In Vivo Three-Dimensional Imaging Analysis of Femoral and Tibial Tunnel Locations in Single and Double Bundle Anterior Cruciate Ligament Reconstructions

Background

Anatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT).

Methods

In this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement.

Results

The femoral tunnel for the SB technique was located 35.07% ± 5.33% in depth and 16.62% ± 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% ± 5.02% in depth, 17.12% ± 5.84% in height and 34.76% ± 5.87% in depth, 45.55% ± 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% ± 4.81% from the anterior margin and 47.62% ± 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% ± 7.83% from the anterior margin, 45.56% ± 2.71% from the medial tibial articular margin and 53.19% ± 3.74% from the anterior margin, 46.00% ± 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique.

Conclusions

Using the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.     

Surgical Technique: Revision ACL Reconstruction With a Rectangular Tunnel Technique

Background  

We developed the rectangular tunnel ACL reconstruction (RT ACLR) using a 10-mm wide bone-patellar tendon-bone (BTB) graft through rectangular tunnels with a rectangular aperture to reduce tunnel size: the cross-sectional area of the tunnels of 50 mm² (5 × 10 mm) in RT ACLR is less than that of 79 mm² in a conventional 10-mm round tunnel technique presuming the technique would be more suitable in revision ACLR with previous improperly placed tunnels.     

Arthroscopic anatomical double bundle anterior cruciate ligament reconstruction: A prospective longitudinal study

Background:

Single bundle anterior cruciate ligament (ACL) reconstruction has been the current standard of treatment for ACL deficiency. However, a significant subset of patients continue to report residual symptoms of instability with a poor pivot control. Cadaveric biomechanical studies have shown double bundle (DB) ACL reconstructions to restore the knee kinematics better. This study evaluates the outcome of DB ACL reconstruction.

Materials and Methods:

30 consecutive patients who underwent anatomic DB ACL reconstruction were included in this prospective longitudinal study. There were all males with a mean age of 25 ± 7.45 years. All patients were prospectively evaluated using GeNouRoB (GNRB) arthrometer, functional knee scores (International Knee Documentation Committee [IKDC] and Lysholm) and postoperative magnetic resonance imaging (MRI) for comparing the graft orientation and footprint of the reconstructed ACL with that of the normal knee.

Results:

The average followup was 36.2 months. At the time of final followup the mean Lysholm score was 93.13 ± 3.31. As per the objective IKDC score, 26 patients (86.6%) were in Group A while 4 patients (13.3%) were in Group B. The mean differential anterior tibial translation by GNRB, arthrometer was 1.07 ± 0.8 mm (range 0.1-2.3 mm). All cases had a negative pivot shift test. MRI scans of operated and the contralateral normal knee showed the mean sagittal ACL tibial angle coronal ACL tibial angle and tibial ACL footprint to be in accordance with the values of the contralateral, normal knee.

Conclusion:

The study demonstrates that DB ACL reconstruction restores the ACL anatomically in terms of size and angle of orientation. However, long term studies are needed to further substantiate its role in decreasing the incidence of early osteoarthritic changes compared to the conventional single bundle reconstructions.     

Outcome of double bundle anterior cruciate ligament reconstruction using crosspin and aperture fixation

Background:

Double bundle anterior cruciate ligament (DBACL) reconstruction is said to reproduce the native anterior cruciate ligament (ACL) anatomy better than single bundle anterior cruciate ligament, whether it leads to better functional results is debatable. Different fixation methods have been used for DBACL reconstruction, the most common being aperture fixation on tibial side and cortical suspensory fixation on the femoral side. We present the results of DBACL reconstruction technique, wherein on the femoral side anteromedial (AM) bundle is fixed with a crosspin and aperture fixation was done for the posterolateral (PL) bundle.

Materials and Methods:

Out of 157 isolated ACL injury patients who underwent ACL reconstruction, 100 were included in the prospective study. Arthroscopic DBACL reconstruction was done using ipsilateral hamstring autograft. AM bundle was fixed using Transfix (Arthrex, Naples, FL, USA) on the femoral side and bio interference screw (Arthrex, Naples, FL, USA) on the tibial side. PL bundle was fixed on femoral as well as on tibial side with a biointerference screw. Patients were evaluated using KT-1000 arthrometer, Lysholm score, International Knee Documentation Committee (IKDC) Score and isokinetic muscle strength testing.

