Tomoaki Kamiya

Comparison of Different Fixation Methods of the Suture-Button Implant for Tibiofibular Syndesmosis Injuries

Background: Suture-button fixation for tibiofibular syndesmosis injuries is a relatively new surgical technique thought to provide semirigid dynamic stabilization. However, adequate information is still not available and there are controversies as to whether it provides enough fixation for syndesmosis injuries. Hypothesis: Optimally directed suture-button fixation brings physiologic dynamic stabilization of the ankle syndesmosis. Study Design: Controlled laboratory study. Methods: Stabilization of the ankle syndesmosis fixed by a suture-button construct was examined using 6 normal fresh-frozen cadaver legs. After initial tests of intact and injured models, suture-button fixation and screw surgical techniques were performed sequentially for each specimen, with single suture-button fixation, double suture-button fixation, anatomic suture-button fixation, and metal screw. Anterior and medial traction forces, as well as external rotation force, were applied to the tibia; the diastasis of the syndesmosis and the rotational angle of the fibula related to the tibia were measured using a magnetic tracking system. Results: Each traction and rotation force significantly increased the diastasis and fibular rotational angles in the created injury models. With single fixation, the diastases increased significantly compared with the intact model with an anterior traction force (P < .001), a medial traction force (P = .005), and an external rotation force (P = .015). The fibular rotational angles increased significantly with a medial traction force (P = .005) and an external rotation force (P < .001). With double fixation, the diastases increased significantly with a medial traction force (P = .004) and an external rotation force (P = .012). The fibular rotational angles increased significantly with a medial traction force (P = .035) and an external rotation force (P = .002). With anatomic fixation, there were no significant differences compared with the intact model. With the metal screw, the diastases decreased significantly with an external rotation force (P = .037). Conclusion: Neither single nor double fixation for syndesmosis injuries provided multidirectionally stabilizing syndesmosis. Anatomic fixation directed from the posterior cortex of the fibula to the anterolateral edge of the tibia allowed dynamic stabilization of intact cadaver specimens. The metal screw provided very rigid fixation. Clinical Relevance: Optimal direction of the suture button can provide adequate stabilization of the ankle and could benefit athletes with syndesmosis injuries.

The arrangement and the attachment areas of three ACL bundles

PurposeNormal anterior cruciate ligament (ACL) can be divided into three fiber bundles—i.e., anteromedial (AM), intermediate (IM), and posterolateral (PL) bundles. However, their arrangement and attachment areas had remained unclear. The purpose of this study was to clarify the arrangement of these three ACL fiber bundles and their attachment sites, and to provide information on the tunnel placement in anatomical triple bundle ACL reconstruction.MethodsSeven non-embalmed human frozen knees were used. ACL fibers were bluntly divided into three bundles. A different-colored thread was wound around each fiber bundle in a spiral. Macroscopical investigation was performed to clarify the arrangement of three ACL bundles. Each fiber bundle was carefully detached from the femur and tibia, and then the distribution of attachment sites of each fiber bundle was observed.ResultsIn knee extension, all bundles consisting of AM, IM and PL bundles ran parallel to each other in the lateral view from the medial side. The AM bundle overlapped with the IM bundle, whereas the PL bundle ran parallel to them on the distal aspects. As the knee flexion increased, the bundles became twisted around each other. On the tibial side, the attachment areas of three fiber bundles formed a triangular shape showing arrangements of AM, IM and PL bundles on the anteromedial, anterolateral and posterior aspects, respectively. On the femoral side, the PL bundle was attached on the distal-posterior areas; the IM bundle was attached distal-anterior to the AM bundle. They were arranged in a triangular shape on the tibia side as well.ConclusionThis study clarified the arrangement of three fiber bundles of ACL and detailed geographical locations of their attachment sites. The detailed anatomic description of the natural ACL attachment might suggest to surgeons where to make tunnels during anatomical double/triple bundle ACL reconstruction.

