The Impact of the Comprehensive Unit-Based Safety Program on the Perioperative Efficiency and Patient Safety of Adult Hip and Knee Arthroplasty Procedures: Retrospective Comparative Study.

BACKGROUND: The complexity of health care delivery systems presents a unique challenge for the perioperative space. In the area of arthroplasty procedures, the shift of complex patients into ambulatory surgery centers and reimbursement that is no longer commensurate with the inflated costs of performing these procedures have created difficulties for hospitals and physicians alike. Thus, there is a critical need to optimize perioperative workflows while maintaining high-quality care provision. METHODS: Our institution implemented the Comprehensive Unit-based Safety Program (CUSP) to improve the quality and efficiency of total knee and hip arthroplasties (TKAs and THAs). This initiative involved extensive collaboration with clinical and administrative teams, as well as 5 intervention-driven workgroups. First-case on-time start rates and duration of first-case delays, case length, anesthesia preparation, in-room patient preparation, operation, patient exit, and room turnover after CUSP implementation were analyzed using independent samples median testing, Mann-Whitney U testing, and a percentage-point difference calculation. RESULTS: After CUSP arthroplasty implementation, first-case on-time start rates increased from 43 to 81%. Statistically significant decreases were observed in median times for first-case delays, case length, in-room patient preparation, operation, patient exit, and room turnover for TKAs and THAs, but not anesthesia preparation. CONCLUSIONS: The implementation of CUSP arthroplasty for TKAs and THAs resulted in significant improvements in nearly all efficiency metrics, as well as preventions of patient safety missteps. These results exemplify the versatility of CUSP as a quality improvement method that can maintain patient safety and perioperative efficiency in the arthroplasty service of a large-scale medical center. LEVEL OF EVIDENCE: III.

2-Octyl-Cyanoacrylate Mesh Dressings for Total Joint Arthroplasty: Dressing Design Influences Risks of Wound Complications.

INTRODUCTION: Recent liquid adhesive skin closure systems with a mesh patch and a 2-octyl cyanoacrylate liquid formula have shown promising results in total joint arthroplasty (TJA). Chemical accelerators are typically included to promote the rapid polymerization of 2-octyl cyanoacrylate. The goal of the study is to distinguish designs and wound complication differences between two similar systems. METHODOLOGY: An eighteen-week retrospective study was conducted from July to December 2023, including 207 total hip arthroplasty (THA) and 212 total knee arthroplasty (TKA) cases from four attending surgeons at one institution that used one of two dressing designs. Both dressings had a 2-octyl cyanoacrylate liquid adhesive formula that applied topically to a polyester-based mesh overlaying the wound. Mesh A (used in 274 cases) included an accelerator, a quaternary ammonium salt, on the mesh patch, whereas Mesh B (used in 145 cases) included a similar accelerator within the adhesive applicator. RESULTS: Wound complications (3.2 versus 7.6%; X2 = 3.86; df = 1; P = 0.049), early periprosthetic joint infections (PJI) (0 versus 2.8%; X2 = 7.63; df = 1; P = 0.006), and 90-day reoperations for wound complications (0.4 versus 3.4%; X2 = 6.39; df = 1; P = 0.011) were significantly lower in patients who received Mesh A versus B, respectively. There was no difference in superficial surgical site infections (SSI) (0.7 versus 0%; X2 = 1.06; df = 1; P = 0.302) or allergy rates (3.3 versus 4.1%; X2 = 0.12; df = 1; P = 0.655) between Mesh A and B. CONCLUSION: We observed significantly different performance in wound complications, early postoperative PJI, and 90-day reoperation between the two designs. Having the accelerator in the applicator rather than on the mesh patch, may lead to premature polymerization before bonding appropriately with the mesh to create the desired wound closure and seal.

Scheduling and Vendor Consistency Improves Turnover Time Efficiency in Total Joint Arthroplasty.

BACKGROUND: Maximizing operative room (OR) efficiency is important for hospital efficiency, patient care, and positive surgeon and staff morale. Reducing turnover time (TOT) has become a popular focus to improve OR efficiency. The present study evaluated if TOT is influenced by changing case type, implant vendor, and/or laterality. METHODS: In total, 444 turnovers from January to July 2023 were retrospectively analyzed. All turnovers were same-surgeon turnovers between primary arthroplasty cases in dedicated, overlapping rooms. Single linear regression models tested the predictability of TOT based on case type, vendor, and laterality. A multivariate multiple regression and 1-way Analyses of Variance analyzed variables against each other. Independent sample t-tests evaluated TOTs when all variables were the same or different. RESULTS: Changing versus keeping the same case type increased TOT by 2.4 minutes (95% confidence interval [CI] = 0.7, 4.0; P = .004). Changing vendors increased TOT by 2.9 minutes (95% CI = 1.1, 4.7; P = .002). Laterality did not affect TOT, with a change of 0.9 minutes (95% CI = -0.6, 2.5; P = .229). Vendor (P = .030) independently predicted TOT when analyzed as a covariate with case type (P = .410). The TOT with same case type and vendor (mean 38.2 minutes; range, 22 to 62) was less than that of different case types and vendors (mean 41.4 minutes; range, 26 to 73) (P = .017). Mean TOT differed by 5.5 minutes when keeping all variables the same versus all different (P = .018). CONCLUSIONS: Maintaining a consistent case type, vendor, and laterality had a synergistic effect in reducing TOT in arthroplasty ORs with the same primary surgeon running 2 overlapping rooms. Changing vendor representatives was found to independently predict TOT increases, which is likely attributed to a disruption in workflow and collaboration of the multidisciplinary OR team. LEVEL OF EVIDENCE: Level III.

