The risk factors of nonunion after intramedullary nailing fixation of femur shaft fracture in middle age patients

Analysis of risk factors and development of a nomogram-based prediction model for defective bony non-union

Objective

To explore risk factors for defective non-union of bone and develop a nomogram-based prediction model for such an outcome.

Methods

This retrospective study analysed the case data of patients with defective bony non-unions who were treated at the authors' hospital between January 2010 and December 2020. Patients were divided into the union and non-union groups according to their Radiographic Union Score for Tibia scores 1 year after surgery. Univariate analysis was performed to assess factors related to demographic characteristics, laboratory investigations, surgery, and trauma in both groups. Subsequently, statistically significant factors were included in the multivariate logistic regression analysis to identify independent risk factors. A nomogram-based prediction model was established using statistically significant variables in the multivariate analysis. The accuracy and stability of the model were evaluated using receiver operating characteristic (ROC) and calibration curves. The clinical applicability of the nomogram model was evaluated using decision curve analysis.

Results

In total, 204 patients (171 male, 33 female; mean [±SD] age, 39.75 ± 13.00 years) were included. The mean body mass index was 22.95 ± 3.64 kg/m2. Among the included patients, 29 were smokers, 18 were alcohol drinkers, and 21 had a previous comorbid systemic disease (PCSD). Univariate analysis revealed that age, occupation, PCSD, smoking, drinking, interleukin-6, C-reactive protein (CRP), procalcitonin, alkaline phosphatase, glucose, and uric acid levels; blood calcium ion concentration; and bone defect size (BDS) were correlated with defective bone union (all P < 0.05). Multivariate logistic regression analysis revealed that PCSD, smoking, interleukin-6, CRP, and glucose levels; and BDS were associated with defective bone union (all P < 0.05), and the variables in the multivariate analysis were included in the nomogram-based prediction model. The value of the area under the ROC curve for the predictive model for bone defects was 0.95.

Conclusion

PCSD, smoking, interleukin-6, CRP, and glucose levels; and BDS were independent risk factors for defective bony non-union, and the incidence of such non-union was predicted using the nomogram. These findings are important for clinical interventions and decision-making.

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.

Effect of postoperative fracture gap on bone union: A retrospective cohort analysis of simple femoral shaft fractures

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.

METHOD

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).

CONCLUSION

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.

Effect of concomitant deformity correction on patient outcomes following femoral (OTA type 32) nonunion repair

INTRODUCTION

The purpose of this study was to determine what effect, if any, concomitant deformity correction has on outcomes following femoral nonunion repair.

METHODS

605 consecutive patients who presented to our center with a long bone nonunion treated by one of 3 surgeons was queried. Sixty-two patients (10 %) with complete follow up were treated for a fracture nonunion following a Type 32 femur fracture (subtrochanteric, femoral shaft or distal third metaphysis) over an 11-year period. Twenty of these patients underwent a deformity correction (DC)-angular, rotational, or a combination of both-as part of their femoral reconstruction. Patient demographics and initial injury information was reviewed and compared. Outcomes including radiographic healing, time to union, postoperative complications, patient reported pain scores, and functional outcome scores using the Short Musculoskeletal Functional Assessment (SMFA) were recorded. Patients with and without deformity correction were analyzed and compared using independent T-tests and Chi-Square tests.

RESULTS

Compared to the non-deformity correction (NDC) cohort, the DC cohort demonstrated a worse complication profile. Notably, the DC cohort had longer time to union (11.6 ± 7.3 months vs 7.6 ± 8.5 months, P = 0.042), reported significantly higher VAS pain scores at 1-year post-op (4.2 ± 2.8 vs 2.3 ± 2.6, P = 0.007), experienced more complications (25 % vs 4.8 %, P = 0.019), and had a higher rate of secondary procedures (30 % vs 4.8 %, P = 0.006). The DC patients reported less improvement in functional capability as displayed by a smaller average improvement in initial and final SMFA scores (P = 0.042) There was no difference in ultimate bone healing (P = 0.585), baseline SMFA (P = 0.294), and latest SMFA (P = 0.066).