Mechanical Stability of the Subtalar Joint After Lateral Ligament Sectioning and Ankle Brace Application: A Biomechanical Experimental Study

Background The roles of each ligament supporting the subtalar joint have not been clarified despite several biomechanical studies. The effects of ankle braces on subtalar instability have not been shown. Hypothesis The ankle brace has a partial effect on restricting excessive motion of the subtalar joint. Study Design Controlled laboratory study. Methods Ten normal fresh-frozen cadaveric specimens were used. The angular motions of the talus were measured via a magnetic tracking system. The specimens were tested while inversion and eversion forces, as well as internal and external rotation torques, were applied. The calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament were sectioned sequentially, and the roles of each ligament, as well as the stabilizing effects of the ankle brace, were examined. Results Complete sectioning of the ligaments increased the angle between the talus and calcaneus in the frontal plane to 51.7° ± 11.8° compared with 35.7° ± 6.0° in the intact state when inversion force was applied. There was a statistically significant difference in the angles between complete sectioning of the ligaments and after application of the brace (34.1° ± 7.3°) when inversion force was applied. On the other hand, significant differences in subtalar rotation were not found between complete sectioning of the ligaments and application of the brace when internal and external rotational torques were applied. Conclusion The ankle brace limited inversion of the subtalar joint, but it did not restrict motion after application of internal or external rotational torques. Clinical Relevance In cases of severe ankle sprains involving the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament injuries, application of an ankle brace might be less effective in limiting internal-external rotational instabilities than in cases of inversion instabilities in the subtalar joint. An improvement in the design of the brace is needed to restore better rotational stability in the subtalar joint.

Dynamic effect of the tibialis posterior muscle on the arch of the foot during cyclic axial loading

BACKGROUND The most common cause of acquired flatfoot deformity is tibialis posterior tendon dysfunction. The present study compared the change in medial longitudinal arch height during cyclic axial loading with and without activated tibialis posterior tendon force. METHODS Fourteen normal, fresh frozen cadaveric legs were used. A total of 10,000 cyclic axial loadings of 500 N were applied to the longitudinal axis of the tibia. The 32-N tibialis posterior tendon forces were applied to the specimens of the active group (n=7). Specimens of another group (non-active group, n=7) were investigated without the tibialis posterior tendon force. The bony arch index was calculated from the displacement of the navicular height. FINDINGS The mean initial bony arch indexes with maximal weightbearing were 0.239 (SD 0.009) in active group and 0.239 (SD 0.014) in non-active group. After 7000 cycles, the bony arch indexes with maximal weightbearing were significantly greater in the active group (mean 0.214, SD 0.013) than in the non-active group (mean 0.199, SD 0.013). The mean bony arch indexes with maximal weightbearing after 10,000 cycles were 0.212 (SD 0.011) in the active group and 0.196 (SD 0.015) in the non-active group. INTERPRETATION The passive supportive structures were inadequate, and the tibialis posterior muscle was essential to maintain the medial longitudinal arch of the foot in the dynamic weightbearing condition. The findings underscore that physical therapy and arch supportive equipments are important to prevent flatfoot deformity in the condition of weakness or dysfunction of the tibialis posterior muscle.

Ultrastructure of the three anterior cruciate ligament bundles

The anterior cruciate ligament (ACL) can be morphologically separated into not only two, but three bundles: the anteromedial‐medial bundle (AM‐MB), the anteromedial‐lateral bundle (AM‐LB), and the posterolateral bundle (PLB). Our hypothesis was that the three bundles differ in their microstructures. The purpose of this study was to clarify the microstructural differences among the three bundles. The normal ACLs of six fresh frozen cadavers were harvested. After the AM‐MB, AM‐LB, and PLB were identified, their fibril structures were analyzed using a transmission electron microscope. The fibril orientation, distribution pattern, and the mass average diameter of the fibrils (MAD) were compared among the AM‐MBs, AM‐LBs, and PLBs. The AM‐MB and AM‐LB fibrils were arranged mostly in the longitudinal direction, while the PLB fibrils were not aligned in a uniform direction. The fibril diameter distribution pattern of AM‐MBs showed a bi‐modal pattern due to the existence of small‐diameter (30‐40 nm) and large‐diameter fibrils (70‐80 nm), while that of the AM‐LBs and PLBs had a unimodal pattern with one prominent high peak at a diameter of 50‐60 nm. The mean MAD of the AM‐MBs (83.2 − 11.2 nm) was significantly larger than that of the PLBs (66.8 − 7.7 nm), while it showed no significant difference compared to that of the AM‐LBs (77.6 − 12.3 nm). The three ACL bundles have different ultrastructures. The AM‐MB predominantly includes thick, uni‐directionally oriented fibrils like tendons, while the PLB consists of thinner, multi‐directionally oriented fibrils. The AM‐LB shows an intermediate structure between the AM‐MB and the PLB. Clin. Anat. 28:910–916, 2015.

