Do graft diameter or patient age influence the results of ACL reconstruction?

Comparative study of Peroneus longus tendon autograft versus Hamstring tendon autograft in arthroscopic anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study is to compare the functional outcomes and donor site morbidities after anterior cruciate ligament reconstruction (ACLR) using peroneus longus (PL) tendon versus hamstring (HST) tendon autografts.

METHODS

The PL tendon autograft was used for ACLR in 36 patients, and in another group, ACLR was performed using the HST tendon autograft in 35 patients between September 2022 and April 2023. The knee functional outcomes were evaluated using the International Knee Documentation Committee (IKDC) and the Lysholm scores at preoperative and at 18 months following ACLR. In addition, the autograft diameter was measured intraoperatively in both groups. Ankle joint donor site morbidities were estimated using the American Orthopedic Foot and Ankle Score (AOFAS) in the PL autograft group.

RESULTS

A total of 71 patients, who underwent ACLR, were assessed with a minimum follow-up of 18 months (range 18-20 months). The diameter of the PL tendon autograft was significantly greater than that of the HST tendon autograft (P < 0.001). No significant differences were found in the functional outcomes between both groups at 18 months follow-up. Evaluation of the AOFAS showed no significant ankle joint dysfunction in the PL tendon autograft group.

CONCLUSIONS

PL tendon autograft can be used as a safe and effective autograft choice for ACLR with excellent functional outcomes comparable to HST tendon autograft and minimal donor site morbidity.

LEVEL OF EVIDENCE

Level II, Prospective randomized comparative study.

A tight anterosuperior intercondylar notch may increase the risk of cyclops syndrome after anterior cruciate ligament reconstruction using a quadruple semi-tendinosus short autograft

BACKGROUND

Cyclops syndrome is loss of terminal knee extension caused by a fibrous nodule developed in the anterior intercondylar notch. The many known risk factors include preoperative motion-range limitation, tibial tunnel malposition, and tight hamstrings. The primary objective of this study was to assess whether intercondylar notch size was associated with the risk of cyclops syndrome or graft tear after anterior cruciate ligament (ACL) reconstruction using a quadruple semi-tendinosis autograft. The secondary objective was to determine whether intercondylar notch size was associated with functional outcomes.

HYPOTHESIS

A narrow intercondylar notch is associated with higher risks of cyclops syndrome and poor functional outcomes.

METHODS

Consecutive patients who underwent ACL reconstruction by quadruple semi-tendinosus autograft were included retrospectively. Preoperative magnetic resonance imaging scans were assessed by a single senior surgeon, who determined the conventional notch width index (NWI) and the anterior NWI (aNWI) for each patient.

RESULTS

The 120 included patients had a mean follow-up of 2.4±0.8 years. Among them, 20 (16.7%) experienced cyclops syndrome and 7 (5.8%) graft rupture. At last follow-up, 26 (21.7%) had not returned to sports and only 47 (39.2%) had returned to sports at the pre-injury level. The mean Lysholm score was 87.9±13.5 and the main subjective IKDC score was 84±13. A narrow notch was significantly associated with lower likelihoods of returning to sports (p=0.001), returning to the same sport (p<0.0001), and returning to the pre-injury sport level (p=0.004). By multivariate analysis, only the aNWI index was significantly associated with the risk of cyclops syndrome (p<0.0001). An aNWI index lower than 0.18 had 85% sensitivity and 78% specificity for predicting cyclops syndrome.

CONCLUSION

A narrow anterosuperior intercondylar notch may increase the risk of cyclops syndrome after ACL reconstruction using a quadruple semi-tendinosus graft but is not associated with the risk of graft rupture.

LEVEL OF EVIDENCE

IV, retrospective observational cohort study.

Remnant Preservation Anterior Cruciate Ligament Reconstruction: Modified All-Inside Technique With Appendiceal Tibial Tunnel

The number of anterior cruciate ligament (ACL) ruptures treated arthroscopically has increased. In most cases, the rupture of the ligament occurs in the femoral attachment, leaving a robust stump attached to the tibia. ACL reconstruction with stump preservation might have some advantages: rapid reinnervation and revascularization of the graft. Most techniques have used an interference screw in tibial fixation, which could be more difficult to achieve the graft diameter within 8 to 10 mm in most situations. Therefore, we describe a technique for modified "all-inside" ACL reconstruction with remnant preservation using an appendiceal tibial tunnel to optimize the graft size. After tunnel drilling in anatomic positions, the ACL stump is bored centrally up to the diameter of the graft to be passed. After passing the graft from the tibial tunnel to the remnant to the femoral tunnel, adjustable loops are used to fix the femoral side and the tibial side by an appendiceal tibial tunnel.

