Lateral meniscus allograft transplantation: clinical and anatomic outcomes after arthroscopic implantation with tibial tunnels versus open implantation without tunnels

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 & Joint Preservation Society grade >3a (OR, 5.32; 95% CI, 2.75-10.31; P < .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.

Bone fixation techniques for managing joint disorders and injuries: A review study

The majority of surgical procedures treating joint disorders require a technique to realize a firm implant-to-tissue and/or a tissue-to-tissue fixation. Fixation methods have direct effects on survival, performance and integration of orthopedic implants This review paper gives an overview of novel fixation techniques that have been evaluated and optimized for orthopaedic joint implants and could be alternatives for traditional implant fixation techniques or inspirations for future design of joint implantation procedures.

METHOD

The articles were selected using the Scopus search engine. Key words referring to traditional fixation methods have been excluded to find potential innovative fixation techniques. In order to review the recent anchorage systems, only articles that been published during the period of 2010-2020 have been included.

RESULTS

A total of 57 studies were analyzed. The result revealed that three main fixation principles are being employed: using mechanical interlockings, employing adhesives, and performing tissue-bonding strategies.

CONCLUSION

The development of fixation techniques demonstrates a transformation from the general anchoring tools like K-wires toward application-specific designs. Several new methods have been designed and evaluated, which highlight encouraging results as described in this review. It seems that mechanical fixations provide the strongest anchorage. Employing (bio)-adhesives as fixation tool could revolutionize the field of orthopedic surgery. However, the adhesives must be improved and optimized to meet the requirements of an anchorage system. Long-term fixation might be formed by tissue ingrowth approaches which showed promising results. In most cases further clinical studies are required to explore their outputs in clinical applications.

Bone bridge fixation has superior biomechanics on posterior knees to bone plug fixation after lateral meniscal allograft transplantation - A biomechanical study simulating partial weight-bearing conditions

BACKGROUND

It remains unknown how biomechanics change in posterior lateral knee using different fixation techniques in lateral meniscal allograft transplantation (MAT)during simulated toe-touch partial weight-bearing. This study aimed tocompare the biomechanical effects on posterior knee between bridgeand bone plug fixation in lateral MAT.

METHODS

Intact knee, bone bridge fixation, and bone plug fixation were tested with 500 N of axial load during knee flexion at 0°, 30°, and 60°, which simulated toe-touch partial weight-bearing. Contact area and peak pressure were assessed on posterior knee and the shift of peak pressure position were measured.

RESULTS

On the posterior lateral compartment, the contact mechanics of bone bridge fixation were similar to those of the intact knee (allP-values > 0.05), but its peak pressure was higher than that of intact knee at 60° (P = 0.002). For bone plug fixation, the contact area of the posterior lateral knee was significantly lower than those of intact knee and bone bridge fixation at 30° and 60° (allP-values < 0.05). The peak pressure of the posterior lateral knee was higher than that of the intact knee at all flexions and higher than that of bone bridge fixation at 30° and 60° (allP-values < 0.05). The peak pressure position of bone plug fixation shifted more laterally and posteriorly compared with intact knee and bone bridge fixation during knee flexion.

CONCLUSION

Bone bridges could maintain posterior knee biomechanics better than bone plug fixation during knee bending during partial weight-bearing.

Prognostic Factors to Determine Survivorship of Meniscal Allograft Transplant: A Systematic Review

Background:

There is much room for improvement and optimization of meniscal allograft survivorship.

Purpose:

To understand prognostic factors for survivorship using evidence-based selection criteria in order to identify patients who would best benefit from meniscal allograft transplant (MAT).

Study Design:

Systematic review; Level of evidence, 4.

Methods:

We conducted this systematic review to analyze prognostic factors for survivorship of MAT. The Cochrane Central Register, PubMed publisher, Embase.com, and Web of Science databases were searched through August 8, 2019. Included studies entailed patients of any age who received MAT with a reported association between prognostic factors and survivorship of the allograft. Two reviewers independently screened all titles and abstracts for eligibility, extracted the data, assessed the risk of bias using the Newcastle-Ottawa Scale, and performed a best-evidence synthesis.

