BACKGROUND:Sleep disturbance is a common, poorly understood complaint following total knee arthroplasty (TKA). We characterized sleep patterns in a cohort of TKA patients. METHODS:We prospectively monitored sleep quality in 93 patients who underwent primary, uncomplicated TKA for primary osteoarthritis. Outcomes included the Pittsburgh Sleep Quality Index (PSQI) recorded two weeks preoperatively to six weeks postoperatively and six objective sleep quality variables measured with a wearable device. Subjective and objective outcomes were compared to the 2-week preoperative baseline using mixed-effects linear regression models. The potential association of PSQI with clinically relevant variables, including having a history of sleep disorder, Visual Analog Scale (VAS) pain scores, and opioid consumption, was assessed. RESULTS:The highest mean PSQI scores, indicating worse perceived sleep, were observed between the second and fourth postoperative weeks (10.6 and 10.4, respectively). The worst sleep quality detected by the wearable device was during postoperative week one (mean change compared to two weeks preoperatively in sleep score = -7.7), with a progressive trend to normalizing by week six (mean change sleep score= -4.0). When patients who did and did not have sleep disturbances were compared, we observed neither any significant differences in subjective and objective sleep outcomes nor in opioid consumption patterns. The linear mixed-effects model demonstrated a significant relationship between PSQI and VAS over the study period, estimating a 0.33-point increase in PSQI (indicating worse perceived sleep quality) for every 1-point increase in VAS pain score (mixed-effect linear regression model estimate: 0.33; 95% confidence interval: 0.17 to 0.48; P < 0.001). CONCLUSIONS:We delineated sleeping patterns in TKA patients utilizing patient- and wearable-reported data. Patients perceived the worst sleep quality during the second and fourth postoperative weeks, whereas objective data indicated the worst sleep in the first week. Patients who have a history of sleep disorders did neither report nor objectively experience worse sleep patterns perioperatively.

BACKGROUND:The Centers for Medicare & Medicaid Services (CMS) mandates reporting of Hip Disability and Osteoarthritis Outcome Score for Joint Replacement and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement to support a hospital-level patient-reported outcome performance measure. The current CMS requires matched preoperative and postoperative patient-reported outcome measures for ≥ 50.0% of all eligible patients, regardless of hospital volume. This may yield unreliable performance estimates for low-volume centers and potentially biased and unnecessarily large estimates for large hospitals. The purpose of this study was to determine the smallest sample required to produce statistically valid patient-reported outcome performance measure estimates. METHODS:We calculated the minimum number of completed patient-reported outcome measures needed in order to achieve a 95% confidence interval width 10.0% (± 5.0%) for hospitals with five, 50, 500, and 5,000 eligible total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases annually, assuming a conservative substantial clinical benefit achievement of 50.0%. These values were compared with current CMS requirements. Sensitivity analyses explored the effects of confidence interval width, hospital volume, and frequency of substantial clinical benefit attainment on required sample sizes. RESULTS:The CMS's volume-proportional rule requires three, 25, 250, and 2,500 patients for hospitals with five, 50, 500, and 5,000 annual cases, respectively. In contrast, a statistically grounded random sampling strategy would require five, 45, 218, and 357 patients, respectively. Sensitivity analyses confirmed that random sampling reduces required sample sizes for high-volume hospitals. CONCLUSIONS:The current CMS reporting rule may produce unreliable performance estimates for low-volume hospitals while imposing excessive reporting burdens and potentially biased results for high-volume hospitals. A random sampling strategy may provide more precise and valid estimates while substantially reducing hospital burden, especially among the hospitals performing 500 or more THA and TKAs per year, which comprise approximately 35.0% of all THAs and TKAs annually.

