Metal artifact reduction sequence-MRI abnormalities in asymptomatic patients with dual-mobility hip prostheses

Aims

Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations.

Methods

A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years' follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels.

Results

Overall, two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels > 3.0 μg/l. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels < 1.0 μg/l. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels < 1.0 μg/l, while one (2.6%) had a cobalt level of 1.4 μg/l. One patient (2.2%) had a chromium level > 3.0 μg/l and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels > 5.0 μg/l without associated MARS-MRI abnormalities.

Conclusion

Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic DM articulations occur infrequently (4.4%), but further assessment is necessary due to implant heterogeneity.

Refining the Role of Routine Synovial Alpha-Defensin in Periprosthetic Joint Infection Following Total Knee Arthroplasty: An Analysis of Limitations

BACKGROUND

The utility of the synovial alpha-defensin test in diagnosing periprosthetic joint infections (PJIs) remains controversial. This study aimed to examine the diagnostic utility of this test.

METHODS

A retrospective review was conducted to identify adults evaluated for PJI following total knee arthroplasty at a single institution. Patient demographics, laboratory results, and operative details were recorded. Using the 2018 Musculoskeletal Infection Society (MSIS) criteria, cases were categorized as definitive, inconclusive, or negative for PJI. The sensitivity, specificity, positive predictive value, and negative predictive value of each MSIS criterion was determined. The number of patients whose PJI diagnosis was contingent on alpha-defensin positivity was calculated.

RESULTS

Overall, 172 total knee arthroplasty patients were included, who had an average age of 70.4 years (range, 39 to 95). Of the 21 patients who met major criteria, 20 (95.2%) were alpha-defensin positive. Of the remaining 151 patients, 85 did not meet minor criteria, all of whom were alpha-defensin negative. Among the 30 patients who met minor criteria, 28 (93.3%) were alpha-defensin positive and 2 (6.7%) were negative. The remaining 36 patients were deemed inconclusive preoperatively. In total, alpha-defensin testing changed the diagnosis in only 9 of 172 patients (5.2%). The sensitivity, specificity, positive predictive value, and negative predictive value of alpha-defensin in this cohort were 94.1, 100, 100, and 97.6, respectively.

CONCLUSION

Alpha-defensin may assist in the diagnosis of PJI when a preoperative workup is inconclusive. However, this test is often unnecessary when the diagnosis of PJI can be made using the 2018 MSIS criteria.

Increased dislocation rates following total hip arthroplasty in patients with ankylosing spondylitis

BACKGROUND

Patients with ankylosing spondylitis (AS) experience abnormal spinopelvic motion due to chronic inflammation of the axial skeleton, predisposing them to impingement and dislocation. The purpose of this study was to evaluate total hip arthroplasty (THA) dislocation rates in AS patients and evaluate the effects of age and gender on dislocation risk.

METHODS

Patients who underwent primary THA from 2005 to 2014 were identified using the PearlDiver database. AS patients were compared to age- and gender-matched controls without AS. Patients with a history of spine pathology or spine surgery were excluded. Univariate analyses were performed based on age and sex to evaluate dislocation rates at 90 days, 6 months, 1 year, and 5 years postoperatively.

RESULTS

A total of 2792 THA patients (59.6% male) with AS were identified and compared to an age- and gender-matched control group of 5582 THA patients (59.5% male) without AS or known spine pathology. At final follow-up, there were 96 dislocations (3.4%) in the AS group and 138 (2.5%) dislocations in the control group (OR 1.40; 95% CI, 1.08-1.83; p = 0.0118). AS patients ⩾70 years old had higher dislocation rates at all time points (OR range, 1.75-2.09; p < 0.05) compared to controls. At 5-year follow-up, dislocation-free survivorship was 95.7% (95% CI, 94.5-96.9%) for AS patients ⩾70 years old compared to 97.3% (95% CI, 96.6-98.0%) for patients ⩾70 years old without AS.

CONCLUSIONS

Older AS patients have higher dislocation rates following THA. This effect is likely related to decreased spinopelvic motion in the sagittal plane, predisposing patients to impinge and dislocate.

Positive COVID-19 Diagnosis Following Primary Elective Total Joint Arthroplasty: Increased Complication and Mortality Rates

BACKGROUND

This study analyzed complication rates following primary elective total joint arthroplasty (TJA) in patients who subsequently contracted COVID-19.

METHODS

A large national database was queried for adult patients who underwent primary elective TJA in 2020. Patients who contracted COVID-19 after total knee arthroplasty (TKA) or total hip arthroplasty (THA) underwent 1:6 matching (age [±6 years], sex, month of surgery, COVID-19-related comorbidities) to patients who did not. Differences between groups were assessed using univariate and multivariate analyses. Overall, 712 COVID-19 patients were matched to 4,272 controls (average time to diagnosis: 128-117 days [range, 0-351]).

RESULTS

Of patients diagnosed <90 days postoperatively, 32.5%-33.6% required COVID-19-driven readmission. Discharge to a skilled nursing facility (adjusted odds ratio [aOR] 1.72, P = .003) or acute rehabilitation unit (aOR 4.93, P < .001) and Black race (aOR 2.28, P < .001) were associated with readmission after TKA. Similar results were associated with THA. COVID-19 patients were at increased risk of pulmonary embolism (aOR 4.09, P = .001) after TKA and also periprosthetic joint infection (aOR 4.65, P < .001) and sepsis (aOR 11.11, P < .001) after THA. The mortality rate was 3.51% in COVID-19 patients and 7.94% in readmitted COVID-19 patients compared to 0.09% in controls, representing a 38.7 OR and 91.8 OR of death, respectively. Similar results were observed for TKA and THA separately.

CONCLUSION

Patients who contracted COVID-19 following TJA were at greater risk of numerous complications, including death. These patients represent a high-risk cohort who may require more aggressive medical interventions. Given the potential limitations presently, prospectively collected data may be warranted to validate these findings.

Cemented versus Cementless Femoral Fixation for Elective Primary Total Hip Arthroplasty: A Nationwide Analysis of Short-Term Complication and Readmission Rates

Cementless fixation during total hip arthroplasty (THA) is the predominant mode of fixation utilized for both acetabular and femoral components during elective primary THAs performed in the United States. This study aims to compare early complication and readmission rates between primary THA patients receiving cemented versus cementless femoral fixation. The 2016-2017 National Readmissions Database was queried to identify patients undergoing elective primary THA. Postoperative complication and readmission rates at 30, 90, and 180 days were compared between cemented and cementless cohorts. Univariate analysis was conducted to compare differences between cohorts. Multivariate analysis was performed to account for confounding variables. Of 447,902 patients, 35,226 (7.9%) received cemented femoral fixation, while 412,676 (92.1%) did not. The cemented group was older (70.0 vs. 64.8, p < 0.001), more female (65.0% vs. 54.3%, p < 0.001), and more comorbid (CCI 3.65 vs. 3.22, p < 0.001) compared to the cementless group. On univariate analysis, the cemented cohort had decreased odds of periprosthetic fracture at 30 days postoperatively (OR: 0.556, 95%-CI 0.424-0.729, p < 0.0001), but higher odds of hip dislocation, periprosthetic joint infection, aseptic loosening, wound dehiscence, readmission, medical complications, and death at all timepoints. On multivariate analysis, the cemented fixation cohort demonstrated reduced odds of periprosthetic fracture at all postoperative timepoints: 30 (OR: 0.350, 95%-CI 0.233-0.506, p < 0.0001), 90 (OR: 0.544, 95%-CI 0.400-0.725, p < 0.0001), and 180 days (OR: 0.573, 95%-CI 0.396-0.803, p = 0.002). Cemented femoral fixation was associated with significantly fewer short-term periprosthetic fractures, but more unplanned readmissions, deaths, and postoperative complications compared to cementless femoral fixation in patients undergoing elective THA.

Anteroposterior pelvic radiograph findings correlate with sagittal spinopelvic motion

It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion. A retrospective chart review was conducted to identify patients undergoing primary total hip arthroplasty (THA). Plain AP pelvic radiographs were reviewed to document the morphological characteristic of osteoarthritic hips. Lateral spine-pelvis-hip sitting and standing plain radiographs were used to measure sacral slope (SS) and pelvic femoral angle (PFA) in each position. Lumbar disc spaces were measured to determine the presence of DDD. The difference between sitting and standing SS and PFA were calculated to quantify spinopelvic motion (ΔSS) and hip motion (ΔPFA), respectively. Univariate analysis and Pearson correlation were used to identify morphological hip characteristics associated with changes in spinopelvic motion. In total, 139 patients were included. Increased spinopelvic motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.05). Loss of hip motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.001). A decreased joint space was associated with a decreased ΔPFA (p = 0.040). The presence of disc space narrowing, disc space narrowing > two levels, and disc narrowing involving the L5-S1 segment were associated with decreased spinopelvic motion (all p < 0.05). Preoperative hip OA as assessed on an AP pelvic radiograph predicts spinopelvic motion. These data suggest that specific hip osteoarthritic morphological characteristics listed above alter spinopelvic motion to a greater extent than others.

