Effect of Posterior Osteophytes on Total Knee Arthroplasty Coronal Soft Tissue Balance: Do They Matter?

BACKGROUND: Achieving coronal plane balance in total knee arthroplasty (TKA) is of paramount importance. There is concern that obtaining balancing before removal of posterior osteophytes may lead to asymmetrical extension balance once removed. We hypothesized that there is a particular posterior osteophyte size and location that does not result in significant change in coronal gap balancing. METHODS: In this study of 245 robotic arm-assisted TKAs, the size and location of posterior osteophytes were obtained from preoperative computer tomography scans. Gap measurements at 10°-25° and 90° flexion after removal of medial and lateral osteophytes, before and after posterior osteophyte removal and bone resection were compared with respect to the size and location of posterior osteophytes. RESULTS: The largest size posterior osteophytes measured >10 mm in 8.2% of cases, 5-10 mm in 34.7%, <5 mm in 23.7%, and 23.7% had no osteophytes. The mean osteophyte size was 5.7 mm. The cohorts with and without posterior osteophytes were both found to have significant but similar changes in all gaps after osteophyte removal and bone resection (mean 0.8-1.4 mm, P < .0001 and mean 0.7-1.7 mm, P < .0001, respectively). Osteophyte size and location had no significant effect on the change in postresection gaps. This included osteophytes greater than 10 mm, but their incidence was small. CONCLUSION: There is a small significant change in gaps between initial assessment and subsequent TKA bone resections, with or without posterior osteophytes. Our study found that where the surgeon thoroughly removes the medial and lateral osteophytes on initial exposure, posterior osteophytes <10 mm can be ignored during initial knee coronal balancing.

Global Budget Revenue on a Single Institution's Costs, Outcomes, and Patient Quality Metrics in Patients Undergoing Total Knee Arthroplasty.

BACKGROUND: Maryland was granted a waiver to implement a Global Budget Revenue (GBR) reimbursement model. Statewide results for combined medical and surgical services have been reported for fiscal years 2015 and 2016. A paucity of studies exists exploring the change in care costs and outcomes for total knee arthroplasty (TKA) recipients under GBR. This study aims to assess the effects of GBR on cost of care and resource utilization related to TKA at a single institution before and after GBR. METHODS: The Maryland Center for Medicare and Medicaid Services database was used to find Medicare patients who underwent TKA at a single institution before (2012-2013) and after (2014-2015) GBR. A total of 150 and 161 TKAs were performed in 2012 and 2015. Cost differences were compared for each inpatient care episode, postacute care period, and readmissions. We also evaluated differences in length of stay, discharge disposition, and complication rates. RESULTS: Mean inpatient cost was significantly lower in 2015 vs 2012 (P = .0014); however, analysis of postacute costs showed a nonsignificant increase in price between years (P = .1008). We demonstrated significant increase in home health (P < .0001) and significant decrease in acute rehabilitation (P = .0481). Durable medical equipment costs significantly decreased (P = .0087). CONCLUSION: We demonstrate lower mean inpatient costs since GBR initiation. We reveal increased mean postacute care costs, which may be due to increased acuity for patients needing postacute care. Our results show nonsignificant reductions in length of stay, complications, and increased rate of home discharge, suggesting GBR may be effective in orchestrating reduced costs for TKA at high-volume institutions.

An Analysis of Centers for Medicare & Medicaid Service Payment in Maryland: Can a Global Budget Revenue Model Save Money in Lower Extremity Arthroplasty?

BACKGROUND: Maryland is the only state utilizing the Global Budget Revenue (GBR) model to reduce costs. The purpose of this study is to evaluate whether the GBR payment model effectively reduced the following: (1) costs of inpatient hospital stays; (2) post-acute care costs; (3) lengths of stay (LOS); (4) readmission rates; and (5) discharge disposition in patients who underwent primary total hip and knee arthroplasty (THA and TKA). METHODS: We evaluated the Maryland Centers for Medicare & Medicaid Service database for THAs and TKAs performed at 6 hospitals 1 year prior to (2012) and after the initiation of GBR (2015). We compared differences in costs for each inpatient care episode, post-acute care periods (total costs, acute rehabilitation, short-term nursing facility, home health, durable medical equipment), readmissions, LOS, and discharge disposition. RESULTS: Hospitals had a significant reduction in mean inpatient care costs for THA and TKA (P < .0001). There was a significant reduction in total post-acute care costs following THA (P < .001). Home healthcare had a significant increase in cost following THA and TKA (P < .0001). There was a significant reduction in durable medical equipment costs for THA (P < .0001). There was a significant decrease in LOS for THA and TKA (P < .0001). There was a significant increase in patients discharged home (THA, P = .0262; TKA, P = .0058). CONCLUSION: The Maryland healthcare model may be associated with a reduction in inpatient and post-acute care costs. Furthermore, implementation of GBR may result in reductions in LOS and readmission rates.

