Anatomic Single-bundle Anterior Cruciate Ligament Reconstruction Research Articles

Mid-bundle positioning of the femoral socket increases graft rupture in anatomic single bundle anterior cruciate ligament reconstruction

BackgroundAnatomic anterior cruciate ligament (ACL) reconstructions are superior to non-anatomic graft placements with regard to controlling rotational laxity. Different techniques of anatomic single-bundle reconstruction exist. The femoral tunnel may be placed in a mid-bundle position (MB) or within the anteromedial bundle footprint (AM) with no definitive consensus as to the preferred position. Our institution, reflecting trends in surgical practice, has experience with both techniques. MethodsInterrogation of our prospectively maintained database yielded all primary ACL reconstructions performed using the anatomic TransLateral single-bundle all-inside technique. A two year minimum follow-up was set. The failure rate of the MB and AM cohorts was compared as a primary outcome. Patient-reported outcomes across cohorts at several time-points were analysed as a secondary outcome. ResultsTwo hundred and seventy-nine primary ACL reconstructions were identified at a median follow-up of 49 months. MB positioning was utilised in 113 cases (40.5%) and AM positioning in 166 (59.5%). There were significantly more failures in the MB cohort (p = 0.029). Logistic regression revealed mid-bundle femoral positioning was associated with greater than fourfold increase in graft failure (odds ratio 4.14, p = 0.039). ConclusionData from this case series suggests that amongst anatomic single-bundle ACL reconstructions, grafts with a mid-bundle femoral tunnel are more than four times more likely to fail versus those with a femoral tunnel placed four millimetres deeper within the anteromedial bundle footprint.

Femoral tunnel length in anatomical single-bundle ACL reconstruction is correlated with height, weight, and knee bony morphology.

The purpose of this study was to reveal the correlation between femoral tunnel length in anatomical single-bundle anterior cruciate ligament (ACL) reconstruction and body size and/or knee morphology. Thirty-one subjects undergoing anatomical single-bundle ACL reconstruction were included in this study (20 female, 11 male; median age 46, 15-63). Pre-operative height, body weight, and body mass index (BMI) were measured. In pre-operative magnetic resonance imaging, the thickness of the quadriceps tendon and the whole anterior-posterior (AP) length of the knee were measured using the sagittal slice. Using post-operative three-dimensional computed tomography, accurate axial and lateral views of the femoral condyle were evaluated. The correlation of femoral tunnel length, which was measured intra-operatively, with the height, weight, BMI, quadriceps tendon thickness, AP length of the knee, trans-epicondylar length, the notch area (axial), length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch were statistically analyzed. Tunnel placement was also evaluated using a Quadrant method. The average femoral tunnel length was 35.6 ± 4.4mm. The average height, body weight, and BMI were 162.7 ± 7.2cm, 61.9 ± 10kg, and 23.4 ± 3.5, respectively. Femoral tunnel length was significantly correlated with height, body weight and the height and area of lateral wall of the femoral intercondylar notch, and the length of the Blumensaat's line. For clinical relevance, the risk of creating a femoral tunnel of insufficient length in anatomical single-bundle ACL reconstruction exists in subjects with small body size. Surgeons should pay careful attention to prevent this from occurring. Case-controlled study, Level III.

Arthroscopic and 3D CT Scan Evaluation of Femoral Footprint of the Anterior Cruciate Ligament in Chronic ACL Deficient Knees.

The outcome of single-bundle anterior cruciate ligament (ACL) reconstruction depends largely on the anatomic placement of bone tunnel. The lateral intercondylar ridge (LIR) and bifurcate ridge (BR) are useful bony landmarks for femoral tunnel placement. The purpose of our study was to compare the bony landmarks of ACL footprint on femur by three-dimensional computed tomography (3D CT) scan and arthroscopy in chronic ACL-deficient knees. Fifty patients above 18 years of age who were diagnosed of having ACL tear were selected for the study. All the cases were more than 6 months old since the injury. Preoperative 3D CT scan of the affected knee was obtained for each of them. They underwent single-bundle anatomic ACL reconstruction. Measurements were done on the preoperative 3D CT and arthroscopy to quantify the position of the LIR and BR. The proximodistal distance of lateral femoral condyle was 21.41+/-2.5 mm on CT scan and 22.02+/-2.02 mm on arthroscopy. On preoperative 3D CT scan, the midpoint of the LIR was found to be located at a mean distance of 11.17±2.11 mm from the proximal margin of the lateral femoral condyle. On arthroscopy, it was at 10.18+/-1.52 mm from the proximal margin the lateral femoral condyle. The "bifurcate ridge"(BR) was not visible in any of the cases during arthroscopy or CT scan. We concluded that LIR is an easily identifiable bony landmark on arthroscopy in all cases. It can also be identified on CT scans. BR is not identified both on arthroscopy and CT scans in chronic ACL tears. The arthroscopic measurements of bony landmarks are quite close to those of CT scan. Midpoint of LIR is at 52.185% of the proximodistal distance on CT scan evaluation and it is at 46.21% on arthroscopic evaluation.

