Lateral Meniscal Allograft Research Articles

Results of Isolated Lateral Meniscus Allograft Transplantation

Background: Although numerous studies have reported outcomes of meniscus allograft transplantation, only a few dealt with isolated procedures or employed objective evaluation methods. Hypothesis: Isolated lateral meniscus allograft transplantation (LMAT) provides clinical improvements and favorable objective results in symptomatic lateral meniscus–deficient knees. Study Design: Case series; Level of evidence, 4. Methods: The authors collected and analyzed the results of 29 consecutive isolated LMATs with a minimum of 24 months’ follow-up. The mean age of the patients was 29.6 years (range, 18-48 years). The modified Lysholm scoring system and the Hospital for Special Surgery score were used to evaluate subjective improvements. Every patient underwent postoperative magnetic resonance imaging (MRI) or second-look arthroscopy or both as objective evaluation. The allograft extrusion and relative percentage of extrusion (RPE) was measured on final MRI. Status of the allograft was classified according to the above 3 categories into 3 grades; satisfactory, fair, or poor. Results: The average length of follow-up was 53.6 months. Symptoms and functions of the involved knee improved in 28 knees (96.6%) at the last follow-up. The average preoperative modified Lysholm score was 69.5, which increased to 89.9 postoperatively (P < .001). The average preoperative Hospital for Special Surgery pain score was 15.3, which increased to 26.7 postoperatively (P < .001). Postoperative MRI alone was performed in 22 knees (75.9%), second-look arthroscopy alone in 1 knee (3.4%), and both examinations in 6 knees (20.7%). The MRI scans revealed 4 gross and 5 small tears in the allograft and also provided valuable information despite magnetic susceptibility artifacts. Mean allograft extrusion was 4.0 mm and mean RPE was 45.4%. At second-look arthroscopy, 3 gross tears and a small flap tear were identified in 4 cases. According to the clinical and the objective criteria, the allografts were graded as satisfactory in 20 cases (69.0%), fair in 5 cases (17.2%), and poor in 4 cases (13.8%). Conclusion: The results of the present study showed remarkable symptomatic improvements and acceptable objective findings in short- to intermediate-term follow-up. Even in cases with favorable clinical results, MRI or second-look arthroscopy was necessary to identify the actual status of the allograft. Isolated LMAT could be an effective treatment for symptomatic, lateral meniscus–deficient knees.

Meniscal allograft transplantation in isolated and combined surgery

The purpose of this study was to report the initial results of meniscus allograft transplantation after a 2-year follow-up period with second-look arthroscopy of 18 patients. Seven medial and 11 lateral meniscus allografts were evaluated with a median follow-up of 24.9 months (range, 18-41 months). The clinical outcome and failure rate were evaluated by use of second-look arthroscopy in all patients, magnetic resonance imaging (MRI) analysis in 17 patients, and standardized outcome scores assessment, including Lysholm score, Knee Injury, and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) on pain and satisfaction and International Knee Documentation Committee (IKDC) objective ratings in all patients. Patients were grouped into medial and lateral subgroups as well as those with isolated or combined procedures. For the second-look arthroscopic findings, 6 meniscus transplants (33%) had normal characteristics, 10 (56%) had altered characteristics, and 2 (11%) failed. On MRI, two grafts had grade III signals and 11 showed partially extruded. Patients demonstrated statistically significant improvements in standardized outcome scores and VAS pain scales. Overall, 67% of the patients reported that they were completely or mostly satisfied with the procedure. There were no significant differences in the medial and lateral subgroups and no significant differences were noted in the isolated and combined subgroups. Arthroscopic meniscus transplantation can achieve satisfying subjective and objective clinical outcomes, with a failure rate of 11% after 1-3 years of follow-up, as documented by second-look arthroscopy.

