Pes Planovalgus Is Associated with Increased Comorbidities and Poor Outcomes After Total Knee Arthroplasty.

Pes planovalgus affects knee biomechanics but there are no studies describing its impact on total knee arthroplasty (TKA). We aim to characterize the demographics, medical, and surgical complications of patients with pes planovalgus undergoing TKA. A Medicare database was queried using ICD-9 codes to identify 5,750 patients with and 23,000 patients without pes planovalgus who underwent TKA from 2005 to 2014. Standard descriptive statistics were used to compare medical and surgical complications at 90 days and 2 years, with alpha < 0.003 after a Bonferroni Correction. Patients with pes planovalgus had an elevated incidence of hypertension (80%, p < 0.001), pulmonary disease (31%, p < 0.001), hypothyroidism (28%, p < 0.001), diabetes (30%, p < 0.001), vascular disease (20%, p < 0.001), obesity (26%, p < 0.001), and depression (23%, p < 0.001). They also had increased odds of deep vein thrombosis (DVT) (odds ratio [OR] 1.3, p < 0.001), stiffness (OR 1.3, p < 0.003) and revision (OR 1.59, p < 0.003) at 90 days. At 2 years, odds of stiffness had increased (OR 1.34, p < 0.001) with similar rates of revision and medical complications. Pes planovaglus is associated with increased medical comorbidities and this patient population may be at an increased risk for postoperative stiffness, early revisions, and DVT after TKA. Arthroplasty surgeons should be conscious of these risks when considering TKA in a patient with pes planovalgus and counsel them appropriately. (Journal of Surgical Orthopaedic Advances 32(3):202-206, 2023).

Impact of Certificate of Need on Lumbar Discectomy Reimbursement and Utilization.

The Certificate of Need (CON) program was established to respond to increasing healthcare costs; however, its impact on spine surgery trends is not well understood. The purpose of this study was to evaluate the impact of CON status on utilization of single-level lumbar discectomy. A combined Medicare and private payor database was used to identify single-level lumbar discectomies performed from 2007 to 2015. Utilization and reimbursement trends were compared using the compound annual growth rate (CAGR) with reimbursement adjusted by the consumer price index. In total, 30,617 lumbar discectomies were analyzed. Procedure utilization increased across all settings. CAGR was highest in the outpatient CON group (19.7%) and lowest in the inpatient non-CON group (0.5%). Reimbursement increased in the outpatient setting (CAGR: 1.2% CON, 1.0% non-CON), but decreased in the inpatient setting (CAGR: -6.1% CON, -5.5% non-CON). These trends are important to consider in a value-based healthcare environment. (Journal of Surgical Orthopaedic Advances 31(1):026-029, 2022).

Impact of Certificate of Need on Lumbar Discectomy Reimbursement and Utilization.

The Certificate of Need (CON) program was established to respond to increasing healthcare costs; however, its impact on spine surgery trends is not well understood. The purpose of this study was to evaluate the impact of CON status on utilization of single-level lumbar discectomy. A combined Medicare and private payer database was used to identify single level lumbar discectomies performed from 2007 to 2015. Utilization and reimbursement trends were compared using the compound annual growth rate (CAGR) with reimbursement adjusted by the consumer price index. For this study, 30,617 lumbar discectomies were analyzed. Procedure utilization increased across all settings. CAGR was highest in the outpatient CON group (19.7%) and lowest in the inpatient non-CON group (0.5%). Reimbursement increased in the outpatient setting (CAGR: 1.2% CON, 1.0% non-CON), but decreased in the inpatient setting (CAGR: -6.1% CON, -5.5% non-CON). These trends are important to consider in a value-based healthcare environment. (Journal of Surgical Orthopaedic Advances 31(4):218-221, 2022).

Notching of the Neck After Acetabular Constraint Necessitating Femoral Component Revision.

A 75-year-old woman who had previously undergone a left revision total hip arthroplasty with the use of a constrained acetabular liner presented with recurrent dislocation of the hip. Intraoperatively, there was metallic staining of the hip capsule and significant notching of the femoral neck, consistent with impingement of the intact locking ring, necessitating stem revision. Constrained acetabular liners have high failure rates due to intraprosthetic impingement, but to our knowledge, failure due to notching of the femoral component and metallosis from repeated impingement has not been described. Surgeons should be aware of this potential mode of failure.

