Sage Journals: Discover world-class research

Abstract

Background:

Meniscal replacement aims to restore function and delay joint degeneration in patients with symptomatic meniscus deficiency; nonetheless, comparative evidence among different implant options—meniscal allograft transplantation (MAT), collagen meniscus implant (CMI), and polyurethane scaffolds—remains limited.

Purpose:

To systematically review and compare the clinical outcomes of MAT, CMI, and Actifit (polyurethane scaffold).

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a standardized search and review strategy was employed to identify clinical evidence of any designation examining clinical outcomes and implant-associated adverse events after meniscal replacement with specified implants. Effect sizes were calculated via standardized mean deviations and illustrated through forest plots to compare against the minimal clinically important difference (MCID) for relevant patient-reported outcome measures. The primary outcomes were clinically significant improvements in functional status and pain relief. Secondary outcomes included failure rates, reoperations, and other reported adverse events, as well as indirect evidence of chondroprotection.

Results:

A total of 50 studies were included. All 3 implant types yielded statistically significant functional improvements (all reported P < .05), with scores such as the International Knee Documentation Committee and the Lysholm often exceeding the MCID. However, pain relief was inconsistent and frequently failed to achieve the MCID. Failure rates differed markedly among implants, with the mean failure rate being lowest for CMI (5.2%), highest for Actifit (15.9%), and intermediate for MAT (11.4%). Radiological evidence indicated a potential chondroprotective effect; nevertheless, it was not conclusive.

Conclusion:

Meniscal replacement effectively improves patient function, but pain relief is unreliable, and failure risks vary by implant type. The current evidence is insufficient to definitively recommend one implant over another. Clinical decisions must be individualized, considering patient-specific factors, concomitant pathologies, and the unique risk profile of each implant. High-quality, head-to-head randomized controlled trials are urgently needed.

Keywords

allograft implant knee meniscus scaffold

The meniscus is crucial for knee joint biomechanics, playing essential roles in load-bearing, shock absorption, and cartilage health. Loss of meniscal tissue increases contact stress, accelerating articular cartilage damage and the onset of osteoarthritis.³

Meniscal allograft transplantation (MAT) is recognized as an effective treatment for young, active patients to restore load-bearing capacity and provide chondroprotective effects.^62,66,67 Long-term studies have shown promising outcomes, with a notable percentage of allografts maintaining functionality even after 10 to 15 years.⁴³ Still, problems with immunological rejection, disease transmission, inadequate long-term chondroprotection, and limited graft availability persist.⁵¹ In response, tissue-engineered meniscus has emerged as a promising implant for meniscal repair, utilizing innovative techniques to regenerate damaged tissues.^15,28,33 Despite extensive in vitro and in vivo studies in this field, its clinical application in humans remains limited.⁶⁵ Currently, 2 commercial scaffolds are available for reconstructing meniscal defects: collagen meniscus implant (CMI) (Ivy Sports Medicine) and polyurethane scaffolds (Actifit) (Orteq Ltd).^12,69 CMI is a biodegradable type 1 collagen scaffold with supplemented glycosaminoglycans derived from bovine Achilles tendons. Actifit is a porous scaffold composed of polycaprolactone (80%) and polyurethane (20%). Although MAT and tissue-engineered scaffolds (eg, CMI and Actifit) are indicated for distinct clinical scenarios—total/subtotal versus partial meniscal deficiency, respectively—a grey zone of clinical uncertainty persists in treatment selection. Furthermore, the literature lacks a comprehensive review that systematically presents the clinical outcomes, failure modes, and risk profiles of these mainstream replacement strategies within their respective indications. Therefore, this systematic review aims to comprehensively analyze the current clinical evidence for MAT, CMI, and Actifit. Our goal is to provide a clearer, evidence-based framework for clinical decision-making across various scenarios, rather than directly determining the superiority of one implant over another.

Methods

Data Sources and Search Strategy

We conducted this systematic review in accordance with the PRISMA-2020 (The Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines,⁴⁴ and the protocol for this systematic review was registered on PROSPERO (International Prospective Register of Systematic Reviews). PubMed, Embase, and Cochrane Library were reviewed for all English-language studies published before September 8, 2024. The search strategy was constructed to maximize sensitivity, combining medical subject headings (MeSH) with free-text words. The core search concepts were “meniscus” and “meniscal replacement.” For example, the full search string for the PubMed/MEDLINE database was as follows: ((("meniscus"[MeSH Terms]) OR ("meniscal"[All Fields])) AND (("transplantation"[MeSH Terms]) OR ("scaffold"[All Fields]) OR ("implant"[All Fields]) OR ("replacement"[All Fields]))). Additionally, the reference lists of all relevant articles were manually reviewed to identify further relevant publications. Two researchers (X.Y. and Y.M.) independently completed the literature search, with discrepancies resolved by a senior author (W.F.).

Inclusion and Exclusion Criteria

To be included, studies had to report on patient-reported outcome measures (PROMs) and implant-related adverse events, have any level of evidence (according to the 5-level system⁷¹), be written in English, include a minimum of 2-year follow-up (FU), and assess meniscal replacement used to treat knees affected by meniscal loss. This review focused specifically on studies evaluating MAT, CMI, and Actifit. We excluded biomechanical reports, case reports, preclinical studies, reviews, articles not written in English, commentaries, and topics not centered on the meniscus.

Data Extraction

Raw data from included studies were extracted independently by the same 2 independent authors based on the predefined eligibility criteria: (1) trial details, including the type of the study, author's initials, publication year, level of evidence, length of FU; (2) participant information, including the number of patients, age, sex, index knee, location of implant; (3) surgical description, including the type of intervention, lesion and implant characteristics, method of allograft preservation, classification of chondropathy, and concomitant procedures; and (4) clinical parameters rated using PROMs. All reported clinical baseline and final follow-up outcome scores were collected and reviewed. Moreover, adverse events, radiological, and histological characteristics were also extracted. The primary purpose of this data extraction phase was to systematically collect all relevant information concerning the predefined primary and secondary outcomes, including specific PROMs, failure definitions and rates, radiological parameters, and second-look arthroscopic findings for each included meniscal replacement type.

Methodology Quality Assessment

The methodological quality of the collected data was assessed using a modified version of the Coleman methodology score (CMS) (Appendix Table 1).³⁷ The risk of bias was appraised according to the type of study identified. The Revised Tool for Risk of Bias in Randomized Trials (RoB 2.0) was used for randomized controlled trials, and the Methodological Index for Non-Randomized Studies (MINORS) was used for nonrandomized studies.^55,59 Two separate reviewers assessed study quality independently, with disagreements resolved by consensus with a third author (W.F.).