Position of the Bony Bridge of Lateral Meniscal Transplants Can Affect Meniscal Extrusion

Background: There are several reported causes of midbody extrusion after lateral meniscal allograft transplantation. However, there are no reports studying the correlation between the position of the bony bridge and extrusion of the midbody after meniscal allograft transplantation. Hypothesis: The position of the bony bridge of lateral meniscal allografts can affect meniscal extrusion. Study Design: Case series; Level of evidence, 4. Methods: Twenty-three consecutive patients underwent a lateral meniscal allograft transplantation using a fresh-frozen graft. The lateral meniscal allograft was prepared with a bony bridge. Postoperative evaluations of the meniscal allografts were performed using follow-up magnetic resonance imaging 6 months postoperatively. On the coronal view, extrusion was measured as the distance between the outer edge of the articular cartilage of the lateral tibial plateau and the outer edge of the meniscal allograft. On the axial view, the length of the entire tibial plateau (PL) and distance between the lateral edge of the lateral tibial plateau and center of the bony bridge (CB) were measured. Measurements of CB were divided by measurements of PL. The correlation test between CB/PL and extrusion was performed to determine whether the position of the bony bridge can affect extrusion of the midbody of meniscal allograft. Results: The mean center of the bony bridge of the meniscal allograft (CB/PL) was positioned at 42.3% (range, 36.1%-49%; standard deviation [SD] = 3.6%) from the outer edge of the lateral tibial plateau. The mean extrusion of meniscal allografts was 3.2 mm (range, 0-6.5 mm; SD = 2.3). The amount of extrusion was correlated with the position of the bony bridge of the graft and the Pearson correlation coefficient was –.567 (P = .003). The cut-off percentage above which extrusion did not occur was 42.05%. Conclusion: The more closely the center of the bony bridge approached 50% of the entire tibial plateau, the less extrusion of the midbody occurred. Anatomic placement of the bony bridge of lateral meniscal allograft is imperative to prevent extrusion after lateral meniscal allograft transplantation.

The High Failure of Rate of Biologic Resurfacing of the Glenoid in Young Patients With Glenohumeral Arthritis (SS-24A)

<h3>Introduction</h3> Biological resurfacing of the glenoid with lateral meniscus allograft or human acellular dermal tissue matrix for treatment of glenohumeral arthritis in young patients has an unacceptably high failure rate at intermediate-term follow up. The purpose of this study is to compare the clinical outcomes of biological interposition arthroplasty of the glenohumeral joint using either a lateral meniscus allograft (LMA) or a human acellular dermal tissue matrix (HADTM). <h3>Methods</h3> 45 patients with a mean age of 42.2 years were treated with biologic resurfacing of the glenoid and followed for an average of 2.8 years. Among the 41 patients (91.1%) available for follow up evaluation LMA resurfacing was used in 31 cases and HADTM interposition was used in 10 cases. <h3>Results</h3> The overall clinical failure rate was 51.2% (21 of 41 patients). Failure was defined as actual or recommended conversion to TSA, revision surgery for graft removal, patient reported disabling pain/loss of function and/or postoperative ASES score of < 50. The LMA cohort had a failure rate of 45.2% with a mean time to failure of 3.4 years. Those treated with a HADTM had a failure rate of 70.0% with a mean time to failure of 2.2 years. Nine patients (22%) failed treatment within 2 years of the procedure. <h3>Conclusion</h3> Biologic resurfacing of the glenoid with LMA or HADTM results in a high rate of clinical failure at intermediate follow-up. Our results suggest that biologic resurfacing of the glenoid may not have a role in the management of glenohumeral arthritis in the young active patient.

Outcomes of Shoulder Arthroplasty After Failure of Biological Resurfacing of the Glenohumeral Joint (SS-24B)

Introduction This study reports the outcomes of patients undergoing total shoulder arthroplasty following failed management of degenerative joint disease with biological resurfacing of the glenoid. The purpose of this study is to report the results of patients who underwent biological resurfacing and were later converted to total shoulder arthroplasty (TSA). Methods Seven patients (mean age 37.4 ± 10.3 years) treated with biologic resurfacing of the glenoid using lateral meniscal allograft (5 patients) or human acellular dermal tissue matrix (2 patients) failed the procedure and were converted to TSA after an average of 2.0 ± 1.4 years. All patients were available for follow up at an average of 3.3 ± 1.8 years. Results Only limited improvement was observed post-conversion. Forward flexion and external rotation improved from 103.3° ± 34.4° and 28.3° ± 12.9° to 109.4° ± 52.9° and 41.0° ± 14.8°, respectively. The mean ASES, SST, and VAS scores for this group were 29.5 ± 12.1, 1.0 ± 1.4, and 6.25 ± 1.7 preoperatively and 38.3 ± 18.6, 3.7 ± 3.5, and 5.3 ± 1.9 postoperatively, respectively. The threshold of failure was set at an ASES score of Conclusion Biological interposition arthroplasty is designed to postpone the need for prosthetic glenoid components and thus delay the risks associated with polyethylene glenoid implants such as component wear, fragmentation, and glenoid loosening or disassociation. The poor clinical outcomes seen in patients who are converted to a TSA after failure of biological resurfacing suggests that TSA may be the preferred primary procedure in young patients with severe glenohumeral arthritis.

