BACKGROUND:Simultaneous bilateral total knee arthroplasty (TKA) is associated with increased perioperative risk compared with unilateral procedures, making accurate risk stratification essential. Several comorbidity indices are widely used in arthroplasty; however, their comparative performance in simultaneous bilateral TKA remains unclear. This study aimed to compare the predictive ability of four commonly used indices, the age-adjusted Charlson Comorbidity Index (aCCI), the Elixhauser Comorbidity Index (ECI), the 5-factor modified Frailty Index (mFI-5), and the health-related quality of life comorbidity index (HRQoL-CI), for postoperative outcomes following simultaneous bilateral TKA. METHODS:This study included 1,785 patients who underwent simultaneous bilateral TKA between 2010 and 2020. The cohort had a mean age of 71 years (range, 51 to 91), 81.0% were women, and the mean body mass index was 28.2 (range, 17.1 to 42.4). The primary outcomes were 90-day readmissions, including medical, surgical, and surgery-related infection complications. The secondary outcomes included 1-year reoperations and prolonged lengths of stay (≥ eight days). Predictive performance of each index was assessed using receiver operating characteristic analyses, with area under the curve (AUC) values compared using DeLong tests. RESULTS:The aCCI demonstrated the highest discriminative ability for overall readmissions (AUC: 0.778), outperforming ECI (AUC: 0.680), mFI-5 (AUC: 0.654), and HRQoL-CI (AUC: 0.698). All indices showed excellent performance for predicting medical readmissions (AUC range, 0.806 to 0.843). For surgical and surgery-related infection readmissions, aCCI consistently demonstrated superior discrimination, with higher AUC values compared with other indices. For 1-year reoperations and prolonged lengths of stay, all indices showed poor to acceptable predictive ability. CONCLUSIONS:Among commonly used comorbidity indices, aCCI demonstrated the most clinically predictive performance for 90-day readmissions following simultaneous bilateral TKA, particularly for surgical and surgery-related infection complications. These findings support the use of aCCI as a practical tool for perioperative risk stratification in this population.
BACKGROUND:Cementless total knee arthroplasty (TKA) has reemerged with advances in implant design promoting improved durability. However, differences in the utilization of emerging orthopaedic technologies persist, and the influence of race and socioeconomic status on cementless fixation adoption remains unclear. This study evaluated national trends in cementless TKA utilization across race and socioeconomic status. METHODS:Medicare fee-for-service claims (2016 to 2022) were used to identify adult patients who underwent primary, elective, inpatient TKA via International Classification of Diseases, Tenth Revision, Procedure Coding System codes. Patients were grouped by race (White, Black, or Hispanic) and dual Medicare-Medicaid eligibility (yes/no) as a proxy for socioeconomic status. Procedures were categorized as cementless or cemented fixation. Cochran-Armitage trend tests and compound annual growth rate (CAGR) were used to evaluate annual trends. Multivariable logistic regression models examined the association between race-socioeconomic subgroups and cementless fixation, adjusting for demographic, clinical, and hospital factors. RESULTS:Among 1,044,345 TKAs, 4.8% (50,141) were cementless, increasing from 2.4% in 2016 to 9.9% in 2022 (CAGR 26.7%; P < 0.0001). The CAGR for cementless TKA was highest for Hispanic non-dual-eligible (CAGR 30.6%) and White non-dual-eligible (CAGR 27.3%) patients and lowest among Hispanic dual-eligible patients (CAGR 16.9%). After multivariable adjustment, Black dual-eligible (odds ratio (OR) 0.92; P = 0.015), Hispanic dual-eligible (OR 0.86; P = 0.004), and Hispanic non-dual-eligible (OR 0.84; P = 0.030) patients had significantly lower odds of receiving cementless fixation versus White non-dual-eligible counterparts. Black non-dual-eligible patients demonstrated higher odds (OR 1.05; P = 0.041). Although several differences reached statistical significance, the magnitude of adjusted odds ratios was modest. CONCLUSION:Cementless TKA grew across all race-socioeconomic categories among Medicare beneficiaries. However, most minority and lower-income subgroups were less likely to receive this reemerging technique, with differences concentrated among Hispanic and dual-eligible patients. These findings highlight variation in adoption of emerging orthopaedic technologies across patient populations.