Efficacy of radial styloid targeting screws in volar plate fixation of intra-articular distal radial fractures: a biomechanical study in a cadaver fracture model

BackgroundThe locking screws target the radial styloid, theoretically provide greater stability against radial styloid fragment. However, it is unknown whether the radial styloid locking screws increased the stability of the volar plating system fixation along the entire distal radius or not. In this study, we evaluated the stability of the volar plating system fixation with or without the radial styloid screws using a biomechanical study in a cadaver fracture model.MethodsSix matched pairs of fresh-frozen human cadaver wrists complete from the proximal forearm to the metacarpal bones were prepared to simulate standardized 3-part intra-articular and severe comminuted fractures. Specimens were fixed using the volar plating system with or without 2 radial styloid screws. Each specimen was loaded at a constant rate of 20 mm/min to failure. Load data was recorded and, ultimate strength and change in gap between distal and proximal fragments were measured. Data for ultimate strength and screw failure after failure loading were compared between the 2 groups.ResultsThe average ultimate strength at failure of the volar plate fixation with radial styloid screws (913.5 ± 157.1 N) was significantly higher than that without them (682.2 ± 118.6 N). After failure loading, the average change in gap between the ulnar and proximal fragment was greater than that between the radial and proximal fragment. The number of bent or broken screws in ulnar fragment was higher than that in radial fragment. The number of specimens with bent or broken screws in cases with radial styloid screws was fewer than that in the fixation without radial styloid screws group.ConclusionThe ulnar fragment is more intensively stressed than the radial fragment under axial loading of distal radius at full wrist extension. The radial styloid screws were effective in stable volar plate fixation of distal radial fractures.

MRI depiction and 3D visualization of three anterior cruciate ligament bundles

The anterior cruciate ligament (ACL) is divided into three fiber bundles (AM‐M: anteromedial‐medial, AM‐L: anteromedial‐lateral, PL: posterolateral). We attempted to depict the three bundles of the human ACL on MRI images and to obtain 3‐dimensional visualization of them. Twenty‐four knees of healthy volunteers (14 males, 10 females) were scanned by 3T‐MRI using the fat suppression 3D coherent oscillatory state acquisition for the manipulation of imaging contrast (FS 3D‐COSMIC). The scanned images were reconstructed after the isotropic voxel data, which allows the images to be reconstructed in any plane, was acquired. We conducted statistical examination on the identification rate of the three ACL bundles by 2D planes. Segmentation and 3D visualization of the fiber bundles using volume rendering were performed. The triple‐bundle ACL was best depicted in the oblique axial plane. While the AM‐M and AM‐L bundles were clearly depicted in all cases, the PL bundle was not clearly visualized in two knees (8%). Therefore, the three ACL bundles were depicted in 22 knees (92%). The results of 3D visualization of the fiber arrangement agreed well with macroscopic findings of previous anatomical studies. 3T‐MRI and the isotropic voxel data from FS 3D‐COSMIC made it possible to demonstrate the identifiable depiction of three ACL bundles in nearly all cases. 3D visualization of the bundles could be a useful tool to understand the ACL fiber arrangement. Clin. Anat. 30:276–283, 2017. 2016 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Tibiotalocalcaneal Arthrodesis Using a Soft Tissue–Preserved Fibular Graft for Treatment of Large Bone Defects in the Ankle

