Acute Isolated Meniscal Pathology
PHYSICAL EXAMINATION
Physical examination, including joint line tenderness, the McMurray test, and the Thesally test, can effectively diagnose acute meniscal tears and may yield more accurate results when combined.
Moderate Recommendation Moderate Recommendation

Due to the relatively low number of high-quality studies and the inconsistent findings between the studies, the strength of the recommendation has been downgraded one level to moderate.

There were four high quality (Goossen, 2015; Porter, 2021; Shantanu, 2021; Syal, 2015) and eight moderate quality (Dhillon, 1985; Imran, 2019; Konan, 2009; Madhusudhan, 2008; Muellner, 1997; Mohan, 2007; Orlando Junior, 2015; Yaseen, 2019) studies that assessed the effectiveness of physical examination in the diagnosis of meniscus tears.

Physical examination is important in the assessment of patients with suspected meniscal injury. Various tests have been described including joint line tenderness, presence of effusion, range of motion, and meniscal provocative maneuvers such as the McMurray, Apley and Thessaly tests.

Goossen et al. studied the Thessaly test alone or when combined with the McMurray test and found similar sensitivity and specificity for the Thessaly test when performed in isolation (64% and 53%, respectively) and when the Thessaly and McMurray tests were performed together (53% and 62%, respectively). Syal et. al. compared a combination of tests including joint line tenderness, McMurray’s and Apley’s tests, with arthroscopic findings to evaluate for isolated meniscal injury and demonstrated a sensitivity and specificity of 75% and 94% respectively for medial meniscus tears and 38% and 100% respectively for lateral meniscus tears. Porter et. al. compared clinical assessment (joint-line tenderness, McMurray’s, and presence of effusion) and showed that clinical assessment was more accurate than MRI for diagnosing lateral meniscus tears (P<0.001) and similar to MRI for diagnosing medial meniscus tears (P=0.12), with arthroscopy being used as the reference standard.

The original publication of the Thessaly test by Karachalios et. al. showed a diagnostic accuracy of 94% and 96% respectively for the diagnosis of medial and lateral meniscus tears, which was higher than joint line tenderness, the McMurray test and the Apley test. This study was not included in the articles used to determine the recommendation as it did not meet clinical practice guideline inclusion criteria.

Benefits/Harms of Implementation
Physical examination will assist clinicians with assessing for the presence of meniscus tears and other knee injuries. There are no known risks from a comprehensive physical examination.

Outcome Importance
The four high quality and eight moderate quality studies demonstrate the importance of physical examination in the diagnosis of meniscus tears, although there is variability in the diagnostic accuracy of individual tests.

Cost Effectiveness/Resource Utilization
A comprehensive physical exam is a low-cost method for assessing patients for meniscus tears.

Acceptability
Physical examination should have high acceptability as it is routinely performed.

Feasibility
Physical examination is a feasible and expected component to evaluating patients for meniscal injury.

Future Research
Future research could determine the most useful and accurate examination maneuver or combination of examination maneuvers for diagnosing patients with meniscal injury.

Additional References
1. Karachalios, T. Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears. J Bone Joint Surg Am. 2005;87(5):955-62. PMID: 15866956.

ADVANCED IMAGINING
MRI is the preferred imaging modality to diagnose acute meniscal tears because of its high accuracy, while CT arthrography or ultrasound can be used, particularly when MRI is not available or is contraindicated.
Strong Recommendation Strong Recommendation

