Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Is There a Hamstring Autograft Diameter Threshold for Anterior Cruciate Ligament Reconstruction?

Background

Hamstring autograft (HA) is a popular graft for anterior cruciate ligament reconstruction (ACLR). Although multiple studies have demonstrated that increasing the graft diameter decreases the risk of failure or revision surgery, the exact minimum graft diameter remains controversial, with the unofficial standard being 8 mm.

Purpose

To evaluate the risk of aseptic revision after HA-ACLR in patients aged ≤25 years, comparing graft diameters of (1) <8 versus ≥8 mm and (2) ≤8 versus >8 mm. A secondary purpose was to determine whether there was a threshold for graft diameter that best identifies patients at a higher risk of aseptic revision.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 5972 primary HA-ACLRs were identified using data from the ACLR registry of Kaiser Permanente. Propensity score-weighted Cox regression was used to evaluate revision risk for HAs with <8 versus ≥8 mm diameter and with ≤8 versus >8 mm diameter. An effect plot and receiver operating characteristic curve and area under the curve (AUC) analysis were also created to model the probability of revision based on the HA diameter to determine whether there was a specific diameter threshold to minimize revision risk.

Results

In the propensity score-weighted Cox model, <8 mm autografts had a higher risk of aseptic revision compared with ≥8 mm autografts (hazard ratio [HR], 1.32 [95% CI, 1.01-1.71]; P = .039); a higher risk was also observed when comparing ≤8 to >8 mm grafts (HR, 1.32 [95% CI, 1.06-1.66]; P = .015). In receiver operating characteristic analysis, an HA diameter that best identified patients at a higher risk for revision after ACLR could not be identified (AUC, 0.56). However, the adjusted effect plot showed a direct decrease in revision risk with each increasing increment in graft size.

Conclusion

A 32% higher risk of revision was observed in smaller graft diameter groups (<8 or ≤8 mm) compared with larger graft sizes (≥8 or >8 mm), regardless of specific diameter cutoff. In a cohort of almost 6000 HA-ACLR, the authors were unable to determine a definitive minimum graft diameter threshold that should be used.

Return to sport at the pre-injury level following anterior cruciate ligament reconstruction is influenced by patients' perceived knee status and psychological readiness, and does not correlate with functional ability

OBJECTIVES

The purposes of this study were to (1) prospectively evaluate clinical and functional outcomes of athletes following anterior cruciate ligament (ACL) reconstruction up to 12 months after surgery, (2) to identify the correlations between functional and subjective tests, and (3) to determine which factors influence patients' capability to resume sports at pre-injury level.

METHODS

Patients who underwent ACL reconstruction using doubled autologous hamstring graft were prospectively assessed pre-operatively, 6, and 12 months after surgery using International Knee Documentation Committee (IKDC) Subjective Knee Form, Tegner activity level, and ACL-Return to Sport after Injury (ACL-RSI) scale. Jumping ability was instrumentally assessed using a test battery including bipodalic squat jump (SJ), bipodalic countermovement jump (CMJ), monopodalic CMJ, and monopodalic side-hop test.

RESULTS

Thirty-three patients were available for clinical evaluation at 12-months follow-up. Average age was 34.0 years (SD 11.5, range 19-50). Male/female ratio was 31:2. Mean overall IKDC, and ACL-RSI scores increased from 52.5 to 47.1 preoperatively, to 89.9 (SD: 12.2, range 36.8-100) and 81.3 (SD 21.7, range 10-98.3), respectively at last follow-up (p ​< ​0.001). Monopodalic jump tests showed improvements at 12-month evaluation compared to 6-month follow-up (p ​< ​0.01). No statistically significant correlation was reported for ACL-RSI and jump limb symmetry index (LSI) (p ​= ​0.08 vs. CMJ; p ​= ​0.07 vs. side-hop test). No differences were observed in terms of jump LSI between patients who returned to pre-injury activity level and those who did not (p ​= ​0.11 for CMJ, p ​= ​0.09 for side-hop test). A significantly higher IKDC score at 6 months was observed in patients who did not return to pre-injury levels (p ​= ​0.009). Patients who did not return to pre-injury activity reported lower ACL-RSI scores at 12-months follow-up (p ​= ​0.007).

CONCLUSIONS

One year after ACL reconstruction, an improvement in jumping ability was observed, while a persistence of lower limbs asymmetries when performing jump tests was noted at 6-months follow-up. The ability to perform vertical jumps was not influenced by psychological outcomes 12 months following surgery. Higher values of subjective knee score and psychological readiness weakly correlated to return to sport at preinjury level, while no correlation was reported concerning jumping performance.

Primary Anterior Cruciate Ligament Reconstruction Performed With Hamstring Tendon Autograft Leads to an Over 4 Times Greater Rate of Second Anterior Cruciate Ligament Rupture After Return to Sport in Patients With Generalized Joint Hypermobility Compared With Bone-Patellar Tendon-Bone Autograft

PURPOSE

To examine the rate of (1) second anterior cruciate ligament (ACL) rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone in patients with generalized joint hypermobility (GJH) at 12 months, at 24 months, and at the longest available time (LAT) following return to sport (RTS) after ACL reconstruction depending on graft choice, that is, hamstring tendon (HT) autograft or bone-patellar tendon-bone (BPTB) autograft.

METHODS

Data were extracted from a rehabilitation registry that comprised patients who had undergone ACL reconstruction between 2014 and 2022. Patients with GJH aged between 16 and 50 years who had minimum 24-month follow-up following RTS after ACL reconstruction with HT autograft (GJH-HT) or BPTB autograft (GJH-BPTB) were included. A Cox proportional hazard regression model was used to examine the rate of (1) second ACL rupture (graft rupture or contralateral ACL rupture) and (2) graft rupture alone at 12 months, at 24 months, and at the LAT after RTS.

RESULTS

This study included 82 patients (54 in the GJH-HT group and 28 in the GJH-BPTB group), of whom 72.0% were female patients, and the average age was 22.7 ± 7.4 years. The proportion of second ACL ruptures was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (11 of 54 [20.4%] vs 0 of 28 [0%], P = .013), at 24 months (13 of 54 [24.1%] vs 1 of 28 [3.6%], P = .028), and at the LAT (16 of 54 [29.6%] vs 2 of 28 [7.1%], P = .024) after RTS. The rate of second ACL rupture was greater in the GJH-HT group than in the GJH-BPTB (hazard ratio = 4.98, P = .032) at the LAT after RTS. The proportion of patients with graft rupture was greater in the GJH-HT group than in the GJH-BPTB group at 12 months (8 of 54 [14.8%] vs 0 of 28 [0%], P = .046), at 24 months (10 of 54 [18.5%] vs 0 of 28 [0%], P = .013), and at the LAT (12 of 54 [22.2%] vs 0 of 28 [0%], P = .006) after RTS.

CONCLUSIONS

An over 4 times greater rate of second ACL rupture after RTS was reported for patients with GJH who underwent ACL reconstruction with HT autograft compared with BPTB autograft. Patients with GJH who were treated with BPTB autograft for ACL reconstruction did not experience graft rupture after RTS.

LEVEL OF EVIDENCE

Level III, retrospective study.

Two-stage revision anterior cruciate ligament reconstruction reduces failure risk but leads to lesser clinical outcomes than single-stage revision after primary anterior cruciate ligament graft failure: a retrospective cohort study

BACKGROUND

There are no studies that compare the outcomes and complications of single-versus two-stage revision anterior cruciate ligament reconstruction (ACLR) after primary ACLR failure. This purpose of this study is to examine clinical and functional outcomes and complications associated with single and two-stage revision ACLR after primary ACLR failure.

METHODS

All patients who underwent single or two-stage revision ACLR after primary ACLR failure between 2012 and 2021 with a minimum of a 2 year follow-up were included. Patients were excluded if they were not treated at our single academic institution, had inadequate follow-up, or had incomplete medical records. Revision intraoperative data, concomitant injuries, and complications were collected by chart review. Return to sport, numerical pain rating scale (NPRS) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Veteran Rands 12-item health survey (VR-12 scores) were collected.

RESULTS

The final analysis included 176 patients. A total of 147 (83.5%) had a single-stage revision ACLR (87 male, 60 female), and 29 (16.5%) had a two-stage revision ACLR (13 male, 16 female). Two-stage revision ACLR was significantly associated with anterior knee pain [odds ratio (OR) 4.36; 95% confidence interval (CI) 1.5 to 12.65; P = 0.007] but with lower failure rates (OR 0.12, 95% CI 0.02 to 0.9; P = 0.04). On multivariate analysis, a two-stage revision ACLR reduced the risk of graft failure by 85% (OR 0.15; 95% CI 0.02 to 1.17; P = 0.07). Two-stage revision ACLR was significantly associated with a lower KOOS pain score (OR -11.7; 95% CI -22.35 to -1.04; P = 0.031), KOOS symptoms score (OR -17.11; 95% CI -28.85 to -5.36; P = 0.004), KOOS Activities of Daily Living (ADL) score (OR -11.15; 95% CI -21.71 to -0.59; P = 0.039) and Veterans RAND 12-Item Health Survey (VR-12) physical component score (OR -9.99; 95% CI -15.77 to -4.22; P = 0.001).

