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Purpose: Meniscal allograft transplantation (MAT) is a valuable option for postmeniscectomy syndrome in young and active patients, which can successfully improve symptoms, function and quality of life. This study aimed to report outcomes and complications in patients treated with isolated MAT or MAT combined with revision anterior cruciate ligament reconstruction (ACLR) and lateral extra‐articular tenodesis (LET). Methods: In total, 18 patients who were treated with MAT using a soft tissue fixation technique were retrospectively analysed. Patients were allocated into two groups, the isolated MAT group and the MAT plus revision ACLR + LET group (MAT+ group). Both groups were assessed using the following Patient‐Reported Outcome Measures (PROMs): Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), Tegner Activity Scale, Lysholm score, EuroQol 5‐Dimension 5‐level (EQ‐5D‐5L) questionnaire and a patient acceptable symptom state (PASS) statement. Results: The mean follow‐up was 3.2 years and the mean age of patients was 29 (±7.6) years. Ten patients were treated with isolated MAT and eight patients were treated with MAT combined with revision ACLR and LET. No complications and no reoperations were reported. In both groups, all PROMs significantly improved postoperatively (p < 0.05), except for the Tegner score in the MAT+ group, which did not reach statistical significance (not significant [n.s.]). No significant difference was found postoperatively in PROMs between the MAT and the MAT+ group; however, differences in the KOOS Symptoms, Sports and Quality‐of‐life subscales reached the minimal clinically important threshold. Mean values were: IKDC 61.2 (±13.9) versus 64.7 (±23.2), KOOS Total 72.8 (±14.9) versus 68.0 (±16.7), Lysholm score 83.2 (±11) versus 84.2 (±8.7) and EQ‐5D‐5L 71.8 (±14.9) versus 72.2 (±22.4). Median values for the Tegner Activity Scale were 4 versus 3. PASS statement was negative in 37.5% of the MAT+ group in comparison to 20% of the MAT group (n.s.). Conclusion: In terms of patient‐reported outcomes, MAT is an effective and safe procedure, even when combined with revision ACLR + LET. Compared to the preoperative assessment, a significant improvement of the postoperative PROMs can be expected either when MAT is performed isolated or in combination with ACLR + LET. However, clinically important differences between the two groups can be noted in favour of the isolated MAT procedure, especially regarding symptoms and sporting activity. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to assess how gender might affect the clinical outcome and survival of meniscal allograft transplantation (MAT). Methods: A total of 358 patients (23.2% women, 76.8% men) were treated with fresh‐frozen nonirradiated allografts implantated arthroscopically using a single‐ or double‐tunnel technique without bone plugs and peripheral suture to the capsule with 'all‐inside' stitches. Results: Patients were evaluated at baseline and 2‐year follow‐up with the Lysholm score, visual analogue scale (VAS) pain, the Knee Osteoarthritis Outcome Score (KOOS) subscales and Tegner score. Women presented higher body mass index (p < 0.0005), poorer baseline VAS (p = 0.012), Lysholm score (p = 0.005), KOOS symptom (p = 0.034) and KOOS pain (p = 0.030), Tegner score (preinjury and basal, p < 0.0001 and p = 0.002, respectively), a lower number of previous (p = 0.039) and concurrent (p = 0.001) anterior cruciate ligament reconstructions and a higher number of concurrent procedures (p = 0.032) and distal femoral osteotomies (p = 0.024). Worse results were documented in women at 2 years, with lower Lysholm score (p = 0.024) and Tegner score (p = 0.007) and a lower clinical survival rate (p = 0.03) (67.5% vs. 82.2%) in the overall patient cohort. However, the matched‐pair analysis only confirmed a lower Tegner score value at 2 years (p = 0.016), while underlying the interplay of sex, age and concomitant cartilage lesions in determining the clinical outcome. The analysis of this large series of patients affected by postmeniscectomy syndrome and treated with MAT revealed gender differences. Conclusion: While both genders benefited from a significant improvement, the female population presents more often with older age, concomitant cartilage lesions and a lower activity level, all factors contributing towards a lower clinical success after MAT. Level of Evidence: Level III, comparative study. [ABSTRACT FROM AUTHOR]

