Suprascapular Nerve Palsy G56.80 354.8




Brachial plexus image



ICD-9 Classification / Treatment
Etiology / Natural History Associated Injuries / Differential Diagnosis
Anatomy Complications
Clinical Evaluation Follow-up Care
Xray / Diagnositc Tests Review References

synonyms: Spinoglenoid Notch Cyst,suprascapular nerve palsy, suprascapular neuropathy

Suprascapular Nerve Palsy ICD-10

Suprascapular Nerve Palsy ICD-9

  • 354.8 (other mononeuritis of upper limb)
  • 354.9 (mononeuritis of upper limb, unspecified)
  • 727.4 (Ganglion and cyst of synovium, tendon and bursa)

Suprascapular Nerve Palsy Etiology / Epidemiology / Natural History

  • Rare.
  • More common in volleyball players (Fehrman DA, JBJS 1987;69A:260), baseballpitchers.
  • May result from stretch injury (overhead activites), repetitive microtrauma, direct compression of the nerve or indirect injury to the vascular supply to the nerve.
  • More common in men than women.
  • Natural history of ganglion cysts about the shoulder is unknown. May enlarge over time with progressive weakness and loss of function.

Suprascapular Nerve Palsy Anatomy

  • Paralabral ganglion cyst can cause compression on the transverse scapular ligament of the spinoglenoid notch.
  • Proximal compression of the suprascapular nerve (scapular notch) causes denervation of the supraspinatus and infraspinatus.
  • Distal compression (spinoglenoid notch) causes denervation of the infraspinatus only.
  • See also Suprascapular nerve anatomy.

Suprascapular Nerve Palsy Clinical Evaluation

  • Weakness and dull aching posterior shoulder pain. Supraspinatus denervation causes abduction weakness. Infraspinatus causes external rotation weakness.
  • Evaluate for infraspinatus and / or supraspinatus atrophy.
  • External Rotation lag signwill indicate infraspinatus weakness.
  • Jobe's testmay indicated supraspinatus weakness.
  • May have positive evaluation findings for SLAP Tear.

Suprascapular Nerve Palsy Xray / Diagnositc Tests

  • AP, scapular lateral and axillaryviews generally normal.
  • MRI: Paralbral cysts are generally located medial to the postersuperior glenoid within the spinoglenoid notch; appear as well-defined, smoothly marginated high signal intensity on T2 images. Chronic denervation is associated with infraspinatus and supraspinatus muscle atrophy. (Tirman PF, Radiology 1994;190:653), (Inokuchni W, JSES 1998;7:223).
  • EMG/NCV: indicated to confirm diagnosis. Demonstrates denervation potentials in the infraspinatus and/or supraspinatus muscles.

Suprascapular Nerve Palsy Classification / Treatment

  • Unidentifiable lesion: organized physical therapy. Pain and weakness may take > one year to reach maximum improvement. PT to maintain ROM, strengthen RTC, deltoid and periscapular muscles. (Martin SD, JBJS 1997;79A:1159).
  • Spinoglenoid notch cyst: arthroscopic decompression with repair of any labral injury to prevent recurrence. (Youm T, Arthroscopy 2006;22:548), (Fehrman DA, Arthroscopy 1995;11;727), (Moore TP, JSES 1997;5:455). Code as: 29823(arthroscopy shoulder; with extensive debridement) or 29807(arthroscopy shoulder with SLAP repair)
  • Supracapular notch compression: shoulder arthroscopy followed by open decompression and release of the hypertrophic transverse scapular ligament.
  • Ultrasound or CT guided aspiration has also been previously reported.

Open Spinoglenoid Notch Decompression Technique

  • Perform shoulder arthroscopy and repair any labral lesion first.
  • 4-6cm longitudinal incision 3cm medial to the posterolateral corner of the acromion.
  • Dissect under 2.5x/3.5x loop magnification down to deltoid. Split deltoid fibers beginning at the scapular spine.
  • Retract superior edge of the infraspinatus inferiorly.
  • Identify suprascapular nerve, suprascapular artery and spinoglenoid notch cyst in the spinoglenoid notch.
  • Excise the cyst.
  • Irrigate.
  • Repair deltoid fascia.
  • Close in layers.

Suprascapular Nerve Palsy Associated Injuries / Differential Diagnosis

  • SLAP Tear/ Labral tears: >95% of spinoglenoid notch cysts are associated with posterior-superior labral tears.
  • Rotator Cuff Tear.

Suprascapular Nerve Palsy Complications

  • Recurrence
  • Suprascapular nerve injury
  • Continued pain
  • Continued muscle atrophy
  • Shoulder arthroscopy risks

Suprascapular Nerve Palsy Follow-up Care

  • 7-10 Days post-op: start PT. Avoid stress the superior labrum for 6 wks if concomitant SLAP/labral repair was done.
  • Supraspinatus and infraspinatus atrophy often persist, even after decompression of associated cysts.
  • Spinoglenoid notch cyst decompression generally resolves associated shoulder pain.
  • 100% successful outcomes for arthroscopic labral repair without formal cyst excision (Youm T, Arthroscopy 2006;22:548) .

Suprascapular Nerve Palsy Review References

  • Piatt BE, JSES 2002;11:600
  • Antoniadis G, J Neurosurg 1996;85:1020
  • Romeo AA, JAAOS, 1999;6:358
  • Cummins CA, JBJS 2000;82A:415
  • Martin SD, JBJS 1997;79A:1159