Letter to the editor: Proximal femoral locking plate versus dynamic hip screw for unstable intertrochanteric femoral fractures.

To the Editor: We read with interest the article by Dhamangaonkar et al.1 May the authors clarify the following points. 1. A dynamic hip screw (DHS) with fixed angle locking screws reduces the risk of implant failure, particularly for patients with osteoporotic bone or less stable fracture configurations.2 Why did the authors compare a proximal femoral locking plate with a non-locking 135o DHS? Comparison of the DHS locking plate with a proximal femoral locking plate would have been more realistic and generalisable. 2. Filling all screw holes may lead to stress concentration and high strain, which can lead to implant failure after cyclic loading.3 The working length has no effect on stiffness, gap motion, and resistance to fatigue.4 What is the authors’ opinion regarding this issue? We believe that in cases of comminution, increasing working length at the level of the fracture enables a larger area of stress distribution on the plate and reduces the strain at the fracture site. 3. Correct placement of screws is of crucial importance and should be ensured in both anteroposterior and lateral planes. Convergence/ divergence of the locking head screws in the anteroposterior/lateral planes enables an angular stable buttress that increases the stability of fracture fixation.3 Did the authors check the screw placement in both planes? 4. The ‘kickstand’ screw has greater axial stiffness and lesser torsional stiffness,5 but its use to reduce the risk for mechanical failure cannot be established.6 What is the authors’ opinion regarding this? 5. Regarding a large posteromedial void, what were the factors that impeded the locking of screws besides osteoporosis? Did the authors attempt bone grafting for the void? 6. The authors stated that “All patients in the DHS group were operated on with a short barrel plate, which increased the risk of jamming of the lag screw.” The lag screw length during the procedure determines the barrel plate sizes, i.e. standard (38 mm) or short (25 mm).7,8 Please comment.