High flexion femoral side remnant preservation positioning technique: a new method for positioning the femoral tunnel in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to find a new method for femoral side preservation positioning in anterior cruciate ligament (ACL) reconstruction and test the accuracy and precision of this method.

METHOD

Fifty patients with isolated ACL rupture (42 males and 8 females) who underwent single-bundle ACL reconstruction in our hospital between July 2022 and July 2023 were included. The lowest point of the cartilage margin of the lateral wall of the intercontinental fossa and the tibial plateau plumb line at 120° of knee flexion were used as the anatomical landmarks for positioning of the femoral tunnel for ACL reconstruction surgery. Femoral side remnant preservation was performed in all cases. Three-dimensional CT was performed 3 days postoperatively to collect the data, which were analyzed using Mimics 21.0 software. We measured the posterior cortical distance of the femoral condyle at 90° of knee flexion and the vertical distance from the center of the bone tunnel to the cortical extension line behind the femur. All femoral tunnel positions were marked on a 4 × 4 grid and visualized using the quadrant method.

RESULTS

Using the new positioning method in 50 knees, the average distance of x was 25.26 ± 2.76% of t and the average distance of y was 23.69 ± 6.19% of h. This is close to the results of previous studies, where x was 24.2 ± 4.0% of t and the average distance of y was 21.6 ± 5.2% of h. Most femoral tunnel positions were located in the same area. The D values were distributed as follows: 60% in the range of 0 to 2 mm, 24% in the range of 2 to 4 mm, and 16% more than 4 mm. The E values were distributed as follows: 80% in the range of 0 to 4 mm and 20% more than 4 mm.

CONCLUSION

In arthroscopic ACL reconstruction, the knee was flexed at 120° and the lowest point of the cartilage edge of the lateral wall of the intercondylar fossa and the tibial plateau plumb line were used as anatomical landmarks for the positioning of the femoral bone tunnel, which resulted in more accurate femoral bone tunnel positioning, better reproducibility, and better preservation of the femoral stump compared to traditional positioning methods.

Estimation Failure Risk by 0.5-mm Differences in Autologous Hamstring Graft Diameter in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

BACKGROUND

Because grafts are made in 0.5-mm increments clinically for anterior cruciate ligament (ACL) reconstruction, it is important to clarify how the failure rate decreases as the diameter increases. Moreover, it is important to know whether even a slight increase in the graft diameter decreases the risk of failure.

HYPOTHESIS

The risk of failure decreases significantly with each 0.5-mm increase in hamstring graft diameter.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

The systematic review and meta-analysis have estimated the diameter-specific failure risk for each 0.5-mm increase in ACL reconstruction using autologous hamstring grafts. We searched for studies describing the relationship between graft diameter and failure rate published before December 1, 2021, in leading databases, such as PubMed, EMBASE, Cochrane Library, and Web of Science, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies using single-bundle autologous hamstring grafts to investigate the relationship between failure rate and graft diameter of 0.5-mm intervals with >1-year follow-up. Then, we calculated the failure risk caused by 0.5-mm differences in autologous hamstring graft diameter. Assuming Poisson distribution for the statistical model, we employed an extended linear mixed-effects model in the meta-analyses.

RESULTS

Five studies containing 19,333 cases were eligible. The meta-analysis revealed that the estimated value of the coefficient of diameter in the Poisson model was -0.2357 with a 95% CI of -0.2743 to -0.1971 (P < .0001). With every 1.0-mm increase in diameter, the failure rate decreased by 0.79 (0.76-0.82) times. In contrast, the failure rate increased by 1.27 (1.22-1.32) times for each 1.0-mm decrease in diameter. The failure rate significantly decreased with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm from 3.63% to 1.79%.

