## 7 Discussion
They achieved a mean of 1.5 cm of postoperative lengthening. Though our series is much smaller, similar functional outcomes are reported with our technique. The Harris Hip Score improved from a preoperative mean of 38 (range 30-44) to 90 (range 88-96) postoperatively; all corresponded to good or excellent results. Additionally, our patients had a similar mean leg lengthening of 8 mm (range 6-12). Figure 7: **(A)** No bone contact is achieved intraoperatively. **(B)** The progressive medialization of the shaft conducted by the DHS will result in interfragmentary bone contact. **(C)** Progressive impaction of the bone ends occurs. The green rectangle illustrates the dynamization of the DHS. The black circle shows the bone contact area through which compression forces (red arrows) are transmitted. Figure 8: (**A**) Immediate postoperative frontal X-ray. This was the only patient in which the nonunion site was refreshed. (**B**) Final radiological result. The yellow arrow shows the sliding of the head screw and the excellent bone callus, with minimal medialization of the shaft. Figure 9: (**A**) Immediate postoperative X-ray. (**B**) Final radiological result. The yellow arrow shows no retrograde exit of the cervical screw through the DHS barrel and may suggest that there has been no dynamism between the fragments. However, the medialization of the diaphysis shows the opposite. This is because sometimes the cervical screw is very short, and even if it slides retrogradely, its exit through the DHS barrel is not visible. In our series, the mean time for union time was five months, and no major complications were reported. They are similar results to the studies reported in the literature [12; 27; 28]. Our results are compared with some in the literature, where the surgical procedure has been performed like ours using an extramedullary device (Table 3). \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Study** & \begin{tabular}{c} **N\({}^{\circ}\) of** \\ **Patients** \\ \end{tabular} & **Design** & **Device Used** & **Follow Up** & **Results** \\ \hline [PERSON] & 12 & Retrospective & \begin{tabular}{c} A reversed DF-LCP \\ with bone grafting \\ \end{tabular} & 13 months & \begin{tabular}{c} 100\% bone union rate at a mean \\ of 9.5 months. No major \\ complications. \\ \end{tabular} \\ \hline [PERSON] & 40 & Retrospective & \
\begin{tabular}{c} Dynamic condylar \\ screw plating along \\ with bone grafting \\ \end{tabular} & 26 months &
\begin{tabular}{c} 93\% bone union rate at \\ 26 months. Thirteen patients \\ required a second surgical \\ procedure due to persistent \\ nonunion (n: 1), persistent \\ nonunion leading to implant \\ failure (n: 9), deep infection \\ (n: 2), and periprosthetic \\ fracture (n: 1). Ultimately, 93\% \\ (n: 37) achieved union at a \\ mean of 12 months. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of our study with those in the literature. Figure 10: (**A**) Immediate postoperative X-ray. (**B**) Final radiological result. The yellow arrow shows slight sliding of the head screw, effective bone union, and minimal medialization of the shaft. The main limitation is the small number of patients treated to date. This nonunion is somewhat unusual, so it is difficult to recruit a large number of patients. Even so, to our knowledge, this is the only prospective study performed on the pseudoarthrosis of subtrochanteric fractures fixed dynamically.