Setting Of Total Hip Arthroplasty Research Articles

Patient-Level Value Analysis in Total Hip Arthroplasty: Optimizing the Value of Care Delivery

Background: Value is defined as the ratio of patient outcomes to the cost of care. One method to assess value is through patient-level value analysis (PLVA). To our knowledge, this tool has not previously been implemented in the setting of total hip arthroplasty (THA). The purposes of this study were to perform PLVA for a 1-year episode of care among patients undergoing primary THA and to identify characteristics that affect value in a metropolitan health-care system. Methods: The patient-reported outcome (PRO) measure database of the institution was queried for all primary THAs from 2018 to 2019. The PRO measure that was utilized was the Hip disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS-JR). Cost was evaluated with use of time-driven activity-based costing (TDABC) for a 1-year episode of care (consisting of the day of surgery, inpatient stay, discharge facility, postoperative appointments, and physical therapy). The primary outcome was the 1-year value quotient, or the ratio of the 1-year change in HOOS-JR to the cost of the episode of care (VHOOS). The value quotient was compared among all included patients and evaluated for variables that may affect the overall value of the episode of care. Results: In total, 480 patients were included in the analysis. The mean improvement in the HOOS-JR was +34.9 ± 16.1 (95% confidence interval [CI]: 33.5, 36.3). The mean cost was $13,835 ± $3,471 (95% CI: $13,524, $14,146). The largest contributor to cost was implants (39.0%), followed by post-recovery care (i.e., inpatient stay and specialized nursing facilities; 24.1%). Change in the HOOS-JR was poorly correlated with the cost of care (r = −0.06; p = 0.19). THAs performed at an ambulatory surgery center (ASC) with discharge to home demonstrated higher value (VHOOS = 0.42) than THAs performed at a hospital with discharge to a rehabilitation facility (VHOOS = 0.15; analysis of variance F-test, p < 0.01). Conclusions: Our study found that PROs did not correlate with costs in the setting of primary THA. Implants were the largest cost driver. Surgical setting (an ASC versus a hospital) and discharge destination influenced value as well. PLVA is a value measurement tool that can be utilized to optimize components of the care delivery pathway. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Systematic Review of Total Hip Arthroplasty Outcomes in Cerebral Palsy Patients and a Comparative Analysis with Rheumatoid Arthritis.

Total hip arthroplasty (THA) is considered a successful treatment option for patients with degenerative hip arthritis. However, in the setting of neuromuscular diseases, patients with cerebral palsy (CP) are considered high-risk due to instability, contractures, and altered muscle tone. The purpose of this systematic review is to analyse the data in the setting of THA in CP patients including indications, types of implants, revision rates, and patient-reported outcomes and compare these with those of a cohort requiring THA due to degenerative arthritis unrelated to neuromuscular disorders. PubMed, Embase, and Cochrane Library were searched from inception until June 10, 2023, to identify the relevant studies for THA on CP patients. The methodological quality of the studies was evaluated using the Newcastle-Ottawa Quality Assessment Scale (NOS). The initial search generated 190 studies out of which 21 met the inclusion criteria. The most frequently reported indication was painful hip dislocation or subluxation due to failure of prior nonoperative treatment. The most frequently reported complication was dislocation affecting overall 7.5% (0-28%) of all patients, while other complications included periprosthetic fractures and heterotrophic ossification. The survival rates of primary THAs ranged from 85% to 100% at 5 years and from 73% to 86% at 10 years. Patients with CP who undergo total hip arthroplasty experience a greater overall rate of complications compared to patients with rheumatoid arthritis (RA) that undergo the same procedure. The current literature suggests that THA is a beneficial procedure for patients with CP through pain reduction and functional improvement. However, the increased rates of potential complications compared to the general population require careful consideration. We suggest that further investigations on the most appropriate time of procedure, implant type, and procedure are needed.

