Influence of Graft Bending Angle on Femoral Tunnel Widening After Double-Bundle ACL Reconstruction: Comparison of Transportal and Outside-In Techniques

Background: Previous studies have suggested that increased mechanical stress due to acute graft bending angle (GBA) is associated with tunnel widening and graft failure after anterior cruciate ligament (ACL) reconstruction. Few studies have compared the GBA between the outside-in (OI) and the transportal (TP) techniques. Purpose: To evaluate the influence of GBA on clinical outcomes and tunnel widening after ACL reconstruction with OI versus TP technique. Study Design: Cohort study; Level of evidence, 3. Methods: Included in the study were 56 patients who underwent double-bundle ACL reconstruction (n = 28 in the OI group and n = 28 in the TP group). Clinical outcomes (Lysholm, International Knee Documentation Committee, Tegner score, and knee laxity) 1 year postoperatively were evaluated. Computed tomography scans at 5 days and 1 year postoperatively were used for imaging measurements, and the femoral tunnel was divided into the proximal third, middle, and aperture sections. The GBA and cross-sectional area (CSA) were measured using image analysis software and were compared between groups. A correlation analysis was performed to determine if the GBA affected clinical outcomes or tunnel widening. Results: No significant difference was observed in clinical outcomes between the groups. The GBA of both the anteromedial (AM) and posterolateral bundles were more acute in the OI group compared with the TP group ( P < .05). The CSA at the AM tunnel aperture increased significantly in the OI group (84.2% ± 64.3%) compared with the TP group (51.4% ± 36.7%) ( P = .04). However, there were no differences in the other sections. In the Pearson correlation test, GBA was not correlated with tunnel widening or clinical outcomes. Conclusion: Regardless of technique, the GBA did not have a significant influence on tunnel widening or clinical outcomes. Considering a wider AM tunnel aperture, a more proximal and posterior AM tunnel position might be appropriate with the OI technique.

Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

Background In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft. Hypothesis/purpose We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction. Study design Cohort study. Methods This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h. Results 209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption. Conclusion Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction. Clinical relevance Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.

Anterolateral ligament reconstruction in addition to primary double-bundle anterior cruciate ligament reconstruction for grade 3 pivot shift improves residual knee instability during surgery

Purpose High-grade pivot shift in the anterior cruciate ligament (ACL) injured knee is a risk factor for postoperative residual pivot shift. Procedures in addition to ACL reconstruction such as anterolateral ligament (ALL) reconstruction have been performed for patients with a high-risk of residual pivot shift. The aim of this study was to investigate the effect of the addition of ALL reconstruction to primary double-bundle ACL reconstruction in patients with preoperative high-grade pivot shift to improve stability as evaluated by quantitative measurement. Methods Patients with ACL injuries who showed preoperative grade 3 subjective pivot shift and who underwent primary double-bundle ACL reconstruction combined with ALL reconstructions were retrospectively enrolled. Anterior tibial translation (ATT) in the Lachman test, and acceleration and external rotational angular velocity (ERAV) in the pivot shift were measured as quantitative values. Quantitative values before surgical intervention for ACL-injured knees (ACLD) and uninjured contralateral knees (intact), after temporary fixation of the isolated ACL grafts (ACLR), and subsequently after temporary fixation of both ACL and ALL grafts (ACLR + ALLR) were measured with the patient under general anaesthesia. Results In total, 18 patients were included. The ATT was lower in ACLR and ACLR + ALLR than in intact (P = .008 and .005), while there was no significant difference between ACLR and ACLR + ALLR (P > .05). The acceleration of ACLR + ALLR was lower than that for ACLR (P = .008), while there was no significant difference between intact and ACLR or ACLR + ALLR (P > .05). The ERAV of ACLR was higher than that of intact (P < .001), while that of ACLR + ALLR was lower than that of ACLR (P < 0.001), and there was no significant difference in ERAV between intact and ACLR + ALLR (P > 0.05). Conclusion According to quantitative assessment of the pivot shift, the addition of ALL reconstruction to primary double-bundle ACL reconstruction improved residual knee instability and restored knee stability during surgery. Combination of ALL reconstruction with primary double-bundle ACL reconstruction was effective for patients with ACL injuries exhibiting a preoperative grade 3 subjective pivot shift. Level of evidence IV

Anatomic single- and double-bundle ACL reconstruction both restore dynamic knee function: a randomized clinical trial—part II: knee kinematics

