Distal femoral megaprosthesis fracture treated by RescueSleeve MEGASYSTEM-C

Escalating revision surgery after megaprosthesis knee replacement sometimes raises the question of "limb salvage". Here we present a salvage technique for megaprosthesis fracture at the junction between the stem and the metaphyseal component. In this young active patient, the short residual proximal femur was not loose and was difficult to extract without prosthetic escalation. The technique described here conserved the well-fixed primary stem and used a custom-made RescueSleeve MEGASYSTEM-C connection sleeve (Link, Hamburg, Germany) plus spacer and a standard epiphyseal implant. This semi-conservative procedure avoided femorotomy or larger morbid segmental femoral resection. It conserved maximal bone stock and achieved rapid functional recovery. To our knowledge, this is the first reported case of this technique using a custom-made connecting part to manage megaprosthesis fracture. LEVEL OF EVIDENCE: IV.

Management of periprosthetic femoral fractures following total knee arthroplasties using locking plates or intramedullary nailing. Comparative study of 567 cases

INTRODUCTION

Proximal femur fractures in elderly patients pose a common problem that requires surgical management. The main objective of this study was to compare the results of treatment by locked plate (LP) and by anterograde (AIN) or retrograde (RIN) intramedullary nailing. The secondary objective was to analyze the complications related to each group. The hypothesis of this study was that the radiological and clinical results of each group were comparable.

MATERIALS AND METHODS

The data of 438 patients from 8 centers were studied retrospectively with 365 LP and 69 cases of intramedullary nailing (49 AIN and 20 RIN). The groups were comparable in terms of mean age (75±2years), mean preoperative Parker score (5.3±0.5) and mean KOOS score (74±2). Most patients lived at home before their fracture [n=375 (86%)]. At follow-up, the joint range of motion, the KOOS and Parker scores, living premises, the time required to regain full weight-bearing, the time required for consolidation as well as the reduction alignment: frontal, sagittal, horizontal.

RESULTS

The average follow-up was: 79±2weeks (65 to 82). The functional and radiological results were comparable, although nailing allowed a faster return to weight-bearing (1±2weeks for nailing versus 7±2weeks for LP, p=0.048) and a better postoperative Parker score (5.5±0.5 for nailing versus 4.7±0.2 for LP, p=0.045). Rotational malalignment in femoral nailing was often in the direction of internal rotation, compared to the LP (p=0.045). Complications were comparable with the exception of mortality, which was more frequent for LP [22.5% in the LP group versus 13% in the nailing group (p=0.045)]. Complications were categorized as: mechanical complications 6.8% of LP, 5.7% of nailing (p>0.05), infections [11% of LP, 5.8% of nailing (p>0.05)], surgical revisions [2% of LP, 10% of nailing (p>0.05)].

DISCUSSION AND CONCLUSION

The hypothesis was refuted. These results show that nailing conferred a faster recovery of weight-bearing, a better Parker score, and is associated with a lower mortality rate. The morbidity rate is comparable between the two techniques. Indeed, when the indication for osteosynthesis by LP or by nailing is made, and both choices are technically justifiable, it would be prudent to favor the technique, which carries the least risk, which in this case is nailing. This conclusion must, however, be taken in to consideration with regard to the reduced number of nailing. A larger series of nailing, particularly retrograde, would be necessary to be able to confirm this last difference between the 2 groups.

LEVEL OF EVIDENCE

IV; comparative retrospective study.

Deep-Learning Automation of Preoperative Radiographic Parameters Associated With Early Periprosthetic Femur Fracture After Total Hip Arthroplasty

BACKGROUND

The radiographic assessment of bone morphology impacts implant selection and fixation type in total hip arthroplasty (THA) and is important to minimize the risk of periprosthetic femur fracture (PFF). We utilized a deep-learning algorithm to automate femoral radiographic parameters and determined which automated parameters were associated with early PFF.

METHODS

Radiographs from a publicly available database and from patients undergoing primary cementless THA at a high-volume institution (2016 to 2020) were obtained. A U-Net algorithm was trained to segment femoral landmarks for bone morphology parameter automation. Automated parameters were compared against that of a fellowship-trained surgeon and compared in an independent cohort of 100 patients who underwent THA (50 with early PFF and 50 controls matched by femoral component, age, sex, body mass index, and surgical approach).

RESULTS

On the independent cohort, the algorithm generated 1,710 unique measurements for 95 images (5% lesser trochanter identification failure) in 22 minutes. Medullary canal width, femoral cortex width, canal flare index, morphological cortical index, canal bone ratio, and canal calcar ratio had good-to-excellent correlation with surgeon measurements (Pearson's correlation coefficient: 0.76 to 0.96). Canal calcar ratios (0.43 ± 0.08 versus 0.40 ± 0.07) and canal bone ratios (0.39 ± 0.06 versus 0.36 ± 0.06) were higher (P < .05) in the PFF cohort when comparing the automated parameters.

CONCLUSIONS

Deep-learning automated parameters demonstrated differences in patients who had and did not have early PFF after cementless primary THA. This algorithm has the potential to complement and improve patient-specific PFF risk-prediction tools.

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.

Clinical characteristics, densitometric parameters and outcomes of patients with atypical femoral fractures related to bisphosphonate treatment for osteoporosis

PURPOSE

We described the clinical and densitometric characteristics and treatment outcomes of patients who developed atypical femoral fractures (AFF) while on bisphosphonate for osteoporosis.

METHODS

We performed a retrospective cohort study including all adults aged ≥50 years who developed AFF while on bisphosphonates between 1 January 2008 and 31 December 2020, and subsequently managed in the Osteoporosis Centre at Queen Mary Hospital in Hong Kong. A control group of patients who developed fragility hip fractures while on bisphosphonates in the same period was included for comparison. We compared the clinical and densitometric characteristics between the two groups, and described the clinical outcomes for the AFF group.

RESULTS

In total, 75 patients were included (AFF: n = 35; fragility hip fracture: n = 40). All were related to oral bisphosphonates. The AFF group was characterised by a longer duration of bisphosphonate use (median of 5 years), higher bone mineral density (BMD) and more acute neck-shaft angle (all p < 0.05). Following AFF, 8 patients (22.9%) did not receive any subsequent bone-active agents: due to refusal to use an injectable, or BMD out of osteoporotic range. Most of those who received bone-active agents were given teriparatide, followed by raloxifene, and achieved stable BMD. However, subsequent fragility risk remained high. Nonetheless, AFF did not confer excess morbidity and mortality.

CONCLUSION

AFF was characterised by usually long duration of bisphosphonate use, higher BMD and more acute neck-shaft angle. AFF did not confer significant impairment in mobility or mortality. Nonetheless, further research work is necessary to optimise bone health among patients who develop AFF.

