Discoid meniscus: Treatment considerations and updates

Abstract

A discoid meniscus is a morphological abnormality wherein the meniscus loses its normal ‘C’ shape. Although most patients are asymptomatic, patients might still present with symptoms such as locking, pain, swelling, or giving way. Magnetic resonance imaging is usually needed for confirmation of diagnosis. Based on a constellation of factors, including clinical and radiological, different approaches are chosen for the management of discoid meniscus. The purpose of this review is to outline the treatment of discoid meniscus, starting from conservative approach, to the different surgical options for this condition. The PubMed and Google Scholar databases were used for this review. Studies discussing the treatment of discoid meniscus from 2018 to 2023 were searched. Initially there were 369 studies retrieved, and after removal of studies using the exclusion criteria, 26 studies were included in this review. Factors such as stability, presence of tear, and morphology can help with surgical planning. Many approaches have been used to treat discoid meniscus, where the choice is tailored for each patient individually. Postoperatively, factors that may positively impact patient outcomes include male sex, body mass index < 18.5, age at symptom onset < 25 years, and duration of symptoms < 24 months. The conventional approach is partial meniscectomy with or without repair; however, recently, there has been an increased emphasis on discoid-preserving techniques such as meniscoplasty, meniscopexy, and meniscal allograft transplantation.

Key Words: Discoid meniscus, Saucerization, Partial meniscectomy, Meniscoplasty, Meniscopexy, Meniscal allograft transplantation, Arthroscopy, Knee

Core Tip: Discoid meniscus can be treated both conservatively and surgically. Conservative approach is mainly used for asymptomatic patients, or for patients whose daily activities are not affected. The classic surgical approach for discoid meniscus had always been partial meniscectomy. Nevertheless, there are newer techniques developed aimed at preserving the meniscus like meniscoplasty, meniscopexy, and meniscal allograft transplantation. This study aims to compare the outcomes of the aforementioned techniques and compare them to one another using standardized criteria including the Knee Documentation Committee scores and Lysholm scores.

INTRODUCTION

A discoid meniscus is a morphological abnormality wherein the tibial plateau is covered with a wide and thick meniscus[1] rather than the normal “C” shape. This abnormality can affect either meniscus; the incidence ranges from 0.4% to 17% for the lateral meniscus and from 0.06% to 0.3% for the medial meniscus[2]. Multiple studies have shown variance in prevalence; according to Kim et al[2], the prevalence ranged from 3% to 5%. There are also discrepancies in the prevalence of bilateral knee involvement. According to Yang et al[3], the prevalence of bilateral knee involvement ranges from 79% to 97%. In 1969, Watanabe et al[4] first proposed a classification system for the discoid lateral meniscus (DLM) (Figure 1). The types include complete DLM, incomplete DLM, and Wrisberg DLM. A complete DLM (type I) (Figure 1A) is a meniscus that covers the entire lateral tibial plateau and has a normal posterior attachment. Incomplete DLM (type II) (Figure 1B) refers to a meniscus that covers most of the lateral tibial plateau with normal posterior attachment as well. Wrisberg DLM (type III) (Figure 1C) has normal discoid morphology but lacks posterior attachment (popliteomeniscal fascicles) and only has the Wrisberg ligament attached; hence, it is more susceptible to “snapping knee syndrome”. Regarding clinical presentation, most patients are asymptomatic and diagnosed incidentally during arthroscopy or magnetic resonance imaging (MRI) assessment[5]. Various factors play a role in patient presentation, such as patient age, meniscal instability, and the presence of associated lesions[5]. The usual symptoms are “snapping knee”, which can be seen in type III or when there is a tear in the meniscus. On physical examination, there might be an audible snap on terminal extension (10°–20°), along with swelling, locking, or pain[6]. Because most patients describe their symptoms as intermittent, vague, and slow in onset and because of the low accuracy rate of the physical examination (29% to 93%)[6], imaging is almost always needed for a definitive diagnosis. Imaging for discoid meniscus includes plain radiographs, ultrasound, and MRI. The standard practice is to start with knee X-ray with standard anterior-posterior, lateral, tunnel, and skyline views. According to Yaniv et al[6], “Lateral joint space narrowing, squaring of the lateral femoral condyle, cupping of the lateral tibial plateau, tibial eminence hypoplasia, and fibular head elevation may be demonstrated” on plain radiographs. Ultrasound can also be used for the diagnosis of meniscal pathology. Achour et al[7] studied the use of ultrasound in 8 pediatric patients aged 6 to 11 years. Their criteria for a discoid meniscus were loss of a normal triangular shape, abnormal elongation and thickness and a heterogeneous central pattern. Arthroscopy confirmed ultrasound findings in all patients involved in their study. Despite this, MRI is considered the gold standard in the diagnosis of discoid meniscus. In 1989, Silverman et al[8] established criteria for the diagnosis of discoid meniscus using the following five MRI features: (1) Three or more 5-mm slices with continuity between the anterior and posterior horns (bow-tie sign) (Figure 2); (2) augmented upper-lower height in the mid-zone generating a bow-tie shape in the sagittal view; (3) differences in size between the anterior and posterior horn, which are usually symmetrical; (4) coronal sections showing a complete meniscus in all sections from anterior to posterior through the knee, which is normally only present in the anterior and posterior sections; and (5) coronal sections showing an increase in transverse diameter ≤ 15 mm or ≤ 20% of the total tibial width. Traditionally, asymptomatic patients with discoid menisci discovered incidentally have been treated conservatively with a ‘wait and see’ approach. Additionally, patients complaining only of ‘snapping’ can also be treated conservatively as long as the function is preserved since the knee has adapted to the discoid anatomy[9]. It only becomes necessary to operate when patients develop symptoms such as pain, locking, swelling, effusion, giving way, or instability[10]. For symptomatic stable knees, total meniscectomy was historically the treatment of choice[11]. Later, it was noted that total meniscectomy is a risk factor for osteoarthritis, and partial meniscectomy, along with other meniscus-preserving approaches, has been more commonly used[12].