Aseptic Revision Total Hip Arthroplasty Through an Anterior Approach: Survivorship and Risk Factors for Re-Revision.

BACKGROUND: The utilization of anterior-based approaches for total hip arthroplasty (THA) is increasing. Literature on the outcomes of revision THA (rTHA) through an anterior approach, however, is sparse. This study reports the survivorship and risk factors for re-revision in patients undergoing aseptic rTHA through an anterior approach. METHODS: This was a single-institution, retrospective cohort analysis of patients who underwent aseptic rTHA through an anterior approach (direct anterior, anterior-based muscle sparing) from January 2017 to December 2021, regardless of the original surgical approach. Exclusion criteria were age <18 years, conversion THA, and septic revisions. Patient demographics, complications, and postoperative outcomes were collected. Kaplan-Meier curves were used to measure survivorship while Cox regression analyses were used to identify risk factors for re-revision of THA. RESULTS: We identified 251 total anterior rTHAs, of which 155 were aseptic anterior revisions. There were 111 patients (111 rTHAs; 63 anterior-based muscle sparing and 48 direct anterior) who met criteria and had a mean follow-up of 4.2 years (range, 2.1 to 6.9). There were a total of 54 (49%) anterior-based index approaches and 57 (51%) posterior index approaches. The most common indications for rTHA were femoral loosening (n = 25, 22.5%), followed by instability (n = 16, 14.4%) and wear or osteolysis (n = 16, 14.4%). At 2 years, the survivorship from reoperation and re-revision was 89% (95% confidence interval: 84 to 95) and 91% (95% confidence interval: 86 to 96), respectively. Reoperation occurred in 14 patients (12.6%) at a mean time of 7.8 months (range, 0.5 to 28.6). Re-revision occurred in 12 patients (10.8%) at a mean time of 7.3 months (range, 0.5 to 28.6). Instability was the most common reason for re-revision (4.5%). Neither index approach type, revision approach type, nor any patient-specific risk factors were identified as predictors of re-revision or reoperation in multivariable regression analysis. CONCLUSIONS: This study demonstrates an acceptable rate of re-revision when aseptic rTHA is performed through an anterior approach, with the most common reason for aseptic re-revision being instability.

Complications and Survivorship After Aseptic Revision Total Hip Arthroplasty: Is There a Difference by Surgical Approach?

BACKGROUND: Revision total hip arthroplasty (rTHA) has traditionally been performed through the posterolateral approach (PA). Anterior-based approaches (AA) for rTHA are increasingly being utilized. The purpose of this study was to compare complications and survivorship from re-revision and reoperation after aseptic rTHA performed using an AA versus a PA. METHODS: We retrospectively reviewed patients who underwent aseptic rTHA either through an AA (Direct Anterior Approach [DAA], Anterior Based Muscle Sparing [ABMS]) or PA from January 2017 to December 2021. There were 116 patients who underwent AA-rTHA (DAA 50, ABMS 66) or PA-rTHA (n = 105). Patient demographics, complications, and postoperative outcomes were collected. RESULTS: The most common indication in both groups was aseptic loosening (n = 26, 22.4% AA, n = 28, 26.7% PA). Acetabular revision alone was most common in the AA group (n = 33, 28.4%), while both components were most commonly revised in the PA groups (n = 47, 44.8%). In all the AA-rTHA group, the index THA was performed through a PA in 51% of patients, while the PA-rTHA group had the index procedure performed via AA in 4.8%. There was no statistically significant difference in re-revision rate between the DAA, ABMS, or PL groups (9.55% versus 5.3% versus 11.4%, respectively, P = 0.11). The most common overall reason for re-revision was persistent instability, with no difference in incidence of post-operative hip dislocation (n = 4, 6.8% DAA, n = 3, 5.3%, n = 10, 9.5% PA; P = 0.31). CONCLUSIONS: This study demonstrates no difference in complication or re-revision survivorship after aseptic rTHA performed through a DAA, AMBS approach, or PA, nor between anterior or posterior-based approaches.

Collateral Ligament Tension and Balance Alone Does Not Ensure Improved Outcome After Total Knee Arthroplasty.

