Abstract Pelvic tilt (PT) affects the functional anteversion and inclination of acetabular components in total hip arthroplasty (THA). One-hundred and thirty-eight consecutive patients who underwent ...unilateral primary THA were reviewed. Most cases had some degree of pre-operative PT, with 17% having greater than 10° of PT on standing pre-operative radiographs. There was no significant change in PT following THA. A computer model of a hemispheric acetabular component implanted in a range of anatomic positions in a pelvis with varying PT was created to determine the effects of PT on functional anteversion and inclination. Based on the study results, tilt-adjustment of the acetabular component position based on standing pre-operative imaging will likely improve functional component position in most patients undergoing THA.
Abstract Background Obesity is frequently associated with complications following total hip arthroplasty (THA), and is often concomitant with malnutrition. The purpose of this study was to ...investigate the independent morbidity risk of malnutrition relative to obesity. Methods The National Surgical Quality Improvement Program from 2005-2013 was queried for elective primary THA cases. Malnutrition was defined as albumin <3.5 g/dL. Propensity scores for having preoperative albumin data were determined from demographics, body mass index (BMI), and overall comorbidity burden. Patients were classified as non-obese (BMI 18.5-29.9), obese I (30-34.9), obese II (35-39.9), or obese III (≥40). Complications were compared across nutritional and obesity classes. Multivariable propensity-adjusted logistic regressions were used to examine associations between obesity and malnutrition with thirty-day outcomes. Results 40,653 THA cases were identified, of which 20,210 (49.7%) had preoperative albumin measurements. Propensity score adjustment successfully reduced potential selection bias, with p >0.05 for differences between those with and without albumin data. Malnutrition incidence increased from 2.8% in obese I to 5.7% in obese III patients. With multivariable propensity-adjusted logistic regression, malnutrition was a more robust predictor than any obesity class for any postoperative complication(s) (odds ratio OR 1.61, 95% confidence interval CI 1.25-2.08), major complications (OR 1.63, 95% CI 1.21-2.19), respiratory complications (OR 2.35, 95% CI 1.27-4.37), blood transfusions (OR 1.71, 95% CI 1.44-2.03), and extended length of stay (OR 1.35, 95% CI 1.14-1.59). Conclusion Malnutrition incidence increased significantly from obese I to obese III patients, and was a stronger and more consistent predictor than obesity of complications following THA.
Abstract The aims of this study were to assess damage on the surface of retrieved oxidized zirconium (OxZr) metal femoral heads, to measure surface roughness of scratches, and to evaluate the extent ...of surface effacement using scanning electron microscopy (SEM). Ceramic zirconia-toughened alumina heads were analyzed for comparison. OxZr femoral heads explanted for recurrent dislocation had the most severe damage ( P < 0.001). The median surface roughness of damaged OxZr femoral heads was 1.49 μm, compared to 0.084 μm for damaged ceramic heads and 0.052 μm for undamaged OxZr ( P < 0.001). This may be of clinical concern because increased surface roughness has the potential to increase the wear of polyethylene liners articulating against these OxZr heads in THA.
Abstract Background Discharge destination, either home or skilled care facility, after total knee arthroplasty (TKA) may be associated with significant variation in post-acute care outcomes. The ...purpose of this study was to characterize the 30-day post-discharge outcomes after primary TKA relative to discharge destination. Methods All primary unilateral TKAs performed for osteoarthritis from 2011-2014 were identified in the National Surgical Quality Improvement Program database. Propensity scores based on pre-discharge characteristics were used to adjust for selection bias in discharge destination. Propensity-adjusted multivariable logistic regressions were used to examine associations between discharge destination and post-discharge complications. Results Among 101,256 primary TKAs identified, 70,628 were discharged home and 30,628 to skilled care facilities. Patients discharged to facilities were more frequently were female, older, higher body mass index class, higher Charlson comorbidity index and American Society of Anesthesiologists scores, had pre-discharge complications, received general anesthesia, and classified as non-independent preoperatively. Propensity adjustment accounted for this selection bias. Patients discharged to skilled care facilities after TKA had higher odds of any major complication (odds ratio OR=1.25; 95% confidence interval CI, 1.13-1.37) and readmission (OR=1.81; 95% CI, 1.50-2.18). Skilled care was associated with increased odds for respiratory, septic, thromboembolic and urinary complications. Associations with death, cardiac and wound complications were not significant. Conclusion After controlling for pre-discharge characteristics, discharge to skilled care facilities versus home after primary TKA is associated with higher odds of numerous complications and unplanned readmission. These results support coordination of care pathways to facilitate home discharge after hospitalization for TKA whenever possible.
