A high level of knee laxity after anterior cruciate ligament reconstruction results in high revision rates

Effect of Slope-Reducing Tibial Osteotomy With Primary Anterior Cruciate Ligament Reconstruction on Clinical and Radiological Results in Patients With a Steep Posterior Tibial Slope and Excessive Anterior Tibial Subluxation: Propensity Score Matching With a Minimum 2-Year Follow-up

BACKGROUND

A steep posterior tibial slope (PTS) and excessive anterior tibial subluxation of the lateral compartment (ASLC) have been considered to be associated with inferior graft outcomes in primary anterior cruciate ligament (ACL) reconstruction (ACLR). Case series studies have demonstrated that combined slope-reducing tibial osteotomy can greatly improve knee functional scores and stability in revision ACLR. However, there is currently no comparative study evaluating the clinical benefits of osteotomy procedures in primary ACLR.

PURPOSE

To assess the feasibility of combined slope-reducing tibial osteotomy and primary ACLR in patients with a steep PTS and excessive ASLC and to explore the suitable threshold for osteotomy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2016 and 2022, of the 108 patients with ACL injuries who had a steep PTS (≥15°) and a follow-up ≥2 years, 30 patients with excessive ASLC (≥6 mm) underwent concomitant slope-reducing tibial osteotomy and ACLR (osteotomy group), and 78 patients underwent isolated ACLR (control group). Propensity score matching at a 1:2 ratio was used to match preoperative variables between the 2 groups. After matching preoperative variables, 25 and 48 patients underwent combined surgery and isolated ACLR, respectively. The primary outcome was ACL graft status (failure and laxity rates). The secondary outcomes were ASLC and anterior tibial subluxation of the medial compartment (ASMC), KT-1000 arthrometer side-to-side difference (SSD), pivot-shift grade, and second-look arthroscopic findings. Stratified analysis was performed with 1° PTS increments to explore the osteotomy threshold.

RESULTS

Both groups were comparable in terms of age, sex, side, body mass index, PTS, graft diameter, time from injury to surgery, ASLC, ASMC, KT-1000 arthrometer SSD, pivot-shift grade, and meniscal injuries (all P > .05). The mean PTS significantly decreased from 18.2° to 6.7° (P < .001) in the osteotomy group. The 2-year rate of ACL graft laxity was 12.0% in the osteotomy group and 35.4% in the control group, with a statistically significant difference (P = .033). There was no significant difference in the 2-year rate of ACL graft failure between the 2 groups (8.0% vs 12.5%, respectively; P = .559). The final follow-up data showed that improvements in ASLC (4.5 vs 6.4 mm, respectively; P = .012) and ASMC (2.8 vs 4.5 mm, respectively; P = .014) were more significant in the osteotomy group compared with the control group. On the second-look arthroscopic examination, the incidence of graft roof impingement in the control group was significantly higher than that in the osteotomy group (22.9% vs 4.0%, respectively; P = .039). No significant differences were observed between the 2 groups in terms of KT-1000 arthrometer SSD and high-grade pivot shift (P > .05). Furthermore, stratified analysis revealed that the combined procedure significantly reduced the ACL graft failure rate and improved the KT-1000 arthrometer SSD in patients with a preoperative PTS ≥16°.

CONCLUSION

Slope-reducing tibial osteotomy combined with primary ACLR significantly decreased the amount of anterior tibial subluxation, the incidence of graft roof impingement, and the graft laxity rate for patients with a steep PTS (≥15°) and excessive ASLC (≥6 mm). Furthermore, in patients with a PTS ≥16°, the combined procedure improved anterior knee stability and reduced the graft failure rate. Therefore, a PTS ≥16° plus ASLC ≥6 mm may be considered an appropriate indication for combining slope-reducing tibial osteotomy with primary ACLR.

Deconstructing the age-washout phenomenon in ACL-R failure: A short survey of anatomical, physiological and genetic risk factors for ACL reinjury

Level V.

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.

