Physical Therapist Interventions Versus or Combined With Surgical Treatment in Nontraumatic Degenerative Meniscal Pathology: A Systematic Review and Network Meta-Analysis

Abstract

Objective

This study aimed to synthesize the evidence from randomized clinical trials in people with nontraumatic degenerative meniscal pathology by comparing physical therapist interventions versus or combined with arthroscopic partial meniscectomy (APM).

Methods

Seven electronic databases were searched. Methodological quality was evaluated using the Physiotherapy Evidence Database scale. Data synthesis was performed with random-effects network meta-analysis, and results were summarized using the standardized mean differences.

Results

From 2103 studies, 10 randomized clinical trials comprising 1411 individuals were included. Ninety percent of the selected randomized clinical trials were classified as good quality according to the Physiotherapy Evidence Database scale. All interventions (physical therapist interventions, APM, and APM plus physical therapist interventions) showed reduced pain and physical impairments at 3-month follow-up. However, when a physical therapist intervention was included, greater reductions in pain at rest (APM vs physical therapist interventions: 0.73 [95% CI = 0.20 to 1.26]; APM vs APM plus physical therapist interventions: 0.59 [95% CI = 0.15 to 1.03]) and greater increases in the strength of knee extensor muscles (APM vs physical therapist interventions: 0.44 [95% CI = 0.07 to 0.80]; APM vs APM plus physical therapist interventions: 0.73 [95% CI = 0.29 to 1.16]) were observed at 3 months. By contrast, no differences were found between treatments beyond 3 months.

Conclusion

Physical therapist interventions based on exercise programs demonstrate superior short-term outcomes in pain reduction and knee extensor strength compared to surgical treatment.

Impact

For nontraumatic degenerative meniscal pathology, conservative treatment utilizing a physical therapist intervention approach should be prioritized as the first choice over surgical treatment. It offers comparable or superior short-term pain reduction and strength improvements, with a lower risk of side effects. In cases where surgery is deemed necessary, including postsurgical, physical therapist interventions are highly recommended to enhance muscle strength and alleviate pain.

Introduction

Meniscal tear injuries are characterized as detached fragments of the meniscus and have an annual incidence rate of 172 per 100,000 individuals. ¹ Typical symptoms include localized pain, functional and strength loss, joint impingement, and palpable clicking.² Meniscal injuries can be classified as either traumatic, which are more prevalent among young individuals, or degenerative, which are associated with aging.³ Degenerative meniscal pathology affects approximately 35% of people older than 50 years, and its prevalence tends to rise with advancing age.⁴ In this regard, the World Health Organization has projected that the proportion of elderly population will double from 11% to 22% between 2000 and 2050.⁵ This demographic shift is expected to result in a direct increase in degenerative pathologies and subsequently contribute to an indirect rise in health care expenditure.⁵ Although certain European countries have experienced a decrease in the surgical rate for meniscal injuries over the past decade,^6,7 the USA still witnesses an estimated 4 million surgeries annually, incurring a substantial cost of over $4 billion per year.^8,9

There are currently 2 main surgical procedures for meniscal tears: arthroscopic partial meniscectomy (APM) and meniscal reconstruction.¹⁰ Meniscal repair has provided better results in patients under 35 years of age injured by traumatic causes,¹¹ although APM is the most common surgical option in all other adults.⁴ On the other hand, physical therapist interventions are the conservative treatment for the rehabilitation of people with degenerative meniscal injury.¹² The main therapeutic goal of physical therapist interventions is to enhance the strength of knee extensor and flexor muscles and to improve functional performance by performing strength training and functional exercise.¹³ Furthermore, another conservative approach consisting of intraarticular cortisone or hyaluronic acid injections can also be provided periodically for short-term relief of severe pain and to facilitate the rehabilitation process.¹⁴

