Medial Calcar Density Measured via Opportunistic Computed Tomography Is Well Represented by the Dorr C Classification.

Introduction The canal-to-calcar isthmus (CC) ratio has been previously correlated with proximal femur osteology, but its relationship with bone density is not well established. Our purpose was to assess the relationship between femoral bone density, measured on opportunistic quantitative CT in Hounsfield units (HU), and CC ratio. Methods A total of 148 THA patients were included. The CC ratio was measured on anteroposterior hip radiographs. Using perioperative CT scans, a 1 cm diameter area was identified on a single mid-coronal slice in the medial calcar just proximal to the intertrochanteric ridge. The mean HU was calculated in this region to represent calcar bone density. Results Twenty-four percent (n = 35) of patients were classified as Dorr A (average CC ratio 0.47 [0.45; 0.48]), 67% (n = 96) as Dorr B (0.62 [0.55; 0.68]), and 11% (n = 17) as Dorr C (0.78 [0.77; 0.80]). There was a significant difference between Dorr A and Dorr C femurs (769 (144) vs. 588 (154) HU) as well as between B and C femurs (718 (166) vs. 588 (154) HU). The CC ratio was correlated with calcar bone density on CT (-0.370). Conclusion CC ratio is correlated with bone density determined by HU measurements on an opportunistic quantitative computed tomography scan, and bone density HU values were able to accurately differentiate bone density in Dorr A and B from Dorr C femurs. These findings suggest that the CC ratio is a reliable measurement to predict bone density in Dorr C femurs. Therefore, arthroplasty surgeons can confidently use the Dorr classification for patients with Dorr C femurs when preoperatively planning for THA.

Success of Same-Day Discharge Total Hip and Knee Arthroplasty: Does Location Matter?

BACKGROUND: Same calendar day discharge (SCDD) following total joint arthroplasty is desirable for patients and surgeons alike. The aim of this study was to compare the success rate of SCDD in an ambulatory surgical center (ASC) versus hospital setting. METHODS: A retrospective analysis was performed on 510 patients who underwent primary hip and knee total joint arthroplasty over a 2-year period. The final cohort was divided into 2 groups based on location of surgery: ASC (N = 255) or hospital (N = 255). Groups were matched for age, sex, body mass index, American Society of Anesthesiologists score, and Charleston Comorbidity Index. Successes of SCDD, reasons for failure of SCDD, length of stay (LOS), and 90-day readmission and complication rates were recorded. RESULTS: All SCDD failures were from the hospital setting (36 [65.6%] total knee arthroplasty [TKA] and 19 [34.5%] total hip arthroplasty [THA]). There were no failures from the ASC. The main causes of failed SCDD in both THA and TKA included failed physical therapy and urinary retention. Regarding THA, the ASC group had a significantly shorter total LOS (6.8 [4.4 to 11.6] versus 12.8 [4.7 to 58.0] hours, P < .001). Similarly, TKA patients had a shorter LOS in the ASC (6.9 [4.6 to 12.9] versus 16.9 [6.1 to 57.0], P < .001). Total 90-day readmission rates were higher in the ASC group (2.75% versus 0%), where all but 1 patient underwent TKA. Similarly, complication rates were higher in the ASC group (8.2% versus 2.75%), where all but 1 patient underwent TKA. CONCLUSION: TJA performed in the ASC, compared to the hospital setting, allowed for reduced LOS and improved success of SCDD.

Incidental findings on CT scans for robot-assisted total joint arthroplasty.

