Luana Torres Melo

Purpose Operative approach in total hip arthroplasty (THA) has long been a topic of debate with each approach having unique benefits and disadvantages. One purported benefit of an anterior approach to THA is that it allows for intraoperative positioning using fluoroscopy rather than manual positioning. Proper positioning allows for improved outcomes including leg length discrepancy and acetabular component angle. This study aims to examine if operative approach and use of imaging in intraoperative positioning impact LLD and cup angle post-operatively. Methods A total of 300 hips were enrolled in the study with 100 hips per approach (anterior with fluoroscopy, lateral, and posterior). Retrospective chart review was conducted to assess patient demographics and radiographic analysis used to determine LLD and acetabular cup angle. Results Of the three groups, those receiving anterior approach THAs were on average older than those in the posterior group. Analysis comparing the LLD and acetabular angle across the three groups showed no statistically significant difference in LLD (p=0.091); this was also reflected when comparing hips that received fluoroscopy with those that did not (p=0.91). For acetabular angle, while no difference existed when comparing hips that received imaging versus those that did not, statistically significant differences were observed when comparing the three intraoperative approaches (p<0.0001). Conclusions Neither intraoperative approach nor the use of intraoperative imaging in THA has a statistically significant effect on LLD post-operatively. However, approach did impact the acetabular cup angle across all three distinct approaches.

Background: This study investigated dyspnoea intensity and respiratory muscle ultrasound early after extubation to predict extubation failure.Methods: The study was conducted prospectively in two intensive care units in France and Canada. Patients intubated for at least 48 h were studied within 2 h after an extubation following a successful spontaneous breathing trial. Dyspnoea was evaluated by a dyspnoea visual analogue scale (Dyspnoea-VAS) ranging from 0 to 10 and the Intensive Care Respiratory Distress Observational Scale (IC-RDOS). The ultrasound thickening fraction of the parasternal intercostal and the diaphragm was measured; limb muscle strength was evaluated using the Medical Research Council (MRC) score (range 0–60).Results: Extubation failure occurred in 21 out of 122 enrolled patients (17%). The median (interquartile range (IQR)) Dyspnoea-VAS and IC-RDOS were higher in patients with extubation failureversussuccess: 7 (4–9)versus3 (1–5) (pversus1.7 (1.5–2.1) (pversus0.3 (0.2–0.5) (pversus52 (44–60) (p=0.012), respectively. The thickening fraction of the parasternal intercostal and its ratio to diaphragm thickening showed the highest area under the receiver operating characteristic curve (AUC) for an early prediction of extubation failure (0.81). AUCs of Dyspnoea-VAS and IC-RDOS reached 0.78 and 0.74, respectively.Conclusions: Respiratory muscle ultrasound and dyspnoea measured within 2 h after extubation predict subsequent extubation failure.

Background: Decreased oxygenation of muscle may be accentuated during exercise at high altitude. Monitoring the oxygen saturation of muscle (SmO₂) during hand grip exercise using near infrared spectroscopy during acute exposure to hypoxia could provide a model for a test of muscle performance without the competing cardiovascular stresses that occur during a cycle ergometer or treadmill test. The purpose of this study was to examine and compare acute exposure to normobaric hypoxia versus normoxia on deoxygenation and recruitment of the flexor digitorum superficialis (FDS) during submaximal intermittent handgrip exercise (HGE) in healthy adults. Methods: Twenty subjects (11 M/9 F) performed HGE at 50% of maximum voluntary contraction, with a duty cycle of 2 s:1 s until task failure on two occasions one week apart, randomly assigned to normobaric hypoxia (FiO₂ = 12%) or normoxia (FiO₂ = 21%). Near-infrared spectroscopy monitored SmO₂, oxygenated (O₂Hb), deoxygenated (HHb), and total hemoglobin (tHb) over the FDS. Surface electromyography derived root mean square and mean power frequency of the FDS. Results: Hypoxic compared to normoxic HGE induced a lower FDS SmO₂ (63.8 ± 2.2 vs. 69.0 ± 1.5, p = 0.001) and both protocols decreased FDS SmO₂ from baseline to task failure. FDS mean power frequency was lower during hypoxic compared to normoxic HGE (64.0 ± 1.4 vs. 68.2 ± 2.0 Hz, p = 0.04) and both decreased mean power frequency from the first contractions to task failure (p = 0.000). Under both hypoxia and normoxia, HHb, tHb and root mean square increased from baseline to task failure whereas O₂Hb decreased and then increased during HGE. Arterial oxygen saturation via pulse oximetry (SpO₂) was lower during hypoxia compared to normoxia conditions (p = 0.000) and heart rate and diastolic blood pressure only demonstrated small increases. Task durations and the tension-time index of HGE did not differ between normoxic and hypoxic trials. Conclusion: Hypoxic compared to normoxic HGE decreased SmO₂ and induced lower mean power frequency in the FDS, during repetitive hand grip exercise however did not result in differences in task durations or tension-time indices. The fiber type composition of FDS, and high duty cycle and intensity may have contributed greater dependence on anaerobiosis.