Results:

The review included 18 studies with a total of 1920 patients. The mean follow-up time was 6.0 years (range, 2.1-11.2 years). A total of 20 prognostic factors were identified and shown to be associated with survivorship of MAT. Strong evidence was found that severe cartilage damage was associated with poor survivorship. Strong evidence was also found showing that sex, knee compartment, surgical side, concomitant anterior cruciate ligament (ACL) reconstruction, and concomitant osteotomy for malalignment had no effect on survivorship. Moderate evidence was found that body mass index (<36), tobacco use, and arthroscopic versus open procedure had no influence on survivorship. Conflicting evidence was found that older age and kissing cartilage lesions (lesions on both the femur and tibia vs on a single side) decreased survivorship.

Conclusion:

Severe cartilage damage decreases the survivorship of MAT. Concomitant ACL reconstruction and osteotomy showed no relationship to survivorship. Many determinants showed conflicting and limited evidence. Older age may be of interest and should be further studied.

Predictors of Meniscal Allograft Transplantation Outcome: A Systematic Review

This systematic review investigates factors associated with outcomes after meniscal allograft transplantation (MAT). The PubMed, Scopus, and Cochrane Central Register databases were used to search relevant articles in April 2018. Studies that evaluated at least one association between a factor and outcomes were extracted. Of 3,381 titles, 52 studies were finally analyzed. Data about predictors, patient-reported outcome scores (PROMs), and failure rates were extracted for quantitative and qualitative analysis. A total of 3,382 patients and 3,460 transplants were identified. Thirty different predictors were reported in the current MAT literature, 18 of which by at least two studies. Subgroup analysis showed that lateral MAT had higher postoperative values than medial MAT in Lysholm's (p = 0.0102) and International Knee Documentation Committee (IKDC; p = 0.0056) scores. Soft tissue fixation showed higher postoperative IKDC scores than bone fixation (p = 0.0008). Fresh frozen allografts had higher Lysholm's scores (p < 0.0001) and showed significantly lower failure rates (p < 0.0001) than cryopreserved allografts. Age (p < 0.015, β = 0.80), sex (p < 0.034, β  =  - 8.52), and body mass index (BMI; p < 0.014, β = -4.87) demonstrated an association with PROMs in the regression model. Qualitative analysis found moderate evidence that a higher number of previous procedures in the same knee are an independent predictor of transplant failure. Conflicting evidence was found with regard to chondral damage, time from meniscectomy, smoke, sport level, worker's compensation status, and preoperative Lysholm's score as predictors of outcomes. Our review suggests that the ideal candidate to undergo MAT may be a young male of normal weight with no previous knee surgeries, treated with a lateral isolated procedure. However, MAT is associated with good outcomes in the majority of patients with many of the PROMs requiring further study to determine their direct effects on long-term outcomes. This study is a systematic review and reflects level of evidence IV.

An original all-arthroscopic technique for bony fixation of lateral meniscus allograft via four tibial tunnels: A cadaver study

Bone fixation of the two roots improves meniscal allograft positioning as compared to simple meniscal peripheral wall fixation. An all-arthroscopic 4-point bone fixation technique could provide rigid primary fixation and a more stable allograft. The technique was implemented on 8 fresh cadavers, under arthroscopy, via tibial bone tunnels at the posterior root, popliteal hiatus, anteromedial segment and anterior root, with cortical buttons for tibial graft fixation. Mean surgery time was 65±5minutes (range, 55-80min). The main difficulty lay in creating the tunnel to fix the anterior horn, which sometimes required an additional lateral portal. This 4-point bone fixation technique proved feasible and reproducible, and offers a novel means of stable primary fixation. LEVEL OF EVIDENCE: IV, cadaver study.

Update on the supply and use of allografts in locomotor system pathologies in France

Allografts are increasingly used in orthopedics. The main aim of the present study was to map the use of locomotor system allografts in France between 2012 and 2016. The study hypothesis was that there are great differences in the distribution and activity of tissue banks and graft preservation procedure quality, failing to meet national requirements.