CONCLUSION

The risk of failure decreased correspondingly with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm. Failure is multifactorial; however, increasing the graft diameter as much as possible to match each patient's anatomic space without overstuffing is an effective precaution that surgeons can take to reduce failures.

Application of the 3D-MRI on post-operative graft assessment in adolescent patients with ACL reconstruction: A minimal 2-year follow-up

Background

The purpose of the present study was to assess the prognostic morphological changes of the reconstructed hamstring auto-grafts by using reconstructed three-dimensional MRI (3D-MRI) in adolescent patients with ACLR.

Methods

22 adolescent patients (less than 17 years old) were retrospective included between January 1, 2018, and October 31, 2020, in our department. The patients were divided into 2 subgroups: subgroup A (<14 years old) and subgroup B (≥14 years old). 3D-MRI was used to detect the total cross-sectional area (TCA) and long-to-short axis (LSA) ratio of the reconstructed ACL graft at the proximal, mid-point, and distal regions. The minimal follow-up was 2 years.

Results

The averaged follow-up of subgroup A and B was 37.8 ± 5.6 and 37.6 ± 6.5 months, respectively. Comparing to the initial graft (ACLR operation), the TCA of reconstructed ACL was increased by 30.6% on average, and the TCAs at proximal, mid-point, and distal regions were increased by 56.4%, 50.0%, and 17.7%, respectively, inner-group comparisons showed that the TCAs of the 3 region in subgroup A were all increased at the follow-up (P = 0.002) (P < 0.001) (P < 0.001), however, only increased mid-point (P = 0.024) and distal TCAs (P < 0.001) were found in subgroup B. Comparing to the native ACL, the proximal LSA ratio in subgroup A was comparable, while it was lower in subgroup B than the native ACL (P = 0.004), the distal LSA ratios in the 2 subgroups were both lower than the native ACL (P = 0.004) (P = 0.006).

Conclusions

3D-MRI assessment can exactly identify the morphological changes of the graft in adolescent patients with ACLR, the TCA of the constructed ACL was increased compared to the initial graft, however, the LSA ratio was still lower than the native ACL. Younger adolescent patients may have a better potential on the ligamentization after ACLR than the older adolescent patients.

Age-related changes in mechanical properties of semitendinosus tendon used for anterior cruciate ligament reconstruction

Background

Hamstring tendons are a popular choice for autografts in anterior cruciate ligament (ACL) reconstruction. However, there is increasing evidence that hamstring tendon autografts carry a high risk of revision and residual instability in young patients. To elucidate the reasons for the inferior outcome of the reconstructed ACL with hamstring tendon autografts in young patients, we investigated the Young’s modulus and the extent of cyclic loading-induced slackening of the semitendinosus tendon used for ACL reconstruction across a broad range of ages.

Methods

Twenty-six male patients (aged 17–53 years), who were scheduled for ACL reconstruction surgery using the semitendinosus tendon autograft, participated in this study. The distal portion of the harvested semitendinosus tendon, which was not used to construct the autograft, was used for cyclic tensile testing to calculate the Young’s modulus and the extent of slackening (i.e., increase in slack length).

Results

Spearman correlation analysis revealed that the Young’s modulus of the semitendinosus tendon was positively correlated with the patient’s age (ρ = 0.559, P = 0.003). In contrast, the extent of tendon slackening did not correlate with the patient’s age.

Conclusions

We demonstrated that the Young’s modulus of the semitendinosus tendon increases with age, indicating that the semitendinosus tendon used for ACL reconstruction is compliant in young patients.

A Partial-Thickness Quadriceps Autograft Reliably Augments the Size of the Hamstring Graft During Anterior Cruciate Ligament Reconstruction

Purpose

To measure the increase in diameter resulting from the augmentation of a hamstring autograft with a partial width rectus femoris tendon band in anterior cruciate ligament reconstruction.

Methods

Thirty-three cadaveric knees were dissected to harvest semitendinosus and gracilis tendons (4S) along with a 6-mm wide tendon band from the rectus femoris. Harvesting was done according to the usual surgical techniques of both harvests. Measures of length and diameter in 4S and 4S augmented with the rectus femoris band (4S +Q) configurations were performed separately by 3 evaluators.