Nineteen high quality (Ahmadi, 2022; Alizadeh, 2013; DeSmet, 1994; Grevitt, 1992; Grevitt, 1993; Jurik, 1986; Lohmann, 1991; Murray, 1990; Nazem, 2006; Nederveen, 1989; Porter, 2021; Rand, 1999; Raunest, 1991; Reicher, 1987; Rubin, 1994; Shantanu, 2021; Shetty, 2008; Syal, 2015; Wareluk, 2012) and twenty-two moderate quality (Abd Elkhalek, 2019; Abdon, 1989; Araki, 1992; Dhillon, 1985; Elshimy, 2021; Evancho, 1990; Gokalp, 2012; Habib, 2023; Mackenzie, 1995; Madhusudhan, 2008; Matava, 1999; McNally, 2002; Muellner, 1997; Nalaini, 2022; Nemec, 2008; Orlando Junior, 2015; Reicher, 1986; Roper, 1986; Schafer, 2006; Tahmasebi, 2005; Vande Berg, 2000; Van Heuzen, 1988) studies evaluated advanced imaging modalities as diagnostic tests for acute meniscal tears. A meta-analysis was performed using findings of acute meniscal pathology on an MRI compared to arthroscopic findings demonstrated acceptable sensitive and specificity of an MRI in the identification of acute meniscal pathology (sensitivity 0.93[0.71,0.99] and specificity 0.83 [0.45, 0.97])[13 High, Alizadeh, Grevitt, Shetty, De Smet, Nazem, Nederveen, Raunest, Reicher, Shantanu, Syal, Porter, Rand, Rubin; 17 Mod, Habib, Mackenzie, Matava, Nemec, Abd Elkhalek, Elshimy, Madhusudhan, McNally, Muellner, Tahmasebi, van Heuzen, Araki, Orlando Junior, Reicher, Evancho, Gokalp, Nailani, Schafer]. Similar findings were observed in both medial and lateral meniscal pathology with lateral meniscus having a higher specificity (0.94 [0.86,0.97] versus 0.78[0.66, 0.86]) and medial meniscus having a higher sensitivity (0.94[0.89, 0.97] versus 0.80 [0.70, 0.87]).
For patients in which an MRI is contra-indicated including, but not limited to, those with cardiac implants (ie pacemaker), spinal implants, some dental implants, infusions pumps, or cochlear implants, ultrasound [4 High, Ahmadi, Alizadeh, Shetty, Wareluk; 1 Mod, Elshimy] and computed tomography/SPECT [4 High, Jurik, Grevit, Lohmann, Murray; 2 Mod. Tahmasebi, Vande Berg], or arthrography [3 Mod, van Heuzen, Abdon, Dhilllon] are acceptable options with added risk for an infection when an arthrogram is performed or radiation exposure.

Benefits/Harms of Implementation
Advantages of MRI to identify acute meniscal pathology is high accuracy compared with ultrasound and computed tomography and avoiding any radiation or intervention (arthrogram). Ultrasound also presented with limited harm with added benefit when applicable.

Computed tomography or a SPECT can afford potential harmful effects of radiation to the patient. Particular harm should be considered in those of childbearing age due to detrimental effects of radiation during pregnancy.

Despite the value of arthrography, there is added risk with injection, which include infection and pain as well as intolerance (ie allergic reaction) to contrast that should be noted.

Outcome Importance
Value to identify acute meniscal pathology will aid in accurate and appropriate treatment.

Cost Effectiveness/Resource Utilization
Recent cost and accessibility of MRI has allowed for reasonable cost associated with this advanced modality compared to other forms of advanced imaging. More cost-effective treatment including ultrasound and CT scan are acceptable options.

Acceptability
MRI and other forms of advanced imaging are readily available and accessible to most modern medical communities. Ultrasound and CT scan may be more accessible in rural or underserved areas and are acceptable options.

Feasibility
Advanced imaging modalities are feasible, however, arthrography may be out of favor with routine assessment of acute meniscal pathology due to its invasiveness.

Future Research
Abundant high-quality studies are available on this topic. Future research may focus on value based imaging modalities and minimizing risks.

