Time from surgery end to discharge following total knee arthroplasty: implications for same day discharge.

BACKGROUND: Understanding the average time from surgery to discharge is important to successfully and strategically schedule cases planned for same day discharge (SDD) for total knee arthroplasty (TKA). The purpose of this study was to (1) evaluate the average time to discharge following unilateral TKA performed in a community hospital and (2) describe patient characteristics and peri-operative factors that may impact SDD. METHODS: This retrospective review included 75 patients having achieved SDD following unilateral TKA between March 2017 and September 2021 at a high-volume multi-specialty community hospital. Time to discharge was calculated from end of surgery, defined as completion of dressing application, to physical discharge from the hospital. Time surgery completed and association with time of discharge was also examined. Pearson's correlations were performed to evaluate the relationship between total time to discharge and patient demographics. RESULTS: The average age for all patients was 66.6 ± 10.9 years (Range: 38 to 86) and average BMI of 29.9 ± 5.6 kg/m2 (Range: 20.4 to 46.3). The average time to discharge was 5.8 ± 1.8 h (range: 2.2 to 10.5 h). Time to discharge was significantly longer for patients finishing surgery prior to noon (6.0 ± 1.8 h), than after noon (4.8 ± 1.4 h, p = 0.046). Total time to discharge was not correlated with age (r = 0.018, p = 0.881) or BMI (r=-0.158, p = 0.178), but was negatively correlated with surgical start time (r=-0.196, p = 0.094). CONCLUSION: An average of six hours was required to achieve SDD following unilateral TKA performed in a community hospital. The time required for SDD was not found to be related to intrinsic patient factors but more likely due to extrinsic factors associated with time of scheduled surgery. To improve success of SDD, focus should be placed on the development of efficient discharge pathways rather than unchangeable intrinsic patient characteristics.

Extended offset stems are infrequently required in anterior approach total hip arthroplasty and low usage does not compromise stability.

INTRODUCTION: Extended offset (EO) stems are commonly used in posterior approach (PA) total hip arthroplasty (THA), but usage rates and complications are not well studied with anterior approach (AA) THA. This study evaluated usage rates, radiographic outcomes and complications following AA THA between patients receiving EO stems and a matched cohort receiving standard offset (SO) stems. MATERIALS AND METHODS: This retrospective review evaluated 1515 consecutive AA THA performed between 2014 and 2021. The recent 100 EO were included in radiographic and complication analysis and were matched to 100 SO stems based on stem size, procedure (unilateral/bilateral), sex, body mass index (BMI), and age. Data collection included patient demographics; pre- and postoperative radiographic measurements of leg length difference (LLD) and global hip offset difference (GHOD); and complications within 1 year. Independent t-tests and Chi-squared analyses compared EO and SO groups. RESULTS: EO was utilized in 8% of all AA THA. Despite matching procedures, the distribution of racial groups was different between EO and SO groups, respectively: Caucasian (75% vs. 43%), Asian (12% vs. 35%), Native Hawaiian/Pacific Islander (NHPI) (9% vs. 13%), and other (4% vs. 9%) (p < 0.001). No fractures, dislocations, or revisions occurred within 1 year after surgery in either group. One deep infection was noted in the SO group. The proportions of patients following surgery who had a GHOD < 6 mm (76% vs. 82%; p = 0.193) and LLD < 6 mm (81% vs. 86%; p = 0.223) were not significantly different between EO and SO groups, respectively. CONCLUSIONS: Prioritizing hip symmetry over stability results in a high proportion of patients achieving hip symmetry without high usage of EO stems in AA THA. Furthermore, low use of EO stems did not result in increased dislocations. Due to racial anatomical differences, Caucasian patients required EO stems to achieve hip symmetry more frequently than Asian and NHPI patients.

Examining racial disparities in utilization rate and perioperative outcomes following knee and hip arthroplasty.