Methods:

Out of 157 isolated ACL injury patients who underwent ACL reconstruction, 100 were included in the prospective study. Arthroscopic DBACL reconstruction was done using ipsilateral hamstring autograft. AM bundle was fixed using Transfix (Arthrex, Naples, FL, USA) on the femoral side and bio interference screw (Arthrex, Naples, FL, USA) on the tibial side. PL bundle was fixed on femoral as well as on tibial side with a biointerference screw. Patients were evaluated using KT-1000 arthrometer, Lysholm score, International Knee Documentation Committee (IKDC) Score and isokinetic muscle strength testing.

Results:

The KT-1000 results were evaluated using paired t test with the P value set at 0.001. At the end of 1 year, the anteroposterior side to side translation difference (KT-1000 manual maximum) showed mean improvement from 5.1 mm ± 1.5 preoperatively to 1.6 mm ± 1.2 (P < 0.001) postoperatively. The Lysholm score too showed statistically significant (P < 0.001) improvement from 52.4 ± 15.2 (range: 32-76) preoperatively to a postoperative score of 89.1 ± 3.2 (range 67-100). According to the IKDC score 90% patients had normal results (Category A and B). The AM femoral tunnel initial posterior blow out was seen in 4 patients and confluence in the intraarticular part of the femoral tunnels was seen in 6 patients intraoperatively. The quadriceps strength on isokinetic testing had an average deficit of 10.3% while the hamstrings had a 5.2% deficit at the end of 1 year as compared with the normal side.

Conclusion:

Our study revealed that the DBACL reconstruction using crosspin fixation for AM bundle and aperture fixation for PL bundle on the femoral side resulted in significant improvement in KT 1000, Lysholm and IKDC scores.     

Evaluation of Femoral Tunnel Positioning Using 3-Dimensional Computed Tomography and Radiographs after Single Bundle Anterior Cruciate Ligament Reconstruction with Modified Transtibial Technique

Background

The purpose of this study is to report a modified transtibial technique to approach the center of anatomical femoral footprint in anterior cruciate ligament (ACL) reconstruction and to investigate the accurate femoral tunnel position with 3-dimensional computed tomography (3D-CT) and radiography after reconstruction.

Methods

From December 2010 to October 2011, we evaluated 98 patients who underwent primary ACL reconstruction using a modified transtibial technique to approach the center of anatomical femoral footprint in single bundle ACL reconstruction with hamstring autograft. Their femoral tunnel positions were investigated with 3D-CT and radiography postoperatively. Femoral tunnel angle was measured on the postoperative anteroposterior (AP) radiograph and the center of the femoral tunnel aperture on the lateral femoral condyle was assessed with 3D-CT according to the quadrant method by two orthopedic surgeons.

Results

According to the quadrant method with 3D-CT, the femoral tunnel was measured at a mean of 32.94% ± 5.16% from the proximal condylar surface (parallel to the Blumensaat line) and 41.89% ± 5.58% from the notch roof (perpendicular to the Blumensaat line) with good interobserver (intraclass correlation coefficients [ICC], 0.766 and 0.793, respectively) and intraobserver reliability (ICC, 0.875 and 0.893, respectively). According to the radiographic measurement on the AP view, the femoral tunnel angles averaged 50.43° ± 7.04° (ICC, 0.783 and 0.911, respectively).

Conclusions

Our modified transtibial technique is anticipated to provide more anatomical placement of the femoral tunnel during ACL reconstruction than the former traditional transtibial techniques.     

How Important is the Tunnel Position in Outcomes Post-ACL Reconstruction: A 3D CT-Based Study

BackgroundDrilling the femoral and tibial tunnels at their anatomical locations are critical for good outcomes and involve seeing the footprints well. We intended to compare two techniques of drilling the tunnels and the patient-reported outcomes and knee stability of patients undergoing single bundle ACL reconstruction using 3D CT to evaluate if the tunnels were anatomical or not.Materials and MethodsSixty single bundle ACL reconstructions were analyzed, 30 each with Technique A and B. Pre-operative and after a minimum 27 month follow-up Lysholm, IKDC, Tegner score, hop test, and Lachman test were noted. 3D CT was done to classify femoral tunnels positions as being well placed, slightly or grossly misplaced and tibial tunnels as optimal or suboptimal and compared.ResultsSixty ACL reconstructions had full follow-up with a mean follow-up of 34 months. There was no significant difference between tunnel positions between the two techniques. Well-placed femoral tunnel had better Lysholm score (62.2 ± 16.2 v/s 48.5 ± 17.2, p 0.002) and IKDC score (62.5 ± 14.3 v/s 52.7 ± 15.1, p 0.012).). Those who had their surgeries within 3 months of their injury had better hop test (4.4 ± 0.9 v/s 3.9 ± 1, p 0.034) and IKDC scores (62.5 ± 15.8 v/s 33.2 ± 13.8, p 0.026) as compared to those that had surgery done after 3 monthsConclusionTibial tunnel positions were optimal in most cases and did not differ between the two techniques. Well-placed femoral tunnels and surgeries done within 3 months of the injury produced best results.     

