Yasuyuki Ishibashi

Anatomical analysis of the anterior cruciate ligament femoral and tibial footprints

BackgroundThe current trend in anterior cruciate ligament (ACL) reconstruction has shifted to anatomical double-bundle (DB) reconstruction, which reproduces both the anteromedial bundle (AMB) and the posterolateral bundle (PLB) of the ACL. Navigation systems have also been recently introduced to orthopedic surgical procedures, including ACL reconstruction. In DB-ACL reconstruction, the femoral and tibial tunnel positions are very important, but a representation of the ACL footprint under an arthroscopic view has not been established even though navigation systems have been introduced. The purpose of this study was to evaluate the anatomical footprints of both the AMB and the PLB using the representation method for application to arthroscopic DB-ACL reconstruction using a navigation system, and to evaluate the validity of the currently determined footprint position compared with other representation methods.MethodsThirty-six cadaveric knees were used for an anatomical evaluation of footprints of the AMB and PLB. On the tibial side, the ACL footprints were evaluated using an original method. On the femoral side, the ACL footprints were evaluated using Watanabe’s method and three other methods: (1) the quadrant method, (2) Mochizuki’s method, and (3) Takahashi’s method.ResultsThe central points of the ACL footprints were represented almost constantly. The present data is in accordance with previous measurement data.ConclusionThis study showed that the anatomical data of the ACL femoral and tibial footprints determined with Watanabe’s method at the femoral side and our original method at the tibial side were both applicable to arthroscopic surgery with a navigation system.

Osteochondral Autograft Transplantation for Osteochondritis Dissecans of the Elbow in Juvenile Baseball Players Minimum 2-Year Follow-up

Background Osteochondral autografts have recently become popular to treat articular cartilage defects, and they are used for unstable osteochondritis dissecans lesions as a means of biological fixation. Purpose To evaluate the clinical results of osteochondral autograft transfer for osteochondritis dissecans of the elbow. Study Design Case series; Level of evidence, 4. Methods Osteochondral autograft transfer was performed on 18 baseball players (mean age, 13.6 years) with osteochondritis dissecans of the elbow. These included 9 lesions that were grade 3 (separated but in situ) and 9 lesions that were grade 4 (displaced fragment with osteochondral defect) based on magnetic resonance imaging. All patients were evaluated with a scoring system, radiographs, and magnetic resonance imaging, with the mean follow-up at 3.5 years. Results In patients with grade 3 lesions, the subjective score was increased, but the objective score did not change. Six of 9 patients returned to their previous sports performance levels. One quit baseball because of academic reasons, 1 changed his position, and 1 changed to softball. In patients with grade 4 lesions, both subjective and objective scores were increased significantly. All but 1 patient returned to their previous sports performance levels. In the 3 grade 4 lesions with a wide osteochondral defect, the irregularity of the articular surface remained on magnetic resonance imaging. Conclusion Osteochondral autograft transplantation is a useful treatment for reattachment of the lesion as well as osteochondral resurfacing of elbow osteochondritis dissecans.

Navigation Evaluation of the Pivot-Shift Phenomenon During Double-Bundle Anterior Cruciate Ligament Reconstruction: Is the Posterolateral Bundle More Important?