Purpose: The optimal treatment approach for the complex pathology of meniscal insufficiency and coexisting full‐thickness cartilage defects remains unclear. The purpose of this study was to evaluate the viability, safety, and efficacy of this combined surgical approach at medium‐term follow‐up. Methods: This is a single‐centre longitudinal study with blinded outcome assessment. All consecutive patients treated with combined all‐arthroscopic meniscal allograft transplantation (MAT) with bone bridge fixation and ACI using chondrospheres at our institution between 2001 and 2021 were eligible for inclusion. Twenty patients with an average follow‐up of 72.6 ± 34.4 months were included in the statistical analysis. Clinical outcomes were assessed pre‐ and postoperatively using the IKDC Subjective Knee Form, Lysholm Score, Tegner Activity Scale, KOOS, and Visual Analog Scale (VAS) for patient satisfaction. Failure and reoperation rates were assessed, and cartilage regeneration tissue was evaluated on postoperative MRI. Results: IKDC scores significantly improved from 52.1 ± 16.9 to 68.5 ± 16.3 (p = 0.003). Lysholm scores improved from 61.5 ± 21.7 to 78.5 ± 12.9 (p = 0.004). Tegner scores improved from 3.5 (1–4) to 4.0 (2–6) (p = 0.014). KOOS scores improved significantly across all subcategories, except 'symptoms', where improvements did not reach statistical significance. VAS for overall patient satisfaction showed improvements but did not reach statistical significance. The combined procedure was successful in 17 patients (85%). Eight patients had to undergo reoperation (40%), comprising mostly small, arthroscopic procedures. Seven reoperations were directly attributable to meniscal allograft transplantation (46.7%). Postoperative Magnetic Resonance Observation of Cartilage Repair Tissue scores were 68.9 ± 16.8 (n = 14). Conclusion: Combined arthroscopic MAT and autologous chondrocyte implantation (ACI) is a viable, safe, and effective treatment approach for younger patients with meniscal insufficiency and coexisting full‐thickness cartilage damage, where alternative treatment options are limited. The combined surgical procedure achieved significant improvements in clinical outcome measures and patient satisfaction with acceptable failure and high arthroscopic reoperation rates. MAT is the limiting part of this combined procedure, with most failures and reoperations being attributable to MAT, as opposed to ACI. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: Severe cartilage damage and advanced knee osteoarthritis (OA) might be associated with poor outcomes of meniscal allograft transplantation (MAT). The purpose of this prospective follow-up study was to explore MAT survivorship and patient satisfaction among young patients with symptomatic meniscal deficiency and radiological OA of different Kellgren–Lawrence (K–L) grades. Methods: Thirty-five consecutive MAT patients were prospectively followed up for 2 years. The lateral meniscus was replaced in 29 patients and the medial meniscus in 6 patients. Outcomes were assessed using the KOOS4 composite score, KOOS subscales, Lysholm knee score, and OA K–L grade progression from weight-bearing knee radiographs. For the outcome analysis, patients were categorized into two groups: 19 in Group A (K–L classification 0–1) and 16 in Group B (K–L classification 2). Results: In terms of KOOS4 and Lysholm scores, the patients showed a clinically significant improvement from baseline to the 1-year follow-up (22.2 points, 95% CI 16.6–27.8 for KOOS4 and 16.8 points, 95% CI 8.9–24.6 for Lysholm), and the improvement remained at 2 years (20.6 points, 95% CI 13.2–28.1 for KOOS4 and 21.5, 95% CI 12.5–30.7 for Lysholm). At the 6-month follow-up, this improvement was not yet observed. Minor between-group differences were observed in the KOOS4 and Lysholm scores for the K–L 0–1 and K–L 2 OA groups, but the estimates were imprecise with wide confidence intervals. A clinically relevant difference between these two study groups could not be found at any timepoint. The reoperation rate was higher in the K–L 2 group than in the K–L 0–1 group (31% vs. 11%). Conclusions: MAT yielded improved patient-reported outcomes and subjective satisfaction at 1 and 2 years postoperatively. The differences from baseline exceeded the minimal clinically important difference (MCID) at all timepoints. The severity of cartilage damage and knee OA in terms of the K–L grade at the time of surgery did not affect the KOOS and Lysholm scores after the MAT procedure. Knee OA progression in terms of K–L grade worsening was not observed in any patients. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the characteristics of anatomically failed grafts within 1 year after meniscal allograft transplantation (MAT) and compare the differences between lateral and medial MATs. Methods: The records of consecutive patients with anatomically failed grafts within 1 year after primary MAT between 2005 and 2018 were reviewed. Anatomical failure was defined as a tear covering > 50% of the allograft or an unstable peripheral rim. The pattern and location of the graft tears were analyzed using magnetic resonance imaging or arthroscopy. Results: A total of 21 patients were included. All 21 patients had anatomical failure with tears involving > 50% of the allograft, whereas 15 had an unstable peripheral rim of the allograft. The mean failure time was 6.6 ± 3.6 months in all patients (lateral MAT, n = 15; medial MAT, n = 6). In the lateral MAT group, meniscocapsular separation was the most common pattern (n = 10, 66.7%), followed by complex (n = 3, 20.0%), radial (n = 1, 6.7%), and longitudinal (n = 1, 6.7%) tear. In the medial MAT group, a root tear was the most common pattern (n = 5, 83.3%), followed by a complex tear (n = 1, 16.7%). Meanwhile, in the lateral MAT, the midbody was the most frequently affected location (n = 9, 60.0%), followed by the posterior (n = 5, 33.3%) and anterior (n = 1, 6.7%) areas; in the medial MAT group, the posterior (n = 5, 83.3%) was the most frequently affected location, followed by the anterior area (n = 1, 16.7%). Significant differences in the pattern (P = 0.002) and location (P = 0.043) of the graft tears were found between lateral and medial MATs. Conclusion: In patients with early failure after MAT, meniscocapsular separation in the midbody of the lateral compartment and root tears in the posterior area of the medial compartment were the most common. Thus, surgeons are encouraged to pay extra attention to these vulnerable areas during the early period after MAT. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To compare the long-term clinical and radiological results of meniscal allograft transplantation (MAT) for discoid lateral meniscus (DLM) patients with MAT for non-discoid lateral meniscus patients and meniscectomy (ME) for DLM patients and, thus, to determine whether DLM patients are suitable candidates for MAT. Methods: Eight MAT cases in DLM patients were identified (discoid MAT group), six MAT cases in non-discoid lateral meniscus patients (non-discoid MAT group) and ten total meniscectomy cases in DLM patients (discoid ME group) were matched as controls. Subjective evaluations, postoperative radiography and magnetic resonance imaging (MRI) were conducted at 5 years and 10–14 years, respectively. Joint degeneration was evaluated by the Kellgren–Lawrance (KL) grade and joint space width (JSW). MRI with T2 mapping sequences was used to quantitatively evaluate degeneration of the joint cartilage and shrinkage of the allografts. Student's t test was used to compare quantitative variables and the Mann‒Whitney U test was used to compare categorical variables. Results: There was no difference in Lysholm, IKDC, Tegner or VAS scores amongst the discoid MAT, non-discoid MAT and discoid ME groups at the final follow-up. No revision surgery was performed in any MAT patient. The JSW narrowing in the discoid MAT group was better than that in the discoid ME group (0.8 ± 0.4 mm vs. 2.1 ± 1.3 mm, p = 0.012) and worse than that in the non-discoid MAT group (0.1 ± 0.1 mm, p = 0.003). The KL progression of the discoid MAT group was less than that of the discoid ME group (1.3 ± 0.7 vs. 2.3 ± 0.9, p = 0.034). The discoid ME group had worse cartilage lesion progression than the discoid MAT and non-discoid MAT groups. The allograft width of the DLM patients shrank more than that of the non-discoid patients at the meniscus midbody (3.6 ± 0.9 mm vs. 6.2 ± 1.9 mm, p = 0.015). Conclusion: Compared to meniscectomy, MAT achieved similar long-term symptom relief and superior chondroprotection in discoid meniscus patients. Despite more graft shrinkage, the outcomes of MAT in discoid meniscus patients were comparable to those in non-discoid meniscus patients. Therefore, DLM patients may be suitable candidates for MAT procedures. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to report return to sports (RTS) and return to work (RTW) outcomes after distraction arthroplasty (DA) plus lateral meniscal allograft transplantation (MAT) combined with cartilage repair in active patients with advanced osteoarthritis. It was hypothesised that DA combined with lateral MAT would improve clinical and radiological outcomes and enable RTS and RTW for most patients.Methods: In total, 21 patients with advanced osteoarthritis (moderate to severe joint space narrowing at lateral edge on Rosenberg view and large cartilage defect of lateral femoral condyle) who underwent concomitant DA and MAT were retrospectively reviewed. Clinical outcomes were assessed using subjective knee scores [Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity scale (TAS)] and functional tests (isokinetic extensor muscle strength test, single-leg vertical jump test, and single-leg hop for distance test). The rates of RTS, RTW, and satisfaction were evaluated. Radiological outcomes were assessed using magnetic resonance imaging (MRI) and X-ray (Rosenberg view).Results: The mean age at surgery and mean follow-up duration were 37.2 ± 5.9 years and 37.1 ± 5.4 months, respectively. All improvements in subjective scores were statistically significant (p < 0.001). The Lysholm score improved from 58.3 ± 8.1 to 84.3 ± 8.2, the IKDC subjective score from 53.9 ± 10.4 to 78.0 ± 7.7, and the TAS from 4.0 ± 0.5 to 5.1 ± 0.8. The limb symmetry index (LSI) (%) of the extensor peak torque at an angular velocity of 60°/s improved from 67.3 ± 19.2 to 88.4 ± 20.3% (p = 0.001). The LSI of the single-leg vertical jump test and single-leg hop for distance test improved from 62.8 ± 21.3 to 87.7 ± 19.5% and from 63.9 ± 20.8 to 85.5 ± 18.1%, respectively (all, p < 0.001). All patients were able to return to any sports activity and work. However, 67% and 90.5% returned to their defined or desired level of sports activity and occupation intensity, respectively. Further, 76.2% were very satisfied or somewhat satisfied with the outcome at the last follow-up. The JSW increased by 0.8 ± 0.4 to 2.3 ± 0.6 mm (p = 0.005). In more than 90% of patients, > 50% of cartilage lesion was covered. The mean graft extrusion was 2.6 ± 1.0 mm.Conclusion: All patients who underwent distraction arthroplasty plus lateral MAT combined with cartilage repair returned to any sports and work at the last follow-up. Significant improvements in clinical outcomes and the radiographic joint space width were observed. However, the activity ability was somewhat reduced compared with the best preoperative level. This one-stage joint salvage treatment is a promising option for young and active patients with advanced OA who wish to return to high levels of sports activity and occupation intensity (≥ Tegner activity scale 4).Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Clinical results of meniscal allograft transplantation (MAT) are not always consistent with graft status. This study aimed to investigate (1) the degree and pattern of mismatch between anatomic and clinical failures in MAT and (2) preoperative factors associated with the mismatch. Methods: Two hundred and ninety-eight consecutive patients who underwent primary medial or lateral MAT during 2004–2015 were reviewed. Anatomic failure was defined as an allograft showing meniscal tear involving > 50% of the graft or unstable peripheral rim. Clinical failure included poor Lysholm score of < 65 and any requirement for re-operations such as arthroplasty, realignment osteotomy, revision MAT, and meniscectomy (more than 50% of the graft or to the zone of meniscocapsular junction). Failure cases were categorised according to the type of failure as follows: (1) type 1, anatomic failure followed by clinical failure; (2) type 2, anatomic failure did not lead to clinical failure; and (3) type 3, clinical failure without anatomic failure. Preoperative factors including age, sex, body mass index, MAT compartment, time from previous meniscectomy, alignment, cartilage status, and accompanying procedures were analysed according to the failure type. Results: Forty (13.4%) patients showed anatomical or clinical failure during the median (25th–75th percentile) follow-up duration of 47 (30–72) months (range 24–178 months). Eleven (3.7%) patients showed both anatomical and clinical failure (type 1 failure). Seventeen (5.7%) patients showed anatomic failure that did not lead to clinical failure (type 2 failure). Twelve (4.0%) patients failed clinically without meniscal tear (> 50% of graft) or unstable peripheral rim (type 3 failure). Comparative analyses among failure types found a significant difference in MAT compartment (p = 0.01). In particular, the incidence of type 3 failure was higher in medial than in lateral MAT (p = 0.003). Conclusion: A notable number of failure cases of MAT showed a mismatch between anatomic and clinical failures. Even with anatomic failure, MAT did not always lead to poor clinical scores or re-operations, whereas MAT could have poor results without substantial allograft problems. Therefore, both anatomic and clinical aspects should be considered when evaluating MAT. In particular, type 3 failure occurred more frequently in medial than in lateral MAT. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Evaluation of survival of meniscal allograft transplantation (MAT) and postoperative patient-reported outcome (PRO), and their association with prior interventions of the knee. Methods: A prospective consecutive study of 109 consecutive patients who had an arthroscopic meniscal allograft transplantation (MAT) between 1999 and 2017 by a single surgeon. Patients were assessed with KOOS scores, preoperative and after a minimal follow-up of 2 years. Furthermore, two anchor questions (whether expectations were met and overall satisfaction, on a five-point Likert scale) were asked. Additionally, prior interventions to MAT were evaluated. Results: Prior to MAT, patients had undergone an average of 2.8 (range 1–14) of surgical procedures of the knee. Overall, mean allograft survival was 16.1 years (95% CI 14.8–17.5 years). Higher age at surgery was associated with lower MAT survival: hazard ratio for MAT failure was 1.19 per year increase (95% CI 1.04 to 1.36, p = 0.009). At 4.5 years (IQR, 2–9) of follow-up, all KOOS score were still improved compared to baseline. Age below 35 years, simultaneous anterior cruciate ligament reconstruction and number of knee surgeries before MAT were associated with lower KOOS scores. Overall patient expectations and overall satisfaction after MAT were not associated with preoperative patient characteristics nor with the number or kind of preoperative interventions. Conclusion: Meniscal allograft transplantation has a good overall survival with a clinically relevant improvement. Both meniscal allograft survival and PRO were associated with age. PRO was lower in patients younger than 35 years at time of MAT and meniscal allograft survival was worse in patients older than 50 years. PRO was associated with preoperative patient characteristics and number of surgical procedures prior to MAT. All patients reported improved postoperative satisfaction and met expectations after MAT, both independent of the preoperative history of knee interventions. Level of evidence: Level III. Trial registration Medical ethical review board (METC) number: 17–104 (7 August 2017). Dutch Trial Register (NTR) number: NTR6630 (4 July 2017). [ABSTRACT FROM AUTHOR]

Purpose: To assess the clinical effectiveness and cost-effectiveness of meniscal allograft transplantation (MAT) after meniscal injury and subsequent meniscectomy.Methods: Systematic review of clinical effectiveness and cost-effectiveness analysis.Results: There is considerable evidence from observational studies, of improvement in symptoms after meniscal allograft transplantation, but we found only one small pilot trial with a randomised comparison with a control group that received non-surgical care. MAT has not yet been proven to be chondroprotective. Cost-effectiveness analysis is not possible due to a lack of data on the effectiveness of MAT compared to non-surgical care.Conclusion: The benefits of MAT include symptomatic relief and restoration of at least some previous activities, which will be reflected in utility values and hence in quality-adjusted life years, and in the longer term, prevention or delay of osteoarthritis, and avoidance or postponement of some knee replacements, with resulting savings. It is likely to be cost-effective, but this cannot be proven on the basis of present evidence.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: Aim of this study is to document if combined meniscal allograft transplantation (MAT) and ACL reconstruction can improve knee function, reduce pain and allow patients with meniscal defect and ACL lesion to resume sport activities.Methods: Fifty MAT, arthroscopically performed without bone plugs and combined with one-stage primary or revision ACL reconstruction, with or without high tibial osteotomy (HTO), were included. Patients (aged 38.2 ± 10.6 years, 87% males) were evaluated at a mean follow-up of 5 years with Lysholm, Tegner and VAS scores. Patient satisfaction was also recorded, together with complications and failures.Results: VAS and Lysholm scores improved significantly (from 63.7 to 24.5 and from 60.6 to 82.7, respectively, p < 0.001), while the Tegner score did not reach pre-injury values (p < 0.001), but it improved significantly compared to pre-surgery