CONCLUSIONS

The clinical outcomes and subjective patient scores significantly differed between the single-stage and two-stage revision ACLR after primary ACLR failure. Patients with a two-stage revision ACLR had a significantly reduced risk of revision graft failure but higher rates of postoperative anterior knee pain, lower pain scores, and lesser knee functional scores than single-stage revision patients.

STUDY DESIGN

Retrospective cohort study; level of evidence, 3.

Inframalleolar harvest of the peroneus longus tendon graft: Surgical technique

Peroneus longus tendon (PLT) graft has recently gained visibility in the literature as a promising option for knee ligament reconstructions. The most used harvesting technique is performed with a single incision posterior to the lateral malleolus, with large series reporting tendon lengths enough to prepare a double or triple anterior cruciate ligament (ACL) graft, resulting in mean diameters greater than 8.0 mm. However, as happens with the hamstrings, some patients may present PLT grafts with a 7-mm diameter, which is associated with higher failure rates and is the minimum acceptable diameter for ACL reconstructions. In turn, the 2-incision technique has longer graft lengths reported, enough to prepare 4-folded grafts, with mean diameters above 9.0 mm, ranging from 8.5 to 10 mm. Once the PLT graft diameter has a direct correlation with anthropometric measurements, as well as larger ACL graft diameters are associated with lower failure rates and revision surgeries, the inframalleolar harvesting seems to be a reasonable option, especially for short-stature patients with a greater risk of insufficient grafts. Additionally, patients who benefit from an extra-articular procedure can have a combined reconstruction of the ACL and anterolateral ligament using the PLT graft with the two-incision technique, with no need for another graft. Therefore, this article aims to describe the step-by-step technique for the inframalleolar PLT harvesting.

Patient-specific cutting guides allow 1° precision in asymmetric anterior closing-wedge osteotomy

Purpose

Asymmetric anterior closing-wedge high tibial osteotomy (ACWHTO) allows correction of both excessive posterior tibial slope (PTS) and varus deformity. However, the complexity of this surgery requires a high degree of accuracy, which is less likely to be achieved with standard instrumentations. This study aimed to determine the accuracy of 3D patient-specific cutting guides (PSCGs) to provide the accurate planned correction in the frontal and sagittal planes.

Methods

Eight sawbones tibiae were identically printed from the same patient data. An ACWHTO with a PSCG was performed on each sawbone. Postoperative measurements of PTS, mechanical medial proximal tibial angle (mMPTA), hinge area and hinge-posterior cruciate ligament (hinge-PCL) distance were compared with the preoperative planned measurements. The precision was defined as the absolute difference (∆) between the target planned values and postoperative values.

Results

The mean accuracy was 0.6° ± 0.74° for PTS, 0.8° ± 0.71° for mMPTA, 0.3 ± 0.2 cm2 for hinge area and 0.1 ± 0.06 mm for hinge-PCL distance.

Conclusion

In the setting of sawbones, the use of PSCGs was a reliable and accurate method of achieving simultaneous correction in the frontal and sagittal planes during asymmetric ACWHTO.

Level of Evidence

Level V, basic science biomechanical laboratory study.

Outcomes of All-Inside Arthroscopic ACL Reconstruction with Lateral Extra-Articular Tenodesis (ACLR + LET)

Background

Anatomic single-bundle ACL reconstruction (ACLR) produces good results when the graft and tunnel are positioned in the anatomic footprint on the femoral and tibial insertion sites in a more oblique orientation. The Anterolateral Complex of the knee and its biomechanical role in controlling rotational laxity, internal rotation, and pivot shift has led to adding adjunctive procedures like extra-articular augmentation and lateral extra-articular tenodesis (LET) to decrease rotational laxity. We prospectively analyzed young adults with rotational instability and generalized laxity undergoing an arthroscopic single bundle ACLR with an additional LET procedure.

Methods

42 patients, aged between 20 and 50, undergoing all-inside ACLR augmented with concomitant lateral extra-articular tenodesis between November 2020 and October 2021 were included. All patients were followed up for one year and functional assessment comprised of the International Knee Documentation Committee [IKDC] score, visual analogue score [VAS], and Lysholm Knee Scoring Scale at 6 months and 1 year. Return to activity was assessed using the Tegner Activity Score.

Results

The Lysholm score, IKDC score, and VAS showed significant improvements at 6 months after ACLR + LET (p < 0.0001) and further improved significantly at 1 year. The patients had a significant decline in the Tegner Activity Scale at 6 months but returned to the near pre-injury level (5.98 ± 0.924) at 1 year (5.67 ± 0.816) which was insignificant (p = 0.1067). Three patients sustained mild complications. 93% were satisfied with the surgery, 66% returned to sports and no patient underwent re-operation.

Conclusions

Combination of LET with ACLR produces good functional outcomes, high rates of return to sports activities, and no graft failure in young patients at high risk of failure.

High incidence of anterior cruciate ligament injuries in professional men's handball: Analysis of the 'ACL registry in German Sports' over seven consecutive seasons

Purpose

The purpose of this study was to generate knowledge about the epidemiology and risk factors for anterior cruciate ligament (ACL) injuries in handball. It was hypothesised that the incidence of ACL injuries is high and comparable to other pivoting sports like football.

Methods

This study is based on the prospective 'ACL registry in German Sports' implemented in the 2016-2017 season. Professional (first and second leagues) male handball players were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2016-2017 to the 2022-2023 season.

Results

A total of 84 ACL injuries were registered. 46.3% of ACL injuries were re-ruptures. This represents a total incidence of 0.044 ACL injuries per 1000 h of exposure in training and matches per player over the study period. An increased incidence rate of 0.064/1000 h in the first league compared to 0.031/1000 h in the second league was reported (p ˂ 0.001). The mean number of injuries in the first division was 8.3, and in the second division, 6.6 ACL ruptures per season. Risk factors for ACL injury include previous knee injury and increased match exposure.

Conclusion

The incidence of ACL injuries in professional handball is high and comparable to football with an increased risk in the first league compared to the second league in Germany. There was a high incidence of re-injury. Other risk factors for ACL injuries include previous injuries to the affected knee in general as well as increased match exposure.

Level of Evidence

Level II prospective cohort study.

Editorial Commentary: Early Outcomes of Suture Tape Augmentation in Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction Are Promising but Require Long-term Proof

The management of anterior cruciate ligament (ACL) injuries continually evolves, with new interest in all-soft tissue quadriceps tendon autograft, as well as new interest in suture tape augmentation of the graft, particularly in high-risk patients with young age; female sex; lower-limb alignment, tibial, or femoral abnormalities; hyperlaxity; concomitant meniscal and/or additional ligamentous injuries; or participation in high-risk sports. Load-sharing suture tape enhances the biomechanical stability of the reconstructed ACL, especially during the initial ingrowth and ligamentization phase, and biomechanical evidence highlights a reduced risk of graft elongation and failure under the loads encountered during daily physical activities and sport. Optimal tape tensioning could be achieved in knee hyperextension, when the ACL is at maximal length, to avoid overconstraint. The published 2-year outcomes of this technique are excellent. Current comparative studies, however, have not shown superiority. Additional controlled studies and studies with longer-term follow-up are needed, as well as comparison to extra-articular tenodesis augmentation.

Preoperative Physical Therapy Is Protective From Construct Failure in Anterior Cruciate Ligament Reconstruction

BACKGROUND

Risk factors for anterior cruciate ligament reconstruction (ACLR) construct failure have been studied extensively. However, while some studies account for variables such as activity level, construct types, preoperative physical therapy, or patient demographics individually, comprehensive studies that control for all these factors simultaneously are scarce.

HYPOTHESIS

By utilizing a robust multivariable analysis, the factors associated with an increased risk of ACLR construct failure can be determined.

STUDY DESIGN

A single-center, retrospective cohort study was conducted, encompassing patients who underwent primary ACLR between January 2015 and December 2021.

LEVEL OF EVIDENCE

Level 3.

METHODS

Eligible patients were identified using the current procedural terminology code 29888. Datapoints collected included demographics, body mass index, injury setting, graft type, graft size, fixation type, concomitant ligamentous injuries, notchplasty, operating surgeon, preoperative physical therapy, and instances of construct failure. The prevalence of construct failure was analyzed using chi-square tests, comparing across all graft and fixation type combinations in ACLR procedures. A mixed-effects logistic regression model was utilized to account for the potential influence of all relevant variables on construct failure.

RESULTS

Out of 1245 patients, the construct failure rate was 5.62% (n = 70), with >95% of patients having >2 years of retrospective follow-up (95% CI [4.34-6.90]), with a median failure time of 502.5 days (interquartile range [265.5-1033.8]). The mixed-effect logistic model identified preoperative physical therapy (odds ratio, 0.404, 95% CI [0.193-0.844]) as the only significant factor in possibly preventing construct failure.

CONCLUSION

Contrary to conventional focus on graft and fixation types, this study emphasizes the protective role of preoperative physical therapy in reducing ACLR construct failure.

CLINICAL RELEVANCE

Our findings suggest the integration of preoperative physical therapy in clinical practices to mitigate ACLR construct failure risk, warranting further exploration in future studies.