JOINT DEGENERATION
When indicated in the treatment of acute meniscal tear, surgery should preserve as much functional meniscal tissue as possible to mitigate patient risk for osteoarthritis.
Moderate Recommendation Moderate Recommendation

One high quality (Hede, 1986) and eleven low quality (Andersson-Molina, 2002; Cohen, 2012; Englund, 2003; Englund, 2004; Englund, 2009; Hulet, 2001; Rockborn, 1995; Roos, 1998; Roos, 2008; Stein, 2010,;Zhang, 2018) articles evaluating joint degeneration after meniscal tear were reviewed. Several studies indicate that meniscal tear is associated with a greater risk of degenerative changes in joint tissues indicative of knee osteoarthritis compared to uninjured knees/intact menisci (Englund, 2009). Additionally, meniscectomy is associated with a greater prevalence of degenerative changes compared to conservative treatment/no meniscectomy (Cohen, 2012; Englund, 2003; Roos, 1998; Hulet, 2001). While partial meniscectomy is associated with a lesser prevalence of degenerative changes compared to total (Andersson-Molina, 2002; Englund, 2004) and subtotal (Rockborn, 1995) meniscectomy, partial meniscectomy also results in a higher prevalence of degenerative changes compared to meniscal repair (Stein, 2010).

The primary limitation of this body of evidence is that the majority of studies were retrospective in nature. Surgical decision making should be based on the clinical scenario (e.g. the extent, type and location of the initial meniscal trauma), thus there are ethical implications that limit the ability to conduct randomized clinical trials in meniscus patients. Therefore, while there is a preponderance of evidence indicating that meniscal tears in general and surgical removal of a larger amount of meniscal tissue are associated with a greater risk of joint degeneration, the supporting evidence is inherently limited by the nature of the investigations. Additionally, these studies generally did not distinguish the potential influences of the location, type, or extent of the meniscal injury on clinical and radiographic outcomes, thus generalizability of the findings to specific meniscal cases is limited.

Benefits/Harms of Implementation
The primary risk of meniscal preservation, specifically meniscus repair, is the higher rate of subsequent surgery as compared to meniscal debridement or meniscectomy, as well as the added cost of and rehabilitation/recovery following the procedure. However, the long-term value of meniscal preservation to delay or prevent advancement of chondral degeneration should be considered.

Outcome Importance
Meniscal preservation has the potential to delay or prevent joint degeneration which minimizes resulting long term disability.

Cost Effectiveness/Resource Utilization
Meniscal repair techniques, use of implants and additional operative time is expected with meniscal preservation techniques, particularly for meniscus repair. There is some evidence that this approach is cost effective over time (Deviandri, 2023).

Acceptability
Meniscus preservation techniques including meniscus repair are readily accepted and accessible.

Feasibility
There are no concerns regarding the feasibility of meniscal preservation techniques for acute meniscal pathology.

Future Research
The optimal indications and techniques for meniscal preservation techniques, specifically meniscal repair, deserve further investigation, particularly in regards to which types of tears are particularly amenable to repair. Longer term follow-up including assessment of joint degeneration with imaging as well as clinical outcomes and subsequent surgery such as knee arthroplasty is needed.

SURGICAL INTERVENTION AFTER NON-OPERATIVE TREATMENT
Patients with acute meniscal tear who have failed conservative treatment may have better outcomes from surgical intervention within 6 months of injury.
Limited Recommendation Limited Recommendation

Two low quality studies (Marder, 1994; Stone, 1988) evaluated the timing of surgical intervention in the management of acute meniscal tears. Appreciating the historical nature of the cited articles, these studies clearly demonstrated a significantly greater ability for patients to return to their prior athletic level with intermittent to no pain when surgical intervention was performed prior to 6 months. An increased percentage of patients had persistent pain or inability to return to prior activity when surgical intervention was performed after 6 months. Additionally, younger patients without radiographic evidence of osteoarthritis have an increased likelihood of resolution of pain and return to athletics following surgical intervention when performed prior to 6 months from onset. For patients who are returning to a level of activity that does not involve increased load such as jumping, landing, and/or pivoting, non-operative initial management is recommended. However, when initial non-surgical management fails to improve symptoms and function adequately, surgical intervention should be performed prior to 6 months.

Benefits/Harms of Implementation
In addition to the general risks for anesthesia and surgical intervention, the ability to comply with activity limitations and duration of rehabilitation following surgical intervention should be considered when determining if operative or non-operative treatment is pursued. Emphasis should also be placed on patient education in order to facilitate rehabilitation compliance. Delayed surgical treatment of acute symptomatic meniscal injury beyond six months has decreased function, increased pain, and increased chondromalacia and post traumatic arthritis.

