A Comparison of Revision Rates for Dislocation and Aseptic Causes Between Dual Mobility and Large Femoral Head Bearings in Primary Total Hip Arthroplasty With Subanalysis by Acetabular Component Size: An Analysis of 106,163 Primary Total Hip Arthroplasties

BackgroundDual mobility (DM) and large femoral head bearings (≥36 mm) both decrease the risk of dislocation in total hip arthroplasty (THA). There is limited comparable data in primary THA. This study compared the revision rates for dislocation and aseptic causes between DM and large femoral heads and subanalyzed by acetabular component size.MethodsData from the Australian Orthopedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis from January 2008 (the year of first recorded DM use) to December 2019. All DM and large femoral head bearings were identified. The primary outcome measure was the cumulative percent revision (CPR) for dislocation and for all aseptic causes. The results were adjusted by age, sex, and femoral fixation. A subanalysis was performed stratifying acetabular component diameter <58 m and ≥58 mm.ResultsThere were 4942 DM and 101,221 large femoral head bearings recorded. There was no difference in the CPR for dislocation (HR = 0.69 (95% CI 0.42, 1.13), P = .138) or aseptic causes (HR = 0.91 (95% CI 0.70, 1.18), P = .457). When stratified by acetabular component size, DM reduced the CPR for dislocation in acetabular component diameter <58 mm (HR = 0.55 (95% CI 0.30, 1.00), P = .049). There was no difference for diameter ≥58 mm. There was no difference in aseptic revision when stratified by acetabular component diameter.ConclusionThere is no difference in revision rates for dislocation or aseptic causes between DM and large femoral heads in primary THA. When stratified by acetabular component size, DM reduces dislocation for acetabular component diameter <58 mm.Level of EvidenceLevel III.     

Augmented Reality for Acetabular Component Placement in Direct Anterior Total Hip Arthroplasty

BackgroundMalposition of the acetabular component of a hip prosthesis can lead to poor outcomes. Traditional placement with fluoroscopic guidance results in a 35% malpositioning rate. We compared the (1) accuracy and precision of component placement, (2) procedure time, (3) radiation dose, and (4) usability of a novel 3-dimensional augmented reality (AR) guidance system vs standard fluoroscopic guidance for acetabular component placement.MethodsWe simulated component placement using a radiopaque foam pelvis. Cone-beam computed tomographic data and optical data from a red-green-blue-depth camera were coregistered to create the AR environment. Eight orthopedic surgery trainees completed component placement using both methods. We measured component position (inclination, anteversion), procedure time, radiation dose, and usability (System Usability Scale score, Surgical Task Load Index value). Alpha = .05.ResultsCompared with fluoroscopic technique, AR technique was significantly more accurate for achieving target inclination (P = .01) and anteversion (P = .02) and more precise for achieving target anteversion (P < .01). AR technique was faster (mean ± standard deviation, 1.8 ± 0.25 vs 3.9 ± 1.6 minute; P < .01), and participants rated it as significantly easier to use according to both scales (P < .05). Radiation dose was not significantly different between techniques (P = .48).ConclusionA novel 3-dimensional AR guidance system produced more accurate inclination and anteversion and more precise anteversion in the placement of the acetabular component of a hip prosthesis. AR guidance was faster and easier to use than standard fluoroscopic guidance and did not involve greater radiation dose.     

Survival Analysis of Total Hip Arthroplasty for High Hip Dislocation Secondary to Developmental Dysplasia or Septic Arthritis of the Hip