Statistical Analysis

Data from all studies were represented with descriptive summary tables. Ranges with medians were provided for all numerical demographics. Forest plots were generated using the RStudio meta package for the most commonly used PROMs—including the Lysholm score, Tegner activity score, visual analog scale for pain (VAS–Pain), and International Knee Documentation Committee (IKDC) subjective form—as they were the most commonly utilized PROMs among included studies.⁶⁰ For each outcome score, postoperative improvement was calculated as the standardized mean difference between baseline (preoperative) and follow-up (postoperative) scores and compared with established minimal clinically important difference (MCID) thresholds for outcomes after knee injuries (IKDC = 9.9; Lysholm = 10.1; Tegner = 1; and VAS–Pain = 2.7), as reported by the American Orthopaedic Society for Sports Medicine (AOSSM) Outcomes Task Force.²⁹

Results

Search Results and Basic Characteristics

The initial search yielded 3346 total results, and after screening the abstracts, 167 full-text articles were assessed for eligibility. Of these, 50 articles met the inclusion criteria (Figure 1). Studies reviewed were published between 1999 and 2023. The age of patients ranged from 19.3 to51 years (median, 36.2 years), with 70.7% being men. Table 1 summarizes the basic characteristics of the included studies, which comprise 1 randomized controlled trial, 6 prospective cohort studies, 1 retrospective cohort study, 3 case-control studies, and 39 case series (all involving >5 patients). Also, 17 of the total 50 studies reported results on MAT, 22 studies on Actifit, 13 studies assessed patients treated with CMI, and 2 studies compared the effects of CMI and Actifit scaffolds.^7,48 Detailed data are presented in Appendix Table 1.

Figure 1.

PRISMA flowchart of study selection. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Table 1

Basic Characteristics of Included Studies^α

Study	Study Design	LOE	Patient	Men/ Women	Age, Years	Medial/Lateral	Left/Right	Follow-up, Months
MAT
Chalmers etal¹⁰ (2013)	Case series	4	13	4/9	19.3	3/10	7/6	Mean, 39.6
Grassi etal²⁴ (2023)	Case series	4	324	248/76	39.5	182/142	142/182	Mean, 68.4
González-Lucena etal²³ (2010)	Case series	4	33	24/9	38.8	14/19	NR	Mean, 78
Ha etal²⁵ (2014)	Case series	4	39	29/10	40	12/27	NR	Mean, 50.4
Marcacci etal³⁹ (2012)	Case series	4	32	23/9	35.6	16/16	14/18	Mean, 40.4
Mahmoud etal³⁸ (2018)	Case series	4	30	16/14	34.9	19/11	17/13	Mean, 117.6
Paša etal⁴⁶ (2021)	Prospective cohort study	2	46	18/28	37.2	36/13	21/26	Mean, 120
Ryu etal⁵² (2002)	Case series	4	25	17/8	34.5	10/16	NR	Mean, 33
Saltzman etal⁵³ (2012)	Case series	4	22	15/7	32.5	13/9	11/11	Mean, 102
Torres-Claramunt etal⁶² (2023)	Case series	3	38	25/13	36.9	23/15	19/19	Mean, 206.4
van der Wal etal⁶⁸ (2009)	Case series	4	57	40/17	39.4	17/34	20/43	Mean, 165
Vundelinckx etal⁶⁶ (2010)	Case series	4	34	18/16	33	13/22	NR	Mean, 105
Vundelinckx etal⁶⁷ (2014)	Case series	4	30	15/15	33	11/19	NR	Mean, 152
Yoon etal⁷² (2014)	Retrospective cohort study	3	91	71/20	33.9	35/56	NR	Mean, 40
Zaffagnini etal⁷⁵ (2016)	Case series	4	147	117/30	40.9	82/65	81/66	Mean, 48
Zaffagnini etal⁷⁴ (2016)	Case series	4	89	74/15	38.5	45/44	41/48	Mean, 50.4
Zhang etal⁷⁹ (2012)	Case series	4	18	9/9	36.5	7/11	NR	Minimum, 18
Actifit
Akkaya etal¹ (2020)	Case series	4	23	16/7	32.3	23/0	15/8	Mean, 38.3
Baynat etal⁴ (2014)	Case series	4	18	13/5	20-46	13/5	NR	Minimum, 24
Bouyarmane etal⁵ (2014)	Prospective cohort study	2	54	37/17	28	0/54	NR	24
Bulgheroni etal⁷ (2016)	Case-control study	3	25	20/5	34.4	NR	12/13	Minimum, 24
Bulgheroni etal⁸ (2013)	Case series	4	19	17/2	32.8	16/2 ^b	NR	24
Condello etal¹¹ (2021)	Case series	4	67	48/19	40.8	54/13	NR	Mean, 36
De Coninck etal¹³ (2013)	Case series	4	26	12/12	35	18/8	NR	24
Dhollander etal¹⁴ (2016)	Case series	4	44	24/20	32.1	29/15	17/27	Minimum, 60
Efe etal¹⁶ (2012)	Case series	4	10	8/2	29	10/0	NR	12
Faivre etal¹⁷ (2015)	Prospective cohort study	2	20	NR	28.7	8/12	NR	24
Filardo etal¹⁸ (2017)	Case series	4	16	9/7	45	12/4	NR	Minimum, 72
Gelber etal²² (2021)	Case series	4	62	46/16	41.3	62/0	NR	Mean, 45
Gelber etal²⁰ (2015)	Prospective cohort study	2	30	21/9	45.1	30/0	NR	Mean, 31.2
Gelber etal²¹ (2015)	Case series	4	54	42/12	40.2	40/14	NR	Mean, 39
Haspl etal²⁶ (2021)	Case series	4	9	5/4	36.0	5/4	NR	Mean, 20.8
Kon etal³² (2014)	Case series	4	18	11/7	45.0	13/5	NR	24
Leroy etal³⁴ (2017)	Prospective cohort study	2	15	8/7	30	6/9	4/11	Minimum, 60
Monllau etal⁴² (2018)	Case series	4	32	25/7	41.3	21/11	18/14	Mean, 70.2
Reale etal⁴⁸ (2022)	Case-control study	3	22	14/8	44.1	14/7	NR	Mean, 130
Schüttler etal⁵⁴ (2015)	Case series	4	18	NR	32.5	18/0	NR	48
Toanen etal⁶¹ (2020)	Case series	4	155	109/46	33.7	101/54	NR	Minimum, 60
Verdonk etal⁶⁴ (2012)	Case series	4	52	39/13	30.8	34/18	27/25	24
CMI
Bulgheroni etal⁶ (2015)	Case-control study	3	17	13/4	32.9	17/0	6/11	Mean, 116.4
Bulgheroni etal⁷ (2016)	Case-control study	3	28	19/9	38.7	28/0	8/20	Minimum, 24
Bulgheroni etal⁹ (2010)	Case series	4	34	25/9	39	34/0	NR	60
Linke etal³⁵ (2007)	Case series	4	23	NR	41.6	23/0	NR	24
Monllau etal⁴¹ (2011)	Case series	4	25	20/5	29.2	25/0	11/14	Minimum, 120
Reale etal⁴⁸ (2022)	Case-control study	3	25	17/8	42.4	16/9	NR	Mean, 125.1
Rodkey etal⁴⁹ (2008)	RCT	1	311	243/68	39.2	311/0	NR	Mean, 59
Rodkey etal⁵⁰ (1999)	Case series	4	8	8/0	40	8/0	NR	Minimum, 24
Steadman and Rodkey⁵⁸ (2005)	Case series	4	8	8/0	40	8/0	NR	Mean, 69.6
Zaffagnini etal⁷³ (2007)	Case series	4	8	NR	39	8/0	3/5	Mean, 81.6
Zaffagnini etal⁷⁶ (2015)	Case series	4	43	30/13	30.1	0/43	19/24	Mean, 24.2
Zaffagnini etal⁷⁸ (2011)	Prospective cohort study	2	33	33/0	40	33/0	NR	Mean, 133
Zaffagnini etal⁷⁷ (2012)	Case series	4	24	20/4	36.3	0/24	9/15	Minimum, 24

