In-vitro external fixation pin-site model proof of concept: A novel approach to studying wound healing in transcutaneous implants.

External fixation is an essential surgical technique for treating trauma, limb lengthening and deformity correction, however infection is common, with infection rates ranging from 4.5 to 100% of cases. Throughout the literature researchers and clinicians have highlighted a relationship between excessive movement of the pin and skin and an increase in the patient's risk of infection, however, currently no studies have addressed this role of pin-movement on pin-site wounds. This preliminary study describes a novel in vitro pin-site model, developed using a full-thickness human skin equivalent (HSE) model in conjunction with a bespoke mechanical system which simulates pin-movement. The effect of pin-movement on the wound healing response of the skin equivalents was assessed by measuring the expression of pro-inflammatory cytokines. Six human skin equivalent models were divided into three test groups: no pin as the control, static pin-site wound and dynamic pin-site wound (n = 3). On day 3 concentrations of IL-1α and IL-8 showed a significant increase compared to the control when a static fixation pin was implanted into the skin equivalent (p < 0.05) and (p < 0.005) respectively. Levels of IL-1α and IL-8 increased further in the dynamic sample compared to the static sample (p < 0.05) and (p < 0.0005). This study demonstrates for the first time the application of HSE model to study external-fixation pin-movement in vitro. The results of this study demonstrated pin-movement has a negative effect on soft-tissue wound-healing, supporting the anecdotal evidence reported in the literature, however further analysis of wound heading would be required to verify this hypothesis.

[Research on Locating Device for the Entry Point of Intramedullary Nail Based on Inertial Navigation].

Objective: To introduce a locating device for the entry point of intramedullary nail based on the inertial navigation technology, which utilizes multi-dimensional angle information to assist in rapid and accurate positioning of the ideal direction of femoral anterograde intramedullary nails' entry point, and to verify its clinical value through clinical tests. Methods: After matching the locating module with the developing board, which are the two components of the locating device, they were placed on the skin surface of the proximal femur of the affected side. Anteroposterior fluoroscopy was performed. The developing angle corresponding to the ideal direction of entry point was selected based on the X-ray image, and then the yaw angle of the locating module was reset to zero. After resetting, the locating module was combined with the surgical instrument to guide the insertion angle of the guide wire. The ideal direction of entry point was accurately located based on the angle guidance. By setting up an experimental group and a control group for clinical surgical operations, the number of guide wire insertion times, surgical time, fluoroscopy frequency, and intraoperative blood loss with or without the locating device was recorded. Results: Compared to the control group, the experimental group showed significant improvement in the number of guide wire insertion times, surgical time, fluoroscopy frequency, and intraoperative blood loss, with a statistically significant difference (P<0.01). Conclusion: The locating device can assist doctors in quickly locating the entry point of intramedullary nail, effectively reducing the fluoroscopy frequency and surgical time by improving the success rate of the guide wire insertion with one shot, improving surgical efficiency, and possessing certain clinical value.

[Influence of anterior fracture line on anterior cortical reduction loss after cephalomedullary nail fixation in intertrochanteric fractures].