INTRODUCTION:Practice guidelines in the United States (US) recommend cemented femoral fixation in hemiarthroplasty (HA) and total hip arthroplasty (THA) to treat femoral neck fractures (FNFs) for older patients. The purpose of this study was to assess regional variation and hospital characteristics associated with cement use for HA and THA used to treat FNFs and to determine the impact of cement use on adverse outcomes. METHODS:All FNF patients ≥ 65 years treated with HA or THA from 2012 to 2021 in the American Joint Replacement Registry (AJRR) were analyzed. There were 81,610 cases included: 15,282 THAs and 66,328 HAs. Patient demographics, cement use stratified by region and hospital type, and adverse outcomes were recorded. Multivariate analyses were performed. RESULTS:Cemented femoral fixation was used in 39.8% of combined HA and THA cases with greater frequency in HA (44.5%) compared with THA (19.2%, P < 0.001). Cement utilization ranged from 6 to 83% by state with 2-fold variation comparing Midwest and Southern regions (56 versus 29%, respectively, P < 0.001). Major teaching centers were more likely to use cement than non-teaching institutions (odds ratio (OR) 1.84, P < 0.001). Cemented compared with cementless fixation had a lower hazard ratio for all-cause revision (hazard ratio (HR): 0.75; P < 0.001), revision at three months (HR: 0.64; CI [confidence interval]: 0.554 to 0.75, P < 0.001), and revision for periprosthetic fracture (HR: 0.21; CI: 0.15 to 0.30, P < 0.001). Cemented fixation had an 8.9% higher hazard for mortality (HR: 1.089; CI: 1.06 to 1.12; P = 0.001). CONCLUSIONS:There is significant regional variation regarding the prevalence of cemented femoral fixation used to treat FNFs with either HA or THA in the US. Cemented fixation resulted in a lower risk of periprosthetic fracture and revision surgery. Higher mortality was associated with cemented fixation, but may relate to selection bias. The observed variation in clinical practice and lack of conformity to published guidelines is an opportunity for quality improvement.
BACKGROUND:Studies show better outcomes with total knee arthroplasty (TKA) when native knee alignment is restored, but few studies examined the relationship between coronal spinal and limb alignment after TKA. METHODS:We retrospectively reviewed 256 patients who had bilateral TKA (BTKA) and had a minimum two-year follow-up (FU). In full-body radiographic imaging, individuals who had symmetrically well-aligned lower limbs were included. The distance between the C7 plumb line (C7PL) and the central sacral vertical line (CSVL) was measured for assessment of coronal spinal imbalance (CSI). Patients were divided into two groups: Group A, balanced spine, and Group B, imbalanced spine. Clinical outcomes and side preference were evaluated. At a mean FU of 35.0 months, 122 patients fulfilled the final evaluation (Group A, n = 51 [41.8%]; Group B, n = 71 [58.2%]) and had a mean age of 69 years (range, 53 to 88). Notably, 81.3% of the patients were women. Overall, 52.5% had neutral mechanical alignment (nMA), and 47.5% had adjusted mechanical alignment (aMA). RESULTS:In Group A, 71.0% showed no significant side preference. In contrast, 91.5% of Group B participants preferred the same knee toward which the spine was shifted (P < 0.0001). The mean Knee Society Score and Forgotten Joint Score of the studied group significantly improved to 154.9 and 71.7 points, respectively, with no difference between the two groups (164.6 versus 148.2, P = 0.203, and 77.6 versus 67.6, P = 0.199). CONCLUSION:Patients who had CSI preferred the knee towards the spinal shift, while both groups showed significantly improved clinical outcomes. As body weight shifts to one side, the muscles around that knee may strengthen, making that knee the dominant side. While most current studies focus on restoring knee phenotype and native alignment in TKA, assessing coronal spinal balance in weight-bearing helps surgeons predict postoperative outcomes.
BACKGROUND:Knee osteoarthritis (KOA) is characterized by complex structural and muscular alterations. Quadriceps muscle atrophy is a critical, but heterogeneous feature influencing pain, function, and postoperative recovery. Understanding muscle phenotypes may provide novel insight into disease heterogeneity and guide personalized rehabilitation. METHODS:This retrospective study included 191 consecutive patients undergoing primary robot-assisted total knee arthroplasty (TKA; 76.4% women; mean age 67 years (range 46 to 86)), with preoperative computed tomography (CT) imaging and six-month follow-up. There were three CT-derived quadriceps muscle volumetric ratios (rectus femoris/intermedius, vastus medialis, and vastus lateralis normalized to femoral volume) entered into latent profile analyses (LPA) to identify distinct muscle phenotypes. Associations between latent classes and functional outcomes were evaluated using linear mixed-effects models. RESULTS:The LPA identified three subgroups: Class 1 (n = 125) with moderate muscle ratios and intermediate function, Class 2 (n = 27) with higher muscle ratios and the best outcomes, and Class 3 (n = 39) with reduced muscle ratios and the worst baseline status. At six months, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC, the improvements of WOMAC in classes 1 to 3 are as follows: 28.6, 41.8, 37.8) and visual analog scale (VAS, the improvements of VAS in classes 1 to 3 are as follows: 3.5, 4.3, 2.8) improved significantly in all classes (all P < 0.05), with significant class × time interactions (all P < 0.001). The range of motion also improved over time (P < 0.001), without a significant class × time interaction (P = 0.562). Overall, Class 2 achieved the best postoperative outcomes. CONCLUSION:The LPA of preoperative CT-derived quadriceps muscle volumes identified three distinct KOA muscular phenotypes associated with different symptom burdens and recovery trajectories after TKA. Patients who have preserved quadriceps muscles achieved the best absolute outcomes, whereas those who had marked atrophy showed greater relative improvement. These findings support CT-based phenotype-guided perioperative rehabilitation.
