Periprosthetic Fracture Research Articles

Total Femur Replacement as a Salvage Procedure for Failed Distal Femur Megaprosthesis: A Case Report and Literature Reviews

Abstract Total femoral replacement (TFR) is not a common surgery and most indications are for oncological pathologies. However, there are few instances where non-oncological indications might necessitate TFR; this may be a salvage surgery for failed previous hip and/or knee surgeries with consequent significant femur bone loss. We present a 59-year-old obese woman with right thigh pain and difficulty with walking of 5 years duration. She had undergone bilateral total knee replacement 10 years earlier on account of severe knee osteoarthritis. She had a fall 3 years prior to presentation and sustained a periprosthetic fracture around the right knee which was managed with a fixed angle blade plate and screws. This was complicated by implant breakage and non-union. She subsequently had implant removal and a right distal femur replacement (DFR) surgery 2 years prior to presentation. A year after the DFR surgery, she began to experience “start-up” pain, instability around the knee and difficulty with walking without support. A clinical and radiologic diagnosis of aseptic loosening of the distal femur megaprosthesis was made and she was offered a revision DFR surgery which also failed due to poor cementing technique, bone loss at the proximal femur, and severe osteoporosis. Patient ended up with a right total femur replacement to salvage the limb. She had improved Lower Extremity Functional Score of 27 after 12-month follow-up. TFR is a viable salvage procedure for severely compromised femur and/or significant bone loss from multiple non-oncological surgeries of the femur.

Total knee arthroplasty and periprosthetic distal femoral fracture: looking beyond the osteoporosis to previous osteoporotic fracture.

Osteoporosis is a risk factor for fractures, including those of the hip, vertebrae, and distal radius; however, the association between osteoporosis and periprosthetic fractures after total knee arthroplasty (TKA) has not been much investigated. Therefore, we aimed to investigate the association of the presence of systemic osteoporosis with periprosthetic fractures after TKA. This study included 34 patients with periprosthetic fractures following primary TKA and 106 controls matched for age and sex. Bone mineral density was evaluated at the femoral neck, total hip, and lumbar spine using dual X-ray absorptiometry. Medical records were reviewed for age; sex; body mass index; smoking; rheumatoid arthritis, endocrine diseases, and cardiovascular diseases; history of glucocorticoid use; medication for osteoporosis; and history of previous osteoporotic fracture. In addition, anterior femoral notching after TKA was evaluated. Univariable and multivariable logistic regression analysis were used to determine factors associated with periprosthetic fracture. The prevalence of osteoporosis in the fracture group was higher than that in the control group (61.8% vs. 40.6%, p=0.045). The rate of medication for osteoporosis was significantly low in the fracture group (47.6 % vs 76.7%, p=0.026). History of previous osteoporotic fracture (odds ratio [OR], 9.1; p=0.015) and osteoporosis (OR, 3.6; p=0.013) were significant risk factors for periprosthetic fractures after TKA. Medication for osteoporosis could decrease the risk of periprosthetic fracture (OR 0.3; p=0.020). Osteoporosis is a major risk factor for periprosthetic distal femoral fractures after TKA. Therefore, careful assessment and proper treatment of osteoporosis need and the importance of taking osteoporotic medication needs to be recognized to the patients following primary TKA, especially in patients with a history of osteoporotic fracture. Prognostic study, level III.

Total Hip Arthroplasty Outcomes in Patients with Gout: A Retrospective Analysis of Matched Large Cohorts.

Gout is the most prevalent form of inflammatory arthritis in the world. Total hip arthroplasty (THA) has emerged as a widely sought-after and highly effective surgical procedure for advanced hip diseases. However, there is a lack of research on the impact of gout on primary THA outcomes in large cohorts. This study aimed to address this gap by primarily investigating complications following THA in patients with or without gout. Patients with records of gout in the 2 years leading up to their primary THA and who also have at least 2 years of follow-up were identified using a national insurance database and compared to a 5:1 matched control. A total of 32,466 patients with gout and 161,514 patients without gout undergoing THA were identified. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. In addition, 90-day emergency department (ED) visits and inpatient readmission were also documented. Patients with gout demonstrated higher rates of medical complications including deep vein thrombosis, transfusion, acute kidney injury, and urinary tract infection than non-gout patients (p < 0.001). Gout patients also showed higher rates of pulmonary embolism (p = 0.017). Increased incidences of surgical complications were identified in gout patients, specifically wound complications and periprosthetic joint infection (p < 0.001). There was an increased risk of revision for gout patients up to 90 days (p = 0.003), 1 year (p = 0.027), and 2 years (p = 0.039). There was also an increased risk of dislocation for gout patients up to 90 days (p = 0.022) and 1 year (p = 0.047), but not at 2 years. No significant difference was observed in aseptic loosening or periprosthetic fracture. Additionally, gout patients also demonstrated a higher likelihood of 90-day ED visits and readmission (p < 0.001). Primary THA in gout patients is associated with increased risks of multiple medical and surgical complications. Our findings provide insights into the planning and expectation of THA for patients with gout. These insights have the potential to benefit the decision-making process for gout patients considering THA.