values (from 2.8 to 4.6, p < 0.001). Medial MAT reported significantly better results compared to lateral MAT. Patients undergoing concomitant HTO reported a significantly higher decrease of VAS. Younger patients with higher pre-operative pain and lower activity level presented higher satisfaction. Eight patients needed a reoperation. Three patients were considered surgical failures while four were considered clinical failures, for a total of 15% failures.Conclusions: Meniscal allograft transplantation combined with ACL reconstruction represents a safe and suitable treatment, which should be considered as a suitable option in the clinical practice. All evaluated patient profiles, ACL injury in a patient with post-meniscectomy syndrome, failed ACL reconstruction in patients with a meniscus defect, and ACL reconstruction in patients with malalignment due to meniscal defect, benefited from the combined MAT procedure at medium-term follow-up.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The primary aim of this systematic review was to examine the hypothesis that meniscal allograft transplantation is chondroprotective by identifying and appraising studies that have assessed the progression of osteoarthritis following meniscal allograft transplantation. The secondary aim was to identify and appraise radiological measures of meniscal allograft integrity following surgery.Methods: Clinical studies on human participants undergoing meniscal allograft transplantation with a minimum follow-up of 6 months were included. The primary outcome measure was any radiological osteoarthritis progression measure. Secondary outcomes included magnetic resonance measures of meniscal integrity including meniscal size, shape, healing, extrusion and signal intensity.Results: Thirty-eight studies with 1056 allografts were included. The weighted mean joint space loss was 0.032 mm at 4.5 years across 11 studies. Other radiological classification systems were reported in small numbers and with variable progression rates. Meniscal extrusion was present in nearly all cases, but was not associated with clinical or other radiological outcomes. Meniscal healing rates were high, although the size, shape and signal intensity were commonly altered from that of the native meniscus. The quality of the included studies was low, with a high risk of bias.Conclusion: There is some evidence to support the hypothesis that meniscal allograft transplantation reduces the progression of osteoarthritis, although it is unlikely to be as effective as the native meniscus. If this is proven, there may be a role for prophylactic meniscal allograft transplantation in selected patients. Well-designed randomised controlled trials are needed to further test this hypothesis.Level Of Evidence: Systematic review of studies, Level IV. [ABSTRACT FROM AUTHOR]

Purpose: The primary objective of this study was to perform an updated systematic review and meta-analysis of meniscal allograft transplantation using patient reported outcome measures at final follow-up as the outcome tool. The secondary objective was to provide an up to date review of the indications, associated procedures, operative technique, rehabilitation, failures, complications, radiological outcomes, and graft healing. Methods: Medline, Embase and CENTRAL databases, trials registries, and Web-of Science were searched for studies using pre-defined eligibility criteria. Included studies were reviewed with Lysholm, International Knee Documentation Committee (IKDC) and Tegner scores, failures and complications pooled. Studies were also qualitatively assessed. Results: There were 1,332 patients (1,374 knees) in 35 studies eligible for analysis. The mean follow-up was 5.1 years. Across all studies, Lysholm scores improved from 55.7 to 81.3, IKDC scores from 47.0 to 70.0, and Tegner activity scores from 3.1 to 4.7 between pre-operative and final follow-up assessments, respectively. The mean failure rate across all studies was 10.6 % at 4.8 years, and complication rate was 13.9 % at 4.7 years. There is a high risk of bias across the studies due to study design and missing outcomes. Conclusion: Based on current evidence, meniscal allograft transplantation appears to be an effective intervention for patients with a symptomatic meniscal deficient knee. This should ideally be confirmed with a randomised controlled trial. There is not currently enough evidence to determine whether it is chondroprotective. [ABSTRACT FROM AUTHOR]