Anterior Total Hip Arthroplasty With Gluteus Medius Repair: A Novel Technique

Introduction: Proper function of the gluteus medius muscle is crucial to performance and outcomes following total hip arthroplasty. Gluteus medius tears are reported in up to 20% of patients undergoing hip replacements. The combination of increasing notoriety for the direct anterior approach and the potential for improved patient outcomes necessitates a technique to address gluteus medius tears in conjunction with total hip arthroplasty. Therefore, we present the following novel technique for transtendinous gluteus medius repair in conjunction with a direct anterior approach for total hip arthroplasty. Technique: The patient is placed supine with the operative leg in slight external rotation. An incision is made to the fascia overlying the tensor fascia latae. Blunt dissection is performed to the tensor fascia latae-sartorius interval. The deep rectus fascia is split, identifying the anterior capsule. Arthroplasty is then performed in the usual manner. Once the arthroplasty is completed, the hip capsule is closed, and the gluteus medius is exposed through an anterolateral approach. Once found, the tear is classified. A split in line with the tendon fibers is made in the mid aspect of the tear. Once visualized, the greater trochanter is decorticated, and suture anchors are placed. Sutures are passed and tied sequentially from distal to proximal. Expected Outcomes: Gluteus medius repair patients experience excellent outcomes, with multiple studies showing decreased pain and restoration in the strength of the abductor complex. In the setting of total hip arthroplasty, most patients display adequate abductor strength and no Trendelenburg gait at 5 years postoperative.

Methylene Blue Infiltration As a Method for Distinguishing Superficial and Deep Infections

BackgroundThere are no established objective methods to reliably differentiate between superficial and deep infection in the setting of total hip arthroplasty. We employed a technique of distinguishing superficial and deep infections by infiltrating methylene blue to a prosthetic hip during infection workup to determine its effectiveness and to characterize its utility in defining the joint cavity where deep debridement is required. MethodsAn analysis was conducted on 35 patients who preoperatively received an injection of methylene blue under radiological guidance to their total hip arthroplasty. Where established periprosthetic joint infection (PJI) criteria were not met, without signs of methylene blue beyond the deep fascia, the infection was considered superficial, and debridement remained superficial to the deep fascia. Where diagnosis of PJI was confirmed preoperatively or the presence of methylene blue in the wound cavity confirmed deep contamination, the prosthesis was addressed with methylene blue staining defining the joint cavity as a guide for debridement. ResultsThere were 11 patients who had no methylene blue extrusion into the superficial compartment and did not meet PJI criteria. Eight patients failed to meet PJI criteria preoperatively, but had extrusion of methylene blue, confirming a deep infection intraoperatively. There were 16 patients who met PJI criteria preoperatively with methylene blue acting as a visual guide to the joint space. ConclusionInfiltrating methylene blue in a prosthetic hip is useful in differentiating between superficial or deep infections where PJI workup is indeterminate. Where deep infection is present, its utility in defining the joint cavity may be advantageous.

INCIDENCE OF VENOUS THROMBOEMBOLISM IN ELECTIVE HIP ARTHROPLASTY SURGERY: A REVIEW OF 8,890 PATIENTS RECEIVING POSTOPERATIVE ASPIRIN VTE PROPHYLAXIS

Venous thromboembolism (VTE) is a preventable cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Clinical Excellence (NICE) has altered their prophylaxis guidance in the setting of total hip arthroplasty (THA). The aim of this study was to present the VTE incidence in 8,890 patients who underwent total hip arthroplasty between January 1997 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis.Analysis of prospective data collection from consecutive patients undergoing THA was performed with the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within 6 months of the index operation as the primary outcome measure. 90-day all-cause mortality of this cohort of patients was also analysed.8890 patients were reviewed. This included 7235 primary, 224 complex primary and 1431 revision cases. The incidence of DVT was 0.64% after elective THA and the incidence of PE was 0.54%. There was no difference in the incidence between primary and revision cases. The 90-day all-cause mortality was 0.88%. Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to VTE.Our results support the use of aspirin as an effective form of prophylaxis against VTE following THA. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other attractive advantages of using aspirin for VTE prophylaxis.

Bibliometric Analysis of Spinopelvic Alignment in Total Hip Arthroplasty.

