Faculty Bibliography

INTRODUCTION/BACKGROUND:Prosthetic dislocation after total hip arthroplasty (THA) is one of the most common causes of revision THA. Dual-mobility (DM) bearings were introduced to mitigate complications; however, there is minimal data on their performance in younger patients. This study compared results of patients who were under 55 years of age undergoing primary THA with DM or fixed-bearing (FB) implants. METHODS:A retrospective review of patients younger than 55 years who underwent primary THA with at least 2 years of follow-up between June 2011 and August 2019 was performed. Patients were stratified into two cohorts based on the implant they received (DM vs. FB). Primary outcomes were 90-day all-cause readmission, dislocation, all-cause revision, 90-day readmission and revision due to dislocation, and implant component survivorship. Demographic differences were assessed using chi-squared and independent samples t-tests. Outcomes were compared using multivariate linear and logistic regressions to control for confounding variables. RESULTS:A total of 803 patients were included (DM = 73, FB = 730). The DM and FB cohorts had similar rates of 90- day all-cause readmission (6.8% vs. 3.2%; p = 0.243) and 90-day readmission due to dislocation (4.1% vs. 0.8%; p = 0.653). At a mean follow-up of 4.42 ± 1.91 years, dislocation (4.1% vs. 1.1%; p = 0.723) and all-cause revision (5.5% vs. 4.9%; p = 0.497) rates between the DM and FB cohorts were similar. Kaplan Meier analysis yielded no significant differences in survivorship between groups for all-cause revision (95.1% vs. 94.5%; p = 0.923), revision due to dislocation (100% vs. 98.9%; p = 0.370), and acetabular component revision (97.3% vs. 98.6%; p = 0.418). CONCLUSION/CONCLUSIONS:Dual mobility implants demonstrate similar dislocation rates and implant survivorship compared to FB in patients less than 55 years of age. Larger trials with long-term follow-up may be required to further elucidate the effects of DM bearings compared to FB inserts in younger patients undergoing primary THA.

Total knee arthroplasty (TKA) is one of the most popular and successful procedures of the past century. However, as the number of TKAs continues to increase, the volume of revision surgeries also will increase. Although revision TKAs are often successful, adult reconstruction surgeons will likely continue to see patients with limited arthroplasty options after multiple failed revision TKAs. This raises the question of limb salvage versus transfemoral amputation as the final procedure option. It is important to review modern techniques for the patient who has undergone multiple revision TKAs with significant bone loss or chronic infection. These techniques include distal femur replacement, total femur arthroplasty, knee arthrodesis, and transfemoral amputation.

BACKGROUND:While the benefits of sonication for improving periprosthetic joint infection (PJI) are well-documented, its potential therapeutic effect against bacterial biofilm remains unstudied. This study aimed to investigate the safety and efficacy of a novel nanoparticle ultrasonication process on methicillin-resistant Staphylococcus aureus (MRSA) bacterial biofilm formation in a PJI rat model. METHODS:This novel ultrasonication process was designed to remove attached bacterial biofilm from implant and peri-articular tissues, without damaging native tissues or compromising implant integrity. Twenty-five adult Sprague-Dawley rats underwent a surgical procedure and were colonized with intra-articular MRSA, followed by the insertion of a titanium screw. Three weeks after the index surgery, the animals received a second procedure during which the screws were explanted, and soft tissue was sampled. The intraoperative use of the nanoparticle sonication treatment was employed to assess the device's safety, while ex vivo treatment on the retrieved tissue and implants was used to evaluate its efficacy. RESULTS: CFU/gram of tissue. Compared to the standard-of-care group (n = 10), implants treated with sonication (n = 15) had significantly lower remaining bacteria, as indicated by crystal violet absorbance measurements (P = 0.012). CONCLUSIONS:This study suggests that nanoparticle sonication technology can successfully remove attached bacterial biofilms from explanted orthopedic hardware and the joint capsule, without negatively affecting native tissue. The study provides initial results supporting the potential of nanoparticle sonication as an adjuvant treatment option during a DAIR (debridement, antibiotics, and implant retention) procedure for PJI, paving the way for future clinical trials.

BACKGROUND/UNASSIGNED:Spinopelvic mechanics are critical in total hip arthroplasty; however, there is no established consensus for adjusting acetabular component positioning based on spinopelvic parameters. This study aimed to (1) validate a recently developed Patient-Specific acetabular safe-zone calculator that factors in spinopelvic parameters and (2) compare differences with hip-spine classification targets. METHODS/UNASSIGNED:A total of 3750 patients underwent primary total hip arthroplasty across 3 academic referral centers, with 33 (0.88%) requiring revision for instability. Spinopelvic parameters were measured before initial total hip arthroplasty, and acetabular component position was measured following the index and revision procedures. Most operations employed either computer navigation or robotic assistance (94%). Surgical approaches included both anterior and posterior techniques. Utilizing our recently developed patient-specific safe-zone calculator, theoretical intraoperative positions were calculated and compared to true component positions before and after revision. RESULTS/UNASSIGNED:< .001). CONCLUSIONS/UNASSIGNED:A patient-specific approach improved acetabular component positioning accuracy within 6° of version and 4° of inclination of stable, revised hips. Patient-specific safe zones provide quantitative targets for nuanced spinopelvic preoperative planning that may mitigate risk of instability and may indicate use of assisted technologies.