Risk factors for anteroposterior laxity increase over time in double-bundle anterior cruciate ligament reconstruction using hamstring autografts

PURPOSE

An anteroposterior (AP) laxity can increase over time after anterior cruciate ligament reconstruction (ACLR) using hamstring tendons; however, the associated risk factors remain unclear. This study aimed to investigate the risk factors of this phenomenon.

METHODS

Overall, 151 patients who underwent ACLR using hamstring autografts were recruited. AP laxity was evaluated using Knee Lax 3 arthrometer at 5 months, 1 and 2 years postsurgery. Patients were categorised into groups I (>1 mm increase) and C (<1 mm increase) based on whether they experienced an irreversible increase in AP laxity after 1 or 2 years compared with 5 months. Patient demographics and Knee injury and Osteoarthritis Outcome Score (KOOS) at 2 years postsurgery were compared between groups.

RESULTS

Group I (n = 33, 21%) showed a side-to-side difference of 4.6 (3.0-7.2) mm in AP laxity preoperatively and 0.3 (-0.7 to 1.3), 1.1 (0.2-1.9) and 2.4 (1.7-3.2) mm at 5 months, 1 and 2 years postoperatively, while group C (n = 119, 79%) showed 4.3 (2.8-5.7) mm preoperatively and 1.3 (0-1.9), 0.9 (0.1-1.8) and 0.6 (-0.3 to 1.5) mm, respectively. No significant differences were observed in the overall KOOS at 2 years (n.s.). However, group I was older (36 [22-46] vs. 28 [19-39] years; p = 0.044), had longer surgical waiting periods (122 [69-341] vs. 81 [52-136] days; p = 0.041) and lower preoperative Tegner activity scale scores (6 [5-7] vs. 7 [6,7]; p = 0.002).

CONCLUSION

While 33 patients (21%) experienced AP laxity increase over time, they had comparable clinical outcomes with group C.

LEVEL OF EVIDENCE

Level III.

Lack of association between revision ACL reconstruction and preoperative, intraoperative and post-operative factors at primary ACL reconstruction in children and adolescents

PURPOSE

To evaluate factors associated with revision anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR in children and adolescents.

METHODS

Children and adolescents (age <20 years at surgery) who underwent primary hamstring tendon ACLR at the Capio Artro Clinic, Stockholm, Sweden, between January 2005 and December 2018 were identified. Revision ACLR within 5 years of primary ACLR was captured in the Swedish National Knee Ligament Registry. Univariable and multivariable logistic regression analyses were used to evaluate the associations between revision ACLR and preoperative (age, sex, body mass index, time from injury to surgery, pre-injury Tegner activity level, medial collateral ligament injury, passive contralateral knee hyperextension [≤-5°]), intraoperative (medial meniscus and lateral meniscus [LM] resection or repair, cartilage injury and graft diameter) and post-operative (KT-1000 side-to-side anterior knee laxity, limb symmetry index for extension and flexion strength and single-leg-hop (SLH) test performance at 6 months) factors at primary ACLR.

RESULTS

A total of 1888 patients (mean age: 16.0 ± 2.0, range: 8-19 years) who underwent primary ACLR were included. The overall incidence of revision ACLR within 5 years was 9.0% (170 out of 1888). Univariable analysis revealed that a time from injury to primary ACLR of <5 months (odds ratio [OR]: 2.27, 95% confidence interval [CI]: 1.61-2.35, p < 0.001) and LM resection (OR: 1.49, 95% CI: 1.00-2.20, p = 0.04) increased the odds of revision ACLR. Multivariable analysis showed that revision ACLR was significantly associated only with a time from injury to primary ACLR of <5 months (OR: 2.56, 95% CI: 1.72-3.70, p < 0.001).

CONCLUSION

There was a lack of association between revision ACLR and preoperative, intraoperative and post-operative factors at primary ACLR in children and adolescents. A time from injury to primary ACLR of <5 months was the only factor associated with revision ACLR within 5 years.

LEVEL OF EVIDENCE

Level III.