Figure 1 Watanabe classification of the discoid lateral meniscus. A: A complete discoid lateral meniscus (DLM) (type I) is a meniscus that covers the entire lateral tibial plateau and has a normal posterior attachment; B: Incomplete DLM (type II) refers to a meniscus that covers most of the lateral tibial plateau with normal posterior attachment as well; C: Wrisberg DLM (type III) (has normal discoid morphology but lacks posterior attachment (popliteomeniscal fascicles) and only has the Wrisberg ligament attached.

Figure 2  Bow-tie sign.

In this review, treatment strategy and considerations were divided into three sections: pretreatment, treatment, and posttreatment.

Source of information, search terms, and delimiting

The PubMed and Google Scholar databases were searched on April 17, 2023. The following MeSH terms were used in the search strategy: “discoid lateral meniscus”, "discoid medial meniscus", “treatment", and “surgery”.

Inclusion and exclusion criteria

The inclusion criteria were studies that discussed discoid meniscus treatment and management that were published between January 2018 and April 2023. Eligible study types included reviews, original articles, prospective studies, retrospective studies, and case series. Non-English studies, animal studies, case reports, opinionated articles, articles criticizing older studies, editorials, in vitro studies, and studies published before 2018 were not included. In addition, articles discussing the management of meniscus pathologies other than discoid meniscus were excluded.

Data extraction

In accordance with the aforementioned criteria, data were extracted, and a spreadsheet was used for data input. The extracted information included the author’s name, year of publication, type of study, number of patients, whether medial or lateral discoids were studied, title of the study, and conclusion/outcome of the study. A total of 369 studies were initially retrieved. After removing non-English studies and studies on animals, 314 studies remained. A total of 271 studies were irrelevant or met at least one of the exclusion criteria, and 17 studies were duplicates. Therefore, 26 studies were ultimately included (Figure 3). Twenty-four studies involved the discoid lateral meniscus, and only 2 involved the discoid medial meniscus.

Figure 3  Flowchart summarizing the identification and selection of articles.

Pretreatment

The classification system for DLM proposed by Watanabe et al[4] is based on the morphological abnormality seen within the meniscus. However, this classification system cannot be used for surgical planning. Yang et al[3] proposed a system to help with surgical planning. Their aim was to distinguish patients in need of saucerization with repair from those who need saucerization without repair. In their proposed classification system, menisci were classified by stability [Stable (S0), Unstable (S1), morphology (Incomplete (M0), Complete (M1)], and tear [No tear (T0), Central tear, isolated (T1), or Central tear, peripheral extension (T2)]. They claim that this system is easy to remember and helps with surgical planning. In their study, they found that patients with unstable knees had 114 times higher odds of undergoing repair than patients with stable knees. Additionally, discoid menisci with peripherally extending tears had 6.4 times higher odds of undergoing repair than those that had an isolated central tear.