INTRODUCTION/UNASSIGNED:Older adults undergoing surgery are at risk of postoperative neurocognitive disorders, prompting the need for preoperative cognitive screening in this population. Traditionally, cognitive screening has been conducted in-person using brief assessment tools such as the Montreal Cognitive Assessment (MoCA) or the Mini-Mental State Examination (MMSE). More comprehensive test batteries, such as the Uniform Data Set (UDS) Neuropsychological Battery, and its remote testing version, the Uniform Data Set version 3 tele-adapted test battery (UDS v3.0 T-cog), have been developed to assess cognitive decline in normal aging and disease conditions, but have not been applied in the perioperative setting. METHODS/UNASSIGNED:We assessed the feasibility of using this remote UDS v3.0 T-cog battery for preoperative cognitive assessment in 81 older adults 65+ scheduled for lower extremity joint replacement surgery. RESULTS/UNASSIGNED:Our results indicate that the UDS v3.0 T-cog achieves 99% completion rates and demonstrates high patient satisfaction. Further, we found 28% of subjects were cognitively impaired in this patient cohort. DISCUSSION/UNASSIGNED:These findings suggest that the UDS v3.0 T-cog is a feasible tool for assessing cognitive function in the older adult perioperative population. To our knowledge, this is the first study to apply this comprehensive remote test battery in the preoperative setting.

BACKGROUND:Jehovah's Witness patients refuse blood transfusion because of their religious beliefs making total hip arthroplasty (THA) challenging. This study aims to determine the safety of THA in Jehovah's Witness patients using standard perioperative protocols as well as evaluate the effectiveness of tranexamic acid (TXA) in controlling blood loss. METHODS:Databases from two tertiary academic centers were queried from 2003 to 2021 to identify THA patients. Demographics, pre- and postoperative hemoglobin (hgb) and hematocrit (hct) lab values, use of TXA intraoperatively, 90-day postoperative hospital utilization, and need for subsequent revision were extracted. Patients who identified as Jehovah's Witness were then compared to a 3:1 propensity score matched cohort of non-Jehovah's Witness patients. Linear regression analysis assessed the effect of intraoperative TXA on change in hgb from pre- to post-THA and logistic regression was used to assess risk of reaching hgb levels < 8.0 g/dL. RESULTS:A total of 207 non-Jehovah's Witness patients and 69 Jehovah's Witness patients who underwent THA were analyzed. Both groups were found to have similar preoperative hgb and hct as well as postoperative hgb, hct, and hgb shift. Of the Jehovah's Witness patients 3 (6.4%) patients reached a hgb < 8.0 g/dL. Additionally, a higher proportion of Jehovah's Witness patients receive intraoperative TXA (55 [79.7%]) compared to non-Jehovah's Witness patients (127 [61.4%]) (p = 0.01; SMD = 0.41). Logistic regression analysis found that Jehovah's Witness did not have greater odds of reaching a hgb < 8.0 g/dL (OR = 1.03 [0.95, 1.10]; p = 0.49) and that patient who received intraoperative TXA had decreased odds of reaching a hgb < 8.0 (OR = 0.87 [0.80, 0.95]; p = 0.001). Multivariate linear regression found that intraoperative TXA was also associated with a smaller decrease in hgb from pre- to post-THA (β = 0.69 [0.16, 1.22]; p = 0.01). Overall, Jehovah's Witness patients had excellent revision-free (97% [93%, 100%]) and infection-free (99% [96%, 100%]) survival at 7 years. CONCLUSION/CONCLUSIONS:Although Jehovah's Witness patients refuse transfusion, THA can be performed safely in these patients with excellent implant survivorship by optimizing preoperative hgb levels and utilizing intraoperative TXA. LEVEL OF EVIDENCE/METHODS:Level III Evidence.

BACKGROUND/UNASSIGNED:Quadriceps weakness following total knee arthroplasty (TKA) delays rehabilitation and increases fall risk. The combined impact of tourniquets and adductor canal blocks (ACBs) on postoperative quadriceps strength has not been defined. This study evaluated the early effects of tourniquet and/or ACB usage on quadriceps strength following TKA. METHODS/UNASSIGNED:Primary, elective TKA patients were assigned to one of four groups based on whether they received an ACB and/or tourniquet. We prospectively measured bilateral, isometric knee extension strength preoperatively and within 36 hours postoperatively. Pre/post-change (Δ) and percent strength change were calculated and standardized to the contralateral leg. Strength, postoperative pain, mobility, knee buckling incidence, and falls were compared across groups. Measurements were collected for 203 patients: 68, 45, 45, and 45 in the tourniquet/ACB, tourniquet/ no ACB, ACB/no tourniquet, and no tourniquet/ no ACB groups, respectively. RESULTS/UNASSIGNED:Tourniquet use was associated with shorter operative time (p=0.004), while ACB use was associated with longer lengths of stay (p=0.005). Average preoperative (p=0.53), postoperative (p=0.12), pre/post-Δ (p=0.60), percent change (p=0.14), and standardized percent change (p=0.85) in strength measures were comparable across groups. Postoperative pain (p=0.67) and knee buckling events (p=0.18) were also comparable across groups. The no tourniquet/no ACB group had decreased postoperative mobility (p=0.004), though it was not clinically significant. No patients sustained inpatient falls. CONCLUSION/UNASSIGNED:.

