Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft

Fragile Statistical Findings in Randomized Controlled Trials Evaluating Autograft Versus Allograft Use in Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To analyze the statistical stability of randomized controlled trials (RCTs) evaluating the surgical management of autografts versus allografts in the anterior cruciate ligament reconstruction (ACLR) literature and calculate the fragility index (FI) and fragility quotient and explore a subgroup analysis by calculating the proportion of outcome events where the FI was less than the number of patients lost to follow-up.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic search in the PubMed and Cochrane databases to identify RCTs published between 2000 and 2022 that investigated the use of autografts versus allografts in ACLR literature and reported dichotomous data. The fragility index of each dichotomous variable was calculated through the reversal of a single outcome event until significance was reversed. The fragility quotient was calculated by dividing each fragility index by the study sample size. The interquartile range also was calculated.

RESULTS

Of the 4407 articles screened, 23 met the search criteria, with 11 RCTs evaluating ALCR using autografts and allografts included for analysis. Two hundred and 18 outcome events with 32 significant (P < .05) outcomes and 186 nonsignificant (P ≥ .05) outcomes were identified. The overall fragility index and fragility quotient for all 218 outcomes were 6 subjects (interquartile range 5-8) and 0.058 (interquartile range 0.039-0.077). Fragility analysis of statistically significant outcomes and nonsignificant outcomes had a fragility index of 3.5 (interquartile range 1-5.5) and 6 (interquartile range 5-8), respectively. All of the studies reported a loss to follow-up where 45.5% (5) reported a loss to follow-up greater or equal to 6.

CONCLUSIONS

The RCTs in the ACLR peer-reviewed literature evaluating autograft versus allograft use are vulnerable to a small number of outcome event reversals and exemplify significant statistical fragility in statistically significant findings.

LEVEL OF EVIDENCE

Level I, systematic review of Level I studies.

The effect of sterilization and storage on the viscoelastic properties of human tendon allografts - Continued: Storage for 0 to 4 months

The role of donor-derived tendons, also known as allografts, in anterior cruciate ligament replacement surgeries is steadily increasing. Before surgery, temporary storage and, in most cases, sterilization are essential. It is, thus, crucial to determine how these procedures alter the grafts' biomechanical properties. The purpose of this research was to analyze the effect of different sterilization methods (native, frozen, frozen + 21 kGy gamma irradiation, frozen + 21 kGy electron beam irradiation) and storage durations (0 to 4 months) on the deformation and creep of two tendon types (tibialis anterior, peroneus longus). 80 tibialis anterior and 83 peroneus longus tendons from 51 human cadavers were included. The samples were removed, placed in a radio-cryoprotectant solution, then slowly cooled, sterilized and stored at -80 °C. All groups were subject to 60 s static creep test with 250 N load. Deformation during the loading phase, creep during static loading, and the ratio of these two were evaluated. Deformation at the end of the loading phase and creep consistently exhibited significantly smaller values in the tibialis anterior compared to the peroneus longus type, as well as in electron beam-sterilized grafts as opposed to gamma beam-sterilized ones. Prolonged storage periods (within 0 to 4 months) resulted in a notable increase in these values, particularly in deformation. Based on the experimental data, the tibialis anterior tendon type and sterilization by gamma beam irradiation are better choices for anterior cruciate ligament reconstruction than the peroneus longus and sterilization by electron beam. Increased storage time affects negatively the evaluated mechanical properties.

Autograft patellar bone-tendon-bone use does not increase operative time in anterior cruciate ligament reconstruction

Background

Anterior cruciate ligament reconstruction (ACLR) is a common procedure that has been shown to have relatively good outcomes amongst various graft types. Operative time in ACLR has been found to influence outcomes and cost. The purpose of this study was to evaluate the association of operative time in primary arthroscopically performed anterior cruciate ligament reconstruction (ACLR) and graft type while controlling for confounders that influence time.

Methods

All patients who received ACLR between 2018 and 2022 were included in this retrospective cohort study. Exclusion criteria consisted of age (≤16 years), revisions, concomitant ligament reconstruction or tendon repairs, or other simultaneously performed procedures that could potentially add substantial variation in operative time. The primary outcome was operative time. Graft types included allograft, bone-tendon-bone (BTB) autograft, hamstring tendon (HS) autograft and quadriceps tendon (QT) autograft.

Results

A total of 1813 primary ACLRs were included. The average operative time was 98.9 ± 33.0 min. Graft utilization varies considerably among surgeons. The most used graft type was BTB autograft (42.6%) followed by HS autograft (32.3%) and allograft (21.4%). Only 68 cases (3.8%) used a QT autograft. Seven of the 15 included surgeons primarily used BTB autograft. One surgeon predominately used QT autograft. No difference in operative time was observed among the autograft types (p = 0.342). Allograft ACLR was significantly faster by 27-33 min compared to using BTB autograft, HS autograft, or QT autograft (p < 0.001).

Conclusion

Operative time did not vary by type of autograft selected. Allograft ACLR was performed approximately 30 min faster than autograft ACLR. Further studies examining the effect on patient outcomes of reduced operative time and minimizing graft harvest morbidity in ACLR is important to more accurately determine the cost-effectiveness of allograft ACLR.

The effect of sterilization and storage on the viscoelastic properties of human tendon allografts

Allografts have become increasingly preferred for anterior cruciate ligament replacement purposes. The risk of infections necessitates thorough sterilization procedures, and the allografts usually need to be stored prior to surgery. Classical mechanical tests have been performed with various types of tendons, however, tibialis anterior and peroneus longus tend to suffer the least biomechanical changes after irradiation. Only few results are available of the strain and creep behaviour of tendons, even though this information is necessary to provide suitable allografts. The aim of the present study is to analyze the effect of different tendon types (T-tibialis anterior, P-peroneus longus), sterilization methods (G-gamma irradiation of 21 kGy, E-electron beam irradiation of 21 kGy) and storage times (5 and 6 months) on the creep behavior, which is characterized by the strain at the end of the loading phase and creep deformation after static loading. Static creep tests were performed with 250 N load during 60 s. Deformation at the end of the loading phase of both tendons was significantly smaller after 5 months long storage than that after 6 months long storage. TE5 showed significantly less creep than group TE6, and TE6 significantly greater than PE6. The creep of TE5 was significantly lower than that of TG5. Based on the data, the peroneus longus sterilized by electron beam and stored deep frozen for 5 months is a better choice for anterior cruciate ligament reconstruction than tibialis anterior sterilized by gamma irradiation stored for 6 months.

The long-term outcomes of different grafts in anterior cruciate ligament reconstruction: a network meta-analysis

OBJECTIVES

To compare the long-term prognosis of patients with different types of grafts used in anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Ovid (MEDLINE and Embase) and the Cochrane library were searched up to Feb 2020. Eligible studies about different grafts in ACLR were searched for identifying the evidence comparing the long-term (mean or median follow-up time or the general description of the follow-up time≥2 years) knee outcomes of different grafts for ACLR. The final included articles and evaluation criteria were confirmed by the authors and senior clinicians to ensure the validity of the included articles. Lysholm score, the results of pivot shift test, Lachman test and International Knee Documentation Committee (IKDC) evaluation were selected as prognostic indicators. A Bayesian network meta-analysis was conducted.

RESULTS

A total of 30 articles were included in our network meta-analysis. Finally, we found that artificial graft or augmentation can provide the not bad Lysholm score but the worse result of IKDC evaluation for patients with ACLR compared with other types of grafts. Double-bundle hamstring autograft can provide a good Lysholm score as well as lower positive rate of pivot shift test and Lachman test. Patellar tendon autograft can provide the better result of IKDC evaluation. The patients with allogeneic tendon graft may get the higher positive rate of pivot shift test and Lachman test. Patients with single-bundle hamstring autograft may get the ordinary result of IKDC evaluation and Lysholm score.

