Trans patellar tendon sagittal tibial cut for lateral unicompartmental knee arthroplasty-location of the split- CT simulation study.

BACKGROUND: In lateral unicompartmental knee arthroplasty (UKA), a sagittal cut is often performed through the patellar tendon (PT). Although the approach is likely widely used, it has not been described in detail, especially regarding the site of the split. This study aimed to clarify where the split should be made. METHODS: This single-center retrospective cohort study included 49 consecutive patients and 51 knees with lateral osteoarthritis. Using preoperative computed tomography, we measured the distance from the medial edge of the PT to the intersection of the PT and the sagittal cutting line, defined as a line parallel to the Akagi's line and passing the tip of the lateral tibial spine. RESULTS: The sagittal cut line passed a mean of 45 ± 11% of the patellar tendon width from the PT medial edge. CONCLUSIONS: The tendon split should be made just medial to the center of the PT because it is where the sagittal cut line for lateral UKA passes.

Clinical Results of Dual SC Screw: A Mini-Sliding Hip Screw with an Anti-rotating Screw for Femoral Neck Fractures.

BACKGROUD: Dual SC screw (DSCS) is a unique concept internal fixation device consisting of a sliding screw and barrel assembly that enables compression force to be applied to the femoral neck fracture side. There are two types of barrels: a thread barrel and a plate barrel that has a one-holed side plate to prevent varus deformity. We report clinical results of the application of a DSCS with combined use of a thread barrel screw as an anti-rotational screw and a plate barrel screw as a compression hip screw. METHODS: We used DSCS for femoral neck fractures in 196 hip joints of 190 patients between November 2005 and June 2017. Among them, 70 hips in 66 patients (13 men and 53 women; mean age, 73.2 years) were followed up for at least 24 months. There were 53 nondisplaced fractures (Garden's classification stage 1 or 2) and 17 displaced fractures (stage 3 or 4). We evaluated the postoperative walking ability of the patients who were followed up for at least 24 months and examined details of all complications. RESULTS: The mean follow-up period was 37.4 months (range, 24-144 months). Forty-two (64%) out of the 66 patients who were followed up for at least 2 years were able to walk independently with or without a cane. The incidence of complications was 11.5% in nondisplaced fractures and 17.5% in displaced fractures, and arthroplasty was required in 5.8% and 5.0%, respectively. The most frequent complication was secondary displacement including cutout and shortening of the femoral neck, but no implants showed varus displacement. CONCLUSIONS: The application of DSCS for the treatment of femoral neck fractures had satisfactory results. The complication rate was low, and there was no postoperative varus displacement of DSCS in either displaced or nondisplaced fractures. We suggest DSCS is a reliable option for both displaced and nondisplaced femoral neck fractures.

Manipulation of Tibial Component to Ensure Avoidance of Bearing Separation from the Vertical Wall of Tibial Component in Oxford Unicompartmental Arthroplasty.

In Oxford unicompartmental knee arthroplasty, the relationship between the mobile bearing and the vertical wall of the tibial tray is important in preventing bearing dislocation. Separation of the bearing from the vertical wall can cause spinning of the bearing with an increased risk of subsequent dislocation. We report on intraoperative adjustment of the tibial tray performed to prevent the bearing from spinning. After tibial and femoral bone cutting and adjustment of the flexion and extension gap, the trial bearing is inserted and the bearing-vertical wall distance is evaluated before the preparation using the tibial template and bearing trial. In the case of separation, it can be resolved by medialization with or without rotational adjustment. The technique is useful and can be easily performed, it is therefore recommendable for all cases of Oxford mobile-bearing unicompartmental arthroplasty.

A Novel Technique for Varus Tibial Cutting for Oxford Unicompartmental Knee Arthroplasty.

To reduce the stress on the medial tibial cortex and to decrease the risk of fracture, a varus cut of the tibia appears to be a reasonable alternative to the orthogonal cut by conventional methods. We present a new instrument and procedure, which enables a varus tibial cut for Oxford unicompartmental knee arthroplasty. We used a custom-made, slidable fixator instead of the standard fixator to set the extramedullary rod on the leg. We also made a numeric formula and a chart to arrange the varus cutting angle using the length of the mediolateral shift of the distal end and the longitudinal extension length of the extramedullary tibial rod. A varus cut up to 4.5° can be controlled. This technique is a simple and useful means of obtaining a varus tibial cut for Oxford unicompartmental knee arthroplasty.

Boron neutron capture therapy for clear cell sarcoma.

Clear cell sarcoma of tendons and aponeuroses (CCS) is a rare, malignant tumor arising in lower extremities with no effective treatment other than wide surgical resection. Here described is a case of primary CCS in the peroneal tendon of the right foot of a 54-year-old woman enrolled to undergo BNCT. The tumor mass post-BNCT disappeared totally without damage to other normal tissue, demonstrating, for the first time, the potential efficacy of BNCT in complete local control of CCS.