Intraoperative Graft Isometry in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction.

PurposeLittle is known about the isometry of anatomic single-bundle anterior cruciate ligament (ACL) tunnel positions in vivo although it is closely related to graft tension throughout the range of motion. The purpose of this study was to evaluate intraoperative graft isometry in anatomic single-bundle ACL reconstruction in vivo.Materials and MethodsGraft length changes were assessed before bio-screw fixation in the tibial tunnel by pulling the graft with tensions of 20 lbs and 30 lbs in full extension at flexion angles of 30°, 60°, 90°, and 120°.ResultsAt the flexion angle of 30°, 20 lbs and 30 lbs of tension showed −0.4 mm and −0.6 mm length changes, respectively. The greater the flexion angle of the knee, the shorter the graft length in the joint. At the flexion angles of 90° and 120°, there was significant difference in the graft length change between 20 lbs and 30 lbs of tension.ConclusionsAnatomic single-bundle ACL reconstruction was non-isometric. The graft length was the longest in full extension. The tension of graft became loose in flexion. At the flexion angles of 90° and 120°, there was significant difference in the graft length change between 20 lbs and 30 lbs of tension.

Graft bending angle affects allograft tendon maturity early after anterior cruciate ligament reconstruction.

The aim of this study was to clarify the association of the anterior cruciate ligament (ACL) graft bending angle and graft maturity of autograft and allograft tendons using high-resolution MRI. Patients with unilateral ACL reconstruction were invited to participate in this study, and they were examined using a 3.0-T MRI scan at 3, 6 and 12months after the operation. Anatomic single-bundle ACL reconstruction was performed on 48 patients using the trans-portal technique, including 28 with autograft hamstring tendons and 20 with allograft tendons. To evaluate graft healing, the signal/noise quotient (SNQ) was measured in four regions of interest (ROIs) of the femoral tunnel, proximal, midsubstance and distal ACL grafts. The graft bending angle was defined as the angle between the femoral bone tunnel and the line connecting the femoral and tibial tunnel apertures. Graft SNQ and graft bending angle were assessed at 3, 6 and 12months postoperatively, and the association between SNQ and the average graft bending angle was analyzed. Generally, the mean graft bending angle of this cohort increased gradually with time. The SNQ value of each graft region increased from 3 to 6months and then decreased from 6 to 12months. In the whole cohort, the graft bending angle had a significant positive association with graft SNQ in the femoral tunnel or proximal site. In the allograft subgroup, the graft bending angle had a significant positive association with the graft SNQ in the femoral tunnel or proximal site at 6months after surgery, while there was no association between the graft bending angle and SNQ at 12months. In the autograft subgroup, the graft bending angle had a significant positive association with graft SNQ in the femoral tunnel or proximal site at 12months after surgery. Generally, the graft bending angle was correlated with a high signal intensity of the proximal graft in the early postoperative period for allograft tendons and in the late postoperative period for allograft tendons. This suggests that the biomechanical effect from the graft bending angle on graft healing may be different for allografts and autografts after ACL reconstruction. III.

Short term outcome of trans-portal anatomic single bundle anterior cruciate ligament reconstruction at BPKIHS

Introduction: Anterior cruciate ligament (ACL) reconstruction is performed to obtain pre-injury stability and to prevent early osteoarthritis of the knee in patients with ACL injury. This study was conducted to evaluate short term clinical and functional outcome of knee after trans-portal anatomic single bundle ACL reconstruction. Methods: It was a prospective longitudinal study conducted in Department of Orthopedics, BPKIHS, Dharan, Nepal from Jan. 2017 to Sept.2017. All the patients with symptomatic ACL injury were included in the study. There were twenty patients who underwent trans-portal anatomic single bundle ACL reconstruction with quadrupled hamstring (Semitendinosus and gracilis) autograft from ipsilateral limb. The graft was fixed in femoral tunnel by an Endobutton CL and in tibia by Bioscrew. Results were assessed at 2 weeks, 6 weeks, 3 month and 6 months. Standard accelerated ACL rehabilitation protocol was followed for postoperative rehabilitation. Results: Out of 20 patients who underwent ACL reconstruction surgery 16 were male and 4 female. Average graft size was 7±0.5mm. The longest follow up was 9 months and shortest follow up was 6 months. 18 patients could do active SLR at two weeks and 2 had extension lag of 10 degree. 19 out of 20 patients attained full range of movement at 6 weeks. Mean Preoperative Tegner Lysolm score was 63.852±1.19 and post-operative Tegner Lysolm score at 6 months was 93±3.94 with P value 0.0001. There was no infection in any case. Conclusion: Transportal anatomical single bundle ACL reconstruction with quadrupled hamstring autograph which is fixed with Endobutton on femur and intrafix bioscrew at tibia is very good method of ACL reconstruction with predictable outcome.

