A meta-analysis of stability of autografts compared to allografts after anterior cruciate ligament reconstruction

Does concomitant meniscus repair and meniscectomy show different efficacy in anterior cruciate ligament reconstruction? A systematic review and meta-analysis

Aims

Currently, it is advised to perform meniscal repair instead of meniscectomy in certain cases of primary anterior cruciate ligament reconstruction (ACLR). However, the level of evidence is low. Therefore, this study aimed to compare the effectiveness of meniscectomy and meniscus repair in addition to ACLR.

Methods

The systematic search was conducted in three online databases (EMBASE, MEDLINE, and Cochrane) from inception until October 2021 for the literature on primary ACLR and concomitant meniscal surgery. Eligible studies compared the following outcomes between meniscal repair and meniscectomy groups: the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, International Knee Documentation Committee (IKDC) score, and KT-arthrometer examinations. Lastly, we calculated pooled mean differences (MDs) with 95 % confidence intervals (CIs) from the change between pre- and post-intervention values.

Results

Of 10,565 studies, 22 met the inclusion criteria, with a follow-up between 6 and 43 months. We found no difference when comparing the KOOS subscale changes-only in the KOOS pain subscale (MD = -1.6; CI: -2.48, -0.72). However, these results were not clinically significant. We analyzed the lateral and media meniscal injuries separately and concluded the same results regarding KOOS changes. We found no significant differences in the Lysholm score change (MD = -2.61; CI: -5.51, 0.29), changes in IKDC score (MD = 1.08; CI: -4.05, 6.21) or the change for the KT-arthrometer side-to-side difference (MD = -0.50; CI: -1.06, 0.06).

Conclusion

Based on our result, we did not find a clinically significant difference between meniscus repair and meniscectomy during primary ACLR regarding patient-reported outcomes in a short-term follow-up.

Translational potential

Our research supports the prompt integration of findings into clinical practice for treating meniscus injuries during ACL reconstruction. We recommend considering both meniscus repair and meniscectomy, as the available data indicate their effectiveness. Further studies are necessary to assess the long-term impacts, particularly on osteoarthritis, and to identify patient subgroups that may benefit most from each technique.

Anterior Cruciate Ligament Reconstruction in French Army: Return to Prior Level of Running on Selected Military Tests

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is frequently encountered in athletes as well as in military personnel. In civilian population, many studies have looked at the return to sport, but return to duty in Army is a topic that requires further research.The purpose of this study was to determine through annual military fitness tests in real conditions, the return to sport in soldiers after ACL reconstruction and factors influencing failure.

MATERIALS AND METHODS

This was a retrospective comparative study. Patients were all soldiers and had followed up in a Military Hospital. The SUCCESS group was military personnel who obtained a result of the specific aptitude test greater than or equal to this same test carried out before reconstruction of the ACL, the FAILURE group comprised the others. Results of the annual specific aerobic fitness tests were collected before and after ACL reconstruction. Preoperative epidemiological data, intraoperative information, and isokinetic test results were collected.

RESULTS

One hundred forty four soldiers were included between January 2011 and December 2017 (94.9% of men with a median age of 27.6 years); 40.3% obtained a result greater than or equal to the preoperative fitness test after ACL reconstruction. Among the soldiers who did not regain their performance, 24.3% were declared unfit or discharged. In the FAILURE group, we found patients with a higher body mass index (25.5 vs. 24.4; P = .04), less patients with isokinetic deficit < 30% on the knee flexors and extensors (26.6% vs. 62.9%; P < .01), more long sick leave (39.5% vs. 13.7%; P < .01), and late resumption of military activities (10.5 vs. 8.9 months; P < .01).

CONCLUSION

Rupture of ACL has a significant impact on the operational capacity of the French army. The proportion of return to the same level in annual specific fitness tests after ACL reconstruction is 40% among soldiers. Several variables are important to consider in the follow-up of these patients to optimize their recovery of sports performance and therefore their operational capacity.

Preserving the hamstring tendon insertion during ACL reconstruction with an autograft: Systematic literature review

INTRODUCTION

The hamstring tendons (gracilis and semitendinosus) are often used as an autograft for anterior cruciate ligament (ACL) reconstruction. Healing of this graft involves a slow biological process called ligamentization. To encourage this process, some authors have proposed preserving the insertion of the hamstring tendons.

HYPOTHESIS

Leaving the tibial insertion of the hamstring tendons intact will provide better early biological incorporation and superior tibial mechanical fixation resulting in various clinical advantages.

MATERIALS AND METHODS

In January 2022, a systematic literature review was carried out independently by two authors of the Medline, PubMed and Embase databases. The keywords used were "pedicular" or "pedicled" or "preservation of tibial attachment" or "hamstring tibial insertion" AND "ACL reconstruction". Each author's data was analyzed separately.

RESULTS

Sixteen articles were analyzed. Preserving the hamstring tibial insertion during ACL reconstruction improves the graft's biological incorporation during the initial postoperative phase according to clinical studies with MRI analysis and provides a mechanical advantage at the graft's tibial attachment according to biomechanical studies (construct up to 65% stiffer). There was no difference in the clinical and functional scores when compared to the conventional technique in which the hamstring tendons are detached from their tibial insertion.

DISCUSSION

The main conclusion of this systematic literature review was that preserving the hamstring tibial insertion during ACL reconstruction appears to improve the graft's ligamentization with biological and mechanical advantages relative to detaching the hamstring tendons. The clinical and functional results were comparable to other techniques. Prospective studies with large cohorts are still needed to confirm these findings.

LEVEL OF EVIDENCE

IV; Systematic review of literature.

Comparison of failure rates and functional outcomes between hamstring autografts and hybrid grafts in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

BACKGROUND

The viability of augmenting small-diameter hamstring autografts with allografts remains unclear. Recent studies have reported different clinical results after allograft augmentation. Hence, we sought to determine whether hamstring autografts and hybrid grafts differed in terms of failure rates and functional outcomes after anterior cruciate ligament (ACL) reconstruction. We also evaluated whether the results of the comparisons differed based on allograft sterilization methods.

PATIENTS AND METHODS

This systematic review and meta-analysis were performed by searching the PubMed, Cochrane Library, and EMBASE databases to identify prospective or retrospective studies (evidence levels 1, 2, or 3) that compared the failure rates and functional outcomes of ACL reconstruction using autografts and hybrid grafts.

RESULTS

We identified 15 relevant studies, including 1,521 patients, with 798 and 723 treated using autografts and hybrid grafts, respectively. Fourteen studies were retrospective comparative studies, and one was a prospective randomized controlled trial. Of these, three studies used non-irradiated allografts. In the analysis of all participants, no significant differences in failure rates and subjective International Knee Documentation Committee (IKDC) scores were observed between the autograft and hybrid graft groups. Comparing the autograft and hybrid graft groups that used non-irradiated allografts, no differences in the failure rates and subjective IKDC scores were also noted. Meanwhile, in the groups that used irradiated allograft, the autograft group demonstrated higher Lysholm knee scores and reduced anterior laxity than the hybrid graft group.

DISCUSSION

Overall, ACL reconstruction using hybrid grafts may not reduce failure rates compared to reconstructions using hamstring autografts, although hybrid grafts with irradiation may decrease functional outcomes.

LEVEL OF EVIDENCE

III; systematic review of level II and III studies.

Bilateral Chronic Quadriceps Tendon Ruptures Treated with Hamstring Autograft Reconstruction: A Case Report

CASE

A 30-year-old semiprofessional football player presented with chronic bilateral quadriceps tendon ruptures. Both quadriceps tendon ruptures were unsuitable for isolated primary repair because of tendon retraction and immobility. A novel reconstruction technique using semitendinosus and gracilis tendon autografts was performed to restore both lower extremities' disrupted extensor mechanisms. At the final follow-up, the patient regained excellent motion of both knees and returned to high-intensity activity.

CONCLUSION

Chronic quadriceps tendon ruptures present challenges related to tendon quality and mobilization. Reconstruction with hamstring autograft using a Pulvertaft weave through the retracted quadriceps tendon in a high-demand athletic patient represents a novel approach for treating this injury.

Allogeneic Tendon Transplantation for the Treatment of Pathological Patellar Ligament Defect in Children: Technical Note and 4-Year Follow-Up

OBJECTIVE

The absence of patellar ligament will bring about a severe negative impact on daily life. Many reconstruction techniques have been described in adults. However, there is a lack of technical introduction regarding the reconstruction of the patellar ligament in children. The purpose of this study was to report a surgical technique for reconstructing the patellar ligament in children.

METHOD

A retrospective analysis of the clinical data on a patellar ligament (tendon sheath fibroma) patient with allogeneic tendon reconstruction. An 8-year-old child with postoperative recurrence of left patellar ligament tumor was enrolled in our study. Anterior tibialis tendon allograft was used to reconstruct the patellar ligament after complete resection of the patellar ligament for the tumor. The tunnels were constructed on the deep surface of the tibial tubercle and the root of the quadriceps tendon (to decrease the harmful impact on patella development), respectively. The allogeneic tendon was passed through the tunnels above in the shape of "8," and the two ends of the tendon were attached to the bleeding bone bed at the inferior edge of the patella with suture anchors to achieve better bone-tendon healing. During the follow-up, the knee's range of motion and imaging manifestations were recorded.