Anatomical relationship between insertion sites,tunnel placement,and lateral meniscus anterior horn injury during single and double bundle anterior cruciate ligament reconstructions: A comparative macroscopic and histopathological evaluation in cadavers

PurposeThe influence of tunnel extension outside the anatomical anterior cruciate ligament (ACL) insertion in single-bundle (SB) or double-bundle (DB) ACL reconstruction is unclear. This study aimed to investigate the anatomical relationship between ACL insertion and tunnel extension in SB and DB ACL reconstruction, and the impact of tibial tunnel extension to the insertion of anterior horn of lateral meniscus in terms of injury.MethodsForty-six paired cadaver knees (mean age, 82.7 ± 10.7 years) were used. Right and left knees were used for SB (10 mm) and DB tunnel reaming (6 mm for the anteromedial and posterolateral bundles). Tibial and femoral tunnels were created to aim at the center of the ACL insertion by arthroscopic visualization. The relationship between tunnel extension and ACL insertion was evaluated macroscopically, and there ratio in two groups were compared by chi-square test. Further, the relative risk for meniscus injury based on tunnel placement was estimated. Coronal section of tibia and parallel section to Blumensaat line in femur were prepared to evaluate the relationship among tunnel position, ACL insertion, and anterior horn of the meniscus histologically.ResultsTibial tunnel extension out of the ACL insertion was observed macroscopically in 9 (39.1%) knees of the SB group, and 3 (13.0%) of the DB group (p = 0.045). In femoral tunnels, extension out of the ACL insertion was seen in 8 (34.8%) knees of the SB group and 1 (4.3%) of the DB group (p = 0.011). Partial injuries of the lateral meniscus anterior horn (LMAH) were observed in 5 (21.7%) knees of the SB group and 1 (4.3%) knee of the DB group (p = 0.091). The relative risk for LMAH injury was calculated as 5.0 (odds ratio, 6.1). Microscopically, SB tunnels appeared to expand out of ACL insertion, both in the femur and tibia.ConclusionsThe incidence of tunnel extension out of the ACL insertion in femur and tibia were higher with SB than with DB reconstruction. Furthermore, injury rate of the LMAH in the DB group was lower.     

Does Viewing the ACL Femoral Footprint End on Using a High Medial Portal Produce Better Tunnel Placement as Compared to Viewing it from a Lateral Portal while Drilling: A 3D CT-based Pilot Study

BackgroundAnatomical placement of an ACL graft is critical to the clinical outcome of an ACL reconstruction. The purpose of the study was to compare the conventional technique of drilling a femoral tunnel from a medial portal while viewing it from a lateral portal versus viewing it from a high anteromedial portal and drilling it from a low medial portal. We hypothesized that the high anteromedial portal possibly provides an end-on view of the tunnel and would lead to a more favourable tunnel position.Materials and MethodsSixty patients underwent arthroscopic single-bundle ACL reconstruction with a soft tissue graft. All patients had the same surgeon and same surgical technique (except viewing portal). Each patient underwent a 3D-CT 1-week post-op. We classified the patients into two groups (technique A and B) of 30 each. Postoperative tunnel position in each patient was visualized on CT scan with 3D reconstruction by the quadrant method described by Bernard et al. The distance of the centre of the femoral tunnel from the superior and posterior border of the Bernard frame was obtained in each patient of the two groups and mean value in each group was obtained and compared by Student ‘t’ test at 5% level of significance. The position of the femoral tunnels was also studied in reference to the lateral intercondylar ridge and classified into type I (well placed), type II (moderately malpositioned) and type III (grossly malpositioned)ResultsThe mean distances in technique A from the posterior and superior border of the lateral femoral condyle was 35.8 ± 8.2 and 35.2 ± 6.7, and in technique B was 38.1 ± 8.6 and 35.8 ± 9.4. The two groups did not differ significantly (P > 0.05) in femoral tunnel position as visualized on 3D-CT scan postoperatively. 53.3% patients had well-placed tunnels (type I) overall with 56.67% of technique A and 50% of technique B in this group. None of the tunnels were grossly malpositioned.ConclusionsThe absence of any statistically significant difference between the groups suggests that a high anterolateral portal close to the patellar tendon gives an almost complete view of the lateral aspect of the notch, if not end on. Both techniques produced a majority of well placed (type I) tunnels     