Sildenafil delays bone remodeling of fractured femora in aged mice by reducing the number and activity of osteoclasts within the callus tissue

The elderly exhibit a reduced healing capacity after fracture, which is often associated with delayed or failed bone healing. This is due to a plethora of factors, such as an impaired bone vascular system and delayed angiogenesis. The phosphodiesterase-5 (PDE-5) inhibitor sildenafil exerts pro-angiogenic and pro-osteogenic effects. Hence, we herein investigated in aged mice whether sildenafil can improve fracture healing. For this purpose, 40 aged CD-1 mice (16-18 months) were daily treated with 5 mg/kg body weight sildenafil (n = 20) or vehicle (control, n = 20) by oral gavage. The callus tissue of their femora was analyzed at 2 and 5 weeks after fracture by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry as well as Western blotting. These analyses revealed a significantly increased bone volume and higher ratio of callus to femoral bone diameter in sildenafil-treated mice at 5 weeks after fracture when compared to controls. This was associated with a reduced number and activity of osteoclasts at 2 weeks after fracture, most likely caused by an increased expression of osteoprotegerin (OPG). Taken together, these findings indicate that sildenafil does not improve fracture healing in the elderly but delays the process of bone remodeling most likely by reducing the number and activity of osteoclasts within the callus tissue.

Minimally invasive femoral head fracture fixation using three-dimensional navigation: a technical note

Femoral head fractures are rare traumatic injuries that are usually associated with hip dislocations. Open reduction and internal fixation are performed when indicated, but can be associated with a higher risk of avascular necrosis. We report the case of a 24-year-old patient with a Pipkin type II fracture dislocation of the femoral head fixed via a minimally invasive three-dimensional navigated internal fixation technique. This technique minimizes deep soft tissue dissection to the hip capsule and associated vascularity and allows for accurate implant positioning.Level of evidence: Therapeutic case report Level IV.

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.

Development and validation of a novel overhead method for anteroposterior radiographs of fractured rat femurs

We aimed to establish a new method of obtaining femur anteroposterior radiographs from live rats. We used five adult male Sprague-Dawley rats and created a femoral fracture model with an 8 mm segmental fragment. After the surgery, we obtained two femoral anteroposterior radiographs, a novel overhead method, and a traditional craniocaudal view. We obtained the overhead method three times, craniocaudal view once, and anteroposterior radiograph of the isolated femoral bone after euthanasia. We compared the overhead method and craniocaudal view with an isolated femoral anteroposterior view. We used a two-sample t-test and intraclass correlation coefficient (ICC) to estimate the intra-observer reliability. The overhead method had significantly smaller differences than the craniocaudal view for nail length (1.53 ± 1.26 vs. 11.4 ± 3.45, p < 0.001, ICC 0.96) and neck shaft angle (5.82 ± 3.8 vs. 37.8 ± 5.7, p < 0.001, ICC 0.96). No significant differences existed for intertrochanteric length/femoral head diameter (0.23 ± 0.13 vs. 0.23 ± 0.13, p = 0.96, ICC 0.98) or lateral condyle/medial condyle width (0.15 ± 0.16 vs. 0.13 ± 0.08, p = 0.82, ICC 0.99). A fragment displacement was within 0.11 mm (2.4%). The overhead method was closer to the isolated femoral anteroposterior view and had higher reliability.

Efficacy of Minimally Invasive Reduction With Cerclage Fixation in Spiral or Oblique Subtrochanteric Femoral Fractures: A Retrospective Cohort Study Comparing Cables and Wires

OBJECTIVES

To compare the outcomes of a minimally invasive reduction (MIR) technique using a cable and wire in spiral or oblique subtrochanteric femoral fractures (SFFs).

METHODS

DESIGN

Retrospective cohort study.

SETTING

Two University Hospitals.

PATIENT SELECTION CRITERIA

Skeletally mature patients with spiral or oblique SFFs (OTA/AO 32A1 and 32A2) treated with intramedullary nailing and MIR with a cerclage wire passer using either a single-loop cable or cerclage wire or MIR without cable or wire between May 2016 and November 2021 were included.

OUTCOME MEASURES AND COMPARISONS

Coronal and sagittal interfragmentary gap, neck-shaft angle, coronal and sagittal angulation, fracture union, time to union, and Radiographic Union Score for Hip (RUSH) at 6 months post operation were compared.

RESULTS

A total of 46 patients were included, with 16 each in the cable and wire groups and 14 in the non-wiring group. There were no differences in demographics ( P > 0.05), fracture classification ( P = 0.710), or operative data ( P > 0.05) between the three groups. The cable group showed significantly better coronal ( P = 0.003) and sagittal ( P = 0.003) interfragmentary gap, shorter union time ( P < 0.001), and higher 6-month RUSH score ( P < 0.001) among the three groups. There were no significant differences in outcome measures between the wire and non-wiring groups (all P > 0.05). No mechanical complications or reoperations were observed in all three groups.

CONCLUSIONS

Minimally invasive reduction using a cable is more effective than wire or non-wiring reduction to improve reduction quality and promote bone union in the SFFs.

LEVEL OF EVIDENCE

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

Interimplant femoral fracture: analysis of risk factors

Interimplant fractures present a significant challenge for orthopedic surgeons. Despite a noticeable rise in these cases in recent years, our understanding of this specific fracture type remains limited. This study aims to analyze and identify the primary risk factors associated with interimplant femoral fractures. We conducted a retrospective analysis involving 20 patients with interimplant femoral fracture (case group) and 18 patients who had both proximal and distal femoral implants but did not experience interimplant fractures (control group). Our analysis focused on demographic factors (age, sex, BMI) and radiographic parameters (implant types, gap between implants, cortical thickness, femoral canal area) to identify potential risk factors. In the case group, all patients were females, whereas in the control group, 16 patients were female and 2 were males. The mean age in the case group was 88 [Formula: see text] 9 years and in the control group was 87 [Formula: see text] 12 years. None of the demographic differences reached statistical significance. The mean cortical thickness in the case group was 6 [Formula: see text] 2.25 mm, whereas in the control group, it was 9 [Formula: see text] 1.75 mm (p-value < 0.001). The median gap between the proximal and distal tips of the implants measured 194 [Formula: see text] 126 mm in the case group and 66 [Formula: see text] 78 mm in the control group (p-value < 0.001). Additionally, the mean femoral canal area was 284 [Formula: see text] 102 mm2 in the case group and 227 [Formula: see text] 26 mm2 in the control group (p-value < 0.010). Our data indicate that a small cortical thickness, a wide femoral canal area, and having a hip arthroplasty despite a gap between the implants exceeding 110 mm are factors that elevate the risk of interimplant femoral fracture. Notably, osteoporosis therapy emerges as a protective factor against these fractures.

Results of a simple treatment protocol for aseptic femoral shaft nonunion in 330 patients

INTRODUCTION

Our primary aim of the study was to assess the results of a treatment protocol for aseptic femoral shaft nonunion treated by three techniques - Exchange Nailing (EN), Plate Augmentation (PA), and Exchange Nailing combined with Plate augmentation (NP). The secondary objective was to assess the radiological outcome, duration of surgery (DOS) and need for blood transfusion (BT) in all the three groups.

MATERIALS AND METHODS

We analyzed 330 patients treated for AFNU between Jan 2007 and Dec 2019. Using a simple treatment algorithm, EN, PA and NP were performed in 24,183 and 123 patients respectively. Patients in all the three groups were assessed for radiological-union (union rate and time to union), DOS and BT.

