Ultrasound-Guided Iliopsoas Bursal Injections for Management of Iliopsoas Bursitis After Total Hip Arthroplasty.

BACKGROUND: Iliopsoas tendonitis can cause persistent pain after total hip arthroplasty (THA). Nonoperative management of iliopsoas tendonitis includes anti-inflammatory drugs and image-guided corticosteroid injections. This study evaluated the efficacy of ultrasound-guided corticosteroid injections (US-CSIs) for iliopsoas tendonitis following THA. METHODS: We retrospectively reviewed 42 patients who received an US-CSI for iliopsoas tendonitis after primary THA between 2009 and 2020 at a single institution. Outcomes including reoperation, groin pain at last follow-up, additional intrabursal injection, and Harris Hip Score (HHS) were evaluated at a minimum of 1 year. Cross-table lateral radiographs (36 patients) or computed tomography scans (6 patients) were reviewed to determine if anterior cup overhang was present, indicating a mechanical etiology of iliopsoas tendonitis. Descriptive statistics and univariate comparison of HHS preinjection and postinjection were performed, with alpha < 0.05. RESULTS: Among the 22 patients who did not have cup overhang, four (18.2%) had persistent groin pain at mean follow-up of 40 months (range, 14-94) after US-CSI. Three patients had a second injection; none had groin pain at most recent follow-up. No patients required acetabular revision. Mean HHS improved from 74 points (range, 52-94 points) to 91 points (range, 76-100 points; P < .001) at last follow-up. Among the 20 patients who had anterior cup overhang, five underwent acetabular revision after only temporary pain relief from injection. Groin pain was resolved in all revised patients at mean follow-up of 43 months (range, 12-60) after revision. Of the remaining 15 patients, five had persistent groin pain at mean follow-up of 35 months (range, 12-83). Mean HHS improved from 69 points (range, 50-96 points) preinjection to 81 (range, 56-98 points; P = .007) at last follow-up. CONCLUSION: Resolution of groin pain was demonstrated in 78.6% of patients in the cohort; however, those who did not have acetabular overhang had higher rates of success. The overall revision rate was 11.9%. US-CSI appears to be safe and effective in the diagnosis and treatment of iliopsoas tendonitis following primary THA. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List.

BACKGROUND: In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates. METHODS: Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions. RESULTS: In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001). CONCLUSION: Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

James A. Rand Young Investigator's Award: Questioning the "Nickel Free" Total Knee Arthroplasty.

BACKGROUND: A study was performed to measure metal ions present in the knee joint after performing a total knee arthroplasty (TKA) with standard cobalt chromium (CoCr) components as well as with "nickel-free" oxidized zirconium femoral and titanium tibial (OxZr/Ti) components. METHODS: Knee joint fluid was collected prior to arthrotomy, and on postoperative day one to determine the amount of metal debris generated when performing a TKA with standard instrumentation from consecutive cases with CoCr components (n = 24) and OxZr/Ti components (n = 16). RESULTS: CoCr implant patients had statistically higher levels of nickel (Ni) (29.7%, P = .033), cobalt (Co), (1,100.7%, P < .0001) and chromium (Cr) (118.9%, P < .0001) postoperatively. The cutting blocks and sawblades do not contain Co, which therefore must have come from the components. The metal ions generated from the sawblades and cutting blocks, therefore, could be discerned from the OxZr/Ti whose components don't contain Co, Cr, or Ni. The OxZr patients had significantly higher Cr (9.5×, P < .001) and Ni (5.1×, P < .001) post-TKA vs pre-TKA; Co levels were not significantly different as expected with the absence of Co in the components (P = .60). The Ni levels generated in performing an Oxinium TKA was 3.3 times higher than when performing a CoCr TKA (1.37 vs. 41 ppb, P < .001). CONCLUSIONS: The substantial degree of Ni generation resulting from performing a hypoallergenic "nickel-free" TKA calls into questions the rationale of utilizing more expensive lower Ni components on the basis of known or suspected Ni or Cr allergy.

Intra-articular administration of vancomycin and tobramycin during primary cementless total knee arthroplasty : determination of intra-articular and serum elution profiles.

AIMS: Intra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA. METHODS: A prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml. RESULTS: A total of 22 patients were included in final analysis. At one, four, and 24 hours postoperatively, mean (95% confidence interval (CI)) serum concentrations were 2.4 (0.7 to 4.1), 5.0 (3.1 to 6.9), and 4.8 (2.8 to 6.9) for vancomycin and 4.9 (3.4 to 6.3), 7.0 (5.8 to 8.2), and 1.3 (0.8 to 1.8) for tobramycin; intra-articular concentrations were 1,900.6 (1,492.5 to 2,308.8), 717.9 (485.5 to 950.3), and 162.2 (20.5 to 304.0) for vancomycin and 2,105.3 (1,389.9 to 2,820.6), 403.2 (266.6 to 539.7), and 98.8 (0 to 206.5) for tobramycin. CONCLUSION: Intra-articular administration of 1 g of vancomycin and 600 mg of tobramycin as a solution after closure of the arthrotomy in primary cementless TKA achieves therapeutic intra-articular concentrations over the first 24 hours postoperatively and does not reach sustained toxic levels in peripheral blood. Cite this article: Bone Joint J 2021;103-B(11):1702-1708.

