Anatomic double-bundle anterior cruciate ligament reconstruction, using CT-based navigation and fiducial markers

Accurate placement of separate anteromedial and posterolateral bundle bone tunnels is crucial for anatomic, double-bundle anterior cruciate ligament (ACL) reconstruction. However, identifying the anatomic footprint at which to make the tibial and femoral bone tunnels is not a straightforward procedure. To overcome this problem, we used a CT-based navigation technique with a registration procedure based on fiducial markers (FMs). Preoperatively, 10 FM points were placed on skin around knee joint and scanned with CT. Imaging data of the knee were recorded on the computer system for preoperative registration and surgical planning. Intraoperatively, with a reference frame fixed to the distal medial aspect of femur and tibia, paired-point matching registration was performed with the use of points marked on skin through FM center holes. During tibial tunnel guide wire placement, tibial aiming guide with tracking device fed back the position of tip and direction of the guide wire on the three-dimensional (3D) tibia bone surface image and multiple image planes in real time. For the femoral side, the navigation pointer was placed at the footprint center with visual guidance of 3D image of lateral wall sagittal view on navigation monitor and marked with navigation awl. The average registration accuracy of 22 consecutive patients was 0.7 +/- A 0.2 mm and 0.6 +/- A 0.2 mm for femoral and tibial bone, respectively. Most of the bone tunnel positions evaluated with 3D-CT image were confirmed to be accurately placed in reference to the preoperative plan. There was no damage to femoral condyle cartilage and no other complication. This new CT-based computer navigation system opens the possibility for surgeons to plan bone tunnel positioning preoperatively and control it during technically demanding anatomic double-bundle ACL reconstruction.ArticleKNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY. 19(3):378-383 (2011)journal articl

Bony Landmarks of the Anterior Cruciate Ligament Tibial Footprint A Detailed Analysis Comparing 3-Dimensional Computed Tomography Images to Visual and Histological Evaluations

Background: Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. Hypothesis: The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. Study Design: Descriptive laboratory study. Methods: This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. Results: In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. Conclusion: There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries.ArticleAMERICAN JOURNAL OF SPORTS MEDICINE. 42(6):1433-1440 (2014)journal articl

Blocking of tumor necrosis factor activity promotes natural repair of osteochondral defects in rabbit knee

Background and purpose Osteochondral defects have a limited capacity for repair. We therefore investigated the effects of tumor necrosis factor (TNF) signal blockade by etanercept (human recombinant soluble TNF receptor) on the repair of osteochondral defects in rabbit knees

Does posterior tibial slope laterality exist? A matched cohort study between ACL‐injured and non‐injured knees

Abstract Purpose The purpose of this study is to examine 1) the degree and frequency of laterality in posterior tibial slope (PTS) with control and anterior cruciate ligament (ACL) injury groups and 2) the laterality of PTS between sides of injury and dominant legs in patients with primary ACL injuries. Methods A total of 187 consecutive patients with clinically diagnosed noncontact ACL injuries and an age‐ and sex‐matched 1:1 control group were identified. PTS was measured using three different methods (aPTS = anterior PTS, mPTS = middle PTS, pPTS = posterior PTS) on a lateral knee radiograph. PTS of the left and right sides were compared between the patients in the control and ACL‐injured groups, and between the injured and non‐injured and dominant and non‐dominant legs among the patients in the ACL‐injured group. The patients with a difference in PTS of ≥ 3° in mPTS were selected. The percentages were compared between left and right between and among both groups, and between the injured and non‐injured, and non‐dominant and dominant leg, for the ACL group. Multiple regression analysis was performed to analyze the factors influencing the degree of mPTS. Results Both control (Right vs Left: aPTS; 9.0 ± 2.5 vs 10.5 ± 3.0, mPTS; 6.6 ± 2.3 vs 8.1 ± 2.7, pPTS; 4.0 ± 2.4 vs 5.6 ± 2.8, respectively, p < 0.01) and ACL injury groups (Right vs Left: aPTS; 10.6 ± 3.0 vs 12.6 ± 2.9, mPTS; 7.6 ± 2.6 vs 9.5 ± 2.6, pPTS; 5.9 ± 3.0 vs 8.0 ± 3.0, respectively, p < 0.01) had a significantly greater PTS on the left than on the right side, and the ACL group had a significantly greater PTS than the control group on both the left and right sides. In the ACL group, PTS was greater on the injured and the non‐dominant leg than on the non‐injured and the dominant leg. The percentage of patients with a PTS difference of ≥ 3° was significantly greater on the left, injured, and non‐dominant leg (95.3% vs 4.7%, 73.8% vs 26.2%, 86.1% vs 13.9%, respectively, p < 0.01). Only the left leg had a significant influence on PTS in the multivariate analysis. Conclusion There was laterality in PTS within control and ACL injury groups, and this information is of benefit for effective treatment of ACL injuries. Level of evidence Level III