BACKGROUND: Previous arthroplasty utilization research predominantly examined Black and White populations within the US. This is the first known study to examine utilization and complications in poorly studied minority racial groups such as Asians and Native Hawaiian/Pacific-Islanders (NHPI) as compared to Whites. RESULTS: Data from 3304 primary total hip and knee arthroplasty patients (2011 to 2019) were retrospectively collected, involving 1789 Asians (52.2%), 1164 Whites (34%) and 320 Native Hawaiians/Pacific Islanders (NHPI) (9.3%). The 2012 arthroplasty utilization rates for Asian, White, and NHPI increased by 32.5%, 11.2%, and 86.5%, respectively, by 2019. Compared to Asians, Whites more often underwent hip arthroplasty compared to knee arthroplasty (odds ratio (OR) 1.755; p < 0.001). Compared to Asians, Whites and NHPI more often received total knee compared to unicompartmental knee arthroplasty (White: OR 1.499; NHPI: OR 2.013; p < 0.001). White patients had longer hospitalizations (2.66 days) compared to Asians (2.19 days) (p = 0.005) following bilateral procedures. Medicare was the most common insurance for Asians (66.2%) and Whites (54.2%) while private insurance was most common for NHPI (49.4%). Compared to Asians, economic status was higher for Whites (White OR 0.695; p < 0.001) but lower for NHPI (OR 1.456; p < 0.001). After controlling for bilateral procedures, NHPI had a lower risk of transfusion compared to Asians (OR 0.478; p < 0.001) and Whites had increased risk of wound or systemic complications compared to Asians (OR 2.086; p = 0.045). CONCLUSIONS: Despite NHPI demonstrating a significantly poorer health profile and lower socioeconomic status, contrary to previous literature involving minority racial groups, no significant overall differences in arthroplasty utilization rates or perioperative complications could be demonstrated amongst the racial groups examined.

The prevalence of bilateral and ipsilateral radiographic osteoarthritis is high in White, Asian and Native Hawaiian/Pacific Islanders presenting for unilateral knee or hip arthroplasty.

BACKGROUND: It is estimated that one-third of patients presenting with unilateral joint pain have contralateral osteoarthritis (OA) at first presentation. Most studies have primarily examined White patient cohorts. The purpose of this study was to determine the prevalence of contralateral joint OA for patients presenting for unilateral total knee (TKA), unicompartmental knee (UKA) or total hip arthroplasty (THA) among Asian, Native Hawaiian/Pacific Islander and White patients. METHODS: Bilateral radiographic reports at initial presentation of 2,312 subjects who underwent unilateral arthroplasties (332 UKAs, 933 TKAs and 1,047 THAs) were reviewed. The presence of contralateral OA was recorded and compared by racial group and type of arthroplasty performed. Parametric statistical analyses were performed to determine differences between groups. Multivariable analyses were completed for each arthroplasty group to determine the influence on the presence of contralateral OA, presented as odds ratios and 95% confidence intervals. RESULTS: Contralateral joint OA was present in 86.7%, 90.4% and 70.4% of UKA, TKA and THA patients, respectively. Concurrent hip OA was present in 41.6% and 59.5% of UKA and TKA patients. No racial differences in the prevalence of contralateral knee OA were found for knee arthroplasty patients. White patients (74.6%) had a greater prevalence of contralateral hip OA compared to Asians (66.5%, p = 0.037) amongst THA recipients. Increased age and body mass index were significantly associated with the presence of contralateral knee OA. Increased age, being male and being White were significant contributors for the presence of contralateral hip OA. CONCLUSION: The prevalence of contralateral joint OA and concurrent hip OA is high in all three racial groups. Due to the extensive prevalence of contralateral and concurrent knee and hip OA, bilateral radiographic evaluation should be considered for all patients presenting with unilateral hip or knee pain due to OA.

Complications following single-stage bilateral total knee arthroplasty and unilateral procedures: experience of a high-volume community hospital.

INTRODUCTION: The safety of single-stage bilateral total knee arthroplasty (SSBTKA) compared to unilateral total knee arthroplasty (TKA) remains controversial. The present study compares the 90-day postoperative complications encountered following SSBTKA and unilateral TKA in an unselected cohort of patients performed at a high-volume community hospital. MATERIALS AND METHODS: The perioperative electronic medical records of an unselected consecutive cohort of 1032 patients (1345 knees) having undergone unilateral or SSBTKA were reviewed. Ninety-day postoperative complications or need for additional procedures were compared between unilateral and SSBTKA groups. RESULTS: A total of 719 and 313 patients underwent unilateral and SSBTKA, respectively. There were no significant differences in age or BMI between groups. Patients undergoing SSBTKA were more likely to be male (p = 0.019), have longer lengths of stay (p < 0.001) and were less likely to discharge directly home (13.1%) compared to unilateral patients (80.9%) (p < 0.001). Patients undergoing SSBTKA were more likely to require a transfusion (14.7%) compared to unilateral patients (2.2%) (p < 0.001). Interestingly, mortality rate following unilateral TKA (1.7%) was significantly higher than SSBTKA (0.0%) (p = 0.013). There were no significant differences regarding other complications or need for additional procedures within 90 days following surgery. CONCLUSION: SSBTKA did not result in greater complications when compared to unilateral TKA in this particular cohort. As expected, transfusion rates will likely be higher and there will be a greater need for acute inpatient care following surgery for SSBTKA patients.