CONCLUSION

Deformity correction, if needed as part of femoral nonunion repair, is associated with an increased time to heal, greater rate of complications and diminished improvement of functionality. Eventual healing and patient reported outcomes were similar whether a deformity correction is necessary or not.

LEVEL OF EVIDENCE

III.

Intramedullary Fixation for Pediatric Femoral Nonunion in Low- and Middle-Income Countries

BACKGROUND

Pediatric femoral shaft nonunion after use of a plate or intramedullary nail (IMN) is uncommon in the United States. In low and middle-income countries, as defined by The World Bank, these complications may occur with greater frequency. We assessed the rates of union and painless weight-bearing after IMN fixation of pediatric femoral shaft nonunion in lower-resource settings.

METHODS

We queried the SIGN (Surgical Implant Generation Network) Fracture Care International online database to identify all pediatric femoral shaft nonunions that had occurred since 2003 and had ≥3 months of follow-up after their treatment; our query identified 85 fractures in 83 patients. We defined nonunion as failure of initial instrumentation >90 days following its placement, lack of radiographic progression on radiographs made >3 months apart, or the absence of signs of radiographic healing >6 months after initial instrumentation. We evaluated the most recent follow-up radiograph to determine a Radiographic Union Scale in Tibial fractures (RUST) score. We also recorded rates of painless full weight-bearing as assessed by the treating surgeon.

RESULTS

Fifty-seven patients with pediatric femoral shaft nonunions (including 42 male and 15 female patients from 18 countries) were included. The average age (and standard deviation) at the time of revision surgery was 13.8 ± 3.0 years (range, 6 to 17 years). The median duration of follow-up was 67 weeks (range, 13 weeks to 7.7 years). The initial instrumentation that went on to implant failure included plate constructs (56%), non-SIGN IMNs (40%), and SIGN IMNs (4%). At the time of the latest follow-up, 52 patients (91%) had a RUST score of ≥10 and 51 (89%) had painless full weight-bearing. No patient had radiographic evidence of femoral head osteonecrosis at the time of complete fracture-healing or the latest follow-up.

CONCLUSIONS

Pediatric femoral shaft nonunion can occur after both plate and IMN fixation in low and middle-income countries. IMN fixation is an effective and safe treatment for these injuries.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Which of the three different intramedullary nail designs is superior in the treatment of femoral shaft fractures?

Aim: The aim of this study a retrospective comparison was the clinical and radiological results results of patients with femoral shaft fracture made oftreated with three different types of intramedullary nail (IMN). Material and Method: The study included 54 patients operated on in our clinic because of femoral shaft fracture. The records were retrospectively examined of 18 patients applied with locked IMN (LIMN), 17 with blade expandable IMN (BEIMN), and 19 with talon distalfix IMN (TDIMN). The groups were compared statistically in respect of age, gender, BMI, affected side, operating time (mins), radiation exposure (number of shots), time to union (weeks), visual analog scale (VAS) score, soft tissue problems associated with implant irritation, amount of shortening (mm), coronal, sagittal and torsional angulation (degrees). Results: The mean VAS score of the TDIMN group was determined to be statistically significantly higher than that of the LIMN and BEIMN groups (p=0.008, p=0.045). The operating times were similar in the BEIN and TDIMN groups (p=0.768) and significantly shorter than in the LIMN group (p

Management of Traumatic Femur Fractures: A Focus on the Time to Intramedullary Nailing and Clinical Outcomes

