Changing practice to a new-generation triple-taper collared femoral component reduces periprosthetic fracture rates after primary total hip arthroplasty.

Aims: Periprosthetic femoral fracture (PPF) is a major complication following total hip arthroplasty (THA). Uncemented femoral components are widely preferred in primary THA, but are associated with higher PPF risk than cemented components. Collared components have reduced PPF rates following uncemented primary THA compared to collarless components, while maintaining similar prosthetic designs. The purpose of this study was to analyze PPF rate between collarless and collared component designs in a consecutive cohort of posterior approach THAs performed by two high-volume surgeons. Methods: This retrospective series included 1,888 uncemented primary THAs using the posterior approach performed by two surgeons (PKS, JMV) from January 2016 to December 2022. Both surgeons switched from collarless to collared components in mid-2020, which was the only change in surgical practice. Data related to component design, PPF rate, and requirement for revision surgery were collected. A total of 1,123 patients (59.5%) received a collarless femoral component and 765 (40.5%) received a collared component. PPFs were identified using medical records and radiological imaging. Fracture rates between collared and collarless components were analyzed. Power analysis confirmed 80% power of the sample to detect a significant difference in PPF rates, and a Fisher's exact test was performed to determine an association between collared and collarless component use on PPF rates. Results: Overall, 17 PPFs occurred (0.9%). There were 16 fractures out of 1,123 collarless femoral components (1.42%) and one fracture out of 765 collared components (0.13%; p = 0.002). The majority of fractures (n = 14; 82.4%) occurred within 90 days of primary THA. There were ten reoperations for PPF with collarless components (0.89%) and one reoperation with a collared component (0.13%; p = 0.034). Conclusion: Collared femoral components were associated with significant decreases in PPF rate and reoperation rate for PPF compared to collarless components in uncemented primary THA. Future studies should investigate whether new-generation collared components reduce PPF rates with longer-term follow-up.

Cemented Femoral Fixation in Total Hip Arthroplasty Reduces the Risk of Periprosthetic Femur Fracture in Patients 65 Years and Older: An Analysis From the American Joint Replacement Registry.

BACKGROUND: Periprosthetic femur fracture (PPFx) is a devastating complication after total hip arthroplasty (THA). Despite concerns for increased PPFx, cementless fixation predominates in the United States. This study used the American Joint Replacement Registry to compare PPFx risk between cemented and cementless femoral fixation for THA. METHODS: An analysis of primary THA cases in patients aged 65 years and more was performed with the American Joint Replacement Registry data linked to Centers for Medicare and Medicaid Services data from 2012 to 2020. Analyses compared cemented to cementless femoral fixation. We identified 279,052 primary THAs, 266,040 (95.3%) with cementless and 13,012 (4.7%) with cemented femoral fixation. Cox proportional hazard regression analyses evaluated the association of fixation and PPFx risk, while adjusting for sex, age, and competing risk of mortality. Cumulative incidence function survival curves evaluated time to PPFx. RESULTS: Age ≥ 80 years (P < .0001) and women (P < .0001) were associated with PPFx. Compared to cemented stems, cementless stems had an elevated risk of PPFx (Hazards Ratio 7.70, 95% Confidence interval 3.2-18.6, P < .0001). The cumulative incidence function curves demonstrated an increased risk for PPFx across all time points for cementless stems, with equal magnitude of risk to 8 years.` CONCLUSION: Cementless femoral fixation in THA continues to predominate in the United States, with cementless femoral fixation demonstrating increased risk of PPFx in patients aged 65 years or more. Surgeons should consider greater use of cemented femoral fixation in this population to decrease the risk of PPFx.

Prophylactic Cerclage Cabling Decreases the Intraoperative Periprosthetic Fracture Rate during Cement-Less Total Hip Arthroplasty in Patients with Severe Developmental Hip Dysplasia.

