Sjogren’s Syndrome is associated with higher healthcare utilization after primary hip, but not primary knee arthroplasty: A U.S. cohort study

Objective: To assess whether Sjogren’s Syndrome (SS) is associated with outcomes after total knee or hip arthroplasty (TKA/THA). Methods: We used the 1998-2014 U.S. National Inpatient Sample data. We performed multivariable-adjusted logistic regression analyses to assess the association of SS with healthcare utilization (hospital charges, length of hospital stay, discharge to non-home setting), and in-hospital complications (implant infection, revision, transfusion, mortality), controlling for important covariates and confounders. In sensitivity analyses, we additionally adjusted the main models for hospital location/teaching status, bed size, and region . Results: We examined 4,116,485 primary THAs and 8,127,282 primary TKAs performed from 1998-2014; 12,772 (0.2%) primary TKAs and 6,222 (0.2%) primary THAs were done in people with SS. In multivariable-adjusted models, SS was associated with a statistically significant higher odds ratio (OR; 95% confidence interval (CI)) of discharge to a rehabilitation/inpatient facility post-THA, 1.13 (1.00, 1.28), but not post-TKA, 0.93 (0.86, 1.02). We noted no differences in the length of hospital stay or hospital charges. SS was associated with significantly higher adjusted odds of in-hospital transfusion post-THA, 1.37 (1.22, 1.55) and post-TKA, 1.21 (1.10, 1.34). No significant differences by SS diagnosis were seen in hospital stay, hospital charges implant infection, implant revision or mortality rates. Conclusions: People with SS had higher transfusion rate post-TKA/THA, and higher rate of discharge to non-home setting post-THA. The lack of association of SS with post-arthroplasty complications should reassure patients, surgeons and policy-makers about the utility of TKA/THA in people with SS undergoing these procedures.

Sjogren’s Syndrome is associated with higher healthcare utilization after primary hip, but not primary knee arthroplasty: A U.S. cohort study

Objective: To assess whether Sjogren’s Syndrome (SS) is associated with outcomes after total knee or hip arthroplasty (TKA/THA).Methods: We used the 1998-2014 U.S. National Inpatient Sample data. We performed multivariable-adjusted logistic regression analyses to assess the association of SS with healthcare utilization (hospital charges, length of hospital stay, discharge to non-home setting), and in-hospital complications (implant infection, revision, transfusion, mortality), controlling for important covariates and confounders. In sensitivity analyses, we additionally adjusted the main models for hospital location/teaching status, bed size, and region.Results: We examined 4,116,485 primary THAs and 8,127,282 primary TKAs performed from 1998-2014; 12,772 (0.2%) primary TKAs and 6,222 (0.2%) primary THAs were done in people with SS. In multivariable-adjusted models, SS was associated with a statistically significant higher odds ratio (OR; 95% confidence interval (CI)) of discharge to a rehabilitation/inpatient facility post-THA, 1.13 (1.00, 1.28), but not post-TKA, 0.93 (0.86, 1.02). We noted no differences in the length of hospital stay or hospital charges. SS was associated with significantly higher adjusted odds of in-hospital transfusion post-THA, 1.37 (1.22, 1.55) and post-TKA, 1.21 (1.10, 1.34). No significant differences by SS diagnosis were seen in hospital stay, hospital charges implant infection, implant revision or mortality rates.Conclusions: People with SS had higher transfusion rate post-TKA/THA, and higher rate of discharge to non-home setting post-THA. The lack of association of SS with post-arthroplasty complications should reassure patients, surgeons and policy-makers about the utility of TKA/THA in people with SS undergoing these procedures.

Effect of Biomechanical and Anatomic Characteristics on Patient-Reported Outcomes Following Total Hip Arthroplasty