APM and physical therapist interventions are considered to be effective interventions for managing pain and physical impairments in patients with degenerative meniscal injury.¹⁰ Previous systematic reviews and meta-analyses have compared physical therapist treatment versus APM^15,16 or combined with APM,^17–19 yielding varied and inconclusive findings regarding the superior treatment option. However, it is essential to mention that some of these studies combined patients with degenerative and traumatic meniscal injuries^16,18 or did not consider the coexistence of severe osteoarthritis^15,17 or anterior cruciate ligament injury¹⁹ as an eligibility criterion. Importantly, none of them conducted a network meta-analysis (NMA) allowing simultaneous comparison between all possible treatment combinations. Therefore, taking into account the latest scientific research, a crucial step is to explore the treatment options or combinations that yield the best outcomes for patients with degenerative meniscal injury.

This systematic review and NMA aimed to synthesize the evidence from randomized clinical trials on knee pain, knee-related symptoms, and knee physical impairments by comparing physical therapist interventions versus APM, physical therapist interventions versus APM combined with physical therapist interventions, or APM versus APM combined with physical therapist interventions.

Methods

Study Design

This systematic review of the available scientific evidence analyzing the effectiveness of physical therapist interventions versus or combined with surgical treatment in people with degenerative meniscal pathology has been conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses²⁰ and the extension for Network Meta-Analyses.²¹ The protocol for the systematic review and NMA was registered in the International Prospective Register of Systematic Reviews database under the number CRD42022320415.

Data Sources and Searches

Seven databases (Web of Science, PubMed, Scopus, Rehabilitation & Sports Medicine Source, SPORTDiscus with Full Text, Cochrane Library, and Physiotherapy Evidence Database) were searched in triplicate by 3 authors (D.S.-C., J.T.-M., and P.B.-L.) from inception to November 15, 2022. The specific search strategy for each database is presented in Supplementary Material 1. PICOS search tool was used to design the search strategy²²: Population: adults with degenerative meniscal pathology; Intervention and Comparator: physical therapist interventions and surgical treatments; Outcome: outcome variables related to pain, knee-related symptoms and physical impairments; and Study type: randomized controlled clinical trial design. Additionally, in order to avoid the loss of potentially eligible studies, an exhaustive review of the references of the selected full-text articles was carried out.

Eligibility Criteria

Type of Studies

Only randomized controlled clinical trials in humans, published in English or Spanish within the last 15 years (ie, 2006 onward), and available in full text were included. Follow-up and secondary studies of an original trial were considered during the data extraction process but were excluded from the total number of articles finally selected.

Type of Participants

Studies of adults older than 35 years and diagnosed with nontraumatic degenerative meniscal pathology were included. Studies of participants who had simultaneous anterior cruciate ligament injury or were diagnosed with Level 4 knee osteoarthritis on the Kellgren–Lawrence scale were excluded because of the presence of concomitant conditions. The Kellgren–Lawrence scale assesses the level of osteoarthritis from 0, if no signs are present, to 4, referring to a severe level of osteoarthritis.²³

Type of Interventions

Studies were selected if participants were divided into a conservative treatment group based on physical therapist interventions, a surgical treatment group, or a combination of both treatments. Studies that included placebo surgery versus or combined with physical therapist treatment were excluded.

Type of Outcome Measures

Studies measuring any outcome variable related to pain, knee-related symptoms, and physical impairment, regardless of the type of scale used, were selected. Short-term effects were considered for those shorter than 6 months and medium-term effects were considered for those between 6 and 24 months.

Study Selection

The article selection process was carried out by 2 researchers independently (D.S.-C. and J.T.-M.) with the help of a third researcher (A.B.-E.), who mediated to reach a consensus in case of discrepancies after full-text screening. All articles retrieved from the different databases were introduced into EndNote software, and duplicates were removed. The studies were initially screened by reviewing the titles and abstracts, and subsequently, the full text of the articles was read.