INTRODUCTION: This study documented the incidence of incidental findings from preoperative computerized-tomography (CT) scans obtained for robotic-arm-assisted total joint arthroplasty (TJA) and its effect on patient management. METHODS: A retrospective review was conducted for patients who underwent robotic-arm assisted primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) from 2016 to 2020. All patients obtained preoperative CT scans which were formally read by fellowship-trained musculoskeletal radiologists. CT's were flagged with incidental findings and those requiring physician follow-up were identified as significant. RESULTS: A total of 1519 patients (mean age, 66 years ±9; 849 females) were evaluated. Seventy-three (4.81%) patients had incidental CT scan findings, and 25 (1.65%) patients had significant incidental findings. Four patients required additional imaging and two patients required intervention. CONCLUSION: This study found a 4.81% incidence of incidental findings from preoperative CT scans for robotic-arm-assisted THA and TKA. Of these findings, less than 2% required physician follow-up and less than 1% required intervention. With the increasing popularity of robotic-arm assisted total joint arthroplasty, it is important to consider the necessity of detection and management of associated incidental findings from preoperative CT scans.

Cost Disclosure of Surgeon "Scorecards": Effects on Operating Room Costs for Total Hip and Knee Arthroplasty.

Background: Rising health care costs, coupled with an emphasis on cost containment, continue to gain importance. Surgeon cost scorecards developed to track case-based expenditures can help surgeons compare themselves with their peers and identify areas of potential quality improvement. Purpose: We sought to investigate what effect surgeon scorecards had on operating room (OR) costs in orthopedic surgery. Methods: Our hospital distributed OR cost scorecards to 4 adult reconstruction fellowship-trained orthopedic surgeons beginning in 2012. The average direct per-case supply cost of procedures was calculated quarterly and collected over a 5-year period, and each surgeon's data were compared with that of their peers. All 4 surgeons were made aware of the costs of other surgeons at the 2-year mark. The initial 2 years of data was compared with that of the final 2 years. Results: The average direct per-case supply cost ranged from $4955 to $5271 for total knee arthroplasty (TKA) and $5469 to $5898 for total hip arthroplasty (THA) during the initial 2-year period. After implementing disclosures, the costs for TKA and THA, respectively, ranged from $4266 to $4515 (14% annual cost savings) and from $5073 to $5727 (5% annual cost savings); 3 of the 4 surgeons said that cost transparency altered their practice. Conclusion: Our comparison suggests that orthopedic surgeons' participation in a program of operative cost disclosure may be useful to them; we found a possible association with reduced per-case costs for TKA and THA at our institution over a 5-year period. More rigorous study that incorporates the effects of the scorecards on patient outcomes is warranted.

Predictors of Successful Early Discharge for Total Hip and Knee Arthroplasty in Octogenarians.

Background: Decreased length of stay after total joint arthroplasty (TJA) is becoming a more common way to contain healthcare costs and increase patient satisfaction. There is little evidence to support "early" discharge in elderly patients. Purpose: We sought to identify preoperative factors that correlated with early discharge (by postoperative day [POD] 1) in comparison to late discharge (after POD2) in octogenarians after TJA. Methods: In a retrospective cohort study from a single institution, we identified 482 patients ages 80 to 89 who underwent primary TJA from January 2014 to December 2017; 319 had total knee arthroplasty (TKA) and 163 had total hip arthroplasty (THA). Data collected included preoperative knee range of motion (ROM), demographics, and comorbidities; 90-day readmission and mortality rates were also evaluated. P values for continuous data were calculated using student's t test and for categorical data using χ2 testing. Results: Of octogenarian patients, 30.9% were discharged by POD1. Early discharge was associated with being male, married, and nonsmoking, as well as having an American Society of Anesthesiologists (ASA) score of 2, independent preoperative ambulation, and a postoperative caregiver. Type of procedure (TKA vs THA), body mass index, laterality, preoperative range of motion (ROM) for TKA, and single vs multilevel home did not affect the probability of early discharge. Discharge on POD1 was not associated with increased 90-day readmission rates. There were no deaths. Conclusion: Early discharge for octogenarians can be successfully implemented in a select subset of patients without increasing 90-day readmission or death rates. There are multiple factors that predict successful early discharge.

Return to Work and Driving After Robotic Arm-Assisted Total Knee Arthroplasty.

