KT-1000 Arthrometer Measurements Research Articles

High Revision Rate After Transphyseal ACL Reconstruction in Skeletally Immature Patients.

Objectives: There remains considerable debate regarding the optimal management of anterior cruciate ligament (ACL) injuries in skeletally immature patients. This study aims to evaluate the clinical outcomes of transphyseal ACL reconstruction in patients with open growth plates. Methods: This retrospective study included skeletally immature patients with full-thickness ACL tears and confirmed open physis. ACL reconstructions were performed using a four-strand semitendinosus autograft, with an additional gracilis tendon graft if needed. The surgical technique emphasized tibial and femoral physeal-sparing tunnel placement to minimize disruption of the growth plates. Clinical assessment included measurements for limb length discrepancy, knee stability, and growth disturbances. Functional outcomes were evaluated using IKDC 2000, Lysholm, and KOOS scores, while ligament stability was assessed with KT-1000 arthrometer measurements at routine follow-up. Results: A total of 31 consecutive patients (15 females, 16 males; mean age 13.6 ± 1.8 years, range 9-16 years) were included. Mean follow-up was 49 ± 26 months (range 18-93 months). The mean time to return to sports was 8.8 ± 4.4 months. Eight patients (26%) experienced ACL graft rupture and underwent revision ACL reconstruction. One additional patient required partial meniscectomy. The overall revision rate was 29%. The mean subjective IKDC score was 91.8 ± 7.2, with Lysholm and KOOS scores of 96.6 ± 7.9 and 94.2 ± 5.3, respectively. No significant growth disturbances were noted. The mean side-to-side difference in KT-1000 testing was 2.2 ± 1.5 mm. Patients who underwent revision ACL reconstruction showed significantly greater length growth compared with those with intact ACL reconstruction (p = 0.02). Spearman correlation revealed a significant association between length growth and anterior tibial translation (p = 0.02, r = 0.46). Conclusions: Transphyseal ACL reconstruction in skeletally immature patients provides favorable clinical and radiological outcomes, with minimal risk of growth disturbance. Most patients returned to pre-injury levels of athletic activity. However, the high revision rate emphasizes the complexity of managing ACL injuries in this population.

Risk for Revision ACLR After Primary All-Inside Quadrupled Semitendinosus Hamstring Tendon Autograft ACLR With Independent Suture Tape Augmentation: A Retrospective Cohort Study.

The rate of failed anterior cruciate ligament reconstruction (ACLR) remains high in the younger and more active patient populations. Suture tape augmentation (STA) in addition to ACLR may reduce the risk for revision surgery. The purpose of this study was to compare patient outcomes between patients who underwent primary all-inside quadrupled semitendinosus hamstring tendon autograft (QST-HTA) ACLR with and without STA. It was hypothesized that the STA cohort would demonstrate a lower incidence of subsequent revision ACLR while maintaining comparable patient-reported outcomes. Cohort study; Level of evidence, 3. All patients ≤40 years of age who received primary all-inside QST-HTA ACLR with and without independent STA augmentation were identified. The following validated patient-reported outcome measures (PROMs) were collected: visual analog scale for pain, Single Assessment Numeric Evaluation, Knee injury and Osteoarthritis Outcome Score subscales, and Tegner activity scale. KT-1000 arthrometer measurements were collected pre- and postoperatively. Cox proportional hazards model and nominal logistic regression analysis were used to assess additional variables associated with revision ACLR. A total of 104 patients with a mean age of <22 years were included in the final data analysis (STA: 36 patients; control: 68 patients). Significantly fewer patients in the STA group sustained a graft failure necessitating revision surgery at the final follow-up (5.6% vs 24%; relative risk, 0.24 [95% CI, 0.06-0.97]; P = .017). Four-year graft survival was significantly higher in the STA group (97.2% vs 82.4%; P = .031). All PROMs significantly improved postoperatively except for Tegner levels, which decreased in both groups compared with their preinjury levels (P < .001). Return to sports was similar in both groups with >70% of patients returning to their previous level of competition. Regression analysis demonstrated increased risk for revision ACLR in younger patients, high school athletes, and those with higher postoperative activity levels. QST-HTA ACLR with STA was associated with reduced risk for revision ACLR compared with nonaugmented QST-HTA ACLR in this young patient population. Furthermore, the addition of suture tape did not appear to affect postoperative patient-reported and return-to-sports outcomes.

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.