Clinical outcomes of cemented distal femur replacements with all-polyethylene tibial components for oncologic indications

BACKGROUND

Endoprosthetic distal femoral replacement (DFR) is a well-established salvage procedure following resection of malignant tumors within the distal femur. Use of an all-polyethylene tibial (APT) component is cost-effective and avoids failure due to locking-mechanism issues and backside wear, but limits modularity and the option for late liner exchange. Due to a paucity of literature we sought to answer three questions: (1) What are the most common modes of implant failure for patients undergoing cemented DFR with APT for oncologic indications? (2) What is the survivorship, rate of all-cause reoperation, and rate of revision for aseptic loosening of these implants? And (3) Is there a difference in implant survivorship or patient demographics between cemented DFRs with APT performed as a primary reconstruction vs those performed as a revision procedure?

AIM

To assess outcomes of cemented DFRs with APT components used for oncologic indications.

METHODS

After Institutional Review Board approval, a retrospective review of consecutive patients who underwent DFR between December 2000 to September 2020 was performed using a single-institutional database. Inclusion criteria consisted of all patients who underwent DFR with a GMRS^® (Global Modular Replacement System, Stryker, Kalamazoo, MI, United States) cemented distal femoral endoprosthesis and APT component for an oncologic indication. Patients undergoing DFR for non-oncologic indications and patients with metal-backed tibial components were excluded. Implant failure was recorded using Henderson's classification and survivorship was reported using a competing risks analysis.

RESULTS

55 DFRs (55 patients) with an average age of 50.9 ± 20.7 years and average body mass index of 29.7 ± 8.3 kg/m² were followed for 38.8 ± 54.9 mo (range 0.2-208.4). Of these, 60.0% were female and 52.7% were white. The majority of DFRs with APT in this cohort were indicated for oncologic diagnoses of osteogenic sarcoma (n = 22, 40.0%), giant cell tumor (n = 9, 16.4%), and metastatic carcinoma (n = 8, 14.6%). DFR with APT implantation was performed as a primary procedure in 29 patients (52.7%) and a revision procedure in 26 patients (47.3%). Overall, twenty patients (36.4%) experienced a postoperative complication requiring reoperation. The primary modes of implant failure included Henderson Type 1 (soft tissue failure, n = 6, 10.9%), Type 2 (aseptic loosening, n = 5, 9.1%), and Type 4 (infection, n = 6, 10.9%). There were no significant differences in patient demographics or rates of postoperative complications between the primary procedure and revision procedure subgroups. In total, 12 patients (21.8%) required a revision while 20 patients (36.4%) required a reoperation, resulting in three-year cumulative incidences of 24.0% (95%CI 9.9%-41.4%) and 47.2% (95%CI 27.5%-64.5%), respectively.

CONCLUSION

This study demonstrates modest short-term survivorship following cemented DFR with APT components for oncologic indications. Soft tissue failure and endoprosthetic infection were the most common postoperative complications in our cohort.

Peripheral Nerve Block Utilization is Associated With Decreased Postoperative Opioid Consumption and Shorter Length of Stay Following Total Knee Arthroplasty

Background

This study aims to examine differences in postoperative complications and opioid consumption associated with perioperative peripheral nerve block (PNB) utilization during primary total knee arthroplasty (TKA).

Methods

The Premier Healthcare Database was queried for adult patients who underwent primary, elective TKA from 2015 to 2020. Patients who received a femoral or adductor canal PNB were compared to patients who did not. PNB utilization was trended from 2015 to 2020. Univariate and multivariate regression analyses were performed to assess differences in the 90-day risk of postoperative complications between groups. The average inpatient opioid consumption in morphine milligram equivalents was assessed as a function of length of stay.

Results

Overall, 609,991 patients were included. PNB utilization increased from 9.29% in 2015 to 30.3% in 2020. After controlling for confounders, the PNB cohort was more likely to have same-day discharge (adjusted odds ratio [aOR] 1.88) and had a decreased risk of periprosthetic joint infection (aOR 0.87), pulmonary embolism (aOR 0.81), and respiratory failure (aOR 0.78). However, there was an increased risk of seroma (aOR 1.75) and hematoma (aOR 1.22) associated with PNB utilization. Lower average overall opioid exposure was seen in the PNB cohort vs no-PNB cohort (82.1 ± 194.7 vs 89.4 ± 214.1 morphine milligram equivalents, P < .001).

Conclusions

PNB utilization during primary TKA is associated with a shorter length of stay and decreased risk of multiple postoperative complications, as well as reduced postoperative opioid consumption. These data provide evidence in support of the safety and efficacy of this emerging practice. However, the clinical relevance of an increased risk of seroma and hematoma formation may warrant further investigation.

Preoperative radiographic findings associated with postoperative spinopelvic risk factors for instability following total hip arthroplasty

Postoperative spinopelvic changes are associated with increased dislocation risk following total hip arthroplasty (THA). The aim of this study was to identify preoperative patient and radiographic factors associated with high-risk postoperative spinopelvic parameters. A retrospective review of consecutive THA patients who received preoperative and postoperative sitting and standing lateral lumbar spine-hip radiographs with minimum radiographic and clinical follow-up of 10 months was performed. Patient demographics were recorded and preoperative standing and sitting sacral slope (SS), anteinclination, pelvic femoral angle (PFA), and combined sagittal index (CSI) were measured. High-risk patients were defined by decreased spinopelvic motion (∆SS from sitting to standing of >10°), increased hip motion (∆PFA from sitting to standing of >10°), or decreased CSI of >10° at final follow-up compared with preoperative measurements. Univariate and multivariate regression analyses were used to identify preoperative demographic and radiographic factors associated with these high-risk categories. One hundred and fifty-three patients were included with an average age of 62 years, average body mass index of 27.8 kg/m² , and average follow-up of 16.2 months. At 1-year follow-up, 43 (28.1%) patients demonstrated a decreased ∆SS > 10° and 67 (43.7%) patients demonstrated an increased ∆PFA > 10° compared with preoperative values. Sitting CSI decreased by >10° in 17 (11.1%) patients. Preoperative increased sitting PFA (adjusted odds ratio [aOR] 1.057, p < 0.001) and decreased preoperative hip motion (∆PFA) were associated with decreased sitting CSI of >10° at 10-month follow-up. Increased spinopelvic motion (∆SS) and decreased hip motion (∆PFA) preoperatively are associated with postoperative radiographic changes that be associated with increased dislocation risk.

Stability analysis of tranexamic acid in the presence of various antiseptic solutions

Tranexamic acid (TXA) effectively reduces blood loss and transfusion risk during total joint arthroplasty. Additionally, intraoperative irrigation with various antiseptic solutions is often utilized for the management and prevention of surgical site infection. However, interactions between various antiseptic solutions and TXA have not been investigated. The purpose of this in vitro study is to evaluate the stability of TXA in the presence of common orthopedic antiseptic solutions. Five antiseptic solutions-0.1% chlorhexidine (CHX) gluconate, 10% povidone-iodine (BTD), 0.5% sodium hypochlorite (Dakin's), 3% hydrogen peroxide (H₂ O₂ ), and 1.5% H₂ O₂ -and a 0.9% normal saline (NS) control were obtained. A stock 100 mg/ml TXA solution was diluted in each antiseptic solution to a concentration of 10.0 mg/ml to generate reference standard and stability samples. TXA stability in each solution was measured using high performance liquid chromatography at t = 0 and t = 120 min and reported as mean percent of theoretical concentration (MPT) with associated relative standard deviation (RSD). All experiments were performed in triplicate at room temperature. At t = 0 min, TXA remained stable when mixed with 0.9% NS, 0.1% CHX, 10% BTD, 3% H₂ O₂ , and 1.5% H₂ O₂ (MPT range: 102.0%-105.0%, RSD range: 0.80%-2.92%). Only 0.5% Dakin's led to significant degradation of TXA at t = 0 min (MPT: 14.3%, RSD:1.28%). At t = 120 min, TXA stability persisted for all compounds except Dakin's 0.5% (MPT: 18.4%, RSD: 28.7%). TXA efficacy may be significantly diminished when 0.5% Dakin's is used as an intraoperative irrigation solution. CHX, BTD, and H₂ O₂ do not degrade TXA.

The Persistent Effects of the COVID-19 Pandemic on Total Joint Arthroplasty Changes in Practice Patterns in the United States From 2020 to 2021

BACKGROUND

The SARS-CoV-2 (COVID-19) pandemic has dramatically disrupted orthopaedic surgery practice patterns. This study aimed to examine differences between patients who underwent total joint arthroplasty (TJA) before the pandemic compared to 2020 and 2021.

METHODS

A retrospective cohort study was performed on all patients who underwent elective inpatient TJA from January 2017 to December 2021 using a national large database. Descriptive statistics were utilized to trend length of stay (LOS) and patient age. Patient demographics, discharge destinations, and rates of medical comorbidities were assessed for patients undergoing TJA in 2020 and 2021 compared to patients from prepandemic years (2017 to 2019). Overall, 1,173,366 TJAs were identified (2017 to 2019: 810,268 TJAs, average 270,089 cases/year; 2020: 175,185 TJAs; 2021: 187,627 TJAs). There was a 35.3% and 30.5% decrease in 2020 and 2021, respectively, when compared to the prepandemic annual average.

