Meniscal Allograft Transplantation Research Articles

Poster 364: Prospective Assessment of Outcomes after Femoral Condyle Osteochondral Allograft with Concurrent Meniscus Allograft Transplantation

Objectives: To report outcomes and associated risk factors for treatment failure (revision surgery or conversion to arthroplasty) in a consecutive series of patients undergoing concurrent femoral condyle osteochondral allograft (OCA) and meniscus allograft (MAT) transplantation using advances in tissue preservation and surgical techniques. Methods: Patients who underwent primary femoral condyle OCA transplantation and concomitant MAT (OCAT+MAT) between 2016-2020 with minimum 2-year follow up data regarding complications, failures, adherence, and patient reported outcome measures (PROMs) were analyzed. Patients who required OCA and/or MAT revision or conversion to artificial arthroplasty were defined as treatment failures. Patient reported outcome measures (PROMs) including VAS pain, IKDC, SANE, PROMIS Global Health and Physical Function, were collected at 3 and 6 months and then yearly after transplantation. Fisher’s exact tests were used to compare proportions and repeated measures ANOVA tests were used to compare longitudinal PROMs data for statistically significant (p<0.05) differences. Results: A total of 21 consecutively enrolled patients met inclusion criteria with mean age of 35 (15-54) years and mean BMI of 27 (19-36) kg/m2. OCAT+MAT was performed in the medial compartment in 14 cases and lateral compartment in 7 cases. Realignment osteotomies were performed in 4 cases. Initial success rate (mean follow-up of 44 mos) was 76% based on 1 revision and 4 arthroplasties performed. Overall success rate was 81% based on successful revision. Statistically significant (p<0.002) and clinically meaningful improvements were noted for all measured PROMs (VAS pain, IKDC, SANE, PROMIS) at 2-year follow up. Patients requiring conversion to arthroplasty were significantly older (mean age, 48.3 v 32.2 years, p=0.0076) than patients with successful outcomes. Nonadherence with postoperative restrictions and rehabilitation protocol was an independent risk factor for conversion to arthroplasty (p=0.022, OR=42). Conclusions: Combined femoral condyle OCA and meniscus allograft transplantation was associated with successful short- to mid-term outcomes in 81% of cases. Older age and nonadherenceto postoperative protocols are risk factors for decreased outcomes.

Paper 34: Midterm Outcomes of Meniscal Allograft Transplantation in the Adolescent Population

Objectives: To report midterm outcomes following primary meniscal allograft transplantation (MAT) from a single surgeon in an adolescent population. Methods: A retrospective review was performed to identify adolescent patients <18 years old at the time of primary MAT from 1999-2016. International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, and Lysholm scores were collected preoperatively and at 1-year, 2-years, and a minimum of 5-years follow-up. Results: Forty-four (female n=33; male n=11) of 62 identified patients (71%) met inclusion criteria with a mean follow-up of 9.5 ± 3.8 years (range: 5.0-17.7). Isolated MAT was performed in 27 (61.3%) patients. Common concomitant procedures included osteochondral allograft transplantation (OCA) (n=14, 31.8%), autologous chondrocyte implantation (ACI) (n=8, 18.1%), and anterior cruciate ligament reconstruction (ACLR) (n=6, 13.6%) (Table 1). Eleven patients (25%) required a reoperation an average 5.9 ± 4.5 years (range: 0.8 – 14.0) post-transplant. Three (6.8%) patients met criteria for failure, requiring revision MAT an average of 3.8 ± 1.1 years (range: 2.8-4.9) post-transplant. Graft survivability at 1, 2, 5, and 10 years was 100.0%, 100.0%, 93.2%, and 93.2%, respectively (Figure 1). When compared to preoperative scores, significant increases in Lysholm, IKDC, and KOOS subscales were observed at 1-year, 2-year, and most recent follow-up (Figure 2 and Supplemental Table 1). 90% of patients reported satisfaction with their current physical status. Conclusions: At midterm follow-up, primary MAT in the adolescent population resulted in predictable improvements in functional outcomes. These improvements were maintained at an average follow-up of 9.5 years. The meniscal reoperation rate was 25% with a 71.3% probability of being reoperation free at 5 years while graft survivability was 93.2% at 5 years. When compared to extant literature profiling MAT in the adult population, adolescents who undergo MAT demonstrate similar functional outcomes and graft survivability. [Table: see text] [Table: see text]

Poster 341: Clinical Outcomes of Concomitant Arthroscopically Assisted Anterior Cruciate Ligament Reconstruction and Meniscal Allograft Transplantation