Reduction in Bone Volume Resection with a Newer Posterior Stabilized Total Knee Arthroplasty Design

Background

Posterior stabilized total knee arthroplasty requires an intercondylar notch to accommodate the cam housing that articulates with the tibial post to create femoral rollback required for deep flexion. The volume of bone resected for the intercondylar notch varies with implant design, and newer designs may accommodate high flexion with less bone resection.

Questions/Purposes

This study aims to analyze the bone volume and density resected from the intercondylar notch for three posterior stabilized implants from a single company: a Posterior Stabilized (PS) system, a Hi-Flex system (HF), and a rounded new box-reamer (RB) system and to further assess whether the newer RB with a cylindrical cutting tool would preserve more native bone.

Materials and Methods

Using a computer model, the PS, HF, and RB femoral components were digitally implanted into CT scans of 19 cadaver femurs. Nine cadavers were fit with a size 4 implant, six with size 3, and four with a size 2. The volume of intercondylar bone resected digitally for femoral preparation was measured. Bone density was measured by CT scans in Hounsfield units (HU). A paired t test was used to compare the mean volume of bone resected for each implant.

Results

For the size 4 femurs, the newer RB design removed 8% less intercondylar bone than the PS design (7,832 ± 501 vs. 8,547 ± 377 mm³, p < 0.001) and 28% less bone than the HF design (7,832 ± 501 vs. 10,897 ± 444 mm³, p < 0.001). The average HU for size 4 femurs for RB design was 427 ± 72 (PS = 399 ± 69, p < 0.001; HF = 379 ± 66, p < 0.001). For the size 3 femurs, the RB design removed 12% less intercondylar bone than the PS (6,664 ± 786 vs. 7,516 ± 648 mm³, p < 0.001) and 27% less bone than the HF (6,664 ± 786 vs. 9,078 ± 713 mm³, p < 0.001). HU for size 3 femurs for the RB design was 452 ± 70 (PS = 422 ± 53, p < 0.1; HF = 410 ± 59, p < 0.01). For the size 2 femurs, the RB design removed 5% less intercondylar bone than the PS (5,730 ± 552 vs. 6,009 ± 472 mm³, p < 0.01) and 22% less bone than the HF (5,730 ± 552 vs. 7,380 ± 532 mm³, p < 0.001). HU for size 2 femurs for the RB design was 430 ± 48 (PS = 408 ± 55, p < 0.01; HF = 385 ± 56, p < 0.01).

Conclusions

The newer RB design removes less bone from the intercondylar notch than the classic PS and HF designs in all sizes tested. The bone-conserving cuts incorporated into this newer implant design appear to preserve native bone without compromising design objectives.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9340-1) contains supplementary material, which is available to authorized users.     

Clinical Results of Technique for Double Bundle Anterior Cruciate Ligament Reconstruction Using Hybrid Femoral Fixation and Retroscrew

Background

Anatomic anterior cruciate ligament (ACL) reconstruction has been presented as a means to more accurately restore the native anatomy of this ligament. This article describes a new method that uses a double bundle to perform ACL reconstruction and to evaluate the clinical outcome.

Methods

Grafts are tibialis anterior tendon allograft for anteromedial bundle (AMB) and hamstring tendon autograft without detachment of the tibial insertion for posterolateral bundle (PLB). This technique creates 2 tunnels in both the femur and tibia. Femoral fixation was done by hybrid fixation using Endobutton and Rigidfix for AMB and by biointerference screw for PLB. Tibial fixations are done by Retroscrew for AMB and by native insertion of hamstring tendon for PLB. Both bundles are independently and differently tensioned. We performed ACL reconstruction in 63 patients using our new technique. Among them, 47 participated in this study. The patients were followed up with clinical examination, Lysholm scales and International Knee Documentation Committee (IKDC) scoring system and radiological examination with a minimum 12 month follow-up duration.