RESULTS

Average LOS decreased from 1.6 days in January 2020 to 0.9 days by December 2021. Same-day discharges increased from 6.2% of cases in 2019 to 30.5% in 2021. Discharge to skilled nursing facilities (SNF) reduced from 11.3% in 2017 to 2019 to 4.3% and 4.5% in 2020 and 2021, respectively. Patients ≥70 years old undergoing elective TJA decreased from 39.6% in 2017 to 2019 to 29.2% in April 2020.

CONCLUSION

In response to the COVID-19 pandemic, same-day discharges following primary elective TJA increased markedly, the average LOS decreased, discharges to SNFs decreased, and a preferential shift toward younger patients was observed.

LEVEL OF EVIDENCE

Therapeutic Level III.

Ceramic Femoral Heads Exhibit Lower Wear Rates Compared to Cobalt Chrome: A Meta-Analysis

BACKGROUND

Wear between the femoral head and acetabular liners continues to limit the longevity of total hip arthroplasty implants despite advances in implant materials. The purpose of this meta-analysis was to compare linear wear rates of cobalt-chromium (CoCr) and fourth-generation ceramic femoral heads on highly cross-linked polyethylene (XLPE) liners.

METHODS

A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted to identify all studies between 2003 and 2020 that examined in vivo wear rates of either fourth-generation ceramics or CoCr femoral heads on XLPE liners. Studies were analyzed in a weighted means analysis of wear rates and a random effects meta-analysis.

RESULTS

A total of 36 studies met inclusion criteria (1,657 CoCr and 659 ceramic patients). The pooled, weighted mean wear rate was 0.063 mm/year (standard deviation [SD]: 0.061, confidence interval [CI]: 0.049-0.077) for CoCr and 0.047 mm/year (SD: 0.057, CI: 0.033-0.062; P < .01) for ceramic (P < .01). A meta-analysis of 4 studies directly comparing ceramic and CoCr found that CoCr heads demonstrated 0.029 mm/year more wear than ceramic heads (95% CI: 0.026-0.059, P = .306). Mean wear for 32-mm heads was significantly higher for ceramic (P < .01), while mean wear for 36-mm heads was significantly higher for CoCr (P < .01).

CONCLUSION

Fourth-generation ceramic femoral heads were found to have significantly lower wear rates than CoCr heads. Unlike previous studies, this meta-analysis included only in vivo studies and those with the same generation of highly XLPE liners.

The Utility of Routine Postoperative Radiographs in the Asymptomatic Total Hip Arthroplasty Patient

BACKGROUND

Total hip arthroplasty (THA) patients often receive routine radiographs in the year following their index surgery. This study sought to investigate the clinical and economic value of obtaining routine postoperative hip radiographs for asymptomatic patients following primary elective THA.

METHODS

A retrospective cohort study of consecutive patients who underwent primary elective THA from 2016 to 2019 was conducted. Patients undergoing nonelective or revision THA, radiographic follow-up <10 months, and patients aged <18 years were excluded. All radiographs were reviewed for abnormalities in the first postoperative year by an arthroplasty fellowship-trained orthopaedic surgeon, blinded to the symptoms of the patient.

RESULTS

Of the 327 patients (351 hips) included, 57.2% were women and 68.2% were White, with an average age of 65 years (range, 22-97 years) and average body mass index of 29.1 kg/m² (range, 16.2-49.8 kg/m²). Only four (0.4%) radiographic series revealed abnormalities with the potential to alter postoperative management. One patient experienced a change in management directly related to their abnormal finding (closed reduction for dislocation at 10.2 months postoperatively). The remaining three abnormal radiographic findings included femoral stem subsidence, progressive radiolucencies around an acetabular component, and cement mantle fracture. The average cost for each radiographic series was $155.27, resulting in total direct charges of $167,691.60.

CONCLUSION

Routine postoperative radiographs may be of limited utility in the asymptomatic patient in the first year following elective primary THA. Consideration should be given to limit postoperative radiographs following standard elective THA, while reserving postoperative radiographic evaluation for patients who are symptomatic.

LEVEL OF EVIDENCE

Level III.

Modern Proximal Femoral Replacement in Revision Total Hip Arthroplasty for Nononcologic Indications

BACKGROUND

Advances in surgical technique and prosthesis design have expanded the non-neoplastic indications for proximal femoral replacement (PFR) to include fracture nonunion, periprosthetic fracture, and severe bone loss in the setting of revision total hip arthroplasty (THA). The purpose of this study is to assess outcomes of PFRs used for nononcologic indications.

METHODS

A single-institution, retrospective, cohort survey study was conducted between August 2015-February 2020 of consecutive patients undergoing PFR for nononcologic indications in revision THA. Patient demographics, surgical variables, complications, and revision procedures were collected. Patient satisfaction and Oxford Hip scores were assessed via a telephone questionnaire. Implant survivorship was estimated using the Kaplan-Meier method.

RESULTS

In total, 24 patients (27 PFRs) were available for analysis with an average age of 69.3 ± 12.9 years (range: 37-90). The average number of operations prior to PFR implantation was 3.1 ± 2.1 (range: 0-7). At a mean follow-up of 2.4 years (range: 0.5-5.1), the mean Oxford Hip Score was 31.7 ± 10.2, and mean patient satisfaction was 4.9/5. Six patients (20.7%) experienced a postoperative complication, with dislocation occurring in three patients (10.3%). None of the patients with dual mobility articulations (n = 4) had dislocation. Three-year survivorship was 85.2% (95% CI 71.8%-98.6%) with all-cause reoperations as the endpoint and 100% (95% CI 100.0%-100.0%) with revision for aseptic loosening as the endpoint.

CONCLUSION

The current study demonstrates excellent short-term survivorship, satisfactory patient-reported outcomes, and high patient satisfaction following PFR for nononcologic indications during revision THA utilizing modern techniques. The most common mode of failure was dislocation requiring reoperation with revision to constrained acetabular components.

Interobserver and Intraobserver Reliability of the Sirveaux Classification of Scapular Notching After Reverse Total Shoulder Arthroplasty

The Sirveaux classification characterizes the severity of scapular notching after reverse total shoulder arthroplasty (rTSA). However, its reliability has not been validated. The goal of the current study was to determine the interobserver and intraobserver reliability of the Sirveaux classification. An online survey was sent to the American Shoulder and Elbow Surgeons (ASES), containing 10 radiographs showing a range of scapular notching. Members were asked to grade the degree of scapular notching with the Sirveaux classification system. Then ASES members from our institution regraded the images a second time after a minimum of 6 weeks. Fleiss' and Cohen kappa coefficients were calculated to determine the degree of interobserver and intraobserver reliability, respectively. A total of 50 ASES members graded the radiographs and 3 regraded images after more than 6 weeks. Fleiss' kappa coefficient was 0.2437, indicating fair interobserver agreement. Surgeons who perform more than 20 rTSA procedures per year (n=34) had a Fleiss' kappa of 0.2864. The mean Cohen kappa coefficient was 0.4763, indicating moderate intraobserver reliability. The Sirveaux classification system has fair interobserver and moderate intraobserver reliability. Surgeons should use additional means to describe the severity of notching, particularly when communicating with other physicians or publishing research. [Orthopedics. 2022;45(4):239-243.].

Elective Inpatient Total Joint Arthroplasty Case Volume in the United States in 2020: Effects of the COVID-19 Pandemic

BACKGROUND

Despite known surgical volume reductions in 2020 during the height of the COVID-19 pandemic, no study has fully quantified the impact of the pandemic on the number of elective inpatient total hip (THA) and total knee arthroplasty (TKA) cases. The purpose of the present study was to analyze THA and TKA case volumes in the United States during the COVID-19 pandemic.

METHODS

The Premier Healthcare Database was utilized to identify adults undergoing primary elective THA or TKA from January 2017 to December 2020. The National Inpatient Sample was cross-referenced to provide nationwide representative sampling weights. Patients undergoing revision total joint arthroplasty (TJA) or non-elective surgery were excluded. Two quantitative models were created from both databases to estimate TJA case volume in 2020. Descriptive statistics were utilized to report monthly changes in elective TJA utilization throughout 2020. Univariate analyses were performed to compare differences between subgroups.

RESULTS

From 2017 to 2019, it was estimated that 1,006,000 elective inpatient TJAs (64.2% TKA and 35.8% THA) were performed annually. In 2020, an estimated 526,000 to 538,000 cases (62.0% TKA and 38.0% THA) were performed, representing a 46.5% to 47.7% decrease in nationwide volume from the prior 3-year average. Moreover, the elective TJA case volume for April 2020 was 1.9% of the average for that month from 2017 through 2019. Subsequently, case volumes for May and June increased compared with the volumes for those months from 2017 through 2019. There was then a decrease in cases for July, corresponding with the "second wave" of COVID-19, followed by an additional steady monthly decline through December, corresponding with the "third wave." Finally, the elective TJA cases for December 2020 represented only 41.0% of the average case volume for that month from 2017 through 2019.

