Predictive factors for one-year mortality after surgery for periprosthetic femoral fracture: A retrospective multicenter (TRON group) study.

BACKGROUND: Periprosthetic femoral fracture (PFF) after total hip arthroplasty (THA) or bipolar hip arthroplasty (BHA) represents a challenging situation and the treatment is associated with high rates of complications and mortality. The aims of this multicenter retrospective study were to determine 1-year mortality and to identify predictors associated with mortality, including patient characteristics and surgical factors, in patients undergoing surgery for PFF after THA or BHA. METHODS: We collected 249 cases of PPF after THA or BHA that were treated in our 11 hospitals (named the TRON group) between January 2010 and December 2019. We excluded patients who were conservatively treated, cases in which the 1-year postoperative outcome was unknown, and Vancouver type A cases. Finally, we analyzed 161 patients. Univariate and multivariate Cox regression analyses were performed to identify factors affecting 1-year mortality. Patient-side factors such as age, BMI, fracture type, and preoperative mobility, and surgical factors such as surgical procedure, time to surgery, and operation time were analyzed respectively. RESULTS: Eighteen of 161 patients (11.2%) died one year after surgery. The multivariate Cox regression analysis identified older age, wheelchair status before injury, and operation time as independent predictors of 1-year mortality (older age: hazard ratio [HR] 1.07, 95% CI 1.01-1.15, P = 0.048; wheelchair status: HR 5.82, 95% CI 1.01-33.47, P = 0.049; operation time: [HR] 1.01, 95% CI 1.00-1.01, P = 0.00929). Meanwhile, fracture type according to the Vancouver classification, body mass index, presence of previous fragility fractures, type of fixation, blood loss during operation, and time to surgery were not independent predictors of 1-year mortality in this analysis. ConclusionThe 1-year mortality rate after surgery for PPFs patients was 11.2%. Factors associated with older and poor activity of daily living (ADL) performance (e.g., wheelchair status before injury), and longer operative time were associated with 1-year mortality after surgery for PPF. Surgeons should carefully plan treatment according to each patient's condition.

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.

Long locking plate combined with locking attachment plate in patients with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty.

BACKGROUND: The purpose of this study was to introduce the surgical technique using long locking plate and locking attachment plate (LAP) in patient with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty (TKA). Moreover, we sought to investigate the outcomes of this fixation technique and to propose a new subtype in the existing classification of periprosthetic femoral fractures. METHODS: From January 2013 to January 2022, thirty-four consecutive periprosthetic femoral fractures around ipsilateral stem following TKA with minimum 1-year follow-up were enrolled in this study. Most cases were fixed with long-locking plate and LAP using the MIPO technique. For subgroup analysis, we classified patients with stemmed hip implant (group H) and stemmed knee implant (group K). Bone union, American Knee Society Score (AKSS) scale, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index for pain and function, and range of motion were investigated. RESULTS: The number of group H and K were 24 patients (70.6%) and 10 patients (29.4%), respectively. The mean age at operation was 71.5 years (range, 65‒85 years), and the mean follow-up period was 27.5 months (range, 12‒72 months). Bone union was confirmed radiographically in all patients, and the mean union time was 4.9 months (range, 3.5‒6 months). There were no significant differences in radiographic and clinical outcomes between the groups. CONCLUSIONS: Long-locking plate combined with LAP showed favorable radiographic and clinical outcomes in patients with periprosthetic femoral fracture around ipsilateral stem after TKA. LEVEL OF EVIDENCE: Level IV, Retrospective Case Series.

Predictive factors for reoperation after periprosthetic femoral fracture: A retrospective multicenter (TRON) study.

