Musculoskeletal ultrasound diagnosis of quadrilateral space syndrome: A case report

Medicine (Baltimore). 2021 Mar 12;100(10):e24976. doi: 10.1097/MD.0000000000024976.


Introduction: Quadrilateral space syndrome (QSS) is a peripheral nerve entrapment disease, which can be misdiagnosed in clinic. In the past, QSS was mainly diagnosed by clinical symptoms combined with magnetic resonance imaging (MRI), electromyography (EMG), and arterial angiography. There are few reports on the diagnosis of QSS by musculoskeletal ultrasound (MSKUS) combined with clinical symptoms.

Patient concerns: A middle-aged female patient had posterolateral pain and numbness in her right shoulder for 2 months.

Diagnoses: At first, she was diagnosed as suprascapular nerve entrapment, while EMG of suprascapular nerve and axillary nerve indicated that nerve conduction was normal. Then, MRI was performed, showing the shoulder had no abnormalities, and EMG and arterial angiography of upper limb showed no abnormalities too. Finally, she was diagnosed as QSS according to MSKUS and lidocaine block test.

Interventions: Two sealing treatments of axillary nerve block in quadrilateral space under the guidance of MSKUS were performed.

Outcomes: After 2 treatments, the pain and numbness in her shoulder disappeared, and her shoulder could move normally. There was no recurrence after 3 months of follow-up.

Conclusion: MSKUS is an effective method to diagnose QSS. It is fast, convenient and inexpensive, and is worth popularizing in clinic.

Publication types

  • Case Reports

MeSH terms

  • Brachial Plexus / diagnostic imaging
  • Brachial Plexus Neuropathies / complications
  • Brachial Plexus Neuropathies / diagnosis*
  • Brachial Plexus Neuropathies / therapy
  • Deltoid Muscle / diagnostic imaging
  • Deltoid Muscle / innervation
  • Diagnosis, Differential
  • Electromyography
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Middle Aged
  • Nerve Block
  • Nerve Compression Syndromes / complications
  • Nerve Compression Syndromes / diagnosis*
  • Nerve Compression Syndromes / therapy
  • Rotator Cuff / diagnostic imaging
  • Rotator Cuff / innervation
  • Shoulder / diagnostic imaging
  • Shoulder / innervation
  • Shoulder Pain / diagnosis*
  • Shoulder Pain / etiology
  • Shoulder Pain / therapy
  • Treatment Outcome
  • Ultrasonography