Background: Pathogenesis of ankle disorders with a large bone defect is varied and treatment for those problems is challenging for orthopaedic surgeons. The aims of this study were to present an operative technique of arthrodesis for the reconstruction of the ankle and hindfoot with a large bone defect using a soft tissue–preserved fibular strut graft and to report outcomes of consecutively treated patients. Methods: Twelve feet from 11 patients, including feet with aseptic necrosis of the talus and total ankle implant loosening, were treated. Bone defects were filled using iliac bone and/or resected fibula and tibiotalocalcaneal arthrodesis was performed using a retrograde intramedullary nail. A modified transfibular approach was used to expose the affected joint while preserving the lateral to posterior skin and soft tissues on the fibula. The periods of bony fusion and outcomes were radiographically and clinically evaluated. The mean follow-up period was 33.4 months. Results: Bony fusion was achieved within 3 months in all cases. Coronal and sagittal alignments were acceptable, and the mean American Orthopaedic Foot & Ankle Score improved from 53.8 to 75.5 at the final follow-up. All patients graded their results of treatment as “satisfied.” Conclusion: This procedure did not require special techniques and it should be applicable to complicated cases with large bone defects. High fusion rates that we believe are due to preserving blood supply to the fibular graft can be expected with preservation of the hindfoot height. Level of Evidence: Level IV, case series.

Repair of Acute Patellar Tendon Rupture Augmented with Strong Sutures

&NA; Rupture of the patellar tendon is an uncommon injury that requires acute surgical repair to restore the function of the knee. Multiple techniques for repair have been described in the literature. Complications with these repair techniques include rerupture and extensor lag caused by gap formation at the site of repair. Thus, many surgeons have suggested augmenting the standard repair. Several methods of augmentation have been described each with disadvantages. The purpose of this article was to present our case series of six patients with acute patella tendon ruptures treated by a novel procedure using strong sutures. In this method, eight strands of four‐strong sutures run within the tendon. At the patellar site, a combination of suture button and figure eight pattern techniques is used, avoiding stress concentration. The optimal tension is applied to each suture, so as the patella might be positioned at the original placement. Then all sutures are secured onto the tibia. Postoperatively with a mean follow‐up of 32.7 months (range: 25–48 months), all patients had a stable knee with mean flexion of 143.3 degrees (range: 140–150 degrees) and without any extension lag. With an improvement in the International Knee Documentation Committee score to 86.8 (range: 80–92), the excellent outcome was noted in all patients. The average postoperative Lysholm score was 98.8 (range: 97–100) and the average Kujala score was 95.2 (range: 92–97). All patients recovered to near‐normal strength and stability of the patellar tendon as well as restoration of function after the operation. This augmentation technique offers a distinct advantage over previous augmentation methods and materials, and may be especially useful in managing patellar tendon rupture caused by rheumatoid arthritis or other systemic conditions. For these reasons, we recommend this procedure for acute patellar tendon ruptures.

Pseudoaneurysm of the superficial femoral artery after retrograde intramedullary nailing for a supracondylar femoral fracture

Vascular complications of distal femoral fractures are rare but can have disastrous consequences if not recognised and treated promptly. We present the case of a 55-year-old woman who developed a pseudoaneurysm of the superficial femoral artery after osteosynthesis to repair a supracondylar femoral fracture. Eight weeks after surgery, swelling of the right thigh persisted and was accompanied by severe pain. Enhanced computed tomography revealed a pseudoaneurysm in the medial aspect of the affected thigh. Open surgical repair was performed by direct arterial suture. Although the true aetiology of the development of the pseudoaneurysm is unknown, a bony fragment from the reduction manoeuvre may have damaged the adventitia of the superficial femoral artery. In cases of continuous thigh swelling after osteosynthesis to repair a supracondylar femoral fracture, a diagnosis of pseudoaneurysm should be considered and treatment should be initiated immediately.