BACKGROUND: It is hypothesized that suboptimal soft tissue and collateral ligament balance is a cause of patient dissatisfaction following total knee arthroplasty (TKA). This analysis examined the association between compartment pressures during TKA and patient-reported outcome measurements (PROMs). METHODS: This single-institution, retrospective cohort study of prospectively collected compartment pressure data measured during TKA comprised 145 patients who underwent surgery between 2015 and 2021 and completed 1-year follow-up PROMs. The primary outcome included pressures, in pounds (lbs), of the medial and lateral compartments in extension (5°), mid-flexion (45°), and flexion (90°), and associated PROMs. The difference been the 1-year and preoperative PROMs was used to separate the top 25% from the bottom 75% performers. Pressures were compared using Student's T-tests and multivariate linear regressions, while controlling for preoperative deformity. A subgroup analysis of the most popular implant was performed. RESULTS: Higher medial compartment pressures were seen in our total cohort (Knee Society Score (KSS) mid-flexion 24 versus 18 lbs, P = .03, flexion 24 versus 17 lbs P = .01) and within our subgroup analysis (Short form- Mental (SF-M) extension 32 versus 21 lbs P = .01, KSS mid-flexion 27 versus 16 lbs P = .005, extension 31 versus 20 lbs P = .003). This trend persisted in the subgroup analysis when controlling for preoperative deformity (KSS extension +16.22 lbs P ≤ .001, mid-flexion +17.6 lbs. P = .001, and flexion +9.2 lbs, P = .005). CONCLUSION: Several groups demonstrated higher medial versus lateral pressures. However, this pattern was not consistent across PROMs, suggesting that compartment pressures at the time of TKA are an important factor but not the sole predictor of patient satisfaction.

Robotic Total Knee Arthroplasty is Associated with Earlier Return of Postoperative Range of Motion.

INTRODUCTION: Postoperative range of motion (ROM) is an important measure for the functional outcome and overall success after total knee arthroplasty (TKA). While robotic knee systems have been shown to reduce pain and improve early function, the return of postoperative ROM specifically has not been adequately studied. The purpose of this study was to compare postoperative ROM in robotic and conventional TKA. We hypothesized that robotic TKA leads to an improvement in postoperative ROM. MATERIALS AND METHODS: A retrospective cohort study of 674 primary TKAs by a single surgeon between January 2018 and February 2023 was completed. Patients that did not have both a two-week follow up and eight-week follow up were excluded. Revision/conversion TKAs were excluded. The population was divided into two cohorts based on technique utilized: robotic versus conventional. Preoperative extension/flexion data, postoperative extension/flexion data at two-week and eight-week follow ups, and manipulation under anesthesia data were collected. ROM was defined as flexion minus extension. Chi-square tests were used to examine for differences between categorical variables and t-tests for continuous variables. RESULTS: A total of 307 robotic and 265 conventional knees were included. There were no differences in demographics, mean follow up, or preoperative ROM between groups. The robotic group had significantly more flexion (99.20° vs. 96.98°; p=0.034) and ROM (97.81° vs. 95.56°; p=0.047) at the two-week follow up. The loss in ROM at the two-week follow up from preoperative ROM was significantly less for the robotic group (-11.21° vs. -14.16°; p=0.031). There were no significant differences in extension at either follow up, in flexion at the eight-week follow up, or in ROM at the eight-week follow up. CONCLUSION: Robotic TKA leads to an improvement in postoperative flexion and ROM when compared to preoperative ROM at two-week follow up. These findings could partially explain the quicker recovery associated with robotic TKA.

Is the Direct Anterior Approach to THA Cost-effective? A Markov Analysis.

