Eiichi Tsuda

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.

The use of porcine small intestinal submucosa to enhance the healing of the medial collateral ligament—a functional tissue engineering study in rabbits

Introduction: Small intestinal submucosa (SIS) from porcine has been successfully used as a collagen scaffold for the repair of various tissues, including those of the human vascular, urogenital, and musculoskeletal systems. The objective of this study was to evaluate whether SIS can be used to enhance the healing process of a medial collateral ligament (MCL) with a gap injury in a rabbit model.

A quantitative analysis of valgus torque on the ACL: A human cadaveric study

The loads needed to elicit a positive pivot shift test in a knee with an anterior cruciate ligament (ACL) rupture have not been quantified. The coupled anteriol tibial translation (ATT), coupled internal tibial rotation (ITR), and the in situ force in the ACL in response to a valgus torque, an inherent component of the pivot shift test, were measured in 10 human cadaveric knee specimens. Using a robotic/universal force–moment sensor testing system, valgus torques ranging from 0.0 to 10.0 N m were applied in nine increments on the intact and ACL‐deficient knee in flexion ranging from 0° to 90°. At 15° of knee flexion, the coupled ATT and ITR were significantly increased in the ACL‐deficient knee when compared to the intact knee. Coupled ATT increased a maximum of 291% (6.7 mm, p < 0.05), while coupled ITR increased a maximum of 85% (5.1°, p < 0.05). At 30°, the increases in coupled ATT and ITR were significant at valgus loads of 3.3 N m and greater with a maximum increase in coupled ATT of 137% (6.3 mm, p < 0.05) and a maximum increase in coupled ITR of 38% (3.6°, p < 0.05). At 45°, coupled ATT increased significantly (maximum of 69%, 4.4 mm, p < 0.05), but only at torques ⩾ 6.7 N m. The in situ force in the ACL was less than 20 N for all flexion angles when a torque between 3.3 and 5.0 N m was applied. Low valgus torque elicited tibial subluxation in the ACL‐deficient knee with low in situ ACL forces, similar to a positive pivot shift test. Thus, application of a valgus torque may be suitable to evaluate ACL‐deficient and ACL‐reconstructed knees, since subluxation can be achieved with minimal harm to the ACL graft. This work is important in understanding one load component needed for the pivot shift examination; further studies quantifying other load components are essential for better comprehension of the in vivo pivot shift examination.

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.

Direct Evidence of the Anterior Cruciate Ligament-Hamstring Reflex Arc in Humans

It has been emphasized that the anterior cruciate ligament plays an important role in the proprioceptive feedback system. The anterior cruciate ligament-hamstring reflex has been revealed in animal experiments, but it has not been established in humans. The purpose of this study was to demonstrate direct evidence of the anterior cruciate ligament-hamstring reflex arc. Nine knees in nine healthy subjects were investigated. The anterior cruciate ligament was stimulated by the use of wire electrodes inserted using an arthroscopic technique. Electromyographic signals from the biceps femoris and the semitendinosus muscles were recorded with surface electrodes. The change in electromyographic activity was analyzed after electrical stimulation in the normal knee condition, and again after intraarticular sensation had been interrupted with a local anesthetic. After electrical stimulation, subjects demonstrated increased electromyographic activity of the hamstring muscles in the normal knee condition. This response indicates the existence of an anterior cruciate ligament-hamstring reflex arc. Conversely, there was no change in activity for the hamstring muscle in the anesthetized knee because the afferent impulse from the neural elements of the anterior cruciate ligament had been removed.

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.