BACKGROUND:Cement fixation for total hip arthroplasty (THA) remains a controversial topic. While cemented stems are associated with lower risk of periprosthetic fractures (PPF), cementless stems may offer superior biological fixation. This study analyzed peri-operative and short-term outcomes of cemented vs. cementless stem fixation in THA. METHODS:A retrospective review was conducted on 15,012 patients who underwent primary elective THA at an academic medical center from 2011 to 2021. Of these patients, 429 were cemented. Patients were stratified into 3 age cohorts (25-69, 70-79 and ≥ 80 years). Cemented stem patients were 1:1 propensity-score matched to cementless stem patients for baseline characteristics. Perioperative and short-term outcomes were compared. RESULTS:The mean operative time for cemented cases was significantly longer across all age cohorts (25-69, P = 0.005; 70-79, P < 0.001; ≥80, P < 0.001). In the 70-79 and ≥ 80 cohorts, cemented patients demonstrated a significantly shorter length of stay (LOS) compared to cementless patients (2.2 vs. 2.6 days, P = 0.017; 3.0 vs. 3.4, P = 0.041, respectively). In the 70-79 and ≥ 80 cohorts, cemented patients were significantly more likely to be discharged home when compared to cementless patients (88.2 vs. 80.5%, P = 0.031; 64.0 vs. 54.2%, P = 0.046, respectively). Across age cohorts, there were no differences in all-cause revision rates (Cohort 1: 5.4% vs. 1.1%, P = 0.108; Cohort 2: 3.0% vs. 1.8%, P = 0.362; Cohort 3: 1.8% vs. 1.2%, P = 0.714). The ≥ 80 cohort demonstrated increased rates of PPF in the cementless cohort compared to cemented (1.2 vs. 0%, P = 0.082, respectively), but it did not reach significance. CONCLUSION/CONCLUSIONS:Patient age has a substantial impact on perioperative outcomes following cemented versus cementless stem THA. Patients > 70 with a cemented femoral stem had improved perioperative outcomes such as shorter LOS, increased discharge to home and reduced rates of PPF compared to their cementless stem counterparts. Patient age should be considered prior to selecting a stem fixation strategy. LEVEL OF EVIDENCE/METHODS:III, Therapeutic Study.

INTRODUCTION/BACKGROUND:The role of advanced imaging in diagnosing aseptic implant loosening following total hip arthroplasty (THA) remains unclear. This study aimed to assess the diagnostic value of magnetic resonance imaging (MRI) in detecting aseptic loosening. METHODS:This was a retrospective review of 342 consecutive patients who underwent revision THA between July 2011 and April 2023 and had a pelvis MRI as part of the preoperative diagnostic evaluation. Among them, 62 patients had an intraoperative diagnosis of aseptic loosening of either the femoral or acetabular component. Patients were stratified based on the concordance between their MRI and radiographs findings. RESULTS:Preoperative MRI showed signs of aseptic loosening in 25/62 patients (sensitivity = 40.3%). Similarly, preoperative radiographs demonstrated signs of aseptic loosening in 27 patients (43.5%). Twelve patients (19.4%) had both MRI and radiographs predictive of aseptic loosening, 22 patients (35.5%) did not show signs of aseptic loosening in either MRI or radiographs, and for 28 patients (45.2%), the results were discordant. Among the patients with a negative radiograph for aseptic loosening (n = 35), 13 patients (37.1%) showed signs of aseptic loosening on MRI. CONCLUSION/CONCLUSIONS:Aseptic loosening remains an elusive diagnosis, and the findings of this study suggest that the utility of MRI and radiographs as part of the diagnostic process is limited. However, in cases of presumed aseptic loosening with inconclusive radiographs findings, MRI may play a role in improving the diagnostic process. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND/UNASSIGNED:Robotic systems for total knee arthroplasty (TKA) may utilize computed tomography three-dimensional modeling and intraoperative ligamentous balancing data to assist surgeons with implant size and position. This study evaluated the effect of such robotic systems on implant selection. METHODS/UNASSIGNED:We reviewed 645 TKAs performed with a single prosthetic design at 2 academic medical centers between 2016 and 2022. A robotic system was utilized in 304 TKAs, 341 were conventionally instrumented. Implant sizing was compared between cohorts. Multivariate analyses assessed for confounding and effect modification on the basis of demographics. RESULTS/UNASSIGNED: = .017). CONCLUSIONS/UNASSIGNED:Robotic-arm assisted TKA with computed tomography-based three-dimensional planning was associated with a larger mean tibial component size and a smaller mean femoral component size when compared to conventionally instrumented TKAs. Observed differences likely reflect differences in the data informing implant size selection; effects on clinical outcomes warrant further study.