Objective: To investigate the position of the anterior fracture line in AO/Orthopaedic Trauma Association (AO/OTA) type A2 unstable intertrochanteric fractures and its impact on the incidence of anterior cortical reduction loss after cephalomedullary nail fixation. Methods: A clinical data of 95 patients with intertrochanteric fractures who met the selection criteria between April 2020 and February 2023 was retrospectively analyzed. All patients were treated with cephalomedullary nail fixation, and the intra- and post-operative imaging data were complete. Among them, there were 37 males and 58 females. The age ranged from 61 to 97 years, with an average of 79.6 years. The time from injury to operation ranged from 7 hours to 11 days, with an average of 2.8 days. According to the 2018-AO/OTA classification standard, there were 39 cases of type 31-A2.2 and 56 cases of type 31-A2.3. Intraoperative fluoroscopy was used to record the number of patients with satisfactory fracture alignment. The preoperative CT data were imported into Mimics17.0 software to simulate the fracture reduction and measure the distance between the anterior fracture line and the intertrochanteric line bony ridge. The fractures were classified as transcapsular fractures, extra-capsular fractures, and intra-capsular fractures according to the distance. CT three-dimensional reconstruction was performed within 2 weeks after operation to observe the number of patients with anterior cortical reduction loss. The postoperative anterior cortical reduction loss incidence in patients with satisfactory fracture alignment, and the relationship between postoperative anterior cortical reduction loss and the position of the anterior fracture line were observed. Results: There were 52 cases (54.7%) of transcapsular fractures, 24 cases (25.3%) of extra-capsular fractures, and 19 cases (20.0%) of intra-capsular fractures. Among them, 41 of the 52 transcapsular fractures had satisfactory fracture alignment, and 4 (9.8%) of them experienced anterior cortical reduction loss after operation; 19 of the 24 extra-capsular fractures had satisfactory fracture alignment, and no anterior cortical reduction loss occurred; 16 of the 19 intra-capsular fractures had satisfactory fracture alignment, and 7 (43.8%) of them experienced anterior cortical reduction loss after operation. There was a significant difference in the incidence of anterior cortical reduction loss between groups ( χ 2=8.538， P=0.003). All patients were followed up 3-26 months (mean, 9 months). Among them, 91 cases had fracture healing, and 4 cases had nonunion. Conclusion: In AO/OTA type A2 unstable intertrochanteric fractures, where the anterior fracture line is located within the joint capsule, there is a high risk of anterior cortical reduction loss after operation.

[Treatment of irreducible intertrochanteric femoral fracture in elderly by folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy].

Objective: To explore the effectiveness of irreducible intertrochanteric femoral fracture in the elderly by treating with folding top technique and right-angle pliers prying and pulling under G-arm X-ray fluoroscopy. Methods: The clinical data of 74 elderly patients with irreducible intertrochanteric femoral fracture admitted between February 2016 and December 2022 and met the selection criteria were retrospectively analyzed. Among them, 38 cases were treated with folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy and intramedullary nailing fixation (study group), and 36 cases were treated with limited open reduction combined with other reduction methods and intramedullary nailing fixation (control group). There was no significant difference in baseline data between the two groups, such as age, gender, cause of injury, affected side and classification of fractures, complicated medical diseases, and time from injury to operation ( P>0.05). The operation time, intraoperative blood loss, hospital stay, fracture reduction time, fracture healing time, and complications of the two groups were recorded and compared. The quality of fracture reduction was evaluated by Baumgaertner et al. and Chang et al. fracture reduction standards. Results: Patients in both groups were followed up 10-14 months, with an average of 12 months. The operation time and intraoperative blood loss in the study group were significantly less than those in the control group ( P<0.05), there was no significant difference in hospital stay between the two groups ( P>0.05). At 2 days after operation, according to the fracture reduction standards of Baumgaertner et al. and CHANG Shimin et al., the quality of fracture reduction in the study group was better than that in the control group, and the fracture reduction time in the study group was shorter than that in the control group, with significant differences ( P<0.05). After operation, the fractures of the two groups all healed, and there was no significant difference in healing time between the two groups ( P>0.05). During the follow-up, there was no complication such as incision infection, internal fixation failure, deep venous thrombosis of lower limbs, intramedullary nail breakage, spiral blade cutting, or hip varus in the two groups, except for 2 cases of coxa vara in the control group. Conclusion: For the irreducible intertrochanteric femoral fracture, using folding top technique combined with right-angle pliers prying and pulling under G-arm X-ray fluoroscopy can obviously shorten the operation time, reduce the intraoperative blood loss, and improve the quality of fracture reduction.

Treatment of Length-Unstable Pediatric Femur Fractures in Children Aged 5 to 11 years: A Focused Review.

Pediatric femur fractures in children aged 5 to 11 years are typically classified as length-stable versus length-unstable. For length-stable fracture patterns, there is frequent consensus among pediatric orthopaedic specialists regarding the appropriateness of flexible intramedullary nails, submuscular plates (SMP), or lateral-entry rigid intramedullary nails (LE-RIMN). With length-unstable fracture patterns, however, the decision is more complex. Age, weight, fracture pattern, fracture location, surgical technique, surgeon experience, several implant-specific details, and additional factors are all important when choosing between flexible intramedullary nail, SMP, and LE-RIMN. These familiar methods of fixation may all be supported by conflicting and sometimes heterogeneous data. When planning to treat length-unstable fractures in young children, surgeons should understand evidence-based details associated with each implant and how each patient-specific scenario affects perioperative decisions.