Radiological outcomes following manual and robotic-assisted unicompartmental knee arthroplasty.

AIMS: The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). METHODS: Postoperative radiological outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic centre were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiologically measured to identify outliers. RESULTS: When assessing the accuracy of RAUKAs, 91.6% of all alignment measurements and 99.2% of all overhang measurements were within the target range. All alignment and overhang targets were simultaneously met in 68.6% of RAUKAs. When comparing radiological outcomes between the RAUKA and MUKA groups, statistically significant differences were identified for combined outliers in FCA (2.3% vs 12.6%; p = 0.006), FSA (17.4% vs 50.2%; p < 0.001), TCA (5.8% vs 41.5%; p < 0.001), and TSA (8.1% vs 18.6%; p = 0.023), as well as anterior (0.0% vs 4.7%; p = 0.042), posterior (1.2% vs 13.4%; p = 0.001), and medial (1.2% vs 14.2%; p < 0.001) overhang outliers. CONCLUSION: Robotic system navigation decreases alignment and overhang outliers compared to manual UKA. Given the association between component placement errors and revision in UKA, this strong significant improvement in accuracy may improve implant survival. Level of Evidence: III Cite this article: Bone Jt Open 2021;2-3:191-197.

The burden and utility of routine follow-up at one year after primary arthroplasty.

AIMS: Routine surveillance of primary hip and knee arthroplasties has traditionally been performed with office follow-up visits at one year postoperatively. The value of these visits is unclear. The present study aims to determine the utility and burden of routine clinical follow-up at one year after primary arthroplasty to patients and providers. METHODS: All patients (473) who underwent primary total hip (280), hip resurfacing (eight), total knee (179), and unicompartmental knee arthroplasty (six) over a nine-month period at a single institution were identified from an institutional registry. Patients were prompted to attend their routine one-year postoperative visit by a single telephone reminder. Patients and surgeons were given questionnaires at the one-year postoperative visit, defined as a clinical encounter occurring at nine to 15 months from the date of surgery, regarding value of the visit. RESULTS: Compliance with routine follow-up at one year was 35%. The response rate was over 80% for all questions in the patient and clinician surveys. Overall, 75% of the visits were for routine surveillance. Patients reported high satisfaction with their visits despite the general time for attendance, including travel, being over four hours. Surgeons found the visits more worthwhile when issues were identified or problems were addressed. CONCLUSION: Patient compliance with follow-up at one year postoperatively after primary hip and knee is low. Routine visits of asymptomatic patients deliver little practical value and represent a large time and cost burden for patients and surgeons. Remote strategies should be considered for routine postoperative surveillance primary hip and knee arthroplasties beyond the acute postoperative period. Cite this article: Bone Joint J 2020;102-B(7 Supple B):85-89.

Pelvic rotation after total hip arthroplasty is dynamic and variable.

AIMS: The aims of this study were to determine the change in the sagittal alignment of the pelvis and the associated impact on acetabular component position at one-year follow-up after total hip arthroplasty (THA). METHODS: This study represents the one-year follow-up of a previous short-term study at our institution. Using the patient population from our prior study, the radiological pelvic ratio was assessed in 91 patients undergoing THA, of whom 50 were available for follow-up of at least one year (median 1.5; interquartile range (IQR) 1.1 to 2.0). Anteroposterior radiographs of the pelvis were obtained in the standing position preoperatively and at one year postoperatively. Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Apparent acetabular component position changes were determined from the change in pelvic ratio. A change of at least 5° was considered clinically meaningful. RESULTS: Pelvic ratio decreased (posterior tilt) in 54.0% (27) of cases, did not change significantly in 34.0% (17) of cases, and increased (anterior tilt) in 12.0% (6) of cases when comparing preoperative to one-year postoperative radiographs. This would correspond with 5° to 10° of abduction error in 22.0% of cases and > 10° of error in 6.0%. Likewise, this would correspond with 5° to 10° of version error in 22.0% of cases and > 10° of error in 44.0%. CONCLUSION: Pelvic sagittal alignment is dynamic and variable after THA, and these changes persist to the one-year postoperative period, altering the orientation of the acetabular component. Surgeons who individualize the acetabular component placement based on preoperative functional radiographs should consider that the rotation of the pelvis (and thus the component version and inclination) changes one year postoperatively. Cite this article: Bone Joint J 2020;102-B(7 Supple B):47-51.