Purpose Compare side-to-side differences for knee kinematics between anatomic single-bundle (SB) and anatomic double-bundle (DB) ACLR during downhill running at 6 and 24 months post ACLR using high-accuracy dynamic stereo X-ray imaging. It was hypothesized that anatomic DB ACLR would better restore tibio-femoral kinematics compared to SB ACLR, based on comparison to the contralateral, uninjured knee. Methods Active individuals between 14 and 50 years of age that presented within 12 months of injury were eligible to participate. Individuals with prior injury or surgery of either knee, greater than a grade 1 concomitant knee ligament injury, or ACL insertion sites less than 14 mm or greater than 18 mm were excluded. Subjects were randomized to undergo SB or DB ACLR with a 10 mm-wide quadriceps tendon autograft harvested with a patellar bone block and were followed for 24 months. Dynamic knee function was assessed during treadmill downhill running using a dynamic stereo X-ray tracking system at 6 and 24 months after surgery. Three-dimensional tibio-femoral kinematics were calculated and compared between limbs (ACLR and uninjured contralateral) at each time point. Results Fifty-seven subjects were randomized (29 DB) and 2-year follow-up was attained from 51 (89.5%). No significant differences were found between SB and DB anatomic ACLR for any of the primary kinematic variables. Conclusions Contrary to the study hypothesis, double-bundle reconstruction did not show superior kinematic outcomes compared to the single-bundle ACLR. While neither procedure fully restored normal knee kinematics, both anatomic reconstructions were similarly effective for restoring near-normal dynamic knee function. The findings of this study indicate both SB and DB techniques can be used for patients with average size ACL insertion sites. Level of evidence Level I

Preoperative Knee Instability Affects Residual Instability as Evaluated by Quantitative Pivot-Shift Measurements During Double-Bundle ACL Reconstruction

Background: The pivot-shift test is an important indicator of functional outcomes after anterior cruciate ligament (ACL) reconstruction (ACLR). Preoperative instability as indicated by the pivot-shift test is associated with residual instability after ACLR. Few studies have used quantitative means to evaluate the pivot shift after ACLR. Purpose: To investigate the relationship between preoperative and residual instability and to identify the risk factors for residual instability by using quantitative measurements of the pivot shift. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 91 patients undergoing primary double-bundle ACLR were retrospectively enrolled. Quantitative measurements of instability for ACL-deficient knees (ACLD) and uninjured contralateral knees (intact) preoperatively, as well as ACLR knees intraoperatively, were performed under general anesthesia using the pivot-shift test, with inertial sensors to measure acceleration and external rotational (ER) angular velocity. The ratios of intact to ACLD (ACLD/I) and intact to ACLR (ACLR/I) were measured. Patients who showed an ACLR/I of >1 were classified into the residual instability group, and those with an ACLR/I of ≤1 were classified into the noninstability group. Regarding demographic, surgical, and quantitative measurement factors, between-group comparisons and multivariate logistic regression were conducted for predictors of residual instability. Receiver operating characteristic curves were used to evaluate the correlations between ACLD/I and ACLR/I and the cutoff value of ACLD/I in predicting residual instability. Results: The predictive factors for intraoperative residual instability included female sex (odds ratio [OR], 0.3 [95% CI, 0.1-0.9]; P = .034) and ACLD/I for acceleration (OR, 1.6 [95% CI, 1.2-2.1]; P < .001), and ACLD/I for ER angular velocity (OR, 1.9 [95% CI, 1.2-3.1]; P = .013). Correlations between ACLD/I and ACLR/I were moderate with respect to both acceleration ( r = 0.435; P < .001) and ER angular velocity ( r = 0.533; P < .001). The cutoff points for ACLD/I were 4.9 for acceleration (sensitivity, 65.1%; specificity, 85.7%; area under the curve [AUC], 0.76) and 2.4 for ER angular velocity (sensitivity, 80.0%; specificity, 50.0%; AUC, 0.74). Conclusion: Greater preoperative instability was a risk factor for residual instability as measured intraoperatively by a quantitatively evaluation in the pivot shift during ACL reconstruction. Quantitative measurements of instability during the pivot shift mechanism under general anesthesia may enable surgeons to predict postoperative residual instability.