Outcome Importance
Addressing meniscal pathology in a timely fashion may result in improved outcomes.

Cost Effectiveness/Resource Utilization
There is no association with cost effectiveness.

Acceptability
Meniscus surgery is an acceptable treatment for acute isolated symptomatic meniscal injury and may be warranted without a trial of non-operative treatment in some circumstances.

Feasibility
Surgical treatment of acute meniscal pathology is feasible and performed regularly within 6 months of injury.

Future Research
High quality studies to prospectively follow acute meniscal injuries are required to determine if and when early operative intervention is indicated.

MENISCUS REPAIR
Meniscus repair can improve patient outcomes compared to partial meniscectomy in acute isolated meniscal tears with healing potential.
Limited Recommendation Limited Recommendation

Six low quality studies (Gan, 2020; Lu, 2020; Mao, 2022; Sochacki, 2020; Stein, 2010; Zhou, 2019) evaluating meniscal repair and meniscectomy were reviewed. One study (Gan) demonstrated improved postoperative patient reported outcome scores in patients with complex tears who underwent repair versus partial meniscectomy. Another (Stein) showed improved results in repair versus partial meniscectomy in regard to osteoarthritis progression and sports activity recovery. When comparing meniscectomy and meniscus repair in a large national insurance database (Sochacki), repairs were found to have lower reoperation rates with higher rates of both complications and total cost.

The primary limitation of this body of evidence is that the majority of studies were retrospective in nature. Surgical decision making should be based on the clinical scenario (e.g. the extent, type and location of the initial meniscal trauma), thus there are ethical implications that limit the ability to conduct randomized clinical trials in meniscus patients. Therefore, while there is a preponderance of evidence indicating that meniscal tears in general and surgical removal of a larger amount of meniscal tissue are associated with a greater risk of joint degeneration, the supporting evidence is inherently limited by the nature of the investigations. Additionally, these studies generally did not distinguish the potential influences of the location, type, or extent of the meniscal injury on clinical and radiographic outcomes, thus generalizability of the findings to specific meniscal cases is limited.

Benefits/Harms of Implementation
There is evidence to suggest that repair of some tears has benefit in regard to decreased reoperation rates and improved outcomes while meniscectomy may have lower costs and complications, but a higher rate of osteoarthritis progression.

Outcome Importance
Mitigating degenerative change in the knee is one of the most important outcomes in the treatment of acute meniscal tears. The potential benefit of meniscal repair over meniscectomy in this area may outweigh disadvantages in terms of cost, complications, and short-term outcomes. Identifying tears more amenable to repair versus meniscectomy, such as peripheral longitudinal tears, can help to guide treatment.

Cost Effectiveness/Resource Utilization
While there is evidence that meniscal repair is cost effective (Deviandri, 2023), determining the optimal tears for repair versus partial meniscectomy may lead to lower costs and decreased complications.

Acceptability
Both treatments are widely acceptable with means to easily perform either.

Feasibility
Both are feasible and should be used according to the appropriate tear pattern.

Future Research
Larger studies with patients stratified by age, activity level, and tear type comparing meniscal repair versus partial meniscectomy are needed.

Additional References:
1. Deviandri, R., Daulay, M. C., Iskandar, D., Kautsar, A. P., Lubis, A. M. T., & Postma, M. J. (2023). Health-economic evaluation of meniscus tear treatments: a systematic review. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 31(9), 3582–3593. https://doi.org/10.1007/s00167-022-07278-8

BIOLOGICAL ENHANCEMENT
Bone Marrow Venting or Platelet Rich Plasma can be considered in patients with acute isolated meniscal tears undergoing surgical repair to improve outcomes.
Moderate Recommendation Moderate Recommendation