BACKGROUND:Concomitant use of nonsteroidal anti-inflammatory drugs (NSAIDs) in anticoagulated patients following total hip arthroplasty (THA) raises concerns about increased bleeding and related complications. This study evaluated postoperative pain, opioid consumption, and complications in anticoagulated THA patients who did and did not use concomitant NSAIDs. METHODS:We retrospectively identified 2,984 patients who underwent primary THA for osteoarthritis between 2016 and 2023 at a single high-volume center and received at least 14 days of postoperative anticoagulation. Outcomes were compared between a study group of 1,285 patients (43%) who received concomitant NSAIDs and a control group of 1,699 patients (57%) who did not. Outcomes included 6-week pain scores, 90-day opioid use, wound complications, readmission, and reoperation. The primary analysis used inverse probability of treatment weighting (IPTW) based on the propensity score to balance baseline covariates in multivariable regression models. The propensity score was estimated from a logistic regression model with group assignment (study versus control) as the outcome and age, sex, body mass index, comorbidity burden, surgical year, and other clinical factors that influence outcomes or group assignment as predictors. Standardized mean differences were used to assess covariate balance. A 1:1 propensity score-matched analysis was performed as a sensitivity analysis. RESULTS:The 6-week pain scores were significantly lower in the study group in univariate analysis (14.9 ± 17.8 versus 18.3 ± 20.0; P = 0.009). In IPTW-weighted linear regression, concomitant NSAID use was associated with lower 6-week pain scores (difference: -4.57; 95% confidence interval: -7.82 to -1.31; P = 0.006). There were no significant differences in 90-day opioid use, venous thromboembolism, myocardial infarction, wound complications, readmission, or reoperation. Among patients requiring reoperation, the control group had a significantly higher rate of additional reoperation within 90 days (32.1 versus 10.0%; P = 0.021). CONCLUSION:In this observational cohort, concomitant, judicious NSAID use was associated with lower 6-week pain scores in IPTW-weighted analyses and was not associated with higher rates of complications, readmission, or reoperation.

BACKGROUND:Tourniquet use in total knee arthroplasty (TKA) remains variable, and its effect on perioperative blood loss in the era of tranexamic acid is debated. This study compared four contemporary tourniquet strategies and their associations with hemoglobin drop, calculated blood loss, and transfusion risk. METHODS:We retrospectively reviewed 15,394 primary TKAs performed from 2019 to 2023 at a high-volume academic center. Tourniquet use was categorized as follows: no-tourniquet, selective use during cementation only, incision-to-cementation (reference), or incision-to-closure. Outcomes included perioperative hemoglobin (Hgb) drop, calculated blood loss using Nadler and Mercuriali's equations, and postoperative transfusion. Mixed-effects linear and logistic regression models quantified associations after adjustment for age, sex, body mass index, surgical time, Charlson Comorbidity Index, fixation method, preoperative hemoglobin, American Society of Anesthesiologists classification, and postoperative venous thromboembolism prophylaxis, with surgeon as a random intercept. RESULTS:Compared with incision-to-cementation, the no-tourniquet group experienced a greater Hgb drop (+0.46 g/dL; 95% confidence interval (CI) 0.38 to 0.54; P < 0.001) and the highest median calculated blood loss (785 mL), with an adjusted increase of +211.3 mL (95% CI 169.8 to 252.7; P < 0.001). Selective tourniquet use was associated with a smaller, but significant increase in Hgb drop (+0.13 g/dL; P < 0.001). Incision-to-closure did not significantly differ. Transfusion was uncommon, but more frequent in the no-tourniquet group, with three times the adjusted odds compared with incision-to-cementation (odds ratio 3.05; 95% CI 1.72 to 5.41; P < 0.001). CONCLUSIONS:Forgoing a tourniquet was associated with increased blood loss and higher odds of transfusion, though the absolute effect was modest in the contemporary tranexamic acid era (number needed to treat approximately 250 to prevent one transfusion). Tourniquet use from incision-to-cementation demonstrated the most favorable blood conservation profile; selective use performed similarly. These findings support a tailored approach to tourniquet use in TKA.

Maximal outcome improvement (MOI), the percentage of total possible patient-reported outcome measure (PROM) score improvement from baseline, is increasingly being used to describe clinical significance of PROMs. This study defines MOI thresholds for the modified Harris Hip Score (mHHS) and International Hip Outcome Tool-12 (iHOT-12) after periacetabular osteotomy (PAO), determines the proportions of threshold achievement, and identifies the predictors of threshold achievement. We analysed 317 patients who underwent PAO for symptomatic acetabular dysplasia with pre- and postoperative PROMs; postoperative surveys were collected at 1-2 years follow-up. MOI thresholds were calculated with receiver operating characteristic curves. Multivariable logistic regression determined predictors of achieving thresholds using pre- and intraoperative characteristics. MOI thresholds were 47.1% (mHHS) and 50.1% (iHOT-12). Proportions of threshold achievement were 63.1% (mHHS), 61.8% (iHOT-12), and 71.0% (either PROM). Variables with increased risk of failing to achieve thresholds were: mHHS-PAO as revision (OR = 2.51, 95% CI = 1.33-4.76, P < .01), higher preoperative lateral centre-edge angle (OR = 1.06, 95% CI = 1.01-1.12, P = .03), and higher T & ouml;nnis grade (OR = 1.90, 95% CI = 1.09-3.30, P = .03); iHOT-12-PAO as revision (OR = 2.30, 95% CI = 1.25-4.26, P < .01), increased body mass index (OR = 1.08, 95% CI = 1.01-1.16, P = .04), and concomitant anterior inferior iliac spine/subspine resection/decompression (OR = 1.81, 95% CI = 1.01-3.26, P = .046). Although newer, MOI provides essential information for contextualizing a patient's recovery course when used alongside other clinical thresholds.