High Prevalence of Radiographic Outliers and Revisions with Unicompartmental Knee Arthroplasty.

BACKGROUND: Alignment outcomes and their impact on implant survival following unicompartmental knee arthroplasty (UKA) are unclear. The purpose of this study was to assess the implant survival and radiographic outcomes after UKA as well as the impact of component alignment and overhang on implant survival. METHODS: We performed a retrospective analysis of 253 primary fixed-bearing and mobile-bearing medial UKAs from a single academic center. All UKAs were performed by 2 high-volume fellowship-trained arthroplasty surgeons. UKAs comprised <10% of their knee arthroplasty practices, with an average of 14.2 medial UKAs per surgeon per year. Implant survival was assessed. Femoral coronal (FCA), femoral sagittal (FSA), tibial coronal (TCA), and tibial sagittal (TSA) angles as well as implant overhang were radiographically measured. Outliers were defined for FCA (>±10° deviation from neutral), FSA (>15° of flexion), TCA (>±5° deviation from neutral), and TSA (>±5° deviation from 7°). "Far outliers" were an additional >±2° of deviation. Outliers for overhang were identified as >3 mm for anterior overhang, >2 mm for posterior overhang, and >2 mm for medial overhang. RESULTS: Among patients with a failed UKA, revision was performed at an average of 3.7 years (range, 0.03 to 8.7 years). The cumulative revision rate was 14.2%. Kaplan-Meier survival analysis demonstrated 5 and 10-year survival rates of 88.0% (95% confidence interval [CI] = 82.0% to 91.0%) and 70.0% (95% CI = 56.0% to 80.0%), respectively. Only 19.0% (48) of the UKAs met target alignment for all 4 alignment measures, and only 72.7% (184) met all 3 targets for overhang. Only 11.9% (30) fell within all alignment and overhang targets. The risk of implant failure was significantly impacted by outliers for FCA (failure rate = 15.4%, p = 0.036), FSA (16.2%, p = 0.028), TCA (17.9%, p = 0.020), and TSA (15.2%, p = 0.034) compared with implants with no alignment or overhang errors (0%); this was also true for far outliers (p < 0.05). Other risk factors for failure were posterior overhang (failure rate = 25.0%, p = 0.006) and medial overhang (38.2%, p < 0.001); anterior overhang was not a significant risk factor (10.0%, p = 0.090). CONCLUSIONS: The proportions of UKA revisions and alignment outliers were greater than expected, even among high-volume arthroplasty surgeons performing an average of 14.2 UKAs per year (just below the high-volume UKA threshold of 15). Alignment and overhang outliers were significant risk factors for implant failure. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Local delivery of tobramycin and vancomycin in primary total knee arthroplasty achieves minimum inhibitory concentrations for common bacteria causing acute prosthetic joint infection.

AIMS: The aim of this study was to determine if the local delivery of vancomycin and tobramycin in primary total knee arthroplasty (TKA) can achieve intra-articular concentrations exceeding the minimum inhibitory concentration thresholds for bacteria causing acute prosthetic joint infection (PJI). METHODS: Using a retrospective single-institution database of all primary TKAs performed between January 1 2014 and May 7 2019, we identified patients with acute PJI that were managed surgically within 90 days of the initial procedure. The organisms from positive cultures obtained at the time of revision were tested for susceptibility to gentamicin, tobramycin, and vancomycin. A prospective study was then performed to determine the intra-articular antibiotic concentration on postoperative day one after primary TKA using one of five local antibiotic delivery strategies with tobramycin and/or vancomycin mixed into the polymethylmethacrylate (PMMA) or vancomycin powder. RESULTS: A total of 19 patients with acute PJI after TKA were identified and 29 unique bacterial isolates were recovered. The mean time to revision was 37 days (6 to 84). Nine isolates (31%) were resistant to gentamicin, ten (34%) were resistant to tobramycin, and seven (24%) were resistant to vancomycin. Excluding one Fusobacterium nucleatum, which was resistant to all three antibiotics, all isolates resistant to tobramycin or gentamicin were susceptible to vancomycin and vice versa. Overall, 2.4 g of tobramycin hand-mixed into 80 g of PMMA and 1 g of intra-articular vancomycin powder consistently achieved concentrations above the minimum inhibitory concentrations of susceptible organisms. CONCLUSION: One-third of bacteria causing acute PJI after primary TKA were resistant to the aminoglycosides commonly mixed into PMMA, and one-quarter were resistant to vancomycin. With one exception, all bacteria resistant to tobramycin were susceptible to vancomycin and vice versa. Based on these results, the optimal cover for organisms causing most cases of acute PJI after TKA can be achieved with a combination of tobramycin mixed in antibiotic cement, and vancomycin powder. Cite this article: Bone Joint J 2020;102-B(6 Supple A):163-169.