The biological enhancement recommendation was downgraded for inconsistency of populations, as some studies only included discoid menisci patients.
One high level study (Kaminski, 2019) supports the use of bone marrow venting to improve outcomes of acute meniscal tears treated with surgical repair. The prospective randomized study showed definite benefits in terms of healing and patient reported outcomes with no change in complications, but it was a small cohort of vertical peripheral meniscal tears at a single study site. The use of PRP has been shown to improve outcomes of surgically repaired acute meniscal tears in one high (Liu, 2019) and three low level studies (Dai, 2019; Everhart, 2019; Pujol, 2015). One high level study showed a slight improvement in patient reported outcomes with the use of PRP, but it was a small cohort of acute tears of discoid menisci with very short-term follow. Another low-level study looking at the use of PRP to augment surgical repair of acute tears in discoid menisci showed no difference in clinical outcomes. One low level study was a retrospective review of a large single surgeon cohort which showed the use of PRP decreased the re-tear rate in the treatment of isolated acute meniscal tears but not tears repaired in conjunction with ACL reconstruction. Another low-level study showed slightly better clinical outcomes with the use of PRP in the repair of acute horizontal meniscus tears.

Benefits/Harms of Implementation
There is some evidence to suggest augmenting repairs of acute meniscal tears can improve healing and clinical outcomes. Bone marrow venting has little risk or cost. PRP has little risk but can have increased associated costs to the patient and health care system.

Outcome Importance
Improving the healing rate of meniscal repairs can improve symptoms and reduce rates of subsequent surgery in the short term and potentially reduce the rates of post-traumatic osteoarthritis in the long term.

Cost Effectiveness/Resource Utilization
Bone marrow venting has negligible cost whereas PRP often adds $500-$1000 or more to the cost of the procedure.

Acceptability
Bone marrow venting is very widely accessible as it can be performed by a variety of widely available surgical tools. PRP requires access to and paying for a system to prepare the sample.

Feasibility
Bone marrow venting is very feasible and should be considered in isolated surgical repair of acute meniscal tears. PRP can be considered depending on availability and cost considerations.

Future Research
Larger cohorts from multiple sites are needed to better understand the efficacy and generalizability of biological augmentation for surgical repair of acute meniscal tears. Studies to compare the efficacy and cost effectiveness of bone marrow venting and PRP would also be helpful.

INDICATIONS FOR ACUTE SURGICAL INTERVENTION
In the absence of sufficient evidence, it is the opinion of the workgroup that patients with a displaced or displacing acute meniscal tear, particularly those restricting knee range of motion, can benefit from acute surgical intervention.
Consensus Recommendation Consensus Recommendation

One low quality study (Marder, 1994) was included, comparing surgical treatment of meniscal tears with nonoperative treatment. There is a paucity of research comparing outcomes from operative and nonoperative treatment of isolated acute meniscal tears. Patients with an isolated meniscal tear that suddenly limits active knee movement, either intermittently or constantly, may benefit from early surgical intervention. Patients active with sports that require loading, pivoting, and/or landing may benefit from early surgical treatment of an acute isolated meniscal injury. The viability to repair torn meniscal tissue may be diminished when surgical intervention is delayed. Nondisplaced tears unlikely to be repairable should be treated initially with physical therapy and undergo surgical management if symptoms persist. Additional future research is needed to compare the short and long-term functional outcomes and return to activity in patients undergoing operative and non-operative treatment of acute isolated meniscal injuries. There is a preponderance of literature of meniscal tears with concomitant injuries. The biological milieu of the knee and following cruciate ligament injuries varies from those with an isolated meniscal injury; therefore, future research is needed in isolated meniscal tears.

Benefits/Harms of Implementation
There is general risk when patients undergo surgery and anesthesia for orthopedic conditions, which may include, but are not limited to death, neurovascular injury, infection, thromboembolic events, and postoperative sequelae such as joint stiffness or degeneration. Nondisplaced tears unlikely to be repairable have little downside if delayed surgical treatment is necessary after initial nonoperative management. However, in the case of displaced meniscal tears blocking knee motion or meniscal tears likely to be repairable, there are potential downsides of delaying surgical intervention.