Data Extraction and Quality Assessment

Two authors (D.S.-C. and J.T.-M.) independently performed qualitative and quantitative data extraction using a standardized table in Microsoft Excel (Microsoft Corp, Redmond, WA, USA). The quantitative extraction included: first author and year of publication, treatment arm, name of variable (ie, test or scale used to measure outcome variables), number of participants, time point of measurement, and arm-level final value score (mean and SD). When it was not possible to extract the required data from the manuscript, up to 3 attempts over a period of 4 weeks were made to contact original study authors via email to request these data. When necessary, values expressed by median and other measures of dispersion were converted to mean and SD using established formulae.²⁴

The methodological quality of the selected studies was assessed independently by 2 researchers (D.S.-C. and J.T.-M.) using the Physiotherapy Evidence Database scale,²⁵ consulting a third researcher (A.B.-E.) to obtain consensus in case of any discrepancies. The Physiotherapy Evidence Database scale scores 11 items, where 1 point is scored if the article meets the criterion, and 0 point is scored if it does not. Item 1 assesses external validity, Items 2 to 9 assess internal validity, and Items 10 and 11 assess the interpretability of the results. The maximum score is 10 points (Item 1 is not considered in the final score). Articles scoring at least 6 of 10 are considered to be good quality; those scoring 4 and 5 of 10 are considered to be fair quality, and articles scoring <4 of 10 are considered to be poor quality.²⁶

Data Synthesis and Analysis

Random-effects NMA within frequentist setting was conducted for connected networks.²⁷ A full design-by-treatment interaction random-effects model (global χ² test) was used to assess the presence of global inconsistency.²⁸ Then, a consistency model was fit if the null hypothesis of inconsistency parameters being equal to 0 was not rejected. Furthermore, network inconsistency was evaluated by analyzing the between-studies heterogeneity (ie, variation in treatment effects between studies) based on the magnitude of the heterogeneity variance parameter (τ²)²⁸ and the presence of incoherence (ie, variation between direct and indirect sources of evidence) based on the node-splitting method.²⁹ Results were summarized using the standardized mean differences (SMDs). SMDs were categorized as small (≥0.2), medium (≥0.5), and large (≥0.8).³⁰ The uncertainty of all estimates was expressed with their 95% CIs.

When direct comparisons between treatment arms were available, SMDs estimated by the Hedges g were pooled with a random-effects meta-analysis following a restricted maximum likelihood estimation.³¹ Additionally, to analyze the change from baseline for each treatment arm, independent of whether direct comparisons were available or not, a random-effects meta-analysis following a restricted maximum likelihood estimation was calculated by pooling the SMDs estimated by the Hedges g from the baseline.³²

All analyses were performed using Stata V.16.1 (StataCorp, College Station, TX, USA) with the mvmeta command and network graphs package.

Role of the Funding Source

The funders played no role in the design, conduct, or reporting of this study.

Results

Study Selection

From 2103 studies obtained after the initial search, 967 studies were screened by title and abstract after removing duplicates. Forty-five studies were screened by full-text reading, of which 35 were excluded. In particular, 17 were not randomized clinical trials, 8 did not meet all inclusion criteria, and 1 study did not involve physical therapist interventions. Furthermore, 9 studies analyzed similar samples through follow-up or consisted of secondary analyses of original articles. In these 9 cases, relevant information was extracted according to the objective of the review, but they were not considered as independent studies. The list of studies excluded after full-text screening is presented in Supplementary Material 2. No additional records were found within the reference list of the reviewed full-text articles. Finally, 10 independent studies were included in the systematic review and NMA. The study selection process is shown in Figure 1.

