Norishige Iizawa

Influence of the Medial Knee Structures on Valgus and Rotatory Stability in Total Knee Arthroplasty

BACKGROUND Precise biomechanical knowledge of individual components of the MCL is critical for proper MCL release during TKA. This study was to define the influences of the deep MCL and the POL on valgus and rotatory stability in TKA using cadaveric knees. METHODS This study used six fresh-frozen cadaveric knees. All TKA procedures were performed using a cruciate-retaining TKA with a CT-free navigation system. We did a sequential sectioning on each knee, S1; femoral arthroplasty only, S2; medial half tibial resection with spacer, S3; anterior cruciate ligament cut, S4; tibial arthroplasty, S5; release of the dMCL, S6; release of the POL. The navigation system monitored motion after application of 10 N-m valgus loads and 5 N-m internal and external rotation torques to the tibia at 0°, 20°, 30°, 60°, and 90° of knee flexion for each sequence. RESULTS There were no significant differences in medial gaps. Internal rotation angles significantly increased after S2 at 0°, 20°, and 30°, and after S6 at 90° compared with those after S1. External rotation angles significantly increased after S3 at 0°, S4 at 60°, S5 at 0°, 30° and 90°, and after S6 at 30°, 60° compared with those after S1. CONCLUSION Significant increases of rotatory instability were seen on release of the dMCL, and then further increased after release of the POL. Surgical approach of retaining the dMCL and POL has a possibility to improve the outcome after primary TKA.

Serum KL‑6 Elevation and Possible Pulmonary Involvement in Patients with Rheumatoid Arthritis Treated with Biological Agents

BACKGROUNDS Interstitial lung disease (ILD) is associated with rheumatoid arthritis (RA) itself and is also induced by biological and non-biological disease-modifying antirheumatic drugs. The glycoprotein Krebs von den Lungen-6 (KL-6) is reported to be a marker for the activity of ILD. OBJECTIVES To elucidate the relationship between serum KL-6 levels in patients with RA treated with biological agents and pulmonary involvement on computed tomography of the chest. METHODS The subjects were 307 patients with RA treated with infliximab, etanercept, adalimumab, or tocilizumab. Medical records were reviewed to investigate serum KL-6 levels, disease activity, and pulmonary imaging findings. RESULTS Levels of KL-6 were abnormally elevated in 25 patients (8.1%): 15 patients (11.2%) treated with infliximab, 6 patients (4.4%) treated with etanercept, and 4 patients (22.2%) treated with adalimumab, but in no patients treated with tocilizumab. However, no clinical pulmonary events developed. Computed tomography of the chest showed the start or progression of interstitial fibrotic change in 5 of 25 (20%) patients with abnormal KL-6 values. The changes in disease activity did not differ significantly between patients who showed elevated KL-6 values and those who did not. CONCLUSIONS Serum KL-6 levels were elevated in 8.1% of patients with RA treated with biological agents. Careful observation is necessary for these patients regarding lung fibrosis.

A computed-tomography-scan-based template to place the femoral component in accurate rotation with respect to the surgical epicondylar axis in total knee arthroplasty

BACKGROUND Femoral rotational alignment is considered an essential factor for total knee arthroplasty because malrotation of femoral components results in poor outcomes. To obtain proper alignment, we developed a superimposable computed tomography (CT) scan-based template to intraoperatively determine the accurate surgical epicondylar axis (SEA), and evaluated the effectiveness of this CT template. METHODS In the experimental group (n=55), three serial slices of CT images, including medial and lateral epicondyles, were merged into a single image, and SEA was overlaid. SEA was traced onto an image of an assumed distal femoral resection level; this combined image was then printed out onto a transparent film as a CT template. Following a distal femoral resection in TKA, SEA was duplicated onto the femoral surface. Thereafter, the posterior condyle was resected parallel to this SEA. In the control group (n=53), posterior condyles were resected at three degrees of the external rotation from the posterior condylar line (PCL). A posterior condylar angle (PCA) between PCL of the femoral component and SEA was postoperatively evaluated. Positive values indicated external rotation of the femoral component from the SEA. RESULTS In the experimental group, PCA was 0.01°±1.61°, and three cases were considered as outliers (greater than three degrees or less than -3 degrees). Conversely, in the control group, PCA was 0.10°±2.4°, and 12 cases were considered as outliers. Consequently, dispersion of PCA data was significantly smaller in the experimental group (P=0.004). CONCLUSIONS The CT template accurately determined intraoperative SEA.