Primary All-Soft Tissue Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction With Suture Tape Augmentation Resulted in Satisfactory Patient Outcomes and a Low Graft Failure Rate in High School and Collegiate Athletes

To evaluate ≥2-year patient outcomes after primary all-soft tissue quadriceps tendon autograft (ASTQ) anterior cruciate ligament reconstruction (ACLR) with suture tape augmentation (STA) in skeletally mature high school and collegiate athletes. All high school and collegiate athletes who underwent primary ASTQ ACLR with STA with a minimum of 2-year follow-up were analyzed retrospectively. Patients were administered validated patient-reported outcome measures (PROMs) pre- and postoperatively. The minimal clinically important difference was calculated for each PROM based on this study population and applied to the individual patient. Return to sport, subsequent surgical intervention including contralateral ACLR, and KT-1000 arthrometer measurements for knee laxity were collected. Complications were assessed by physical examination, radiologic studies, or obtained via telephone. In total, 60 patients were included in the final data analysis, with a mean age of 16.8 years (95% confidence interval 13-23) and mean final follow-up of 37.1 months (95% confidence interval 33.1-41.1). Twelve patients (20%) required subsequent surgery on the ipsilateral knee, which included 7 patients having a subsequent meniscal procedure and 3 patients who underwent arthrolysis. None sustained a graft failure, and 6 patients sustained a contralateral ACL injury necessitating surgery. All PROMs improved at the final follow-up (P < .001). In addition, KT-1000 arthrometer measurements significantly improved postoperatively at 1-year clinical follow-up (P < .001). Most patients obtained the minimal clinically important difference thresholds for each PROM at the final follow-up. There were 48 patients (80%) who participated in pivoting sports. The return-to-sport rate at same level was 54 patients (90%), with 6 patients (10%) not returning to the same level because of graduation. ASTQ ACLR with STA in a young athletic patient population may result in a low graft failure rate while maintaining satisfactory patient outcomes at short-term follow-up, including a return to sport at the same level of 90%. Level IV, retrospective case series.

A Systematic Review of Noncircular (Rectangle, Oval) Femoral Tunnel Anterior Cruciate Ligament Reconstruction: Does it Improve Outcomes?

Purpose: The purpose of this study is to systematically review the clinical and biomechanical studies regarding noncircular (rectangular and oval) femoral tunnel anterior cruciate ligament reconstruction (ACLR). We hypothesized that noncircular femoral tunnel ACLR has its advantages in unique situations while maintaining comparable clinical and radiographic outcomes when compared to conventional techniques. Methods: A systematic review of the literature was performed in PubMed and Scopus databases to identify published articles on the clinical outcomes of noncircular (rectangle and oval) ACLR. The results of the eligible studies were analyzed in terms of instrumented laxity measurements, Lachman test, pivot-shift test, Lysholm and Tegner scores, objective and subjective International Knee Documentation Committee (IKDC) scores, and surgical complications/failures. A meta-analysis was performed on Lysholm scores and KT side-to-side data comparing noncircular ACLR with the conventional round technique. Results: A total of 22 papers for the rectangle group (n = 1314) met the inclusion criteria. With an average follow-up of 15.8 months (±10.4 months), the mean reported Lysholm score was 97.8 (±0.80) and the mean reported KT-1000 arthrometer measurement was 1.2 (±1.9). When comparing the rectangle technique to the conventional round, no significant differences were seen regarding the Lysholm score (P = 0.95) or KT-1000 arthrometer measurements (P = 0.14) at the final follow-up. In the oval group, a total of 5 studies (n = 322) met the eligibility criteria. With an average follow-up of 20.2 months (±13.7 months), the mean reported Lysholm score was 94.4 (±2.0), the mean IKDC subjective was 90.4 (±1.2), and the mean KT-1000 arthrometer measurement was 1.6 (±0.4). The scarcity of randomized controlled trials available for this analysis limited the amount of data available for meta-analysis. Conclusions: Noncircular femoral tunnel ACLR has shown reasonable and comparable clinical outcomes to the conventional technique, demonstrating no difference between the two techniques and making it a valuable option for primary or revision ACLR.

Primary Anterior Cruciate Ligament Reconstruction with Suture Tape Augmentation: A Case Series of 252 Patients.

Anterior cruciate ligament reconstruction (ACLR) using suture tape augmentation to internally brace is a relatively new technique. The primary goal of this study was to prospectively collect patient-reported outcomes (PROs) and surgical history from patients who underwent primary ACLR with internal bracing to determine if internal bracing resulted in a low graft failure rate while maintaining acceptable PROs. A total of 252 patients with a mean age of 23.6 years (95% confidence interval [CI]: 22.1-25.1) and a mean follow-up of 37.9 months (95% CI: 35.8-40.0) were included in this study. Patients who underwent primary ACLR with internal brace augmentation between July 12, 2016 and July 31, 2021 were eligible. A total of 222 patients were contacted via telephone and administered the visual analog scale (VAS), the single assessment numeric evaluation (SANE), the Lysholm knee score scale, and, if applicable, the short version ACL return to sport after injury (SV-ACL-RSI) survey. Additionally, patients were asked to give an updated orthopaedic history. Thirty additional patients were included from either our institution's registry or by completing their surveys in-office or by e-mail. The minimal clinically important difference (MCID) and patient-acceptable symptom states (PASS) were calculated based on our patient population and applied to each individual patient. The patients' electronic health record (EHR) was searched for pre- and postoperative clinical data including KT-1000 arthrometer measurements. Two patients (0.8%) had subsequent graft failures and one patient (0.4%) required a revision surgery. MCID was achieved in 242 patients (96.0%) for the Lysholm, 227 patients (90.1%) for the SANE, and 146 patients (57.9%) for the VAS. PASS was achieved in 214 patients (84.9%) for the Lysholm, 198 patients (78.6%) for the SANE, and 199 (80.0%) patients for the VAS, postoperatively. Of note, 65 patients (25.8%) exceeded the PASS threshold for the VAS preoperatively. A total of 127 patients (84.4%) met the cutoff of ≥60/100 for the SV-ACL-RSI survey postoperatively. Postoperative KT-1000 measurements showed near-identical side-to-side differences at both the 13.6-kg pull and manual maximum pull. When stratifying patients based on age at the time of surgery, it was noted that patients younger than 25 years had significantly higher SANE scores (91.6 [95% CI: 90.2-92.9] vs. 82.6 [95% CI: 79.0-86.2]; p < 0.0001) and lower VAS pain scores (0.7 [95% CI: 0.5-0.8] vs. 1.2 [95% CI: 0.8-1.5]; p = 0.004). Primary ACLR with internal bracing led to acceptable patient outcomes and a graft failure rate of less than 1%. LEVEL OF EVIDENCE:: case series, IV.