Outcome Importance
In addition to the general risks for anesthesia and surgical intervention, the ability to comply with activity limitations and duration of rehabilitation following surgical intervention should be considered when determining if operative or non-operative treatment is pursued. Since MRI evaluation is less accurate than direct arthroscopic visualization to determine meniscal tear type, location and tissue viability, which guide the decision to repair or resect, treatment plans may change during surgery and modify postoperative rehabilitation and recovery.

Cost Effectiveness/Resource Utilization
Non-operative management with skilled physical therapy or directed rehabilitation at home can be an effective treatment for acute non-displaced meniscus tears. However, patients who fail conservative management may still require surgical intervention, which delays but does not decrease medical cost. Insufficient rehabilitation or delay in surgical management when indicated can delay recovery and return to work and increase the risk of less optimal outcomes.

Acceptability
Patients returning to pivoting or landing activities may benefit from early surgical intervention for a quicker return to play or work, even in the absence of limited knee motion. Even patients without “symptomatic” knees, as defined above, who receive salaries from athletics could benefit from surgical intervention for a quicker and more reliable return to play. However, the short-term benefit of quicker recovery after resection compared to repair has to be weighed against the risk of more rapid joint degeneration over time, which can reduce performance and durability.
Feasibility
No obvious barriers to identify.

Future Research
Topics to be addressed with future research include:
Which meniscal tear, i.e., location, type and length of tear, would normally need and therefore benefit from surgery vs initial nonoperative management?
How long should high-level verses lower-level athletes trial nonoperative treatment before undergoing surgical intervention?
How do variables such as age, body mass index, and type and level of activity influence optimal treatment and outcomes from acute isolated meniscal tears?

Additional References
1. Cook C.E. et al. (2021). Does Surgery for Cruciate Ligament and Meniscus Injury Increase the Risk of Comorbidities at 2 Years in the Military System? The Journal of Knee Surgery.
2. van der Graaff SJA, Eijgenraam SM, Meuffels DE et al. (2022). Arthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in a young study population: a randomised controlled trial. Br J Sports Med(56), 870-876.

INDICATIONS FOR ACUTE SURGICAL INTERVENTION
In the absence of sufficient evidence, it is the opinion of the workgroup that patients with a symptomatic acute meniscal tear who could benefit from a repair should be considered for early surgical intervention.
Consensus Recommendation Consensus Recommendation

One low quality study (Marder, 1994) was included, comparing surgical treatment of meniscal tears with nonoperative treatment. There is a paucity of research comparing outcomes from operative and nonoperative treatment of isolated acute meniscal tears. Patients with an isolated meniscal tear that suddenly limits active knee movement, either intermittently or constantly, may benefit from early surgical intervention. Patients active with sports that require loading, pivoting, and/or landing may benefit from early surgical treatment of an acute isolated meniscal injury. The viability to repair torn meniscal tissue may be diminished when surgical intervention is delayed. Nondisplaced tears unlikely to be repairable should be treated initially with physical therapy and undergo surgical management if symptoms persist. Additional future research is needed to compare the short and long-term functional outcomes and return to activity in patients undergoing operative and non-operative treatment of acute isolated meniscal injuries. There is a preponderance of literature of meniscal tears with concomitant injuries. The biological milieu of the knee and following cruciate ligament injuries varies from those with an isolated meniscal injury; therefore, future research is needed in isolated meniscal tears.

Benefits/Harms of Implementation
There is general risk when patients undergo surgery and anesthesia for orthopedic conditions, which may include, but are not limited to death, neurovascular injury, infection, thromboembolic events, and postoperative sequelae such as joint stiffness or degeneration. Nondisplaced tears unlikely to be repairable have little downside if delayed surgical treatment is necessary after initial nonoperative management. However, in the case of displaced meniscal tears blocking knee motion or meniscal tears likely to be repairable, there are potential downsides of delaying surgical intervention.

Outcome Importance
In addition to the general risks for anesthesia and surgical intervention, the ability to comply with activity limitations and duration of rehabilitation following surgical intervention should be considered when determining if operative or non-operative treatment is pursued. Since MRI evaluation is less accurate than direct arthroscopic visualization to determine meniscal tear type, location and tissue viability, which guide the decision to repair or resect, treatment plans may change during surgery and modify postoperative rehabilitation and recovery.

