Factors affecting knee laxity following anterior cruciate ligament reconstruction using a hamstring tendon

Predictors of lower knee function improvement two years after anterior cruciate ligament reconstruction

OBJECTIVES

The extent to which knee functions improve after anterior cruciate ligament reconstruction (ACLR) varies. This study aimed to determine the factors that affect lower knee function improvement after two years of ACLR.

METHODS

The study included 159 patients who underwent ACLR in the Indonesian ACL community between August 2018 and April 2020. The concomitant injury and graft types of ACLR were determined using patients' pre-surgical MRI and medical records. The five subscales of the knee injury and osteoarthritis outcome score (KOOS) were used to evaluate the patient at baseline, first year, and second year following ACLR. A linear mixed-effect model (LMEM) was used to predict the longitudinal improvement models for the five-subscales KOOS score after ACLR.

RESULTS

The LMEM predicted lower KOOS subscales scores improvements by 0.5 for QOL, 0.1 for symptom, ADL, and QOL, and 0.2 for sports/recreation, respectively, for a one score increase of age and time from injury to surgery. Male patients had higher KOOS subscale scores with the improvement of pain, symptom, and ADL by 5.7, 5.9, and 6.3 compared to female patients, respectively, while patients with patellar tendon grafts had lower improvement of KOOS score pain by 6.5 compared to hamstring tendon grafts.

CONCLUSION

As the age and time from injury to surgery increased, the KOOS subscales scores of QOL and symptoms, ADL, sports/recreation, and QOL decreased. Male patients reported higher KOOS subscales scores for pain, symptoms, and ADL, while patients with patella tendon grafts had a lower improvement in pain score.

Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction

INTRODUCTION

Although anterior cruciate ligament reconstruction (ACLR) is considered a successful procedure, residual pivot-shift after surgery remains to be solved. The purpose of this study was to comprehensively evaluate the risk factors of residual pivot-shift after anatomic double-bundle (DB) ACLR.

MATERIALS AND METHODS

A total of 164 patients who underwent primary anatomic DB-ACLR between January 2014 and December 2019 and screw removal after the index ACLR in our hospital were included in this retrospective case-control study. The manual pivot-shift test was performed under general anesthesia during screw removal surgery, and patients with grade 1 or higher pivot-shift were classified as the positive pivot-shift group, and those with grade 0 were defined as the negative pivot-shift group. Univariate and logistic regression analyses were performed to identify the factors associated with postoperative residual pivot-shift. Assessment included sex, age, time to surgery, preoperative Tegner activity scale, preoperative pivot-shift grade, preoperative anterior tibial translation by the KT-2000 arthrometer measurement, meniscus injury and its surgical procedure, knee hyperextension, cartilage damage, Segond fracture, medial and lateral posterior tibial slope, lateral-medial slope asymmetry, participation in pivoting sport/activity at the time of injury, and return to sports at postoperative one year line.

RESULTS

Postoperative positive pivot-shift was observed in 14 (8.5%) of 164 patients. The KT-2000 measurement at 1-year postoperatively was significantly higher in the residual pivot-shift-positive group than in the negative group (P < 0.05). Logistic regression analysis revealed that age of patients < 20 years [P < 0.05, odds ratio (OR): 6.1)], preoperative pivot-shift grade (P < 0.05, OR: 4.4), and hyperextended knee (P < 0.05, OR: 11.8) were risk factors of postoperative pivot-shift. There were no statistically significant differences between other variables.

CONCLUSIONS

Patients < 20 years of age, with high-grade preoperative pivot-shift, or hyperextended knees had a higher risk of residual postoperative pivot-shift.

Lateral posterior tibial slope does not affect femoral but does affect tibial tunnel widening following anatomic anterior cruciate ligament reconstruction using a Bone-Patellar Tendon-Bone graft

Background

Tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction has been a research area of interest in ACL reconstruction. In recent years, it has been noted that posterior tibial slope (PTS) affects several types of outcomes after ACL reconstruction including TW. However, the relationships between femoral and tibial TW and between PTS and TW following anatomical ACL reconstruction using a bone–patellar tendon–bone (BTB) graft are often not understood. Therefore, the purpose of this study was to retrospectively clarify the magnitude of femoral and tibial TW and the effect of PTS on TW following anatomical ACL reconstruction using a BTB graft.

Methods

A total of 111 patients who underwent isolated ACL reconstructions using BTB grafts were included in this study. Femoral and tibial tunnel aperture areas were measured using three-dimensional computed tomography (3D CT) at 1 week and 1 year postoperatively, and femoral and tibial TW (%) was calculated. Lateral and medial PTS was also measured using 3D CT.

Results

As compared with 1 week postoperatively, the mean tibial tunnel aperture areas increased by 30.6% ± 28.5%, and the mean femoral tunnel aperture areas increased by 28.3% ± 27.9% when measured at 1 year postoperatively. Although no significant difference was observed between femoral and tibial TW, a significant positive correlation was noted between femoral and tibial TW (r = 0.240, p = 0.011). A significant correlation was observed only between lateral PTS and tibial TW (r = 0.354, p < 0.001). There was no significant correlation between medial PTS and tibial TW, lateral PTS and femoral TW, or medial PTS and femoral TW.

