Faculty Bibliography

BACKGROUND:Imageless computer navigation improves component placement accuracy in total hip arthroplasty (THA), but variations in the registration process are known to impact final accuracy measurements. We sought to evaluate the registration accuracy of an imageless navigation device during THA performed in the lateral decubitus position. METHODS:A prospective, observational study of 94 patients undergoing a primary THA with imageless navigation assistance was conducted. Patient position was registered using 4 planes of reference: the patient's coronal plane (standard method), the long axis of the surgical table (longitudinal plane), the lumbosacral spine (lumbosacral plane), and the plane intersecting the greater trochanter and glenoid fossa (hip-shoulder plane). Navigation measurements of cup position for each plane were compared to measurements from postoperative radiographs. RESULTS:Mean inclination from radiographs (41.5° ± 5.6°) did not differ significantly from inclination using the coronal plane (40.9° ± 3.9°, P = .39), the hip-shoulder plane (42.4° ± 4.7°, P = .26), or the longitudinal plane (41.2° ± 4.3°, P = .66). Inclination measured using the lumbosacral plane (45.8° ± 4.3°) differed significantly from radiographic measurements (P < .0001). Anteversion measured from radiographs (mean: 26.1° ± 5.4°) did not differ significantly from the hip-shoulder plane (26.6° ± 5.2°, P = .50). All other planes differed significantly from radiographs: coronal (22.6° ± 6.8°, P = .001), lumbosacral (32.5° ± 6.4°, P < .0001), and longitudinal (23.7° ± 5.2°, P < .0001). CONCLUSION/CONCLUSIONS:Patient registration using any plane approximating the long axis of the body provided a frame of reference that accurately measured intraoperative cup position. Registration using a plane approximating the hip-shoulder axis, however, provided the most accurate and consistent measurement of acetabular component position.

BACKGROUND:Thorough irrigation and debridement using an irrigation solution is a well-established treatment for both acute and chronic periprosthetic joint infections (PJIs). In the absence of concrete data, identifying the optimal irrigation agent and protocol remains challenging. METHODS:A thorough review of the current literature on the various forms of irrigations and their additives was performed to evaluate the efficacy and limitations of each solution as pertaining to pathogen eradication in the treatment of PJI. As there is an overall paucity of high-quality literature comparing irrigation additives to each other and to any control, no meta-analyses could be performed. The literature was therefore summarized in this review article to give readers concise information on current irrigation options and their known risks and benefits. RESULTS:Antiseptic solutions include povidone-iodine, chlorhexidine gluconate, acetic acid, hydrogen peroxide, sodium hypochlorite, hypochlorous acid, and preformulated commercially available combination solutions. The current literature suggests that intraoperative use of antiseptic irrigants may play a role in treating PJI, but definitive clinical studies comparing antiseptic to no antiseptic irrigation are lacking. Furthermore, no clinical head-to-head comparisons of different antiseptic irrigants have identified an optimal irrigation solution. CONCLUSION/CONCLUSIONS:Further high-quality studies on the optimal irrigation additive and protocol for the management of PJI are warranted to guide future evidence-based decisions.

BACKGROUND:Registry data suggest increasing rates of early revisions after total hip arthroplasty (THA). We sought to analyze modes of failure over time after index THA to identify risk factors for early revision. METHODS:We identified 208 aseptic femoral revision THAs performed between February 2011 and July 2019 using an institutional database. We compared demographics, diagnoses, complications, and resource utilization between aseptic femoral revision THA occurring within 90 days (early), 91 days to 2 years (mid), and greater than 2 years (late) after index arthroplasty. RESULTS:Early revisions were 33% of revisions at our institution in the time period analyzed. Periprosthetic fractures were 81% of early, 27% of mid, and 21% of late femoral revisions (P < .01). Women were more likely to have early revisions than men (75% vs 53% of mid and 48% of late revisions; P < .01). Patients who had early revisions were older (67.97 ± 10.06) at the time of primary surgery than those who had mid and late revisions (64.41 ± 12.10 and 57.63 ± 12.52, respectively, P < .01). Index implants were uncemented in 99% of early, 96% of mid, and 64% of late revisions (P < .01). Early revisions had longer postoperative length of stay (4.4 ± 3.3) than mid and late revisions (3.0 ± 2.2 and 3.7 ± 2.1, respectively, P = .02). In addition, 58% of early revisions were discharged to an inpatient facility compared with 36% of mid and 41% of late revisions (P = .03). CONCLUSION/CONCLUSIONS:Early aseptic femoral revisions largely occur in older women with uncemented primary implants and primarily due to periprosthetic fractures. Reducing the incidence of periprosthetic fractures is critical to decreasing the large health care utilization of early revisions.