Cost Effectiveness/Resource Utilization
Non-operative management with skilled physical therapy or directed rehabilitation at home can be an effective treatment for acute non-displaced meniscus tears. However, patients who fail conservative management may still require surgical intervention, which delays but does not decrease medical cost. Insufficient rehabilitation or delay in surgical management when indicated can delay recovery and return to work and increase the risk of less optimal outcomes.

Acceptability
Patients returning to pivoting or landing activities may benefit from early surgical intervention for a quicker return to play or work, even in the absence of limited knee motion. Even patients without “symptomatic” knees, as defined above, who receive salaries from athletics could benefit from surgical intervention for a quicker and more reliable return to play. However, the short-term benefit of quicker recovery after resection compared to repair has to be weighed against the risk of more rapid joint degeneration over time, which can reduce performance and durability.
Feasibility
No obvious barriers to identify.

Future Research
Topics to be addressed with future research include:
Which meniscal tear, i.e., location, type and length of tear, would normally need and therefore benefit from surgery vs initial nonoperative management?
How long should high-level verses lower-level athletes trial nonoperative treatment before undergoing surgical intervention?
How do variables such as age, body mass index, and type and level of activity influence optimal treatment and outcomes from acute isolated meniscal tears?

Additional References
1. Cook C.E. et al. (2021). Does Surgery for Cruciate Ligament and Meniscus Injury Increase the Risk of Comorbidities at 2 Years in the Military System? The Journal of Knee Surgery.
2. van der Graaff SJA, Eijgenraam SM, Meuffels DE et al. (2022). Arthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in a young study population: a randomised controlled trial. Br J Sports Med(56), 870-876.

PHYSICAL THERAPY
In the absence of sufficient evidence, it is the opinion of the workgroup that physical therapy/rehabilitation may benefit patients with an acute isolated meniscal tear undergoing non-operative treatment or recovering from meniscal surgery.
Consensus Recommendation Consensus Recommendation

One low quality study (Katsuri, 2020) was included. While this investigation demonstrated that physical therapy/rehabilitation (i.e. conservative management) improved pain, range of motion, and functional ability in patients with meniscal tears, generalizability and application of the findings is limited due to a lack of information regarding the parameters of the rehabilitation scheme and the appropriateness of the statistical approach. In the absence of additional evidence, it is the opinion of the workgroup that physical therapy/rehabilitation may be beneficial to patients who present with an acute non-displaced isolated meniscal tear not amenable to repair when implemented as a non-operative treatment option as well as for those recovering from meniscal surgery. Complications developing or increasing, such as pain or tear size, are not noted with a trial of rehabilitation following atraumatic or traumatic mechanisms of injury.

Benefits & Harms:
No additional harm noted for a trial of conservative rehabilitation.

Cost Effectiveness/Resource Utilization:
Nonoperative rehabilitation that treats the symptoms of an acute meniscal tear provides cost-saving by avoiding surgical intervention. However, patients who fail rehabilitation and then undergo surgery obviously incur the cost of pre-surgical rehabilitation in addition to the surgical intervention.

Acceptability:
Physical therapy, including Mulligan techniques, is widely available at reasonable cost. There is little risk or downside to physical therapy.

Feasibility:
Physical therapy is widely available at reasonable cost. Mulligan technique is a mode of intervention within manual physical therapy with no additional cost.

Future Research:
Topics to be addressed with future research include:
The benefit of a home exercise program compared to a supervised program?
If and when patients return to high-level (dynamic, pivoting) or moderate-level (running, cycling) sports (was not objectively measured)

SURGICAL REPAIR TECHNIQUE
It is the opinion of the workgroup that, when performing repair of acute isolated meniscal tears, surgeons may favor the inside out technique to reduce the risk of repair failure in certain tear patterns or all inside techniques to reduce the risk of other complications.
Consensus Recommendation Consensus Recommendation

The most recent meta-analysis and systematic review (Schweizer C/Nepple) on all inside versus inside out repair showed no significant difference in pooled failure rates between all inside versus inside out repair. Another low-level study (Borque) demonstrated a higher rate of failure of medial meniscus tears treated with the all inside technique versus inside out technique, but this may be limited by the study population and tear morphology. Biomechanical studies (Rosso) have demonstrated similar responses to cyclic loading with all inside versus inside out repairs.