RESULT

Postoperative pathology suggests chondromesenchymal hamartoma, a rare benign soft tissue tumor different from the previous operation (tendon sheath fibroma). During the 4-year follow-up, the patient's active range of motion of the knee achieved 0° to 120°; and the patient could walk normally without any external help. Physical examinations (the apprehension sign and J sign) showed no ligamentous instability or patellar ligament tenderness. Imaging analysis showed that the ratio length of the patellar ligament to the patella was almost normal. The integrity, continuity, and shape of the allogeneic ligament showed excellent results in MRI. Combined with clinical and imaging findings, allogeneic tendon patellar ligament reconstruction was deemed successful.

CONCLUSION

Allogeneic ligament reconstruction technique can provide a treatment option by reconstructing the extensor mechanism, minimizing the impact on patellar development, and augmenting biological healing for children with the absence of the patellar ligament.

Categorize the existing clamps used for tensile test of human graft- a systematic review

Background

The use of tendon allografts for orthopedic repair has gained wide acceptance in recent years, most notably in anterior cruciate tendon reconstruction. Multiple studies support the use of tendon allografts and the benefits of its use are well accepted and understood. One of the important criteria of the use of tendon allografts is statistically similar histological and biomechanical properties to autographs. The aim of this systematic literature review is to investigate and categorize existing clamps used in the determination of the biomechanical properties of tendons such as maximum load, maximum strength, modulus of elasticity, ultimate strain, and stiffness. A variety of clamps for use during the endurance test of tendons were categorized according to the temperature used during the measurement. The clamps are divided into three groups: room temperature, cooled and heated clamps. The second goal of our review is to overview of clamps on the following aspects: name of clamp, author and date, type of clamps, type of endurance test (static or dynamic), type preloading (dynamic or static), type of tendon and measured and calculated parameters, and summarize in Table 3, as a comprehensive catalogue.

Methods

This systematic review was carried out in keeping with the PRISMA 2020 E&E and the PRISMA-S guidelines and checklists. A search was conducted for publications dating between 1991 and February 28th 2022 through three electronic databases (Web of Science, Scopus, and PubMed). We used Critical Appraisal Skills Program checklist to check the quality of included articles.

Results

The database search and additional sources resulted in 1725 records. 1635 records eliminated during the screening for various reasons (case report, other languages, book chapter, unavailable text/conference abstract, unrelated topic). The number of articles used in the final synthesis was 90. A variety of clamps for use during the endurance test of tendons were identified and categorized according to the temperature used during the measurement. Based on this, the clamps are divided into three groups: room temperature, cooled or heated clamps.

Conclusions

On the basis of the systematic literature review, mechanical parameters determined by usage with cooled clamps proved to be more reliable than with those at room temperature and with heated clamps. The collected information from the articles included name of clamp, author and date, type of clamps, type of endurance test (static or dynamic), type preloading (dynamic or static), type of tendon and measured and calculated parameters given in Table 3. summarized. The main advantage of the cooled clamps is that there is no limit to the type and length of the tendon. This study provides an overview of clamps and does not represent the modernity of any method.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05650-w.

Return to Baseline Physical Activity After Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autografts are the most utilized grafts for primary anterior cruciate ligament (ACL) reconstruction. The ability of a patient to return to a preinjury level of physical activity is a key consideration in choice of graft; the influence of graft choice on this metric lacks consensus in the literature.

PURPOSE

To assess the effects of autograft choice (BPTB vs HT) for primary ACL reconstruction on return to baseline level of physical activity and/or sports participation.

STUDY DESIGN

Meta-analysis; Level of evidence, 1.

METHODS

A systematic review of randomized controlled trials comparing the use of BPTB and HT autografts for primary ACL reconstruction was conducted. The electronic databases EMBASE, MEDLINE, Cochrane CENTRAL, and Web of Science were comprehensively queried through September 23, 2019. The primary outcome was return to preinjury level of activity/sports. Secondary outcomes included knee stability testing (Lachman, KT-1000 arthrometer, and pivot-shift tests) and clinical subjective knee scores (Tegner, Cincinnati, International Knee Documentation Committee, and Lysholm). Two independent reviewers were involved in the screening of titles and abstracts, data extraction, and the assessment of risk of bias. Meta-analyses were performed respecting the Cochrane Handbook for Systematic Reviews of Intervention.

RESULTS

A total of 29 studies (N = 3099 patients) were eligible for this review, of which 13 (n = 1029 patients) reported on return to baseline level of sports as an endpoint. The risk ratio (RR) of using BPTB vs HT on return to baseline sport level was 1.03 (0.91-1.17; P = .63). Absence of a positive pivot-shift test was the only secondary outcome, with a statistically significant RR of 0.66 (95% CI, 0.50-0.86) in favor of BPTB autografts (P = .002).

CONCLUSION

In reviewing the current literature, no recommendation can be made on the optimal graft choice when using a return to baseline level of physical activity and/or sports participation as a primary metric.

Comparable outcome for autografts and allografts in primary medial patellofemoral ligament reconstruction for patellofemoral instability: systematic review and meta-analysis

PURPOSE

This study updates the current evidence on the role of allografts versus autografts for medial patellofemoral ligament (MPFL) reconstruction in patients with patellofemoral instability.

METHODS

The study was performed according to the PRISMA guidelines. In March 2021, a literature search in the main online databases was performed. Studies reporting quantitative data concerning primary MPFL reconstruction using an allograft were considered for inclusion. The Coleman Methodology Score was used to assess the methodological quality of the selected articles.

RESULTS

Data from 12 studies (474 procedures) were retrieved. The mean follow-up was 42.2 (15-78.5) months. The mean age was 21.1 ± 6.2 years. 64.9% (285 of 439) of patients were female. At the last follow-up, the Tegner (p < 0.0001), Kujala (p = 0.002) and the Lysholm (p < 0.0001) scores were minimally greater in the autografts. The similarity was found in the rate of persistent instability sensation and revision. The allograft group evidenced a lower rate of re-dislocations (p = 0.003).

CONCLUSION

Allografts may represent a feasible alternative to traditional autograft for MPFL reconstruction in selected patients with patellofemoral instability. Allograft tendons yielded similar PROMs, rates of persistent instability, and revision. Allograft reconstructions tended to have modestly lower re-dislocation rates.

LEVEL OF EVIDENCE

IV.

Optimizing anterior cruciate ligament reconstruction: Individualizing the decision-making process using data from the Kaiser Permanente ACLR Registry: 2018 OREF award paper

Despite years of study, controversy remains regarding the optimal graft for anterior cruciate ligament reconstruction (ACLR), suggesting that a single graft type is not ideal for all patients. A large community based ACLR Registry that collects prospective data is a powerful tool that captures information and can be analyzed to optimize surgery for individual patients. The studies highlighted in this paper were designed to optimize and individualize ACLR surgery and have led to changes in surgeon behavior and improvements in patient outcomes. Kaiser Permanente (KP) is an integrated health care system with 10.6 million members and more than 50 hospitals. Every KP member who undergoes an ACLR is entered into the Registry, and prospectively monitored. The Registry uses a variety of feedback mechanisms to disseminate Registry findings to the ACLRR surgeons and appropriately influence clinical practices and enhance quality of care. Allografts were found to have a 3.0 times higher risk of revision than bone-patellar tendon-bone (BPTB) autografts. Allograft irradiation >1.8 Mrad, chemical graft processing, younger patients, BPTB allograft, and male patients were all associated with a higher risk of revision surgery. By providing feedback to surgeons, overall allograft use has decreased by 27% and allograft use in high-risk patients ≤21 years of age decreased 68%. We have identified factors that influence the outcomes of ACLR. Statement of Clinical Significance: We found that information derived from an ACLR Registry and shared with the participating surgeons directly decreased the use of specific procedures and implants associated with poor outcomes.

Use of an iliac bone graft with the tensor fasciae latae for the reconstruction of capitellum and radial collateral ligament in wind swept elbow

Traumatic elbow injuries often result in wounds and exposure of the nerves, tendons, and bone with defects in the soft tissue. A severe type of wind swept injury causes loss of the capitellum and radial collateral ligament (RCL), which leads to severe instability of the elbow. For reconstructing a defect of the capitellum and RCL, we applied an autogenous iliac bone graft with the fascia of the tensor fasciae latae muscle, which has never been reported with successful results. This bone-tendon unit may be a strong candidate for the reconstruction of defects of the radiocapitellar joint in a wind swept injury.