Objectives: Single-stage meniscus allograft transplantation (MAT) with concomitant anterior cruciate ligament reconstruction (ACLR) is a technically challenging procedure for management of knee pain and instability in younger patients. However, there is limited data on specific outcomes of this procedure, such as return to work and functional status relative to the U.S. population at large. The purpose of this study was to assess surgical and patient-reported outcomes following concomitant ACLR and MAT. Methods: We conducted a retrospective review of patients who underwent concomitant ACLR and MAT at our institution from 2010 to 2021. We included patients who underwent either concomitant primary or revision ACLR and medial or lateral MAT with a minimum follow-up of 8 months. Complications, graft failures, and reoperations were abstracted from patient records and Visual Analog Scale (VAS) pain, satisfaction, Lysholm Knee Scale, return to sport, and return to work outcomes were assessed using an email survey. Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference, Pain Intensity, and Physical Function Scores were used to measure patients’ functional status relative to the U.S. population. All p-values less than 0.05 were considered significant. Results: The cohort consisted of 18 knees of 17 individual patients (16 unilateral, 1 bilateral). The cohort were majority male (15 patients; 83%) with mean age of 31.6 years (range 19-49) and mean BMI of 27.6 (range 22.2-53.3). Mean follow-up time was 47.3 months (range 8-101). A majority underwent revision ACLR (12 patients; 67%) with medial MAT (18 patients; 92%). Reoperation rate was high (5 patients; 28%) but only one patient experienced recurrence of painrequiring TKA. Patient-reported outcomes (n = 14) were generally positive with low VAS pain (mean 2.2), high satisfaction (mean 77.9%), and fair Lysholm score (mean 81.1) though satisfaction was lower among revision ACLR patients versus primary ACLR patients (mean 67% vs 100%; p = 0.04). Return to work rate was high (13 patients; 93%) while return to sport rate was low (6 patients; 43%). Postoperative PROMIS scores were comparable or superior to the national average and correlated significantly with patient satisfaction (p < 0.05). Conclusions: The concomitant ACLR and MAT procedure is associated with excellent knee pain and functional outcomes, low rates of complications and meniscus graft failure, and high rate of return to work after surgery. However, rate of return to sport is low and satisfaction is worse among revision ACLR patients. Overall, the single-stage ACLR and MAT procedure appears to be a safe and efficacious treatment option for patients with concomitant ACL and meniscus deficiency.

Paper 52: Pre- and Post-operative Patient Management by an Integrated Care Team Reduces Postoperative Failure Rates Following Osteochondral Allograft Transplantation in the Knee

Objectives: To assess the effects of an integrated care team including a health behavior psychologist on postoperative adherence and associated outcomes for patients undergoing osteochondral and/or meniscus allograft transplantation in the knee. Methods: With IRB approval and documented informed consent, patients were prospectively enrolled into a registry dedicated to following outcomes after OCA and meniscus allograft transplantation surgery between January of 2016 and April of 2021. Patients undergoing primary osteochondral and/or meniscus allograft transplantation to address symptomatic full-thickness cartilage loss and/or meniscus deficiency were included. Patient adherence rates and outcomes were compared based on two cohorts: patients that did not see a behavioral health psychologist preoperatively, and patients that met preoperatively identify potential barriers to adherence, set expectations for postoperative protocols, and identify a plan to moderate risk factors to non-adherence. Patients in both cohorts met preoperatively with the rest of the integrated care team specializing in joint preservation. Data were collected preoperatively, and at all follow-up visits at 3 months, 6 months, and yearly post-operatively. Visual analog scale (VAS) pain scores, International Knee Documentation Committee scores, PROMIS Global Health, and PROMIS Pain interference scores were collected. Treatment failure was defined as any reoperation to revise any of the osteochondral and/or meniscus allografts (revision) or for conversion to arthroplasty in the affected knee. Functional survival (success) was defined as patient- reported pain and function scores improved from pre-operative levels without need for revision or arthroplasty. Patients were categorized as nonadherent when documented evidence of a break from the physical therapy protocol was recounted to a member of the healthcare team by the patient or their physical therapy provider. Data were included for analyses when applicable registry data were available for at least one year following surgery. Chi-square or Fisher’s exact tests were used to analyze differences in proportions, while unpaired t-Tests, one-way analysis of variance tests, or rank sum tests were used to assess significant differences in variables with continuous data. Significance was set a priori at p < 0.05. Results: For patients in the study (n=213), 23.4% were documented to be nonadherent. Of those who were nonadherent, 4 (8.0%) were in the Health Psych cohort versus 46 (92.0%) who were not. Patients in the No Health Psych cohort were significantly more likely to be nonadherent to postoperative rehabilitation protocols (p = .023, OR = 3.4). Tobacco use (p<.001, OR = 7.9), higher preoperative PROMIS Pain Interference score (p<.001), lower preoperative PROMIS Mental Health score (p<.001), older age (p<.001) and higher BMI (p<.001) were also significantly associated with nonadherence. 81.6% of adherent patients had successful outcomes (mean final follow-up 46.7 months, range 12-75), while 40% of nonadherent patients required revision or total knee arthroplasty during the study period, such that nonadherent patients were 3x more likely (p = .004) to experience treatment failure. In this cohort of patients, male sex (p<.001, OR = 3.4) and bipolar OCA transplantation surgeries (p<.001, OR = 5.0) were also significantly associated with increased risk for treatment failure. Conclusions: Preoperative education and postoperative support for patients provided by an integrated care team including a health psychologist can significantly improve adherence and outcomes following osteochondral and meniscal allograft transplantation in the knee.