RESULTS

Of these 330 patients, 327 (99 %) patients achieved radiological union at a mean duration of 6.07 months. Union rate is highest with NP followed by PA and EN. The union rate in patients with NP, PA and EN were 100 %, 99.5 % and 91.7 % respectively (p < 0.01). Time to union was lowest for NP followed by PA and EN (p < 0.001).The mean time to union for NP, PA and EN were 3.76, 7.2and 9.21 months respectively (p < 0.001). The mean DOS in minutes for NP, EN and PA was 107, 94 and 82 respectively (p < 0.01). The mean need for BT in the form of packed red blood cells for NP, PA and EN were 1.95, 1.87 and 1.38 units respectively (p < 0.01).

CONCLUSION

Following a simple algorithm to decide treatment protocol on a case-to case basis helps to achieve good results in an optimal time period. When compared with EN and PA, NP is associated with 100 % union rate with least time to union making NP a reasonably effective procedure with a very high success rate.

LEVEL OF EVIDENCE

IV.

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.

Biomechanical analysis of combi-hole locking compression plate during fracture healing: A numerical study of screw configuration

Locking compression plates (LCPs) have become a widely used option for treating femur bone fractures. However, the optimal screw configuration with combi-holes remains a subject of debate. The study aims to create a time-dependent finite element (FE) model to assess the impacts of different screw configurations on LCP fixation stiffness and healing efficiency across four healing stages during a complete fracture healing process. To simulate the healing process, we integrated a time-dependent callus formation mechanism into a FE model of the LCP with combi-holes. Three screw configuration parameters, namely working length, screw number, and screw position, were investigated. Increasing the working length negatively affected axial stiffness and healing efficiency (p < 0.001), while screw number or position had no significant impact (p > 0.01). The time-dependent model displayed a moderate correlation with the conventional time-independent model for axial stiffness and healing efficiency (ρ ≥ 0.733, p ≤ 0.025). The highest healing efficiency (95.2%) was observed in screw configuration C125 during the 4-8-week period. The results provide insights into managing fractures using LCPs with combi-holes over an extended duration. Under axial compressive loading conditions, the use of the C125 screw configuration can enhance callus formation during the 4-12-week period for transverse fractures. When employing the C12345 configuration, it becomes crucial to avoid overconstraint during the 4-8-week period.

Immediate weightbearing is safe after revision total hip arthroplasty for Vancouver B2/B3 periprosthetic femur fractures

INTRODUCTION

Modular fluted, tapered stems provide a reliable treatment for Vancouver B2/B3 fractures. Historically, these patients had weightbearing restrictions postoperatively. Although full immediate postoperative weightbearing may provide benefits in this patient population, stem subsidence is a concern.

QUESTIONS/PURPOSES

The objective of this study was to investigate the effect of post-operative weight-bearing status on stem subsidence in patients treated with modular tapered stems for Vancouver B2 and B3 periprosthetic fractures. We sought to answer two questions: (1) Does full immediate postoperative weightbearing after revision total hip arthroplasty for periprosthetic femur fracture lead to increased stem subsidence compared to protected weightbearing? (2) Is there a mortality difference between these two groups of patients with different weightbearing restrictions?

METHODS

From 2009 to 2015 all patients who underwent revision for Vancouver B2/B3 fractures were made non-weightbearing (NWB) for six weeks postoperatively. After 2015, immediate weightbearing as tolerated (WBAT) was allowed postoperatively. We compared stem subsidence between immediate postoperative and final radiographs. Additionally, we performed a Kaplan-Meijer analysis with one-year mortality as an endpoint.

RESULTS

The final cohort included forty-seven patients with an average follow-up of 254 days. The average stem subsidence was 1.0 mm (95 % CI, 0.5-1.5 mm) in the NWB cohort and 0.3 mm (95 % CI, 0-0.7 mm) in the WBAT cohort (P = 0.10). In our survivorship analysis, we noted no deaths in the WBAT cohort compared to 17 % mortality in the NWB cohort at the one-year timepoint.

CONCLUSION

Allowing patients to weight bear immediately after revision does not increase stem subsidence. Further studies are needed to determine whether early weightbearing provides a mortality benefit.

Segmental femoral fracture malunion: evidence and prognostic analysis of medical intervention in the third century BC

We examined the remains of an individual who was unearthed from the Tuchengzi site and was believed to be from the Warring States period in China. The remains exhibited segmental femoral fracture. We aimed to deduce the cause of fracture, medical interventions, healing process, and motion behavior after fracture healing using several techniques, including macroscopic observation, computed tomography (CT), and finite element analysis. Based on the morphology of the long bones, it appeared that the individual was male. The fractures resulted in an adduction angle of 5.47° and an anterior flexion angle of 21.34° in the proximal femur, while the femoral neck anteversion angle had been replaced by a retroversion angle of 10.74°. Additionally, the distal femur formed an abnormal anterior convex angle of 144.60°. CT revealed mature callus formation and visible trabecular bundles. The finite element analysis indicated that the maximum von Mises stress in the femur was 17.44 MPa during standing and 96.46 MPa during walking. We suggest that medical practitioners in the Warring States period possessed a good knowledge of thigh anatomy, enabling them to perform fracture reduction and fixation. Reasonable medical intervention facilitated fracture healing and load recovery. Satisfactory fracture healing ensured that the individual could engage in normal standing and walking activities after rehabilitation.

Comparison of radiological and functional results in osteoporotic distal femur fractures operated with single plating, lateral incision, and double plating, anterior paramedial incision: A retrospective study

Treatment of osteoporotic distal femur fractures is often complicated by a high rate of nonunion and varus collapse. For such fractures, lateral plating with lateral incision and double plating with anterior paramedial incision have shown promising results in the recent literature. The hypothesis of this study was that bilateral plating of comminuted distal femur fractures in osteoporotic patients would result in higher union rates and lower revision rates compared to an isolated lateral locking plate. The study included 56 patients (23 males, 33 females) with supracondylar femur fracture. According to the OA/OTA classification, 9 were type A3, 8 were A2, 13 were C1, 16 were C2, and 10 were C3. The mean follow-up period was 12 months, with 29 patients treated using lateral mini-incision, lateral locking plate, and 27 patients treated with anterior paramedial incision, dual plating. The clinical and radiological results were evaluated. The mean duration of radiological union in the studied population was 15 ± 2.1 months (range, 11-21 months) in the single plate group (Group A), and 13.5 ± 2.6 months (range, 9-19 months) in the double plate group (Group B). Mean ROM was 112.3° and flexion contracture 4° in Group A, and ROM 108.3° and flexion contracture 6.7° in Group B. (P = .15). The average Western Ontario and McMaster Universities Arthritis Index (WOMAC) score was 85.6 points in Group A and 83.5 points in Group B (P = .2278). The postoperative anteversion measurement in the operated extremity ranged from -15 to 19 in Group A, and from 5 to 18 in Group B. When the anteversion degrees were compared between the injured and uninjured extremities in the postoperative period, a significant difference was observed within Group A (P = .0018), but no significant difference was observed in Group B (P = .2492). Dual plate fixation using the anterior paramedial approach is an effective operative method for osteoporotic distal femur fractures. This has many advantages such as precise exposure, easy manipulation, anatomic reduction, and stable fixation. However, for surgical indications and medial bone defects > 1 cm, grafting should be performed.

