Subacromial Bursa: A Neglected Tissue Is Gaining More and More Attention in Clinical and Experimental Research

Abstract

The subacromial bursa has long been demolded as friction-reducing tissue, which is often linked to shoulder pain and, therefore, partially removed during shoulder surgery. Currently, the discovery of the stem cell potential of resident bursa-derived cells shed a new light on the subacromial bursa. In the meanwhile, this neglected tissue is gaining more attention as to how it can augment the regenerative properties of adjacent tissues such as rotator cuff tendons. Specifically, the tight fibrovascular network, a high growth factor content, and the large progenitor potential of bursa-derived cells could complement the deficits that a nearby rotator cuff injury might experience due to the fact of its low endogenous regeneration potential. This review deals with the question of whether bursal inflammation is only a pain generator or could also be an initiator of healing. Furthermore, several experimental models highlight potential therapeutic targets to overcome bursal inflammation and, thus, pain. More evidence is needed to fully elucidate a direct interplay between subacromial bursa and rotator cuff tendons. Increasing attention to tendon repair will help to guide future research and answer open questions such that novel treatment strategies could harvest the subacromial bursa’s potential to support healing of nearby rotator cuff injuries.

Arthroscopic Biological Augmentation With Subacromial Bursa for Bursal-Sided Partial-Thickness Rotator Cuff Tears

“…Discussions about whether the subacromial bursa is the cause of shoulder pathologies or the source of the regeneration ability of the shoulder still continue. 11,12 According to the authors who claim that the subacromial bursa is deleterious, the bursa is in close relationship with the rotator cuff tendons it covers, and the pathological changes like villus formation, inflammation, and bursal adhesion cause changes in the rotator cuff muscles as well. 11 Studies on biological augmentation using subacromial bursa in arthroscopic rotator cuff repairs started to increase after it was determined that bursal tissue is a source of MSCs.…”

Microfracture Lateral to the Greater Tuberosity of the Humerus Enhances Tendon-to-Bone Healing in a Rat Rotator Cuff Model

“…In studies regarding rotator cuff repair after injury, some researchers have suggested that healing always seems to begin on the lateral side of the bursa. 12,22,26,30 Intriguingly, histologic cartilage staining reportedly shows that the generation of new cartilage in the tendon-bone transition area is always faster on the lateral side of the tendon. 31,32 Thus, the lateral side is the main and more reliable source of rotator cuff healing, and the healing speed is significantly faster than that of the medial side, especially at the tendon-bone junction.…”

“…Several recent studies have shown that the lateral tendon is promising and important in healing promotion in the shoulder joint. 12,18,22,26 However, no relevant study has explored lateralized microfracture in an animal model.…”

Analysis of risk factors for procedure-related hemorrhage in rotator cuff repair surgery under shoulder arthroscopy

“…After rotator cuff injury, the local inflammatory exudation of the shoulder joint causes pain in the shoulder joint, which in turn affects joint activities and significantly impacts work and life. [9,14] It is generally believed that arthroscopic rotator cuff repair is a minimally invasive surgery with less bleeding. Kawaguchi et al [15] reported the average blood loss of the arthroscopic rotator to be 355.5 ± 191.2 mL during arthroscopic rotator cuff repair.…”