Meniscus allograft transplantation is an established surgical treatment indicated in symptomatic meniscus-deficient patients with minimal to no arthritis. Treatment decision making should be individualized after a thorough history and physical examination, with diagnostic imaging and arthroscopy to assess the status of the meniscus. The senior author prefers to use a bridge-in-slot technique, where osseous fixation of the allograft is completed through passage of a bone bridge to a tibial slot. Outcomes in meniscus allograft transplantation are favorable, with reported significant improvements in clinical outcome and low failures in short- and midterm follow-up studies.
In young patients with persistent pain after total meniscectomy, meniscal allograft transplantation may be indicated to alleviate symptoms and delay the onset of osteoarthritis.
Ideal candidates are those who have failed conservative management and meniscectomy, with minimal to no osteoarthritis, a low to normal body mass index, and are younger.
There are several different techniques used in meniscal allograft transplantation, which are broadly categorized into using bony fixation (using bone plugs or a bridge-in-slot technique) and soft tissue fixation.
Outcomes in patients with meniscal allograft transplantation are promising, with long-term favorable graft survival rates in patients undergoing isolated procedures and with concomitant anterior cruciate ligament reconstruction or a cartilage preservation procedure.
The menisci act as shock absorbers, by decreasing tibiofemoral contact area and contact pressure, thus enhancing the stability of the knee joint . Removal of the meniscus via partial or total meniscectomy can, therefore, result in altered biomechanics of the knee in a manner that depends on the amount of meniscus removed. Meniscal deficiency, such as in patients who have previously undergone a meniscectomy, can lead to the onset and progression of knee osteoarthritis (OA). Additionally, for some patients with meniscal pathology, the symptoms of pain, swelling, instability, and functional limitation do not subside after initial meniscectomy. In these patients with persistent pain in a meniscal deficient knee, meniscal allograft transplantation (MAT) may be indicated to restore the force distribution across the knee and reduce symptoms ( Box 1 ). Because MAT is considered a salvage procedure, it is still relatively rare with an estimated 3295 performed from 2007 to 2011 and an incidence of 0.24 procedures per year per 100,000 patients. Although MAT is less common than other meniscal procedures, it gives patients with debilitating pain and functional limitations a viable treatment option that may improve symptoms and function, and it may contribute to a more biomechanically stable knee.
Indications for meniscal allograft transplant
Less than 55 years old
Unicompartmental pain at the joint line
Pain is the predominant symptom
No significant OA (Kellgren-Lawrence grades 1–2)
Contraindications for meniscal allograft transplant
Diffuse arthritic changes
Joint infection, previous or active
Note: Malalignment, ligamentous insufficiency, and chondral defects are not absolute contraindications to MAT. These pathologies do; however, need to be addressed concomitantly or via a staged procedure to receive optimal patient outcomes.
Patient evaluation and preoperative planning
Careful patient selection is crucial for successful outcomes after MAT. To determine if a patient is an appropriate candidate for this procedure, a thorough history and physical examination is essential. Ideal candidates are relatively young patients (too young for knee arthroplasty), have undergone a partial or total meniscectomy, and continue to have joint line pain specific to the meniscectomized compartment with Kellgren-Lawrence grade 2 OA or less. There has not been a firm consensus on the upper age limit of MAT, but a review of the current literature indicates that most physicians do not perform MAT in patients more than 45 to 55 years old because patients with meniscal deficiency over this age often have significant arthritis.
Physeal status should be assessed carefully in younger patients to avoid causing a physeal arrest and alignment deformities. Obesity should be considered as a relative contraindication to perform MAT; some authors contraindicate this procedure in patients with a body mass index of more than 30 because it increases the load within the knee compartments, resulting in an increased risk of allograft failure.
It is important to review radiographs, including anteroposterior weight bearing views, lateral non-weight bearing views, Rosenberg views (posteroanterior 45° flexion weight bearing views), and merchant views (axial views of the patellofemoral joint) ( Fig. 1 ), because the ideal candidate for MAT does not have radiographic evidence of diffuse OA. Candidates for MAT should present with radiographs showing minimal joint space narrowing, no osteophytes, and no significant bony flattening in the involved compartment. These views should be obtained with a sizing marker to determine the graft size needed for MAT. Mechanical axis views should also be reviewed to evaluate the patient’s alignment and potential need for a realignment procedure concurrently or before the transplant. An MRI should be obtained to evaluate the meniscus, specifically the amount of meniscus remaining ( Fig. 2 ). The MRI will also assess for any subchondral edema, cartilage damage, or ligamentous insufficiency, because focal chondral defects or ligamentous pathology may need to be addressed concomitantly.
