Peter Chaftari

Background: Kyphoscoliosis Ehlers-Danlos Syndrome (kEDS) is a rare genetic disorder that results in hypermobile joints that are highly susceptible to shoulder dislocations.¹ People with kEDS have a mutation in the FKBP22 protein, a chaperone protein that assists in the proper folding of collagen type III in the rough endoplasmic reticulum (ER).^1,2 The majority of these shoulder dislocations are anterior dislocations (85-98%) and can often result in glenoid or humeral bone loss and ligament tears resulting in recurrent dislocations and shoulder instability.^3,4 Surgical intervention is the most effective method to treat shoulder instability.^5,6 Bankart repair involves arthroscopically anchoring the labrum back to the glenoid fossa, and the open Latarjet repair involves using a portion of the coracoid process to reconstruct the glenoid fossa.⁷

Methods: PubMed database was searched using keyword searches “shoulder instability”, “anterior shoulder dislocations”, “kyphoscoliosis ehlers-danlos”, and “Bankart vs Latarjet” and included publication dates between 2017 and 2024.

Results: A 3D model of mutated FKBP22 reveals no significant structural changes but did show local net charge changes near the active site.^1,2 Studies show decreased binding affinity with collagen type III, resulting in lower collagen type III production.^1,2 Cartilage with decreased levels of collagen III exhibits more laxity.⁸ In a short-term study of 2864 procedures occurring between 2005 and 2014, arthroscopic Bankart approaches are more successful than open Latarjet as they resulted in lower complication rates (0.6% vs. 5.5 %, respectively), operation times (81 min vs. 131 min, respectively), admissions (7.6% vs. 33.7%, respectively), 30-day readmissions (0.2% vs. 3.1%, respectively), and 30-day reoperations (0.2% vs. 4.3%, respectively).⁹ However, in a longitudinal study following 121 patients, including 19 with hypermobility syndromes, those undergoing arthroscopic Bankart approaches, when compared to Latarjet approaches, had more re-dislocations events (21% vs. 2 %, respectively).¹⁰ They were also less likely to return to their previous level of activity if they played competitive sports (56% vs 9%, respectively).¹⁰

Conclusions: Dysfunction of FKBP22 seen in kEDS could lead to decreased levels of collagen type III. As a result, articular cartilage and fibrocartilage becomes more plastic and dislocations can be more frequent. Bankart surgeries have lower complication rates, but patients could encounter more dislocation events when compared to the Latarjet approach. Further studies should be conducted using solely patients with Ehlers-Danlos to better understand the outcomes of surgical intervention in these patients.

Works Cited:

1. Ishikawa Y, Bonna A, Gould DB, Farndale RW. Local Net Charge State of Collagen Triple Helix Is a Determinant of FKBP22 Binding to Collagen III. Int J Mol Sci. 2023;24(20):15156. Published 2023 Oct 13. doi:10.3390/ijms242015156
2. Ishikawa Y, Mizuno N, Holden P, et al. The novel missense mutation Met48Lys in FKBP22 changes its structure and functions. Sci Rep. 2020;10(1):497. Published 2020 Jan 16. doi:10.1038/s41598-019-57374-y
3. Varacallo M, Musto MA, Mair SD. Anterior Shoulder Instability. [Updated 2023 Aug 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538234/
4. Abrams R, Akbarnia H. Shoulder Dislocations Overview. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459125/
5. Ladd LM, Crews M, Maertz NA. Glenohumeral Joint Instability: A Review of Anatomy, Clinical Presentation, and Imaging. Clin Sports Med. 2021;40(4):585-599. doi:10.1016/j.csm.2021.05.001
6. Galvin JW, Ernat JJ, Waterman BR, Stadecker MJ, Parada SA.The Epidemiology and Natural History of Anterior Shoulder Instability. Curr Rev Musculoskelet Med. 2017;10(4):411-424. doi:10.1007/s12178-017-9432-5
7. Fares MY, Boufadel P, Daher M, Koa J, Khanna A, Abboud JA. Anterior Shoulder Instability and Open Procedures: History, Indications, and Clinical Outcomes. Clin Orthop Surg. 2023;15(4):521-533. doi:10.4055/cios23018
8. Wang C, Brisson BK, Terajima M, et al. Type III collagen is a key regulator of the collagen fibrillar structure and biomechanics of articular cartilage and meniscus. Matrix Biol. 2020;85-86:47-67. doi:10.1016/j.matbio.2019.10.001
9. Bokshan SL, DeFroda SF, Owens BD. Comparison of 30-Day Morbidity and Mortality After Arthroscopic Bankart, Open Bankart, and Latarjet-Bristow Procedures: A Review of 2864 Cases. Orthop J Sports Med. 2017;5(7):2325967117713163. Published 2017 July 3.
10. Kukkonen J, Elamo S, Flinkkilä T, et al. Arthroscopic Bankart versus open Latarjet as a primary operative treatment for traumatic anteroinferior instability in young males: a randomized controlled trial with 2-year follow-up. Br J Sports Med. 2022;56(6):327-332. doi:10.1136/bjsports-2021-104028