Poster 344: Reduced Incidence of Anterior Cruciate Ligament Reconstruction Revision with Internal Brace Augmentation: A Retrospective Matched Cohort Study with a minimum 2-year Follow-up

Objectives: The primary purpose of this study was to investigate retear rates in patients who underwent ACLR with and without internal bracing in a matched cohort study. Additionally, we also sought to investigate if there were any differences in clinical and patient-reported outcomes between the groups. We hypothesized that ACLR with internal bracing would reduce the incidence of revisions in a safe and effective manner. Methods: A total of 200 patients were included in this study. Patients between the ages of 13-39 at the time of surgery who underwent primary autograft ACLR with internal bracing (IB group) between October 2010 and July 2020 and were enrolled in our institution’s registry with a minimum of 2-year follow-up were identified and matched 1:1 with a non-internal brace (no-IB) group based on patient demographics and concomitant procedures. Every patient completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), Marx Activity Rating Scale (MARS), Veterans RAND 12-Item Health Survey (VR- 12), and the Visual Analog Scale (VAS) pre- and postoperatively. KT-1000 arthrometer measurements were included in the pre- and postoperative objective, clinical assessments. Results: The IB group underwent significantly less revision ACLRs (1% vs. 8%, p = 0.017). Additionally, the average time elapsed from the original ACLR to the revision did not differ significantly and the average ages for the IB and the no-IB groups were comparable (19.0-years-old vs. 19.9-years-old). 5 patients in the no-IB group underwent a total of 9 meniscal procedures among them at the time of their revision ACLR compared to just one in the IB group (p = 0.009). There were also 4 patients in the no-IB group that underwent anterolateral ligament reconstruction at the time of their revisions (4 vs. 0, p = 0.043). All postoperative patient-reported outcome measures (PROMs) significantly increased in both groups with the exception of the MARS score which significantly decreased in both groups postoperatively. KT-1000 measurements significantly improved in both groups following surgery with the IB and no-IB cohorts yielding comparable results at the manual maximum pull (0.97mm vs. 0.65mm). Conclusions: ACLR with internal bracing resulted in an 88% decrease in revision ACLRs while maintaining comparable patient reported outcomes. Incorporating an Internal brace into ACLR is therefore safe and effective within these study parameters. [Table: see text][Table: see text][Table: see text]

Effect of Radiological Evidence of Kaplan Fiber Injury on the Clinical and Functional Outcomes After Acute Anterior Cruciate Ligament Reconstruction

Background: A paucity of information is available regarding the clinical outcomes of patients with radiological evidence of Kaplan fiber (KF) injury who undergo anterior cruciate ligament (ACL) reconstruction (ACLR). Purpose/Hypothesis: The purpose was to compare clinical and functional outcomes in patients undergoing acute primary ACLR with and without magnetic resonance imaging (MRI) evidence of KF injury. The hypothesis was that there would be no difference in clinical or functional outcomes in patients with versus those without radiological evidence of KF injury. Study Design: Cohort study; Level of evidence, 3. Methods: MRI analysis was conducted on patients in a longitudinal prospective study of ACL injury. Only patients who had an MRI scan and had undergone isolated primary ACLR within 60 days of injury were included. MRI was performed using standard knee protocols, and diagnostic criteria were applied to identify KF injury. A total of 32 patients with KF injury (mean age, 24.2 years; 21 male, 11 female) were identified and matched for sex, age, graft type, and preinjury activity with 90 patients who had intact KF. Patients were followed up at 12 months with KT-1000 arthrometer measurements of side-to-side difference in anterior knee laxity, single- and triple-hop limb symmetry index (LSI), Marx activity and International Knee Documentation Committee (IKDC) scores, and return to sport (RTS) rates at 12 months and 24 months. Results: No differences were found in anterior knee laxity and single- and triple-hop LSI values between the KF-intact and KF-injured cohorts at 12 months. No differences in Marx and IKDC scores were found between the groups at 12 months and 2 years. The overall rate of RTS within 24 months was 75% (92/122), and 5 patients (2 KF-injured; 3 KF-intact) had a subsequent graft rupture. Conclusion: We found no difference in clinical or functional outcomes in patients with and without radiological evidence of KF injury who underwent acute primary ACLR. Based on these findings, the radiological presence of KF injury at the time of acute ACL injury should not be regarded as a risk factor for a negative prognosis after ACLR.

Diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect anterior cruciate ligament injuries in children and adolescents: a prospective diagnostic study

BackgroundDiagnosing anterior cruciate ligament (ACL) injuries in children and adolescents are more challenging compared to adults. Delayed diagnosis may result in meniscal or chondral injuries. The aim of this study was to determine the diagnostic values of history taking, physical examination and KT-1000 arthrometer for suspect ACL injuries in children and adolescents.MethodsIn this prospective diagnostic study, all children and adolescents (< 18 years) with post-traumatic knee complaints presenting at the out-patient department of the Máxima MC were eligible for inclusion. One experienced knee specialised orthopaedic surgeon was blinded and performed history taking, physical examination and KT-1000 arthrometer measurement. All patients had a magnetic resonance imaging (MRI) for the final diagnosis. Diagnostic values of interest were sensitivity, specificity, positive and negative predictive values (PPV and NPV). The outcomes of the KT-1000 arthrometer were drafted in a relative operating characteristics (ROC) curve to determine the optimal cut-off points.ResultsSixty-six patients were included, of which 50 had an ACL rupture and 16 had no ACL rupture on MRI. Report of a popping sensation during trauma had a specificity and PPV of 100% for diagnosing ACL injuries. The PPV and NPV of the Lachman test (in case of describing end-feel) were 95 and 82%, of the anterior drawer test 87 and 90% and of the pivot shift test 95 and 81% respectively. The optimal cut-off point of the KT-1000 arthrometer at 133 N force was an absolute translation of ≥7 mm with a PPV and NPV of 97 and 88% respectively.ConclusionsReport of a popping sensation during trauma has a specificity and PPV of 100% for diagnosing ACL injuries in children and adolescents. Although potentially difficult in children, the Lachman test, anterior drawer test and pivot shift test have a high PPV and NPV when performed by an experienced orthopaedic surgeon. An absolute anterior translation of ≥7 mm of the injured knee in the KT-1000 arthrometer at 133 N has the highest diagnostic values of all tests for diagnosing ACL injuries.Level of evidence3

Association Between Early Postoperative Graft Signal Intensity and Residual Knee Laxity After Anterior Cruciate Ligament Reconstruction.

Background:Magnetic resonance imaging (MRI) graft signal intensity is associated with graft damage after anterior cruciate ligament reconstruction (ACLR). However, little is known about the relationship between graft signal intensity and residual laxity of the reconstructed knee based on patient age.Purpose/Hypothesis:To evaluate the relationship between graft signal intensity and residual laxity in younger and older patients who underwent ACLR. We hypothesized that higher graft signal intensity would be associated with reduced postoperative knee stability.Study Design:Cohort study; Level of evidence, 3.Methods:A total of 192 patients who underwent double-bundle ACLR were recruited. Proton density–weighted and T2-weighted MRI was performed at 3, 6, and 12 months after surgery, and the signal intensity ratio (SIR) of the anteromedial and posterolateral bundles was measured as the graft signal intensity reference values. At 12 months after surgery, if the KT-1000 arthrometer measurement exhibited a side-to-side difference of ≥2 mm, the patient was determined as having anterior knee laxity. Rotatory knee laxity was defined as a positive pivot shift with International Knee Documentation Committee grade ≥1. The Mann-Whitney U test was used to compare the SIR in patients with and without residual laxity. The Spearman correlation coefficient was used to evaluate the relationship between demographic parameters and the SIR. Based on receiver operating characteristic curves, the optimal SIR cutoff values to predict residual laxity were calculated, and logistic regression analysis was conducted.Results:Of 192 patients, 26 (13.5%) had anterior knee laxity, and 20 (10.4%) had rotatory knee laxity. The SIR was negatively correlated with age. In younger patients (<30 years; n = 135), those with residual laxity had a significantly higher SIR than those without laxity; this relationship was not significant in older patients (≥30 years; n = 57). Based on receiver operating characteristic curves and logistic regression analysis, the cutoff values that were determined for the SIR were significantly associated with a higher odds ratio of residual laxity.Conclusion:Graft signal intensity decreased with patient age. Patients with higher graft signal intensity in the early postoperative phase after ACLR exhibited a higher prevalence of residual laxity, particularly in younger patients.

Clinical Outcomes and Postoperative Complications After All-Epiphyseal Double-Bundle ACL Reconstruction for Skeletally Immature Patients.