BACKGROUND: The surgical treatment of periprosthetic femoral fracture (PFF) can be technically demanding and it is associated with high rates of complications and repeat surgery. However, repeat surgery is uncommon and few studies have examined survival and the functional prognosis following reoperation after the surgical treatment of PFF. We aimed to estimate the rate of reoperation for any reason, to determine the survival rate after reoperation for PFF, and to identify predictors associated with reoperation after PFF surgery in a multicenter (TRON group) study. METHODS: Two hundred forty-six patients were admitted for treatment of PFF. After excluding patients managed conservatively and those with Vancouver type A fracture, we analyzed 184 patients. Unadjusted risk ratios (RRs) were calculated, and multiple logistic regression was used to calculate adjusted RRs. We used the Kaplan-Meier method to create survival curves and a log-rank test to determine survival from the date of repeat surgery. RESULTS: Fifteen of the 184 patients (8.2 %) underwent reoperation after PFF surgery. The 1-year survival rate after reoperation for PFF was 66.7 % (11 of 15). Vancouver B3 and Vancouver C were identified as independent risk factors for reoperation after PFF surgery (Vancouver B3: Risk ratio [RR] 19.0, 95 % CI 1.10-329 P < 0.001; Vancouver C: RR 13.3, 95 % CI 1.4-123.0, P = 0.023). CONCLUSION: The reoperation rate after PFF surgery and the mortality after reoperation PFF surgery were relatively high. The fracture type is associated with reoperation after PFF surgery.

Periprosthetic femoral fractures around the original cemented polished triple-tapered C-stem femoral implant: a consecutive series of 500 primary total hip arthroplasties with an average follow-up of 15 years.

INTRODUCTION: The true incidence of periprosthetic femoral fracture (PFF) around cemented polished taper-slip implants remains largely unknown. Registries usually only capture PFFs that result in revision, missing those managed non-operatively or treated by open reduction and internal fixation (ORIF). This study reports the long-term rate of PFF with the original triple-tapered C-stem femoral implant. MATERIALS AND METHODS: A prospective review of a consecutive series of 500 primary total hip arthroplasties (THAs) performed at a single centre between March 2000 and December 2005, with average follow-up of 15 years (12-19 years). RESULTS: There were 500 consecutive THAs in 455 patients. Seven PFFs (1.4%) occurred in seven patients at an average of 7.9 years (range 2-11.5) from the primary arthroplasty. Five PFFs were managed by ORIF, one Vancouver B3 fracture was revised for a loose implant and one patient was treated non-operatively. Average age at primary operation was 74 years (67-87) and BMI averaged 27.3 (22-31). There was no typical fracture pattern and no statistically significant associations with patient demographics (age, gender, BMI, diagnosis) or prosthetic details (size, offset, alignment, cement mantle, subsidence). Survivorship to the occurrence of PFF was 99% (97.3-99.6%) at 10 years and 97.8% (95.5-99.0%) at 15. CONCLUSION: A PFF rate of 1.4% at an average follow-up of 15 years represents the true incidence of PFF with the use of the original triple-tapered C-Stem femoral implant, similar to that of published Exeter series (1.85%) but lower than the CPT (3.3%).

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.

Comparable outcomes of in-cement revision and uncemented modular stem revision for Vancouver B2 periprosthetic femoral fracture at 5 years.

INTRODUCTION: Periprosthetic femoral fractures (PFF) are detrimental for patients. Vancouver B2 fractures about a cemented stem can be revised to a longer uncemented stem or using an in-cement revision, if the cement mantle is adequate. There are reports documenting the success of both techniques. The aim of this single centre study was to perform a direct comparison of these two procedures. MATERIALS AND METHODS: A retrospective study of consecutive Vancouver B2 PFFs around a cemented stem during 16 years was performed. All study cases were treated either using an in-cement revision or with an uncemented stem revision. Preoperatively, the groups were compared based upon age, gender, ASA, BMI, and Charlson comorbidity score. The outcome measures were surgical time, complications, in-hospital stay, revisions, 1-year readmission rate, and survivorship. RESULTS: After a median of 3.5 years, there were 70 patients in the uncemented and 31 in the in-cement group. There was no difference in any of the preoperative variables. Surgical time was shorter for in-cement revisions by a mean of 45 min (p < 0.001). There was no difference in in-hospital stay, surgical complications or readmissions. Implant survival at 5 years was 93.5% for the in-cement and 94.4% for the uncemented revision (p = 0.946). Patient survivorship at 5 years was 62.5% for the in-cement and 69.8% for the uncemented group (p = 0.094). CONCLUSIONS: This study demonstrates that in-cement revision is a valid treatment option for Vancouver B2 fractures, comparable to uncemented stem revision, if certain criteria are met. There was no difference in revision rate, patient survivorship, complications, readmissions or in-hospital stay.