Treatment

Conservative management: As previously mentioned, treatment of the discoid meniscus has been divided into conservative and surgical treatments. However, it remains unclear when the conservative approach should be chosen. According to Yang et al[13], there are three indications for a conservative approach: if the lesion is asymptomatic and discovered incidentally; if the clinical manifestations are mild and do not affect daily activities or general sports; and if the symptoms are severe and caused by another concomitant disease, such as osteoarthritis or rheumatoid arthritis. Their rationale was to treat the combined disease before arthroscopy for discoid meniscus. The authors described the conservative approach as physical therapy and avoidance of overload in sports activity. In another study by Tapasvi et al[14], the authors advised that if symptoms are present without locking, then a conservative approach should be tried first. They also advised the use of physiotherapy for a conservative approach, while they claimed that there is no evidence supporting the notion that exercise keeps DLM asymptomatic. Regarding the success rate of conservative therapy, a study by Logan et al[15] examined the clinical data of 401 patients, 83 of whom underwent conservative management instead of surgery. The failure rate was 39% (32/83), and those patients had to be switched to surgical treatment.

Surgery

Prophylactic surgery: Saavedra et al[16] advised against the use of prophylactic surgery in the asymptomatic contralateral knee in a symptomatic patient. They claim that the natural history of discoid meniscus is not well understood and that patients can resume their lives normally; moreover, there is no emphasis on educating the patient to seek medical advice if they start developing symptoms[16].

Partial meniscectomy with or without repair: According to Yang et al[3], there are two indications for surgical treatment: whether the discoid meniscus lesion has an impact on the patient's daily life and general sports and if the symptoms are mild but the patient is young. In their study, they mentioned options for surgical intervention, including partial meniscectomy (such as saucerization or reshaping), partial meniscectomy with repair, subtotal or total meniscectomy, and meniscal allograft transplantation. Many factors play a role in the choice of the approach, including patient age, DLM classification, types and location of DLM lesions, knee stability, and sports demand. The authors suggest that partial meniscectomy is a good choice because it preserves meniscus width and thickness. Additionally, they suggest that meniscal allograft transplantation can be used for young patients with damaged DLMs and higher sports demand. Nicholson et al[17] and Perkins et al[18] claim that if partial meniscectomy is performed, the remaining meniscal tissue should be inspected thoroughly both for the presence of instability and for residual tears. Nicholson et al[17] added that tears should be repaired with a combination of all-inside sutures placed into the posterior horn, inside-out sutures placed into the midbody, and outside-in sutures placed into the anterior horn.

There is controversy regarding how much meniscus should be kept, but most researchers agree that 6 mm to 8 mm of the periphery should be kept[19]. Moreover, for the unstable type, repair of the posterior tibial detachment is necessary to prevent osteoarthritis[20]. It should be noted that after saucerization, the remaining meniscus is at risk for tearing since the abnormally thick structure of the meniscus is still present[21]. One complication of meniscus surgery observed after either partial or total meniscectomy is called osteochondritis dissecans (OCD) of the lateral femoral condyle. It is thought that repeated impaction in the immature chondral structure after resection of the discoid meniscus might be the cause of OCD[22].

Dai et al[23] wanted to determine whether platelet-rich plasma (PRP) had any effect on the discoid meniscus after a patient underwent arthroscopic saucerization. The study included 29 patients with DLM tears within a stable knee that was arthroscopically treated with meniscal suture repair. Fourteen of those received PRP, and 15 did not. Patients were evaluated at baseline (the day before surgery) and then 12 and 24 months after the last injection. The scores that were used for evaluation were the Lysholm score, Ikeuchi grade, and visual analog scale (VAS) score for pain and failure rate. The authors defined failure as patients developing symptoms of joint line pain, locking, swelling or requiring repeat arthroscopy. The study showed that there was no difference in the failure rate between the PRP group (1 in 14) and the non-PRP group (1 in 15). Nevertheless, both groups had statistically significant improvements in the Lysholm score, the Ikeuchi grade and the VAS score for pain.