BackgroundThis retrospective study was conducted to know clinical and radiographic outcomes, complication rate, and survival of THA in patients with high hip dislocation secondary to developmental dysplasia(DDH) or septic arthritis of the hip(SSH).MethodsBetween March 2005 and September 2014, there were consecutive series of 53 THAs in patients with a highly dislocated hip secondary to DDH or SSH. Of these, 48 hips (DDH 24 and SSH 24) were reviewed at a mean follow-up of 7.9 years(range, 5.0-14.3 years). The mean age at the time of THA was 39.1 years(range, 18.0-59.0 years).ResultsIntraoperative blood loss, total drainage and blood transfusion amounts, and mean time to greater trochanter union were significantly lower in the DDH group than in the SSH group (P = .001, P = .039 and P = .014, and P = .015, respectively). No significant difference in Kaplan–Meier survivorship was observed between groups (log-rank, P = .343). The survival rates with an endpoint of cup aseptic loosening in cases with a cemented cup at 7.9 and 10 years (68.1% and 60.5%, respectively) were significantly lower than those in cementless cup cases (100%) at the same checkpoints (P = .019)..ConclusionWe found similar clinical outcomes between the DDH and SSH groups. However, due to poor bone quality and a lack of containment, cementless acetabular cups could not be performed in more than 50% of patients. Our experience shows that revision cementless fixation cup was possible due to reconstitution of the acetabulum in cases with failed cemented fixation.     

Rural Hospital Designation Is Associated With Increased Complications and Resource Utilization After Primary Total Hip Arthroplasty: A Matched Case-Control Study

BackgroundAs the prevalence of hip osteoarthritis increases, the demand for total hip arthroplasty (THA) has grown. It is known that patients in rural and urban geographic locations undergo THA at similar rates. This study explores the relationship between geographic location and postoperative outcomes.MethodsIn this retrospective cohort study, the Truven MarketScan database was used to identify patients who underwent primary THA between January 2010 and December 2018. Patients with prior hip fracture, infection, and/or avascular necrosis were excluded. Two cohorts were created based on geographic locations: urban vs rural (rural denotes any incorporated place with fewer than 2500 inhabitants). Age, gender, and obesity were used for one-to-one matching between cohorts. Patient demographics, medical comorbidities, postoperative complications, and resource utilization were statistically compared between the cohorts using multivariate conditional logistic regression.ResultsIn total, 18,712 patients were included for analysis (9356 per cohort). After matching, there were no significant differences in comorbidities between cohorts. The following were more common in rural patients: dislocation within 1 year (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.08-1.41, P < .001), revision within 1 year (OR 1.17, 95% CI 1.05-1.32, P = .027), and prosthetic joint infection (OR 1.14, 95% CI 1.04-1.34, P = .033). Similarly, rural patients had higher odds of 30-day readmission (OR 1.31, 95% CI 1.09-1.56, P = .041), 90-day readmission (OR 1.41, 95% CI 1.26-1.71, P = .023), and extended length of stay (≥3 days; OR 1.52, 95% CI 1.22-1.81, P < .001).ConclusionTHA in rural patients is associated with increased cost, healthcare utilization, and complications compared to urban patients. Standardization between geographic areas could reduce this discrepancy.     

Component Placement in Direct Lateral vs Minimally Invasive Anterior Approach in Total Hip Arthroplasty: Radiographic Outcomes From a Prospective Randomized Controlled Trial

BackgroundEnd-stage coxarthrosis is increasingly common; however, limited evidence exists on the effect of direct lateral approach (DLA) and minimally invasive direct anterior approach (MIDA) on component placement in total hip arthroplasty (THA). We therefore conducted a prospective, randomized controlled trial to determine the component placement in DLA vs MIDA in THA.MethodsBetween January 2012 and June 2013, 164 patients with clinically and radiologically confirmed coxarthrosis aged 20-80 years were randomized to either DLA or MIDA (active comparator). Excluded were patients with previous ipsilateral hip surgery, a body mass index >35 kg/m², and/or mental disability. Primary clinical outcomes have been published elsewhere. Secondary outcomes included radiographic assessment of the acetabular component (cement-mantle thickness, inclination, and anteversion), femoral stem position (varus/valgus and THA index), offset restoration, and leg length discrepancy.ResultsThe mean cement-mantle was significantly thicker in zone 1 in the MIDA group (mean difference = 0.51 mm, 95% confidence interval [CI] 0.09-0.93, P = .018), and the mean degrees of inclination and anteversion were higher in the MIDA group (mean difference = 2.5°, 95% CI 0.3-4.6, P = .023 and mean difference = 3.6°, 95% CI 2.2-5.0, P < .0001, respectively). According to the defined reference range, cup inclination was more often adequate in the DLA group (67.9% (53/78) in the DLA group vs 52.4% (43/82) in the MIDA group, P = .045). There were no differences in frontal or lateral femoral stem position, global offset restoration, or leg length discrepancy.ConclusionIn this population of Norwegian patients with coxarthrosis, radiographic assessment showed limited differences in component placement between MIDA and DLA. The findings suggest that component placement is similar in the 2 surgical approaches.     