Vancouver B and C periprosthetic fractures around the cemented Exeter Stem: sex is associate with fracture pattern.

INTRODUCTION: The aim of this study was to identify factors associated with the level of periprosthetic fracture involving a cemented polished tapered stem: Vancouver B or Vancouver C. METHODS: A retrospective cohort study of 181 unilateral periprosthetic fractures involving Exeter stems was assessed by three observers (mean age 78.5, range 39-103; mean BMI 27.1, 17-39; 97 (54%) male). Patient demographics, deprivation scores, BMI and time since primary prosthesis were recorded. Femoral diameter, femoral cortical thickness, Dorr classification and distal cement mantle length were measured from calibrated radiographs. Interobserver reliability was calculated using intraclass correlation coefficients (ICCs). Univariate and multivariate analysis was performed to identify associations with Vancouver B or C fractures. RESULTS: 160/181 (88%) Vancouver B and 21/181 (12%) Vancouver C-level fractures occurred at a mean of 5.9 ± 5.4 years (0.2-26.5) following primary surgery. Radiographic measurements demonstrated excellent agreement (ICC > 0.8, p < 0.001). Mortality was significantly higher following Vancouver C compared to B fractures: 90 day 14/160 Vs 5/21 (p = 0.05); 1 year 29/160 Vs 8/21 (p = 0.03). Univariate analysis demonstrated that Vancouver C fractures were associated with female sex, bisphosphonate use, cortical bone thickness, and distal cement mantle length (p < 0.05). On multivariate analysis, only female sex was an independent predictor of Vancouver C-level fractures (R2 =0.354, p = 0.005). CONCLUSION: Most PFFs involving the Exeter stem design are Vancouver B-type fractures and appear to be independent of osteoporosis. In contrast, Vancouver C periprosthetic fractures display typical fragility fracture characteristics and are associated with female sex, thinner femoral cortices, longer distal cement mantles and high mortality.

Modular tapered conical revision stem in hip revision surgery: mid- term results.

BACKGROUND: The aim of this paper is to evaluate the clinical and radiological outcomes of a fluted tapered modular distal-fixation stem at medium to long-term follow-up. The hypothesis of this investigation was to verify if the use of this implant design may have provided potential advantages in femoral revisions and post-traumatic instances where the restoration of the anatomy was the prime concern. METHODS: We retrospectively reviewed 62 cases of femoral revision surgeries, performed in Paprosky type IIIA and IIIB bone defects between January 2001 and December 2011 with a mean follow-up of 8.5 ± 1.5 years (range 5.1-15.9 years) where a modular fluted stem was used. The clinical assessment was performed with the Harris Hip Score (HHS), and the radiographic evaluation was carried in order to assess the stability of the femoral component. Intra-operative and postoperative complications were recorded, and the rates of complications and revisions for any cause were determined. RESULTS: Mean HHS improved 35.4 points from the preoperative assessment. Radiographic evaluation showed a stable stem anchorage in 90.3% of the cases at the last follow-up. Five (8%) implants required additional surgery. Neither breakage of the stem nor loosening of the taper junction were recorded. Kaplan-Meier survivorship was 89.4% (CI: 88.8-90%) for any complication and 92.3% (CI: 91.8-92.7%) according to revision for any causes at 81 months follow-up. CONCLUSIONS: Our findings suggest that this stem design is a reliable option in cases of complex femoral bone defects, as well as in cases with high functional deficiencies, with promising survivorship.

