulders) of the suprascapular notch were performed. In left shoulders, the posterolateral prominence of the acromion, the T1 spinous process, and the suprascapular notch were marked (K-wires). Distances from the posterolateral prominence of the acromion to the suprascapular notch and to the T1 spinous process were measured, and the proportion of those distances (distance to the suprascapular notch/distance to the T1 spinous process) was calculated to indicate the portal's location. In right shoulders, arthroscopy anatomically assessed that proportion's reliability.

RESULTS

Median distances from the posterolateral prominence of the acromion to the T1 spinous process and to the suprascapular notch were 175.7 mm (average 180.4, SD 11.8 mm) and 72.3 mm (average 73.9, SD 4.9), respectively. The medians of the proportions of the defined distances were 40.9 % (range 40-42 %) and 41 % (range 39.3-42.1 %), respectively.

CONCLUSION

Locating the portal at the lateral, 41 % of the distance between the posterolateral prominence of the acromion and the T1 spinous process was accurate and reproducible for suprascapular notch visualization. Clinically, this portal seems to eliminate perioperative morbidity by reducing excessive soft-tissue dissection with a shorter arthroscopic route and avoiding the ligamentous damage.

Spectrum of suprascapular nerve lesions: normal and abnormal neuromuscular imaging appearances on 3-T MR neurography

OBJECTIVE. In this article, we will review the normal anatomy and imaging features of various neuromuscular abnormalities related to suprascapular neuropathy. CONCLUSION. Suprascapular neuropathy can be difficult to distinguish from rotator cuff pathology, plexopathy, and radiculopathy. Electrodiagnostic studies are considered the reference standard for diagnosis; however, high-resolution 3-T MR neurography (MRN) can play an important role. MRN enables direct visualization of the nerve and simultaneous assessment of the cervical spine, brachial plexus, and rotator cuff.

Suprascapular neuropathy after distal clavicle resection and coracoclavicular ligament reconstruction: a resident's case problem

STUDY DESIGN

Resident's case problem.

BACKGROUND

Acromioclavicular joint pathology is reported to be present in up to 30% of all patients complaining of shoulder dysfunction. The operative approach to treating acromioclavicular joint disease often includes a distal clavicle excision and, in circumstances of acromioclavicular joint instability, reconstruction of the coracoclavicular and/or the acromioclavicular ligament. Surgical complications for these procedures are rare, but potentially include suprascapular neuropathy secondary to the course of the suprascapular nerve posterior to the clavicle prior to entering the supraspinatus fossa.

DIAGNOSIS

A 28-year-old Caucasian woman reported directly to an outpatient physical therapy clinic with a complaint of right shoulder weakness. Three years prior, the patient underwent a distal clavicle excision and coracoclavicular ligament reconstruction. A detailed examination, including diagnostic imaging, identified infraspinatus atrophy and weakness, increasing the suspicion for suprascapular nerve injury. Electromyography was ordered to confirm the clinical and imaging diagnosis of suprascapular neuropathy and to rule out other nerve lesions, especially considering the selective atrophy of the infraspinatus muscle without mechanical explanation.

DISCUSSION

The clinical decision making and systematic use of diagnostic testing resulted in identifying a rare case of suprascapular neuropathy, selective to the infraspinatus, in a patient who previously underwent a distal clavicle excision and coracoclavicular ligament reconstruction. Without a spinoglenoid cyst or other suprascapular nerve lesion identified on advanced imaging, it is likely that the suprascapular neuropathy identified in this case was related to the surgical procedure.

LEVEL OF EVIDENCE

Differential diagnosis, level 4.

Arthroscopic Treatment of Suprascapular Neuropathy from a Suprascapular Notch Cyst Using a Lateral Subacromial Approach

Introduction

We describe a safe surgical technique for arthroscopic decompression of a suprascapular notch cyst in the setting of compressive suprascapular neuropathy.

Step 1: Position the Patient

Position the patient in the standard beach-chair position.

Step 2: Mark Anatomic Landmarks

Palpate and mark the subcutaneous landmarks of the shoulder in preparation for later arthroscopy.

Step 3: Diagnostic Arthroscopy

Create standard anterior and posterior portals for glenohumeral visualization.

Step 4: Perform Suprascapular Cyst Decompression Through a Lateral Subacromial Approach

Establish accessory superior and lateral portals and transition to a lateral viewing portal to perform suprascapular notch decompression.

Step 5: Release the Transverse Scapular Ligament

Establish a G Portal and release the transverse scapular ligament using arthroscopic scissors.

Step 6: Closure

Perform arthroscopic lavage of the subacromial space and glenohumeral joint and close arthroscopic portals.