CONCLUSIONS

In the midst of the 2020 COVID-19 pandemic, approximately 526,000 to 538,000 elective inpatient TJA cases were performed, representing a 46.5% to 47.7% decrease compared with the 3 previous years. The effects of the COVID-19 pandemic persisted through the end of that year, with decreased case volume through December 2020.

Midterm Survivorship of Robotic-Assisted Lateral Unicompartmental Knee Arthroplasty

BACKGROUND

Lateral unicompartmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) for patients with isolated lateral compartment osteoarthritis. Few studies have investigated outcomes following robotic-assisted lateral UKA. The purpose of this study is to evaluate mid-term survivorship and patient-reported outcomes of robotic-assisted lateral UKA.

METHODS

A retrospective case series was conducted on all robotic-assisted lateral UKAs performed by a single surgeon between 2013 and 2019. Patient demographics, surgical variables, and Kozinn and Scott criteria were collected. Implant survivorship was estimated using the Kaplan-Meier method with all-cause reoperation and conversion to TKA as endpoints. Participating patients were assessed for patient satisfaction and the Forgotten Joint Score-12. Correlations between patient demographics and patient outcome scores were investigated.

RESULTS

In total, 120 lateral UKAs were identified, 84 of which met inclusion criteria, with a mean follow-up of 4.0 years (range 2.0-7.0). Five-year survivorship was 92.9% (95% confidence interval [CI] 84.5-96.7) with all-cause reoperation as the endpoint, and 100% (95% CI 95.0-100) with conversion to TKA as the endpoint. One patient was converted to TKA after the 5-year mark, resulting in a 6-year survival for conversion to TKA of 88.9% (95% CI 44.9-98.5). Average Forgotten Joint Score-12 score was 82.7/100, and patient satisfaction 4.7/5. Mean coronal plane correction was 2.5° ± 1.9° toward the mechanical axis. Neither final postoperative alignment nor failure to meet classic Kozinn and Scott criteria for UKA resulted in differences in patient-reported outcomes.

CONCLUSION

The current study demonstrates high mid-term survivorship and excellent patient-reported outcomes with robotic-assisted lateral UKA. Robotic-assisted lateral UKA is a viable treatment option for isolated lateral compartment arthritis even in patients who do not meet classic indications.

Timing of Total Hip Arthroplasty Affects Lumbar Spinal Fusion Outcomes

STUDY DESIGN

This is a retrospective cohort study of consecutive patients undergoing lumbar spinal fusion (LSF) within the PearlDiver Humana research database from 2010 to 2018.

OBJECTIVE

The aim of this study was to determine if timing of total hip arthroplasty (THA) affects LSF outcomes.

SUMMARY OF BACKGROUND DATA

In patients with both spine and hip pathology, outcomes of THA have been shown to be affected by the timing of THA relative to LSF. However, few studies have assessed postoperative outcomes following LSF in this clinical scenario.

MATERIALS AND METHODS

A national database was queried for patients undergoing lumbar fusion and divided into 4 groups: (1) those who underwent LSF without THA (No THA); (2) those who underwent THA at least 2 years before LSF (>2 Prior THA); (3) those who underwent THA in the 2 years before LSF (0-2 Prior THA); and (4) those who underwent THA after LSF (THA After). We assessed lumbar-specific outcomes, including pseudarthrosis, revision, mechanical failure, and adjacent segment disease (ASD); as well as systemic complications. Controlling for age, sex, and Charlson comorbidity index, complication rates between all groups were assessed using univariate and multivariate logistic regression analysis. Post hoc comparisons were performed using the Fisher exact test with Bonferroni correction to account for multiple pairwise comparisons, resulting in an adjusted threshold for statistical significance of P<0.007.

RESULTS

When compared with the no THA group, those in the THA After group had a higher rate of ASD on multivariate analysis [adjusted odds ratio: 1.53, 95% confidence interval: 1.20-1.94, P<0.001]. When compared with all patients who underwent THA before LSF, patients who underwent THA after LSF had an increased risk of ASD (adjusted odds ratio: 3.80, 95% confidence interval: 2.21-6.98, P<0.001).

CONCLUSIONS

Patients who undergo THA after LSF have an increased rate of lumbar-related complications both when compared with patients who do not undergo THA and when compared with patients who undergo THA before LSF.

The Use of Telesurgery Mentoring and Augmented Reality to Teach Arthroscopy

Surgical teaching methods may be enhanced with telesurgery mentoring technology through virtual, visual, and audio interactions in the operating room, irrespective of geographic restrictions. The use of telesurgery mentoring carries the potential for accelerated learning in arthroscopic and surgical education. A telesurgery platform enables the establishment of a global network of surgeons with the goal of bridging gaps in surgical training via an accessible, cost-effective communication pathway. Specifically, such a platform allows a local surgeon to deliver real-time and live virtual assistance to a remote surgeon over a standard internet connection and removes the geographic barriers that prevent the practice of high-quality surgical care, thereby expanding virtual surgical collaboration. The purpose of our study is to describe our technique of telesurgery mentoring using a telesurgery internet platform (SurgTime; www.surgtime.com) and its applicability to teaching arthroscopic surgery skills both within the United States and in developing countries across the globe.

Utilization of technology-assisted total hip arthroplasty in the United States from 2005 to 2018

Background

Successful outcomes in total hip arthroplasty (THA) rely in part on accurate component positioning, which may be optimized through the use of computer navigation and robot-assistance. Therefore, we queried a large national database to characterize national trends in technology-assisted THA utilization, determine whether these technologies were associated with increased hospital charges, and identify demographic factors associated with technology-assisted THA.

Methods

Using the Nationwide Inpatient Sample database, patients that underwent conventional THA, computer-navigated THA, and robot-assisted THA from 2005 to 2018 were identified. Patient and hospital demographics, charge data, and payer characteristics were collected. Temporal trends in utilization were reported. Univariate analyses were performed to compare differences between groups with multiple logistic regression analysis to account for confounders.

Results

In total, 3,428,208 patients undergoing THA from 2005 to 2018 were identified, of which 63,136 (1.8%) used computer navigation and 32,660 (1.0%) used robot-assistance. National utilization of computer navigation in THA increased from 0.1% to 1.9% between 2005 and 2018, while utilization of robot-assisted THA increased from <0.1% to 2.1% from 2008 to 2018. On multivariate analysis, technology-assisted THA was most commonly performed in urban hospitals in the Northeastern United States. Median hospital charges were increased for technology-assisted THAs relative to conventional THAs ($66,089 ± $254 vs $55,418 ± $43).

Conclusions

Computer navigation and robot-assistance in THA demonstrated a consistent increase in utilization during the period examined, representing 4.0% of THAs performed in 2018. Patient and hospital characteristics including risk of mortality, geographic region, and teaching status were associated with increased utilization. Utilization of computer navigation was associated with increased hospital charges.

Cemented Vs Cementless Femoral Fixation for Total Hip Arthroplasty After Displaced Femoral Neck Fracture: A Nationwide Analysis of Short-Term Complications and Readmission Rates

BACKGROUND

Active patients with displaced femoral neck fractures are often treated with total hip arthroplasty (THA). However, optimal femoral fixation in these patients is controversial. The purpose of this study was to compare early complication and readmission rates in patients with hip fracture treated with THA receiving cemented vs cementless femoral fixation.

METHODS

The National Readmissions Database was queried to identify patients undergoing primary THA for femoral neck fracture from 2016 to 2017. Postoperative complications and unplanned readmissions at 30, 90, and 180 days were compared between patients treated with cemented and cementless THA. Univariate and multivariate analyses were performed to compare differences between groups and account for confounding variables.

RESULTS

Of 17,491 patients identified, 4427 (25.3%) received cemented femoral fixation and 13,064 (74.7%) cementless. The cemented group was significantly older (77.2 vs 71.1, P < .001), had more comorbidities (Charlson comorbidity index: 4.44 vs 3.92, P < .001), and had a greater proportion of women (70.5% vs 65.2%, P < .001) compared with the cementless group. On multivariate analysis, cemented fixation was associated with reduced rates of periprosthetic fracture (odds ratio: 0.052, 95% confidence interval: 0.003-0.247, P = .004) at 30 days but similar readmission rates at 30, 90, and 180 days (odds ratio range: 1.012-1.114, P > .05) postoperatively compared with cementless fixation. Cemented fixation was associated with greater odds of medical complications at 180 days postoperatively (odds ratio:: 1.393, 95% confidence interval: 1.042-1.862, P = .025).

CONCLUSION

Cemented femoral fixation was associated with a lower short-term incidence of periprosthetic fractures, higher incidence of medical complications, and equivalent unplanned readmission rates within 180 days postoperatively compared with cementless fixation in patients undergoing THA for femoral neck fracture.

LEVEL OF EVIDENCE

Level III.

Patient Perception Regarding the Safety of Elective Joint Arthroplasty Surgery During the COVID-19 Pandemic

BACKGROUND

Total joint arthroplasty (TJA) practices have been dramatically impacted by the COVID-19 pandemic. To date, no study has assessed trends in patient perceptions regarding the safety of elective TJA.