BACKGROUND: The use of the direct anterior approach, a muscle-sparing technique for THA, has increased over the years; however, this approach is associated with longer procedure times and a more expensive direct cost. Furthermore, studies have shown a higher revision rate in the early stages of the learning curve. Whether the clinical advantages of the direct anterior compared with the posterior approach-such as less soft tissue damage, decreased short-term postoperative pain, a lower dislocation rate, decreased length of stay in the hospital, and higher likelihood of being discharged home-outweigh the higher cost is still debatable. Determining the cost-effectiveness of the approach may inform its utility and justify its use at various stages of the learning curve. QUESTIONS/PURPOSES: We used a Markov modeling approach to ask: (1) Is the direct anterior approach more likely to be a cost-effective approach than the posterior approach over the long-term for more experienced or higher volume hip surgeons? (2) How many procedures does a surgeon need to perform for the direct anterior approach to be a cost-effective choice? METHODS: A Markov model was created with three health states (well-functioning THA, revision THA, and death) to compare the cost-effectiveness of the direct anterior approach with that of the posterior approach in five scenarios: surgeons who performed one to 15, 16 to 30, 31 to 50, 51 to 100, and more than 100 direct anterior THAs during a 6-year span. Procedure costs (not charges), dislocation costs, and fracture costs were derived from published reports, and model was run using two different cost differentials between the direct anterior and posterior approaches (USD 219 and USD 1800, respectively). The lower cost was calculated as the total cost differential minus pharmaceutical and implant costs to account for differences in implant use and physician preference regarding postoperative pain management. The USD 1800 cost differential incorporated pharmaceutical and implant costs. Probabilities were derived from systematic review of the evidence as well as from the Australian Orthopaedic Association National Joint Replacement Registry. Utilities were estimated from best available literature and disutilities associated with dislocation and fracture were incorporated into the model. Quality of life was expressed in quality-adjusted life years (QALYs), which are calculated by multiplying the utility of a health state (ranging from 0 to 1) by the duration of time in that health state. The primary outcome measure was the incremental cost-effectiveness ratio, or the change in costs divided by the change in QALYs when the direct anterior approach was used for THA. USD 100,000 per quality-adjusted life years was used as a threshold for willingness to pay. One-way and probabilistic sensitivity analyses were performed for the scenario in which the direct anterior approach is cost-effective to further account for uncertainty in model inputs. RESULTS: At a cost differential of USD 219 (95% CI 175 to 263), the direct anterior approach was associated with lower cost and higher effectiveness compared with the posterior approach for surgeons with an experience level of more than 100 operations during a 6-year span. At a cost differential of USD 1800 (95% CI 1440 to 2160), the direct anterior approach remained a cost-effective strategy for surgeons who performed more than 100 operations. At both cost differentials, the direct anterior approach was not cost-effective for surgeons who performed fewer than 100 operations. One-way sensitivity analyses revealed the model to be the most sensitive to fluctuations in the utility of revision THA, probability of revision after the posterior approach THA, probability of dislocation after the posterior approach THA, fluctuations in the probability of dislocation after direct anterior THA, cost of direct anterior THA, and probability of intraoperative fracture with the direct anterior approach. At the cost differential of USD 219 and for surgeons with a surgical experience level of more than 100 direct anterior operations, the direct anterior approach was still the cost-effective strategy for the entire range of values. CONCLUSION: For high-volume hip surgeons, defined here as surgeons who perform more than 100 procedures during a 6-year span, the direct anterior approach may be a cost-effective strategy within the limitations imposed by our analysis. For lower volume hip surgeons, performing a more familiar approach appears to be more cost-effective.

No Benefit to Sensor-guided Balancing Compared With Freehand Balancing in TKA: A Randomized Controlled Trial.

BACKGROUND: Soft tissue balancing in TKA has traditionally relied on surgeons' subjective tactile feedback. Although sensor-guided balancing devices have been proposed to provide more objective feedback, it is unclear whether their use improves patient outcomes. QUESTIONS/PURPOSES: We conducted a randomized controlled trial (RCT) comparing freehand balancing with the use of a sensor-guided balancing device and evaluated (1) knee ROM, (2) patient-reported outcome measures (PROMs) (SF-12, WOMAC, and Knee Society Functional Scores [KSFS]), and (3) various surgical and hospital parameters (such as operative time, length of stay [LOS], and surgical complications) at a minimum of 2 years of follow-up. METHODS: A total of 152 patients scheduled for primary TKA were recruited and provided informed consent to participate in this this study. Of these, 22 patients were excluded preoperatively, intraoperatively, or postoperatively due to patient request, surgery cancellation, anatomical exclusion criteria determined during surgery, technical issues with the sensor device, or loss to follow-up. After the minimum 2-year follow-up was accounted for, there were 63 sensor-guided and 67 freehand patients, for a total of 130 patients undergoing primary TKA for osteoarthritis. The procedures were performed by one of three fellowship-trained arthroplasty surgeons (RPS, HJC, JAG) and were randomized to either soft tissue balancing via a freehand technique or with a sensor-guided balancing device at one institution from December 2017 to December 2018. There was no difference in the mean age (72 ± 8 years versus 70 ± 9 years, mean difference 2; p = 0.11), BMI (30 ± 6 kg/m 2 versus 29 ± 6 kg/m 2 , mean difference 1; p = 0.83), gender (79% women versus 70% women; p = 0.22), and American Society of Anesthesiology score (2 ± 1 versus 2 ± 1, mean difference 0; p = 0.92) between the sensor-guided and freehand groups, respectively. For both groups, soft tissue balancing was performed after all bony cuts were completed and trial components inserted, with the primary difference in technique being the ability to quantify the intercompartmental balance using the trial tibial insert embedded with a wireless sensor in the sensor-guided cohort. Implant manufacturers were not standardized. Primary outcomes were knee ROM and PROMs at 3 months, 1 year, and 2 years. Secondary outcomes included pain level evaluated by the VAS, opioid consumption, inpatient physical therapy performance, LOS, discharge disposition, surgical complications, and reoperations. RESULTS: There was no difference in the mean knee ROM at 3 months, 1 year, and 2 years postoperatively between the sensor-guided cohort (113° ± 11°, 119° ± 13°, and 116° ± 12°, respectively) and the freehand cohort (116° ± 13° [p = 0.36], 117° ± 13° [p = 0.41], and 117° ± 12° [p = 0.87], respectively). There was no difference in SF-12 physical, SF-12 mental, WOMAC pain, WOMAC stiffness, WOMAC function, and KSFS scores between the cohorts at 3 months, 1 year, and 2 years postoperatively. The mean operative time in the sensor-guided cohort was longer than that in the freehand cohort (107 ± 0.02 versus 84 ± 0.04 minutes, mean difference = 23 minutes; p = 0.008), but there were no differences in LOS, physical therapy performance, VAS pain scores, opioid consumption, discharge disposition, surgical complications, or percentages of patients in each group who underwent reoperation. CONCLUSION: This RCT demonstrated that at 2 years postoperatively, the use of a sensor-balancing device for soft tissue balancing in TKA did not confer any additional benefit in terms of knee ROM, PROMs, and clinical outcomes. Given the significantly increased operative time and costs associated with the use of a sensor-balancing device, we recommend against its routine use in clinical practice by experienced surgeons. LEVEL OF EVIDENCE: Level I, therapeutic study.