Meniscoplasty: In most of the literature, partial meniscectomy with or without repair is recommended as the standard procedure for the treatment of discoid menisci. However, Ng et al[24] considered meniscoplasty to be the gold standard in the treatment of discoid menisci. The aim of meniscoplasty is to recreate the semilunar morphology of the lateral discoid meniscus, which is achieved by resection of the ‘discoid’ portion of the meniscus. An arthroscopic radiofrequency wand is used to make a more precise meniscal cut while avoiding damage to the underlying chondral surface. The meniscus is debrided and 8 mm of the rim is preserved, as Hayashi et al[25] showed higher rates of meniscal retear when more than 8 mm of the rim was preserved. In their study, 24 knees had undergone meniscoplasty with or without concomitant meniscal repair or partial meniscectomy. Patients had a mean follow-up of 84 months. The Lysholm score and Ikeuchi grade were used for assessment. The authors concluded that meniscoplasty improved mid-term to long-term outcomes for children and adolescents with discoid lateral meniscus. Additionally, concomitant meniscal repair or partial meniscectomy did not improve or worsen mid-term to long-term outcomes in the same patients.

Meniscopexy: One of the side effects of meniscectomy is osteoarthritis. According to Johnson et al[26] 15%-34% of meniscus resections lead to an increase of 350% in tibiofemoral contact pressure. They reported that partial or total meniscectomy is a risk factor for early-onset knee osteoarthritis in children. In their paper, they described the outcomes of meniscopexy, which is a meniscus-sparing technique used to treat discoid menisci. After freeing the anterior horn of the lateral meniscus from the overlying fat pad, heavy stay sutures are passed through the anterior horn and utilized to pull the lax portion of the meniscus anteriorly. Once the meniscus has been subluxed anteriorly, the lax tissue behind the condyle no longer leads to clicking during flexion or extension. Fluoroscopy is then used to identify the bony epiphysis of the proximal tibia, and a linear bed is prepared for the anterior rim of the meniscus. The meniscus is firmly held in place with two or three bone anchors[26]. There were 11 patients (12 knees) with MRI-confirmed DLM who underwent the procedure. The median follow-up duration was 4.5 years (2-14), and the median Lysholm knee score postoperatively was 91 (86-100). MRIs that were performed postoperatively all showed normalization of meniscal morphology with time. They concluded that meniscopexy is an effective alternative to partial meniscectomy for the management of symptomatic discoid lateral meniscus without meniscal tears[26].

Meniscal allograft transplantation: Another modality of treatment aimed at circumventing osteoarthritis-related meniscectomy is meniscal allograft transplantation (MAT). Wang et al[27] compared the outcomes of patients with DLM treated with MAT or partial meniscectomy. In the follow-up, Lysholm, the International Knee Documentation Committee (IKDC), Tegner and VAS scores were used for assessment. The authors concluded that compared to meniscectomy, MAT achieved similar long-term symptom relief and reduced the incidence of osteoarthritis development in discoid meniscus patients. Table 1 summarizes conservative and surgical options for the treatment of discoid meniscus.

Table 1 Summary of conservative and surgical options in the treatment of discoid meniscus.

Conservative therapy	Physical therapy
	Prevention of overload sports
Surgical options	Partial meniscectomy with or without repair
	Meniscoplasty
	Meniscopexy
	Meniscal allograft transplantation

Because of the low prevalence of discoid medial meniscus (DMM) compared to DLM, few studies have discussed the management of DMM. A study by Anderson et al[28] included 21 patients with 22 knees with a discoid medial meniscus. All 22 knees had undergone arthroscopic saucerization, 7 of which had torn menisci and had also undergone repair. Four of the 7 knees that underwent repair had to undergo reoperation. They concluded that there is a strong association between a torn DMM and the need for reoperation (P = 0.0048). They also concluded that there is no major difference in the presentation or management between DMM and DLM. Another study by Feroe et al[29] had 446 knees diagnosed arthroscopically with discoid meniscus; DLM was observed in 434 knees (97.3%), and DMM was observed in 12 knees (2.7%). Again, presentation and management were similar to those with DLM. Postoperatively, patients showed good symptom resolution in the short term; however, in the long term, retears were observed in 4/11 knees (36%) at a mean of 25.8 months postoperatively.

A summary of the surgical procedure used and outcomes is presented in Table 2.

Table 2 Summary of surgical procedure used and outcomes.