BACKGROUND:Precise acetabular component positioning depends heavily on accurately recreating pelvic tilt (PT) during total hip arthroplasty (THA). The direct anterior approach (DAA) facilitates intraoperative fluoroscopy for real-time assessment, yet the accuracy of recreating preoperative standing PT intraoperatively remains unexplored. This study evaluated the precision of intraoperative PT recreation between pre- and intra-operative antero-posterior (AP) radiographic images during DAA THA. METHODS:This retrospective cohort included 325 patients undergoing primary unilateral DAA THA by a single surgeon between July 2022 and July 2024. Sagittal PT was measured on preoperative EOS radiographs in both standing and sitting positions. There were two validated parameters, anteroposterior PT and the sacro-femoral-pubic (SFP) angle, that were then calculated for both standing as well as intraoperative fluoroscopic images. There were two blinded observers who independently performed all measurements using the intraclass correlation coefficient (ICC greater than 0.80). The primary outcome was the proportion of patients in whom intraoperative PT was reproduced within ± 7.0 and ± 14.0° of standing values, thresholds corresponding to approximately 5.0 and 10.0° of anteversion inaccuracy. The secondary outcomes assessed correlations between pre- and intra-operative alignment parameters. RESULTS:Both AP PT and the Delta SFP (standing-to-sitting) angle demonstrated moderate-to-strong correlations with sagittal standing PT and Delta PT, confirming measurement accuracy before intraoperative analysis. Intraoperative fluoroscopy reproduced standing PT within ± 7.0° in 76% of patients and within ± 13.0° in 95%. However, preoperative standing and intraoperative AP PT demonstrated low correlation (r = 0.294), indicating substantial variability. The change in SFP (standing to supine) demonstrated moderate correlation with the change in AP PT (r = 0.422), further reflecting the limited precision of the PT recreation. CONCLUSION:Visual fluoroscopic recreation of standing PT during DAA THA demonstrated moderate accuracy, with three-quarters of patients achieving clinically relevant precision. Variability in reproducing functional PT suggests that visual assessment alone may benefit from adjunctive verification to improve consistency in acetabular positioning.

Purpose The Hip Disability and Osteoarthritis Outcome Score – Joint Replacement (HOOS-JR) and the Knee Injury and Osteoarthritis Outcome Score – Joint Replacement (KOOS-JR) are validated, short-form versions of the HOOS and KOOS patient reported outcome measures (PROMs) that are used to assess “joint health.” Developed in response to the Centers for Medicare & Medicare's (CMS) pay-for-performance policy, HOOS-JR and KOOS-JR evaluate patients before in-office visits. New mandatory CMS reporting requirements raise challenges for collecting PROMs. Telephone administration of PROMs may reduce reliability issues and increase collection rates. This study aimed to evaluate the reliability of telephone-administered HOOS-JR and KOOS-JR compared with in-person administration. It was hypothesized that telephone administration of PROMs will be a reliable modality for collection. Methods Phone interviews were conducted for new patients seeking care for hip- or knee-related disabilities (66 hips, 66 knees). Patients answered demographic questions and either the HOOS-JR or KOOS-JR. At their in-office visit, patients completed the same PROM via self-administration. To reduce recall bias, a minimum of 7 days between phone interview and self-administration was ensured. Test–retest reliability, using an intraclass correlation coefficient (ICC), was calculated. Results The overall cohort had a mean age of 65 ​± ​10.7 years and was primarily female (60.6%) having less than a postgraduate degree (63.6%). The HOOS-JR telephone interview showed good reliability compared with self-administration [ICC 0.80, 95% confidence interval (CI) 0.70–0.87], while KOOS-JR showed moderate agreement (ICC 0.70, 95% CI 0.55–0.81). Patients preferred to self-administer HOOS-JR or KOOS-JR (78.0%). Within self-administration, patients preferred email administration (65%), followed by paper (25%), and tablet (10%). Conclusion Telephone administration of HOOS-JR and KOOS-JR is a reliable alternative to self-administration. Incorporating phone interviews into clinical practice may enhance care delivery and increase required PROM capture rates.