Impact of Tourniquet Strategy on Perioperative Results of Modern TKA.

Recent changes in perioperative management of total knee patients including tranexamic acid, multimodal pain management, and periarticular injection make previous data on tourniquet use during total knee arthroplasty (TKA) less relevant. The purpose of this study was to evaluate the effect of tourniquet use on short-term postoperative outcomes in the era of modern TKA. Our institutional database was utilized to retrospectively identify three cohorts (long, short, and no tourniquet) of consecutive patients after unilateral TKA with a single surgeon. These three groups were compared using analysis of variance (ANOVA) and post hoc Tukey's tests. Primary endpoints being hemoglobin index (difference in preoperative and postoperative hemoglobin), inpatient narcotic use, surgical time, length of hospital stay (total hours and % day1 discharges), and distance ambulated prior to discharge. The no-tourniquet group used significantly less narcotic than the short-tourniquet (2.4 vs. 2.9 morphine equivalent/hour, p = 0.004) and long-tourniquet groups (2.4 vs. 3.4 morphine equivalents/hour, p < 0.001). The no-tourniquet group ambulated significantly further than patients in the short (108 vs. 57 feet, p < 0.001) and long (108 vs. 76 feet, p < 0.001) groups. Finally, the no-tourniquet group had significantly shorter duration of hospitalization than the long-tourniquet group in both hours in the hospital (35 vs. 57 hours, p < 0.001) and % postoperative day 1 discharge (57 vs. 12%, p < 0.001). TKA without the use of a tourniquet is associated with less narcotic consumption and increased distance ambulated prior to discharge compared with cohorts of patients utilizing tourniquet for a short or long duration.

Early Clinical and Radiological Outcomes of the Metaphyseally Fixed Totally Stabilized Knee Prosthesis in Primary Total Knee Arthroplasty.

The use of valgus-varus constrained (VVC) implant designs in primary total knee arthroplasty (TKA) is considered in situations of severe deformities, bone loss, and inadequate soft tissue balance. It is not known whether the use of such prosthesis designs may predispose to reduced function owing to its constraining design. The components are usually implanted with diaphyseal stem extensions to dissipate the increased forces. The totally stabilized (TS) implant is a contemporary VVC design with metaphyseal fixation only. It has a conforming articulation with increased rotational freedom compared with conventional VVC designs. The aim of this study was to assess whether the use of the contemporary TS implant with its metaphyseally fixed components would be associated with inferior outcomes compared with conventional standard primary posterior stabilized (PS) implants. We reviewed 38 consecutive complex primary TKAs performed using the metaphyseally fixed TS implant and 76 matched patients receiving primary PS TKA, at a minimum follow-up of 24 months. The mean follow-up was 61.1 months (24-102). Only patients with osteoarthritis were included. Clinical outcome was assessed using range of motion (ROM) and Oxford knee score (OKS). Radiographic assessment was performed using the femorotibial angle (FTA) at 6 weeks followed by assessment of bone-implant interface lucencies at final follow-up. There were no major early postoperative complications. The mean postoperative ROM in the TS and PS groups were 114.1 and 112.0, respectively. There was no difference in the mean ROM and OKS between the two groups. The mean FTA for patients in both groups was within 3° of the expected. There was no evidence of progressive lucencies or implant migration at final follow-up. The metaphyseally fixed TS knee design achieves comparable short-term functional outcomes when compared with conventional PS designs in primary knee arthroplasty. Long-term follow-up studies are required to assess survivorship.

A Microarray Study of Articular Cartilage in Relation to Obesity and Severity of Knee Osteoarthritis.

OBJECTIVE: To query the transcript-level changes in the medial and lateral tibial plateau cartilage in tandem with obesity in patients with end-stage osteoarthritis (OA). DESIGN: Cartilage was obtained from 23 patients (20 obese [body mass index > 30 kg/m2], 3 overweight [body mass index < 30 kg/m2]) at the time of total knee replacement. Cartilage integrity was assessed using Outerbridge scale, while radiographic changes were scored on preoperative X-rays using Kellgren-Lawrence (K-L) classification. RNA was probed for differentially expressed transcripts between medial and lateral compartments using Affymetrix Gene 2.0 ST Array and validated via real-time polymerase chain reaction. Gene ontology and pathway analyses were also queried. RESULTS: Scoring of cartilage integrity by the Outerbridge scale indicated that the medial and lateral compartments were similar, while scoring by the K-L classification indicated that the medial compartment was more severely damaged than the lateral compartment. We observed a distinct transcript profile with >50% of transcripts unique between medial and lateral compartments. MMP13 and COL2A1 were more highly expressed in medial versus lateral compartment. Polymerase chain reaction confirmed expression of 4 differentially expressed transcripts. Numerous transcripts, biological processes, and pathways were significantly different between overweight and obese patients with a differential response of obesity on medial and lateral compartments. CONCLUSIONS: Our findings support molecular differences between medial and lateral compartments reflective of the greater severity of OA in the medial compartment. The K-L system better reflected the molecular results than did the Outerbridge. Moreover, the molecular effect of obesity was different between the medial and lateral compartments of the same knee plausibly reflecting the molecular effects of differential biomechanical loading.