Characteristics of Clinical Trials

Table 1 shows the main characteristics of the studies selected. The follow-up ranged from 3 to 60 months. Regarding treatment comparisons, 4 studies compared physical therapist interventions versus APM,^33–36 4 studies compared physical therapist interventions versus APM plus physical therapist interventions,^37–40 and 2 studies compared APM versus APM plus physical therapist interventions.^41,42

The selected studies comprised a total of 1411 participants. The study with the smallest sample size included 17 participants,³⁵ and the largest sample accounted for 330 participants.³⁸ The mean age ranged from 42 to 59 years, with 41% of participants being women, and the mean body mass index ranged from 25.0 to 30.0. Furthermore, regarding the classification of participants according to the degree of osteoarthritis using the Kellgren–Lawrence scale, all studies classified participants as having Grades 0 to 3, except in 3 trials that did not report this information.^35,37,42 However, the 2 studies by Østerås et al excluded participants as having Grade 3 or 4 on the Kellgren–Lawrence scale.^35,42 Likewise, Herrlin et al excluded individuals presenting obliteration of the joint space in accordance with the Ahlbäck classification of knee osteoarthritis.³⁷

Participants underwent different rehabilitation treatments lasting for 1 to 3 months, performing 2 or 3 physical therapist sessions per week of 30 to 60 minutes. The sessions included a variety of strengthening, cardiovascular, proprioception, flexibility, and mobility exercises. On the other hand, the surgical treatment was APM in all cases. Additionally, only 2 studies considered a recent episode of intraarticular injections as an exclusion criterion.^33,38

The postintervention assessments consisted of 1,^35,39,41 2,^33,37,42 3,^34,38 or even 4^36,40 follow-up measurements using different measurement instruments to assess the main variables. Knee-related pain was evaluated using the visual analog scale (VAS). Self-reported knee symptoms were measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Western Ontario and McMaster Universities Osteoarthritis Index, the Subjective Knee Form of the International Knee Documentation Committee, the Lysholm Knee Scoring Scale, and the Tegner Activity Scale. Physical impairments were assessed through range of motion and dynamometry of the quadriceps and hamstring muscles. In addition, anecdotally, some studies also assessed other outcome measures such as quality of life, levels of physical activity, need for total knee replacement, presence of adverse effects, economic costs, and patient satisfaction, among others.

All the studies reported improvements between baseline and the end of follow-up in both treatment arms for the main variables. However, several randomized clinical trials showed significant differences between groups in specific outcomes, indicating the superiority of physical therapist interventions, both for physical therapist interventions versus APM or for the combination of physical therapist interventions plus APM versus APM.^{33–35,39,40,42} Specifically, Yim et al, who compared a physical therapist intervention group versus an APM plus physical therapist intervention group in 2013, found that symptoms improvement was maintained longer in the physical therapist intervention group.⁴⁰ Østerås et al, who compared physical therapist interventions and APM in 2012, found better scores in the KOOS quality of life subscale at the 3-month follow-up in favor of the physical therapist interventions group.³⁵ Kise et al, who compared physical therapist interventions and APM in 2016, and Stensrud et al, who compared physical therapist interventions and APM plus physical therapist interventions in 2015, found greater improvements in muscle strength in the physical therapist interventions group.^34,39 Additionally, Başar et al, who compared physical therapist interventions and APM in 2021, found better results in the physical therapist interventions group in terms of range of motion.³³ Finally, Østerås et al, who compared APM and APM plus physical therapist interventions in 2014, found better improvements in favor of the AMP plus physical therapist interventions in all outcome measures, including knee pain and muscle strength.⁴²

Methodological Quality

The methodological quality of the included studies is presented in Supplementary Material 3. After assessment of the 10 studies selected by using the Physiotherapy Evidence Database scale, 8 studies were considered to be of good quality,^{33,34,36,38–42} and the remaining 2 studies were considered to be of fair quality.^35,37 Thus, the median score of the trials was 6.5 points, indicating good quality (ie, ≥6 points).

All studies performed random allocation of participants (Item 2), included statistical comparisons between groups (Item 10) and within-group points estimates and variability (Item 11). However, none of the trials assessed conducted blinding of participants (Item 5) or of the therapist delivering the treatment (Item 6). Nevertheless, 4 studies informed about blinding of the assessor (Item 7).^33,34,39,41

Three studies did not conduct intention-to-treat analyses (Item 9)^33,37,42 and 3 trials did not perform a concealed allocation process in their methodologies (Item 3).^35,37,38 In addition, 1 study did not comply with the principle of comparability between treatment groups at baseline (Item 4),³⁵ and another study showed a ratio of losses to dropouts during the follow-up of higher to 15% (Item 8).³³

Figure 2 shows a bar graph summarizing the percentage of trials that met each individual quality criterion of the Physiotherapy Evidence Database scale.