PURPOSE The purpose of this study was to assess the pivot-shift phenomenon during double-bundle anterior cruciate ligament (ACL) reconstruction using a navigation system. METHODS Ninety patients who received navigated double-bundle ACL reconstruction were included in this study. The mean age of the patients was 21.9 years. During reconstruction, pivot-shift tests were performed 4 times: before reconstruction, after the posterolateral bundle fixation, after the anteromedial bundle fixation, and after the double-bundle reconstruction. Both tibial internal rotation and anterior translation under the pivot-shift test were measured at each phase by the additional functions of the navigation. The navigation system used in this study was the image-free, which does not require preoperative or intraoperative images, OrthoPilot ACL (version 2.0; B. Braun Aesculap, Tuttlingen, Germany). RESULTS Before ACL reconstruction, average (+/- standard deviation) tibial internal rotation and anterior translation under the pivot-shift test were 23.7 degrees +/- 6.1 degrees and 5.2 +/- 2.4 mm. They were significantly decreased to 20.9 degrees +/- 6.4 degrees and 2.3 +/- 1.1 mm after the posterolateral bundle fixation, and also decreased to 22.2 degrees +/- 5.7 degrees and 2.4 +/- 1.1 mm after the anteromedial bundle fixation. There was no significant difference between the groups. After double-bundle reconstruction, they improved to 20.3 degrees +/- 6.3 degrees and 2.0 +/- 1.0 mm. CONCLUSIONS Our results indicate that both the posterolateral and the anteromedial bundle similarly control both anterior translation and internal rotation during pivot-shift testing. Double-bundle reconstruction may further improve knee stability. LEVEL OF EVIDENCE Level II, development of diagnostic criteria on basis of consecutive patients with universally applied reference gold standard.

Comparison of Scintigraphy and Magnetic Resonance Imaging for Stress Injuries of Bone

ObjectiveTo compare findings of radiography, scintigraphy, and magnetic resonance imaging (MRI) in stress injuries of bone and evaluate changes of these findings with time correlated with clinical symptoms. DesignProspective study. SettingA primary care hospital outpatient orthopedic clinic. PatientsAll 31 patients with stress injuries of bone who visited our clinic from July 1996 to June 2000. InterventionRadiography, scintigraphy, MRI, and clinical examinations were performed on the same day or at least within 1 week of eachother, and the findings were compared. If symptoms of stress injury of bone continued, these examinations were repeated at intervals of 2 months until symptoms disappeared. These radiologic findings were assessed by an independent radiologist who was blinded to the clinical symptoms of the patients. Main Outcome MeasuresCorrelation accuracy of MRI and scintigraphy findings with clinical symptoms. ResultsEven with negative initial radiographic findings, all initial scintigraphy and MRI indicated stress injury of bone. There were no patients with positive/negative examinations. Grade of scintigraphy and MRI were closely correlated, and these findings also correlated with the degree of clinical symptoms. Compared with scintigraphy, MRI showed more diagnostic information, such as fracture line and periosteal edema. Areas of increased activity in scintigraphy were consistent with the grades of MRI, especially high signal intensity areas of STIR (short tau inversion recovery) image. ConclusionsFrom these observations, MRI is less invasive, provides more information than scintigraphy, and is recommended for initial diagnosis and assessment stages of stress injury of bone.

Techniques for Reducing Anterior Knee Symptoms after Anterior Cruciate Ligament Reconstruction Using a Bone-Patellar Tendon-Bone Autograft

Seventy-five patients underwent unilateral anterior cruciate ligament reconstruction with an ipsilateral bone-patellar tendon-bone autograft at our institution. The graft was harvested using a two-transverse-incision technique, and patellar and tibial bony defects were repaired with cored bone grafts collected by reaming the femoral socket and the tibial socket or tunnel. We evaluated the incidence of anterior knee pain, donor site tenderness, and sensory disturbance after use of these procedures. We also analyzed the correlation between anterior knee pain and age, sex, bone plug length, range of motion, postoperative stability, patellar tendon shortening, infrapatellar nerve injury, and the size of the patellar defect. Thirteen patients reported anterior knee pain. Donor site tenderness was detected in 10 patients and was located on the inferior pole of the patella, the tibial tubercle, or both. Sensory disturbance was found over the infrapatellar nerve area in 13 patients. Statistical analysis showed that anterior instability (side-to-side difference of 3 mm) and residual patellar bony defect (depth 2 mm) were risk factors for anterior knee pain. The results of our study suggest that cored cancellous bone grafting for complete restoration of the donor site bony defects and the two-transverse-incision technique to preserve the infrapatellar branch of the saphenous nerve contribute to prevention of anterior knee symptoms.