The Safety and Efficacy of the Anterior Approach Total Hip Arthroplasty as per Body Mass Index

BackgroundObesity is associated with component malpositioning and increased revision risk after total hip arthroplasty (THA). With anterior approaches (AAs) becoming increasingly popular, the goal of this study was to assess whether clinical outcome post-AA-THA is affected by body mass index (BMI).MethodsThis multicenter, multisurgeon, consecutive case series used a prospective database of 1,784 AA-THAs (1,597 patients) through bikini (n = 1,172) or standard (n = 612) incisions. Mean age was 63 years (range, 20-94 years) and there were 57.5% women, who had a mean follow-up of 2.7 years (range, 2.0-4.1 years). Patients were classified into the following BMI groups: normal (BMI < 25.0; n = 572); overweight (BMI: 25.0-29.9; n = 739); obese (BMI: 30.0-34.9; n = 330); and severely obese (BMI ≥ 35.0; n = 143). Outcomes evaluated included hip reconstruction (inclination/anteversion and leg-length, complications, and revision rates) and patient-reported outcomes including Oxford Hip Scores (OHS).ResultsMean postoperative leg-length difference was 2.0 mm (range: ?17.5 to 39.0) with a mean cup inclination of 34.8° (range, 14.0-58.0°) and anteversion of 20.3° (range, 8.0-38.6°). Radiographic measurements were similar between BMI groups (P = .1-.7). Complication and revision rates were 2.5% and 1.7%, respectively. The most common complications were fracture (0.7%), periprosthetic joint infection (PJI) (0.5%), and dislocation (0.5%). There was no difference in dislocation (P = .885) or fracture rates (P = .588) between BMI groups. There was a higher rate of wound complications (1.8%; P = .053) and PJIs (2.1%; P = .029) among obese and severely obese patients. Wound complications were less common among obese patients with the ‘bikini’ incision (odds ratio 2.7). Preoperative OHS was worse among the severely obese (P < .001), which showed similar improvements (Change in OHS; P = .144).ConclusionAA-THA is a credible option for obese patients, with low dislocation or fracture risk and excellent ability to reconstruct the hip, leading to comparable functional improvements among BMI groups. Obese patients have a higher risk of PJIs. Bikini incision for AA-THA can help minimize the risk of wound complications.     

Total Hip Arthroplasty With Subtrochanteric Shortening Osteotomy in Patients With High Hip Dislocation Secondary to Childhood Septic Arthritis: A Matched Comparative Study With Crowe IV Developmental Dysplasia

BackgroundTotal hip arthroplasty (THA) with subtrochanteric shortening osteotomy (SSO) is performed to manage hips with high dislocations. We compared outcomes of THA with SSO in patients with high hip dislocation resulting from childhood septic arthritis and Crowe IV developmental dysplasia of the hip (DDH).MethodsWe reviewed 60 THAs with SSO performed between May 1996 and December 2013. Thirty-one cases were classified as sequelae of childhood infection and 29 as DDH. Twenty-five hips were selected for each group after the propensity score was matched with preoperative demographics and leg length discrepancy (LLD). Clinical scores, complication and reoperation rates, radiographic results, and survivorships were compared. The mean duration of follow-up was 12.3 (range 5-22) years.ResultsThe average correction in LLD was 2.5 cm for childhood infection and 3.6 cm for DDH (P = .002). The infection group received more transfusions (mean 3.3 vs 2.0 units, P = .002), required more time for union of osteotomy site (mean 6.8 vs 5.2 months, P = .042), and reported lower Harris Hip Score (mean 85.1 vs 91.3, P = .017). Reoperations were performed in 11 (44%) previously infected hips and 3 (12%) DDHs (P = .012). Kaplan-Meier survivorship with an endpoint of revision for any reason was lower in the infection group (83.6%) than in the DDH group (100%) at 10 years (log rank, P = .040).ConclusionTHA with SSO in high hip dislocation secondary to childhood septic arthritis demonstrated less favorable clinical outcomes with increased risks of complication, compared with those performed in Crowe IV DDH with similar degree of chronic dislocation.     