CONCLUSIONS

Double-bundle hamstring autograft may be a better choice because of more items of good prognosis for the patients with ACLR. Patellar tendon autograft is a right choice which only shows the disadvantage on the Lysholm score. The prognosis of patients with single-bundle hamstring autograft is ordinary. The effect of artificial graft or augmentation needs more evidence to prove. Allogeneic tendon graft is not a better choice when compared with other grafts referred in our network meta-analysis.

TRANSLATIONAL POTENTIAL STATEMENT

In this study, we made a comprehensive comparison of the grafts commonly used in anterior cruciate ligament reconstruction. The evidence presented in this study provides a reference for clinicians to select a suitable anterior cruciate ligament graft.

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.

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.

Knee and Leg Injuries

Knee and leg injuries are extremely common presentations to the emergency department. Understanding the anatomy of the knee, particularly the vasculature and ligamentous structures, can help emergency physicians (EPs) diagnose and manage these injuries. Use of musculoskeletal ultrasonography can further aid EPs through the diagnostic process. Proper use of knee immobilizers can also improve long-term patient outcomes.

Italian consensus statement for the use of allografts in ACL reconstructive surgery

PURPOSE

Graft choice for primary anterior cruciate ligament reconstruction (ACL-R) is debated, with considerable controversy and variability among surgeons. Autograft tendons are actually the most used grafts for primary surgery; however, allografts have been used in greater frequency for both primary and revision ACL surgery over the past decade. Given the great debate on the use of allografts in ACL-R, the "Allografts for Anterior Cruciate Ligament Reconstruction" consensus statement was developed among orthopedic surgeons and members of SIGASCOT (Società Italiana del Ginocchio, Artroscopia, Sport, Cartilagine, Tecnologie Ortopediche), with extensive experience in ACL-R, to investigate their habits in the use of allograft in different clinical situations. The results of this consensus statement will serve as benchmark information for future research and will help surgeons to facilitate the clinical decision making.

METHODS

In March 2017, a formal consensus process was developed using a modified Delphi technique method, involving a steering group (9 participants), a rating group (28 participants) and a peer-review group (31 participants). Nine statements were generated and then debated during a SIGASCOT consensus meeting. A manuscript has been then developed to report methodology and results of the consensus process and finally approved by all steering group members.

RESULTS

A different level of consensus has been reached among the topics selected. Strong agreement has been reported in considering harvesting, treatment and conservation methods relevant for clinical results, and in considering biological integration longer in allograft compared to autograft. Relative agreement has been reported in using allograft as the first-line graft for revision ACL-R, in considering biological integration a crucial aspect for rehabilitation protocol set-up, and in recommending a delayed return to sport when using allograft. Relative disagreement has been reported in using allograft as the first-line graft for primary ACL-R in patients over 50, and in not considering clinical results of allograft superior to autograft. Strong disagreement has been reported in using allograft as the first-line graft for primary ACL-R and for skeletally immature patients.

CONCLUSIONS

Results of this consensus do not represent a guideline for surgeons, but could be used as starting point for an international discussion on use of allografts in ACL-R.

LEVEL OF EVIDENCE

IV, consensus of experts.

Allograft for knee ligament surgery: an American perspective

PURPOSE

Allografts are frequently use for ligamentous reconstruction at the knee. In the United States, tissue donation and distribution are highly regulated processes with thorough oversight from private and government entities. Allograft is widely available in the United States and allograft procurement is a large industry with varying procurement, sterilization, processing, and distribution procedures. It is important to understand allograft regulation and processing which may affect graft mechanical properties and biological graft integration.

METHODS

English-language literature, United States government and regulatory agency statues pertaining to allograft procurement, distribution, and usage were reviewed and the findings summarized.

RESULTS

During the processing of allograft, multiple factors including sterilization procedures, irradiation, storage conditions, and graft type all affect the biomechanical properties of the allograft tissue. Biological incorporation and ligamentization of allograft does occur, but at a slower rate compared with autograft. For ligamentous reconstruction around the knee, allograft offers shorter operative time, no donor-site morbidity, but has shown an increased risk for graft failure compared to autograft.

CONCLUSION

This article reviews the regulations on graft tissue within the United States, factors affecting the biomechanics of allograft tissue, differences in allograft tissue choices, and the use of allograft for anterior cruciate ligament reconstruction and multiligamentous knee injury reconstruction.

LEVEL OF EVIDENCE

V.

Autograft or allograft for reconstruction of anterior cruciate ligament: a health economics perspective

PURPOSE

To assess the clinical and cost-effectiveness of allografts versus autografts in the reconstruction of anterior cruciate ligaments.

METHODS

Systematic review of comparative clinical effectiveness and cost-effectiveness analysis.

RESULTS

Both autograft and allograft reconstruction are highly effective. Recent studies show little difference in failure rates between autografts and allografts (about 6% and 7%, respectively). In cost-effectiveness analysis, the price differential is the main factor, making autografts the first choice. However, there will be situations, particularly in revision ACL reconstruction, where an allograft may be preferred, or may be the only reasonable option available.

CONCLUSION

In ACL reconstruction, clinical results with autografts are as good as or slightly better than with allografts. Allografts cost more, indicating that autografts are more cost-effective and should usually be first choice.

LEVEL OF EVIDENCE

II.

Knee osteoarthritis risk is increased 4-6 fold after knee injury - a systematic review and meta-analysis

OBJECTIVE

To estimate knee osteoarthritis (OA) risk following anterior cruciate ligament (ACL), meniscus or combined ACL and meniscus injury.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, SPORTDiscus, CINAHL and Web of Science until November 2018.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective or retrospective studies with at least 2-year follow-up including adults with ACL injury, meniscal injury or combined injuries. Knee OA was defined by radiographs or clinical diagnosis and compared with the contralateral knee or non-injured controls.

STUDY APPRAISAL AND SYNTHESIS

Risk of bias was assessed using the SIGN50 checklist. ORs for developing knee OA were estimated using random effects meta-analysis.

RESULTS

53 studies totalling ∼1 million participants were included: 185 219 participants with ACL injury, mean age 28 years, 35% females, 98% surgically reconstructed; 83 267 participants with meniscal injury, mean age 38 years, 36% females, 22% confirmed meniscectomy and 73% unknown; 725 362 participants with combined injury, mean age 31 years, 26% females, 80% treated surgically. The OR of developing knee OA were 4.2 (95% CI 2.2 to 8.0; I²=92%), 6.3 (95% CI 3.8 to 10.5; I²=95%) and 6.4 (95% CI 4.9 to 8.3; I²=62%) for patients with ACL injury, meniscal injury and combined injuries, respectively.

CONCLUSION

The odds of developing knee OA following ACL injury are approximately four times higher compared with a non-injured knee. A meniscal injury and a combined injury affecting both the ACL and meniscus are associated with six times higher odds compared with a non-injured knee. Large inconsistency (eg, study design, follow-up period and comparator) and few high-quality studies suggest that future studies may change these estimates.

CLINICAL RELEVANCE

Patients sustaining a major knee injury have a substantially increased risk of developing knee OA, highlighting the importance of knee injury prevention programmes and secondary prevention strategies to prevent or delay knee OA development.PROSPERO registration number CRD42015016900.

Autograft or Allograft? Irradiated or Not? A Contrast Between Autograft and Allograft in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

PURPOSE

To compare the clinical outcomes and adverse events associated with irradiated and nonirradiated allografts in anterior cruciate ligament (ACL) reconstruction.

METHODS

PubMed, Web of Science, and EMBASE were searched for randomized controlled trials from January 1990 to March 2018 to compare autograft with allograft in ACL reconstruction. Both objective and subjective outcomes of the function and adverse events were meta-analyzed. Two comparisons were summarized: (1) autograft and nonirradiated allograft and (2) autograft and irradiated allograft. The bias risk was based on the Cochrane Handbook for Systematic Reviews of Interventions. The overall risk ratio or weighted mean difference was calculated using a fixed- or random-effects model. Heterogeneity between studies was evaluated by the Q and the I² statistics.

