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.
CONCLUSIONS: 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.
METHODS: Level III, retrospective cohort study.

BACKGROUND: Indirect reduction of minimally invasive plate osteosynthesis (MIPO) can often result in delayed union in tibia fractures. This study evaluated several factors in MIPO in relation to bone union.
OBJECTIVE: We hypothesized that the fracture gap, plate - tibia distance, or working length would have a substantial effect on the tibia union rate.
METHODS: Forty-one patients with simple diaphyseal or distal metaphyseal tibia fractures who underwent internal fixation surgery using the MIPO technique were divided into two groups: patients with delayed union and patients without delayed union. Non-actionable factors involving AO/OTA classification, fibula fracture and actionable factors including postoperative fracture gap, plate - tibia distance, working length in relation to parameters of bone union were compared between the two groups. Also cumulative rates of bone union and risk factors of delayed union according to variables of interest were investigated.
RESULTS: AO/OTA classification, site of fibula fracture, postoperative fracture gap, working length, and bone union rate of the two groups significantly differed (p<0.05). The cumulative rate of bone union during 1-year follow-up according to 43A tibia fracture, distal fibula fracture, fracture gap, and working length significantly differed between the two groups (p<0.05). By univariate Cox proportional hazards model, 43A tibia fracture, distal fibula fracture, facture gap, and short working length were risk factors for delayed union (p<0.05).
CONCLUSIONS: Non-actionable factors involving AO/OTA classification, distal fibula fracture and actionable factors including postoperative fracture gap, working length were significant factors affecting bone union after MIPO. The present study indicated that small fracture gap and long working length during MIPO might facilitate bone healing in tibia fracture.
METHODS: IV; single-center retrospective cohort study.

BACKGROUND: The development of fracture gap during intramedullary nailing in tibial fractures is associated with poor fracture fragment contact and increased time to union and complications. This study aimed to evaluate the effect of the fracture level in the development of the fracture gap and the effect of the fracture gap on pain, radiologic and functional outcomes, and complication rate.
METHODS: A total of 45 patients who underwent reamed intramedullary nailing due to closed transverse or short oblique tibial shaft fractures were divided into the proximal fracture group and the distal fracture group. The correlations between the visual analog scale (VAS) score, modified radiograph union score for tibias (RUST), and postoperative 1-year lower extremity functional scale scores, residual fracture gap, and time to union were evaluated.
RESULTS: The mean fracture gap amounts in the immediate postoperative anteroposterior and lateral radiographs were 5.6 ± 1.7 and 6.0 ± 1.7 mm in proximal fractures and 0.3 ± 2.4 mm and 0.4 ± 2.3 mm in distal fractures, respectively (p < 0.001 and p < 0.001, respectively). The mean time to union was 21.9 ± 2.9 weeks in the proximal fracture group and 16.7 ± 2.4 weeks in the distal fracture group (p < 0.000). The residual fracture gap amount significantly correlated with the level of fracture (r = 0.811, p < 0.001).
CONCLUSIONS: Tibial shaft fractures proximal to the isthmus level tend to develop significantly larger fracture gaps than distal fractures. It is associated with increased time to union and radiographic union scores as well as slightly higher complication and reoperation rates.

Cephalomedullary nailing of unstable intertrochanteric fractures has been established as a fruitful surgical approach with relatively limited complications. Anatomic fracture reduction and proper implant positioning are vital to attaining a favorable long-term surgical outcome. Appropriate intraoperative fracture compression augments stability and invigorates healing. The amount of compression permitted by cephalomedullary nails cannot always adequately reduce large fragment gaps. This paper presents a novel technical trick of double compression of the fracture site, in order to achieve the essential extra compression and reduction when required, thus decreasing the risk of postoperative implant cut-out. The technique was used in 14 out of 277 peritrochanteric fractures treated with cephalomedullary nailing in our trauma center for 12 months, with satisfactory outcomes regarding both fracture site union and postoperative functional capacity.

BACKGROUND: Intramedullary nailing (IMN) is considered the gold-standard treatment for femoral shaft fractures. The post operative fracture gap is commonly recognized as a risk factor for nonunion. However, no evaluation standard for measuring the fracture gap size has yet been established. In addition, the clinical implications of the fracture gap size have also not been determined so far. This study aims to clarify how we should evaluate fracture gaps when assessing simple femoral shaft fractures with radiographs and to determine the acceptable cut-off value of the fracture gap size in simple femoral shaft fractures.
METHODS: A retrospective observational study with a consecutive cohort was conducted at the trauma center of a university hospital. We investigated the fracture gap using postoperative radiography and the postoperative bone union of transverse and short oblique femoral shaft fractures fixed by IMN. The receiver operating characteristic curve analysis was conducted to obtain the fracture gap\'s mean, minimum, and maximum cut-off values. Fisher\'s exact test was used at the cut-off value of the most accurate parameter.
RESULTS: In the four nonunions among the 30 cases, the analysis using ROC curves revealed that the maximum value had the highest accuracy among the maximum, minimum, and mean values of fracture-gap size. The cut-off value was determined to be 4.14 mm with high accuracy. Fisher\'s exact test showed that the incidence of nonunion was higher in the group with a maximum fracture gap of 4.14 mm or greater (risk ratio = not applicable, risk difference = 0.57, P = 0.001).
CONCLUSIONS: In simple transverse and short oblique femoral shaft fractures fixed with IMN, the fracture gap on radiographs should be evaluated by the maximum gap in the AP and lateral views. The remaining maximum fracture gap of ≥4.14 mm would be a risk factor for nonunion.

