The role of suprascapular nerve decompression

1. The Role of Suprascapular Nerve
Decompression
Jeremy Granville-Chapman
Upper Limb Fellow

2. Aims
• Epidemiology
• Anatomy
• Aetiology
• Diagnosis
• Management Options
• Techniques for decompression
• Some evidence

3. Epidemiology
• Incidence unknown
• Relatively uncommon
• 1959-2001 only 88 reported cases
• By 2011, largest case series 53 pts
• Seems to have bimodal age distribution
– Overhead athletes/ sporting injury
– 50s and older +/- rotator cuff tears
• Isolated infraspinatus involvement more
common in younger patients
• Suprascapular notch more common with cuff
tear

4. Anatomy
• Upper trunk brachial plexus
• C4 C5 C6
• Passes beneath superior
transverse scapula ligament
• Wraps around spinoglenoid
notch
• Motor branches into Supra
and Infra
• First of 2 branches to supra
arises in notch

5. Aetiology
• Overhead sport
– Possibly SGL hypertrophy alongside GIRD
– SGL blends with post capsule
• Trauma – clavicle fracture, dislocation, SLAP tear –
(EMG changes in 29% prox humeral #/dislocations)
• Tumour
• Ganglion with SLAP tear
• Retracted rotator cuff tear
• Narrow ossified notch
• Surgery – SLAP repair anchors, Latarjet screw
XS study of 84 pro-volleyball
30% incidence infraspinatus atrophy 1
1. Lajtai G et al. The shoulders of professional beach volleyball players: High prevalence of infraspinatus muscle atrophy.
Am J Sports Med 2009; 37(7):1375-1383

6. Diagnosis
• History and Exam
– dull poorly localised ache and weakness, made worse with
overhead activity. Wasting and weakness
• XR/CT
• MRI
– Ganglion with SLAP
– degree wasting of muscles
– Rotator cuff tear
• EMG
– Fibrillations, reduced amplitude
– Can help localise site of compression proximal or distal
– Excludes more generalized plexopathies
– Predicts outcome with surgery?

7. Space Occupying
Lesion & EMG
changes
Overuse/Non
Compressive
lesion
Address cause
(SLAP repair) +/-
decompress
ganglion/SSN
Conservative Rx
NSAIDS,
avoidance
Capsular
stretching
Young athlete
Series1: 15 pts
Good/excellent
12/15
3 needed surgery
– with mixed
results
1. Martin SD et al. Suprascapular neuropathy: Results of non-operative treatment. JBJS(Am) 1997;79(8):1159-1165
2. Piatt BE et al. Clinical evaluation and treatment of spinoglenoid notch ganglion cysts. JSES 2002;11(6):600-604
3. Antoniou et al. (Iannotti). Suprascapular neuropathy: variability in the diagnosis, treatment and outcome. Clin Orthop
Relat Res 2001;386:131-138
Series2: 46 pts total
Surgery - 26/27 pts satisfied
Non-operative - 10/19 satisfied
Decompress
nerve?
Conservative as
good as (open)
surgery in non-
compressive
lesions3

8. SLAP patients - do we need to aspirate
the ganglion or decompress the nerve
if repairing a SLAP tear?
10 patients with SGN ganglion and SLAP tears
All underwent SLAP repair only
4/10 with pre-op EMG underwent post-op: EMG normalized
8/10 had post-op MRI: all had complete cyst resolution
1. Youm T et al. Treatment of patients with spinoglenoid cysts associated with superior labral tears without cyst
aspiration, debridement or excision. Arthroscopy 2006;22(5:548-552

9. SSN in older patients without cuff
tear or compression
Lafosse 2007 Shah 2011
• 10 pts (Age 50)
• EMG +ve chronic comp.
• Arthroscopic release
• 15 mth f/u Improved:
• EMG 7/8 complete recovery
• Constant score
• Strength AB/ER
• 9/10 excellent with
• complete pain relief
• 27 pts (Age 49)
• 24/27 +ve EMG
• Arthroscopic release
• 22 mth f/u Improved:
• VAS 17/24
• SSV 17/24
• ASES 18/24
• No post-op EMG

10. Neuropathy and Rotator cuff tear –
why does it happen?
• Supraspinatus supplied by only two
motor branches
– Proximal branch dominant
– Branch arises in notch in 9/12 cadavers 2
– Normal angle is 142 degrees
– Retraction kinks this branch
– All motor branches taught at 2-3cm
retraction
2. Abritton MJ et al. JSES 2003; 12(5):497-500c
1cm
142 °
98 °
35 °
Normal
5 cm

11. Does reduction of retracted tears
threaten the SSN?
Warner JP, Gerber C et al. Anatomy and relationships of the suprascapular
nerve: Anatomical constraints to mobilization of the Supraspiantus and
Infraspinatus muscles in the management of rotator cuff tears. JBJS (Am)
1992;74:36-45
• Cadaveric study
• Suggests risk of SSN traction injury with
reduction >3cm of supraspinatus, BUT..