Results

Significant improvement was seen on Lachman test and pivot-shift test between preoperative and last follow-up. Only one of participants had flexion contracture about 5 degrees at last follow-up. In anterior drawer test by KT-1000, authors found improvement from average 8.3 mm (range, 4 to 18 mm) preoperatively to average 1.4 mm (range, 0 to 6 mm) at last follow-up. Average Lysholm score of all patients was 72.7 ± 8.8 (range, 54 to 79) preoperatively and significant improvement was seen, score was 92.2 ± 5.3 (range, 74 to 97; p < 0.05) at last follow-up. Also IKDC score was normal in 35 cases, near normal in 11 cases, abnormal in 1 case at last follow-up.

Conclusions

Our new double bundle ACL reconstruction technique used hybrid fixation and Retroscrew had favorable outcomes.     

Long term results after double and single bundle ACL reconstruction: Is there any difference? A meta - analysis of randomized controlled trials

ObjectiveThe double-bundle (DB) techniques are considered to yield better stability of the knee compared with single-bundle (SB) for anterior cruciate ligament (ACL) reconstruction. However, most studies followed up patients in short to middle-term within 5 years, and the longer-term efficacy of SB and DB ACL reconstruction is still beyond consensus. The purpose of this meta-analysis is to compare the longer-term efficacy between double-bundle (DB) and single-bundle (SB) techniques.MethodsPubMed, EMBASE, and Cochrane Library databases were searched for relevant articles published up to November, 2017 with an English language restriction. The searches were limited to human subjects and randomized controlled trials (RCTs). In addition, the reference lists of identified articles were checked manually to avoid missing other potentially eligible studies. This process was performed iteratively until no additional articles could be included. The quality of the included studies was assessed using The Cochrane Collaboration's risk of bias tool. All statistical analyses were performed with Review Manager soft-ware.ResultsA total of five RCTs involving 294 patients were included finally. No studies were excluded due to insufficient data or low quality. The pooled results showed no statistically significant difference between SB and double bundle DB reconstructions for Lysholm, IKDC, pivot shift, KT scores, and the development of osteoarthritis at a minimum of 5 years. No significant heterogeneity was found across all outcomes.ConclusionThe best available evidence demonstrated that SB and DB techniques could yield similar efficacy for ACL reconstruction. And no superiority was founded in DB ACL reconstruction with a minimal 5-year follow-up. Given that, the relatively simple and proven techniques of SB ACL reconstruction may be preferable for orthopedic surgeons.Level of evidence: Level I, Therapeutic Study.     

Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

Background

The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction.

Methods

Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction.

Results

Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees.

Conclusions

Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction.     

Outcome of transtibial AperFix system in anterior cruciate ligament injuries

Background:

The anterior cruciate ligament (ACL) is one of the major stabilizing factor of the knee that resist anterior translation, valgus and varus forces. ACL is the most commonly ruptured ligament of the knee. The graft fixation to bone is considered to be the weakest link of the reconstruction. According to the parallel forces to the tibial drill hole and the quality of tibial metaphyseal bone is inferior to femoral bone stock, graft fixation to the tibia is more difficult to secure. AperFix system (Cayenne Medical, Inc., Scottsdale, Arizona, USA) which consists femoral and tibial component that includes bioinert polymer polyetheretherketone (PEEK) is one of the new choice for ACL reconstruction surgery. aim of this study was to assess the clinical outcomes and fixation durability of the AperFix (Cayenne Madical, Inc., Scottsdale, Arizona, USA) system and to determine the effect of patient''s age in arthroscopic reconstruction of the anterior cruciate ligament.

Materials and Methods:

Patients with symptomatic anterior cruciate ligament rupture underwent arthroscopic reconstruction. Patients were evaluated in terms of range of motion (ROM) values; Lysholm, Cincinati and Tegner activity scales; laxity testing and complications. Femoral tunnel widening was assessed by computer tomography scans. Early postoperative and last followup radiographs were compared.