Assessment of sheep knee joint after ACL replacement with Achilles tendon autograft and PLA-based implant

In this study, we propose a new approach in the anterior cruciate ligament (ACL) replacement to provide stability and integration with bone tunnel. A polylactide (PLA)-based tubular implant was used to support the graft stabilization in femoral and tibial bones and to stimulate the healing process after (ACL) replacement on a sheep model. The ACL was replaced with an autologous Achilles tendon split graft. The tendon-to-bone healing in the model was analyzed after 6 and 12 weeks. Two groups of animals were compared, i.e. the group with the PLA-based implant used in the ACL replacement and the control group without the implant. The knee joints were mechanically and clinically evaluated, including the histopathology tests, to determine their stability and integrity. The results indicated that the bioresorbable PLA-based tubular implant may facilitate integration of the tendon graft with bone. Remodeling the allograft inside the implant improves the joint mobility from the first week of healing: no pathological changes were observed at the surgery site and in the animals' mobility. After 6 and 12 weeks of healing no significant changes in the mechanical parameters of the knee joint were observed, regarding the joint failure force, knee displacement, angular mobility range and joint stiffness. Relatively small values of the non-destructive tests in the knee displacement, already 6 weeks after surgery, indicated the early stabilization of the knee joint. The studies showed that the failure forces of knee joints after the ACL replacement with the PLA-based implant are lower than those of an intact joint, although their biomechanical features, including strain-at- failure, are similar. The biomechanical parameters of the knee joint were significantly improved due to the selected method of attaching the autograft ends to the femoral and tibial bone surfaces. After 12 weeks the intra-tunnel tendon-bone site with the PLA implant revealed the better tibia-femur joint mechanical stability, linear force-strain function and the decreasing strain-to-failure value, as compared to the control group.

Anterior Cruciate Ligament Reconstruction Graft Technique Reliably Yields Grafts With 8.0-mm Diameter or Larger

The significance of graft diameter in anterior cruciate ligament reconstruction (ACLR) with soft tissue grafts is well established, with a minimum graft diameter of 8.0 mm associated with lower rates of revision surgery. Consistently achieving grafts that meet or exceed the ideal diameter of 8.0 mm is still a concern with traditional tibial screw fixation, even with quadrupled hamstring autografts. The authors hypothesized that following a simple intraoperative algorithm selectively incorporating the gracilis tendon in an 8-stranded construct for all-inside ACLR with suspensory fixation on both ends of the graft would consistently achieve graft diameters of 8.0 mm or larger by allowing more of the graft material to contribute to increased diameter instead of increased length for screw fixation, with no allograft tissue required. A total of 113 eligible cases were identified, including 70 male patients and 43 female patients (mean±SD age, 25.92±6.47 years; range, 14-49 years). All 113 grafts (100%) were at least 8.0 mm in diameter. There were 8 grafts that were 8.0 mm. Overall mean±SD graft diameter was 9.32±0.71 mm (median, 9.5 mm; range, 8.0-11.0 mm). There were no cases in which allograft tissue was needed to increase graft size. An analysis of 113 cases of all-inside hamstring autograft ACLR with dual suspensory fixation showed that a graft diameter of at least 8.0 mm was achieved in every case, without the use of allograft tissue. These results suggest that this technique for ACLR is reliable in producing grafts that meet or exceed the recommended minimum diameter of 8.0 mm. [Orthopedics. 2021;44(4):e539-e545.].

Comparison of Bone-Patellar Tendon-Bone Graft, Semitendinosus-Gracilis Graft and Semitendinosus-Gracilis with Preserved Tibial Insertion Graft in Anterior Cruciate Ligament Reconstruction in Sports Persons

Introduction

Bone-patellar tendon-bone (BPTB) and semitendinosus-gracilis (STG) are the commonest grafts used for ACL reconstruction. However even after having been debated for years, there is no consensus about the ideal graft. Moreover, the literature is deficient about STG graft with preserved tibial insertion (STGPI) which preserves the proprioception. Our aim is to compare the outcome of BPTB, free STG and STGPI grafts after ACL reconstruction in professional sports persons. We compared the outcome in terms of mechanical stability, functional outcome, return to sports activity and degenerative changes.

Material and Methods

Professional sports persons aged between 16-50 years operated for ACL tear using BPTB, free STG and STGPI grafts with minimum follow-up of two years were identified from hospital records. Patients with associated knee injuries were excluded. Patients, divided in three groups according to graft used, were compared in terms of mechanical stability (arthrometric examination KT-1000 score), functional outcome (Lysholm Score), return to sports activity (Tegner score and difference in thigh circumference) and degenerative changes (KL grading).

Results

BPTB graft group was found to be better than free STG and STGPI graft groups in terms of KT-1000 score. There was no statistically significant difference among the groups in terms of Lysholm score, Tegner score, difference in thigh circumference and KL grading.

Conclusion

BPTB graft is better than free STG and STGPI grafts in terms of knee stability. When compared for patient reported outcome, return to sports activity, osteoarthritic changes and graft failure there is no significant difference among the three types of grafts.

Patellar tendon versus artificial grafts in anterior cruciate ligament reconstruction: a systematic review and meta-analysis

Background

The aim of anterior cruciate ligament reconstruction (ACLR) is to restore the function of the knee joint, protect the cartilage, and reduce the occurrence of osteoarthritis. However, due to the structural limitations of the human body, it is not possible to perform ACLR with conventional sutures. To restore normal functioning of the anterior cruciate ligament (ACL), a new ligament must be reconstructed in the position of the previous ACL.

Objective

To compare autografts and synthetic grafts in terms of postoperative knee stability and function

Search methods

The protocol for this study was registered with PROSPERO (CRD42021243451). Two reviewers independently searched the PubMed, Embase, and the Cochrane Library databases from database inception though February 10, 2021. The following search method was used: ((Autograft) OR (Autologous) OR (Autotransplant)) OR Artificial Ligament AND (Anterior Cruciate Ligament Injury [MeSH Terms]) AND (Randomized controlled trial [MeSH Terms]). Methodological quality was assessed by the Cochrane risk of bias tool.

Selection criteria

We only included randomized controlled trials (level I) that compared autograft and synthetic graft interventions in participants with ACL injury. We included trials that evaluated ACLR using at least one outcome (Lachman test, pivot shift test, IKDC grades, or complications).

Results

A total of 748 studies were identified in the initial literature search, and seven studies that examined only bone-patellar tendon-bone (BPTB) grafts compared with artificial grafts met the predetermined inclusion criteria. The results showed that BPTB grafts were associated with significantly better pivot shift test and Lachman test results and better IKDC grades and lower complication rates than synthetic grafts.

Conclusions

This review indicates that for adults, BPTB grafts perform more favorably than synthetic grafts in ACLR in terms of knee stability, function, and complication. More research is needed to compare autologous tendons and allogeneic tendons with artificial ligaments, especially in elderly individuals.

Level of evidence

Level I, systematic review and meta-analysis

Different sterilization and disinfection methods used for human tendons - a systematic review using mechanical properties to evaluate tendon allografts

Background

It is important to know the biomechanical properties of an allograft. This is because when looking to do a transplant of a tendon, the tendon must have very similar biomechanical properties to the original tendon. To use tendon allografts, it is critical to properly sterilize the tendon before implantation. In past decades, several sterilization procedures have been used. This study aimed to systematically evaluate the existing literature to compare the values of failure load/ultimate strength and Young’s modulus of elasticity of different sterilization methods on commonly used tendon allografts. Five major scientific literature databases (Web of Science, Science Direct, Scopus, PLOS ONE, Hindawi) and additional sources were used.

Results

Studies used had to show a particular sterilization method. Studies were identified to meet the following inclusion criteria: is a controlled laboratory study, gamma irradiation (dose reported), and other sterilization methods. Search for publications dated between 1991 and March 31st, 2020. The database search and additional sources resulted in 284 records. Two hundred thirty records eliminated during the screening for various reasons. The number of articles used in the final synthesis was 54.

Conclusions

Identified sterilization methods (gamma irradiation, ethylene oxid, supercritical carbon dioxide (SCCO2), BioCleanse, Electron Beam) are offered as a catalog of potential methods.

As a result of the broadness of the present research, it provides an overview of sterilization methods and their effect on the mechanical properties (failure load and Young’s modulus of elasticity) of tendons. It does not stand for the state-of-the-art of any single process. Based on a systematic literature review, we recommend freezing and gamma irradiation or electron beam at 14.8–28.5 kGy. These methods are effective at keeping or improving the mechanical properties, while fully sterilizing the inside and the outside of the tendon. Other sterilization method (ethylene oxide, supercritical carbon dioxide (SCCO2), BioCleanse) deteriorated the mechanical properties. These methods are not recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04296-4.

A Novel Approach to Augmenting Allograft Hamstring Anterior Cruciate Ligament Reconstructions Utilizing a Resorbable Type I Collagen Matrix with Platelet Rich Plasma

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is one of the most common lower extremity orthopedic surgeries performed in the United States. Annually, between 100,000 and 200,000 ACL tears affect 1 in 3,000 people. The selection of autograft versus allograft for ACLR has been widely discussed in terms of risk of graft failure. Allograft reconstructions have been shown to have higher rerupture rates. One factor contributing to this risk is delayed biologic graft incorporation.

METHODS

A retrospective review was performed examining 14 patients who underwent an augmented quadruple-stranded hamstring allograft ACLR with a type I resorbable collagen matrix impregnated with platelet-rich plasma (PRP).

RESULTS

Within our clinical practice, the augmentation of quadruple-stranded hamstring allograft ACLR with a type I resorbable matrix impregnated with PRP has yielded good early clinical success at 2-year outcomes (N = 14). Zero ACLR failures have been reported to date in this series.

CONCLUSION

This case series offers a novel approach for soft tissue allograft ACLR augmented with a type I collagen matrix impregnated with PRP. The authors theorize that this augmentation may improve biologic graft incorporation into the host bone tunnels.