Background:The treatment strategy for pediatric anterior cruciate ligament (ACL) tears, especially in patients with open physes, remains controversial.Purpose:To assess clinical outcomes and postoperative complications after all-epiphyseal double-bundle ACL (DB-ACL) reconstruction for patients with open physes.Study Design:Cohort study; Level of evidence, 3.Methods:Included were 102 patients aged ≤15 years who underwent ACL reconstruction at a single institution and had a minimum of 2 years of follow-up. Of these patients, 18 had undergone all-epiphyseal DB-ACL reconstruction (mean age, 12.4 ± 1.2 year) and 84 had undergone conventional DB-ACL reconstruction (mean age, 14.1 ± 0.9 year). The outcomes of the all-epiphyseal group were compared with those of the conventional group. Objective clinical outcomes included KT-1000 arthrometer measurements of side-to-side difference in anterior tibial translation, Lachman test grade, and pivot-shift test grade. Radiographic angular deformity (defined as >3° of the side-to-side difference in femorotibial angle) and incidence of second ACL injury were also compared.Results:The postoperative side-to-side difference in laxity significantly improved from 6.1 ± 2.4 to 0.6 ± 0.9 mm in the all-epiphyseal group (P = .001), and postoperative laxity was similar to that of the conventional group (0.4 ± 0.8 mm; P = .518). A Lachman grade 1 positive result was observed in 20% of the all-epiphyseal group and 3% of the conventional group (P = .042), and a pivot-shift grade 1 positive result was observed in 22% of the all-epiphyseal group and 4% of the conventional group (P = .074). A total of 4 patients (26.7%) in the all-epiphyseal group and 4 (6.1%) in the conventional group demonstrated angular deformity (P = .035). The incidence of postoperative ipsilateral ACL tear was 16.7% in the all-epiphyseal group and 23.8% in the conventional group (P = .757). The incidence of contralateral ACL tear was 11.1% in the all-epiphyseal group and 14.3% in the conventional group (P ≥ .999).Conclusion:All-epiphyseal DB-ACL reconstruction for skeletally immature patients achieved satisfactory clinical outcomes compared with conventional DB-ACL reconstruction. The incidence of ipsilateral graft rupture was relatively high in both groups. The all-epiphyseal group had a significantly higher incidence of angular deformity.

Association Between Psychological Readiness and Knee Laxity and Their Predictive Value for Return to Sport in Patients With Anterior Cruciate Ligament Reconstruction

Background: Deciding when patients are ready to return to sport (RTS) after an anterior cruciate ligament (ACL) reconstruction (ACLR) is challenging. The understanding of which factors affect readiness and how they may be related is limited. Therefore, despite widespread use of RTS testing, there is a lack of knowledge about which tests are informative on the ability to resume sports. Purpose: To examine whether there is an association between knee laxity and psychological readiness to RTS after ACLR and to evaluate the predictive value of these measures on sports resumption. Study Design: Cohort study; Level of evidence, 2. Methods: Patients aged ≥16 years engaged in physical activity/sports before injury were recruited at routine clinical assessment 9-12 months after ACLR. Exclusion criteria were concomitant ligament surgery at ACLR and/or previous ACL injury in the contralateral knee. At baseline, a project-specific activity questionnaire and the ACL–Return to Sport After Injury (ACL-RSI) scale were completed. Knee laxity was assessed by use of the Lachman test, KT-1000 arthrometer, and pivot-shift test. Two years after surgery, knee reinjuries and RTS status (the project-specific questionnaire) were registered. Associations between psychological readiness and knee laxity were evaluated with the Spearman rho test, and predictive ability of the ACL-RSI and knee laxity tests were examined using regression analyses. Results: Of 171 patients screened for eligibility, 132 were included in the study. There were small but significant associations between the ACL-RSI score and the Lachman test (rho = −0.18; P = .046) and KT-1000 arthrometer measurement (rho = −0.18; P = .040) but no association between the ACL-RSI and the pivot-shift test at the time of recruitment. Of the total patients, 36% returned to preinjury sport level by 2 years after surgery. Higher age, better psychological readiness, and less anterior tibial displacement (KT-1000 arthrometer measurement) were significant predictors of 2-year RTS (explained variance, 33%). Conclusion: Small but significant associations were found between measurements of psychological readiness and anterior tibial displacement, indicating that patients with less knee laxity after ACLR feel more ready to RTS. ACL-RSI and KT-1000 arthrometer measurements were independent predictors of 2-year RTS and should be considered in RTS assessments after ACLR.

Serum cartilage oligomeric matrix protein is correlated with quantitative magnetic resonance imaging and arthroscopic cartilage findings in anterior cruciate ligament deficient knees without osteoarthritic changes.