Ref.	No. of patients	Mean age (range)	DLM/DMM	Procedure	Mean follow-up and results
Perkins et al[18]	44	12.4 (5-17)	DLM	Arthroscopic meniscus repair	At 19 months: Saucerization and repair of discoid lateral meniscus tears in the pediatric population have good outcomes with low rates of reoperation
Anderson et al[28]	21 (22 knees)	12.8 (9-16.6)	DMM	Arthroscopic saucerization; repair for torn menisci	At 24 months: Tears were present in over half of knees with discoid medial menisci, and reoperation was more common in knees that underwent repair of tears than those without repair
Feroe et al[29]	8 (12 knees)	13.8 (7.8-19.8)	DMM	Arthroscopic saucerization; repair for torn menisci	At 25.8 months: Symptom resolution is common short-term, but long-term outcomes include recurrent meniscal tears
Dai et al[23]	29	Not available	DLM	Group A (14); PRP augmented; Group B (15) non-PRP augmented	At 24 months: No significant difference observed in the Lysholm score, the Ikeuchi grade and the VAS score for pain at the last follow-up between the two groups
Ng et al[24]	24 (24 knees)	14 (8-21)	DLM	Meniscoplasty	At 84 months: Lysholm score; Preop: 53 (11-95) vs postop: 100 (60-100); Ikeuchi grade; 23 patients (excellent), 1 patient (good)
Johnson et al[26]	11 (12 knees)	9 (6-14)	DLM	Meniscopexy	At 4.5 yr: Lysholm score, 91 (86-100)
Wang et al[27]	18	Not available	DLM	Group A (8) MAT; Group B (10) ME	At 12 yr: No difference in Lysholm, IKDC, Tegner or VAS scores among both groups. Compared to meniscectomy, MAT achieved similar long-term symptom relief and superior chondroprotection in discoid meniscus patients

DLM: Discoid lateral meniscus; DMM: Discoid medial meniscus; PRP: Platelet-rich plasma; VAS: Visual analog scale; MAT: Meniscal allograft transplantation; ME: Meniscectomy; IKDC: International Knee Documentation Committee.

Technical consideration: As previously discussed, the standard surgical approach for discoid meniscus injury is arthroscopy. Zhou et al[30] claim that the conventional arthroscopic technique makes visualizing and excising the lower layers of an injured meniscus difficult, even for experienced surgeons. In their retrospective study of 60 patients with injured discoid menisci, they used a technique called the assisted inferior anterolateral portal under the anterior horn of the lateral meniscus (UAHLM portal). The authors claim that this technique is convenient for arthroscopic discoid meniscoplasty and meniscus repair. Fifty-four of the 60 patients did not need to undergo reoperation. Patients showed improved Lysholm and IKDC scores when followed up at 24 and 48 months.

Posttreatment

Postoperative lower limb axial alignment: In a study by He et al[31], 161 patients with lateral meniscal tears underwent partial meniscal resection. They were divided into a discoid meniscus group (DMG) and an ordinary meniscus group (OMG). Preoperative and postoperative full-length weight-bearing radiographs of the lower limb were obtained and used to measure the mechanical axis deviation (MAD), proximal tibia angle (PTA), and distal femoral angle (DFA) in the axial alignment of the lower limb. There was a statistically significant difference in the MAD and DFA in both groups postoperatively; the MAD and DFA decreased. There was a statistically significant difference in the PTA in the DMG group; it became larger. Additionally, there was no statistically significant difference in the PTA in the OMG group postoperatively. Another study by Zhang et al[32] assessed the axial alignment of 60 patients who underwent either meniscectomy or meniscoplasty for their DLM. The results showed that there were apparent changes in the lower limb axial alignment after surgery (P < 0.01). The changes were more noticeable after total meniscectomy than after meniscoplasty but were insignificant (P > 0.05).