Results:

Fifty one patients were evaluated with mean followup of 29 months (range 25–34 months). Mean age at the surgery was 26.5 ± 7.2 years. Lysholm, Cincinati and Tegner activity scales were significantly higher from preoperative scores (Lysholm scores: Preoperative: 51.4 ± 17.2, postoperative: 88.6 ± 7.7 [P < 0.001]; Tegner activity scores: Preoperative 3.3 ± 1.38, postoperative: 5.3 ± 1.6 [P < 0.001]; Cincinati scores: Preoperative: 44.3 ± 17, postoperative: 81.3 ± 13.9 [P < 0.001]). The mean femoral tunnel diameter increased significantly from 9.94 ± 0.79 mm postoperatively to 10.79 ± 0.95 mm (P < 0.05). The mean ROM deficit (involved vs. contra knee) was −7.2 ± 16 (P < 0.001). There was no significant difference for knee score, ROM deficits (<30 years: −7.3 ± 15 and >30 years −7.06 ± 19) and femoral tunnel enlargement (<30 years: 0.83 ± 0.52 and >30 years 0.87 ± 0.43) of the patients with below and above 30 year. There was no significant difference for knee scores and femoral tunnel enlargement between patients with meniscal injuries and don’t have meniscus lesions.

Conclusion:

The AperFix system gives satisfactory clinical and radiological results with low complication rate. However, long term clinical and radiological results are needed to decide the ideal anterior cruciate ligament reconstruction method.     

Double-bundle reconstruction cannot restore intact knee kinematics in the ACL/LCL-deficient knee

Introduction  

The aim of this study was to evaluate the effect of single-bundle (SB) and anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction on the resulting knee kinematics in a simulated clinical setting with ACL rupture and associated extra-articular damage to the lateral structures. It was hypothesized that anatomic DB ACL reconstruction restores the intact knee kinematics in ACL/LCL-deficient knees, whereas SB ACL reconstruction fails to restore the intact knee kinematics.     

Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Using a Gracilis Autograft without Bone Tunnel

Background

Several tendon graft and fixation methods have been introduced in medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. The purpose of this study was to evaluate the results of MPFL reconstruction using a gracilis autograft fixation without bone tunnel in patients with recurrent patellar instability.

Methods

Nine patients (four males and five females) diagnosed with recurrent patellar instability from July 2009 to January 2013 and had MPFL reconstruction using a gracilis autograft were included. The average age of the patients was 24.6 years (range, 13 to 48 years), and the average follow-up period was 19.3 months (range, 12 to 30 months). For every patient, femoral attachment was fixed using suture anchors securing the patella by suturing the periosteum and surrounding soft tissue. Clinical evaluation included the Kujala, Lysholm, and Tegner scores; in addition, patients were examined for any complication including recurrent dislocation. The congruence angle and patella alta were assessed radiologically before and after surgery.

Results

The Kujala score improved from an average of 42.7 ± 8.4 before surgery to 79.6 ± 13.6 (p = 0.008) at final follow-up; the Lysholm score improved from 45.8 ± 5.7 to 82.0 ± 10.5 (p = 0.008); and the Tegner score improved from 2.8 ± 0.8 to 5.6 ± 1.5 (p = 0.007). The Insall-Salvati ratio changed from 1.16 ± 0.1 (range, 0.94 to 1.35) before surgery to 1.14 ± 0.1 (range, 0.96 to 1.29; p = 0.233) at the final follow-up without significance. The congruence angle significantly improved from 26.5° ± 10.6° (range, 12° to 43°) before surgery to -4.0° ± 4.3° (range, -12° to 5°; p = 0.008) at final follow-up. Subluxation was observed in one patient and hemarthrosis occurred in another patient 2 years after surgery, but these patients were asymptomatic.

Conclusions

We achieved good results with a patellar fixation technique in MPFL reconstruction using a gracilis autograft employing soft tissue suturing in patients with recurrent patellar dislocation.     

Remnant Preservation is Helpful to Obtain Good Clinical Results in Posterior Cruciate Ligament Reconstruction: Comparison of Clinical Results of Three Techniques

Background

The purpose of the present study was to compare the clinical results of 3 posterior cruciate ligament reconstruction techniques according to the time from injury to surgery and remnant PCL status and to evaluate the efficiency of each technique.

Methods

The records of 89 patients who underwent primary PCL reconstructions with a posterolateral corner sling were analyzed retrospectively. Thirty-four patients were treated by anterolateral bundle (ALB) reconstruction with preservation of the remnant PCL using a transtibial tunnel technique in the acute and subacute stages of injury (group 1). Forty patients were treated with remnant PCL tensioning and an ALB reconstruction using the modified inlay technique in the chronic stage (group 2), and fifteen patients were treated with double-bundle reconstruction using the modified inlay technique (group 3). The double-bundle reconstruction was performed if there was a very weak or no PCL remnant.