The effect of screw orientation on internal fixation of Letenneur type II Hoffa fractures: a biomechanics study

BACKGROUND

To investigate the biomechanical effects of screw orientation and fracture block size on the internal fixation system for Letenneur type II Hoffa fractures.

METHODS

The fracture models were randomly divided into six groups according to the fracture subtypes and the direction of nail placement, and a plumb line of the posterior condylar tangent was made across the base of the posterior femoral condyle. The fracture blocks of the three types of fracture were calculated and recorded in the sagittal position, and the biomechanical performance of the six groups was evaluated by biomechanical tests. The axial load on the fracture block at a displacement of 2 mm was set as the failure load, a gradually increasing axial load was applied to each fracture model using a customized indenter at a load of 250-750 N, and the displacements and failure loads of the six groups were recorded at different axial loads.

RESULTS

Biomechanical test results showed that the larger the fracture block, the greater was the stability when nailing from front to back, and the smaller the fracture block, the greater was the strength when nailing from back to front (p < 0.001). As the fracture block became larger, the biomechanical advantage of nailing from posterior to anterior decreased.The displacement under 250 N load were 1.351 ± 0.113 mm, 1.465 ± 0.073 mm for Group IIa AP and Group IIa PA. The displacement under 500 N load were 2.596 ± 0.125 mm, 2.344 ± 0.099 mm for Group IIa AP and Group IIa PA. The displacement under 750 N load were 3.997 ± 0.164, 3.386 ± 0.125 mm for Group IIa AP and Group IIa PA. The failure loads were 384 ± 14 N, 415 ± 19 N for Group IIa AP and Group IIa PA. In the type IIa fracture group, the difference was no longer significant (p > 0.001). Therefore, there is a mechanical threshold that ranges from 38.36 to 52.33% between type IIa and type IIb fractures.

CONCLUSIONS

The effect of the nailing direction on the strength of fixation has a fracture-block critical point, which is consistent overall with the trend that the larger the fracture block is, the greater the stability when nailing from anterior to posterior, and the smaller the fracture block is, the greater the strength when nailing from posterior to anterior.

Biomechanical comparison of distal femoral fracture fixation: Polyaxial vs. uniaxial locking screws with different blocking screw configurations in retrograde femoral nailing

INTRODUCTION

Clinical studies have indicated reduced reliance on blocking screws with the introduction of polyaxial locking nails, yet the biomechanical superiority of polyaxial locking over blocking screws remains unverified, specifically for distal dia-metaphyseal femur fractures.

HYPOTHESIS

We hypothesized that the combination of multiaxial locking using three screws and parallel locking reinforced by two blocking screws would result in superior outcomes compared to utilizing only parallel locking with two screws and one blocking screw.

MATERIALS AND METHODS

Third-generation custom-made femur models representing AO/OTA 32 A1.2 dia-metaphyseal comminuted oblique fractures were divided into four groups (n=10/group). Group A employed distal fixation with three 4.5-mm polyaxial screws. Group B used two parallel locking screws and two blocking screws, Group C used two parallel locking screws and one blocking screw, and Group D used only two parallel screws. Specimens underwent axial and torsional load testing to assess fatigue strength, ultimate strength, axial stiffness (N/mm), torsional stiffness (N/mm/deg), axial load to failure (N), torsional load to failure (N/mm), coronal and sagittal angulations, and fracture site collapse.

RESULTS

Group C exhibited statistically superior torsional stiffness compared to Groups B and D (p=0.039 and p=0.034, respectively). Axial load to failure was highest in Group B and lowest in Group D (p=0.032). Group C demonstrated the highest torsional strength, while Group B exhibited the lowest (p=0.006). Coronal displacement was greatest in Group B, while Group A showed the highest resistance (p=0.009). Group A demonstrated the greatest resistance to fracture site collapse, with the weakest specimens observed in Groups B and C (p=0.01).

DISCUSSION

The performance of a single laterally positioned blocking screw is comparable to using two blocking screws. Medial positioning of a second blocking screw is unnecessary for stability enhancement. Multiaxial locking prevents fracture site collapse and coronal plane angulation more effectively than other methods. Multiaxial locking and/or parallel screws with a single laterally positioned blocking screw provide superior stiffness and stability for treating unstable dia-metaphyseal distal femoral fractures.

LEVEL OF EVIDENCE

N/A.

Plate fixation optimization for distal femoral fractures with segmental bone loss: Defining the preferred screw distribution using finite element analysis

OBJECTIVES

Distal femur fractures can exhibit extensive comminution, and open fractures may result in bone loss. These injuries are under high mechanical demands when stabilized with a lateral locked plate (LLP), and are at risk of non-union or implant failure. This study investigates the optimal LLP screw configuration for distal femur fractures with a large metadiaphyseal gap of 5 cm.

METHODS

A finite element (FE) model, validated against experimentally measured strains and displacement, evaluated pull-out forces and stress concentration on typical implants under clinical conditions corresponding with the 10 % point during the stance phase of the gait cycle.

RESULTS

Maximum stress was up to 83 % less when the ratio (Cp) between the proximal screw-distribution-length and the distance of the first screw to the fracture was less than 0.2; maximum pull-out force was 99 % less when this ratio was higher than 0.4.

CONCLUSIONS

Screw configuration based on either normal or osteopenic bone quality plays an important role in determining the risk of construct failure for a major (50 mm) distal femoral metadiaphyseal segmental defect. This study provides valuable information when planning definitive fixation for distal femur fractures with extensive comminution or segmental bone defects, to mitigate the risk of implant failure and subsequent nonunion.

Is there genetic susceptibility for atypical femoral fractures?

The mechanisms underlying AFF remain unclear, with hypotheses including bone turnover suppression and morphological variation. Recent studies have suggested a potential genetic susceptibility to AFF. A scoping review was conducted using PubMed to identify studies published since 2016. Twenty-one studies were identified, focusing on histological and genetic analysis of AFF patients and Bisphosphonates users. Biopsies and imaging modalities were used to assess histological and morphometric parameters, while genetic sequencing was performed to identify variants in target genes. Genetic studies identified variants in geranylgeranyl diphosphate synthase 1 (GGPS1) and CYP1A1 genes, which play roles in osteoclast function and drug metabolism, respectively. Functional analysis revealed reduced enzymatic activity in mutant variants of these genes, which could be further inhibited by BP use. Other genes, such as ATRAID, ALPL, and COL1A2, were also associated with AFF. Histomorphometric studies supported the hypothesis of bone turnover suppression in AFF, with alterations in tissue mechanical properties and microarchitecture observed, particularly in cortical bone. The findings suggest a potential genetic susceptibility to AFF, with variants in GGPS1 and CYP1A1 genes affecting osteoblast and osteoclast function. Bone turnover suppression and altered tissue properties contribute to the pathogenesis of AFF.

