A novel suture technique for Achilles tendon repair: Superior biomechanical strength compared to krackow and bunnell methods

Abstract

Acute Achilles tendon rupture is common, particularly in middle-aged individuals engaged in high-intensity sports. While surgical repair is generally preferred for active patients, there is no consensus on the optimal suture technique. The strength and stability of tendon repair depend significantly on the suture method. This study introduces a novel percutaneous suture technique and compares its biomechanical performance with the well-established Krackow and Bunnell techniques. Eighteen fresh sheep Achilles tendons were divided into three groups and repaired using the Bunnell (Group 1), the Krackow (Group 2), and the novel suture technique (Group 3). Biomechanical testing was performed using an Instron mechanical testing device to measure maximum load, elongation at maximum load, and stiffness. Statistical analysis was conducted using the Kruskal-Wallis and Mann-Whitney U tests, with significance at p < 0.05. The novel suture technique demonstrated the highest maximum load (153.55±33.87 N) and stiffness (4.03±1.48 N/mm), significantly outperforming both the Bunnell and Krackow techniques (p = 0.037, and p = 0.010, respectively). No significant differences in elongation at maximum load were found between the groups (p > 0.05). Failure mode analysis showed that all tendons repaired with the novel technique failed by suture breakage, whereas the Bunnell and the Krackow groups exhibited both suture breakage and tendon pullout. The novel percutaneous suture technique provides superior biomechanical strength and stability compared to traditional methods, suggesting potential benefits for earlier mobilization and improved rehabilitation. However, its ex vivo nature and small sample size limit generalizability. Future in vivo studies and clinical trials are needed to confirm its long-term efficacy and clinical applicability, potentially reshaping Achilles tendon repair strategies.

Keywords

• Achilles Tendon Rupture
• Krackow
• Bunnell
• Biomechanical Study
• Novel Suture Technique

Ethical Statement

The study was conducted with approval from the Karabuk University Training and Research Hospital Clinical Research Ethics Committee of the university (Date: 26.04.2017, Decision No: 4/15).

References

1. Holm C, Kjaer M, Eliasson P. A chilles tendon rupture–treatment and complications: a systematic review. Scandinavian journal of medicine & science in sports. 2015;25(1):e1-e10.
2. Olsson N, Petzold M, Brorsson A, Karlsson J, Eriksson BI, Grävare Silbernagel K. Predictors of clinical outcome after acute Achilles tendon ruptures. The American journal of sports medicine. 2014;42(6):1448-55.
3. Heckman DS, Gluck GS, Parekh SG. Tendon disorders of the foot and ankle, part 2: achilles tendon disorders. The American journal of sports medicine. 2009;37(6):1223-34.
4. Reddy SS, Pedowitz DI, Parekh SG, Omar IM, Wapner KL. Surgical treatment for chronic disease and disorders of the Achilles tendon. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2009;17(1):3-14.
5. Thevendran G, Sarraf K, Patel N, Sadri A, Rosenfeld P. The ruptured Achilles tendon: a current overview from biology of rupture to treatment. Musculoskeletal surgery. 2013;97:9-20.
6. Daghino W, Enrietti E, Sprio AE, di Prun NB, Berta GN, Massè A. Subcutaneous Achilles tendon rupture: A comparison between open technique and mini-invasive tenorrhaphy with Achillon® suture system. Injury. 2016;47(11):2591-5.
7. Bunnell S. Repair of tendons in the fingers. Surg, Gynecol Obstet. 1922;35:88-97. Krackow K, Thomas S, Jones L. A new stitch for ligament-tendon fixation. Brief note. JBJS. 1986;68(5):764-6.
8. Bhandari M, Guyatt GH, Siddiqui F, Morrow F, Busse J, Leighton RK, et al. Treatment of acute Achilles tendon ruptures a systematic overview and metaanalysis. Clinical Orthopaedics and Related Research®. 2002;400:190-200.

9. DeVries JG, Scharer BM, Summerhays BJ. Acute Achilles rupture percutaneous repair: approach, materials, techniques. Clinics in podiatric medicine and surgery. 2017;34(2):251-62.
10. Čukelj jr F, Blažević D, Čukelj F, Sabalić S, Benčić I, Ćuti T, et al. Comparison of percutaneous and open repair of Achilles tendon rupture: results and complications from a single institution. BMC Surgery. 2024;24(1):47. doi: 10.1186/s12893-024-02333-2.
11. Kauwe M. Acute Achilles tendon rupture: clinical evaluation, conservative management, and early active rehabilitation. Clinics in podiatric medicine and surgery. 2017;34(2):229-43.
12. Al-Mouazzen L, Rajakulendran K, Najefi A, Ahad N. Percutaneous repair followed by accelerated rehabilitation for acute Achilles tendon ruptures. Journal of Orthopaedic Surgery. 2015;23(3):352-6.
13. Krueger H, David S. The effectiveness of open repair versus percutaneous repair for an acute Achilles tendon rupture. Journal of Sport Rehabilitation. 2016;25(4):404-10.
14. Ververidis AN, Touzopoulos P, Drosos GI, Tilkeridis KE, Kazakos KI. Percutaneous repair of the Achilles tendon rupture in athletic population. Journal of orthopaedics. 2016;13(1):57-61.
15. Guzzini M, Lanzetti RM, Proietti L, Mazza D, Fabbri M, Monaco E, et al. Interlocking horizontal mattress suture versus Kakiuchi technique in repair of Achilles tendon rupture: a biomechanical study. Journal of Orthopaedics and Traumatology. 2017;18:251-7.
16. Miyamoto W, Imade S, Innami K, Kawano H, Takao M. Acute Achilles tendon rupture treated by double side-locking loop suture technique with early rehabilitation. Foot & Ankle International. 2017;38(2):167-73.
17. Yammine K, Assi C. Efficacy of repair techniques of the Achilles tendon: a meta-analysis of human cadaveric biomechanical studies. The Foot. 2017;30:13-20.
18. Mait JE, Hayes WT, Blum CL, Pivec R, Zaino CJ, Jauregui JJ, et al. A biomechanical comparison of different tendon repair techniques. Journal of Long-Term Effects of Medical Implants. 2016;26(2).
19. Herbort M, Haber A, Zantop T, Gosheger G, Rosslenbroich S, Raschke MJ, et al. Biomechanical comparison of the primary stability of suturing Achilles tendon rupture: a cadaver study of Bunnell and Kessler techniques under cyclic loading conditions. Archives of orthopaedic and trauma surgery. 2008;128:1273-7.
20. Backus JD, Marchetti DC, Slette EL, Dahl KD, Turnbull TL, Clanton TO. Effect of suture caliber and number of core strands on repair of acute Achilles ruptures: a biomechanical study. Foot & Ankle International. 2017;38(5):564-70.
21. Docheva D, Müller SA, Majewski M, Evans CH. Biologics for tendon repair. Advanced Drug Delivery Reviews. 2015;84:222-39. doi: https://doi.org/10.1016/j.addr.2014.11.015.
22. Carmont MR, Rossi R, Scheffler S, Mei-Dan O, Beaufils P. Percutaneous & Mini Invasive Achilles tendon repair. Sports Med Arthrosc Rehabil Ther Technol. 2011;3:28. Epub 20111114. doi: 10.1186/1758-2555-3-28. PubMed PMID: 22082172; PubMed Central PMCID: PMC3227582.