The serial changes of static anterior tibial subluxation on MRI after double-bundle anterior cruciate ligament reconstruction

Objectives: Static anterior tibial subluxation after an anterior cruciate ligament (ACL) injury highlights the abnormal relationship between the tibia and femur in patients with ACL insufficiency. One of the aims of ACL reconstruction is to restore the normal tibiofemoral relationship. However, several studies indicated that an abnormal tibiofemoral relationship remained after single-bundle (SB) ACL reconstruction. The purpose of this study was to determine the serial changes of static relationship between tibia and femur in patient who had double-bundle ACL reconstruction with acute and chronic injuries. Methods: Thirty five patients who underwent double-bundle ACL reconstruction between January 1 to July 31, 2017 were included in this prospective study and divided two groups: the acute ACL injury group and the chronic ACL injury group (more than 6 month after injury). All participants underwent preoperative and postoperative magnetic resonance imaging (MRI) at 3 weeks, 3, 6 and 12 months. Anterior tibial subluxation (ATS) of the medial and lateral compartments relative to the femoral condyles were measured on MRI. Results: There were no significant differences in the age and KT side to side difference between both groups (Table 1). The ATS measurements are shown in table 2. In lateral compartment, the ATS in the acute ACL injury group was 5.3mm before surgery, while it was -0.31mm, 3.4mm, 3.5mm and 4.9mm at 3 weeks, 3, 6, 12months after surgery, respectively. The ATS in the chronic ACL injury group was 6.7mm before surgery, while it was 0.47mm, 3.9mm, 4.6mm and 5.9mm at 3 weeks, 3, 6, 12months after surgery, respectively. No significant difference was found between 2 groups. In medial compartment, the ATS in the acute ACL injury group was 1.8mm before surgery, while it was -1.6mm, 0.28mm, 0.93mm and 2.1mm at 3 weeks, 3, 6, 12months after surgery, respectively. The ATS in the chronic ACL injury group was 2.5mm before surgery, while it was -1.4mm, 1.6mm, 1.7mm and 3.0mm at 3 weeks, 3, 6, 12months after surgery, respectively. No significant difference was found between 2 groups. Conclusion: In both of lateral and medial compartment, the ATS was not significant different between acute and chronic ACL injuries before surgery. In lateral compartment, at 3 weeks, 3months and 6months after surgery, ATS was significantly less than before surgery in both groups. At 12 months, ATS was not significant different from before surgery in both groups. In medial compartment, at 3 weeks, ATS were significantly less than before surgery in both groups. After 3 months, ATS was not significant different from before surgery in both groups. The ATS was not significant different between acute and chronic ACL injuries in the same period after surgery. [Figure: see text][Figure: see text][Figure: see text][Figure: see text]

Clinical and Radiographic Outcomes of Double-Bundle Anterior Cruciate Ligament Reconstruction for Asian Patients with Bone-Patellar Tendon-Bone and Gracilis Tendon Grafts: A Matched-Control Comparison

For anterior cruciate ligament (ACL)-deficient patients, using a single bone-patellar tendon-bone (BPTB) graft for the double-bundle concept is one of the suitable approaches for acquiring better stability and reducing bone tunnel enlargement compared with the use of hamstring grafts. At least 10-mm width of BPTB autograft is needed to achieve this concept; however, it is larger than one-third of the patellar tendon width for small or middle physique patients. This study aimed to assess the clinical and radiographic outcomes of BPTB and gracilis (G) composite autografts for primary double-bundle ACL reconstruction in Asian athletes. Thirty-two Asian patients undergoing double-bundle ACL reconstruction with 7.0 to 7.5 mm of BPTB and 5.0 to 5.5 mm of G composite grafts were compared with 43 double-bundle ACL reconstruction with hamstring graft cases. The BPTB graft was used for the anteromedial bundle (AMB), with the G graft for the posterolateral bundle (PLB). Percentage of femoral bone tunnel enlargement compared with the original size was determined by computed digital radiographs on the first postoperative day and at 12 months in the anteroposterior (AP) and lateral views. Standard clinical evaluations, including the limb symmetry index (LSI), were also performed. Less PLB tunnel enlargement was found in the BPTB + G group than in the hamstring group in the AP (101.9 ± 22.9 vs.113.7 ± 20.6%, p = 0.031) and lateral views (104.4 ± 18.1 vs. 120.6 ± 23.4%, p < 0.01).There was no significant difference between the groups in 12-month postoperative clinical outcomes (Lysholm's score, Tegner's activity level scale, and International Knee Documentation Committee subjective knee evaluation score).The side-to-side difference was significantly less in the BPTB + G group (0.2 ± 1.3 vs. 0.9 ± 1.1 mm, p = 0.026). Despite the small sizes of the BPTB and G grafts, there was no significant difference in the knee extensor LSI between the groups (92.9 ± 10.1 vs. 93.3 ± 12.2%, p = 0.707), whereas the knee flexor LSI was significantly higher in the BPTB + G group (97.7 ± 14.8 vs. 90.1 ± 13.3%, p = 0.033). Double-bundle ACL reconstruction with a small size BPTB and G composite graft procedure provided good clinical outcomes and significantly less femoral bone tunnel enlargement than the hamstring procedure 12 months after surgery. It is thus a useful surgical option for ACL-deficient Asian athletes. This study reflects level of evidence III.