Imageless robotic-assisted total knee arthroplasty leads to similar 24-month WOMAC scores as compared to conventional total knee arthroplasty: a retrospective cohort study.

PURPOSE: Robotic-assisted total knee arthroplasty (RA-TKA) was introduced to improve limb alignment, component positioning, soft-tissue balance and to minimize surgical outliers. This study investigates perioperative outcomes, complications, and early patient-reported outcome measures (PROMs) of one imageless RA-TKA system compared to conventional method TKA (CM-TKA) at 24-month follow-up. METHODS: This multi-surgeon retrospective cohort analysis compared 111 imageless RA-TKA patients to 110 CM-TKA patients (n = 221). Basic demographic information, intraoperative and postoperative data, and PROMs, including the functional score of the Knee Society Score (KSS-FS), The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form 12 Mental and Physical scores (SF-12M and P), were collected and recorded preoperatively, at 3-, 12- and 24-months postoperatively. Range of motion (ROM), estimated blood loss (EBL), surgical duration, and complications were also collected. RESULTS: There were no baseline patient demographic differences between groups. EBL (240 vs. 190 mL, p < 0.001) and surgical duration (123 vs. 107 min, p < 0.001) were significantly greater in RA-TKA. There were no significant differences in postoperative complications, ROM, length of stay (LOS), and PROMs between cohorts at 3-, 12-, 24-months postoperatively. CONCLUSIONS: Imageless RA-TKA is associated with greater EBL and surgical duration compared to CM-TKA. However, at 24-month follow-up, there were no significant differences in ROM, LOS, complications and PROMs between cohorts. Imageless robotic surgery leads to similar 24-month clinical outcomes as compared to CM-TKA. LEVEL OF EVIDENCE: III.

Cemented Femoral Fixation in a High-Risk Cohort Diminishes Risk of Early Postoperative Periprosthetic Fracture.

BACKGROUND: Early periprosthetic fractures (PPFx) following primary total hip arthroplasty (THA) create significant morbidity. Established risk factors for early PPFx include age, gender, body mass index, surgical approach, and implant fixation. We investigated the role of femoral fixation on early PPFx (<90 days postoperatively) in a high-risk cohort undergoing direct anterior approach (DAA) THA. METHODS: The final cohort comprised 344 consecutive patients (390 hips) with risk factors for PPFx (age >68 years and body mass index <25 kg/m2) who underwent primary DAA THA between May 4, 2009 and December 31, 2019 and had 90-day follow-up. Noncemented fixation was used in 229-hips, while cemented fixation was used in 161 hips. The primary outcome was early PPFx. Fisher's exact test was used for categorical variables, while t-tests were used to compare continuous variables. RESULTS: We observed 8 early PPFx (2.1%), all fractures occurring in the noncemented group. Baseline demographics were similar but not equal, with the cemented group being older (78.0 versus 76.3 years; P = .004) with a greater proportion of females (91.9% versus 69.4%; P < .001). The rate of early PPFx was significantly higher with noncemented fixation compared to cemented fixation (3.5% versus 0.0%; P = .023). A post hoc power analysis confirmed sufficient power (1-ß = 0.81). CONCLUSION: Although baseline risk factors for early PPFx are not easily modifiable, surgical factors can be modified. Cemented fixation has the potential to markedly reduce the risk of early PPFx in high-risk patients undergoing DAA THA.

Randomized Controlled Trial of Incisional Negative Pressure Following High-Risk Direct Anterior Total Hip Arthroplasty.