Comparison of the clinical outcomes between proximal femoral nail anti-rotation with cement enhancement and hemiarthroplasty among elderly osteoporotic patients with intertrochanteric fracture.

BACKGROUND: The proximal femoral nail anti-rotation (PFNA) with cement enhancement enhances the anchorage ability of internal fixation in elderly with osteoporotic intertrochanteric fracture. However, whether it is superior to hemiarthroplasty is still controversial. The present study aimed to determine which treatment has better clinical outcomes among older patients. METHODS: We retrospectively analyzed 102 elderly patients with osteoporosis who developed intertrochanteric fractures and underwent PFNA combined with cement-enhanced internal fixation (n = 52, CE group), and hemiarthroplasty (n = 50, HA group) from September 2012 to October 2018. All the intertrochanteric fractures were classified according to the AO/OTA classification. Additionally, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion rates, postoperative weight-bearing time, hospitalization time, Barthel Index of Activities Daily Living, Harris score of hip function, visual analog (VAS) pain score, and postoperative complications were compared between the two groups. RESULTS: The CE group had significantly shorter operative time, lesser intraoperative blood loss, lower blood transfusion rate, and longer postoperative weight-bearing time than the HA group. The CE group had lower Barthel's Index of Activities of Daily Living, lower Harris' score, and higher VAS scores in the first and third months after surgery than the HA group, but no difference was observed between the two groups from 6 months to 12 months. There was no significant difference in the total post-operative complications between the two groups. CONCLUSION: The use of PFNA combined with a cement-enhanced internal fixation technique led to shorter operative time and lesser intraoperative blood loss and trauma in elderly patients as compared to HA.

Intertrochanteric (Reverse Oblique) Fracture Subclassifications AO/OTA 31-A3 Have No Effect on Outcomes or Postoperative Complications.

Background: Reverse oblique intertrochanteric fractures (ROFs) are unstable extracapsular hip fractures that present a mechanical challenge. These fractures are classified as AO/Orthopaedic Trauma Association (OTA) 31-A3 according to the Trauma Association classification system and can further be subclassified into 3 subtypes based on their specific characteristics. The study aimed to evaluate and compare the radiographic and clinical outcomes of the 3 subtypes of ROFs. Methods: A retrospective study was conducted at a single high-volume, tertiary center, where data were collected from electronic medical records of consecutive patients who underwent surgical fixation of AO/OTA 31-A3 fractures. Patients with less than 1-year follow-up, pathological fractures, and revision surgery were excluded. The subtypes of fractures were classified as 31-A3.1 (simple oblique), 31-A3.2 (simple transverse), and 31-A3.3 (wedge or multi-fragmentary). The operation was done using 4 different fixation methods, and radiological evaluation was performed at routine intervals. Results: The final population consisted of 265 patients (60.8% women) with a mean age of 77.4 years (range, 50-100 years) and the mean follow-up time was 35 months (range, 12-116 months). The incidence of medical complications was similar across the groups. However, there was a trend toward a higher incidence of orthopedic complications and revision rates in the 31-A3.2 group, although this was not statistically significant (p = 0.21 and p = 0.14, respectively). Conclusions: Based on the findings of this study, no significant differences were observed between the groups, indicating that the subclassifications of AO/OTA 31-A3 fractures do not have a significant impact on surgical outcomes or the occurrence of postoperative complications.

Radiographic outcomes and non-union factor analysis in fragmentary segmental femoral shaft fractures (AO/OTA 32C3) treated with reamed antegrade nailing.

This study retrospectively assessed radiographic outcomes and risk factors associated with non-union in femoral shaft fragmentary segmental fractures (AO/OTA 32C3) treated with reamed antegrade intra-medullary nailing. Radiological outcomes, including union and alignment, were evaluated. The risk factors for non-union were investigated, including demographics and treatment-related characteristics, such as the number of interlocking screws, segmentation length, main third fragment length, distance of the main third fragment, width ratio and exposed nail length in one cortex from immediate post-operative radiographs. Multivariate logistic regression was used for statistical analysis. Among 2295 femoral shaft fracture patients from three level-1 trauma centers, 51 met the inclusion criteria. The radiological union was achieved in 37 patients (73%) with a mean union time of 10.7 ± 4.8 months. The acceptable axial alignment was observed in 30 patients (59%). Multiple logistic regression analysis identified only exposed nail length as a significant risk factor for non-union (odds ratio: 1.599, p = 0.003) and the cut-off value was 19.1 mm (sensitivity, 0.786; specificity, 0.811). The study revealed high rates of non-union (27%) and malalignment (41%). Therefore, patients who underwent intramedullary nailing with an exposed nail length greater than 19.1 mm or about twice the nail diameter should be cautioned of the potential non-union.