Meniscal Allograft Transplantation

Meniscal allograft transplantation (MAT) has become an accepted treatment option for patients undergoing meniscectomy with recalcitrant pain in the corresponding compartment. Whether MAT can oppose cartilage degeneration is unclear. Our purpose was to perform a systematic review of available literature to answer the following: (1) Does MAT prevent advancing chondrosis? (2) Who is the ideal candidate for MAT? (3) What is the survival time for allograft in a stable knee? (4) Can MAT be successful when performed with concomitant procedures? (5) Is there an outcome difference between medial and lateral meniscal allograft transplants? (6) What is the expected function of a knee that has undergone MAT? Two authors performed a systematic review of the literature pertaining to MAT. Included in the review are studies with at least 2 years' follow-up, studies with validated outcome measures, and studies in which the allograft meniscal horns were secured with bony fixation. We identified 14 clinical articles that satisfied our inclusion and exclusion criteria. Thirteen of the articles provided Level IV evidence, and one article provided Level III evidence. MAT can result in alleviation of knee pain, improvement in knee function, and good patient satisfaction if performed in the optimal candidate. Improvements in both objective and subjective outcome measures were shown in relatively young patients without significant chondromalacia who underwent concomitant procedures for cartilage defects, limb malalignment, and/or knee instability. We detected no significant difference in outcomes when comparing medial and lateral meniscal allograft transplants. We detected no significant difference when comparing isolated MAT with MAT performed with concomitant procedures. Level IV, systematic review of Level III and IV studies.

Arthroscopic Glenoid Resurfacing: Results in Patients With Failed Previous Arthroscopic Debridement (SS-14)

To evaluate the efficacy of treatment in patients who underwent arthroscopic glenoid resurfacing with a lateral meniscal allograft as an alternative treatment of glenohumeral arthrosis. All patients in this review failed previous arthroscopic treatments. We are reporting the two year functional outcomes of these patients.

Humeral Head Arthroplasty and Meniscal Allograft Resurfacing of the Glenoid

Biological glenoid resurfacing with prosthetic humeral head replacement has been suggested as a means to avoid the potential complications of polyethylene use in younger patients with glenohumeral arthritis. The purposes of this report were (1) to describe a technique that was developed to facilitate biological resurfacing of the glenoid with use of meniscal allograft tissue and (2) to report the effectiveness of hemiarthroplasty in conjunction with meniscal allograft glenoid resurfacing. Thirty patients (thirty shoulders) with glenohumeral arthritis were treated with hemiarthroplasty and lateral meniscal allograft resurfacing of the glenoid. Clinical assessments were performed at regular intervals with use of visual analog scales for pain, shoulder comfort, and function and with use of patient self-assessments including the American Shoulder and Elbow Surgeons score and the Simple Shoulder Test. A detailed radiographic analysis was performed to evaluate glenohumeral subluxation, glenoid bone loss, and the glenohumeral joint space. Twenty-seven patients (twenty-seven shoulders) were followed for a minimum of two years. The mean duration of follow-up was three years. For the Simple Shoulder Test and the visual analog scale measures for level of pain, pain at rest, and pain with strenuous activity, the results at the final follow-up evaluation were significantly better than the preoperative results. Similarly, all ten functions of the American Shoulder and Elbow Surgeons questionnaire were significantly improved at the time of the latest follow-up. Over the time frame of the study, there was radiographic evidence of glenohumeral joint-space narrowing. Lateral meniscal allograft resurfacing of the glenoid can protect the glenoid from erosion, can minimize glenohumeral subluxation, and is associated with significant pain relief and improved function for two to five years when used in conjunction with hemiarthroplasty in younger patients with glenohumeral arthritis. However, the progressive decrease in glenohumeral joint space noted radiographically raises concern for both the long-term functional outcome and the durability of the glenoid bone-sparing effect.