The Impact of Surgeon Volume and Training Status on Implant Alignment in Total Knee Arthroplasty.

BACKGROUND: Implant malalignment may predispose patients to prosthetic failure following total knee arthroplasty (TKA). A more thorough understanding of the surgeon-specific factors that contribute to implant malalignment following TKA may uncover actionable strategies for improving implant survival. The purpose of this study was to determine the impact of surgeon volume and training status on malalignment. METHODS: In this retrospective multicenter study, we performed a radiographic analysis of 1,570 primary TKAs performed at 4 private academic and state-funded centers in the U.S. and U.K. Surgeons were categorized as high-volume (≥50 TKAs/year) or low-volume (<50 TKAs/year), and as a trainee (fellow/resident under the supervision of an attending surgeon) or a non-trainee (attending surgeon). On the basis of these designations, 3 groups were defined: high-volume non-trainee, low-volume non-trainee, and trainee. The postoperative medial distal femoral angle (DFA), medial proximal tibial angle (PTA), and posterior tibial slope angle (PSA) were radiographically measured. Outlier measurements were defined as follows: DFA, outside of 5° ± 3° of valgus; PTA, >±3° deviation from the neutral axis; and PSA, <0° or >7° of flexion for cruciate-retaining or <0° or >5° of flexion for posterior-stabilized TKAs. "Far outliers" were defined as measurements falling >± 2° outside of these ranges. The proportions of outliers were compared between the groups using univariate and multivariate analyses. RESULTS: When comparing the high and low-volume non-trainee groups using univariate analysis, the proportions of knees with outlier measurements for the PTA (5.3% versus 17.4%) and PSA (17.4% versus 28.3%) and the proportion of total outliers (11.8% versus 20.7%) were significantly lower in the high-volume group (all p < 0.001). The proportions of DFA (1.9% versus 6.5%), PTA (1.8% versus 5.7%), PSA (5.5% versus 12.6%), and total far outliers (3.1% versus 8.3%) were also significantly lower in the high-volume non-trainee group (all p < 0.001). Compared with the trainee group, the high-volume non-trainee group had significantly lower proportions of DFA (12.6% versus 21.6%), PTA (5.3% versus 12.0%), PSA (17.4% versus 33.3%), and total outliers (11.8% versus 22.3%) (all p < 0.001) as well as DFA (1.9% versus 3.9%; p = 0.027), PSA (5.5% versus 12.6%; p < 0.001), and total far outliers (3.1% versus 6.4%; p = 0.004). No significant differences were identified when comparing the low-volume non-trainee group and the trainee group, with the exception of PTA outliers (17.4% versus 12.0%; p = 0.041) and PTA far outliers (5.7% versus 2.6%; p = 0.033). Findings from multivariate analysis accounting for the effects of patient age, body mass index, and individual surgeon demonstrated similar results. CONCLUSIONS: Low surgical volume and trainee status were risk factors for outlier and far-outlier malalignment in primary TKA, even when accounting for differences in individual surgeon and patient characteristics. Trainee surgeons performed similarly, and certainly not inferiorly, to low-volume non-trainee surgeons. Even among high-volume non-trainees, the best-performing cohort in our study, the proportion of TKA alignment outliers was still high. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of Adductor Canal Block on Acute Perioperative Pain and Function in Total Knee Arthroplasty.

BACKGROUND: Multimodal pain management strategies are commonplace in perioperative management of total knee arthroplasty (TKA), although controversy remains regarding the role of adductor canal blocks (ACB) in this algorithm. The purpose of this study is to independently evaluate the effect of ACB on short-term postoperative outcomes including (1) length of stay (LOS), (2) postoperative narcotic utilization, and (3) function with physical therapy in the era of modern TKA. METHODS: We retrospectively identified a cohort of consecutive patients from January 2014 to January 2018 who had undergone unilateral primary TKA using a single-shot ACB in addition to a standardized multimodal pain regimen vs those who only received a multimodal pain regimen. These 2 groups were compared using independent sample t-tests with primary end points of interest being LOS, distance ambulated with therapy, and inpatient narcotic use. RESULTS: There were 624 patients in the ACB group, with a mean age of 64.5 years. The group without ACB consisted of 69 patients, with a mean age of 67.2 years. We observed no significant difference in narcotic utilization postoperatively (2.361 vs 2.097, P = .088). The ACB group ambulated significantly further with therapy (75.8 vs 59.9 ft, P = .008) and had a shorter LOS in both total hours and percentage of postoperative day 1 (%POD1) discharges (34.8 vs 40.6 hours, P = .01, 83% vs 66.6%, P = .01). CONCLUSION: ACB did not decrease postoperative pain medication utilization. The modest improvement in distance ambulated with therapy on POD1 (16 ft) and LOS (16% greater POD1 discharges) may not support the cost-effectiveness of this intervention. LEVEL OF EVIDENCE: III, Retrospective Cohort.