Results

The quadriceps augmentation led to an average increase of 1.49 mm (95% confidence interval 1.03-1.95 mm) in diameter of the 4-strand hamstring grafts. The previously demonstrated threshold diameter of 8.5 mm was attained in only 30% of 4S grafts within this population in comparison with 88% when augmented with a quadriceps band.

Conclusions

In conclusion, supplementing doubled hamstring graft (4S) with quadricipital tendon in anterior cruciate ligament reconstruction (ACLR) increases the graft diameter by an average of 1.49 mm. It has the physical potential to reliably augment hamstring grafts that measure 7.5 mm in diameter or more in order to obtain an 8.5 mm when necessitated.

Clinical Relevance

Increased graft diameter is associated with a decreased risk of graft failure after ACLR. Because of this, it is important to identify methods to increase the size of grafts. This study investigates the use of a partial-width rectus femoris tendon band as an option to reliably augment graft sizes during ACLR.

Hamstring graft diameter above 7 mm has a lower risk of failure following anterior cruciate ligament reconstruction

PURPOSE

Multi-stranded hamstring-tendon autografts have been widely used for anterior cruciate ligament reconstruction (ACLR) surgeries. Recently, smaller diameter hamstring autografts have been linked with the risk of failure or graft rupture. However, there is limited evidence concerning the optimal diameter of the hamstring autografts for ACLR. The current systematic review and meta-analysis analysed the association of ACLR failure with the diameter of hamstring autografts.

METHODS

A systematic search of three major scientific databases (Pubmed, EMBASE, and Cochrane library) was conducted to identify studies that presented ACLR failure-related outcomes with different diameters of hamstring autografts. The pooled data from the included studies were analysed to investigate the association between ACLR failure and the cut-off diameters of 6, 7, 8, and 9 mm. Subgroup analyses based on the level of evidence and follow-up duration were also performed at each cut-off diameter.

RESULTS

Of the 2282 studies screened, 16 reported failure rates with hamstring autografts of different diameters, 15 of which were included in the meta-analysis. A graft diameter ≥ 7 mm was associated with significantly lower ACLR failure rates than a graft diameter < 7 mm (p = 0.005), based on pooled data of 19,799 cases. Age < 20 years and higher physical activity were associated with significantly higher ACLR failure rates.

CONCLUSION

The current systematic review suggests that the hamstring graft diameter for ACLR should be more than 7 mm considering the significantly higher failure rates with graft diameters less than 7 mm.

LEVEL OF EVIDENCE

Level IV.

Insufficient evidence to support peroneus longus tendon over other autografts for primary anterior cruciate ligament reconstruction: a systematic review

IMPORTANCE

Graft choice for anterior cruciate ligament reconstruction (ACLR) remains a subject of interest among orthopaedic surgeons because no ideal graft has yet been found. Peroneus longus tendon (PLT) has emerged as an alternative autograft for reconstruction in kneeling populations and in simultaneous anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries.

OBJECTIVE

To evaluate the current evidence on the outcome of primary ACLR with PLT autograft in adults and donor ankle morbidity, in addition to determining the average PLT graft dimensions from published studies.

EVIDENCE REVIEW

Two independent reviewers searched PubMed, CENTRAL, EMBASE, Scopus and Virtual Health Library databases using the terms "anterior cruciate ligament," "peroneus longus" and "fibularis longus" alone and in combination with Boolean operators AND/OR. Studies evaluating clinical and stability outcomes, graft-donor ankle morbidity and graft dimensions of PLT in ACLR were included. Methodological quality was assessed using the Modified Coleman Methodology Score (mCMS). A narrative analysis is presented using frequency-weighted means wherever feasible. Publication bias was assessed using the ROBIS tool.

FINDINGS

Twelve articles with intermediate-level methodological quality were included. Eight studies assessing the clinical and stability outcomes of reconstruction with PLT showed satisfactory outcomes, similar to those of hamstring tendons (HT). No studies assessed anterior knee pain as an outcome. Six studies evaluated the graft-donor ankle morbidity using general functional foot and ankle scores and non-validated tools, showing favourable outcomes. Nine studies assessed PLT graft diameter, revealing grafts consistently larger than 7 mm among the different preparation techniques, which is comparable with reports of HT grafts.