Effect of Comorbidity Burden on the Risk of Venous Thromboembolic Events After Total Knee Arthroplasty.

BACKGROUND: Venous thromboembolic events (VTEs) are common after total knee arthroplasty (TKA). The rate of VTEs has improved with early mobilization, mechanical prophylaxis, and appropriate chemoprophylaxis. The aim of this study was to analyze the contribution of medical comorbidities to the risk of VTE after TKA. METHOD: Medicare claims from 2005 to 2014 were queried. International Classification of Diseases, Ninth revision (ICD-9), and Current Procedural Terminology codes were used to identify the diagnoses, procedures, and complications. 157,200 primary TKAs were age, sex, and Elixhauser Comorbidity Index (ECI) matched with 157,200 osteoarthritis controls. First instances of deep venous thrombosis (DVT) and pulmonary embolism were tracked at 90 days and 2 years. Odds ratios (ORs), confidence intervals, and P-values (p) were calculated and used to investigate the contribution of comorbidities. RESULTS: 90 days after TKA or OA diagnosis, comorbidities were associated with 45% of the DVT risk, 38% of the PE risk. 1 in 92 patients would be expected to be diagnosed with VTE after TKA and 1 in 136 patients after only the diagnosis of osteoarthritis. After 90 days, medical comorbidities were associated with 70% of the DVT risk, 68% of the PE risk. CONCLUSION: Nearly 50% of DVTs and 40% of PEs within 90 days of TKA may be related to the baseline health of OA patients. Venous thromboembolic events after TKA are a "never" event according to Center of Medicare and services that appropriate VTE prophylaxis likely cannot be neutralized.

The Impact of Certificate of Need Status on the Utilization and Reimbursement of Open and Endoscopic Carpal Tunnel Release.

A certificate of need (CON) permits a healthcare organization to build new facilities only if significant medical needs exist. Many states have implemented CON programs to prevent procedure overutilization and price inflation. We hypothesized that there are no differences in reimbursement or utilization for open and endoscopic carpal tunnel release (CTR) when comparing states with and without CON programs. We queried a private-payer database to identify open and endoscopic CTRs performed between 2007 and 2015. In total, 82,689 CTRs were identified: 70,160 open, 12,529 endoscopic. Reimbursement increased for open procedures (compound annual growth rate [CAGR] 1.0% CON, 1.4% non-CON) but only marginally increased or decreased in the endoscopic group (CAGR -0.8% CON, 0.2% non-CON). Utilization increased across all settings, and was highest in the endoscopic CON group (CAGR 17.9%). Least growth was seen in the open non-CON group (CAGR 10.0%). Overall, CON programs may not actually decrease CTR spending or utilization. (Journal of Surgical Orthopaedic Advances 30(2):090-092, 2021).

Use of Navigation-Enhanced Instrumentation to Mitigate Surgical Outliers During Total Knee Arthroplasty.

Computer-assisted orthopedic surgery improves mechanical alignment and the accuracy of surgical cuts in the context of total knee arthroplasty (TKA). A simplified, navigation-enhanced instrumentation system was assessed to determine whether the same effects could be achieved with a less intrusive system. Two cohorts of surgeons (experienced and trainees) performed a series of TKA cuts using models with and without navigation-enhanced instrumentation. The accuracy of each system was determined via the rate of outliers, measured as any cut that deviated from the planned cut by more than 2° or 2 mm. The effect of experience level was limited, with only the outlier rate for tibial varus or valgus measurement showing a significant difference between user groups with conventional instrumentation (P=.004). The use of navigation-enhanced instrumentation significantly reduced the total outlier rate compared with conventional instrumentation from 35% to 4% for experienced users (P<.001) and from 34% to 10% for trainees (P<.001). These results suggest that navigation-enhanced instrumentation is a viable alternative to conventional instrumentation to reduce outlier rates and improve cut accuracy. This trial also showed that additional experience may not correlate with improved surgical accuracy. Outliers may not reflect individual surgical ability as much as limitations of the instrumentation or other unidentified factors. [Orthopedics. 2021;44(1):54-57.].