Results

As suprascapular nerve entrapment is a relatively rare entity, with only a limited number of studies from which to draw conclusions regarding the outcomes of arthroscopic suprascapular nerve release, Shah et al. recently reported on their results in twenty-four patients using this surgical technique.

Indications

Contraindications

Pitfalls & Challenges

Quantification of the learning curve for arthroscopic suprascapular nerve decompression: an evaluation of 300 cases

PURPOSE

This study aimed to quantify the learning curve for arthroscopic suprascapular nerve decompression (SSND) using the log-linear model.

METHODS

Three hundred consecutive patients underwent arthroscopic SSND by release of the transverse scapular ligament at the suprascapular notch by a single surgeon. Cases with a bony suprascapular nerve foramen were excluded. The arthroscopic SSND time was defined as the time from the beginning of shaving the soft tissue medial to the acromioclavicular joint until the completion of the transverse scapular ligament release. Regression analysis was applied to predict the time required for SSND on the basis of the cumulative case volume after logarithmic transformation of both statistics.

RESULTS

The mean SSND time decreased from the first 50 cases (mean, 29.5 minutes) to the last 50 cases (mean, 6.2 minutes). The estimated SSND times of the first and last 50 cases were 25.1 minutes and 5.5 minutes, respectively. A significant linear correlation was observed between the SSND time and the cumulative volume of cases after logarithmic transformation (r(2) = 0.481, P < .01), and the best-fit linear equation was calculated as log y = -0.52 log x + 4.6, where y represents the estimated SSND time and x represents the cumulative volume of cases, resulting in an estimated learning rate of 69.7% (which equals 2(-0.52)).

CONCLUSIONS

This study presents the overall time reduction in arthroscopic SSND in support of a learning-curve effect. Furthermore, this study quantifies the learning rate, estimated as approximately 70%, indicating that the time required for arthroscopic SSND can decrease by up to 30% when the cumulative volume of cases doubles.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Arthroscopic all-intra-articular decompression and labral repair of paralabral cyst in the shoulder

BACKGROUND

The purpose of this study was to report the outcomes of all-intra-articular arthroscopic decompression and labral repair in patients with symptomatic paralabral cysts.

METHODS

From 2005 to 2011, 20 consecutive cases of symptomatic paralabral cysts were included in this study. All surgical procedures were conducted with intra-articular arthroscopic decompression by use of a probe through the site of labral tear for cyst evacuation and suture anchor repair for the associated posterosuperior labrum. Clinical scores and magnetic resonance imaging (MRI) were obtained preoperatively and at follow-up. MRI was used to evaluate the size and segmentation of the cyst and the presence of the labral tear.

RESULTS

MRI revealed paralabral cysts in association with labral tears in all cases. Cysts were extended in the spinoglenoid notch with a mean size of 2.5 × 2.6 × 2.2 cm on MRI. Cysts were nonsegmented in 5 cases (25%) and had multiple segments in 15 cases (75%). Mean follow-up was 42.8 ± 21.22 months. The mean visual analog scale score for pain, the American Shoulder and Elbow Surgeons score, and the Simple Shoulder Test score significantly improved at the last follow-up (P < .001, P < .001, and P = .001, respectively). The postoperative MRI study performed at a mean of 6 months for 18 of 20 cases (90%) revealed complete cyst removal. The satisfaction level with surgery was good to excellent in 18 patients, fair in 1 patient, and poor in 1 patient. No complication was related to the surgical procedure.

CONCLUSION

Arthroscopic all-intra-articular decompression and labral repair of paralabral cyst can be a simple and effective treatment, regardless of segmentation or size. It also resulted in complete removal of the cyst at a mean of 6 months postoperatively as revealed by MRI. An additional subacromial procedure might not be necessary for complete decompression.

Suprascapular notch variations: a 3DCT study

BACKGROUND

Although cadaveric studies have revealed suprascapular notch shape variations, few have investigated the association between suprascapular notch variation and age or gender. The purpose of this study was to investigate suprascapular notch shape variations by use of three-dimensional computed tomography (3DCT) and to determine if there was any association with age or gender.

METHODS

Three-dimensional CT images of 762 shoulders of 762 patients were analyzed in this study. Participants comprised 404 men and 358 women, with an average age of 58.2 ± 19.1 years. Suprascapular notch shape variations were classified into six types on the basis of Rengachary's classification.

RESULTS

Of the total study population, 11.4% were classified as type I, 23.5% as type II, 30.1% as type III, 14.8% as type IV, 15.9% as type V, and 4.3% as type VI. Average age was 56.5 ± 20.5 years for type I, 57.0 ± 19.5 years for type II, 55.5 ± 20.0 years for type III, 56.4 ± 18.5 years for type IV, 65.5 ± 14.4 years for type V, and 68.0 ± 13.4 years for type VI. Statistically significant age differences were found between types I-IV and V, between types I-IV and VI, and between the non-ossification group (types I-IV) and the ossification group (types V and VI). Male-to-female ratio among each type, and between the non-ossification group and the ossification group, were not statistically significantly different.