The influence of mental health on early outcomes following total hip arthroplasty.

BACKGROUND: Poor mental health is difficult to recognize and as a result, its association with recovery from total joint arthroplasty is difficult to assess. The purpose of this study was to investigate the relationship between overall mental health scores and outcomes in the early postoperative period following unilateral total hip arthroplasty (THA). METHODS: This is a retrospective review of prospectively collected data involving 142 patients who underwent primary unilateral THA. Independent variables included patient demographics and preoperative Patient-Reported Outcomes Measurement Information System (PROMIS), Global Physical Health (GPH) and Global Mental Health (GMH) and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR) scores as well as diagnoses of depression or anxiety. Dependent variables included length of stay (LOS), disposition at discharge, narcotic consumption until discharge, 6-week postoperative GPH, GMH and HOOS JR scores and magnitude of change compared to preoperative scores. Preoperative GMH and postoperative outcomes were compared using Pearson correlation coefficient, independent t-tests, Pearson's Chi-Square test, and univariate logistic regression. RESULTS: Patients with preoperative GMH scores below the 25% quartile were less likely to be discharged home and resulted in lower GPH, GMH and HOOS JR scores at 6-week follow-up compared to patients with preoperative GMH scores in the top 25% quartile. However, patients with low preoperative GMH scores demonstrated a greater magnitude of improvement in both the GPH and GMH scores compared to patients in the top 25% quartile. There was no difference in opioid consumption or LOS between either groups. When comparing patients with and without depression/anxiety, no difference was seen in any of the outcomes measured. CONCLUSION: Unilateral THA offers significant improvements in both physical and mental function to patients with hip osteoarthritis and poor mental health, though overall scores remain lower than in those with better mental health.

Severe patellofemoral arthritis does not compromise 6-month post-operative range of motion or function following unicondylar knee arthroplasty.

BACKGROUND: The presence of significant patellofemoral arthritis (PFA) is still considered a contraindication for unicondylar knee arthroplasty (UKA) by many surgeons. The purpose of this study was to determine if the presence of severe PFA at the time of UKA compromised early (< 6 months) post-operative knee range of motion or functional outcomes. METHODS: This retrospective review evaluated unilateral and bilateral UKA (323 patients; 418 knees) between 2015 and 2019. Procedures were grouped by degree of PFA present at the time of surgery, including mild PFA (Group 1; N = 266), moderate to severe PFA (Group 2; N = 101), and severe PFA with lateral compartment bone-on-bone contact (Group 3; N = 51). Knee range of motion and Knee Society Knee (KSS-K) and Function (KSS-F) scores were collected both before and at 6 months following surgery. Group differences were evaluated with Kruskal-Wallis and Chi-square tests for continuous and categorical variables, respectively. Univariate and multivariable logistic regressions were performed to determine influential variables associated with post-operative knee flexion being ≤ 120° and presented as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Pre-operative flexion was lowest in Group 3 (p = 0.010) with 17.6% of knees having flexion ≤ 120°. Post-operative flexion was lowest in Group 3 (119.1° ± 8.4°, p = 0.003) with 19.6% knees having flexion ≤ 120° compared to 9.8% and 8.9% in Groups 1 and 2, respectively. No significant difference in KSS-F following surgery was found; all three groups demonstrated similar clinical improvement. Increased age (OR 1.089, CI 1.036-1.144; p = 0.001) and body mass index (OR 1.082, CI 1.006-1.163; p = 0.034) were found to be associated with post-operative knee flexion ≤ 120°, while high pre-operative flexion (OR 0.949, CI 0.921-0.978; p = 0.001) was found to be inversely associated with poor knee flexion following surgery. CONCLUSION: Patients with severe PFA demonstrate similar clinical improvement following UKA at 6 months as patients with less severe PFA.