Background: Robotic arm-assisted total knee arthroplasty (RATKA) has demonstrated improved patient-reported outcome measures. Less evidence has been reported on how frequently patients return to complex activities of daily living. Our purposes were to investigate (1) hospital lengths of stay (LOSs) (2) discharge dispositions and (3) the rates and postoperative time intervals at which patients returned to driving and working. Methods: A total of 50 RATKA patients who were employed prior to surgery were included. Outcomes included hospital LOS, discharge dispositions, return to driving, and return to work. Results: A total of 48 patients (96%) were discharged home with self-care or health aid discharge after a mean LOS of 1.2 ± 0.6 days. Twelve patients (24%) returned to driving within 3 weeks of surgery. In our study, 100% of patients who underwent RATKA returned to driving after a mean of 29 days (range, 4 to 62 days). Forty-five patients (90%) returned to their preoperative level of work after a mean of 46 days (range, 2 to 96 days). Nineteen patients (38%) returned to work within 3 weeks. Conclusions: This study showed fast recovery after RATKA, with >90% returning to driving and working at full capacity within 2 months. Many (38%) returned to work within 3 weeks. Further studies to demonstrate the value of RATKA with respect to recovery of complex activities are needed. Compared to controls from previously published literature on manual total knee arthroplasties, it appears that patients who undergo RATKA have similar or better outcomes in reference to return to driving.

Improved Component Placement Accuracy with Robotic-Arm Assisted Total Knee Arthroplasty.

Component position of total knee arthroplasty (TKA) has been shown to influence prosthetic survivorships and clinical outcomes. Our objective was to compare the three-dimensional accuracy to plan of robotic-arm assisted TKA (RATKA) with conventional TKA for component position. We conducted a nonrandomized, prospective study comparing 143 RATKA with 86 conventional TKA operated at four U.S. centers between July 2016 and October 2018. Computed tomography (CT) scans obtained approximately 6 weeks postoperatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons' femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. Differences of absolute deviations were tested using stratified Wilcoxon's tests that controlled for study center. Patient-reported outcome measures collected through 1 postoperative year were modeled using multiple regression controlling for age, sex, body mass index, study center, and the preoperative score. RATKA demonstrated greater accuracy for tibial component alignment (median [25th, 75th percentiles] absolute deviation from plan of all centers combined for conventional vs. RA, 1.7 [0.9, 2.9] vs. 0.9 [0.4, 1.9] degrees, p < 0.001), femoral component rotation (1.5 [0.9, 2.5] vs. 1.3 [0.6, 2.5] degrees, p = 0.015), and tibial slope (2.9 [1.5, 5.0] vs. 1.1 [0.6, 2.0] degrees, p < 0.001). In multivariable analyses, RATKA showed significantly greater Veterans RAND 12-item health survey (VR-12) physical component scores (adjusted mean difference [95% confidence interval (CI)]: 2.4 [0.2, 4.5] points, p = 0.034) and qualitatively greater Knee Society (KS) composite functional scores (3.5 [-1.3, 8.2] points, p = 0.159), though not statistically significant. Compared with conventional instrumentation, RATKA demonstrated greater three-dimensional accuracy to plan for various component positioning parameters and clinical improvements in physical status and function with no major safety concerns during the first postoperative year. These results may be attributed to the preoperative CT scan planning, real-time intraoperative feedback, and stereotactic-guided cutting that takes into consideration patient-specific bony anatomy. These findings support the use of RATKA for enhanced arthroplasty outcomes.

The successful implementation of the Navio robotic technology required 29 cases.

Robotic-assisted total knee arthroplasty (RA-TKA) has potential benefits of improved restoration of mechanical alignment, accuracy of bony resection, and balancing. The purpose of this study was to determine the number of cases necessary for a single surgeon to achieve a constant, steady-state surgical time. The secondary purpose was to identify which steps demonstrated the most time reduced. This was a prospective study assessing intraoperative time for 60 RA-TKA with the Navio surgical system. Overall arthroplasty time and duration for each step were recorded. Statistical analysis included a nonlinear regression and survival regression. Successful implementation required 29 cases to achieve a steady-state. The average time decreased from 41.8 min for the first cohort to 31.1 min for the last cohort, a 26% decrease. The step with the greatest reduction was the "Review of Intraoperative Plan" with a reduction of 2.1 min. This study demonstrates surgical times averaging below 60 min and a learning curve that is complete in 29 cases with the surgeon reporting a high level of confidence with the system at 10 cases. Though Navio assisted TKA showed a significantly slower operative time, we are hopeful that future generations of robotic technology will be more efficiently implemented by surgeons.