MATERIAL AND METHODS

Data from activity reports of the French Biomedicine Agency (ABM) were collected for the period 2012-2016. Existing viral inactivation procedures were described. Preliminary results from a study of allograft requirements by the French Society of Arthroscopy (SFA) were reported.

RESULTS

Nineteen tissue banks were located. Four dealt exclusively with cryopreserved tissue, 3 exclusively with virus-inactivated bone, and 12 with both. Distribution analysis found wide disparities in geographic location and in type of activity. Viral inactivation is presently implemented only for femoral heads derived from hip replacement. Stocks of long bones, femoral heads and ligaments/tendons increased constantly over the study period, by 8.3%, 50.8% and 316.2% respectively. The SFA questionnaire confirmed a serious shortage of tissues, necessitating importation of allografts.

DISCUSSION

Each tissue bank had its own specificities and specialization. They should probably be coalesced, so as to centralize both supply and demand and improve nationwide response to requirements. Locomotor system tissue harvesting also needs to be expanded to meet increasing demand.

Collection and reconstruction after harvesting donor tissues from the musculoskeletal system: Technique specific to the lower limbs

The lack of available musculoskeletal grafts in France forces us to import a very large quantity of these tissues to use in complex reconstruction procedures. The goal of this article is to describe methods for collecting donor tissues from the musculoskeletal system and for reconstructing the harvested areas. We also provide a summary of the collection procedures performed, harvested grafts and available tissues. While tissue collection requires a significant time investment, the emergence of dedicated teams may be a solution for increasing the number and quality of human musculoskeletal allograft tissues.

Meniscal allograft transplantation using a novel all-arthroscopic technique with specifically designed instrumentation

The present study describes a novel all-arthroscopic technique for medial and lateral meniscal allograft transplantation (MAT). Surgical instruments were specifically designed to assist in the all-arthroscopic approach for MAT. The bone plug attachment technique, either the arthroscopic-assisted or all-arthroscopic approach, attaches bone plugs to the anterior and posterior horns. In the present study, two sets of surgical implements were designed: One to produce bone plugs of predefined sizes in the anterior and posterior horns of the allograft meniscus (bone plug implements) and a second to create bone tunnels in the receptor tibial plateau to hold the bone plugs (bone tunnel implements). The present study demonstrated that an all-arthroscopic approach to MAT was feasible. Furthermore, the specifically designed surgical instruments allowed for consistent preparation of grafts and recipient tissues, contributing to a standardized approach to MAT. The present findings indicate that an all-arthroscopic approach to MAT may be achievable. They also provide the incentive for future clinical studies to directly compare the outcomes and to initiate the standardization of the procedure to optimize MAT and maximize patient outcomes and quality of life.

Lateral Meniscal Allograft Transplant via a Medial Approach Leads to Less Extrusion

BACKGROUND

Accurate positioning of the bony bridge is crucial to prevent extrusion of meniscal allografts after transplant. However, oblique or lateralized placement of the bony bridge of the lateral meniscal allograft may occur due to technical error or a limited visual field. The patellar tendon may be an obstacle to approaching the anterior horn of the lateral meniscus, resulting in a laterally placed allograft. Therefore, lateral meniscal transplant through a medial arthrotomy would be an alternative approach. However, no report exists regarding allograft extrusion when comparing medial and lateral arthrotomy techniques in lateral meniscal transplants.

HYPOTHESIS

Extrusion of the midbody of the allograft is less severe and the rotation of the bony bridge is less oblique in lateral meniscal allograft transplants through the medial parapatellar approach than those through the lateral approach.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A bony bridge was used to perform 55 lateral meniscal transplants through either a medial or a lateral arthrotomy. Thirty-two allografts were transplanted through a medial arthrotomy and 23 were transplanted through a lateral arthrotomy, not randomly. Because correct positioning of the bony trough through the medial arthrotomy was easier than that through the lateral arthrotomy, the method of the arthrotomy was changed for the latter. The procedure for both groups was identical except for the arthrotomy technique, and rehabilitation was identical for both groups. Follow-up magnetic resonance imaging was conducted for all patients to measure the postoperative extrusion and obliquity of the bony bridge of the allograft. 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, a line (line B) was drawn along the longitudinal axis of the bony bridge. The posterior tibial condylar tangential line was drawn between the medial and lateral posterior tibial condylar cortices. A line (line T) was drawn perpendicular to the posterior tibial condylar tangential line. The angle (trough angle) between lines B and T was measured. Postoperative extrusion and the trough angle were compared between the medial and lateral arthrotomy groups.

