Carson Benner

Background: The meniscus consists of two semilunar structures in the knee joint responsible for shock absorption and cartilage protection.¹ Many ordinary and athletic activities can produce excessive rotational or shear forces that damage these structures, making meniscal tears are a common orthopedic injury. The incidence of meniscal tears is conservatively estimated at 60 per 100000, and this condition accounts for two-thirds of knee injuries in the general population.^2,3 Despite numerous surgical approaches, there exists a persistent lack of high-level evidence to guide management of meniscal tears.^4-6 The outcomes of meniscal resection, inside-out (IO) meniscal repair, and all-inside (AI) meniscal repair in both athletes and the general population will be comparatively evaluated here.

Search Method: PubMed searches included, but not limited to, the terms: “meniscal repair”, “all inside meniscal repair,” “inside out meniscal repair,” and “meniscal repair outcomes.”

Results: Compared to meniscal repair, meniscal resection offers a lower short-term reoperation rate in the general population and a more rapid return to play (RTP) for elite athletes.^5,7 However, meniscal repair is associated with reduced rates of advanced knee osteoarthritis, decreased progression to knee arthroplasty, and longer athletic careers in the long term.^5-8 In the general population, AI repairs are associated with greater rates of implant site irritation, and IO repairs are associated with greater rates of neurovascular injury, but overall complication rates, failure rates, and clinical outcomes do not differ significantly between techniques.^4,9  Athletes with AI repairs report a significantly higher rate of RTP at a pre-injury level, but rates of re-injury and chronic pain are significantly lower for IO repairs.^6,10 AI and IO repairs have been shown to have different biomechanical properties. AI repairs have higher stiffness and primary fixation strength values than IO repairs, but the repair devices can eventually induce fatigue damage leading to repair failure.^5,11 IO sutures are smaller, meaning greater suture densities and theoretically more durable repairs can be achieved.⁶

Conclusions: Meniscal repair offers superior long-term outcomes to meniscal resection in both athletes and the general population. AI and IO techniques produce minimal differences in outcomes in the general population, but outcomes differ meaningfully between techniques in athletes. AI repairs appear to offer improved short-term performance upon RTP, while IO repairs seem to produce better long-term rates of re-injury and chronic pain. These results could be mediated by differences in mechanical properties between repair types. Further research is essential to understand the interplay between repair techniques and other factors for surgical planning.

Works Cited:

1. Doral MN, Bilge O, Huri G, Turhan E, Verdonk R. Modern treatment of meniscal tears. EFORT Open Rev. May 2018;3(5):260-268. doi:10.1302/2058-5241.3.170067
2. Bhan K. Meniscal Tears: Current Understanding, Diagnosis, and Management. Cureus. Jun 13 2020;12(6):e8590. doi:10.7759/cureus.8590
3. Ekhtiari S, Khan M, Kirsch JM, Thornley P, Larson CM, Bedi A. Most elite athletes return to competition following operative management of meniscal tears: a systematic review. Journal of ISAKOS. 2018;3(2):110-115. doi:10.1136/jisakos-2017-000181
4. Nepple JJ, Dunn WR, Wright RW. Meniscal repair outcomes at greater than five years: a systematic literature review and meta-analysis. J Bone Joint Surg Am. Dec 19 2012;94(24):2222-7. doi:10.2106/jbjs.K.01584
5. Smoak JB, Matthews JR, Vinod AV, Kluczynski MA, Bisson LJ. An Up-to-Date Review of the Meniscus Literature: A Systematic Summary of Systematic Reviews and Meta-analyses. Orthop J Sports Med. Sep 2020;8(9):2325967120950306. doi:10.1177/2325967120950306
6. Borque KA, Laughlin MS, Webster E, Jones M, Pinheiro VH, Williams A. A Comparison of All-inside and Inside-out Meniscal Repair in Elite Athletes. The American Journal of Sports Medicine. 2023;51(3):579-584. doi:10.1177/03635465221147058
7. Paxton ES, Stock MV, Brophy RH. Meniscal Repair Versus Partial Meniscectomy: A Systematic Review Comparing Reoperation Rates and Clinical Outcomes. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2011/09/01/ 2011;27(9):1275-1288. doi:https://doi.org/10.1016/j.arthro.2011.03.088
8. Migliorini F, Schäfer L, Bell A, Weber CD, Vecchio G, Maffulli N. Meniscectomy is associated with a higher rate of osteoarthritis compared to meniscal repair following acute tears: a meta-analysis. Knee Surg Sports Traumatol Arthrosc. Dec 2023;31(12):5485-5495. doi:10.1007/s00167-023-07600-y
9. Grant JA, Wilde J, Miller BS, Bedi A. Comparison of inside-out and all-inside techniques for the repair of isolated meniscal tears: a systematic review. Am J Sports Med. Feb 2012;40(2):459-68. doi:10.1177/0363546511411701
10. Migliorini F, Asparago G, Oliva F, Bell A, Hildebrand F, Maffulli N. Greater rate of return to play and re-injury following all-inside meniscal repair compared to the inside-out technique: a systematic review. Arch Orthop Trauma Surg. Oct 2023;143(10):6273-6282. doi:10.1007/s00402-023-04933-8
11. Bachmaier S, Krych AJ, Smith PA, et al. Primary Fixation and Cyclic Performance of Single-Stitch All-Inside and Inside-Out Meniscal Devices for Repairing Vertical Longitudinal Meniscal Tears. Am J Sports Med. Aug 2022;50(10):2705-2713. doi:10.1177/03635465221107086