Background: Femur shaft factures (FSF) are common injuries following high-energy mechanisms mainly involving motor vehicle crashes (MVC). We evaluated the timings of nailing management and analyzed the pattern of fracture union and outcome in a level 1 trauma center. Methods: This was a retrospective observational study of all the admitted trauma patients who sustained femoral fractures between January 2016 and September 2020. Data were analyzed and compared based on time to Intramedullary Nailing (IMN) (<12 h, 12–24 h and >24 h) and outcomes of FSF (union, delayed union and nonunion). Results: A total of 668 eligible patients were included in the study, of which the majority were males (90.9%) with a mean age of 34.5 ± 15.8, and 54% of the injuries were due to MVCs. The chest (35.8%) was the most commonly associated injured body region, followed by the pelvis (25.9%) and spine (25.4%). Most of femur fractures (93.3%) were unilateral, and 84.4% were closed fractures. The complete union of fractures was observed in 76.8% of cases, whereas only 4.2% and 3.3% cases had delayed union and nonunion, respectively, on the clinical follow-up. Patients in the delayed IMN (>24 h) were severely injured, had bilateral femur fracture (p = 0.001) and had higher rate of external fixation, blood transfusion, pulmonary complications and prolonged hospitalization. Non-union proportion was greater in those who had IMN <24 h, whereas a delayed union was greater in IMN done after 24 h (p = 0.5). Those with a nonunion femur fracture were more likely to have bilateral fracture (p = 0.003), frequently had retrograde nailing (p = 0.01), and high-grade femur fracture (AO type C; p = 0.04). Conclusion: This study showed that femur fracture is not uncommon (8.9%), which is manifested with the variety of clinical characteristics, depending on the mechanism, management and outcome in our center. Bilateral fracture, retrograde nailing and AO classification type C were the significant risk factors of non-union in patients with diaphyseal fractures. The timing of IMN has an impact on the fracture union; however, it is not a statistically significant difference. Therefore, the treating physicians should consider the potential risk factors for a better outcome by careful selection of treatment in sub-groups of patients.

Does obesity affect diaphyseal femoral fracture healing treated with intramedullary locking nail?

OBJECTIVES

This study aims to evaluate the effect of obesity on radiological fracture union in diaphyseal femoral fractures (DFFs) treated with intramedullary nailing (IMN).

PATIENTS AND METHODS

Between January 2017 and December 2018, a total of 120 patients (101 males, 19 females; mean age: 35.1±3.0 years; range, 18 to 72 years) treated with IMN for closed DFFs were retrospectively analyzed. Data including age, sex, location, weight, height, comorbidities such as diabetes mellitus, hypertension or kidney injury, date of injury, mechanism of injury, type of femoral fractures (AO classification), date of surgery, duration of surgery, IMN length and diameter used, date of radiological fracture union and complications of surgery such as nonunion, delayed union, and infections were recorded.

RESULTS

Of the patients, 63 had obesity and 57 did not have obesity. There was a statistically significant difference in fracture configuration among patients with obesity; they sustained type B (p=0.001) and type C (p=0.024), the most severe fracture configuration. The nonunion rate was 45%. Obesity had a significant relationship with fracture nonunion with patients with obesity having the highest number of nonunion rates (n=40, 74.1%) compared to those without obesity (n=14, 25.9%) (p=0.001). Fracture union was observed within the first 180 days in 78.9% of patients without obesity, while it developed in the same time interval in only 38.1% of patients with obesity (p=0.001).

CONCLUSION

Fracture union time for the patients with obesity was longer, regardless of the fracture configuration. Obesity strongly affects fracture union time in DFFs treated with an IMN. Obesity should be considered a relative risk in decision-making in the choice of fixation while treating midshaft femoral fractures.

Optimal concentration of mesenchymal stem cells for fracture healing in a rat model with long bone fracture

BACKGROUND

There is still no consensus on which concentration of mesenchymal stem cells (MSCs) to use for promoting fracture healing in a rat model of long bone fracture.

AIM

To assess the optimal concentration of MSCs for promoting fracture healing in a rat model.

METHODS

Wistar rats were divided into four groups according to MSC concentrations: Normal saline (C), 2.5 × 10⁶ (L), 5.0 × 10⁶ (M), and 10.0 × 10⁶ (H) groups. The MSCs were injected directly into the fracture site. The rats were sacrificed at 2 and 6 wk post-fracture. New bone formation [bone volume (BV) and percentage BV (PBV)] was evaluated using micro-computed tomography (CT). Histological analysis was performed to evaluate fracture healing score. The protein expression of factors related to MSC migration [stromal cell-derived factor 1 (SDF-1), transforming growth factor-beta 1 (TGF-β1)] and angiogenesis [vascular endothelial growth factor (VEGF)] was evaluated using western blot analysis. The expression of cytokines associated with osteogenesis [bone morphogenetic protein-2 (BMP-2), TGF-β1 and VEGF] was evaluated using real-time polymerase chain reaction.