Before MAT, the senior author (BJC) recommends the patient undergo a diagnostic arthroscopy to further evaluate and confirm the status of the meniscus ( Fig. 3 ), cartilage damage, and concomitant pathologies. The diagnostic arthroscopy helps to elucidate other possible causes of knee pain to ensure the patient is an appropriate MAT candidate. This diagnostic arthroscopy is ideally completed within 6 months of MAT in the absence of outside index information that would otherwise verify the intra-articular pathology.
Graft Selection and Sizing
Preoperative radiographs with sizing markers are essential for ordering a size-matched meniscal allograft. Meniscal allografts are matched to the patient’s laterality, specific compartment, and size. Size matching is important because an improperly sized meniscus can lead to increased contact pressures in unwanted areas. Sizing is as described by Pollard and colleagues, on anteroposterior films in which 2 vertical lines are drawn perpendicular to the joint line and are used to measure meniscal width. In a medial meniscus, the first line is tangential to the medial tibial metaphyseal margin and the second is through the peak of the medial tibial eminence. For a lateral meniscus, the first line is tangential to the lateral tibial margin and the second is through the peak of the lateral tibial eminence. The distance between these 2 lines is said to be the meniscal width. Of note, it is important to measure from the margin of the tibial metaphysis rather than the joint space. Meniscal length is measured on lateral radiographs in a similar manner. The first line is drawn at the anterior tibial surface above the tuberosity and the second is a parallel line tangent to the posterior margin of the tibial plateau. The medial meniscus length is 0.8 times this distance, and the lateral meniscal length is 0.7 times the distance.
In the senior author’s practice, fresh-frozen allografts are preferred. Fresh-frozen meniscal allografts are able to be stored for 5 years at −80°C in a physiologic solution with an antibiotic. Although freezing the meniscus has been shown to result in decreased cell viability, this has not been reported to have negative effects on patient outcomes or graft survivorship. Other graft options include cryopreserved and fresh grafts. Because fresh grafts do not offer the same ability to plan in advance, fresh-frozen allografts ease the burden on both the physician and patient. Meniscal allografts have shown excellent integration and repopulation with host trabeculae when a bony bed is used with minor risk of immunologic reaction.
The senior author’s preferred technique, bone bridge in slot, and positioning have been described previously.
After induction with general anesthesia, the patient is positioned supine on the operating table with the foot of the bed dropped and the hips in line with the end of the bed. The contralateral leg is positioned in a well-leg holder in flexion, abduction, and external rotation. The operative knee is positioned in a thigh holder with a tourniquet in place and allowed to hang off the end of the bed. Standard preoperative antibiotics are administered before any incisions. An examination under anesthesia is performed to assess ligamentous stability. The patient limb is then prepped and draped sterilely.
The senior author performs the same technique for both medial and lateral MATs. After creation of the anterolateral and anteromedial portals, arthroscopy is performed to evaluate once more for focal chondral defects or ligamentous insufficiency. After the evaluation of concomitant pathologies via arthroscopy, the remaining meniscus in the index compartment is debrided taking care to not violate the capsule. This should be done until there is a 1- to 2-mm peripheral rim remaining with punctate bleeding. The anterior and posterior horn remnants can serve as a footprint for allograft insertion. The residual meniscal rim is left in place to prevent radial displacement of the allograft and function as a firm bed for meniscal fixation. A limited notchplasty can be performed at this time to enhance visualization and ease of graft passage. The anterior cruciate ligament fibers at the tibial insertion should be released, as minimally as possible, to allow for visualization of the medial tibial spine.
A posteromedial or posterolateral approach is made starting one-third of the way above the level of the joint line and extending two-thirds of the way below the level of the joint line, which will later be used to pass the sutures (as described elsewhere). Next, a 3-cm transpatellar tendon incision is made, into which a 4.5-mm burr is inserted to create a provisional slot, in line with the insertion of the anterior and posterior horns. After a depth gauge is inserted into the slot to verify appropriate depth (usually 10 mm), a guide pin is placed directly underneath and seated in the posterior cortex to establish the bottom of the slot. Fluoroscopic guidance may be used to ensure proper placement of the guide pin and to not violate the posterior cortex. An 8-mm cannulated reamer is placed over the guidewire, and a box cutter osteotome is used to widen the slot to 8 mm wide and 10 mm deep. A rasp is then used to even out all the edges in the slot and to maximize congruency with the bone bridge.