METHODS

A single-institution, prospective cohort study was conducted between May 11th and August 10th, 2020. All patients who underwent elective hip and knee arthroplasty were contacted via telephone or emailed surveys. Two-hundred and thirty-five consecutive patients were screened, and 158 agreed to participate. The average age was 65.9 ± 11.5 years, with 51.0% of patients being female. The percentage of participants who underwent total knee, total hip, and unicompartmental knee arthroplasty was 41.4%, 37.6%, and 21.0%, respectively. Survey components assessed demographic data, level of concern and specific concerns about the pandemic, and factors increasing patient comfort in proceeding with surgery.

RESULTS

Older age (P = .029) and female sex (P = .004) independently predicted higher concern on multivariate analysis. Race (P = .343), surgical site (knee vs hip, P = .58), and procedure type (primary vs revision, P = .26) were not significantly related to degree of concern. Most participants (71.5%) disagreed that the pandemic would negatively affect the outcome of their surgery. Patient concern mirrored statewide COVID-19 cases and deaths, rather than local municipal trends. The most cited reassuring factors were preoperative COVID-19 testing, personal protective equipment usage by hospital staff, and surgeon support.

CONCLUSIONS

Patient concern regarding the safety of elective TJA may follow broader policy-level events rather than local trends. Surgeons should note that universal preoperative COVID-19 testing, adequate personal protective equipment, and surgeon support were reassuring to patients.

LEVEL OF EVIDENCE

Level IV Therapeutic.

Limb Length Discrepancy in Total Hip Arthroplasty: Is the Lesser Trochanter a Reliable Measure of Leg Length?

BACKGROUND

Limb length discrepancy (LLD) after total hip arthroplasty may affect clinical outcomes and patient satisfaction. Preoperative LLD estimates on anteroposterior pelvic radiographs fail to account for anatomical limb variation distal to the femoral reference points. The objective of this study is to determine how variations in lower limb skeletal lengths contribute to true LLD.

METHODS

Full-length standing anteroposterior radiographs were used to measure bilateral leg length, femoral length, and tibial length. Leg length was evaluated using 2 different proximal reference points: the center of the femoral head (COH) and the lesser trochanter (LT). Mean side-to-side discrepancy (MD) and percentage asymmetry (%AS) for each measurement were evaluated in the overall cohort and when stratified by patient demographic variables.

RESULTS

One hundred patients were included with an average age of 62.9 ± 11.2 years. Average femoral length was 434.0 ± 39.8 mm (MD 4.3 ± 3.5 mm) and tibial length was 379.9 ± 34.6 mm (MD 5.9 ± 12.7 mm). Average COH-talus was 817.5 ± 73.2 mm (MD 6.4 ± 5.1 mm). Average LT-talus was 760.5 ± 77.6 mm (MD 5.8 ± 5.1 mm). Absolute asymmetry >10 mm was detected in 16% of patients for COH-talus and 15% for LT-talus, while %AS >1.5% was detected in 13% of patients for COH-talus and 18% for LT-talus. Female gender was associated with increased femoral length %AS (P = .037).

CONCLUSION

Approximately 1 in 6 patients have an LLD of >10 mm when measured from either the LT or COH. Surgeons using either of these common femoral reference points to estimate LLD on pelvic radiographs should consider these findings when planning for hip reconstruction.

LEVEL OF EVIDENCE

Level III.

Dose-Dependent Early Postoperative Opioid Use Is Associated with Periprosthetic Joint Infection and Other Complications in Primary TJA

BACKGROUND

Opioids are commonly prescribed for postoperative pain following total joint arthroplasty. Despite widespread use, few studies have examined the dose-dependent effect of perioperative opioid use on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Therefore, we examined the dose-dependent relationship between opioid use and postoperative complications following primary THA and TKA.

METHODS

We queried the Premier Healthcare Database to identify adult patients who underwent primary elective THA or TKA from 2004 to 2014, and quantified opioid consumption within the first 3 postoperative days. Opioid consumption was standardized to morphine milligram equivalents (MMEs). Patients were divided into quintiles on the basis of MME exposure: <54, 54 to 82, 83 to 116, 117 to 172, and >172 MMEs. Primary outcomes included postoperative periprosthetic joint infection, pulmonary embolism, deep venous thrombosis, and pulmonary complications. Secondary outcomes included wound infection, wound dehiscence, and readmission within 30 and 90 days postoperatively. Univariate and multivariate analyses were performed to compare differences between groups and to account for confounders.

RESULTS

A total of 1,525,985 patients were identified. The mean age was 65.7 ± 10.8 years, 598,320 patients (39.2%) were male, and 1,174,314 patients (77.0%) were Caucasian. On multiple logistic regression analysis, increasing MME exposure was associated with a dose-dependent increased risk of postoperative complications. Compared with patients receiving <54 MMEs, exposure to >172 MMEs was associated with greater odds of periprosthetic joint infection (adjusted odds ratio [aOR], 1.37; 95% confidence interval [CI], 1.33 to 1.42), deep venous thromboembolism (aOR, 1.34; 95% CI, 1.30 to 1.38), pulmonary embolism (aOR, 1.29; 95% CI, 1.25 to 1.34), and pulmonary complications (aOR, 1.06; 95% CI, 1.05 to 1.08). Exposure to >172 MMEs was associated with increased risk of wound infection (aOR, 1.37; 95% CI, 1.33 to 1.41), wound dehiscence (aOR, 1.24; 95% CI, 1.19 to 1.31), and readmission within 30 (aOR, 1.21; 95% CI, 1.20 to 1.22) and 90 days (aOR, 1.20; 95% CI, 1.19 to 1.21).

CONCLUSIONS

Increasing opioid use within the early postoperative period following THA or TKA was associated with a dose-dependent increased risk of periprosthetic joint infection and venous thromboembolic events.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Delayed debridement of open tibia fractures beyond 24 and 48 h does not appear to increase infection and reoperation risk

PURPOSE

Surgical debridement is critical to the treatment of open tibia fractures, although the effects of delayed debridement have not been well-established. Other factors such as Gustilo-Anderson type, prompt initiation of antibiotics, and time to definitive closure may be more predictive of infection than time to surgery. We sought to determine the effect of a prolonged delay to surgical debridement with respect to infection and reoperation rates for open tibia fractures.

METHODS

All open diaphyseal tibia fractures with > 12-week follow-up were evaluated. Patient demographics, Gustilo-Anderson type, and rates of deep infection and all-cause reoperation were recorded. Patients were divided into 3 groups based on time to surgery: early (< 24 h), delayed (24-48 h), and late (> 48 h). Univariate and multivariate analyses were performed to evaluate the relationship between time to surgery, fracture type, infection, and reoperation.

RESULTS

In total, 96 open tibia fractures with average follow-up of 59.3 weeks and infection rate of 13.5% were included. Infection rates for the early, delayed, and late groups were 13.3%, 17.2%, and 9.1%, respectively (p = 0.70). Reoperation rates for the early, delayed, and late groups were 29.8%, 31.0%, and 22.7%, respectively (p = 0.80). The groups did not vary in proportion of Gustilo-Anderson fracture types; infection rates between Gustilo-Anderson types were similar (p = 0.57). Type IIIA-C fractures required more reoperations than other fracture types (p = 0.01).

CONCLUSION

Delayed surgical debridement of open tibia fractures did not result in greater rates of infection or reoperation. Gustilo-Anderson classification was more predictive of reoperation, with Type IIIA-C injuries having a significantly higher reoperation rate.

Medical Students' Reflections on the Recent Changes to the USMLE Step Exams

The United States Medical Licensing Examination (USMLE) consists of Step 1, Step 2 Clinical Knowledge, Step 2 Clinical Skills, and Step 3. To be licensed to practice medicine in the United States, medical students must pass all parts of the USMLE. However, in addition to that pass/fail grade, students are currently given a numerical score for Step 1, Step 2 Clinical Knowledge, and Step 3. Residency program directors have come to use the Step 1 score to efficiently screen a growing number of residency applicants. As a result, a deleterious environment in undergraduate medical education has been created, given the importance of Step 1 to medical students matching to their preferred residency program. It was announced in February 2020 that the score-reporting protocol for Step 1 would be changed from a 3-digit numerical score to pass/fail only, beginning no earlier than January 1, 2022. This decision will undoubtedly impact medical students, medical schools, and residency program directors. Here, the authors discuss the impact that the change to Step 1 scoring will have on these key stakeholder groups, from their perspective as students at MD-granting medical schools in the United States. They also call attention to outstanding issues with the USMLE that must be addressed to improve undergraduate medical education for all stakeholders, and they offer advice for further improvements to the residency application process.