Postoperative dislocation of unclear etiology remains a concern after total hip arthroplasty (THA). Interest is growing in the importance of spinopelvic alignment on stability in THA. The purpose of this study was to analyze publication trends, areas of interest, and future research direction of spinopelvic alignment in THA. Articles on the topic of spinopelvic alignment in THA published between 1990 and 2022 were obtained through Web of Science Core Collection of Clarivate Analytics (WSCCA). Results were screened by title, abstract, and full text. The inclusion criterion was English-language peer-reviewed journal publications on the clinical topic of spinopelvic alignment in THA. Bibliometric software was used to characterize publication trends. We screened 1,211 articles, yielding 132 meeting the inclusion criterion. From 1990 to 2022, published articles have steadily increased, peaking in 2021. Countries that have been the most productive in contributions to research are those in which THA is the most prevalent. Our analysis of keyword frequency showed increasing interest in "pelvic tilt," "anteversion," and "acetabular component" position. Our study identified that increasing attention is being given to spinopelvic mobility and PT in the setting of THA. The United States and France produced the most studies related to spinopelvic alignment.

Outcomes of fixation of Vancouver B periprosthetic fractures around cemented versus uncemented stems

BackgroundThe incidence of periprosthetic femur fracture (PPFF) in the setting of total hip arthroplasty (THA) is steadily increasing. We seek to address whether there is a difference in outcomes between Vancouver B fracture types managed with ORIF when the original stem was a press-fit stem versus a cemented stem.MethodsIn this retrospective cohort study at a level 1 trauma center, we identified 136 patients over 65 years-of-age with Vancouver B-type fractures sustained between 2005 and 2019. Patients were treated by ORIF and had either cemented or press-fit stems prior to their injury. Outcomes were subsidence of the femoral implant, time to full weight bearing, rate of the hip implant revision, estimated blood loss (EBL), postoperative complications, and the one-year mortality rate.ResultsA total of 103 (75.7%) press-fit and 33 (24.3%) cemented patients were reviewed. Patient baseline characteristics, Vancouver fracture sub-types, and implant characteristics were not found to be significantly different between groups. The difference in subsidence rates, postoperative complications, and time to weight bearing were not significantly different between groups. EBL and one-year mortality rate were significantly higher in the cemented group.ConclusionsIn geriatric patients with Vancouver B type periprosthetic fractures managed with ORIF, patients with an originally press fit stem may have lower mortality, lower estimated blood loss, and similar subsidence and hospital length of stays when compared to those with a cemented stem.

Perioperative management of leg-length discrepancy in total hip arthroplasty: a review.

Leg-length discrepancy (LLD) presents a significant management challenge to orthopedic surgeons and remains a leading cause of patient dissatisfaction and litigation after total hip arthroplasty (THA). Over or under-lengthening of the operative extremity has been shown to have inferior outcomes, such as dislocation, exacerbation of back pain and sciatica, and general dissatisfaction postoperatively. The management of LLD in the setting of THA is multifactorial, and must be taken into consideration in the pre-operative, intra-operative, and post-operative settings. In our review, we aim to summarize the best available practices and techniques for minimizing LLD through each of these phases of care. Pre-operatively, we provide an overview of the appropriate radiographic studies to be obtained and their interpretation, as well as considerations to be made when templating. Intra-operatively, we discuss several techniques for the assessment of limb length in real time, and post-operatively, we discuss both operative and non-operative management of LLD. By providing a summary of the best available practices and strategies for mitigating the impact of a perceived LLD in the setting of THA, we hope to maximize the potential for an excellent surgical and clinical outcome.

