Ryota Yamagami

Remnant-Preserving Anterior Cruciate Ligament Reconstruction Using a Three-Dimensional Fluoroscopic Navigation System

Introduction Recently, remnant-preserving anterior cruciate ligament (ACL) reconstruction has been increasingly performed to achieve revascularization, cell proliferation, and recovery of high-quality proprioception. However, poor arthroscopic visualization makes accurate socket placement during remnant-preserving ACL reconstruction difficult. This study describes a surgical technique used to create an anatomical femoral socket with a three-dimensional (3D) fluoroscopy based navigation system during technically demanding remnant-preserving ACL reconstruction. Surgical Technique After a reference frame was attached to the femur, an intraoperative image of the distal femur was obtained, transferred to the navigation system and reconstructed into a 3D image. A navigation computer helped the surgeon visualize the entire lateral wall of the femoral notch and lateral intercondylar ridge, even when the remnant of the ruptured ACL impeded arthroscopic visualization of the bone surface. When a guide was placed, the virtual femoral tunnel overlapped the reconstructed 3D image in real time; therefore, only minimal soft tissue debridement was required. Materials and Methods We treated 47 patients with remnant-preserving ACL reconstruction using this system. The center of the femoral socket aperture was calculated according to the quadrant technique using 3D computed tomography imaging. Results The femoral socket locations were considered to be an anatomical footprint in accordance with previous cadaveric studies. Conclusions The 3D fluoroscopy-based navigation can assist surgeons in creating anatomical femoral sockets during remnant-preserving ACL reconstruction.

Comparison of mouse and human ankles and establishment of mouse ankle osteoarthritis models by surgically-induced instability

OBJECTIVE Prevalence of ankle osteoarthritis (OA) is lower than that of knee OA, however, the molecular mechanisms underlying the difference remain unrevealed. In the present study, we developed mouse ankle OA models for use as tools to investigate pathophysiology of ankle OA and molecular characteristics of ankle cartilage. DESIGN We anatomically and histologically examined ankle and knee joints of C57BL/6 mice, and compared them with human samples. We examined joints of 8-week-old and 25-month-old mice. For experimental models, we developed three different ankle OA models: a medial model, a lateral model, and a bilateral model, by resection of respective structures. OA severity was evaluated 8 weeks after the surgery by safranin O staining, and cartilage degradation in the medial model was sequentially examined. RESULTS Anatomical and histological features of human and mouse ankle joints were comparable. Additionally, the mouse ankle joint was more resistant to cartilage degeneration with aging than the mouse knee joint. In the medial model, the tibiotalar joint was markedly affected while the subtalar joint was less degenerated. In the lateral model, the subtalar joint was mainly affected while the tibiotalar joint was less altered. In the bilateral model, both joints were markedly degenerated. In the time course of the medial model, TdT-mediated dUTP nick end labeling (TUNEL) staining and Adamts5 expression were enhanced at early and middle stages, while Mmp13 expression was gradually increased during the OA development. CONCLUSION Since human and mouse ankles are comparable, the present models will contribute to ankle OA pathophysiology and general cartilage research in future.

The role of medial meniscus posterior root tear and proximal tibial morphology in the development of spontaneous osteonecrosis and osteoarthritis of the knee

BACKGROUND Medial meniscus posterior root tear (MMPRT) has been reported to play a key role in the development of spontaneous osteonecrosis of the knee (SONK) and osteoarthritis (OA) of the knee. However, little is known about the differences in the development of SONK and OA after MMPRT. The purpose of this study was to investigate the factors contributing to the development of these conditions. METHODS We evaluated the existence of MMPRT and the extent of medial meniscal extrusion in preoperative magnetic resonance images and proximal tibial morphology in radiographs of 45 patients with SONK and 104 patients with OA who underwent knee surgery. RESULTS There were no significant differences in age, gender, height, weight, and body mass index between the two groups. The incidence of MMPRT and the mean posterior tibial slope (PTS) were significantly higher in SONK than in OA patients (62.2% versus 34.3%, P=0.002, and 12.8° versus 10.5°, P<0.001, respectively). The mean extent of meniscal extrusion was larger in OA than in SONK patients (7.5mm versus 5.3mm, P<0.001). The mean tibial varus angle was 4.8° in SONK and 5.4° in OA, with no significant difference between the two (P=0.088). Multivariable logistic regression analysis showed that compared with OA, SONK was more closely associated with the existence of MMPRT and had a smaller extent of medial meniscus extrusion and higher PTS. CONCLUSION MMRPT and higher PTS were more closely associated with the development of SONK than with that of OA.

Secure fixation of femoral bone plug with a suspensory button in anatomical anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft.

PURPOSE the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft. METHODS thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes. RESULTS the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference. CONCLUSIONS the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Development of the Japanese Version of the Leeds Assessment of the Neuropathic Symptoms and Signs Pain Scale: Diagnostic Utility in a Clinical Setting.

We aimed to assess the diagnostic utility of the linguistically validated Japanese version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale (LANSS‐J) as a screening tool for neuropathic pain in the clinical setting.