RESULTS

Eleven trials were included in this review for meta-analysis. A total of 1,172 patients were involved (465 autograft and 461 nonirradiated allograft; 141 autograft and 138 irradiated allograft patients). The average follow-up varied from 2 to >10 years. The mean patient age varied from 22 to 32.8 years. The total failure rate was 2.5%. Our analyses demonstrated better clinical outcomes in autograft than irradiated allograft, which could be observed clearly through the International Knee Documentation Committee score (3.84; 95% confidence interval [CI], 1.93-5.76; P < .0001; I² = 0%), Lysholm score (2.94; 95% CI, 0.66-5.22; P = .01; I² = 0%), and Tegner score (0.14; 95% CI, -0.08 to 0.36; P = .22; I² = 0%) with fewer adverse events 0.20 (95% CI, 0.11-0.39; P < .00001; I² = 0%). There were no significant differences in autograft and nonirradiated allograft groups (P = .47, P = .27, P = .24, and P = .24, respectively).

CONCLUSIONS

Autograft offered greater advantages in functional outcomes and adverse events than irradiated allograft in ACL reconstruction; however, there were no significant differences between autograft and nonirradiated allograft in ACL reconstruction.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and Level II studies.

Meta-analysis of the Risk of Infections After Anterior Cruciate Ligament Reconstruction by Graft Type

BACKGROUND

An infection after anterior cruciate ligament (ACL) reconstruction is a relatively rare but challenging complication. There are no meta-analyses comparing the incidence of infections after ACL reconstruction with the various available graft choices.

PURPOSE

To compare the incidence of infections after ACL reconstruction with bone-patellar tendon-bone (BPTB) autografts compared with hamstring autografts, with a secondary aim of comparing the incidence of infections after reconstruction with autografts compared with allografts.

STUDY DESIGN

Meta-analysis.

METHODS

A systematic review was performed to identify level 1 and 2 studies that reported the incidence of infections by graft type after ACL reconstruction. Studies that evaluated patients undergoing primary ACL reconstruction with an autograft, allograft, or combination of autograft and allograft and reported the number of postoperative infections by graft type utilized were considered for inclusion. Studies were excluded if they included revision ACL reconstruction or did not specify the number of infections by graft type. Study findings were reviewed, and meta-analysis was performed when data were sufficiently homogeneous.

RESULTS

Twenty-one studies meeting criteria were identified from the literature review. Meta-analysis revealed a significant difference in the incidence of deep infections between BPTB autografts and hamstring autografts, with the BPTB group displaying a 77% lower incidence of infections compared with the hamstring group (relative risk [RR], 0.23; 95% CI, 0.097-0.54). The incidence of infections was 66% lower with BPTB autografts compared with all other graft types, with a pooled RR of 0.33 (95% CI, 0.15-0.71). There was no significant difference in the incidence of infections after ACL reconstruction with autografts compared with allografts (RR, 1.035; 95% CI, 0.589-1.819).

CONCLUSION

The findings of this meta-analysis demonstrate a significantly lower incidence of deep infections after ACL reconstruction with BPTB autografts compared with hamstring autografts but not compared with allografts.

CLINICAL RELEVANCE

Although the overall infection rate after ACL reconstruction is relatively low, the significantly higher rate of infections with hamstring autografts compared with BPTB autografts should be a consideration when discussing graft choices for ACL reconstruction.

Variance in Anterior Cruciate Ligament Reconstruction Graft Selection based on Patient Demographics and Location within the Multicenter Orthopaedic Outcomes Network Cohort

The purpose of this study is to determine whether any regional or age-related patterns exist in graft choice for patients undergoing primary anterior cruciate ligament reconstruction (ACLR) within a large multicenter consortium. A retrospective cohort study was performed using data collected from the Multicenter Orthopaedic Outcomes Network (MOON) on patients having undergone primary ACLR. Patients were stratified by age group (younger than 20, 20-29, 30-39, 40-49, and 50+ years) and four demographic regions (Midwest, Southeast, Northeast, and West). A total of 2,149 patients (1,288 males, 861 females) were included. At least 70% of the patients were treated by a single surgeon in three of the four demographic regions. There were no clinically significant differences in body mass index (BMI), and no statistically significant differences in Marx activity rating scale (p > 0.05) between regions within any particular age group. There were significant differences in the proportion of autografts versus allografts used for primary ACLR between regions in every age group (p < 0.01). There were also significant differences in autograft (p < 0.001) and allograft (p < 0.001) harvest location based on demographic region. The Southeast and Northeast were more likely to use bone-patellar-tendon-bone autograft while the West and Midwest were likely to use hamstring autograft. Within our consortium, regional patterns exist both in autograft versus allograft use in patients undergoing primary ACLR, as well as harvest location of autografts and allografts. Given the similarities in average patient BMI and activity level between regions, as well as the single surgeon influence in three of the four regions, the regional patterns in graft use are likely due to surgeon preference.

[The time-related risk for knee osteoarthritis after ACL injury. Results from a systematic review]

AIM

The aim of this review was to evaluate the time-related risk for knee osteoarthritis in patients after ACL injury.

MATERIALS AND METHODS

The primary search was carried out in different medical databases with the deadline 12.01.2014. The search strategy for the evaluation was [ACL] AND [osteoarthritis] including "all fields". All 1656 title/abstracts were reviewed by two independent researchers who selected 140 papers for full text review. Finally, a total of 21 relevant publications were identified for inclusion in this current paper.

RESULTS

The incidence of knee osteoarthritis rises significantly over time. Two years after injury it was 6.9%, after 5 years 32.2%, after 7 years 36.3%, and after 10 years 79.6%. At the same time, the crude relative risk of OA rises as the time interval since injury increases. The relative risk of OA has already doubled by 2 years after ACL injury). By 7 years it has increased fivefold and compared with OA status at the time of injury it is still increasing significantly after 10 years.

CONCLUSIONS

The ACL injury is a significant risk factor for the development of early-onset secondary knee osteoarthritis. Within 5 years of the injury the knee shows clear signs of osteoarthritis on MRI. However, these lesions are often not associated with any clinical signs. Knee osteoarthritis as a severe disease starts 8 years or later after the injury, when it requires treatment.

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.

Hamstring tendon autograft versus fresh-frozen tibialis posterior allograft in primary arthroscopic anterior cruciate ligament reconstruction: a retrospective cohort study with three to six years follow-up

INTRODUCTION

Selection of various grafts for anterior cruciate ligament (ACL) reconstructions have been employed in order to improve on stability and function of the knee. This study aimed to compare stability and function of the knee after ACL arthroscopic reconstruction by single-loop tibialis posterior (TP) allograft and four-strand hamstring tendon (HT) autograft.

MATERIALS AND METHODS

The retrospective cohort study included 104 patients in the TP group matched with 118 patients in the HT group in terms of demographic characteristics, associated meniscus injury, subjective and objective knee characteristics. All patients were followed up for at least three years with regards to mentioned criteria and time of return to former activities.

RESULTS

The mean (range) age of TP (88 males and 16 females) and HT (99 males and 19 females) groups was 34.4 (19-48) and 36.9 (20-51) years, respectively. Median (range) follow-up durations were 55 (37-71) and 56 (36-72) months, respectively. No significant differences were observed post-operatively, regarding subjective and objective evaluations. Additionally, time duration for return to former activity was similar in both groups. Post-operative paresthesia and numbness of medial aspect of the calf were observed for two months in eight patients of the HT group which persisted to the final visit in one case. No similar symptom was seen in the TP group.

CONCLUSION

In arthroscopic ACL reconstruction, fresh frozen doubled TP allograft compared to HT autograft was equally effective in restoring function and stability of knee, permitting return to former activities.