The meniscal allograft is prepared on the back table during arthroscopy. The meniscal allograft is delivered by the tissue bank as a hemiplateau with attached meniscus, with all nonmensical tissue removed. The graft is debrided so only true attachment sites remain and is then prepared to dimensions appropriate for the arthroscopic tibial slot preparation ( Fig. 4 ). Of note, the bone bridge is undersized by 1 mm as a preventive measure for ease of graft passage and minimization of potential bridge fracture. As a standard, the bone bridge is cut to a width of 7 mm and a height of 10 mm. Excess bone beyond the posterior horn attachment is removed to ensure proper alignment of the bone bridge posterior wall and posterior edge of the slot. To help with graft insertion, excess bone beyond the anterior horn is preserved. The junction of the posterior horn and middle third of the meniscus are secured using a no. 0 polydioxanone with a vertical mattress traction suture ( Fig. 5 ). In the event that the anterior horn is larger, the bone bridge width on the anterior horn insertion should be appropriately increased, with the remaining bone bridge cut to 7 mm.
First, the arthroscope is placed in the corresponding compartment portal (ie, anteromedial for medial MAT), and a repair cannula is placed in the contralateral portal, aiming toward the intended position of the junction of the middle and posterior portions of the graft.
A flexible suture-passing wire is then inserted through the meniscal repair cannula, and out the posterolateral/posteromedial portal. The ends from the traction stitch of the graft are threaded through the loop of the suture passing wire, which is retrieved from the transpatellar incision. The wire and sutures are then pulled through the posterolateral/posteromedial incision, and the meniscus is carefully inserted through the anterior incision, while simultaneously pulling on the polydioxanone traction suture and applying the appropriate stress (varus for a lateral MAT and valgus stress for a medial MAT) to insert the bridge into its position ( Fig. 6 ). Proper reduction of the meniscus and visualization of the bone block in the bridge is then done arthroscopically. After a few cycles of flexion and extension to ensure appropriate graft placement relative to the condyles, a 4.75 or 5.75 mm Swivelock anchor (Arthrex, Naples, FL) is placed to fix the bone bridge ( Fig. 7 ). Eight to 10 vertical mattress sutures are then placed using an inside-out technique, taking care to not tie them until any concomitant procedures are complete ( Fig. 8 ). The anterior horn of the meniscus is repaired with an outside-in technique. After concomitant procedures are complete, the inside-out sutures are tied while the knee is in full extension.
Concomitant procedures, when indicated, can and should be performed at the time of MAT or via staged procedure. These may include high tibial or distal femoral osteotomies for varus or valgus malalignment, respectively, ligamentous procedures for ligament insufficiency or rupture, and cartilage procedures, such as microfracture, autologous chondrocyte implantation, osteochondral allograft, or osteochondral autograft, for focal chondral defects. Any chondral defects should be addressed after the MAT, because the frequent varus/valgus manipulations associated with the MAT procedure can cause improper seating of the osteochondral graft. The concomitant procedure may alter the postoperative rehabilitation protocol slightly, all of which should be discussed with the patient preoperatively.
The posterolateral/posteromedial lesions are closed in a layered fashion, and portal holes are closed with 3-0 nylon interrupted sutures. After closure, local anesthesia is injected to maximize postoperative pain relief.
The postoperative rehabilitation protocol recommended by the senior author (BJC) is as follows. The patient is made heel touch weight bearing with crutches for the first 6 weeks and can progress to full weight bearing 6 to 8 weeks postoperatively. The patient is restricted from weight bearing with flexion greater than 90° for the first 8 weeks. The brace is locked in full extension for sleeping and all activities for the first 2 weeks, after which time the brace is locked at 0° to 90° and can be removed at night. Before 6 weeks, all exercises should be done with the brace. After this timepoint, activities can be done without the brace as tolerated. The brace can be discontinued 8 weeks postoperatively. The patient should avoid any tibial rotation for 8 weeks to protect the meniscus. Range of motion should be limited to 0° to 90° when non-weight bearing for the first 2 weeks and then can progress as tolerated over weeks 2 to 8. The patient should have full range of motion by weeks 8 to 12. After 8 weeks, hamstring work, lunges, proprioception exercises, and stationary bike can begin and progress as tolerated through 20 weeks. Around 6 months, the patient is able to advance to sport-specific drills, running, and jumping after physician clearance.