Intercondylar fracture of the distal humerus in a 7-year-old child: A case report and a review of the literature

Rationale: Intercondylar fracture of the distal humerus is an extremely rare injury in children, especially in those under 8 years of age. To our best knowledge, there have been 55 reported cases of this fracture type in children in the English literature, 12 of which involved children under 8 years of age. Patient Concerns: We report a case of intercondylar fracture of the distal humerus in a7-year-old boy fell in a gymnasium, injuring his left elbow. Interventions: Closed reduction was initially attempted under fluoroscopic guidance, but anatomic reduction could not be achieved because the fragments were extremely unstable and irreducible. Considering the displacement and the failure of closed reduction, ORIF through a posterior approach was performed. Open reduction and double cross-pinning across the medial and lateral condylar fragments were performed through a posterior approach. Diagnoses: Plain radiographs showed a displaced intercondylar fracture of the distal humerus. Arthrography under general anesthesia showed a severely displaced intra-articular fracture, with rotational displacement of the lateral condyle. Outcomes: Thirteen months after surgery, there was no functional disturbance or radiographic evidence of avascular necrosis or epiphyseal growth arrest. Lessons: Open reduction and double cross-pinning through a posterior approach can be a reliable procedure for intercondylar fracture of the distal humerus in children.

Midterm Result of Arthroscopic Bicruciate Ligament Sutures for Multiligament Knee Injury in an Adolescent Patient

BACKGROUND Treatment of multiligament knee injuries, especially in adolescent patients, is challenging for orthopedic surgeons. Repair of collateral ligaments and reconstruction of cruciate ligaments are usually performed, however, ligament reconstruction with transphyseal or physeal-sparing techniques may lead to physeal damage and growth disturbances in skeletally immature patients. We present a case report on performing bicruciate ligament sutures arthroscopically in an adolescent patient. PATIENT AND METHODS The patient was a 14-year-old boy, who was diagnosed with injuries to the anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament. Single-stage arthroscopic primary suturing of the anterior and posterior cruciate ligaments and open medial collateral ligament suturing were performed 7 days after the injury. RESULTS AND DISCUSSION The patient returned to routine activities, including high-level competitive sports, at 8 months post-surgery, and currently, 8.5 years after surgery, remains without complications. Suture repair was able to minimize the size of the bone tunnels and to re-establish knee stability with native tissues. Therefore, the application of sutures may be a useful option for repairing multiligament knee injuries, particularly in adolescent patients.

Superior Dislocation of the Patella in a Young Woman without Osteophytes: A Case Report

Superior dislocation of the patella without patellar ligament injury is an extremely rare condition. A review of the English-language literature found only 23 reported cases. In addition, the primary factor for dislocation in most of these cases was considered to be osteophytes in the inferior pole of the patella and the anterior surface of the femoral condyle; only 1 case had no osteophytes. We treated a 19-year-old woman who sustained a painful locking of the left knee after colliding with a friend. Plain radiography and computed tomography showed superior-lateral dislocation of the patella and an interlocking between notches in the inferior pole of the patella and the anterior surface of the femoral condyle. Closed reduction without sedation was performed without difficulty, and the patient was able to walk home without pain. After 1 week, the knee was without problems. The patient had no osteophytes in the knee and had no other common risk factors, such as patella alta, ligamentous laxity, genu recurvatum, and paralytic disorders. After a comparison with previously reported cases of superior patella dislocation, we concluded that the primary factor in the present case might have been a different condition.