Anterior cruciate ligament injury patterns and their relationship to fatigue and physical fitness levels - a cross-sectional study

Anterior cruciate ligament (ACL) injury is one of the most common knee injuries that leads to many consequences such as early osteoarthritis and knee joint instability.To explore the association of the types of ACL tear (complete and partial) and side of injury (dominant vs nondominate) with types of playing surfaces, sports, shoes, and mechanism of injuries as well as to determine whether higher levels of fatigue and physical fitness are risk factors for complete ACL tear.This cross-sectional study used a questionnaire to collect information from young male adults with a confirmed ACL injury who were attending rehabilitation programs. The outcomes of interest were patterns of ACL injury, levels of fatigue before the injury on a 0 to 10 scale, and levels of physical fitness (hours per week). Mann-Whitney U and Kruskal Wallis tests were used to assess the differences between groups, while the odds ratios were calculated to evaluate risk factors for complete ACL tear.One hundred thirteen young male adults with a confirmed ACL injury were enrolled. Most of the reported ACL injuries in this study were complete tear (80.5%) and occurred more frequently in the dominant leg (74.6%) due to noncontact mechanism (63.6%). More ACL injuries happened while playing soccer (97.2%) on artificial turf (53.3%). The level of fatigue before ACL injury was significantly higher in partial ACL tear injuries compared to complete ACL tear injuries (P = .014). For every 1-point increase in the level of fatigue on a 0-10 scale, there was a 25% reduction in complete ACL injury risk (P = .023).The pattern of ACL types of tear and side of injury varies in different playing surfaces and mechanisms of injuries. Higher levels of fatigue seem to be associated with a partial tear of the ACL and reduction of a complete ACL tear risk factor.

Autograft versus allograft tenodesis for chronic ankle instability: a single-center retrospective comparative study

Aim: To compare the outcomes of patients who underwent autograft tenodesis with those who underwent allograft tenodesis for the treatment of chronic mechanical ankle instability. Patients & methods: Ten patients who underwent allograft lateral tenodesis were compared with 15 patients who underwent lateral tenodesis using a split peroneus brevis tendon. Patients were followed up after an average time of 10.5 years. Results: No statistically significant differences concerning American Orthopaedic Foot and Ankle Society and Karlsson-Peterson scores were reported (p = n.s.). A reduced average radiographic anterior talar translation was observed in the autograft group compared with the allograft group (1.4 and 4.0 mm respectively, p < 0.001). Conclusion: Both surgical techniques significantly improved subjective and objective outcomes in patients suffering from chronic ankle instability compared with pre-operatory status. Autograft stabilization provided reduced post-operative anterior talar translation compared with allograft tenodesis.

Functional results of allograft vs. autograft tendons in anterior cruciate ligament (ACL) reconstruction at 10-year follow-up

PURPOSE

The anterior cruciate ligament (ACL) tear is one of the most common sports injuries of the knee, and the arthroscopic reconstruction is the gold standard. Nevertheless, controversies about the surgical techniques and the type of graft still exist. Allografts have been considered by many surgeons as valid alternative to autografts. The aim of this study was to assess the effectiveness of allografts compared to autografts at approximately 10 years of follow-up, investigating the level of physical activity currently performed by patients of each group.

METHODS

Ninety-four patients, divided into two groups (allografts and autografts), have been retrospectively studied. The two groups did not significantly differ in preoperative sport activity level, age (mean 40.70 years for autografts and 41.23 for allografts) and characteristics. Allograft group received a fresh-frozen graft from the musculoskeletal tissues bank. Evaluations were made using the International Knee Documentation Committee (IKDC) and Lysholm score; every patient was interviewed for complications.

RESULTS

The mean follow-up time was approximately 10 years for both groups, with a minimum of 8 years. There were no statistically significant differences between the two groups. Average IKDC scores were 75.21 (SD 15.36) and 80.69 (SD 13.65) for the allograft and autograft groups, respectively. The mean Lysholm score was 87.57 (SD 9.43) for the allografts and 89.10 (SD 8.33) for the autografts. No major complications linked to the allograft tissue arose.

CONCLUSION

Both groups achieved almost the same functional outcomes at an average 10 years of follow-up, indicating fresh-frozen allografts as a reasonable alternative for ACL reconstruction.

LEVEL OF EVIDENCE

IV, Retrospective case-control study.

Comparative Efficacy of Graft Options in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Network Meta-Analysis

Purpose

To evaluate the effectiveness of various graft options for anterior cruciate ligament reconstruction using network meta-analysis.

Methods

A medical literature search was conducted of PubMed, the Cochrane Library, Embase, SCOPUS, and Web of Science from their inception through March 1, 2019. The outcomes, including International Knee Documentation Committee (IKDC) form, Lachman test, Lysholm score, Pivot shift test, and Tegner score, were evaluated among graft options. Data extraction was carried out according to inclusion and exclusion criteria, and a network meta-analysis was performed using STATA 14.0.

Results

A total of 45 trials with 3992 patients were included. The forest plots revealed no significant differences in IKDC, Lysholm, or Tegner score among the grafts. In Lachman score, a significant difference was found in the comparisons of hamstring tendon allograft (HT-AL) versus patellar tendon autograft (PT-AU) and HT-AL versus hamstring tendon autograft (HT-AU). In pivot shift test, PT-AU was superior to all the other grafts, and quadriceps tendon autograft (QT-AU) was superior to HT-AL and artificial ligament (Art-L) in the number of cases with negative results. According to surface under the cumulative ranking area (SUCRA), PT-AU had the highest probability to be the best intervention in Lachman test and Tegner score; tibialis anterior tendon allograft (TA-AL) in IKDC and Lysholm score; and QT-AU in pivot shift test. Based on the cluster analysis of SUCRA, PT-AU was considered the most appropriate intervention by IKDC and Lachman test.

Conclusion

This study suggests that PT-AU may be the most appropriate graft for ACL reconstruction according to IKDC and Lachman test results.

Level of Evidence

Level I, network meta-analysis of randomized controlled trials.

Tissue-Engineered Decellularized Allografts for Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction with allografts is limited by high immunogenicity, poor cellularization, and delayed tendon-bone healing. Decellularized tendons (DAs) have been used as bioscaffolds to reconstruct ligaments with variable success. In the study, four kinds of decellularized allogeneic hamstring tendons were prepared and their microstructure and cytocompatibility were examined in vitro. The results showed that decellularized allografts neutralized by 5% calcium bicarbonate had typical reticular and porous microstructures with optical cytocompatibility. Tissue-engineering decellularized allografts (TEDAs) were prepared with the selected decellularized allografts and tendon stem/progenitor cells and used for ACL reconstruction in a rabbit model. Histological staining showed that the TEDAs promoted cellular infiltration and new vessel formation significantly and improved tendon-bone healing moderately compared to decellularized allografts. Better macroscopic scores and biomechanical results were observed in TEDA groups, but there were no significant differences between DA and TEDA groups at months 1, 2, and 3 postoperatively. Immunohistochemical data showed that the tissue-engineering decellularized allografts enhanced the expression of collagen I at each timepoint and collagen III at months 1 and 2. ELISA analysis showed that the tissue-engineering decellularized allografts reduced the secretion of IgE and IL-1β within 1 month and promoted the secretion of IL-2, IL-4, IL-10, and IL-17 after 1 month. The results showed that tissue-engineering decellularized allografts strengthened intra-articular graft remodeling significantly and provided moderate improvements in tendon-bone healing by creating more suitable immune responses than decellularized allografts. The study revealed that tissue-engineering decellularized allografts as a promising option for ACL reconstruction could achieve more favorable outcomes.

The Effectiveness of Autograft Used in Anterior Cruciate Ligament Reconstruction of the Knee: Surgical Records for the New Generations of Orthopedic Surgeons and Synthetic Graft Revisit

Objective

In this article, we aim to revisit the synthetic graft and review the advantages and disadvantages between different types of grafts for patients who underwent anterior cruciate ligament (ACL) reconstruction in a tertiary medical institute for the new generations of surgeons.

Patients and Methods

Retrospectively, we identified 115 patients who underwent arthroscopic ACL reconstruction between 2006 and 2009. We were able to retrieve 74 patients from them. The 74 patients were divided into 32 patients who underwent primary arthroscopic ACL reconstruction with hamstring and patellar tendon autograft and 42 cases with an active biosynthetic composite (ABC) ligament. The mean the follow-up period for both groups was 7 years. The following information was obtained: standard demographic information (age, sex), clinical presentation, presence of trauma, associated injuries, types of grafts (autograft versus synthetic graft) and postoperative complications. Moreover, functional and clinical outcomes in addition to the satisfaction of patients using the international knee documentation committee (IKDC) score and knee injury and osteoarthritis outcome score (KOOS) were measured.

Results

We found that the natural (autograft) was better in terms of clinical and functional outcome than the synthetic one (the scores of KOOS and IKDC were better in natural grafts). Furthermore, the immediate postoperative results for the pivot and Lachman tests were better in natural grafts. On the other hand, the rate of re-rupture was similar for both groups. However, the long-term inflammatory changes and stiffness that is attributed to the immunological reactions were more in the synthetic grafts.