Utilization and Reimbursement Trends Based on Certificate of Need in Single-level Cervical Discectomy.

OBJECTIVE: To compare utilization and reimbursement for cervical discectomy in certificate of need (CON) and non-CON states. SUMMARY OF BACKGROUND DATA: Cervical discectomy is a commonly performed procedure, but little is known about utilization and reimbursement patterns in the CON setting. INTRODUCTION: Cervical discectomy is increasingly used and remains effective. Increasing healthcare costs have led to decreased reimbursement and a push toward outpatient procedures. CON programs were established to ensure that expansion of medical facilities were within acceptable use; however, the literature on their impact in spine surgery is limited. The purpose of this study was to examine the impact of CON status on both reimbursement and utilization in cervical decompression in both inpatient and outpatient settings. METHODS: We analyzed a private payer and Medicare database from 2007 to 2015. All single-level cervical discectomies were selected then split into CON and non-CON states. Each group was then further split into inpatient and outpatient. Utilization and reimbursement were analyzed using the compound annual growth rate (CAGR), with reimbursement adjusted by the US Bureau of Labor Statistics Consumer Price Index. RESULTS: We identified 1,580 single level cervical decompressions in our study period: 888 were done in the inpatient setting, whereas 692 were done in the outpatient setting. Adjusted reimbursement only increased in the non-CON outpatient setting, with a CAGR of 2.0%. All other settings had decreased reimbursement. Utilization increased across all four settings, with the highest growth seen in the CON outpatient setting, with a CAGR of 12.7%. The highest average reimbursement was in the non-CON outpatient setting at $4,237. DISCUSSION: Cervical discectomy is seeing increased utilization most rapidly in the outpatient setting, although reimbursement is declining with the exception of procedures done in the non-CON outpatient setting. Surgeons should be aware of these trends in the changing healthcare economic climate. STUDY DESIGN: A retrospective database review.

Reimbursement and Complications in Outpatient vs Inpatient Unicompartmental Arthroplasty.

BACKGROUND: Increasing utilization of unicompartmental knee arthroplasty (UKA) has driven a greater push for outpatient treatment and cost containment in the setting of bundled payments. The purpose of this study is to evaluate utilization trends of inpatient vs outpatient UKA, index episode and 90-day reimbursement, and any differences in medical or surgical complications. METHODS: The PearlDiver database was employed to identify all inpatient and outpatient UKAs performed between 2007 and 2016 with 2-year follow-up. Patients were matched by age, gender, and Elixhauser Comorbidity Index. We tracked index procedure and global period reimbursement, 90-day medical and surgical complications, and 2-year surgical complications. RESULTS: The reimbursement and utilization cohort included 3181 outpatient and 5490 inpatient UKAs. Outpatient UKA and overall utilization of UKA increased over the study period. Mean index reimbursement of inpatient UKA was $2486.16 higher per procedure (P < .001) while mean global period reimbursement was $2782.13 higher per inpatient procedure (P < .001). Ninety-day medical complications including postoperative anemia (P < .001), transfusion (P = .024), and arrhythmia (P = .004) were more common with inpatient UKAs, whereas surgical wound complications (P = .001) and operative debridement (P = .028) were more common among outpatient UKAs. Outpatient UKA was not associated with an increased risk of periprosthetic joint infection (P > .05), aseptic loosening (P > .05), or revision surgery (P > .05) when compared to inpatient UKA. CONCLUSION: Outpatient UKA utilization is increasing and is associated with decreased reimbursement compared to inpatient UKA without increased risk of major medical complications, although it is associated with increased risk of wound complication and need for operative debridement at 90 days.

Use and Cost of Reverse Shoulder Arthroplasty Versus Hemiarthroplasty for Acute Proximal Humerus Fractures.