A High Grade of Postoperative Knee Laxity Is Associated With an Increased Hazard of Revision Surgery: A Cohort Study of 4697 Patients With Primary ACL Reconstruction

BACKGROUND

There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.

STUDY DESIGN

Cohort study, Level of evidence 3.

METHODS

Patients who underwent primary ACLR with a hamstring tendon autograft at the authors' institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015).

CONCLUSION

A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome.

Transphyseal ACL reconstruction and tenodesis in skeletally immature patients demonstrates encouraging clinical scores, without growth disturbance, excessive laxity or re-injury

Purpose

Paediatric patients demonstrate high re-rupture rates after anterior cruciate ligament reconstruction (ACLR), with numerous surgical techniques proposed to deal with this challenging cohort. This study investigated the early clinical outcomes, complications, return to sport (RTS) and re-rupture rates up until 2-years post-surgery in paediatric patients presenting with open growth plates undergoing transphyseal ACLR that was combined with an extra-articular tenodesis (LET).

Methods

Between October 2017 and September 2020, 20 skeletally immature patients were consecutively recruited and underwent transphyseal ACLR and LET. Patient reported outcome measures (PROMs), KT-1000 laxity, knee range of motion (ROM), maximal isokinetic knee torque and a 3-hop battery were assessed at 6-, 12- and 24-months. Limb Symmetry Indices (LSIs), RTS rates, complications, re-ruptures and re-operations were reviewed.

Results

All PROMs improved (p < 0.05). No change (p = 0.903) in laxity between limbs was seen, while 18 patients (90%) demonstrated normal (<3 mm) or near normal (3-5 mm) laxity differences. Peak knee flexion ROM improved over time (p = 0.028), while LSIs for knee extensor strength (p < 0.001), the single (p = 0.002) and triple crossover (p = 0.038) hop tests improved. At 24 months, 18 patients (90%) were participating in their pre-injury pivoting sport activities. No complications, growth disturbances, re-injuries or subsequent surgeries were observed.

Conclusions

Transphyseal ACLR combined with LET, undertaken in skeletally immature paediatric patients, demonstrated high scoring PROMs, physical performance and RTS overall, without evidence of growth disturbance or excessive graft laxity. No re-injuries have been observed at this time with ongoing review required in this high-risk cohort.

Evaluation of Anterior Tibial Translation Under Physiological Axial Load After ACL Reconstruction With Lateral Extra-articular Tenodesis

Background

Postoperative laxity correlates with negative clinical outcomes after anterior cruciate ligament reconstruction (ACLR). The influence of lateral extra-articular tenodesis (LET) on anteroposterior translation is unclear.

Purpose/Hypothesis

This study aimed to evaluate the reduction in radiographic static anterior tibial translation (SATT) and dynamic anterior tibial translation (DATT) after LET as an adjunctive procedure to ACLR. It was hypothesized that adding a LET procedure would have no effect on postoperative SATT and DATT.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent primary ACLR with hamstring tendon autografts between 2020 and 2022 were reviewed, and those who underwent ACLR and LET as an anterolateral associate procedure were paired 1 to 1 with those who underwent isolated ACLR (control) based on age, sex, preoperative SATT, and posterior tibial slope (PTS). The indications for LET were age <18 years and anterolateral rotary instability (grade ≥2 pivot shift). A previously validated technique was used to measure SATT, DATT, and PTS on lateral weightbearing and lateral stress knee radiographs. Preoperative and 9-month postoperative radiographs were compared between the 2 groups.