Total Hip Arthroplasty Using Imageless Computer-Assisted Hip Navigation: A Prospective Randomized Study

In a prospective randomized study of two groups of 65 patients each, we compared the acetabular component position when using the imageless navigation system compared to the freehand conventional technique for cementless total hip arthroplasty. The position of the component was determined postoperatively on computed tomographic scans of the pelvis. There was no significant difference for postoperative mean inclination (P = 0.29), but a significant difference for mean postoperative acetabular component anteversion (P = 0.007), for mean deviation of the postoperative anteversion from the target position of 15° (P = 0.02) and for the outliers regarding inclination (P = 0.02) and anteversion (P < 0.05) between the computer-assisted and the freehand-placement group. Our results demonstrate the importance of imageless navigation for the accurate positioning of the acetabular component.     

The Association Between Surgeon Age and Early Surgical Complications of Elective Total Hip Arthroplasty: Propensity-Matched Cohort Study (122,043 Patients)

BackgroundThe aim of this study was to examine the relationship between surgeon age and early surgical complications following primary total hip arthroplasty (THA), within a year, in Ontario, Canada.MethodsIn a propensity-matched cohort, we defined consecutive adults who received their first primary THA for osteoarthritis (2002-2018). We obtained hospital discharge abstracts, patient’s demographics and physician claims. Age of the primary surgeon was determined for each procedure and used as a continuous variable for spline analysis, and as a categorical variable for subsequent matching (young <45; middle-age 45-55; older >55). The primary outcome was early surgical complications (revision, dislocation, infection). Secondary analyses included high-volume vs low-volume surgeons (≤35 THA per year).ResultsWe identified 122,043 THA recipients, 298 surgeons with median age 49 years. Younger, middle-aged, and older surgeons performed 39%, 29%, and 32% THAs, respectively. Middle-aged surgeons had the lowest rate of complications. Younger surgeons had a higher risk of composite complications (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.09-1.44, P = .002), revision (OR 1.28, 95% CI 1.07-1.54, P = .007), and infection (OR 1.39, 95% CI 1.12-1.71, P = .003). Older surgeons also had higher risk for composite complications (OR 1.18, 95% CI 1.03-1.36, P = .019), revision (OR 1.33, 95% CI 1.10-1.62, P = .004), and dislocation (OR 1.37, 95% CI 1.08-1.73, P = .009). However, when excluding low-volume surgeons, older high-volume surgeons had similar complications to middle-aged surgeons.ConclusionYounger surgeons (<45 years) had the highest recorded complications rate while the lowest rate was for surgeons aged 45-55. Volume rather than age was more important in determining rate of complications of older surgeons.Level of EvidenceIV.     

Impact of Perioperative Urinary Tract Infection on Surgical Site Infection in Patients Undergoing Primary Hip and Knee Arthroplasty