Higher intra-operative narcotic requirements and weakness with quadratus lumborum compared to paravertebral nerve block for total hip arthroplasty.

BACKGROUND: This was a prospective single-blinded study comparing the peri-operative opioid consumption and motor weakness for patients undergoing total hip arthroplasty (THA) with either a Quadratus Lumborum Type 3 Nerve Block (QLB) or a Paravertebral Nerve Block (PVB). METHODS: A consecutive cohort of patients undergoing elective anterior approach (AA) THA by a single high-volume surgeon were randomly assigned an anesthesiologist by the charge anesthesiologist. One anesthesiologist performed all QLBs, and the other six anesthesiologists performed the PVBs. Pertinent data include prospectively collected qualitative surveys from blinded medical personnel, floor nurses, and physical therapists as well as demographic information and post-operative complications. RESULTS: Overall, 160 patients were included in the study divided equally between the QLB and PVB groups. The QLB group had a statistically higher peri-operative narcotic use (p < 0.001), greater intra-operative peak systolic blood pressure (p < 0.001) and respiratory rate (p < 0.001), and higher incidence of post-operative lower extremity muscle weakness (p = 0.040). There were no statistical group differences for floor narcotic use, post-operative hemoglobin levels or hospital length of stay. CONCLUSION: The QLB required greater intraoperative narcotic use and resulted in greater post-operative weakness, however provided nearly equal post-operative pain management and did not adversely affect rapid discharge success. LEVEL OF EVIDENCE: III, Non-randomized controlled cohort/follow-up study.

Influence of obesity and intra-operative imaging guidance technology on acetabular cup positioning in total hip arthroplasty.

BACKGROUND: Accuracy of acetabular cup positioning during total hip arthroplasty (THA) can be improved with intra-operative imaging but may be influenced by body mass index (BMI). This study assessed the influence of BMI (kg/m2) on cup accuracy when using intra-operative fluoroscopy (IF) alone or supplemented with a commercial product. METHODS: This retrospective review included four consecutive cohorts of patients having undergone anterior approach THA with IF alone (2011-2015), IF and Overlay (2015-2016) (Radlink Inc., Los Angeles, CA), IF and Grid (2017-2018) (HipGrid Drone™, OrthoGrid Systems Inc., Salt Lake City, UT) and IF and Digital (2018-2020) (OrthoGrid Phantom®, OrthoGrid Systems, Inc., Salt Lake City, UT). Component placement accuracy was measured on 6-week post-operative weight bearing radiographs and compared between four BMI patient groups (BMI ≤ 25, 25 < BMI ≤ 30, 30 < BMI ≤ 35, and 35 < BMI). Total fluoroscopy times were also recorded directly from the fluoroscopy unit. RESULTS: Abduction angle significantly increased as BMI increased (p = 0.003) with IF alone but no difference was present in groups with guidance technology. Anteversion was significantly different between BMI groups for IF alone (p = 0.028) and Grid (p = 0.027) but was not different in Overlay (p = 0.107) or Digital (p = 0.210). Fluoroscopy time was significantly different between BMI categories for IF alone (p = 0.005) and Grid (p = 0.018) but was not different in Overlay (p = 0.444) or Digital (p = 0.170). CONCLUSION: Morbid obesity (BMI > 35) increases risk for malpositioning of acetabular cups and increases surgical time with IF alone or the Grid. Additional IF guidance technology (Overlay or Digital) increased cup positioning accuracy without decreasing surgical efficiency.

Preoperative Educational Classes in Elderly Patients May Not be Necessary Prior to Elective Joint Arthroplasty.

Preoperative arthroplasty classes decrease complications and readmissions, however, in-person classes are inconvenient for elderly patients with mobility limitations. This retrospective review included 232 patients (305 joints) with in-person preoperative educational classes (IPC) and 155 patients (192 joints) with telephone preoperative educational classes (TC). Compared to IPC, TC patients had a shorter length of stay (P<.009), but a greater percentage made at least one postoperative clinic call (22.8% vs 40%; P<.001). No differences were noted in complications, but emergency room visits significantly decreased for total knee TC patients (P=.039). The increase in clinic calls may be addressed through focused changes to the preoperative telephone dialogue, providing a safe and efficient alternative to IPCs.