PURPOSE OF THE STUDY Cementless stems in highly dysplastic hips are considered to increase the risk of femoral fracture and associated morbidity. Several authors speculated to use prophylactic cabling in this patient group to prevent intraoperative fractures. This study aims to reveal objective results regarding the perioperative complications in a large and consecutive patient group with respect to use of prophylactic cabling. MATERIAL AND METHODS A retrospective comparative study was planned. A total of 122 consecutive patients with dysplastic hips of Crowe type 3 or 4, operated on with total hip arthroplasty (THA) and shortening osteotomy using a rectangular femoral stem were included. Patients were stratified according to use of a diaphyseal prophylactic cerclage cable. Perioperative complications were recorded. Clinical outcome was measured in terms of Harris Hip Score and Visual Analog Scale (VAS) for pain. All results were compared between the groups. RESULTS The mean follow-up time was 27 months. Two (2%) versus five (14%) patients had a fracture at the diaphyseal level in cabled versus non-cabled groups. Difference between groups was statistically significant (p=0.01). Relative risk of fracture in case of a non-cabling was 5.8 (p=0.03). Eleven (9%) patients had a non-displaced fracture at the metaphyseal level. No significant differences were detected with respect to preoperative clinical outcome scores or change in these scores between groups. CONCLUSIONS Femoral diaphyseal fracture rates are low when cementless, rectangular stems are used in dysplastic high riding hips. Prophylactic cerclage cabling further decreases the fracture risk and eases treatment in case of a fracture without causing additional complications and therefore is recommended. Key words: intraoperative fracture, periprosthetic fracture, total hip arthroplasty, cerclage cabling, developmental hip dysplasia, transverse shortening osteotomy.

Use of a circular fixator construct to facilitate closed reduction and percutaneous stabilization of a distal femoral physeal fracture in a dog.

Background: Fractures of the distal femoral physis are the most common physeal fracture sustained by skeletally immature dogs. Reduction and stabilization of these fractures can sometimes be achieved through closed reduction, primarily in fractures that are nominally displaced. Circular external fixator constructs have been used to assist in indirect, closed reduction of fractures at other anatomic locations in dogs and this report describes application of this method to reduce a displaced Salter-Harris type II fracture of the distal femur in a 1-year-old dog. Case Description: A 1-year-old female spayed Akita was referred for treatment of a Salter-Harris type II fracture of the right distal femur. The epiphyseal segment was laterally and slightly caudally displaced. Multiple attempts to manually reduce the fracture during surgery were unsuccessful, so a two-ring circular external fixator construct was applied to facilitate distraction and reduction. The construct was applied by placing a medial-to-lateral Kirschner wire in both the mid-femoral diaphysis and in the distal femoral epiphysis. Distraction of the construct provided sufficient separation of the fracture segments to facilitate near anatomic reduction. The fracture was stabilized with two percutaneously placed Steinmann pins placed in Rush fashion. Radiographic union was confirmed 5 weeks after surgery. The dog was not lame and was bearing more weight on the right pelvic limb, as assessed using force plate analysis, 9 months following surgery. Goniometric measurements of stifle range of motion and thigh muscle circumference were similar between the pelvic limbs. Conclusion: Application of a two-ring circular construct would appear to be useful to facilitate closed reduction and percutaneous stabilization of distal femoral physeal fractures.

Risk factors for femoral fracture in lateral decubitus direct anterior approach total hip arthroplasty using conventional stems: a retrospective analysis.

OBJECTIVE: To provide guidelines for surgery and reduce the incidence of fracture, this study analyzed the relationship between femoral fracture and related factors in direct anterior approach (DAA) total hip arthroplasty (THA) in the lateral decubitus position. METHOD: A retrospective series of 273 consecutive patients who underwent THA with the DAA in the lateral decubitus position was analyzed. Each surgery was performed by the same surgeon with a conventional operation bed and femoral stem. The correlations between the incidence of fracture and sex, age, body mass index (BMI), height, osteoporosis, the anterior superior iliac spine-greater trochanter distance (ASIS-GTD), and hip joint disease were analyzed by univariate analysis and logistic regression analysis. RESULTS: Among all hip arthroplasty procedures, 35 hips had femoral fractures, including 30 greater trochanter fractures, 4 proximal femoral splits, and 1 femoral perforation. The incidence of fracture was 12.82%. Univariate analysis showed no significant difference in the incidence of fracture by sex, BMI, or age. However, osteoporosis caused an increase in the incidence of fracture, while the incidence of fracture decreased as height and the ASIS-GTD increased. The incidence of femoral neck fracture was lower in cases of osteonecrosis of the femoral head than in cases of other diseases. Logistic regression showed a significant correlation between osteoporosis, the ASIS-GTD, and fractures. Patients with osteoporosis had a high possibility of fracture (OR = 2.414); the possibility of fracture decreased with increasing ASIS-GTD (OR = 0.938). CONCLUSION: Lateral decubitus DAA THA can be successfully performed using a conventional operation bed and stem, effectively saving medical resources. Osteoporosis and a shorter ASIS-GTD were independent risk factors for femoral fracture.