BackgroundThe literature lacks clear consensus regarding the association between postoperative urinary tract infection (UTI) and surgical site infection (SSI). Additionally, in contrast to preoperative asymptomatic bacteriuria, SSI risk in patients with preoperative UTI has been incompletely studied. Therefore, our goal was to determine the effect of perioperative UTI on SSI in patients undergoing primary hip and knee arthroplasty.MethodsUsing the National Surgical Quality Improvement Program database, all patients undergoing primary hip and knee arthroplasty were identified. Univariate and multivariate regressions, as well as propensity matching, were used to determine the independent risk of preoperative and postoperative UTI on SSI, reported as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsPostoperative UTI significantly increased the risk for superficial wound infection (OR 2.147, 95% CI 1.622-2.842), deep periprosthetic joint infection (PJI) (OR 2.288, 95% CI 1.579-3.316), and all SSIs (superficial and deep) (OR 2.193, 95% CI 1.741-2.763) (all P < .001). Preoperative UTI was not associated with a significantly increased risk of superficial infection (P = .636), PJI (P = .330), or all SSIs (P = .284). Further analysis of UTI present at the time of surgery using propensity matching showed no increased risk of superficial infection (P = 1.000), PJI (P = .624), or SSI (P = .546).ConclusionPostoperative UTI was associated with SSI, reinforcing the need to minimize factors which predispose patients to the risk of UTI after surgery. The lack of association between preoperative UTI and SSI suggests that hip and knee arthroplasty can proceed without delay, although initiating antibiotic treatment is prudent and future prospective investigations are warranted.     

Incidence and Risk Factors of Iliopsoas Tendinopathy After Total Hip Arthroplasty: A Radiographic Analysis of 1,602 Hips

BackgroundIliopsoas tendinopathy (IPT) can cause persistent groin pain and lead to dissatisfaction after total hip arthroplasty (THA). This study aimed to report the characteristics, incidences, risk factors, and treatment outcomes of IPT after THA.MethodsWe reviewed primary THAs performed at a single institution between January 2012 and May 2018. Clinical and radiographic analyses were performed on 1,602 THAs (1,370 patients). Patient characteristics, component sizes, inclination and anteversion angles, and antero-inferior cup prominence (≥8 millimeters (mm)), were compared between the groups with and without IPT. Changes in teardrop to lesser trochanter distance were measured to estimate changes in leg length and horizontal offset caused by THA. Logistic regression models were used to identify the risk factors for IPT. IPT was identified in 53 hips (3.3%).ResultsPatients with IPT had greater leg lengthening (12.3 versus 9.3 mm; P = .001) and higher prevalence of antero-inferior cup prominence (5.7 versus 0.4%; P = .002). There was no significant difference in inclination, anteversion, and horizontal offset change between the two groups. In multivariate analyses, greater leg lengthening, prominent acetabular cup, women, and higher body mass index were associated with IPT. All patients reported improvement in groin pain after arthroscopic tenotomy, while 35.7% with nonoperative management reported improvement (P < .001).ConclusionsSymptomatic IPT occurred in 53 (3.3%) of the 1,602 primary THAs. Our findings suggest that leg lengthening as well as prominent acetabular cup in THAs can be associated with the development of IPT. Arthroscopic tenotomy was effective in relieving groin pain caused by IPT.     

When is Surgery Performed? Trends,Demographic Associations,and Phenotypical Characterization of Baseline Patient-Reported Outcomes Before Total Hip Arthroplasty