Perioperative periprosthetic femur fracture associated with direct anterior total hip arthroplasty using metaphyseal fit and fill stem

INTRODUCTION

This study aims to identify radiographic and clinical risk factors of perioperative periprosthetic femur fracture associated with the direct anterior approach (DAA) using a metaphyseal fit and fill stem. We hypothesize stem malalignment with this femoral implant places increased stress on the medial calcar region, which leads to an increased risk of periprosthetic fracture.

METHODS

We compared patients with periprosthetic femur fractures following DAA total hip arthroplasty (THA) utilizing the Echo Bi-Metric Microplasty Stem (Zimmer Biomet, Warsaw, IN) to a cohort of patients who did not sustain a periprosthetic fracture from five orthopedic surgeons over four years. Postoperative radiographs were evaluated for stem alignment, neck cut level, Dorr classification, and the presence of radiographic pannus. Univariate and logistic regression analyses were performed. Demographic and categorical variables were also analyzed.

RESULTS

Fourteen hips sustained femur fractures, including nine Vancouver B2 and five AG fractures. Valgus stem malalignment, proud stems, extended offset, and patients with enlarged radiographic pannus reached statistical significance for increased fracture risk. Low femoral neck cut showed a trend toward statistical significance.

CONCLUSION

Patients undergoing DAA THA using a metaphyseal fit and fill stem may be at increased risk of perioperative periprosthetic fracture when the femoral stem sits proudly in valgus malalignment with extended offset and when an enlarged pannus is seen radiographically. This study identifies a specific pattern in the Vancouver B2 fracture cohort with regard to injury mechanism, time of injury, and fracture pattern, which may be attributed to coronal malalignment of the implant.

Characteristics of Femoral Shaft Fractures That Predict Ipsilateral Femoral Neck Fractures

INTRODUCTION

This study aims to characterize radiographic features and fracture characteristics in femoral shaft fractures with associated femoral neck fractures, with the goal of establishing predictive indicators for the presence of ipsilateral femoral neck fractures (IFNFs).

METHODS

A retrospective cohort was collected from the electronic medical record of three level I trauma centers over a 5-year period (2017 to 2022) by current procedural terminology (CPT) codes. Current CPT codes for combined femoral shaft and IFNFs were identified to generate our study group. CPT codes for isolated femur fractures were identified to generate a control group.

RESULTS

One hundred forty patients comprised our IFNF cohort, and 280 comprised the control cohort. On univariate, there were significant differences in mechanism of injury (P < 0.001), Orthopedic Trauma Association (OTA)/Arbeitsgemeinshaft fur Osteosynthesefragen (AO) classification (P = 0.002), and fracture location (P < 0.001) between cohorts. On multivariate, motor vehicle crashes were more commonly associated with IFNFs compared with other mechanism of injuries. OTA/AO 32A fractures were more commonly associated with IFNFs when compared with OTA/AO 32B fractures (adjusted odds ratio = 0.36, P < 0.001). Fractures through the isthmus were significantly more commonly associated with IFNFs than fractures more proximal (adjusted odds ratio = 2.52, P = 0.011).

DISCUSSION

Detecting IFNFs in femoral shaft fractures is challenging. Motor vehicle crashes and motorcycle collisions, OTA/AO type 32A fractures, and isthmus fractures are predictive of IFNFs.

The influence of femoral lytic tumors segmentation on autonomous finite element analysis

BACKGROUND

The validated CT-based autonomous finite element system Simfini (Yosibash et al., 2020) is used in clinical practice to assist orthopedic oncologists in determining the risk of pathological femoral fractures due to metastatic tumors. The finite element models are created automatically from CT-scans, assigning to lytic tumors a relatively low stiffness as if these were a low-density bone tissue because the tumors could not be automatically identified.

METHODS

The newly developed automatic deep learning algorithm which segments lytic tumors in femurs, presented in (Rachmil et al., 2023), was integrated into Simfini. Finite element models of twenty femurs from ten CT-scans of patients with femoral lytic tumors were analyzed three times using: the original methodology without tumor segmentation, manual segmentation of the lytic tumors, and the new automatic segmentation deep learning algorithm to identify lytic tumors. The influence of explicitly incorporating tumors in the autonomous finite element analysis on computed principal strains is quantified. These serve as an indicator of femoral fracture and are therefore of clinical significance.

FINDINGS

Autonomous finite element models with segmented lytic tumors had generally larger strains in regions affected by the tumor. The deep learning and manual segmentation of tumors resulted in similar average principal strains in 19 regions out of the 23 regions within 15 femurs with lytic tumors. A high dice similarity score of the automatic deep learning tumor segmentation did not necessarily correspond to minor differences compared to manual segmentation.

INTERPRETATION

Automatic tumor segmentation by deep learning allows their incorporation into an autonomous finite element system, resulting generally in elevated averaged principal strains that may better predict pathological femoral fractures.

What Is the Likelihood of Union and Frequency of Complications After Parallel Plating and Supplemental Bone Grafting for Resistant Distal Femoral Nonunions?

BACKGROUND

Management of resistant distal femur nonunions is challenging because patients not only have disability from an unhealed fracture, but also often have a shortened femur, stiff knee, deformities, and bone defects to address during revision surgery. Dual plating of the distal femur in such a setting can maintain stability that allows the nonunion to heal while also addressing bone defects and correcting deformities simultaneously. Dual-plating techniques that have been described lack standardization with regard to the size and type of medial-side implants and configuration of the dual-plate construct.

QUESTIONS/PURPOSES

(1) What proportion of patients achieve radiologic evidence of union after parallel plating of resistant distal femoral nonunions? (2) What improvements in function are achieved with this approach, as assessed by improvements in femoral length discrepancy, knee flexion, and patient-reported outcome scores? (3) What complications are associated with the technique?

METHODS

Between 2017 and 2020, the senior author of this study treated 38 patients with resistant distal femoral nonunions, defined here as nonunions that persisted for more than 12 months since the injury despite a minimum of two previous internal fixation procedures. During the study period, our preferred technique for treating aseptic, resistant distal femoral nonunions was to use dual plates in a parallel configuration augmented with autografts. Of 38 patients, three patients with active signs of infection who underwent resection and reconstruction using bone transport techniques and two patients older than 65 years with deficient distal femur bone stock who underwent endoprosthetic reconstruction were excluded. Of the 33 included patients, 67% (22 of 33) were male. The median age was 40 years (range 20 to 67 years). Nonunion was articular and metaphyseal in 13 patients and metaphyseal only in 20 patients. Our surgical approach was to remove existing implants, perform intraoperative culturing to rule out infection, debride the nonunion, correct the deformity, perform intra-articular and extra-articular lysis of adhesions with quadriceps release, and apply fixation using medial and lateral fixed-angle anatomic locked implants positioned in a parallel configuration. Every attempt to improve length was undertaken, and the defects were filled with autografts. A total of 97% of patients were followed until union occurred (one of 33 was lost to follow-up before union was documented), and 79% (26 of 33) were assessed for functional outcomes at a minimum of 2 years (median 38 months [range 25 to 60 months]) after excluding patients lost to follow-up and those in whom union did not occur after parallel plating. Union was defined as evidence of central trabecular bridging on AP radiographs and posterior cortical bridging on lateral radiographs. These radiologic criteria were defined to overcome difficulties in assessing radiologic healing in patients with lateral and medial plates. With parallel plating, bridging trabecular bone along the posterior cortex on lateral radiographs and the central region on AP radiographs is visualized and can be appreciated and interpreted as evidence of healing in two orthogonal planes. Preoperative and follow-up clinical assessment of knee ROM, the extent of femoral length correction based on calibrated femoral radiographs before and after surgery, and the evaluation of improvement in lower limb function based on the preoperative and follow-up differences in responses to the lower extremity functional scale (LEFS) were studied (the LEFS is scored from 0 to 80, with higher scores representing better function). Complications and secondary surgical procedures to address them were abstracted from a longitudinally maintained trauma database.