Background and Hypothesis: The success of total hip arthroplasty (THA) is often reported in terms of infection and dislocation rates. While studies have examined the effect of acetabular cup position, anteroposterior (AP) femoral stem alignment, changes in leg length and femoral stem offset on dislocation rates, few studies have investigated the effect of these biomechanical parameters on patient-reported outcome measures (PROMS). The purpose of this study was to evaluate how PROMS may differ by THA component placement in a consecutive series of primary THAs. Awareness of the importance of implant positioning may lead to improved surgical technique and optimized PROMS. Experimental Design or Project Methods: 933 consecutive posterolateral approach primary THAs performed between 2011 and 2018 by one surgeon were retrospectively reviewed. Acetabular cup abduction, femoral stem alignment, changes in leg length and total femoral offset were measured on APview radiographs. Prospectively collected Hip Disability and Osteoarthritis Outcome Score/HOOS Jr., University of California Los Angeles/UCLA Activity Level, and satisfaction (5-point Likert scale) were evaluated at minimum one-year. Results: 743 THAs were analyzed. Mean age and BMI were 64 years and 31 kg/m2, respectively. After multivariate analysis, females with neutral to valgus stem placement (p=0.020) and patients with neutral to valgus stem placement regardless of lumbar pain (p=0.034) were more satisfied. In addition, patients with lumbar pain (p<0.001) and patients with high BMI in combination with increased change in femoral offset (p=0.056) had lower overall HOOS Jr. scores. Interestingly, change in leg length was not a significant predictor of any PROMS (power [1-β]≥88.4%). Conclusion and Potential Impact: AP stem alignment may play a role in increased activity level and satisfaction. In addition, high BMI in combination with increased change in femoral offset negatively influenced HOOS Jr. scores. Unsurprisingly, the presence of lumbar pain continues to negatively affect PROMS. Further research is warranted on the influence of THA component placement, spinopelvic parameters, and PROMS.

Relative Contribution of Acetabular and Femoral Reconstruction to Prosthetic Joint Instability Risk after Primary Total Hip Arthroplasty

Prosthetic joint instability is a challenging concern for a minority of total hip arthroplasty (THA) patients. Placement of the acetabular component within the traditional safe zone does not eliminate dislocation, and the relative contribution of femoral length and offset to instability risk has not been well defined. The authors compared 53 dislocated primary THAs treated against an age- and gender-matched cohort of 134 stable primary THAs. Anteroposterior and cross-table lateral radiographs were used to determine whether reconstructions met targets for acetabular inclination (30–50 degrees), acetabular anteversion (5–30 degrees), femoral length (0–9.9 mm) and femoral offset (0–9.9 mm). Statistical analysis was performed to assess univariate and multivariate relationships with an instability event; statistical significance was set using a two-sided p-value < 0.05. Forty-seven (88.7%) of the dislocating hips had nonoptimal acetabular or femoral reconstructions. While a similar proportion of patients in the study and control groups had acetabular reconstruction within the safe zone (51.5 vs. 47.2%, p = 0.63) patients with unstable hips were more likely to have acetabular component inclination outside of the target zone (30.2 vs. 7.5%, p < 0.01), acetabular anteversion < 15 degrees (30.2 vs. 3.7%, p < 0.0001), reduced femoral length (35.9 vs. 3.7%, p < 0.0001), and reduced femoral offset (41.5 vs. 7.46%, p < 0.0001). Stepwise multivariate logistic regression was performed and identified femoral head size less than 32 mm (OR 2.9, 95% CI 1.4–6.2) and higher inclination angle (OR 1.1, 95% CI 1.04–1.2) as significant independent risk factors for hip instability. The authors' study findings suggest that insufficient acetabular anteversion, femoral length, and femoral offset reconstruction contribute significantly to instability risk following THA. Using a larger femoral head is protective, but should be balanced against long-term volumetric wear risk.

Uniformly low serum cobalt levels after modular dual-mobility total hip arthroplasties with ceramic heads

Aims Modular dual-mobility constructs reduce the risk of dislocation after revision total hip arthroplasty (THA). However, questions about metal ions from the cobalt-chromium (CoCr) liner persist, and are particularly germane to patients being revised for adverse local tissue reactions (ALTR) to metal. We determined the early- to mid-term serum Co and Cr levels after modular dual-mobility components were used in revision and complex primary THAs, and specifically included patients revised for ALTR. Patients and Methods Serum Co and Cr levels were measured prospectively in 24 patients with a modular dual-mobility construct and a ceramic femoral head. Patients with CoCr heads or contralateral THAs with CoCr heads were excluded. The mean age was 63 years (35 to 83), with 13 patients (54%) being female. The mean follow-up was four years (2 to 7). Indications for modular dual-mobility were prosthetic joint infection treated with two-stage exchange and subsequent reimplantation (n = 8), ALTR revision (n = 7), complex primary THA (n = 7), recurrent instability (n = 1), and periprosthetic femoral fracture (n = 1). The mean preoperative Co and Cr in patients revised for an ALTR were 29.7 μg/l (2 to 146) and 21.5 μg/l (1 to 113), respectively. Results Mean Co and Cr levels were 0.30 μg/l and 0.76 μg/l, respectively, at the most recent follow-up. No patient had a Co level ≥ 1 μg/l. Only one patient had a Cr level ≥ 1 μg/l. That patient’s Cr level was 12 μg/l at 57 months after revision THA for ALTR (and decreased ten-fold from a preoperative Cr of 113 μg/l). Conclusion At a mean of four years, no patient with a modular dual-mobility construct and ceramic femoral head had elevated Co levels, including seven patients revised specifically for ALTR. While further studies are required, we support the selective use of a modular dual-mobility construct in revision and complex primary THAs for patients at high risk for instability. Cite this article: Bone Joint J 2019;101-B(6 Supple B):57–61.