There are many variables that make MAT outcomes difficult to assess and generalize. These include conjoined analysis of medial and lateral MATs, different graft types (fresh, cryopreserved, and fresh frozen), a variety of concomitant procedures, differing techniques and surgeon experience, and the low levels of evidence of current studies. Thus, with many of the studies reporting on patients undergoing concomitant realignment, cartilage or ligamentous procedures, it can be difficult to ascertain the contribution of an MAT on the patient’s clinical outcome. When looking at short and long-term MAT outcomes with and without concomitant procedures, studies typically evaluate patient-reported outcome measures, return to activity, subsequent procedures, complications, graft survival, and failures, often defined as the need for revision MAT or the progression to arthroplasty. Additionally, recently an emphasis has been put on determining the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) in patient-reported outcome measures. Other important outcomes after MAT include the progression of OA as well as graft extrusion and the clinical implications of these. Overall reported results have been encouraging mainly for the treatment of the symptoms and functional improvement. A summary of many of these studies is included in Table 1 .
|Author||No. of Patients||Laterality||Graft Preservation Technique||Mean Age (y)||Mean F/u (y)||Mean BMI (kg/m 2 )||Time to Surgery (y)||Workers Comp||Concomitant Procedures||Clinical/Radiographic Outcomes||Failures, Complications||Overall Survival Rate/Reoperation Rate||Conclusion|
|Lee et al, 2019||130 (4 studies)||NR||NR||25.1 ± 6.2||NR||NR||NR||NR||NR.||Return to sport ranged from 7.6 to 16.5 mo.||NR.||3/4 studies reported reoperation rates of 12%, 25%, and 30% of athletes.||67%–85.7% of athletes returned to sport within an average of 7.6–16.5 mo after MAT, which was longer and lower rate than those undergoing partial meniscectomies. There were no significant differences between patients with different degrees of chondral damage or in laterality.|
|Liu et al, 2019||98||57 medial, 41 lateral||Fresh frozen||29.4 ± 9.0||≥1 y||26.8 ± 5.2||NR||NR||82 (84%): (n = 10) ACLR, (n = 4) chondroplasty, (n = 12) MFx, (n = 3) OAT, (n = 50) OCA, (n = 6) ACI, (n = 4) HTO, (n = 3) DFO.||Of the 34 patients who completed satisfaction surveys, MCID and PASS were established for Lysholm, IKDC, and KOOS; 28 patients were satisfied with their surgery and 6 were not satisfied.||NR.||NR.||Patients who had lower scores preoperatively were more likely to achieve the thresholds for MCID and PASS established by this study. Workers’ compensation patients and patients with higher BMIs were less likely to achieve these values for certain outcome measures.|
|Lee et al, 2018||53 patients who underwent lateral MAT with the keyhole technique assigned to either (n = 25) standard rehabilitation or delayed rehabilitation (n = 28; ie, 3 wk immobilization followed by use of unloading braces for 9 wk)||All lateral||Fresh frozen||30.6||2.1||NR||NR||NR||None.||The number of patients and absolute/relative percent extrusion was greater in the group assigned to standard rehabilitation. Significant correlations between coronal graft extrusion and postoperative joint space width was found.||None.||NR.||Patients who underwent the delayed rehabilitation program had statistically less extrusion on coronal MRI at 24 mo as well as less progression of OA compared with those in the standard program, although no differences in clinical outcomes between the groups were observed.|