RESULTS

Micro-CT showed that BV and PBV was significantly increased in groups M and H compared to that in group C at 6 wk post-fracture (P = 0.040, P = 0.009; P = 0.004, P = 0.001, respectively). Significantly more cartilaginous tissue and immature bone were formed in groups M and H than in group C at 2 and 6 wk post-fracture (P = 0.018, P = 0.010; P = 0.032, P = 0.050, respectively). At 2 wk post-fracture, SDF-1, TGF-β1 and VEGF expression were significantly higher in groups M and H than in group L (P = 0.031, P = 0.014; P < 0.001, P < 0.001; P = 0.025, P < 0.001, respectively). BMP-2 and VEGF expression were significantly higher in groups M and H than in group C at 6 wk post-fracture (P = 0.037, P = 0.038; P = 0.021, P = 0.010). Compared to group L, TGF-β1 expression was significantly higher in groups H (P = 0.016). There were no significant differences in expression levels of chemokines related to MSC migration, angiogenesis and cytokines associated with osteogenesis between M and H groups at 2 and 6 wk post-fracture.

CONCLUSION

The administration of at least 5.0 × 10⁶ MSCs was optimal to promote fracture healing in a rat model of long bone fractures.

Effectiveness and Biomechanical Analysis of the Ortho-Bridge System on Femoral Fracture Healing: A Retrospective Analysis

BACKGROUND

Among the surgical methods for femoral fractures, the Ortho-Bridge System (OBS) appears to heal fractures via an uncommon process. We compared its effectiveness and biomechanical aspects to those of a locking compression plate (LCP) and explained the healing process demonstrated by the OBS.

METHODS

Eleven femoral shaft fracture cases treated with OBS between July 2017 and May 2020 were retrospectively reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits and assessed via the Harris Hip Score and Knee Society Score. We performed biomechanical experiments of OBS. We simulated different fracture conditions and selected appropriate screw holes at the fracture's far and near segments. The OBS module was placed according to the position of LCP's locking hole at both ends of the fracture; then, a static three-point bending test was performed.

RESULTS

All patients had contralateral callus growth with secondary fracture healing. Healing time was 3-5 months with excellent hip and knee function. When the key screw distance was 22-34 mm, the OBS was significantly less stiff than the LCP (P < 0.05). The stiffness of LCP and OBS decreased significantly when the key screw distance was 49-82 mm, with the LCP being slightly stronger (P < 0.05).

CONCLUSIONS

Femoral shaft fracture treatment with OBS demonstrated secondary healing. When the distance between the key screws was 20-40 mm, the elasticity was higher in OBS than in LCP, possibly producing axial micro-motion to stimulate callus formation and promote fracture healing, which differ from the plate's primary healing process.

Localization of VEGF, TGF-β1, BMP-2, and Apoptosis Factors in Hypertrophic Nonunion of Human Tubular Bones

We studied localization of VEGF, TGF-β1, BMP-2, caspase-3, Bcl-2, and TNFα in the callus samples obtained from 5 patients (4 women and 1 man) aged 41-53 years during planned surgery for nonunion and pseudarthrosis of the clavicle (n=1), ulna (n=1), femur (n=1), and tibia (n=2) bones. Two control groups included material of hypertrophied callus (n=3) with consolidated fractures of long bones and samples of intact bones (n=3) obtained by postmortem autopsy of subjects without pathology of the musculoskeletal system. A nonuniform distribution of the studied markers was revealed. Active expression of VEGF was observed in fibroblast-like cells of the fibrous tissue, osteoblasts of the periosteum and osteons. Osteoblasts expressing BMP-2 were localized in the periosteum and the loose connective tissue of the Haversian canals. The number of immunopositive cells expressing TGF-β1 and TNFα in the callus exceeded that in the control and correlated with the expression of caspase-3 in fibroblast-like cells, osteoblasts, chondroblasts, and microvascular endotheliocytes. The results allow considering fracture nonunion as a result of overproduction of cytotoxic and proapoptotic factors in chronic inflammation and dysfunction of the expression of morphogenetic proteins. The morphochemical patterns of the studied markers open up prospects for the development of new methods of pharmacological correction of fracture repair.