Clinical outcomes and survival rates of a uncemented modular revision stem system in hip arthroplasty: a 10-year single-institution study on a frail population

IntroductionThe increasing prevalence of primary hip arthroplasty has led to a parallel rise in revision cases. Femoral revision often entails compromised bone integrity, requiring consideration of various solutions for optimal reconstructive options. Despite technological advancements, there is limited evidence on the clinical outcomes of the latest modular revision stems. This study aimed to evaluate the clinical outcomes and survival rates of next generation uncemented modular revision stem in patients undergoing hip revision surgery.Materials and methodsThis retrospective single-center study assessed the survival and failure causes of a specific uncemented modular stem in 48 patients undergoing hip revision surgery between 2012 and 2022. Data included preoperative parameters, surgical details, and postoperative outcomes measured through clinical and radiographic assessments. Forty-eight patients (25 males, 23 females; mean age 72 years) were included, with a mean Charlson Comorbidity Index of 5. Preoperative diagnoses varied, with periprosthetic joint infection (PJI) being the most common (45.8%), followed by periprosthetic fractures (27.1%). Partial revisions occurred in 60.4%, total revisions in 39.6%. According to Paprosky classification of femoral bone loss, type II and III were the most represented, respectively 35.4% and 50%.ResultsAt a mean follow-up of 4.6 years, stem survival was 92.5%. Complications (20%) included dislocation, PJI, fracture, and loosening; the overall reoperation rate was 12.5%. The SF-12 physical score was 43.6, while the mental score was 51.1. The HOOS score was 71.8, and the HHS score was 71.4. Radiographic analysis identified nonprogressive osteolysis in 15.1% of patients.ConclusionsThis study on this uncemented modular revision stem demonstrated favorable outcomes in an elder fragile population with moderate to severe femoral bone loss. The implant’s modularity provides versatility in addressing various defects, without any implant breakage observed during the study period. Literature comparison highlighted similar outcomes despite sample size differences. The promising results warrant continued investigation into the long-term survivorship of this modular stem system.

Short-term clinical and radiographic outcomes with modular long stem for revision reverse total shoulder arthroplasty

BackgroundWhen performing reverse total shoulder arthroplasty with compromised proximal bone fixation, surgeons must consider using specialized stems with a distal press-fit design. In this study, the authors report on the clinical and radiographic outcomes of patients who underwent surgical management with modular diaphyseal press-fit stems. MethodsIn 2017-2021, patients who underwent revision reverse total shoulder arthroplasty reconstruction with diaphyseal press-fit stems (Aequalis Adjustable Stem [AS] or Aequalis Flex Revive Stem [RS]; Stryker, Kalamazoo, MI, USA) with minimum 1-year follow-up were identified. Patients with complex proximal humerus and scapula fractures, neurological injuries, and custom humeral replacements were excluded. Demographics and clinical follow-up data including range of motion, Visual Analog Scale (VAS), Simple Shoulder Test (SST), American Shoulder Elbow Surgeons (ASES) Score, and Single Assessment Numeric Evaluation were retrospectively reviewed. Postoperative radiographs were reviewed for aseptic humeral loosening, periprosthetic instability, stress shielding, periprosthetic fractures, and humeral stem failure. ResultsSixty-five patients (29 AS and 36 RS) had mean follow-up of 25 months (standard deviation ± 16). Mean anterior elevation improved from 57° ± 39 preoperative to 121° ± 31 postoperatively. Mean external rotation improved from 3° ± 17 to 34° ± 16. Mean internal rotation improved from 4° ± 13 to 35° ± 26. Mean VAS improved from 6.7 ± 2.2 to 2.9 ± 1.5. Mean SST improved from 13% ± 13% to 65% ± 22%. Mean ASES score improved from 19 ± 13 to 60 ± 18. Mean Single Assessment Numeric Evaluation improved from 25% ± 18% to 71% ± 17%. There were statistically significant differences in mean postoperative VAS (P = .0017), SST (P = .025), and ASES score (P = .0228) in favor of the RS group. There were no other notable differences between groups. The most common complications were aseptic humeral stem loosening (24% vs. 3%, P = .018) and periprosthetic instability (10% vs. 6%, P = .649) for the AS and RS cohorts, respectively. There was no statistically significant difference between surgical revision rates between the AS and RS cohorts (24% vs. 8%, respectively. P = .096). DiscussionDiaphyseal press-fit modular humeral stem can provide a viable surgical alternative in compromised proximal humeral bone. At short-term follow-up, the clinical and radiographic outcomes are comparable to other stem designs. Further studies are necessary to identify risks and causes of failure associated with modular diaphyseal press-fit stems.