CONCLUSIONS AND RELEVANCE

The clinical and stability outcomes of ACLR with different PLT autograft preparation techniques are comparable with those of HT during short-term follow-up; however, there is insufficient evidence to support its use in the populations that motivated its implementation. Thus, stronger evidence obtained with the use of validated tools reporting negligible donor-graft ankle morbidity after PLT harvesting is required prior to recommending its routine use, despite the consistency of its dimensions.

LEVEL OF EVIDENCE

Level III.

Influence of hamstring autograft diameter on graft failure rate in Chinese population after anterior cruciate ligament reconstruction

Background

There has been limited literature regarding the influence of hamstring autograft diameter on the outcome of anterior cruciate ligament (ACL) reconstruction in Asian population. This study was undertaken to investigate the failure rate after ACL reconstruction among Chinese patients treated with hamstring tendon autografts of different diameters. Our hypothesis was that an increase in hamstring tendon autograft diameter would reduce the risk of graft failure.

Methods

A retrospective review of 394 consecutive patients who underwent ACL reconstruction using quadrupled semitendinous and gracillis autografts from 2009 to 2018 at our centre was performed. Logistic regression analysis was used to determine the relationship between graft failure rate and predictor variables, including hamstring graft diameter, gender and age.

Results

Hamstring graft diameter of 8.0 mm or more was found to be associated with significant reduction of risk in graft failure rate (P = 0.001, Relative Risk 0.19). No significant association was found between graft failure rate and gender or age.

Conclusion

Hamstring graft diameter 8.0 mm or greater is associated with decreased graft failure rate and revision rate in our local Chinese population.

Hamstring Autograft Versus Hybrid Graft for Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND

Hamstring tendon autografts are commonly used for primary anterior cruciate ligament (ACL) reconstruction. Some patients have small hamstring tendons however, which may compromise the clinical outcome of the autograft. To solve this problem, many surgeons use hybrid grafting that involves augmentation of small hamstring autografts with allograft tissue.

PURPOSE/HYPOTHESIS

The purpose was to compare the clinical outcomes between primary ACL reconstructions performed with hamstring autografts and those performed with hybrid grafts in terms of patient-reported evaluation, failure rate, and knee stability. The hypothesis was that primary ACL reconstruction performed with hamstring autograft alone will not differ significantly from that performed with a hybrid graft in terms of patient-reported evaluation, failure rate, or knee stability.

STUDY DESIGN

Systematic review.

METHODS

A systematic review was performed to identify prospective and retrospective comparative studies and cohort studies (evidence levels 1-3) comparing outcomes of primary ACL reconstructions performed with hamstring autografting alone and hybrid grafting. Outcomes included patient-reported evaluation, failure rate, and knee stability.

RESULTS

Ten studies were included: 1 of level 2 and 9 of level 3. Collectively, they included 398 autografts and 341 hybrid grafts. Mean respective follow-up durations ranged from 24.0 to 69.6 months and from 24.0 to 70.8 months. Patient-reported evaluations, including Lysholm, Tegner, and subjective International Knee Documentation Committee scores, were reported in 8 of 10 studies. Failure rates were reported in all 10 studies. Results of knee stability examinations-including KT-1000 arthrometer measurements, the pivot-shift test, Lachman test, and overall International Knee Documentation Committee results-were reported in 4 of 10 studies. In this review, there were no statistically significant differences between autografts and hybrid grafts in terms of patient-reported evaluations, failure rates, or KT-1000 measurements.

CONCLUSION

In this systematic review, there was no significant difference in patient-reported evaluation or failure rate between primary ACL reconstructions performed with autografts alone and those performed with hybrid grafts. Whether there is a substantial difference in knee stability examination results between autografts and hybrid grafts remains unknown, given a relative lack of reports on knee stability.