CONCLUSIONS

Our results suggest that transverse scapular ligament ossification is associated with aging whereas individual variation explains differences among types I, II, III, and IV. Three-dimensional CT provides useful information for arthroscopic resection of the transverse scapular ligament, when the wide variety of suprascapular notch shape variations is considered.

LEVEL OF EVIDENCE

Level IV.

Upper extremity nerve entrapment syndromes in sports: an update

Peripheral nerve entrapment syndromes are difficult diagnoses to make. Symptoms are often vague and mimic other musculoskeletal pathology. Clinicians' best diagnostic tools for entrapment neuropathies are a good history, physical examination, and anatomical knowledge. Neurodiagnostic testing and advanced imaging have some role to play in entrapment neuropathies, but these are not always necessary or helpful. Most entrapment neuropathies resolve with nonoperative treatment. This article will look at upper extremity entrapment neuropathies and review updated literature from the last decade.

Complete Fatty infiltration of intact rotator cuffs caused by suprascapular neuropathy

Suprascapular neuropathy is generally considered to be a diagnosis of exclusion, although it has been described in association with several activities and conditions. To our knowledge, this is the first description of suprascapular neuropathy with complete neurogenic fatty replacement in patients with intact rotator cuff tendons in the absence of traction or compression mechanisms. We present 4 cases of patients who presented with complete fatty infiltration of the supraspinatus (1 patient), infraspinatus (2 patients), and both (1 patient) resulting from suprascapular neuropathy. Each of these patients underwent arthroscopic suprascapular nerve decompression and subsequently had immediate improvement in pain and subjective shoulder value.

Suprascapular nerve entrapment due to a stenotic foramen: a variant of the suprascapular notch

Suprascapular nerve (SSN) entrapment is an uncommon cause of posterior shoulder pain. Entrapment can be relieved arthroscopically in some cases.

Evaluation and treatment of upper extremity nerve entrapment syndromes

Nerve entrapment syndromes in the upper extremity are being recognized with increasing frequency. Prompt and correct diagnosis of these injuries is important. This article is a review of the common entrapment nerve injuries seen in the upper extremity. Each of these clinical syndromes is discussed independently, reviewing the anatomy, compression sites, patient presentation (history and examination), the role of additional diagnostic studies, and management.

Reconstruction of shoulder abduction by multiple nerve fascicle transfer through posterior approach

PURPOSE

To evaluate the feasibility and clinical efficacy of multiple nerve fascicle transfer through posterior approach for reconstruction of shoulder abduction in patients with C5 or upper brachial plexus injury.

METHODS

11 patients (aged between 17 and 56 years) with dysfunction of shoulder abduction post C5 or upper brachial plexus injury were recruited in this study. Among them, four out of 11 patients also had dysfunction of elbow flexion simultaneously. The duration from injury to the surgery ranged from 4 to 12 months, with an average of 6.7 months. The affected shoulder joints showed abduction, extension and elevation dysfunction, but the muscle strength of shoulder shrugging and elbow extension was graded to M4 or higher. Accessory nerve was transferred to the suprascapular nerve and triceps muscle was branched to the axillary nerve through posterior approach. Ulnar fascicle was transferred to the motor branches of biceps for the 4 patients involved with elbow flexion dysfunction.

RESULTS

Ten out of 11 cases were followed-up for 15-36 months. Neo-potential of deltoid and supraspinatus/infraspinatus was documented at 4-5 months post surgery. Shoulder abduction (and elbow flexion) was reanimated at 4-8 months post surgery. Significant improvement was observed at 15-36 months post surgery, shoulder abduction regained to 40-160° (mean: 92.5°), muscle strength of supraspinatus/infraspinatus and deltoid were graded to M3-M5 (mean: 4.0 and 4.1); 3 cases muscle strength of elbow flexion was graded from M4 to M5- (mean: 4.4) with 1 case loss. Shoulder shrugging of trapezius was graded to M5 in 5 cases, M5- in 2 cases, M4 in 2 cases and M3 in 1 case (mean: 4.5). All cases showed normal elbow extension and muscle strength of triceps (M5).

CONCLUSION

It is feasible to carry out multiple nerve fascicle transfers for early reconstruction of shoulder abduction by posterior approach. Patients who received this procedure achieved good functional recovery and their donor site morbidity/injury was minimal.

Suprascapular nerve: is it important in cuff pathology?