BACKGROUND: The direct anterior (DA) approach to total hip arthroplasty (THA) is associated with higher rates of surgical site complications (SSCs) compared to other approaches, particularly among high-risk patients. Closed incision negative pressure therapy (ciNPT) is effective in reducing SSCs and surgical site infections (SSIs) in other populations. We asked whether ciNPT could decrease SSCs in high-risk patients undergoing DA THA. METHODS: This prospective randomized controlled trial (RCT) enrolled high-risk DA THA patients at 3 centers. Patients were offered enrollment if they had previously identified risk factors for SSC: Body mass index (BMI) >30 kg/m2, diabetes, active smoking, or before hip surgery. Patients were randomized after closure to either an occlusive (control) dressing or ciNPT dressing for 7 days. All 90-day SSCs were recorded. A priori power analysis demonstrated 116 patients were required to identify a 4.5x relative reduction in SSCs. Chi-square tests were used to evaluate probability of complications. RESULTS: One hundred and twenty two patients enrolled; 120 completed data collection. SSCs occurred in 18.3% (11/60) of control patients compared to 8.3% (5/60) of ciNPT patients (χ2 = 2.60, P = .107). SSCs included dehiscence to the subcutaneous level (13) and prolonged drainage (3). Nine control (15.0%) and 2 ciNPT (3.3%) patients met CDC criteria for superficial SSI (χ2 = 4.90, P = .027). Fifteen of 16 SSCs resolved with local wound care. One in the ciNPT group required reoperation for acute PJI. CONCLUSION: Among patients at risk of surgical site complications undergoing DA THA, we identified a significant reduction in superficial SSIs and a trend toward lower overall SSCs with ciNPT.

Registration of Bony Landmarks and Soft Tissue Laxity during Robotic Total Knee Arthroplasty is Highly Reproducible.

INTRODUCTION: There is growing interest and enthusiasm for robotic total knee arthroplasty (TKA). Many robotic systems require registration of bony landmarks as well as a dynamic soft tissue evaluation to plan femoral and tibial resections. Variability in this user-driven registration can introduce error and undermine the purported precision and accuracy offered by robotics. The purpose of this study was to evaluate inter- and intrarater reliability in robotic registration with a new robotic system (ROSA®; Zimmer-Biomet, Warsaw, IN). METHODS: Two unpaired cadaveric knee specimens were exposed, and optical arrays were placed into the femur and tibia. Three separate evaluators conducted repeated trials of anatomic registration and assessment of soft tissue laxity, as well as coronal alignment, sagittal alignment, femoral size, and maximum opening in the medial and lateral compartments in both flexion and extension. Repeated trials were conducted using these specimens with and without preoperative imaging for landmarking (image-based and image-free workflows). An Intraclass Correlation Coefficient (ICC) was calculated for each observer and across observers to determine intra-and interrater reliability, respectively, in robotic registration. RESULTS: There was good to excellent reliability for all conditions, and all correlation coefficients were >0.767. On average, ICCs for intrarater reliability were excellent for Doctor 1 (0.952), Doctor 2 (0.975), and Doctor 3 (0.925). On average, the ICCs for interrater reliability were excellent for both the "Registration + Gap Assessment" condition (0.961) and the "Gap Assessment" condition (0.994). CONCLUSION: Our results show a high repeatability of registration of anatomic landmarks and gap assessment among observers using this robotic system for both image-based and image-free software.

Quantifying the Surgeon's Increased Burden of Postoperative Work for Modern Arthroplasty Surgery.

BACKGROUND: Arthroplasty payment traditionally includes 118 minutes for postoperative rounds and 69 minutes for postoperative office visits, amounting to 187 minutes and 7 work relative value units. Rapid recovery, ambulatory procedures, and bundled payments have altered the burden of care, with multiple studies showing an increase in physician work. Policy changes during the COVID-19 pandemic allow for precise documentation of patient touchpoints. We analyzed the duration of video, telephone, and text messaging to quantify modern arthroplasty work. METHODS: Consecutive primary hip, knee, and partial knee arthroplasties, performed 30 days before March 15, 2020 (date of practice closure), were included from a single institution, yielding 47 cases. We retrospectively quantified the duration of video telehealth documentation, telephone logs, and text messages over 90 days to calculate the postoperative work required in modern arthroplasty using descriptive statistics. RESULTS: An average of 9.4 touchpoints (2-14) by the surgeons occurred during the global period for this cohort, totaling 219 minutes (51-247 minutes). This included an average of 21 minutes of day-0 calls to family, 117 minutes for video visits, 52 minutes for phone calls, and 29 minutes for text messaging and wound photos. CONCLUSION: We found an undervaluation of 32 minutes of work. AAHKS leadership advocates for the fair payment of modern arthroplasty work. Cell phones have opened channels of contact that did not exist before, including phone accessibility, text messaging, and video calls. These data help defend against current payer efforts to cut work relative value units for arthroplasty. LEVEL OF EVIDENCE: II.

Iliopsoas Impingement After Direct Anterior Approach Total Hip Arthroplasty: Epidemiology, Risk Factors, and Treatment Options.

