Comparison of Clinical Outcome of Autograft and Allograft Reconstruction for Anterior Cruciate Ligament Tears

Randomized Controlled Trials Comparing Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts in Anterior Cruciate Ligament Reconstruction Surgery Are Statistically Fragile: A Systematic Review

PURPOSE

To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction.

METHODS

The PubMed, Embase, and MEDLINE databases were queried for RCTs published since 2010 comparing autograft type (bone-patellar tendon-bone vs hamstring tendon) in ACL reconstruction surgery. The fragility index (FI) and reverse FI (rFI) were determined for significant and nonsignificant outcomes, respectively, as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) and reverse FQ, representing fragility as a proportion of the study population, were calculated by dividing the FI and rFI, respectively, by the sample size.

RESULTS

We identified 19 RCTs reporting 55 total dichotomous outcomes. The median FI of the 55 total outcomes was 5 (interquartile range [IQR], 4-7), meaning a median of 5 outcome event reversals would alter the outcomes' significance. Five outcomes were reported as statistically significant with a median FI of 4 (IQR, 2-6), meaning a median of 4 outcome event reversals would change outcomes to be nonsignificant. Fifty outcomes were reported as nonsignificant with a median rFI of 5 (IQR, 4-7), meaning a median of 5 outcome event reversals would change outcomes to be significant. The FQ and reverse FQ for significant and nonsignificant outcomes were 0.025 (IQR, 0.018-0.045) and 0.082 (IQR, 0.041-0.106), respectively. For 61.8% of outcomes, patients lost to follow-up exceeded the corresponding FI or rFI.

CONCLUSIONS

There is substantial statistical fragility in recent RCTs on autograft choice in ACL reconstruction surgery given that altering a few outcome events is sufficient to reverse study findings. For over half of outcomes, maintaining patients lost to follow-up may have been sufficient to reverse study conclusions.

CLINICAL RELEVANCE

We recommend co-reporting FIs and P values to provide a more comprehensive representation of a study's conclusions when conducting an RCT.

Design and bioprinting for tissue interfaces

Tissue interfaces include complex gradient structures formed by transitioning of biochemical and mechanical properties in micro-scale. This characteristic allows the communication and synchronistic functioning of two adjacent but distinct tissues. It is particularly challenging to restore the function of these complex structures by transplantation of scaffolds exclusively produced by conventional tissue engineering methods. Three-dimensional (3D) bioprinting technology has opened an unprecedented approach for precise and graded patterning of chemical, biological and mechanical cues in a single construct mimicking natural tissue interfaces. This paper reviews and highlights biochemical and biomechanical design for 3D bioprinting of various tissue interfaces, including cartilage-bone, muscle-tendon, tendon/ligament-bone, skin, and neuro-vascular/muscular interfaces. Future directions and translational challenges are also provided at the end of the paper.

Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary: Management of Anterior Cruciate Ligament Injuries

Management of Anterior Cruciate Ligament Injuries: Evidence-based Clinical Practice Guideline is based on a systematic review of published studies for the treatment of anterior cruciate ligament injurie in both skeletally mature and immature patients. This guideline contains eight recommendations and seven options to assist orthopaedic surgeons and all qualified physicians managing patients with ACL injuries based on the best current available evidence. It is also intended to serve as an information resource for professional healthcare practitioners and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development.

Allograft for Anterior Cruciate Ligament Reconstruction (ACLR): A Systematic Review and Meta-Analysis of Long-Term Comparative Effectiveness and Safety. Results of a Health Technology Assessment

Purpose

To evaluate whether allograft anterior cruciate ligament reconstruction (ACLR) is superior or inferior to autograft ACLR or conservative management in terms of effectiveness and safety.

Methods

A systematic review of the evidence for allograft ACLR was conducted. Randomized controlled trials with a minimum mean follow-up time of 5 years were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the EUnetHTA-Core-Model were used as reporting standards. A meta-analysis was conducted for selected crucial outcomes using a random-effects model. The strength of the available evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

Results

Six randomized trials were included comparing allograft with autograft. Patients were on average between 28 and 32.8 years of age (allograft group) and 28.9 and 31.7 years of age (autograft group). Based on the crucial outcomes, the meta-analyses showed no statistically significant differences in Lysholm score, Tegner score, and Cincinnati Knee Score between groups. A small statistical difference favoring autografts was found across studies in the subjective International Knee Documentation Committee score (–2.25; 95% confidence interval –3.02 to –1.47; I² = 0%; range of all scores: 73.7-90). Two of six studies reported on graft failure, with a statistically significant difference to the detriment of using allografts (13/49 [26.5%] vs 4/48 [8.3%] in one study, 13/43 [30.2%] vs 3/40 [7.5%] in the other study).