Although reverse total shoulder arthroplasty (RTSA) may outperform hemiarthroplasty (HSA) for acute proximal humerus fractures (PHF), both the RTSA implant and the procedure are more expensive. The goal of this study was to compare the use and longitudinal cost of care for RTSA vs HSA for the treatment of PHF. Patients were selected from a private payer database with a surgical date between 2010 and 2015. The International Classification of Diseases, 9th Revision, Clinical Modification(ICD-9-CM), codes were used to identify patients who underwent RTSA and HSA for PHF. The 1-year cost follow-up was guaranteed. During the study period, a total of 1038 patients underwent RTSA and 1046 patients underwent HSA for the treatment of PHF. A total of 601 patients who underwent RTSA and 431 patients who underwent HSA with at least 1 year of follow-up were matched by age and sex. The average Charlson Comorbidity Index for the RTSA and HSA groups was 4, indicating similar health status. From 2010 to 2015, the use of RTSA increased linearly (R2=0.986), whereas the use of HSA decreased linearly (R2=0.796). The average index admission cost was higher for RTSA than for HSA ($15,263 vs $14,356, respectively; mean difference [MD], $907; 95% confidence interval [CI], $58-$1760; P=.04). At 1 year postoperatively, however, no statistically significant difference was noted in cost (P=.535). The 1-year physical and occupational therapy cost per patient was higher after HSA than after RTSA (MD, $723; CI, $718-$728; P<.001), but no difference was noted in discharge disposition or 1-year revision or readmission rates. The results of this study suggest that despite the higher initial cost of RTSA, the total cost of care in the year after RTSA and HSA is similar. Therefore, RTSA should be considered in the appropriate clinical setting. [Orthopedics. 2020;43(2):119-125.].

Venous thromboprophylaxis after total hip arthroplasty: aspirin, warfarin, enoxaparin, or factor Xa inhibitors?

INTRODUCTION: Debate over the ideal agent for venous thromboembolism (VTE) prophylaxis after total hip arthroplasty (THA) has led to changes in prescribing trends of commonly used agents. We investigate variation in utilisation and the differences in VTE incidence and bleeding risk in primary THA after administration of aspirin, warfarin, enoxaparin, or factor Xa inhibitors. METHODS: 8829 patients were age/sex matched from a large database of primary THAs performed between 2007 and 2016. Utilisation was calculated using compound annual growth rate. Incidence of postoperative deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding-related complications, postoperative anaemia, and transfusion were identified at 2 weeks, 30 days, 6 weeks, and 90 days. RESULTS: Aspirin use increased by 33%, enoxaparin by 7%, and factor Xa inhibitors by 31%. Warfarin use decreased by 1%. Factor Xa inhibitors (1.7%) and aspirin (1.7%) had the lowest incidence of DVT followed by enoxaparin (2.6%), and warfarin (3.7%) at 90 days. Factor Xa inhibitors (12%) and aspirin (12%) had the lowest incidence of blood transfusion followed by warfarin (15%) and enoxaparin (17%) at 90 days. There was no difference in incidence of blood transfusion or bleeding-related complications nor any detectable difference in symptomatic PE incidence. CONCLUSIONS: The utilisation of aspirin and factor Xa inhibitors increased over time. Aspirin and factor Xa inhibitors provided improved DVT prophylaxis with lower rates of postoperative anaemia compared to enoxaparin and warfarin.

The Cost of Malnutrition in Total Joint Arthroplasty.

BACKGROUND: Malnutrition is a known risk factor for complications and adverse outcomes after elective total joint arthroplasty (TJA), but little is known about the burden this risk factor places on the healthcare system. The purpose of this study was to evaluate the 90-day impact of malnutrition on medical and surgical complications and understand the increase in global reimbursements associated with TJA in malnourished patients. METHODS: We queried a combined private-payer and Medicare database from 2007 to 2016 for TJA using International Classification of Diseases, 9th revision and Current Procedural Terminology codes. Patients with serum albumin level of <3.5 g/dL were gender, age, and mean Elixhauser Comorbidity Index matched against a cohort with a normal serum albumin level. Odds ratios and confidence intervals were calculated for complications at 90 days postoperatively. Mean index and 90-day global reimbursements were calculated for the two matched groups and compared using P-values. RESULTS: 3053 protein malnourished patients receiving TJA were identified, and 12,202 matched protein nourished patients receiving TJA served as controls. At 90 days, the malnourished groups had increased risk for failure of multiple organ systems, periprosthetic joint infection, and reoperation. The mean 90-day increase in reimbursement was $3875 associated with performing a TJA on a protein malnourished patient (P < .001). CONCLUSION: This study demonstrates an association between malnourished patients and postoperative complications as well as significantly increased reimbursements. Understanding the reimbursement increases at 90 days for TJA in protein malnourished patients is important in the era of bundled payments.

