In this study, we aimed to explore surgical variations in the Femoral Neck System (FNS) used for stable fixation of Pauwels type III femoral neck fractures. Finite element models were established with surgical variations in the distance between the implant tip and subchondral bone, the gap between the plate and lateral femoral cortex, and inferior implant positioning. The models were subjected to physiological load.Aims
Methods
The purpose of this double-blinded prospective study was to evaluate the effectiveness of electromyography (EMG)-guided preoperative femoral nerve block (FNB) for postoperative analgesia in total knee arthroplasty (TKA). Forty knees of primary TKA by one surgeon were included in our study. One doctor performed a single injection FNB with an EMG guide in EMG group (23 knees) and with a blind maneuver in control group (17 knees). The same 10ml of 0.375% ropivacaine was injected in both groups. Same postoperative rehabilitation protocol was applied to all patients. Continuous passive motion was started at postoperative 1st day and weight bearing was started as soon as possible. Intravenous patient-controlled analgesics which contained 30mg of morphine were used until postoperative 72 hours and no additional intravenous, intramuscular or oral analgesics were used. Pain was evaluated by Visual Analogue Scale (VAS) and Postoperative Pain Score (PPS) at postoperative 4, 24, 48 and 72 hours. The amount of opioid consumption and complication were compared between two groups. VAS score was 6.8 in EMG group and 8.0 in control group at postoperative 4 hours, 6.2 and 7.1 at postoperative 24 hours, 5.3 and 5.9 at postoperative 48 hours, and 4.6 and 5.7 at postoperative 72 hours, respectively. PPS was 2.2 in EMG group and 2.2 in control group at postoperative 4 hours, 2.1 and 2.1 at postoperative 24 hours, 1.6 and 1.7 at postoperative 48 hours, and 1.4 and 1.6 at postoperative 72 hours, respectively. The amount of opioid consumption was 6.0mg in EMG group and 7.2mg in control group during postoperative 24 hours, 2.7mg and 3.2mg during postoperative 24–48 hours, and 1.7mg and 3.2mg during postoperative 48–72 hours, respectively. There was no complication in either group. Pain tended to decrease more in EMG group than control group, especially VAS at postoperative 4, 24 and 72 hours (p<
0.05). The demand of opioid was significantly smaller in EMG group during postoperative 24 hours and 48–72 hours (p<
0.05). EMG-guided single FNB before TKA allowed better postoperative pain relief and reduced the demand of pain killer.
The purpose of this prospective study was to investigate the necessity of gender-specific design in total knee arthroplasty (TKA) for Korean women. One hundred and seventeen women (151 knees) who underwent primary TKA by one surgeon with Nexgen® LPS (Zimmer, Warsaw, IN) were evaluated. The mean age was 70 (range 52–80) years. The size of the implant was determined by considering anteroposterior (AP) dimension and the amount of posterior condylar resection. Size C was used in 72 knees, size D in 57 and size E in 22. We measured the mediolateral (ML) widths of distal femur at four points (anterior, distal anterior, distal posterior, posterior) intraoperatively after bone cutting, and compared them with the ML widths of the corresponding femoral implants. The ML/AP ratio was calculated in each size group. The mean ML widths of the distal femur checked at all four points were larger than those of the implants. The ML/AP ratio of the distal femur decreased as the size increased from C to E, especially that of the anterior point. Overhanging occurred in 7 cases (4.6%, size C -2 cases, size D -2 cases, E -3 cases) : Nexgen® LPS implant was used in 5 cases because there was only minimal antero-lateral overhanging, resulting in no postoperative problem such as pain or limited motion. Gender-specific design was used in only 2 cases (1.3%, size D -1 case, size E -1 case) with trochlear dysplasia due to general overhanging. In conclusion, gender-specific design of Nexgen® TKA was rarely necessary in 117 Korean women(151 knees); overhanging occurred in 7 knees (6 women) and gender-specific design was used in only two knees (1.3%) with trochlear dysplasia. Further research is obviously mandatory to assess the necessity of gender-specific design.