Indications for allografts

Do Outcomes of Meniscal Allograft Transplantation Differ Based on Age and Sex? A Comparative Group Analysis

PURPOSE

To analyze the effect of patient age, sex, and associated preoperative factors on patient-reported outcome (PRO) measures and graft survival following primary meniscal allograft transplantation (MAT).

METHODS

A prospectively collected database was retrospectively reviewed to identify patients who underwent primary MAT with a minimum of 2 years of follow up between 1999 and 2017. Demographic, intraoperative, and postoperative outcome data were collected for each patient. Postoperative outcomes were stratified based on age and sex, and comparative statistical analysis was performed between sexes, both >40 and <40.

RESULTS

A total of 238 patients underwent primary MAT during the study period, of which 212 patients (mean age, 28.5 ± 9.0 years; range, 15.01-53.67 years) met the inclusion criteria with a mean follow-up of 5.1 ± 3.4 years (range 2.0-15.9 years). At final follow-up, patients ≥40 and <40 years of age demonstrated statistically significant improvements in nearly all PRO scores (P < .05 for both groups). There were no significant differences between either group for achievement of minimal clinically important difference for International Knee Documentation Committee (P = .48) or Knee Injury and Osteoarthritis Outcome Score symptoms (P = .76). Because of insufficient numbers, a statistically significant difference could not be demonstrated in reoperation rate (≥40: 1.49 ± 1.77 years, <40: 1.87 ± 1.98 years, P = .591), failure rate (≥40: 7/32 [21.9%], <40: 19/180 [10.6%], P = .072), or complication rate (≥40: 2/32 [6.3%], <40: 12/180 [6.7%], P = .930) based on age. Both sexes showed a significant improvement in PROs, whereas female patients were more likely to undergo revision surgery (P = .033), with no significant differences based on time to reoperation, failure, or complication rates.

CONCLUSIONS

PROs similarly improved following MAT in both patients aged ≥40 and those <40 at final follow-up with no significant differences in minimal clinically important difference achievement rate, complication rate, reoperation rate, time to reoperation, or failure rate between groups. Female patients may be more likely to undergo revision surgery after MAT.

LEVEL OF EVIDENCE

III; therapeutic retrospective comparison study.

Obesity and Meniscal Transplant Failure: A Retrospective Cohort Study

The purpose of this study was to analyze the effect of obesity and other clinical factors on the outcome of meniscal allograft transplantation (MAT) with transosseous fixation. A retrospective cohort study was performed on patients who underwent a MAT between 2002 and 2017. All the participants had a minimum follow-up period of 24 months. The variables assessed were age at the time of the transplant, side, sex, transplanted meniscus (lateral/medial), body mass index (BMI), smoking status, and previous surgeries. Lysholm, Tegner, and International Knee Documentation Committee (IKDC) test outcomes, and patient satisfaction were recorded. Image assessment was performed using plain standing X-rays and a follow-up magnetic resonance imaging scan. Thirty-five patients fulfilled the inclusion criteria. The mean follow-up time was of 75.7 standard deviation (SD) 43.4 months. Patients with a BMI ≥ 30 underwent medial meniscal transplants (88.9 vs. 42.3%, p = 0.022, respectively) more frequently. Obese patients had a significantly lower IKDC (48.6 SD 19.9 vs. 61.7 SD 13.1, p = 0.038, power: 57.5%) and Lysholm (60.3 SD 19.2 vs. 79.4 SD 14.3, p = 0.004, power: 88.7%) scores compared with nonobese patients. The satisfaction and Tegner scores were also lower in obese patients (55.6 vs. 80.7%, p = 0.136, and 2.8 SD 1.0 vs. 4.0 SD 1.9, p = 0.104, respectively); however, these differences were not statistically significant. Obese patients had higher rates of meniscal transplant failure compared with nonobese patients (adjusted hazard ratio: 11.8 [95% confidence interval: 1.5-91.4]). No differences were observed between obese and nonobese patients regarding age, sex, side, smoking status, and follow-up time. In this study, a BMI ≥ 30 kg/m² resulted in higher MAT failure rates. Nonobese patients had better knee functional results compared with obese individuals.

Revision of meniscal transplants: long-term clinical follow-up

PURPOSE

The primary aim is to document objective and subjective clinical outcome after knee arthroplasty for failed meniscal allograft transplantation; secondly, to investigate the influence of previous meniscal allograft surgery on the clinical outcome after a knee arthroplasty procedure; thirdly, to identify possible prognostic factors for the failure of meniscal allograft, such as potential number of concomitant procedures or pre-transplantation HSS-scores. The study population was compared to a control group of primary total knee arthroplasties.

METHODS

The pre-operative phase, prior to meniscal allograft transplantation, was evaluated by the HSS questionnaire. At final follow-up, the clinical outcome was evaluated by the HSS, KOOS and SF-36 questionnaires. The mean follow-up was 16 years and 2 months. The control group, matched for age and sex, comprised patients with primary total knee arthroplasty.