Suprascapular nerve and rotator cuff function are intimately connected. The incidence of suprascapular neuropathy has been increasing due to improved understanding of the disease entity and detection methods. The nerve dysfunction often results from a traction injury or compression, and a common cause is increased tension on the nerve from retracted rotator cuff tears. Suprascapular neuropathy should be considered as a diagnosis if patients exhibit posterosuperior shoulder pain, atrophy or weakness of supraspinatus and infraspinatus without rotator cuff tear, or massive rotator cuff with retraction. Magnetic resonance imaging and electromyography studies are indicated to evaluate the rotator cuff and function of the nerve. Fluoroscopically guided injections to the suprascapular notch can also be considered as a diagnostic option. Nonoperative treatment of suprascapular neuropathy can be successful, but in the recent decade there is increasing evidence espousing the success of surgical treatment, in particular arthroscopic suprascapular nerve decompression. There is often reliable improvement in shoulder pain, but muscle atrophy recovery is less predictable. More clinical data are needed to determine the role of rotator cuff repair and nerve decompression in the same setting.

Arthroscopic suprascapular nerve decompression: transarticular and subacromial approach

Entrapment of the suprascapular nerve (SSN) is an increasingly recognized entity that can occur due to traction or compression-related etiology. Traction injuries of the SSN are unlikely to respond to surgical management and frequently improve with rest and avoidance of overhead activity. Compression injuries, on the other hand, frequently require surgical decompression for pain relief. SSN entrapment caused by compression at the suprascapular notch by the transverse scapular ligament gives rise to pain and atrophy of both the supraspinatus and infraspinatus muscles. However, compression at the spinoglenoid notch is more insidious because pain fibers may not be involved, causing isolated external rotation weakness. We present our preferred surgical technique for safe decompression of the SSN at the suprascapular and spinoglenoid notch using a subacromial and intra-articular approach, respectively. The key to ensuring efficient and uncomplicated decompression of the SSN relies on an intimate knowledge of the neurovascular anatomy and related landmarks.

Recovery of sensory disturbance after arthroscopic decompression of the suprascapular nerve

BACKGROUND

The existence of sensory branches of the suprascapular nerve (SSN) has recently been reported, and sensory disturbance at the lateral and posterior aspect of the shoulder has been focused on as a symptom of SSN palsy. We have performed arthroscopic release of SSN at the suprascapular notch in patients with sensory disturbance since 2006. The purposes of this study were to introduce the arthroscopic surgical technique and investigate postoperative recovery of sensory disturbance.

MATERIALS AND METHODS

The study included 11 men and 14 women (25 shoulders), with an average age of 63.9 years (range, 41-77 years). Arthroscopic decompression of the SSN was performed using a suprascapular nerve (SN) portal as a landmark for approaching the suprascapular notch. Sensory disturbance of the shoulder was evaluated preoperatively and postoperatively. The average follow-up was 18.5 months (range, 12-30 months).

RESULTS

The arthroscopic procedures were performed safely. The preoperative sensory disturbance fully recovered postoperatively in all shoulders.

CONCLUSION

Arthroscopic release of the SSN is a useful procedure for SSN entrapment at the suprascapular notch. The sensory disturbance at the lateral and posterior aspect of the shoulder can be used as one of the criteria of diagnosing SSN palsy, especially in shoulders with massive rotator cuff tear, in which diagnosing and assessing the treatment results of associated SSN palsy is usually difficult.

Suprascapular neuropathy: diagnosis and management

Although historically considered a diagnosis of exclusion, suprascapular neuropathy may be more common than once believed, as more recent reports are describing the condition as a cause of substantial pain and weakness in patients with and without concomitant shoulder pathology. The etiology is traction or compression of the suprascapular nerve. This can result from a space-occupying lesion, such as a ganglion cyst, or a traction injury as a result of repetitive overhead activities. More recent studies have cited cases of traction injuries occurring with retraction of a large rotator cuff tear. Atrophy of the infraspinatus and/or supraspinatus rotator cuff muscles with resultant weakness in forward flexion and/or external rotation of the shoulder on physical examination may be demonstrated. Magnetic resonance imaging (MRI) is the preferred modality to assess atrophy of the rotator cuff muscles as well as assess potential causes of suprascapular nerve compression. Electromyography and nerve conduction velocity studies remain the gold standard for confirmation of the diagnosis of suprascapular neuropathy; however, nerve pain may occur even in the setting of a negative electromyography. Initial management is usually nonoperative, consisting of activity modification, physical therapy, and nonsteroidal anti-inflammatory drugs. Surgical intervention is considered for patients with nerve compression by an external source or for symptoms refractory to conservative measures. Decompression of the suprascapular nerve may be accomplished through an open approach, although arthroscopic surgical approaches have become more common in the past several years.