Finite element analysis of double-plate fixation using reversed locking compression-distal femoral plates for Vancouver B1 periprosthetic femoral fractures.

BACKGROUND: Internal fixation is recommended for treating Vancouver B1 periprosthetic femoral fractures. Although several fixation procedures have been developed with high fixation stability and union rates, long-term weight-bearing constructs are still lacking. Therefore, the aim of the present study was to evaluate the stability of a double-plate procedure using reversed contralateral locking compression-distal femoral plates for fixation of Vancouver B1 periprosthetic femoral fractures under full weight-bearing. METHODS: Single- and double-plate fixation procedures for locking compression-distal femoral plates were analysed under an axial load of 1,500 N by finite element analysis and biomechanical loading tests. A vertical loading test was performed to the prosthetic head, and the displacements and strains were calculated based on load-displacement and load-strain curves generated by the static compression tests. RESULTS: The finite element analysis revealed that double-plate fixation significantly reduced stress concentration at the lateral plate place on the fracture site. Under full weight-bearing, the maximum von Mises stress in the lateral plate was 268 MPa. On the other hand, the maximum stress in the single-plating method occurred at the defect level of the femur with a maximum stress value of 1,303 MPa. The principal strains of single- and double-plate fixation were 0.63 % and 0.058 %, respectively. Consistently, in the axial loading test, the strain values at a 1,500 N loading of the single- and double-plate fixation methods were 1,274.60 ± 11.53 and 317.33 ± 8.03 (× 10- 6), respectively. CONCLUSIONS: The present study suggests that dual-plate fixation with reversed locking compression-distal femoral plates may be an excellent treatment procedure for patients with Vancouver B1 fractures, allowing for full weight-bearing in the early postoperative period.

Periprosthetic Femoral Fracture Is a Leading Cause of Early Revision With Taper-Slip Stems in Primary Total Hip Arthroplasty: An Analysis of 2765 Total Hip Arthroplasties From a High-Volume Hospital.

BACKGROUND: In 2016, the CPT stem replaced the Exeter stem as the main cemented stem at our institution. We assessed the prevalence of revision for periprosthetic femoral fracture (PFF) in patients operated on with either CPT or Exeter stem and compared the risk for revision between these stems. METHODS: Primary total hip arthroplasties either performed in 2012-2015 with Exeter stem (n = 1443) or in 2017-2018 with CPT stem (n = 1322) were included. The prevalence of revision for PFF was compared. The Kaplan-Meier estimated survivorships were calculated for the 2 stem designs. The risk for revision was analyzed using the Cox proportional hazard regression model. RESULTS: At 2 years, PFF was the most common reason for revision in the study population (1.3% prevalence, comprising 35% of all revisions). Moreover, 1.6% (95% confidence interval [CI] 1.0-2.4) of the CPT and 1.0% (95% CI 0.6-1.6) of the Exeter stems had been revised due to PFF. The 3-year Kaplan-Meier probability estimates for all-cause revision were 4.8% for the CPT (95% CI 3.6-6.0) and 3.3% for the Exeter stem (95% CI 2.3-4.3). The hazard ratio for revision due to any reason was 1.1 (95% CI 0.3-3.8) during the first 2 weeks, and 1.8 (95% CI 1.2-2.7, P = .006) from 2 weeks onwards for the CPT compared with the Exeter stem. CONCLUSION: The considerable number of PFF revisions with taper-slip stems, especially with CPT stems, is a matter of concern. Alternative cemented stems should be considered in patients at high risk for PFF.

Periprosthetic Atypical Femoral Fractures Exist: A Retrospective Study at a Single Institution. Prevalence on 115 Periprosthetic Femoral Fractures Around a Primary Hip Stem.