Background The potential benefits of preoperative weight loss with bariatric surgery in reducing short-term complications of total joint arthroplasty (TJA) have been questioned. We studied the odds of 90-day postoperative complications by comparing TJA patients who had a history of bariatric surgery to a control group. Methods There were 678 patients who had undergone bariatric surgery before TJA (199 total hip arthroplasty [THA], 479 total knee arthroplasty [TKA]) matched 1:4 for body mass index at the time of TJA, age, sex, replaced joint, and American Society of Anesthesiologists Class with a control group of 2,301 TJA (644 THA; 1,657 TKA) patients who did not have bariatric surgery. Matching was performed using propensity scores with refined calipers to ensure comparability. The 90-day complication data was collected through chart review. The primary outcome was the incidence of Hip Society or Knee Society complications, emergency department visits, and wound complications requiring deviation from the standard of care. Results There were significantly more complications in the THA study than in the control group (11.6 and 6.3%, respectively, P = 0.018). The THA study group demonstrated 1.96 times higher odds of developing complications compared to controls (95% confidence interval 1.12 to 3.43). There were similar rates of complications in the study and control TKA groups (12.4 and 10.1%, respectively, P = 0.129). Wound-related complications were more common in the THA study group affecting 4.5 and 1.4% of study and control patients, respectively (P = 0.02). Conclusions While Bariatric surgery remains an effective weight loss intervention, its utility as a risk-reduction strategy before THA is not supported by our findings.

BACKGROUND:Periacetabular osteotomy (PAO) is widely used to treat symptomatic hip dysplasia; however, the long-term effect of age at PAO on patient-reported outcome measures (PROMs) remains controversial. We aimed to determine whether age at PAO influences long-term PROMs. METHODS:We conducted a retrospective cohort study involving 111 patients (126 hips) who had a mean follow-up of 19.5 years after PAO. The Forgotten Joint Score-12 (FJS-12) and Oxford Hip Score (OHS) were collected via postal survey. Patients were clustered into three groups using k-means clustering based on PROMs. A cluster with the highest scores-exceeding the patient acceptable symptom state threshold for FJS-12 and showing differences beyond minimal clinically important difference-was defined as "excellent." The remaining native hips and those converted to total hip arthroplasty (THA) were grouped as controls. Multivariable logistic regressions identified indicators of excellent outcomes. RESULTS:The "excellent" group (n = 64) had mean scores of FJS-12: 84.1 and OHS: 46.6. The control group (n = 93) included native hips with lower PROMs and 31 hips converted to THA. The mean age at PAO was 41 years in the excellent group and 44 years in controls (P = 0.133). Age at PAO was not a negative indicator of excellent outcomes (adjusted odds ratio (OR) per year, 1.02; 95% confidence interval (CI), 0.98 to 1.06). Using Tönnis Grade 1 as a reference, Grade 0 was a positive indicator (OR 3.35; 95% CI, 1.16 to 10.5), and Grade 2 was a negative indicator (OR 0.13; 95% CI, 0.04 to 0.37). Higher body mass index (BMI) was also a negative indicator (OR per unit, 0.83; 95% CI, 0.73 to 0.94). CONCLUSIONS:Age at PAO does not reduce the likelihood of excellent 20-year PROMs in native hips. Therefore, age alone should not be a limiting factor when considering PAO in appropriately selected patients.