Results

A total of 72 patients were included in the analysis (n = 36 patients in each group). The inter- and intraobserver reliability of the SATT, DATT, and PTS measurements was excellent (intraclass correlation coefficients, 0.88-0.99). The mean pre- and postoperative SATT in the ACLR+LET group was 2.44 ± 2.90 mm and 2.44 ± 2.38 mm, respectively, compared with 2.60 ± 2.99 mm and 2.12 ± 2.74 mm, respectively, in the control group. The mean pre- and postoperative reduction in side-to-side DATT in the ACLR+LET group was 5.44 ± 4.65 mm and 1.13 ± 2.95 mm, respectively, compared with 5.03 ± 3.66 mm and 2 ± 3.12 mm, respectively, in the control group. There was no pre- to postoperative difference in SATT (P = .51). However, the side-to-side DATT was reduced by 3.66 ± 3.37 mm postoperatively (P < .001), without significant differences between groups (P = .24).

Conclusion

Including a LET procedure for patients undergoing ACLR did not reduce SATT; that is, it did not decrease the amount of tibial translation due to physiological axial load.

Responsiveness of the Various Short-Form Versions of the Knee Injury and Osteoarthritis Outcome Score Between 2 and 5 Years After Anterior Cruciate Ligament Reconstruction

Background

Various short-form versions of the Knee injury and Osteoarthritis Outcome Score (KOOS) have been developed in an attempt to minimize responder burden. However, the responsiveness of these short-form measures in patients who have undergone anterior cruciate ligament (ACL) reconstruction has not been compared at midterm follow-up.

Purpose

To determine the responsiveness of 3 short-form versions of the KOOS (KOOS-12, KOOS-Global, and KOOS-ACL) in patients who have undergone ACL reconstruction.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

In 276 patients (149 male, 127 female), we administered the KOOS and a measure of overall knee function at both 2 and 5 years after ACL reconstruction. From the full KOOS, the following short-form versions were calculated: KOOS-12, KOOS-Global, and KOOS-ACL. Responsiveness was assessed using several distribution and anchor-based methods for each of the short-form versions. From distribution statistics the standardized response mean (SRM) and smallest detectable change (SDC) were calculated. Using the anchor-based method, the minimally important change (MIC) that was associated with an improvement in knee function was determined using receiver operating characteristic (ROC) analysis.

Results

High ceiling effects were present for all measures. KOOS-Global scores increased significantly over time, whereas KOOS-12 and KOOS-ACL did not change. The KOOS-Quality of Life (QOL) subscale, which can be derived from both KOOS-Global and KOOS-12, also increased significantly between assessments. Both these increases were associated with a small (0.2-0.3) SRM. The MIC was smallest for KOOS-Global (3.2 points) and largest for KOOS-QOL (9.4 points), and, for all measures, the MIC was larger than the SDC at a group level. KOOS-Global was the only measure for which the mean difference between the 2- and 5-year assessments exceeded both the SDC (group level) and the MIC.

Conclusion

Of the 3 short-form versions of the KOOS currently available, the KOOS-Global had the greatest responsiveness to change between the 2- and 5-year assessments after ACL reconstruction. High ceiling effects were present for all versions.

Similar outcomes after anterior cruciate ligament reconstruction in paediatric and adult populations: a 1-year follow-up of 506 paediatric operations in Denmark

PURPOSE

To present 1-year results after all paediatric anterior cruciate ligament (ACL) reconstructions in Denmark (5.9 M inhabitants) for the 10½ year period, 1 July 2011 to 31 December 2021.

METHODS

All children who had an ACL reconstruction were enrolled. They were asked to complete Pedi-IKDC preoperatively and at 1-year follow-up. Independent observers performed pivot shift test and instrumented laxity assessment preoperatively and at 1-year follow-up.

RESULTS

The median age of the 506 children (47.2% girls) was 14.3 years (9.3-15.9). The Pedi-IKDC score increased from preoperatively 61.6 ± 15.8 (mean ± SD) to 85.9 ± 13.0 at 1-year follow-up (p < 0.0001). There were concomitant injuries (to meniscus and/or cartilage) in 49.9%, but these children had preoperative and follow-up Pedi-IKDC scores similar to the scores for children with isolated injury to ACL (n. s.). Instrumented anterior laxity was 4.3 ± 1.4 (mean ± SD) mm preoperatively and 1.4 ± 1.4 mm at follow-up (p < 0.0001). Preoperatively, 3% had no pivot shift whilst this was the case for 68% postoperatively (p < 0.0001). Twenty-five children (5.6%) had 4 mm instrumented laxity or more relative to the unoperated knee at follow-up. Two patients (0.4%) had an operatively treated deep infection, three (0.5%) were operated on for reduced range of motion and two (0.4%) had a revision ACL reconstruction.