COVID-19 had Limited Impact on Resumption of Elective Joint Arthroplasty and Ethnic Disparities.

In response to the COVID-19 pandemic, federal and state recommendations included the postponement of elective arthroplasties until adequate safety measures could be implemented. Following resumption of arthroplasties, exposure fears and financial concerns may have restricted access for some demographics. Therefore, the purpose of this study was to (1) investigate how the COVID-19 pandemic impacted the incidence of arthroplasty, both overall and by various demographics, and (2) evaluate if pre-operative patient-reported measures were different throughout the pandemic. Data were collected prospectively as part of an on-site joint registry between January 2019 and April 2021. Phase 1 (N=518) included all patients prior to the cancelation of elective procedures (average 36 cases/month), Phase 2 (N=121) was defined from restart until monthly caseload met/surpassed the average Phase 1 caseload (5 months), and Phase 3 (N=277) included all remaining cases. Multiple analysis of variance and chi-squared tests were performed to compare patient demographics and outcomes between phases. No significant differences were noted in patient demographics, with the exception of a decrease in Native Hawaiian/Pacific Islander patients and an increase in Asian patients during Phase 2 (P =.004). Length of stay decreased for unilateral arthroplasty from Phase 1 (0.9±1.1 days) to Phase 2 (0.4±0.6 days) and Phase 3 (0.6±0.7 days) (P <.001), while pre-operative patient reported outcomes remained similar across the 3 time periods. By implementing proper safety measures, the current orthopedic center achieved a timely recovery with no long-lasting inconsistencies in patient cohorts upon resumption of arthroplasties.

Can single-stage bilateral unicompartmental knee arthroplasty be safely performed in patients over 70?

Background: For patients with bilateral, symptomatic unicompartmental knee arthritis, single-stage bilateral unicompartmental knee arthroplasty (ssBUKA) presents an attractive option. However, most studies have examined younger patient cohorts and the safety of ssBUKA remains controversial for older individuals. Therefore, the purpose of this study was to compare complication rates following ssBUKA for patients ≤70 and > 70 years old. Methods: A retrospective chart review of 238 patients having undergone ssBUKA was performed, including 134 patients ≤70 and 104 patients >70. Post-operative complications were recorded at the six-week post-operative visit, along with emergency room visits and hospital readmissions within 90 days. Results: Compared to patients ≤70, patients >70 were more frequently female (43.3% and 55.8%, respectively) (p = 0.037) and had significantly lower body mass index (30.41 ± 4.64 and 27.30 ± 3.68, respectively) (p < 0.001). Patients >70 were discharged home (50%) less commonly than patients ≤70 (73.1%) (p < 0.001). Two patients ≤70 (1.5%) and two patients >70 (1.9%) sought emergency room treatment (p = 0.589), with respiratory complications most common. There were no differences regarding any postoperative complications between patients ≤70 and > 70 years old. Conclusion: These results suggest that patients >70 can safely undergo ssBUKA, as it does not appear to increase the incidence of early post-operative complications compared to patients ≤70. However, 50% of patients >70 were not able to discharge directly home following surgery.

Favorable outcomes of posterior cruciate-stabilized inserts over ultracongruent inserts in total knee arthroplasty.