BACKGROUND: Some periprosthetic femoral fractures (PFFs) present history and radiographic aspect consistent with an atypical femoral fracture (AFF), fulfilling the criteria for AFF except that PFFs by themselves are excluded from the diagnosis of AFFs. The aim of this study is to evaluate in a single institution series of PFFs if any of them could be considered a periprosthetic atypical femoral fracture (PAFF), and their prevalence. METHODS: Surgical records were searched for PFFs around a primary hip stem from January 2013 to December 2019. Cases were classified according to Vancouver classification. Demographic and medical history was extracted. Fisher's exact test was used for statistical analysis. RESULTS: One hundred fifteen PFFs were identified, 59 of them were type B1 and 16 were type C. Radiographs and medical records were available for all patients. Twenty-four patients (32%) have been treated with bisphosphonates (BPs) for longer than 4 years. Four patients presented a fracture with characteristics of PAFF. When enlarged to all PFFs of the series, no other PAFF was found: prevalence of PAFFs was 5.3% for type B1 and C cases and 3.5% for all surgically treated PFFs. Statistical significative difference between PAFFs and PFFs was found for prolonged BP assumption and for the level of fracture clear of the stem. CONCLUSION: Fracture with characteristics of AFFs can also happen over a prosthetic stem, configuring themselves as PAFFs, and they are related to prolonged BP use. As a correct diagnosis is mandatory for proper treatment, a revision of criteria for AFFs should be considered, accepting that PAFFs exist.

Early Surgery Does Not Improve Outcomes for Patients with Periprosthetic Femoral Fractures-Results from the Registry for Geriatric Trauma of the German Trauma Society.

Background and Objectives: Appropriate timing of surgery for periprosthetic femoral fractures (PFFs) in geriatric patients remains unclear. Data from a large international geriatric trauma register were analyzed to examine the outcome of patients with PFF with respect to the timing of surgical stabilization. Materials and Methods: The Registry for Geriatric Trauma of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie (DGU)) (ATR-DGU) was analyzed. Patients treated surgically for PFF were included in this analysis. As outcome parameters, in-house mortality rate and mortality at the 120-day follow-up as well as mobility, the EQ5D index score and reoperation rate were analyzed in relation to early (<48 h) or delayed (≥48 h) surgical stabilization. Results: A total of 1178 datasets met the inclusion criteria; 665 fractures were treated with osteosynthesis (56.4%), and 513 fractures were treated by implant change (43.5%). In contrast to the osteosynthesis group, the group with implant changes underwent delayed surgical treatment more often. Multivariate logistic regression analysis of mortality rate (p = 0.310), walking ability (p = 0.239) and EQ5D index after seven days (p = 0.812) revealed no significant differences between early (<48 h) and delayed (≥48 h) surgical stabilization. These items remained insignificant at the follow-up as well. However, the odds of requiring a reoperation within 120 days were significantly higher for delayed surgical treatment (OR: 1.86; p = 0.003). Conclusions: Early surgical treatment did not lead to decreased mortality rates in the acute phase or in the midterm. Except for the rate of reoperation, all other outcome parameters remained unaffected. Nevertheless, for most patients, early surgical treatment should be the goal, so as to achieve early mobilization and avoid secondary nonsurgical complications. If early stabilization is not possible, it can be assumed that orthogeriatric co-management will help protect these patients from further harm.

Non-traumatic Atypical Peri-implant Femoral Fracture at the Distal Screw after Short Femoral Nail Fixation for a Pertrochanteric Fracture.

This is the second report of an atypical peri-implant femoral fracture occurring at the distal screw after intramedullary nail fixation of a pertrochanteric fracture. A 94-year-old Japanese female with a 5-year history of alendronate intake presented with prodromal pain in her right thigh after intramedullary nail fixation. Plain radiographs showed an incomplete noncomminuted transverse fracture at the distal screw, suggesting an atypical peri-implant femoral fracture. The pathogenesis of an atypical peri-implant femoral fracture could be a combined systemic bone metabolism disorder and repetitive overloading at the screw, similar to the pathogenesis of an atypical periprosthetic femoral fracture around stem implantation.