Conclusion

This study revisited the synthetic graft and provided evidence that the natural grafts are more beneficial with less complications, as they had better immediate and long-term postoperative clinical and functional outcomes. We recommend the utilization of autograft as first choice and the synthetic not to be used given the current criteria.

Autografts vs Synthetics for Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

To describe the outcomes of autografts and synthetics in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction with respect to instrumented laxity measurements, patient‐reported outcome scores, complications, and graft failure risk. We searched PubMed, Cochrane Library, and EMBASE for published randomized controlled trials (RCT) and case controlled trials (CCTs) to compare the outcomes of the autografts versus synthetics after cruciate ligament reconstruction. Data analyses were performed using Cochrane Collaboration RevMan 5.0. Nine studies were identified from the literature review. Of these studies, three studies compared the results of bone–patellar tendon–bone (BPTB) and ligament augmentation and reconstruction system (LARS), while six studies compared the results of four‐strand hamstring tendon graft (4SHG) and LARS. The comparative study showed no difference in Lysholm score and failure risk between autografts and synthetics. The combined results of the meta‐analysis indicated that there was a significantly lower rate of side‐to‐side difference > 3 mm (Odds Ratio [OR] 2.46, 95% confidence intervals [CI] 1.44–4.22, P = 0.001), overall IKDC (OR 0.40, 95% CI 0.19–0.83, P = 0.01), complications (OR 2.54, 95% CI 1.26–5.14, P = 0.009), and Tegner score (OR −0.31, 95% CI −0.52–0.10, P = 0.004) in the synthetics group than in the autografts group. This systematic review comparing long‐term outcomes after cruciate ligament reconstruction with either autograft or synthetics suggests no significant differences in failure risk. Autografts were inferior to synthetics with respect to restoring knee joint stability and patient‐reported outcome scores, and were also associated with more postoperative complications.

Patient and Parent Perceptions of Rehabilitation Factors That Influence Outcomes After Anterior Cruciate Ligament Reconstruction and Clearance to Return to Sport in Adolescents and Young Adults

BACKGROUND

Wide variation in outcomes after anterior cruciate ligament reconstruction (ACLR) exists among adolescents and young adults. However, little evidence is available regarding key rehabilitation factors that may be driving these differences.

OBJECTIVE

To explore patient and parent perceptions of key rehabilitation drivers related to outcomes after ACLR.

METHODS

In this qualitative study, which used an interpretive phenomenological methodology, semi-structured interviews were conducted with patients who had returned to sport after ACLR and with their parents. The interviews asked about respondents' experience with physical therapy and how it related to their outcomes after ACLR. The interviews were recorded, transcribed, and coded. Themes were then identified using open and axial coding processes.

RESULTS

There were 3 primary themes that patients and parents perceived as key factors influencing their rehabilitation outcomes after ACLR: (1) patient attributes (ie, motivation, confidence, accountability, access to resources, and social support), (2) physical therapist-patient relationship qualities (physical therapist as guide, motivator, booster of confidence, fosterer of perseverance, and coordinator of care), and (3) elements of the system (ie, availability and utilization of therapy visits, clinic environment, and coordination among care providers).

CONCLUSION

Patient and parent perspectives of key drivers that influence ACLR rehabilitation outcomes include patient, therapist, and system factors. Developing specific strategies to target these factors may enhance patient and parent perceptions of the experience. The awareness gained from these results provides a foundation for future studies examining how these factors affect outcomes and how to improve rehabilitation after ACLR.

LEVEL OF EVIDENCE

Therapy, level 3. J Orthop Sports Phys Ther 2019;49(8):576-583. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8608.

Outcome After Anterior Cruciate Ligament Revision

PURPOSE OF REVIEW

To describe the current literature related to anterior cruciate ligament (ACL) revision in terms of surgical aspects, graft choices, concomitant injuries, patient-reported outcome, return to sport, and objective measurement outcome.

RECENT FINDINGS

An ACL rupture is a common knee injury, and the number of primary ACL reconstructions is increasing, implying a subsequent increase of ACL revisions in the future. It is widely accepted that an ACL revision is surgically challenging with a myriad of graft options to choose from. In many cases, simultaneous injuries to the index limb including meniscal and chondral lesions, respectively, are observed in the setting of a secondary ACL injury. Furthermore, the general understanding is that an ACL revision results in inferior outcome compared with a primary ACL reconstruction. Surgical treatment of an ACL revision can be performed as one-stage or two-stage procedure depending on, for example, the presence of limb malalignments, concomitant injuries, and tunnel widening. Nonirradiated allografts and autologous patella tendon, hamstring tendon, and quadriceps tendon are feasible options for ACL revision. Concomitant injuries to the affected knee such as intraarticular chondral lesions are more common in the setting of an ACL revision compared with primary ACL reconstruction while a lower presence of concomitant meniscal pathology is reported at ACL revision. Patients undergoing ACL revision have lower clinical and patient-reported outcome and lower rates of return to sport when compared with primary ACL surgery cases. However, long-term follow-ups with large study cohorts evaluating outcome of ACL revision are limited. Further research is needed to confirm the present findings of this review.

The use of allograft tissue in posterior cruciate, collateral and multi-ligament knee reconstruction

PURPOSE

Currently both autograft and allograft tissues are available for reconstruction of posterior cruciate, collateral and multi-ligament knee injuries. Decision-making is based on a complex interplay between anatomical structures, functional bundles and varying biomechanical requirements. Despite theoretically better biological healing and reduced risk of disease transmission autografts are associated with donor site morbidity as well as being limited by size and quantity. The use of allografts eliminates donor-site morbidity but raises cost and issues of clinical effectiveness. The purpose of this paper is to review current concepts and evidence for the use of allografts in primary posterior cruciate, collateral and multi-ligament reconstructions.

METHODS

A narrative review of the relevant literature was conducted for PCL, collateral ligament and multi-ligament knee reconstruction. Studies were identified using a targeted and systematic search with focus on recent comparative studies and all clinical systematic reviews and meta-analyses. The rationale and principles of management underpinning the role of allograft tissue were identified and the clinical and functional outcomes were analysed. Finally, the position of postoperative physiotherapy and rehabilitation was identified.

RESULTS

The review demonstrated paucity in high quality and up-to-date results addressing the issue especially on collaterals and multi-ligament reconstructions. There was no significant evidence of superiority of a graft type over another for PCL reconstruction. Contemporary principles in the management of posterolateral corner, MCL and multi-ligament injuries support the use of allograft tissue.

CONCLUSION

The present review demonstrates equivalent clinical results with the use of autografts or allografts. It remains, however, difficult to generate a conclusive evidence-based approach due to the paucity of high-level research. When confronted by the need for combined reconstructions with multiple grafts, preservation of synergistic muscles, and adapted postoperative rehabilitation; the current evidence does offer support for the use of allograft tissue.

LEVEL OF EVIDENCE

IV.

The Stability study: a protocol for a multicenter randomized clinical trial comparing anterior cruciate ligament reconstruction with and without Lateral Extra-articular Tenodesis in individuals who are at high risk of graft failure

Background

The purpose of anterior cruciate ligament reconstruction (ACLR) is to restore stability to the knee. Persistent rotational laxity following ACLR has been correlated with poor outcome and graft failure. We hypothesize that anterolateral complex reconstruction by way of a Modified Lemaire Lateral Extra-articular Tenodesis (LET) in combination with single bundle ACLR would reduce the risk of persistent rotatory laxity in young individuals who are deemed as being at high risk of failure. We will conduct a pragmatic, multicenter, randomized clinical trial comparing standard single bundle hamstring ACLR with combined ACLR and LET.

Methods

Six-hundred patients (300 per group) aged 25 years or less with an ACL deficient knee that meet two of the following three criteria will be included: 1) Grade 2 pivot shift or greater; 2) Returning to high risk cutting or pivoting sports; 3) Generalized ligamentous laxity. Participants will be seen at 3-months, 6-months, 12-months and 24-months post-operatively. The primary outcome measure is graft failure requiring revision ACLR or symptomatic instability associated with a positive asymmetric pivot shift indicating persistent rotational laxity. Patients will complete secondary outcome measures at each follow-up visit including patient-reported outcome measures, functional and biomechanical testing, and magnetic resonance imaging.

Discussion

This protocol is the first adequately powered randomized clinical trial investigating the effects of augmenting ACLR with an LET in patients at high-risk of graft failure. The successful completion of this trial has the potential to change surgical practice and provide evidence for the role of the LET in ACLR.

Trial registration

The trial is registered at ClinicalTrials.gov: NCT02018354, 23-12-2013.