LEVEL OF EVIDENCE

Retrospective comparative, Level III.

Bone-Patellar Tendon-Bone Versus Soft-Tissue Allograft for Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To describe the outcomes of bone-patellar tendon-bone (BPTB) and soft-tissue allografts in anterior cruciate ligament (ACL) reconstruction with respect to graft failure risk, physical examination findings, instrumented laxity, and patient-reported outcomes.

METHODS

A search of the PubMed, Scopus, CINAHL (Cumulative Index to Nursing and Allied Health Literature) Complete, Cochrane Collaboration, and SPORTDiscus databases was performed. English-language studies with outcome data on primary ACL reconstruction with nonirradiated BPTB and soft-tissue allografts were identified. Outcome data included failure risk, physical examination findings, instrumented laxity measurements, and patient-reported outcome scores.

RESULTS

Seventeen studies met the inclusion criteria. Of these studies, 11 reported on BPTB allografts exclusively, 5 reported on soft-tissue allografts exclusively, and 1 compared both types. The comparative study showed no difference in failure risk, Lachman grade, pivot-shift grade, instrumented laxity, or overall International Knee Documentation Committee score between the 2 allograft types. Data from all studies yielded a failure risk of 10.3% (95% confidence interval [CI], 4.5% to 18.1%) in the soft-tissue group and 15.2% (95% CI, 11.3% to 19.6%) in the BPTB group. The risk of a Lachman grade greater than 5 mm was 6.4% (95% CI, 1.7% to 13.7%) in the soft-tissue group and 8.6% (95% CI, 6.3% to 11.2%) in the BPTB group. The risk of a grade 2 or 3 pivot shift was 1.4% (95% CI, 0.3% to 3.3%) in the soft-tissue group and 4.1% (95% CI, 1.9% to 7.2%) in the BPTB group.

CONCLUSIONS

One comparative study showed no difference in results after ACL reconstruction with nonirradiated BPTB and soft-tissue allografts. Inclusion of case series in the analysis showed qualitatively similar outcomes with the 2 graft types.

Autograft Versus Allograft in Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Randomized Controlled Trials and Systematic Review of Overlapping Systematic Reviews

PURPOSE

To compare autograft with allograft in anterior cruciate ligament reconstruction by conducting a meta-analysis of randomized controlled trials (RCTs) and a systematic review of overlapping systematic reviews.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched through June 28, 2014, to identify Level I and II evidence RCTs with a minimum follow-up of 2 years and systematic reviews that compared autograft with allograft in anterior cruciate ligament reconstruction. Both objective and subjective outcomes with respect to knee stability and function were meta-analyzed and summarized. The overall risk ratio (RR) or the weighted mean difference (WMD) was calculated using either a fixed- or random-effects model. The quality of evidence of the systematic review of overlapping systematic reviews was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

RESULTS

Nine RCTs and 10 systematic reviews were included. In general, statistically significant differences in favor of autograft were observed for clinical failure (RR, 0.47; P = .0007), the Lachman test (RR, 1.18; P = .03), the instrumented laxity test (WMD, -0.88; P = .004), and the Tegner score (WMD, 0.36; P = .004). When subgroup analyses were conducted based on whether irradiation was used, autograft achieved better clinical outcomes than irradiated allograft in terms of the Lysholm score, clinical failure, the pivot-shift test, the Lachman test, the instrumented laxity test, and the Tegner score. In addition, there were no significant differences between the autograft and nonirradiated allograft groups for all 8 indices. The final results of this systematic review of overlapping systematic reviews were in accordance with our meta-analysis.

CONCLUSIONS

Autograft had greater advantages than irradiated allograft with respect to function and stability, whereas there were no significant differences between autograft and nonirradiated allograft.

LEVEL OF EVIDENCE

Level IV, meta-analysis of Level II, III, and IV studies.

ANTERIOR CRUCIATE LIGAMENT INJURY: TREATMENT AND REHABILITATION. CURRENT PERSPECTIVES AND TRENDS

Objective: The aim of this study was to evaluate the procedures used by knee surgeons in Brazil for treating and rehabilitating anterior cruciate ligament injuries. Methods: A questionnaire consisting of 21 closed questions was developed, addressing topics relating to treatment and rehabilitation after anterior cruciate ligament reconstruction. The questionnaire was applied to Brazilian knee surgeons during the three days of the 42^nd Brazilian Congress of Orthopedics and Traumatology in 2010. Results: A total of 226 surgeons filled out the questionnaire completely. The most commonly used types of graft were hamstrings tendons and the central third of the ipsilateral patellar tendon, which were used by 82.3% and 53.5% of the sample, respectively. The technique of reconstruction with a single transtibial band was the first preference and was used by 66.4% of the participants. A period of 1 to 4 weeks between injury and surgical procedure was considered ideal by most participants (52.65%). Complaints from patients that the knee was ‘giving way’ or unstable and presence of a positive pivot shift maneuver were the most decisive factors considered in making the decision to operate the patient. Patient satisfaction and absence of complaints of instability during the postoperative period were the criteria deemed to be most important for the surgery to be considered a success. Conclusions: There are clearly evolving trends in treating and rehabilitating the anterior cruciate ligament in Brazil. However, more prospective controlled studies are needed in order to evaluate the clinical and scientific benefits of these trends.

A meta-analysis of anterior cruciate ligament reconstruction with autograft compared with nonirradiated allograft

BACKGROUND

To compare autograft with non-irradiated allograft for reconstruction of anterior cruciate ligament.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases, as well as unpublished and ongoing studies were searched through up to 20 July 2013 to identify studies meeting the pre-stated inclusion criteria.

RESULTS

A total of 12 studies (n=1167, including 597 patients in the autograft group and 570 patients in the allograft group) were included. The methodological scores for randomized controlled trials ranged from two to four (total score: seven), and for non-randomized prospective studies and cohort studies ranged from four to seven (total score: 12). Except for the Lysholm score (WMD, -1.46; P<0.05) showing a statistically significant difference but a small and clinically irrelevant difference, there was no significant difference between autograft and non-irradiated allograft with respect to the overall IKDC (International Knee Documentation Committee) level, subjective IKDC score, Tegner score, complication, ROM (range of motion), Pivot-shift test, Anterior drawer test, Lachman test, Daniel's one-leg hop test, Harner's vertical jump test, and Instrumented knee laxity test. The results were consistent across a series of sensitivity analyses and subgroup analyses.

CONCLUSIONS

Patients with autograft exhibited little clinical advantage over non-irradiated allograft with respect to knee stability, function and side effects. The robustness of the findings might need to be further validated due to the relatively small number of randomized controlled trials.

LEVEL OF EVIDENCE

Level II, meta-analysis of prospective studies.

A Systematic Review of Failed Anterior Cruciate Ligament Reconstruction With Autograft Compared With Allograft in Young Patients

CONTEXT

The advantages of allograft anterior cruciate ligament reconstruction (ACLR), which include shorter surgical time, less postoperative pain, and no donor site morbidity, may be offset by a higher risk of failure. Previous systematic reviews have inconsistently shown a difference in failure prevalence by graft type; however, such reviews have never been stratified for younger or more active patients.

OBJECTIVE

To determine whether there is a different ACLR failure prevalence of autograft compared with allograft in young, active patients.

DATA SOURCES

EMBASE, MEDLINE, Cochrane trials registry.

STUDY SELECTION

Comparative studies of allograft versus autograft primary ACL reconstruction in patients <25 years of age or of high-activity level (military, Marx activity score >12 points, collegiate or semiprofessional athletes).

STUDY DESIGN

Systematic review with meta-analysis.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Manual extraction of available data from eligible studies. Quantitative synthesis of failure prevalence and Lysholm score (outcomes in ≥3 studies) and I (2) test for heterogeneity. Assessment of study quality using CLEAR NPT and Newcastle-Ottawa Scale (NOS).