Early regulation of brain aromatase (cyp19a1b) by estrogen receptors during zebrafish development

Early expression of estrogen receptors (esr) and their role in regulating early expression of cyp19a1b encoding brain aromatase were examined in the brain of zebrafish. Using in toto hybridization and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), a significant increase in the expression of esr1, esr2a, and esr2b was observed between 24 and 48 hours postfertilization (hpf). In toto hybridization demonstrated that esr2a and esr2b, but not esr1, are found in the hypothalamus. Using real-time RT-PCR, an increase in cyp19a1b mRNAs occurs between 24 and 48 hpf, indicating that expression of cyp19a1b is temporally correlated with that of esr. This increase is blocked by the pure anti-estrogen ICI182,780. Furthermore, E2 treatment of cyp19a1b-GFP (green fluorescent protein) transgenic embryos results in appearance of GFP expression in the brain as early as 25 hpf. These results indicate that basal expression of cyp19a1b expression in the brain of developing zebrafish most likely relies upon expression of esr that are fully functional before 25 hpf.

In vivo and in vitro ethanol exposure in prenatal rat brain: GABA(B) receptor modulation on dopamine D(1) receptor and protein kinase A

We have investigated the effects of prenatal ethanol exposure on GABA(B) receptors (GABA(B)Rs), protein kinase A (PKA), and DA D(1) receptor (DAD(1)R) expressions. GABA(B1)R and GABA(B2)R showed different age-dependent expressions in in vivo fetal rat forebrain from gestational days (GD) 15.5 to 21.5 upon 10% ethanol treatment to mother, with and without baclofen at a dose of 10 mg/kg body weight/day. The protein level changes could not be attributed to changes in the level of transcription since GABA(B)R mRNA presented different expression patterns upon in vivo ethanol treatment. Using in vitro cultivated cortical neurons from GD 17.5 fetuses, we also explored the modulatory effects of ethanol on PKA and DAD(1)R through GABA(B)Rs, under 50 microM baclofen and 100 microM phaclofen administrations, with or without 100 mM of ethanol treatment in the culture media. The results showed that 20 min ethanol treatment without baclofen or phaclofen had increasing effects on both the GABA(B)Rs. Further, baclofen and phaclofen administration significantly affected PKA and GABA(B)R levels upon 20 min and 1 h ethanol treatment. In contrast, DAD(1)R showed increasing effects upon ethanol treatment, which was modulated by GABA(B)R's agonist baclofen and antagonist phaclofen. Therefore the present study suggested that the GABA(B)R activity could modulate ethanol's cellular effects, which possibly including PKA and DAD(1)R activities, and may be an underlying cause of ethanol's effects.

Ethanol's effect on intracellular signal pathways in prenatal rat cortical neurons is GABAB1 dependent

To confirm the modulation role of GABA(B) on ethanol' effects, we studied the effects of ethanol on the neuronal intracellular signals, protein kinase A (PKA) and cAMP-response element binding protein (CREB), by using a system where GABA(B1) receptors were specifically knocked down in the in vitro cultivated cortical neurons. The results showed that the PKA alpha subunit was increased with ethanol treatment, and could be further increased by administering baclofen and phaclofen. By contrast, baclofen and/or phaclofen could decrease ethanol's up-regulation effects on PKA alpha subunit expression in primary cultured cortical neurons in which the GABA(B1) receptor was specifically knocked down using GABA(B1) receptor RNA interference. Furthermore, these effects could lead to changes of phospho (p)-CREB expression, which showed the same expression pattern as PKA. Finally, we observed changes of GABA(B1), PKA, and p-CREB distribution within the same neuronal cells. These results showed that the GABA(B) receptors are critical to ethanol's cellular effects, which occur via modulating the PKA and CREB transcription pathway, and may be an underlying cause of ethanol's effects.

Prenatal GABAB1 and GABAB2 receptors: cellular and subcellular organelle localization in early fetal rat cortical neurons

Gamma-aminobutyric acid (GABA)(B) receptors appear to influence developmental events, depending on whether they are found at a synapse or in extrasynaptic areas. Little, if anything, is known as to the cellular and subcellular localization of GABA(B1) and GABA(B2) receptors during early fetal development. We used Western blots, immunohistochemistry, and postembedding immunoelectronmicroscopy to investigate fetal rat brain expression and distribution of these receptor proteins. GABA(B1) is expressed as early as gestational day (GD) 11.5 and 12.5, with immunoreactivity found in the all neuroepithelium, and a high expression in the mantel zone and the cortical area's plate; no immunolabeling for GABA(B2) receptor was observed. Our immunogold studies define a pattern of early GABA(B1) receptor protein in dendrite processes, endoplasmic reticulum, and axon terminals of the cortical neuroepithelium on GD 11.5. On GD 12.5, GABA(B1) receptor immunogold was found in dendrite processes, spines and tree, axon terminals, mitochondria, and intracellular organelles of the cortical neuroepithelium. No synapse formation was apparent as no synaptophysin could be found on either GD 11.5 or 12.5. We suggest that GABA(B1) has a functional role in the early fetal brain during neuronal proliferation and migration, and that it is different from the established functional GABA(B) receptor.

Evaluation of androgens in the scalp hair and plasma of patients with male-pattern baldness before and after finasteride administration

BACKGROUND

Finasteride, a competitive inhibitor of the enzyme 5alpha-reductase II, is widely used as a medical treatment for patients with male-pattern baldness (MPB), which is affected by the distribution of androgenic steroids. It is also notable that the androgenic effect in MPB is different for each region of the head.

OBJECTIVES

To study the effect of the drug finasteride, we quantified androgenic steroids in the vertex and occipital scalp hair and in the plasma of patients with MPB.

METHODS

The patients with MPB, aged 23-52 years, were treated with finasteride 1 mg daily for 5 months. The hair and plasma samples were hydrolysed, extracted with n-pentane, and derivatized with MSTFA:NH4I:DTE (1000:4:5, v/w/w). We analysed the concentrations of dihydrotestosterone (DHT) and testosterone (T) in the hair and plasma using gas chromatography-mass spectrometry (GC-MS).

RESULTS

In the hair, the ratio of DHT/T was decreased in the vertex scalp hair after the individual received finasteride (P < 0.005). However, we found no significant difference in the ratio of DHT/T in the occipital scalp hair before and after individuals received finasteride. Like the results in the vertex scalp hair, the ratio of DHT/T in the plasma was remarkably decreased after finasteride administration (P < 0.001).

CONCLUSIONS

This study supports the effect of finasteride in patients with MPB by examining the decreased level of DHT/T in scalp hair and in plasma. Thus, in view of the androgenic effect in the different hair regions, the vertex scalp hair plays a more important role for patients with MPB treated with finasteride than does the occipital hair.

Ethanol modulates the expression of GABAB receptor mRNAs in the prenatal rat brain in an age and area dependent manner

Prenatal ethanol exposure has various deleterious effects on neuronal development. As GABA(B) receptor is known to play an important role during the development of the CNS, we now focused on its mRNA expression pattern in the rat brain during the late gestational days (GD) from 15.5 to GD 21.5. Ethanol's effect was also observed from GD 11.5 to GD 21.5. GABA(B1) receptor mRNA showed a high expression level in GD 15.5 and 19.5, while GABA(B2) receptor mRNA did in GD 15.5 and 21.5. The mRNAs levels depended on age and area during development. Ethanol exposure decreased GABA(B1) receptor from GD 11.5 to GD 19.5 with slight increases in GD 21.5. The decreasing effects were area dependent, with the highest effects in the forebrain including cortex, whereas slight effects were observed in the midbrain and hindbrain. The present results suggest an important role of GABA(B) receptor in the effects of ethanol on prenatal brain developmental processes.

Endogenous urinary steroids in premenopausal women with uterine leiomyomas

OBJECTIVES

To study the effect of endogenous steroids on the presence of uterine leiomyomas.

METHODS

Urine samples of 27 premenopausal women with leiomyomas and 25 age-matched healthy premenopausal women were collected. The concentration of estrogens and androgens in the urine samples of the two groups were determined using a gas chromatography mass spectrometer and the two groups were compared. To study metabolic changes in patients indirectly, the concentration ratios of precursor metabolite to product metabolite of the two groups were also compared.

RESULTS

Urinary concentrations of 17beta-estradiol, 5-androstene-3beta, 16beta, 17beta, triol, 11-keto-ethiocholanolone, 11beta-hydroxy-androsterone, 11beta-hydroxy-etiocholanolone, THS, THA, THE, alpha-cortol and beta-cortol were significantly higher in patients than in controls. The concentration ratios of 17beta-estradiol/estrone and 11/beta-hydroxy-ethiocholanolone/11beta-hydroxy-androsterone increased in patients.

CONCLUSIONS

The presence of uterine leiomyomas correlates with an increase in urinary concentrations of estrogens and androgens, and it appears to be caused by a decrease in patients' metabolism of steroids.

Relationship between urinary profile of the endogenous steroids and postmenopausal women with stress urinary incontinence

AIMS

The aims of this study were to investigate whether endogenous steroid hormones are (1) related to pathogenesis of stress urinary incontinence after menopause, (2) are related to severity of stress urinary incontinence, and (3) are related to prognostic parameters of stress urinary incontinence.

