The impact of stem fixation method on Vancouver Type B1 periprosthetic femoral fracture management

Introduction: Our understanding of the impact of the stem fixation method in total hip arthroplasty (THA) on the subsequent management of periprosthetic femoral fractures (PFF) is still limited. This study aimed to investigate and quantify the effect of the stem fixation method, i.e., cemented vs. uncemented THA, on the management of Vancouver Type B1 periprosthetic femoral fractures with the same plate. Methods: Eight laboratory models of synthetic femora were divided into two groups and implanted with either a cemented or uncemented hip prosthesis. The overall stiffness and strain distribution were measured under an anatomical one-legged stance. All eight specimens underwent an osteotomy to simulate Vancouver type B1 PFF’s. Fractures were then fixed using the same extramedullary plate and screws. The same measurements and fracture movement were taken under the same loading conditions. Results: Highlighted that the uncemented THA and PFF fixation constructs had a lower overall stiffness. Subsequently, the mechanical strain on the fracture plate for the uncemented construct was higher compared to the cemented constructs. Conclusion: PFF fixation of a Vancouver type B1 fracture using a plate may have a higher risk of failure in uncemented THAs.

Risk factors of early periprosthetic femoral fracture after total knee arthroplasty

Background Periprosthetic femoral fracture (PFF) is a serious complication after total knee arthroplasty (TKA). However, the risk factors of PFF in the early postoperative setting are not well documented. This study determines the risk factors of early PFF after primary TKA. Methods This study recruited 24 patients who had early PFF within postoperative 3 months and 96 control patients. Demographic data (age, gender, weight, height, body mass index, Deyo-Charlson comorbidity index, diagnosis, operated side, underlying diseases and history of steroid usage intraoperative outcomes), intraoperative outcomes (operative time, surgical approach, type and brand of the prosthesis), and radiographic outcomes (distal femoral width; DFW, prosthesis-distal femoral width ratio; PDFW ratio, anatomical lateral distal femoral angle; LDFA, the change of LDFA, femoral component flexion angle; FCFA and anterior femoral notching; AFN) were recorded and compared between groups. Details of PFF, including fracture pattern, preoperative deformity, and time to PFF were also documented. Results In univariate analysis, the PFF group had significantly older, right side injury, rheumatoid, dyslipidemia, Parkinson patients than the control group (p < 0.05). No cruciate-retaining design was used in PFF group (p = 0.004). Differences between the prosthetic brand used were found in this study (p = 0.049). For radiographic outcomes, PFF group had significantly lower DFW but higher PDFW ratio and postoperative LDFA than the control group (p < 0.05). While the change of LDFA, FCFA and AFN were similar between groups. The fracture patterns were medial condylar (45.8%), lateral condylar (25.0%) and supracondylar fracture (29.2%). The mean overall time to PFF was 37.2 ± 20.6 days (range 8–87 days). Preoperative deformity was significantly different among the three patterns (p < 0.05). When performed multivariate analysis using the logistic regression model, age was only an independent risk factor for early PFF. The cut-off point of age was > = 75 years, with a sensitivity of 75.0% and specificity of 78.1%. Conclusion This study determined that age was the independent risk factors for early PFF. However, further well-controlled studies with a larger sample size were needed to address this issue.

Management of a Complex Supracondylar Periprosthetic Femur Fracture with Intramedullary Strut Allograft and Bilateral Locking Plates

Supracondylar periprosthetic femoral fractures occurring above total knee replacements have been considered a rare entity. However, they continue to increase in frequency with the increasing number of arthroplasties and the improvement in morbidity and mortality in the concerned patient population. The management of periprosthetic distal femoral fractures is a challenging orthopedic problem. In this brief communication, a case of 49-year-old woman with rheumatoid arthritis who sustained a low distal comminuted periprosthetic femoral fracture is presented. Her fracture was eventually managed with an intramedullary fibular strut allograft and bilateral locking plate placement reaching satisfactory healing and restoration of alignment. The primary aim of this report is to provide insight into this novel technique as a successful alternative to other standard surgical options.

Risk Factors for Periprosthetic Femoral Fracture in Non-cemented Total Hip Arthroplasty Through the Direct Anterior Approach