Abnormal Spinopelvic Motion and Spine Deformity are Associated With Native Femoral Retroversion in the Setting of Total Hip Arthroplasty

BackgroundThe effect of spinopelvic pathology on femoral version is unclear. This study investigated variability in native femoral anteversion in patients undergoing total hip arthroplasty (THA) and its relationship to the patient’s underlying spinopelvic pattern. MethodsA retrospective chart review was performed to include in the study all patients undergoing robot-assisted THA over a 3-year period. Native femoral version was measured for each patient using a preoperative computed tomography scan and categorized as excessive, normal, or retroverted. Additionally, a subset analysis was performed for all patients with sit-to-stand dynamic pelvic radiographs available, and cases were classified by spinopelvic pattern. ResultsA total of 119 patients were included in the study with a mean age of 68.6 years; 61 (51%) were female. The median femoral anteversion for the entire study group was 6.0° (−32° to 40°, interquartile range 13.5°). Eleven patients (9.2%) had excessive femoral anteversion, 54 of the 119 (45.4%) had normal femoral version, and 54 of the 119 (45.4%) had native retroversion. Forty-two patients (35.3%) had sit-to-stand radiographs available and were subclassified by femoral version type and spinopelvic parameters. Welch’s analysis of variance demonstrated a significant difference in femoral version among spinopelvic patterns (F = 7.826, P = .003), with Games-Howell post hoc analysis showing increased retroversion in deformity-stiff patients compared to deformity-normal mobility patients (P = .003). ConclusionsThis study demonstrates that native femoral retroversion is present in a significant number of patients undergoing THA and is more common in patients with stiff spine deformities. Based on this observation, currently available spinopelvic classification systems should be modified to account for native femoral version.

Outcomes After Operative Fixation of Vancouver B2 and B3 Type Periprosthetic Fractures

The incidence of periprosthetic femur fracture in the setting of total hip arthroplasty is steadily increasing. Although the traditional dogma is that loose femoral components must be revised, we propose that in a frail geriatric population, anatomic reduction and fixation of Vancouver B2 and B3 periprosthetic fracture variants can restore stem stability and provide similar outcomes as revision arthroplasty. Retrospective cohort study. Level 1 trauma center, tertiary academic medical center. We identified 94 patients over 65 years of age with Vancouver B2 and B3 fractures sustained between 2005 and 2019. Patients were treated by either open reduction and internal fixation (ORIF) or revision arthroplasty (RA) with or without fixation. Outcomes were mortality, time to full weight-bearing after surgery, intraoperative estimated blood loss, perioperative complications, reoperation, subsidence rate, and Patient-Reported Outcomes Measurement Information System pain and physical function scores. A total of 75 (79.8%) ORIF and 19 (20.2%) RA patients were reviewed. One-year mortality for our cohort was 26.3%, and there was no significant difference between groups. Mean time to weight bear and surgical complication rates were similar between groups. The ORIF group had a significantly shorter time to surgery than the RA group. The RA group had greater incidence and amount of subsidence as well as estimated blood loss than the ORIF group. In geriatric patients with Vancouver B2 and B3 type periprosthetic fractures with known loose stems, ORIF may offer a similarly safe method of treatment than revision arthroplasty. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lumbar Spine Fusion and Symptoms of Leg Length Discrepancy After Hip Arthroplasty

BackgroundHip length discrepancy (HLD) is common after total hip arthroplasty (THA); however, the effect of spinal fusion on perceived leg length discrepancy (LLD) symptoms after THA has not been examined. This study tested the hypothesis that LLD symptoms are increased in patients who underwent lumbar spinal fusion and THA, compared with patients with THA only. MethodsThis retrospective cohort study included 67 patients who underwent lumbar spinal fusion and THA, along with 78 matched control patients who underwent THA only. Hip and spine measurements were taken on postoperative, standing anterior-posterior pelvic, lateral lumbar, and anterior-posterior lumbar spinal radiographs. Perceived LLD symptoms were assessed via telephone survey. ResultsBetween the spinal fusion and control groups, there was no significant difference in HLD (M = 7.10 mm, SE = 0.70 and M = 5.60 mm, SE = 0.49) (P = .403). The spinal fusion patients reported more frequently noticing a difference in the length of their legs than the control group (P = .046) and reported limping “all the time” compared with the control group (P = .001). Among all patients with an HLD ≤10 mm, those in the spinal fusion group reported limping at a higher frequency than patients in the control group (P = .008). Patients in the spinal fusion group were also more likely to report worsened back pain after THA (P = .011) than the control group. ConclusionFrequencies of a perceived LLD, limping, and worsened back pain after THA were increased in patients with THA and a spinal fusion compared with patients who had THA only, even in a population with HLD traditionally considered to be subclinical. The results indicate that in patients with prior spinal fusion, precautions should be taken to avoid even minor LLD in the setting of THA.