Benefits & Harms:
All inside meniscal repair has the potential to decrease operative time as well as morbidity by avoiding additional incisions and dissection. All inside devices do not eliminate the risk for neurovascular injury however and present a risk for iatrogenic cartilage injury and can break or malfunction. Inside out repair has risks of iatrogenic nerve injury and additional surgical dissection.

Outcome Importance:
The relative risk of complications and retear likely depends on tear and patient specific variables. Determining the ideal indication for various repair techniques could optimize outcomes.

Cost Effectiveness/Resource Utilization:
Cost of increased OR time with an inside out repair versus increased cost of all inside implants should be weighed.

Acceptability:
Both techniques are accepted treatment modalities for meniscal repair with the inside out repair being the historical gold standard.

Feasibility:
Both techniques are widely available for use.

Future Research:
Future research should investigate how tear and patient specific variables relate to the impact of meniscal repair technique on outcomes, complications, and cost in the treatment of acute meniscal tears.

Additional References:

  1. Schweizer C, Hanreich C, Tscholl PM, Blatter S, Windhager R, Waldstein W. Meniscal Repair Outcome in 3829 Patients With a Minimum Follow-up From 2 Years Up to 5 Years: A Meta-analysis on the Overall Failure Rate and Factors Influencing Failure. Am J Sports Med. 2023 Apr 6:3635465231158385. doi: 10.1177/03635465231158385. Epub ahead of print. PMID: 37022676
  2. 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. Am J Sports Med. 2023 Mar;51(3):579-584. doi: 10.1177/03635465221147058. Epub 2023 Feb 6. PMID: 36745037.
  3. Nepple JJ, Block AM, Eisenberg MT, Palumbo NE, Wright RW. Meniscal Repair Outcomes at Greater Than 5 Years: A Systematic Review and Meta-Analysis. J Bone Joint Surg Am. 2022 Jul 20;104(14):1311-1320. doi: 10.2106/JBJS.21.01303. Epub 2022 Apr 19. PMID: 35856932.
  4. Rosso C, Kovtun K, Dow W, McKenzie B, Nazarian A, DeAngelis JP, Ramappa AJ. Comparison of all-inside meniscal repair devices with matched inside-out suture repair. Am J Sports Med. 2011 Dec;39(12):2634-9. doi: 10.1177/0363546511424723. Epub 2011 Oct 13. PMID: 21997730.

ACKNOWLEDGEMENTS

Guideline Work Group:

  • Robert Brophy, MD, FAAOS, Co-Chair
  • Matthew Best, MD, Co-Chair 
  • Andrea Aagesen, DO
  • Troy Blackburn, PhD, ATC
  • Andrew Dominguez, DPT
  • Matthew Ellington, MD, FAAOS
  • Henry Ellis, MD, FAAOS

Contributing Members:

  • Asheesh Bedji, MD, FAAOS

Non-Voting Members:
Aaron Chamberlain, MD, FAAOS, MSc, MBA - Oversight Chair

AAOS Staff:

  • Jayson N. Murray, MA, EMBA - Managing Director, Clinical Quality & Value
  • Kaitlyn Sevarino, MBA, CAE
  • Danielle Schulte, MS, EMBA - Manager, Clinical Quality & Value
  • Tyler Verity, MSLIS - Medical Librarian, Clinical Quality & Value
  • Jennifer Rodriguez, MBA - Manager, Clinical Qualitiy & Value
  • Kristine Sizemore, MPH - Research Analyst, Clinical Quality & Value
  • Anushree Tiwari, MPH - Research Analyst, Clinical Quality & Value

Former AAOS Staff:

  • Lyric Knowles, MPH - Research Analyst, Clinical Quality & Value