|Masferrer-Pino et al, 2018||LMAT: 15 with bony fixation, 14 with suture fixation through bone tunnel after capsulodesis||All lateral||Fresh frozen||38.2||2.1||NR||NR||NR||Not discussed.||After excluding the first 4 cases, which showed the worst cases of extrusion from the analysis as a learning curve for the new technique, there was a significantly lower percentage of extrusion seen in the capsulodesis group at 36–48 mo of F/u.||NR.||NR.||Although the capsulodesis technique in LMAT presented a lesser degree of meniscal extrusion than the bone bridge fixation if the first 4 cases were excluded, clinical outcome did not differ significantly between the 2 groups.|
|Saltzman et al, 2018||60 patients undergoing isolated MAT||27 medial, 13 lateral||NR||26.1 ± 9.3||58.8 ± 27.6||25.5 ± 5.2||NR||25%||None.||Significant improvements in IKDC, KOOS Pain, and SF-12 physical were noted postoperatively ≥2 y.||4 (15%): (n = 2) total meniscectomies, (n = 1) TKA, (n = 1) revision MAT at postoperative 30.84 ± 16.80 mo.||95% graft survival at 24 mo and 87% graft survival at 60 mo. 11 Revisions: (n = 4) partial meniscectomy, (n = 2) total meniscectomy, (n = 1) revision MAT, (n = 1) plica excision, (n = 1) OCA, (n = 1) de novo NT, (n = 1) synovectomy.||Increasing BML size correlates with worse postoperative pain scores and lower activity ratings but no significant differences in graft survivorship was found based on gradings.|
|Frank et al, 2018||100: 50 with OCA + MAT, 50 MAT||29 medial, 29 lateral||Fresh frozen||31.7 ± 9.8||4.9 ± 2.7||25.0 ± 4.8||NR||14%||50: (n = 45) OCA + MAT, (n = 3) OCA + MAT + DFO, (n = 2) OCA + HTO + DFO.||Both groups showed statistically significant improvements in Lysholm, IKDC, KOOS, WOMAC and SF-12 physical scores as compared with preoperative scores.||2 (4%): local cellulitis (n = 1), postoperative arthrofibrosis requiring adhesiolysis; 17 reoperations.||86% at 3.34 y; 7 failures.||At final F/u, patients in both groups experienced statistically significant improvements in Lysholm, IKCD, KOOS, WOMAC, and SF-12 physical subscale outcomes, with no significant differences in PROs between the groups. There were no significant differences between complication rates or reoperations between the 2 groups.|
|Saltzman et al, 2018||91: 22 with no defect (Outerbridge 0/I), 69 with full thickness defect (Outerbridge IV)||NR||Fresh frozen||28.6||4.5 ± 2.6||25.7||NR||NR||10 in no defect group: (n = 2) realignment procedures, (n = 8) ACLR. 69 cartilage procedures in full thickness group: (n = 48) OCA, (n = 13) ACI, (n = 9) MFx, (n = 3) OAT, (n = 1) de novo NT, (n = 7) realignment, (n = 8) ACLR.||No significant differences in postoperative or final F/u delta patient reported outcomes, number of subsequent surgeries, or failures between the no defect (grade 0/I) and full thickness defect (grade IV) groups.||1 complication in the full-thickness defect group, with 0 in no defect group. Three failures: 1 (5%) in no defect group, 2 (3.3%) in full thickness defect group.||10: 2 (10%) in no defect group, 8 (12.9%) in full thickness group. 86% survivorship in both full-thickness and no defect group.||Chondral damage that is treated with cartilage restoration at the time of MAT may not affect the clinical outcomes of MAT.|
|Kim et al, 2018||46||All lateral||Fresh frozen||31.6 ± 10.8||51.1 ± 7.1||NR||NR||NR||4: (n = 2) ACLR, (n = 2) MFx.||Relative extrusion in the coronal plane did not differ significantly at 6 wk, 1 y, and 3–5 y postoperatively in either the coronal or sagittal plane||NR||NR||Extrusion following LMAT did not significantly progress in either plane during F/u at 3–5 y.|
|Riboh et al, 2016||32||5 Medial, 27 Lateral||Fresh-frozen||15.4 ± 1.0, (range 13–16)||7.2 ± 3.2||22.1 ± 3.6||NR||NR||13 (41%): (n = 10) ACI, (n = 2) ACLR, (n = 1) ACI biopsy, (n = 1) OAT, (n = 3) OCA, (n = 1) HTO.||Significant improvements were seen in Lysholm, IKDC, WOMAC pain, function and stiffness, SF-12 physical, and all KOOS subscores except KOOS Symptoms. IKDC significantly declined from 2 y to final F/u.||No revisions or failures.||6% meniscal reoperation rate: (n = 2) debridements for torn MAT, overall reoperation rate 22% (n = 8).||Improvements in functional outcomes for adolescent patients was seen after MAT with a low meniscal reoperation rate.|