BACKGROUND: The objective of this study is to evaluate the incidence, natural history, response to treatment, and risk factors for anterior iliopsoas impingement (AIPI) after direct anterior approach (DAA) total hip arthroplasty (THA). METHODS: Between January 1, 2009 and January 4, 2014, 600 patients (655 hips) who underwent primary DAA THA were retrospectively reviewed. AIPI incidence was calculated. Natural history and response to a stepwise treatment approach was assessed. Radiographic anterior acetabular component overhang was measured. Asymptomatic controls were used to identify risk factors for the development of AIPI. RESULTS: In total, 518 patients (559 hips) met the inclusion criteria. The incidence of AIPI was 32/559 (5.7%). Symptom resolution occurred in 22/32 (68.8%) patients at final follow-up. Nonoperative management was successful in 15/32 (46.9%) patients. Operative intervention resulted in symptom resolution in 5/8 (62.5%) patients. On univariate analysis, female gender (odds ratio [OR] 2.79), acetabular component to native femoral head diameter ratio above 1.1 (OR 3.85), and any measurable overhang (OR 7.07) significantly raised the risk of AIPI, while increasing native femoral head diameter was protective for AIPI (OR 0.83). CONCLUSION: AIPI is a cause of groin pain after DAA THA, which often improves with conservative measures. Significant predisposing factors for AIPI include female gender, small native femoral head diameter, increased acetabular component to femoral head diameter ratio, and most notably, any measurable acetabular component overhang. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Tibial cement mantle thickness is not affected by tourniquetless total knee arthroplasty when performed with tranexamic acid.

PURPOSE: Evidence exists that tourniquet use leads to increased cement penetration in total knee arthroplasty (TKA) due to decreased blood and fat in the bone during cementation. The use of tranexamic acid (TXA) has led to decreased blood loss and transfusion rates. The purpose of this study was to determine if the use of a tourniquet while utilising modern TXA protocols affects the tibial cement mantle penetration. METHODS: 140 patients who underwent primary TKA with and without a tourniquet (70 in each group) were retrospectively reviewed. All patients received a standard TXA protocol. The primary outcome measure was cumulative depth of cement mantle penetration of the tibial plateau on post-operative radiographs. Secondary outcome measures included post-operative change in haemoglobin and hematocrit levels, blood loss, and transfusion rates. RESULTS: There was no significant difference in age, sex, or pre-operative haemoglobin or hematocrit levels between groups. Tourniquet use resulted in significantly lower blood loss (100.0 mL versus 154.7 mL, p < 0.001), and significantly reduced drop in haemoglobin (1.8 g/dL vs 2.5 g/dL, p < 0.001) and hematocrit (5.7% vs 7.4%, p = 0.04) levels. However, depth of tibial cement mantle penetration did not differ between the tourniquet group (15.3 mm) and non-tourniquet group (15.0 mm, p value n.s.). No patient in either group required a blood transfusion. CONCLUSIONS: Tourniquet use in primary TKA results in decreased blood loss and less change in pre-operative vs post-operative haemoglobin and hematocrit levels. However, with the use of TXA, not using a tourniquet resulted in similar cement mantle penetration around the tibial component as with a tourniquet.

Does Femoral Component Cementation Affect Costs or Clinical Outcomes After Hip Arthroplasty in Medicare Patients?

BACKGROUND: Bundled payment initiatives were introduced to reduce costs and improve quality of care. Cemented vs cementless femoral fixation is a modifiable variable that may influence the cost and quality of care. New bundled payment data from the Centers for Medicare and Medicaid Services allowed us to study the influence of femoral fixation strategy on (1) 90-day costs; (2) readmission rates; (3) reoperation rates; (4) length of stay (LOS); and (5) discharge disposition for Medicare patients undergoing total hip arthroplasty. METHODS: We retrospectively studied 1671 primary total hip arthroplasty Medicare cases, comparing 359 patients who received cemented femoral fixation to 1312 patients who received cementless fixation. Centers for Medicare and Medicaid Services cost data as well as clinical data were reviewed. Demographic differences were present between the 2 cohorts. Statistical analyses were performed, including multiple regression models to adjust for baseline differences. RESULTS: Controlling for cohort differences, cemented patients were significantly more likely to be discharged home compared to cementless patients. Cemented patients also demonstrated trends toward lower costs, lower readmission rates, and shorter LOS compared to cementless patients. All reoperations within the early postoperative period occurred in patients managed with cementless femoral fixation. CONCLUSION: Among Medicare patients, cemented femoral fixation outperformed cementless fixation with respect to discharge disposition and also trended toward superiority with regards to LOS, readmission, cost of care, and reoperation. Cemented femoral fixation remains relevant and useful despite the rising popularity of cementless fixation.

The Effect of Preoperative Anemia on Complications After Total Hip Arthroplasty.

