Zachary Mendoza

Background: The shoulder joint is the 3rd most common site of musculoskeletal disease, and accounts for 4.5 million chief complaints, with 30-40% being rotator cuff related[1,2,3]. Overall, cadaveric studies estimate RC pathologies in 5-39% of the population at any given time[3]. The gold-standard RC surgery is arthroscopic repair due to its minimally invasive nature in comparison with open surgery. However, there are many risk factors of repair outcomes, with a range of 34-94% of cases failing or retearing[4]. After injury and surgery, the tendon undergoes a three-stage healing process to its original strength: inflammation, proliferation, and remodeling. With such a high and wide range of retear/failure possibilities, this study investigated current literature associated with RC tendon healing through augmentation of the surgical procedure and environment.

Search Methods: PubMed searches including the terms: “rotator cuff augmentation,” “rotator cuff surgery,” and “tendon regeneration.”

Results: There were many results investigating best practices for rotator cuff injury rehabilitation, but specific to surgical techniques, three different interventions showed promise to improve patient outcomes. Each of the augmentations demonstrated increases in shoulder healing, with various improvements throughout. Dermal allografts allow the tendon to gain structural support after surgery, while also creating an environment hypothesized to support cell-seeding and proliferation[5,6]. This promotes improvement of long-term outcomes – in contrast, use of AMLT had no increase in long-term rehabilitation, but supplementing the site with these injections showed marked increases in the short-term “sprint” healing post-op[7]. Interestingly, the use of beige FAPs showed significantly increased healing rates while minimizing adverse outcomes in mice without needing surgery[8]. Each method requires some combination of MRI, histology, or questionnaires to elicit a “snapshot” of the shoulder’s progress. The use of a specific MRI sequence called T1ρ imaging, has been shown to monitor extracellular properties, most specifically through providing quantitative collagen amounts[9]. Given extensive literature regarding tendon regeneration, collagen remains an increasing variable as healing occurs. Exploiting this property could indicate repair quality and ensure proper recovery.

Conclusions: The detrimental outcomes associated with disability of the shoulder joint and the high rates of repair failure indicates a need to increase the efficacy of healing for these patients. Addition of already high-performing dermal allografts shows extreme promise for the field, and investigation of synergistic effects when coupled with AMLT remains unknown. To ensure these augmentations are assisting in the tendon repair, MRI sequences such as T1ρ can accentuate the healing process by providing “quality checks” for patients post-op.

Works Cited:

1. Hinsley H, Ganderton C, Arden NK, Carr AJ. Prevalence of rotator cuff tendon tears and symptoms in a Chingford general population cohort, and the resultant impact on UK Health Services: A cross-sectional observational study. BMJ Open. 2022;12(9). doi:10.1136/bmjopen-2021-059175
2. Agha O, Diaz A, Davies M, Kim HT, Liu X, Feeley BT. Rotator cuff tear degeneration and the role of fibro‐adipogenic progenitors. Annals of the New York Academy of Sciences. 2020;1490(1):13-28. doi:10.1111/nyas.14437
3. Grusky AZ, Song A, Kim P, et al. Factors associated with symptomatic rotator cuff tears. American Journal of Physical Medicine & Rehabilitation. 2021;100(4):331-336. doi:10.1097/phm.0000000000001684
4. Abtahi AM. Factors affecting healing after arthroscopic rotator cuff repair. World Journal of Orthopedics. 2015;6(2):211. doi:10.5312/wjo.v6.i2.211
5. Wong I, Sparavalo S, King JP, Coady CM. Bridging Allograft Reconstruction Is Superior to Maximal Repair for the Treatment of Chronic, Massive Rotator Cuff Tears: Results of a Prospective, Randomized Controlled Trial. Am J Sports Med. 2021;49(12):3173-3183. doi:10.1177/03635465211039846
6. Lee GW, Kim JY, Lee HW, Yoon JH, Noh K-C. Clinical and anatomical outcomes of arthroscopic repair of large rotator cuff tears with allograft patch augmentation: A prospective, single-blinded, randomized controlled trial with a long-term follow-up. Clinics in Orthopedic Surgery. 2022;14(2):263-271. doi:10.4055/cios21135
7. Randelli PS, Cucchi D, Fossati C, et al. Arthroscopic Rotator Cuff Repair Augmentation With Autologous Microfragmented Lipoaspirate Tissue Is Safe and Effectively Improves Short-term Clinical and Functional Results: A Prospective Randomized Controlled Trial With 24-Month Follow-up. The American Journal of Sports Medicine. 2022;50(5):1344-1357. doi:10.1177/03635465221083324
8. Lee C, Liu M, Agha O, Kim HT, Feeley BT, Liu X. Beige FAPs Transplantation Improves Muscle Quality and Shoulder Function After Massive Rotator Cuff Tears. J Orthop Res. 2020;38(5):1159-1166. doi:10.1002/jor.24558
9. Noehren B, Hardy PA, Andersen A, et al. T1Ρ imaging as a non‐invasive assessment of collagen remodelling and organization in human skeletal muscle after ligamentous injury. The Journal of Physiology. 2021;599(23):5229-5242. doi:10.1113/jp281964