BackgroundEvaluating trends and drivers of baseline patient-reported outcome measures (PROMs) is critical to understanding when patients and providers elect to undergo surgery. We aimed to assess the following: (1) 5-year trends in baseline PROMs pre-THA (total hip arthroplasty) stratified by patient determinants; (2) patient factor associated with poor preoperative hip pain/function; (3) phenotypes of combined pain/function PROMs at baseline; and (4) intersurgeon variability in PROM thresholds at surgery.MethodsA prospective cohort of 6,902 primary THAs was enrolled (January 2016 to December 2020). Patient/surgeon details and PROMs were collected at point of care preoperatively. Outcomes included trends (5 years; 20 quarters) in Hip disability and Osteoarthritis Outcome Score (HOOS)-Pain and HOOS-PS (Physical Function Short-Form), stratified by patient demographics. Patients were further classified into phenotype categories of above or equal to median pain/function (P+PS+); below median pain/function (P?PS?); above or equal to median pain but below median function (P+PS?); and below median pain but above or equal to median function (P?PS+).ResultsBaseline HOOS-Pain was consistent across the study period (P-trend = .166), while HOOS-PS demonstrated increasing function (P-trend = .015). Such trends were appreciable in males, females, and White (P-trend < .001, each) but not Black patients (P-trend = .67). Higher odds ratio (OR) of low baseline HOOS-Pain and HOOS-PS were detected among females (HOOS-Pain: OR 1.75, 95% confidence interval [CI] 1.55-1.98, P < .001; HOOS-PS: OR 1.56, 95% CI 1.38-1.77, P < .001), Black patients (HOOS-Pain: OR 1.64, 95% CI 1.35-2.82, P < .001; HOOS-PS: OR 1.59, 95% CI 1.34-1.89, P < .001), and smokers (HOOS-Pain: OR 1.56, 95% CI 1.29-1.89, P < .001; HOOS-PS: OR 1.52, 95% CI 1.25-1.85, P < .001). The P?PS? cohort (32.4%) had lowest age (65.2 ± 11.1 years), highest body mass index (31.6 ± 6.9 kg/m²), females (64.8%), Black (15.8%), and current smokers (12.2%). There was significant intersurgeon preoperative PROM variation in HOOS-Pain and HOOS-PS (P < .001, each).ConclusionIn contrast to the general population, Black patients have consistently received THA at lower functional levels throughout the 5-year period. Females, smokers, and Black patients were more likely to have poorer pain and function at THA. PROMs assessment as combined pain-function phenotypes may provide a more comprehensive interpretation of patient status preoperatively.     

The Association of Preoperative Smoking With Postoperative Outcomes in Patients Undergoing Total Hip Arthroplasty

BackgroundPreoperative smoking is an easily modifiable risk factor and has associations with increased postoperative morbidity and mortality. It is important to clarify these risks for specific procedures to provide improved and evidence-based quality of care. The purpose of the present study aims to identify the associations between preoperative smoking and 30-day postoperative outcomes in patients undergoing total hip arthroplasty.MethodsWe used R statistics to conduct a multivariable logistic regression analysis followed by a propensity score matching analysis to explore the association between preoperative smoking and postoperative outcomes.ResultsA final cohort of 67,897 patients who underwent total hip arthroplasty was selected for analysis. After adjusting for potential confounders, the odds of postoperative pulmonary complications (odds ratio [OR], 1.352; 95% confidence interval [95% CI], 1.075-1.700; P = .01), infectious complications (OR, 1.310; 95% CI, 1.094-1.567; P = .003), and extended hospital stay (OR, 1.17; 95% CI, 1.099-1.251; P < .001) were all significantly higher in the smoking population. After propensity matching these cohorts, both infectious complications (P = .017) and extended hospital stays (P = .001) were significantly higher in smoking patients.ConclusionsAfter controlling for potential confounding variables, our multivariable regression analysis revealed a significant increase in pulmonary and infectious complications as well as significantly longer hospital stays in our smoking population. When using a propensity score matching analysis, an increase in infectious complications as well as extended hospital stay was observed. Given the concerning prevalence of smoking in the United States, our data provide updated information toward a growing mass of literature supporting smoking cessation before surgical operations.     

Intraoperative Complications and Early Return to the Operating Room in Total Hip Arthroplasty Performed Through the Direct Anterior and Posterior Approaches. An Institutional Experience of Surgeons After Their Learning Curve

BackgroundProponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA).MethodsA total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year.ResultsIntraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02).ConclusionThis comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.     

Acetabular Diameter Assessment and Three-Dimensional Simulation for Acetabular Reconstruction in Dysplastic Hips