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.

Incidence and pattern of periprosthetic hip fractures around the stem in different stem geometry.

BACKGROUND: The number of total hip arthroplasties (THA) is expected to increase worldwide; thus, complications are likely to increase at the same ratio. In this scenario, periprosthetic femoral fractures (PFFs) are an increasing concern. Identifying the predisposing factors is important in order to prevent as much as possible the risk of PFF in the future. PATIENTS AND METHODS: The purpose of this study was to correlate the risk of periprosthetic femoral fractures to the most common patients' comorbidities and stem geometry. We reviewed all THA for non-oncologic indications between 2004 and 2014 with a mean follow-up of six years (range, 2-12). Three thousand two hundred forty-eight patients (3593 implants) were enrolled in the study, and 45 PFF were registered during this time period. Two thousand five hundred seventy-seven implants (71%) were straight stems, and 1015 (28.3%) were anatomic stems. All X-rays were then analyzed and classified according to the modified Vancouver classification. RESULTS: Periprosthetic femoral fractures incidence was associated with anatomic stem geometry (p < 0.001, OR = 2.2), BMI (p < 0.001), and diabetes (p < 0.001, OR = 5.18). PFFs were not significantly associated with age, gender, and all the other variables. Fracture pattern was different between straight and anatomic stems. Clamshell fractures were more likely to occur in anatomic stems compared to straight stems (p < 0.005). CONCLUSIONS: Periprosthetic femoral fractures are highly associated with obesity and osteoporosis. Anatomic stems reported a higher incidence of PPF than straight stems. The typical fracture type for anatomical stems is the clamshell pattern, while straight stems are more likely affected by type B fractures.

Femoral Stem Survivorship in Dorr Type A Femurs After Total Hip Arthroplasty Using a Cementless Tapered Wedge Stem: A Matched Comparative Study With Type B Femurs.

BACKGROUND: There is a lack of understanding on relationship between the femoral geometry and outcomes of total hip arthroplasty (THA). We investigated clinical and radiographic outcomes of THA using a cementless tapered wedge stem in patients with Dorr type A proximal femoral morphology and compared with those of type B femurs at a minimum follow-up of 5 years. METHODS: We analyzed 1089 hips (876 patients) that underwent THA using an identical cementless tapered wedge stem. We divided all femurs into 3 types (Dorr type A, B, and C). Type A and B femurs were statistically matched with age, gender, body mass index, and diagnosis by using propensity score matching. Clinical, radiographic results, and stem survivorship were compared between the matched 2 groups. RESULTS: A total of 611 femurs (56%) were classified as type A, 427 (39%) as type B, and 51 (5%) as type C. More radiolucent lines around femoral stems were found in type A femurs (7.8%) than in type B femurs (2.5%) (P < .001). Patients with radiolucency showed worse Harris Hip Score (86.2 points) compared with those without radiolucency (93.0 points) (P < .001). The stem survivorship of type A femur (97.8%) was lower than that of type B femur (99.5%) (P = .041). The reasons for femoral revision in type A femurs were periprosthetic fracture (67%), aseptic loosening (22%), and deep infection (11%). CONCLUSIONS: This study showed a higher rate of complications after THAs using a cementless tapered wedge stem in Dorr type A femurs than those performed in type B femurs.

Cumulative Long-Term Incidence of Postoperative Periprosthetic Femoral Fractures Using an Uncemented Tapered Titanium Hip Stem: 26- to 32-Year Results.