To investigate the association between serum biomarker [cartilage oligomeric matrix protein (COMP) and matrix metalloproteinase-3 (MMP-3)] levels and clinical, magnetic resonance imaging (MRI), and arthroscopic findings in anterior cruciate ligament (ACL)-deficient knees without osteoarthritic changes on radiographs. Patients with ACL injury of Kellgren-Lawrence grade 0 or 1 were enrolled. Serum COMP and MMP-3 levels were measured preoperatively. Correlations of serum biomarker levels with age, body mass index (BMI), duration from time of injury, Tegner activity scale (TAS) score, Lysholm knee score, International Knee Documentation Committee score, KT-1000 arthrometer measurements, whole-organ MRI score (WORMS), MRI T2 relaxation time, and arthroscopic International Cartilage Research Society (ICRS) grade were assessed by calculating Spearman correlation coefficients. Associations between intraoperative findings (cartilage, meniscus) and serum biomarker levels were determined using the Mann-Whitney U test. Multiple regression analysis was performed to investigate the correlations between serum biomarker levels and MRI and arthroscopic findings. Ninety-eight patients with a mean age of 23.7 years were enrolled. Higher serum COMP level was correlated with older age and higher BMI, TAS score, serum MMP-3 level, WORMS, and T2 relaxation times (medial femur, medial tibia). Multivariate analysis showed that the serum COMP level was independently associated with WORMS and ICRS grade. The serum COMP level was correlated with age, BMI, TAS score, and MMP-3 level in ACL-deficient knees and was independently correlated with WORMS and ICRS grade. Thus, the serum COMP level can help detect cartilage degeneration even in patients without radiographic osteoarthritic changes. Key Points • Serum COMP correlated with WORMS and ICRS grade in ACL deficient knee. • The serum COMP level could help in detecting cartilage degeneration, even in patients with no radiographic osteoarthritic changes.

Radiological maturation and clinical results of double-bundle and single-bundle anterior cruciate ligament reconstruction. A 5-year prospective case-controlled trial.

The aim of the study was to make a prospective comparison of the radiological and clinical outcomes of patients undergoing single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction. This prospective, case-controlled study included 65 patients, separated into 2 groups as 33 patients undergoing single bundle (SB), and 32 patients undergoing double bundle (DB) ACL reconstruction. The patients were evaluated clinically using the International Knee Documentation Committee (IKDC) and the Lysholm knee scores. Stability was evaluated with the KT-1000 Arthrometer Measurement, the Lachman and pivot shift tests. Magnetic resonance images (MRI) at 1 and 5years postoperatively were evaluated by a musculoskeletal radiologist. All the operations were performed by a single surgeon and the clinical evaluations were made by an independent researcher. Evaluation was made of a total of 53 patients (SB: 28, DB: 25). No statistically significant difference was determined between the groups regarding the postoperative IKDC and Lysholm scores. The pivot shift tests were negative in the DB group and positive in two patients of the SB group. The Lachman test was negative in all the patients. No significant difference was determined between the groups. No statistically significant difference was determined between the two groups in respect of the arthrometer measurements. In the SB group, revision surgery was performed in two patients due to graft failure. No graft failure findings were determined in the DB group, and no statistically significant difference was determined between the groups in respect of graft failure. On the MRIs taken at 1 year postoperatively, the ACL was seen to be hyperintense in 16 patients in the DB group and 6 patients in the SB group (p = 0.004). On the 5-year MRIs, ACL hypointensity could not be seen in three patients of the SB group and two of the DB group, with no difference determined between the groups (p > 0.05). In the 5-year follow-up period, no difference was determined between patients undergoing SB ACL reconstruction and those undergoing DB ACL reconstruction regarding clinical scores, knee stability, and MRI findings, but graft maturation occurs later the patients undergoing DB reconstruction.

Reliable ligamentous stability and high return-to-sport rates after arthroscopic reduction and internal fixation of tibial eminence fractures

PurposeTo investigate functional and clinical outcomes, and physical activity after arthroscopic suture fixation of tibial eminence fractures with regard to postoperative stability, range of motion (ROM), complications, and return to sports.MethodsPatients undergoing arthroscopic reduction and internal fixation (ARIF) of tibial eminence fractures using a suture fixation technique were included. Outcome was evaluated retrospectively after a minimum follow-up of 24 months using KT-1000 arthrometer measurements, clinical examination, outcome scores (Lysholm score, Tegner Activity Scale), and a questionnaire about sport activities.ResultsA total of 23 patients (44% male, 57% female) with a mean age of 25 ± 15 years were included. Mean follow-up was 57 ± 25 months. KT-1000 arthrometer measurements of anterior tibial translation revealed a mean side-to-side difference of 0.9 ± 1.0 mm. Clinical examination showed 100% normal or nearly normal anterior translation of the tibia. Two patients (9%) received an ACL reconstruction due to traumatic ACL re-instability and were, therefore, considered as failures. An extension deficit concerning hyperextension occurred in 29% of patients postoperatively. Further postoperative complications occurred in 14% of patients and included postoperative stiffness with ROM limitations and secondary dislocation of a fragment. Mean postoperative Lysholm score was 89 ± 14. Comparing pre- and postoperative values, no significant change of the Tegner Activity Scale was observed. All patients (failures excluded) returned to high impact sports activities after ARIF.ConclusionExcellent reliable ligamentous stability and high rates of return to high impact sports can be expected after ARIF using a suture fixation technique for type II–IV tibial eminence fractures. Complications, such as limitations in ROM, commonly occur in up to 30% after ARIF. Therefore, regular follow-up examinations remain important in this usually young patient cohort.Level of EvidenceLevel IV.

Good Short-Term Clinical Outcomes and Low Rates of Return to Sports after Repeat Revision ACL Reconstruction.