A probabilistic approach for assessing the mechanical performance of intertrochanteric fracture stabilized with proximal femoral nail antirotation.

Maintaining post-operative mechanical stability is crucial for successfully healing intertrochanteric fractures treated with the Proximal Femoral Nail Antirotation (PFNA) system. This stability is primarily dependent on the bone mineral density (BMD) and strain on the fracture. Current PFNA failure analyses often overlook the uncertainties related to BMD and body weight (BW). Therefore, this study aimed to develop a probabilistic model using finite element modeling and engineering reliability analysis to assess the post-operative performance of PFNA under various physiological loading conditions. The model predictions were validated through a series of experimental test. The results revealed a negative nonlinear relationship between the BMD and compressive strain. Conversely, the BW was positively and linearly correlated with the compressive strain. Importantly, the compressive strain was more sensitive to BW than to BMD when the BMD exceeded 0.6 g/cm3. Potential trabecular bone compression failure is also indicated if BMD is equal to or below 0.15 g/cm3 and BW increases to approximately 2.5 times the normal or higher. This study emphasizes that variations in the BMD significantly affect the probability of failure of a PFNA system. Thus, careful planning of post-operative physical therapy is essential. For patients aged > 50 years restrictions on high-intensity activities are advised, while limiting strenuous movements is recommended for those aged > 65 years.

Clinical efficacy and complications of blocking screw in the treatment of lower limb long bone fracture: An updated systematic review and meta-analysis.

BACKGROUND: Blocking screw technique has been widely applied in the treatment of long shaft fractures. However, the evidence with regard to whether intramedullary nail combined with blocking screw technique has better clinical efficacy over other is not clear. The aim of the study was to explore the clinical efficacy and complications of intramedullary nail combined with blocking screw technique in the treatment of femoral or tibial shaft fractures. METHODS: The PuMed, Embase, OVID, Cochrane library, Web of Science, Wanfang, CNKI and Weipu data were searched for studies of intramedullary nail combined with blocking screw in treatment of femoral or tibial shaft fracture published up to Aug 31 2023. Methodological quality of the trials was assessed, relevant data were extracted, and RevMan 5.3 and Stata 15.0 software were used to perform the meta-analysis of parameters related to the consequences. RESULT: Twenty articles were included, including 1267 patients. Meta-analysis results showed that compared with the non-blocking screw group, the blocking screw group had longer operation time (WMD = 13.24; 95% CI = 5.68-20.79, P = .0006) and more intraoperative fluoroscopy times (WMD = 57.62; 95% CI = 25.82-89.42, P = .0002). However, the postoperative therapeutic response rate was higher (OR = 5.60; 95% CI = 2.10-14.93, P = .0006), postoperative ankle joint function was better (OR = 3.48; 95% CI = 1.20-10.13, P = .02), and fracture healing rate was higher (OR = 3.56; 95% CI = 1.43-8.89, P = .006), fracture healing time was shorter (WMD = -3.59; 95% CI = -4.96 to -2.22, P < .00001), intraoperative blood loss was less (WMD = -54.80; 95% CI = -88.77 to -20.83, P = .002), hospitalization time was shorter (WMD = -1.66; 95% CI = -2.08 to -1.24, P < .00001), and complications were less (OR = 0.38; 95% CI = 0.16-0.89, P = .01). There was no statistical significance in the range of motion of knee joint between the 2 groups (WMD = 10.04; 95% CI = -1.51 to 21.59, P = .09). CONCLUSIONS: Current evidence shows that intramedullary nail combined with blocking screw technique in the treatment of lower limb long bone fracture has the advantages of good clinical efficacy, high fracture healing rate, short fracture healing time, good joint function, less complications and so on, which is worthy of clinical recommendation.

Stable elastic nail application with poller K-wire for Irreducible distal radius metaphyseal-diaphyseal Junction fractures in preadolescents: a new operative technique.

