Nowadays, there are towering up number of displaced intracapsular hip fracture which will have a significantly impact on the life level of patients and cast a huge economic burden on society, and the displaced intracapsular hip fracture is still a challenge of orthopedic surgeons because patients may occur many complications even refracture after operation. Three cannulated screw were usually performed for displaced intracapsular hip fracture in elder, Wani et al reported that 50 patients with displaced fracture of the femoral neck were underwent closed reduction and internal fixation with cannulated screw. The patients had yield satisfied clinical outcome, such as the HHS was improved to 90.6 ± 2.2 at the final follow-up visit time but there were 4 patients occurred nonunion and 6 were avascular necrosis.15 Similarly, Dong et al reported that 30 patients with displaced intracapsular hip fracture (Pauwels’s III) underwent ordinary cannulated screw fixation. They have got significantly improvement in HHS and EQ-5D but 17/30 patients occurred femoral neck shorting (> 5mm) at final follow-up visit.16
In order to minimize the orthopedic complications and femoral neck shorting, more and more surgeons are focus on the Targon locking plate and fully threaded cannulated screw for displaced intracapsular hip fracture. Parker et al reported that 208 patients with displaced intracapsular hip fracture underwent internal fixation with Targon locking plate. There was significantly recovery in pain mobility score and 148 of 208 (71.1%) patients were uneventful fracture healing.17
And some finite-element studies also demonstrated that Li et al reported a finite-element analysis about comparison of ordinary cannulated screw, dynamic hip screw with derotational screw and cannulated screw with Targon locking plate. And found that cannulated screw with Targon locking plate can perform better in resisting shearing and rotational force.18 Boraiah et al had retrospectively collected 54 patients younger than 65 years old treated with open reduction and internal fixation using fully threaded cannulated screw. A total of 51/54 patients were healed successfully without any complications, and the average shorten of femoral neck was 0.54 mm (Range from 0 to 2.7).19
In this study, a total of 75 patients with displaced intracapsular hip fracture who underwent internal fixation were enroll in our study and 35 were two cannulated screws combined one fully threaded cannulated screw with Targon locking plate, others 40 patients were treated with three cannulated screws.
Our outcome shown that TCS-TLP group have a better improvement in hip function, decreased the orthopedic complication and minimized femoral neck shorting. At 12 and 24 months followed-up visit, the MHHS were significantly better increased in TCS-TLP group than TSC group (P < 0.05). Similarly, 15 of 40 patients was detected femoral neck shorting more than 5 mm and 3 of 35 patients in the TCS-TLP group (P < 0.05). Moreover, there were total of 5 patients presented orthopedic complications and 1 patient had wound infection in the TCS-TLP group, whereas, 15 patients occurred orthopedic complications and 2 had wound infection in the TCS group. Some already published articles reported similarly outcomes, Warschawski et al documented that there were 23 (28.4%) patients had orthopedic complications in patients with cannulated screws and 6 (17.6%) patients in the patients treated with Targon locking plate. But the patients using Targon locking plated had more pain score than patients treated with cannulated screws. Whereas they didn’t have measured the femoral neck shorting.20 And Thein et al retrospectively collected 31 patients treated with Targon FN and other 47 patients were underwent internal fixation using multiple cannulated screws, and detected that patients treated with Targon FN had significantly less orthopedic complication rate and revision than patients underwent multiple cannulated screws (P < 0.05).21
In our study, the femoral neck shorting rate was 37.5%, and others articles reported similarly outcomes that the femoral neck shorting rate is around 27%~31% in femoral neck fracture patients treated with multiple cannulated screws.22 And there were only 3 (8.6%) patients underwent two cannulated screws combined one fully threaded cannulated screw with Targon locking plate had femoral neck shorting. Wang et al reported that 8 of 34 (23.5%) patients treated with three partial threaded cannulated with dynamic screws occurred femoral neck shorting.23 And Alves et al found fully threaded cannulated screw can provide better biomechanical support and prevent femoral neck shortening in femoral neck fractures receiving internal fixation.24 Similarly, Alshameeri et al reported that patients treated with Targon lock plated shown less rate of non-union and reoperation than patients with cannulated cancellous screws.25
The possible reason for more orthopedic complications occurred in patients treated with three cannulated screws maybe insufficient resisting shearing and rotational force. Whereas, the Targon locking plate can not only provident stronger support in the femoral neck, but also prevent the loosening or cut-out of screws.23 Three screws inserted in an inverted triangle can keep stability in the fractured site, and one fully threaded cannulated screw can avoid femoral neck collapse after operation.9 So that Targon locking plate show superior improvement in diminish orthopedic complication and achieved better clinical efficacy than three cannulated screws infixation.
Some limitations of this study are as follow, this study was conducted in a single center and the sample size is small. It could be better to set patients treated with three partial threaded cannulated screw with dynamic locking screw as control group but the cases are few in our hospital. Finally, biomechanical or finite element analysis should be further conducted to analyze the force distribution after operation.