INTRODUCTION:The use of enabling technologies, including handheld navigation, fluoroscopic-assisted navigation, and image-based robotics, in primary total hip arthroplasty (THA) has increased markedly in recent years. Although surgeons and institutions adopt these guidance systems for diverse reasons, their economic impact remains incompletely defined. The present study compared standardized episode-of-care costs for technology-assisted and manual THA, encompassing both index hospitalization and 90-day postoperative expenditures. METHODS:A retrospective, propensity-matched cohort study was conducted using our institutional total joint registry to compare standardized episode-of-care costs for technology-assisted versus manual primary THA performed between 2019 and 2023. There were 513 technology-assisted THAs matched 1:1 to manual THAs based on age, sex, body mass index, year of surgery, femoral head size/material, surgical approach, and implant construct. Cost outcomes included index hospitalization cost, 90-day postoperative cost, and total episode-of-care cost, calculated using Medicare cost-to-charge ratios and reimbursement rates. Capital acquisition and service fees for enabling technologies were excluded. RESULTS:Technology-assisted THA was associated with higher index procedure costs ($17,377 versus $16,814; P < 0.001) and higher 90-day postoperative costs ($2,661 versus $1,440; P = 0.013), resulting in greater episode-of-care costs ($20,038 versus $18,255; P < 0.001). Subgroup analyses showed increased costs across all technology types, with handheld navigation and image-based robotics also demonstrating higher total episode-of-care costs. Lengths of stay were slightly reduced in the technology-assisted cohort (1.1 versus 1.2 days; P = 0.004). CONCLUSION:Technology-assisted THA was associated with modest increases in index and 90-day episode-of-care costs compared with manual techniques. Although lengths of stay were marginally reduced, no compensatory reduction in postoperative costs was observed. While surgeons and hospitals adopt technology for diverse reasons, further evaluation of cost-effectiveness and broader clinical benefits is warranted as the use of enabling technologies expands.
INTRODUCTION:Unrestricted kinematic alignment (KA) total knee arthroplasty (TKA) may accept tibial component varus beyond conventional thresholds, yet outcomes in marked proximal tibial varus remain understudied in Southeast Asian populations. Our study evaluated two-year outcomes after unrestricted KA-TKA in patients who had severe proximal tibial varus, using mechanically aligned TKA (MA-TKA) as control. METHODS:This retrospective, propensity score-matched cohort study included 238 unrestricted KA-TKAs and 476 MA-TKAs with minimum two-year follow-up. The KA cohort was stratified by preoperative medial proximal tibial angle (MPTA): ≥ 84° (Group 1, n = 156, mean MPTA 86.6°) versus less than 84° (Group 2, n = 82, mean MPTA 81.6°). The following variables were compared: (1) demographic data, (2) patient-reported outcome measures (PROMs) including Short-Form 36 (SF-36) domains, Oxford Knee Score (OKS), Knee Society Function and Knee Score (KSFS and KSKS), patient satisfaction and expectations, and (3) radiological parameters including MPTA, lateral distal femoral angle, arithmetic hip-knee-ankle angle, and joint line obliquity. Kaplan-Meier analysis assessed revision-free survival. RESULTS:At six months, Group 1 demonstrated significantly better KSKS than Group 2 and MA-TKA (P = 0.033 and P < 0.001, respectively). This persisted for two years, with Group 1 achieving significantly better KSKS (P = 0.032) than MA-TKA, but not against Group 2 (P = 0.555). There were no between-group differences detected for other PROMs, but significantly more patients were satisfied in Groups 1 and 2 compared with MA-TKA at six months and two-year follow-up (P = 0.015 and P = 0.017, respectively). Kaplan-Meier curves showed excellent two-year revision-free survival with two surgical revisions and four knee manipulations. CONCLUSION:At two-year follow-up, in patients who have severe proximal tibial varus (mean MPTA 81.6°), unrestricted KA-TKA achieved comparable PROMs, excellent patient satisfaction, and survivorship relative to patients who had less severe deformity and the MA-TKA cohort.