Objectives: Compare acute complication and mortality rates of geriatric patients with acetabular fractures (AFs) matched to hip fractures (HFs). Design: Retrospective cohort study. Setting: American College of Surgeons National Surgical Quality Improvement Project. Patients: Using Current Procedural Terminology codes, the American College of Surgeons National Surgical Quality Improvement Project registry was used to identify all patients ≥60 years from 2011 to 2016 treated for AFs undergoing open reduction internal fixation (ORIF) and HFs (undergoing ORIF, hemiarthroplasty, or cephalomedullary nail). Outcome Measurements: Patient characteristics, comorbidities, functional status, acute complications, and mortality rates were recorded. Patients were matched 1:5 (AF:HF). Chi-square, Fisher exact, and Mann–Whitney U tests were used to compare groups, and multivariable logistic regression was used to compare the risk of complications or death while adjusting for relevant covariates. Results: A total of 303 AF patients (age: 78.2 ± 9.2 years/59.7% females/27.1% wall, 28.4% one column and 45.2% 2 columns ORIF) were matched to 1511 HF patients (age: 78.3 ± 9.1 years/60.2% females/37.2% hemiarthroplasty, 16.3% ORIF and 47.4% cephalomedullary nail). Length of stay (8.4 ± 7.1 vs. 6.4 ± 5.9 days) and time to surgery [(TS) 2.3 ± 1.8 versus 1.2 ± 1.4 days] were longer in the AF group (P < 0.01). Unadjusted mortality rates were nonsignificantly higher for AFs versus HFs (6.6% vs. 4.6%, P = 0.14). After covariable adjustment, the risk of mortality was significantly higher for AFs versus HFs (odds ratio: 1.89, 95% confidence interval: 1.07–3.35). Conclusion: Geriatric AFs pose a significantly higher adjusted mortality risk when compared with HF patients. Strategies to mitigate risk factors in this population are warranted. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Purpose: This study aimed to compare muscle activation of the diaphragm (DIA), scalenes (SA), parasternal intercostals (PS), and sternomastoid (SM) during submaximal intermittent neck flexion (INF) versus submaximal inspiratory threshold loading (ITL) until task failure in healthy adults. Methods: Twelve healthy adults performed submaximal ITL or INF tests in random order for 2 d. Surface electromyography was monitored to acquire root mean square (RMS) and median power frequency (MPF) from the SA, PS, SM, and DIA. Maximal inspiratory pressures and maximal voluntary contraction for neck flexion were determined. Next, participants performed the first submaximal test—ITL or INF—targeting 50% ± 5% of the maximal inspiratory pressure or maximal voluntary contraction, respectively, until task failure. After a rest, they performed the other test until task failure. Two days later, they performed ITL and INF but in the opposite order. The Borg scale assessed breathlessness and perceived exertion. Results: Endurance times for ITL and INF were 38.1 and 26.3 min, respectively. INF activated three of four inspiratory muscles at higher average RMS (PS, SM, and SA) and at different MPF (PS, SM, and DIA but not SA) compared with ITL. During ITL, RMS did not change in the four inspiratory muscles over time, but MPF decreased in PS, SM, and SA (P < 0.04). In contrast, RMS increased in three of four inspiratory muscles (SM, PS, and SA) during INF, but MPF did not change throughout its duration. Borg rating was 3.9-fold greater than ITL compared with INF. Conclusion: At a similar percentage of maximal load, INF evokes greater activation of primary muscles of inspiration (PS and SA) and a major accessory muscle of inspiration (SM) compared with ITL during a prolonged submaximal protocol.