Conclusions

Although no substantial difference in patient-reported function, activity level, and symptoms was demonstrated, evidence from the included studies showed a greater risk for graft failure or revision that may make allograft a less safe treatment modality in ACLR. The strength of available evidence is low based on the crucial outcomes due to the lack of high-quality research and the present increased risk of bias in primary studies. Priority should be shifted toward reflecting on whether there is a subpopulation for whom allograft ACLR may still be advantageous in theory (e.g., less-active older patients) and further conduct RCTs in this population.

Level of Evidence

Level II, systematic review of Level II evidence studies.

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.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

Treatment of Anterior Cruciate Ligament Injuries in Professional Soccer Players by Orthopedic Surgeons

Objective  To describe the treatment provided by specialists for ACL lesions in professional soccer players. Methods  A cross-sectional study in which orthopedic surgeons affiliated to soccer teams competing in the Brazilian Soccer Championship answered a questionnaire about the treatment of ACL injuries in professional soccer players. Results  The specialists wait between one to four weeks after the ACL injury to perform the surgical treatment. They use a single incision and single-bundle reconstruction, assisted by arthroscopy, femoral tunnel drilling by an accessory medial portal, and quadruple flexor tendon autografts or patellar tendon autografts. After three to four months, the players are allowed to run in a straight line; after four to six months, they begin to practice exercises with the ball without contact with other athletes; and, after six to eight months, they return to play. The main parameter used to determine the return to play is the isokinetic strength test. The specialists estimate that more than 90% of elite soccer players return to playing professionally after an ACL reconstruction, and 60 to 90% return to play at their prior or at a greater level of performance. Conclusion  The present article successfully describes the main surgical practices and post-surgery management adopted by specialists in this highly-specific population of patients.

Effects of Graft Selection in Arthroscopic Anterior Cruciate Ligament Reconstruction: Midterm Functional Results

Objectives:

This study is a comparison of the midterm clinical results of patients who underwent anterior cruciate ligament (ACL) reconstruction using an allograft and those who had an autograft procedure.

Methods:

The results of 70 patients who underwent ACL reconstruction with an anterior tibial tendon (ATT) allograft (n=18) or a hamstring (HT) autograft (n=52) were evaluated retrospectively. At the last follow-up, International Knee Documentation Committee (IKDC) and Tegner-Lysholm scores were used to assess functional status, as well as results of the Lachman test, the anterior drawer test, and the pivot-shift test.

Results:

There was no significant difference between the 2 groups in terms of age, gender, length of time before operation, graft thickness, or femoral tunnel length (p>0.05). The results were satisfactory in both groups in the postoperative period in terms of the length of time until a return to sports, IKDC score, Tegner-Lysholm score, range of motion, quadriceps circumference, and laxity, with no significant difference between the groups (p>0.05).

Conclusion:

The results of this study suggested that midterm clinical outcomes of ACL reconstruction with an ATT allograft or an HT autograft are similar when the correct technique is used according to the appropriate indications by an experienced surgeon and a successful rehabilitation program implemented after the operation.

A Single Bundle Anterior Cruciate Ligament Reconstruction (ACL-R) Using Hamstring Tendon Autograft and Tibialis Anterior Tendon Allograft: A Comparative Study

The main purpose of this study was to compare the clinical outcomes of patients undergoing a single bundle anterior cruciate ligament reconstruction (ACL-R) of using quadrupled hamstring (4HT) autografts and two-strand tibialis anterior (2TA) allografts, and to find out the rate of graft failure and possible causes. We hypothesized that there would be no difference in the clinical outcome, and graft failure would be associated with the use of small sized allograft in young active males with high demand of sports activities. We retrospectively evaluated 222 patients (male, n=167, female, n=55) undergoing ACL-R between January 2010 and July 2014. Of 222 patients, 115 were included in the 4HT autograft group and 107 patients in the 2TA allograft group. Inclusion criteria were primary unilateral ACL-R with a minor MCL (<grade II) injury with or without meniscus tear and had at least 2.5 years of follow-up. Subjective evaluation was performed using Tegner-Lysholm score, modified Cincinnati knee score, and IKDC knee form. Anteroposterior laxity was assessed using ADT and Lachman test whereas rotational laxity was assessed using pivot shift test. Similarly, functional assessment was performed using range of motion (ROM), Daniel's one-leg hop test, and overall IKDC score. Clinical outcomes were satisfactory and comparable in both groups with no statistically significant difference in all the respective parameters. No statistically significant difference was observed in graft re-rupture rate. However, most graft failures occurred in young active males with high demand of sports activities, graft size smaller than 8 mm, and use of allograft. An autograft with at least 8 mm diameter should be considered in a young active male with high demand of sports activities to avoid graft failure.

Increased lateral tibial posterior slope is related to tibial tunnel widening after primary ACL reconstruction

PURPOSE

The purpose of the study was to determine the influence of femoral and tibial bone morphology on the amount of femoral and tibial tunnel widening after primary anatomic ACL reconstruction. It was hypothesized that tibial and femoral bone morphology would be significantly correlated with tunnel widening after anatomic ACL reconstruction.