RESULTS

The median extrusion of the midbody of the allograft was 2.2 mm (interquartile range [IQR], 2.4 mm; range, 0-4.6 mm) in the medial arthrotomy group and 3.1 mm (IQR, 1.5 mm; range, 0-5.3 mm) in the lateral arthrotomy group ( P = .001). Seven (21.9%) patients demonstrated extrusion in the medial arthrotomy group, and 15 (65.2%) patients had extrusion in the lateral group ( P = .002). The median trough angle was 0.9° (IQR, 9.3°; range, -8.8-15.8°) in the medial arthrotomy group and 11.6° (IQR, 2.8°; range, 3-19.8°) in the lateral arthrotomy group ( P < .001).

CONCLUSION

Based on this experience, lateral meniscal allograft transplant through a medial arthrotomy is preferred to decrease postoperative extrusion of the allograft.

Long-term assessment of meniscal extrusion after meniscal repair

BACKGROUND

Arthroscopic meniscal repair limits the medium-term risk of radiological osteoarthritis. Magnetic resonance imaging (MRI) cannot provide an accurate assessment of meniscal healing but may show harbingers of osteoarthritis such as meniscal extrusion. The objective of this study was to assess long-term meniscal extrusion after meniscal repair.

HYPOTHESIS

Arthroscopic meniscal suture is not followed by meniscal extrusion and can, therefore, provide good knee function in the long-term.

METHODS

Consecutive patients who underwent arthroscopic meniscal suture on a stable or stabilised knee were included retrospectively. MRI was performed to measure absolute meniscal extrusion (AME), relative meniscal extrusion (RME), anterior sagittal extrusion (ASE), posterior sagittal extrusion (PSE), coronal cartilage coverage index (cCCI), and sagittal cartilage coverage index (sCCI).

RESULTS

After a mean follow-up of 8.8±0.87 years, there was no evidence of meniscal extrusion in these patients with stable or stabilised knees: AME, 1.7±1.03 and 2.3±0.93mm, RME, 17±0.10% and 28±0.12%, ASE, 2.52±1.43 and 1.71±2.42mm, PSE, 0.29±3.49 and 0.22±2.35mm, cCCI, 23±0.08% and 20±0.09%, and sCCI, 49±0,10% and 53±0.09%.

CONCLUSION

In the long-term after meniscal repair, osteoarthritis is limited and meniscal function seems preserved.

LEVEL OF EVIDENCE

IV, retrospective study.

Meniscal Transplants and Scaffolds: A Systematic Review of the Literature

The reported incidence of meniscal tears is approximately 61 per 100,000. In instances where preservation of the native meniscus is no longer a feasible option, meniscal allograft transplantation (MAT) and implants or scaffolds may be considered. The goal of this review was to compare the success and failure rates of two techniques, MAT and meniscal scaffolds, and make an inference which treatment is more preferable at the present time and future. Studies that met inclusion criteria were assessed for technique used, type of transplant used, number of procedures included in the study, mean age of patients, mean follow-up time, number of failures, failure rate, and reported reoperation rate. Fifteen studies for the MAT group and 7 studies for the meniscal scaffold group were identified. In this selection of studies, the average failure rate in the MAT group was 18.7% and average reoperation rate was 31.3%. The average failure rate in the meniscal scaffold group was 5.6%, and average reoperation rate was 6.9%. It appears that although MAT is associated with high reoperation and failure rates, the limited number of studies on both MAT and scaffolds and mainly short-term results of scaffold studies make it difficult to make an objective comparison.

Risk Factors for Radiographic Progression of Osteoarthritis After Meniscus Allograft Transplantation

PURPOSE

To identify risk factors that predict radiographic progression of osteoarthritis after meniscus allograft transplantation (MAT) using multivariate logistic regression.