Data are presented as n, mean. CMI, collagen meniscal implant; LOE, level of evidence; MAT, meniscal allograft transplantation; NR, not reported; RCT, randomized controlled trial.

16 in the medial, 2 in the lateral, and 1 bilateral.

Methodology Quality Assessment

The modified CMS scores of the included studies ranged from 41 to 77 (median, 64), suggesting a moderate overall methodological quality, although a considerable range in quality was observed (Appendix Table 1). As evaluated with RoB 2.0, the only randomized controlled trial was graded as having some concerns. The MINORS score ranged from 10 to 22 (median, 14) (Appendix Table 2).

PROMS and MCID

Of the 50 studies meeting the inclusion criteria, 17 different scoring systems were presented in the literature: the most frequently collected PROMs were the Lysholm score (n = 36), followed by the VAS–Pain (n = 34), the Tegner activity score (n = 32), and the IKDC subjective form (n = 27). Statistically significant improvements were observed in all groups for all PROMs from preoperative values to final follow-up (P < .05) (Table 2). In the included studies, the mean recorded improvements in the Lysholm score were higher than the MCID values for all groups (Figure 2). Similarly, IKDC scores generally exceeded the MCID for the MAT and Actifit groups (Figure 3). In 10 out of 14 investigations, the Tegner score exceeded the MCID (6 of 7 for MAT; 2 of 4 for Actifit; and 2 of 3 for CMI) (Figure 4). In stark contrast to these encouraging functional gains, however, pain relief was far less consistent. Of the 23 studies reporting VAS scores, only 9 demonstrated improvements exceeding the MCID, with none in the CMI group reaching the MCID threshold (Figure 5).

Table 2

Preoperative and Final Follow-up PROMs^α

Knee Scoring Scale	MAT
Knee Scoring Scale	Studies	Patients	Preop	Postop
Lysholm	14	892	53 (9.61)	78.4 (7.64)
VAS–Pain	9	722	6.3 (0.72)	2.6 (0.77)
Tegner	6	537	2.8 (0.75)	4.1 (0.93)
IKDC subjective form	5	204	43.4 (7.14)	69 (7.78)
	Actifit
	Studies	Patients	Preop	Postop
Lysholm	4	258	60 (6.1)	82.9 (5.97)
VAS-Pain	8	386	5.3 (0.32)	2.2 (0.81)
Tegner	10	293	3.7 (1.31)	4.5 (1.02)
IKDC subjective form	9	402	44.3 (4.07)	69.3 (3.89)
	CMI
	Studies	Patients	Preop	Postop
Lysholm	4	112	61 (3.67)	93.6 (0.82)
VAS-Pain	3	66	5.1 (0.61)	2.1 (0.6)
Tegner	9	220	2.7 (0.83)	5 (0.79)
IKDC subjective form	2	48	53.6 (9.55)	72.6 (14.78)

Data are presented as n (%). Statistical significance was set at P < .05 for all groups. Actifit, polyurethane scaffold; CMI, collagen meniscal implant; IKDC, International Knee Documentation Committee; MAT, meniscal allograft transplantation; Postop, postoperative; Preop, preoperative; PROM, patient-reported outcome measure; VAS–Pain, visual analog scale for pain.

Figure 2.

Forest plot with the MCID line for the Lysholm score. Actifit, polyurethane scaffold; CMI, collagen meniscus implant; CMS, Coleman methodology score; FU, follow-up; MCID, minimal clinically important difference; MAT, meniscal allograft transplantation; MD, mean difference; MINORS, Methodological Index for Nonrandomized Studies; SMD, standardized mean difference.

Figure 3.

Forest plot with the MCID line for the IKDC score. Actifit, polyurethane scaffold; CMI, collagen meniscus implant; CMS, Coleman methodology score; FU, follow-up; MCID, minimal clinically important difference; MAT, meniscal allograft transplantation; MD, mean difference; MINORS, Methodological Index for Nonrandomized Studies; SMD, standardized mean difference.

Figure 4.

Forest plot with the MCID line for the Tegner score. Actifit, polyurethane scaffold; CMI, collagen meniscus implant; CMS, Coleman methodology score; FU, follow-up; MCID, minimal clinically important difference; MAT, meniscal allograft transplantation; MD, mean difference; MINORS, Methodological Index for Nonrandomized Studies; SMD, standardized mean difference.

Figure 5.

Forest plot with the MCID line for the VAS–Pain score. Actifit, polyurethane scaffold; CMI, collagen meniscus implant; CMS, Coleman methodology score; FU, follow-up; MCID, minimal clinically important difference; MAT, meniscal allograft transplantation; MD, mean difference; MINORS, Methodological Index for Nonrandomized Studies; SMD, standardized mean difference. VAS–Pain, visual analog scale for pain.

Surgical Findings

The mean length of the Actifit implant ranged from 35.6 to 46.1 mm (median, 42.9 mm), whereas in the CMI group, it ranged from 34 to 48.2 mm (median, 45 mm) (Appendix Table 3). The most adopted preservation method of allograft used was fresh-frozen, exclusively in 10 studies,^{10,23-25,39,53,57,62,72,74,75} cryopreserved allografts in 3 studies,^66-68 and deep-frozen allografts in 2 studies.^46,79 Seventeen studies reported distinct operative techniques for the fixation of graft; in summary, most studies employed the bone bridge technique (bridge in-slot,^10,38,53,72 keyhole^25,38,57,72) for lateral MAT, and the bone plug technique for medial MAT.^{10,25,38,53,62,72,79} A soft tissue fixation technique was used in 5 studies.^{23,24,39,74,75} The Actifit and CMI scaffolds were solely sutured to the residual meniscal tissue for fixation. Only 1 study reported on isolated MAT,⁷⁹ whereas concomitant procedures were performed in the remaining studies. The concomitant surgeries of the studies could be classified as ligament reconstructions, osteotomies, and cartilage treatments. The most frequent associated procedures were anterior cruciate ligament reconstruction (ACLR), high tibial osteotomy (HTO), and microfracture.

