Distribution and analysis of subacromial spurs and the relationship with acromial classification and angle in healthy individuals

PLoS One. 2024 Mar 28;19(3):e0301066. doi: 10.1371/journal.pone.0301066. eCollection 2024.

Abstract

Background: Subacromial spurs are considered the one of the pathology underlying shoulder impingement syndrome. Furthermore, few studies have focused on the morphology of the subacromial spurs in normal Chinese people. This study aimed to study the spur distribution and to illustrate the morphology of spurs, which may help guide the extent of acromioplasty.

Methods: A total of 93 normal individuals were enrolled, and both shoulders of all enrolled individuals were analyzed. The subjects were divided and classified into three different groups by ages: group I = 18-40 years, group II = 41-60 years, and group III ≥ 61 years. The osteophyte distribution, osteophyte area, subacromial surface area and osteophyte area/subacromial surface area ratio were measured and illustrated using Mimics and 3-matic software. The shape of the acromion was classified according to the Bigliani and Morrison classification system. The acromial angle was also classified. Then, the relationship between osteophytes, acromial classification and acromial angle was analyzed.

Results: Type II (curved shape) was the most common type of acromion, and the hooked shape was a rare form. A significant increase in the left subacromial surface area in males was observed in group III compared with group I (P < 0.001) and group II (P = 0.004). The total spur/subacromial area ratio was significantly higher in group II than I. An obvious increase in the right subacromial area was observed in group III compared with group I (P = 0.004). Furthermore, there was a significant increase in the right spur area (P = 0.021) and total spur/subacromial area ratio (P = 0.006) in females in group II compared with group I. Fewer spurs were observed on the left than on the right side (p = 0.0482). One spur was most common among type II acromions (29/36) (80.56%) on the left side and the right side (34/52, 65.38%).

Conclusions: Spurs osteophytes are mainly distributed with an irregular shape and mostly run through the medial and lateral sides of the subacromial surface in normal subjects. The characteristics of subacromial spurs are so diverse that a surgeon must conduct subacromial decompression completely based on the morphology of individual spurs.

MeSH terms

  • Acromion* / anatomy & histology
  • Acromion* / diagnostic imaging
  • Adolescent
  • Adult
  • Arthroplasty
  • East Asian People*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Osteophyte* / diagnostic imaging
  • Osteophyte* / pathology
  • Shoulder Impingement Syndrome / diagnostic imaging
  • Young Adult

Supplementary concepts

  • Chinese people

Grants and funding

The research was supported by National Natural Science Foundation of China (82002281 and 82072523) and The Natural Science Foundation of Hebei (H2021206054 and H2020206193), the Main Medical Scientific Research of Hebei (20210543, 20221209), 2023 Government-funded training of outstanding clinical medical talents (ZF2023083) and the 14th Five-Year Clinical Medicine Innovation Research Team (2022LCTD-B27, 2022LCTD-A9). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.