12. SSN recovers with repair of MCT
Costouros 2007 3
• 26 MCT. Retraction, fatty
change and weakness
• 38% had EMG evidence SSN
neuropathy (7/26)
– (4/26 had Ax neuropathy)
• These 7 pts underwent
arthroscopic full or partial
repair (unachievable in 1)
• Post op EMG in 6 repairs – full
nerve recovery
• Complete pain relief
• Increased function
Mallon 2006 4
• 8pts. 5cm MCT, retraction,
fatty change, EMG+, active
FE<40 degrees
• 4 no surgery: no improvement
2yr
• 4 mini-open partial repair and
convergence:
– 2 of 4 had post-op EMG
partial/near complete recovery
– 4 of 4, >90 degrees FE, hand
behind head
3. Costouros JG (Warner JJ) et al. Reversal of suprascapular neuropathy following arthroscopic repair of massive supra and
infra rotatior cuff tears. Arthroscopy 2007;23(11):1152-1161
4. Malllon WJ et al. The association of suprascapular neuropathy with massive rotator cuff tears: a preliminary report.
JSES 2006;15(4):395-398

13. So, do we need to release nerve at
same time as MCT repair?
• No comparative studies I could find
• A few reports of pain and EMG dysfunction
after RC repair (Lafosse cites 3 patients in
2007 paper), but..
• Several series show improvement in nerve
function after MCT repair
• …probably not, but would EMG pts if sig.
pain and weakness remain post RC repair

14. Options with cuff tear and SS
Neuropathy?
• Attempt repair/partial repair, if not..
• Consider decompressing nerve at STSL
• OR.. Consider ablation ..

15. Irreparable MCT/CTA: Nerve Ablation
• 57 chronic shoulder pain patients 7
• 480sec ablation PRF
• Shoulder pain verbal numeric rating scale
• >50% pain relief in 74% at 3 mths
• Further 18% <50% improvement, but still relief
• No complications
• 79% still reported improvement at 6 mths
7. Luleci N et al. Evaluation of patients' response to pulsed radiofrequency treatment
applied to the suprascapular nerve in patients with chronic shoulder pain
Back and Musculoskeletal Rehabilitation. 2011; 24(3):189-194

16. Nerve Ablation - 2
• 12 pts with painful CTA. Mean age 68 8
• PRF ablation
• Constant, Oxford scores improved at 3 and 6
months
• Non sig. improvement VAS which deteriorated
between 3-6 months
• Authors conclude useful adjunct in those unfit
for surgery
8. Kane TP et al. Pulsed radiofrequency applied to the suprascapular nerve in painful cuff tear
arthropathy. JSES 2008;17(3):436-440

17. • 13 PRF ablations in 11 pts with chronic
shoulder pain 9
• 1 month
– 77% had >50% VAS reduction. 7.5 to 2.8
• 6 months
– 69% still enjoyed >50% VAS benefit (mean 2.5)
– Shoulder pain and disability index improved
– 9/11 pts had reduced analgesia regimens
9. Lilang P-C et al. Pulsed Radiofrequency Lesioning of the Suprascapular Nerve for Chronic
Shoulder Pain: A Preliminary Report. Pain Medicine 2009; 10(1):70-75
Nerve Ablation - 3

18. Open Surgical Techniques
• Suprascapular notch4
– Bra strap incision
– Trapezius split
– Supraspinatus retracted posteriorly
• Spinoglenoid notch5
– Vertical incision 3cm medial PL corner acromion
– Deltoid split (care Ax n)
– Infra fascia incised and muscle retracted inferiorly
– Follow inf. border of spine laterally to notch
4. Romeo AA et al. Suprascapular neuropathy. J Am Acad Orthop Surg 1999;7[6]:358-367
5. Piasecki DP (Romeo AA) et al. Suprascapular neuropathy. J Am Acad Orthop Surg 2009;
17(11):665-676

19. Arthroscopic STSL release
• DeBeer6 and Lafosse7 separately reported
techniques in 2006
• Trans-bursal approach + one or two medialized
Neviaser portals (7cm from lat edge acromion) for
retraction and separation of the STSL
– Anterior gutter bursectomy
– Follow CA lig to coracoid
– Head medially over base of coracoid to CC lig
– Just postero-medial to this is the notch
– Identify vessel over, nerve beneath and release
ligament
6. Bhatia DN, De Beer JF et al: Arthroscopic suprascapular nerve decompression at the suprascapular
notch. Arthroscopy 2006;22(9): 1009-1013
7. Lafosse L et al. Technique for endoscopic release of suprascapular nerve entrapmentat the suprascapular
notch. Tech Shoulder Elbow Surg 2006;7:1-6

21. Arthroscopic SG Notch decompression
Bursal route Articular route
6. Werner CM and Gerber C: Combined intra- and extra-articular arthroscopic treatment of entrapment
neuropathy of the infrapinatus…. Arthroscopy 2007;23(3):e1-e3
• Bursectomy and view
• Define scapular spine (keel)
• Accessory posterior portal –
Langenbeck retractor to pull
infra down to expose cyst
and notch from above
• View from
anterosuperolateral portal
• Trans-cuff (Wilmington)
working portal
• Enter cyst via SLAP tear or
above labrum
• Nerve on floor notch
medially 2-3cm from biceps
anchor

22. Summary
• Overhead athletes
– If space-occupying lesion with wasting/EMG changes,
likely to do well with surgery, probably just SLAP repair
– Post capsular programme etc as effective as surgery if no
compressive lesion
• SSN neuropathy no tear no compression
– If conservative Rx failed, series show decompression at
STSL effective
• Painful Massive Cuff Tear
– Consider repair/partial repair
– Surgical decompression at suprascapular notch
– If not possible/not fit, consider ablation via US

23. Questions?