Anterior Cruciate Ligament Reconstruction in a Rabbit Model Using a Decellularized Allogenic Semitendinous Tendon Combined with Autologous Bone Marrow-Derived Mesenchymal Stem Cells

As a regular adoptable material for anterior cruciate ligament (ACL) reconstruction, free tendon allograft exhibits unsatisfactory outcomes, such as retarded ligamentization and tendon–bone integration. The application of bone marrow‐derived mesenchymal stem cells (BMSCs), as well as a decellularized free tendon allograft developed by our group, was proven to be effective in improving ACL reconstruction results. This study aimed to investigate the efficacy and feasibility of decellularized allogenic semitendinous tendon (ST) combined with autologous BMSCs used as a substitute to free tendon allograft in a rabbit model. This study finally shows that the decellularized allogenic ST combined with autologous BMSCs could significantly improve ACL reconstruction results compared with allograft. stem cells translational medicine2019;8:971&982

Comparison of efficacy and safety of different fixation devices for anterior cruciate ligament reconstruction: A Bayesian network meta-analysis protocol

BACKGROUND

Anterior cruciate ligament (ACL) injury is a common ligament injury to the knee joint, and often lead to limited function, osteoarthritis after knee trauma, secondary damage to meniscus and cartilage, and impaired quality of life. ACL reconstruction is the gold standard surgical treatment for ACL injury, and ligament fixation after reconstruction is the key factor of ACL reconstruction success. However, the optimal fixation device for ACL reconstruction remains unclear. This study aims to evaluate the efficacy and safety of different fixation devices and to find the best fixation device for ACL reconstruction.

METHODS

The PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese Biomedicine Literature will be searched to identify relevant studies from inception to December 2018. We will include randomized controlled trials (RCTs) comparing the effects of different fixation devices fixed on the femoral side in arthroscopically assisted ACL reconstruction. Risk of bias assessment of the included RCTs will be conducted according to the Cochrane Handbook 5.1.0. A Bayesian network meta-analysis (NMA) will be performed using R software.

RESULTS

The results of this NMA will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This NMA will summarize the direct and indirect evidence to evaluate the effect of different fixation devices for ACL reconstruction.

Allograft Tissue Safety and Technology

Allograft tissues are commonly used by orthopedic surgeons and are processed using a variety of technologies to increase safety and clinical use. For safety, although disease transmission is a tangible risk, this possibility has been dramatically minimized through modern tissue-processing methods. These include steps to prevent processing tissues with unacceptable bioburden through rigorous screening using donor medical and social histories along with microbial testing of recovered tissue and viral testing of donor serum. Potential bioburden is also controlled through aseptic recovery and processing methods and then reduced through disinfection steps that can include antibiotics, detergents, mechanical process, chemical solutions, and terminal sterilization. Processing steps may also include decellularization methods to lower immunogenic potential of some tissues. To enhance fusion potential of bone void fillers, demineralization steps may be used, and the resultant demineralized bone matrices may be combined with a carrier to improve handling. Bone void fillers and osteochondral allografts may also be specially processed to retain a living cellular component. To preserve relevant biological, biochemical, and physical properties of allografts for clinical use and ease of handling, a number of methods may be used which include: (1) refrigeration in media, (2) freeze-drying, (3) cryopreservation, (4) freezing, and (5) media storage at room temperature. As academic and industry research continue to drive advances, the future direction of allograft tissue likely includes injectables, coatings, cellular therapies, and combinations with other materials. The technology approaches outlined here will be further described along with future directions.

Anterolateral Complex Reconstruction: Another Fad or Method to Improve ACL Outcomes?

Anterolateral rotational laxity of the knee is a persistent problem following anterior cruciate ligament reconstruction (ACLR) that can lead to increased rates of graft failure. Renewed interest in the anterolateral complex of the knee has led to a resurgence in the use of adjunctive techniques such as lateral extra-articular tenodesis and anterolateral ligament reconstruction. Use of these techniques can restore normal knee kinematics and potentially thereby reduce the rate of graft failure. Historically, experience with modified ACLR techniques such as the double-bundle ACLR have shown that improved biomechanics is not always reflected in clinical outcome trials. Additional procedures also come with additional costs and further economic analysis needs to be performed to clarify whether these additional costs are offset by improved clinical and societal outcomes in the longer-term.

Anterior cruciate ligament reconstruction without the use of a tourniquet

INTRODUCTION

Anterior cruciate ligament tears are a common ligamentous knee injury and are usually managed with arthroscopic reconstruction surgery using a tourniquet. The employment of a tourniquet in the management of an anterior cruciate ligament tear has been a debatable topic for some time. Here, we discuss our technique in the reconstruction of anterior cruciate ligament tears without the use of a tourniquet.

MATERIALS AND METHODS

We performed 26 anterior cruciate ligament reconstruction surgeries using hamstring grafts without the use of a tourniquet. The outcomes measured were pain using the visual analogue scale, knee swelling, range of movement and bleeding.

RESULTS

Using this technique, we have noted considerable reduction in knee swelling and pain. In addition, there was considerable improvement in the range of movement postoperatively, and there were no bleeding complications noted.

CONCLUSIONS

We consider ACL reconstruction without a tourniquet to be an excellent alternative to conventional reconstruction with the use of tourniquet.

Comparison of clinical outcomes after anterior cruciate ligament reconstruction with hamstring tendon autograft versus soft-tissue allograft: A meta-analysis of randomised controlled trials

BACKGROUND

Hamstring tendon autografts and soft-tissue allograft are commonly used for anterior cruciate ligament (ACL) reconstruction. However, the clinical outcomes between these two grafts are controversial. This meta-analysis was performed to compare clinical outcomes of primary ACL reconstruction with hamstring tendon autografts versus soft-tissue allografts.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were searched through 8 September 2017 to identify randomized controlled studies that compared hamstring tendon autografts with soft-tissue allografts for primary ACL reconstruction. Two authors independently graded the methodological quality of each eligible study using the Cochrane Collaboration tool and extracted relevant data. Statistical heterogeneity among the trials was evaluated with chi-square and I-square tests. A sensitivity analysis was conducted to explore sources of heterogeneity. Subgroup analysis was performed to identify potential differences according to type of reconstruction technique (single-bundle or double-bundle).

RESULTS

Eight studies with 785 combined patients (396 hamstring tendon autografts and 389 soft-tissue allografts) were included. Two studies had a high risk of bias. The other six studies had unclear risk of bias. There were significant differences between the groups in subjective International Knee Documentation Committee (IKDC) score (mean difference [MD], 2.43; 95%CI, 0.69-4.18; p = 0.006), Tegner score (MD, 0.24; 95%CI, 0.03-0.45; p = 0.03), and side-to-side difference (MD, -1.37; 95%CI, -2.44 to -0.30; p = 0.01). There was no significant difference between the groups in Lysholm score, complications, pivot shift test, anterior drawer test, Lachman test, overall IKDC score, or range of motion. Subgroup analysis demonstrated that for primary ACL reconstruction using the single-bundle technique, soft-tissue allografts were inferior to hamstring tendon autografts in subjective IKDC score, anterior drawer test, and side-to-side difference.

CONCLUSION

Soft-tissue allografts are inferior to hamstring tendon autografts with respect to subjective patient evaluation and knee stability but superior in the complication of hypoesthesia for patients undergoing primary ACL reconstruction.

The anatomical and imaging study of pes anserinus and its clinical application

BACKGROUND

The pes anserinus was an important graft choice for anterior cruciate ligament (ACL) reconstruction. The infrapatellar branch of the saphenous nerve (IPBSN) might be damaged in this surgery. This study aimed to provide anatomic and ultrasonic measurement data of pes anserinus and superficial nerves.

METHODS

Eighty lower limb specimens of forty adult cadavers were dissected. The length, width, thickness, and the position of the tibial attachment of pes anserinus tendons were anthropometric measured, as well as the distance between the infrapatellar branch of the saphenous nerve and the pes anserinus. Sixty healthy adult participants were enrolled for ultrasonic research. The length, width, thickness of pes anserinus was also measured and the saphenous nerve was also assessed.

RESULTS

Anatomic results showed that there were 3 types of pes anserinus, the infrapatellar branch of the saphenous nerve (IPBSN) was almost paralleled to the upper edge of the pes anserinus tendon, and the average of distance between them was about 0.95 cm. The length of semitendinosus and gracilis tendons were 146.49 ± 12.83 mm and 124.62 ± 8.86 mm, the width of sartorius tendon was 25.58 ± 4.65 mm, wider than other tendons. The classification of pes anserinus tendons and the saphenous nerves could be identified in ultrasonic image. The length of semitendinosus and gracilis tendons were 151.35 ± 9.65 mm and 120.86 ± 8.99 mm, the width of sartorius tendon was 22.84 ± 3.83 mm. And there was no significance difference between anatomic and ultrasonic measurement (P > .05).

CONCLUSION

The morphology of pes anserinus and its peripheral structures could be identified and measured precisely by ultrasound device, a presurgical ultrasonic examination was recommended. The arrangement of pes anserinus tendons was classified into 3 types according to our results. The incision should be performed medial to tibial eminence 1.5 cm and under the tibial tubercle level 2 to 3 cm, an oblique incision formed an angle of 50° with tibial transection was recommend, which was parallel to the direction of pes anserinus tendon.