Proximal Row Carpectomy: Role of a Radiocarpal Interposition Lateral Meniscal Allograft

The purpose of this study was to determine whether use of a lateral meniscal interposition allograft combined with proximal row carpectomy would reduce the peak joint contact pressures and increase the contact area when compared with proximal row carpectomy alone. Six cadaver wrists were cyclically moved through flexion-extension and radioulnar deviation ranges of motion. Joint contact pressure was measured with the carpus intact, after proximal row carpectomy, and after insertion of a lateral meniscal allograft. Contact pressure data were also collected with the wrist in 5 static positions. Proximal row carpectomy caused statistically greater peak pressures and smaller contact areas when compared with the intact wrist. Insertion of the allograft statistically restored the pressures and areas to that observed in the intact wrist. These results support the clinical trial of a lateral meniscal interposition allograft in patients with contraindications for proximal row carpectomy, such as pre-existing arthritis in the capitate head or lunate facet of the radius.

A Modified Keyhole Technique for Minimizing Size Mismatches During a Smaller than Optimal Lateral Meniscal Allograft Transplantation

Despite careful preoperative and intraoperative sizing of lateral menisci in recipient knees, size mismatches between allografts and recipient menisci are often encountered. To minimize size mismatches during the transplantation of smaller than expected lateral meniscal allografts, we devised a modified keyhole technique by dividing the central bone bridge into 2 bony fragments. The fragments are attached to the anterior and posterior horns. In the event of mismatch, the anterior bony fragment is moved anteriorly in the keyhole tunnel. Although the technique of meniscal transplantation is technically demanding, the central bone bridge can be divided without difficulty. The described technique is considered a useful alternative method during lateral meniscal transplantation.

Allografts in the Treatment of Athletic Injuries of the Shoulder

As allogeneic musculoskeletal tissue is readily available, has minimal limitation in size or shape, and carries no donor site morbidity, it has become attractive for use in reconstructive shoulder surgery. Allograft is a viable option for treating osseous defects associated with glenohumeral instability and has been shown to achieve a stable shoulder with good clinical outcomes. Although there are mixed results on the use of allograft as rotator cuff augments or substitutes, new commercially processed materials such as GraftJacket are being tested to address the high failure rates associated with massive rotator cuff repair. Interposition arthroplasty as a treatment for glenohumeral arthritis in the young and active patient is a novel concept in which the arthritic glenoid is biologically resurfaced. Satisfactory results have been described using lateral meniscus and Achilles tendon allograft. Despite the promising reports on the use of allograft in reconstructive shoulder surgery, most of the published literature exists as retrospective, case reports. Additional large, controlled research is needed to prove the efficacy and safety of allograft tissue in the treatment of athletic injuries of the shoulder.

Lateral meniscus allograft biologic glenoid arthroplasty in total shoulder arthroplasty for young shoulders with degenerative joint disease

To avoid potential polyethylene problems in younger shoulders with degenerative joint disease (DJD) requiring arthroplasty, lateral meniscus allograft (LMA) was used as a biologic resurfacing of the glenoid. We report preliminary, short-term results of this technique in a younger, higher-demand population. The shoulders of 20 men and 10 women, with an average age of 42 years (range, 18 to 52 years), underwent total shoulder arthroplasty with a LMA. A metallic prosthesis was used on the humerus. Etiology of the DJD was osteoarthritis in 16, postinstability surgery in 8, traumatic in 4, and failed open reduction with internal fixation in 2. Twenty-two (73%) had previous shoulder surgery. Preoperative average scores were American Shoulder and Elbow Surgeons (ASES), 38; Simple Shoulder Test (SST), 3.3; and Visual Analogue Scale (VAS), 6.4. The average active forward elevation was 96 degrees and external rotation was 26 degrees . Average follow-up was 18 months (range, 12 to 48 months). Postoperative average scores were ASES, 69; SST, 7.8; and VAS, 2.3. Active forward elevation was 139 degrees and external rotation was 53 degrees . All were significant improvements (P < .02). Most (94%) would have the surgery again. Radiologic evaluation at 1 year revealed an average joint space of 1.8 mm on anteroposterior views and 1.6 mm on axillary views. Five complications (17%) occurred within the first postoperative year, all of which required reoperation. Pain resulted in 2 conversions to a polyethylene glenoid. Polyethylene glenoids in young shoulders risk early failure. For young, high-demand shoulders with DJD requiring arthroplasty, the LMA shows promise. Most problems presented within the first year. Although not perfect, it provided significant pain relief, range-of-motion gains, and patient satisfaction without the risk of poly wear or loosening. Longer-term follow-up will be required to determine ultimate durability.