Poster 260: Influence of Donor Demographics on Graft Survival following Knee Osteochondral Allograft Transplantation

Objectives: To evaluate whether donor and recipient factors such as donor age, sex mismatch, and time from death to graft implantation affect graft survival following knee osteochondral allograft (OCA) transplantation. Methods: Patients undergoing OCA transplantation in the knee from 2003-2016 were prospectively followed. Inclusion criteria consisted of primary OCA transplantation and minimum 2-year follow-up. Patient and donor demographic data were collected. Patients were evaluated for failure, defined as (1) subchondral collapse of the OCA as confirmed on postoperative MRI scans, or via second-look arthroscopy in the setting of persistent symptoms, (2) removal or revision of the primary OCA, or (3) conversion to arthroplasty. Multivariate cox proportional hazards modelling was utilized to evaluate associations between demographic variables and graft failure. Results: A total of 220 patients undergoing OCA transplantation met inclusion criteria and were followed for a mean of 5.9 ± 2.8 years (range: 2.0 – 16.3, Table 1). The most common concomitant procedure was meniscal allograft transplantation (Table 2). A mismatch in donor and recipient sex was present for significantly more female patients (65%) than male patients (10%, p < 0.001). The mean days from donor death until implantation was 24.1 days (range: 15 – 28). Thirty-nine patients (18%) met criteria for graft failure at a mean of 4.3 ± 3.2 years (Table 3). Log-rank testing did not determine a difference in survivability between those with a donor-recipient sex mismatch for female or male patients (P = .130 and .831, respectively). Upon multivariate cox regression, no association existed between donor-recipient sex mismatch or time from donor death to implantation with graft survival. Of note, increased donor age was associated with failure for female patients (P = .020) and trended towards significance in males (P = .166). Conclusions: OCA graft survival appears to be most strongly influenced by donor age. In contrast to previous historic data, no substantial survival difference was noted for sex mismatched donors and recipients. These data can help inform graft selection and outcome optimization following OCA. [Table: see text][Table: see text][Table: see text]

Osteochondral Allograft and Concurrent Meniscal Allograft Transplantation

Background: Symptomatic, full-thickness chondral defects often are associated with meniscal deficiencies. These are difficult problems to manage in the young, high-demand patient population. A number of differing techniques have been published with no consensus. While more recent techniques have favored minimally invasive approaches, an open approach with tubercle osteotomy to maximize visualization of all knee compartments can still provide favorable outcomes when using a careful technique and postoperative protocol. Indications: Young, high-demand patients with long-standing meniscal deficiency and resultant chondral defects are indicated for cartilage restoration and preservation procedures. A meniscal allograft transplantation is indicated in symptomatic patients with prior total or subtotal meniscectomy. It is important to address other concomitant pathology such as instability, alignment, and chondral defects. Concomitant procedures are often performed with meniscal transplants, including osteochondral allograft transplantation for larger defects. Technique Description: This surgical technique video demonstrates a tibial tubercle osteotomy approach to gain access to both the medial and lateral tibiofemoral compartments. An arthroscopic-assisted bone slot technique was performed for meniscal allograft transplantation. Appropriately sized osteochondral allograft bone plugs were then transplanted onto the medial and femoral condyles with a press fit technique. Results: At 1-year follow-up, the presented patient has regained full motion and are back to full activities. Discussion/Conclusion: Full-thickness chondral defects associated with meniscal deficiency in a young, high-demand patient is a difficult problem to manage. Recent results using minimally invasive approaches have demonstrated favorable mid- and long-term outcomes. In patients with pathology that may preclude a minimally invasive approach, an open technique with osteotomy can still have a promising outcome. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Poster 371: A Comparison of Fresh-frozen Tendon versus Fresh Meniscus Allograft Transplantation for Acetabular Labrum Reconstruction