Complications following harvesting of patellar tendon or hamstring tendon grafts for anterior cruciate ligament reconstruction: Systematic review of literature

Anterior cruciate ligament (ACL) reconstruction can be performed with an autograft, which is most often harvested from the patient's hamstring tendon (HT) or patellar tendon (PT). However, autograft harvesting leads to morbidity that is by no means insignificant. A systematic review of literature was performed to define the incidence of complications related to graft harvesting and the methods to prevent these complications. In March 2017, a systemic review of literature was performed using the keywords"harvesting", "harvest", "morbidity", "complication", "cruciate ligament". No time limit was applied. The studies had to be written in French or English with their abstract available online. This initial search based on the title and abstract identified 133 articles. Two independent observers analyzed each article entirely, including the references. In all, 36 articles were retained. The main complication of HT harvesting was sensory deficit because of damage to the infrapatellar branches of the saphenous nerve. This complication occurred in 39.7% to 88% of patients. This risk can be reduced by using a horizontal or oblique incision. The main complication following PT harvesting is anterior knee pain, reported in up to 46% of patients. There are substantial numbers of short-, medium- and long-term complications related to the harvesting of the two main ACL autografts. Effective means of prevention exist to reduce the risk of these complications.

LEVEL OF EVIDENCE

II Systematic review of literature.

An evidence-based evaluation on the use of platelet rich plasma in orthopedics - a review of the literature

Within orthopedics, the use of platelet-rich plasma (PRP) has been rapidly increasing in popularity, however, its true effectiveness has yet to be fully established. Several studies find that injecting PRP to the site of injury does not provide any significant benefit with respect to clinical outcomes; however, many others report the contrary. Due to the conflicting evidence and multiple meta-analyses conducted on the topic, a literature review of high-quality evidence on the use of PRP for common orthopaedic conditions was performed. Thus far, the evidence appears to suggest that PRP may provide some benefit in patients who present with knee osteoarthritis or lateral epicondylitis. On the other hand, evidence appears to be inconsistent or shows a minimal benefit for PRP usage in rotator cuff repair, patellar and Achilles tendinopathies, hamstring injuries, anterior cruciate ligament (ACL) repair, and medial epicondylitis. There is limited confidence in the conclusions from the published meta-analyses due to issues with statistical pooling, and limited subgroup analyses exploring the substantial heterogeneity across studies. Evidence-based clinicians considering the use of PRP in their patients with musculoskeletal injuries should be weary that the literature appears to be inconsistent and thus far, inconclusive.

Increased Risk of Revision After Anterior Cruciate Ligament Reconstruction With Soft Tissue Allografts Compared With Autografts: Graft Processing and Time Make a Difference

BACKGROUND

The optimal graft for anterior cruciate ligament reconstruction (ACLR) remains controversial.

PURPOSE

To compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts, hamstring autografts, and soft tissue allografts.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Prospectively collected ACLR cases reconstructed with BPTB autografts, hamstring autografts, and soft tissue allografts were identified using the Kaiser Permanente ACLR Registry. Aseptic revision was the endpoint. The type of graft and allograft processing method (nonprocessed, <1.8-Mrad irradiation with and without chemical processing [Allowash or AlloTrue], ≥1.8-Mrad irradiation with and without chemical processing, and chemical processing alone [BioCleanse]) were the exposures evaluated. Analyses were adjusted for age, sex, and race. Kaplan-Meier curves and Cox proportional hazards models were employed.

RESULTS

The cohort included 14,015 cases: there were 8924 (63.7%) male patients, there were 6397 (45.6%) white patients, 4557 (32.5%) ACLRs used BPTB autografts, 3751 ACLRs (26.8%) used soft tissue allografts, and 5707 (40.7%) ACLRs used hamstring autografts. The median age was 34.6 years for soft tissue allografts, 24.3 years for hamstring autografts, and 22.0 years for BPTB autografts. The crude nonadjusted revision rates were 85 (1.9%) in BPTB autograft cases, 132 (2.3%) in hamstring autograft cases, and 83 (2.2%) in soft tissue allograft cases. After adjusting for age, sex, and race, compared with hamstring autografts, a higher risk of revision was found with allografts with ≥1.8 Mrad without chemical processing after 2.5 years (hazard ratio [HR], 3.88; 95% CI, 1.48-10.12) and ≥1.8 Mrad with chemical processing after 1 year (HR, 3.43; 95% CI, 1.58-7.47) and with BioCleanse processed grafts at any time point (HR, 3.02; 95% CI, 1.40-6.50). Nonprocessed allografts and those irradiated with <1.8 Mrad with or without chemical processing were not found to have a different risk of revision compared with hamstring autografts. Compared with BPTB autografts, a higher risk of revision was seen with hamstring autografts (HR, 1.51; 95% CI, 1.15-1.99) and BioCleanse processed allografts (HR, 4.67; 95% CI, 2.15-10.16). Allografts irradiated with <1.8 Mrad with chemical processing (Allowash or AlloTrue) (HR, 2.19; 95% CI, 1.42-3.38) and without chemical processing (HR, 2.31; 95% CI, 1.40-3.82) had a higher risk of revision, as did allografts with ≥1.8 Mrad without chemical processing after 2 years (HR, 6.30; 95% CI, 3.18-12.48) and ≥1.8 Mrad with chemical processing (Allowash or AlloTrue) after 1 year (HR, 5.03; 95% CI, 2.30-11.00) compared with BPTB autografts. Nonprocessed allografts did not have a higher risk of revision compared with autografts. With the numbers available, direct comparisons between the specific allograft processing methods were not possible.

CONCLUSION

When soft tissue allografts are used for ACLR, processing and time from surgery affect the risk of revision. Tissue processing has a significant effect on the risk of revision surgery, which is most profound with more highly processed grafts and increases with increasing follow-up time. Surgeons and patients need to be aware of the increased risks of revision with the various soft tissue allografts used for ACLR.

Increased Risk of Revision After Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Allografts Compared With Autografts

BACKGROUND

The use of allograft tissue for anterior cruciate ligament reconstruction (ACLR) remains controversial.

PURPOSE

To compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts and BPTB allografts.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A retrospective cohort study of prospectively collected data was conducted using the Kaiser Permanente ACLR Registry. A cohort of patients who underwent primary unilateral ACLR with BPTB autografts and BPTB allografts was identified. Aseptic revision was the endpoint. The type of graft and allograft processing method (nonprocessed, <1.8-Mrad, and ≥1.8-Mrad irradiation) were the exposures of interest evaluated. Age (≤21 and ≥22 years) was evaluated as an effect modifier. Analyses were adjusted for age, sex, and race. Kaplan-Meier curves and Cox proportional hazards models were employed. Hazard ratios (HRs) and 95% CIs are provided.

RESULTS

The BPTB cohort consisted of 5586 patients: 3783 (67.7%) were male, 2359 (42.2%) were white, 1029 (18.4%) had allografts (nonprocessed: 155; <1.8 Mrad: 525; ≥1.8 Mrad: 288), and 4557 (81.6%) had autografts. The median age was 34.9 years (interquartile range [IQR], 25.4-44.0) for allograft cases and 22.0 years (IQR, 17.6-30.0) for autograft cases. The estimated cumulative revision rate at 2 years was 4.1% (95% CI, 2.9%-5.9%) for allografts and 1.7% (95% CI, 1.3%-2.2%) for autografts. BPTB allografts had a significantly higher adjusted risk of revision than BPTB autografts (HR, 4.54; 95% CI, 3.03-6.79; P < .001). This higher risk of revision was consistent with all allograft processing methods when compared with autografts and was also consistently higher in patients with allografts regardless of age.

CONCLUSION

When BPTB allograft tissue was used for ACLR, an overall 4.54 times adjusted higher risk of revision was observed compared with surgery performed with a BPTB autograft. Whether the tissue was irradiated with either high- or low-dose radiation, chemically processed, or not processed at all made little difference in the risk of revision. The differences in the revision risk were also consistent in younger and older patients. Surgeons and patients should be aware of the increased risk of revision when a BPTB allograft is used for ACLR.

A comparative study of effect of autograft compared with allograft anterior cruciate ligament reconstruction on expressions of LOXs and MMPs

The present study aimed to compare the effect of autograft or allograft anterior cruciate ligament (ACL) reconstruction on the expressions of lipoxygenases (LOXs) and matrix metalloproteinases (MMPs) in a New Zealand white rabbit model. New Zealand white rabbits were divided randomly into control, sham, autograft and allograft groups. At the 4th and 8th week after operation, biomechanical testing was performed to measure the primary length, cross-sectional area, maximum tensile load and stiffness of ACL, and HE staining was used to observe cell morphology and fibre alignment of ACL. At the 2nd, 4th and 8th week after operation, quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry were applied to detect LOXs and MMPs expressions, and expressions of adenomatous polyposis coli (APC)/Wnt signalling pathway-related proteins. At the 4th and 8th week after operation, the maximum tensile load and stiffness were higher in the autograft group than in the allograft group, and the values at the 8th week were higher than those at the 4th week after operation. The fibroblast proliferation in the allograft group was more significant than that in the autograft group. Compared with the control group, LOXs and MMPs expressions and the positive expression rates of LOXs and MMPs proteins were elevated, and the values in the allograft group were higher than those in the autograft group at all time points. At 8th week after operation, compared with the autograft group, Wnt expression was higher and APC expression was lower in the allograft group. Autograft and allograft ACL reconstruction can promote LOXs and MMPs expressions by activating the APC/Wnt signalling pathway.