Oh, My Quad: A Clinical Commentary And Evidence-Based Framework for the Rehabilitation of Quadriceps Size and Strength after Anterior Cruciate Ligament Reconstruction

Quadriceps weakness after anterior cruciate ligament reconstruction (ACLR) is a well-known phenomenon, with more persistent quadriceps weakness observed after ACLR with a bone-patellar tendon-bone or quadriceps tendon autograft than with a hamstring tendon autograft. Longstanding quadriceps weakness after ACLR has been associated with suboptimal postoperative outcomes and the progression of radiographic knee osteoarthritis, making the recovery of quadriceps size and strength a key component of ACLR rehabilitation. However, few articles have been written for the specific purpose of optimizing quadriceps size and strength after ACLR. Therefore, the purpose of this review article is to integrate the existing quadriceps muscle basic science and strength training literature into a best-evidence synthesis of exercise methodologies for restoring quadriceps size and strength after ACLR, as well as outline an evidence-informed quadriceps load-progression for recovering the knee's capacity to manage the force-profiles associated with high-demand physical activity. Level of Evidence: 5.

Age and Surgical Volume Impact Likelihood and Technique of Lateral Extra-Articular Augmentation During Primary Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate the current utilization trends of practicing surgeons performing and lateral extra-articular augmentation (LEA) at the time of primary anterior cruciate ligament reconstruction (ACLR).

METHODS

The survey was distributed via e-mail in August 2023 to members of the Arthroscopy Association of North America who identified as knee surgeons and was available online on the Arthroscopy Association of North America website from January to September 2023. The 18-question survey was designed regarding surgeons' surgical utilization patterns of LEA during ACLR. Survey questions were created based on prior published research and recommendations regarding indications for LEA, as well as surgeon factors that have been shown to influence operative decision-making. Data were analyzed by surgeon geographics, procedure preferences, patient-based decision factors, surgeon-based decision factors, and surgeon age.

RESULTS

The survey was completed by 165 sports medicine surgeons who identified as arthroscopic knee surgeons. Majority practice types included private practice (42.1%), academic centers (26.8%), and hospital systems (20.7%). Surgeon age was 50.36 years (range, 33-77 years). In total, 6.8% perform <20 ACLRs per year, 30.2% perform 20 to 40, 26.5% perform 40 to 60, 10.5% perform 60 to 80, and 25.9% perform >80 per year. Of the surgeons, 79.4% conduct LEA, with the modified Lemaire being the most common technique (43.5%), followed by other lateral extra-articular tenodesis (LET) techniques (42.0%) and anterolateral ligament reconstruction (ALL) (27.5%). Some surgeons (14.5%) use more than 1 technique. High-volume (>60 ACLR/year) surgeons were more likely to perform LEA (23.1% vs 10.0%, P = .061) and more likely to perform anterolateral ligament reconstruction (32.2% vs 16.5%, P = .034). Younger surgeons (age <50) were more likely to use the modified Lemaire (44.4% vs 24.3%, P = .014). Decision-making to perform LEA weighted highly on patient hyperlaxity, pivot-shift severity, knee hyperextension, sport type, and age, respectively. The most reported surgeon-related factor influencing LEA utilization was training bias (38.9%).

CONCLUSIONS

Most orthopaedic surgeons with diverse geographics, demographics, practice setting, and ACLR volume perform LEA. Younger surgeons perform more frequently LEA, and surgeons admit to training bias in decision-making. Patient factors highly impacting utilization of LEA are hyperlaxity, pivot-shift severity, knee hyperextension, sport, and age.

CLINICAL RELEVANCE

LEA procedures for ACLR have become increasingly utilized in populations at high risk for rerupture. However, there is not currently a clear standard of care with regard to LEA procedure type or indications for augmentation.

Outcomes from different aspects indicate the all-inside technique may serve as an ideal option for anterior cruciate ligament reconstruction

PURPOSE

To evaluate the postoperative outcomes of the all-inside technique in arthroscopic anterior cruciate ligament reconstruction (ACLR).

METHODS

Patients who underwent ACLR using the all-inside technique between 2018 and 2021 were retrospectively assessed. All patients were followed up for at least 2 years. Functional recovery and pain relief were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS). Instrumented laxity was assessed via side-to-side difference using the Kneelax3 arthrometer. Graft maturity was estimated using the signal-to-noise quotient value based on magnetic resonance imaging (MRI). Adverse events during and after the surgery were recorded.

RESULTS

A total of 78 patients were included in this study, with a mean age of 28.1 ± 7.6 years. The IKDC (p < 0.001), Lysholm (p < 0.001) and KOOS (p < 0.001 for all subgroups) scores at the final follow-up were significantly higher than those before the surgery. The VAS scores (p < 0.05) were significantly lower than those before surgery. The side-to-side difference results indicated that 50 patients had a difference of less than 3 mm, indicating a tight graft, whereas only 1 patient had a difference of >5 mm, indicating a loose graft. The median signal-to-noise quotient of the graft on MRI was 1.4 (P25, P75: 1.0, 2.0). No intraoperative adverse events were observed. Postoperative adverse events included three cases of infection, three cases of graft rerupture, two cases of cyclops lesion and one case of surgical intervention for a meniscal tear.

CONCLUSION

ACLR using the all-inside technique offers promising results in patients with ACL rupture.

LEVEL OF EVIDENCE

Level IV.

The in vitro elution characteristics of vancomycin from the ligament augmentation and reconstruction system

Purpose

In this study, we aimed to characterize the elution profile of the ligament augmentation and reconstruction system (LARS) immersed in different concentrations of vancomycin using different immersion methods and determine whether the amount of vancomycin released was lower than the toxic concentrations for osteoblasts and chondroblasts.

Methods

The LARS was presoaked with 5, 2.5 or 1.25 mg/mL vancomycin solutions or wrapped in presoaked sterile gauze. After 10 min, the rinsed and unrinsed LARS samples were eluted in 100 mL agitated 37°C phosphate-buffered saline. An ultraviolet spectrophotometer was used to analyze 1 mL samples taken after 10 min and 0.5, 1, 6, 12, 24h.

Results

Initially, no hysteresis was observed with vancomycin release into the solution at the tested conditions. The LARS elution profiles for different concentrations of the vancomycin solutions varied significantly. The amount of vancomycin released after 24 h was 9.10 ± 1.21, 5.29 ± 0.63 and 2.28 ± 0.59 mg for the 5, 2.5 and 1.25 mg/mL solutions, respectively. The amount of vancomycin released in the soaked group was significantly higher than in the rinsed and wrapped groups. The released amounts of vancomycin were below the toxic concentrations for osteoblasts and chondrocytes.

Conclusion

Soaked LARS can act as a reservoir for vancomycin, with the amount released and the elution profile dependent on rinsing, soaking solution concentration and soaking method. The eluted concentrations of vancomycin were lower than those previously reported for osteoblast and chondrocyte toxicity and higher than the minimal inhibitory concentrations for Staphylococci.

Level of Evidence

N/A.

Age under 20 years, pre-operative participation in pivoting sports, and steep posterior tibial slope of more than 12° are risk factors for graft failure after double-bundle anterior cruciate ligament reconstruction

Purpose

Younger age and steep posterior tibial slope (PTS) have been reported as risk factors for graft failure after anterior cruciate ligament reconstruction (ACLR). Few studies have evaluated these risk factors simultaneously in a large cohort of patients undergoing double-bundle ACLR (DB-ACLR). Therefore, this retrospective study aimed to simultaneously investigate known risk factors such as PTS and age in DB-ACLR, determine their thresholds and calculate odds ratios (ORs).

Methods

We investigated 482 knees that underwent DB-ACLR with a follow-up period of at least 2 years. Receiver operating characteristic analysis determined cut-off values for age and PTS for graft failure. Subsequently, logistic regression analysis was conducted to evaluate the effects of age, sex, height, weight, laterality, surgical waiting period, pre-operative sport type and level, meniscal injury, hyperextension, general joint laxity and PTS on graft failure.

Results

Graft failure was observed in 33 out of 482 knees (6.8%). Notably, the graft failure group was significantly younger (18.0 ± 5.0 years [standard deviation] vs. 30.4 ± 13.1 years, p < 0.01) and had a steeper PTS (11.9 ± 2.3° [standard deviation] vs. 9.6 ± 2.9°, p < 0.01) than the group with no graft failure. The cut-off values were 20.0 years for age (specificity, 64.6%; sensitivity, 87.9% and area under the curve, 0.808) and 12.0° for PTS (specificity, 70.9%; sensitivity, 69.7% and area under the curve, 0.734). Logistic regression analysis identified an age of <20 years (OR = 10.1; p < 0.01), PTS of ≥12° (OR = 5.6; p < 0.01) and pre-operative participation in pivoting sports (OR = 6.0; p < 0.01) as significant risk factors for graft failure.

Conclusion

We identified an age of <20 years, PTS of ≥12° and pre-operative participation in pivoting sports as significant risk factors for graft failure after DB-ACLR.

Level of Evidence

Level III.