INTRODUCTION:Peri-incisional blistering following total knee arthroplasty (TKA) is a recognized, but underreported, complication that negatively impacts postoperative recovery and overall patient satisfaction. This retrospective study examined the incidence of postoperative blistering, associated patient and surgical risk factors, and its relationship with adverse outcomes, including reoperation and periprosthetic joint infection. METHODS:We retrospectively identified 23,405 elective unilateral primary TKAs performed in 20,035 patients at a single high-volume center between March 2016 and May 2022. The TKAs meeting inclusion criteria were identified through an electronic medical record keyword search for "blister" documented within 30 days of surgery and confirmed by manual chart review. Multivariable logistic regression models adjusting for patient age, sex, race, body mass index (BMI), Charlson Comorbidity Index, and year of surgery were used to examine the association of these factors with blister formation and adverse outcomes. RESULTS:The incidence of 30-day peri-incisional blistering was 3.1% (714 of 23,405 TKAs). In adjusted analyses, preoperative anticoagulation and BMI ≥ 40.0 were associated with increased odds of postoperative blister formation (odds ratio [OR] 1.25; 95% confidence interval [CI], 1.07 to 1.47 and OR 1.59; 95% CI, 1.25 to 2.02, respectively). Blister formation was the strongest associated factor for both reoperation and infection (OR 2.13; 95% CI, 1.50 to 3.02 and OR 4.24; 95% CI, 2.52 to 7.16, respectively), exceeding current smoking status, the next strongest associated factor for infection (OR 2.05; 95% CI, 1.09 to 3.82). The use of advanced surgical dressings had lower odds of blister formation (OR 0.57; 95% CI, 0.46 to 0.69). All associations had P-values < 0.05. CONCLUSION:Postoperative blister formation following TKA was associated with increased risk of reoperation and infection. Postoperative blistering may serve as a clinical marker identifying patients who are at elevated risk and who warrant heightened monitoring and wound management.
Background This study evaluated the effectiveness of secondary patellar resurfacing (SPR) on clinical outcomes in patients who experienced anterior knee pain (AKP) following primary total knee arthroplasty (TKA) without concomitant patellar resurfacing. The study also investigated the association between radiographic parameters and postoperative AKP and explored whether a novel radiographic index was associated with postoperative AKP. Methods A retrospective cohort of 246 patients was analyzed, including 82 patients who had idiopathic AKP following TKA and were treated with SPR, and 164 matched controls who underwent primary TKA without patellar resurfacing and did not develop postoperative AKP. Patient-reported outcome measures (PROMs), including the Visual Analog Scale (VAS), Knee Society Score (KSS), and Oxford Knee Score (OKS), showed statistically significant improvement in the SPR group (P < 0.005), while radiographic parameters demonstrated limited discriminative value. Results A newly developed metric, the GC Index, defined as the ratio of anterior femoral offset (AFO) to anterior patellar displacement (APD), demonstrated good discriminative performance within the present cohort, with a sensitivity of 82.93% and specificity of 85.37%, and remained independently associated with postoperative AKP after adjustment for relevant confounding factors. Conclusion These findings support the potential role of SPR in managing persistent AKP after TKA and suggest that the GC Index may represent a potential adjunctive radiographic marker requiring further prospective validation.
INTRODUCTION:Gastrointestinal (GI) bleeding is common in older adults and contributes to immune dysregulation, yet its impact on total hip (THA) and total knee (TKA) arthroplasty outcomes is poorly understood. We evaluated the association between GI bleeding history with risk of periprosthetic joint infection (PJI) and other complications up to two years following THA and TKA. METHODS:A retrospective review identified patients who had a history of GI bleeding within two years prior to THA or TKA. Patients were matched to a control cohort who had no GI bleeding history. The THA cohort included 6,420 GI bleed and 6,420 control patients. The TKA cohort included 9,688 GI bleed and 9,688 control patients. Odds ratios were calculated for 90-day and 2-year outcomes. RESULTS:In the THA cohort, GI bleed within two years prior to surgery was not associated with PJI (odds ratio (OR): 1.1 [0.8 to 1.4]; P = 0.544) at two years; however, it was associated with increased odds of mechanical loosening (OR: 1.6 [1.01 to 2.5]; P = 0.044) and revision surgery (OR: 1.4 [1.1 to 1.8]; P = 0.002). In the TKA cohort, GI bleed history was associated with greater 2-year odds of PJI (OR: 1.3 [1.1 to 1.7]; P = 0.012) and revision surgery (OR: 1.4 [1.2 to 1.7]; P < 0.001). The GI bleed patients in both cohorts demonstrated greater 90-day medical complication odds, including urinary tract infection (P < 0.05). CONCLUSION:A GI bleeding history was associated with increased 90-day medical and 2-year surgical complications following THA and TKA. Patients undergoing THA had higher odds of mechanical loosening, whereas TKA patients demonstrated higher odds of PJI. While the complication rate was low, these findings should be interpreted cautiously and viewed as hypothesis-generating. Further prospective studies are needed to better characterize postoperative risk factors in this population.