The characteristics and influence of iatrogenic fracture comminution following antegrade interlocking nailing for simple femoral shaft fractures, a retrospective cohort study

AIM

The incidence and characteristics of iatrogenic comminution (IC) are unknown, and the influence of IC on fracture union is unclear. This study was aimed to investigate the (1) incidence and characteristics of IC and (2) the outcomes of IC following antegrade interlocking nailing of simple femoral shaft fractures.

METHODS

We retrospectively collected data on patients who experienced simple femoral shaft fractures and underwent antegrade interlocking nailing between February 2009 and December 2016. The incidence and characteristics of IC were examined. According to the presence of IC, patients were divided into two groups: an IC group and a non-IC (NIC) group. Demographic information and nonunion rates were compared between the two groups. Potential risk factors for IC (age, gender, body mass index (BMI), nail fit ratio, reduction technique, and greater trochanter nail entry) were analyzed using univariate and multivariate logistic regression. The aforementioned variables, along with IC occurrence, were also assessed as potential risk factors for nonunion at 12 and 24 months after operation using multivariate logistic regression.

RESULTS

Of the 211 total patients, IC occurred in 20.9% (n = 44) of patients. Most ICs were found at the level of the isthmus, and involved the medial cortex. Compared with the NIC group, higher nonunion rates were observed in the IC group at 12 months (31.8% vs. 12.5%, p = 0.002) and 24 months (18% vs. 6.5%, p = 0.017) after surgery. Age older than 35 years old was related with the occurrence of IC in univariate analysis. Multivariate analysis found no risk factor associated with IC. Open reduction technique, IC occurrence and higher BMI were identified as the risk factors of nonunion at 12 months and 24 months after surgery in multivariate analysis.

CONCLUSION

IC is a non-rare complication in antegrade interlocking nailing of simple femoral shaft fractures and was associated with higher nonunion rate. Age older than 35 years old showed a trend toward increasing risk of iatrogenic fracture comminution. In multivariate analysis, open reduction technique, IC occurrence and higher BMI significantly correlated with fracture nonunion.

LEVEL OF EVIDENCE

Level IV.

Perforation of the Knee Joint Following Antegrade Intramedullary Nailing of a Comminuted Femoral Diaphyseal Fracture: A Case Report

A 63-year-old man with a comminuted spiral femoral shaft fracture was treated with closed reduction and internal fixation with a cephalomedullary nail. Two weeks postoperatively, one of the two static distal interlocking bolts began backing out and was removed. The nail ultimately migrated distally and perforated the knee joint at four months postoperatively. The patient was successfully treated with an exchange nail and percutaneous bone graft to the fracture site.

A single static distal interlocking bolt may be inadequate to maintain length in a healing comminuted spiral femur shaft. Multiple distal interlocking bolts should be in place until the completion of fracture healing.

Risk Factors for Development of a Recalcitrant Femoral Nonunion: A Single Surgeon Experience in 122 Patients

OBJECTIVES

The goals of the study were (1) to document the healing rates of femoral nonunions stratified by those that healed as intended, healed after a subsequent intervention, and those that did not heal; (2) to report the prevalence of recalcitrant femoral nonunions and (3) to identify specific demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

DESIGN

Longitudinal observational cohort study.

SETTING

Academic Level 1 trauma center.

PATIENTS/PARTICIPANTS

One hundred twenty-two femoral nonunions treated with either a plate or intramedullary nail by a single surgeon between 1991 and 2018.

INTERVENTION

Bivariate and multivariate regression analysis were performed to identify specific demographic, injury, and treatment factors in patients who developed a recalcitrant nonunion.

RESULTS

Although 83.6% of the femoral nonunions eventually healed, only 66% "healed as intended" with 17.2% requiring 1 or more additional procedures to consolidate and 16.4% of nonunions failing to unite. There were no statistically significant differences in the recalcitrance rate when we compared treatment with conventional versus locked plates or primary versus exchange nailing. Risk factors for developing a recalcitrant nonunion were deep infection, current smokers, metabolic bone disease, and patients who had undergone 3 or more prior surgical procedures.

CONCLUSIONS

The use of both intramedullary nails and modern plates were associated with a high rate of recalcitrance. Infection, current smokers, metabolic bone disease, and 3 or more prior surgical procedures were predictors for the development of a recalcitrant nonunion.