People Are More Variable Than Their Hop Test Would Suggest: Hop Performance and Self-Reported Outcomes Over 11 Years Following ACL Reconstruction

We aimed to report the trajectory of self-reported outcomes up to 11 years post-ACLR. We also explored the relationship between hop performance at 1 year and: (i) future self-reported knee outcomes; and (ii) risk of subsequent knee events. 124 participants (43 women, mean age 31 ± 8 years) were recruited at 1 year following hamstring-autograft ACLR. Hop performance was assessed with single-forward and side-hop tests. Follow-up was completed at 3 (n = 114), 5 (n = 89) and 11 years (n = 72) post-ACLR. Self-reported outcomes were assessed at each follow-up with the Knee injury Osteoarthritis Outcome Score (KOOS) pain and quality of life (QOL) subscales. Generalized linear mixed models estimated the relationship between hop performance and self-reported outcomes. Subsequent knee events (new injury/surgery) to either knee were recorded, with the relationship between hop performance and risk of subsequent knee events analyzed with Cox proportional hazards. Self-reported knee outcomes were stable (mean change < 10 points) across all timepoints but with major within-sample variability. There was a modest relationship between greater hop performance at 1 year and better future KOOS-pain (average marginal effect [AME] % improvement with + 1 cm single forward hop = 0.06% [95% CI 0.02-0.10]). A nonlinear spline relationship showed better single-forward hop performance was associated with better KOOS-QOL for scores < 108 cm, not present for higher hop scores > 108 cm. There were 21 index and 11 contralateral subsequent knee events. Hop performance was not related to risk of a subsequent knee event (hazard ratio index knee 0.99 [95% CI 0.98-1.02]). In conclusion, self-reported knee pain and quality of life were generally stable across the 11-year follow-up period. Greater hop performance at 1-year post-ACLR was related to better self-reported knee outcomes up to 11-year follow-up (of questionable clinical importance), but not associated with the risk of subsequent knee injury/surgery.

No Clinical Advantage of Harvesting a Patellar Bone Block Compared With All Soft-Tissue Graft in Primary Quadriceps Tendon Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare patient-reported outcomes measurements and subsequent surgical interventions in patients treated with anterior cruciate ligament reconstruction (ACLR) using either quadriceps tendon autograft with a patellar bone block (bQT) or soft tissue only (sQT).

METHODS

All ACLRs performed between January 2010 and March 2022 were prospectively followed for 24 months and retrospectively evaluated. All primary ACLRs with full 24 months of follow-up data, without any previous surgery or any additional ligamentous interventions, were matched for major ACL risk factors, including sex, age, Tegner activity level [TAL], pivoting sports, and concomitant injuries. Patient-reported outcomes measurements (Lysholm score, visual analog scale for pain, and TAL) and subsequent surgical interventions were registered after 6, 12, and 24 months postoperatively. Binary logistic regression was used to assess the influence of graft type, age, preinjury TAL, sex, pivoting sports, and concomitant interventions on the need to undergo subsequent surgery.

RESULTS

After matching, 246 patients were included in the final analysis. Both groups did not differ regarding any preoperative patient demographics or intraoperative details. At final follow-up, no significant differences in mean Lysholm score (sQT: 90.8 ± 10.6, bQT: 91.8 ± 10.6, P = .46), median TAL (sQT: 6 [1-10], bQT: 6 [1-10], P = .53), and visual analog scale for pain (sQT: 0.7 ± 1.1, bQT: 0.7 ± 1.2, P = .70) were reported between both groups. A total of 70.3% (sQT-A: 70.7%, bQT: 69.9%, P = .89) of patients returned to or exceeded their preinjury activity level. In terms of revision ACLR, there was no statistically significant difference between bQT (3.3%) and sQT (4.1%). Similarly, no difference was observed in contralateral ACLR (bQT: 7.3% sQT: 11.4%). Regression analysis indicated that none of the studied factors, including the use of a patellar bone block, influenced subsequent surgery, revision ACLR, or contralateral ACLR.

CONCLUSIONS

Harvesting an additional patellar bone block in quadriceps tendon ACLR does not seem to affect postoperative patient-reported outcomes, ACL revision, or contralateral ACL reconstruction rates.

LEVEL OF EVIDENCE

Level III, cohort study.

Increased anterior tibial subluxation and differences between anterior tibial subluxation in the lateral and medial compartments are associated with failure of primary anterior cruciate ligament reconstruction: A systematic review and meta-analysis

PURPOSE

The purpose of this study is to investigate whether increased anterior tibial subluxation (ATS) and differences between ATS in the lateral and medial compartments (ATSL-M) are associated with primary anterior cruciate ligament (ACL) reconstruction (ACLR) failure.

METHODS

PubMed, Scopus, Embase and Web of Science were systematically searched from their inception through 21 November 2023. The focus was on comparative studies reporting ATS in patients who experienced primary ACLR failure, in contrast to patients after primary ACLR with no evidence of graft failure. A random-effects model was employed to calculate the overall standardized mean difference between the two groups.

RESULTS

A total of eight studies involving 963 patients were included in the final review. Three studies (64 cases and 171 controls) measured ATS on radiographs. The failed ACLR group exhibited a significantly increased ATS on radiographs compared to the control group (p < 0.001). Six studies (324 cases and 488 controls) measured lateral ATS on magnetic resonance imaging and five of them (285 cases and 374 controls) also measured medial ATS. The average values of lateral and medial ATS, as well as ATSL-M, were calculated and compared between the two groups. The failed ACLR group demonstrated significantly increased lateral (p < 0.001) and medial ATS (p < 0.001), the average value of lateral and medial ATS (p < 0.001) and ATSL-M (p = 0.039) compared to the control group.

CONCLUSION

Increased ATS and ATSL-M are associated with primary ACLR failure. The measurement of tibiofemoral position shows promise for its application in preoperative planning and postoperative management of ACLR.

LEVEL OF EVIDENCE

Level III.

Single-bundle ACL combined with ALL reconstruction yields comparable outcomes in patients with varied anatomical risk factors for ACL graft failure

BACKGROUND

Anterior cruciate ligament (ACL) graft failure is influenced by factors such as meniscal tears and tibial plateau slope. Combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has reduced failure rates; however, its efficacy in high-risk patients remains unclear. This study hypothesized that combined ACL and ALL reconstruction would yield similar clinical outcomes in patients with varying risks of ACL failure.

PATIENTS AND METHODS

A total of 76 patients who underwent primary single-bundle ACL reconstruction combined with ALL reconstruction between June 2018 and June 2021 were included. The medial tibial slope (MTS), lateral tibial slope (LTS), and anterior tibial translation (ATT) were measured using magnetic resonance imaging and plain radiography of the knee joint. The meniscal lesions were assessed during surgery. Preoperative clinical assessments and final follow-up were conducted using patient-reported outcome measurements (PROMs), including the International Knee Documentation Committee (IKDC) evaluation, Lysholm knee scoring scale, and Tegner Activity scale. PROMs were collected at least two years postoperatively.

RESULTS

The average follow-up was 32.5 ± 7.4 months. There were no significant differences in postoperative IKDC score, Lysholm score, or Tegner activity score between patients with or without medial meniscus injury (p = 0.155, 0.914, and 0.042, respectively), with or without lateral meniscus injury (p = 0.737, 0.569, and 0.942, respectively), medial tibial slope > 12° or ≤ 12° (p = 0.290, 0.496, and 0.988, respectively), or lateral tibial slope > 7.4° or ≤ 7.4° (p = 0.213, 0.625, and 0.922, respectively). No significant correlations were found between anterior tibial translation and postoperative IKDC (R = -0.058, p = 0.365), Lysholm (R = -0.017, p = 0.459), or Tegner activity scores (R = -0.147, p = 0.189).

CONCLUSION

Our study demonstrates that single-bundle ACL reconstruction combined with ALL reconstruction provides reliable and comparable clinical outcomes in patients with high-risk factors for ACL graft failure, such as increased tibial slope or meniscal injury. Our results suggest that the indications for ALL reconstruction may be expanded to include patients with a high tibial slope or meniscal injury, because these factors have been shown to contribute to increased rotational instability and high rates of ACL graft failure. Future prospective randomized controlled trials with large patient cohorts and long follow-up periods are needed to validate these findings and establish clear guidelines for patient selection and surgical decision-making.

LEVEL OF EVIDENCE

Level 3.

Medial Meniscectomy at the Time of ACL Reconstruction Is Associated With Postoperative Anterior Tibial Translation: A Retrospective Analysis

Background

Medial meniscal pathology and management have not been associated with postoperative anterior tibial translation (ATT) after anterior cruciate ligament reconstruction (ACLR).

Purpose

The purpose of this study was to evaluate the role of medial meniscal injury and treatment on pre- and postoperative ATT in the setting of primary ACLR. More specifically, the association between repairable medial meniscal tears, medial meniscectomy, and postoperative ATT, along with rates of revision surgery, was examined.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective review was performed for patients who underwent ACLR between January 1, 2010 and December 31, 2015 at a single center. Descriptive data were obtained from an institutional database for a total of 396 patients included in this study and followed for 1 year postoperatively. Statistical analysis was performed to examine associations of meniscal treatment with postoperative ATT measurements made by KT-1000 arthrometer.

