4.0. New strategies of meniscal tears management: A review

https://doi.org/10.30574/wjarr.2021.10.3.0234 Abstract The incidence of meniscal tear injuries is rising, predominately due to the sporting activities of young adults. There are different methods in orthopedics of meniscal tear management. An Arthroscopic Partial Meniscectomy (APM) is the most practiced orthopedic procedure globally. However, recent literature reported serious concerns about its positive outcome. Meniscal repair is another recommended technique and growing rapidly due to its less incision requirement. Partial Meniscal implant is a modern management strategy with the excellent outcomes but still required further large-scale research. Concluding to the modern strategies of meniscus tear management “Save the meniscus!” is the emerging approach. This review critically analyzed the most adapted management strategies of meniscal tear and the emerging


Introduction
Meniscal tear is the most commonly reported pathology of the knee joint with a yearly incidence of 66 per 100000 [1,2]. The affected groups are generally the young people, sports personnel, and elderly ones with an excessive annual cost burden [3]. Initially, it was assumed that a meniscus has no functional ability and mostly responded to open total meniscectomy [4]. Reportedly, there are two menisci in the literature, U-shaped (medial) and S-shaped (lateral) [2]. The associated risk factors are also summarized in two ways with firm supporting evidence; first is the male gender, older age > 60 years, activity-related kneeling, stairs climbing, and squatting. The other one is the daily sitting activity for more than 2 hours at least, minimizing the risk of Meniscal tears strongly [1,5]. Additionally, the acute presentation of Meniscal tear is associated with playing sports like soccer and rugby, and 12 months time span between Anterior Cruciate Ligament (ACL) injury and its alignment and reconstruction [1,5].
A comprehensive clinical examination, especially the patient's history gives the major clue of the meniscal tear. Patient of meniscal tear usually presents with a complaint of pain, swelling, sensation or sound during injury. The usual mechanical symptoms are popping, range limitation during movement, joint lock, catching, etc. The important factor which should be considered during treatment, that severity and type of pathology are not linked with symptoms and clinical presentation of the patient [6].
The classification of meniscal tears depends upon its orientation, etiology, and MRI; and presented as vertical longitudinal, vertical radial, horizontal, oblique, or complex [3,7]. The International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine classifies the meniscal tear in a concise, and reliable manner depends upon the depth of tear, its pattern, length, radial position, and tissue quality [8]. The traumatic longitudinal-vertical and degenerative tears are usually found in active young individuals and in elderly people. The most usual sites seen are the medial meniscus and the posterior horn of the menisci [3,9].
There are many strategies reported for the management of meniscal tears, some are traditional and some modern ones. The management decision depends upon several factors; such as patient's age, level of physical activity, lifestyle, health status, associated risks, location, type of lesion, tissue quality, etc. An orthopedic surgeon should gather all information of history, examination, radiological findings, and clinical expertise to finalize a management decision [1,3].
The adapted management ways of Meniscal tears are;

Non-operative management
Minor outlying tears in young individuals can be managed without surgical procedures. The trouble in these cases is to decide the stability of the tear. Studies reported that stable and firm vertical tears of the peripheral areas have potentially high healing responses [10]. Physiotherapy is another helpful approach in individuals with degenerative meniscus tears. In the former circumstances, the 'PRICE' process was followed. PRICE is the "protection, rest, ice, compression, elevation" protocol. This non-operative management protocol was advisable to follow for approximately three to six months. Anti-inflammatory and analgesic therapeutics, strengthening of quadriceps, modification of daily activities, unloader bracing and intra-articular injectable shots, etc. are helpful ways of non-operative management. In case, of unsuccessful outcome of a non-operative procedure, the surgical or operative management procedure will choose, according to the patient's condition [1,11,12].

Total meniscectomy
Total meniscectomy is the obsolete treatment choice and rarely practiced now. The development of arthroscopic techniques better understand the biomechanics of meniscal tear and treatment option shifted towards the shielding of the meniscus tissue rather than its removal [3,13].

Open repair
Open repair was one of the initial procedures of meniscus tear repairing [15].

Arthroscopic repair
An Arthroscopic Partial Meniscectomy (APM) is currently the most adapted technique of meniscal tear management and one of the most performed surgical procedures in orthopedics [13,14]. Though, new scientific studies reported that APM does not have a superior outcome after a sham/placebo surgical procedure [16]. Many other scientific studies labeled it as a useless procedure, and which also endorsed by recent guidelines and recommendations in opposition of this surgical procedure [17].

Meniscal rasping
Meniscal rasping is followed to clean the shred outlines of the meniscus. This procedure is mostly advisable in stable and longitudinal meniscal tears, seen in the vascular regions. If a patient had an unstable knee or rupturing seen in the vascular region, this approach is not suitable [13].