BackgroundThis study aimed to investigate the relationship between acetabular width, three-dimensional (3D) simulation, and surgical results in total hip arthroplasty patients who have developmental dysplasia of the hip (DDH).MethodsThis retrospective study included 216 DDH cases. Inner and outer acetabular width (OAW) was measured at the plane passing through the center of acetabular fossa. 3D simulation and 2D standard templating were performed. The actual cup size and the use of augments during surgery were recorded. Association among the indices and their distribution in different types of DDH were analyzed.ResultsA difference of 13 to 14 millimeters (mm) was found between the inner acetabular width and actual cup size used in type II, III, and IV cases, while the difference was 0.2 to 3.6 mm for OAW. The accuracy of 2D templating and 3D simulation in predicting cup size was comparable in Crowe type I (86.5 versus 76%, P = .075), type II (72.7 versus 51.5%, P = .127), and type III (93.3 versus 66.7%, P = .169). The 3D simulation was significantly more accurate in Crowe type IV (89.1% versus 60.9%, P = .001). Augments and bone grafts were significantly more commonly used in type II (25%) than in the other types (0 to 6.5%).ConclusionOAW more accurately predicted actual cup size than inner acetabular width. The supero-lateral acetabular bone defects in type II cases require additional attention. Compared with 2D templating, 3D simulation is more accurate in predicting actual cup size in dysplastic hips with severe deformity and may be recommended in these selected cases, especially for Crowe IV patients.     

Acetabular Component Positioning in Total Hip Arthroplasty With and Without a Computer-Assisted System: A Prospective,Randomized and Controlled Study

In a study of the acetabular component in total hip arthroplasty, 20 hips were operated on using imageless navigation and 20 hips were operated on using the conventional method. The correct position of the acetabular component was evaluated with computed tomography, measuring the operative anteversion and the operative inclination and determining the cases inside Lewinnek's safe zone. The results were similar in all the analyses: a mean anteversion of 17.4° in the navigated group and 14.5° in the control group (P = .215); a mean inclination of 41.7° and 42.2° (P = .633); a mean deviation from the desired anteversion (15°) of 5.5° and 6.6° (P = .429); a mean deviation from the desired inclination of 3° and 3.2° (P = .783); and location inside the safe zone of 90% and 80% (P = .661). The acetabular component position's tomography analyses were similar whether using the imageless navigation or performing it conventionally.     

Variability in Acetabular Component Position in Patients Undergoing Direct Anterior Approach Total Hip Arthroplasty Who Have Concomitant Spine Pathology

BackgroundHip instability following total hip arthroplasty (THA) can be a major cause of revision surgery. Physiological patient position impacts acetabular anteversion and abduction, and influences the functional component positioning. Osteoarthritis of the spine leads to abnormal spinopelvic biomechanics and motion, but there is no consensus on the degree of component variability for THAs performed by anterior approach. Therefore, we sought to present guidelines for changes in acetabular component positioning between supine and standing positions for patients undergoing primary THA by a uniform anterior approach.MethodsPerioperative patient radiographs of the pelvis and lumbar spine were collected. Images were used to determine acetabular component positioning and degree of coexisting spinal pathology, categorized as a Lane Grade (LG). Final analysis of variance was performed on a sample size of 643 anterior primary THAs.ResultsFrom supine to standing position, as the severity of lumbar pathology increased the change in anteversion also increased (LG:0 = ?0.11° ± 4.65°, LG:1 = 2.02° ± 4.09°, LG:2-3 = 5.78° ± 5.72°, P < .001). The mean supine anteversion in patients with absent lumbar pathology was 19.72° ± 5.05° and was lower in patients with worsening lumbar pathology (LG:1 = 18.25° ± 4.81°, LG:2-3 = 16.73° ± 5.28°, P < .001).ConclusionPatients undergoing primary THA by anterior approach with worsening spinal pathology have larger increases in component anteversion when transitioning from supine to standing positions. Consideration should be given to this expected variability when placing the patient’s acetabular component.     

Preoperative Patient Factors and Postoperative Complications as Risk Factors for New-Onset Depression Following Total Hip Arthroplasty