BACKGROUND: Although falling is becoming a major problem in the elderly, little is known about the long-term incidence of postoperative periprosthetic femoral fractures (PFF) after total hip arthroplasty (THA) using uncemented stems with a minimum follow-up of 26 years postoperatively. METHODS: In a consecutive series, the cumulative incidence of PFF after uncemented THA using a straight, collarless, tapered titanium stem was retrospectively reviewed in 354 hips (326 patients). After a mean follow-up of 28 (26-32) years postoperatively, 179 hips had died and 5 hips had been lost to follow-up. Kaplan-Meier survival analysis was used to estimate cumulative percentage probability of PFF. RESULTS: At final follow-up, a total of 27 fractures in 27 patients had occurred. In 15 hips, the stem had to be revised, and in 10 the fracture was treated by open reduction and internal fixation. Two patients declined further surgery. The cumulative percentage probability of PFF was 1.6% (95% confidence interval, 0.7 to 3.8) at 10 years and 13.2% (95% confidence interval, 8.5 to 20.2) at 29 years after primary THA. There was no association between the occurrence of fracture and gender, age at primary THA, cup revision, or canal fill index. CONCLUSION: Our findings indicate that PFF is the major mode of failure in the long term after uncemented THA using a tapered titanium stem. More research is needed to evaluate the reasons and risk factors for PFF after THA, thus providing better prophylaxis for those at risk and to compare the long-term incidence using different fixation methods and implants. LEVEL OF EVIDENCE: IV.

Periprosthetic femoral fracture as cause of early revision after short stem hip arthroplasty-a multicentric analysis.

BACKGROUND: The objective of this study was to analyze the prevalence and causes of early re-operation after hip replacement surgery using short bone-preserving stems in a large multicentre series. Specifically, we evaluated the clinical features of periprosthetic fractures occurring around short stems. METHODS: A total of 897 patients (1089 hips) who underwent primary total hip arthroplasty or bipolar hemiarthroplasty from January 2011 to February 2015 using short bone-preserving femoral stems were recruited. Mean patient age was 57.4 years (range, 18-97 years), with a male ratio of 49.7% (541/1089). Re-operation for any reason within two years was used as an endpoint. The incidence and clinical characteristics of the periprosthetic femoral fractures were also recorded. Mean follow-up period was 5.1 years (range, 2-7.9 years). RESULTS: Early re-operation for any reason was identified in 16 (1.5%) of 1089 hips. The main reason for re-operation was periprosthetic femoral fracture, which accounted for eight (50%) of the 16 re-operations. The overall incidence of periprosthetic femoral fracture at two years was 1.1% (12/1089). According to the Vancouver classification, two fractures were AG type and the other ten were B1 type. Advanced age, higher American Society of Anesthesiologist grade, femur morphology of Dorr type C, and the use of a calcar-loading stem increased the risk for periprosthetic femoral fracture. CONCLUSION: Periprosthetic femoral fracture was the major reason for re-operation after hip replacement surgery using short bone-preserving stems accounting for 50% (8/16) of re-operations two years post-operatively, but did not seem to deteriorate survivorship of implanted prostheses.

The Baba classification focused on implant designs is useful in setting the therapeutic strategy for interprosthetic femoral fracture.

PURPOSE: The purpose of this study was to investigate the clinical outcomes of femoral fracture with implants on the proximal and distal sides to verify whether actual fracture morphologies follow the fracture types of Baba classification focusing on implant designs useful for periprosthetic femoral fracture. METHODS: Prosthesis was present in 85 with periprosthetic femoral fractures. Excluding 73 patients with fracture around the femoral stem or fracture of the TKA femoral component alone, 12 patients with 14 legs with both implants were investigated. All patients were radiographically assessed for implant stability according to the Baba classification. For clinical evaluation, intra- and postoperative complications, the operation time, and intra-operative blood loss were investigated. RESULTS: The Baba classification fracture type showed the implant as unstable and stable types in 3 and 11 legs, respectively. The consistency rate between the Baba classification-based judgment of plain radiograms acquired at the time of injury and actual surgical findings was 100%. As a result of treatment according to the Baba classification, bone union was achieved in all patients. There were no intra- or postoperative complications. CONCLUSIONS: Applying the Baba classification, implant stability could be sufficiently evaluated in not only periprosthetic femoral fractures following hip arthroplasty, but also interprosthetic femoral fractures, thereby verifying its usefulness in setting the treatment strategy.