Radiological and Second-Look Arthroscopic Findings

One of the most commonly evaluated parameters by the authors was meniscal extrusion (ME). The extruded meniscus was more usual in the MAT (7 of 17 studies) and Actifit (12 of 22 studies) groups, but not for the CMI scaffolds. As for the extrusion rates, Marcacci etal³⁹ found 69% of the allografts extruded, Torres-Claramunt etal⁶² reported ME increased from 29.7% obtained at the 5-year FU to 72.5% observed at the last FU. The absolute ME of the Actifit scaffolds can be achieved by 3.5 mm in 4 studies.^1,18,22,26 Of note, 6 studies revealed that the extrusion findings in magnetic resonance imaging (MRI) did not correlate with clinical outcomes.^{1,13,16,18,25,46,54} Although considerable ME was observed, 5 studies showed that the maximal extrusion was stabilized at mid-term follow-up and remained unchanged at the final follow-up.^{1,25,26,34,46} Regarding the side of extrusion, 2 studies identified that it was not statistically different between the medial and lateral grafts.^17,72

Regarding the chondroprotective effect of the implants, there is some evidence from radiographs and MRI studies included in the analysis. A stable cartilage status of the index compartment in the Actifit group was demonstrated in 6 studies compared with the baseline.^{4,8,14,16,34,61,64} Radiographs showed that the joint space width remained almost unchanged from the initial evaluation up to the final FU measurement for the MAT (4 studies^23,53,62,79) and CMI (3 studies^41,50,78) groups.

Second-look arthroscopy was described in 15 studies (5 on MAT^{23,46,52,72,79}; 4 on Actifit^5,8,26,65; and 6 on CMI^{9,49,50,58,73,76}). Two studies demonstrated that the allografts were completely intact and had excellent peripheral vascularization.^23,79 In the Actifit and CMI scaffolds, 8 studies showed that scaffolds were well integrated with the surrounding neotissue but reduced in size compared with the original implant.^{5,7-9,26,49,50,73} For the cartilage status during relook arthroscopies, Paša etal⁴⁶ reported that 19 of 23 patients who underwent second-look arthroscopy demonstrated improved cartilage condition compared with the condition before meniscal allograft transplantation. Bulgheroni etal⁷ found that the articular cartilage appeared intact in most patients in both the Actifit and CMI groups, without signs of progression of any existing articular injury. These findings may suggest the chondroprotective effect of these implants.

Adverse Events

The most commonly reported adverse events were implant failures (Appendix Table 4). A treatment failure was deemed to have occurred if an additional surgical intervention was required for the index defect, and the surgeon determined that the necessity for this supplementary procedure was attributable to an uncertain, potential, likely, or definitive link to the scaffold and/or the initial procedure. In the included studies, total knee arthroplasty, unicompartmental knee arthroplasty, allograft removal or revision, and re-transplantation were considered surgical failures for the initial MAT.^{24,38,53,62,66-68,75} Failure rates for the MAT group ranged from⁷⁵ 4.8% to⁶² 42.1%, with a mean of 11.4% (89 failures in 779 allografts); in the Actifit group, failure rates varied from¹¹ 6% to¹⁴ 31.8%, with a mean of 15.9% (62 failures in 391 scaffolds); only 2 studies in the CMI group reported that the failure rates were 4.5% and 8%, with a mean of 5.2% (6 failures in 116 scaffolds).^27,41

Discussion

The principal finding of this systematic review is not to declare a superior meniscal replacement strategy, but to systematically identify a prevalent function-pain discrepancy and to quantify the distinct failure rates of major implant types within their respective clinical contexts. Our analysis confirms that while all implant types significantly improve functional scores, this success contrasts starkly with the outcomes for pain, where improvements frequently failed to reach the MCID. The most probable explanation for this persistent pain lies in the patient's preoperative articular cartilage status. Meniscectomy initiates a degenerative cascade by creating abnormal jointcontact stresses that accelerate chondral wear.² Consequently, many candidates for meniscal replacement already have significant, often painful, chondral lesions. In this context, a crucial study by Parkinson etal⁴⁵ identified severe preexisting cartilage damage (Outerbridge grade 3-4) as the single most powerful independent predictor of MAT failure and inferior clinical outcomes. This suggests that while a meniscal implant may address the meniscus problem, it cannot reverse the established arthritis problem. Therefore, a critical clinical implication is the need for rigorous preoperative patient selection and counseling.

Although a key rationale for meniscal replacement is the potential to protect articular cartilage from further degradation, our review finds that the evidence supporting this effect remains suggestive rather than conclusive. Observations of stable joint space width on radiographs and preserved cartilage on MRI are encouraging but must be interpreted with significant caution. These are indirect, surrogate endpoints whose correlation with the true histological health of the cartilage is unproven. A pivotal systematic review by Smith etal⁵⁶ concluded that while some evidence for chondroprotection after MAT exists, it is derived from studies of generally low quality with a high risk of bias. The long-term follow-up by Torres-Claramunt etal⁶² provides a sobering perspective, showing that despite good clinical outcomes at 15 years, ME and joint space narrowing progressed over time, with a graft failure rate of 42.1%. A deeper issue lies in the inherent limitations of diagnostic imaging. For instance, a study by Kim etal³¹ comparing postoperative MRI with second-look arthroscopy after MAT found that MRI had low specificity and accuracy for assessing the anterior portion of the graft, often overestimating the degree of pathology. This demonstrates a clear disconnect between imaging findings and the graft's true biological state. Furthermore, the lack of studies comparing radiological outcomes to a contralateral healthy knee or a nonoperative control group significantly limits the persuasiveness of the current evidence. Thus, while meniscal replacement may offer a chondroprotective potential, it should not be presented to patients as a guaranteed method to halt arthritis. Honesty about the limited evidence is essential for ethical clinical practice.

The failure rates reported in this review—averaging 11.4% for MAT, 15.9% for Actifit, and 5.2% for CMI—represent not just a statistic, but a significant event with profound long-term consequences for the patient, often leading to revision surgery or arthroplasty. The underlying reasons for failure differ substantially between allografts and synthetic scaffolds, reflecting their distinct biological and mechanical risk profiles. MAT carries risks inherent to transplantation, including the potential for an immune response, particularly when fixed with bone plugs, and the albeit minimal risk of disease transmission.⁵¹ Conversely, synthetic scaffolds, such as CMI and Actifit, face challenges related to materials science. Histological studies of explanted scaffolds reveal that CMI, a collagen-based implant, tends to remodel into vascularized fibrocartilage, whereas Actifit, a polyurethane scaffold, is more often replaced by avascular, cartilage-like tissue.⁷ This biological difference may influence long-term durability, as vascularized tissue could possess superior integration and repair capacity, potentially explaining the lower failure rate of CMI observed in our review. The failure of scaffolds can also result from incomplete tissue ingrowth, material degradation, or a chronic foreign body reaction, leading to mechanical incompetence. Clinicians must weigh these distinct risk profiles—immunology and supply for MAT versus biomaterial performance for scaffolds—and select the most appropriate implant based on the patient's specific anatomy, pathology, and activity demands.