Comparative study on fixed versus adjustable-length loop device for femoral fixation of graft in anterior cruciate ligament reconstruction

Aims and Objectives: Cortical suspension devices have been widely used in ACL reconstruction for femoral side graft fixation. Fixed-length and adjustable-length loop devices are two common suspensory loop devices that are used in ACL reconstruction. They both have their own biomechanical pros and cons. The purpose of this study is to determine the difference in functional outcome of anatomical single bundle ACL reconstruction using fixed length versus adjustable length loop in femoral fixation of quadrupled hamstring graft. Material and methods: It is a longitudinal prospective study conducted in Bone and Joint Centre, Kokilaben Dhirbhai Ambani Hospital (KDAH), Mumbai from Jan 2014 to June 2016. There were 60 patients enrolled in the study. The first 30 patients were treated with Arthroscopic ACL reconstruction in the first 30 patients were done with quadrupled hamstring graft from ipsilateral limb fixed with Endobutton on femoral side and bio-absorbable intrafix tibial screw, similarly in subsequent 30 patients ACL reconstruction were done with quadrupled hamstring graft from ipsilateral limb fixed with Tightrope on femoral side and bio-absorbable intrafix tibial screw. Their clinical and functional status were assessed pre-operatively on the day prior to surgery and the last follow up at one following the surgery with Tegner-Lysholm Score and 2000 IKDC scores. Results: The average Tegner- Lysolm score before surgery in Endobutton group was 56.63±6.7 and post op score at last follow up was 93.97±4.1 and for Tightrope group it was 56.5±7.1 and 94.7±3.7 respectively. The average 2000 IKDC score before surgery in Endobutton group was 46.16±6.1and post-op score at last follow up was 82.52±4.2 and for Tightrope group it was 46.57±6.5 and 83.98±4.1 respectively. Two sample student t-test was conducted to compare the mean of post-operative Tegner-Lysolm score and 2000 IKDC for each group it showed P value for Tegner-Lysolm score to be 0.75 and that for 2000 IKDC score to be 0.7, which not statistically significant to reject the null hypothesis. Discussion and conclusion: Cortical suspension devices for femoral tunnel graft fixation are very efficient devices whether Fixed-length or adjustable length. Fixed-length and adjustable loop cortical suspension devices are equally effective in femoral fixation of graft in ACL reconstruction.

Lateral Intercondylar Ridge: Is it a reliable landmark for femoral ACL insertion?: An anatomical study

BackgroundIncorrect femoral tunnel placement is the most common cause of graft failure during Anterior Cruciate Ligament (ACL) Reconstruction. A reliable landmark can minimize errors. AimTo identify whether the Lateral Intercondylar Ridge (LIR) is a consistent anatomical structure and define its relationship with the femoral ACL insertion. Materials and methodsPhase 1: we studied 23 femoral dry bone specimens macroscopically. Using a digital microscribe, the medial surface of the lateral femoral condyle was reconstructed (3D) to evaluate whether there was an identifiable bony ridge.Phase 2: 7 cadaveric specimens with intact soft tissues were dissected to identify the femoral ACL insertion. A 3D reconstruction of the femoral ACL insertion and the surface allowed us to define the relationship between the LIR and the ACL insertion. ResultsAll specimens had a defined LIR on the medial surface of the lateral femoral condyle. The ridge was consistently located just anterior to the femoral ACL insertion. The ACL footprint was present in the depression between the ridge and the Inferior Articular Cartilage Margin (IACM). The mean distance from the midpoint of the IACM to the LIR was 10.1 mm. ConclusionsThis is the first study to use the microscribe to digitally reconstruct the medial surface of the lateral femoral condyle. It shows that the LIR is a consistent anatomical structure that defines the anterior margin of the femoral ACL insertion, which guides femoral tunnel placement. Our findings support the ruler technique, which is a commonly used method for anatomic single bundle ACL reconstruction.

Restoring tibiofemoral alignment during ACL reconstruction results in better knee biomechanics.

Anterior cruciate ligament (ACL) reconstruction (ACLR) aims to restore normal knee joint function, stability and biomechanics and in the long term avoid joint degeneration. The purpose of this study is to present the anatomic single bundle (SB) ACLR that emphasizes intraoperative correction of tibiofemoral subluxation that occurs after ACL injury. It was hypothesized that this technique leads to optimal outcomes and better restoration of pathological tibiofemoral joint movement that results from ACL deficiency (ACLD). Thirteen men with unilateral ACLD were prospectively evaluated before and at a mean follow-up of 14.9 (SD = 1.8)months after anatomic SB ACLR with bone patellar tendon bone autograft. The anatomic ACLR replicated the native ACL attachment site anatomy and graft orientation. Emphasis was placed on intraoperative correction of tibiofemoral subluxation by reducing anterior tibial translation (ATT) and internal tibial rotation. Function was measured with IKDC, Lysholm and the Tegner activity scale, ATT was measured with the KT-1000 arthrometer and tibial rotation (TR) kinematics were measured with 3Dmotion analysis during a high-demand pivoting task. The results showed significantly higher TR of the ACL-deficient knee when compared to the intact knee prior to surgery (12.2°±3.7° and 10.7°±2.6° respectively, P = 0.014). Postoperatively, the ACLR knee showed significantly lower TR as compared to the ACL-deficient knee (9.6°±3.1°, P = 0.001) but no difference as compared to the control knee (n.s.). All functional scores were significantly improved and ATT was restored within normal values (P < 0.001). Intraoperative correction of tibiofemoral subluxation that results after ACL injury is an important step during anatomic SB ACLR. The intraoperative correction of tibiofemoral subluxation along with the replication of native ACL anatomy results in restoration of rotational kinematics of ACLD patients to normal levels that are comparable to the control knee. These results indicate that the reestablishment of tibiofemoral alignment during ACLR may be an important step that facilitates normal knee kinematics postoperatively. Level II, prospective cohort study.