What Is the Frequency of Noise Generation in Modern Knee Arthroplasty and Is It Associated With Residual Symptoms?

BACKGROUND: Prior investigations have recognized the presence of patient-perceived noise generation after total knee arthroplasty (TKA). However, questions remain regarding its overall frequency after both TKA and unicompartmental knee arthroplasty (UKA) as well as with respect to its association with demographic and prosthesis-related factors and its association with patient-reported outcomes. QUESTIONS/PURPOSES: The purposes of this study were (1) to determine the frequency with which patients report noise coming from the knee after TKA or UKA; (2) to identify patient and prosthesis-related factors associated with noise generation; and (3) to ascertain whether noise coming from the knee is associated with residual symptoms after knee arthroplasty. METHODS: A five-center survey study was designed to identify patient-perceived noise and to quantify the degree of residual symptoms and functional deficits in patients after TKA or UKA. Data were collected by an independent, third-party survey center, which administered questions about residual symptoms, function, and pre- and postoperative activity levels. Patients meeting prespecified inclusion criteria were specifically questioned regarding perceived noises from their knee within the last 30 days; those who reported hearing noises sometimes, often, or extremely often were categorized as positive. We retrospectively identified 2671 patients who underwent TKA and 744 patients who underwent UKA and who met inclusion criteria; the final survey population included 1580 patients who underwent TKA and 476 patients who underwent UKA (68% response rate). TKA implant types included cruciate-retaining (59%), posterior-stabilized (16%), rotating-platform (13%), gender-specific (7%), and high-flex (5%). Differences in baseline demographic variables were accounted for using multiple logistic regression statistical analyses. Chi square analyses were used to compare the frequency of residual symptoms in those patients with and without noise generation. RESULTS: Overall, 27% (557 of 2056; 95% confidence interval [CI], 25-29) of all patients undergoing knee arthroplasty reported hearing grinding, popping, or clicking from their operative knee in the last 30 days. Men (odds ratio [OR], 1.3; 95% CI, 1.0-1.6; p = 0.02) and younger patients (χ2 [df = 7] = 67.3; p < 0.001) were more likely to report noise generation. After controlling for potential confounding variables, noise generation was more common after TKA (29%) than UKA (21%; OR, 1.5; 95% CI, 1.2-2.0; p < 0.001). Among TKA designs, the likelihood of noise generation was greater in posterior-stabilized (41%; OR, 2.5; 95% CI, 1.8-3.7; p < 0.001), rotating-platform (45%; OR, 2.8; 95% CI, 1.9-4.2; p < 0.001), and gender-specific (36%; OR, 2.0; 95% CI, 1.2-3.2; p = 0.007) designs than in cruciate-retaining (23%) knees. Patient-perceived noise generation was associated with residual symptoms, including difficulty getting in and out of a chair (38% versus 25%, p < 0.001), limp (39% versus 25%, p < 0.001), swelling (42% versus 24%, p < 0.001), and stiffness (40% versus 23%, p < 0.001) compared with those who did not report noise generation after TKA. CONCLUSIONS: Patients frequently perceive noises coming from the knee after arthroplasty, more so in TKA than UKA. Patients reporting noises from the knee were more likely to report functional limitations and the presence of a limp, swelling, and stiffness. Surgeons should inform patients preoperatively of this possibility, because unmet patient expectations are known to negatively impact patient satisfaction after surgery. Subsequent investigations should focus on determining if there is a causal relationship between noise generation and residual symptoms after knee arthroplasty. LEVEL OF EVIDENCE: Level III, therapeutic study.

Acetabular Component Position and the Risk of Dislocation Following Primary and Revision Total Hip Arthroplasty: A Matched Cohort Analysis.