Repeat revision anterior cruciate ligament reconstruction (ACL-R) is a rare, demanding procedure and, as such, has not been well studied. Most of the available literature shows improved functional outcomes compared with preoperative state but inferior results when compared with primary ACL-R, particularly regarding return to preinjury level of sports. The purpose of this study was to assess functional outcomes in patients who had undergone repeat revision ACL-R. The secondary aims were to register return to sports, associated meniscal and/or chondral lesions, and evaluate radiological anatomical parameters. Nine patients between 2011 and 2017 were evaluated, who had a minimum follow-up of 2 years. Median age at repeat ACL-R was 32 years (interquartile range [IQR], 30-34 years) and the median follow-up was 27 months (IQR, 24-39 months). Data collected prior to surgery and at last follow-up included patient demographics, operative findings, physical examination findings including pivot shift and KT-1000 arthrometer measurement; Lysholm and International Knee Documentation Committee (IKDC) subjective scores; and return to sports and level using the Tegner score. Knee Injury and Osteoarthritis Outcome Score (KOOS) subjective score and radiographic anatomical parameters were recorded at last follow-up. Mean IKDC and Lysholm score improvement was 25 points (confidence interval [CI] 12-37) and 25 points (CI 11-39), respectively (p < 0.001). The median postoperative KOOS score was pain: 93 (IQR, 64-96); symptoms: 94 (IQR, 83-97); activities of daily life: 96 (IQR, 90-100); sports: 75 (IQR, 50-90); and quality of life: 50 (IQR, 43-81). Postoperative median side-to-side KT-1000 arthrometer difference was 2 mm (IQR, 1-8 mm). The median radiographic posterior tibial slope was 10 degrees (IQR, 9-10). One patient was considered a failure at 16 months postoperative. Only 44% (four out of nine) patients were able to return to their sports. None of these patients had a cartilage injury, while three out of five patients who did not return to their sports had International Cartilage Regeneration & Joint Preservation Society grade III or IV cartilage injury. Patients should be counseled on the challenging outcomes of repeat revision ACL-R. This is Level IV, therapeutic case series.

Maturity Progression of the Entire Anterior Cruciate Ligament Graft of Insertion-Preserved Hamstring Tendons by 5 Years: A Prospective Randomized Controlled Study Based on Magnetic Resonance Imaging Evaluation

Background: It has been reported that insertion-preserved hamstring tendon autografts (IP-HT) have better maturity than free hamstring tendon autografts (FHT) at 2 years after anterior cruciate ligament reconstruction (ACLR); however, whether insertion preservation improves the maturity of the entire autograft and clinical outcomes at 5 years after ACLR is still unclear. Purpose: To investigate the clinical outcomes and maturity of different segments using insertion-preserved and free hamstring tendon autografts up to 5 years after ACLR. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: 45 patients who underwent isolated ACLR with hamstring tendon autografts were enrolled and randomized into 2 groups. The study group had ACLR with IP-HT, whereas the control group had ACLR with FHT. The International Knee Documentation Committee and Tegner scores, Lysholm activity score, and KT-1000 arthrometer measurements were evaluated preoperatively and at 6, 12, 24, and 60 months postoperatively. Three-dimensional-reconstruction MRI examinations were performed at 6, 12, 24, and 60 months to evaluate the signal/noise quotient (SNQ) values of femoral tunnel graft, intra-articular graft, and tibial tunnel graft. Results: At 60 months, the SNQ values of the intra-articular and tunnel sections for the grafts in both groups showed no difference; the clinical outcomes were improved compared with before surgery (P < .001) and were similar in both groups. In the early stage, all graft segments in the IP-HT group had lower SNQ values than those of the FHT group. At 6 months, the entire graft in the FHT group and the femoral tunnel section in the IP-HT group had the maximum SNQ values, whereas the femoral tunnel graft had the highest SNQ value compared with intra-articular and tibial tunnel graft in each group. SNQ values of the intra-articular and tibial tunnel graft in the IP-HT group had no significant change within 60 months. Conclusion: All patients had similar clinical outcomes and graft maturity at 60 months postoperatively. The SNQ values and progressions varied at different graft sites and were highest for the femoral tunnel graft. All significantly changing SNQ values reached the maximum value at 6 months. Compared with FHT autograft, the graft maturity of IP-HT autograft recovered earlier and appeared more stable within the 60-month follow-up; however, no significant association was found between graft maturity and clinical scores.

No differences in clinical outcomes and graft healing between anteromedial and central femoral tunnel placement after single bundle ACL reconstruction.