Global Budget Revenue on a Single Institution's Costs and Outcomes in Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: The state of Maryland was granted a waiver by the Center for Medicare and Medicaid Services to implement a Global Budget Revenue (GBR) reimbursement model. This study aims to compare (1) costs of inpatient hospital stays; (2) postacute care costs; (3) lengths of stay (LOS); and (4) discharge disposition who underwent primary total hip arthroplasty at a single Maryland-based orthopedic institution before and after the implementation of GBR. METHODS: The Maryland Center for Medicare and Medicaid Services database was queried to obtain all Medicare patients who underwent total hip arthroplasty at a single institution before and after the implementation of GBR. We compared the differences in costs for the following: inpatient care, the postacute care period, and readmissions. In addition, we evaluated differences in LOS, discharge disposition, and complication rates. RESULTS: There was a significant decrease in inpatient costs ($26,575 vs $23,712), an increase in mean home health costs ($627 vs 1608), and a decrease in mean durable medical equipment costs ($604 vs $82) and LOS (2.92 days vs 2.33 days). There was an increase in discharge to home rates (72.3% vs 78.9%) and a decrease in discharge to acute rehabilitation (4.3% vs 1.8%) CONCLUSION: Under the GBR model, our institution experienced significant cost savings during the inpatient and postacute care episodes. Thus, GBR may serve as a viable solution to reducing costs to Medicare for high-volume arthroplasty institutions with a large Medicare population. Multicentered studies are needed to verify our results.

How to Approach a Recalled Dual Modular Hip Implant: An Update.

BACKGROUND: The aim of this study was to provide an update on the "Modular taper junction corrosion and failure: how to approach a recalled total hip arthroplasty implant" (Pivec et al JOA 2014) publication. METHODS: We performed a comprehensive review of the literature in English, with search terms referencing to the diagnosis, management, and outcomes of patients who underwent total hip arthroplasty with a recalled dual modular hip implant. RESULTS: Based on this review and the new guidelines by the American Academy of Orthopedic Surgeons and the Hip Society, we propose an updated algorithm for the diagnosis and management of patients with these recalled implants. CONCLUSION: When encountering patients with these prostheses, it is imperative to take a step-by-step approach to evaluate whether patients are having potential complications. We hope that this has further clarified the appropriate steps that need to be carried out when confronted with these recalled devices.

Femoral Component Revision of Total Hip Arthroplasty.

Modern primary total hip arthroplasty (THA) is among the most successful operations in medicine. It has been a consistently effective treatment for end-stage osteoarthritis of the hip. With the increasing number of primary THA procedures being performed and the decreasing age of patients undergoing the procedure, there is an inevitable associated increase in revision burden for arthroplasty surgeons. Revision THA is most often indicated for instability, aseptic loosening, osteolysis, infection, periprosthetic fracture, component malposition, and catastrophic implant failure. Understanding the etiology of THA failure is essential for guiding clinical decision making. Femoral component revision presents a complex challenge to the arthroplasty surgeon because of modern implant design as well as bone loss in the proximal femur. Thorough patient evaluation, defect classification, and well-executed surgical reconstruction based on comprehensive preoperative planning may determine the postoperative results. Knowledge of various reconstructive options and the indications for each is necessary to achieve a successful outcome. This article highlights the most common indications for revision after THA and offers recommendations for how to approach revision of the femoral component. Specifically, the authors review preoperative assessment, common classification systems for femoral deficiency, techniques for component extraction, and modalities of femoral component fixation. [Orthopedics. 2016; 39(6):e1129-e1139.].

Patellar Resurfacing Versus Circumferential Denervation of the Patella in Total Knee Arthroplasty.

This study compared the rates of anterior knee pain and functional outcomes between resurfaced patellas and non-resurfaced patellas with a circumpatellar denervation. One hundred ten patients who underwent patellar resurfacing or a circumpatellar denervation were evaluated for knee pain and functional outcomes at a minimum of 2 years after total knee arthroplasty. There were no significant differences between the 2 groups regarding Knee Society Scores, anterior knee pain scores, or visual analog scale scores. The groups had similar incidences of anterior knee pain. Most patients reported no to mild effect of anterior knee pain on daily living. Patients in each group reported increased pain with kneeling, squatting, and departing an automobile. Similar proportions of patients were disappointed with their overall outcomes in each group. Circumpatellar denervation and patellar resurfacing during total knee arthroplasty lead to similar incidences of anterior knee pain. [Orthopedics. 2016; 39(5):e1019-e1023.].

Radiographic Evaluation of Hip Dislocations Necessitating Revision Total Hip Arthroplasty.