Intraoperative Evaluation of the Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction With the OrthoPilot Navigation System

The purpose of this study was to assess double-bundle anterior cruciate ligament (ACL) reconstruction, which reproduces the anteromedial bundle and posterolateral bundle, using a navigation system. In 32 patients, anteroposterior (AP) displacement and rotation of the tibia were measured before reconstruction and after posterolateral bundle fixation, anteromedial bundle fixation, and double-bundle ACL reconstruction (in posterolateral and anteromedial bundles fixation). The posterolateral bundle has an important role in the extension position, whereas the anteromedial bundle restricts AP displacement from extension to flexion. AP displacement after double-bundle ACL reconstruction was significantly improved compared to AP displacement after posterolateral bundle or anteromedial bundle fixation. Although traditional reconstruction for reproducing the anteromedial bundle is reasonable, double-bundle ACL reconstruction is recommended for improved knee stability.

Results of Arthroscopic Fixation of Osteochondritis Dissecans Lesion of the Knee with Cylindrical Autogenous Osteochondral Plugs

Background In situ fixation of unstable lesions of osteochondral dissecans of the knees with cylindrical osteochondral autograft transplantation has been reported to provide excellent results with healing of the osteochondral dissecans fragment. Purpose To evaluate the clinical results and magnetic resonance imaging findings of the osteochondral dissecans of knees treated with in situ fixation of the osteochondral fragments with osteochondral autograft transplantation. Study Design Case series; Level of evidence, 4. Methods Twelve knees (12 patients; mean age, 16.0 years) with osteochondral dissecans lesions were treated with in situ fixation with autogenous osteochondral plugs. The mean lesion size was 2.4 cm2 (range, 1.0-4.9 cm2). The osteochondral dissecans lesions were located on the medial femoral condyle in 10 patients and on the lateral femoral condyle in 2 patients. Seven lesions were located in the weightbearing area. The International Cartilage Repair Society classification in arthroscopic findings was grade II in 1 patient, grade III in 8 patients, and grade IV in 3 patients. All patients were evaluated with the Hughston Rating Scale form with the mean follow-up at 4.5 years (range, 2.8-5.9 years). The interface between the osteochondral fragment and subchondral bone and changes in donor site of the osteochondral graft were evaluated with T2-weighted magnetic resonance image up to 12 months postoperatively. Results The Hughston Rating Scale scored 8 knees as excellent, 3 as good, and 1 as fair. The interface between the osteochondral fragment and subchondral bone had disappeared on magnetic resonance image by 3 months postoperatively in all cases. No complications arising from the donor site area were observed. Signal intensity of donor site changed from high signal preoperatively to homogeneous surrounding cancellous bone by 1 year postoperatively. Conclusion Biological fixation of the osteochondral dissecans lesion with cylindrical osteochondral autograft provided healing of the osteochondral fragments.

Tunnel Position and Relationship to Postoperative Knee Laxity After Double-Bundle Anterior Cruciate Ligament Reconstruction With a Transtibial Technique