Results

A total of 243 patients underwent isolated ACLR with autograft, 72 patients underwent autograft ACLR and partial medial meniscectomy (MMx) (ACLR + MMx), and 81 patients underwent autograft ACLR and medial meniscal repair (MMR) (ACLR + MMR). Patients with ACLR + MMx had higher mean age and body mass index compared with patients in the other groups. Patients who underwent ACLR + MMx had greater postoperative side-to-side ATT compared with patients undergoing ACLR (1.55 mm vs 1.07 mm; P = .04) or patients undergoing ACLR + MMR (1.55 mm vs 1.01 mm; P = .03). The ACLR + MMx group was less likely to have symmetric (<3-mm side-to-side difference) postoperative ATT compared with the ACLR group (85% vs 93%; P = .03). There was no difference in postoperative ATT between ACLR and ACLR + MMR. Postoperative return to the operating room was greater in the ACLR + MRR group compared with the ACLR + MMx group (21.9% vs 8.2%; P = .05).

Conclusion

MMx at the time of ACLR led to higher postoperative ATT compared with isolated ACLR or ACLR + MMR.

The Role of Osteotomy in Anterior Cruciate Ligament Reconstruction

Coronal and sagittal plane knee malalignments have been shown to increase the forces on anterior cruciate ligament (ACL) grafts after ACL reconstruction (ACLR). Studies have shown the benefit of high tibial osteotomy to address coronal and sagittal imbalance in revision ACLR. The purpose of this article is to further describe the use of osteotomy by reviewing preoperative planning, indications, techniques, and outcomes of high tibial opening and closing wedge as well as anterior tibial closing wedge osteotomies in the setting of ACLR.

Return to the Pre-Injury Level of Sport after Anterior Cruciate Ligament Reconstruction: A Practical Review with Medical Recommendations

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

Anterior Cruciate Ligament Repair Augmented With Dynamic Intraligamentary Stabilization Is Equivalent to Hamstring Autograft Reconstruction at Short- and Mid-Term Follow-Up: A Systematic Review

PURPOSE

To compare clinical outcomes, knee stability and complications, failure, and revision rates after anterior cruciate ligament repair (ACLr) with dynamic intraligamentary stabilization (DIS) versus anterior cruciate ligament reconstruction (ACLR) with hamstring autograft for primary ACL ruptures at short and mid-term follow-up.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of PubMed/MEDLINE and Scopus was performed. Studies that evaluated patients undergoing ACLr with DIS or ACLR with hamstring autograft were considered for inclusion. Studies were excluded if patients were affected by concomitant meniscal, ligamentous, or chondral injuries needing surgical treatment, because of their potential confounding effect on postoperative outcomes. The Risk of Bias-2 tool was used to assess the risk of bias in the included studies. The quality of available evidence was rated according to Grading of Recommendations Assessment, Development, and Evaluation recommendations. The study protocol was registered in the PROSPERO database (ID: CRD42023394558).

RESULTS

Five randomized controlled trials comparing the outcomes of ACLr with DIS versus ACLR with hamstring autograft met the inclusion criteria. No major differences in terms of patient-reported outcomes (International Knee Documentation Committee subjective form, Lysholm score, Tegner activity scale, Knee injury and Osteoarthritis Outcome Score, visual analog scale satisfaction) or rates of complications, revisions, and failures were found in included studies at all time points. Repair showed greater International Knee Documentation Committee subjective form scores at 5 years in one study, whereas ACLR displayed significantly increased knee stability at 6 months and 5 years in 2 different studies, although the clinical relevance of these differences is doubtful.

CONCLUSIONS

The results of this study suggest that ACLr with DIS is not inferior to ACLR with hamstring autograft in terms of rates of clinical outcomes, knee stability, risk of failure, complications, and revision surgery. Therefore, ACLr with DIS may be a viable alternative to ACLR with hamstring autograft in selected patients.

LEVEL OF EVIDENCE

Level I, systematic review of Level I studies.

Comparison of physical therapy utilization, timing of return-to-sport test completion, and hop test performance by age and between sexes in youth athletes after anterior cruciate ligament reconstruction

OBJECTIVE

To compare physical therapy (PT) utilization, timing of return-to-sport (RTS) test and hop test performance by age and between sexes in youth after anterior cruciate ligament reconstruction (ACLR).

DESIGN

Multicenter retrospective cohort.

METHODS

A retrospective review of adolescents after primary ACLR was conducted. Participants completed return-to-sport (RTS) tests including single-legged hop testing. PT frequency, average weekly visits, and timing of RTS test were calculated. T-tests assessed the effect of age and sex on average weekly PT visits and multivariable logistic regressions assessed odds of passing hop tests.

RESULTS

289 participants were included (15.7 ± 1.9 years). There was no difference in average weekly PT visits (p = 0.321) or time to RTS test (p = 0.162) by age. There were significant differences in average weekly PT visits (p = 0.047) and mean time from surgery to RTS test (p = 0.048) between sexes with small effect sizes (d = 0.24 and d = 0.21, respectively). Age and sex had no effect on odds of passing hop tests (OR, 1.29; 95% CI, 0.71-2.35 and OR, 0.79; 95%CI, 0.43-1.45, respectively).

CONCLUSION

In a youth cohort, age and sex may have no clinically important effect on PT visit utilization, timing of RTS test or hop test performance.

Double-bundle anterior cruciate ligament reconstruction resulted in better International Knee Documentation Committee objective grading at fifteen year follow-up compared to single-bundle reconstruction

PURPOSE

The aim of this prospective randomized study was to evaluate whether the use of the anatomic double-bundle (DB) method for anterior cruciate ligament (ACL) reconstruction results in better clinical outcomes and a lower incidence of graft failure compared with the anatomic single-bundle (SB) method. The hypothesis was that DB ACL reconstruction would result in a lower incidence of graft failure.

METHODS

Patients were randomly assigned to either the SB group (n = 78) or the DB group (n = 75). Evaluation included clinical testing, subjective assessments, functional testing, and International Knee Documentation Committee (IKDC) objective grading. Surgical techniques were anatomic, and the rehabilitation protocol was standardized.

RESULTS

At 15-year follow-up, information was available on 100 patients (65%), of whom 55 (36%) were accepted in the final statistical analysis. There were almost three times as many graft failures in the SB group, but the result wasn´t statistically significant. Subjective assessments, knee stability (KT -1000 and pivot shift), range of motion (ROM), and functional one leg hop test showed no statistically significant differences between the groups. However, DB ACL reconstruction resulted in better International Knee Documentation Committee objective grading (P < 0.001).

CONCLUSION

At the 15-year follow-up, double-bundle surgery resulted in significantly better International Knee Documentation Committee objective grading compared to single-bundle surgery.

Press-Fit-Hybrid Technique for Anterior Cruciate Ligament Reconstruction With Autologous Hamstring Tendons

Arthroscopic-assisted anterior cruciate ligament reconstruction follows standardized protocols. Multiple fixation techniques are known. Discussion has been raised about osseus fixation and integration. To improve a biological osseous fixation of the anterior cruciate ligament transplant, a Press-Fit-Hybrid technique has been developed. The basic principle is to recycle bony cylinders obtained from the femoral and tibial tunnel to fix the transplant in the femoral and tibial tunnel. In addition to the biological advantage, there are additional economic benefits, such as no extra fixation material is necessary compared with common fixation techniques, and the overall surgical procedure requires minimal effort.

Increased risk for early revision with quadriceps graft compared with patellar tendon graft in primary ACL reconstructions

PURPOSE

Bone patella-tendon bone (BPTB) and hamstring tendon (HT) autografts are the most used grafts in primary anterior cruciate ligament (ACL) reconstructions (ACLR) in Norway. Quadriceps tendon (QT) autograft has gained more popularity during the past years. The purpose of this study is to compare revision rates and patient-reported outcomes of primary QT with BPTB and HT autograft ACL reconstructions in Norway at 2-year follow-up. It was hypothesized that there would be no difference in 2-year revision rates between all three autografts.

METHODS

Data included primary ACLR without concomitant ligament surgeries, registered in the Norwegian Knee Ligament Register from 2004 through 2021. Revision rates at 2 years were calculated using Kaplan-Meier analysis. Hazard ratios (HR) for revision were estimated using multivariable Cox regression analysis with revision within 2 years as endpoint. Mean change in patient-reported outcome was recorded preoperatively and at 2 years through the Knee Injury and Osteoarthritis Outcome Score (KOOS) subcategories 'Sport' and 'Quality of Life' was measured for patients that were not revised and analysed with multiple linear regression.

RESULTS

A total of 24,790 primary ACLRs were identified, 10,924 with BPTB, 13,263 with HT and 603 with a QT graft. Patients in the QT group were younger (23.5 years), more of them were women (58.2%) and over 50% had surgery <3 months after injury. The QT group had the highest prevalence of meniscal injuries (61.9%). Revision estimates at 2-years were 3.6%, 2.5% and 1.2% for QT, HT and BPTB, respectively (p < 0.001). In a Cox regression analysis with QT as reference, BPTB had a lower risk of revision (HR 0.4, 95% Cl 0.2-0.7, p < 0.001). No significant difference was observed in the revision risk between QT and HT (HR 1.1, 95% Cl 0.7-1.8, n.s.). The two most common reported reasons for revision were: traumatic graft rupture and nontraumatic graft failure. There were no differences between the groups in change of KOOS in subcategories 'Sport' and 'Quality of Life' at 2-years follow-up.