Data Synthesis

Five authors were contacted to retrieve additional information that could not be extracted from a total of 6 articles. Three of these 5 authors provided additional data corresponding to 4 articles. Data from each single study used in the NMA are presented in Supplementary Material 4.

The global χ² test rejected the presence of global inconsistency for all outcome measures (P ≥ .05). No between-studies heterogeneity was found (ie, τ² < 0.1), and the P value after the node-splitting method rejected the presence of incoherence between direct and indirect estimates (ie, P ≥ .05) for any of the outcome measures at the 3-month follow-up (Tab. 2). However, signs of between-studies heterogeneity for VAS weight bearing at 6 months and incoherence between direct and indirect estimates of the KOOS pain subscale at 12 months were observed (Tab. 2).

Table 2 presents a synthesizes of the network estimates for the VAS for weight bearing, VAS at rest, KOOS pain subscale, KOOS symptoms subscale, KOOS activities of daily living subscale, KOOS sport subscale, KOOS quality of life subscale, and strength of knee extensor muscles at 3 months after intervention. Only for the VAS for weight bearing and for KOOS pain subscale, it was possible to conduct an NMA at 6 and 24 months and at 12 months after intervention, respectively. Changes are expressed in SMDs.

For the VAS for weight bearing, no treatment differences were found at 3, 6, or 24 months. For the VAS at rest, higher reductions were observed at 3 months when a physical therapist intervention was included (APM vs physical therapist interventions: 0.73 [95% CI = 0.20 to 1.26]; APM vs APM plus physical therapist interventions: 0.59 [95% CI = 0.15 to 1.03]).

For KOOS pain subscale, higher score improvements were observed at 3 months in APM plus physical therapist interventions versus physical therapist interventions (0.23 [95% CI = 0.05 to 0.41]), but no differences between treatment groups were found at 12 months. For the other KOOS subdomains, no differences between treatment groups were found at 3 months.

Finally, higher indicators of the strength of knee extensor muscles were observed at 3 months when a physical therapist intervention was included (APM vs physical therapist interventions: 0.44 [95% CI = 0.07 to 0.80]; APM vs APM plus physical therapist interventions: 0.73 [95% CI = 0.29 to 1.16]).

Forest plots for direct comparisons between the treatment arms are presented in Supplementary Material 5. Significantly, higher score improvements were observed at 3 months in KOOS pain subscale for physical therapist interventions compared to APM plus physical therapist interventions and in the knee extensor strength for physical therapist interventions and APM plus physical therapist interventions compared to APM.

Individual forest plots for each variable representing the change from baseline and grouped by treatment arms are presented in Supplementary Material 6. Physical therapist interventions showed significant improvements from baseline for all of the studied variables at all time points. However, APM did not show significant improvements from baseline for the VAS for weight bearing (Fig. 3), KOOS quality of life subscale (Suppl. Material 7), and knee extensor strength (Fig. 4) at 3 months. Similarly, APM plus physical therapist interventions did not show significant improvements from baseline for the KOOS symptoms subscale (Suppl. Material 8), KOOS activities of daily living subscale (Suppl. Material 9), and KOOS quality of life subscale (Suppl. Material 7) as well as knee extensor strength (Fig. 4) at 3 months.

Discussion

This systematic review and NMA aimed to synthesize evidence from randomized clinical trials on knee pain, knee-related symptoms, and knee physical impairment by comparing physical therapist interventions versus APM, physical therapist interventions versus APM combined with physical therapist interventions, or APM versus APM combined with physical therapist interventions.