Does ACDF Utilization and Reimbursement Change Based on Certificate of Need Status?

INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) remain an effective treatment option for multiple pathologies of the cervical spine. As the health care economic climate has changed, so have reimbursements with a concomitant push toward outpatient procedures. Certificate of Need (CON) programs were established in response to burgeoning health care costs which require states to demonstrate need before expansion of medical facilities. The impact of this program on spine surgery is largely unknown. The purpose of this study was to examine the impact of CON status on reimbursement and utilization trends of ACDF in both inpatient and outpatient settings. MATERIALS AND METHODS: We queried a combined private payer and Medicare database from 2007 to 2015. All single-level ACDFs were identified. We then split each procedure into those performed in CON versus non-CON states. We then further split each group into the inpatient and outpatient settings. Compound annual growth rate (CAGR) was used to compare utilization and reimbursement trends. Reimbursement was adjusted for inflation using the United States Bureau of Labor Statistics consumer price index. RESULTS: A total of 32,727 single-level ACDFs were identified, of which 28,441 were performed in the inpatient setting, and 4286 were performed in the outpatient setting. Reimbursement decreased across all settings, with the most pronounced decrease in the non-CON outpatient setting with an adjusted CAGR of -11.0%. Utilization increased across all groups, although the fastest growth was seen in the outpatient CON setting with a CAGR of 47.7%, and the slowest growth seen in the inpatient non-CON setting at a CAGR of 12.9%. CONCLUSIONS: ACDF utilization increased most rapidly in the outpatient setting, and CON status did not appear to hinder growth. Reimbursement decreased across all settings, with the outpatient setting in non-CON states most affected. Surgeons should be aware of these trends in the changing health care environment.

Timing of Lumbar Spinal Fusion Affects Total Hip Arthroplasty Outcomes.

Many patients are affected by concurrent disease of the hip and spine, undergoing both total hip arthroplasty (THA) and lumbar spinal fusion (LSF). Recent literature demonstrates increased prosthetic dislocation rates in patients with THA done after LSF. Evidence is lacking on which surgery to do first to minimize complications. The purpose of this study was to evaluate the effect of timing between the two procedures on postoperative outcomes. METHODS: We queried the Medicare standard analytics files between 2005 and 2014. Four groups were identified and matched by age and sex: THA with previous LSF, LSF with previous THA, THA with spine pathology without fusion, and THA without spine pathology. Revision THA or LSF and bilateral THA were excluded. Comorbidities and Charlson Comorbidity Index were identified. Postoperative complications at 90 days and 2 years were calculated after the most recent surgery. Four-way chi-squared and standard descriptive statistics were calculated. RESULTS: Thirteen thousand one hundred two patients had THA after LSF, 10,482 patients had LSF after THA, 104,820 had THA with spine pathology, and 492,654 had THA without spine pathology. There was no difference in the Charlson Comorbidity Index score between the THA after LSF and LSF after THA groups. There was a statistically significant difference in THA dislocation rate, with LSF after THA at 1.7%, THA without spine pathology at 2.3%, THA with spine pathology at 3.3%, and THA after LSF at 4.6%. There was a statistically significant difference in THA revision rate, with THA without spine pathology at 3.3%, LSF after THA at 3.7%, THA with spine pathology at 4.2%, and THA after LSF at 5.7%. CONCLUSION: LSF after THA is associated with a reduced dislocation rate compared with THA after LSF. Reasons may include decreasing pelvic mobility in a stable, well-healed THA or early postoperative spine precautions after LSF restricting positions of dislocation.