Background: Although total hip arthroplasty (THA) performed through the direct anterior (DA) approach is frequently marketed as superior to other approaches, there are concerns about increased risks of intraoperative and early postoperative femoral fracture. Purpose: We sought to assess patient-specific and radiographic risk factors for intraoperative and early postoperative (90-day) periprosthetic femoral fracture (PPFx) following DA approach THA. Methods: We retrospectively reviewed 1107 consecutive, primary, non-cemented DA THAs, performed between April 2009 and January 2015, for intraoperative and early postoperative PPFx. Patients lost to follow-up before 90 days (63), cemented or hybrid THA (52), or early femoral failure for another indication (3) were excluded, yielding 989 hips for analysis. Demographic variables and patient comorbidities were analyzed as risk factors for PPFx. Continuous variables were initially compared with 1-way analysis of variance (ANOVA) and categorical variables with chi-square test. A demographic matched-paired radiographic analysis was performed for femoral stem canal fill and compared using univariate logistic regression. Results: The incidence of perioperative PPFx was 2.02%, including 10 intraoperative and 10 early postoperative fractures. Sustaining a postoperative PPFx was associated with being 70 years old or older with a body mass index (BMI) of less than 25, or with having either osteoporosis or Parkinson disease. Radiographs demonstrated that intraoperative PPFx was associated with stems that filled greater proximally rather than distally. Conclusion: Our cohort study found older age, age over 70 with BMI of less than 25, osteoporosis, and Parkinson disease were associated with increased risk for early postoperative PPFx following DA approach THA. Intraoperative fractures may occur with disproportionate proximal femoral canal fill. Further study can evaluate whether cemented femoral components may mitigate risk in these patient populations.

Simplified Mechanical Tests Can Simulate Physiological Mechanics of a Fixation Construct for Periprosthetic Femoral Fractures

Plate fractures after fixation of a Vancouver Type B1 periprosthetic femoral fracture (PFF) are difficult to treat and could lead to severe disability. However, due to the lack of direct measurement of in vivo performance of the PFF fixation construct, it is unknown whether current standard mechanical tests or previous experimental and computational studies have appropriately reproduced the in vivo mechanics of the plate. To provide a basis for the evaluation and development of appropriate mechanical tests for assessment of plate fracture risk, this study applied loads of common activities of daily living (ADLs) to implanted femur finite element (FE) models with PFF fixation constructs with an existing or a healed PFF. Based on FE simulated plate mechanics, the standard four-point-bend test adequately matched the stress state and the resultant bending moment in the plate as compared with femur models with an existing PFF. In addition, the newly developed constrained three-point-bend tests were able to reproduce plate stresses in models with a healed PFF. Furthermore, a combined bending and compression cadaveric test was appropriate for risk assessment including both plate fracture and screw loosening after the complete healing of PFF. The result of this study provides the means for combined experimental and computational preclinical evaluation of PFF fixation constructs.

Mortality, Risk Factors and Risk Assessment after Periprosthetic Femoral Fractures—A Retrospective Cohort Study

Periprosthetic femoral fracture (PFF) is a devastating complication. Here, the authors aimed to determine the influence of the timing of surgery as a risk factor for mortality and poor postoperative outcome in patients suffering from PFF. A retrospective descriptive analysis of patients treated for PFF between January 2010 and March 2018 was performed. In addition to patient and treatment characteristics, we assessed mortality rates and postoperative functional outcome by using the Harris Hip and WOMAC score. One-year mortality after PFF was 10.7%. Delayed surgery after 48 h did not negatively influence mortality after PFF. The postoperative hospital stay did not influence the mortality rate, nor did it correlate with medical scores of comorbidities, general health or functionalities. Cementation of stem correlated negatively with the WOMAC score. Deceased patients had a higher Charlson Comorbidity Index (CCI) score, while American society of Anaesthesiologists (ASA) scores did not show a significant difference. There were no differences between ORIF and revision arthroplasty. In conclusion, delayed surgery after 48 h does not negatively influence mortality after PFF. The CCI seems to be a suitable tool to assess patients’ risk for increased mortality after PFF, while the usually used ASA score is not able to achieve a relevant risk assessment.

Atypical periprosthetic femoral fractures after arthroplasty for fracture are at high risk of complications

It is difficult to investigate clinical features in a single-center study because atypical periprosthetic femoral fracture (APFF) is rare. This study aims to perform a nationwide survey of APFF to investigate the characteristics of this fracture and compare the clinical outcome with that of typical periprosthetic femoral fracture (typical PFF). A nationwide survey was performed asking for cooperation from 183 councilors of the Japanese Society for Fracture Repair. The subjects were patients with APFF injured between 2008 and 2017. The control group was comprised of patients with typical PFF of our facility injured in the same period. A total of 43 patients met the APFF definition. The control group was comprised of 75 patients with typical PFF. The rate of bisphosphonate use was significantly higher in the APFFs group than in the typical PFF group (62.8% and 32%, p < 0.02). The rate of cemented stem was significantly higher in the APFFs group than in the typical PFF group (30.2% and 6.7%, p < 0.001). In the patients with arthroplasty for hip fracture, multivariable logistic regression analyses showed that APFF was an independent risk factor of complications following the initial management (Odds ratio 11.1, 95% confidence interval 1.05–117.2, p = 0.045). However, no significant association between PFF and APFF was observed in the patients with arthroplasty for other hip diseases. The risk of complications was higher in the APFF group than in the typical PFF group in the patients with arthroplasty for fracture. When AFPP after arthroplasty for the fracture is suspected, it may be necessary to add not only internal fixation with a normal plate but also some additional treatment.