Aims:The adoption of robotic assistance for unicondylar knee arthroplasty (UKA) is increasing, driven by reports of improved implant positioning. However, its impact on short-term patient outcomes remains debated. This study aimed to compare postoperative pain, opioid consumption, and length of hospital stay between manual (maUKA) and robotic-assisted (raUKA) procedures in a large, real-world cohort. Materials and methods:We retrospectively identified 1369 opioid-naïve patients undergoing medial, unilateral UKA at a single institution between 2019 and 2023 (417 manual, 952 robotic). We collected data on Numeric Pain Rating Scale (NRS) scores, opioid consumption in morphine milligram equivalents (MMEs), and length of hospital stay. Multivariable linear regression was used to compare outcomes while controlling for patient-level confounders. Results:After multivariable adjustment, we found no statistically significant difference between the manual and robotic groups in length of hospital stay (p = 0.6206) or total 90-day opioid consumption. Patients in the raUKA group reported slightly higher pain scores at the first postoperative measurement (Estimate -0.7, p < 0.001); however, no significant differences were observed in average, minimum, or maximum in-hospital pain scores. There was no significant difference in total inpatient opioid consumption. Conclusion:In this large single-institution analysis, robotic assistance was not associated with improvements in postoperative pain, opioid use, or length of hospital stay compared to the manual technique. These findings suggest that potential benefits of robotic UKA related to implant accuracy may not translate to improved short-term clinical outcomes, a crucial consideration in the context of technology acquisition and healthcare costs.

BACKGROUND:Body mass index (BMI) cut-off values have been proposed to determine eligibility for elective total hip arthroplasty (THA) in obese patients. However, the relationship between the severity of obesity and reoperations remains poorly understood. We evaluated whether the World Health Organization (WHO) obesity class is independently associated with the risk, invasiveness, or timing of reoperations after THA in obese patients. METHODS:There were 7,022 patients who had a BMI ≥ 30 who underwent elective, unilateral THA for primary osteoarthritis between 2016 and 2022 at a tertiary care institution. The patients were grouped according to the WHO obesity classification: class 1 (60.7%, n = 4,265); 2 (26.2%, n = 1,840); and 3 (13.1%, n = 917). A chart review was conducted to identify individuals who underwent any closed or open reoperation requiring anesthesia, and to determine characteristics, including invasiveness and timing. Kaplan-Meier survival analysis was used to estimate the probability of survival over time. The reoperation was defined as the event of interest. The Cox proportional hazards regression model was used to analyze the impact of obesity class on time to reoperation, adjusting for age, sex, race, and Charlson Comorbidity Index. RESULTS:There were 67 patients (1.0%) who required at least one reoperation, with 17 undergoing two or more. The reoperation rates for class 1, 2, and 3 were 1% (n = 44), 0.9% (n = 17), and 0.7% (n = 6), respectively (P = 0.77). There were five minor procedures (7.5%), 27 open procedures with or without liner exchange (40.3%), and 35 revisions with acetabular and/or femoral component exchange (52.2%) performed. Survival analysis did not show a statistically significant difference between groups. CONCLUSIONS:In this cohort of obese patients who underwent THA, the WHO obesity class was not associated with risk, invasiveness, or timing of reoperations. Policies that preclude patients fromreceiving THA based solely on BMI may have limited efficacy in reducing reoperations following THA.