Predicting the graft diameter of the peroneus longus tendon for anterior cruciate ligament reconstruction

The aim of this study was to evaluate the correlation between various anthropometric parameters and the graft diameter of the peroneus longus tendon (PLT).We retrospectively analyzed the data of 156 patients who underwent anterior cruciate ligament reconstruction (ACLR) with the PLT graft at our institution. Anthropometric parameters, including height, weight, gender, age, duration of injury, and preinjury activity levels, were recorded. t tests, correlation coefficients (Pearson r), and a multiple linear regression analysis were used to evaluate the influence of these anthropometric variables on the diameter of the graft obtained.The mean PLT graft diameter was 8.3 mm, and 21 patients (13.5%) had a diameter less than 8 mm; 85 patients (54.5%) had a diameter between 8 and 9 mm, and 50 patients (32.0%) had a diameter greater than or equal to 9 mm. The correlation analysis showed that height (P < .001), weight (P < .001), and duration of injury (P = .012) were significantly related to graft diameter. On the basis of these 3 predictors, the following regression equation was obtained: Diameter = 2.28 + 0.028*height (cm) + 0.013*weight (kg) + 0.289*duration of injury (0 or 1). Patients who were short and shin were more likely to own smaller graft diameters (<8 mm), especially the one ruptured his or her anterior cruciate ligament (ACL) over 3 months.Height, weight, and duration of injury were associated with the diameter of PLT. They are important preoperative information for surgeon about the size of PLT and can be used for alternative graft source planning and patient counseling.Level of evidence: IV.

Risk Factors for Abnormal Anteroposterior Knee Laxity After Primary Anterior Cruciate Ligament Reconstruction

PURPOSE

To identify preoperative and intraoperative factors associated with abnormal anterior knee laxity after primary anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 5,462 patients who underwent primary ACL reconstruction at our institution from January 2000 to October 2015, with no associated ligament injuries, were included. Demographic data, information regarding graft used, concomitant meniscal surgery, and instrumented laxity were reviewed. The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and at 6-month follow-up. Patients were considered to have abnormal anterior knee laxity if the postoperative side-to-side difference was greater than 5 mm (International Knee Documentation Committee laxity grade C or D). A logistic regression analysis was used to evaluate whether patient age, gender, preoperative knee laxity, graft type, and presence of medial or lateral meniscus resection or suture were risk factors for abnormal knee laxity.

RESULTS

The risk of having abnormal anterior knee laxity was significantly related to younger age (<30 years) (odds ratio [OR] 1.44; 95% confidence interval [CI], 1.07-1.95; P = .016), preoperative side-to-side difference greater than 5 mm (OR, 6.57; 95% CI, 4.94-8.73; P < .001), hamstring tendon graft (OR, 1.83; 95% CI, 1.08-3.11; P = .025), and medial meniscus resection (OR, 2.22; 95% CI, 1.61-3.07; P < .001). Female gender (OR, 0.96; 95% CI, 0.72-1.28; P = .80), medial meniscus suture (OR, 0.82; 95% CI 0.42-1.62; P = .58), lateral meniscus resection (OR, 0.73; 95% CI 0.49-1.10; P = .13), and lateral meniscus suture (OR, 0.99; 95% CI, 0.46-2.11; P = .98) were not associated with increased risk of abnormal knee laxity.

CONCLUSIONS

Age less than 30 years, preoperative side-to-side difference greater than 5 mm, hamstring tendon graft, and medial meniscus resection are associated with increased risk of having abnormal anterior knee laxity 6 months after primary ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Comparison of Clinical Outcomes After Anterior Cruciate Ligament Reconstruction Using a Hybrid Graft Versus a Hamstring Autograft

PURPOSE

This study aimed to compare the clinical outcomes of patients who underwent anterior cruciate ligament (ACL) reconstruction with a hybrid graft versus an autograft after 3 years of follow-up.

METHODS

Among 57 patients with an ACL injury who underwent ACL reconstruction, 28 patients received a hybrid graft (gracilis and semitendinosus tendon autograft plus a soft tissue allograft) and 29 patients received an autograft (gracilis and semitendinosus tendon autograft). The 2 groups were compared after a minimum 3-year follow-up regarding International Knee Documentation Committee (IKDC) assessment of knee function and stability, pivot-shift test, Lachman test, and KT-1000 side-to-side differences. The patient-reported Tegner activity score, Lysholm score, and subjective IKDC score were also compared. Graft failures were identified by patient-reported outcomes, physical examinations, or magnetic resonance imaging, and were confirmed on second-look arthroscopy; failure rate was compared between groups.