INTRODUCTION:Lumbar spinal fusion (LSF) influences outcomes following total hip arthroplasty (THA). However, no prior investigation has utilized a time to minimal clinically important difference (MCID) analysis. This study compared time to MCID after THA in patients who also underwent LSF versus patients who did not, and secondarily evaluated the effect of surgical sequence (LSF before versus after THA). METHODS:We identified 183 patients from a multi-institutional registry who underwent THA and LSF within three years. A one-to-four propensity-score match generated 732 patients who did not undergo LSF. We compared rates of achievement and time to MCID in the following measures: Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form-10a (PF-10a), PROMIS Global Physical, and the Hip Disability and Osteoarthritis Outcome Score-Physical Function Short Form (HOOS-PS). We also compared groups by order of procedure (LSF prior to THA: n = 117; THA prior to LSF: n = 66). RESULTS:Patients who required both LSF and THA had delayed time to MCID in the PROMIS Global Physical (5.91 versus 5.15 months; P = 0.031) and PROMIS PF-10a (7.03 versus 6.25 months; P = 0.044). Patients who underwent LSF prior to THA had a similar time to MCID as control patients. However, patients who underwent THA prior to LSF had delayed time to MCID in the PROMIS Global Physical (7.35 months; P = 0.002) and PROMIS PF-10a (7.61 months; P = 0.028), whereas there was no difference in HOOS-PS scores (4.83 versus 5.05 months; P = 0.80). CONCLUSION:Patients requiring both THA and LSF demonstrated delayed global recovery compared to THA alone. When stratified by surgical sequence, patients who underwent THA prior to LSF had delayed improvement timelines. Thus, performing LSF first in appropriate candidates may help ensure improvement timelines are more similar to controls.
BACKGROUND:Total knee arthroplasty (TKA) in the setting of retained periarticular hardware presents technical challenges and may influence surgical complexity and outcomes. This study aimed to evaluate whether hardware retention at the time of conversion TKA impacts reoperation risk, perioperative outcomes, and patient-reported outcome measures. METHODS:A retrospective cohort study was conducted of 320 patients who underwent conversion or primary TKA between 2009 and 2019. Patients were categorized into three groups: no retained hardware (n = 171), retained "minor" hardware (n = 90), and retained "major" hardware (n = 59), based on intraoperative complexity. The primary outcome was risk of reoperation and was assessed using a risk-adjusted Fine-Gray subdistribution hazard model that adjusted for death as a competing event. The secondary outcomes included operative time, blood loss, lengths of stay, complications, and patient-reported outcome measures (University of California, Los Angeles (UCLA) Activity Score, Veterans RAND 12-Item (VR-12) Health Survey Physical and Mental Component Scores) were assessed using univariate tests. RESULTS:There were no significant differences in the risk of reoperation among the three groups (multivariable Fine-Gray analysis: P = 0.162). Operative time and blood loss were significantly higher in the major hardware group (P < 0.001). Lengths of stay and complication rates also varied across groups (P < 0.05). The PROMs at one and two years showed minor differences, with lower improvements in VR-12 Mental Scores and UCLA scores in the major hardware group at one year (P = 0.034 and P = 0.016, respectively). CONCLUSION:While periarticular hardware retention in conversion TKA was associated with increased operative time, blood loss, and early complications, especially with plates or intramedullary nails, it was not associated with higher reoperation rates or two-year patient-reported outcomes.