A Case of Prefemoral Fat Pad Impingement Syndrome Caused by Hyperplastic Fat Pad

Case. We report a rare case of prefemoral fat pad impingement syndrome that was caused by a hyperplasia of the normal suprapatellar fat pad. Pain and catching were observed in the proximal-lateral patellofemoral joint, and MRI imaging confirmed a hyperplasic mass in the same area. Although conservative treatment showed no signs of improvement, symptoms improved after an arthroscopic excision of the mass. Conclusion. Prefemoral fat pad impingement syndrome is related to patellar motion and should be considered as one of the underlying causes of anterior knee pain (AKP). Surgeons should recognize that a small hyperplasia composed of normal adipose tissue can cause AKP

Clinical outcome of a new remnant augmentation technique with anatomical double-bundle anterior cruciate ligament reconstruction: Comparison among remnant preservation, resection, and absent groups

Purpose: The aim of this study was to verify the effects of a new remnant augmentation technique with anatomical double-bundle anterior cruciate ligament (ACL) reconstruction for postoperative clinical scores, anterior stability and frequency of complications compared to remnant removal and cases with remnant defects. Methods: The 105 patients who underwent anatomical double-bundle ACL reconstruction were divided into three groups. If the remnant was a Crain I-III type, remnant-preserving bone tunnel creation was attempted. After the creation of the bone tunnel, good continuity was maintained in 34 patients (preserved group). Due to lost continuity, the remnant was resected in 26 patients (resected group). No identifiable remnant continuity remained (Crain IV) in 45 patients (absent group). The Lysholm knee score, Tegner activity scale, International Knee Documentation Committee (IKDC) subjective score, anterior stability measured using the KT-1000 arthrometer at 2 years postoperatively, and frequency of complications were compared among the three groups. Univariate and multiple linear regression analysis were performed to clarify the factors affecting postoperative anterior stability. Results: The Lysholm knee score, Tegner activity scale, IKDC subjective score, and frequency of complications were not significantly different among the groups. The mean side-to-side difference of anterior stability was significantly better in the preserved group (0.3 ± 1.6 mm) compared to the resected group (1.6 ± 2.3 mm, p = 0.003) and absent group (1.6 mm ± 1.7, p = 0.009). The multiple linear regression analysis showed remnant preservation significantly related to postoperative anterior stability. Conclusion: Although there were no differences in clinical scores, the ACL reconstruction with new preservation technique showed good anterior stability and no difference in the frequency of complications