Purpose: To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation (MAT): optimal timing for transplantation, outcomes, return to competition, associated procedures, and prevention of osteoarthritis. Methods: A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies). Specific inclusion criteria were determined for the outcomes and prevention of osteoarthritis topics. Results: Twenty-four studies were finally included: two optimal timing, seven outcomes, three return to competitive sport, 16 MAT and associated procedures, and 5 MAT and prevention of osteoarthritis (some studies were categorized in more than one topic). These studies corresponded to 2 animal studies and 31 in vivo human studies (1 level II, 1 level III, and 29 level IV). Conclusions: The principal conclusions were as follows: (a) there is no evidence to support that MAT has to be performed at the same time or immediately after meniscectomy to prevent development of postmeniscectomy syndrome; (b) MAT successfully improves symptoms, function, and quality of life at 7-to-14 years of follow-up (level IV evidence); (c) the overall failure rate (need for knee arthroplasty) is 10-29 % at long-term follow-up; (d) MAT allows return to same level of competition in 75-85 % of patients at short- to mid-term follow-up (only three studies level IV evidence with small sample size); (e) associated cartilage procedures or anterior cruciate ligament reconstruction to MAT does not worsen the results; (f) MAT may prevent progression of cartilage damaged at long-term follow-up, but may not prevent degeneration in previously healthy cartilage. Level of evidence: Systematic review of level II-IV studies, Level IV. [ABSTRACT FROM AUTHOR]

Purpose: To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation: graft biology, shrinkage, extrusion, sizing, and fixation. Methods: A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies). Results: Sixty-two studies were finally included: 30 biology, 3 graft shrinkage, 11 graft extrusion, 17 graft size, and 6 graft fixation (some studies were categorized in more than one topic). These studies corresponded to 22 animal studies, 22 in vitro human studies, and 23 in vivo human studies (7 level II, 10 level III, and 6 level IV). Conclusions: The principal conclusions were as follows: (a) Donor cells decrease after MAT and grafts are repopulated with host cells form synovium; (b) graft preservation alters collagen network (deep freezing) and causes cell apoptosis with loss of viable cells (cryopreservation); (c) graft shrinkage occurs mainly in lyophilized and gamma-irradiated grafts (less with cryopreservation); (d) graft extrusion is common but has no clinical/functional implications; (e) overall, MRI is not superior to plain radiograph for graft sizing; (f) graft width size matching is more important than length size matching; (g) height appears to be the most important factor influencing meniscal size; (h) bone fixation better restores contact mechanics than suture fixation, but there are no differences for pullout strength or functional results; and (i) suture fixation has more risk of graft extrusion compared to bone fixation. Level of evidence: Systematic review of level II-IV studies, Level IV. [ABSTRACT FROM AUTHOR]

Purpose: The primary aim is to document objective and subjective clinical outcome after knee arthroplasty for failed meniscal allograft transplantation; secondly, to investigate the influence of previous meniscal allograft surgery on the clinical outcome after a knee arthroplasty procedure; thirdly, to identify possible prognostic factors for the failure of meniscal allograft, such as potential number of concomitant procedures or pre-transplantation HSS-scores. The study population was compared to a control group of primary total knee arthroplasties. Methods: The pre-operative phase, prior to meniscal allograft transplantation, was evaluated by the HSS questionnaire. At final follow-up, the clinical outcome was evaluated by the HSS, KOOS and SF-36 questionnaires. The mean follow-up was 16 years and 2 months. The control group, matched for age and sex, comprised patients with primary total knee arthroplasty. Results: Statistical analysis showed that for the HSS-scores, there was no significant difference between the study population and the control group. KOOS data showed that the control group scored better overall. There was no significant difference between the HSS-scores after the transplantation and after the knee prosthesis. However, both showed a significant improvement regarding the clinical condition before meniscal transplantation. Conclusions: The clinical results after revised meniscal transplantation by means of knee prosthesis are highly variable with a tendency to have a lower score than patients with a primary knee prosthesis. Patients who underwent a revision of their meniscal allograft transplantation by means of a knee arthroplasty still had a significant better clinical outcome than prior to the meniscal allograft transplantation. There were no prognostic factors found by which one can determine whether a meniscal allograft will have a good survival or not. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The purposes of this study were to evaluate the effect on tibiofemoral contact mechanics of repair of the posterior root of the medial meniscus and the effect of meniscal allograft transplantation (MAT) with medial collateral ligament (MCL) release at different flexion angles. Methods: Ten fresh-frozen human cadaveric knees (five pairs) were used. A digital pressure sensor was inserted by capsulotomy, and experiments were performed serially under the following six conditions, that is, with an intact medial meniscus (normal controls), with a root tear, after root repair, after total meniscectomy, after MAT, and after MAT plus MCL release. During each experiment, knees were positioned at 0°, 30°, 60°, and 90° of flexion, and peak pressure (kPa) and contact area (cm) were measured. Results: At 0° of flexion, contact pressure did not differ among the six experimental settings. However, at 30° and 60° of flexion, contact pressure differed significantly between root tear and root repair specimens ( p = 0.04 and 0.03, respectively), and between total meniscectomy and MAT specimens ( p = 0.02 and 0.03, respectively). On the other hand, mean contact pressures were different between normal (476.7 ± 473.1 and 573.3 ± 479.1 kPa) and root repair (575.7 ± 357.8 and 598.6 ± 415.8), and between normal and MAT (635.7 ± 437.4 and 674.3 ± 533.2). At 0°, 30°, 60°, and 90° of flexion, contact areas differed significantly between normal and total meniscectomy specimens ( p = 0.02, 0.01, 0.02, and 0.02, respectively), and between MAT and total meniscectomy specimens ( p = 0.03, 0.02, 0.02, and 0.03, respectively). Contact areas differed significantly between root tear and root repair specimens at 60° of flexion ( p = 0.04), and between normal control and root repair specimens at 60° and 90° of flexion ( p = 0.03 and 0.04, respectively). The effects of MAT plus MCL release on contact mechanics were not different from the effects of MAT alone ( n.s.). Conclusions: Both meniscal root repair and transplantation of meniscus improved contact mechanics, but it did not appear that repair of the meniscal root or transplantation of meniscus restores the biomechanical function back to normal level. The MAT plus MCL release was similar to those after MAT alone. Therefore, it is better to preserve meniscus and MCL release could be done during the MAT. [ABSTRACT FROM AUTHOR]

Purpose: Technique for guide wire placement during meniscal allograft transplantation (MAT) is usually based on the parapatellar approach that is not in the anatomical direction of meniscal horn bony insertions. Here, we present a surgical technique to achieve the correct anatomical position of the meniscal graft using the transpatellar approach. Methods: A guide wire was introduced through the patellar tendon in the direction of the meniscal insertion sites passing the lateral tibial spine. The insertion plane of the guide wire was approximately at the medial aspect of the tibial tuberosity and slightly medial to the midplane of the patellar tendon. After confirmation with C-arm, the guide wire was cut at the level just beneath the patellar tendon. The knee was then brought to the extension position which lessened the tension of the patellar tendon and retracted it to the medial aspect to expose the end of the guide wire. Drilling and insertion of bone block was performed accordingly. Results: Eleven consecutive patients with total or near-total meniscectomy of the knee underwent MAT with the described technique. The mean extrusion taken on 1-year postoperative non-weight-bearing MRI was 1.6 mm (range 0.5-2.9 mm). None of the patients presented with symptoms requiring a secondary surgery at the time of review. Conclusion: The described technique focuses on achieving correct positioning of the tibia tunnel through the patellar tendon and tunnel reaming in the extended knee position via the mini-open parapatellar approach during lateral MAT. This 'transpatellar approach' could be an effective method for anatomical placement of meniscal graft. [ABSTRACT FROM AUTHOR]