We evaluated the impact of a variable-pitch headless screw\'s angle of insertion relative to the fracture plane on fracture gap closure and reduction.
Variable-pitch, fully threaded headless screws were inserted into polyurethane blocks of \"normal\" bone model density using a custom jig. Separate trials were completed with a 28-mm screw placed perpendicular and oblique/longitudinal to varying fracture planes (0°, 15°, 30°, 45°, and 60°). Fluoroscopic images were taken after each turn during screw insertion and analyzed. Initial screw push-off, residual fracture gap at optimal fracture gap reduction, and malreduction were determined in each trial. Statistical analysis was performed via a 1-way analysis of variance followed by Student t tests.
Malreduction was found to be significantly different between the perpendicular (1.88 mm ± 1.38) and the oblique/longitudinal (0.58 mm ± 0.23) screws. The malreduction increased for the perpendicular screw as the fracture angle increased (60° > 45°=30° > 15° > 0°). Residual fracture gap at optimal fracture gap reduction was also found to be significantly different between the perpendicular (0.97 ± 0.42) and oblique/longitudinal (1.43 ± 1.14) screws. The residual fracture gap increased for the oblique/longitudinal screw as the fracture angle increased, although the oblique/longitudinal screw with a 60° fracture angle was the only configuration significantly larger than all the other configurations. Screw push-off was not found to be significantly different between the oblique/longitudinal screw and perpendicular screw trials.
The perpendicular screw had a larger malreduction that increased with fracture angle, whereas the oblique/longitudinal screw had a larger residual fracture gap that increased with fracture angle.

The treatment of posterior malleolar fractures is a popular issue. Anatomic reduction of posterior malleolar fractures is critical for re-establishing the stability of the ankle mortise and ligamentous union after trauma. Inappropriate treatment ultimately leads to poorer functional outcomes and lower quality of life. Open reduction and internal fixation through a posterolateral approach are preferred over indirect reduction and anterior-posterior screw fixation. Although the posterolateral approach, which is more common and direct, provides good exposure to the fracture site, it has some limitations. In this report, we describe the posterolateral approach through the lateral ankle fracture gap for the treatment of posterior ankle fractures. Moreover, we discuss the indications, benefits, and limitations of this approach.

OBJECTIVE: This study aimed to estimate the risk factors for distal phalangeal nonunion in cases involving Kirchner wire fixation after successful fingertip replantation.
METHODS: This study retrospectively analyzed 116 digits of 111 patients, including 74 and 42 digits with replantation in Tamai zones I and II, respectively. Univariate and multivariable analyses were performed to assess the influences of 15 independent variables on nonunion, including age, sex, medical history of diabetes mellitus, history of smoking, injured hand and digit, injury type (clean, blunt, and crush-avulsion), amputation type (complete or incomplete), length of the distal bone fragment (mm), fracture type (simple or comminuted), presence of a bone defect, length of the fracture gap after fixation (mm), number of Kirchner wires used, evidence of venous repair, and the occurrence of pin tract infections after fixation.
RESULTS: At 12 months after replantation, 100 digits showed bony union and 16 (13.8%) digits showed radiographic nonunion or equivalent complications, including 9 digits with asymptomatic nonunion without a secondary operation, 5 that underwent an additional operation for nonunion or a complication, and 2 with distal bone resorption. A multivariable analysis indicated that the postfixation fracture gap was the only significant predictor influencing nonunion (odds ratio, 3.30; 95% confidence interval, 1.92-5.68).
CONCLUSIONS: The extent of the postfixation fracture gap had the greatest influence on preventing distal phalangeal nonunion, indicating the importance of reducing the fracture gap in primary fixation as much as possible.
METHODS: Prognostic IV.

We appreciate the interest by Drs. Hagiyama and coauthors in our work entitled \"Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures\". They discussed several pertinent points and it is our pleasure to respond their concerns in order. Firstly, we agree that calcar fracture gap and anteromedial cortical support are different concepts, though both of them were used to evaluate the displacement of fracture reduction quality. Secondly, our primary outcome parameter was the threshold distance of calcar fracture gapping in anteroposterior and lateral fluoroscopies, which was calculated based on sensitivity and specificity by receiver operating characteristic curves. Thirdly, we took immediate post-operative fluoroscopic images in 3 views to describe the initial reduction quality as baseline to compare and calculate the changes with three-dimensional computed tomography, which was taken about one week after operation for confirming secondary stability after head-neck sliding and impaction. Lastly, the parameters selected in multivariable analysis. Future work with better study-design is needed to improve the prediction of patient outcomes.

A recently published article by Song H et al. investigated the risk factors for anteromedial cortical support loss in pertrochanteric fractures treated with cephalomedullary nails. In this Correspondence, we would like to raise some concerns. Specifically, calcar fracture gap and anteromedial cortical support are different concepts in evaluating reduction quality. In addition, calcar fracture gap using immediate postoperative radiographic images has measurement bias. Lastly, explanatory variables selected for multivariable analysis are inappropriate. We would like to discuss and suggest solutions for these problems.