This systematic review, like most published studies in the field, was unable to perform a subgroup analysis comparing the clinical outcomes of medial versus lateral meniscal replacements. The fundamental reason is that the primary studies overwhelmingly report these outcomes as a consolidated group.This practice masks crucial anatomical, biomechanical, and prognostic differences between the 2 compartments, severely limiting our precise understanding of treatment efficacy. Multiple studies have confirmed that joint degeneration is more rapid and clinical symptoms are more severe after lateral meniscectomy.^30,40 Correspondingly, after meniscal replacement, lateral MAT yields superior clinical outcomes (eg, IKDC and Knee injury and Osteoarthritis Outcome Scores) compared with medial MAT.⁷⁰ Conversely, medial MATs exhibit greater graft extrusion, and medial implantation has been identified as an independent predictor of surgical failure.⁴⁵ This is likely because the biomechanical environment of the medial compartment places higher demands on graft fixation and integration. Therefore, it is imperative that all future clinical studies on meniscal replacement report and analyze medial and lateral outcomes separately. The practice of lumping them together is no longer scientifically tenable and must be considered a major methodological flaw.

The vast majority of cases included in this review involved concomitant procedures, most commonly ACLR and HTO. This represents a major confounding variable that makes it nearly impossible to attribute the observed clinical improvements solely to the meniscal implant. ACLR is itself a highly successful procedure for restoring knee stability and is known to improve PROMs significantly.¹⁹ When ACLR is performed concurrently with MAT, the improvements in function and satisfaction may largely be driven by the restoration of stability from the ligament reconstruction, not the meniscal graft.⁶³ Similarly, HTO is a powerful intervention designed to unload the affected compartment by altering limb alignment, thereby alleviating pain and improving function.³⁶ An authoritative editorial has explicitly questioned the added value of combining MAT with HTO, highlighting that this combined approach significantly increases reoperation rates without proven benefit in delaying total knee arthroplasty.⁴⁷ This phenomenon reveals a core issue: in many combined procedures, the meniscal implant may be the passenger, while the ACLR or HTO is the driver of the clinical outcome. Due to limitations in the primary data, this systematic review could not quantify the specific contributions of these concomitant procedures through subgroup or regression analysis. This severely weakens our ability to determine the independent therapeutic effect of meniscal replacement. We therefore strongly advocate for more targeted future research designs. Only through such rigorous investigation can we parse out the true, independent therapeutic value of meniscal replacement in the complex environment of multi-pathology knees.

Given the complex considerations of implant choice, prognostic factors, and confounding variables, a structured framework is essential to guide clinical practice. To this end, we developed a stratified clinical decision-making flowchart based on the findings of this review (Figure 6). This algorithm offers a clear, evidence-based roadmap that addresses the grey zone in treatment selection by first triaging patients based on defect type. It then guides clinicians in integrating critical modifying factors, such as chondral status and limb alignment, thereby improving shared decision-making. By systematically identifying the function-pain discrepancy and quantifying implant-specific risks, our framework equips clinicians to better manage patient expectations regarding pain relief and long-term outcomes, potentially enhancing patient satisfaction and reducing unnecessary revisions. This systematic approach underscores the importance of a holistic surgical plan and aims to support individualized, evidence-based patient care.

Figure 6.

Clinical decision-making flowchart for meniscal replacement. Actifit, polyurethane scaffold; ACL, anterior cruciate ligament; ACLR, anterior cruciate ligament reconstruction; Actifit, polyurethane scaffolds; CMI, collagen meniscus implant; DFO, distal femoral osteotomy; HTO, high tibial osteotomy; MAT, meniscal allograft transplantation; MRI, magnetic resonance imaging; TKA, total knee arthroplasty; UKA, unicompartmental knee arthroplasty.

Limitations

The most significant limitation of this review is the inclusion of treatment strategies with distinct indications (MAT vs scaffolds) within a single analysis. We must emphasize that our intent was not a direct head-to-head comparison, as these technologies are not clinically interchangeable. Instead, by systematically presenting their evidence side by side, we aimed to provide a comprehensive view of the current meniscal replacement landscape. Beyond this overarching conceptual limitation, our findings are also constrained by several weaknesses inherent to the available literature. Primarily, the majority of studies were Level 4 evidence, which directly limits the applicability of our conclusions across all clinical scenarios. Additionally, significant heterogeneity existed among the primary studies in both methodology (eg, inclusion criteria, definitions of failure) and patient populations (eg, age, activity level, body mass index). Combined with the small sample sizes and short follow-up periods common in many studies, these factors collectively reduce the certainty of the current evidence. These deficiencies in the primary data, in turn, imposed several analytical constraints on our review. A key limitation was our inability to perform a subgroup analysis comparing medial and lateral meniscal replacements, as most primary studies did not report these outcomes separately, potentially obscuring important prognostic differences. Similarly, inconsistent reporting of material-specific complications (eg, scaffold dissolution, secondary synovitis) precluded a systematic quantitative analysis. The frequent use of concurrent procedures (eg, ACLR, HTO) also acted as a major confounding variable, and their specific contributions to the outcomes could not be isolated in this review. Finally, it must be acknowledged that the narrow indications for meniscal grafting inherently limit the feasibility of conducting large-scale, high-level studies. Despite these challenges, systematic reviews such as this one are crucial for synthesizing the current landscape of evidence and identifying subtle signals in the data that can inform future research directions. These limitations, alongside the inherent difficulties in this field of research, may collectively explain why the clinical application of meniscal implants remains limited.

Conclusion

This systematic review confirms that while meniscal replacement (MAT, CMI, Actifit) effectively improves patient function, its efficacy for pain relief is unreliable, and failure risks differ among implants. The quality and quantity of the current evidence are insufficient to support any single implant as a universally superior option. Therefore, clinical decision-making must be highly individualized, based on a meticulous assessment of patient age, chondral status, concomitant pathologies, and the specific risk profile of each implant. Future research must adopt more rigorous designs, specifically head-to-head randomized controlled trials with stratified analyses for compartmental location and concurrent procedures, to truly advance evidence-based practice in this field.

Supplemental Material

sj-docx-1-ojs-10.1177_23259671251394376 – Supplemental material for Clinical Outcomes of Meniscal Replacement for Meniscus Deficiency: A Systematic Review of Current Evidence

Supplemental material, sj-docx-1-ojs-10.1177_23259671251394376 for Clinical Outcomes of Meniscal Replacement for Meniscus Deficiency: A Systematic Review of Current Evidence by Xiaolong Yang, Yunhe Mao, Yi Zhou, Tianhao Xu and Weili Fu in Orthopaedic Journal of Sports Medicine

Footnotes

Acknowledgements

The authors did not utilize any writing assistance for this manuscript. In accordance with the TITAN Guideline Checklist 2025, the authors declare that no artificial intelligence (AI) or AI-assisted tools were used in the research or preparation of this manuscript.