METHODS

Forty-nine consecutive patients (mean age 21.8 ± 8.1 years) who underwent primary single-bundle anatomic ACL reconstruction with hamstring autograft were enrolled. Two blinded observers measured the bone morphology of tibia and femur including, medial and lateral tibial posterior slope, medial and lateral tibial plateau width, medial and lateral femoral condyle width, femoral notch width, and bicondylar width on preoperative magnetic resonance imaging (MRI) scans. Tibial and femoral tunnel width at three points (aperture, mid-section, and exit) were measured on standard anteroposterior radiograph from 1 week and 1 year postoperatively (mean 12.5 ± 2 months). Tunnel width measurements at each point were compared between 1 week and 1 year to calculate percent of tunnel widening over time. Multivariable linear regression was used to analyze correlations between bone morphology and tunnel widening.

RESULT

Increase in lateral tibial posterior slope was the only independent bony morphology characteristics that was significantly correlated with an increased tibial tunnel exit widening (R = 0.58). For every degree increase in lateral tibial posterior slope, a 3.2% increase in tibial tunnel exit width was predicted (p = 0.003). Excellent inter-observer and intra-observer reliability were determined for the measurements (ICC = 0.91 and 0.88, respectively).

CONCLUSION

Increased lateral tibial posterior slope is an important preoperative anatomic factor that may predict tunnel widening at the tibial tunnel exit. In regard to clinical relevance, the results of this study suggest that lateral tibial posterior slope be measured preoperatively. In patients with increased lateral tibial posterior slope, more rigid graft fixation and a more conservative physical therapy regiment may be preferred. Level of evidence IV.

Evaluating the Functional Results and Complications of Autograft vs Allograft Use for Reconstruction of the Anterior Cruciate Ligament: A Systematic Review

The aim of our review is to identify the reconstruction technique that has a superior functional outcome and decreased number of complications for the anterior cruciate ligament (ACL). We have divided our review into 2 sections. Our primary question evaluates the functional results and complications of autografts compared to allografts for ACL reconstruction. Our subsidiary question evaluates the functional results and complications of bone-patellar tendon-bone (BPTB) autografts compared to hamstring tendon autografts. We conducted a systematic review (SR) based on high quality evidence provided by Cochrane, PubMed and National Health Service evidence searches for papers comparing different ACL reconstruction techniques. Results from 2 primary studies, 1 SR and 1 meta-analysis showed no significant statistical difference when comparing clinical outcomes such as pain, range of motion, laxity, International Knee Documentation Committee score, single assessment numerical evaluation score, Tegner activity score and patient reported satisfaction with regards to autografts vs allografts. Allografts had worse outcomes for postoperative tibial tunnelling and graft failure. Results of 3 SRs showed statistically significant differences in incidence of anterior knee pain, kneeling pain and knee stability, which were all found to be greater amongst those who had received a BPTB autograft. Knee extension was significantly reduced in patients with BPTB grafts when compared to patients with Hamstring tendon autografts. However, with regards to return to prior levels of activity, there was no statistically significant difference between those that received BPTB autografts and those that received Hamstring tendon autografts. Autograft reconstruction of the ACL was shown to provide better postoperative outcomes when compared to allograft reconstruction, although the difference was not statistically significant. When researching different autograft options BPTB autografts were associated with greater pain but also greater stability of the knee joint postoperatively when compared to hamstring tendon autografts.

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.

Autograft versus allograft in anterior cruciate ligament reconstruction: A meta-analysis with trial sequential analysis

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction is considered as the standard surgical procedure for the treatment of ACL tear. However, there is a crucial controversy in terms of whether to use autograft or allograft in ACL reconstruction. The purpose of this meta-analysis is to compare autograft with allograft for patients undergoing ACL reconstruction.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for randomized controlled trials that compared autograft with allograft in ACL reconstruction up to January 31, 2016. The relative risk or mean difference with 95% confidence interval was calculated using either a fixed- or random-effects model. The risk of bias for individual studies according to the Cochrane Handbook. The trial sequential analysis was used to test the robustness of our findings and get more conservative estimates.

RESULTS

Thirteen trials were included, involving 1636 participants. The results of this meta-analysis indicated that autograft brought about lower clinical failure, better overall International Knee Documentation Committee (IKDC) level, better pivot-shift test, better Lachman test, greater Tegner score, and better instrumented laxity test (P < 0.05) than allograft. Autograft was not statistically different from allograft in Lysholm score, subjective IKDC score, and Daniel 1-leg hop test (P > 0.05). Subgroup analyses demonstrated that autograft was superior to irradiated allograft for patients undergoing ACL reconstruction in clinical failure, Lysholm score, pivot-shift test, Lachman test, Tegner score, instrumented laxity test, and subjective IKDC score (P < 0.05). Moreover, there were no significant differences between autograft and nonirradiated allograft.

CONCLUSIONS

Autograft is superior to irradiated allograft for patients undergoing ACL reconstruction concerning knee function and laxity, but there are no significant differences between autograft and nonirradiated allograft. However, our results should be interpreted with caution, because the blinding methods were not well used.