Twice cutting method reduces tibial cutting error in unicompartmental knee arthroplasty

BACKGROUND Bone cutting error can be one of the causes of malalignment in unicompartmental knee arthroplasty (UKA). The amount of cutting error in total knee arthroplasty has been reported. However, none have investigated cutting error in UKA. The purpose of this study was to reveal the amount of cutting error in UKA when open cutting guide was used and clarify whether cutting the tibia horizontally twice using the same cutting guide reduced the cutting errors in UKA. METHODS We measured the alignment of the tibial cutting guides, the first-cut cutting surfaces and the second cut cutting surfaces using the navigation system in 50 UKAs. Cutting error was defined as the angular difference between the cutting guide and cutting surface. RESULTS The mean absolute first-cut cutting error was 1.9° (1.1° varus) in the coronal plane and 1.1° (0.6° anterior slope) in the sagittal plane, whereas the mean absolute second-cut cutting error was 1.1° (0.6° varus) in the coronal plane and 1.1° (0.4° anterior slope) in the sagittal plane. Cutting the tibia horizontally twice reduced the cutting errors in the coronal plane significantly (P<0.05). CONCLUSION Our study demonstrated that in UKA, cutting the tibia horizontally twice using the same cutting guide reduced cutting error in the coronal plane.

Bone-Patellar Tendon-Bone Autograft versus Hamstring Tendon Autograft for Anatomical Anterior Cruciate Ligament Reconstruction with Three-Dimensional Validation of Femoral and Tibial Tunnel Positions

Abstract The purpose of this retrospective study was to first compare the clinical outcome of anatomical double‐bundle (DB) anterior cruciate ligament reconstruction (ACLR) with hamstring tendon (HT) autografts and anatomical rectangular tunnel ACLR with bone‐patellar tendon‐bone (BPTB) autografts. Secondly, we aimed to demonstrate the quantitative locations of the femoral and tibial tunnel apertures using postoperative three‐dimensional computed tomography (3D CT). Twenty‐five patients underwent anatomical rectangular tunnel ACLR using BPTB grafts (Group B) and 23 patients underwent anatomical DB ACLR using HT grafts (Group H). All patients underwent subjective postoperative evaluations using the Lysholm score and Knee Injury and Osteoarthritis Outcome Score. Patients also underwent objective evaluations by the International Knee Documentation Committee score, the Lachman test, the pivot‐shift test, and range of motion. In addition, we quantitatively assessed anterior knee stability using a KneeLax3 arthrometer and thigh strength. All evaluations except for thigh strength were assessed for a minimum 2 years of follow‐up period. Femoral and tibial tunnel aperture locations were quantitatively evaluated postoperatively using 3D CT images in all patients. BPTB grafts showed significantly better anterior knee stability than HT grafts (0.1 mm versus 1.1 mm, p = 0.01), although there were no significant differences in other objective and all subjective evaluations between the two graft types. Morphometric analysis of femoral and tibial tunnel locations revealed that the two procedures were based on the same anatomical concept. In conclusion, BPTB grafts showed significantly better anterior knee stability than HT grafts, although no significant differences in other objective evaluations and all subjective evaluations were detected between the two graft types in anatomical ACLR. Additional 3D CT data validated the anatomical concepts of these two procedures.

Myositis ossificans after navigated knee surgery: A report of two cases and literature review

Computer-assisted surgery is now a common procedure in the field of orthopedics. We present two patients who developed myositis ossificans, a rare complication after navigated knee surgery. Due to careful follow-up and conservative treatment, surgical excision was avoided in both patients with good clinical results. Development of myositis ossificans after navigated knee surgery should be considered in cases of thigh pain and restricted range of motion of the knee.

The Relationship between Soft-Tissue Balance and Intraoperative Kinematics of Guided Motion Total Knee Arthroplasty

&NA; A new design of the so‐called “guided‐motion” total knee arthroplasty (TKA) is expected to produce normal‐like kinematics. The implant behaves strictly as a mechanically constraint‐guided motion system. However, no previous reports have demonstrated the most appropriate surgical technique or soft‐tissue balance that would reproduce ideal kinematics. The purpose of this study was to clarify the relationship between soft‐tissue balance and the intraoperative kinematics of guided‐motion TKA. In this study, intraoperative kinematics of 95 patients whose TKA was performed with a guided‐motion prosthesis (Journey II BCS Smith and Nephew) were measured using the computed tomography (CT)‐free navigation system. All procedures were performed via the same soft‐tissue balancing technique, which focused on the medial compartment because guided‐motion TKA must acquire medial stability to induce medial pivot motion. We measured the extension and flexion osteotomy gaps using a force‐controlled compartment‐specific ligament tensioner with a distraction force of 80 N for each compartment and divided patients into three groups based on the relationship between extension and flexion joint osteotomy gaps of the medial compartment: group1‐ loose flexion gap, group 2‐equal joint gap, and group 3‐tight flexion gap. We compared the preoperative demographic characteristics, implant alignment, and intraoperative kinematics among the three groups. There was no difference between the preoperative demographic characteristics and postoperative implant alignment in the three groups. The relative tibial internal rotational angles in groups 1 and 2 were significantly larger than that in group 3 at 60°, 90°, and maximum flexion (p < 0.05). The appropriate soft‐tissue balance of the medial compartment for guided‐motion TKA was an equal joint osteotomy gap or a larger flexion than extension gap. A tight flexion gap should be avoided.

Snapping Pes Syndrome after Unicompartmental Knee Arthroplasty

Snapping pes syndrome is defined as a snapping sensation in the medial knee caused by pes anserinus and rarely occurs. Snapping pes syndrome after unicompartmental knee arthroplasty (UKA) has not been reported yet. We experienced two cases with this syndrome after UKA. Conservative treatment was effective in one case, while surgical excision of the gracilis tendon was necessary to relieve painful snapping in the other case. The main cause of the first case might be posteromedial overhang of the tibial tray that reached up to 5 mm. The probable cause of the second case was posteromedial overhang of the mobile bearing.