BACKGROUND:Periprosthetic femur fractures (PFF) involving primary total hip arthroplasty (THA) remain a significant concern. The purpose of this study was to evaluate the effect of surgical approach during primary THA on early PFF with respect to fracture timing, incidence, radiographic parameters, and surgery-related factors. METHODS:A retrospective review of all patients with PFF during or after primary THA from 2011 to 2019 was conducted at a single, urban academic institution. Of the study cohort of 11,915 patients, 79 patients with PFF were identified (0.66%). Direct anterior (DA), posterior anterior (PA), and laterally based (LA) cohorts were formed based on the surgical approach. PA and LA groups were combined to form a nonanterior (NA) cohort. Radiographic parameters, surgical factors, and fracture mechanism were analyzed. RESULTS:The incidence of fracture across approaches was 0.70% (33/4707; DA), 0.63% (35/5600; PA), and 0.68% (11/1608; LA) (P = .97). Time from THA to fracture was significantly shorter in the DA cohort (12.5 ± 14.1 days) than the NA cohort (48.2 ± 120.6 days) (P = .05). Postoperatively identified, atraumatic PFFs were more common in the DA cohort (78.3%, 18/23) than the NA cohort (51.6%, 16/31) (P = .045). There were no differences between groups in radiographic or other clinical parameters. CONCLUSION/CONCLUSIONS:Patients who underwent DA THA have significantly shorter time to PFF and were more often identified postoperatively with an atraumatic mechanism than patients who underwent NA approaches. The known difficulty in femoral exposure and stem placement with the DA approach may play a role in contributing to a higher rate of intraoperative or early postoperative PFF.

This study examined an early iteration of an inpatient opioid administration-reporting tool, which standardized patient opioid consumption as an average daily morphine milligram equivalence per surgical encounter (MME/day/encounter) among total knee arthroplasty (TKA) recipients. The objective was to assess the variability of inpatient opioid administration rates among surgeons after implementation of a multimodal opioid sparing pain protocol. We queried the electronic medical record at our institution for patients undergoing elective primary TKA between January 1, 2016 and June 30, 2018. Patient demographics, inpatient and surgical factors, and inpatient opioid administration were retrieved. Opioid consumption was converted into average MME for each postoperative day. These MME/day/encounter values were used to determine mean and variance of opioids prescribed by individual surgeons. A secondary analysis of regional inpatient opioid consumption was determined by patient zip codes. In total, 23 surgeons performed 4,038 primary TKA. The institutional average opioid dose was 46.24 ± 0.75 MME/day/encounter. Average intersurgeon (IS) opioid prescribing ranged from 17.67 to 59.15 MME/day/encounter. Intrasurgeon variability ranged between ± 1.01 and ± 7.51 MME/day/encounter. After adjusting for patient factors, the average institutional MME/day/encounter was 38.43 ± 0.42, with average IS variability ranging from 18.29 to 42.84 MME/day/encounter, and intrasurgeon variability ranging between ± 1.05 and ± 2.82 MME/day/encounter. Our results suggest that there is intrainstitutional variability in opioid administration following primary TKA even after controlling for potential patient risk factors. TKA candidates may benefit from the implementation of a more rigid standardization of multimodal pain management protocols that can control pain while minimizing the opioid burden. This is a level of evidence III, retrospective observational analysis.