Introduction of a New Treatment Algorithm Reduces the Number of Periprosthetic Femoral Fractures After Primary Total Hip Arthroplasty in Elderly Females.

BACKGROUND: Increasing global usage of cementless prostheses in total hip arthroplasty (THA) presents a challenge, especially for elderly patients. To reduce the risk of early periprosthetic femoral fractures (PFFs), a new treatment algorithm for females older than 60 years undergoing primary THA was introduced. The aim of this study was to determine the impact of the new treatment algorithm on the early risk of perioperative and postoperative PFFs and guideline compliance. METHODS: A total of 2405 consecutive THAs that underwent primary unilateral THA at our institution were retrospectively identified in the period January 1, 2013-December 31, 2018. A new treatment algorithm was introduced on April 1, 2017 with female patients aged older than 60 years intended to receive cemented femoral components. Before this, all patients were scheduled to receive cementless femoral components. Demographic data, number of perioperative and postoperative PFFs, and surgical compliance were recorded, analyzed, and intergroup differences compared. RESULTS: The utilization of cemented components in female patients older than 60 years increased from 12.3% (n = 102) to 82.5% (n = 264). In females older than 60 years, a significant reduction in the risk in early postoperative and intraoperative PFF after introduction of the new treatment algorithm was seen (4.57% vs 1.25%; P = .007 and 2.29% vs 0.31%; P = .02, respectively). Overall risk for postoperative and intraoperative fractures combined was also reduced in the entire cohort (4.1% vs 2.0%; P = .01). CONCLUSION: Use of cemented fixation of the femoral component in female patients older than 60 years significantly reduces the number of PFFs. Our findings support use of cemented femoral fixation in elderly female patients.

A Calcar Collar Is Protective Against Early Torsional/Spiral Periprosthetic Femoral Fracture: A Paired Cadaveric Biomechanical Analysis.

BACKGROUND: Periprosthetic fracture is a leading reason for readmission following total hip arthroplasty. Most of these fractures occur during the early postoperative period before bone ingrowth. Before ingrowth occurs, the femoral component can rotate relative to the femoral canal, causing a spiral fracture pattern. We sought to evaluate, in a paired cadaver model, whether the torsional load to fracture was higher in collared stems. The hypothesis was that collared stems have greater load to fracture under axial and torsional loads compared with collarless stems. METHODS: Twenty-two cadaveric femora (11 matched pairs) with a mean age of 77 ± 10.2 years (range, 54 to 90 years) were harvested. Following dissection, the femora were evaluated with use of a dual x-ray absorptiometry scanner and T scores were recorded. We utilized a common stem that is available with the same intraosseous geometry with and without a collar. For each pair, 1 femur was implanted with a collared stem and the contralateral femur was implanted with a collarless stem with use of a standard broaching technique. A compressive 68-kg load was applied to simulate body weight during ambulation. A rotational displacement was then applied until fracture occurred. Peak torque prior to fracture was measured with use of a torque meter load cell and data acquisition software. RESULTS: The median torque to fracture was 65.4 Nm for collared stems and 43.1 Nm for uncollared stems (p = 0.0014, Wilcoxon signed-rank test). The median T score was -1.95 (range, -4.1 to -0.15). The median difference in torque to fracture was 29.18 Nm. As expected in each case, the mode of failure was a spiral fracture around the implant. CONCLUSIONS: Collared stems seemed to offer a protective effect in torsional loading in this biomechanical model comparing matched femora. CLINICAL RELEVANCE: These results may translate into a protective effect against early periprosthetic Vancouver B2 femoral fractures that occur before osseous integration has occurred.

The limitations of today's clinical guidance: Atypical femoral fracture and long-term bone-modifying agents in the oncology setting.

While bone-modifying agents such as bisphosphonates and denosumab are crucial to preventing skeletal-related events in patients with bone metastases, the optimal duration remains undefined. Extended duration may be associated with adverse effects such as osteonecrosis of the jaw and atypical femoral fracture. Although uncommon, atypical femoral fracture represents a serious consequence of prolonged bone-modifying agent use and are characterized by a prodrome and distinct radiographic findings. The oncology setting encompasses a unique set of atypical femoral fracture risk factors and considerations, with hormonal therapy in early stage disease, bone metastases in the advanced setting, and new targeted agents that may affect bone homeostasis. As outcomes in cancer treatment continue to improve, the questions of risks versus benefits of long-term bone-modifying agents and how to mitigate atypical femoral fracture risk become increasingly pertinent.

