Robust revascularization, despite impaired VEGF production, after meniscus allograft transplantation in rabbits

A Transplant or a Patch? A Review of the Biologic Integration of Meniscus Allograft Transplantation

» After transplantation revascularization does occur although data are only available for animal models.» The time zero biomechanics, that is, the biomechanical properties at the time of transplant, of a meniscus allograft transplantation appear to appropriately mimic the original so long as the graft is sized correctly within 10% of the original and bone plug fixation is used.» Allograft type, that is, fresh vs. frozen, does not appear to affect the integration of the allograft.

A Versatile Surgical Method for Studying Meniscus Implantation in a Rabbit Model

Meniscus injury is a health problem that greatly affects people's quality of life. In recent years, the number of diagnosed meniscus injury is increasing year by year. If not treated in time and correctly, it causes severe damages to the cartilage. Owing to the meniscus' limited healing ability, synthetic/tissue-engineered meniscus has emerged as a new treatment modality in recent years. Rabbit models, which have been proved to be a feasible animal model, have been extensively used to study meniscus implantation. However, there is not a unified and minimally invasive surgical method for meniscus implantation in rabbits, and the current surgical methods have unsolved problems, such as long incisions, patella valgus, and cutting of the medial collateral ligament. Therefore, the goal of this study is to provide a minimally invasive and versatile meniscus implantation method. Compared with the control group, our study showed less trauma to the animal model, and we believe that it has the application significance on tissue-engineered meniscus implantation. Impact statement Meniscal injury is a central area of sports medicine research because of the high and increasing global rate. With its profound potential implications for patients' functions and the subsequent development of arthritis, there is a great need for the synthetic/tissue-engineered menisci. Animal meniscus implantation models allow studying meniscus implantation with synthetic/tissue-engineered meniscus, and the rabbit model is a gold method for meniscus implantation in the laboratory. However, there has not yet been a minimally invasive and versatile surgical technique describing this surgery method. This article, therefore, provides a detailed description of the rabbit meniscus implantation method, including step-by-step surgical instructions and accompanying pictures.

Acetabular labral reconstruction with medial meniscal allograft: preliminary results of a new surgical technique

PURPOSE

Reconstruction of the acetabular labrum during femoroacetabular impingement (FAI) surgery is accepted when the labrum is deficient and irreparable. Here we describe a novel technique using fresh-frozen medial meniscal allograft for labral reconstruction during surgical hip dislocation for correction of pincer FAI due to acetabular overcoverage.

METHODS

The results from seven hips (six patients) that underwent this procedure with 1 year minimum follow-up, and radiographs are presented.

RESULTS

Six of the seven hips had improvements in pain, hip flexion, hip abduction, and Merle d'Aubigné-Postel scores. Only one patient with pre-existing osteoarthritis underwent reoperation with conversion to total hip arthroplasty. All digastric trochanteric osteotomies healed, and there were no cases of femoral head osteonecrosis or progression of Tönnis grades.

CONCLUSIONS

The medial meniscus is a morphologically and clinically suitable option for labral reconstruction and effectively restores the hip fluid seal.

Meniscal allograft transplantation. Part 1: systematic review of graft biology, graft shrinkage, graft extrusion, graft sizing, and graft fixation

PURPOSE

To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation: graft biology, shrinkage, extrusion, sizing, and fixation.

METHODS

A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies).

RESULTS

Sixty-two studies were finally included: 30 biology, 3 graft shrinkage, 11 graft extrusion, 17 graft size, and 6 graft fixation (some studies were categorized in more than one topic). These studies corresponded to 22 animal studies, 22 in vitro human studies, and 23 in vivo human studies (7 level II, 10 level III, and 6 level IV).

CONCLUSIONS

The principal conclusions were as follows: (a) Donor cells decrease after MAT and grafts are repopulated with host cells form synovium; (b) graft preservation alters collagen network (deep freezing) and causes cell apoptosis with loss of viable cells (cryopreservation); (c) graft shrinkage occurs mainly in lyophilized and gamma-irradiated grafts (less with cryopreservation); (d) graft extrusion is common but has no clinical/functional implications; (e) overall, MRI is not superior to plain radiograph for graft sizing; (f) graft width size matching is more important than length size matching; (g) height appears to be the most important factor influencing meniscal size; (h) bone fixation better restores contact mechanics than suture fixation, but there are no differences for pullout strength or functional results; and (i) suture fixation has more risk of graft extrusion compared to bone fixation.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, Level IV.