Factors influencing postoperative outcomes in patients with DLM: A study by Yang et al[33] included 502 patients who underwent arthroscopic surgery for their DLM. Knee function was assessed using IKDC score. Out of 14 variables that were chosen as factors for this study, the authors claim that male, body mass index (BMI) < 18.5 kg/m², age at onset < 25 years (especially < 14 years) and symptom duration < 24 months are conducive to good postoperative outcomes. In a different study conducted by the same author[34], the postoperative results worsened with increasing BMI, work intensity, age at onset, duration of symptoms, and severity of cartilage lesions. The aim of another study conducted by Ohnishi et al[35] was to determine whether age or type of procedure had any effect. Patients were divided into 2 groups. The first group had 16 patients aged < 13 years, and the second group had 36 patients aged 13 years and above. IKDC scores and Lysholm scores were used for assessment. Additionally, the Kellgren-Lawrence classification was used for radiographic evaluation of degenerative changes. All patients had undergone saucerization only or saucerization with repair or centralization. Patients were followed up for 30 months (range 24-72). The results showed that patients < 13 years old had better IKDC scores than the other group; however, there was no difference in degenerative changes using the Kellgren-Lawrence classification. Additionally, no differences were found at the final follow-up between saucerization only and saucerization with repair or centralization across both groups. Although Yang et al[33] and Yang et al[34] and Ohnishi et al[35] suggest that age plays a role in good postoperative outcomes, Su et al[36] claim that sex and age do not affect IKDC or Physical Activity Questionnaire scores. Finally, Yang et al[3] found multiple factors that affect postoperative outcomes, whether they bring satisfactory or worse outcomes. The only satisfactory outcome was seen in younger patients. Additionally, factors associated with worse outcomes were high BMI, high labor intensity, longer duration of symptoms and total meniscectomy (cartilage degeneration), instability (higher retear chances), and smaller width and thickness of the remnant meniscus (higher chance of extrusion). Although most studies claim that younger age is associated with favorable clinical outcomes, Kim et al[2] agree with this finding but argue that retear is still associated with younger age. Lins et al[37] claimed that rim preservation surgery showed satisfactory results after a 15-year follow-up regarding the development of degenerative processes. Some studies have shown that race might also play a role in the prognosis. Milewski et al[38] has shown that Hispanic/Latino patients were more likely to undergo surgery for discoid meniscus. Table 3 lists the good and unfavorable prognostic factors.

Table 3 Good and unfavorable prognostic factors.

Good prognostic factors	Male sex
	BMI < 18.5
	Age of onset < 25 yr
	Symptoms duration < 24 months
Unfavorable prognostic factors	Increased work intensity
	Increased severity of cartilage lesion
	Preoperative cartilage instability
	Smaller width and thickness of the remnant meniscus

BMI: Body mass index.

Postoperative meniscus morphological changes and complications: To assess postoperative morphological changes in symptomatic DLM patients who underwent arthroscopic reshaping surgery, Nishino et al[39] conducted a case-control study that included 61 knees in 54 patients. Imaging was performed postoperatively at 3, 6, 12, and 24 months, and the width, height, and extrusion of the residual meniscus were measured. The results showed that the width of the anterior horn, midbody, and posterior horn decreased significantly from 3 to 24 months after surgery. Midbody had the highest percentage of decreased width, with an average of 19% during the period of follow up. Moreover, authors claim that increased intrameniscal signals on preoperative MRI scans are associated with an increased risk of a decreased meniscal width, which should be considered for surgical planning in order to know the amount of resection. Another study by Kim et al[40] assessed postoperative morphology. They had 52 patients with DLM who underwent arthroscopic surgery and 50 matched controls. The results showed a significant decrease in height compared to the control group and a significantly larger relative percentage of extrusion compared to the control group. Preoperative meniscal shift and partial meniscectomy with repair were the major factors associated with extrusion. In addition, the width of the meniscus showed no changes; however, the position was found to be more anterior and lateral than that of normal controls.

Sabbag et al[41] reported that patients who underwent surgical treatment had higher rates of meniscal tears (59% of patients within the first 8 years), and 50% developed symptomatic lateral compartment osteoarthritis 8 years after diagnosis. Furthermore, reoperation-free survival rates dropped from 89% at 2 years follow up to 61% after 8 years.

CONCLUSION

A discoid meniscus is a morphological abnormality where the meniscus loses its normal “C” shape or stability. For most patients, the discoid meniscus is asymptomatic and might be diagnosed incidentally. Whenever symptomatic, patients might present with locking, instability, swelling, or pain. Since the symptoms and physical examination are usually inconclusive, imaging is always needed for confirmation. Standard radiography or ultrasound can help with diagnosis, but the gold standard is MRI. Conservative treatment might be considered for asymptomatic patients or elderly patients whose daily function is not affected, while for young patients whose daily life function and sport activity are affected, surgical treatment is advised. There are a variety of surgical approaches that include partial meniscectomy with or without repair, which is the standard of treatment, or novel meniscus conserving approaches such as meniscoplasty, meniscopexy, and meniscal allograft transplantation. Many factors that affect postoperative complications have been studied and documented, including age at onset, sex, BMI, and symptom duration. Complications include osteoarthritis, mechanical axis deviation, loss of meniscus width, and increased risk of retear.