BACKGROUND:Patient dual eligibility status for Medicare and Medicaid is known to be a well-established proxy for socioeconomic vulnerability. Many studies have examined the impact that dual eligibility status has on patient outcomes after total joint arthroplasty (TJA), but its association with surgeon-level reimbursement after TJA remains insufficiently characterized. This study evaluated whether surgeon dual eligibility proportion was independently associated with standardized Medicare reimbursement per procedure for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) in 2023. METHODS:A cross-sectional retrospective analysis of a Medicare database was performed for 2023. A total of 4,506 THA surgeons performing 161,221 procedures and 6,618 TKA surgeons performing 297,919 procedures were identified. Surgeons performing primary THA and primary TKA in 2023 were identified and stratified into quartiles based on the proportion of their patient panel that was dual-eligible. The primary outcome was mean standardized Medicare reimbursement per procedure. Multivariable linear regressions were used to evaluate independent associations. Surgeon panel covariates included Hierarchical Condition Category (HCC) risk score, minority beneficiary proportion, and practice rurality. RESULTS:For THA, mean standardized reimbursement declined from $1,002 in Q1 to $971 in Q4 (P < 0.001). For TKA, mean reimbursement declined from $1,005 in Q1 to $981 in Q4 (P < 0.001). A higher dual eligibility proportion was independently associated with lower reimbursement for both THA (β = -1.58, P < 0.001) and TKA (β = -1.04, P < 0.001) after adjustment for rurality, HCC risk score, and minority beneficiary proportion per surgeon. CONCLUSIONS:Among surgeons performing primary TJA, a higher dual-eligible patient proportion was associated with reduced standardized reimbursement, despite the greater medical comorbidity and psychosocial complexity characterizing this population. These findings suggest that existing reimbursement frameworks may be associated with lower reimbursement for surgeons who disproportionately serve socioeconomically disadvantaged patients, with potential implications for equitable access to total joint arthroplasty. LEVEL OF EVIDENCE:Level III, retrospective cross-sectional study.
BACKGROUND:The ability to kneel and squat after knee arthroplasty is a key determinant of patient satisfaction, especially in Asian populations where deep-flexion postures are culturally important. However, many patients remain unable to perform these activities postoperatively. This study aimed to identify the factors influencing both the ability and inability to kneel and squat after knee arthroplasty. METHODS:A retrospective analysis of 888 knees in 830 patients undergoing primary knee arthroplasty was conducted. Pre-, intra-, and postoperative variables, including range of motion (ROM), flexion, Oxford Knee Score question 4 (OKS Question 4, kneeling confidence), operation type and implant constraint, and body mass index (BMI), were analyzed. Univariate and multivariate models were used to determine predictors of the ability and inability to kneel, squat, or perform both at one year post-surgery. RESULTS:At one year, 42% of patients could squat, 36% could kneel, and 30% could perform both, with corresponding inability rates of 58 (squat), 64 (kneel) and 70% (both). The ability to kneel and squat correlated with greater postoperative flexion (P = 0.028), ROM (P = 0.002), and higher postoperative OKS Question 4 (P < 0.001). Conversely, inability was independently predicted by higher BMI, lower preoperative ROM and flexion, poor preoperative kneeling confidence, older age, and women (all P < 0.05). Medial unicompartmental knee arthroplasty showed a non-significant trend toward better high-flexion recovery. Functional outcomes and quality of life were substantially better in patients able to squat and kneel. CONCLUSION:This study reinforced the fact that kneeling and/or squatting cannot be achieved in roughly two-thirds of patients after knee arthroplasty surgery. Both ability and inability to kneel and squat are governed by the same factors acting in opposite directions. Optimizing preoperative BMI, ROM, and kneeling confidence through targeted prehabilitation and expectation-based counselling may enhance postoperative satisfaction and functional recovery.
BACKGROUND Femoral neck fractures (FNFs) are common in the elderly and are typically treated operatively. Tools like frailty assessments may be critical for evaluating peri- and postoperative patient needs. Our study evaluated the utility of frailty, measured by the Risk Analysis Index (RAI) and the Modified 5-Item Frailty Index (mFI-5), in predicting 30-day mortality in patients undergoing hemiarthroplasty (HA) or total hip arthroplasty (THA) for FNFs. METHODS A national database was queried from 2015 to 2020 for patients 18 years of age or older undergoing HA or THA for FNFs. A total of 14,913 patients who had surgically managed FNFs were included. The primary outcome was 30-day mortality. Multivariate regressions were used to evaluate predictive value, and receiver operating characteristic curves assessed frailty accuracy. RESULTS Frailty as measured by the mFI-5 and RAI was predictive of increased odds of 30-day mortality in HA (RAI = odds ratio (OR): 1.46, 95% confidence interval (CI): 1.31 to 1.64; mFI-5 = OR: 1.10 (1.08 to 1.12, P < 0.001 for both)) and THA (RAI = OR: 1.15 (CI: 1.106 to 1.190, P < 0.001), mFI-5 = OR: 1.50 (CI: 1.167 to 1.923, P = 0.002)). The RAI demonstrated superior risk discrimination when compared to the mFI-5 for THA (RAI = C-statistic: 0.84, 95% CI: 0.45 to 0.83 versus mFI-5 = C-statistic: 0.69, 95% CI: 0.68 to 0.71) and HA (RAI = C-statistic: 0.74, 95% CI: 0.73 to 0.75 versus mFI-5 = C-statistic: 0.62, 95% CI: 0.61 to 0.63). CONCLUSION Frailty was found to be a predictor of mortality in patients who had FNFs undergoing THA and HA. Compared to the mFI-5, the RAI demonstrated superior predictive value for mortality across both operations. Thus, the RAI may be a powerful tool for assessing preoperative risk in patients undergoing arthroplasty for FNFs.