The Utility of MRI With Multiacquisition Variable-Resonance Image Combination (MAVRIC) in Diagnosing Deep Total Hip Arthroplasty Infection.

Background: The 2010 American Academy of Orthopaedic Surgeons Clinical Practice Guidelines report insufficient evidence to address the diagnostic efficacy of magnetic resonance imaging (MRI) for periprosthetic joint infection (PJI). Questions/Purposes: The purpose of this study was to determine the utility of MRI with multiacquisition variable-resonance image combination (MAVRIC) metal artifact suppression techniques in diagnosing PJI in the setting of total hip arthroplasty (THA). Methods: Multiacquisition variable-resonance image combination MRIs obtained of THAs between November 2012 and November 2016 were queried. Radiology reports were classified as positive (suspicious for infection), negative (no features of infection), or inconclusive (infection cannot be excluded or correlation with aspiration suggested if clinically concerned). Chart review identified cases of deep PJI according to the modified Musculoskeletal Infection Society criteria. Results: Of 2156 MRIs of THAs included, MRI was concerning for infection in 1.8% (n = 39), inconclusive in 1.2% (n = 26), and negative in 97.0% (n = 2091). Deep PJI was identified in 53 (2.5%) patients, 30 of whom (56.6%) had conclusively positive finding on MRI (false-negative rate: 43.4%, sensitivity: 56.6%). Of 2103 aseptic THAs, only 9 (0.4%) MRIs were read as suspicious for infection (false-positive rate: 0.4%; specificity: 99.6%). Conclusion: Magnetic resonance imaging with MAVRIC is a highly specific test for PJI with a low false-positive rate. This indicates that when clinicians are provided with an MRI that unexpectedly suggests infection, a formal evaluation for infection is indicated. In patients with otherwise equivocal diagnostic findings, MRI may help confirm, but not refute, a diagnosis of PJI. Prospective study with more experienced image reviewers may further support the use of MRI in PJI.

The Effect of Modern Antiretroviral Therapy on Complication Rates After Total Hip Arthroplasty.

Background:Antiretroviral therapy (ART) remains the cornerstone of decreasing morbidity and mortality in patients with human immunodeficiency virus (HIV), but additional information on its impact on total hip arthroplasty (THA) complication rates is needed to mitigate risks postoperatively. Therefore, we sought to examine patients with HIV who were and were not taking ART compared with a cohort without HIV in the setting of primary THA with respect to the following outcomes: length of stay, readmissions, and postoperative infection.Methods:A retrospective database review was performed with PearlDiver for patients who underwent THA from 2010 to 2019 (n = 729,101). Patients with HIV who were and were not taking ART were then identified and were matched with patients without HIV at a 1:1:1 ratio based on age, sex, Charlson Comorbidity Index, diabetes, obesity, and tobacco use, resulting in 601 patients in each cohort. Length of stay, 30-day readmissions, and complications at 90 days and 1 year were analyzed. Continuous outcomes were measured via Student t tests, and categorical outcomes were measured via chi-square analyses.Results:Patients with HIV who were and were not taking ART were found to have similar lengths of stay compared with patients without HIV (range, 4.1 to 4.3 days). Readmission rates were slightly higher in patients with HIV who were taking ART at 4.2% (odds ratio [OR], 1.96 [95% confidence interval (CI), 0.99 to 3.87]) and patients with HIV who were not taking ART at 3.5% (OR, 1.63 [95% CI, 0.81 to 3.30]) compared with patients without HIV at 2.1%. Periprosthetic joint infection rates at 1 year were slightly higher among patients with HIV who were not taking ART at 5.3% (OR, 1.41 [95% CI, 0.82 to 2.45]) compared with patients with HIV who were taking ART at 4.2% (OR, 1.09 [95% CI, 0.61 to 1.94]) and patients without HIV at 3.8%.Conclusions:Patients with HIV who are and are not taking ART are approaching normalization to the general population in the setting of THA. It is important to note that, although complications may have been mitigated by modern therapy, extreme care should be taken while clinically evaluating these patients prior to the surgical procedure given the complexity of their clinical status. The findings of this study underscore the utility of ART and patient optimization to reduce risk in this patient population.Level of Evidence:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Three-dimensional femoral morphology in Hartofilakidis type C developmental dysplastic hips and the implications for total hip arthroplasty.