CONCLUSION

ACL reconstruction resulted in a clinically meaningful increase in Pedi-IKDC, an improved instrumented stability, a reduction in the grade of pivot shift and the complication rate was low at 1-year follow-up. The risk of graft insufficiency at 1-year follow-up was the same as in an adult population.

LEVEL OF EVIDENCE

II.

Good clinical scores, no evidence of excessive anterior tibial translation, a high return to sport rate and a low re-injury rate is observed following anterior cruciate ligament reconstruction using autologous hamstrings augmented with suture tape

INTRODUCTION

Augmented anterior cruciate ligament reconstruction (ACLR) techniques have been proposed to reduce the high reported re-injury rates and low rates of return to sport (RTS). This study reports clinical outcomes, RTS and re-injury rates in patients undergoing ACLR using autologous hamstrings augmented with suture tape.

MATERIALS AND METHODS

A total of 53 patients were prospectively recruited, undergoing ACLR using hamstrings with suture tape augmentation, combined with a structured rehabilitation programme. Outcomes were collected to 24 months, including patient-reported outcome measures (PROMs), KT-1000 measurements, peak isokinetic knee strength and a four hop test battery. Limb Symmetry Indices (LSIs) were calculated for performance measures, whilst RTS rates, re-tears and re-operations were presented.

RESULTS

There were no significant side-to-side differences in anterior tibial translation between the operated and non-operated knees at 6 months (p = 0.433), with no increase (p = 0.841) in side-to-side anterior tibial translation from 6 to 24 months. At 24 months, 98.0% of patients demonstrated normal (< 3 mm) or near normal (3-5 mm) side-to-side differences. LSIs for peak knee extensor torque (p < 0.0001) and the single (p = 0.001), triple (p = 0.001) and triple crossover (p < 0.0001) hop tests for distance significantly improved. All PROMs significantly improved (p < 0.0001), with 70.2% and 85.7% of patients actively participating in pivoting sports at 12 and 24 months, respectively. Three patients underwent secondary procedures for meniscal symptoms. One patient suffered an ACL re-tear (17 months), with no further ipsilateral or contralateral injuries.

CONCLUSION

ACLR with suture tape augmentation demonstrated no evidence of excessive anterior tibial translation, high-scoring PROMs, sound performance scores, a high rate of RTS and low re-injury rate.

Double-bundle non-anatomic ACL revision reconstruction with allograft resulted in a low revision rate at 10 years

PURPOSE

This study aimed at reporting the long-term second revision rate and subjective clinical outcomes from a cohort of patients who underwent a double-bundle (DB) ACLR first revision with allograft at a single institution.

METHODS

The Institutional database was searched according to the following inclusion criteria: (1) patients that underwent DB-ACL first revision with Achilles tendon allograft, (2) surgery performed between January 2000 and December 2012, (3) age at revision ≥ 18 y/o. Patients' general information, history, surgical data, and personal contacts were extracted from charts. An online survey platform was implemented to collect responses via email. The survey questions included: date of surgeries, surgical data, date of graft failure and subsequent second ACL revision surgery, any other surgery of the index knee, contralateral ACLR, KOOS score, and Tegner scores.

RESULTS

Eighty-one patients were included in the survival analysis, mean age at revision 32 ± 9.2 y/o, 71 males, mean BMI 24.7 ± 2.7, mean time from ACL to revision 6.8 ± 5.4 years, mean follow-up time 10.7 ± 1.4 years. There were 12 (15%) second ACL revisions during the follow-up period, three females and nine males, at a mean of 4.5 ± 3 years after the index surgery. The overall survival rates were 85% from a second ACL revision and 68% from all reoperations of the index knee. Considering only the successful procedures (61 patients), at final follow-up, the mean values for the KOOS subscales were 84 ± 15.5 for Pain, 88.1 ± 13.6 for Symptoms, 93 ± 11.6 for ADL, 75 ± 24.5 for Sport, and 71 ± 19.6 for Qol. Twenty-nine (48%) patients performed sports activity at the same level as before ACLR failure.