BACKGROUND CONTEXT: The inter-relationship between the hip and spine has been increasingly studied in recent years, particularly as it pertains to the effect of spinal deformity and hip osteoarthritis (OA). Changing from standing (ST) to seated (SE) requires rotation of the femur from an almost vertical plane to the horizontal. OA of the hip significantly limits hip extension, resulting in less ability to recruit pelvic tilt (PT) in ST, and requiring increased PT in SE to compensate for loss of hip flexion. To date, the effect of total hip arthroplasty (THA) in altering spinopelvic SE and ST mechanics has not been reported. PURPOSE: To investigate the change in spinopelvic alignment parameters between seated and standing positions in pre and post THA patients. STUDY DESIGN/SETTING: Retrospective review at a single academic institution. PATIENT SAMPLE: Adult patients undergoing THA with full body sitting and standing radiographs pre- and post-THA. OUTCOME MEASURES: Spinopelvic alignment measures including pelvic incidence (PI), pelvic tilt (PT), T1 pelvic angle (TPA), sacral slope (SS), sagittal vertical axis (SVA), pelvic incidence and lumbar lordosis mismatch (PI-LL), and lumbar lordosis (LL).
METHOD(S): Patients >=18yo undergoing THA for hip OA with full spine SE and ST radiographs pre and post THA were included. Spinopelvic alignment was analyzed pre-THA and post-THA in both ST and SE positions in a relaxed posture with the fingers on the clavicles. Paired t-test analysis was performed to compare Pre-and Post-THA groups. The effect of TL deformity (SVA>50, TPA>20, PI-LL>10) on these changes was also analyzed. Statistical significance set at p<0.05.
RESULT(S): There were 192 patients assessed. 179 patients had thoracolumbar (TL) deformity; TPA>20 (N=46), PI-LL>10 (N=55), and SVA>50 (N=78). In standing position, patients have a significant reduction in SVA post THA vs pre THA (34.09+/-42.69 vs 45.03+/-46.87, p=0.001) as a result of an increase in PT (15.7+/-9.74 o vs 14.6+/-9.88o,p=0.028), without significant changes in spinal alignment parameters including lumbar lordosis (-51.26+/-14.59 vs -50.26+/-14.87, p=0.092), thoracic kyphosis (35.98+/-12.72 vs 35.40+/-13.16, p=0.180), sacral slope (38.15+/-10.77 vs 38.83+/-11.31, p=0.205), T1 pelvic angle (14.22+/-9.94 vs 14.51+/-10.13, p=0.053) and PI-LL mismatch (2.59+/-14.61 vs 3.35+/-14.92, p=0.183). This change in ST_SVA was larger in patients with TL deformity, specifically in those with SVA>50 (61.29+/-45.69 vs 89.48+/-35.91, p=0.001), in PI-LL > 10 (59.08+/-45.49 vs 73.36+/-48.50, p=0.001) and in TPA>20 subsets (62.14+/-49.94 vs 82.28+/-49.55, p=0.001). When moving from ST to SE, the DELTAPT was reduced post THA (16.70+/-15.27o vs 20.85+/-17.27o, p=0.001) in addition to a smaller SE_PT vs pre-THA (32.41+/-14.47 vs 35.46+/-14.20, p=0.006).
CONCLUSION(S): Post Total Hip Arthroplasty (THA), patients demonstrated an increased recruitment of pelvic retroversion to achieve a better global balance by reduction in standing SVA. This compensation was achieved solely by greater mobility of their hip and pelvis, and without a significant change in spinal alignment. ST_SVA reduction was more pronounced in patients with thoracolumbar (TL) spinal deformity (SVA>50, TPA>20, PI-LL>10). On the converse, PT was reduced in sitting (SE) post-THA compared to pre-THA, and the compensatory change in PT was also reduced between ST and SE as a result of restoration of hip flexion. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
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BACKGROUND:Range of motion (ROM) after revision total knee arthroplasty (RTKA) is an important clinical outcome, as decreased ROM can lead to patient dissatisfaction and diminished mobility. This study sought to determine the effect of type of revision, implant constraint level, and reason for revision has on RTKA ROM. METHODS:A retrospective review of 832 RTKA cases from 2011 to 2019 was conducted at a single, urban academic institution. Patients who underwent aseptic RTKA and had preoperative and 1-year postoperative ROM in their chart were included. The ΔROM was calculated by subtracting the preoperative ROM from the 1-year postoperative ROM. ROM was compared between tibial polyethylene liner-only revisions (liner) and all other revision types (component) and based on reason for revision. Subanalysis was performed within the liner and component revision cohorts to determine the effect of reason for revision and implant constraint level on ROM. RESULTS:In total, 290 patients qualified. Forty-two patients had liner revisions (14.5%) and 248 had component revisions (85.5%). The ΔROM for component revision cases was significantly higher than liner exchange only (10° ± 24° vs.1° ± 19°; P = .03). ΔROM was not significant when comparing the level of implant constraint nor was it when separating and comparing by type of revision. Component revisions due to instability were found to significantly decrease ΔROM. CONCLUSION/CONCLUSIONS:Component revision cases have significantly improved ΔROM when compared with liner-only revision. Constraint level is not significantly associated with changes in ROM in either liner or component revisions. Component revisions due to instability significantly reduce ΔROM.

INTRODUCTION/UNASSIGNED:Third-generation hemispheric, titanium porous-coated (HTPC) acetabular cups have been shown to achieve good biologic fixation through enhanced porous ingrowth surfaces. They also allow for a wide range of bearing options, including polyethylene, dual-mobility, and ceramic liners. The purpose of the study is to review the mid-term clinical outcomes an HTPC acetabular cup with a minimum of 7-year follow-up. METHODS/UNASSIGNED:A retrospective, observational study was conducted on all consecutive patients who underwent total hip arthroplasty (THA) with an HTCP acetabular cup at an urban, tertiary referral centre. Descriptive statistics were used describe baseline patient characteristics. Outcomes collected included postoperative complications, survival free of reoperations, and presence of osteolysis at latest imaging follow-up. Implant survival was analysed using the Kaplan-Meier method. RESULTS/UNASSIGNED:118 cases (114 primary, 4 revision) underwent THA with the HTCP acetabular cup at an average follow-up of 8.16 ± 0.85 years (range 7.02-10.28 years). Mean patient age at the time of surgery was 61.29 ± 12.04 years. All cases utilised a high molecular weight polyethylene (HMWPE) liner. None of the acetabular cups showed loosening or migration at the latest follow-up. There were 2 revisions in our study, 1 for abductor mechanism disruption and 1 due to surgical site infection where the acetabular cup was revised. Kaplan-Meier Survivorship analysis for all-cause revision at 7 and 10-year follow-up showed a survival rate of 99.1% (95% confidence interval, 94.1-99.9%). Survivorship analysis for aseptic acetabular revision at 10-year follow-up showed a survival rate of 100%. CONCLUSIONS/UNASSIGNED:At long-term follow-up, no radiologic and minimal clinical complications were identified in this series. The HTPC acetabular cup system, used in conjunction with a HMWPE liner, demonstrates excellent outcomes and survivorship when compared to earlier mid-term studies published in the literature.

BACKGROUND:Vancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections. METHODS:We reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups. RESULTS:We reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012). CONCLUSION/CONCLUSIONS:Late infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.