RESULTS

At final follow-up, the 2 groups significantly differed in pivot-shift test result (P = .013) and Lachman test result (P = .027). The failure rate tended to be greater in the hybrid graft group (14.3%) than in the autograft group (3.4%) (P = .148). All 5 patients with failed graft reconstruction were revised after second-look arthroscopy. The KT-1000 side-to-side differences at final follow-up were significantly inferior in the hybrid graft group (3.5 ± 2.0) compared with the autograft group (2.5 ± 1.0, P = .024). The hybrid graft group also had a lower mean Lysholm score (P = .000) and subjective IKDC score (P = .006) than the autograft group. The mean Tegner activity score was 6.8 ± 0.8 in the hybrid graft group and 6.9 ± 0.6 in the autograft group (P = .436).

CONCLUSIONS

The knee stability and patient-reported scores in the autograft-irradiated allograft hybrid graft ACL reconstruction group were significantly inferior compared with those in the autograft ACL reconstruction group.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Hamstring autograft size importance in anterior cruciate ligament repair surgery

Graft size in hamstring autograft anterior cruciate ligament (ACL) surgery is an important factor directly related to failure. Most of the evidence in the field suggests that the size of the graft in hamstring autograft ACL reconstruction matters when the surgeon is trying to avoid failures.

The exact graft diameter needed to avoid failures is not absolutely clear and could depend on other factors, but newer studies suggest than even increases of 0.5 mm up to a graft size of 10 mm are beneficial for the patient. There is still no evidence to recommend the use of grafts > 10 mm.

Several methods – e.g. folding the graft in more strands – that are simple and reproducible have been published lately to address the problem of having an insufficient graft size when performing an ACL reconstruction. Due to the evidence presented, we think it is necessary for the surgeon to have them in his or her arsenal before performing an ACL reconstruction.

There are obviously other factors that should be considered, especially age. Therefore, a larger graft size should not be taken as the only goal in ACL reconstruction.

Cite this article: EFORT Open Rev 2018;3:93-97. DOI: 10.1302/2058-5241.3.170038

Allograft Augmentation of Hamstring Autograft for Younger Patients Undergoing Anterior Cruciate Ligament Reconstruction

BACKGROUND

Younger patients and those with smaller hamstring autograft diameters have been shown to be at significantly greater risk of graft failure after anterior cruciate ligament (ACL) reconstruction. To date, there is no information in the literature about the clinical success and/or cost-effectiveness of increasing graft diameter by augmenting with semitendinosus allograft tissue for younger patients.

HYPOTHESIS

Hybrid hamstring grafts are a cost-effective treatment option because of a reduced rate of graft failure.

STUDY DESIGN

Cohort study (economic and decision analysis); Level of evidence, 3.

METHODS

We retrospectively identified patients younger than 18 years who had undergone ACL reconstruction by a single surgeon between 2010 and 2015. During this period, the operating surgeon's graft selection algorithm included the use of bone-patellar tendon-bone (BTB) autografts for the majority of patients younger than 18 years. However, hamstring autografts (hamstring) or hybrid hamstring autografts with allograft augment (hybrid) were used in skeletally immature patients and in those whom the surgeon felt might have greater difficulty with postoperative rehabilitation after BTB graft harvest. Patient demographics, graft type, graft diameter, the time the patient was cleared to return to activity, and the need for secondary surgical procedures were compared between the hamstring and hybrid groups. The clinical results were then used to assess the potential cost-effectiveness of hybrid grafts in this select group of young patients with an ACL injury or reconstruction.

RESULTS

This study comprised 88 patients (hamstring group, n = 46; hybrid group, n = 42). The 2 groups did not differ in terms of age, sex, timing of return to activity, or prevalence of skeletally immature patients. Graft diameters were significantly smaller in the hamstring group (7.8 vs 9.9 mm; P < .001), which corresponded with a significantly greater rate of graft failure (13 of 46 [28.3%] vs 5 of 42 [11.9%]; P = .049). As a result of the reduced revision rate, the hybrid graft demonstrated incremental cost savings of US$2765 compared with the hamstring graft, and the hybrid graft was the preferred strategy in 89% of cases.

CONCLUSION

Driven by increased graft diameters and the reduced risk of revision, hybrid grafts appear to be a more cost-effective treatment option in a subset of younger patients with an ACL injury.