Background Several laboratory studies have pointed out a potential risk of femoral tunnel misplacement in anterior cruciate ligament reconstruction with a transtibial technique. The tunnel malposition away from the anatomic attachment may result in increased postoperative knee laxity in double-bundle reconstruction. Purpose This study was conducted to evaluate the femoral and tibial tunnel positions in transtibial double-bundle reconstruction, and to determine the relationship between the tunnel positions and the results of the postoperative knee laxity examinations. Study Design Case series; Level of evidence, 4. Methods Fifty-three of 71 patients who underwent transtibial double-bundle reconstruction from 2004 to 2005 were followed more than 24 months. The tunnel positions for the anteromedial and posterolateral grafts were measured using 3-dimensional computed tomography images applying the quadrant method. The postoperative knee laxity was examined with the KT-1000 arthrometer manual maximum test, anterior drawer test, and pivot-shift test. Results The deep-shallow position (parallel to Blumensaats line) and high-low position (perpendicular to Blumensaats line) of the femoral tunnels were 27.7% ± 5.6% from the most posterior condylar contour and 16.3% ± 5.2% from Blumensaats line for the anteromedial graft, and 35.5% ± 6.4% and 48.0% ± 5.4% for the posterolateral graft. The medial-lateral and anterior-posterior positions of the tibial tunnels were 46.1% ± 2.6% from the most medial contour and 36.5% ± 4.9% from the most anterior contour for the anteromedial graft, and 47.5% ± 3.1% and 51.6% ± 5.0% for the posterolateral graft. There was no statistical correlation between any parameters of the femoral or tibial tunnel position and the results of the knee laxity tests. Conclusion The femoral tunnels placed in transtibial double-bundle reconstruction were located appropriately in high-low and deep-shallow orientation, but had larger variability than the previously reported data of the anatomic femoral attachment. However, the variability of the femoral tunnel position was not so large as to result in graft insufficiency with increased postoperative knee laxity.

Intraoperative Biomechanical Evaluation of Anatomic Anterior Cruciate Ligament Reconstruction Using a Navigation System Comparison of Hamstring Tendon and Bone–Patellar Tendon–Bone Graft

Background Recently, more anatomic anterior cruciate ligament reconstructions have been developed to improve knee laxity. Purpose The objective of this study is to assess knee kinematics after double-bundle reconstruction with hamstring tendon and after anatomically oriented reconstruction with a patellar tendon using navigation during surgery. Study Design Cross-sectional study; Level of evidence, 3. Methods Eighty knees received double-bundle reconstruction with a hamstring tendon graft, and 45 knees received anatomically oriented reconstruction with a patellar tendon graft. Before reconstruction, knee laxity was measured using a navigation system. After the posterolateral bundle or anteromedial bundle was temporarily fixed during double-bundle reconstruction, knee laxity was measured to assess the function of each bundle. After double-bundle reconstruction or anatomically oriented reconstruction with patellar tendon, knee laxity was measured in the same manner. Results Both double-bundle reconstruction and anatomically oriented reconstruction similarly improved knee laxity compared With before reconstruction in all knee flexion angles. Regarding the function of the anteromedial and posterolateral bundles in double-bundle reconstruction, the 2 grafts showed contrasting behavior. The posterolateral bundle restrained tibial displacement mainly in knee extension, whereas the anteromedial bundle restrained it more in the knee flexion position. The posterolateral bundle has a more important role in controlling rotation of the tibia than the anteromedial bundle. Conclusion Although the posterolateral bundle has an important role in the extension position, the anteromedial bundle is more important in the flexion position. Therefore, both bundles should be reconstructed to improve knee laxity throughout knee range of motion. Even with single-bundle reconstruction using a patellar tendon, anatomic reconstruction might improve knee laxity similar to double-bundle reconstruction.

Stability evaluation of single-bundle and double-bundle reconstruction during navigated ACL reconstruction.

Recently, anatomic double-bundle anterior cruciate ligament (ACL) reconstructions, which reproduce the anteromedial and posterolateral bundles, have been developed to improve knee laxity. However, there are little data on the in vivo biomechanics after such reconstructions. In this paper, we will review biomechanical and clinical studies that have compared single-bundle and double-bundle reconstruction, and introduce our intraoperative evaluation of double-bundle reconstruction using a navigation system. In the navigation evaluation, knee kinematics before and after ACL reconstruction were assessed, and functions of the anteromedial and posterolateral bundles were evaluated. Although the posterolateral bundle has an important role in the knee extension position, the anteromedial bundle improved knee laxity during the more knee flexion positions. Furthermore, double-bundle reconstruction improved knee laxity compared with either posterolateral or anteromedial bundle reconstruction throughout knee range of motion. Although traditional single-bundle reconstruction, reproducing the anteromedial bundle, is a reasonable procedure, double-bundle reconstruction has the potential to improve knee stability after ACL reconstruction.