Abstract Background Surgery produces a rapid rise in interleukin 6 (IL-6) which may increase the risk of deep vein thrombosis and medical complications. Perioperative corticosteroids suppress IL-6 ...release in patients undergoing total knee arthroplasty. This study evaluates the effects of a perioperative corticosteroid regimen on IL-6 formation, thrombogenesis, fibrinolysis, and clinical outcomes in patients undergoing unilateral, uncemented, total hip arthroplasty. Methods Twenty-seven patients (14 placebo and 13 study) were enrolled in this randomized, double-blind, placebo-controlled trial. The study group received 20 mg of prednisone orally followed by 2 doses of intravenous hydrocortisone, each 8 hours apart. Blood was drawn at several time points for IL-6, prothrombin fragment 1.2, and plasmin-alpha-2-antiplasmin complex, a marker of fibrinolysis. In-hospital visual analog pain (visual analog scale) scores, patient-controlled analgesia use, and ability to climb stairs were recorded. Results Mean serum IL-6 levels at 6 and 24 hours postoperatively were significantly lower for the study group, whereas serum prothrombin fragment 1.2 and plasmin-alpha-2-antiplasmin were not statistically different at any study time point. Average pain scores were similar ( P > .05), but study group experience less severe pain ( P < .01) and less patient-controlled analgesia ( P = .02). At 3 months, 4 patients in the placebo and 1 patient in the study group had difficulty going up and down staircases ( P = .08). Conclusion The use of corticosteroids was associated with a statistically significant decrease in IL-6 at 6 and 24 hours postoperatively but did not affect thrombogenic markers. The study group had improved postoperative analgesia and a trend toward improved functional outcome at 3 months postoperatively.
Abstract Background The severity and location of adverse local tissue reaction seen in metal-on-polyethylene (MoP) total hip arthroplasty (THA) is not well described. Methods We retrospectively ...reviewed the records of patients who underwent a revision THA using our biomechanics database. We included all patients who underwent revision surgery for the diagnosis of ALTR with THA implants that had modularity solely at the head-neck junction and excluded patients with implant modularity at sites other than the head-neck junction. Magnetic resonance imaging (MRI) was evaluated by a fellowship trained radiologist who specializes in evaluating metal artifact reducing MRI sequences in order to quantify the ALTR lesions. Histology was evaluated for findings of ALTR using the Campbell score. Results We identified eleven patients in the database. Eight patients had a MRI ALTR grade of severe and seven did based on the histology score. The mean synovial volume was 218,658 mm3 (range 23,461-451,435 mm3) with a mean maximal synovial thickness of 15.3 mm (range 3-34.3 mm). A disruptive infiltration of the abductors due to pseudocapsule invasion was seen in 67% of the patients with three not having abductor involvement. Mean preoperative cobalt and chromium levels were 5.4 ppb (range 1-12.3) and 1.1 ppb (range 0.6-2.4) respectively. Conclusion Patients with ALTR from head-neck junction corrosion in MoP THA may present with large pseudotumors that have previously been under appreciated. Mean preoperative serum cobalt and chromium ion levels remained relatively low, and MRI was an effective way to characterize the size and location of these lesions.