BACKGROUND: Recently, the importance of acetabular component positioning in the Lewinnek "safe zone" in preventing prosthetic dislocation following total hip arthroplasty (THA) has been questioned. The purpose of this study was to determine the proportion of acetabular components within the Lewinnek safe zone between primary and revision THAs that have sustained a dislocation vs matched controls without a dislocation event. METHODS: This was a retrospective, institutional review board-approved investigation of THAs performed at our institution or referred to our institution between 1997 and 2013. Ninety-six primary THAs and 60 revision THAs that sustained a dislocation were included and matched 1:1 based on age, gender, and body mass index with nondislocated controls. Acetabular component inclination and anteversion were performed using Martell Hip Analysis Suite and compared between the 2 cohorts for both primary and revision THAs. RESULTS: The proportion of acetabular components within the safe zone for both inclination and anteversion was 23 of 96 (24%) in primary THA dislocators vs 48 of 96 (50%, P < .001) in controls. The proportion of acetabular components within the safe zone for both inclination and anteversion was 28 of 60 (47%) in revision THA dislocators vs 40 of 60 (66%, P = .03) in controls. CONCLUSION: Patients sustaining a dislocation following a primary or revision THA had acetabular components less frequently positioned within the safe zone compared to control patients. This study suggests acetabular component positioning remains an important variable in decreasing the risk of dislocation following primary and revision THA.

Panobinostat sensitizes cyclin E high, homologous recombination-proficient ovarian cancer to olaparib.

OBJECTIVE: Homologous recombination (HR) proficient ovarian cancers, including CCNE1 (cyclin E)-amplified tumors, are resistant to poly (ADP-ribose) polymerase inhibitors (PARPi). Histone deacetylase inhibitors (HDACi) are effective in overcoming tumor resistance to DNA damaging drugs. Our goal was to determine whether panobinostat, a newly FDA-approved HDACi, can sensitize cyclin E, HR-proficient ovarian cancer cells to the PARPi olaparib. METHODS: Expression levels of CCNE1 (cyclin E), BRCA1, RAD51 and E2F1 in ovarian tumors and cell lines were extracted from The Cancer Genome Atlas (TCGA) and Broad-Novartis Cancer Cell Line Encyclopedia (CCLE). In HR-proficient ovarian cancer cell line models (OVCAR-3, OVCAR-4, SKOV-3, and UWB1.289+BRCA1 wild-type), cell growth and viability were assessed by sulforhodamine B and xenograft assays. DNA damage and repair (pH2AX and RAD51 co-localization and DRGFP reporter activity) and apoptosis (cleaved PARP and cleaved caspase-3) were assessed by immunofluorescence and Western blot assays. RESULTS: TCGA and CCLE data revealed positive correlations (Spearman) between cyclin E E2F1, and E2F1 gene targets related to DNA repair (BRCA1 and RAD51). Panobinostat downregulated cyclin E and HR repair pathway genes, and reduced HR efficiency in cyclin E-amplified OVCAR-3 cells. Further, panobinostat synergized with olaparib in reducing cell growth and viability in HR-proficient cells. Similar co-operative effects were observed in xenografts, and on pharmacodynamic markers of HR repair, DNA damage and apoptosis. CONCLUSIONS: These results provide preclinical rationale for using HDACi to reduce HR in cyclin E-overexpressing and other types of HR-proficient ovarian cancer as a means of enhancing PARPi activity.

Hard-on-Hard Bearings Are Associated With Increased Noise Generation in Young Patients Undergoing Hip Arthroplasty.