Background The utility of patient-reported outcome measures (PROMs) has been well established, but their interpretation relies on population-specific definitions of meaningful improvement. As such, the minimum clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) thresholds have become prominent metrics in the orthopaedic evidence to ascribe clinical relevance to numeric PROM scores. Studies assessing outcomes of periacetabular osteotomy (PAO) relative to the MCID and PASS have previously evaluated patients against thresholds defined for hip arthroscopy for the treatment of femoroacetabular impingement or distribution-based MCID calculations. These scores may not accurately reflect the status or expectations of patients with a different symptom profile undergoing open hip preservation surgery. Questions/purposes For patients treated with PAO, we sought to (1) define the MCID, SCB, and PASS threshold values for the mHHS (modified Harris hip score) and International Hip Outcome Tool 12 (iHOT-12) using anchor-based methods; (2) assess the validity of MCID and SCB estimates against minimal detectable change (MDC) values; and (3) determine the proportion of patients who achieved a clinically meaningful threshold. Methods Between February 2011 and May 2023, a total of 690 patients underwent PAO for symptomatic acetabular dysplasia at one institution and were included in a longitudinally maintained hip preservation registry. The cohort used to define and validate MCID, SCB, and PASS threshold values consisted of those with a completed postoperative anchor questionnaire, which yielded 456 patients as potentially eligible. An additional 139 patients were excluded because of missing mHHS or iHOT-12 scores during the eligibility window (1 to 2 years postoperatively), leaving 70% (317 of 456) of patients to define and validate MCID, SCB, and PASS at a mean ± SD of 1.0 ± 0.3 years of follow-up. A minimum 1-year follow-up was chosen to reduce recall bias. The cohort for defining MCID, SCB, and PASS (94% [298 of 317] women, mean ± SD age at time of surgery 27 ± 8 years) included 21% (68 of 317) of patients with prior ipsilateral surgery. From those registry patients without complete anchor questionnaires, 37% (137 of 373) were identified with pre- and postoperative PROM scores at a mean ± SD of 1.0 ± 0.9 years of follow-up to form the sample for assessing the proportion of patients achieving a clinically meaningful threshold. The MCID, SCB, and PASS thresholds for the mHHS and iHOT-12 were calculated through an anchor-based approach, using area under the receiver operating curve to determine cut points that best identified positive responses, according to quality of life–based anchor questions. The MDC was calculated with confidence intervals (CIs) reflecting 80%, 90%, and 95% certainty to determine the smallest change in the PROM scores that can be considered above the level of measurement error. The validity of MCID estimates was assessed by confirming that they exceeded corresponding MDC values. The validity of SCB estimates were assessed by confirming that they exceeded corresponding MCID values. The proportion of patients achieving a clinically meaningful threshold was determined by calculating the percentage of patients who met the defined anchor-based scores. Results The MCID, SCB, and PASS thresholds for the mHHS were 18, 23, and 71, respectively. The MCID, SCB, and PASS thresholds for the iHOT-12 were 26, 42, and 65, respectively. The MDC ranged from 8 to 12 for the mHHS and 10 to 16 for the iHOT-12. The MCID values for the mHHS and iHOT-12 exceeded corresponding values of the MDC at all CIs. The SCB thresholds exceeded all corresponding MDC and MCID values. Across the mHHS and iHOT-12, the proportion of patients who achieved an MCID at the first time point ranged from 60% to 73%, the proportion of patients who achieved the SCB ranged from 49% to 56%, and the proportion of patients who achieved the PASS threshold ranged from 55% to 79%. Among the cohort for defining MCID, SCB, and PASS, the proportion of patients achieving any MCID, SCB, or PASS was 79%, 66%, and 81%, respectively. Among the sample for assessing the proportion of patients achieving a clinically meaningful threshold, the proportion achieving any MCID, SCB, or PASS threshold was 74%, 58%, and 72%, respectively. Conclusion We found that using a sample of patients undergoing PAO, the anchor-based values for the MCID and SCB were generally larger than previous distribution- and anchor-based scores that have been defined for hip preservation, whereas PASS threshold scores were similar. All MCID and SCB thresholds exceeded corresponding MDC values, confirming these scores to be valid estimates. These metrics provide more rigorous, procedure-specific definitions for the evaluation of treatment success and failure after PAO. As anchor-based metrics are defined based on patients’ perceptions, they should be used preferentially for postoperative assessment over distribution-based scores. Level of Evidence Level III, therapeutic study.

Background:Robotic assistance in total hip arthroplasty (THA) has increased, but the influence on outcomes compared to manual THA remains uncertain. With the growing emphasis on reducing opioid consumption after arthroplasty, we studied whether robotic assistance was associated with length of stay (LOS), pain, and opioid use after THA. Materials and methods:We included 14,501 opioid-naïve patients who underwent THA at a single institution between 2019 and 2023 (8900 manual and 5601 robotic). In-hospital pain scores (NRS), LOS, and opioid consumption patterns were collected. Opioid dosages were converted to morphine milligram equivalents (MMEs). After preliminary bivariate analysis, multivariable linear regression analyses were performed adjusting for age, sex, race, BMI, ASA-class, smoking status, cement use, marital status, year of surgery, surgeon experience, approach and periarticular injection. Results:Robotic THA was associated with significantly shorter LOS (Estimate: 6.8 h, 95 %CI: 8.0, -5.6, p < 0.0001). Robotic THA patients had higher minimal and mean pain scores (Estimate: 0.03, 95 %CI: 0.02-0.05, p < 0.001; Estimate: 0.08, 95 %CI: 0.03, 0.14, p = 0.0042). Robotic THA patients used less MMEs per hour of hospitalization (Estimate -0.11 MMEs, 95 %CI -0.174, -0.039, p = 0.0021), but were prescribed more MMEs at discharge (Estimate: 3.59 MMEs, 95 %CI: 0.323, 6.856, p = 0.0312). The differences in MMEs refilled after discharge and total 90-day opioid prescription patterns were not significant. Conclusion:Robotic assistance in THA was independently associated with a slightly shorter LOS. The significantly higher pain scores (0.08 points of NRS) and lower in-hospital opioid consumption (0.11 MMEs/hour) suggest that while some statistically significant differences exist between robotic-assisted and manual THA, these differences may not be clinically meaningful.