The aim of this study was to describe and compare the femoral morphologies of Hartofilakidis types C1 and C2 developmental dysplasia of the hip (DDH), and discuss the potential influence on subsequent total hip arthroplasty (THA). We analyzed preoperative CT data from 81 patients (42 C1 and 39 C2 subtypes) who underwent THA for arthritis secondary to Hartofilakidis type C DDH. The CT data was three-dimensionally reconstructed and measured of following parameters: neck-shaft angle, femoral neck length, anteversion, medial inclination, femoral offset, height of the greater trochanter and femoral head, mediolateral (ML) and anteroposterior (AP) widths of the medullary canal. The canal flare indices and ML-to-AP ratio were further calculated. We also reviewed surgical and follow-up records to compare the different implants utilized and the clinical results between C1 and C2 hips. The C2 femurs had a significantly lower neck-shaft angle (119.0° vs. 124.0°), shorter femoral neck (37.0mm vs. 41.2mm), larger medial cortical inclination (158.8° vs. 149.1°), and higher position of the greater trochanter. The C2 femurs were narrower and had a smaller canal flare index (2.88 ± 0.50) than C1 femurs (3.64 ± 0.69). The ML-to-AP ratio of the proximal femoral medullary canal was significantly smaller in the C2 group. Accordingly, C2 femurs required thinner stems, more non-sprouted sleeves, and had a higher rate and required a longer length of shortening osteotomies. At an average follow-up of 36.0months, the C1 and C2 groups had a similar Harris Hip Score (83.5 ± 14.3 vs. 84.2 ± 9.8, P= 0.771) and no stem loosening occurred in either group. C1 and C2 proximal femurs have substantial differences in the coronal, sagittal, and axial planes. In the setting of THA, C2 femurs may therefore require thinner stems, more non-sprouted sleeves, and have a higher rate and require a longer length of shortening osteotomies.

Reconsidering the Affordable Care Act's Restrictions on Physician-Owned Hospitals: Analysis of CMS Data on Total Hip and Knee Arthroplasty.

Concerns about financial incentives and increased costs prompted legislation limiting the expansion of physician-owned hospitals in 2010. Supporters of physician-owned hospitals argue that they improve the value of care by improving quality and reducing costs. The purpose of the present study was to determine whether physician-owned and non-physician-owned hospitals differ in terms of costs, outcomes, and patient satisfaction in the setting of total hip arthroplasty (THA) and total knee arthroplasty (TKA). With use of the U.S. Centers for Medicare & Medicaid Services (CMS) Inpatient Charge Data, we identified 45 physician-owned and 2,657 non-physician-owned hospitals that performed ≥11 primary TKA and THA procedures in 2014. Cost data, patient-satisfaction scores, and risk-adjusted complication and 30-day readmission scores for knee and hip arthroplasty patients were obtained from the multiyear CMS Hospital Compare database. Physician-owned hospitals received lower mean Medicare payments than did non-physician-owned hospitals for THA and TKA procedures ($11,106 compared with $12,699; p = 0.002). While the 30-day readmission score did not differ significantly between the 2 types of hospitals (4.48 compared with 4.62 for physician-owned and non-physician-owned, respectively; p = 0.104), physician-owned hospitals had a lower risk-adjusted complication score (2.83 compared with 3.04; p = 0.015). Physician-owned hospitals outperformed non-physician-owned hospitals in all patient-satisfaction categories, including mean linear scores for recommending the hospital (93.9 compared with 87.9; p < 0.001) and overall hospital rating (93.4 compared with 88.4; p < 0.001). When controlling for hospital demographic variables, status as a non-physician-owned hospital was an independent risk factor for being in the upper quartile of all inpatient payments for Medicare Severity-Diagnosis Related Group (MS-DRG) 470 (odds ratio, 3.317; 95% confidence interval, 1.174 to 9.371; p = 0.024), which may be because of a difference in CMS payment methodology. Our findings suggest that physician-owned hospitals are associated with lower mean Medicare costs, fewer complications, and higher patient satisfaction following THA and TKA than non-physician-owned hospitals. Policymakers should consider these data when debating the current moratorium on physician-owned hospital expansion. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Myocardial Cobalt Levels Are Elevated in the Setting of Total Hip Arthroplasty.