Meniscus Allograft Transplantation: Ten-Year Results of Cryopreserved Allografts

We report the results of cryopreserved meniscus allograft transplantations with 10 or more years of follow-up. Fourteen medial and 8 lateral meniscus allografts were evaluated with a mean follow-up of 141 months (range, 115 to 167 months). The clinical outcome and failure rate was evaluated by use of a Lysholm score and modified pain score in 22 patients. The results of radiographic and magnetic resonance imaging (MRI) analysis were reported in 15 and 7 patients, respectively. Overall, 25% of medial allografts and 50% of lateral allografts failed. The combined failure rate was 35%. There was a 90% improvement in Lysholm scores, as well as pain scores. There were no discernible Lysholm or pain score differences for both lateral and medial allografts. Furthermore, there was no discernible difference in both Lysholm and pain scores between bone plug and soft-tissue methods of graft fixation. Ten of fifteen allografts showed radiographic joint space narrowing, and twelve had progression of degenerative joint disease. On MRI, all grafts had moderate meniscus shrinkage and five had grade III signal intensities. Eighty-five percent of patients underwent subsequent procedures, 5 of whom required total allograft resection and 2 of whom required partial allograft resection. One allograft required repair. Although transplantation of cryopreserved allografts improved knee pain and function, the average knee function was fair at long-term follow-up. Fifty-five percent of allografts failed when failure criteria for second-look surgery, knee improvement surveys, and MRI were added to Lysholm and pain score failures. The protective benefits of meniscus allografts remain debatable, and inferences cannot be made from this study. Level IV, therapeutic case series.

Glenoid Resurfacing With Use of a Lateral Meniscal Allograft

Glenoid loosening after total shoulder arthroplasty is a concern that has prompted the use of alternative resurfacing materials, especially in younger patients with glenohumeral arthritis. Meniscal allografts have been used by many shoulder surgeons recently as a biologic interposition graft. It is attached to the glenoid and functions as a spacer and resurfacing material. Used in conjunction with a standard metal prosthesis on the humeral side, it is an alternative type of glenohumeral arthroplasty. The indications, technique, and outcomes for glenoid resurfacing with use of a lateral meniscal allograft are presented here and discussed. Although it is an exciting concept, early results have been quite variable. We feel that the best material for biologic resurfacing of the glenoid and technique for implantation is currently unknown.

Effect of Lateral Meniscal Allograft Sizing on Contact Mechanics of the Lateral Tibial Plateau

Background A mismatch of the original lateral meniscus and a lateral meniscus allograft by inaccurate preoperative radiographic sizing can have significant consequences on ultimate function. Hypothesis The size of a lateral meniscal allograft affects the contact mechanics of the femoral condyle on the tibial plateau. Study Design Controlled laboratory study. Methods Four right and 2 left knees were tested as intact joints, after meniscectomy, and after replantation with the original menisci and 16 right or 9 left human, fresh-frozen lateral meniscal allografts, respectively. The allografts were allocated into 7 groups according to their outer and inner anteroposterior and mediolateral diameters. Biomechanical testing was performed as compressive loadings with constrained motions in extension and 30° of flexion. Measurements were done with Fuji pressure-sensitive films for contact parameters of the direct femorotibial and meniscotibial contact. Results Oversized lateral meniscal allografts led to greater forces across the articular cartilage, whereas undersized allografts resulted in normal forces across the articular cartilage but greater forces across the meniscus. Two undersized transplants failed. Most of the contact parameters of allografts 10% smaller or larger than the original menisci were in the range of the intact knees. The knees after meniscectomy showed greater forces of the direct femorotibial contact areas than did the intact knees and the knees with the replanted original menisci. The contact mechanics of the knees with the replanted original menisci were close to normal. Conclusion The size of a lateral meniscal allograft has a significant effect on the contact mechanics of the tibial plateau. Clinical Relevance Preoperative radiographic sizing needs to be performed precisely to identify a suitable lateral meniscal allograft. A mismatch may be the reason for failure of the allograft or subsequent development of degenerative changes. A mismatch on graft selection of less than 10% of the size of the original meniscus may be acceptable.