Transportal Anterior Cruciate Ligament Reconstruction with Quadrupled Hamstring Tendon Graft: A Prospective Outcome Study.

Background:Anterior cruciate ligament (ACL) reconstruction has been one of the most commonly performed procedures throughout the world. Unsatisfactory outcome with conventional ACL reconstruction has been attributed to nonanatomic graft placement. Researchers have advised placing the graft in the native footprint of ACL to avoid nonanatomic graft placement. The goal of this study was to analyze the outcome of anatomic single bundle ACL reconstruction using transportal technique.Materials and Methods:This was a prospective outcome study conducted on 85 consecutive patients of ACL reconstruction of which 62 patients met inclusion and exclusion criteria and were analyzed for final results. All the patients underwent ACL reconstruction by quadrupled hamstring tendon graft using transportal technique and the accessory anteromedial (AAM) portal for femoral tunnel creation. The graft was fixed with endobutton on femoral side and bioabsorbable screw on the tibial side. Patients were evaluated for range of motion, International Knee Documentation Committee (IKDC) score, and Lysholm scores at a minimum followup period of 2 years. The mean pre- and postoperative scores were compared using Wilcoxon signed-rank test.Results:The mean Lysholm and IKDC scores improved significantly (P < 0.0001) from preoperative value. According to IKDC score, 90.3% (n = 56) were either normal or near normal at final followup. According to Lysholm score, 75.8% of patients had excellent and 13.3% had good results. Preoperatively, pivot shift was present in 85.5% (n = 53) of patients which reduced to 4.8% (n = 3) postoperatively. Infection and knee stiffness occurred in two patients, and femoral tunnel blowout and graft re-rupture occurred in one patient each.Conclusion:Anatomic ACL reconstruction by AAM portal is a reproducible technique which gives good clinical outcome at short-term followup.

Novel Anatomical Single Bundle ACL Reconstruction Using a Rounded Rectangular Dilator

We have designed and developed an original rounded rectangular dilators and sizing block to perform novel anatomical single bundle ACL reconstruction. Compared with conventional anatomical single bundle ACL reconstruction, rounded rectangular femoral tunnel ACL reconstruction created a large femoral tunnel and improved anteroposterior, rotational laxity and clinical results. During the past 10 years, the main trend for ACL reconstruction has shifted to anatomic reconstruction, regardless of single bundle or double bundle techniques. There is no significant difference in the postoperative stability and clinical results between single and double bundle ACL reconstruction. Therefore, attention has returned to single bundle reconstruction with grafts that are placed at the center of anatomical footprint. It is widely accepted that the smaller hamstring autograft size (tunnel diameter < 8mm) is a predictor of poorer clinical results. However, the shortcoming of conventional anatomical single bundle ACL reconstruction is that the creation of a large anatomical bone tunnel is not possible because of roof impingement or breakage of posterior femoral bone tunnel. Furthermore several anatomical studies have reported that the femoral insertion of the ACL has a rounded rectangle shape, and we have also realized that the quadrupled semitendinosus tendons appear to be a rounded rectangular, rather than circular. Therefore, we created an original femoral dilator and sizing block and developed a new ACL reconstruction technique: “rounded rectangular femoral tunnel ACLR” (RFTR). This study aimed to compare the area of femoral tunnel and clinical results between conventional anatomical single bundle ACL reconstruction (ASBR) and RFTR. The hypothesis was that RFTR could have a larger femoral tunnel and improve clinical results. Between May 2010 and Aug. 2015, 157 primary ACL reconstructions were performed. After implementation of inclusion criteria, 116 ACL reconstructions were analyzed (ASBR = 57 patients, 25 male, 32 female; age, 24.1±9.3 years; RFTR = 59 patients, 34 male, 25 female; age, 24.5±10.1 years). Both ACL reconstructions were performed using a semitendinosus graft (with or without the gracilis tendon). The evaluation items were area of the femoral tunnel, anteroposterior laxity with KT-1000, pivot-shift test, and Lysholm score. We determined the femoral tunnel size using a sizer during arthroscopy. The tunnel exists within the native ACL footprint, and we chose the maximum size possible without going beyond the lateral intercondylar ridge. RFTR created a bigger femoral tunnel area than did ASBR (average area, 52.7±4.8 mm2 vs 47.0±7.3 mm2; P<0.01). RFTR resulted in better anteroposterior stability and Lysholm score than did ASBR (average side-to-side difference for anterior tibial translation, 0.8±1.1 mm vs 1.8±1.2 mm; P<0.01); average Lysholm score, 98.9±2.4 vs 97.6±3.3; P<0.01). Differences in rotational laxity between groups were statistically significant (negative pivot shift, 93.3% vs 82.5%; P<0.01). Compared with conventional anatomical single bundle ACL reconstruction, rounded rectangular femoral tunnel ACL reconstruction created a large femoral tunnel and improved anteroposterior, rotational laxity and clinical results. This technique simple and can address the shortcomings of conventional anatomical single bundle ACL reconstruction.