According to our findings, at 3 months, conservative treatment based on physical therapist interventions for nontraumatic degenerative meniscal pathology appears to be a preferable option compared to surgical treatment (ie, APM), where physical therapist interventions seem to be more cost-effective than APM.⁴³ Although surgical treatment remains widely implemented in orthopedic health care services and is unlikely to change immediately,⁴⁴ our findings emphasize the importance of accompanying surgical interventions with physical therapist interventions when surgery is necessary for the patient. This combined approach seems to enhance the muscle strength and reduce pain, and it should be considered in cases where surgical treatment is chosen as the primary option. Overall, these results are consistent with previous systematic reviews, which suggest that the combination of physical therapist interventions after surgery can effectively control pain and reduce physical impairments in the short term.^18,19 Nevertheless, Li et al reported better short-term results after arthroscopy, but when considering the follow-up data after 24 months, the combination with physical therapist interventions was identified as essential for reducing pain and increasing functionality.¹⁵

Knee-Related Pain

In relation to the outcomes included in the study, the results showed the clinical significance of physical therapist interventions on reducing pain at rest. Both physical therapist interventions and APM plus physical therapist interventions versus APM showed SMDs classified as a medium effect size, indicating the superiority of including exercise training in the treatment of patients with nontraumatic degenerative meniscus pathology. The analgesic effect might be influenced by the activation of the endogenous opioid system, which has one of its most important functions as reducing the intensity of pain.⁴⁵ On the other hand, physical activity modulates the local immune system, producing a greater number of antiinflammatory cytokines compared to inflammatory ones, in contrast to inactivity.⁴⁶ Another consequence of exercise is weight loss, which favors the reduction of pain by imposing less load,⁴⁷ in this case, on the knee joint. Additionally, studies have investigated that adults who engage in regular physical activity have a lower sensitivity to pain.⁴⁸

Self-Reported Knee Symptoms

Regarding the KOOS, none of the subscales, except for activity limitations because of pain, showed differences between the groups at 3 months. Specifically, the pain subscale showed a small effect size in the group in which physical therapist interventions were performed after surgery compared to physical therapist interventions alone. However, no differences were observed between the groups at 12 months. Since a group of patients received surgical treatment, there might be some factors that can mediate the outcome, such as previous expectations related to surgery or a potential placebo effect. Although quantitative pain measures are vital to understanding pain management,⁴⁹ they often overlook important attributes of the subjective experience, such as personal context and meaning, which can profoundly shape the experience.⁵⁰ On the other hand, the placebo effect refers to the reduction of symptoms caused by the psychosocial context, such as positive expectations, and not by the properties of the treatment itself.⁵¹

Physical Impairments

Regarding the knee extensor strength, more favorable outcomes were observed when a physical therapist intervention was included. Specifically, small-to-moderate effect sizes were found, indicating the greatest and fastest recovery of quadriceps strength in the short term. Physical therapist programs have demonstrated their efficacy in various pathologies by incorporating strengthening and neuromuscular control exercises, leading to enhanced lower limb muscle strength and improved knee proprioception.^52–54 This finding emphasizes the importance of strengthening the muscles around the knee joint, which contributes to better mobility and increased ease in performing daily activities.⁵⁵

Physical Therapist Procedures Based on Exercise

The physical therapist procedures used in the selected studies mainly consisted of active exercises performed by the patient. Although a detailed description of the progression of load, volume, and intensity was not available on a session-by-session basis in the studies, the common element in the training was a focus on neuromuscular and strengthening bodyweight exercises. Interestingly, studies that included cardiovascular or aerobic exercises did not show significant improvements compared to the alternative arm of treatment with APM.^35–38,42 By contrast, those studies where the core part of the physical therapist treatment was essentially based on neuromuscular and strengthening exercises showed greater benefits in favor of the physical therapist arm in terms of pain and physical impairments reductions.^33,34,39,40 It is known that strength training results in increased strength of the exercised muscles because of early neuromuscular adaptations and subsequent increases in muscle cross-sectional area and alterations in connective tissue stiffness when maintained over time.⁵⁶ Additionally, although aerobic exercise has the ability to activate the cardiovascular system to a greater extent and has widely recognized benefits for pain management, strength training has also been shown to induce exercise-induced hypoalgesia.⁵⁷ Therefore, if there is limited time available for exercise sessions as part of physical therapist treatment, prioritizing neuromuscular and strengthening exercises at the core of the sessions may be more appropriate.