OBJECTIVE: Posterior cruciate-stabilized (PS) and ultracongruent (UC) inserts are used during total knee arthroplasty (TKA), but superiority in gaining postoperative knee flexion and functionality remains contested. Therefore, this study compared postoperative outcomes between PS and UC inserts. METHODS: A retrospective review evaluated unilateral or bilateral TKAs with PS or UC inserts from August 2011 to March 2020. Nonparametric statistics were performed to evaluate differences in patient demographics, pre- and postknee flexion and Knee Society Knee (KSS-K) and Function Score (KSS-F). Univariate and multivariable regressions were performed to evaluate the influence on postoperative knee flexion ≥ 120°, presented as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Patient demographics were not significantly different between the 577 PS and 399 UC knees evaluated. Postoperatively, a larger proportion of UC knees demonstrated knee flexion < 120° (36.0% vs. 18.6%, p < 0.001) and lower KSS-K (91.0 ± 8.7 vs. 91.6 ± 10.3, p < 0.001) and KSS-F (76.8 ± 21.6 vs. 79.9 ± 21.6, p = 0.007) than the PS group. The PS group had greater improvement in flexion angle (4.9° ± 14.9° vs. 1.0° ± 15.6°, p < 0.001) and KSS-F (27.3 ± 23.3 vs. 23.1 ± 25.3, p = 0.007) as compared to that of UC patients. Patients with preoperative flexion < 120° (OR 2.787, CI 2.066-3.761; p < 0.001), higher body mass index (OR 1.033, CI 1.006-1.061; p = 0.017) and UC insert (OR 2.461, CI 1.832-3.307; p < 0.001) were less likely to achieve flexion ≥ 120°. CONCLUSION: Favorable clinical and functional outcomes were noted in the PS group as compared to UC inserts in TKA. The greater improvement in overall knee flexion may suggest the PS insert may be especially appropriate for patients with lower preoperative range of motion. LEVEL OF EVIDENCE: III, retrospective comparative study.

Can a community hospital successfully transition to outpatient total knee arthroplasty in unselected patients?

BACKGROUND: The removal of total knee arthroplasty (TKA) from the Inpatient-Only list in 2018 created pressure on community hospitals to develop rapid discharge protocols (RAP) to increase outpatient discharge. The purpose of this study, therefore, was to compare the efficacy, safety and barriers in achieving outpatient discharge between the standard discharge protocol and newly developed RAP in unselected, unilateral TKA patients. METHODS: This retrospective chart review included 288 standard protocol patients and the first 289 RAP patients following unilateral TKA in a community hospital. The RAP focused on patient discharge expectations and post-operative patient management, with no change in post-operative nausea or pain management. Non-parametric tests were performed to compare demographics, perioperative variables and 90-readmission/complication rates between standard and RAP groups, as well as between inpatient and outpatient discharged RAP patients. Multivariate, stepwise logistic regression was performed to evaluate patient demographics and discharge status, presented as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Demographics were similar between groups, however, outpatient discharge significantly increased from 22.2% to 85.8% for standard discharge and RAP, respectively (p < 0.001), with no significant difference in post-operative complications. For RAP patients, age (OR:1.062, CI:1.014-1.111; p = 0.011) and female gender (OR:2.224, CI:1.042-4.832; p = 0.039) increased the risk of inpatient and 85.1% of RAP outpatients were discharged home. CONCLUSIONS: While RAP was successful, 15% of patients required inpatient care and 15% of patients achieving outpatient discharged were not discharged to their home environment, emphasizing the difficulties of achieving true outpatient status in 100% of patients from a community hospital.

Do older patients fare worse following unilateral or single stage bilateral total knee arthroplasty?

INTRODUCTION: The safety and benefits of single stage bilateral total knee arthroplasty (SSBTKA) among older patients as compared to unilateral TKA remains controversial. This study aimed to evaluate the influence of age and comorbidities on complications and early outcomes for unilateral and BTKA in patients over and under 70 years of age. MATERIALS AND METHODS: This prospective study compared postoperative complications and early patient-reported outcomes at 6 weeks of 142 unilateral TKA patients (N = 75, ≤ 70; N = 67, > 70) and 89 SSBTKA patients (N = 48, ≤ 70; N = 41, > 70). Patients completed the KOOS JR and PROMIS Global Mental (GMH) and Global Physical Health (GPH) surveys. Knee Society Scores for Knee (KSS-K) and Function (KSS-F) were completed in the clinic. Parametric tests were performed for comparisons of unilateral and BTKA outcomes and complications for patients over and under 70. RESULTS: While patient demographics were similar, patients > 70 had more comorbidities than patients ≤ 70 (p < 0.004). There were no significant differences in postoperative complications or readmissions between age groups or procedures. Unilateral TKA patients > 70 had significantly lower pre- (p < 0.001) and post-operative (p = 0.011) KSS-F scores compared to those ≤ 70. SSBTKA patients > 70 had significantly higher preoperative GMH (p = 0.029), postoperative KSS-K (p = 0.027), KOOS JR scores (p = 0.039) and satisfaction (p = 0.048) compared to those ≤ 70. CONCLUSION: Age did not influence the risk of early postoperative complications. Additionally, the greater improvements in KOOS JR and higher patient satisfaction for SSBTKA patients > 70 suggests that SSBTKA may meet elderly patient expectations and should not necessarily be discouraged due to safety concerns.