Results

The mean side-to-side differences in posterior tibial translation on the stress radiographs were reduced from 10.1 ± 2.5 mm in group 1, 10.6 ± 2.4 mm in group 2, and 12.8 ± 3.2 mm in group 3 preoperatively to 2.3 ± 1.4 mm in group 1, 2.3 ± 1.5 mm in group 2, and 4.0 ± 2.5 mm in group 3 at the last follow-up (p < 0.001, p < 0.001, and p < 0.001, respectively). Statistical analyses revealed that group 1 and group 2 were similar in terms of side-to-side difference changes in posterior tibial translation on the stress radiographs; however, group 3 was inferior to group 1 and group 2 at the last follow-up (p = 0.022). The clinical results were not significantly different among the three groups.

Conclusions

Excellent posterior stability and good clinical results were achieved with ALB reconstruction preserving the injured remnant PCL in the acute and subacute stages and remnant PCL tensioning with ALB reconstruction in the chronic stage. The PCL injuries could be surgically corrected with different techniques depending on both the remnant PCL status and the interval between the knee trauma and operation.     

Technique of anatomical footprint reconstruction of the ACL with oval tunnels and medial portal aimers

Purpose

The purpose of this article was to demonstrate an anterior cruciate ligament (ACL) reconstruction technique using oval tunnels. Aim of this single bundle technique is to fit the footprint anatomy of the ACL as closely as possible.

Technique and patients

The presented technique is a single bundle technique using a semitendinosus graft. For femoral tunnel placement, a specific medial portal aimer (Karl Storz, Tuttlingen, Germany) is used. Aiming and drilling of the femoral tunnel are performed via the medial portal. Oval tunnels are created by stepwise dilatation with ovally shaped dilatators. The position of the femoral tunnel is visualized and controlled with the arthroscope via the medial portal. For the tibial tunnel placement, a specific aimer was used as well. With this technique, 24 patients were operated and all intra- and postoperative complications were analyzed prospectively. The tunnel position was documented postoperatively by CT scan.

Results

There were no significant intra- and postoperative complications associated with the oval tunnel technique. The postoperative 3D CT scan revealed that all femoral and tibial tunnels were located within the area of the anatomical ACL insertions.

Conclusions

This article presents an ACL reconstruction technique using oval dilatators and medial portal aimers to create oval tunnels. These oval tunnels match the insertion site anatomy much closer than round tunnels do.

Level of Evidence

Level IV, case series.     

ACL reconstruction in sports active people: transtibial DB technique with ST/G vs. transtibial SB technique with BPTB: preliminary results

The single-bundle ACL reconstruction ensures good outcomes and it is a well-established and widespread technique. Nevertheless, some patients still present residual pain and instability. Recent studies have showed that the double-bundle technique restores better natural ACL-fitting kinematics. Long-term clinical studies comparing the two surgical techniques are not frequent and there is no instrument to evaluate function and kinematics during the knee rotation in vivo.In this randomised prospective study performed on sportive people, we compare the BPTB single-bundle ACL reconstruction technique, which is the most common surgical technique performed on these patients’ category, with the ACL double-bundle reconstruction technique (DB), in order to evaluate possible differences between the groups.Comparing the two groups, no statistically significant difference regarding the post-operative Lysholm score (p = 0.368) the Tegner activity scale (p = 0.519) and the arthrometric evaluation with KT-1000 (p = 0.74) have been observed. On the contrary, the IKDC evaluation showed a statistically significant difference (p = 0.004) better results of the DB group. Moreover, as assessed by the Tegner activity scale, only patients of the DB group were able to return to sports at a pre-injury level.Our data suggest that the double bundle ST/G ACL reconstruction technique results into slightly better outcome than the traditional technique of single-bundle BPTB. The verification and quantification of the advantages of this technique is anticipated with future studies focusing to the accurate measurement of knee rotation during different activities.     

Three-Dimensional Reconstruction Computed Tomography Evaluation of Tunnel Location during Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of Transtibial and 2-Incision Tibial Tunnel-Independent Techniques

Background

Anatomic tunnel positioning is important in anterior cruciate ligament (ACL) reconstructive surgery. Recent studies have suggested the limitations of a traditional transtibial technique to place the ACL graft within the anatomic tunnel position of the ACL on the femur. The purpose of this study is to determine if the 2-incision tibial tunnel-independent technique can place femoral tunnel to native ACL center when compared with the transtibial technique, as the placement with the tibial tunnel-independent technique is unconstrained by tibial tunnel.