BACKGROUND: Surgical treatment of irreducible distal radius diaphyseal- metaphyseal junction fractures involves difficulties as the fracture remains too proximal for K-wire fixation and too distal for the elastic stable intramedullary nail. Our study aims to present the clinical results of applying an elastic stable intramedullary nail with a poller K-wire to achieve both reduction and stable fixation. PATIENTS AND METHODS: A retrospective analysis was performed on 26 patients who underwent ESIN with a poller K-wire for distal radius diaphyseal-metaphyseal region fracture. Reduction parameters such as residual angulation and alignment were evaluated on postoperative follow-up radiographs. Changes in angular and alignment parameters on follow-up radiographs were recorded. Wrist and forearm functions were evaluated at the last follow-up. RESULT: There were 17 male and nine female patients with an average age of 10.9. The residual angulation in coronal and sagittal planes on immediate postoperative radiographs was 4.0 ± 1.62° and 3.0 ± 1.26°, respectively. The mean translation rate on immediate postoperative radiographs was 6.0 ± 1.98% and 5.0 ± 2.02% in the coronal and sagittal planes, respectively. No change was observed in translation rates in the last follow-ups. The mean angulation in the coronal and sagittal planes measured on 6th-week radiographs was 4.0 ± 1.72°and 3.0 ± 1.16°, respectively. No significant difference was observed in angular changes in the sagittal and coronal planes at the last follow-up (p > 0.05). No tendon injury or neurovascular injury was observed in any of the patients. CONCLUSION: In the surgical treatment of pediatric DRDMJ fractures, applying ESIN with poller K-wire is an effective, safe, and novel method for achieving reduction and stable fixation.

[Clinical observation of different intramedullary fixation methods for the treatment of intertrochanteric fracture].

OBJECTIVE: To explore clinical efficacy of proximal femoral nail anti-rotation(PFNA),InterTan and proximal femoral bionic intramedullary nail (PFBN) in treating femoral intertrochanteric fracture. METHODS: Clinical data of 120 patients with intertrochanteric fracture who were underwent closed reduction intramedullary nail-internal fixation from January 2020 to January 2021 were retrospectively analyzed. According to methods of internal fixation,patients were divided into 3 groups. There were 25 patients in PFBN group,including 16 females and 9 males,aged from 69 to 79 years old with an average of (73.67±5.16) years old. There were 55 patients in PFNA group,including 38 females and 17 males,aged from 68 to 80 years old with an average of (74.23±5.57) years old. There were 40 patients in InterTan group,including 26 females and 14 males,aged from 68 to 79 years old with an average of (73.45±5.34) years old. Operative time,intraoperative blood loss,incision length,hospital stay,weight-bearing time,fracture healing time and complications among 3 groups were compared,and clinical effect was evaluated by Harris score of hip function before operation,1,6 and 12 months after opertaion,respectively. RESULTS: Patients among 3 groups were successfully completed operation and were followed up for more than 12 months. There were no significant difference in hospital stay,operative time,intraoperative blood loss and incision length among 3 groups (P>0.05). Weight bearing time of PFBN group (7.98±1.34) d and InterTan group (8.22±0.46) d were earlier than that of PFNA group (10.27±0.66) d(P<0.01). Fracture healing time of PFBN group (10.14±2.33) weeks and InterTan group (11.87±2.48) weeks were earlier than that of PFNA group (13.68±2.36) weeks (P<0.01). One month after operation,Harris score in PFBN group (70.52±5.34) and InterTan group (69.81±6.17) was higher than that of PFNA group (51.46±5.36),and there was no significant difference between PFBN group and InterTan group (P>0.05). There were no significant difference in Harris scores among 3 groups before operation,6 and 12 months after opertaion(P>0.05). Cases of complication of InterTan group and PFNA group were lower than that of PFNA group (P<0.05). CONCLUSION: PFBN and InterTan for the treatment of intertrochanteric fracture have advantages of faster fracture healing,earlier weight-bearing time and fewer postoperative complications than traditional PFNA,but three operations could achieve higher effective rates without significant difference in long-term results.

Fixation devices made of poly-L-lactide composite for rib reconstruction after thoracotomy.