High Rates of Early Septic Failure, but Low Rates of Aseptic Loosening After Revision Total Knee Arthroplasty With Contemporary Rotating-Hinge Prostheses

BackgroundThe purpose of this study was to determine implant survivorship and functional outcomes for revision total knee arthroplasty (rTKA) with contemporary rotating-hinge knee implants. MethodsA retrospective review identified 115 rTKAs using contemporary rotating-hinge implants from 2014 to 2018 for the treatment of instability (34, 30%), reimplantation after periprosthetic joint infection (PJI) (33, 29%), aseptic loosening (25, 22%), arthrofibrosis (14, 12%), periprosthetic fracture (4, 3%), osteolysis (4, 3%), and femoral component fracture (1, 1%). There were 70 women (61%), and the mean age was 67 years (range, 27 to 94). The mean follow-up was 3 years (range, 2 to 6). Kaplan-Meier analysis and Cox proportional hazard models estimated survivorship. ResultsThe re-revision rate was 20% (23 of 115) at an average of 18 months postoperatively. Re-revision indications included PJI (n = 14), aseptic loosening (n = 4), arthrofibrosis (n = 2), instability/malalignment (n = 1), femoral stem fracture (n = 1), and hinge mechanism disruption (n = 1). At 2 and 5 years, survivorship free from all-cause re-revision was 86 and 64%, and survivorship free from re-revision for aseptic loosening was 100 and 87%, respectively. Use of a rotating-hinge implant in reimplantation after PJI was a risk factor for subsequent re-revision (hazard ratio = 2.4, P = 0.046). On a radiographic review of unrevised rotating-hinges, there were major radiolucent lines around 2 femoral and 5 tibial components. The mean Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement increased from 43 preoperatively to 60 at 1 year (P < 0.001). ConclusionsIn patients treated with a rotating-hinge implant for rTKA, there were relatively poor 2-year (86%) and 5-year (64%) survivorship free from all-cause re-revision, most commonly due to PJI. Midterm survivorship free from re-revision for aseptic loosening was modest (87%). There should be a goal to mitigate complications in complex rTKAs with rotating-hinge implants, namely PJI.

Outcomes of Dual Mobility Versus Fixed-Bearing Components in Revision Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BackgroundDual mobility (DM) implants have received increasing interest in revision surgery due to their increased stability. The aim of this systematic review was to compare outcomes of DM versus conventional fixed-bearing (FB) implants in revision total hip arthroplasty (rTHA). MethodsA comprehensive search was performed using the PubMed, Embase, and MEDLINE databases between January 2000 and 2023. Outcome measures included rerevision due to dislocation, rerevision for other causes, all-cause rerevision, total complication rate, and functional outcome measures. The Methodological Index for Nonrandomized Studies assessment tool was used to evaluate methodological quality and the risk of bias. A pooled meta-analysis was conducted, with an assessment of heterogeneity using the Chi-square and Higgins I2 tests. A further subgroup analysis was performed between DM implants and larger femoral head (> 36 mm) FB implants. ResultsA total of 13 studies met the final inclusion criteria, with an overall number of 5,004 rTHA hips included (2,108 DM and 2,896 FB). The DM implants had significantly lower odds of rerevision due to dislocation (odds ratio [OR] 0.38, P < 0.001), aseptic loosening (OR 0.54, P = 0.004), and all-cause rerevision (OR 0.55, P < 0.001) compared to FB implants. No statistically significant difference was seen in the odds of rerevision due to periprosthetic joint infection (OR 0.99, P = 0.94) or periprosthetic fracture (OR 0.59, P = 0.13) between the 2 groups. The total number of complications showed an odds benefit in favor of DM implants (OR 0.43, P < 0.001). In the subgroup analysis, there was no significant difference in the odds of rerevision due to dislocation (OR 0.69, P = 0.11) between DM and larger femoral head FB implants. ConclusionsBased on current literature, it appears DM implants are an effective modality for reducing dislocation following rTHA with lower complication rates compared to FB implants. However, further prospective randomized controlled trials with longer term follow-up are required.