RESULTS

Seven studies met inclusion criteria (1 level 1; 2 level 2, 4 level 3), including 788 patients treated with autograft tissue and 228 with various allografts. The mean age across studies was 21.7 years (64% male), and follow-up ranged between 24 and 51 months. The pooled failure prevalence was 9.6% (76/788) for autografts and 25.0% (57/228) for allografts (relative risk, 0.36; 95% CI, 0.24-0.53; P < 0.00001; I (2) = 16%). The number needed to benefit to prevent 1 failure by using autograft was 7 patients (95% CI, 5-10). No difference between hamstrings autograft and patella tendon autograft was noted. Lysholm score was reported in 3 studies and did not differ between autograft and allograft.

CONCLUSION

While systematic reviews comparing allograft and autograft ACLR have been equivocal, this is the first review to examine young and active patients in whom allograft performs poorly.

Analysis of irradiation on the clinical effectiveness of allogenic tissue when used for primary anterior cruciate ligament reconstruction

BACKGROUND

It is unclear whether the use of low-dose irradiation or other tissue-processing methods, such as preservation by fresh-frozen (FF), freeze-drying (FD), or cryopreservation (CP) methods, affects the clinical outcomes of primary anterior cruciate ligament reconstruction (ACLR) using allograft.

HYPOTHESIS

Low-dose gamma irradiation (<2.5 Mrad) and method of allograft preservation do not affect subjective and objective clinical outcomes after primary ACLR in studies reviewed between November 2010 and September 2012.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

A computerized search of multiple electronic databases was conducted from November 2010 to September 2012 for prospective and retrospective studies involving primary allograft ACLR. Inclusion criteria were English-language publications with a minimum average of 2 years' follow-up. Studies were excluded if they involved revision surgery, open surgery, multiple ligament procedures, autograft, xenograft, meniscal allograft, skeletally immature patients, or grafts treated with ethylene oxide, Tutoplast, or irradiation>2.5 Mrad or if the tissue-processing methods were not specified. Clinical outcomes were evaluated using the Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) score, KT-1000/2000 arthrometer score, Lachman test, and pivot-shift test, as well as by assessing complications related to graft rupture, revision surgery, and infections.

RESULTS

A total of 21 publications met the criteria, involving a total of 1453 patients, with 415 irradiated and 1038 nonirradiated allografts. Mean follow-up was 49.8 months (range, 12-170 months). Mean age of the patients was 32.2 years. Knees with nonirradiated allografts had higher mean Lysholm scores (89.8 vs 84.4; P<.05), and a higher proportion of <5-mm difference on KT-1000/2000 arthrometer (0.97 vs 0.84; P<.0001), grade 0 and 1 pivot-shift (0.99 vs 0.94; P<.0001), and grade 0 and 1 Lachman (0.94 vs 0.89; P<.01) than those with irradiated grafts. Knees with irradiated allografts had a higher proportion of grade A and B IKDC outcomes (0.91 vs 0.86; P<.05) and revision surgery (0.0250 vs 0.0022; P<.001) compared with those with nonirradiated allografts. The lack of data for FD and CP allografts meant no statistical analysis could be made comparing FF versus FD versus CP allografts. The effect of irradiation was similar within FF allografts. The effect of graft type and surgical technique could not be determined because of insufficient data.

CONCLUSION

These results suggest that primary ACLRs using nonirradiated allografts may provide superior clinical outcomes than those using low-dose (<2.5 Mrad) irradiated grafts.

Myth busters: an AOA symposium: AOA critical issues

One of the goals of the annual American Orthopaedic Association (AOA) meeting is to address controversy, both in leadership and clinical practice. A panel of experts in their respective fields presented the background and literature behind three "myths" in orthopaedic management and made conclusions as to their validity. First, Dr. Kocher took on the myth of prophylactic pinning on the contralateral "normal" side for a patient with a slipped capital femoral epiphysis. Second, Dr. Probe evaluated the myth that all intertrochanteric fractures are best treated with intramedullary devices. Last, Dr. Foster and Dr. Silvestri tackled the myth that autograft is always the best choice for anterior cruciate ligament (ACL) reconstruction. All three of these topics are subjects of current debate. The panel's careful examination of the available data along with their expertise in the management of these problems is presented in this thought-provoking JBJS Critical Issues article.

Autograft versus nonirradiated allograft tissue for anterior cruciate ligament reconstruction: a systematic review

BACKGROUND

An autograft has traditionally been the gold standard for anterior cruciate ligament reconstruction (ACLR), but the use of allograft tissue has increased in recent years. While numerous studies have demonstrated that irradiated allografts are associated with increased failure rates, some report excellent results after ACLR with nonirradiated allografts. The purpose of this systematic review was to determine whether the use of nonirradiated allograft tissue is associated with poorer outcomes when compared with autografts.

HYPOTHESIS

Patients undergoing ACLR with autografts versus nonirradiated allografts will demonstrate no significant differences in graft failure risk, laxity on postoperative physical examination, or differences in patient-oriented outcome scores.

STUDY DESIGN

Systematic review.

METHODS

A systematic review was performed to identify prospective or retrospective comparative studies (evidence level 1, 2, or 3) of autografts versus nonirradiated allografts for ACLR. Outcome data included graft failure based on clinical findings and instrumented laxity, postoperative laxity on physical examination, and patient-reported outcome scores. Studies were excluded if they did not specify whether the allograft had been irradiated. Quality assessment and data extraction were performed by 2 examiners.

RESULTS

Nine studies comparing autografts and nonirradiated allografts were included. Six of the 9 studies compared bone-patellar tendon-bone (BPTB) autografts with BPTB allografts. Two studies compared hamstring tendon autografts to hamstring tendon allografts, and 1 study compared hamstring tendon autografts to tibialis anterior allografts. The mean patient age in 7 of 9 studies ranged from 24.5 to 32 years, with 1 study including only patients older than 40 years and another not reporting patient age. The mean follow-up duration was 24 to 94 months. Six of 9 studies reported clinical graft failure rates, 8 of 9 reported postoperative instrumented laxity measurements, 7 of 9 reported postoperative physical examination findings, and all studies reported patient-reported outcome scores. This review demonstrated no statistically significant difference between autografts and nonirradiated allografts in any outcome measure.

CONCLUSION

No significant differences were found in graft failure rate, postoperative laxity, or patient-reported outcome scores when comparing ACLR with autografts to nonirradiated allografts in this systematic review. These findings apply to patients in their late 20s and early 30s. Caution is advised when considering extrapolation of these findings to younger, more active cohorts.

Post-operative complications following primary ACL reconstruction using allogenic and autogenic soft tissue grafts: increased relative morbidity risk is associated with increased graft diameter

BACKGROUND

The purpose of this study is to compare the risk of peri-operative complication events associated with allogenic and autogenic grafts during routine follow-up for six months after primary arthroscopic anterior cruciate ligament (ACL) reconstruction surgery.

METHODS

A retrospective cohort study identified patients that underwent ACL reconstruction via an arthroscopically assisted single tunnel technique. Fixation was primarily cortical suspension (endobutton) from the femora and bicortical fixation (Washer-loc) in the tibia. Patients were monitored for six months following surgery. Morbidity was defined as complications during this period requiring medical or surgical intervention. Risk of complications was compared according to tissue type and patient characteristics. The Cochran-Mantel-Haenszel method was applied to estimate risk ratios (RR) and confidence intervals (CI) as the measure of association between graft type and morbidity risk.

RESULTS

The cohort included 413 eligible patients. Sixty six percent received allograft tissue, while the remainder received autograft tissue. Morbidity risk was 7.0% among patients receiving allograft tissue and 2.8% among patients receiving autograft tissue. Allograft demonstrated elevated risk of complication versus autograft (RR=2.3 (95% CI: 0.9-7.2)), though the data are of borderline significance (p=0.11). Complications were associated with larger graft diameter in comparison to patients who experienced no complication (9.0+/-1.2 mm v. 8.4+/-1.0mm, p=0.005).