CONCLUSION

The 2-year risk of revision after ACLR with QT was higher than BPTB and similar to HT. No difference was found between the groups in patient-reported outcomes. This study provides valuable insights for both surgeons and patients when making decisions about the choice of autografts in primary ACL reconstructions.

LEVEL OF EVIDENCE

Level II.

Limb asymmetries persist 6 months after anterior cruciate ligament reconstruction according to the results of a jump test battery

Objectives

Test batteries used to assess a patient's return-to-sports (RTS) following anterior cruciate ligament reconstruction (ACLR) are currently undergoing continual development, although no consensus exist on tests to be administered to athletes before allowing return to play. A simple standardized jump test battery was developed to objectively evaluate knee function following ACLR, thereby aiding in RTS decision-making.

Methods

Thirty-three patients who underwent ACLR were prospectively assessed pre-operatively, 6, and 12 months after surgery. Knee function was assessed using a device for optical detection using a test battery consisting of three jump tests: monopodalic countermovement jump (CMJ), drop jump, and monopodalic side-hop. Limb symmetry index (LSI) was reported for all tests at all time points. LSI ≥90% was defined as RTS criteria.

Results

At 12-month evaluation, mean LSI significantly improved compared to 6-month follow up (p < 0.01), and also compared to baseline (p < 0.01), reporting a mean value of 92.6% for CMJ, 90.6 for drop jump and 96.9% for side hop test. Most patients fulfilled the RTS criteria 12 months after surgery (LSI ≥90%). The percentages of patients demonstrating LSI ≥90% at 6 months was 7/33 (21.2%) for CMJ, 12/33 (36.4%) for drop jump, and 11/33 (33.3%) for side-hop test. One year after surgery, percentages grew up to 66.6% (22/33), 63.6% (21/33), and 81.8% (27/33) respectively.

Conclusion

Six months after ACLR, knee functional performance was unsatisfactory in most patients, whereas a significantly higher percentage of patients met RTS criteria 1 year after surgery. The results of the jump test battery proposed in this study support the idea that timing for resumption of cutting and pivoting sports should be delayed later than 6 months, as still limb asymmetries persist at this time point.

Study on the use of 3D printed guides in the individualized reconstruction of the anterior cruciate ligament

OBJECTIVE

Evaluation of the accuracy and effectiveness of 3D printed guides to assist femoral tunnel preparation in individualised reconstruction of the anterior cruciate ligament.

METHODS

Sixty patients who attended the Affiliated Hospital of Binzhou Medical College for autologous hamstring single bundle reconstruction of the anterior cruciate ligament from October 2018 to October 2020 were selected and randomly divided into two groups, including 31 cases in the 3D printing group (14 males and 17 females, mean age 41.94 ± 10.15 years) and 29 cases in the control group (13 males and 16 females, mean age 37.76 ± 10.34 years). Patients in both groups were assessed for intraoperative femoral tunnel accuracy, the number of intraoperative positioning and the time taken to prepare the femoral tunnel, the length of the anteromedial approach incision, the pre-planned bone tunnel length and intraoperative bone tunnel length in the 3D printed group, IKDC score and Lysholm score preoperatively and at 3, 6 and 12 months postoperatively, the Lachman、pivot-shift test preoperatively and at 6 months postoperatively, gait analysis to assess internal and external rotation in flexion of the knee at 12 months postoperatively and postoperative complications in both groups.

RESULTS

There was no statistical difference in functional knee scores and anteromedial approach incision length between the 3D printed and control groups (p > 0.05), while there was a statistical difference in the accuracy of tunnel positioning, the time taken to prepare the femoral bone tunnel and the degree of external rotation of the knee in flexion between the two groups (p < 0.05). There was no statistical difference between the preoperative planning of the bone tunnel length and the intraoperative bone tunnel length (p > 0.05).

COMPLICATIONS

One case in the 3D printing group developed intermuscular vein thrombosis in the affected lower limb after surgery, which disappeared after treatment, while three cases in the control group developed intermuscular vein thrombosis in the affected lower limb. No complications such as bone tunnel rupture, deep vein thrombosis in the lower limb and infection occurred in either group.

CONCLUSION

3D printed guides assisted with individualized ACL reconstruction may improve the accuracy of femoral tunnel positioning, which is safe and effective, while reducing the operative time and the number of intraoperative positioning, without increasing the length of incision, and may obtain higher functional scores and rotational stability of the knee joint, which is in line with the concept of individualized ACL reconstruction.

The Role of Artificial Intelligence in Anterior Cruciate Ligament Injuries: Current Concepts and Future Perspectives

The remarkable progress in data aggregation and deep learning algorithms has positioned artificial intelligence (AI) and machine learning (ML) to revolutionize the field of medicine. AI is becoming more and more prevalent in the healthcare sector, and its impact on orthopedic surgery is already evident in several fields. This review aims to examine the literature that explores the comprehensive clinical relevance of AI-based tools utilized before, during, and after anterior cruciate ligament (ACL) reconstruction. The review focuses on current clinical applications and future prospects in preoperative management, encompassing risk prediction and diagnostics; intraoperative tools, specifically navigation, identifying complex anatomic landmarks during surgery; and postoperative applications in terms of postoperative care and rehabilitation. Additionally, AI tools in educational and training settings are presented. Orthopedic surgeons are showing a growing interest in AI, as evidenced by the applications discussed in this review, particularly those related to ACL injury. The exponential increase in studies on AI tools applicable to the management of ACL tears promises a significant future impact in its clinical application, with growing attention from orthopedic surgeons.

No Association Between Hamstrings-to-Quadriceps Strength Ratio and Second ACL Injuries After Accounting for Prognostic Factors: A Cohort Study of 574 Patients After ACL-Reconstruction

BACKGROUND

The stress on the anterior cruciate ligament (ACL) induced by the quadriceps can be attenuated by activation of the hamstrings by exerting an opposing torque to the anterior translation of tibia. Consequently, considering the ratio between strength of the hamstrings-to-quadriceps (HQ-ratio) may be of value to reduce the odds of second ACL injuries. The objective was therefore to evaluate (1) the association between HQ-ratio and the occurrence of a second ACL injury in patients after ACL-reconstruction within 2 years of return to preinjury sport level and (2) to compare the HQ-ratio between males and females after ACL reconstruction.

METHODS

Patients who had undergone primary ACL reconstruction and participated in knee-strenuous activity preinjury were included. Demographics, the occurrence of a second ACL injury, and muscle strength test results before returning to preinjury sport level were extracted from a rehabilitation registry. The endpoint was set at a second ACL injury or 2 years after return to preinjury sport level. A multivariable logistic regression was used to analyze the association between the HQ-ratio and a second ACL injury.

RESULTS

A total of 574 patients (50.0% female) with a mean age of 24.0 ± 9.4 years at primary ACL reconstruction were included. In the univariable logistic regression analysis, the odds of sustaining a second ACL injury decreased by 3% for every 1% increase in the HQ-ratio (OR 0.97 [95% CI 0.95-1.00], p = 0.025). After adjusting for the time from reconstruction to return to preinjury sport level, sex, preinjury sport level, graft choice, age, and body mass index, the results were no longer significant (OR 0.98 [95% CI 0.95-1.01], p = 0.16). Females had a higher HQ-ratio compared with males for both the ACL-reconstructed and uninjured side (3.7% [95% CI 5.7; 1.8%], p = 0.0002 and 3.3% [95% CI 4.6; 2.1], p < 0.001, respectively).

CONCLUSION

The HQ-ratio did not significantly affect the odds for sustaining a second ACL injury upon return to preinjury sports level after primary ACL reconstruction. Females had a significant higher HQ-ratio than males for both the ACL reconstructed and uninjured side.

Metal interference screw fixation combinations show high revision rates in primary hamstring tendon ACL reconstruction

BACKGROUND

Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Therefore, the purpose of this study was to determine ACL revision rates for specific combinations of femoral and tibial fixation methods within 2 years of primary hamstring tendon autograft ACLR based on data from the Swedish National Knee Ligament Registry (SNKLR).

METHODS

Patients that underwent primary hamstring tendon autograft ACLR between 2005 and 2018 in the SNKLR were included. The collected data included patient characteristics (age, sex, body mass index [BMI]), activity at time of injury, surgical information (concomitant injuries, time from injury to surgery, fixation types at the femur and tibia), and subsequent revision ACLR. Revision rate within 2 years of the index procedure was chosen, as ACLR fixation is most likely to contribute to ACLR revision within the first 2 years, during graft maturation.

RESULTS

Of the 23,238 included patients undergoing primary hamstring ACLR, 581 (2.5%) underwent revision ACLR within 2 years of the index procedure. Among the combinations used for > 300 patients, the femoral metal interference screw/tibial metal interference screw fixation combination had the highest revision rate followed by metal interference screw/resorbable screw and Endobutton/AO screw fixation combinations, with respective revision rates of 4.0, 3.0, and 3.0%. The lowest revision rate within 2 years of ACLR was found in the Endobutton/metal interference screw with backup Osteosuture fixation combination, used in 433 cases, with a failure rate of 0.9%.