Final revision submitted July 23, 2025; accepted October 17, 2025.

The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

ORCID iDs

Xiaolong Yang

Yi Zhou

Weili Fu

References

Akkaya

Şimşek

Gürsoy

Çay

Bozkurt

Medial meniscus scaffold implantation in combination with concentrated bone marrow aspirate injection: minimum 3-year follow-up. J Knee Surg. 2020;33(08):838-846. doi:10.1055/s-0040-1701452

Allende

Dzidzishvili

Garcia

, et al. Partial meniscectomy yields comparable outcomes and failure rates to meniscal repair for horizontal cleavage tears, with fewer complication rates but greater progression of degenerative changes. Arthroscopy. 2025 ;41(7):2680-2694. doi:10.1016/j.arthro.2024.10.009

Baratz

Mengato

Meniscal tears: the effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee. Am J Sports Med. 1986;14(4):270-275. doi:10.1177/036354658601400405

Baynat

Andro

Vincent

, et al. Actifit synthetic meniscal substitute: experience with 18 patients in Brest, France. Orthop Traumatol Surg Amp Res. 2014;100(suppl 8):S385-S389. doi:10.1016/j.otsr.2014.09.007

Bouyarmane

Beaufils

Pujol

, et al. Polyurethane scaffold in lateral meniscus segmental defects: clinical outcomes at 24 months follow-up. Orthop Traumatol Surg Amp Res. 2014;100(1):153-157. doi:10.1016/j.otsr.2013.10.011

Bulgheroni

Grassi

Bulgheroni

Marcheggiani Muccioli

Zaffagnini

Marcacci

Long-term outcomes of medial CMI implant versus partial medial meniscectomy in patients with concomitant ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2015;23(11):3221-3227. doi:10.1007/s00167-014-3136-9

Bulgheroni

Grassi

Campagnolo

Bulgheroni

Mudhigere

Gobbi

Comparative study of collagen versus synthetic-based meniscal scaffolds in treating meniscal deficiency in young active population. Cartilage. 2016;7(1):29-38. doi:10.1177/1947603515600219

Bulgheroni

Regazzola

Mazzola

Polyurethane scaffold for the treatment of partial meniscal tears. Clinical results with a minimum two-year follow-up. Joints. 2013;01(04):161-166. doi:10.11138/jts/2013.1.4.161

Bulgheroni

Murena

Ratti

Bulgheroni

Ronga

Cherubino

Follow-up of collagen meniscus implant patients: clinical, radiological, and magnetic resonance imaging results at 5 years. Knee. 2010;17(3):224-229. doi:10.1016/j.knee.2009.08.011

10.

Chalmers

Karas

Sherman

Cole

BJ.

Return to high-level sport after meniscal allograft transplantation. Arthroscopy. 2013;29(3):539-544. doi:10.1016/j.arthro.2012.10.027

11.

Condello

Dei Giudici

Perdisa

, et al. Polyurethane scaffold implants for partial meniscus lesions: delayed intervention leads to an inferior outcome. Knee Surg Sports Traumatol Arthrosc. 2021;29(1):109-116. doi:10.1007/s00167-019-05760-4

12.

Dangelmajer

Familiari

Simonetta

Kaymakoglu

Huri

Meniscal transplants and scaffolds: a systematic review of the literature. Knee Surg Relat Res. 2017;29(1):3-10. doi:10.5792/ksrr.16.059

13.

De Coninck

Huysse

Willemot

Verdonk

Verstraete

Verdonk

. Two-year follow-up study on clinical and radiological outcomes of polyurethane meniscal scaffolds. Am J Sports Med. 2013;41(1):64-72. doi:10.1177/0363546512463344

14.

Dhollander

Verdonk

Treatment of painful, irreparable partial meniscal defects with a polyurethane scaffold. Am J Sports Med. 2016;44(10):2615-2621. doi:10.1177/0363546516652601

15.

Dou

, et al. Meniscus heterogeneity and 3D-printed strategies for engineering anisotropic meniscus. Int J Bioprinting. 2023;9(3):693. doi:10.18063/ijb.693

16.

Efe

Getgood

Schofer

, et al. The safety and short-term efficacy of a novel polyurethane meniscal scaffold for the treatment of segmental medial meniscus deficiency. Knee Surg Sports Traumatol Arthrosc. 2012;20(9):1822-1830. doi:10.1007/s00167-011-1779-3

17.

Faivre

Bouyarmane

Lonjon

Boisrenoult

Pujol

Beaufils

Actifit scaffold implantation: influence of preoperative meniscal extrusion on morphological and clinical outcomes. Orthop Traumatol Surg Amp Res. 2015;101(6):703-708. doi:10.1016/j.otsr.2015.06.016

18.

Filardo

Kon

Perdisa

, et al. Polyurethane-based cell-free scaffold for the treatment of painful partial meniscus loss. Knee Surg Sports Traumatol Arthrosc. 2017;25(2):459-467. doi:10.1007/s00167-016-4219-6

19.

Gabr

Fontalis

Robinson

, et al. The impact of concomitant meniscal surgery on the clinical outcomes of anterior cruciate ligament reconstruction. Bone Jt Open. 2024;5(11):1003-1012. doi:10.1302/2633-1462.511.BJO-2024-0147.R1

20.

Gelber

Isart

Erquicia

Pelfort

Tey-Pons

Monllau

JC.

Partial meniscus substitution with a polyurethane scaffold does not improve outcome after an open-wedge high tibial osteotomy. Knee Surg Sports Traumatol Arthrosc. 2015;23(1):334-339. doi:10.1007/s00167-014-3206-z

21.

Gelber

Petrica

Isart

Mari-Molina

Monllau

JC.

The magnetic resonance aspect of a polyurethane meniscal scaffold is worse in advanced cartilage defects without deterioration of clinical outcomes after a minimum two-year follow-up. Knee. 2015;22(5):389-394. doi:10.1016/j.knee.2015.01.008

22.

Gelber

Torres-Claramunt

Poggioli

Pérez-Prieto

Monllau

JC.

Polyurethane meniscal scaffold: does preoperative remnant meniscal extrusion have an influence on postoperative extrusion and knee function?

J Knee Surg. 2021;34(14):1555-1559. doi:10.1055/s-0040-1710377

23.

González-Lucena

Gelber

Pelfort

Tey

Monllau

JC.

Meniscal allograft transplantation without bone blocks: a 5- to 8-year follow-up of 33 patients. Arthroscopy. 2010;26(12):1633-1640. doi:10.1016/j.arthro.2010.05.005

24.

Grassi

Di Paolo

Coco

, et al. Survivorship and reoperation of 324 consecutive isolated or combined arthroscopic meniscal allograft transplants using soft tissue fixation. Am J Sports Med. 2023;51(1):119-128. doi:10.1177/03635465221131522

25.