Bony Landmarks of the Anterior Cruciate Ligament Tibial Footprint

Background: Although the importance of tibial tunnel position for achieving stability after anterior cruciate ligament (ACL) reconstruction was recently recognized, there are fewer detailed reports of the anatomy of the tibial topographic footprint compared with the femoral side. Hypothesis: The ACL tibial footprint has a relationship to bony prominences and surrounding bony landmarks. Study Design: Descriptive laboratory study. Methods: This study consisted of 2 anatomic procedures for the identification of bony prominences that correspond to the ACL tibial footprint and 3 surrounding landmarks: the anterior ridge, lateral groove, and intertubercular fossa. In the first procedure, after computed tomography (CT) was performed on 12 paired, embalmed cadaveric knees, 12 knees were visually observed, while their contralateral knees were histologically observed. Comparisons were made between macroscopic and microscopic findings and 3-dimensional (3D) CT images of these bony landmarks. In the second procedure, the shape of the bony prominence and incidence of their bony landmarks were evaluated from the preoperative CT data of 60 knee joints. Results: In the first procedure, we were able to confirm a bony prominence and all 3 surrounding landmarks by CT in all cases. Visual evaluation confirmed a small bony eminence at the anterior boundary of the ACL. The lateral groove was not confirmed macroscopically. The ACL was not attached to the lateral intercondylar tubercle, ACL tibial ridge, and intertubercular space at the posterior boundary. Histological evaluation confirmed that the anterior ridge and lateral groove were positioned at the anterior and lateral boundaries, respectively. There was no ligament tissue on the intercondylar space corresponding to the intercondylar fossa. In the second investigation, the bony prominence showed 2 morphological patterns: an oval type (58.3%) and a triangular type (41.6%). The 3 bony landmarks, including the anterior ridge, lateral groove, and intertubercular fossa, existed in 96.6%, 100.0%, and 96.6% of the cases, respectively. Conclusion: There is a bony prominence corresponding to the ACL footprint and bony landmarks on the anterior, posterior, and lateral boundaries.ArticleAMERICAN JOURNAL OF SPORTS MEDICINE. 42(6):1433-1440 (2014)journal articl

Posterior Opening-Wedge Osteotomy for Posterior Tibial Slope Correction of Failed Anterior Cruciate Ligament Reconstruction

A large posterior tibial slope (PTS) has been widely recognized as a potential risk factor in loosening and retear after anterior cruciate ligament reconstruction. Anterior closed-wedge osteotomy is an effective surgical approach to mitigate this risk factor but presents several disadvantages. We describe in this Technical Note an original PTS correction technique called the posterior open-wedge osteotomy. The posterior surface of the proximal tibia is exposed, and 2 K-wires are inserted anteroposteriorly as osteotomy guides, and one wire is inserted mediolaterally as a hinge blocker. The osteotomy is performed from the posterior side and advanced to the anterior side using a single-bladed reciprocating saw. The slope is corrected by opening the osteotomy plane posteriorly with a spreader. The correction is maintained by inserting the harvested fibula fragments into the open space, and the fixation is completed with a locking plate to ensure firm fixation and allow early rehabilitation. This procedure can be an effective solution for patients with various risk factors for retear of the anterior cruciate ligament graft, including abnormal PTS

Tibial Tunnel Positioning Technique Using Bony/Anatomical Landmarks in Anatomical Anterior Cruciate Ligament Reconstruction

Because various biomechanical studies and clinical results have shown the effectiveness of an anatomical approach for anterior cruciate ligament (ACL) reconstruction, this approach has become gradually commonplace to improve postoperative performance. Standard tunnel positioning methods with accuracy, reproducibility, and adaptability to varied concepts are essential for the success of anatomical ACL reconstruction. However, there were no standard tibial tunnel positioning methods to satisfy these conditions. This technical note reports our tibial tunnel positioning technique using bony and/or anatomical landmarks for anatomical ACL reconstruction

Anatomical Remnant-Preserving Double-Bundle ACL Reconstruction With a New Remnant Augmentation Technique

Anterior cruciate ligament (ACL) remnant preservation techniques have been recently introduced for covering the graft with remnant to improve the clinical results of ACL reconstruction. Several theoretical advantages exist for this technique; however, clinical results remain inconsistent and controversial. We have focused on the biomechanical function of the remnant and have been performing a new remnant-preserving reconstruction procedure that augments the graft with residual remnant. Preserving the structure and continuity of good-quality remnants may help maintain the early postoperative stress on the tendon graft, thereby providing a positive effect on remodeling. Although our concept is significantly different from previously reported remnant preservation techniques and has several pitfalls, the surgical technique that we outline in this report is simple and does not require specialized equipment. The procedure will also work more advantageously in preserving the residual mechanoreceptors in the remnant. We believe that this method can be a procedure with better results for patients with remnants that are in good condition