Morbidity and mortality following surgical treatment in periprosthetic femoral fractures. Is time to surgery the key?

Morbidity and mortality following surgical treatment in periprosthetic femoral fractures. Is time to surgery the key?

Managing B2 periprosthetic femoral fractures: ORIF vs stem-revision

BackgroundThe gold-standard treatment for Vancouver type B2 and B3 fractures is revision arthroplasty. This procedure can be prolonged and complex, posing challenges for patients with severe medical comorbidities and reduced physical status. Recently, osteosynthesis has been proposed as an alternative treatment for B2 periprosthetic femoral fractures (PFF) in frail patients, though its efficacy compared to revision arthroplasty has not been studied in detail. MethodsA retrospective study was conducted from 2012 to 2022, comparing complications, mortality, length of stay, gait ability, hemoglobin decrease, and blood transfusion rates between 44 patients undergoing treatment for B2 or B3 PPF with either stem-revision arthroplasty (n = 28) or open reduction and internal fixation (ORIF) with plates and screws (n = 16). ResultsThe results showed no significant differences in mortality, complications, hemoglobin decrease, blood transfusion rate, or length of stay between the two groups. In the stem-revision group, 11 patients (60.7 %) experienced a medical complication, while 7 patients (43.8 %) in the ORIF group had complications (p = 0.778). The mortality rate within the first year post-surgery was 17.9 % (5 patients) in the stem-revision group compared to 18.8 % (3 patients) in the ORIF group (p = 0.943). Surgical complications occurred in 2 patients (7.1 %) in the stem-revision group and in 4 patients (25 %) in the ORIF group (p = 0.101). Blood transfusions were required in 17 patients (60.7 %) in the stem-revision group and in 8 patients (50 %) in the ORIF group (p = 0.829). ConclusionsThis study suggests that ORIF is an acceptable treatment option for patients with B2 or B3 PFF, especially for those with severe medical comorbidities and reduced physical status who may not tolerate revision arthroplasty. However, further research with larger sample sizes and longer follow-up periods is needed to confirm these findings. Level of EvidenceIV

Periprosthetic Femoral Fractures-Beyond B2.

The proliferation of hip arthroplasty has seen concomitant increases in periprosthetic femoral fractures (PFFs). The most common pattern involves fracture at the level of a loose prosthesis (B2). B2 PFFs have a unique mechanopathogenesis linked to the tendency of polished taper-slip cemented stems to subside in the cement. Such stems carry a much higher PFF risk than other cemented designs. Mega-data, consistent across national registries, suggest that increasing application of the taper-slip principle has resulted in the emergence of highly polished, very low friction cemented prostheses. These have the propensity to migrate within the cement, increasing B2 PFF risk. This would explain the strong association between cobalt-chromium stems and PFF. Is PFF the mode of failure of polished taper-slip stems rather than aseptic loosening? Established wisdom teaches that B2 PFFs should be managed with revision surgery. There is a large body of new evidence that, in certain instances, fixation results in outcomes at least equivalent to revision arthroplasty, with shorter surgical time, decreased transfusion requirements, and lower dislocation risk. This is so in B2 PFFs around cemented polished taper-slip stems with an intact bone-cement interface. We outline advances in understanding of B2 PFF with special reference to mechanopathogenesis and indications for fixation.

Periprosthetic Ulna Fractures Following Aptis Distal Radioulnar Joint Arthroplasty: A Series of Four Cases

Periprosthetic Ulna Fractures Following Aptis Distal Radioulnar Joint Arthroplasty: A Series of Four Cases