BACKGROUND: Patient-perceived noise from prostheses after total hip arthroplasty (THA) does occur, yet questions remain including the overall frequency of this finding, demographic and prosthesis-related factors, and the association of noise generation with patient-reported outcomes. QUESTIONS/PURPOSES: The purposes of this study were (1) to determine the frequency with which patients report noise coming from the hip after THA; (2) to identify patient and prosthesis-related factors associated with noise generation; and (3) to ascertain if noise generation is associated with pain or functional impairment after THA. METHODS: A five-center study was designed to quantify the degree of residual symptoms and functional deficits in patients undergoing THA. Three centers were academic practices, whereas two centers were private practices that provided training programs for orthopaedic residents and fellows. Each contributing surgeon was fellowship-trained and specialized in joint replacement. Inclusion criteria for this study were (1) men between 18 and 60 years old and women between 18 and 55 years old; (2) patients requiring primary hip surgery as a result of noninflammatory arthritis such as osteoarthritis, traumatic arthritis, or avascular necrosis; (3) a UCLA activity score of 6 or more before they were limited by pain; and (4) patients who had undergone a primary THA within 1 to 4 years before the start of the study and had a minimum of 1 year of clinical followup. Attempts were made to contact all identified patients meeting these inclusion criteria. Data were collected by an independent, third-party survey center blinded to the implant design and bearing surface used who administered questionnaires about residual symptoms, function, and pre- and postoperative activity levels using previously published survey instruments. Patients were specifically queried regarding perceived noise from their THA. We retrospectively identified 1242 eligible patients. Of the 1242 patients, 105 were found to have exclusions during the screening section of the questionnaire: postoperative infection (six THAs), fracture (two), dislocation (seven), or revision (17); limited activity level because of an operation on the opposite hip (34); and premorbid UCLA score of less than 6 (39). In addition, 128 individuals refused to participate, 156 were never available, 108 were not found as a result of a bad address/phone number, 48 were contacted but did not complete the interview, nine had died, and six had a language barrier. This left 682 of the 1137 eligible patients with completed surveys (60% response rate). The mean age was 50 ± 8 years at the time of surgery with 63% being men, and they were contacted at a mean of 3 ± 1 years postoperatively. Bearing surfaces (femoral head-acetabular liner) included 210 (31%) metal-on-metal, 144 (21%) ceramic-on-ceramic, 142 (21%) ceramic-on-polyethylene, 141 (21%) cobalt-chromium-on-polyethylene, and 44 (6%) oxidized zirconium-on-polyethylene. Differences in baseline demographic variables were accounted for using multiple logistic regression statistical analyses. Pearson's correlation coefficients were used to determine the association of noise generation with residual symptoms. RESULTS: Overall, 9% (61 of 682; 95% confidence interval [CI], 7-11) of young patients undergoing primary THA reported noise generation. Females (12% [30 of 251 patients]) were noted to have an increased likelihood of reporting noise versus males (7% [30 of 431 patients]; odds ratio, 1.8; 95% CI, 1.1-3.1; p = 0.03). After controlling for potential confounding variables including female sex and length of followup, patients receiving a ceramic-on-ceramic or metal-on-metal bearing surface (14% [50 of 355]) reported an increased frequency of grinding, popping, and clicking in the 30 days before survey administration versus those receiving a polyethylene liner with a ceramic, oxidized zirconium, or cobalt-chromium femoral head (3% [10 of 327 patients]; odds ratio, 5.6; 95% CI, 2.7-11.5; p < 0.001). Noise generation was associated with increased pain (r = 0.23, p < 0.001) and stiffness (r = 0.22, p < 0.001) after THA. CONCLUSIONS: When interviewed by an independent third party, patients receiving a metal-on-metal or ceramic-on-ceramic bearing reported a higher frequency of noise generation versus patients receiving a polyethylene liner after THA. Young patients undergoing THA should be counseled that noise generation could be associated with increased pain after THA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Radiographic parameters associated with pain following total hip and surface arthroplasty.

Pain following total hip arthroplasty (THA) and surface arthroplasty (SRA) remains a significant source of patient dissatisfaction. Two hundred twenty-four SRA and 196 THA patients completed a pain drawing questionnaire and postoperative radiographic measurements of component positioning were performed. In the SRA cohort, 11 of 21 patients (52%) with acetabular uncoverage of ≥5 mm versus 43 of 147 (29%) with acetabular uncoverage of ≤4.9 mm reported groin pain (P=.03). In the THA cohort, an increased distal-third canal fill ratio and a lower canal calcar ratio trended towards a higher incidence of thigh pain (P=.10 and .06), while a decreased mid-third canal fill ratio was associated with increased severity of thigh pain (P=.04). This study identifies associations between radiographic findings and pain following THA and SRA.

Is pain and dissatisfaction after TKA related to early-grade preoperative osteoarthritis?

BACKGROUND: There is growing evidence to suggest many patients experience pain and dissatisfaction after TKA. The relationship between preoperative osteoarthritis (OA) severity and postoperative pain and dissatisfaction after TKA has not been established. QUESTIONS/PURPOSES: We explored the relationship between early-grade preoperative OA with pain and dissatisfaction after TKA by (1) determining the incidence of early-grade preoperative OA in painful TKAs with no other identifiable abnormality; and (2) comparing this incidence with the incidence of early-grade OA in three other cohorts of patients undergoing TKA. METHODS: We evaluated all (n = 49) painful TKAs in a 1-year period that had no evidence of loosening, instability, malalignment, infection, or extensor mechanism dysfunction and classified the degree of preoperative OA according to the scale of Kellgren and Lawrence. For comparison, we identified three other cohorts of TKAs from the same center and classified their preoperative grade of OA: Group B (n = 100) was a consecutive series of primary TKAs performed for OA during the same year; Group C (n = 80) were asymptomatic TKAs from 1 to 4 years postoperatively; and Group D (n = 80) were TKAs with some degree of pain at 1 to 4 years postoperatively. RESULTS: Patients in Group A had a higher incidence of early-grade OA is preoperatively (49%) compared with any of the comparison groups: Group B, 5%; Group C, 6%; and Group D, 10%. CONCLUSIONS: A high percentage of patients referred for unexplained pain after TKA had early-grade osteoarthritis preoperatively. Patients undergoing TKA for less than Grade 3 or 4 OA should be informed that they may be at higher risk for persistent pain and dissatisfaction.