Effect of lateral meniscus allograft on shoulder articular contact areas and pressures

The objective of this study was to determine the effect of a lateral meniscus allograft on the articular contact area and pressures across the glenohumeral joint under compressive loads of 220 N and 440 N. Eight fresh-frozen shoulders were used, and contact areas and pressures were determined with a Tekscan flexible tactile force sensor. Testing conditions included a normal glenohumeral joint and one interposed with a lateral meniscus allograft. Using the Tekscan sensing equipment, we evaluated the total force (in Newtons), contact area (in square millimeters), mean contact pressure (in kilograms per square centimeter), peak force (in Newtons), and peak contact pressure (in kilograms per square centimeter). The interposed lateral meniscus allograft group showed a statistically significant decrease in total force at both 220 N and 440 N, as well as a decrease in contact area for the 220-N testing condition. There were no statistically significant differences between the two groups in contact area at 440 N or in peak forces or peak contact areas for either 220-N or 440-N testing condition. Biomechanically biologic resurfacing with a lateral meniscus allograft of the glenohumeral joint is supported by decreased forces on the glenoid surface.

Clinical Outcomes Following Isolated Lateral Meniscal Allograft Transplantation

The purpose of our study was to determine the clinical outcomes following isolated lateral meniscal allograft transplantation. Thirty-two patients were retrospectively reviewed following isolated lateral meniscal allograft transplantation. Twenty-five were available for subjective follow-up, and 17 were available for a complete physical examination and postoperative radiographs. The average duration of follow-up was 3.3 years (range, 2 to 6 years), and the average age of the subjects was 30 years (range, 19 to 45 years). In all, 17 patients had bony fixation and 8 had suture fixation of the anterior and posterior horns of the meniscal allograft. Ninety-six percent of patients believed that their overall function and activity level were improved following surgery. Short Form-36 (SF-36) physical and mental component summary scores for these subjects were higher than age- and sex-matched scores from the US population. Joint space narrowing of the transplanted lateral compartments was not significantly different when compared with the joint space narrowing of the lateral compartment of the contralateral knee. In addition, preoperative and postoperative radiographic joint space measurements of the involved lateral compartment were significantly associated with subjective assessment, symptoms, sports activity score, Lysholm score, and final International Knee Documentation Committee (IKDC) rating at latest follow-up. Finally, patients fixed with the bony technique had significantly better range of motion, according to IKDC criteria at latest follow-up, compared with the suture fixation group. Our results suggest that isolated meniscal allograft transplantation can be a beneficial procedure in properly selected symptomatic patients with a lateral meniscus-deficient knee. The data also suggest that earlier meniscal transplantation, before the onset of significant joint space narrowing, may result in improved outcomes. Finally, bony fixation may have a significant advantage over suture fixation, particularly with regard to knee range of motion. Level IV, therapeutic case series.

Arthroscopic Glenoid Resurfacing with a Meniscal Allograft (SS-49)

The chronically painful arthritic glenohumeral joint recalcitrant to non-surgical treatment modalities generally has been treated with an open arthroplasty type of procedure. Certain patients may benefit from a less invasive surgical technique in which a meniscal allograft is utilized to resurface the glenoid arthroscopically, resulting in decreased pain and increased function. The following paper describes the early results of the first ten patients that have undergone this procedure. Ten consecutive with glenohumeral arthritis were selected as suitable candidates for this procedure. All ten patients underwent arthroscopic glenoid resurfacing with a lateral meniscal allograft. Preoperative modified UCLA shoulder scores, American Shoulder and Elbow Society Shoulder scores and visual analog pain measurements were obtained as were follow-up scores at three and six months postoperatively. These scores and the patients clinical outcomes have been evaluated. The results have demonstrated very promising short term results of this procedure with improvement in modified UCLA shoulder scores, American Shoulder and Elbow Society Shoulder scores and visual analog pain measurements in 90% of the patients when compared to their preoperative scores. Nine of the ten patients are satisfied and would undergo the procedure again. This arthroscopic technique in the treatment of glenohumeral arthritis offers a less invasive option than an open arthroplasty procedure with promising short term results. Continual evaluation of these results over time is essential to determine the long term efficacy of the utilization of this procedure in the treatment of these patients.