CONCLUSION

The relative morbidity risk was about two-fold greater among patients receiving allograft tissue. Regardless of tissue type, graft size was larger among patients who experienced a complication.

LEVEL OF EVIDENCE

Level III.

Central-third bone-patellar tendon-bone allografts demonstrate superior biomechanical failure characteristics compared with hemi-patellar tendon grafts

BACKGROUND

Reconstruction of the anterior cruciate ligament (ACL) is commonly performed with a bone-patellar tendon-bone (BTB) allograft. However, grafts may result from harvesting the central region of a whole graft (C-BTB), the medial 10 mm of a lateral hemi-BTB (L-BTB) graft, or the lateral 10 mm of a medial hemi-BTB (M-BTB) graft.

PURPOSE

To quantify potential differences in graft biomechanical properties when comparing whole versus hemi-BTB grafts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten pairs of human BTB allografts (irradiated with 1.0-1.2 Mrad) were randomized to preparation as whole grafts or hemigrafts. From these, 10-mm grafts were prepared from the center or the most central portion, respectively. After measurements of tendon thickness, width, and length, specimens underwent cyclic tensile testing, followed by load-to-failure analysis. Biomechanical outcomes included cyclic elongation and creep strain along with the following failure characteristics: maximum load, elongation at maximum load, maximum stress, strain at maximum stress, and linear stiffness.

RESULTS

Regionally, the mean thickness of the C-BTB (5.18 ± 0.75 mm), M-BTB (5.08 ± 0.56 mm), and L-BTB (5.32 ± 0.62 mm) grafts were comparable (P > .72). Similarly, the mean length of the C-BTB (47.4 ± 6.73 mm), M-BTB (47.0 ± 5.45 mm), and L-BTB (50.7 ± 6.42 mm) grafts were alike (P > .43). While differences in cyclic elongation and strain were not significant, the M-BTB graft tended to elongate more (0.204 ± 0.13 mm; P = .075) and experience greater strain (0.56% ± 0.32%; P = .054) compared with the C-BTB graft (0.09 ± 0.03 mm and 0.23% ± 0.07%, respectively). Load-to-failure testing demonstrated a higher maximum load (2293 ± 531 N) and stiffness (356 ± 46 N/mm) of the C-BTB graft as compared with the M-BTB graft (1575 ± 325 N [P < .007] and 275 ± 37 N/mm [P < .008], respectively) and L-BTB graft (1585 ± 452 N [P < .008] and 277 ± 65 N/mm [P < .009], respectively). No differences were noted with respect to elongation or stress at maximum load among the grafts. Maximum stress in the C-BTB graft (45.4 ± 11.5 MPa) was greater than in the L-BTB graft (29.7 ± 10.6 MPa) (P < .03) and tended to be greater than the M-BTB graft (34.1 ± 6.27 MPa) (P = .087).

CONCLUSION

Biomechanical failure properties (maximum load, stress, and stiffness) of the central portion of a whole BTB graft are superior to those of the medial portion of a lateral hemi-BTB graft and the lateral portion of a medial hemi-BTB graft. However, cyclic loading characteristics did not differ between grafts.

CLINICAL RELEVANCE

Although the true central-third BTB graft is biomechanically superior to hemi-BTB grafts, future studies are necessary to determine if the use of hemigrafts leads to an increased incidence of clinical failure.

Transtibial versus independent drilling techniques for anterior cruciate ligament reconstruction: a systematic review, meta-analysis, and meta-regression

BACKGROUND

While numerous cadaveric, in vivo, and clinical studies have compared transtibial and independent drilling of femoral tunnels during anterior cruciate ligament reconstruction, there is no evidence-based consensus on which technique affords the best outcome.

HYPOTHESIS

There is no difference in clinical outcome between transtibial and independent drilling of femoral tunnels.

STUDY DESIGN

Systematic review with meta-analysis and meta-regression.

METHODS

Cadaveric, in vivo, and clinical studies comparing transtibial and independent drilling techniques were systematically identified. A qualitative synthesis of nonrandomized studies and meta-analysis of randomized controlled trials (RCTs) were performed. In addition, a meta-regression analysis of RCTs that did not directly compare drilling techniques was performed.

RESULTS

A total of 49 studies were included in the qualitative review, and 15 were included in the meta-analysis; 22 studies were included in the meta-regression. In biomechanical studies, independent drilling placed the center of the femoral tunnel closer to the center of the femoral footprint (mean difference, 2.69 mm; 95% CI, 0.46-4.92; P < .00001). Independent drilling reduced anterior tibial translation with the Lachman examination (mean difference, 2.2 mm; 95% CI, 0.34-4.07; P = .02), 134 N of anterior load (mean difference, 1 mm; 95% CI, 0.29-1.71; P = .006), and simulated pivot shift (mean difference, 3.36 mm; 95% CI, 1.88-4.85; P < .00001). The meta-analysis showed improved Lysholm scores with independent drilling (mean difference, -0.62 points; 95% CI, -1.09 to -0.55; P = .009), although the clinical relevance of this small difference is questionable. There were no significant differences in International Knee Documentation Committee (IKDC) objective scores or Tegner scores between groups. With the meta-regression, there were no significant differences in failure rates or IKDC objective scores.

CONCLUSION

While there are biomechanical data suggesting improved knee stability and more anatomic graft placement with independent drilling, no significant clinical differences were found between the 2 techniques.

CLINICAL RELEVANCE

The current evidence shows that transtibial and independent drilling techniques have equivalent clinical outcomes at short-term to midterm follow-up. The long-term effects of subtle differences in tunnel position and postoperative knee kinematics should be further studied in dedicated, prospective cohort and randomized studies.

Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: a meta-analysis of 5182 patients

BACKGROUND

Bone-patellar tendon-bone (BPTB) is a common autograft and allograft source used for anterior cruciate ligament (ACL) reconstruction. Although the failure rate is generally higher for allografts, donor site morbidity and anterior knee pain can be issues with BPTB autografts. Controversy exists regarding the functional outcomes, complications, and knee stability of these grafts, previous comparisons of which have been based on smaller samples of case series.

PURPOSE

To compare BPTB autografts to allografts for ACL reconstruction, specifically with regard to patient satisfaction, return to preinjury activity level, and postoperative functional outcomes.

STUDY DESIGN

Meta-analysis.

METHODS

A total of 76 studies published between 1998 and 2012, including a total of 5182 patients, were reviewed. It was not required for studies to be comparative in nature. Outcomes evaluated were graft rupture rate, return to preinjury activity level, overall and subjective International Knee Documentation Committee (IKDC), Lysholm, Tegner activity, Cincinnati Knee Rating System, pivot shift, and single-legged hop tests, as well as KT-1000 arthrometer side-to-side difference and presence of anterior knee pain. Summary odds ratios with 95% confidence intervals were calculated to compare BPTB autografts to allografts for each outcome.

RESULTS

Outcomes on subjective IKDC, Lysholm, Tegner, single-legged hop, and KT-1000 arthrometer were statistically significantly in favor of autografts. Return to preinjury activity level, overall IKDC, pivot shift, and anterior knee pain were significantly in favor of allografts, although allograft BPTB demonstrated a 3-fold increase in rerupture rates compared with autograft (12.7% vs 4.3%). There was no significant difference between the 2 groups for Cincinnati Knee scores.

CONCLUSION

Patients undergoing ACL reconstruction with BPTB autografts demonstrate lower rates of graft rupture, lower levels of knee laxity, and improved single-legged hop test results and are more generally satisfied postoperatively compared with patients undergoing reconstruction with allograft BPTB.