Graft Fixation Sequence in One-Stage Anterior Cruciate Ligament and Posterior Cruciate Ligament Reconstruction

According to the results of this study, the best fixation sequence for combined ACL/PCL reconstruction is when the ACL graft fixed first at close to full extension followed by the PCL graft fixation. There is no consensus regarding the best protocol for the sequence of graft tensioning and fixation in one-stage reconstruction of combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL). This study sought to determine the effect of ACL/PCL graft tensioning and fixation protocol on knee biomechanics. It is hypothesized that the sequence to best restore intact knee kinematics and the intact tibial position will be the ACL graft fixed first at close to full extension and the PCL graft fixed second with the knee flexed. Twelve fresh-frozen mature porcine hind limbs (n=12) were used. The knees were tested using a robotic testing system with a universal force-moment sensor. One-stage, combined anatomic single bundle (SB) ACL and PCL reconstructions were performed with and 8 mm grafts from bovine extensor tendon. The knee states tested were: (1) intact ACL and intact PCL, (2) deficient ACL and deficient PCL, and (3) one-stage ACL and PCL reconstruction. Five fixation sequences were performed in each knee in a randomized order: (1) PCL fixed 1st at 30° and ACL fixed 2nd at 30° (Recon 1), (2) PCL fixed 1st at 90° and ACL fixed 2nd at 30° (Recon 2), (3) ACL fixed 1st at 30° and PCL fixed 2nd at 30° (Recon 3), (4) ACL fixed 1st at 30° and PCL fixed 2nd at 90° (Recon 4) and (5) ACL and PCL fixed simultaneously at 30° (Recon 5). Both grafts were tensioned to 40 N. Two external loading conditions were tested: an 89 N anterior tibial and a posterior tibial load at 30° (full extension in the porcine knee). A 3-dimensional digitizer was used to measure the anterior-posterior (A-P) shift of the tibia in each of the reconstructed knee positions from the intact knee position in the unloaded knee. Data was analyzed using one-way repeated measures ANOVA, and statistical significance was set at p<0.05. None of the reconstructions restored the range of A-P translation to that of the intact knee at 30° of flexion, where the A-P translation is the sum of the anterior tibial translation (ATT) and posterior tibial translation (PTT). The mean A-P translation was: 7.9 ±1.3 mm at intact ACL and PCL, 16.4 ± 3.7 mm at deficient ACL and PCL, 12.3 ± 2.2 mm at Recon 1, 12.1 ± 3.2 mm at Recon 2, 12.8 ± 3.3 mm at Recon 3, 13.5 ± 2.6 mm at Recon 4, and 13.1 ± 2.6 mm at Recon 5. The mean anterior shift was: 2.69 ± 1.41 mm in Recon 1, 2.73 ± 2.88 mm in Recon 2, 0.05 ± 0.60 mm in Recon 3, 0.44 ± 1.27 mm in Recon 4, and 1.02 ± 1.39 mm in Recon 5. From the results of this study, if the PCL graft is fixed first the tibia will shift anteriorly regardless of flexion angle of the knee. However, while the knee is at full extension (30° in the porcine knee), fixation of the ACL graft first only causes a smaller shift of the tibia. Thus, the ACL graft should be fixed first while the knee is at full extension, and then the PCL graft can be fixed at either a low or high flexion angle. While fixation of the ACL graft first at 30° of flexion does not cause a large shift of the tibia, the A-P translation is not restored by any of the five fixation sequences.

Calcium phosphate-hybridized tendon grafts reduce femoral bone tunnel enlargement in anatomic single-bundle ACL reconstruction.