RESULTS

Statistical analysis showed that for the HSS-scores, there was no significant difference between the study population and the control group. KOOS data showed that the control group scored better overall. There was no significant difference between the HSS-scores after the transplantation and after the knee prosthesis. However, both showed a significant improvement regarding the clinical condition before meniscal transplantation.

CONCLUSIONS

The clinical results after revised meniscal transplantation by means of knee prosthesis are highly variable with a tendency to have a lower score than patients with a primary knee prosthesis. Patients who underwent a revision of their meniscal allograft transplantation by means of a knee arthroplasty still had a significant better clinical outcome than prior to the meniscal allograft transplantation. There were no prognostic factors found by which one can determine whether a meniscal allograft will have a good survival or not.

Allograft replacement for absent native tissue

Context:

Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports. Traditionally, allografts were employed to reinforce weakened tissue. However, they can also be employed to substitute deficient or functionally absent tissue, particularly in the sports medicine setting.

Objective:

This article presents a series of 6 cases that utilized allografts to restore functionally deficient anatomic architecture, rather than just simply augmenting the degenerated or damaged native tissue. Detailed discussions are presented of the use of allografts as a successful treatment strategy to replace functionally weakened tissue, often after failed primary repairs.

The tips and pitfalls of meniscus allograft transplantation

When faced with an irrepairable meniscus or a patient who has had a total or subtotal meniscectomy, meniscus allograft transplantation (MAT) is the preferred modality to restore biomechanical function of the meniscus. The indications for meniscus allograft transplantation are yet to be established. However, currently, MAT has previously been indicated for symptomatic patients who have mild or early osteoarthritis, are younger than 50 years of age, and present with an Outerbridge grade II or lower. The short- to intermediate-term results confirmed noteworthy clinical improvements and consistent objective findings. On the other hand, the successful outcome would be reduced by various complications. Therefore, long-term observation required to evaluate the longevity of these results. The purpose of this article is to review the current research of concerns on the results of MAT, and to describe the technical tips and pitfalls so as to successful clinical results.

TruFit CB bone plug: chondral repair, scaffold design, surgical technique and early experiences

The TruFit CB osteochondral scaffold plug is a commercially available and licensed scaffold implant for the treatment of chondral and osteochondral defects of the knee. A number of surgical techniques have been described that are designed to achieve neocartilaginous tissue cover of a chondral defect, but many result in fibrocartilage tissue, not type II collagen hyaline cartilage. This fibrocartilage layer can fail with high shear forces in the knee joint, and lead to ongoing articular surface irregularity and subsequent secondary arthritic change. Recent research and clinical interest has focused on employing tissue-engineering techniques utilizing scaffolds in an attempt to obtain cartilage repair tissue that is histologically and biomechanically superior. The TruFit CB implant is one such device. This article describes the techniques of attempted chondral repair and the problems that can be experienced. Current concepts in chondral scaffold design are discussed, and the surgical technique and early experiences with the TruFit CB implant are presented.

Bone graft substitutes and allografts for reconstruction of the foot and ankle

In reconstructive foot and ankle surgery, the use of bone graft is common. Whether for trauma, acquired or congenital deformities, arthrodeses, joint replacement, bone loss from infection, or bone tumor resection, the foot and ankle surgeon must be knowledgeable about current bone grafting options to make informed decisions. Innovation and technologic advances have produced an impressive and exciting array of options, advancing us closer to mimicking the gold standard: autograft. However, the sheer volume of available products makes it challenging for the foot and ankle surgeon to stay abreast of current bone graft technology. The purpose of this article is to simplify and classify current bone grafting options, discuss advantages and disadvantages, and provide relevant clinical examples.

Osteochondral allografts: state of the art

The use of osteochondral allografts to treat focal osteochondral lesions continues to gain popularity, supported by long-term results. Clinicians must be knowledgeable concerning the possible risks of disease transmission, graft rejection, infection, and graft failure to advise the patient and obtain an informed consent. With advancing scientific and clinical research, future operative indications will likely continue to expand. A significant amount of literature regarding storage methods has recently been published; it is hoped that continued research will lead to techniques for prolonged graft storage to prevent availability concerns.

Storage conditions do not have detrimental effect on allograft collagen or scaffold performance

Musculoskeletal allografts are a valuable alternative to autograft tissue in orthopaedic surgeries. However, the effects of the allografts' storage history on the collagen and subsequent allograft scaffold properties are unknown. In this study, we hypothesized that freezing and refrigeration of allografts for 1 week would alter the biologic performance and mechanical properties of the allograft collagen. Allograft collagen was characterized by SDS-PAGE migration pattern, amino acid profile and measured denaturation. Scaffolds made from allograft collagen were evaluated for fibroblast proliferation, platelet activation and scaffold retraction. Collagen gelation kinetics (elastic and inelastic moduli and the viscous-elastic transition point) were also evaluated. Fibroblast proliferation, platelet activation and scaffold retraction results showed only minor, though statistically significant, differences between the storage groups. In addition, there were no significant differences in rheological properties or collagen biochemistry. In conclusion, this study suggests that freezing or refrigeration for 1 week does not appear to have any detrimental effect on the mechanical properties and biologic performance of the collagen within allografts.