BACKGROUND:Optimal coronal alignment strategy during total knee arthroplasty (TKA) remains controversial. Joint-line alteration has been associated with abnormal knee kinematics, ligament imbalance, and patient dissatisfaction; however, the isolated biomechanical consequences of lateral femoral joint-line distalization on lateral collateral ligament (LCL) strain remain poorly understood. METHODS:There were six non-arthritic cadaver knees that underwent robotic-assisted TKA using restricted kinematic alignment (rKA) to approximate native joint-line orientation. A motion capture technique utilizing reflective markers applied to the LCL quantified strain across knee flexion angles (0, 30, 60, and 90°). Progressive distalization of the lateral femoral condyle was simulated using 2-mm shims placed between the implant and the lateral distal femur. The median peak LCL strain across flexion arcs and ligament regions was recorded and compared using paired statistical testing. RESULTS:Native LCL strain demonstrated physiologic relaxation with increasing knee flexion. Following rKA TKA, the baseline median peak LCL strain measured 1.6%. Progressive lateral femoral joint-line distalization resulted in increases in strain to 1.9, 6.0, and 8.1% with 2-, 4-, and 6-mm distalization, respectively. Statistically significant increases in strain were observed between zero and four mm, zero and six mm, and four and six mm distalization (P < 0.05). A stepwise strain response was observed, demonstrating a potential biomechanical threshold between two and four mm distalization. CONCLUSIONS:Lateral distal femoral joint-line distalization independently increases LCL strain following TKA. Distalization exceeding approximately four mm results in strain magnitudes associated with a microstructural injury threshold based on in vitro studies of animal ligaments. These findings suggest that joint-line alteration may contribute to lateral soft-tissue imbalance and postoperative dissatisfaction.
BACKGROUND:Patient-reported outcome measures (PROMs) may not fully characterize the limitations patients experience nor describe patient expectations. Patient-defined outcomes (PDOs) enable patients to articulate their limitations and goals. This study aimed to determine PDOs in patients who have hip osteoarthritis (OA), the effect of patient demographics, and compare PDOs to PROMs in patients who have hip OA. METHODS:This retrospective case-control study included all patients who had hip OA and presented to a tertiary hip center from March 9, 2023, to October 3, 2024. Patients who had Tonnis Grade 2 or 3 arthritis were included. Patients who have hip conditions such as osteonecrosis, Perthes, and previous hip surgery were excluded. Outcome measures included PDOs, Hip Disability and Osteoarthritis Outcome Score (HOOS) global, International Hip Outcome Tool (iHot 12), and Patient-Reported Outcome Measurement Information System Physical Function (PROMIS PF). Patients were classified by age as adults (20 to 60 years) or as senior adults (greater than 60 years). Outcome measures were analyzed using multiple linear regression models, two-sample t-tests, and Fisher's exact tests. A total of 237 patients met the inclusion criteria for this study. There were 91 adult patients and 146 senior adult patients. RESULTS:Senior adults reported interest in improving low-intensity and low-range-of-motion (ROM) activities. Adults reported interest in high-intensity and high-ROM activities. Importance level did not change among age cohorts. Difficulty did not correlate with age. There were no differences (P > 0.05) between the adult and senior adult groups across all selected PROMs and PDO scores. CONCLUSION:Patients in both groups report trouble with Activity of Daily Living (ADLs) and want to be able to walk without pain. However, some patients in both groups wanted to return to higher-intensity activities like sports, running, hiking, and dancing. The PDOs help align provider and patient expectations.