Arthroplasty implants commonly contain elemental metal that may undergo wear-related release. Recently, cases of hip implant-associated myocardial injury have been reported. However, we are not aware of any previous study that has systematically measured myocardial metal levels or examined the relationship with total hip arthroplasty (THA). Archives of our institution were queried for autopsies of individuals who had undergone THA between 1990 and 2013. Myocardial tissue samples were analyzed for cobalt (Co) and chromium (Cr) levels with inductively coupled plasma mass spectroscopy. Seventy-five Co/Cr-on-polyethylene THA cases were included (mean age at time of death = 77.4 years; 49% women) as were 73 non-arthroplasty controls matched for age, sex, and history of hypertension and diabetes mellitus. Significantly higher median myocardial concentrations of Co were observed in individuals with THA compared with controls (0.12 versus 0.06 μg/g, p < 0.0001). The median Co concentration was 69% higher in patients who had undergone THA revision (0.169 μg/g) than in those who underwent primary THA (0.100 μg/g; p = 0.004). In general, higher Co levels were observed in those with multiple replaced joints, although this finding only trended toward significance. Cardiomegaly, interstitial fibrosis, and decreased ejection fraction were observed more frequently in the postmortem samples of patients with implants than in those of controls (p = 0.0002, 0.044, and 0.0039, respectively). We believe this to be the first study to quantify metal levels in cardiac tissue in patients with and without joint replacement. The elevated Co levels, in concert with cardiomegaly and increased interstitial fibrosis found during autopsy, in the arthroplasty cohort are novel, important findings. Although Co levels were significantly elevated above those in controls, the majority were below those seen in clinical case reports of death from Co cardiotoxicity associated with metal-on-metal prostheses. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Change in Axial Rotation of the Femur in the Resting Supine Position Following Total Hip Arthroplasty.

Stem anteversion in the setting of total hip arthroplasty (THA) is usually measured by referencing the posterior condylar line (PCL). However, stem anteversion may not express the functional torsion of the femur if a consistent horizontal tilt in the PCL is observed after THA. Herein, the horizontal tilt of the PCL at the resting neutral position of the hip was retrospectively measured in 53 THA patients from three computed tomography (CT) datasets: (i) preoperative (preop-CT), (ii) 3 weeks after THA (1st postop-CT), and (iii) more than 2 years after THA (2nd postop-CT). Factors including sex, surgical approach, change in femoral anteversion, leg length, leg lateral length, and pelvic sagittal tilt, were analyzed to determine if they were predictors for the rotational change in PCL, and the number of cases in which the horizontal tilt of the PCL remained within 10° in the three CT images was calculated. Comparing the preop-CT to the 1st postop-CT demonstrated that the PCL underwent internal rotation by (mean ± standard deviation) 13.1° ± 8.6°; only leg lateralization was significantly correlated to the change in PCL (β = 0.278, P = 0.046). Comparing the preop-CT to the 2nd postop-CT demonstrated that the PCL was internally rotated by 9.7° ± 9.3°; no factors were correlated to the change in PCL. There were only 12 hips (23%) in which the horizontal tilt of the PCL remained within 10°. In conclusion, the PCL in the resting position was internally rotated shortly after THA and remained internally rotated from the preoperative position at two or more years following THA. Thus, stem anteversion measured by referencing the PCL may not represent functional torsion of the femur.