This study aimed to clarify the effect of calcium phosphate (CaP)-hybridized tendon grafting versus unhybridized tendon grafting on the morphological changes to the bone tunnels at the aperture 1year after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction. Seventy-three patients were randomized to undergo the CaP (n=37) or the conventional method (n=36). All patients underwent computed tomography (CT) evaluation 1week and 1year post-operatively. The femoral and tibial tunnels at the aperture were evaluated on reconstructed 3D CT images. Changes in the cross-sectional area (CSA) and diameters of the femur and the tibia, and the translation rate of the tunnel walls and the morphological changes of both tunnels were assessed. There was a significant reduction in the increase in the CSA and the anterior-posterior and proximal-distal tunnel diameters on the femoral side in the CaP group as compared with the conventional group. On the femoral side, the translation rate of the posterior wall was significantly larger in the CaP group than in the conventional group, whereas the translation rate of the distal wall was significantly smaller in the CaP group than in the conventional group. As compared with the conventional method, the CaP-hybridized tendon graft reduced bone tunnel enlargement on the femoral side 1year after anatomic single-bundle ACL reconstruction due to an anterior shift of the posterior wall and reduced distal shift in the femoral bone tunnel. Clinically, the CaP-hybridized tendon grafts can prevent femoral bone tunnel enlargement in anatomic single-bundle ACL reconstruction. I.

Comparison of Clinical Outcomes Following Anatomic Single vs. Double-Bundle ACL Reconstruction: A Randomized Clinical Trial

Objectives:The shortcomings of anterior cruciate ligament reconstruction (ACL), including failure to restore normal structure and function of the knee, limited return to pre-injury level of sports participation and failure to prevent the development of post-traumatic knee osteoarthritis (OA) have recently been recognized. Anatomic methods to reconstruct the ACL, including anatomic single-bundle (SB) and double-bundle (DB) reconstruction, have been proposed to improve clinical outcomes after ACL reconstruction. We performed a double-blinded randomized clinical trial to compare clinical outcomes of anatomic SB to anatomic DB ACL reconstruction. We hypothesized that anatomic DB ACL reconstruction with a quadriceps tendon autograft with bone block would result in reduced knee laxity, better range of motion, patient-reported outcomes (PROs), return to sports and reduced risk of re-injury compared to anatomic SB ACL reconstruction.Methods:Individuals between 14 and 50 years of age participating in at least 100 hours of Level 1 or 2 sports activities that presented within 12 months of injury to both bundles of the ACL with or without injury to the medial or lateral meniscus were eligible to participate in this study. Individuals with prior injury or surgery of the ipsilateral or contralateral knee or greater than a grade 1 concomitant knee ligament injury were excluded. If the ACL insertion sites were between 14 and 18mm, as measured with an arthroscopic ruler at the time of arthroscopy, the subject was randomized to undergo SB or DB ACL reconstruction with a 10 mm quadriceps tendon autograft harvested with a patellar bone block. A single, anatomically placed femoral tunnel was used for all cases. For DB ACL reconstruction, the graft was split into to two arms and passed through two anatomically placed tibial tunnels. Subjects were followed at 3, 6, 12 and 24 months after randomization, with the primary endpoints occurring at 24 months. Outcome measures included the KT-1000 (side to side difference) and pivot shift tests, range of motion (ROM), IKDC Subjective Knee Form (IKDC-SKF) and return to pre-injury level of sports participation.Results:Fifty-seven subjects were randomized (29 DB) and two-year follow-up was attained from 51 (89.5%). There were no differences between groups in terms of age, proportion of males, body mass index (BMI), participation in competitive or recreational sports or concomitant meniscus procedures. At 24-month follow-up there were no between groups differences for the pivot shift and KT-1000 tests, ROM and IKDC-SKF scores (Table 1). Twenty-three (85.2%) DB’s and 24 (87.5%) SB’s reported returning to pre-injury level of sports 2 years after surgery (p=0.81). Three subjects (2 SB’s, 5.9% of total) suffered a graft rupture and 5 individuals (4 SB’s, 9.8% of total) had a subsequent meniscus injury.Conclusion:With the available sample size, we were unable to demonstrate significant differences in clinical outcome between anatomic SB and DB ACL reconstruction when performed with a quadriceps tendon autograft with a bone block in individuals with ACL insertion sites that ranged from 14 to 18 mm. Furthermore, both anatomic SB and DB ACL reconstruction lead to clinical outcomes that are comparable or superior to those reported for non-anatomical ACL reconstruction with minimal recurrent instability.Table 1Clinical Outcomes at 24 MonthsDouble Bundle (n=27)Single Bundle (n=24)p value6Normal Pivot Shift (n, %)25, 92.6%23, 95.8%0.48KT Arthrometer1 (30 lb) (mean ± SD)0.5 ± 1.30.6 ± 1.60.80KT Arthrometer1 (max manual) (mean ± SD)0.7 ± 1.20.8 ± 1.50.79Passive Extension of Involved Knee2 (mean ± SD)3.9 ± 3.03.8 ± 2.80.90Passive Extension Difference3 (mean ± SD)2.1 ± 1.91.7 ± 2.60.53Active Flexion of Involved Knee4 (mean ± SD)140.7 ± 5.7140.2 ± 6.30.76Active Flexion Difference5 (mean ± SD)0.3 ± 4.2-1.1 ± 9.00.47IKDC Subjective Knee Score (mean ± SD)89.4 ± 10.390.2 ± 11.10.791 Values are involved minus non-involved side to side difference in millimeters2Values are in degrees. Positive values indicate hyperextension 3 Non-involved minus involved knee difference in passive knee extension. Values are in degrees. Positive values indicate a loss of extension of the involved knee 4 Values are in degrees 5 Non-involved minus involved knee difference in active knee flexion. Values are in degrees. Positive values indicate a loss of flexion of the involved knee. 6 Independent t-tests were used for continuous variables and Fisher Exact Tests were used for nominal variables. p values were not adjusted for multiple comparisons.