CONCLUSIONS

Double-bundle ACL revision with fresh-frozen Achilles allograft yields satisfactory results at long-term follow-up, with an 85% survival rate from a second ACL revision at mean 10 years' follow-up and good patient-reported clinical scores.

LEVEL OF EVIDENCE

Level IV.

Scoping Review on ACL Surgery and Registry Data

PURPOSE OF REVIEW

To present an overview of registry-based anterior cruciate ligament (ACL) research, as well as provide insight into the future of ACL registries.

RECENT FINDINGS

During the past decades, the ACL registries have had an important role in increasing our understanding of patients with ACL injuries and their treatment. The registry data has deepened our understanding of factors that have been associated with an increased risk of sustaining an ACL injury and for evaluation of treatment factors and their impact on patient-related outcomes. Recently, registry-based ACL research using artificial intelligence (AI) and machine learning (ML) has shown potential to create clinical decision-making tools and analyzing outcomes. Thus, standardization of collected data between the registries is needed to facilitate the further collaboration between registries and to facilitate the interpretation of results and subsequently improve the possibilities for implementation of AI and ML in the registry-based research. Several studies have been based on the current ACL registries providing an insight into the epidemiology of ACL injuries as well as outcomes following ACL reconstruction. However, the current ACL registries are facing future challenges, and thus, new methods and techniques are needed to ensure further good quality and clinical applicability of study findings based on ACL registry data.

Adjustable-loop implants are non-inferior to fixed-loop implants for femoral fixation in anterior cruciate ligament reconstruction

PURPOSE

Button implants with an adjustable-loop device (ALD) are often used in anterior cruciate ligament reconstruction (ACLR). Clinical research comparing ALDs with fixed-loop devices (FLD) has mainly been conducted in small patient populations with short follow-up times. To determine whether ALDs are safe to use in ACLR, a non-inferiority study with a large sample population and a long follow-up period would be beneficial. This study compared ALDs with FLDs to determine non-inferior revision surgery rates, knee stability, and patient-reported outcomes (PROM) in ACLRs.

METHODS

This non-inferiority register-based cohort study was conducted using data from the Danish Knee Ligament Reconstruction Registry (DKRR). A total of 12,723 patients > 15 years of age with primary ACLR using hamstring tendon autografts and either an FLD or ALD for femoral fixation were included: 9719 patients were in the FLD group, and 3014 patients were in the ALD group. The primary outcome was revision ACLR with a non-inferiority margin for ALDs at 4% at the 2-year follow-up. The secondary outcomes were anterior and rotatory knee stability and PROMs based on the Knee Injury and Osteoarthritis Outcome Score (KOOS) at the 1-year follow-up.

RESULTS

The crude cumulative revision rates in ALD implants at 2 and 5 years were 2.1% (95% CI 1.62-2.68) and 5.0% (95% CI 4.22-5.96), respectively. In the FLD group, the rates were 2.2% (95% CI 1.89-2.48) at 2 years and 4.7% (95% CI 4.31-5.20) at 5 years. The 1-year side-to-side differences were 0.97 mm (95% CI 0.90-1.03) in the ALD group and 1.45 mm (95% CI 1.41-1.49) in the FLD group. In the FLD group, 13% had a positive pivot shift, and in the ALD group, 6% had a positive pivot shift. There were no differences in KOOS.

CONCLUSION

ALDs were non-inferior to FLDs regarding revision rates, knee stability, and patient-reported outcomes. Based on this conclusion, ALDs are safe to use for femoral fixation in ACLR.

LEVEL OF EVIDENCE

III.