Anterior cruciate ligament reconstruction: principles of treatment

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures in sports medicine. Several areas of controversy exist in ACL tear management which have engaged surgeons and researchers in debates towards identifying an ideal approach for these patients.

This instructional review discusses the principles of ACL reconstruction in an attempt to provide guidelines and initiate a critical thinking approach on the most common areas of controversy regarding ACL reconstruction.

Using high-level evidence from the literature, as presented in randomised controlled trials, systematic reviews, and meta-analyses, operative versus conservative treatment, timing of surgery, and rehabilitation are discussed. Also, the advantages and disadvantages of the most common types of autografts, such as patellar tendon and hamstrings as well as allografts are presented.

Key considerations for the anatomical, histological, biomechanical and clinical data (‘IDEAL’) graft positioning are reviewed.

Cite this article: Paschos NK, Howell SM. Anterior cruciate ligament reconstruction: principles of treatment. EFORT Open Rev 2016;398-408. DOI: 10.1302/2058-5241.1.160032.

Tunnel widening prevention with the allo-Achilles tendon graft in anterior cruciate ligament reconstruction: Surgical tips and short term followup

BACKGROUND

Tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction can be a serious complication, and there is controversy over how to prevent it. This study aimed to suggest surgical approaches to prevent TW using an allo-Achilles tendon graft, and then to evaluate TW after these surgical tips were applied.

MATERIALS AND METHODS

Sixty two patients underwent ACL reconstruction with an allo-Achilles tendon graft. Four surgical approaches were used: Making a tibial tunnel by bone impaction, intraarticular reamer application, bone portion application for the femoral tunnel, and an additional bone plug application for the tibial tunnel. After more than 1-year, followup radiographs including anteroposterior and lateral views were taken in 29 patients encompassing thirty knees. The diameter of the tunnels at postoperation day 1 (POD1) and at followup was measured and compared.

RESULTS

In 18 knees (60%), there were no visible femoral tunnel margins on the radiographs at POD1 or followup. In the other 12 cases, which had visible femoral tunnel margins on followup radiographs, the mean femoral tunnel diameter was 8.6 mm. In the tibial tunnel, the mean diameters did not increase on all three levels (proximal, middle, and distal), and there was no statistically significant difference between the diameters at POD1 and followup.

CONCLUSION

The suggested tips for surgery involving an allo-Achilles tendon graft can effectively prevent TW after ACL reconstruction according to this case series. These surgical tips can prevent TW.

Arthroscopic anatomic double-bundle ACL reconstruction using irradiated versus non-irradiated hamstring tendon allograft

PURPOSE

To analyse the clinical outcome of anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with irradiated versus non-irradiated hamstring allograft.

METHODS

One hundred and twelve patients who met the inclusion and exclusion criteria of the study were prospectively randomized consecutively into irradiated hamstring tendon allograft (Ir-Allo) group and non-irradiated allograft (Non-ir-Allo) group. All surgeries were done by the same senior surgeon with double-bundle reconstruction technique. Before surgery and at follow-up points, patients were evaluated by the same observer according to clinical evaluations.

RESULTS

Eighty-three patients (Non-ir-Allo, 44; Ir-Allo, 39) fulfilled complete follow-up and got full clinical evaluations. The mean follow-up period was 5.7 years (ranging from 5.0 to 6.5 years). At the final follow-up, significant differences were found when comparing the results of the two groups according to Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing (P < 0.05). According to KT-2000, 86.4 % of patients in the Non-ir-Auto group and 35.9 % in the Ir-Allo group had a side-to-side difference of <3 mm. According to the overall IKDC, functional, subjective evaluations and activity level testing, no significant differences were found between the two groups. Regarding the arthritic progression, there was significant difference between the two groups (Ir-Allo group: 30.8 %, Non-ir-Allo group: 11.4 %, P < 0.05).

CONCLUSION

A significant increase in anterior and rotational laxity in patients of the Ir-Allo group was found according to evaluations. No significant differences in activity level and functional scores were found between the two groups. We do not advocate the irradiated hamstring tendon allograft for ACL reconstruction.

LEVEL OF EVIDENCE

I.

Prediction of length and diameter of hamstring tendon autografts for knee ligament surgery in Caucasians

PURPOSE

Prediction of hamstring tendon autograft size facilitates preoperative planning of knee ligament surgery and may reduce the need for allografts in complex knee reconstructions. The aim of this study was to analyse whether length and diameter of hamstring tendon autografts can be predicted preoperatively with anthropometric parameters and patient characteristics.

METHODS

In this observational study, 725 consecutive Caucasian patients scheduled for ACL reconstruction were included. Preoperatively gender, age, height and weight were recorded. After harvest, tendon lengths of both gracilis and semitendinosus tendons were measured. Diameter of the final four-strand hamstring autograft was recorded. Relationship between length and diameter of tendon grafts and different anthropometric parameters were assed by linear and logistic regression analyses.

RESULTS

Mean lengths of the semitendinosus and gracilis tendon autografts were 28.9 ± 3.1 and 27.7 ± 3.0 cm, respectively. Length of the gracilis and semitendinosus grafts was independently related to patient height. Female gender was correlated with smaller graft diameter. One in nine female patients had a diameter <8 mm. The ratio in men was 1 in 36.

CONCLUSION

Hamstring autograft length and size can be predicted in Caucasians. Length of the gracilis and semitendinosus tendons was related to patient height. Smaller graft diameter was related to female gender.

LEVEL OF EVIDENCE

II.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With a Hamstring Tendon Autograft and Fresh-Frozen Allograft: A Prospective, Randomized, and Controlled Study

PURPOSE

To compare the clinical outcome of anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with a hamstring tendon autograft versus fresh-frozen allograft.

METHODS

Between January 2010 and December 2011, in a prospective randomized study, we included 157 patients who were planned to receive anatomic DB ACL reconstruction with a hamstring tendon autograft or fresh-frozen allograft. All surgeries were performed by the same senior surgeon with the DB reconstruction technique. The fixation of femoral side grafts was by means of an EndoButton, and the tibial side grafts were fixed with a bioabsorble interference screw augmented with a staple. The same rehabilitation protocol was applied to all the patients. Patients were evaluated preoperatively and at the follow-up points. Evaluations included detailed history, physical examination, radiograph, functional knee ligament testing, KT-2000 arthrometer testing, Harner's vertical jump and Daniel's one-leg hop tests, Lysholm score, Tegner score, the International Knee Documentation Committee (IKDC) standard evaluation form, and Cincinnati knee score.

RESULTS

One hundred and twenty-one patients (Auto, 62; Allo, 59) fulfilled complete follow-up and got full clinical evaluations. The mean follow-up was 4.6 years (4.0 to 5.5 years) for both groups. No significant differences were found between the 2 groups according to the evaluations aforementioned except that patients in the Allo group had shorter operation time compared with the Auto group (P = .001). Fifty-three (85.5%) patients in the Auto group and 50 (84.7%) patients in the Allo group had a side-to-side difference of less than 3 mm. Four (6.5%) patients in the Auto group and 4 (6.8%) patients in the Allo group had a side-to-side difference of more than 5 mm. Fifty-nine (95.8%) patients in the Auto group and 55 (93.2%) patients in the Allo group were normal or nearly normal according to the overall IKDC. According to the subjective IKDC, the average scores were 90 and 89 points, respectively, for the Auto and Allo groups. The mean Lysholm and Tegner scores were 90 points and 7.9 points for the Auto group, respectively, and 89 points and 7.8 points for the Allo group, respectively. For the Cincinnati knee score, the average scores were 91 and 90 points, respectively, for the Auto and Allo groups. A total of 11.3% (7 of 62) of patients in the Auto group and 11.9% (7 of 59) of patients in the Allo group had an arthritic progression. There was no statistical difference between the 2 groups at the final follow-up.

CONCLUSIONS

With the anatomic DB ACL reconstruction technique, comparable objective and subjective clinical results can be achieved with the use of a fresh-frozen hamstring tendon allograft compared with an autograft.

LEVEL OF EVIDENCE

Level II, prospective randomized clinical trial.

Improved ACL reconstruction outcome using double-layer BPTB allograft compared to that using four-strand hamstring tendon allograft

BACKGROUND

This study compared the clinical outcomes of anterior cruciate ligament reconstruction using double-layer bone-patellar tendon-bone (DBPTB) allografts and four-strand hamstring (4SHS) grafts.

METHODS

This prospective randomized controlled trial included 101 patients. Of these, 50 patients received DBPTB allografts, and 51 received 4SHS grafts. Evaluations included KT-1000 arthrometer measurements, Lachman tests, pivot-shift tests, the International Knee Documentation Committee (IKDC) classification and Lysholm scores at three year postoperative follow-up.

RESULTS

Two DBPTB patients (four percent) and nine 4SHS patients (17.6%) had graft failures, which was significantly different (P=0.028). The DBPTB group had significantly better Lachman test, IKDC knee score and Lysholm score results than the 4SHS group (P<0.05). However, these differences were below the threshold for clinical significance.

CONCLUSIONS

DBPTB allografts had fewer graft failures at three years than 4SHS grafts for anterior cruciate ligament reconstruction; and there were statistically significant differences but not clinically significant differences between DBPTB and 4SHS grafts in terms of the KT1000 test, IKDC and Lysholm scores.