GRAND FIX mesh-type plates and pins (Gunze, Kyoto, Japan) are thin, bioabsorbable fixation devices made of poly-L-lactide (PLLA) composite. These devices are new, and how best to use them in clinical practice remains to be determined. Thus, we describe our approach to rib fixation after thoracotomy in an aortic surgery using GRAND FIX mesh-type plates and pins. The advantage of our approach is that it is easy to perform, but careful attention should be paid to fix the ribs appropriately.

No difference in clinical and hospital quality outcomes in treatment of reverse obliquity intertrochanteric Hip fractures (AO/OTA 31.A3) based on Cephalomedullary nail length.

INTRODUCTION: The purpose of this study was to evaluate outcomes following reverse obliquity (RO) intertrochanteric hip fractures based on the use of short cephalomedullary nails (CMNs) compared to long CMNs for fixation. METHODS: An IRB-approved prospectively collected hip fracture registry at an urban academic medical center was queried for all AO/OTA 31A3.1-3 reverse obliquity intertrochanteric (RO) fractures. One hundred and seventy patients with age > 55 years old and minimum 6-month follow-up were identified for analysis. Data was collected for patient demographics, injury details, intraoperative radiographic parameters, perioperative physiologic parameters, hospital quality measures, and outcomes including radiographic time to healing, need for reoperation, nonunion, and mortality. Comparative analyses were conducted between cohorts. Additional multivariable binary logistic and linear regression analyses were performed to evaluate for factors independently associated with short and long nail usage. RESULTS: The mean age of the entire cohort was 80.91±10.09 years: 103 patients had a long CMN implanted, and 67 patients had a short CMN implanted. There were no demographic differences or differences in radiographic time to healing, rates of mortality, readmission, nonunion, and need for reoperation. Univariable analysis revealed that short CMN had lower intraoperative blood loss (111.19±83.97 mL vs 176.72±161.45 mL, p = 0.002), decreased need for transfusion (37% vs. 55 %, p = 0.022), and shorter procedures (118.67±57.87 min vs. 148.95±77.83 min, p = 0.002. Multivariable analysis revealed that short nail usage was associated with decreased intraoperative blood loss, decreased need for transfusion, and shorter operative times. CONCLUSION: Nail length does not affect healing or hospital quality outcomes in the treatment of RO hip fractures. The use of short CMNs for these fractures did correlate with lower intraoperative blood loss, operative time, and need for blood transfusion, with non-inferior outcomes and similar hospital quality measures when compared to long CMNs.

Femoral Shaft Fracture Developed Late-Onset Infection in 27 Years after Intramedullary Nailing: A Case Report.

Postoperative late-onset infections more than 1 year after intramedullary nail surgery for femoral shaft fractures are very rare. We show an extremely rare case of developed late-onset infection 27 years after surgery, report on risk factors for late-onset infection, and infer why the infection occurred.

Flexible nailing: Pushing the indications for diametaphyseal lower-extremity fractures.

Elastic stable intramedullary nailing (ESIN) has been shown to be an effective form of surgical management for lower-extremity diametaphyseal fractures in pediatric patients, but studies are limited because ESIN treatment for these fractures is relatively uncommon. We sought to determine whether ESIN can be used effectively in the most distal or proximal short-segment forms of these fractures. We queried the electronic medical record system at Johns Hopkins Hospital using Current Procedural Terminology codes for femur and tibia fractures treated with ESIN in patients under 18 years old between January 2015 and October 2022. Preoperative and postoperative radiographs were subsequently reviewed to identify patients with a proximal or distal third femoral or tibial shaft fracture treated with ESIN and to define criteria for short-segment diametaphyseal fractures. We used Beaty radiological criteria to evaluate radiographic outcomes and Flynn titanium elastic nails (TENs) outcome scale to assess clinical recovery after radiographic evidence of union. There were 43 children who met the inclusion criteria. Among them, 10 patients had short-segment diametaphyseal fractures. There were 22 (51.2%) who sustained femur fractures and 21 (48.8%) who sustained tibia fractures. Using Beaty radiologic criteria, ESIN was associated with more satisfactory outcomes in patients with distal or proximal third shaft fractures (32/33) than in patients with short-segment diametaphyseal fractures (7/10) (P = .03). Using the TENs outcome scale, 21 (63.4%) patients with distal or proximal third shaft fractures had excellent results, 11 (33.3%) had satisfactory results, and 1 (3%) had a poor result. Among patients with short-segment diametaphyseal fractures, 4 (40%) had excellent results, 5 (50%) had satisfactory results, and 1 (10%) had a poor result. There were no differences in TENs outcomes between the groups (P = .24). Patients with short-segment lower-extremity diametaphyseal fractures treated with ESIN had worse radiographic outcomes but did no worse clinically than patients with distal or proximal third shaft fractures. Consequently, ESIN should be considered a safe and effective surgical management option for pediatric patients with even the most distal or proximal forms of these fractures.