METHODS

Inclusion criteria were consecutive patients who underwent medial or lateral MATs from January 2005 to September 2012 by one surgeon. Exclusion criteria were lack of postoperative magnetic resonance image, loss to follow-up for a minimum of 3 years, and simultaneous surgery on articular cartilage or the anterior cruciate ligament. According to the change of Kellgren-Lawrence (KL) grade at the mean final follow-up of 56.2 months, the enrolled MATs were sorted into the no progression of osteoarthritis (NOA) and progression of osteoarthritis (POA) groups. Multivariate logistic regression was used to analyze risk factors, including age, sex, body mass index, time from previous meniscectomy to MAT, extent of previous meniscectomy, previous anterior cruciate ligament reconstruction, knee alignment angle, KL grade, side of transplanted meniscus, Outerbridge grade, posterior repair technique, and relative percentage of extrusion.

RESULTS

In comparison between the NOA (n = 38) and the POA (n = 31) groups, a significant risk factor for radiographic progression of osteoarthritis after MAT was medial MAT compared with lateral MAT. Medial MAT compared with lateral MAT was also a significant risk factor (adjusted odds ratio, 3.763; 95% confidence interval, 1.212-11.683).

CONCLUSIONS

Patients need to be counseled about the increased risk of osteoarthritis progression after MAT over time, particularly for medial MAT.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Multivariate Analysis of Risk Factors of Graft Extrusion After Lateral Meniscus Allograft Transplantation

PURPOSE

To identify risk factors that predict major graft extrusion (>3 mm in relation to the margin of the tibial plateau) on magnetic resonance imaging (MRI) after lateral meniscus allograft transplantation (MAT) using multivariate logistic regression.

METHODS

In this retrospective trial, inclusion criteria were consecutive lateral MATs from January 2004 to June 2013. Exclusion criteria were the lack of postoperative MRI, loss to follow-up for minimum 2 years, and simultaneous surgery of the articular cartilage or anterior cruciate ligament. According to the measured extent of graft extrusion in postoperative MRI, the lateral MATs were sorted into minor extrusion and major extrusion groups. Multivariate logistic regression was used to analyze risk factors including age, gender, body mass index, time from previous meniscectomy to MAT, extent of previous meniscectomy, previous anterior cruciate ligament reconstruction, knee alignment angle, Kellgren-Lawrence grade, lateral peripheral osteophyte, Outerbridge grade, posterior repair technique the position of bony bridge, and axial plane trough angle.

RESULTS

Enrolled 72 lateral MATs were sorted into minor extrusion (n = 34) and major extrusion groups (n = 38). As time from previous meniscectomy to lateral MAT increased, the risk of the major graft extrusion after lateral MAT increased (adjusted odds ratio: 1.554, 95% confidence interval: 1.089 to 2.218). Increased axial plane trough angle was also a significant risk factor (adjusted odds ratio: 8.449, 95% confidence interval: 1.710 to 42.250). The other parameters were not significant risk factors.

CONCLUSIONS

Most meniscal grafts after lateral MATs showed major graft extrusion. Significant risk factors for the major graft extrusion included delayed time from previous meniscectomy to MAT and increased axial plane trough angle.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Meniscus tear surgery and meniscus replacement

OBJECTIVE

the menisci are easily injured and difficult to repair. The aim of this study was to analyze the current state of meniscal surgery aimed at preserving morphology and conserving the biomechanics of the knee to prevent joint degeneration.

METHODOLOGY

a search of the electronic medical literature database Medline was conducted, from http://www.ncbi.nlm.nih.gov/pubmed. The search was not limited by language. Candidate articles were identified by searching for those that included the keywords meniscus, surgery, suture, implant, allograft. The limits were included for clinical research and clinical trials. Basic research was not included. The studies selected were evaluated and classified in three different categories: basic science, reconstruction (suture and meniscectomy) and implants (scaffolds and allograft).

RESULTS

the consequences of meniscectomy performed at a young age can lead to a joint cartilage degeneration twenty years later. There are few surgical options for the repair of meniscal injuries in order both to preserve the meniscus and to ensure the long term survival of the knee joint, meniscectomy, repair, suturing the tear, or reconstruction, when a meniscal allograft or synthetic substitute is used to replace the meniscus, but the biomechanical properties of the native meniscus are not reproduced entirely by the scaffolds that exist today.