Computer Navigation vs Conventional Total Hip Arthroplasty: A Medicare Database Analysis.

BACKGROUND: Computer-assisted surgery (CAS) is applied to total hip arthroplasty (THA) in an attempt to optimize implant positioning. The effect of CAS on postoperative complications after THA remains unknown. Our study aims to assess the change in complication rates when CAS is used in THA. METHODS: The Medicare database was studied from 2005 to 2012. All THAs performed with CAS were identified. A total of 64,944 THAs were identified, including 5412 CAS-THAs and 59,532 conventional THAs. Medical and surgical adverse events were collected at various time points. RESULTS: CAS-THA was not associated with a decreased rate of dislocation at 30 days (1.0% vs 1.2%; odds ratio [OR], 1.14; P = .310), 90 days (1.1% vs 1.4%; OR, 1.23; P = .090), or 2 years (2.3% vs 2.3%; OR, 1.01; P = .931). CAS-THA was associated with a significantly higher rate of periprosthetic fracture at 30 days (0.4% vs 0.6%; OR, 1.46; P = .040) as well as revision THA at 30 days (1.0% vs 1.4%; OR, 1.43; P = .003) and 90 days (1.2% vs 1.7%; OR, 1.42; P < .002) when compared to conventional THA. CAS-THA was associated with a significantly lower rate of deep vein thrombosis and pulmonary embolism when compared to conventional THA at all time points (P < .05). CONCLUSION: Administrative coding data fail to demonstrate any clinically significant reduction in short-term adverse events with CAS-THA. Further study is warranted to evaluate whether the purported benefits of CAS result in a reduction of the adverse events after THA.

Statin use is associated with less postoperative cardiac arrhythmia after total hip arthroplasty.

INTRODUCTION: While statins have been found to reduce postoperative atrial fibrillation after cardiac surgery, little is known about their use in total hip arthroplasty (THA). This study investigated if statins would similarly reduce postoperative arrhythmias in patients undergoing THA. METHODS: We queried a large Medicare and private-payer database from 2005 to 2012 and identified 12,075 patients who were on a statin prior to THA. We then age and sex matched 34,446 non-statin users who underwent THA. Baseline comorbidities and postoperative complications were obtained and assessed via standard descriptive statistics. RESULTS: The statin users had more preoperative comorbidities including congestive heart failure, valvular heart disease, pulmonary and renal disease, diabetes, hypertension, obesity, and anaemia (all p values < 0.001). Postoperatively, the statin users had a statistically higher 90-day incidence of transfusion, acute renal failure, heart failure, pneumonia, and sepsis/shock. All new-onset cardiac arrhythmia was significantly less frequent in the statin group at 2 weeks (3.88% vs. 4.72%, p < 0.001), 30 days (4.47% vs. 5.29%, p < 0.001), and 90 days (5.44% vs. 6.31%, p = 0.001) postoperative. There was no difference in the frequency of venous thromboembolism, myocardial infarction, postoperative anaemia, or bleeding at 90 days postoperative. DISCUSSION: Despite being medically sicker at baseline with multiple risk factors for atrial fibrillation compared to the non-statin users, the statin users displayed a consistently lower occurrence of postoperative cardiac arrhythmia in this retrospective cohort study. Statins may therefore be beneficial in the preoperative optimisation of medically complex patients undergoing THA.

Effect of Computer Navigation on Complication Rates Following Unicompartmental Knee Arthroplasty.