RESULTS

Sixty-seven percent (22 of 33) of nonunions showed radiologic healing by 24 weeks, and another 24% (eight of 33) healed by 36 weeks. Six percent (two of 33) did not unite, and one patient was lost to follow-up before union was documented. In the 79% (26 of 33) of patients available for final functional outcome assessment, the median femoral shortening had improved from 2.4 cm (range 0 to 4 cm) to 1.1 cm (range 0 to 2.3 cm; p < 0.001), and the median knee ROM had improved from 70° (range 20° to 110°) to 100° (range 50° to 130°; p = 0.002) after surgery. The median LEFS score improved to 63 (range 41 to 78) compared with 22 (range 15 to 33; p < 0.001) before surgery. Serious complications, including major thromboembolic events, iliac graft site infection, knee stiffness (flexion < 60°), and medial plate impingement necessitating removal, were seen in 30% (10 of 33) of patients. Secondary surgical interventions were performed in 24% (eight of 33) of patients to address procedure-related complications.

CONCLUSION

Based on our findings, a high likelihood of union and improvements in knee and lower limb function can be expected with parallel plating of resistant distal femur nonunions using anatomic locked plates. However, the increased frequency of complications observed in our study suggests the need for improvements in dual-plating techniques and to explore possible alternative fixation methods through larger multicenter comparative studies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Intramedullary Nailing of Intertrochanteric Femoral Fractures in a Level I Trauma Center in Finland: What Complications Can be Expected?

BACKGROUND

Intertrochanteric hip fractures are one of the most common fractures in older people, and the number is estimated to increase. These fractures are often treated with intramedullary nailing; however, various complications have been reported. It is important to identify the potential complications and investigate whether the choice of implant and patient-related factors are associated with the risk of complications to develop better strategies for preventing them.

QUESTIONS/PURPOSES

(1) In the treatment of intertrochanteric fractures with intramedullary nailing, what are the risks of major complications and 30-day mortality? (2) Which implant types are associated with greater odds of major complications? (3) Which patient-related factors are associated with increased odds of major complications?

METHODS

In this retrospective, comparative study, we reviewed the health records of 2397 patients with a femoral fracture treated at one Level I trauma center between January 2014 and November 2020. Of those, we considered patients who were treated with intramedullary nailing for an intertrochanteric fracture after sustaining a low-energy injury as potentially eligible. Based on this criterion, 53% (1279) were eligible; a further 47% (1118) were excluded because the fixation method was other than intramedullary nailing, the fracture pattern was other than intertrochanteric fracture, or the fracture was caused by a high-energy injury mechanism. Another 4% (97) were excluded because they had incomplete datasets because of follow-up less than 12 months, leaving 49% (1182) for analysis. During the study period, intramedullary nails were generally used to treat nearly all intertrochanteric fractures at our hospital. The risk of complications was then assessed by chart review. Acute myocardial ischemia, cutout, nail breakage, pulmonary embolism, sepsis, stroke, and wound infection were defined as major complications. Cutout, nail breakage, and wound infection were defined as major complications leading to reoperation. To examine the association of implant type and major complications, a logistic regression analysis was performed. Additionally, the risks of major complications leading to reoperation were compared between implants. Finally, a univariable logistic regression analysis was performed to examine the association between patient-related factors and major complications.

RESULTS

The overall proportion of patients experiencing complications was 16% (183 of 1182), and the crude percentage of 30-day mortality was 9% (107 of 1182) based on the hospital`s medical records. After controlling for patient-related factors such as disease, age, and smoking, we found that nail type was not associated with odds of major complications leading to reoperation (Gamma3: OR 0.86 [95% CI 0.44 to 1.67]; p = 0.67; Trochanteric Fixation Nail: OR 0.61 [95% CI 0.2 to 1.53]; p = 0.33; Proximal Femoral Nail Antirotation: OR 0.55 [95% CI 0.16 to 1.49]; p = 0.29) compared with the Trochanteric Fixation Nail Advanced. Anticoagulation (OR 1.70 [95% CI 1.11 to 2.59]; p = 0.01), congestive heart failure (OR 1.91 [95% CI 1.13 to 3.11]; p = 0.01), and hypertension (OR 1.67 [95% CI 1.08 to 2.63]; p = 0.02) were associated with a major complication. Liver disease (OR 5.19 [95% CI 0.78 to 20.8]; p = 0.04) was associated with a major complication leading to reoperation.

CONCLUSION

This study provides a better understanding of the occurrence of surgical and medical complications after intramedullary nailing of intertrochanteric fractures. The new-generation nail types are comparable options based on the risk of reoperation. Anticoagulation, congestive heart failure, and hypertension were associated with major complications, highlighting the need for careful management and monitoring of these comorbidities during intramedullary nailing procedures.Level of Evidence Level III, therapeutic study.

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.

Pediatric femoral shaft fracture requiring revision surgery for nonunion associated with vitamin D and K deficiencies: a case report

BACKGROUND

Nonunion of femoral shaft fractures in children is rare, and there is no clear treatment protocol. In this case report, a pediatric femoral shaft fracture that developed in nonunion due to vitamin deficiency after osteosynthesis, which was successfully treated with vitamin augmentation and replacement with a rigid antegrade intramedullary nail, is described.

CASE PRESENTATION

The patient is an 11-year-old Japanese girl. She injured her right femoral shaft fracture when she hit a wall after kickboarding down a hill and underwent osteosynthesis with a titanium elastic nail. Six months postoperatively, she developed nonunion, was found to be deficient in vitamins D and K, and was started on vitamin supplementation. She underwent replacement with a rigid antegrade intramedullary nail at 7 months postoperatively, and bone union was achieved 3 months after reoperation.

CONCLUSION

When delayed union of a fracture is observed postoperatively, even in children without underlying disease, the cause of the problem must be investigated and treated promptly.

Cerebral fat emboli in a patient with paraplegia caused by bilateral femur fractures

Cerebral fat embolism is a rare cause of stroke and therefore an overlooked diagnosis. Often it is seen as a consequence of major bone fractures or after arthroplasty, and can lead to respiratory or circulatory collapse. We present a case of a patient with a history of paraplegia after a thoracic spinal cord injury that developed cerebral fat embolism following a bilateral femur fracture. Since the patient was paraplegic and with an altered mental state upon admission, femoral bone fractures were not initially suspected. The case shows the difficulties in diagnosing this condition.