Bovine cancellous xenograft in the treatment of tibial plateau fractures in elderly patients

The objective was to evaluate the efficacy of xenografts to improve the outcomes in elderly patients with tibial plateau fractures. Nineteen cases with a mean age of 74 years were followed prospectively from 1998 to 2003. Six patients each belonged to Schatzker types III, IV and V and one patient belonged to type II. Open reduction with fixation and xenograft impaction was carried out. Clinical and radiological union was assessed including infection rate, incorporation of the xenograft and average collapse of the fracture. The average union time was 20 weeks. No patient had wound infection and all had excellent incorporation of the xenograft with union. The average collapse was 4 mm on follow-up. This series shows the use of only an xenograft in acute fixation of these fractures with favourable outcome. Furthermore, it reduces operative time, bleeding and associated co-morbidities, which is of more significance in an elderly age group.

No influence of collagenous proteins of Achilles tendon, skin and cartilage on the virus-inactivating efficacy of peracetic acid–ethanol

The risk of transmitting human pathogenic viruses via allogeneic musculoskeletal tissue transplants is a problem requiring effective inactivation procedures. Virus safety of bone transplants was achieved using peracetic acid (PAA)-ethanol sterilisation. Proteins are known to have an adverse effect on the virus-inactivating capacity of PAA. Therefore we investigated virus inactivation by PAA in collagenous tissues. Achilles tendon, skin and cartilage were cut into small pieces, lyophilised and contaminated with pseudorabies virus (PRV) or porcine parvovirus (PPV). The inactivating capacity of PAA-ethanol was investigated by determining virus titres in the supernatant or the tissue pellet at different time-points. In all virus-contaminated tissue samples treatment for 10 min with PAA-ethanol resulted in titre reductions by a factor of >10(3). PRV was rapidly inactivated below the detection limit (< or =2.8 x 10(1) TCID(50)/ml). After 240 min a reduction by a factor of >10(4) was obtained for PPV in all samples, but a residual infectivity remained. Collagenous proteins of Achilles tendon, skin and cartilage had no adverse effect on the virus-inactivating capacity of PAA. PAA-ethanol used in the production process at the Charité tissue bank can therefore be recommended for treatment of non-osseous musculoskeletal tissues.

Arthroscopic grafting of greater tuberosity cyst and rotator cuff repair

Cysts of the greater tuberosity can be a normal finding independent of age and concurrent rotator cuff tear. The presence of a large greater tuberosity cyst can present a challenge at the time of rotator cuff repair. We present a 1-step arthroscopic technique to address these defects at the time of rotator cuff repair using a synthetic graft (OsteoBiologics, San Antonio, TX) originally designed to address osteoarticular defects. With the viewing portal established laterally, a portal allowing perpendicular access to the cyst is established. The cyst is thoroughly debrided, and a drill sleeve is then introduced perpendicular to the surrounding bone, serving as a guide for the matching drill to create a circular socket. A correspondingly sized TruFit BGS cylindrical implant (OsteoBiologics) is then implanted by use of the included instrumentation. The scaffold is placed flush with the surrounding bone. Because our arthroscopic rotator cuff protocol uses a tension-band technique with placement of suture anchors distal and lateral to the rotator cuff footprint, we are subsequently able to proceed with routine rotator cuff repair.

The pharmacokinetics and metabolism of Kö592 in man, dog and rat

Nowadays, there are four types of meniscal allografts known: fresh, cryopreserved, deep-frozen and lyophilized ones but only two of them are widely used in clinical practice. Use of different types of meniscal allografts still remains controversial due to preparation method, their biomechanical properties as well as cost which is connected with processing and storage. The main aim of this review is to present the current status of knowledge concerning meniscal allograft preservation and sterilization, especially the advantages and disadvantages of each method. Authors wanted to show a broad spectrum of methods used and conceptions presented by other authors. The second aim is to gather available information about meniscal preservation and sterilization methods in one paper. Deep-frozen and cryopreserved meniscal allografts are the most frequently used ones in the clinical practice. The use of fresh grafts stays controversial but also has many followers. Lyophilized grafts in turn are not applied at present due to some serious drawbacks including reduction of tensile strength, poor rehydration, graft shrinkage and post-transplantation joint effusion as well as increased risk of meniscal size reduction. An application of sterilizing agents make the meniscal allograft free from the bacteria and viruses, but also it may cause serious structure changes. Therefore, choosing just one ideal method of meniscal allograft preservation and sterilization is complicated and should be based on broad knowledge and experience of surgeon performing the transplantation.