CONCLUSION

Different early ACL revision rates were found across different combinations of femoral and tibial fixation devices within 2 years of primary hamstring tendon autograft ACLR. Metal interference screw fixation, particularly when performed on both the femoral and tibial sides, most frequently resulted in revision ACLR. These findings may be helpful for surgeons in selecting appropriate fixation devices for hamstring ACLR.

LEVEL OF EVIDENCE

IV.

The Posterior Tibial Slope Is Not Associated With Graft Failure and Functional Outcomes After Anatomic Primary Isolated Anterior Cruciate Ligament Reconstruction

BACKGROUND

Biomechanical studies have shown that an increased medial posterior tibial slope (MPTS) may affect anteroposterior knee laxity and tibial shear forces, ultimately increasing the risk for graft failure after anterior cruciate ligament (ACL) reconstruction. Previous clinical studies have, however, reported inconclusive results.

PURPOSE

The purpose of this study was to evaluate the relationship between the MPTS and graft failure as well as functional outcomes after anatomic primary isolated ACL reconstruction using a hamstring tendon autograft. It was hypothesized that an increased MPTS would be associated with a higher ACL graft failure rate. Furthermore, a higher MPTS would negatively correlate with functional outcomes in patients without ACL graft failure.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Consecutive patients who underwent isolated primary ACL reconstruction with an anteromedial portal drilling technique between January 2011 and December 2019 were retrospectively reviewed. The MPTS was measured on preoperative lateral knee radiographs. At a minimum of 24 months postoperatively, the ACL graft failure rate and patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form, Lysholm score, Tegner Activity Scale, visual analog scale for pain and subjective instability) were evaluated. Differences in the MPTS between patients with and without ACL graft failure as well as the frequency of graft failure between those with an MPTS <12° and those with an MPTS ≥12° were assessed for statistical significance. Binary logistic regression analysis was performed to stratify the risk of graft failure with the following variables: MPTS, age at surgery, and sex. Correlation analysis was performed to evaluate the relationship between the MPTS and PROM in patients without ACL graft failure.

RESULTS

In total, 326 patients were included (median follow-up, 71.0 months [IQR, 49.0-104.0 months]). There was no significant difference in the MPTS between patients with and without graft failure (10.6°± 3.2° vs 11.2°± 2.8°, respectively; P = .264). Additionally, there was no significant difference in the frequency of graft failure between patients with an MPTS <12° and those with an MPTS ≥12° (15.6% vs 16.5%, respectively; P = .835). Binary logistic regression showed that younger age at the time of surgery (odds ratio, 1.069 [95% CI, 1.031-1.109]) was associated with graft failure; sex and MPTS were not associated with graft failure. In patients without ACL graft failure, there was no significant correlation between the MPTS and PROM.

CONCLUSION

In patients who underwent anatomic primary isolated ACL reconstruction, an increased MPTS was not associated with a higher rate of graft failure or inferior functional outcomes. Younger age was a significant nonmodifiable risk factor for ACL graft failure.

A hamstring autograft diameter ≤ 8 mm is a safe option for smaller, lighter and female athletes who want to return to pivoting sports after ACL reconstruction : Results from a retrospective evaluation of a local ACL register

PURPOSE

To investigate the association between hamstring autograft diameter and ACL graft failure rate in athletes who successfully returned to pivoting sports after ACL reconstruction.

METHODS

Retrospective evaluation of ACL graft failure rates in athletes who underwent ACL reconstruction with all-inside hamstring autograft and successfully returned to pivoting sports following postoperative rehabilitation. Athletes were divided into a ≤ 8 mm group and a > 8 mm group. Data about return to pivoting sports and ACL graft failures after ACL reconstruction were collected via a digital questionnaire. ACL graft failures were in all cases confirmed by an orthopaedic surgeon and/or MRI. The association between hamstring autograft diameter and ACL graft failure rate was investigated using a Fisher's exact test in the subgroup of athletes who completed the digital questionnaire and returned to pivoting sports.

RESULTS

Two-hundred and twenty-nine of the 422 athletes who completed the digital questionnaire (54.2%) returned to a pivoting sport and were included for final analyses. Ninety-seven (42.4%) of the athletes who returned to sport were in the ≤ 8 mm group (8 graft failures) and 132 (57.6%) in the > 8 mm group (10 graft failures). There were significantly more women (49.5 and 13.6% respectively; p < 0.001) and significantly smaller (1.75 and 1.81 m respectively; p < 0.001), lighter (72.2 and 79.6 kg respectively; p < 0.001) and younger (23.6 and 26.1 years old respectively; p = 0.015) athletes in the ≤ 8 mm group compared to the > 8 mm group. There was no significant association between hamstring autograft diameter and ACL graft failure rate.

CONCLUSION

A hamstring autograft diameter of ≤ 8 mm is a legitimate option for smaller, lighter and female athletes without increasing the risk for ACL graft failure.

LEVEL OF EVIDENCE

III.

Quadriceps tendon autograft has similar clinical outcomes when compared to hamstring tendon and bone-patellar tendon-bone autografts for revision ACL reconstruction: a systematic review and meta-analysis

PURPOSE

Research regarding revision anterior cruciate ligament reconstruction (RACLR) with quadriceps tendon (QT) autografts is lacking. The purpose of this study was to perform a systematic review and meta-analysis of RACLR with QT and compare its patient outcomes to RACLR with hamstring tendon (HT) and bone-patellar tendon-bone (BTB) autografts.

METHODS

Adhering to PRISMA guidelines, a search for studies using QT in RACLR was performed within PubMed, Scopus, and CINAHL from database date of inception through December 26, 2022. Primary outcomes sought included: failure rate, Lysholm scores, International Knee Documentation Committee (IKDC) scores, IKDC grades, arthrometric knee side-to-side differences (STSD), pivot shift grade, donor site morbidity, return to sport, visual analog scale (VAS) pain scores.

RESULTS

Nine studies were included consisting of 606 RACLR: 349 QT, 169 HT, and 88 BTB. Overall failure rates were 7.6% QT, 13.3% HT, and 8.7% BTB. Mean weighted Lysholm scores were 85.8 ± 3.8 QT, 82.5 ± 3.8 HT and 86.6 ± 4.5 BTB. IKDC average scores were 82.3 ± 1.6 QT, 80.1 ± 1.7 HT, and 81.7 ± 5.5BTB. Combined rates of IKDC A/B grades were 88.4% and 80.0% for QT and HT, respectively. VAS average scores were 0.9 ± 1.1 QT, 1.4 ± 0.2 HT, and 0.7 ± 0.8 for BTB. Side-to-side difference was reported for QT and HT with average values of 1.7 ± 0.6 mm and 2.1 ± 0.5 mm, respectively. Grade 0 or 1 pivot shifts were reported in 96.2% of QT patients and 91.3% of HT. Donor site morbidity, only reported for QT and HT, was 14.6 ± 9.7% and 23.6 ± 14.1%, respectively. QT resulted in a mean Tegner score of 5.9 ± 1.5 versus HT 5.7 ± 1.5. Rate of return to pivoting sports was 38.0% QT, 48.6% HT, and 76.9% BTB. Across all outcomes, there was no significant difference when comparing QT to HT, QT to BTB, and QT compared to HT and BTB combined.

CONCLUSIONS

RACLR with QT yields satisfactory patient reported outcomes, satisfactory improvement in knee laxity, expected return to sport rates, and has an overall 7.6% failure rate. Outcomes are comparative to those of HT and BTB making it an acceptable graft choice for RACLR. Surgeons should consider using QT autograft for RACLR, especially when other autografts are unavailable.

LEVEL OF EVIDENCE

IV.

Complications of peroneus longus tendon harvesting: a retrospective review of 82 cases

OBJECTIVE

Peroneus longus tendon (PLT) has become a reliable autologous graft option for various ligament reconstructions. But there are potential risks and complications associated with its use as a graft. This retrospective study aimed to examine the complications and donor site morbidity following PLT harvesting.

PATIENTS AND METHODS

A retrospective review was performed on an institutional digital patient database, and all patients who underwent ligament reconstruction using PLT autograft were identified. Intraoperative, early, and late complications were reviewed using digital patient notes and patients underwent a complete physical examination during their final follow-up. Ankle function was assessed using the AOFAS score, and manual ankle muscle testing was performed on both sides. Sural nerve iatrogenic injury was evaluated with a dermatomal light touch examination. Cosmetic satisfaction due to incision scar and footwear complaints were also assessed.

RESULTS

82 patients (74 male, eight female) with a mean age of 31.9 ± 10.4 years (range, 16-66) were included in the final analysis. The mean follow-up time was 46.6 ± 30.3 months (range, 6-109). The mean AOFAS score for the donor side was 98.7 ± 3.3 (range, 87-100), and the contralateral side score was 100, with manual muscle testing graded as 5 in all movements and similar to the contralateral side. Fifteen patients (18.3%) had hypoesthesia over the dorsolateral aspect of the foot distal to the incision scar, two patients (2.4%) had hyperalgesia over the distal incision scar, and one patient (1.2%) had mild ankle instability. There were two cases (2.4%) of compartment syndrome, both of which were treated with fasciotomy and had complete regression of symptoms after 5 days. One patient (1.2%) had a transient peroneal nerve injury and foot drop that resolved in the sixth month.