Knee Kinematics Following Anatomic Single vs. Double Bundle ACL Reconstruction: A Randomized Clinical Trial

Objectives:A randomized clinical trial was conducted to compare knee kinematics during gait and running 24 months after ACL reconstruction, using either single-bundle (SB) or double-bundle (DB) quadriceps tendon grafts. We hypothesized that DB reconstruction would better restore kinematics than SB reconstruction, in comparison to the uninjured, contralateral knee.Methods:Subjects were between 14 and 50 years of age, participated in at least 100 hours of Level 1 or 2 sports activities and presented within 12 months of injury to both bundles of the ACL (with or without meniscal injury). Exclusion criteria included prior injury or surgery of the ipsilateral or contralateral knee or greater than a grade 1 concomitant knee ligament injury. Subjects were randomized to undergo SB or DB ACL reconstruction with a 10 mm quadriceps tendon autograft harvested with a patellar bone block. A single, anatomically placed femoral tunnel was used for all cases. For DB ACL reconstruction, the soft tissue portion of the graft was split and passed through two anatomically placed tibial tunnels. Biplane radiographic images were acquired 24 months after surgery while subjects performed downhill running on a treadmill (3.0 m/s, 10 degree slope, 150 images/s) and level gait (1.3 m/s, 100 images/s). Subject specific bone models were generated from computed tomography images and matched to the biplane radiographs using a previously validated model-based tracking process to determine tibiofemoral kinematics. Rotations of the tibia relative to the femur were calculated using the rotational component of the Joint Coordinate System originally described by Grood and Suntay. Displacements of the tibia relative to the femur were expressed in an orthogonal anatomical coordinate system fixed to the tibia. Primary outcome variables were based on previous findings of abnormalities in knee kinematics after ACL injury/reconstruction, and included peak knee external rotation, adduction and anterior translation during heelstrike to mid-stance. Three trials were collected for each limb and each task, and averaged for statistical analysis. Differences between SB and DB kinematics were determined using Wilcoxon Signed Rank tests, with significance level p < 0.05.Results:No significant differences were found in any of the primary kinematic variables between single and double bundle anatomic ACL reconstruction (Table). Differences between reconstructed and contralateral (uninjured) limbs were small, averaging less than 2 degrees in rotation and 2 mm in translation. Rotational differences were smaller during gait than during downhill running.Conclusion:Conclusions: Contrary to the study hypothesis, DB reconstruction was not found to be superior to SB reconstruction. While some abnormalities remained (particularly during the more stressful downhill running evaluation), both anatomical reconstructions were equally effective at restoring normal knee kinematics.kinematic differences between limbs (affected-contralateral) during gait and downhill runningSingle BundleSingle BundleSingle BundleDouble BundleDouble BundleDouble BundleNMeanStd DevNMeanStd DevWilcoxon pRunningPeak Knee Adduction25-0.231.1221-0.211.160.71RunningPeak External Rotation25-1.564.0421-0.173.120.20RunningPeak Anterior Translation250.572.62212.022.750.13GaitPeak Knee Adduction26-0.061.1921-0.051.110.83GaitPeak External Rotation26-0.444.3421-0.113.550.77GaitPeak Anterior Translation260.832.97212.002.560.20

Does anatomic single-bundle ACL reconstruction using hamstring autograft produce anterolateral meniscal root tearing?

BackgroundTo determine if tibial tunnel reaming during anatomic single-bundle anterior cruciate ligament (ACL) reconstruction using hamstring autograft can result in anterolateral meniscal root injury, as diagnosed by magnetic resonance imaging (MRI).MethodsA case series of 104 primary anatomic single-bundle ACL reconstructions using hamstring autograft was retrospectively reviewed. Pre- and post-operative (>1 year) MRIs were radiologically evaluated for each patient, with a lateral meniscus extrusion > 3 mm at the level of the medial collateral ligament midportion on a coronal MRI, to establish anterolateral meniscal root injury.ResultsNo patients presented radiological findings of anterolateral meniscal root injury in this case series.ConclusionsExamining a single-bundle ACL reconstruction technique using hamstring autograft that considered tibial tunnel positioning in the center of the tibial footprint, this case series found no evidence of anterolateral meniscal root injury in patient MRIs, even more than 1-year post-operation.

