The correlation of the spinoglenoid ganglion cyst size with the electrophysiological alterations of suprascapular nerve and the rotator cuff muscle power

Sung-Min Rhee; Vivek Bansal; Ho Yeon Jeong; Young Dae Jeon; Hyeon Jang Jeong; Joo Han Oh

doi:10.1016/j.jos.2023.06.004

The correlation of the spinoglenoid ganglion cyst size with the electrophysiological alterations of suprascapular nerve and the rotator cuff muscle power

J Orthop Sci. 2023 Jun 24:S0949-2658(23)00147-1. doi: 10.1016/j.jos.2023.06.004. Online ahead of print.

Authors

Sung-Min Rhee¹, Vivek Bansal², Ho Yeon Jeong³, Young Dae Jeon⁴, Hyeon Jang Jeong⁵, Joo Han Oh⁶

Affiliations

¹ Shoulder & Elbow Clinic, Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
² Department of Orthopaedic Surgery, PCC & MH, Bathinda, Punjab, India.
³ Department of Orthopaedic Surgery, Yonsei The Bareun Hospital, Gimpo, Republic of Korea.
⁴ Department of Orthopaedic Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea.
⁵ Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea.
⁶ Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea. Electronic address: ohjh1@snu.ac.kr.

PMID: 37365077
DOI: 10.1016/j.jos.2023.06.004

Abstract

Background: Although various treatment options are available for spinoglenoid cyst, including conservative and surgical methods, there is no standard guideline for its surgical decompression. Thus, the purpose of the study was to correlate the size of the spinoglenoid notch ganglion cyst (GC) as revealed by magnetic resonance imaging (MRI) with electrophysiological alterations, muscle power, and pain severity, and to estimate a cut-off value of cyst size to perform a decompression.

Methods: Between January 2010 and January 2018, the patients with a GC at the spinoglenoid notch diagnosed on MRI, and who had a minimum follow-up of 2 years after the decompression were included. Maximum cyst diameter as measured on MRI was used for comparison. Electromyography (EMG) and nerve conduction velocity (NCV) studies were performed before the surgery. Peak torque deficit (PTD) percentage compared to opposite shoulder was calculated preoperatively and at 1 year after surgery. Pain severity was estimated using visual analogue scale (VAS) preoperatively.

Results: Ten (50%) of 20 patients with GC > 2.2 cm and 1 (5.9%) of 17 patients with GC < 2.2 cm showed EMG/NCV abnormalities (p = 0.019). There was a correlation between the cyst size and the positive EMG/NCV findings (Correlation coefficient (CC) = 0.535, p < 0.001). The preoperative peak torque deficit on the external rotation was correlated with the positive EMG/NCV findings (CC = 0.373, p = 0.021). The PTD was improved significantly at 1 year postoperatively in patients with a GC size >2.2 cm (p = 0.029). The cyst size was not related to the preoperative pain VAS and muscle power.

Conclusions: The spinoglenoid cyst size >2.2 cm, but not pain severity or muscle power, correlates with the positive finding of EMG for compressive suprascapular neuropathy. The GC size >2.2 cm can be a reference to decide the need of decompression surgery.

Level of evidence: IV, case series.

Keywords: Cyst size; Electromyography; Isokinetic muscle performance test; Nerve conduction study; Spinoglenoid notch ganglion cyst; Suprascapular nerve.