Jang

Jung

Cho

Kim

JG.

Clinical and radiologic outcomes after meniscus allograft transplantation at 1-year and 4-year follow-up. Arthroscopy. 2014;30(11):1424-1429. doi:10.1016/j.arthro.2014.05.032

26.

Haspl

Trsek

Lovric

Strahonja

Matokovic

Functional and magnetic resonance imaging outcome after polyurethane meniscal scaffold implantation following partial meniscectomy. Int Orthop. 2021;45(4):971-975. doi:10.1007/s00264-020-04844-y

27.

Hirschmann

Keller

Hirschmann

, et al. One-year clinical and MR imaging outcome after partial meniscal replacement in stabilized knees using a collagen meniscus implant. Knee Surg Sports Traumatol Arthrosc. 2013;21(3):740-747. doi:10.1007/s00167-012-2259-0

28.

Huey

Athanasiou

KA.

Unlike bone, cartilage regeneration remains elusive. Science. 2012;338(6109):917-921. doi:10.1126/science.1222454

29.

Irrgang

Anderson

Dunn

. AOSSM Outcomes Task Force. Summary of Clinical Outcome Measures for Sports-Related Knee Injuries. Published online in 2012. Accessed October 7, 2018. https://www.arthroscopyjournal.org/article/S0749-8063(18)31150-2/abstract

30.

Jeong

Lee

CS.

Meniscectomy. Knee Surg Relat Res. 2012;24(3):129-136. doi:10.5792/ksrr.2012.24.3.129

31.

Kim

Jeon

, et al. Comparison of postoperative magnetic resonance imaging and second-look arthroscopy for evaluating meniscal allograft transplantation. Arthroscopy. 2015;31(5):859-866. doi:10.1016/j.arthro.2014.11.041

32.

Kon

Filardo

Zaffagnini

, et al. Biodegradable polyurethane meniscal scaffold for isolated partial lesions or as combined procedure for knees with multiple comorbidities: clinical results at 2 years. Knee Surg Sports Traumatol Arthrosc. 2014;22(1):128-134. doi:10.1007/s00167-012-2328-4

33.

Kwon

Brown

Lee

, et al. Surgical and tissue engineering strategies for articular cartilage and meniscus repair. Nat Rev Rheumatol. 2019;15(9):550-570. doi:10.1038/s41584-019-0255-1

34.

Leroy

Beaufils

Faivre

Steltzlen

Boisrenoult

Pujol

Actifit polyurethane meniscal scaffold: MRI and functional outcomes after a minimum follow-up of 5 years. Orthop Traumatol Surg Amp Res. 2017;103(4):609-614. doi:10.1016/j.otsr.2017.02.012

35.

Linke

Ulmer

Imhoff

AB.

Replacement of the meniscus with a collagen implant (CMI). Eur J Trauma Emerg Surg. 2007;33(4):435-440. doi:10.1007/s00068-007-2188-7

36.

Liu

Agarwalla

Gomoll

AH.

High tibial osteotomy and medial meniscus transplant. Clin Sports Med. 2019;38(3):401-416. doi:10.1016/j.csm.2019.02.006

37.

Longo

Rizzello

Loppini

, et al. Multidirectional instability of the shoulder: a systematic review. Arthroscopy. 2015;31(12):2431-2443. doi:10.1016/j.arthro.2015.06.006

38.

Mahmoud

Young

Bullock-Saxton

Myers

Meniscal allograft transplantation: the effect of cartilage status on survivorship and clinical outcome. Arthroscopy. 2018;34(6):1871-1876.e1. doi:10.1016/j.arthro.2018.01.010

39.

Marcacci

Zaffagnini

Marcheggiani Muccioli

, et al. Meniscal allograft transplantation without bone plugs. Am J Sports Med. 2012;40(2):395-403. doi:10.1177/0363546511424688

40.

McDermott

Amis

AA.

The consequences of meniscectomy. J Bone Joint Surg Br. 2006;88-B(12):1549-1556. doi:10.1302/0301-620x.88b12.18140

41.

Monllau

Gelber

Abat

, et al. Outcome after partial medial meniscus substitution with the collagen meniscal implant at a minimum of 10 years’ follow-up. Arthroscopy. 2011;27(7):933-943. doi:10.1016/j.arthro.2011.02.018

42.

Monllau

Poggioli

Erquicia

, et al. Magnetic resonance imaging and functional outcomes after a polyurethane meniscal scaffold implantation: minimum 5-year follow-up. Arthroscopy. 2018;34(5):1621-1627. doi:10.1016/j.arthro.2017.12.019

43.

Novaretti

Patel

Lian

, et al. Long-term survival analysis and outcomes of meniscal allograft transplantation with minimum 10-year follow-up: a systematic review. Arthroscopy. 2019;35(2):659-667. doi:10.1016/j.arthro.2018.08.031

44.

Page

McKenzie

Bossuyt

, et al. The PRISMA 2020 Statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. doi:10.1136/bmj.n71

45.

Parkinson

Smith

Thompson

Spalding

Meniscal allograft transplantation: factors predicting failure. Orthop J Sports Med. 2017;5(5_suppl 5):2325967117S00196. doi:10.1177/2325967117S00196

46.

Paša

Kužma

Herůfek

Prokeš

Jarkovský

Havlas

Meniscus transplantation—prospective assessment of clinical results in two, five and ten year follow-up. Int Orthop. 2021;45(4):941-957. doi:10.1007/s00264-020-04638-2

47.

Piper

Gallo

RA.

Editorial commentary: meniscus allograft transplantation with concomitant high tibial osteotomy and cartilage restoration risks reoperations and potential worsening outcomes following subsequent total knee arthroplasty. Arthroscopy. 2025;41(5):1459-1461. doi:10.1016/j.arthro.2024.09.035

48.

Reale

Lucidi

Grassi

Poggi

Filardo

Zaffagnini

A comparison between polyurethane and collagen meniscal scaffold for partial meniscal defects: similar positive clinical results at a mean of 10 years of follow-up. Arthroscopy. 2022;38(4):1279-1287. doi:10.1016/j.arthro.2021.09.011

49.

Rodkey

DeHaven

Montgomery

, et al. Comparison of the collagen meniscus implant with partial meniscectomy. J Bone Joint Surg Am. 2008;90(7):1413-1426. doi:10.2106/JBJS.G.00656

50.

Rodkey

Steadman

ST.

A Clinical study of collagen meniscus implants to restore the injured meniscus. Clin Orthop Relat Res. 1999;367:S281-S292. doi:10.1097/00003086-199910001-00027

51.

Rosso

Bisicchia

Bonasia

Amendola

Meniscal allograft transplantation. Am J Sports Med. 2015;43(4):998-1007. doi:10.1177/0363546514536021

52.

Ryu

RKN

Dunbar

V WH

Morse

GG.

Meniscal allograft replacement: a 1-year to 6-year experience. Arthroscopy. 2002;18(9):989-994. doi:10.1053/jars.2002.36104

53.