BACKGROUND: We evaluated whether the complication and revision rates of unicompartmental knee arthroplasty (UKA) performed with intraoperative computer-based navigation differ from standard UKAs performed without intraoperative computer-based navigation. METHODS: A Medicare database containing administrative claims data from 2005 to 2014 was queried. Patients who underwent a single UKA and had a minimum of 2 years of follow-up were included in the study. Data from 1025 UKAs performed with navigation were compared against 9228 age and gender-matched UKAs performed without it. Postoperative complications were identified using International Classification of Diseases, Ninth Revision, codes and evaluated at 30 days, 90 days, and 2 years. RESULTS: Orthopedic complications after UKA are rare, and the use of navigation did not affect the rate of conversion to total knee arthroplasty at 2-year follow-up (3.8% in navigated UKAs vs 4.7% in standard UKAs, P = .218). There were also no significant differences in the rates of knee arthrotomy at 2-year follow-up (1.3% in navigated UKAs vs 1.6% in standard UKAs, P = .379). The rates of deep vein thrombosis at 90-day follow-up did not significantly differ between the 2 groups (1.4% in navigated UKAs vs 2.0% in standard UKAs, P = .157). CONCLUSION: This is one of the first studies to use a large cohort to compare outcomes in computer-assisted surgery-UKA against standard UKAs without navigation. The results, particularly that there was not a difference in the rate of conversion to total knee arthroplasty, are directly relevant to clinical decision-making when surgeons are considering employing navigation during UKA.

Comparison of Postoperative Complications Following Metal-on-Metal Total Hip Arthroplasty With Other Hip Bearings in Medicare Population.

BACKGROUND: The use of metal-on-metal (MoM) hip bearings has declined in the recent years due to strong evidence of their high complication rates and early failure. Hip implants with highly cross-linked polyethylene liners and ceramic bearings have become the modern implants of choice. We sought to determine if MoM implants are associated with higher complication and revision rates when compared to other hip bearings in the Medicare population. METHODS: We retrospectively reviewed a Medicare database (2005-2011) for patients who underwent a primary total hip arthroplasty with a MoM, metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), or ceramic-on-ceramic (CoC) implant (minimum 2 years of follow-up). Patient comorbidities and medical/surgical complication rates were analyzed at various time points postoperatively. RESULTS: We identified 288,118 patients, including 81,520 patients with a MoM implant, 162,881 with MoP, 33,819 with CoP, and 9898 with CoC implant. Surgical complication rates were higher for MoM implants including infection, osteolysis/polywear, mechanical complications, and need for hip irrigation and debridement. Overall revision rates were significantly higher for MoM implants (5.28%) compared to MoP (4.28%, odds ratio [OR] 1.26, P < .001) and CoP (3.52%, OR 1.55, P < .001) but only by one to two percent. MoM revision rates were similar to CoC implants (4.94%, OR 1.00, P = .096). CONCLUSIONS: MoM implants were associated with higher revision rates (5.28%) compared to MoP (4.28%) and CoP (3.52%) implants in the Medicare population. Both complication and revision rates were comparable to CoC implants.

Dual Diagnosis and Total Hip Arthroplasty.

The co-occurrence of a mental illness and a substance abuse disorder (SUD) is common and has been referred to as a "dual diagnosis" (DD). Although studies have independently investigated mental illness alone and SUD alone, few have examined the effects of these entities combined on complications. A search of the Medicare database from 2005 to 2012 identified 2000 DD patients who underwent total hip arthroplasty (THA). They were compared with 86,976 patients with mental illness only and 590,689 controls (no mental illness or SUD). Medical comorbidities and postoperative complications at 30-day, 90-day, and minimum 2-year time points were analyzed. There was a significant increase (P<.001) in 7 (53.8%) of 13 recorded postoperative medical complications, including acute renal failure (odds ratio [OR], 1.78), postoperative anemia (OR, 1.31), and blood transfusion (OR, 1.24), at the 90-day time point. In addition, there was a statistically significant increase overall in periprosthetic infection (periprosthetic joint infection OR, 4.30; P<.001), periprosthetic fracture (OR, 2.80; P<.001), dislocation (OR, 6.38; P<.001), and the need for THA revision (OR, 3.58; P<.001). When compared with patients with mental illness only, DD patients remained at significantly (P<.001) increased risk for 90-day and overall postoperative surgical complications, including dislocation, periprosthetic joint infection, and THA revision. Patients with a DD were at significant risk for perioperative complications compared with both control patients and patients with mental illness only. Studies investigating only psychiatric disease or only SUD may miss a vulnerable cohort. Further investigation is needed to exactly define to what extent DD amplifies complication rates. [Orthopedics. 2018; 41(3):e321-e327.].