Complications after reverse shoulder arthroplasty for proximal humerus nonunion

BackgroundProximal humerus nonunion is a challenging complication of fractures that can be treated surgically with either open reduction internal fixation (ORIF) or reverse total shoulder arthroplasty (RTSA). The few studies published on this subject have shown high rates of complications and revision surgery when RTSA has been performed for proximal humerus nonunion. The purpose of this study was to determine the rates of complications and revision of this procedure at our institution, as well as to identify any variables that may impact risks of complications and reoperations. MethodsA single-institution retrospective review of all patients who underwent RTSA for proximal humerus nonunion between 2005 and 2021 was performed. Nonunion was defined as imaging evidence of lack of union, at least 90 days after the index fracture. Patients with less than one year of clinical follow-up were excluded. Fifty patients were included, with the majority being female (78%). The mean age at time of RTSA was 71 (range: 54-86) years and most patients were initially treated nonoperatively (74%). Mean total follow-up was 49 (range: 11-130) months. Demographic and surgical variables were recorded. Primary outcomes were complications and reoperations. Complications were divided into surgical (those directly related to RTSA), or other (those unrelated to RTSA). Secondary outcomes included VAS pain scores and range of motion. ResultsA total of 17 shoulders (34%) sustained complications after RSA, with 10 (20%) requiring reoperation. Six patients (12%) sustained dislocations and 5 (10%) had radiographic evidence of humeral loosening. No variables examined, including nonoperative vs surgical management of the index fracture, prosthesis type, or management of tuberosities, influenced the risk of dislocation. Survivorship free from reoperation at 2 years was 73%. Younger age at time of RTSA and the presence of diabetes mellitus both increased the risk of reoperation significantly (p=0.013 and p=0.037, respectively). There was a trend towards increased risk of reoperation in patients who were treated with initial ORIF (HR=2.95); however, this did not reach statistical significance (p=0.088). Three patients (6%) sustained a periprosthetic fracture after a fall. ConclusionRTSA provides improved pain and function for properly selected patients with proximal humerus nonunion. Dislocation, humeral loosening, and reoperation rates remain high when RTSA is performed for nonunion compared to other diagnoses. In this study, younger age and diabetes mellitus increased the odds of reoperation. Every effort must be made to optimize implant stability and humeral component fixation when RTSA is performed for proximal humerus nonunion.

Association between disease activity of rheumatoid arthritis and risk of complications following total hip arthroplasty: a retrospective cohort study

BackgroundIdentifying rheumatoid arthritis patients at higher risk of complications after total hip arthroplasty could make perioperative management more effective. Here we examined whether disease activity is associated with risk of such complications.MethodsWe retrospectively analyzed data for 337 rheumatoid arthritis patients at our medical center who underwent primary total hip arthroplasty. Rheumatoid arthritis patients were categorized according to the simplified disease activity index (SDAI), the values of which at admission and follow-up were averaged together. Logistic regression was used to examine associations of mean SDAI with rates of dislocation, infection, periprosthetic fracture and aseptic loosening. As controls, 337 osteoarthritis patients who did not have systemic inflammation and who underwent the same procedure were matched across numerous clinicodemographic variables.ResultsAmong the 337 rheumatoid arthritis patients, 38 (11.3%) had postoperative complications, the rates of which varied significantly from 0 to 17.5% (p = 0.003) among the four subgroups whose disease activity based on mean SDAI was categorized as high, moderate, low or in remission. Each 1-unit increase in mean SDAI was associated with a significant increase in risk of postoperative complications (OR 1.015, 95% CI 1.001–1.029, p = 0.035). Across all rheumatoid arthritis patients, rate of complications did not differ significantly between patients who received disease-modifying anti-rheumatic drugs or other treatments. Rates of dislocation, of infection or of all postoperative complications combined were significantly lower among osteoarthritis controls than among rheumatoid arthritis patients.ConclusionGreater mean SDAI is associated with higher risk of dislocation, infection and composite postoperative complications after total hip arthroplasty in rheumatoid arthritis patients. These patients show a significantly higher rate of postoperative complications than osteoarthritis patients, likely reflecting the influence of systemic inflammation. Disease activity should be reduced as much as possible in rheumatoid arthritis patients before they undergo total hip arthroplasty.