True "outpatient discharge" following single-stage bilateral unicompartmental knee arthroplasty may be unrealistic for most.

BACKGROUND: Single-stage bilateral unicompartmental knee arthroplasty (BUKA) has shown post-operative function and cost benefits over staged bilateral procedures, without increased complications. A rapid discharge protocol at the current study site has reported outpatient discharge for the unilateral procedure exceeding 97%. However, the feasibility of outpatient discharge following BUKA remains unclear. Therefore, the purpose of this study was to determine the success of achieving outpatient (< 24 h) discharge following BUKA, and identify patient variables associated with failure. METHODS: A retrospective chart review was completed for 104 BUKA patients. All patients with bilateral, symptomatic unicompartmental knee arthritis were offered the single-stage procedure. Data collection included patient demographics, discharge status, and disposition location. Independent t tests (continuous) and Chi-squared tests (categorical) determined differences between discharge (outpatient/inpatient) and disposition (home/other) groups. Variables associated with discharge status and location were assessed with multivariable regression. RESULTS: While 96 (92.3%) patients discharged within 24 h, only 63.5% were able to discharge directly home. Patients requiring a longer hospital stay (> 24 h) were more likely to require a pre-operative assistive device (62.5% and 25.0%, p = 0.037) and live alone (37.5 vs 8.3%, p = 0.033). For those discharged within 24 h, living alone significantly increased the risk (odds ratio: 5.800, p = 0.038) of requiring an acute inpatient facility prior to transition home. CONCLUSION: Achieving "true" outpatient discharge is only modestly successful for most BUKA patients, as many required an acute inpatient or short-term rehabilitation facility prior to returning home. BUKA should be differentiated from the unilateral procedure regarding outpatient discharge expectations. LEVEL OF EVIDENCE: III, Case-control study; Retrospective comparative study.

Impact of intraoperative fluoroscopic beam positioning relative to the hip and pelvis on perceived acetabular component position.

Background: Parallax is poorly understood and can mislead surgeons using intraoperative fluoroscopy (IF) to guide cup placement during anterior approach (AA) total hip arthroplasty. The purpose of this study was to examine how changes in fluoroscopic beam positioning in relation to the hip and pelvis affects the projected acetabular image. Methods: An acetabular component was positioned in an anatomic pelvis model in 45° and 20° of abduction and anteversion, respectively using a computer assisted cup targeting system. Fluoroscopic images were taken at various caudal and cranially directed angles with the fluoroscopic beam centered over the hip then pelvis. In each position, four independent observers measured the abduction and anteversion angles of the projected cup image using the same computer targeting system. Results: Cup abduction and anteversion measured 43.5° and 19.5° when IF was centered over the hip and 40.5 and 27.5° when centered over the pelvis in the neutral position. Increasing the caudal direction of the beam 20° increased the projected abduction/anteversion angles by approximately 7°/12° and 9°/16° when centered over the hip and pelvis respectively. Increasing the cranial direction of the beam 20° decreased the measured abduction/anteversion angles by roughly 4°/20° and 4°/24° when centered over the hip and pelvis, respectively. Conclusion: The projected image of the acetabular component can change dramatically depending on fluoroscopic beam position relative to the hip and pelvis. Recognizing the approximate direction and magnitude of change with differing fluoroscopy positions may help surgeons avoid cup malpositioning.

A smaller femoral stem is needed for asian females.

BACKGROUND: Current femoral implants are manufactured based on Western anatomical structures and may be too large for smaller physiques, such as those of Asian females. This study reviewed the femoral stem size distribution used in a high-volume total hip arthroplasty (THA) practice and evaluated malalignment in patients receiving a size one implant. MATERIALS AND METHODS: A consecutive cohort of female patients self-reported as Asian (257 patients, 331 hips) or Caucasian (158 patients and 190 hips) were retrospectively evaluated. A single femoral stem type was used in all cases, performed by a single surgeon. Global hip offset (GHO) and leg length difference (LLD) were measured before and 6 weeks following THA. Differences between races were evaluated through Mann-Whitney U tests and chi-squared tests for continuous and categorical variables, respectively. RESULTS: The proportion of size one implants was higher amongst Asian patients (20.5%) than Caucasian patients (2.6%) (p < 0.001). A LLD greater than 6 mm was noted in 24.6% of size one patients and 11.4% of all other sizes (p = 0.010). Varus malalignment occurred in 47.9% of size one patients and 22.1% of all other sizes (p < 0.001). No fractures occurred in size one patients, and nine fractures (one intraoperative and eight post-operative) occurred in all other sizes (p = 0.258). CONCLUSION: The high proportion of size one stems required in Asian females and the higher incidence of LLD > 6 mm and varus malalignment suggest a distinct need for smaller femoral implants, especially for Asian females.