METHODS

Twenty post-partum women with clinically diagnosed stress urinary incontinence and 20 age-matched postmenopausal women without stress urinary incontinence (control group) were evaluated. We compared urinary profile of the endogenous steroid hormones patients with stress urinary incontinence and controls, and between grade I and grade II of stress urinary incontinence. We also investigated the relationship between urinary profile of the endogenous steroid hormones and prognostic parameters of stress urinary incontinence (maximal urethral closure pressure, functional urethral length, Valsalva leak point pressure, cough leak point pressure, posterior urethrovesical angle, bladder neck descent, and stress urethral axis). The ages of the patients and those in the control group were 64.3 +/- 5.6 and 57.5 +/- 3.8 years old and the body mass indexes were 24.96 +/- 3.14 and 22.11 +/- 2.73 kg/m2 in patients and in normal subjects, respectively. Nine patients were grade I and 11 were grade II. Estrone and 17beta-estradiol only were detected in all subjects, regardless of control or patient group. It is noteworthy that there were no significant differences (P > 0.05) in the levels of estrone and 17beta-estradiol in the urine of postmenopausal normal subjects compared with in the urine of postmenopausal patients with urinary incontinence. E2/E1 ratio was not different between the two groups (P > 0.05). Among the objective steroids, DHEA, Delta4-dione, Delta5-diol, Te, DHT, 16alpha-DHT, 11-keto An, THDOC, and THB were not detected either in the urine of normal subjects and nor in the urine of the patients. After comparing androgen levels between normal subjects and patients, no significant differences (P>0.05) were detected, except for 5alpha-THB and 5alpha-THF. Neither 5alpha-THB or 5alpha-THF were detected in the patients' urine. Et/An (11beta-OH Et/11beta-OH An) concentration ratios were not significantly different between the two groups, either (P > 0.05). There were not significant differences of concentrations (micromol/g creatinine) of urinary steroids between grade I and grade II of stress urinary incontinence. Pregnanediol was significantly related to bladder neck descent in supine and sitting positions (R = 0.79, P = 0.01, and R = 0.73, P = 0.03, respectively), and pregnanetriol was significantly related to maximal urethral closure pressure and functional urethral length (R = 0.68, P = 0.04, and R = -0.79, P = 0.01, respectively). Androsterone was significantly related to bladder neck descent in supine and sitting positions (R = 0.68, P = 0.04, and R = 0.78, P = 0.01, respectively). 5-AT was significantly related to bladder neck descent in sitting position and stress urethral axis (R = 0.72, P = 0.03, and R = -0.71, P = 0.03). 11-keto Et was significantly related to bladder neck descent in supine and sitting positions and related to stress urethral axis (R = 0.82, P = 0.01, and R = 0.81, P = 0.01, R = -0.67, P = 0.04, respectively). THS was significantly related to bladder neck descent in supine and sitting positions and related to stress urethral axis (R = 0.76, P = 0.02, and R = 0.74, P = 0.02, R = -0.68, P = 0.04, respectively). THE was significantly related to bladder neck descent in sitting position (R = 0.67, P = 0.04).beta-Tetrahydrocortisol/alpha-tetrahydrocortisol (beta-THF/alpha-THF) and alpha-cortol were significantly related to maximal urethral closure pressure and functional urethral length (R = 0.74, P = 0.02, and R = -0.92, P = 0.01; R = 0.71, P = 0.36, and R = -0.87, P = 0.000, respectively). 17beta-estradiol (E2) was significantly related to bladder neck descent in supine position (R = -0.62, P = 0.04) and 17beta-estradiol/estrone (E2/E1) was significantly related to cough leak point pressure (R = 0.79, P = 0.01). In conclusion, the urinary concentrations of endogenous steroid metabolites in postmenopausal patients with stress urinary incontinence were not significantly different from normal patients and were not significantly different between grade I and grade II patients with stress urinary incontinence. Some endogenous steroid metabolites were positively or negatively significantly related to prognostic parameters of stress urinary incontinence.

Relationships of urinary phyto-oestrogen excretion to BMD in postmenopausal women

OBJECTIVE

Phyto-oestrogens are plant compounds with both oestrogenic and anti-oestrogenic properties. However, it is not known whether natural phyto-oestrogens are beneficial or harmful in human osteoporosis. This study was performed to investigate the relationships between urinary phyto-oestrogens and bone mineral density (BMD) in Korean postmenopausal women.

DESIGN

The subjects were classified into osteoporotic, osteopenic and normal groups according to their BMD as defined by WHO criteria. We compared the urinary phyto-oestrogens of each group and studied whether urinary phyto-oestrogens correlate with BMD.

PATIENTS

The subjects were 75 Korean postmenopausal women with ages ranging from 52 to 65 years (mean 58 +/- 1.1 years). Mean number of years after menopause was 7.3 +/- 1.3.

MEASUREMENTS

Twenty-four-hour urinary phyto-oestrogens were measured by gas chromatography-mass spectrometry (GCMS) and BMD by dual-energy X-ray absorptiometry (DXA, Lunar Expert-XL, Lunar Co., WI, USA).

RESULTS

In Korean postmenopausal women, urinary enterolactone (1.46 +/- 1.11 micromol/day) was lower and daidzein (2.59 +/- 3.25 micromol/day) was higher than in western women, and both levels were comparable to those in Japanese women. Daily urinary excretion of genistein and apigenin were 1.09 +/- 0.912 and 0.48 +/- 0.40 micromol/day, respectively. In subjects with osteoporosis, urinary enterolactone was lower (P < 0.05) but apigenin was significantly higher (P < 0.05) than in the controls. BMD of L2-L4 correlated positively with urinary enterolactone (r = 0.388, P < 0.01), and BMD of the femoral neck and Ward's triangle correlated positively with urinary enterolactone (r = 0.271, P < 0.05 and r = 0.322, P < 0.05) but negatively with apigenin (r = -0.412, P < 0.01 and r = -0.395, P < 0.01). By multiple stepwise regression, the variables associated with spinal BMD were age, the amount of urinary apigenin and body mass index (BMI). The variables associated with femoral neck BMD were age and urinary apigenin.

CONCLUSIONS

From these results, we conclude that urinary phyto-oestrogens, especially enterolactone and apigenin, are related to BMD in Korean postmenopausal women. Our results also suggest the possibility that phyto-oestrogens have differential effects on bone density. Further studies are needed to clarify the exact biological roles of phyto-oestrogenic components on bone metabolism.

Characterization of duplicated zebrafish cyp19 genes

The zebrafish has recently been developed as a good genetic model system. We report here the use of zebrafish to study the regulation of estrogen biosynthesis. The CYP19 gene encodes cytochrome P450 aromatase, which catalyzes the synthesis of estrogens. Two cyp19 genes, termed cyp19a and cyp19b, have been isolated from zebrafish. Sequence comparison shows that Cyp19a and Cyp19b belong to two separate Cyp19 subfamilies. The cyp19a gene is expressed in the ovary, whereas cyp19b is expressed in the brain. The cyp19a and cyp19b genes are located on zebrafish chromosomes LG 18 and 25, respectively. Our data indicate that these gene loci arose through an ancient chromosomal duplication event. The expression of duplicated genes in distinct tissues may have evolutionary significance.

Urinary profile of endogenous steroids in postmenopausal women with stress urinary incontinence

OBJECTIVE

To predict the role of estrogen in prevention of and therapy for stress urinary incontinence by comparing the urinary levels of estrogens and androgens and, to indirectly evaluate metabolism of estrogens and androgens by comparing the concentration ratios of precursor metabolites with those in controls (normal subjects).

STUDY DESIGN

Urine samples collected for 24 hours were obtained from postmenopausal women with stress urinary incontinence (n = 20) and from age-matched, postmenopausal, normal female subjects (n = 14). The urinary levels of 20 estrogens and 25 androgens were analyzed by gas chromatography/mass spectrometry.

RESULTS

The urinary levels of androgens were significantly higher in patients with stress urinary incontinence than normal subjects, and the urinary levels of estrogens were somewhat higher in patients than normal subjects. However, there were no significant differences between the groups, nor were there significant differences in the metabolism of estrogens and androgens between two groups.

CONCLUSION

The urinary levels of endogenous steroids were rather higher in patients with stress urinary incontinence than in normal subjects, so it appears that estrogen should not play a significant role in prevention of and therapy for stress urinary incontinence.

Measurement of ketoprofen in horse urine using gas chromatography-mass spectrometry

A gas chromatographic-mass spectrometric (GC-MS) method for the determination of ketoprofen, a non-steroidal anti-inflammatory drug (NSAID), in horse urine by selected ion monitoring (SIM) mode is described. Urine samples (2 mL) were extracted by liquid-liquid extraction with diethyl ether. The residues were then evaporated, derivatized and injected into the GC-MS system. Validation of the GC-MS method in the SIM mode using flurbiprofen as the internal standard (IS) included linearity studies (10-10 000 ng/mL), recovery (95%) and limit of quantitation (LOQ) (10 ng/mL). The response was linear, with a correlation coefficient (0.9998) for ketoprofen. When applied to horse urine samples, the present method allowed detection of ketoprofen up to 16 days in FULL SCAN mode after a topical application of 1.1 g of ketoprofen in a gel formulation.