Total elbow arthroplasty and hemiarthroplasty in the treatment of distal humerus fractures in the elderly: Experience from a tertiary referral centre

BackgroundThere is no clear consensus on whether total elbow arthroplasty (TEA) or hemiarthroplasty (HA) is superior for treating distal humerus fractures in the elderly. This study analysed the functional outcomes and re-operation rates following TEA and HA for intra-articular distal humerus fractures in patients aged ≥65 years. Methods19 patients (TEA = 12, HA = 7) treated between 2016 and 2022 were retrospectively reviewed. Mean age was 73 years and mean follow-up was 46 months. Functional outcomes and quality of life were assessed using the Mayo Elbow Performance Score (MEPS), Quick-DASH (Q-DASH), Oxford Elbow Score (OES), SF-12 Physical Component Score (PCS) and Mental Component Score (MCS), and EQ-5D. Complications requiring re-operation were recorded. ResultsHA showed superior outcomes in MEPS (93.6 vs 75.0, p = 0.0339), Q-DASH (13.3 vs 31.3, p = 0.0182), OES (41.7 vs 33.2, p = 0.0346), SF-12 PCS (55.5 vs 36.9, p = 0.0008) and EQ-5D (83 vs 67, p = 0.0023). One HA patient required revision to TEA for prosthetic joint infection. One TEA patient required revision for a periprosthetic ulna fracture. ConclusionHA provides better functional outcomes compared to TEA in the treatment of distal humerus fractures in the elderly. Data is limited by selection bias and low patient numbers with a multicentre randomised controlled trial warranted.

Atypical Periprosthetic Femoral Fracture Might be Considered a Distinct Subtype of Atypical Femoral Fracture: A Retrospective Study.

The exact relationship among atypical periprosthetic femoral fractures (APFFs), typical periprosthetic femoral fractures (PFFs), and atypical femur fractures (AFFs) remains unclear. This study aimed to investigate the prevalence of APFFs among PFFs and to identify the clinical characteristics, management, and prognosis that distinguish APFFs from typical PFFs and AFFs to further determine the relationship among these three fracture types. In this retrospective study, we reviewed the clinical data of 117 consecutive patients who had PFFs after hip arthroplasty between January 2012 and December 2022 and further classified them into an APFF group and a typical PFF group according to the revised ASBMR diagnostic criteria for AFF. Moreover, patients who had subtrochanteric or femoral shaft fractures in the same period and met the diagnostic criteria for AFF were recruited and classified into the AFF group. Demographic information, minor features of AFF, comorbidities, history of medication usage, management, and complications were collected and compared among patients with typical PFFs, APFFs, and AFFs. Eleven PFFs were identified as APFFs, and the prevalence of APFFs among PFFs was 9.4%. Significant differences were found in generalized increase in cortical thickness (p = 0.019), prodromal symptoms (p < 0.001), and the incidence of bilateral fractures (p = 0.010) among the groups, where the incidences of these minor features in the APFF group and the AFF group were higher than those in the typical PFF group. Of note, the duration of fracture healing of APFFs was significantly longer than that of typical PFFs and AFFs (p < 0.001 and p = 0.004, respectively). In addition, the APFF group and the AFF group had higher proportions of patients with rheumatoid arthritis (p = 0.004 and p = 0.027, respectively), bisphosphonate (BP) usage (p = 0.026 and p < 0.001, respectively), and longer duration of BP usage (p = 0.003 and p = 0.007, respectively) than the typical PFF group. Furthermore, significant differences were found in management (p < 0.001) and complication rate (p = 0.020) among the groups, and the rate of complications in the APFF group and the AFF group was higher than that in the typical PFF group. APFFs not only fulfilled the mandatory and major diagnostic criteria for AFF but also had many clinical characteristics, management and prognosis distinguishing them from typical PFFs but resembling AFFs; hence, the diagnostic criteria for AFF might be revised to incorporate APFF as a distinct subtype of the condition.

Biomechanical analysis of patient specific cone vs conventional stem in revision total knee arthroplasty

BackgroundIn revision total knee arthroplasty, addressing significant bone loss often involves the use of cemented or press-fit stems to ensure implant stability and long-term fixation. A possible alternative to stem was recently introduced utilizing custom-made porous metaphyseal cones, designed to reconstruct the missing tibial and femoral geometries. Early clinical and radiological assessments have shown promising results. The objective of this research was to biomechanically evaluate the performances of these custom-made cones.MethodsThe biomechanical study was conducted using a validated finite element model. The bone geometries of a patient (selected for their history of four knee revisions due to infection and periprosthetic fractures, followed by a successful treatment with custom-made 3D-printed metaphyseal cones) were employed for the study. On these bone models, different revision scenarios were simulated and examined biomechanically: (A) custom-made cementless metaphyseal cones; (B) cemented stems; (C) press-fit stems; (D) distal femoral reconstruction with press-fit stem. All the models were analyzed at 0 °and 90 °of flexion, under physiological load conditions simulating daily activities; stress distribution, average Von-Mises stresses and risk of fracture were then analyzed and compared among configurations.ResultsThe use of custom-made 3D-printed cones exhibited the most favorable stress distribution in both femoral and tibial bones. Tibial bone stress was evenly distributed in custom-made cone configurations, while stress concentration was observed in distal regions for the other scenarios. Additionally, custom-made cones displayed overall homogeneity and lower stress levels, potentially contributing to limit pain. Symmetrical stress distribution was observed between the lateral and medial proximal tibia in custom-made cone models, whereas other scenarios exhibited uneven stress, particularly in the anterior tibial bone.ConclusionsThe biomechanical analysis of porous custom-made metaphyseal cones in re-revision arthroplasties is in agreement with the positive clinical and radiological outcomes. These findings provide valuable insights into the potential benefits of using custom-made cones, which offer more uniform stress distribution and may contribute to improve patient outcomes in revision TKA procedures. Further studies in this direction are warranted to validate these biomechanical findings.