Atypical femur fracture in a male without history of bisphosphonate use: a case report

BACKGROUND

Atypical femur fractures are a rare occurrence, especially in bisphosphonate-naïve men, and merit reporting owing to their unusual presentation and clinical implications. This case report highlights a unique instance of atypical femur fractures in a 73-year-old male with no prior bisphosphonate exposure.

CASE PRESENTATION

The patient, a 73-year-old Indian male with no history of bisphosphonate use, presented with left thigh pain and swelling following a minor fall. Radiographic assessment unveiled a closed left mid diaphyseal femoral shaft fracture. Subsequent imaging revealed an impending fracture in the contralateral femur. A comprehensive diagnostic evaluation, encompassing radiographic analysis, laboratory tests, and clinical assessment confirmed the diagnosis. Surgical management via intramedullary nailing was pursued for both fractures. Notably, the patient's medical history was characterized by radiographic manifestations, the infrequent occurrence of atypical femur fractures in men, and associated risk factors. Treatment encompassed anabolic bone therapy employing teriparatide, alongside discontinuation of antiresorptive agents.

CONCLUSIONS

This case underscores the significance of considering atypical femur fractures in older individuals with limited trauma history. It accentuates the role of anabolic agents in the therapeutic regimen and contributes to the evolving understanding of atypical femur fractures. The report underscores the need for vigilant monitoring and tailored management strategies in similar cases, thereby enhancing clinical practice and patient care.

Bone reconstruction with modified Masquelet technique in open distal femoral fractures: a case series

BACKGROUND

Large bone defects require complex treatment, multidisciplinary resources, and expert input, with surgical procedures ranging from reconstruction and salvage to amputation. The aim of this study was to provide the results of a case series of open comminuted intra-articular distal femoral fractures with significant bone loss that were managed by early fixation using anatomical plates and a modified Masquelet technique with the addition of surgical propylene mesh.

METHODS

This retrospective study included all patients referred to our institution with OTA/AO C3 distal femur open fractures and meta-diaphyseal large bone loss between April 2019 and February 2021. We treated the fractures with irrigation and debridement, acute primary screw and plate fixation in the second look operation, and Masquelet method using shell-shaped antibiotic beads supplemented by propylene surgical mesh to keep the cements in place. The second step of the procedure was conducted six to eight weeks later with bone grafting and mesh augmentation to contain bone grafts. Surprisingly, hard callus formation was observed in all patients at the time of the second stage of Masquelet procedure.

RESULTS

All five patients' articular and meta-diaphyseal fractures with bone loss healed without major complications. The average union time was 159 days. The mean knee range of motion was 5-95 degrees. The average Lower Extremity Functional Score (LEFS) was 49 out of 80.

CONCLUSIONS

Combination of early plate fixation and the modified Masquelet technique with polypropylene mesh is an effective method for managing large bone defects in open intra-articular distal femoral fractures with bone loss, resulting in shorter union time possibly associated with the callus formation process. This technique may also be applicable to the management of other similar fractures specially in low-income and developing areas.

The effects of hydroxychloroquine-induced oxidative stress on fracture healing in an experimental rat model

OBJECTIVES

The purpose of this study was to investigate whether hydroxychloroquine (HCQ) sulfate causes oxidative stress (OS) and its effect on fracture healing in an experimental rat model.

MATERIALS AND METHODS

In this experimental study, open diaphyseal femur fractures were induced in 24 eight-week-old male rats (mean weight: 225±25 g; range, 200 to 250 g) and then fixed with K-wire. The rats were divided into four groups: HCQ-2, control-2 (C-2), HCQ-4, and control-4 (C-4). During the study period, rats in the HCQ groups received an HCQ solution (160 mg/kg/day), whereas rats in the control groups received saline. The HCQ-2 and C-2 groups were sacrificed on the 14th day, and the HCQ-4 and C-4 groups were sacrificed on the 28th day. After sacrifice, malondialdehyde levels induced by OS were calculated for each rat, and fracture healing was evaluated radiographically, histomorphometrically, histopathologically, and immunohistochemically.

RESULTS

Malondialdehyde levels were higher in the HCQ groups than in the control groups (p<0.05). Hydroxychloroquine caused OS in rats. The ratio of total callus diameter to femur bone diameter was lower in HCQ groups compared to control groups (p<0.05). No differences were observed when comparing radiological and histological healing results between the control and HCQ groups. Alkaline phosphatase levels were lower in the HCQ-4 group than the C-4 group at week four (p<0.05), although osteocalcin and osteopontin levels did not differ between groups (p>0.05). Oxidative stress had no adverse effects on histologic healing outcomes and osteoblast functions. Cathepsin K and tartrate-resistant acid phosphatase-5b levels were higher in the HCQ-4 group than in the C-4 group (p<0.05). While the number and function of osteoclasts increased due to OS in callus tissue, a decrease in the number of chondrocytes was observed.

CONCLUSION

Hydroxychloroquine-induced OS increases the number and function of osteoclasts and decreases the number of hypertrophic chondrocytes and endochondral ossification but has no significant effect on mid-late osteoblast products and histological fracture healing scores.

Early weight bearing versus late weight bearing after intramedullary nailing for distal femoral fracture (AO/OTA 33) in elderly patients: A multicenter propensity-matched study

BACKGROUND

This study aimed to assess differences in implant failure and bone union rates, amount of change in alignment of lower extremities, and walking ability between early weight-bearing (EWB) and late weight-bearing (LWB) groups following retrograde intramedullary nailing (RIMN) for distal femoral fracture (AO/OTA 33) (DFF) at multiple centers using propensity score matching.

METHODS

The data of 213 patients who underwent RIMN from 2012 to 2019 in multiple tertiary hospitals were extracted from our database. Cases with the following factors were excluded: age <60, open fracture, AO/OTA-type 33-C3 fracture, preoperative New Mobility Score (NMS) < 3, postoperative follow-up <3 months, and unknown weight-bearing start time. Eighty-four patients were divided into the EWB and LWB groups. EWB group patients were encouraged to perform partial weight-bearing walking at ≤4 weeks after surgery. LWB group patients were not allowed weight bearing for >4 weeks after surgery. After propensity score matching was applied, 26 cases remained in each group.

RESULTS

There were no cases of nail failure in either the EWB group or LWB group (P = 1). Screw failure occurred in 0 cases in the EWB group and in 1 case (4.5%) in the LWB group (P = 1.0). Non-union occurred in 5 patients (19.2%) in the EWB group and 4 patients (15.3%) in the LWB group (P = 1). The mean amount of change in lower extremities alignment did not differ between the two groups. The median Knee Society Score was 95.5 (59-100) vs. 93 (72-100) points (P = 0.39). The median NMS was 7 (0-9) vs. 7 (4-9) points (P = 0.82).

CONCLUSIONS

There were no significant intergroup differences in the rates of implant failure, bone union at one year after surgery, amount of change in lower extremities alignment, or walking ability. We suggest that early weight bearing after RIMN for DFF may not be harmful in elderly people.

Capsular distension in high-energy femoral shaft fractures is associated with occult femoral neck fracture: a preliminary retrospective comparative study

OBJECTIVES

To determine the association between hip capsular distension, the computed tomography (CT) capsular sign, and lipohemarthrosis as they relate to occult femoral neck fracture (FNF) in the setting of ipsilateral femoral shaft fracture (FSF).