Is There an Association Between Prophylactic Femur Stabilization and Survival in Patients with Metastatic Bone Disease?

BACKGROUND: The femur is the most common site of metastasis in the appendicular skeleton, and metastatic bone disease negatively influences quality of life. Orthopaedic surgeons are often faced with deciding whether to prophylactically stabilize an impending fracture, and it is unclear if prophylactic fixation increases the likelihood of survival. QUESTIONS/PURPOSES: Is prophylactic femur stabilization in patients with metastatic disease associated with different overall survival than fixation of a complete pathologic fracture? METHODS: We performed a retrospective, comparative study using the national Veterans Administration database. All patient records from September 30, 2010 to October 1, 2015 were queried. Only nonarthroplasty procedures were included. The final study sample included 950 patients (94% males); 362 (38%) received prophylactic stabilization of a femoral lesion, and 588 patients (62%) underwent fixation of a pathologic femur fracture. Mean followup duration was 2 years (range, 0-7 years). We created prophylactic stabilization and pathologic fracture fixation groups for comparison using Common Procedural Terminology and ICD-9 codes. The primary endpoint of the analysis was overall survival. Univariate survival was estimated using the Kaplan-Meier method; between-group differences were compared using the log-rank test. Covariate data were used to create a multivariate Cox proportional hazards model for survival to adjust for confounders in the two groups, including Gagne comorbidity score and cancer type. RESULTS: After adjusting for comorbidities and cancer type, we found that patients treated with prophylactic stabilization had a lower risk of death than did patients treated for pathologic femur fracture (hazard ratio = 0.75, 95% CI, 0.62-0.89; p = 0.002). CONCLUSIONS: In the national Veterans Administration database, we found greater overall survival between patients undergoing prophylactic stabilization of metastatic femoral lesions and those with fixation of complete pathologic fractures. We could not determine the cause of this association, and it is possible, if not likely, that patients treated for fracture had more aggressive disease causing the fracture than did those undergoing prophylactic stabilization. Currently, most orthopaedic surgeons who treat pathological fractures stabilize the fracture prophylactically when reasonable to do so. We may be improving survival in addition to preventing a pathological fracture; further study is needed to determine whether the association is cause-and-effect and whether additional efforts to identify and treat at-risk lesions improves patient outcomes. LEVEL OF EVIDENCE: Level III, therapeutic study.

Inter-implant fractures: an unmet medical need-a preventive approach proposal.

Inter-implant fractures are associated with reduced quality of life and increased 1-year mortality. For that reason, we propose, instead of treating, a novel, preventative surgical approach that involves splinting the inter-implant femoral shaft interval. In patients with a previous femoral implant in whom a second surgery for new material implantation was necessary (including knee or hip arthroplasty, plate or femoral nailing), an overlapping technique using the minimally invasive plate osteosynthesis technique was performed during the second surgery. Nine patients were included, all females with median (range) age of 78 (55-88) years. No surgery-related complications or mortality occurred. Two patients suffered fractures from a casual fall postoperatively with no implant failure or hospital admission required. In conclusion, instead of treating such fractures after they occur, we propose an effective, safe and reproducible preventative surgical approach, not previously reported, which involves internal femoral splinting, a plate and the minimally invasive plate osteosynthesis technique.

Prevention of Pathological Fracture of the Proximal Femur: A Systematic Review of Surgical and Percutaneous Image-Guided Techniques Used in Interventional Oncology.

Background and objectives: Patients suffering from bone metastasis are at high risk for pathological fractures and especially hip fractures. Osteolytic metastases can induce a high morbidity rate (i.e., pain, facture risk, mobility impairment), and operation on them can be difficult in this frail population having a reduced life expectancy. Several medical devices have been investigated for the prevention of these pathological hip fractures. Materials and Methods: To investigate these solutions, a literature review and a meta-analysis of primary studies was performed. Data sources included electronic databases (PubMed, CENTRAL and ClinicalTrials.gov) from 1990 until 1 January 2019. Titles, abstracts and full-text articles were reviewed in order to select only studies evaluating the performance of the studied solution to prevent osteoporotic and/or pathological hip fracture. The main outcomes were the occurrence of hip fracture, pain evaluation (VAS score) and adverse events occurrence (including severe adverse events and deaths). All randomised controlled trials (RCTs) and cohort studies were considered. A Bayesian cumulative meta-analysis was undertaken on the primary studies conducted in patients with bone metastasis. Results: A total of 12 primary studies were identified, all were cohort studies without a control group, and one compared two devices, and were thereafter considered separately. In those 12 samples, 255 patients were included, mean age 61.7 years. After implantation, the cumulative risk of fracture was 5.5% (95% confidence interval, 3.0% to 8.6%), and adverse event occurrence was 17.4% (95%CI, 12.6 to 22.8%), with a median follow-up of 10 months. The posterior probability of a fracture rate below 5% was 40.3%. Conclusions: The literature about medical devices evaluation for preventing hip fractures in metastatic patients is poor and mostly based on studies with a limited level of evidence. However, this systematic review shows promising results in terms of efficacy and tolerance of these devices in patients with bone metastases. This treatment strategy requires further investigations.