Use of locking plates for fixation of the greater trochanter in patients with hip replacement.

BackgroundFixation of the greater trochanter with total hip replacement is challenging and associated with short- and long-term complications. Locking plate technology has been used for fixation of other bones and may be applied successfully in trochanteric fixation. The purpose of this retrospective study was to analyze the utility of the use of trochanteric locking plates in total hip arthroplasty (THA) patients.MethodsFrom 2004 to 2014, 32 procedures were performed to fix the greater trochanter in patients with trochanteric fracture, osteotomy, or nonunion in the setting of THA. The median age at the time of surgery was 69 years. This was a primary arthroplasty in 8 of the patients, conversion from prior hip surgery in 5, and a revision in 19. The greater trochanter was fixed with locking plate alone in 15 hips and with the addition of a single cerclage cable in 17 hips. Patients were followed clinically and radiographically until healing occurred. The median duration of radiographic follow-up was 41.6 months (range: 10-112 months).ResultsOsseous union occurred in 29 (90.6%) of 32 hips. The median Harris hip score was 94 (range 54-100, standard deviation = 10.4) at latest follow-up. Complications included broken hardware in 5 (15.6%) patients, of which 3 underwent subsequent hardware removal. Two additional patients elected hardware removal due to trochanteric pain.ConclusionsLocking plate technology is a successful method of fixation of the greater trochanter in patients with THA. Postoperative trochanteric pain and reoperation for hardware-related issues remain a challenge.

Subspine Impingement: 2 Case Reports of a Previously Unreported Cause of Instability in Total HIP Arthroplasty

Background Instability is a common cause of revision hip arthroplasty and is frequently due to improper component placement and subsequent component impingement. Impingement of the greater trochanter upon the anterior inferior iliac spine (AIIS) has been described as a cause of symptomatic femoroacetabular impingement (FAI), but has never been described as a cause of instability following total hip arthroplasty (THA). Case review We present 2 cases of patients undergoing THA. Each patient was evaluated preoperatively and found to have a prominent AIIS, which was concerning due to it overhanging the anterolateral acetabular lip. Both patients had intraoperative posterior instability of their THA, the cause of which was determined to be impingement of the greater trochanter upon a prominent AIIS. Open resection of the AIIS was performed with subsequent resolution of impingement. Literature review AIIS impingement has been reported as a cause of symptomatic FAI. In these case reports, open or arthroscopic resection of the AIIS resulted in resolution of symptoms. Morphologically distinct subtypes of the AIIS have been previously described based upon computed tomography, and some subtypes are associated with a high risk of impingement in the native hip. No previous studies have described this phenomenon in the setting of THA. Clinical relevance Instability is a common cause of revision THA. Impingement of the greater trochanter upon a prominent AIIS is a previously unreported cause of THA instability which can be addressed with intraoperative resection of the AIIS with good result.

Efficacy of Multimodal Pain Control Protocol in the Setting of Total Hip Arthroplasty

BackgroundThis study evaluated the benefits and safety of a multimodal pain control protocol, which included a periarticular injection of local anesthetics, in patients undergoing total hip arthroplasty.MethodsBetween March 2006 and March 2007, 60 patients undergoing unilateral total hip arthroplasty were randomized to undergo either a multimodal pain control protocol or a conventional pain control protocol. The following parameters were compared: the preoperative and postoperative visual analogue scales (VAS), hospital stay, operative time, postoperative rehabilitation, additional painkiller consumption, and complication rates.ResultsThere was no difference between the groups in terms of diagnosis, age, gender, and BMI. Although both groups had similar VAS scores in the preoperative period and on the fifth postoperative day, there was a significant difference between the groups over the four-day period after surgery. There were no differences in the hospital stay, operative time, additional painkiller consumption, or complication rate between the groups. The average time for comfortable crutch ambulation was 2.8 days in the multimodal pain control protocol group and 5.3 days in the control group.ConclusionsThe multimodal pain control protocol can significantly reduce the level of postoperative pain and improve patients' satisfaction, with no apparent risks, after total hip arthroplasty.