Transplantation of Viable Meniscal Allograft

Few medium-term or long-term reports on meniscal allograft transplantations are available. In this study, we present the results of a survival analysis of the clinical outcomes of our first 100 procedures involving transplantation of viable medial and lateral meniscal allografts performed in ninety-six patients. Thirty-nine medial and sixty-one lateral meniscal allografts were evaluated after a mean of 7.2 years. Survival analysis was based on specific clinical end points, with failure of the allograft defined as moderate occasional or persistent pain or as poor function. An additional survival analysis was performed to assess the results of the sixty-nine procedures that involved isolated use of a viable allograft (twenty of the thirty-nine medial allograft procedures and forty-nine of the sixty-one lateral allograft procedures) and of the thirteen viable medial meniscal allografts that were implanted in combination with a high tibial osteotomy in patients with initial varus malalignment of the lower limb. Overall, eleven (28%) of the thirty-nine medial allografts and ten (16%) of the sixty-one lateral allografts failed. The mean cumulative survival time (11.6 years) was identical for the medial and lateral allografts. The cumulative survival rates for the medial and lateral allografts at ten years were 74.2% and 69.8%, respectively. The mean cumulative survival time and the cumulative survival rate for the medial allografts used in combination with a high tibial osteotomy were 13.0 years and 83.3% at ten years, respectively. Transplantation of a viable meniscal allograft can significantly relieve pain and improve function of the knee joint. Survival analysis showed that this beneficial effect remained in approximately 70% of the patients at ten years. This study identified the need for a prospective study comparing patients with similar symptoms and clinical findings treated with and without a meniscal allograft and followed for a longer period with use of clinical evaluation as well as more objective documentation tools regarding the actual fate of the allograft itself and the articular cartilage.

Meniscal allograft transplantation: long-term clinical results with radiological and magnetic resonance imaging correlations

Long-term data on the clinical outcome and the fate of the meniscus allograft after transplantation are scarce. In this study we present the clinical, radiological and MRI outcome of the meniscus graft and the articular cartilage after 42 meniscus allograft transplantations in 41 patients with a minimum follow-up of 10 years. A total of 27 medial and 15 lateral meniscal allografts were transplanted. Eleven of the medial allograft procedures were associated with a high tibial osteotomy. The patients were evaluated clinically at the time of transplantation and at the final follow-up using the modified HSS scoring system. The knee injury and osteoarthritis outcome score (KOOS) was used as an evaluation tool for patient-related outcome at the final follow-up. Joint space width narrowing and Fairbank changes were radiological outcome parameters, which were available for 32 patients. Femoral and tibial cartilage degeneration, graft extrusion and signal intensity were scored on MRI scans obtained in 17 patients approximately 1 year after transplantation and at the final follow-up (>10 years). For statistical analysis the patients were divided into three groups: lateral meniscal allograft (LMT), medial meniscal allograft transplantation with a high tibial osteotomy (MMT+HTO) and without (MMT). The modified HSS score revealed a significant improvement in pain and function at the final follow-up for all groups. Further analysis also revealed that an MMT+HTO procedure resulted in a greater improvement at the final follow-up when compared to MMT. Nonetheless, the KOOS scores obtained at the final follow-up revealed the presence of substantial disability and symptoms, in addition to a reduced quality of life. Radiographical analysis revealed no further joint space narrowing in 13/32 knees (41%). Fairbank changes remained stable in 9/32 knees (28%). MRI analysis showed no progression of cartilage degeneration in 6/17 knees (35%). An increased signal intensity of the allograft was present, as was partial graft extrusion in the majority of patients at the final follow-up. Seven cases had to be converted to a total knee arthroplasty during the follow-up; the overall failure rate was 18%. Long-term results after viable meniscus allograft transplantation are encouraging in terms of pain relief and improvement of function. Despite this significant improvement, substantial disability and symptoms were present in all investigated subgroups. Progression of further cartilage degeneration or joint space narrowing was absent in a considerable number of cases, indicating a potential chondroprotective effect. Level of evidence is therapeutic study, Level IV and retrospective analysis of prospectively collected data.