Methodological Quality of the Included Studies

As depicted in Supplementary Material 3, any study performed blinding of participants or therapists, and the evaluators were also not blinded in less than half of the studies (4/10). On the one hand, it does not seem possible or ethical to achieve blinding of surgeons and patients receiving APM for reasons inherent to the study designs and research questions. Blinding of therapists who administered exercise to patients also cannot be achieved, mainly if the exercise program was supervised or combined with other physical agents (eg, electrotherapy). A potential alternative to achieve pseudoblinding of therapists could be to report whether the therapists were outsiders to the clinical trial design and naive to the research question. Whereas, blinding of participant would involve an ethically questionable surgical simulation (preoperative, anesthesia, incision, drainage, etc.) or an omission of the content of the physical therapist treatment prior to signing the informed consent form. On the other hand, blinding of the evaluator was only reported in 4 studies^33,34,39,41 by using, for example, sleeves to cover both knees and hide possible surgical scars. The rest of the studies^{35–38,40,42} did not blind assessors, which was considered to be a substantial limitation even if part of the assessment was based on self-reported outcomes.

Overall, most studies avoided the presence of other biases and were classified as good quality. Nevertheless, it would be highly recommendable that future studies contemplate blinding of the evaluator and include a follow-up period of at least 1 year. In addition, physical therapist interventions showed a lack of homogeneity in the exercise procedures, so it would be necessary to establish reproducible treatment protocols to avoid intervention bias. Moreover, the prior use of intraarticular injections should be recorded, and recent episodes should be considered as an exclusion criterion or a confounder.

Limitations

This NMA presents some limitations. First, 2 of the included studies were classified as fair quality rather than good quality. Second, some baseline characteristics, such as pain intensity or physical impairment levels, as well as the timing and type of physical therapist interventions, varied across studies. However, no meta-regression or subgroup analyses were conducted to investigate their potential effects on the outcomes because of the small number of included studies. Last, the lack of homogeneity in the follow-up period among the included studies resulted in inconclusive results for outcomes beyond 3 months. Therefore, it is not possible to assume the superiority of either intervention in the medium or long term, and future studies will need to address this question as more research with longer follow-ups is generated.

Conclusions

Conservative treatment for nontraumatic degenerative meniscal pathology, based on a physical therapist intervention approach, should be considered as a preferable option to surgical treatment. It has been shown to achieve superior moderate effects in pain and physical impairment outcomes in the short term, with lower risk of side effects. Nevertheless, in cases where surgery is deemed necessary, it is recommended that APM be accompanied by physical therapist interventions to increase the muscle strength and reduce knee pain.

Author Contributions

Daniel Solsona-Carcas (Conceptualization, Methodology, Writing—original draft), Javier Trenado-Molina (Formal analysis, Investigation, Methodology, Supervision, Writing—original draft), Almudena Buesa-Estéllez (Formal analysis, Supervision, Writing—review & editing), Maria Pilar López-Royo (Investigation, Supervision, Writing—review & editing), and Pablo Bellosta-López (Conceptualization, Formal analysis, Investigation, Methodology, Supervision, Writing—original draft)

Funding

A.B.-E., M.P.L.-R., and P.B.-L. are members of the research group MOTUS supported by “Gobierno de Aragón” (n. B60_23D).

Systematic Review Registration

The protocol for the systematic review and NMA was registered in the International Prospective Register of Systematic Reviews database (CRD42022320415).

Disclosures

The authors completed the ICMJE Form for Disclosure of Potential Conflicts of Interest and reported no conflicts of interest.

References