Growth factor-mediated augmentation of long bones: evaluation of a BMP-7 loaded thermoresponsive hydrogel in a murine femoral intramedullary injection model.

BACKGROUND: Due to our aging population, an increase in proximal femur fractures can be expected, which is associated with impaired activities of daily living and a high risk of mortality. These patients are also at a high risk to suffer a secondary osteoporosis-related fracture on the contralateral hip. In this context, growth factors could open the field for regenerative approaches, as it is known that, i.e., the growth factor BMP-7 (bone morphogenetic protein 7) is a potent stimulator of osteogenesis. Local prophylactic augmentation of the proximal femur with a BMP-7 loaded thermoresponsive hydrogel during index surgery of an osteoporotic fracture could be suitable to reduce the risk of further osteoporosis-associated secondary fractures. The present study therefore aims to test the hypothesis if a BMP-7 augmented hydrogel is an applicable carrier for the augmentation of non-fractured proximal femurs. Furthermore, it needs to be shown that the minimally invasive injection of a hydrogel into the mouse femur is technically feasible. METHODS: In this study, male C57BL/6 mice (n = 36) received a unilateral femoral intramedullary injection of either 100 µl saline, 100 µl 1,4 Butan-Diisocyanat (BDI)-hydrogel, or 100 µl hydrogel loaded with 1 µg of bone morphogenetic protein 7. Mice were sacrificed 4 and 12 weeks later. The femora were submitted to high-resolution X-ray tomography and subsequent histological examination. RESULTS: Analysis of normalized CtBMD (Cortical bone mineral density) as obtained by X-ray micro-computed tomography analysis revealed significant differences depending on the duration of treatment (4 vs 12 weeks; p < 0.05). Furthermore, within different anatomically defined regions of interest, significant associations between normalized TbN (trabecular number) and BV/TV (percent bone volume) were noted. Histology indicated no signs of inflammation and no signs of necrosis and there were no cartilage damages, no new bone formations, or new cartilage tissues, while BMP-7 was readily detectable in all of the samples. CONCLUSIONS: In conclusion, the murine femoral intramedullary injection model appears to be feasible and worth to be used in subsequent studies that are directed to examine the therapeutic potential of BMP-7 loaded BDI-hydrogel. Although we were unable to detect any significant osseous effects arising from the mode or duration of treatment in the present trial, the effect of different concentrations and duration of treatment in an osteoporotic model appears of interest for further experiments to reach translation into clinic and open new strategies of growth factor-mediated augmentation.

Effectiveness of distally slotted proximal femoral nails on prevention of femur fractures during and after intertrochanteric femur fracture surgery.

INTRODUCTION: Intra- and post-operative femoral shaft fractures related with nailing remain of concern. Although manufacturers have sought to solve the problem by providing distally slotted nails, it is not clear that these implants reduce fractures. We compare two distally slotted proximal femoral nails [trochanteric nail (TRON) and proximal femur intramedullary nail (PROFIN)]. PATIENTS AND METHODS: The medical records of 195 hips treated with TRONs (distally slotted in four places in the sagittal and coronal planes) and 583 hips treated with PROFINs (distally slotted in two places in the coronal plane) in two institutes were retrospectively evaluated. The inclusion criteria were follow-up for at least 6 months; pertrochanteric fractures and age over 55 years. RESULTS: In total, 161 hips in the TRON group and 512 hips in the PROFIN group were included. The mean follow-up time was 28.5 (range: 6-84) months in whole group. The demographic characteristics of the groups were similar. Only 2 intraoperative shaft and 3 proximal lateral cortex fracture was detected in PROFIN group, there wasn't any postoperative fracture. Four proximal lateral cortex and 2 femur shaft fractures were detected in TRON group (one during operation and one at postoperative 8th month after a fall at pedestrian way). CONCLUSIONS: Distal cephalomedullary nail slotting prevented intra- and post-operative femoral fractures. A distal slot 50 mm in length may increase nail elasticity and reduce nail tip stress to a greater extent than a 30-mm slot. Distal slotting in both the sagittal and coronal planes afforded no advantage compared to coronal slotting only. LEVEL OF EVIDENCE: Level III retrospective study.