Osteoporosis should be evaluated by bone mineral density at the combination of the lumbar spine and ipsilateral femoral neck in female patients with knee osteoarthritis scheduled for knee arthroplasty: A retrospective observational study

BackgroundKnee arthroplasty is a well-established surgery with good clinical outcomes. However, periprosthetic fractures and aseptic loosening negatively impact clinical outcomes, and osteoporosis is one of the causes of such complication. Osteoporosis is usually evaluated by bone mineral density of the lumbar spine and hip using dual-energy X-ray absorptiometry (DXA). However, the prevalence of this disease in patients with knee osteoarthritis scheduled for knee arthroplasty may be underestimated due to differences in the measurement sites. This study aimed to determine the appropriate measurement site for DXA that would not miss osteoporosis in female patients with knee osteoarthritis undergoing knee arthroplasty. MethodsWe measured bone mineral density preoperatively in the consecutive 50 female patients with knee osteoarthritis scheduled for knee arthroplasty by dual-energy X-ray absorptiometry at five sites: the lumbar spine, bilateral-total hip, and femoral neck. We then compared the prevalence of osteoporosis among the four combinations of the lumbar spine and single hip site (ipsilateral or contralateral total hip or femoral neck). ResultsOsteoporosis prevalence in the combination of the lumbar spine and ipsilateral or contralateral total hip was 32%, and that in the combination of the lumbar spine and contralateral femoral neck was 44%. Notably, the disease's prevalence in the combination of the lumbar spine and ipsilateral femoral neck was 50%, which was significantly higher than that in the other combinations. ConclusionOsteoporosis should be evaluated by bone mineral density in the combination of the lumbar spine and ipsilateral femoral neck in female patients with knee osteoarthritis scheduled for knee arthroplasty.

Callus formation after total hip arthroplasty using a short tapered-wedge stem.

The incidence of periprosthetic fractures after total hip arthroplasty using a short tapered-wedge stem is high. Callus formation preceding this fracture, which indicates postoperative stress fracture around the stem, has been reported. However, previous studies on postoperative callus are limited. Hence, the current study aimed to evaluate the prevalence and risk factors of postoperative callus after total hip arthroplasty with a short tapered-wedge stem. This retrospective study included 127 patients who underwent total hip arthroplasty using a cementless short tapered-wedge stem. The depth of stem insertion was measured as the distance from the lateral corner of the stem to the most medial point of the lesser trochanter along the body axis. Postoperative callus was defined as a bridging callus on the lateral femoral cortex at the distal end of the porous coating of the stem. Plain radiography was performed before surgery and immediately and at 1, 3, and 6months after surgery to assess postoperative callus. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for PC. In total, 60 (47.2%) of 127 patients presented with postoperative callus. Multivariate logistic regression analysis with postoperative callus as the dependent variable revealed that the stem depth at 1month after total hip arthroplasty (odds ratio, 1.14; 95% confidence interval, 1.04-1.24, p = 0.002) was a significant and independent risk factor of postoperative callus. Deep insertion of a short tapered-wedge stem is a risk factor for postoperative callus.

Prediction of Early Adverse Events After THA: A Comparison of Different Machine-Learning Strategies Based on 262,356 Observations From the Nordic Arthroplasty Register Association (NARA) Dataset.