Saltzman

Bajaj

Salata

, et al. Prospective long-term evaluation of meniscal allograft transplantation procedure: a minimum of 7-year follow-up. J Knee Surg. 2012;25(02):165-176. doi:10.1055/s-0032-1313738

54.

Schüttler

Pöttgen

Getgood

, et al. Improvement in outcomes after implantation of a novel polyurethane meniscal scaffold for the treatment of medial meniscus deficiency. Knee Surg Sports Traumatol Arthrosc. 2015;23(7):1929-1935. doi:10.1007/s00167-014-2977-6

55.

Slim

Nini

Forestier

Kwiatkowski

Panis

Chipponi

Methodological index for non-randomized studies (MINORS): development and validation of a new instrument. ANZ J Surg. 2003;73(9):712-716. doi:10.1046/j.1445-2197.2003.02748.x

56.

Smith

Parkinson

Hutchinson

Costa

Spalding

Is meniscal allograft transplantation chondroprotective? A systematic review of radiological outcomes. Knee Surg Sports Traumatol Arthrosc. 2016;24(9):2923-2935. doi:10.1007/s00167-015-3573-0

57.

Smith

Parsons

Wright

, et al. A pilot randomized trial of meniscal allograft transplantation versus personalized physiotherapy for patients with a symptomatic meniscal deficient knee compartment. Bone Joint J. 2018;100(1):56-63. doi:10.1302/0301-620X.100B1.BJJ-2017-0918.R1

58.

Steadman

Rodkey

WG.

Tissue-engineered collagen meniscus implants: 5- to 6-year feasibility study results. Arthroscopy. 2005;21(5):515-525. doi:10.1016/j.arthro.2005.01.006

59.

Sterne

JAC

Savović

Page

, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ. 2019;366:l4898. doi:10.1136/bmj.l4898

60.

García-Mansilla

Kelley

, et al. Clinical outcomes of meniscal allograft transplantation with respect to the minimal clinically important difference. Am J Sports Med. 2022;50(12):3440-3446. doi:10.1177/03635465211036116

61.

Toanen

Dhollander

Bulgheroni

, et al. Polyurethane meniscal scaffold for the treatment of partial meniscal deficiency: 5-year follow-up outcomes: a European multicentric study. Am J Sports Med. 2020;48(6):1347-1355. doi:10.1177/0363546520913528

62.

Torres-Claramunt

Morales-Avalos

Perelli

Padilla-Medina

Monllau

JC.

Good clinical outcomes can be expected after meniscal allograft transplantation at 15 years of follow-up. Knee Surg Sports Traumatol Arthrosc. 2023;31(1):272-278. doi:10.1007/s00167-022-07106-z

63.

Vasavada

Avila

DeClouette

, et al. Poster 341: Clinical outcomes of concomitant arthroscopically assisted anterior cruciate ligament reconstruction and meniscal allograft transplantation. Orthop J Sports Med. 2023;11(7_suppl 3):2325967123S00308. doi:10.1177/2325967123S00308

64.

Verdonk

Beaufils

Bellemans

, et al. Successful treatment of painful irreparable partial meniscal defects with a polyurethane scaffold. Am J Sports Med. 2012;40(4):844-853. doi:10.1177/0363546511433032

65.

Veronesi

Vandenbulcke

Ashmore

, et al. Meniscectomy-induced osteoarthritis in the sheep model for the investigation of therapeutic strategies: a systematic review. Int Orthop. 2020;44(4):779-793. doi:10.1007/s00264-020-04493-1

66.

Vundelinckx

Bellemans

Vanlauwe

Arthroscopically assisted meniscal allograft transplantation in the knee. Am J Sports Med. 2010;38(11):2240-2247. doi:10.1177/0363546510375399

67.

Vundelinckx

Vanlauwe

Bellemans

Long-term subjective, clinical, and radiographic outcome evaluation of meniscal allograft transplantation in the knee. Am J Sports Med. 2014;42(7):1592-1599. doi:10.1177/0363546514530092

68.

van der Wal

RJP

Thomassen

BJW

van Arkel

ERA.

Long-term clinical outcome of open meniscal allograft transplantation. Am J Sports Med. 2009;37(11):2134-2139. doi:10.1177/0363546509336725

69.

Wang

Gonzalez-Leon

Rodeo

Athanasiou

KA.

Clinical replacement strategies for meniscus tissue deficiency. Cartilage. 2021;13(suppl 1):S262-S270. doi:10.1177/19476035211060512

70.

Wei

Liang

Shang

Chen

JF.

Comparison of medial versus lateral meniscus allograft transplantation: literature review and meta-analysis. Saudi Med J. 2016;37(6):613-623. doi:10.15537/smj.2016.6.13983

71.

Wright

Swiontkowski

Heckman

. Introducing levels of evidence to the journal. J Bone Joint Surg Am. 2003;85(1):1-3.

72.

Yoon

Lee

Park

Kim

Chung

KY.

Meniscus allograft transplantation. Am J Sports Med. 2014;42(1):200-207. doi:10.1177/0363546513509057

73.

Zaffagnini

Giordano

Vascellari

, et al. Arthroscopic collagen meniscus implant results at 6 to 8 years follow up. Knee Surg Sports Traumatol Arthrosc. 2007;15(2):175-183. doi:10.1007/s00167-006-0144-4

74.

Zaffagnini

Grassi

Marcheggiani Muccioli

, et al. Is sport activity possible after arthroscopic meniscal allograft transplantation? Am J Sports Med. 2016;44(3):625-632. doi:10.1177/0363546515621763

75.

Zaffagnini

Grassi

Marcheggiani Muccioli

, et al. Survivorship and clinical outcomes of 147 consecutive isolated or combined arthroscopic bone plug free meniscal allograft transplantation. Knee Surg Sports Traumatol Arthrosc. 2016;24(5):1432-1439. doi:10.1007/s00167-016-4035-z

76.

Zaffagnini

Grassi

Marcheggiani Muccioli

, et al. Two-year clinical results of lateral collagen meniscus implant: a multicenter study. Arthroscopy. 2015;31(7):1269-1278. doi:10.1016/j.arthro.2015.01.025

77.

Zaffagnini

Marcheggiani Muccioli

Bulgheroni

, et al. Arthroscopic collagen meniscus implantation for partial lateral meniscal defects. Am J Sports Med. 2012;40(10):2281-2288. doi:10.1177/0363546512456835

78.

Zaffagnini

Marcheggiani Muccioli

Lopomo

, et al. Prospective long-term outcomes of the medial collagen meniscus implant versus partial medial meniscectomy. Am J Sports Med. 2011;39(5):977-985. doi:10.1177/0363546510391179

79.

Zhang

Liu

Wei

, et al. Meniscal allograft transplantation in isolated and combined surgery. Knee Surg Sports Traumatol Arthrosc. 2012;20(2):281-289. doi:10.1007/s00167-011-1572-3

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.16 MB