|Saltzman et al, 2016||40 patients undergoing combined MAT with ACLR||33 medial, 7 lateral||Cryopreserved||30.3 ± 9.6||5.7 ± 3.2||27.7 ± 4.2||9.1 ± 6.6||17.5%||19: (n = 9) HWR, (n = 9)OCA.||Significant improvement in all PROs analyzed except for Tegner score, which significantly decreased, WOMAC stiffness, and SF-12 scores. 9/18 athletes returned to sport.||8: (n = 2) graft failures at 7.3 y, (n = 6) arthroplasty 8.3 y. Two minor complications involving surgical drainage.||98% graft survival rate at 1.7 y, 84% at 5 y and 45% at 10 y; 14 reoperations: most commonly (n = 8) debridement, (n = 4) partial meniscectomy, 2 HW.||Concomitant ACLR/MAT can provide significant improvement in clinical outcomes and knee stability for patients.|
|Zaffagnini et al, 2016||89||45 medial, 44 lateral||Fresh frozen||38.5 ± 11.2||4.2 ± 1.9||23.8 ± 6.1||1.2 ± 0.9 from index meniscectomy||None||41 (45%): (n = 12) HTO, (n = 1) HTO + ACLR, (n = 1) HTO + OCA, (n = 2) DFO, (n = 9) ACLR, (n = 2) revision ACLR, (n = 2) mosaicplasty, (n = 3) OCA, (n = 9) MFx.||At latest F/u, patients who returned to sport had significantly better Tegner scores and KOOS subscores (ADL, QoL, KOOS total) as well as higher knee function, and global satisfaction than those who did not return to sport.||1 failure: UKA.||11 (12%): (n = 3) partial meniscectomy, (n = 3) arthroscopic debridement, (n = 1) peroneal nerve release, (n = 1) UKA, (n = 3) HWR, (n = 1) patellar tendon repair.||49% were able to return to preinjury level of play and 74% were able to return to sport after 8.6 ± 4.1 mo, and those who returned to sport had superior subjective outcomes to those who did not return to sport.|
|Roumazeille et al, 2015||22||2 medial, 20 lateral||Fresh frozen||37 ± 7.5||4.4 ± 1.6||NR||NR||NR||5 ACLR.||10/14 grafts were fully or partially healed (Henning’s criteria). At final F/u, the extrusion had increasing to 3.6 ± 1.9 mm, a relative percentage of extrusion of 46% ± 29.9%, and all KOOS subscales and IKDC scores had improved significantly.||1 hematoma.||2 second-look arthroscopies.||MAT without bone plugs achieved good clinical outcomes and graft healing. No correlation was found between percent extrusion and graft healing, and despite meniscus extrusion in most patients on MRI, pain and knee function scores were significantly improved compared with baseline.|
|McCormick et al, 2014||172||NR||Fresh frozen||34.4 ± 10.3||4.9||25 ± 3.4||1.75 (range 0.2–8.9 y), 73% within 2 y||10%||119 (60%): MAT + cartilage procedure (n = 37), MAT + Cartilage procedure + osteotomy (n = 14), MAT + ACLR (n = 11), MAT + osteotomy (n = 8).||NR.||64 (32%): debridement/scar excision/MUA (n = 38), treatment of progressive disease (n = 17), graft repair or debridement <50%, second look arthroscopy (n = 3), revision MAT/arthroplasty (n = 8).||88% in revision MAT or TKA, 98% in patients with no subsequent procedures. A 32% reoperation rate for MAT, with a mean 95% allograft survival at 5 y. 73% of patients who underwent secondary surgery did so at mean of 21 mo.||There was a 32% reoperation rate for MAT, and those requiring secondary surgery within 2 y of the MAT had an OR of 8.4 for a subsequent revision MAT or TKA.|
|Yanke et al, 2014||8 revision MAT||2 medial, 6 lateral||Fresh frozen||31.6 ± 10.2||3.8 ± 1.3||NR||Time to index procedure was 3.45 ± 2.52 y||NR||4: (n = 1) ACLR, (n = 1) DFO, (n = 2) OCA.||Patients demonstrated significant improvements in IKDC, KOOS pain scores, and subjective symptom rating scale. No significant differences were seen in Outerbridge grading between initial and revision. Seven of 8 patients reported they would undergo the procedure again.||2 TKA.||75% at final F/u.||Revision MAT achieved high patient satisfaction and improvement in IKDC and KOOS, showing that outcomes after revision MAT would be improved compared with preoperative conditions, with no correlation between preoperative radiographic evidence and outcomes after revision MAT.|
