Fueled by an ageing population and rising cases of osteoporosis, hip fractures are expected to affect more people, and so it is important to understand which treatment plan and which device will be more effective for various patients. If treated poorly, this fracture has a tendency to malunion, resulting in shortening, varus, medialization of the shaft, and external rotation deformity, and as such, it is important to achieve near-anatomic reduction to reduce morbidity and complications.
Recent studies have shown a trend towards using cephalic intramedullary devices over sliding hip screws for intertrochanteric fractures attributed to the improvements in the intramedullary devices’ implant design, and the biomechanical advantages of intramedullary fixation resulting to a lower rate of reoperation than in fixations with the sliding hip screw2,13,14.
Some studies have shown that the sliding hip screw is able to afford satisfactory results for stable types of fractures, such as AO/OTA 31-A1.1 and 31-A1.2 fractures, whereas for severely unstable types of fractures, the cephalic intramedullary device should be the standard treatment for 31-A2.2, 31-A2.3 and 31-A3 fractures. However, proper treatment for the unique fracture type of AO/OTA A1.3 with intact lateral wall remains still controversial15,16. The evidence in this study indicate that when a sliding hip screw is used for relatively unstable fractures (AO/OTA 31-A1.3), in patients with poor bone quality, intra-operative iatrogenic fracture of lateral wall is an issue of concern, and post-operative lateral wall fractures may lead to shortening or medialization of the shaft.7,17
The gamma3 group in this study were shown to be effective for unstable intertrochanteric femoral fractures in the unique fracture pattern of AO/OTA 31-A1.3, fractured lesser trochanter with completeness of lateral walls. Complications were found in 16.4% (14 patients) of the patients in the gamma3 group, including screw cut-outs, aseptic loosening and femoral head necrosis. The DHS group showed no advantages in duration of surgery, wound size, length of hospital stay (LOS) and radiographic parameters such as neck shortening and neck-shaft angle change.
Femoral neck shortening is typically considered a common poor outcome predictor for post-operative recovery, and excessive shortening of over 5mm can lead to weakened gluteus medius strength and hip joint movement limitations18. Randomized studies have demonstrated that cephalic intramedullary nails enabled patients with unstable 31-A2 fractures to return to mobility faster than those treated with sliding hip screws15. Additionally, while no correlation has been found between the degree of femoral shortening and functional outcome, there were less cases of femoral shortening in patients who were treated with the cephalic intramedullary nails19. The results of our study, that the cephalic intramedullary device leads to a better post-operative recovery, corroborates these studies as well.
The need for cut-outs is considered the most concerning complication following ITF surgery, as it’s occurrence greatly impacts the patient’s functional outcome, increases the probability for further revision surgeries, and even decreases their life expectancy. 20 Other studies have shown that poor bone quality, reductions and TAD are correlated with the risk of cut-outs approaching statistical significance.21,22 Specifically, they found that a TAD >25mm is an important cut-off value that can predict the need for screw cut-outs in ITF surgical treatments23–25.
Our statistical analysis of TAD alone indicated no significant difference between the two groups for post-operative TAD (18.88 ± 5.9 vs. 20.66 ± 1.22 for Gamma3 and DHS respectively), and also did not reveal a significant enough TAD result to properly analyze and predict cut-outs (P=0.49). We have found that this is because TAD does not take into consideration the reduction quality of the fracture, and as such, post-operative reduction parameters must be taken into to consideration.
Our statistical analysis for the reduction quality to predict factors will lead to potential cut-outs, over-traction, medialization and tilting are as follows. (Figure 1) Over-traction is a significant factor that is highly correlated (OR=4.438) with cut-outs for this fracture type. While Bretherton et al. reported that medialization of more than 50% in the femoral canal group had a higher revision rate (2.1% vs. 14.3%, p=0.014) when treated with either the intramedullary nail or sliding hip screw.15 our statistical findings did not show significant correlation between medialization and tilting parameters with cut-out (P= 0.148, P=0.657 separately). The concept of reduction parameters should be confirmed by further studies in the future.
There were several limitations in this study. This study was a retrospective and more randomized controlled studies should be considered to conclusively verify our findings. The operations were not performed by a single surgeon, and different operative techniques may impact treatment outcome. Patients’ bone quality data were unable to be obtained, and finally, Osteoporosis in the elderly is an uncertain factor for implant failure.