Abstract Background The recent experiences with adverse local tissue reactions have highlighted the need to establish what are normal serum levels of cobalt (Co), chromium (Cr), and titanium (Ti) ...after hip arthroplasty. Methods Serum Co, Cr, and Ti levels were measured in 80 nonconsecutive patients with well-functioning unilateral total hip arthroplasty and compared among 4 bearing surfaces: ceramic-on-ceramic (CoC); ceramic-on-polyethylene (CoP); metal-on-polyethylene (MoP), and dual mobility (DM). The preoperative and most recent University of California, Los Angeles (UCLA) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were compared among the different bearing surfaces. Results No significant difference was found among serum Co and Cr levels between the 4 bearing surface groups ( P = .0609 and P = .1577). Secondary analysis comparing metal and ceramic femoral heads demonstrated that the metal group (MoP, modular dual mobility (Stryker Orthopedics, Mahwah, NJ) metal) had significant higher serum Co levels compared with the ceramic group (CoC, CoP, MDM ceramic) (1.05 mg/L ± 1.25 vs 0.59 mg/L ± 0.24; P = .0411). Spearman coefficient identified no correlation between metal ion levels and patient-reported outcome scores. Conclusion No serum metal ion level differences were found among well-functioning total hip arthroplasty with modern bearing couples. Significantly higher serum Co levels were seen when comparing metal vs ceramic femoral heads in this study and warrants further investigation. Metal ion levels did not correlate with patient-reported outcome measures.
Abstract Background Significant variability exists across orthopedic surgeons in the management of the displaced femoral neck fracture in the elderly patient (>75 years old). These patients tend to ...be less healthy, have inferior bone quality, and gait instability leading to increased risk of periprosthetic fracture, compromised implant fixation, dislocation, and need for revision. The surgeon’s goals should be to restore mobility while eliminating pain and need for reoperation. Methods In this review article, we examine the best available evidence in the literature to determine which strategy achieves optimal outcomes. We examine outcome studies comparing use of hemiarthroplasty and total hip arthroplasty, unipolar and bipolar hemiarthroplasty, and cemented vs cementless fixation of femoral stems. Results and Conclusions For the active, healthy, and lucid patient, or one who has preexisting groin pain, who sustains a displaced femoral neck fracture, the literature supports a total hip arthroplasty. Patients sustaining a displaced femoral neck fracture and who are less active, have decreased bone mass, and are at increased risk of falls would benefit most from a device that optimally balances the need for revision surgery, restores ambulation, and eliminates pain. Thus, the current evidence favors cemented, unipolar hemiarthroplasty for the dependent osteopenic elderly patient with a displaced femoral neck fracture.
Abstract Ceramic femoral heads have had promising results as a bearing surface in total hip arthroplasty. Our objective was to evaluate a series of retrieved alumina-zirconia composite ceramic ...femoral heads for evidence of the tetragonal to monoclinic zirconia phase transformation, metal transfer and articular surface roughness. Raman spectra showed evidence of the zirconia phase transformation in all retrieved specimens, with distinct monoclinic peaks at 183, 335, 383, and 479 cm − 1 . All components displayed metal transfer. An increase in the zirconia phase transformation was seen with increasing time in vivo. No correlation between extent of zirconia phase transformation and the surface roughness was found. These short-term results suggest that the use of an alumina-zirconia composite ceramic is a viable option for femoral heads in THA.
Abstract Healthcare reorganization and bundled payment schemes have resulted in increased patient travel distances in orthopedics. Travel distance has been previously associated with increased ...complication risk but has yet to be studied in orthopedics. We analyzed the impact of patient travel distance on short-term complications. We reviewed 38,887 TJAs performed between 2008 and 2011 and identified 1606 complications in 1110 procedures. There was no significant association between complication risk and patient travel distance. Complication risk was associated with age, ASA class, Medicare and Medicaid status ( P < 0.0001 for all). Regional centers of excellence appear to be a viable model in healthcare reorganization however continued attention should be paid to attenuating the individual patient factors associated with complication at these institutions.
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