Can Prophylactic Cables Stop Crack Propagation in Revision Arthroplasty: A Biomechanical Study.

BACKGROUND: Intraoperative femur fractures are a common complication of revision hip arthroplasty. This study examined the use of a prophylactic cable in stopping a crack from propagating beyond the cable. METHODS: Seventy sheep femora were prepared. A 5-mm vertical incision was performed. Using a force-controlled materials testing machine, a Wagner shaft was advanced until a crack occurred. Cracks were visualized with green ink. In the first part, the control group without any cable (n = 10) was compared with polyethylene (n = 15) and single CoCr cable (n = 15) groups. The cables were positioned 15 mm distal to the osteotomy. In the second part, three different CoCr configurations were compared, single-wrapped (n = 15), double-wrapped (n = 125), and two separate cables at 10 and 15 mm distal to the osteotomy (n = 15). RESULTS: The polyethylene cable stopped only 3 of 15 cracks (20%), whereas the CoCr cable stopped 11 of 15 cracks (73%) (P = .009). The force needed to initiate the crack between the different groups was not significant. Twelve (80%) of 15 cracks were stopped at the level of the cable with two separate CoCr cables and 15 (100%) of 15 cracks with a double-wrapped cable (P = .11). CONCLUSION: This study demonstrated that an elastic cable is not suitable for preventive cabling. The force required to form a crack is not improved with the use of a prophylactic cable placed 10-15 mm below the osteotomy. While the results on the different configurations were not conclusive, the double-wrapped cable was able to stop all cracks from progressing distally.

Where is the Target Point to Prevent Cortical Hinge Fracture in Medial Closing-Wedge Distal Femoral Varus Osteotomy?

The purpose of this study was to investigate whether the location of the hinge affects the incidence of hinge fracture during medial closing-wedge distal femoral varus osteotomy (DFVO). Twenty knees from 10 fresh-frozen human cadavers (mean age, 75 ± 17 years) were used to perform uniplanar medial closing-wedge DFVO with a 7-mm wedge. Each specimen was randomly assigned to either group A (supracondylar hinge) or group B (lateral condylar hinge). The incidence of hinge fracture and stability was compared between both groups after uniplanar medial closing-wedge DFVO. In group A, 8 of 10 knees had a lateral cortex fracture during closure of the osteotomy gap, and all fractured knees were unstable. Two knees with an intact lateral cortical hinge showed stability under manual valgus and varus forces. After intentional breakage of the lateral cortical hinge, both knees were found to be unstable under the same force. In group B, 2 of 10 knees had a lateral cortex fracture, and 8 knees had no fractures. All specimens were found to be stable under manual valgus and varus forces. After intentional breakage of the lateral cortical hinge in group B, 2 knees were unstable, while 8 knees remained stable. This study showed a significantly higher incidence of lateral cortical hinge fracture and instability in group A than in group B during closure of the osteotomy gap.

What Is the Adverse Event Profile After Prophylactic Treatment of Femoral Shaft or Distal Femur Metastases?