Plate augmentation and hybrid bone grafting are effective treatments for atrophic nonunion of the femur with the original intramedullary nail retained in situ.

The purpose of this study is to evaluate the efficacy of plate augmentation and hybrid bone grafting for treating atrophic nonunion of the femur with original intramedullary nail retained in situ.In this study, 36 patients with atrophic nonunion of the femur who underwent surgery using the technique of plate augmentation and a hybrid bone grafting while retaining the original intramedullary nail in situ in Xi'an Honghui Hospital from January 2019 to December 2021 were enrolled. 28 patients who met the inclusion and exclusion criteria were ultimately included in the study. These 28 patients, consisting of 20 males and 8 females with a mean age of 38 years, were evaluated based on factors such as operation time, intraoperative blood loss, the average hospitalization days. Additionally, the results and function of these patients were evaluated by union time, Wu's scores of limb function and incidence of serious complications.All 28 patients achieved bone union at the 12 month follow-up, with an average follow-up time of 14.6 ± 4.2 months.The average operation time was 68.3 ± 11.2 min, and the average intraoperative blood loss was 140 ± 22.6 ml. Patients were hospitalized for an average of 5.8 ± 1.1 days. Full clinical and radiological bone union was achieved on average at 5.1 ± 1.9 months. The mean value of Wu's scores at the 12 month follow-up was significantly higher than before the operation. Limb function was excellent in 27 patients and good in one patient at the 12 month follow-up. However, five patients experienced the lower limb vein thrombosis, including one deep vein thrombosis and four lower limb intermuscular vein thromboses. One patient had a superficial infections of the surgical incision site, while three patients reported pain and numbness where their iliac bone graft was extracted at the 12 month follow-up. The technique of plate augmentation and hybrid bone grafting, combined with retaining the original intramedullary nail in situ has been shown to be a safe, effective, simply and standardizable practice for treating atrophic femoral nonunion with an intact original IMN fixation.

Primary stability in locking plate fixation for proximal humeral fractures may be increased by using an additional nail osteosynthesis in combination with locking plate osteosynthesis-A biomechanical comparison.

BACKGROUND: Stability is regarded as an important factor for proper healing and avoiding secondary dislocation in osteoporotic fractures of the proximal humerus. Several surgical techniques have been proposed for treatment, including intramedullary nail osteosynthesis and locking plate fixation. This study introduces a novel approach that combines both techniques and compares its primary stability with conventional methods. METHODS: The study involved 25 osteoporotic humeri with two-part fracture models, which were randomly assigned to locking-plate fixation, intramedullary nailing, or a combination of both techniques. The specimens were subjected to sinusoidal loading at 250 N in 20° abduction for 5000 cycles and then to quasi-static loading until failure. Fracture movement, failure mode, and failure load were measured and compared among the groups. FINDINGS: The groups fixated with intramedullary nailing and the groups fixated with intramedullary nailing and locking plate fixation showed significantly lower fracture motion than the group using locking plate fixation only (p < 0.005) and significantly higher load to failure (p = 0.007 and p = 0.0062, respectively). There was no significant difference between the group using intramedullary nailing and the group using locking-plate fixation and intramedullary nailing in fracture movement or load-to-failure (p > 0.005). INTERPRETATION: The results indicate that locking plate fixation provides less primary stability than intramedullary nailing or the combined of both techniques. This combined approach may offer advantages as a treatment for complex proximal humeral fractures in osteoporotic bone, and specific implants should be developed to ensure optimal treatment.

[Off target of distal interlocking screw in short cephalomedullary nail fixation for intertrochanteric femur fractures].