Preoperative risk prediction models can support shared decision-making before total hip arthroplasties (THAs). Here, we compare different machine-learning (ML) approaches to predict the six-month risk of adverse events following primary THA to obtain accurate yet simple-to-use risk prediction models. We extracted data on primary THAs (N = 262,356) between 2010 and 2018 from the Nordic Arthroplasty Register Association dataset. We benchmarked a variety of ML algorithms in terms of the area under the receiver operating characteristic curve (AUROC) for predicting the risk of revision caused by periprosthetic joint infection (PJI), dislocation or periprosthetic fracture (PPF), and death. All models were internally validated against a randomly selected test cohort (one-third of the data) that was not used for training the models. The incidences of revisions because of PJI, dislocation, and PPF were 0.8%, 0.4%, and 0.3%, respectively, and the incidence of death was 1.2%. Overall, Lasso regression with stable iterative variable selection (SIVS) produced models using only four to five input variables but with AUROC comparable to more complex models using all 32 variables available. The SIVS-based Lasso models based on age, sex, preoperative diagnosis, bearing couple, fixation, and surgical approach predicted the risk of revisions caused by PJI, dislocations, and PPF, as well as death, with AUROCs of 0.61, 0.67, 0.76, and 0.86, respectively. Our study demonstrates that satisfactory predictive potential for adverse events following THA can be reached with parsimonious modeling strategies. The SIVS-based Lasso models may serve as simple-to-use tools for clinical risk assessment in the future.

OUTCOMES OF DISTAL FEMUR FRACTURE IN THE ELDERLY TREATED WITH EITHER SINGLE PLATE OR DUAL PLATING OR NAIL-PLATE COMBINATION: A RETROSPECTIVE ANALYSIS FROM A SINGLE CENTRE

IntroductionDistal femur fracture fixation in elderly presents significant challenges due to osteoporosis and associated comorbidities. There has been an evolution in the management of these fractures with a description of various surgical techniques and fixation methods; however, currently, there is no consensus on the standard of care. Non-union rates of up to 19% and mortality rates of up to 26 % at one year have been reported in the literature. Delay in surgery and delay in mobilisation post-operatively have been identified as two main factors for high rate of mortality. As biomechanical studies have proved better stability with dual plating or nail-plate combination, a trend has been shifting for past few years towards rigid fixation to allow early mobilisation. Our study aims to compare outcomes of distal femur fractures managed with either single plate (SP), dual plating (DP) or nail-plate construct (NP).MethodsA retrospective review of patients aged above 65 years with distal femur fractures (both native and peri-prosthetic) who underwent surgical management between June 2020 and May 2023 was conducted. Patients were divided into three groups based on mode of fixation - single plate or dual plating or nail-plate construct. AO/OTA classification was used for non-periprosthetic, and Unified classification system (UCS) was used for periprosthetic fractures. Data on patient demographics, fracture characteristics, surgical details, postoperative complications, re-operation rate, radiological outcomes and mortality rate were evaluated. Primary objective was to compare re-operation rate and mortality rate between 3 groups at 30 days, 6 months and at 1 year.ResultsA cohort of 32 patients with distal femur fractures were included in this study. 91% were females and mean age was 80.97 (range 68–97). 18 (53%) were non-periprosthetic fracture and 14 (47%) were periprosthetic fractures.18 patients underwent single plate fixation (AO/OTA 33A – 8, 33B/C – 2, UCS V3B – 5, V3C – 3),10 patients had dual plate fixation (AO/OTA 33A – 1, 33B/C – 4, UCS V3B – 3, V3C – 2) and 4 patients underwent nail-plate combination fixation (AO/OTA 33A – 4). 70.5% patients had surgery within 36 hours of admission and 90% within 48 hours. Analysis showed no re-operation at 30 days, 6 months in all 3 groups. At 1 year one patient had re-operation in dual-plating periprosthetic group (Distal femur replacement done for failed fixation). Three patients (16%) in single plate group had re-operation at 2 years (2 for peri-implant fracture and 1 for infection). None of the patients treated with Nail-plate combination had re-operation. Mortality rate at 30 days was 0% in among all the 3 groups. At 6 months, it was 16% in single plate group and 0% in DP and NP groups at 6 months and at 1 year mortality rate was 27% in SP group, 10% in DP and 0% in NP group. Combined mortality rate was 0% at 30 days, 9% at 6 months and 18.7% at one year.ConclusionOur analysis provides insights into fixation methods of distal femur fractures in elderly patients. We conclude that a lower re-operation rate and mortality rate can be achieved with early surgery and rigid fixation with either dual plating or nail-plate construct to allow early mobilisation. Further prospective studies are warranted to confirm these findings and guide the selection of optimal surgical strategies for these challenging fractures.