Arthroscopic single-bundle ACL reconstruction with modified double-layer bone-patellar tendon-bone allograft

PURPOSE

The objective of present study was to introduce a modified double-layer bone-patellar tendon-bone (BPTB) allograft for arthroscopic single-bundle ACL reconstruction and investigate the clinical outcomes.

METHODS

From 2007 to 2009, a total of 136 patients underwent arthroscopic single-bundle ACL reconstructions with BPTB allograft. Of which, 66 patients were with double-layer BPTB allograft (Group 1), and 70 patients were with conventional BPTB allograft (Group 2). Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and Lysholm and Tegner activity scores were compared between the two groups at a 2-year minimum follow-up.

RESULTS

Forty-six patients in each group were at a two-year minimum follow-up. The mean side-to-side difference on the KT-1000 arthrometer was 1.2 ± 1.2 mm for group 1 and 2.1 ± 1.9 mm for group 2, with significant difference between the two groups (p = 0.017). The knee function was significantly better for group 1 than for group 2, because the mean Lysholm score was 94.2 ± 4.8 points versus 86.6 ± 7.1 points (p = 0.000), and the median Tegner score was 8 (range 5-10) points versus 6 (range 4-10) points (p = 0.001).

CONCLUSIONS

On the basis of the KT-1000 arthrometer evaluation and clinical measures, single-bundle ACL reconstruction with double-layer BPTB allograft achieves significantly lesser anterior laxity and better knee function than a single-layer allograft reconstruction.

LEVEL OF EVIDENCE

Therapeutic, retrospective comparative study, Level III.

Risk factors for recurrent anterior cruciate ligament reconstruction: a population study in Ontario, Canada, with 5-year follow-up

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is routinely performed for symptomatic instability. Although it is a common procedure, there remain differences in surgical technique. Hospital administrative records in a public health care system were used to investigate the effect of patient, provider, and surgical factors on the risk of revision ACLR.

PURPOSE

To define the rate and risk factors for ACL reoperation in Ontario, Canada, including both ipsilateral revision and contralateral primary procedures.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All primary elective ACLR procedures performed in Ontario (July 2003 to March 2008) in patients aged 15 to 60 years were identified via physician billing and hospital databases. Revision and contralateral ACLR were sought until January 2012. Patient factors (age, sex, comorbidity, income quintile, length of index hospital admission), provider factors (surgeon volume, academic hospital status), and surgical factors (allograft vs autograft; fixation type [screw, button, staple]; concomitant operative procedures) were used as covariates in a Cox proportional hazards survivorship model to generate hazard ratios (HRs) with confidence intervals (CIs) (α = .05). Kaplan-Meier survivorship curves with ACL revision as the end point were generated.

RESULTS

A total of 12,967 ACLR procedures with a mean follow-up of 5.2 years were eligible for study using preset criteria. The revision rate was 2.6% (mean ± SD, 2.91 ± 1.71 years to revision). The rate of primary contralateral ACLR was 4.6% (mean, 2.95 ± 1.81 years). In the Cox model, younger age (15-19 years) (HR, 2.1; 95% CI, 1.5-2.9; P < .001), ACLR performed at an academic hospital (HR, 1.6; 95% CI, 1.2-2.1; P < .001), and the use of allograft (HR, 1.7; 95% CI, 1.1-2.6; P = .02) significantly increased the risk of revision ACLR. Only younger age (HR, 2.1; 95% CI, 1.6-2.7; P < .001) was associated with an increased risk of contralateral ACLR.

CONCLUSION

Contralateral ACLR was more frequent than revision ACLR in this population, while both surgical procedures were most common in patients younger than 20 years. Academic hospital status, but not surgeon volume, as well as the use of allograft also increased the risk for revision ACLR.

To study the incidence of heterotopic ossification after anterior cruciate ligament reconstruction

INTRODUCTION

Previous studies have enumerated the advantages of an arthroscopic Anterior Cruciate Ligament (ACL) reconstruction with the use of a Bone Patellar Tendon Bone (BPTB) graft. Complications are extremely rare in such surgeries and one such known complication, which is an extra-articular heterotophic ossification at the femoral tunnel site, is rarely seen only in few patients.

AIM

To evaluate the incidence of heterotrophic ossifications at the femoral tunnel site and the efficacy of the preventive measures which were undertaken, in patients who had undergone ACL reconstructions with the use of bone patellar tendon bone grafts.

MATERIAL AND METHODS

A total of 285 patients who had ACL tears within a duration of six years, were evaluated prospectively for the incidence of heterotrophic ossifications after they underwent arthroscopic reconstructions with the use of bone patellar tendon bone grafts by the double incision technique. The effect of the efficacy of various preventive measures on the incidence of the heterotophic ossifications post surgery was also studied.

RESULTS

The observed incidence of the heterotophic ossifications was 2.58% in patients whom preventive measures were not used. In contrast, an incidence of 1.54% of similar complications was recorded, after preventive measures were undertaken. Our results showed that heterotophic ossifications after arthroscopic reconstructions with the use of bone patellar tendon bone grafts were a rare complication and that their incidence could be further reduced if preventive measures were taken.

CONCLUSION

The heterotophic ossification is a rare complication after an ACL reconstruction is done with the use of a bone patellar tendon bone graft by the double incision technique. Its incidence reduces significantly after preventive measures are undertaken.

Reconstruction of the anterior cruciate ligament: association of graft choice with increased risk of early revision

We examined the association of graft type with the risk of early revision of primary anterior cruciate ligament reconstruction (ACLR) in a community-based sample. A retrospective analysis of a cohort of 9817 ACLRs recorded in an ACLR Registry was performed. Patients were included if they underwent primary ACLR with bone-patellar tendon-bone autograft, hamstring tendon autograft or allograft tissue. Aseptic failure was the main endpoint of the study. After adjusting for age, gender, ethnicity, and body mass index, allografts had a 3.02 times (95% confidence interval (CI) 1.93 to 4.72) higher risk of aseptic revision than bone-patellar tendon-bone autografts (p < 0.001). Hamstring tendon autografts had a 1.82 times (95% CI 1.10 to 3.00) higher risk of revision compared with bone-patellar tendon-bone autografts (p = 0.019). For each year increase in age, the risk of revision decreased by 7% (95% CI 5 to 9). In gender-specific analyses a 2.26 times (95% CI 1.15 to 4.44) increased risk of hamstring tendon autograft revision in females was observed compared with bone-patellar tendon-bone autograft. We conclude that allograft tissue, hamstring tendon autografts, and younger age may all increase the risk of early revision surgery after ACLR.

Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts

PURPOSE

Allograft anterior cruciate ligament (ACL) reconstruction obviates donor site morbidity and may accelerate postoperative recovery. However, allograft use can lead to increased rates of surgical failure, particularly when chemical processing or irradiation is used. Few studies have rigorously evaluated the comparative outcomes of autografts and fresh-frozen allograft tissue for ACL reconstruction.

METHODS

We performed a PubMed search to identify and systematically evaluate outcomes of autograft and non-chemically treated non-irradiated allograft tissue in ACL reconstruction between 1980 and 2012. We included studies with Level of evidence of I to III, determinate graft treatment, a minimum of 25 patients per treatment arm, a minimum 2-year follow-up, and selected subjective and objective outcome measures.

RESULTS

After the exclusion of 585 citations, we isolated 11 studies for further review. All patients showed improvement in clinical outcome measures and knee stability end points from injury to definitive surgical management. No statistically significant differences were detected between autografts and non-chemically processed non-irradiated allografts in Lysholm scores, International Knee Documentation Committee (IKDC) scores, Lachman examinations, pivot-shift testing, KT-1000 measurements, or failure rates.

CONCLUSIONS

Further large-scale, well-designed studies are required to better evaluate the comparative outcomes after fresh-frozen allograft ACL reconstruction. The current study suggests that the results after autograft ACL reconstruction are comparable to those using non-chemically processed nonirradiated allograft tissue.