Developmental expression of cytochrome P450 aromatase genes (CYP19a and CYP19b) in zebrafish fry (Danio rerio)

Cytochrome P450 aromatase (CYP19) is the terminal enzyme in the steroidogenic pathway that converts androgens (e.g., testosterone) into estrogens (e.g., estradiol). Regulation of this gene dictates the ratio of androgens to estrogens; therefore, appropriate expression of this enzyme is critical for reproduction as well as being pivotal in sex differentiation for most vertebrates. It is assumed that most vertebrates have a single CYP19 gene that is regulated by multiple tissue-specific promoter regions. However, the zebrafish (Danio rerio) has two genes (CYP19a and CYP19b), each encoding a significantly different protein and possessing its own regulatory mechanism. The primary purpose of this study was to determine the pattern of expression of each of the CYP19 genes in the developing zebrafish. A fluorescent-based method of real-time, quantitative RT-PCR provided the sensitivity and specificity to determine transcript abundance in single embryos/juveniles harvested at days 0 through 41 days post-fertilization (dpf), which encompasses the developmental events of sex determination and gonadal differentiation. CYP19 transcripts could be detected as early as 3 or 4 dpf, (CYP19a and CYP19b, respectively) and peak abundance was detected on day five. In general, the CYP19 genes differed significantly in the ontogeny of their expression. In most cases, the gonadal form of CYP19 (CYP19a) was more abundant than the brain form (CYP19b); however, unlike CYP19a, the pattern of CYP19b expression could be clearly segregated into two populations, suggesting an association with sex differentiation. Pharmacological steroids (ethinylestradiol and 17 alpha-methyltestosterone) enhanced the expression of the CYP19b gene at all three days examined (4, 6, and 10 dpf). These data suggest that the timely and appropriate expression of CYP19 is important in development and that the expression of CYP19b (the "extra-gonadal" form) may be associated with sexual differentiation if not sexual determination. J. Exp. Zool. 290:475-483, 2001.

Development of rat prostatitis model by oral administration of isoflavone and its characteristics

Inflammation of the prostate can be induced experimentally in rats by the subcutaneous administration of estrogen. However, it is usually achieved at the price of some alteration in the sex steroid hormone balance and morphological changes in the prostate. In this study, a soy-extracted isoflavone mixture with weak estrogenic activity was administered orally in an attempt to induce prostatitis in a more physiologic way and to characterize the inflammation induced. A total of 36 male Sprague-Dawley rats, 8 weeks old, were divided into 2 groups. The control group was fed with only an AIN-76A diet containing no detectable phytoestrogen and the experimental group was fed with AIN-76A and a soy- extracted isoflavone mixture (genistein 60.0% and daidzein 19.6%), 300 mg/kg body weight for 9 weeks. The sequential body weight and prostate weight at necropsy were measured. A histologic examination and histomorphometry assessed the changes in the prostate. The serum concentrations of testosterone and dihydrotestosterone were measured to estimate the effects on the androgen level. Intraprostatic concentrations of genistein and daidzein were measured by gas chromatography/ mass spectroscopy (GC/MS). While no sign of prostate inflammation was apparent in the control group, severe inflammatory changes in the stroma, increased epithelial detachment and inflammatory exudates within the glandular lumen of the dorsolateral prostate were observed in more than 80%(15/18) of the experimental group. However, there was no significant difference in the ventral prostate between the two groups. The daidzein and genistein concentrations in both the lateral and ventral prostates were significantly higher in the experimental group than in the control group where no isoflavone was detectable. In addition, the concentrations were much higher in the dorsolateral than in the ventral prostate. Although the body weight gain was not consistent in the experimental group, there were no significant differences in the prostate weight and serum androgen level between groups. In summary, when a soy-extracted genistein and daidzein-rich isoflavone mixture was administered orally into rats, prostatic inflammation with characteristic lobe specificity developed. The present method of inducing prostatitis seems to be a more physiologic than an estrogen-induced experimental model, and sequential pharmacokinetic studies might help in establishing this model as a more valuable tool in assisting future research in this field.

Influence of buffer composition and sample pretreatment on efficiency separation for monitoring neuropeptides in plasma using capillary electrophoresis

More efficient and faster separation conditions for qualitative as well as quantitative analysis of neuropeptides in human plasma using capillary zone electrophoresis (CZE) have been developed. The analysis method for neuropeptides has been improved specifically to study thyroid hormone related neuropetides for the regulation of thyroid disease. In this study, we investigated the pretreatment methods, composition of the running buffer and rinsing procedures between runs in order to obtain more sensitive and faster separation of trace neuropeptides in plasma by CZE. The tested neuropeptides were somatostatin (SOMA), vasopressin (VP), neurotensin (NT), and thyrotropin-releasing hormone (TRH). Plasma samples were pretreated by deproteinization and solid-phase extraction method. The fraction of neuropeptides was reconstituted in 40% acetonitrile followed by ultrafiltration, and then analyzed by CZE. Resolution and sensitivity was improved using the separation buffer composition with 100 mM Tris-phosphate buffer (pH 2.0) while the sensitivity was further improved via a stacking method using the sample buffer of 40% acetonitrile. These sample pretreatment methods and buffer condition permit quantitative analysis on tested neuropeptides at the 20 ng/mL level. The rinsing procedures between runs using 90% ethanol dramatically shortened the rinsing time to 30 min.

Measurement of testosterone and pregnenolone in nails using gas chromatography-mass spectrometry

An efficient method for the determination of testosterone and pregnenolone in human nails using gas chromatography-mass spectrometry (GC-MS) with d3-testosterone as an internal standard is described. The method involves alkaline digestion and liquid-liquid extraction, with subsequent conversion to mixed pentafluoropenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive analysis in the selected-ion monitoring (SIM) mode. The limit of detection (LOD) and limit of quantification (LOQ) were lowered to 0.1 and 0.2 pg/g, respectively, when 100 mg of nail-clippings were used. The mean recoveries of testosterone and pregnenolone were 89.8 and 86.7%, respectively, while good overall precision (% C.V.; 4.5-9.5) and accuracy (% bias; 3.9-8.4) were demonstrated. Linearity as a correlation coefficient was 0.9913 (testosterone) and 0.9965 (pregnenolone). When applied to fingernail and toenail samples from seven healthy men and nine healthy women, testosterone and pregnenolone were positively detected in the concentration range of 0.24-5.80 ng/g. The levels of two steroids studied in the nails were found to be higher in the male subjects than in the female subjects, and except for the toenails of the females, the levels of testosterone were higher than those of pregnenolone.

Differential inhibition of progesterone synthesis in bovine luteal cells by estrogens and androgens

We investigated the roles of estrogens and androgens in the progesterone biosynthesis of bovine luteal cells. The responsiveness of primary luteal cells to the stimulation of tropic agents was observed in a dose-dependent manner. Estrogens and androgens significantly inhibited tropic agent-induced progesterone secretions, but glucocorticoids did not, which indicated the inhibitions were specific. The failure of exogenous 8-Br-cAMP to prevent these inhibitions suggested that took place at the post-cAMP steps. The immunoblot showed that testosterone remarkably decreased the amount of induced P450scc protein after 6-hour treatment, yet 17beta-estradiol did not. The 3beta-HSD activity assays demonstrated that both 17beta-estradiol and testosterone efficiently blocked induced 3beta-HSD activities. Both inhibitory effects of E2 and T on progesterone synthesis were observed one hour after treatment and accompanied with suppressed 3beta-HSD activities. This study presents that estrogens and androgens specifically inhibit bovine luteal function through different mechanisms.

N-isobutyloxycarbonylation for improved detection of 3'-hydroxystanozolol and its 17-epimer in doping control

An improved screening method was developed for 3'-hydroxystanozolol and its 17-epimer in human urine involving gas chromatography-mass spectrometry (GC-MS) with N-isobutyloxycarbonyl (isoBOC) and O-trimethylsilyl (TMS) derivatization. A procedure was reported previously for the pentane extraction of many steroids from urine in doping control, but it was not suitable for the detection of stanozolol metabolites. Compared with the n-pentane extraction method, which gave a poor recovery (< 10%), isoBOC extraction resulted in a good recovery (> 80%). The sensitivity and specificity of mixed N-isoBOC-O-TMS derivatization were adequate for the detection of 3'-hydroxystanozolol and its 17-epimer when 3 ml of urine was used with spiking at a level of 2 ng ml-1. When applied to a stanozolol-positive urine sample, the proposed method allowed rapid and sensitive screening for the detection of 3'-hydroxystanozolol and its 17-epimer.

Regulation of steroidogenesis in transgenic mice and zebrafish

Steroid hormones are important physiological regulators in the body. Steroid hormones are mainly synthesized in the adrenal and gonads. Their synthesis is stimulated by pituitary hormones through cAMP as an intracellular mediator. The first and rate-limiting step for steroid biosynthesis is catalyzed by CYP11A1. Important regulatory elements for the control of the CYP11A1 gene expression have been characterized both in vitro and in vivo. The SF-1-binding sites are cis-acting elements controlling the basal and cAMP-stimulated gene expression. Our transgenic mouse studies showed that the 2.3kb promoter contains information controlling developmentally regulated gene expression. Finally, we present our results on the cloning of steroidogenic genes in zebrafish, a new model organism for genetic studies.