Methods

In sixty-nine patients, single-bundle ACL reconstruction with preservation of remnant bundle using hamstring tendon autograft was performed. Femoral tunnel locations were measured with quadrant methods on the medial to lateral view of the lateral femoral condyle. Tibial tunnel locations were measured in the anatomical coordinates axis on the top view of the proximal tibia. These measurements were compared with reference data on anatomical tunnel position.

Results

With the quadrant method, the femoral tunnel centers of the transtibial technique and tibial tunnel-independent technique were located. The mean (± standard deviation) was 36.49% ± 7.65% and 24.71% ± 4.90%, respectively, from the over-the-top, along the notch roof (parallel to the Blumensaat line); and at 7.71% ± 7.25% and 27.08% ± 7.05%, from the notch roof (perpendicular to the Blumensaat line). The tibial tunnel centers of the transtibial technique and tibial tunnel-independent technique were located at 39.83% ± 8.20% and 36.32% ± 8.10%, respectively, of the anterior to posterior tibial plateau depth; and at 49.13% ± 4.02% and 47.75% ± 4.04%, of the medial to lateral tibial plateau width. There was no statistical difference between the two techniques in tibial tunnel position. The tibial tunnel-independent technique used in this study placed femoral tunnel closer to the anatomical ACL anteromedial bundle center. In contrast, the transtibial technique placed the femoral tunnel more shallow and higher from the anatomical position, resulting in more vertical grafts.

Conclusions

After single-bundle ACL reconstruction, three-dimensional computed tomography showed that the tibial tunnel-independent technique allows for the placement of the graft closer to the anatomical femoral tunnel position when compared with the traditional transtibial technique.     

Validation of Porcine Knee as a Sex-specific Model to Study Human Anterior Cruciate Ligament Disorders

Background

Animal models have long been considered an important modality for studying ACL injuries. However, to our knowledge, the value of these preclinical models to study sex-related phenomena associated with ACL injury and recovery has not been evaluated.

Questions/purposes

We asked whether (1) prominent anatomic and (2) biomechanical factors differ between female and male porcine knees, particularly those known to increase the risk of ACL injury.

Methods

Eighteen intact minipig knees (nine males, nine females) underwent MRI to determine the femoral bicondylar width, intercondylar notch size (width, area and index), medial and lateral tibial slope, ACL size (length, cross-sectional area, and volume), and medial compartment tibiofemoral cartilage thickness. AP knee laxity at 30°, 60°, and 90° flexion and ACL tensile structural properties were measured using custom-designed loading fixtures in a universal tensile testing apparatus. Comparisons between males and females were performed for all anatomic and biomechanical measures. The findings then were compared with published data from human knees.

Results

Female pigs had smaller bicondylar widths (2.9 mm, ratio = 0.93, effect size = −1.5) and intercondylar notches (width: 2.0 mm, ratio = 0.79, effect size = −2.8; area: 30.8 mm², ratio = 0.76, effect size = −2.1; index: 0.4, ratio = 0.84, effect size = −2.0), steeper lateral tibial slope (4.3°, ratio = 1.13, effect size = 1.1), smaller ACL (length: 2.7 mm, ratio = 0.91, effect size = −1.1; area: 6.8 mm², ratio = 0.74, effect size = −1.5; volume: 266.2 mm³, ratio = 0.68, effect size = −1.5), thinner medial femoral cartilage (0.4 mm, ratio = 0.8, effect size = −1.1), lower ACL yield load (275 N, ratio = 0.81, effect size = −1.1), and greater AP knee laxity at 30° (0.7 mm, ratio = 1.32, effect size = 1.1) and 90° (0.5 mm, ratio = 1.24, effect size = 1.1) flexion compared with their male counterparts. These differences were significant for all parameters (p ≤ 0.04). Observed sex-related differences were similar to those reported for the human knee.

Conclusions

Significant differences exist between knees of male and female pigs with respect to prominent anatomic and biomechanical factors. Our findings strongly agreed with published data regarding human knees.

Clinical Relevance

The findings highlight the use of the porcine large animal model to study the role of sex on ACL injuries and surgical outcome. This validated preclinical model may facilitate the development of novel, sex-specific interventions to prevent and treat ACL injuries for male and female patients.