LEVEL OF EVIDENCE

Systematic review of Level I to III studies.

A review of anterior cruciate ligament injuries and reconstructive techniques. Part 2: Treatment

The aims of treatment of anterior cruciate ligament rupture are to eliminate pain, restore stability and allow early return to activity while preventing early degeneration. Ruptures can be treated conservatively, which requires careful patient selection and avoidance of high-risk activity. Each patient must be treated on an individual basis with consideration given to the level of activity, desire to return to sport, donor site morbidity and compliance with post-operative regimes. Through the evolution of single incision, arthroscopic anatomic reconstruction, our knowledge of the native anterior cruciate ligament anatomy and knee kinematics has progressed. The current gold standard uses four-stranded hamstring autograft with endobutton and interference screw fixation. Double-bundle reconstruction is technically challenging with greater risk and best reserved for larger knees with larger native ligaments. Although treatment has advanced considerably over the years, there are still a number of contentious issues which are considered in this review. Part two of this review discusses the short- and long-term objectives of surgery, the indications and timing of surgery, different graft materials, tunnel positions and rehabilitation programmes. We also evaluate the role of anatomical reconstruction and single- versus double-bundle anterior cruciate ligament reconstructions.

The biomechanical effects of 1.0 to 1.2 Mrad of γ irradiation on human bone-patellar tendon-bone allografts

BACKGROUND

Recent data suggest that anterior cruciate ligament (ACL) reconstruction with irradiated allograft tissue may lead to increased failure rates.

HYPOTHESIS

Low-dose (1.0-1.2 Mrad) gamma irradiation does not significantly alter the preimplantation biomechanical properties of bone-patellar tendon-bone (BTB) allografts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Cyclic and failure mechanical properties were evaluated for 20 paired central-third human BTB allografts, with and without 1.0 to 1.2 Mrad of gamma irradiation. Testing included cyclic loading at 0.5 Hz for 100 cycles from 50 to 200 N and failure testing at a strain rate of 10% per second.

RESULTS

Cyclic elongation did not change significantly (P = .151) with irradiation, increasing from a mean ± SD of 9.4 ± 2.1 mm to 11.3 ± 3.4 mm. Cyclic creep strain approached a significant increase with irradiation (1.3% ± 0.8% to 2.6% ± 1.5%; P = .076). Failure testing was not affected with irradiation with regard to maximum load (1680 ± 417 mm to 1494 ± 435 mm), maximum stress (40.8 ± 10.6 MPa to 37.5 ± 15.7 MPa), elongation (7.85 ± 1.35 mm to 8.67 ± 2.05 mm), or strain at maximum stress (0.158 ± 0.03 to 0.175 ± 0.03). Graft stiffness significantly decreased by 20% with irradiation (278 ± 67 N/mm to 221 ± 50 N/mm; P = .035).

CONCLUSION

Low-dose (1.0-1.2 Mrad) gamma irradiation decreases BTB graft stiffness by 20%, but it does not affect other failure or cyclic parameters.

CLINICAL RELEVANCE

Aside from graft stiffness during load to failure testing, low-dose (1.0-1.2 Mrad) gamma irradiation of central-third human BTB allografts is not deleterious to preimplantation biomechanical properties.

Long-term results of arthroscopically assisted anatomical single-bundle anterior cruciate ligament reconstruction using patellar tendon autograft: are there any predictors for the development of osteoarthritis?

PURPOSE

The primary purpose of our study was to analyse the long-term outcome of patients treated for anterior cruciate ligament (ACL) tears by anatomical single-bundle ACL reconstruction with patellar tendon autograft. The secondary purpose was to identify predictive factors for good outcome and occurrence of osteoarthritis.

METHODS

Sixty-three patients (m:f = 54:9; mean age at surgery, 27 ± 7 years) treated by ACL reconstruction were evaluated with a mean follow-up of 16 ± 1 years using IKDC2000, the SF36, Lysholm and Tegner score, Knee Society score, visual analogue scale for pain and satisfaction and KOOS. The femoral tunnel position was evaluated according to Sommer. It was also assessed in percentage of the Blumensaat line and the tibial tunnel position in percentage of the total anterior-posterior plateau length. The extent of osteoarthritis was graded according to the Kellgren-Lawrence score.

RESULTS

The total IKDC2000 was normal in 20 (32 %), nearly normal in 29 (46 %), abnormal in 12 (19 %) and severely abnormal in 3 (5 %) of patients. The mean total SF-36 was 89 ± 13, the Lysholm score 95 ± 12, the Knee Society score 191 ± 16 and the total KOOS 84 ± 19. The Tegner score decreased from pre-injury 7(4-10) to 6 (2-10) at follow-up. The Kellgren-Lawrence score was normal in 17 (27 %), suspected osteoarthritis in 25 (40 %), minimal osteoarthritis in 5 (8 %), moderate osteoarthritis in 9 (14 %) and severe osteoarthritis in 3 patients (5 %). The femoral tunnel was in zone A in 43 patients (68 %), in zone B in 16 (25 %) and in zone C in 4 patients (7 %). The femoral tunnel position in percentage of the Blumensaat line was 49 ± 3 (range, 44-57), and the tibial tunnel position in percentage of the total anterior-posterior plateau length was 32 ± 6 (range, 21-46). Patients with meniscal lesion at the time of ACL tear showed significantly less favourable outcomes than those without.

CONCLUSIONS

Patients treated by the proposed ACL reconstruction technique showed on average good to excellent long-term results. A meniscal lesion at the time of ACL tear was highly predictive for less favourable outcome.

Ligamentous injuries of the knee: anterior cruciate, medial collateral, posterior cruciate, and posterolateral corner injuries

This article discusses athletic injuries of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and posterolateral corner. Best evidence to date validates that conservative management of ACL ruptures is a reasonable strategy. Current data also seem to advocate nonoperative management of PCL injuries. All isolated MCL injuries, regardless of grade, are usually treated with a brief period of immobilization and symptomatic management. Although the surgical literature often advocates surgical treatment of posterolateral corner injuries, there have been no randomized trials substantiating that these injuries are best treated surgically.

Single-bundle anterior cruciate ligament reconstruction in active young men using bone-tendon achilles allograft versus free tendon achilles allograft

PURPOSE

The purpose was to prospectively compare the outcomes of anterior cruciate ligament (ACL) reconstruction using bone-tendon Achilles allograft with those of free tendon Achilles allograft in 2 groups of active young men.

METHODS

We enrolled 72 subjects in the study. Of these, 33 subjects who had ACL reconstruction with Achilles allograft with calcaneal bone block on its end (group I) and 34 who had ACL reconstruction with free tendon Achilles allograft (group II) were followed up for a minimum of 2 years. The Lachman test, pivot-shift test, and 1-leg hop test were evaluated at the last follow-up. The International Knee Documentation Committee classification, Lysholm score, and side-to-side difference were assessed preoperatively and at the last follow-up. The Tegner activity scale was evaluated before injury and at the last follow-up.

RESULTS

The mean follow-up period was 30.9 months (range, 26 to 38 months). At the last follow-up, there were no statistically significant differences between the 2 groups for the Lachman test, pivot-shift test, 1-leg hop test, International Knee Documentation Committee classification, Lysholm score, and side-to-side difference (P > .05). Three subjects in group I and three in group II showed an activity level 2 steps below the preinjury activity level. The rest of the subjects returned to the preinjury activity level or showed a level 1 step below the preinjury activity level.

CONCLUSIONS

There were no significant differences in clinical outcomes of ACL reconstructions using Achilles allograft between the bone-tendon group and the free tendon group in active young men. Free tendon Achilles allograft may be considered an option for ACL reconstruction.

LEVEL OF EVIDENCE

Level II, therapeutic study, randomized controlled trial.