Objectives: To document indications, surgical technique, and outcomes for acetabular labrum reconstruction in the initial series of cases using fresh meniscus allograft transplantation in comparison to a contemporaneous cohort of cases using fresh-frozen tendon allografts. The study was designed to test the hypothesis that patients undergoing labral reconstructions using fresh meniscus allograft transplantation would have better short-term outcomes compared to those using fresh-frozen tendon allografts based on patient-reported measures of pain and function. Methods: With IRB approval and documented informed consent, patients were prospectively enrolled into a dedicated registry designed to follow outcomes after allograft transplant surgeries in the hip. Included patients underwent acetabular labral reconstruction for irreparable acetabular labral insufficiency between November 2015 and June of 2021 with at least 1-year of follow-up available. Cohort assignment was defined based on type of allograft used for acetabular labrum reconstruction, as follows: Fresh meniscus allograft transplant (MAT) utilized to reconstruct the acetabular labrum; Frozen tendon allograft transplant (TAT) utilized to reconstruct the acetabular labrum. Patient reported outcome measures were collected pre-operatively and at regular intervals after surgery (6 weeks, 3 months, 6 months, and then yearly). Visual analog scale for pain (VAS), Hip disability and Osteoarthritis (HOOS) junior, and Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function scores were collected via electronic data capture. Patient electronic medical records were used to obtain patient demographic, operative, complications, and re-operations data. Treatment failures were defined as any revision surgery involving the hip joint or total hip arthroplasty (THA). Patients were considered successful when they were recorded as having returned to functional activities without revision or arthroplasty at final follow-up at least one year post-operatively. Initial success rate was calculated using the formula: 100% - (%revision + %THA). Final follow up was defined at 1 year (Range = 12-81 mos; mean 34.5 mos). Fisher exact tests were used to assess for significant differences in proportions. t-Tests or rank sum tests were used to assess for significant differences between cohorts at each time point. Repeated measures analysis of variance was used to assess for significant differences within cohorts over time. Significance was set at P<0.05. Results: A total of 27 patients (12 male, 15 female) were included for analysis. Mean age was 30.7 ± 9.2 years (range: 18-48) and mean body mass index (BMI) was 27.1 ± 5.4 kg/m2 (range: 20.1-44.0). Initial success rate for the entire group of 27 patients was 88.9%. Initial success rate in the TAT cohort was 80% with one patient undergoing THA at 4 months after transplantation. Initial success rate in the MAT cohort was 90.1% with two patients undergoing THA at 9 and 38 months after transplantation. Initial treatment success rates were not significantly different between cohorts (p=0.47). Treatment failure was significantly associated with concurrent femoral head OCA transplantation (p=.029, OR = 19.9). For the MAT cohort, clinically meaningful and statistically significant improvements in HOOS JR (p=.004, p=.023), VAS pain (p<.001, p=.<.001), and PROMIS PF (p=.044, p=.035) scores were noted at 1-year and final follow-up. For the TAT cohort, clinically meaningful improvements in HOOS JR and VAS pain scores were noted at 1-year but were not sustained at final follow-up. Conclusions: These data support consideration for use of fresh meniscus allografts as an option for acetabular labrum reconstruction when indicated. MAT for acetabular labrum reconstruction was associated with better short-term patient reported scores and success rate when compared to TAT, which may be related to biologic and biomechanical differences in graft types and transplantation techniques. However, only concurrent femoral head OCA transplantation was associated with a significantly higher treatment failure rate.

Poster 286: Biomechanical Analysis Evaluating Meniscal Extrusion Following Knotless Suture Anchor Fixation for Segmental Medial Meniscus Allograft Transplantation

Objectives: Segmental medial meniscus allograft transplantation (MAT) has been shown to restore knee biomechanics, however, stable fixation of the transplant is critical to avoid extrusion and maximize healing. The purpose of this study was to evaluate the degree of meniscal extrusion and biomechanical function of segmental MAT performed with meniscocapsular sutures versus repair augmentation with knotless suture anchors. Methods: Ten fresh frozen cadaveric knees underwent central midbody medial meniscectomy (15-mm defect) and subsequently segmental medial MAT. Knees were loaded in a dynamic tensile testing machine to 1000 N for 20 seconds at 0°, 30°, 60°, and 90° of flexion. Four conditions were tested: (1) intact, (2) segmental defect, (3) inside-out segmental repair, and (4) anchors plus inside-out segmental repair of the MAT. Meniscal extrusion was measured for each test state using high-fidelity ultrasound imaging by three independent observers. Submeniscal medial and lateral pressure-mapping sensors assessed the mean contact pressure, peak contact pressure, mean contact area, and pressure mapping. Assessment of inter- and intraobserver reliability of measurements were done using intraclass correlation coefficients. A two-way repeated measures ANOVA was computed in order to evaluate whether there is a significant interaction between meniscal states and knee flexion angles on the outcome variables. If the P value was ≤ 0.05, a pairwise comparison of the means was determined using the Bonferroni method. Results: At 0° of knee flexion, the segmental defect demonstrated the statistically significant higher degree of meniscal extrusion (2.08 mm ± 0.78 mm) compared with intact (1.02 mm ± 0.86 mm, P = 0.039) and anchor plus inside-out segmental repair (1.44 mm ± 0.76 mm, P = 0.044), but not for an inside-out segmental repair (1.55 mm ± 0.49 mm, P = 0.08). The segmental defect state also showed a higher degree of meniscal extrusion compared with all other states at 90° of knee flexion (P < 0.01). There was no difference in the degree of meniscal extrusion between the intact state and the inside-out repair or anchor plus inside-out segmental repair in all knee flexion angles (P > 0.05). Three observers showed good-to-strong intra-rater and moderate-to-strong inter-rater reliabilities for extrusion measurements. There was no significant difference in the mean contact pressure and peak contact pressure among four states in all knee flexion angles for both medial and lateral compartments except for that at 0° of knee flexion, there was a significantly lower peak pressure at the medial compartment after anchor plus inside-out segmental repair compared with the segmental defect state (P = 0.048). The medial contact area of the intact state was significantly higher than the other states at 0° of knee flexion (P < 0.05). However, the lateral contact area after anchor plus inside-out repair showed no significant difference compared with the intact state (P = 0.13). Conclusions: Segmental meniscus transplantation mechanics may be improved at full extension (0° of knee flexion) with the addition of knotless anchors. However, in terms of meniscus extrusion, the knotless anchors provided limited benefit over inside-out repair. Overall, a robust repair is achieved of a segmental meniscus with sutures and knotless anchors. Although, additional work is needed to assess long-term in vivo results.