BACKGROUND: Current literature suggests that preoperative hematocrit levels may play an important role in determining risk for complications after total hip arthroplasty (THA). The purpose of this study was to determine the role of preoperative anemia status on 30-day complications after THA. METHODS: Using the National Surgical Quality Improvement Program registry from 2006 to 2016, we identified all patients who underwent primary THA. Patients were placed into 3 cohorts based on preoperative hematocrit levels (normal > 36% [N = 166,538], mild anemia 27%-36% [N = 13,214], and severe anemia <27% [N = 541]). Differences in 30-day postoperative medical complications and readmission rates were compared using bivariate and multivariate analyses. RESULTS: Multivariate logistic regression analysis identified mild anemia compared with normal hematocrit as a significant risk factor for total complications (OR: 1.46, P < .001), mortality (OR: 2.06, P < .001), renal complications (OR: 2.59, P < .001), respiratory complications (OR: 1.89, P < .001), sepsis (OR: 2.01, P < .001), wound infection (OR: 1.36, P < .001), and urinary tract infection (OR: 1.44, P < .001). Severe anemia was also risk factor, with a higher odds ratio, for total complications (OR: 1.99, P < .001). Both mild and severe anemia were significant risk factors for increased rates of perioperative blood transfusion (mild: OR, 4.04, severe: OR, 5.58), nonhome discharge (OR: 1.74, OR: 1.64), and unplanned hospital readmissions (OR: 1.42, OR: 1.66). CONCLUSION: Preoperative anemia is a significant risk for perioperative complications after primary THA. Even mild anemia can lead to significantly increased risks of mortality, medical complications, and unplanned hospital readmissions in THA. This study further supports the need for screening and preoperative intervention for patients in this at-risk group.

Risk Factors for Periprosthetic Femur Fracture and Influence of Femoral Fixation Using the Mini-Anterolateral Approach in Primary Total Hip Arthroplasty.

BACKGROUND: The mini-anterolateral (AL) approach for total hip arthroplasty (THA) has gained popularity. In contrast to other approaches, risk factors for periprosthetic femur fractures have not been well established for the AL approach. METHODS: Six hundred eighty-four primary THAs performed using the AL approach were retrospectively reviewed for risk factors associated with perioperative periprosthetic femur fractures within 3 months of surgery. Risk factors evaluated were gender, age, body mass index, laterality, and Dorr ratio of the proximal femur. Cemented stems and collared uncemented stems were compared to uncemented tapered-wedge and meta-diaphyseal stems. A Student's t-test was used for continuous variables, and a chi-squared test was used for categorical variables. RESULTS: Of 684 primary THAs performed, 57 (8.3%) resulted in fracture. Twenty-eight (4.1%) occurred intraoperatively and 29 (4.2%) occurred postoperatively within 90 days. All intraoperative fractures were fixed at the time of surgery and healed uneventfully. Of the postoperative fractures, 15 (2.2%) were amenable to nonoperative management and healed. Fourteen (2.0%) required revision arthroplasty. There was a significantly lower rate of fracture in patients receiving cemented or collared stems (0%, n = 101) than in those receiving tapered-wedge or meta-diaphyseal fitting stems (9.8%, n = 583; P = .0009). Odds of fracture increased with female gender (P = .0063) and increasing Dorr ratio (P = .0003). Analysis showed a trend toward increased risk with older age, but did not achieve statistical significance. Body mass index and laterality showed no statistically significant effect. CONCLUSION: Performing primary THA via the AL approach, 2.0% of patients had a postoperative fracture requiring revision within the first 3 months. With cemented and collared stems, the fracture rate was significantly lower. Surgeons should consider using cemented or collared stems in high-risk patients.

Adverse Local Tissue Reaction due to Mechanically Assisted Crevice Corrosion Presenting as Late Instability Following Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Mechanically assisted crevice corrosion (MACC) at modular junctions can cause a spectrum of adverse local tissue reactions (ALTRs) in patients who have undergone total hip arthroplasty (THA). The purpose of this study is to describe the presentation, treatments, and related complications of a cohort of patients presenting with late instability following metal-on-polyethylene THA due to underlying MACC and ALTR. METHODS: This multicenter retrospective case series presents 17 patients (12 women, mean age 62.6, range 42-73) presenting with late instability secondary to ALTR and MACC. All patients had a metal (Cobalt Chrome)-on-polyethylene bearing surface. Patients experienced a mean 2.7 dislocations (range 1-6) at mean 4.3 years (range 0.4-17.0) following their index surgery. Serum metal levels (n = 12) demonstrated a greater elevation of cobalt (mean 6.9, range 0.13-20.88 ng/mL) than chromium (mean 1.9, range 0.13-3.23 ng/mL). RESULTS: Patients were revised for instability at a mean of 6.8 years (range 2.1-19.4) following their index surgery. ALTR was encountered in every case and the modular head-neck junction demonstrated visible corrosion. An exchange of the CoCr head to a ceramic head with a titanium sleeve and placement of a constrained liner was performed for a majority of patients (n = 15, 88.2%). Five patients (29.4%) had complications postoperatively including peroneal palsy (n = 2), periprosthetic joint infection (n = 2), and ALTR recurrence (n = 1). CONCLUSION: Recurrent instability in the setting of otherwise well-positioned THA components and without another obvious cause should raise concern for ALTR as a potential underlying etiology.