INTRODUCTION:Lateral compartment osteoarthritis (OA) of the knee represents a relatively uncommon clinical entity, accounting for approximately 5 to 10% of patients presenting with symptomatic unicompartmental arthritis. This retrospective study assessed clinical outcomes, complications, and implant survivorships of lateral unicompartmental knee arthroplasty (UKA). METHODS:In this single-institution retrospective study, data from 113 fixed-bearing lateral UKAs in 108 patients who had a mean follow-up of 13.7 years (range, 0.5 to 22) were analyzed. The mean age of the participants was 64 years (range, 36 to 91). All arthroplasties were performed between 2004 and 2014 in patients who were diagnosed with advanced lateral compartment knee OA. The primary outcome measure was the implant survivorship. The secondary outcome measures included the Oxford Knee Score (OKS, 0 low to 48 high) assessed preoperatively and at one, two, and five years postoperatively, in addition to all-cause mortality. RESULTS:With survival data from 113 knees in 108 patients included in a Kaplan-Meier analysis, the estimated implant survivorship was 97% at five years, 93% at 10 years, 89% at 15 years, and 87% at 20 years, with 20-year data based on a limited number at risk. The survival distribution did not differ by sex (P = 0.677), laterality (P = 0.761), or age (P = 0.558). The preoperative and five-year OKS were 17.61 (7.46) and 37.36 (10.5), respectively. The mean difference in Oxford Knee Score between the preoperative and five-year postoperative measurements was 19.75 (95% confidence interval [CI] 16.84 to 22.66; P < 0.001). There were 31 deaths from any cause in this series of patients, with none attributed to the index procedure. CONCLUSIONS:Fixed-bearing lateral UKA appears to be a safe and effective option for patients who have isolated unicompartmental lateral knee osteoarthritis. Excellent survivorship was demonstrated for patients treated with this lateral UKA.
BACKGROUND:Revision total joint arthroplasty (rTJA) volumes are rising in parallel with the rapid migration of arthroplasty to ambulatory surgery centers. Despite this shift, evidence defining the safety, outcome, and appropriate patient selection for outpatient rTJA remains limited. METHODS:A systematic review and pooled quantitative analysis were performed to compare inpatient and outpatient/accelerated discharge rTJA. Studies reporting patient demographics, revision types, surgical indications, comorbidities, and complications following revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA) were included. There were 14 studies that met the inclusion criteria, with 11 eligible for quantitative synthesis. RESULTS:Outpatient rTKA patients were healthier, reflected by lower mean body mass index (BMI), lower mean Charlson Comorbidity Index (CCI) score, and more American Society of Anesthesiologists (ASA) classes I or II patients (91.7 versus 50.2%; P < 0.001). Outpatient rTKA patients commonly underwent less complex procedures such as polyethylene exchanges. Postoperatively, rTKA outpatients demonstrated lower or similar rates of all medical complications compared with inpatients, including periprosthetic joint infection (PJI) (9.0 versus 13.0%; P < 0.001). The outpatient rTHA cohort also had a lower mean BMI, lower mean CCI score, and more ASA classes I or II patients (73.6 versus 49.5%; P < 0.001). Outpatient hip revisions appeared to more commonly involve lower-complexity procedures, including head/liner exchanges. Reported outpatient rTHA medical complication rates were generally comparable to inpatient cohorts, although interpretation is limited by smaller sample sizes and variable reporting across studies. Notably, transfusions were lower in the outpatient rTHA cohort (6.2 versus 21.9%; P < 0.001). CONCLUSION:In appropriately selected patients, outpatient rTKA and rTHA appear to represent a safe alternative to traditional inpatient care. These findings reinforce the importance of surgeon-driven patient selection and support the continued expansion of outpatient rTJA in the setting of evolving policy and site-of-service reform.
INTRODUCTION:When a patient presents on antibiotics for a suspected periprosthetic joint infection (PJI), antibiotics are often withheld prior to diagnostic aspiration. Failure to withhold antibiotics may compromise culture sensitivity. Although recent studies suggest preoperative antibiotics may not affect culture results, the small sample size limits the reliability of these findings. Since treatment failure often involves organisms different than those detected at resection, timing of antibiotic delivery becomes critical. We investigated the difference in culture results and infection control when antibiotics were administered prior to resection versus when antibiotics were withheld. METHODS:Review of patients undergoing staged treatment for PJI was performed. Inclusion required accessible preoperative aspiration and intraoperative cultures. Patients were grouped by timing of antibiotic administration- before or after obtaining intraoperative cultures. Organisms cultured on preoperative aspiration and those cultured at resection were compared. Patients experiencing reimplantation failure were identified, and causative organism was documented. Of the 169 procedures that met inclusion criteria (92 knees, 77 hips), 29.0% (49 of 169) received antibiotics prior to intraoperative cultures (21 knees, 28 hips) while 71% (120 of 169) did not (71 knees, 49 hips). RESULTS:Among patients receiving preoperative antibiotics, the discordance rate (defined as mismatch between preoperative aspiration and resection cultures) was 42.9% (nine of 21) for knees and 39.3% (11 of 28) for hips. Among patients having antibiotics withheld until resection cultures were taken, the discordance rate was lower- 29.6% (21 of 71) for knees and 24.5% (12 of 49) for hips (P = 0.091). The overall success rate was significantly lower in the group receiving antibiotics compared to the group where antibiotics were withheld (79.6 versus 90% P = 0.014). CONCLUSIONS:These findings suggest that withholding antibiotics until cultures are obtained may reduce culture discordance and reimplantation failure.