Meniscal allograft transplantation, anterior cruciate ligament reconstruction, and valgus high tibial osteotomy for meniscal-deficient, unstable, and varus knees: surgical technique and clinical outcomes.

The aim of this study was to determine the clinical and functional outcome of a salvage surgical approach with the combined procedures meniscal allograft transplantation (MAT), anterior cruciate ligament reconstruction (ACLR), and high tibial osteotomy (HTO), in a cohort of patients treated for complex knee lesions evaluated up to a mid-term follow-up. Eight patients (38.8 ± 4.6 years, 88% males) were treated arthroscopically with MAT without bone plugs combined with primary or revision ACLR and HTO and evaluated at basal, at a minimum of two years (short follow-up), and at a mean follow-up of 5.1 years (mid-term follow-up) with the VAS score for pain, Lysholm score, IKDC subjective score, WOMAC Osteoarthritis index, and Tegner score. Physical examination (Lachman and pivot-shift tests, arthrometer assessment) and radiographic evaluation (pre- and post-operative x-rays) were obtained. Complications and failures were also recorded. A statistically significant improvement was observed from baseline to five years in all clinical scores. In particular, the IKDC subjective score improved from 33.3 ± 20.7 to 73.1 ± 18.4 at short follow-up (p < 0.05), up to 78.3 ± 9.8 at the final follow-up (p < 0.05). A similar trend was demonstrated with the Lysholm, VAS, WOMAC, and Tegner score, even though only one patient reached the pre-injury activity level. Two patients had a worsening of the Kellgren-Lawrence (KL) grade from preoperative (grade 1) to final follow-up (grade 2). No major complications and surgical failures were documented. The combined procedure of MAT, ACLR, and HTO presents few complications and failures and showed to be a valid option to reduce pain, recover knee function, and slow down the osteoarthritis process even in complex patients, with good and stable results up to a mid-term follow-up.

Meniscus Allograft Transplantation Augmented With Autologous Bone Marrow Aspirate Concentrate

Meniscus allograft transplantation (MAT) has been shown to be a feasible surgical option for younger patients, below 50 years of age who have meniscal insufficiency and have failed conservative treatment measures. In this technical note, we describe a procedure of harvesting and injecting bone marrow aspirate concentrate in a meniscus allograft during a MAT procedure, which may allow for longer lasting transplants and improve patient outcomes. In this technical note, bone marrow aspirate concentrate is harvested arthroscopically from the intercondylar notch at the surgical site, which prevents additional donor site morbidity, as seen with harvesting from other locations, such as the iliac crest. This also reduces operating time, since harvesting from the iliac crest requires different patient positioning and usually additional anesthesia. The authors of this surgical technique believe that biological augmentation during MATs will assist surgeons in maximizing graft survivorship and, ultimately, lead to better patient outcomes.

Risk Factors for Graft Failure After Meniscal Allograft Transplantation: A Systematic Review and Meta-analysis

Background: Graft failure after meniscal allograft transplantation (MAT) may necessitate revision surgery or conversion to arthroplasty. A comprehensive understanding of the risk factors for failure after MAT of the knee may facilitate more informed shared decision-making discussions before surgery and help determine whether MAT should be performed based on patient risk. Purpose: To perform a systematic review and meta-analysis of risk factors associated with graft failure after MAT of the knee. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed, OVID/Medline, and Cochrane databases were queried in October 2021. Data pertaining to study characteristics and risk factors associated with failure after MAT were recorded. DerSimonian-Laird binary random-effects models were constructed to quantitatively evaluate the association between risk factors and MAT graft failure by generating effect estimates in the form of odds ratios (ORs) with 95% CIs. Qualitative analysis was performed to describe risk factors that were variably reported. Results: In total, 17 studies including 2184 patients were included. The overall pooled prevalence of failure at the latest follow-up was 17.8% (range, 3.3%-81.0%). In 10 studies reporting 5-year failure rates, the pooled prevalence of failure was 10.9% (range, 4.7%-23%). In 4 studies reporting 10-year failure rates, the pooled prevalence was 22.7% (range, 8.1%-55.0%). A total of 39 risk factors were identified, although raw data presented in a manner amenable to meta-analysis only allowed for 3 to be explored quantitatively. There was strong evidence to support that an International Cartilage Regeneration &amp; Joint Preservation Society grade &gt;3a (OR, 5.32; 95% CI, 2.75-10.31; P &lt; .001) was a significant risk factor for failure after MAT. There was no statistically significant evidence to incontrovertibly support that patient sex (OR, 2.16; 95% CI, 0.83-5.64; P = .12) or MAT laterality (OR, 1.11; 95% CI, 0.38-3.28; P = .85) was associated with increased risk of failure after MAT. Conclusion: Based on the studies reviewed, there was strong evidence to suggest that degree of cartilage damage at the time of MAT is associated with graft failure; however, the evidence was inconclusive on whether laterality or patient sex is associated with graft failure.