The purpose of this study was to compare clinical outcomes and graft healing after anterior cruciate ligament (ACL) reconstruction with anteromedial and central femoral tunnel placement. During 2016 and 2018, 110 consecutive patients underwent single bundle ACL reconstruction; 85 patients met the inclusion criteria, and each patient underwent 3D-CT within 1week and MRI 1.5years after the operation. The central point of the femoral tunnel and signal/noise quotient (SNQ) of three regions of interest (ROI) in the intra-articular graft were measured to analyse the tunnel position and graft healing extent. Clinical assessments, including functional scores, KT-2000 arthrometer measurements and pivot-shift tests, were evaluated at the 2-year follow-up. Patients were divided into two groups depending on the femoral tunnel position: the anteromedial position group (Group A) and the centre position group (Group B). Seventy-one patients were available for the 2-year follow-up and MRI examination: 34 patients in Group A and 35 patients in Group B, and 2 patients were excluded for an eccentric tunnel position. No graft failure occurred, and compared with the preoperative assessment outcomes, the outcomes of both groups improved at the final follow-up. Group A was significantly better than Group B regarding the KT-2000 arthrometer measurements (P = 0.031). No significant differences were observed in terms of functional scores, pivot-shift test results, or the SNQ between groups. No differences in clinical outcomes or graft healing were found between AM and central femoral tunnel placements in single bundle ACL reconstruction. Therefore, satisfactory clinical outcomes, knee stability and graft healing can be obtained for both femoral tunnel placements. II.

Quantitative Evaluation of Functional Instability Due to Anterior Cruciate Ligament Deficiency.

Background:A safe and simple procedure to evaluate functional instability due to anterior cruciate ligament (ACL) deficiency (ACLD) has not been established. The angle of trunk backward tilting, which is known as a posture at risk for ACL injuries, could be used as a parameter to evaluate functional instability due to ACLD.Purpose:To measure the backward tilt angle of the trunk with participants standing upright on 1 leg and to investigate its usefulness to quantitatively evaluate functional instability due to ACLD.Study Design:Cohort study (diagnosis); Level of evidence, 3.Methods:Our cohort included 50 participants with unilateral ACLD and 40 participants with bilateral healthy knees. The trunk backward tilt (TBT) test was conducted as follows: the participant was asked to maximally tilt the trunk backward in a single-leg standing position, while forward tilt of the index leg was blocked with a custom-made device. The TBT angle was measured using a side-view photograph. Subjective knee instability during the test was recorded using a visual analog scale (VAS). The relative and absolute reliability of the TBT test were verified in a sample of healthy participants and those with ACLD, and comparisons between indicators were performed. Multiple regression analysis was performed with the injured/uninjured side ratio (I/U ratio) of the TBT angle as the dependent variable and the following independent variables: (1) I/U ratio of knee extension muscle strength, (2) I/U ratio of knee flexion muscle strength, (3) side-to-side difference (SSD) of the KT-1000 arthrometer measurement, (4) sex, and (5) SSD of the VAS score.Results:The TBT test had high reliability among healthy participants and those with ACLD. The TBT angle was significantly smaller and the VAS score was significantly higher on the injured side compared with the uninjured side and with healthy knees (P < .001 for all). Among the independent variables, the SSD of the VAS score had a negative influence on the I/U ratio of the TBT angle (R 2 = 0.59; P < .001).Conclusion:The TBT test is a simple, safe, and reliable method for quantitatively evaluating functional instability due to ACLD under weightbearing conditions that reflect subjective knee instability. The test will provide an index of treatment outcomes and return to sports through additional objective measurements before and after ACL reconstruction.

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

Background: Hamstring tendon autografts are commonly used for primary anterior cruciate ligament (ACL) reconstruction. Some patients have small hamstring tendons however, which may compromise the clinical outcome of the autograft. To solve this problem, many surgeons use hybrid grafting that involves augmentation of small hamstring autografts with allograft tissue. Purpose/Hypothesis: The purpose was to compare the clinical outcomes between primary ACL reconstructions performed with hamstring autografts and those performed with hybrid grafts in terms of patient-reported evaluation, failure rate, and knee stability. The hypothesis was that primary ACL reconstruction performed with hamstring autograft alone will not differ significantly from that performed with a hybrid graft in terms of patient-reported evaluation, failure rate, or knee stability. Study Design: Systematic review. Methods: A systematic review was performed to identify prospective and retrospective comparative studies and cohort studies (evidence levels 1-3) comparing outcomes of primary ACL reconstructions performed with hamstring autografting alone and hybrid grafting. Outcomes included patient-reported evaluation, failure rate, and knee stability. Results: Ten studies were included: 1 of level 2 and 9 of level 3. Collectively, they included 398 autografts and 341 hybrid grafts. Mean respective follow-up durations ranged from 24.0 to 69.6 months and from 24.0 to 70.8 months. Patient-reported evaluations, including Lysholm, Tegner, and subjective International Knee Documentation Committee scores, were reported in 8 of 10 studies. Failure rates were reported in all 10 studies. Results of knee stability examinations—including KT-1000 arthrometer measurements, the pivot-shift test, Lachman test, and overall International Knee Documentation Committee results—were reported in 4 of 10 studies. In this review, there were no statistically significant differences between autografts and hybrid grafts in terms of patient-reported evaluations, failure rates, or KT-1000 measurements. Conclusion: In this systematic review, there was no significant difference in patient-reported evaluation or failure rate between primary ACL reconstructions performed with autografts alone and those performed with hybrid grafts. Whether there is a substantial difference in knee stability examination results between autografts and hybrid grafts remains unknown, given a relative lack of reports on knee stability.