Fixed 6° distal femoral cut consistently achieves neutral alignment for Asians, Caucasians, and Native Hawaiian/Pacific Islanders.

BACKGROUND: Restoration of a neutral mechanical axis (MA) is important to the success of total knee arthroplasty (TKA). While known differences are present between Asians and Caucasians regarding native knee alignment, it is unknown whether such differences exist amongst Native Hawaiian/Other Pacific Islanders (NHPI) or if utilizing a fixed distal femoral cut of 6° can consistently achieve a neutral MA in these minority racial groups. This study examines the preoperative deformities presented by Asians, Caucasians, and NHPI, and the resulting knee alignment achieved following TKA when a fixed 6° distal femoral cut is targeted for all patients. METHODS: Preoperative and postoperative MA was measured from 835 Asian, 447 Caucasian, and 163 NHPI hip-to-ankle radiographs. All patients underwent TKA in which a standard distal femoral cut of 6° valgus was targeted for all patients. Data were evaluated as continuous variables and by groupings of varus (MA < - 3°), valgus (MA > 3°), and neutral (- 3° ≤ MA ≤ 3°) alignment. RESULTS: Preoperative deformity ranged from 38° varus to 29° valgus. The proportion of Asian and NHPI presenting with varus alignment prior to surgery was significantly greater than Caucasian patients in both males (Asians: 80.6%; Caucasians: 67.0%; NHPI: 79.0%, p = 0.001) and females (Asians: 66.1%; Caucasians: 45.7%; NHPI: 63.2%, p < 0.001). There was no difference in the proportion of patients (72-79%) achieving a neutral MA amongst all three racial groups. CONCLUSION: NHPI appear to have similar preoperative deformities to Asians with both groups having significantly more varus alignment than Caucasians. Despite a wide range of preoperative deformity, application of a fixed distal femoral cut of 6° valgus successfully established a neutral MA equally in the majority of patients across all three racial groups.

Reducing transfusion in hip arthroplasty: tranexemic acid diminishes influence of anesthesia administered.

BACKGROUND: The risk of transfusion following total hip arthroplasty (THA) continues to be problematic. The best choice of anesthesia (spinal vs general) and impact of tranexamic acid (TXA) use in reducing transfusions following surgery remain unclear. Therefore, the purpose of this study was to compare rates of blood transfusion following THA via the anterior approach using three different anesthesia protocols with and without TXA. MATERIALS AND METHODS: This retrospective review included 1399 patients (1659 hips), receiving spinal anesthesia (SA) without (248 patients) and with TXA (77 patients), general anesthesia (GA) without (151 patients) and with TXA (171) and general anesthesia with paravertebral block (GA-PVB) and TXA (748 patients). All procedures were performed by a single surgeon. Chi-Squared tests and logistic regression were performed to evaluate the rate and risks of transfusion between groups. RESULTS: Without TXA, transfusion rate with GA (24.5%) was higher than SA (13.4%) (p = 0.004). With TXA, there was no difference in transfusion rates between GA (4.6%), SA (3.9%) or GA-PVB (4.0%). The multivariable regression revealed bilateral (Odds Ratio (OR): 6.473; p < 0.001), female (OR: 2.046; p = 0.004), age (OR: 1.028; p = 0.012) and pre-operative anemia (OR: 2.604; p < 0.001) as increasing the risk of transfusion while use of TXA (OR: 0.168; p < 0.001) significantly reduced transfusion risk. CONCLUSION: The use of TXA during THA via the anterior approach removed the influence of anesthesia type regarding risk of transfusion. The use of TXA may reverse presumed disadvantages of GA alone, potentially facilitating rapid discharge following surgery.