Survivorship After Lateral Meniscal Allograft Transplantation Plus Concurrent Cartilage Procedure in Patients With Poor Cartilage Status: A Comparative Study

Background: The effect of a concurrent cartilage procedure in lateral meniscal allograft transplantation (MAT) in patients with bipolar cartilage lesions (high-grade lesions on both the femoral and the tibial side) is not well studied. An objective evaluation of graft status after MAT and a concurrent cartilage procedure has not been reported. Purpose: To investigate the effect of concurrent cartilage procedures and lateral MAT on objective and clinical outcomes, including survival, in patients with bipolar cartilage lesions. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 149 patients with high-grade (International Cartilage Regeneration & Joint Preservation Society grade 3 or 4) cartilage lesions were enrolled and assigned to 1 of 3 groups based on the cartilage procedure and cartilage status at the time of MAT. Femoral cartilage procedures (microfracture, n = 18; osteochondral autograft transfer, n = 13) and lateral MAT were performed in 31 patients with bipolar cartilage lesions (cartilage procedure group). Another 70 patients with bipolar lesions underwent only lateral MAT without cartilage procedure (bipolar lesion group). The remaining 48 patients, who had high-grade lesions only on the tibial side and underwent lateral MAT without a cartilage procedure, were selected as a control group (unipolar lesion group). Anatomic survival was objectively assessed by follow-up magnetic resonance imaging and second-look arthroscopy. Clinical survivorship was determined with a Lysholm score <65 or need for additional surgery, such as revision MAT. Results: The mean Lysholm score improved from 67.2 ± 15.9 preoperatively to 86.7 ± 11.1 with a mean follow-up of 78.0 ± 51.2 months (P < .001). The postoperative scores were not significantly different between the 3 groups. The estimated 5-year anatomic survival rate in the cartilage procedure group (86.7%) was higher than that in the bipolar lesion group (65.0%; P = .043) but comparable with that in the unipolar lesion group (90.2%; P = .572). The estimated 5-year clinical survival rates were not significantly different between the groups (P = .187). Conclusion: A concurrent femoral cartilage procedure improved the anatomic survival rate in patients with bipolar chondral lesions who underwent lateral MAT. This finding suggests that the cartilage procedure is an effective treatment choice and may improve the status of an allograft after lateral MAT for patients with bipolar cartilage lesions.

Isolated Meniscus Allograft Transplantation Effectively Reduces Knee Laxity In the Presence of Previous Meniscectomy: In-Vivo Navigation of 18 Consecutive Cases

Isolated Meniscus Allograft Transplantation Effectively Reduces Knee Laxity In the Presence of Previous Meniscectomy: In-Vivo Navigation of 18 Consecutive Cases

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation

Background: Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically. Purpose/Hypothesis: The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation. Results: Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (–41%) (all P &lt; .05 vs intact), while LMAT restored all outcome measures (all P &gt; .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (–0.0479 N/mm2), 5.9% (–0.154 N/mm2), and 1.4% (–6.99 mm2) for the lateral compartment and 7.3% (+0.034 N/mm2), 12.6% (+0.160 N/mm2), and 4.3% (+20.53 mm2) for the medial compartment, respectively. Conclusion: Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile. Clinical Relevance Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Effect of High Body Mass Index on Survivorship After Lateral Meniscal Allograft Transplantation: A Propensity Score Matching Analysis

