Influence of striking technique on maximum striking velocities-experimental and statistical investigation.

Forensic experts often have to assess injury and fatality risks in the context of violent blunt force trauma. Maximum striking velocities in one- and two-handed strikes with a rod-like implement can be of particular interest. Current literature lacks studies addressing this problem. The purpose of this study was therefore to measure and analyse maximum striking velocities in one-handed and two-handed strikes in female and male volunteers. We hypothesised higher striking velocities in two-handed strikes compared to one-handed strikes. Fifty volunteers performed one- and two-handed strikes from top to bottom using a steel rod of 65 cm length and 1000 g weight. A Qualisys™ Motion Analysis system registered displacements of reflecting markers fixed to the rod as well as to the volunteer's body. In one-handed strikes, the mean maximum striking velocity was 17.2 m/s in the female sample and 23.9 m/s in the male sample. Statistically not significantly different maximum striking velocities were found in two-handed strikes with mean values of 18.3 m/s in the female sample and 24.2 m/s in the male sample. Female and male volunteers also yielded similar mean maximum striking velocities in two-handed strikes comparing 'overhead' and 'overshoulder' striking techniques. In conclusion, the striking technique did not relevantly influence maximum striking velocities in our setup.

Forward-striking technique in simple femoral shaft fractures: a comparative cohort study.

BACKGROUND: A persistent fracture gap following femoral nailing increases the risk of delayed and nonunion development. A forward-striking technique for reducing the gap in femoral nailing has been described, but its efficacy and therapeutic consequences have not been investigated in comparative studies. We provide the results of a comparative study that investigated the forward-striking technique's efficacy in terms of remaining fracture gaps and surgical outcomes. METHODS: Between 2017 and 2022, a retrospective cohort study was undertaken on 193 skeletal mature patients obtaining reamed femoral nailing for closed femoral shaft fractures. Comparisons of residual fracture gaps, timing to union, complications and re-operation rates were made between 80 patients (41.45%) undergoing femoral nailing with the forward striking procedure and 113 patients (58.55%) undergoing traditional nailing, accompanied by minimal 1-year follow-ups. In addition, the potential difference between fracture gaps before and after applying the forward striking procedure was compared. RESULTS: Both groups had similar age, sex, presence of diabetes, smoking status, body mass index and time to surgery. However, the forward-striking group demonstrated significantly lower rates of postoperative complications, including delayed, nonunion, and the need for re-operation. Conversely, no significant differences were found in time to union (p = 0.222). The forward-striking procedure can significantly reduce residual fracture gaps from 3.99 to 1.66 mm (p < 0.001). No major complications in the forward-striking group including nonunion were observed. CONCLUSION: This study suggests that the forward-striking technique effectively reduces residual fracture gap during femoral nailing. The technique not only could be easily performed but is also reproducible. In addition, it can lower the risk of delayed union, nonunion and obviates the necessity for re-operation. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Medium-Term Outcomes of a Forward-Striking Technique to Reduce Fracture Gaps during Long Cephalomedullary Nailing in Subtrochanteric Femoral Fractures.

INTRODUCTION: A residual fracture gap after intramedullary nailing is a known risk factor for delayed union and non-union. This study aimed to report the outcomes of a forward-striking technique to reduce fracture gaps during long cephalomedullary nailing in subtrochanteric femoral fractures (SFFs). METHODS: A retrospective cohort study was conducted on patients with SFFs treated in a single institution between February 2013 and October 2018. A total of 58 patients treated via long cephalomedullary nailing with a forward-striking technique were included. The width of the fracture gap, location of the cephalic screw, tip-apex distance (TAD), and time to bone union were evaluated using intraoperative and postoperative radiographs. Complication rates, including fixation failure, non-union, implant breakage, and infection, were assessed. The mean follow-up duration was 4 (range, 2‒8) years. RESULTS: Of the 58 patients (mean age, 67.9 years), 38 (65.5%) were female. Thirty-two cases (55.2%) were classified as atypical femoral fractures. The mean fracture gap reduced from 5.1 mm to 1.6 mm by forward striking (P<0.001). The reduced fracture gap was significantly greater in atypical SFFs (mean, 4.9 mm vs. 1.7 mm; P<0.001). The lag screw was located in the center-center or center-inferior zones of the femoral head in 54 patients (93.1%). The mean TAD was 14.2 mm and was under 25 mm in 55 patients (94.8%). Bone union was achieved in all cases without reoperation at a mean of 5.4 months. One incident of lag screw breakage was noted at 5 months, but bone union was achieved at 7 months. CONCLUSIONS: The forward-striking technique with a long cephalomedullary nail demonstrated a 100% bone union rate in a consecutive series of 58 SFFs. This technique is effective in reducing the fracture gap as well as placing the cephalic screw into the optimal position. The forward-striking technique was particularly effective in reducing atypical SFFs with a transverse or short oblique configuration.

A forward-striking technique for reducing fracture gaps during intramedullary nailing: A technical note with clinical results.

INTRODUCTION: A residual postoperative fracture gap between major bone fragments following intramedullary nailing of long-bone fractures is recognised as one of the major risk factors for delayed union and non-union. The most common method for reducing a fracture gap after nail insertion is through application of the backstroke technique. We introduce forward-striking as a new and simple technique that can be used to reduce fracture gaps during cephalomedullary or intramedullary nailing. PATIENTS AND METHODS: The forward-striking technique was used in 20 patients with subtrochanteric or femoral shaft fractures and three patients with tibial shaft fractures who underwent cephalomedullary or intramedullary nailing at two university teaching hospitals between February 2013 and March 2014. RESULTS: Bone union was achieved in all cases, with a mean time of 5.7 months (range, 3-9 months). No major complications, including, non-union, implant failure, or infection, were encountered during the follow-up period. CONCLUSION: A forward-striking technique is simple, convenient, and highly efficient in terms of reducing fracture gaps during cephalomedullary or intramedullary nailing. The advantage of this technique is that it carries no risk of deforming the proximal interlocking screw, prevents excessive protrusion of the nail, and enables the lag screw to be placed into the optimal lag screw position relative to the femoral head at the time of cephalomedullary nailing. The forward-striking technique is particularly useful if no compression screw system is available.