BACKGROUND: Prophylactic surgical treatment of the femur is commonly offered to patients with metastatic disease who have a high risk of impending pathologic fracture. Prophylactic fixation is associated with improved functional outcomes in appropriate patients selected based on established criteria, but the perioperative complication profile has received little attention. Given the substantial comorbidity in this population, it is important to characterize surgical risks for surgeons and patients to improve treatment decisions. QUESTIONS/PURPOSES: (1) What is the incidence of postoperative adverse events after prophylactic surgical stabilization of metastatic lesions of the femoral shaft or distal femur? (2) How does this complication profile compare with stabilization of pathologic fractures adjusted for differences in patient demographics and comorbidity? METHODS: We performed a retrospective study using the National Surgical Quality Improvement Program (NSQIP) database. We identified patients undergoing prophylactic treatment of the femoral shaft or distal femur by Current Procedural Terminology (CPT) codes. Patients undergoing treatment of a pathologic fracture were identified by CPT code for femur fracture fixation as well as an International Classification of Diseases code indicating neoplasm or pathologic fracture. We tracked adverse events, operative time, blood transfusion, hospital length of stay, and discharge to a facility within 30 days postoperatively. There were 332 patients included in the prophylactic treatment group and 288 patients in the pathologic fracture group. Patients in the prophylactic treatment group presented with greater body mass index (BMI), whereas the pathologic fracture group presented with a greater incidence of disseminated cancer. The odds of experiencing adverse events were initially compared between the two groups using bivariate logistic regression and then using multivariate regression controlling for age, sex, BMI, and American Society of Anesthesiologists (ASA) class and disseminated cancer causing marked physiological compromise per NSQIP guidelines. RESULTS: With multivariate analysis controlling for age, sex, BMI, and ASA class, patients with pathologic fracture were more likely to experience any adverse event (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.03-2.29; p = 0.036), major adverse events (OR, 1.61; 95% CI, 1.01-2.55; p = 0.043), death (OR, 1.90; 95% CI, 1.07-3.38; p = 0.030), blood transfusion (OR, 1.57; 95% CI, 1.08-2.27; p = 0.017), and hospital stay ≥ 9 days (OR, 1.51; 95% CI, 1.05-2.19; p = 0.028) compared with patients undergoing prophylactic treatment. However, when additionally controlling for disseminated cancer, the only difference was that patients with pathologic fractures were more likely to receive a blood transfusion than were patients undergoing prophylactic fixation (OR, 1.61; 95% CI, 1.12-2.36; p = 0.011). CONCLUSIONS: After controlling for differences in patient characteristics, prophylactic treatment of femoral metastases was associated with a decreased likelihood of blood transfusion and no differences in terms of the frequency of other adverse events. In the context of prior studies supporting the mechanical and functional outcomes of prophylactic treatment, the findings of this cohort suggest that the current guidelines have achieved a reasonable balance of morbidity in patients with femoral lesions and further support the current role of prophylactic treatment of impending femur fractures in appropriately selected patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Association of the Anterolateral Thigh Osteomyocutaneous Flap With Femur Structural Integrity and Assessment of Prophylactic Fixation.

Importance: The chimeric anterolateral thigh osteomyocutaneous (ALTO) free flap is a recently described microvascular option for head and neck osseous defects associated with complex soft-tissue requirements. To date, the association of ALTO flap harvest with femur structural integrity and the need for routine prophylactic fixation following harvest has been incompletely described. Objective: To investigate the association of ALTO flap harvest, with and without prophylactic fixation, on femur structural integrity as measured by 4-point bend and torsional biomechanical testing. Design and Setting: At a research laboratory, 24 synthetic fourth-generation composite femurs with validated biomechanical properties underwent 10-cm-long, 30% circumferential osteotomies at the proximal middle third of the femur; 6 femurs served as controls. Osteotomized femurs with and without fixation underwent torsional and 4-point bend biomechanical testing. Femur fixation consisted of intramedullary nail and distal interlock screw placement. Main Outcomes and Measures: Force and torque to fracture (expressed in kilonewtons [kN] and Newton meters [N∙m], respectively) were compared between controls, osteotomized femurs without fixation, and osteotomized femurs with fixation. Additional outcome measures included femur stiffness and fracture patterns. Results: On posterior to anterior (PA) 4-point bend testing, force to fracture of osteotomized femurs was 22% of controls (mean difference, 8.3 kN; 95% CI, 6.6-10.0 kN). On torsional testing the torque to fracture of osteotomized femurs was 12% of controls (mean difference, 351.1 N∙m; 95% CI, 307.1-395.1 N∙m). Following fixation there was a 67% improvement in PA force to fracture and a 37% improvement in torque to fracture. However, osteotomized femurs with fixation continued to have a reduced PA force to fracture at 37% of controls (mean difference, 6.8 kN; 95% CI, 4.5-9.2 kN) and torque to fracture at 16% of controls (mean difference, 333.7 N∙m; 95% CI, 306.8-360.6 N∙m). On torsional testing, all osteotomized femurs developed similar spiral fractures through a corner of the distal osteotomy site. This fracture pattern changed after prophylactic fixation with femurs developing nondisplaced fractures through the proximal osteotomy site. There were no underlying hardware failures during testing of osteotomized femurs with fixation. Conclusions and Relevance: Anterolateral thigh osteomyocutaneous flap harvest results in significant changes in the structural integrity of the femur. Postoperative stabilization should be strongly considered, with future research directed at investigating the clinical significance of residual biomechanical changes following femur fixation.