Background: There is a paucity of research regarding the relationship between anemia and postoperative morbidity and mortality among geriatric patients presenting with hip fracture. The objective of this study was to determine the effect of anemia at presentation on 30-day morbidity and mortality among geriatric patients with hip fracture. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all hip fracture patients ≥60 years old from 2011 to 2016. Included were all emergency unilateral, nonpathological hip fractures (femoral neck, intertrochanteric, or subtrochanteric) treated with arthroplasty, intramedullary nailing, or open reduction and internal fixation. Anemia was classified as a hematocrit (HCT) level of <0.41 and <0.36 for male and female patients, respectively. Age, body mass index (BMI), race, comorbidities, smoking status, American Society of Anesthesiologists (ASA) class, baseline functional status, time to surgery, operative time, anesthesia type, need for transfusion, fixation method, length of stay (LOS), and discharge destination were collected. Our primary outcome of interest was 30-day postoperative mortality, with all-cause readmission and any postoperative ischemic events (cerebrovascular accident [CVA] and myocardial infarction [MI]) analyzed as secondary outcomes. A multivariable regression analysis was performed and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated while controlling for confounding variables. Results: Of 34,805 patients identified, 22,469 (65%) were anemic at presentation (63% female; mean age, 80 ± 8 years), while 12,336 (35%) were non-anemic (85% female; mean age, 79 ± 8 years). Anemia at presentation was independently associated with higher odds of mortality (OR,1.3 [95% CI, 1.1 to 1.5]) and readmission (OR, 1.2 [95% CI, 1.1 to 1.3]), while no relationship was observed for MI (OR, 1.1 [95% CI, 0.9 to 1.4]) or CVA (OR, 0.8 [95% CI, 0.6 to 1.1]). Conclusions: Our findings suggest that anemia at presentation is associated with greater 30-day postoperative morbidity and mortality in geriatric hip fracture patients. Additional research should focus on elucidating this modifiable risk factor and advancing the preoperative optimization of hip fracture patients. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: The ideal bearing combination for total hip arthroplasty (THA) remains debatable. Highly cross-linked polyethylene (XLPE) is widely used, but long-term wear rates are not fully known, nor is how much the initial “creep,” if any, affects overall wear. Additionally, the use of oxidized zirconium (OxZir) is purported to lower polyethylene wear rates, but this has not been proven. We present the 10-year data of a cohort of patients who underwent THA. Patients were prospectively randomized to 1 of 4 bearing combinations: a conventional ultra-high molecular weight polyethylene (UHMWPE) or XLPE acetabular liner coupled with either a cobalt-chromium (CoCr) or OxZir femoral head. The aims of the study were to (1) assess the extent to which creep affected overall wear rates and (2) assess wear rates between OxZir and CoCr with polyethylene. Methods: A total of 92 hips (92 patients) between the ages of 22 and 65 years (mean, 52.2 ± 9.3 years) were randomized to 4 groups. At 10 years, 70 (76%) of the hips were available for analysis; patients who had undergone revision, had died, or were lost to follow-up were excluded from final analysis. Radiographic analysis was performed using a validated digital assessment program to determine linear, volumetric, and directional wear of the polyethylene for all 4 bearing couples. Radiographic assessments were performed immediately postoperatively, at 6 and 12 weeks, and then annually for a minimum of 10 years. Results: XLPE had significantly lower wear rates than UHMWPE. Once creep was eliminated, annual and overall wear rates were nearly 50% lower than have been previously reported. This was proportionally more important in the XLPE group than in the UHMWPE group. There was a nonsignificant trend toward a lower wear rate with OxZir heads. Conclusions: Creep plays a notably more important role than first thought. Once creep was eliminated, the overall wear rate was even lower than previously assumed. This has important implications for the overall survivorship of hip arthroplasty implants. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.