Factors That Predict Failure in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Background: Anatomic graft placement in anterior cruciate ligament (ACL) reconstruction has become the preferred technique for many surgeons. The predictive factors for graft failure in anatomic single-bundle ACL reconstruction are relatively unknown. Purpose: To determine the risk factors for graft failure and the relative importance of those factors in anatomic single-bundle ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: All primary anatomic ACL reconstructions undertaken at a single institution over a 2-year period were evaluated for subjective and objective measures of graft failure. Risk factors evaluated included time since ACL rupture, age, sex, body mass index, intact or deficient medial and lateral meniscus, meniscal repair, hamstring graft size, and femoral and tibial tunnel position as assessed by 3D computed tomography (CT) scan. The significant factors predicting failure and the relative importance of those factors were determined. Results: At a median follow-up of 26 months, 123 patients were available for analysis. Ninety-seven patients underwent postoperative 3D CT for tunnel positions, including all 20 cases with graft failure. The significant predictors of graft failure were medial meniscal deficiency (hazard ratio [HR] 15.1; 95% CI, 4.7-48.5; P < .001), lateral meniscal deficiency (HR 9.9; 95% CI, 3-33; P < .001), shallow nonanatomic femoral tunnel positioning (HR 4.3; 95% CI, 1.6-11.6; P = .004), and younger patient age (HR 0.9; 95% CI, 0.9-1; P = .008). Conclusion: Meniscal deficiency is the most significant factor to predict graft failure in single-bundle anatomic ACL reconstruction. Shallow nonanatomic femoral tunnel positioning and younger patient age are additional risk factors for failure, but their relative importance is less.

Sagittal femoral condyle morphology correlates with femoral tunnel length in anatomical single bundle ACL reconstruction.

The purpose of this study was to reveal the correlation between femoral tunnel length and the morphology of the femoral intercondylar notch in anatomical single bundle anterior cruciate ligament (ACL) reconstruction using three-dimensional computed tomography (3D-CT). Thirty subjects undergoing anatomical single bundle ACL reconstruction were included in this study (23 female, 7 male: average age 45.5 ± 16.7). In the anatomical single bundle ACL reconstruction, the femoral and tibial tunnels were created close to the antero-medial bundle insertion site with trans-portal technique. Using post-operative three-dimensional computed tomography (3D-CT), accurate axial and lateral views of the femoral condyle were evaluated. The correlation of femoral tunnel length, which was measured intra-operatively, with the transepicondylar length (TEL), notch width index, notch outlet length, the notch area (axial), length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch was statistically analyzed. Tunnel placement was also evaluated using a Quadrant method. The average femoral tunnel length was 35.4 ± 4.4mm. The average TEL, NWI, notch outlet length, and the axial notch area, were 76.9 ± 5.1mm, 29.1 ± 3.8%, 19.5 ± 3.9mm, and 257.4 ± 77.4mm2, respectively. The length of Blumensaat's line and the height and area of the lateral wall of the femoral intercondylar notch were 33.8 ± 3.2mm, 22.8 ± 2.3mm, and 738.7 ± 129mm2, respectively. The length of Blumensaat's line, the height, and the area of the lateral wall of the femoral intercondylar notch were significantly correlated with femoral tunnel length. Femoral tunnel placement was 23.4 ± 4.5% in a shallow-deep direction and 35.4 ± 8.8% in a high-low direction. The length of Blumensaat's line, height, and area of the lateral wall of the femoral intercondylar notch are correlated with femoral tunnel length in anatomical single bundle ACL reconstruction. For clinical relevance, these parameters are useful in predicting the length of the femoral tunnel in anatomical single bundle ACL reconstruction for the prevention of extremely short femoral tunnel creation. Case controlled study, Level III.

In vivo knee rotational stability 2years after double-bundle and anatomic single-bundle ACL reconstruction.

The objective of this study was to evaluate knee rotational stability at least 2years after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction (SB) and double-bundle ACL reconstruction (DB) in comparison with the contralateral healthy knee joint. The Cincinnati, Lysholm and IKDC scores were analysed too. There were 40 patients in both groups, the mean follow-up was 27months. For all measurements, the navigation system OrthoPilot was used. Measurement started with the patient in the standing position in neutral rotation. Then, the patient achieved in 30° knee flexion under weight-bearing maximal external trunk rotation and returned to the neutral position. The same measurement was done for the internal trunk rotation. For the anterior-posterior stability, KT-1000 arthrometer was used. All measurements were repeated three times for each knee joint. After the DB reconstruction, the mean external rotation of the tibia (ER) was 8.2° and the internal rotation (IR) was 10.2°. In the contralateral healthy knee joint, ER was 8.5° (p = 0.597) and IR was 12.1° (p = 0.064). After the SB reconstruction, ER was 9.4° and IR was 13.1°. In the contralateral healthy knee joint, ER was 7.7° (p = 0.066) and IR was 9.8° (p = 0.005). Anterior-posterior translation was to the same extent for both groups. The DB reconstruction of the ACL restores the rotational stability of the knee joint without any significant difference in comparison to the contralateral healthy knee (p>0.05). The main finding of this study is that the internal rotational stability of the knee joint after the anatomic SB technique is not sufficient.

Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts

ObjectiveThe objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft. Patients and methodsA total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test. ResultsSupplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group. ConclusionThe use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft. Level of EvidenceLevel I Therapeutic study