Objective To report a new offset parameter for total hip arthroplasty (THA)—greater trochanter offset (GTO), and analyze the effectiveness and feasibility of this parameter based on clinical data. Methods The 47 patients who met the selection criteria and admitted between January 2016 and May 2020 were selected as the research object. The global offset (GO) was used as the offset parameter in preoperative design. Firstly, the test-retest reliability and inter-rater reliability of GTO were analyzed based on pelvic X-ray films. The GTO reconstruction was defined as the difference between the operative side and the healthy side within ±5 mm, and 47 patients were divided into the reconstruction group and the non-reconstruction group. General data (age, gender, type and side of fracture, the interval between injury and operation), visual analogue scale (VAS) score, Harris score, gait score, and leg length discrepancy (LLD) were recorded and compared between two groups. Then, the GTO was used as the offset parameter in preoperative design of 21 patients (GTO group) admitted between June 2020 and December 2020. The pre- and post-operative clinical data were compared between GTO group and GO group to explore the feasibility of GTO for THA.Results Statistical analysis showed that GTO had good test-retest reliability (P<0.001) and inter-rater reliability (P<0.001). There was no significant difference in gender, age, type and side of fracture, the interval between injury and operation, preoperative VAS score, and LLD at 1 year after operation between the GTO reconstruction group and the non-reconstruction group, as well as between the GO and GTO groups (P>0.05). The Harris score and gait score at 1 year after operation, and difference of VAS score between pre- and post- operation in the reconstruction group and GTO group were significantly better than those in the non-reconstruction group and GO group, respectively (P<0.05). There were 23 cases (48.9%) in the GO group and 19 cases (90.5%) in the GTO group with GTO reconstruction, and the difference was significant (χ2=10.606, P=0.001). There were 25 cases (53.2%) in the GO group and 13 cases (61.9%) in the GTO group with GO reconstruction, and the difference was not significant (χ2=0.447, P=0.504). There were 34 cases (72.3%) in the GO group and 19 cases (90.5%) in the GTO group with LLD reconstruction, and the difference was not significant (χ2=2.777, P=0.096). Conclusion GTO has reliable test-retest reliability and inter-rater reliability. GTO as a parameter of preoperative offset reconstruction plan of THA can obtain good reconstruction of offset and limb length, and obtain a good effectiveness.
Objective To investigate the feasibility and effectiveness of self-made auxiliary devices in assisting the guide pin placement and precise temporary fixation of the main nail in proximal femoral nail antirotation (PFNA) internal fixation of intertrochanteric fractures. Methods A prospective randomized controlled study was conducted to analyze the clinical data of 60 patients with femoral intertrochanteric fractures over 65 years old who met the selection criteria between January 2020 and June 2022 and were treated with PFNA internal fixation. The patients were randomly divided into the trial group (auxiliary device guided main nail guide pin placement and temporary fixation) and the control group (conventional treatment), with 30 cases in each group. There was no significant difference in baseline data such as gender, age, cause of injury, time from injury to operation, fracture side, AO/Orthopaedic Trauma Association (AO/OTA) classification, and combined medical diseases between the two groups (P>0.05). The operation time, times of main nail guide pin placement, intraoperative fluoroscopy frequency, intraoperative blood loss, and perioperative blood transfusion were recorded and compared between the two groups. The quality of fracture reduction was evaluated by CHANG Shimin et al. Harris score was used to evaluate the hip function at 1 year after operation. Results In the trial group, 2 temporary fixation needles were successfully placed 2-5 times, including 2 times in 13 cases (43.3%), 3 times in 8 cases (26.7%), 4 times in 7 cases (13.3%), and 5 times in 2 cases (6.7%). The operation time, times of main nail guide pin placement, intraoperative fluoroscopy frequency, and intraoperative blood loss in the trial group were significantly less than those in the control group, and the reduction quality score was significantly better than that in the control group (P<0.05). There was no significant difference in perioperative blood transfusion between the two groups (P>0.05). All patients were followed up 12-19 months (mean, 15 months). There was no complication such as incision infection, deep vein thrombosis, and internal fixation loosening. At 1 year after operation, the Harris score of the affected hip joint in the trial group was significantly higher than that in the control group (P<0.05). Conclusion The technique of main nail guide pin placement and temporary fixation under the guidance of auxiliary devices in PFNA internal fixation can achieve faster insertion of the main nail guide pin, accurate temporary fixation to maintain reduction, and avoid the subsequent operation space, so as to improve the effectiveness.