DESIGN

Retrospective comparative study.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Two hundred and forty-two patients with high-energy FSF and no evidence of FNF on preoperative radiographs and pelvis CT. All patients were stabilized with non-reconstruction style nails.

INTERVENTION

Pelvis CT scans were examined for hip capsular distension irrespective of the other side, differing side-to-side measurements of capsular distension (i.e., the CT capsular sign), and lipohemarthrosis.

MAIN OUTCOME MEASUREMENTS

FNF was observed for on postoperative radiographs. Relative risk (RR), number needed to treat (NNT), sensitivity (SN), and specificity (SP) were determined.

RESULTS

Fifty-eight patients (24.0%) had capsular distension. Forty-two patients (17.4%) had differing capsular measurements (i.e., the CT capsular sign), and 16 (6.6%) had symmetrical distension from bilateral hip effusions. Eight patients (3.3%) had lipohemarthrosis. Four FNFs (1.7%) were identified. Three patients had capsular distension, 2 had CT capsular signs, and 1 had lipohemarthrosis. The last patient had no CT abnormalities. Only capsular distension (RR = 10, CI = 1.001-90, P = 0.049; SN = 75%, SP = 77%; NNT = 22) and lipohemarthrosis (RR = 23, CI = 1.6-335, P = 0.022; SN = 50%, SP = 96%; NNT = 8) were associated with occult FNF.

CONCLUSIONS

Capsular distension is associated with FNF irrespective of the contralateral hip. Preemptive stabilization using a reconstruction nail could be considered in the setting of capsular distension or lipohemarthrosis to prevent displacement of an occult FNF.

LEVEL OF EVIDENCE

Diagnostic Level III.

Unfavorable cortical hypertrophy potentially predisposes to periprosthetic "axe splitter" fracture in a collarless polished curved triple-tapered cemented stem: The time-dependent radiographic change in five SC-stem cases

BACKGROUND

The periprosthetic fracture of cemented polished tapered stems is occasionally called a "unique" or "axe splitter" fracture. However, there has been insufficient evidence regarding the association between the radiographic findings prior to incidence and this cumbersome fracture. To determine if there are any radiographic interpretations associated with this fracture pattern, we report the five SC-stem cases with total hip arthroplasty.

METHODS

We investigate the patient characteristics and serial radiographs of five fracture cases and evaluate the time-dependent specific radiographical changes around the stem between pre-arthroplasty and fracture.

RESULTS

Fractures developed at 3.5-6.4 years after surgery with low-grade injury or with no particular incentive. Femoral cortical hypertrophy at the distal medial side around the stem was observed in all cases before the development of fractures, at 2-6 years after primary surgery. The duration between cortical hypertrophy appearance to the development of fracture was 0.4-3.1 years.

CONCLUSIONS

The appearance of this zone-specific cortical hypertrophy might play a key role in the occurrence of periprosthetic fractures. Further studies with larger sample sizes should be conducted to elucidate this eccentric periprosthetic fracture.

Locking plate for periprosthetic femoral fractures according to Vancouver C: Outcome and radiological subanalysis of 40 patients

PURPOSE

Periprosthetic femoral fractures (PFF) according to type Vancouver C are less common and outcome is limited reported. Therefore, we conducted this retrospective single center study.

METHODS

We performed analysis of patients who underwent open reduction and internal fixation (ORIF) with locking plates for PPF occurring distally of a primary standard hip stem. Data on demographics, revisions, fracture patterns, and mortality were evaluated. At least two years after operation, we examined outcome using the Parker and Palmer mobility score. Primary aim of this study was revision, outcome and mortality. Secondary aim was evaluation of fracture subtypes within type Vancouver C fractures.

RESULTS

Between 2008 and 2020, 383 patients with periprosthetic femoral fracture after hip replacement were surgically treated according to our database. Among them, 40 patients (10.4%) with type Vancouver C fractures were enrolled for this study. The mean patient age was 81.5 years (59-94) at the time of fracture. Thirty-three patients were women, and 22 fractures were on the left side. Without exception, locking plates were used. The 1-year mortality rate for the sample was 27.5% (n = 11). Three revisions (7.5%) were performed for plate breakage. Rate of infection and non-union was zero. Three different fracture patterns were assessed: (1) transverse or oblique fractures below the tip of the stem (n = 9); (2) spiral-shaped fractures within the diaphysis (n = 19); and (3) burst fractures at the supracondylar region (n = 12). Demographic or outcome effects between fracture patterns were not found. On average of 4.2 years (2.0-10.4) after treatment, the mean reported Parker score was 5.5 (1-9).

CONCLUSION

ORIF with a single lateral locking plate is safe for type Vancouver C fractures with a well-fixed hip stem. Therefore, we do not recommend routinely revision arthroplasty or orthogonal double plating. Three subtypes of fractures within Vancouver C demonstrated no significant differences in baseline data and outcome.

Treatment of pediatric femur supracondylar fractures: comparison of K-wire fixation versus plate-screw fixation

This study aims to compare the clinical and radiological results of patients who underwent plate-screw fixation and K-wire fixation in supracondylar femur fractures in the pediatric population. Patients aged 5-14 years suffering from supracondylar femoral fractures who underwent K-wire and plate-screw fixation were included in the study. Of all patients, follow-up period, age, fracture union time, gender, leg length discrepancy, and Knee Society Score (KSS) data were analyzed. The patients were divided into two groups; fixation with plate (Group A) and fixation with K-wires (Group B). Forty-two patients participated in the study. There was no significant difference between the two groups in terms of age, gender, and follow-up time ( P  > 0.05). When comparing the KSS results, no statistically significant difference was found between the two groups ( P  = 0.612). A statistically significant difference was detected between the two groups regarding union time ( P  = 0.01). When both groups were analyzed, no significant difference was found between the two groups in terms of functional results. Good results can be obtained in both plate-screw and K-wires in pediatric supracondylar femur fractures.

Submuscular nonlocking plates: an effective option for pediatric extra-articular proximal femur fractures

The aim of this study is to evaluate the results of submuscular plating using nonlocking plates for extra-articular proximal femur fractures (EPFF) in children. From our hospital records, we retrieved data of 15 children treated with submuscular plating with nonlocking dynamic compression plates (DCP) for EPFF between January 2010 and September 2021. EPFF was defined as a proximal femur fracture within 10% of the femoral length below the lesser trochanter. Patients' demographics, as well as details of the duration of operation, type of DCP used, time to union, complications, and outcomes using Flynn criteria were noted. There were nine males and six females. Mean age of the patients was 10.8 ± 1.9 years (range 7-14 years). All the patients had fracture union and two patients had union with an angulation less than 10°. All fractures healed uneventfully with a mean time to union of 11.8 ± 1.2 weeks (range 10-15 weeks). No patient required surgery for complications or malunion. Using Flynn criteria, excellent outcomes were seen in 13 out of 15 patients. There were no poor outcomes. Our study shows that submuscular plating using nonlocking plates is an effective option for treating pediatric EPFF. Treatment of these tricky fractures with submuscular plating using nonlocking plates shows excellent outcomes with minimal complications.