Meniscal suturing
Traditionally, meniscal suturing gives the most satisfactory results in longitudinal tears. Stable knee is the most important recovery indicator. Meniscal suturing in unstable knee leads to treatment failure. Recent studies also reported positive outcomes of meniscal repair in cases of full-thickness radial tears [18].

Meniscal suturing techniques -Outside-in meniscal suturing techniques
This was the primary arthroscopic node methodology and now the minimum used technique. This was fit for middle and anterior tear found 1/3 section of the meniscus. The disadvantage of this technique is to trouble in reaching the extended tears [13].

Meniscal suturing techniques -Inside-out meniscal suturing techniques
This technique has vast application and can be adapt to tears of every site, but more reliable for rear and middle 1/3 section tears. The disadvantage of this technique is the requirement of second incision and this technique is also dangerous in the posterior insertion of the meniscus [13].
This systemic review was designed to see the evolution in management strategies of meniscal tear from past to the new decade.

Meniscal Allograft Transplantation [MAT]
MAT is also emerging these days but it's actually not a new idea. It was initially reported in the beginning of 1990s [3].

Study Selection Criteria
Two authors were designated to perform an extensive data search in electronic databases including Cochrane, Pubmed, and Google scholar up to December 2020. No restrictions of age, gender, and language were imposed. Diverse keywords were used to avoid any data loss (Meniscal tears and Management OR Meniscal tears and treatment OR Meniscal tear OR Meniscal tear and management techniques OR Meniscal tear and techniques).

Inclusion and Exclusion Criteria
The defined inclusion criteria was (1) Published studies on the management of meniscal tears and evaluating any specific techniques (2) No age and gender restriction, People of all age groups and both genders were included (3) All management strategies either surgical or non-surgical were used. (4) All studies must be published as full-text studies (5) all included studies were published in the English language.
The exclusion criteria was: (1) Incomplete Studies (2) Any poster, oral or Scientific Conference Presentations (3) Opinion articles, and Case reports (4) Reviews and Meta-analysis.

Study selection
Two authors independently screen the extracted data and compile the study selection. Disagreements were identified and resolved by mutual discussion of all authors and agreement done for final selection of studies. The full version of selected articles was retrieved for further evaluation and selection confirmation.

Data extraction
Data was extracted twice by two different authors as per defined criteria and keywords, to avoid any risk of bias [19].

Methodology Statement
This review has following the Preferred Reporting Items for Systematic Reviews and Metanalysis (PRISMA) statement for selection process of studies [15]. There were no restrictions imposed on different population group, race, origin, ethnicity, and language. PRISMA flow diagram preferred Reporting Items for Systematic Review and Meta-Analysis

Results and discussion
The data from selected studies suggested that from 1998 till now; after evaluating 2 decades of meniscal tear management, suturing technique and the Arthroscopic Meniscectomy was the most adapted ones, see Table  1. Arthroscopic Meniscectomy and Meniscal repair specifically seen mostly in the last decade. However, different studies adapted other comparative methods also such as Physical therapy and conservative methods. The recent studies also reported the evaluation of TKA, F-MMA.
There are different modern approaches published which reportedly have a better outcome and designed due to related disadvantages of conventional treatment options. Meniscus fixators are one of the methods which evolve due to the related concerns of incisions and vascular complications of the sewing method. This method is technically more superior with no complexities of incision and vascular problems. There are some serious concerns also associated with Meniscus fixators such as reduced mechanical force, and destruction of articular cartilage [13].
There are some healing methods which also described in the literature to provide relief in meniscal tear. These methods are Fibrin clot technique, Trephination technique, Synovial abrasion, Synovial flap transfer, Texture adhesives, Growth factors in the meniscus repair, Rehabilitation in patients with meniscus repair, Scaffolds, Meniscus transplantation, and Allograft transplantation.

Modern Management Approach
The current scientific literature emphasizing the shifting of meniscus management from resection to preservation, repair, rectify, and reconstruction. However, several factors influence this approach such as patient's age, associated comorbidities, presenting symptoms, meniscus type, and location [63]. Meniscal repair is one of the recommended techniques from the listed ones, having advantages of its effectiveness, and viability, and short-term outcomes with a minimum failure rate of <10%. Other techniques like suturing and meniscal fixators have failure rates of 23 to 30% [13].
Other healing reducing methods are also emerging and meniscal allografting is the most reported one. It's a complicated procedure with 89.2% follow-up survival [64]. FDA also recently approved a meniscal scaffold which is less complicated and less invasive. Partial meniscal substitute is another emerging option, which restores load balance across the knee and creates a chondroprotective effect [13].

Conclusion
Meniscal tears, although a most frequent orthopedic concern, still a challenge to manage. The management of meniscal tears is evolving from the 1800s which leads to total resection in the 1970s. Presently, the modern approach of meniscal management is "Save the meniscus" rather take it out. This "Save the meniscus" approach leads to new and better alternatives in the coming future.