Background: Preoperative body mass index (BMI) is one of the correctable factors before surgery. Few studies have investigated the effect of BMI on the survivorship of lateral meniscal allograft transplantation (MAT). Hypothesis: Patients with a high BMI have inferior survivorship after lateral MAT when compared with those with a normal BMI. Study Design: Cohort study; Level of evidence, 3. Methods: Overall, 306 consecutive patients who underwent lateral MAT were retrospectively reviewed. According to the classification criteria of the World Health Organization, patients were split into 2 groups: normal weight (BMI <25.0) and overweight (BMI ≥25.0). There were 104 patients (34.0%) allocated into the overweight group. Given the demographic heterogeneity between the groups, propensity score matching was performed. Before and after propensity score matching, the anatomic and clinical survival rates of the 2 groups were compared by Kaplan-Meier survival analysis. Anatomic failure was defined as a tear covering >50% of the allograft or unstable peripheral rim on follow-up magnetic resonance imaging and second-look arthroscopy. Clinical failure was defined as a Lysholm score <65 or need for additional surgery, such as revision MAT. Results: For all patients, the mean ± SD follow-up period was 6.9 ± 4.2 years. The mean BMI of the overweight and normal weight groups was 27.8 ± 2.6 and 22.0 ± 1.9, respectively. The mean Lysholm scores at the last follow-up were not significantly different between the groups. However, the anatomic survival rate in the overweight group (77.9%) was significantly lower than that in the normal weight group (90.1%) (P < .001). The clinical survival rate (82.7%) in the overweight group was significantly lower than that in the normal weight group (95.0%) (P < .001). After propensity score matching for patient characteristics, which left 87 patients per group, the anatomic and clinical survival rates were significantly lower in the overweight group. Conclusion: Preoperative high BMI was associated with inferior anatomic and clinical survival rates. The results of the current study suggest that weight loss before lateral MAT may be required in overweight patients for the improvement of anatomic and clinical survival rates.

Bone bridge technique for lateral meniscal allograft transplantation: no difference in clinical outcome compared to the soft tissue technique.

There is considerable debate regarding the optimal method of fixation for lateral meniscus allograft transplantation (MAT), with bone bridge techniques technically harder but allowing maintenance of root attachments, while soft tissue techniques are potentially more challenging for healing. The aim of this study was to compare the clinical results of the bone bridge and soft tissue techniques for lateral MAT in terms of failure, re-operation rate, complications and patient reported outcomes. Retrospective analysis of prospectively collected data for patients undergoing primary lateral MAT with a minimum of 12-month follow-up. Patients following surgery utilising the bone bridge technique (BB) were compared with historical control patients who underwent MAT with the soft tissue technique (ST). Outcome was assessed by failure rate, defined as removal or revision of the meniscus transplant, survivorship by Kaplan-Meir analysis, re-operation rates, and other adverse event. Patient-reported outcome measures (PROMs) were compared using data at the 2-year point or 1year if not reached 2years. One-hundred and twelve patients following lateral meniscal transplants were included, 31 in the BB group and 81 in the ST historical control group, with no differences in demographics between both groups. Median follow-up for the BB group was 18 (12-43) months compared to 46 (15-62) months for the ST group. There were 3 failures (9.6%) in the BB group v 2 (2.4%) in the ST group (n.s.) with a mean time to failure of 9months in both groups. 9 patients (29%) required a re-operation (all cause) in the BB group v 24 patients (29.6%) in the ST group (n.s). There was no difference in complications between both groups. There was significant improvement (p < 0.0001) in all PROMs (Tegner, IKDC, KOOS and Lysholm) between baseline and 2-year follow-up for both groups but no between-group differences. Lateral MAT has a high success rate for symptomatic meniscal deficiency with significant benefits irrespective of the fixation technique. There is no advantage in performing the more technically demanding BB technique over ST fixation. Level 2.

Meniscal Allograft Transplants in Skeletally Immature Patients: A Systematic Review of Indications and Outcomes.

Meniscal lesions in skeletally immature patients can lead to joint degradation and knee instability. Meniscal allograft transplant (MAT) surgery is a solution to maintain knee stability. There is a lack of consensus on MAT surgery outcomes in pediatric patients. A systematic review was conducted according to the PRISMA guidelines. PubMed, Scopus and EMBASE databases were searched from 1965 to June 2022. Studies were evaluated using the Newcastle-Ottawa Scale (NOS). Three studies were selected, and 58 patients were included (mean age 15.9 years) in total. The lateral meniscus was involved in 82.8% of all MAT surgeries. Post-meniscectomy syndrome and discoid meniscus were the main indications for MAT surgery. All studies reported improved subjective clinical scores and levels of sport after the surgery. The complication rate was 27.5%. Partial meniscectomy, meniscus knot removal, chondral defect treatment and lysis of adhesions were the most frequent procedures performed during reoperation. MAT surgery can improve clinical outcomes in pediatric patients with strictly selected indications. MAT surgery is safe when there are no limb asymmetries or malalignments, but it remains a challenging procedure with a high complication rate. Long-term follow-up is needed for definitive statements on the use of MAT in skeletally immature patients.