Background Given the heightened risk of postoperative complications associated with obesity, delaying total hip arthroplasty (THA) in patients who have a body mass index (BMI) > 40 to maximize preoperative weight loss has been advocated by professional societies and orthopaedic surgeons. While the benefits of this strategy are not well-understood, previous studies have suggested that a 5% reduction in weight or BMI may be associated with reduced complications after THA. Methods We identified 613 patients who underwent primary THA in a single institution during a 7-year period and who had a BMI >40 recorded from 9 to 12 months prior to surgery. Subjects were stratified into 3 cohorts based on whether their baseline BMI decreased by >5% (147 patients, 24%), was unchanged ( ± 5%) (336 patients, 55%), or increased by >5% (130 patients, 21%) on the day of surgery. The frequency of 90-days Hip Society and Centers for Medicare & Medicaid Services complications was compared between these cohorts. There were significant baseline differences between the cohorts with respect to baseline American Society of Anesthesiologists class (P < .001) and hemoglobin A1C (P = .011), which were accounted for in a multivariate regression analysis. Results In univariate analysis, there was a lower incidence of readmission (P = .025) and total complications (P = .005) in the increased BMI cohort. The overall complication rate was 18.4% in the decreased BMI cohort, 17.6% in the unchanged cohort, and 6.2% in the increased cohort. However, multivariable regression analysis controlling for potential confounders did not find that preoperative change in BMI was associated with differences in 90-days complications between cohorts (P > .05). Conclusions Patients who have a BMI >40 and achieved a clinically significant (>5%) BMI reduction prior to THA did not have a lower risk of 90-days complications or readmissions. Thus, delaying THA in these patients to encourage weight loss may result in restricting access to a beneficial surgery without an appreciable safety benefit.

Physical examination of the knee joint is used to diagnose the type and severity of knee ligament injury; however, these exams are qualitative and subjective. To perform common physical examinations, we developed an arthrometer which quantitatively measures the load-displacement response in anterior-posterior (AP) translation, internal-external rotation (IER) and varus-valgus (VV) rotation. Here we describe safety, reliability, minimum detectable changes (MDCs), and absolute side-to-side differences in twenty young, healthy subjects (ten male, ten female, mean age: 28 ± 6 years). The arthrometer consists of an instrumented mechanical linkage, a force-moment sensor, and software for real-time visualization and recording of the load-displacement responses. During testing, the subject sits reclined in a chair with their knee fixed at 30° of flexion. Two examiners tested both knees of each subject twice to assess reliability via intraclass correlation coefficients (ICC). All subjects completed the test protocol with minimal pain and stated that they would volunteer to be tested again. Each knee required on average five minutes to test. All intra-test reliabilities were excellent (≥0.91). Intra-examiner reliabilities ranged from good to excellent (0.62-0.89), and inter-examiner reliabilities were good to excellent (≥0.72). MDCs for repeat measures were ≤ 4.5 mm, 4.6°, and 2.3° for AP, IER, and VV, respectively. The absolute side-to-side differences for this cohort averaged 3.8 mm in AP, 5.5° in IER, and 2.2° in VV. Our arthrometer was safe, testing was time-efficient, and MDCs in our cohort of healthy subjects support utilization of this device for clinical research.