A Role for Modern Primary Cementless Femoral Stems in Revision Hip Arthroplasty.

BACKGROUND: In revision total hip arthroplasty (THA) cases with preserved femoral metaphyseal bone, tapered proximally porous-coated "primary" femoral stems may be an option. The objective of this study was to compare outcomes of patients with Paprosky I or II femoral bone loss undergoing revision THA with either a primary metaphyseal-engaging cementless stem or a revision diaphyseal-engaging stem. METHODS: This was a retrospective analysis of 70 patients with Paprosky I or II femoral bone loss who underwent femoral revision. 35 patients who were revised using a primary cementless femoral stem were compared with 35 patients who underwent femoral revision using a revision diaphyseal-engaging stem. The groups were similar regarding age, gender, body mass index, and American Society of Anesthesiologists. Clinical and radiographic outcomes and complications were compared over an average follow-up of 2.9 years (SD 1.4). RESULTS: Revision THA was most commonly performed for periprosthetic joint infection (N = 27, 38.6%). The groups were similar with regards to Paprosky femoral classification (P = .56), length of stay (P = .68), discharge disposition (P = .461), operative time (P = .20), and complications (P = .164). There were no significant differences between primary and revision femoral stem subsidence (0.12 vs. 0.75 mm, P = .18), leg length discrepancy (2.3 vs. 4.05 mm, P = .37), and Hip Disability and Osteoarthritis Outcome Score Jr (73.1 [SD 21.1] vs. 62.8 [SD 21.7], P = .088). No patient underwent additional revision surgery involving the femoral component. CONCLUSION: Use of modern primary cementless femoral stems is a viable option for revision hip arthroplasty in the setting of preserved proximal femoral metaphyseal bone. Outcomes are not inferior to those of revision stems and offer potential benefits.

Incidence of COVID-19 After Nonelective Hip and Knee Surgery During the Peak of the Pandemic: The New Jersey Experience.

In an attempt to preserve essential equipment and health care system capacity and slow the spread of coronavirus disease 2019 (COVID-19) infection, Governor Murphy suspended all elective surgeries performed in New Jersey from March 27, 2020, through May 25, 2020. The objective of this study was to determine the incidence of postoperative COVID-19 infection following nonelective hip and knee surgery during the peak of the COVID-19 pandemic in New Jersey during this time. A retrospective cohort of 149 patients who underwent nonelective hip and knee surgery from March 27, 2020, through May 25, 2020, at 2 institutions was identified. The cohort was divided into hip fracture and non-fracture patients to compare the postoperative experience of these patient populations. The primary outcome was the incidence of postoperative COVID-19 infection diagnosed via severe acute respiratory syndrome coronavirus 2 nasopharyngeal real-time reverse transcription polymerase chain reaction. Secondary outcomes included length of stay, discharge disposition, postoperative complications, and mortality rate. A total of 149 patients underwent nonelective hip and knee surgeries, including 76 hip fracture cases and 73 nonelective hip and knee arthroplasty cases. A postoperative diagnosis of COVID-19 was made for 5 (6.6%) of 76 hip fracture patients, and 2 of the 5 died secondary to COVID-19. There were no infections in the arthroplasty cohort. This study describes a low incidence of COVID-19 infection after nonelective hip and knee surgery during the surge of the COVID-19 pandemic in New Jersey. Patients who underwent hip fracture surgery had an increased incidence of postoperative COVID-19 infection. [Orthopedics. 2021;44(3):180-186.].