Is computerised 3D templating more accurate than 2D templating to predict size of components in primary total hip arthroplasty?

Introduction: The aim of this study was to compare the accuracy of preoperative templating in total hip arthroplasty (THA) using conventional 2-dimensional (2D) and computed tomography (CT)-based 3-dimensional (3D) measures. Methods: One hundred and sixteen consecutive primary THAs were analysed. The preoperative diagnosis was primary osteoarthritis in all cases. The 2D templating and the 3D templating were performed by two different residents. All templating results were available for the orthopaedic surgeon performing the procedure. Accuracies with regard to the predicted and actual implant sizes were determined for each procedure. Implantation of the size as planned was defined as “exact”, whereas the use of components within one size larger or smaller (±1) as planned were defined as “accurate.” Results: The 3D templating was significantly more accurate in predicting implant sizing compared to 2D templating for primary total hip arthroplasty (THA). The difference was statistically significant for the cup templating (‘‘exact’’ p = 0.02; ‘‘accurate’’ p = 0.01) and for the stem templating (‘‘exact’’ p = 0.04; ‘‘accurate’’ p = 0.01). Conclusion: Our results support the superiority of 3D templating over 2D templating in predicting implant size.

Decline in allogeneic blood transfusion usage in total hip arthroplasty patients: National Inpatient Sample 2009 to 2013

Introduction: Although total hip arthroplasty (THA) is an effective treatment for end-stage arthritis, it is also associated with substantial blood loss that may require allogeneic blood transfusion. However, these transfusions may increase the risk of certain complications. The purpose of our study is to evaluate: (i) the incidence/trends of allogeneic blood transfusion; (ii) the associated risk factors and adverse events; and (iii) the discharge disposition, length of stay (LOS), and costs for these patients between 2009 and 2013. Methods: The National Inpatient Sample database was used to identify 1,542,366 primary THAs performed between 2009 and 2013. Patients were stratified based on demographics, economic data, hospital characteristics, comorbidities, and whether or not allogeneic transfusion was received. Logistic regression was performed to evaluate the risk factors for transfusion and postoperative complications. Results: From 2009 to 2013, allogeneic transfusions were used in 16.9% of primary THAs, with a declining annual incidence. Except for obesity, all comorbidities were associated with increased likelihood of receiving a transfusion. Allogeneic transfusion patients were more likely to experience surgical site infections or pulmonary complications (p<0.001 for all). These patients were more likely to be discharged to a short-term care facility (p<0.001). Additionally, they had a greater mean LOS (p<0.001) and higher median hospital costs and charges when compared to their non-transfused counterparts. Conclusions: While the observed decline in allogeneic transfusion usage is encouraging, further efforts should focus on preoperative patient optimisation. Given the projected increase in demand for primary THAs, orthopaedic surgeons must be familiar with safe and effective blood conservation protocols.

Clinical Predictors for Possible Failure after Total Hip Arthroplasty

Introduction With the rising number of total hip arthroplasties (THAs) each year, it is increasingly important for surgeons to have evidence-based information on which to determine how often patients should be examined postoperatively. The purpose of this research was to determine whether it is possible to identify – based on Harris Hip Score (HHS) – early signs or predictors of THA failure so that methods of postoperative follow-up can be scheduled in advance of the time frame indicated by those predictors of failure. Methods The HHS of 9,949 primary THAs performed from 1973 to 2012 was reviewed retrospectively to identify the clinical predictors of failure. 1,131 hips were completely lost to follow-up, leaving 8,331 primary THAs in 6,979 patients. Time to failure was recorded with Kaplan-Meier analysis performed with aseptic loosening or revision of any component as the endpoint. Results Regression analysis revealed that a pain score of 30 or less at any time of follow-up (p<0.0001) was a significant risk and strongly indicative of later failing. A low distance walked score of 5 or less at 6 months (p = 0.0087) and 1 year (p = 0.0167) served as an early predictor of future failure. A lower stairs score of 2 or less was also an early predictor at 1 year (p = 0.0343) and at 3 years (p = 0.0245). A lower limp score of 8 or less was a mid-term predictor at 3 (p = 0.0001), 5 (p = 0.0002), 7 (p = 0.0191) and 10 (0.0028) years postoperative follow-up. Conclusions Pain, walk, stairs and limp scores are predictive of THA failure. Surgeons with patients who present with these indicators should optimise postoperative follow-ups to alert their patients.