|Marcacci et al, 2014||12 male professional soccer players||6 medial, 6 lateral||Fresh frozen||24.5 ± 3.6||3.0||23.2 ± 1.1||3.1 ± 2.6 y from meniscectomy to MAT||NR||7: (n = 3) MFx, (n = 1) OCA, (n = 2) ACLR, (n = 1) ACI biopsy.||92% of players returned to soccer at a mean 10.5 ± 2.6 mo postoperatively. Tegner, Lysholm, IKDC, WOMAC, and VAS pain were significantly improved 12 mo after surgery and were stable at 36 mo.||1 failure: patient was treated for infection but stopped playing soccer.||NR.||Return to sport in soccer players after MAT was 75% at 36 mo F/u, with a mean time to return to previous athletic level of 16.5 mo.|
|Harris et al, 2014||35 patients undergoing cartilage procedure with (n = 15) and without concomitant MAT||NR||Fresh frozen||29.6 ± 10.5||3.7 ± 1.7||23.9 ± 4.1||2.51 ± 3.52||NR||15: (n = 1) LMAT + MFx, (n = 8) LMAT + ACI, (n = 1) LMAT + OAT, (n = 4) LMAT + OCA (n = 1) LMAT + DFO + OCA.||At F/u, patients undergoing isolated articular cartilage surgery had a significantly higher KOOS QoL subscore than did those undergoing articular cartilage surgery and lateral MAT, with no other significant postoperative differences in any outcome score between the 2 groups.||1 patient with superficial wound infection.||No conversions to TKA or MAT revisions’; 14% overall reoperation rate: (n = 1) lateral release, (n = 1) partial lateral meniscectomy, (n = 5) chondroplasty, (n = 1) revision OCA.||When indicated, meniscal deficiency, malalignment, and chondral defects can be addressed concomitantly without compromising clinical outcomes.|
|Chalmers et al, 2013||13 high school or college athletes||3 medial, 10 lateral||Fresh frozen||19.3||3.3||NR||23.9 ± 23.5 from index meniscectomy||None||7: (n = 3) ACLR, (n = 2) OCA, (n = 1) OCA + DFO, (n = 1) MFx.||Significant improvements in IKDC, Lysholm, KOOS pain, symptoms, activity of daily living, and sport subscores at final F/u.||1 failure: LMAT.||3 (23%): (n = 1) revision MAT, (n = 1) partial meniscectomy, (n = 1) meniscal repair.||77% returned to their previous level of activity and 70% returned to their desired level of play, with a mean time to return to previous athletic level of 16.5 mo with significant improvement in clinical and functional outcomes.|
|Cole et al, 2012||22||13 medial, 9 lateral||Fresh frozen||32.5 ± 12.3||8.5 ± 1.3||8 patients with BMI <25, 14 with BMI >25||NR||NR||14 (64%): ACI (n = 5), ACL revision (n = 3), Mfx (n = 2), OCA (n = 2), OAT (n = 2), HWR (n = 3), PCL thermal shrinkage (n = 1).||Mean postoperative satisfaction was 8.8/10; 77% RTS at mean of 17 mo. At 7 y postoperatively, the Overall Knee Condition, IKDC, Lysholm, and all 5 KOOS subgroup scores improved significantly ( P < .05) compared with baseline.||3 patients were identified as failures at 24 mo, 54 mo and 68 mo for undergoing either revision MAT (24, 54 mo) or unicompartimental arthroplasty (68 mo).||88% survivorship.||MAT performed with appropriately indicated concomitant procedures showed statistically significant greater improvements in Lysholm, KOOS Pain, and KOOS QoL as compared with the improvements seen with isolated MAT.|
|Rue et al, 2008||31: 16 with ACI and 15 with OCA||20 medial, 11 lateral||Majority cryopreserved, those after 2004 fresh frozen||29.9||3.1||NR||NR||4 (13%)||3 in OCA group: 1 HTO, 2 HWR.||Significant improvements in Lysholm, IKDC, KOOS, Noyes Symptom scores in both groups. Absolute outcome scores for ACI were significantly better than those for OCA in IKDC and KOOS (all subscores).||2 failures: revision MAT (3 y), complete meniscectomy (2.4 y).||94% survival at a mean of 3.1 y.||Outcomes of combined cartilage and MAT procedures are comparable to reports of these procedures performed in isolation.|