Effects of Patient Assessment and Education by an Integrated Care Team on Postoperative Adherence and Failure Rates After Osteochondral Allograft and Meniscal Allograft Transplantation in the Knee

Patient nonadherence with prescribed rehabilitation protocols is associated with up to 16 times higher likelihood of treatment failure after osteochondral allograft transplantation (OCA) and meniscal allograft transplantation. Patients who completed counseling with an orthopaedic health behavior psychologist as part of an evidence-based shift in practice at our institution would have significantly lower rates of nonadherence and surgical treatment failure versus patients who did not participate in counseling. Cohort study; Level of evidence, 2. Patients in a prospective registry who underwent OCA and/or meniscal allograft transplantation between January 2016 and April 2021 were included for analysis when 1-year follow-up data were available. Of 292 potential patients, 213 were eligible for inclusion. Patients were categorized based on whether they participated in the preoperative counseling and postoperative patient management program: no health psych group (n = 172) versus health psych group (n = 41). Nonadherence was defined as documented evidence of a deviation from the prescribed postoperative rehabilitation protocol. In this cohort of patients, 50 (23.5%) were documented to be nonadherent. Patients in the no health psych cohort were significantly more likely to be nonadherent (P = .023; odds ratio [OR], 3.4). Tobacco use (OR, 7.9), higher preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference score, lower preoperative PROMIS Mental Health score, older age, and higher body mass index were also significantly associated with nonadherence (P < .001 for all). Patients who were nonadherent with the prescribed postoperative rehabilitation protocol during the first year after transplantation were 3 times more likely (P = .004) to experience surgical treatment failure than those who were adherent. Overall, 26.2% of patients in the no health psych group experienced surgical treatment failure versus 12.2% in the health psych cohort. Data from the present study suggest that preoperative counseling with a health behavior psychologist is associated with an improved rate of patient adherence and a lower proportion of surgical treatment failure after OCA and meniscal allograft transplantation. Patients who remained adherent to the postoperative protocol were 3 times more likely to have a successful short-term (≥1 year) outcome.

Patient-Specific Variables Associated with Failure to Achieve Clinically Significant Outcomes After Meniscal Allograft Transplantation at Minimum 5 Year Follow-Up

To determine the improvements in patient-reported outcome measures (PROMs) necessary to achieve minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) after primary meniscal allograft transplantation (MAT) at a minimum of 5-year follow-up, while identifying variables predictive of achieving clinically significant outcomes (CSOs). A retrospective review was performed to identify patients undergoing primary MAT at a single institution from 1999 to 2016. Lysholm, International Knee Documentation Committee (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were collected before surgery and at a minimum of 5-year follow-up. A distribution-based approach was used to calculate MCID, whereas an anchor-based approach was used to calculate SCB and PASS. Multivariate logistic regression was performed to determine factors associated with CSO achievement. A total of 202 patients undergoing MAT (56% medial, 44% lateral) were included with a mean follow-up of 9.8 ± 4.1 years, age of 29.7 ± 8.5 years, and body mass index (BMI) of 26.5 ± 4.7. Thresholds for achieving MCID, PASS, and SCB, respectively, at a minimum 5-year follow-up for Lysholm (10.3, 74.5, 32.5), IKDC (12.1, 55.6, 29.1), and KOOS subscales questionnaires (Pain [11.0, 70.7, 25.1], Symptoms [11.0, 60.8, 19.6], Activities of Daily Living [10.5, 90.3, 17.9], Sport [16.2, 47.4, 37.5], and Quality of Life [13.6, 40.5, 37.3]) were calculated. Reduced odds of achieving MCID were associated with higher preoperative PROM scores, BMI, patient age, concomitant osteotomy, male sex, and worker's compensation (WC) status. Reduced odds of achieving PASS were associated with lower preoperative PROM scores, higher BMI (particularly ≥30), patient age, and WC status. Reduced odds of achieving SCB were associated with higher preoperative PROM scores and WC status. This study established the MCID, PASS, and SCB at 5-year minimum follow-up for the Lysholm score, IKDC, and KOOS subscales in patients who underwent MAT. Increased BMI and patient age, male sex, performance of concomitant osteotomy, WC status, and preoperative PROM scores were associated with failure to achieve CSOs after primary MAT at a minimum of 5-year follow-up. Level IV, therapeutic study, retrospective case series.

Meniscal Allograft Transplantation: Does Surgical Technique Influence Clinical Outcomes?

Meniscal allograft transplantation is intended to address painful knees with symptoms that can be attributed to meniscal deficiency through injury or meniscectomy. Initially viewed as an experimental procedure, refinements in patient selection and surgical technique have led to improved clinical outcomes with wider acceptance. Our intention with this paper is to provide a review of meniscal allograft transplantation, with the focus on the different surgical techniques employed and their influence on outcomes. The main debate regarding surgical technique is using bone or only soft tissue for fixation of the meniscal horns. Biomechanical and other basic science studies show improved function and less extrusion when the grafts are secured with bone. However, several clinical studies show no difference in outcomes. Long-term studies have shown improved success with less graft extrusion and may illustrate the important function of bone fixation. Many clinical studies, including those with long-term outcomes, have shown meniscal allografts can decrease patient pain and improve function. It is a technically challenging procedure with good clinical outcomes regardless of the method of graft fixation. Bone fixation provides less extrusion which is associated with improved graft function and decreased rate of joint deterioration. Further study is needed to determine if other methods to decrease extrusion are able to improve graft function and outcomes.