Conclusion

Significant positive correlation was observed between femoral and tibial TW. Steeper lateral PTS correlated with greater tibial TW; on the other hand, medial PTS did not correlate with tibial TW. Although lateral PTS affected tibial TW, it did not affect femoral TW.

Delaying ACL reconstruction beyond 6 months from injury impacts likelihood for clinically significant outcome improvement

BACKGROUND

The effect of surgical latency on outcomes of anterior cruciate ligament reconstruction (ACLR) is a topic that is heavily debated. Some studies report increased benefit when time from injury to surgery is decreased while other studies report no benefit. The purpose of our analysis was to compare achievement of clinically significant outcomes (CSOs) in patients with greater than six months of time from injury to ACLR to those with less than or equal to six months of time to surgery.

METHODS

Patients undergoing primary ACLR between January 2017 and January 2018 with minimum one year follow-up were included. International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected. Multivariate logistic regression was performed for outcome achievement and risk of revision ACLR and Weibull parametric survival analysis was performed for relative time to outcome achievement. The level of significance was set at α = 0.05.

RESULTS

379 patients were included of which, 140 patients sustained ACL injury greater than six months prior to surgery. This group of patients experienced reduced likelihood to achieve patient-acceptable symptomatic state (PASS) on the IKDC (p = 0.03), KOOS Pain (p = 0.01) and a greater likelihood to undergo revision ACLR (p = 0.001). There was no impact of surgical timing on minimal clinically important difference (MCID).

CONCLUSION

Patients with greater than 6 months from injury to ACLR reported reduced likelihood to achieve CSOs, delayed achievement of CSOs, and increased rates of revision surgery.

Computer-Assisted System in Stress Radiography for Anterior Cruciate Ligament Injury with Correspondent Evaluation of Relevant Diagnostic Factors

We sought to design a computer-assisted system measuring the anterior tibial translation in stress radiography, evaluate its diagnostic performance for an anterior cruciate ligament (ACL) tear, and assess factors affecting the diagnostic accuracy. Retrospective research for patients with both knee stress radiography and magnetic resonance imaging (MRI) at our institution was performed. A complete ACL rupture was confirmed on an MRI. The anterior tibial translations with four different methods were measured in 249 patients by the designed algorithm. The diagnostic accuracy of each method in patients with all successful measurements was evaluated. Univariate logistic regression analysis for factors affecting diagnostic accuracy of method four was performed. In the inclusive 249 patients, 177 patients (129 with completely torn ACLs) were available for analysis. Mean anterior tibial translations were significantly increased in the patients with a completely torn ACL by all four methods, with diagnostic accuracies ranging from 66.7% to 75.1%. The diagnostic accuracy of method four was negatively associated with the time interval between stress radiography and MRI as well as force-joint distance on stress view, and not significantly associated with age, gender, flexion angle, intercondylar distance, and force-joint angle. A computer-assisted system measuring the anterior tibial translation in stress radiography showed acceptable diagnostic performance of complete ACL injury. A shorter time interval between stress radiography and MRI as well as shorter force-joint distance were associated with higher diagnostic accuracy.

Hamstring Co-Contraction in the Early Stage of Rehabilitation After Anterior Cruciate Ligament Reconstruction: A Longitudinal Study

OBJECTIVE

Hamstring co-contraction may affect recovery from anterior cruciate ligament reconstruction. The aim of the study was to evaluate the changes in hamstring co-contraction during the early postoperative stages.

DESIGN

Twenty-five patients with anterior cruciate ligament reconstruction were followed up for 1-3 mos postoperatively, during which the Lysholm and International Knee Documentation Committee questionnaires were completed and surface electromyograms were assessed during terminal knee extension maximum voluntary contraction and step-up tests. The integrated electromyogram of the tested muscles and co-contraction ratio were analyzed.

RESULTS

Co-contraction ratio during terminal knee extension maximum voluntary contraction at 3 mos postoperatively was significantly less than that at 1 mo postoperatively (P < 0.0083), and it did not significantly differ from that of the uninvolved knee. In contrast, the co-contraction ratio during step-up was significantly higher at 2 and 3 mos postoperatively than that before surgery (P < 0.0167) and for the uninvolved knee (P < 0.05). Moreover, the postoperative hamstring co-contraction ratio in patients with a chronic injury was significantly higher during the step-up test than in patients with an early injury (P = 0.017).

CONCLUSIONS

Hamstring co-contraction ratio during terminal knee extension maximum voluntary contraction recovers during the early postoperative stages. However, hamstring co-contraction ratio during step-up, which may be related to knee joint proprioception, remains high, particularly for patients with a chronic injury.

CLINICAL TRIAL

ChiCTR-COC-17011167.