BackgroundDepression is known to be a risk factor for complication following primary total hip arthroplasty (THA), but little is known about new-onset depression (NOD) following THA. The purpose of this study is to determine the incidence of NOD and identify risk factors for its occurrence after THA.MethodsThis is a retrospective cohort study of the Truven MarketScan database. Patients undergoing primary THA were identified and separated into cohorts based on the presence or not of NOD. Patients with preoperative depression or a diagnosis of fracture were excluded. Patient demographic and comorbid data were queried, and postoperative complications were collected. Univariate and multivariate regression analysis was then performed to assess the association of NOD with patient-specific factors and postoperative complications.ResultsIn total, 111,838 patients undergoing THA were identified and 2517 (2.25%) patients had NOD in the first postoperative year. Multivariate analysis demonstrated that preoperative opioid use, female gender, higher Elixhauser comorbidity index, preoperative anxiety disorder, drug or alcohol use disorder, and preoperative smoking were associated with the occurrence of NOD (P ≤ .001). The following postoperative complications were associated with increased odds of NOD: prosthetic joint infection (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.42-2.34, P < .001), aseptic revision surgery (OR 1.47, 95% CI 1.06-2.04, P = .019), periprosthetic fracture (OR 1.72, 95% CI 1.13-2.61, P = .01), and non-home discharge (OR 1.59, 95% CI 1.42-1.77, P < .001).ConclusionsNOD is common following THA and there are multiple patient-specific factors and postoperative complications which increase the odds of its occurrence. Providers should use this information to identify at-risk patients so that pre-emptive prevention strategies may be employed.     

Portable Accelerometer-Based Navigation System for Cup Placement of Total Hip Arthroplasty: A Prospective,Randomized, Controlled Study

BackgroundMalposition of the acetabular component during total hip arthroplasty (THA) is associated with increased risk of dislocation, reduced range of motion, and accelerated wear. The purpose of this study is to compare cup positioning with a portable, accelerometer-based hip navigation system and conventional surgical technique.MethodsIn a prospective, randomized, clinical study, cups were implanted with a portable, accelerometer-based hip navigation system (navigation group; n = 55) or conventional technique (conventional group; n = 55). THA was conducted in the lateral position and through posterior approach. The cup position was determined postoperatively on pelvic radiograph and computed tomography scans.ResultsAn average cup abduction of 39.2° ± 4.6° (range, 27° to 50°) and an average cup anteversion of 14.6° ± 6.1° (range, 1° to 27.5°) were found in the navigation group, and an average cup abduction of 42.9° ± 8.0° (range, 23° to 73°) and an average cup anteversion of 11.6° ± 7.7° (range, −12.1° to 25°) in the conventional group. A smaller variation in the navigation group was indicated for cup abduction (P = .001). The deviations from the target cup position were significantly lower in the navigation group (P = .001, .016). While only 37 of 55 cups in the conventional group were inside the Lewinnek safe zone, 51 of 55 cups in the navigation group were placed inside this safe zone (P = .006). The navigation procedure took a mean of 10 minutes longer than the conventional technique.ConclusionUse of the portable, accelerometer-based hip navigation system can improve cup positioning in THA.     

Hypogonadism Is Associated With Increased Risks of Postoperative Complications Following Total Hip Arthroplasty

BackgroundDespite being a relatively common problem among aging men, hypogonadism has not been previously studied as a potential risk factor for postoperative complications following total hip arthroplasty (THA).MethodsIn total, 3903 male patients with a diagnosis of hypogonadism who underwent primary THA from 2006 to 2012 were identified using a national insurance database and compared to 20:1 matched male controls using a logistic regression analysis.ResultsHypogonadism was associated with an increased risk of major medical complications (odds ratio [OR] 1.24, P = .022), urinary tract infection (OR 1.43, P < .001), wound complications (OR 1.33, P = .011), deep vein thrombosis (OR 1.64, P < .001), emergency room visit (OR 1.24, P < .001), readmission (OR 1.14, P = .015), periprosthetic joint infection (OR 1.37 and 1.43, P < .05), dislocation (OR 1.51 and 1.48, P < .001), and revision (OR 1.54 and 1.56, P < .001) following THA. A preoperative diagnosis of hypogonadism was associated with increased total reimbursement and charges by $390 (P < .001) and $4514 (P < .001), respectively.ConclusionThe diagnosis of hypogonadism is associated with an elevated risk of postoperative complications and increased cost of care following primary THA. Data from this study should influence the discussion between the patient and the provider prior to undergoing joint replacement and serve as the basis for further research.