BACKGROUND:Patients undergo total knee arthroplasty (TKA) at widely disparate stages of osteoarthritis, raising the possibility of high heterogeneity among patients enrolled in TKA research studies. Obscuration of treatment effectiveness and other problems that may stem from cohort heterogeneity can be controlled in clinical studies by rigorously defining target patients. The purpose of this review was to determine the extent to which randomized controlled trials (RCTs) on TKA use osteoarthritis severity, as defined by radiographic grade or patient-reported outcome measures (PROMs), in their inclusion criteria, and to investigate potential impact on outcome. METHODS:A search of PubMed, Embase, Scopus, Web of Science, and Cochrane databases used a combination of terms involving TKA, PROMs, and radiographic scoring. A total of 1,227 studies were independently reviewed by 2 screeners for the above terms. RCTs with ≥100 patients (236) and with <100 patients (325) undergoing TKA were analyzed with regard to the specific inclusion criteria and recruitment process. RESULTS:Among the identified RCTs with ≥100 patients, 18 (<8%, with a total of 2,952 randomized patients) used specific radiographic scoring or PROM thresholds in their inclusion criteria. Eleven of the 18 studies used specific radiographic scoring, such as the Kellgren-Lawrence or Ahlbäck classifications. Three studies used preoperative PROM thresholds: Knee Society Knee Score of <60, Knee Society Function Score of <60, Oxford Knee Score of <20, and Hospital for Special Surgery Score of <60. Among studies with <100 patients, 48 (<15%) used specific inclusion criteria. CONCLUSIONS:The vast majority of RCTs (>85%) did not enroll patients based on disease severity, as measured by PROM score thresholds or radiographic classifications, in their inclusion criteria. The lack of consistent inclusion criteria likely results in heterogeneous cohorts, potentially undermining the validity of RCTs on TKA. LEVEL OF EVIDENCE:Prognostic Level I . See Instructions for Authors for a complete description of levels of evidence.

Background: The use of technology during total knee arthroplasty (TKA) has been associated with more accurate component position and less blood loss. Yet to date, the risk of developing prosthetic joint infection (PJI) associated with computer navigation (CN) or robotic assistance (RA) has not been thoroughly evaluated. This study used propensity score-matching (PSM) in a large cohort of primary TKA patients to compare the rate of PJI following conventional TKA (TKA) versus CN-TKA and RA-TKA. Methods: We retrospectively reviewed 13,015 knees in 11,727 patients who underwent primary TKA at a single institution from 2018 to 2021. The cohort was stratified into TKA, CN-TKA, and RA-TKA groups. 1:1 PSM was applied to 11,834 patients. Propensity score-matching was performed using logistic regression accounting for age, sex, body mass index, Charlson Comorbidity Index (CCI) score, CCI components, and smoking status. Univariate and multivariable analyses were performed to evaluate differences in surgical time and PJI rate. Results: Significantly longer median operating times were noted in the RA-TKA group (14 minutes) compared to TKA (P < .001). The PJI rates among matched cohorts were similar among RA-TKA (0.3%), CN-TKA (0.3%), and conventional TKA (0.5%). Multivariable logistic regressions demonstrated that the use of robotic assistance (odds ratio (OR) = 0.5, P =.423) or computer navigation (OR = 0.61, P =.128) was not associated with increased risk of PJI when compared to conventional TKA. Conclusions: Use of computer navigation and robotic assistance during primary TKA are associated with longer surgical times, but no difference in PJI frequency within 90 days of surgery. (c) 2023 Elsevier Inc. All rights reserved.

BACKGROUND:Body mass index (BMI) cutoffs for morbidly obese patients otherwise indicated for total knee arthroplasty (TKA) have been widely proposed and implemented, though they remain controversial. Previous studies suggested that a 5% reduction in BMI may be associated with fewer postoperative complications. Thus, the purpose of this study was to determine whether a substantial reduction in preoperative BMI in morbidly obese patients improved 90-day outcomes after TKA. METHODS:There were 1,270 patients who underwent primary TKA at a single institution and had a BMI > 40 recorded during the year prior to surgery. Patients were stratified into three cohorts based on whether their BMI within 3 months to 1 year preoperatively had decreased by ≥ 5% (228 patients [18%]); increased by ≥ 5% (310 [24%]); or remained unchanged (within 5%) (732 [58%]) on the day of surgery. There were several baseline differences between the cohorts with respect to medical comorbidities. The rate of 90-day complications and six-week patient-reported outcome measures were compared via univariate and multivariable analyses. RESULTS:On univariate analysis, individual and total complication rates were similar between the cohorts (P > .05). On multivariable logistic regression, the risk of complications was similar in patients who had decreased versus unchanged BMI (OR [odds ratio] 1.0; P = .898). However, there was a higher risk of complications in the increased BMI cohort compared to those patients who had an unchanged BMI (OR 1.5; P = .039). The six-week patient-reported outcome measures were similar between the cohorts. CONCLUSIONS:Patients who have a BMI > 40 who achieved a meaningful reduction in BMI prior to TKA did not have a lower rate of 90-day complications than those whose BMI remained unchanged. Furthermore, considering that nearly one in four patients experienced a significant increase in BMI while awaiting surgery, postponing TKA may actually be detrimental.