LEVEL OF EVIDENCE

Therapeutic Leve IV. See Instructions for Authors for a complete description of levels of evidence.

Antegrade nailing in femoral shaft fracture patients - comparison of outcomes of isolated fractures, multiple fractures and severely injured patients

INTRODUCTION

Femoral shaft fractures in adults are high-energy fractures typically accompanied by additional fractures of the upper and lower extremities and brain, thoracic, or abdominal injuries. Intramedullary nailing enables early ambulation with a few complications, but rates of non-union remain high. Therefore, we aimed to compare bone union after femoral shaft fractures in adults (20-65 years old) depending on the injury severity and presence of multiple fractures.

PATIENTS AND METHODS

This study retrospectively examined 178 patients (145 male and 33 female) who underwent intramedullary nailing for a femoral shaft fracture (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association 32 type) between January 2014 and December 2018 and were followed up for at least 1 year. Patients who underwent intramedullary nailing after the preliminary application of an external fixator were excluded. Patients were divided into groups with isolated femoral shaft fractures (IS group), an injury severity score of ≤14, and multiple fractures of the extremities and the pelvic bone (at least three locations), including a femoral shaft fracture (MU group), and severely injured (injury severity score ≥15) with femoral shaft fractures (SE group). Non-union rate by group and risk factors related to bone union and bone union rate according to time to full weight bearing were analyzed.

RESULTS

In total, 29, 54, and 95 patients were assigned to the IS group, MU group, and SE group, respectively. Non-union was observed in two patients in the IS group (6.9%), six patients in the MU group (11.1%), and 11 patients in the SE group (11.6%). There were no significant differences in the bone union rate, according to multiple fractures (p=0.515) and injury severity score (p=0.561). Additionally, no differences in the bone union rate were observed according to the time to full weight bearing. Depending on open fracture (p=0.004) and fracture severity (p=0.011), the non-union rate showed a difference of up to four times or greater.

CONCLUSIONS

When intramedullary nailing is performed to treat femoral shaft fractures, multiple fractures and severe trauma do not directly affect bone union. However, it should be noted that open fracture and greater fracture severity lead to higher chances of non-union.

The flipped third fragment in femoral shaft fractures: A reason for open reduction?

OBJECTIVES

First introduced by Kuntscher in the 1940s, closed intramedullary nailing of femoral shaft fractures has become the standard of care, with reported union rates up to 99% in some series. However, fractures with large intercalary segments, which are present in 10-34% of femoral shaft fractures, present unique challenges. In particular, how to treat flipped intercalary segments has remained controversial, with some advocating open reduction of these fractures. The purpose of this study was to evaluate the union rates of femoral shaft fractures with flipped intercalary segments treated with closed reduction and intramedullary nail fixation.

METHODS

A retrospective review of patients with femoral shaft fractures and flipped intercalary segments from January 2000 until January 2018 was performed at a single academic level one tertiary care referral center. All patients between the ages of 16-80 with minimum 6-month follow-up were included. Union rates were evaluated using the radiographic union score of the femur (RUSF). Patients with non-diaphyseal femur fractures, pathologic fractures, incomplete radiographic or clinical follow-up, or open reduction at the time of initial surgery were excluded.

RESULTS

Twenty-six patients (18 male and 8 female) with a mean age of 32 years (SD 12.8, range 19-65 years) and mean follow-up of 15.9 months (range, 6-82 months) met inclusion criteria. Seven patients had open fractures. The mean size of the flipped intercalary segments was 71.3 mm (range: 30-174 mm), with mean displacement of 6.6 mm (range: 1-37 mm). The mean radiographic union scale in femoral (RUSF) at 6 months was 9 (standard deviation: 1.35). There were two patients who went on to non-union. The overall union rate was 92% (24 patients); the non-union rate was 8% (2 patients).

CONCLUSIONS

Though uncommon, femoral shaft fractures with flipped intercalary segments present unique challenges to surgical treatment. While previous studies have found the presence of large intercalary segments to be associated with higher rates of non-union, the results of this study challenge prior evidence. In conclusion, the presence of flipped intercalary segments may not require different surgical management than the treatment of conventional femoral shaft fractures.

LEVEL OF EVIDENCE

IV.