CONCLUSION

therapies that successfully repair or replace the meniscus are therefore likely to prevent or delay osteoarthritis progression.

Actifit® scaffold implantation: Influence of preoperative meniscal extrusion on morphological and clinical outcomes

BACKGROUND

Meniscal substitutes have been suggested for the treatment of knee pain after partial meniscectomy. However, despite the partial nature of the initial meniscectomy, secondary extrusion of the substitute is common. The primary objective of this study was to evaluate morphological outcomes of meniscal substitute implantation and their potential associations with preoperative meniscal extrusion.

HYPOTHESIS

Preoperative absolute meniscal extrusion in the coronal plane predicts poorer morphological and clinical outcomes.

MATERIAL AND METHODS

Consecutive patients who received an Actifit(®) meniscal substitute between 2008 and 2011 were included prospectively. After 1 year and 2 years, the IKDC score and KOOS were determined and magnetic resonance imaging performed. The morphological evaluation consisted in measuring meniscal extrusion and cartilage coverage by the substitute in the coronal and sagittal planes.

RESULTS

Twenty patients were included. Among them, 3 required subsequent removal of the substitute. The mean subjective IKDC score increased from 48.1 preoperatively to 56.4 after 2 years. Over the same period, the function/sports/recreational activities component of the KOOS improved significantly (42.9 vs. 55.0, P=0.04). Positive correlations between preoperative and 1-year values were demonstrated for both cartilage coverage in the coronal and the sagittal planes (P=0.03 and P=0.04, respectively) and coronal absolute meniscal extrusion (P=0.05). No significant differences were found between preoperative and 2-year values of cartilage coverage in the coronal and sagittal planes (P=0.38). There was a negative correlation linking preoperative meniscal extrusion in the coronal plane to 1-year cartilage coverage in the coronal and sagittal planes (P=0.01 and P=0.04, respectively). Preoperative absolute meniscal extrusion in the coronal plane correlated negatively with the subjective IKDC score after 1 year (P=0.02).

DISCUSSION

Preoperative meniscal extrusion in the coronal plane strongly predicts clinical and morphological outcomes. Marked preoperative meniscal extrusion, even in a patient with symptoms after partial meniscectomy, should prompt an appraisal of whether allograft replacement may be more appropriate than a meniscal substitute.

LEVEL OF EVIDENCE

IV, prospective study.

X-ray microtomography-based measurements of meniscal allografts

BACKGROUND

X-ray microcomputed tomography (XMT) is a technique widely used to image hard and soft tissues. Meniscal allografts as collagen structures can be imaged and analyzed using XMT. The aim of this study was to present an XMT scanning protocol that can be used to obtain the 3D geometry of menisci. It was further applied to compare two methods of meniscal allograft measurement: traditional (based on manual measurement) and novel (based on digital measurement of 3D models of menisci obtained with use of XMT scanner).

HYPOTHESIS

The XMT-based menisci measurement is a reliable method for assessing the geometry of a meniscal allograft by measuring the basic meniscal dimensions known from traditional protocol.

MATERIALS AND METHODS

Thirteen dissected menisci were measured according the same principles traditionally applied in a tissue bank. Next, the same specimens were scanned by a laboratory scanner in the XMT Lab. The images were processed to obtain a 3D mesh. 3D models of allograft geometry were then measured using a novel protocol enhanced by computer software. Then, both measurements were compared using statistical tests.

RESULTS

The results showed significant differences (P<0.05) between the lengths of the medial and lateral menisci measured in the tissue bank and the XMT Lab. Also, medial meniscal widths were significantly different (P<0.05).

DISCUSSION

Differences in meniscal lengths may result from difficulties in dissected meniscus measurements in tissue banks, and may be related to the elastic structure of the dissected meniscus. Errors may also be caused by the lack of highlighted landmarks on the meniscal surface in this study.

CONCLUSION

The XMT may be a good technique for assessing meniscal dimensions without actually touching the specimen.