Not All Patients Undergoing Stabilization of Impending Pathologic Fractures for Renal Cell Carcinoma Metastases to the Femur Need Preoperative Embolization.

BACKGROUND: Preoperative transarterial embolization has been utilized in the surgical treatment of metastatic renal cell carcinoma of the femur to decrease perioperative blood loss. However, few studies have documented its efficacy in decreasing the proportion of patients receiving transfusions in the setting of prophylactic treatment of impending pathologic femur fractures. QUESTIONS/PURPOSES: In a population of patients with metastatic renal cell carcinoma of the femur who underwent prophylactic fixation, the purpose of this study was to quantify and compare the proportion of patients who received at least one transfused unit of blood between a group treated with preoperative embolization and a group without preoperative embolization. METHODS: A retrospective study was performed using a Medicare claims-based database. International Classification of Diseases, 9 Revision and Current Procedural Terminology codes were used to identify 1285 patients with metastatic renal cell carcinoma of the femur who underwent prophylactic fixation. The proportion of patients who received one or more blood transfusions was compared between 135 patients who underwent preoperative embolization and a group of 1150 concurrent control patients who did not undergo preoperative embolization. The control group was older than the embolization group, with 44% of these patients > 75 years old and 33% of the embolization group > 75 years. There was no difference in the female:male ratio between groups. Statistical comparisons of outcomes related to transfusion percentages were performed using Pearson chi square analysis with p < 0.05 considered significant. With the numbers available, we had 80% power to detect a difference in the percentage of patients transfused of 11% between the study groups at α = 0.05. RESULTS: No difference in transfusion percentage was observed between preoperative transarterial embolization (41 of 135 [30%]) and the control group (359 of 1150 [31%]; relative risk, 0.973; 95% confidence interval, 0.743-1.274; p = 0.84). The percentage of all patients who received a transfusion was 31% (400 of 1285). CONCLUSIONS: Preoperative embolization may not be mandatory in the prophylactic treatment of metastatic renal cell carcinoma of the femur, as demonstrated by the 69% of patients who received zero units of blood despite not receiving embolization. However, assessment of the efficacy of embolization in decreasing blood loss in the current study is limited as a result of biases associated with the database design of the study; the decision of whether to send a patient for embolization should be made on a case-by-case basis. The current study does not identify specific risk factors that should factor into this decision and underscores the need for further research in this regard. A plausible future research design to account for the low numbers and selection bias that limited the current study as well as the existing studies might be a multicenter, retrospective case-control study. LEVEL OF EVIDENCE: Level III, therapeutic study.

Lateral fixation: an alternative surgical approach in the prevention of complete atypical femoral fractures.

Little evidence is available on how to treat incomplete atypical fractures of the femur. When surgery is chosen, intramedullary nailing is the most common invasive technique. However, this approach is adopted from the treatment of other types of ordinary femoral fracture and does not aim to prevent the impending complete fracture by interrupting the mechanism underlying the pathology. We suggest a different surgical approach that intends to counteract the underlying biomechanical conditions leading to a complete atypical fracture and thus could be better suited in selected cases. Here, we share an alternative surgical approach and present two cases treated accordingly.

Optimum stem length for mitigation of periprosthetic fracture risk following primary total knee arthroplasty: a finite element study.

PURPOSE: Due to age-related changes to the material properties and thinning of the cortical bone structure, older patients with osteoporosis may be at greater risk of femoral fracture following total knee arthroplasty. This study investigates whether there is a potential role for stemmed prostheses in such scenarios to help mitigate peri-implant fracture risk, and if so what should the optimum stem length be to balance surgical bone loss with reduced fracture risk. METHODS: Finite element models of the distal femur implanted with four different implant types: a posterior stabilising implant, a total stabilising implant with short stem (12 mm × 50 mm), a TS implant with medium stem (12 mm × 75 mm), and a TS implant with long stem (12 mm × 100 mm), were developed and analysed in this study. Osteoporotic properties were applied to the implanted femurs and the periprosthetic stresses and strains of each were recorded. RESULTS: All stem lengths examined were found to lead to a reduction in periprosthetic stress in comparison with a primary stemless implant, with short-, medium-, and long-stemmed implants leading to an 11, 26, and 29% reduction in stress, respectively. CONCLUSION: The results of this study show that periprosthetic stress and therefore fracture risk in old osteoporotic patients may be reduced through the use of stemmed femoral components. Of the three stems investigated, a medium-length stem is found to represent the best balance between bone preservation at the time of surgery and reduction in periprosthetic stress following implantation.