Objective: To analyze the causes and treatment of off target of the distal interlocking screws when short cephalomeduallry nails were installed through jig-guided targeting device, and to put forward the technical points to prevent off target. Methods: Retrospective analysis of 9 patients with intertrochanteric fractures treated between July 2014 and June 2023 was conducted, in which off target occurred during the insertion of the distal interlocking screw by jig-guided targeting device in short cephalomedullary nailling (<24 cm). There were 1 male and 8 females, with an average age of 82.7 years (range, 73-94 years). There were 3 cases of type A1, 5 cases of type A2, and 1 case of type A3 according to 2018-AO/Orthopaedic Trauma Association (AO/OTA) fracture classification. As for the misaligned distal interlocking screw, six parameters were collected and analyzed, including the time of finding, the position, the type of passing through the cortical bone, the special circumstances during operation (such as the need to remove the intramedullary nail for reaming the diaphysis, hammering, etc.), the treatment, and the patient follow-up results. Results: In the 9 patients, the off target of the distal interlocking screw was found in 7 cases during operation and in 2 cases after operation; the locking screw was located behind the nail in 7 cases and in front of the nail in 2 cases; the off target locking screw was passing tangentially in transcortical patern in 6 cases and in bicortical pattern through the medullary cavity in 3 cases. Three cases were attributed to the mismatch between the nail and the femur, two of which were attributed to the narrow femoral medullary cavity, one of which was attributed to the large anterolateral femoral bowing, and the other 6 cases were attributed to technical errors such as the loosening of the jig-guided targeting device, the tension of the fascia lata, and the blunt of the drill. In the 7 cases found during operation, the misaligned interlocking screw was removed first and the screw hole was left vacant, then in 2 cases, the interlocking screw was not used further; in 1 case, the distal dynamic hole was successfully inserted with a dynamic guide frame, and in 4 cases, the interlocking screw was successfully put after 2-3 attempts, leaving a large hole in the lateral cortex. No special treatment was performed in 2 cases found after operation. One patient was out of bed early after operation, 7 patients were in bed for 1 month, and 1 patient deteriorated to A3 type after operation and was in bed for 3 months. All the 9 patients were followed up 6-12 months, with an average of 8 months. Fracture healing was achieved in 8 patients. One patient with vacant interlocking screw had a secondary spiral fracture of the femoral shaft 3 months later, and was refixed with a long cephalomedullary nail and circlage wiring. Conclusion: Distal interlocking screw off target is rare, but when it occurs, it leaves a large cortical hole in the osteoporotic femoral shaft, reducing bone strength; the use of precision instruments and attention to technical details can reduce this adverse phenomenon.

[Research progress on distal interlocking screws of cephalomedullary nails in intertrochanteric fractures].

Objective: To summarize the new research progress in distal interlocking screws of cephalomedullary nails for the treatment of intertrochanteric fractures. Methods: Relevant domestic and foreign literature was extensively reviewed to summarize the static/dynamic types of distal interlocking screw holes, biomechanical studies, clinical studies and application principles, effects on toggling in the cavity, and related complications of distal interlocking screws. Results: The mode of the distal interlocking screw holes can be divided into static and dynamic. Distal interlocking screws play the role of anti-rotation, maintaining femur length, resisting compression stress, increasing torque stiffness, resisting varus stress, etc. The number of the screws directly affects the toggling of the main nail in the cavity. At present, regardless of whether long or short nails are used, distal interlocking screws are routinely inserted in clinical practice. However, using distal interlocking screws can significantly increase the duration of anesthesia and operation, increase fluoroscopy exposure time, surgical blood loss, and incision length. There is a trend of trying not to use distal interlocking screws in recent years. No significant difference is found in some studies between the effectiveness of dynamic and static interlocking for AO/Orthopaedic Trauma Association (AO/OTA) 31-A1/2 fractures. At present, the selection of the number and mode of distal interlocking screws is still controversial. When inserting distal interlocking screws, orthopedists should endeavor to minimize the occurrence of complications concerning miss shot, vascular injuries, local stress stimulation, and peri-implant fractures. Conclusion: Distal interlocking screws are mainly used to prevent rotation. For stable fractures with intact lateral walls, long cephalomedullary nails can be used without distal interlocking screws. For any type of intertrochanteric fractures, distal interlocking screws are required when using short cephalomedullary nails for fixation. Different interlocking modes, the number of interlocking screws, and the application prospects of absorbable interlocking screws may be future research directions.