CONCLUSIONS

The results of this retrospective study suggest that harvesting the PLT is associated with a high rate of complications and donor site morbidity. The most common complication was hypoesthesia around the lateral side of the foot, although the ankle functions were not affected significantly. Two cases of compartment syndrome and one transient peroneal nerve injury were observed. Care should be taken while harvesting PLT autograft, and it should be kept in mind that peroneal nerve injury might occur.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Combining return to sport, psychological readiness, body mass, hamstring strength symmetry, and hamstring/quadriceps ratio increases the risk of a second anterior cruciate ligament injury

PURPOSE

To investigate the combinations of variables that comprise the biopsychosocial model domains to identify clinical profiles of risk and protection of second anterior cruciate ligament injury.

METHODS

One hundred and forty-five patients for return-to-sport testing after anterior cruciate ligament (ACL) reconstruction (ACLR) were contacted, and 97 were deemed eligible. All were evaluated between 6 and 24 months and followed up for 2 years. Participants answered the International Knee Documentation Committee (IKDC) and Anterior Cruciate Ligament-Return to Sport after Injury Scale (ACL-RSI), performed the postural stability assessment using the Biodex Balance System, and assessed muscle strength at 60° and 300°/s on the isokinetic dynamometer. Personal factors (age, gender, body mass index), body structures (graft type and concomitant injuries), and environmental factors (time between surgery and evaluation) were also collected. The participants were asked about the occurrence of a second ACL injury and return to sport after 2 years of follow-up. Classification and regression tree (CART) analysis was used to determine predictors of a second ACL injury. The receiver operating characteristic (ROC) curve was performed to verify the accuracy of the CART analysis, in addition to the sensitivity, specificity, and relative risk (RR) of the model.

RESULTS

Of the initial 97 participants, 88 (89.8%) responded to follow-up and 14 (15.9%) had a second ACL injury (11 graft ruptures and three contralateral ACL). CART analysis identified the following variables as predictors of second ACL injury: return to sport, hamstring strength symmetry at 300°/s, ACL-RSI score, hamstrings/quadriceps ratio at 60°/s, and body mass index (BMI). CART correctly identified 9 (64.3%) of the 14 participants who were reinjured and 71 (95.9%) of the 74 participants who were not. The total correct classification was 90.9%. The area under the ROC curve was 0.88 (95% CI 0.72-0.99; p < 0.001), and the model showed a sensitivity of 75% (95% CI 42.8-94.5), specificity of 93.4% (95% CI 85.3-97.8), and RR of 15.9 (95% CI 4.9-51.4; p < 0.0001).

CONCLUSION

The combination of hamstring strength symmetry, hamstring/quadriceps ratio (body functions); return to sport (activity and participation); psychological readiness; and BMI (personal factors) could identify three clinical risk profiles for a second ACL injury with good accuracy.

LEVEL OF EVIDENCE

IV.

Ceiling Effect of the Combined Norwegian and Danish Knee Ligament Registers Limits Anterior Cruciate Ligament Reconstruction Outcome Prediction

BACKGROUND

Clinical tools based on machine learning analysis now exist for outcome prediction after primary anterior cruciate ligament reconstruction (ACLR). Relying partly on data volume, the general principle is that more data may lead to improved model accuracy.

PURPOSE/HYPOTHESIS

The purpose was to apply machine learning to a combined data set from the Norwegian and Danish knee ligament registers (NKLR and DKRR, respectively), with the aim of producing an algorithm that can predict revision surgery with improved accuracy relative to a previously published model developed using only the NKLR. The hypothesis was that the additional patient data would result in an algorithm that is more accurate.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Machine learning analysis was performed on combined data from the NKLR and DKRR. The primary outcome was the probability of revision ACLR within 1, 2, and 5 years. Data were split randomly into training sets (75%) and test sets (25%). There were 4 machine learning models examined: Cox lasso, random survival forest, gradient boosting, and super learner. Concordance and calibration were calculated for all 4 models.

RESULTS

The data set included 62,955 patients in which 5% underwent a revision surgical procedure with a mean follow-up of 7.6 ± 4.5 years. The 3 nonparametric models (random survival forest, gradient boosting, and super learner) performed best, demonstrating moderate concordance (0.67 [95% CI, 0.64-0.70]), and were well calibrated at 1 and 2 years. Model performance was similar to that of the previously published model (NKLR-only model: concordance, 0.67-0.69; well calibrated).

CONCLUSION

Machine learning analysis of the combined NKLR and DKRR enabled prediction of the revision ACLR risk with moderate accuracy. However, the resulting algorithms were less user-friendly and did not demonstrate superior accuracy in comparison with the previously developed model based on patients from the NKLR alone, despite the analysis of nearly 63,000 patients. This ceiling effect suggests that simply adding more patients to current national knee ligament registers is unlikely to improve predictive capability and may prompt future changes to increase variable inclusion.

No difference in revision risk between autologous hamstring graft less than 8 mm versus hybrid graft 8 mm or larger in anterior cruciate ligament reconstruction

PURPOSE

Hamstring autograft (HA) is commonly used for primary anterior cruciate ligament reconstruction (ACLR). However, if the harvested HA is inadequate in diameter, it is often augmented with an allograft tendon, forming a hybrid graft (HY). This study sought to evaluate aseptic revision risk following HA versus HY ACLR.

METHODS

A retrospective cohort study was performed using data obtained from our healthcare system's ACLR registry. Patients ≤ 25 years of age who underwent primary isolated ACLR were identified (2005-2020). Graft type and diameter size was the primary exposure of interest: < 8 mm HA and ≥ 8 mm HY. A secondary analysis was performed to examine 7 mm HA and 7.5 mm HA vs ≥ 8 mm HY. Propensity score-weighted Cox proportional hazard regression was used to evaluate the risk of aseptic revision.

RESULTS

The study sample included 1,945 ACLR: 548 ≥ 8 mm HY, 651 7 mm HA, and 672 7.5 mm HA. The crude cumulative aseptic revision probability at 8-years for ≥ 8 mm HY was 9.1%, 11.1% for 7 mm HA, and 11.2% for 7.5 mm HA. In adjusted analysis, no difference in revision risk was observed for < 8 mm HA (hazard ratio [HR] 1.15, 95% confidence interval [CI] 0.72-1.82), 7 mm HA (HR 1.23, 95% CI 0.71-2.11), or 7.5 mm HA (HR 1.16, 95% CI 0.74-1.82) compared to ≥ 8 mm HY.

CONCLUSION

In a US-based cohort of ACLR patients aged ≤ 25 years, we failed to observe any differences in aseptic revision risk for HA < 8 mm compared to HY ≥ 8 mm. Augmentation of a HA as small as 7 mm is not necessary to prevent a revision surgery.

LEVEL OF EVIDENCE

Level III.

Small Hamstring Tendon Graft for Anterior Cruciate Ligament Reconstruction Combined With Anterolateral Ligament Reconstruction Results in the Same Failure Rate as Larger Hamstring Tendon Graft Reconstruction Alone

PURPOSE

To compare patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring grafts 7 mm or less in diameter combined with anterolateral ligament (ALL) reconstruction versus isolated ACL reconstruction with grafts greater than 7 mm in diameter.

METHODS

We retrospectively evaluated the descriptive data and clinical outcomes of patients who underwent primary ACL reconstruction with hamstring grafts from June 2013 to January 2020 and had a minimum follow-up period of 2 years. Patients with quadrupled or quintupled semitendinosus and gracilis autograft 7 mm or less in diameter combined with single-strand ALL reconstruction (ACL-ALL group) were matched in a 1:2 propensity ratio to patients who underwent isolated single-bundle ACL reconstruction with hamstring grafts greater than 7 mm (ACL group).

RESULTS

We identified 30 patients in our database who met the criteria for the ACL-ALL group. The patients in this group were matched to 60 patients comprising the ACL group. Both groups were similar regarding all preoperative matched and unmatched variables. The mean ACL graft diameter was 6.8 ± 0.4 mm in the ACL-ALL group and 8.6 ± 0.6 mm in the ACL group (P < .001). The ACL-ALL group presented 1 failure (3.3%), and the ACL group presented 3 failures (5%) (P = .717). Postoperative KT-1000 measurements were similar between the groups (2.1 ± 1.1 mm vs 1.9 ± 1.2 mm, P = .114), as were postoperative pivot-shift grades (P = .652). Subjective International Knee Documentation Committee scores and Lysholm scores did not present any differences between the groups (P = .058 and P = .280, respectively).

CONCLUSIONS

Patients who undergo combined ACL-ALL reconstruction with an ACL graft diameter of 7 mm or less can achieve similar results to patients who undergo isolated ACL reconstruction with a graft diameter greater than 7 mm. An associated ALL reconstruction can be performed to increase knee stability in patients with small-diameter hamstring grafts.

LEVEL OF EVIDENCE

Level III, retrospective, comparative therapeutic trial.