Although prosthetic hip dislocation is a common reason for revision arthroplasty, few studies have comprehensively evaluated the radiographic factors that may lead to the need for revision. Therefore, the authors radiographically evaluated all prosthetic hip dislocations that were treated at one institution. They then specifically assessed those that required revision surgery. The authors found that the prosthetic center of rotation (pCOR) was located superolateral and inferolateral to the native COR (nCOR) in all patients. Most hips had pCOR distances more than 5 mm from the nCOR. Furthermore, most patients had cup inclination and anteversion angles within Lewinnek's previously defined "safe zone." Determining these similarities and properly planning these procedures may help decrease the instability rate and therefore improve the overall success of this procedure. [Orthopedics.2016; 39(5):e1011-e1018.].

Cementless Tapered Femoral Stems for Total Hip Arthroplasty in Octogenarians.

BACKGROUND: The use of cementless femoral components has become the standard in younger patients due to increased implant survivorship and decreased loosening. However, it remains controversial whether these femoral stems can provide comparable results in elderly patients. Therefore, our purpose was to compare the (1) incidence of revisions; (2) clinical outcomes; (3) incidence of postoperative blood transfusions; and (4) differences in complications between the 2 cohorts. METHODS: Seventy-four consecutive patients (78 hips) aged 80 years or older, who underwent primary total hip arthroplasty using a cementless, tapered, femoral stem were retrospectively compared with a matched cohort of 76 patients (78 hips) who were less than 80 years. Mean age was 83 years (range, 80-91 years) vs 59 years (range, 17-79 years) for the matched group. Minimum follow-up was 2 years. Revision rates, clinical outcomes using the Harris Hip Score, incidences of complications, and postoperative transfusion rates were evaluated. RESULTS: In the octogenarian cohort, the aseptic survivorship was 99%, compared with 95% in the matched group. There were 2 aseptic loosenings (2.6%): 1 femoral implant loosening (1.3%) and 1 acetabular loosening, but only 1 revision was performed, as one of the patients declined revision surgery. In the matched cohort, there were 6 revisions (7.7%). There were no significant differences in revision rates between the 2 cohorts, and no significant differences in final Harris Hip Score scores. The incidence of blood transfusion in the study group was 42% vs 19% in control group (P < .01). CONCLUSION: The use of cementless, tapered, femoral stems yielded excellent results in the octogenarian group, although adequate patient preoperative optimization is necessary given the significantly higher transfusion incidence.

Can We Really "Feel" a Balanced Total Knee Arthroplasty?

BACKGROUND: Balancing techniques in total knee arthroplasty are often based on surgeons' subjective judgment. However, newer technologies have allowed for objective measurements of soft tissue balancing. This study compared the use of sensor technology to the 30-year surgeon experience regarding (1) compartment loads, (2) soft tissue releases, and (3) component rotational alignments. METHODS: Patients received either sensor-guided soft tissue balancing (n = 10) or manual gap balancing (n = 12). Wireless, intraoperative sensor tibial inserts were used to measure intracompartmental loads. The surgeon was blinded to values in the manual gap-balancing cohort. In the sensor cohort, the surgeon was unblinded, and implant trials were placed after normal releases were performed to guide further ligament releases after femoral and tibial resections, as needed. Load measurements were taken at 10°, 45°, and 90°. RESULTS: The sensor cohort had lower medial and lateral compartment loading at 10°, 45°, and 90°. The sensor group had lower mean differences in intercompartment loading at 10° (-5.6 vs -51.7 lbs), 45° (-9.8 vs -45.9 lbs), and 90° (-4.3 vs -27 lbs) compared to manually balanced patients. There were 10 additional soft tissue releases in the sensor cohort (2 initial ones before sensor use), compared to 2 releases in the gap-balanced cohort. In the gap-balanced cohort, tibial trays were positioned at a mean 9° external rotation, compared to a mean 1° internal rotation in the sensor-guided cohort. CONCLUSION: Sensor-balanced total knee arthroplasties provide objective feedback to perform releases and potentially improve knee balancing and rotational alignment. Future work may clarify whether these changes are beneficial for our patients.

Characteristics and Complications of Super-Obese Patients Who Underwent Total Knee Arthroplasty.

Preoperative demographic characteristics, comorbidities, length of stay and surgery, and postoperative complications were compared between super-obese (n=1042) and nonobese (n=19,929) patients who underwent total knee arthroplasty. Super-obese patients were younger, were predominantly women, had an increased incidence of comorbid conditions such as diabetes and hypertension as well as a high rate of superficial and deep wound infections, and had a longer mean length of stay and operative time. Although super-obese patients have unique demographic characteristics and increased postoperative complications and length of stay, they may still benefit from total knee arthroplasty. Surgeons should note their high incidence of infections. [Orthopedics. 2016; 39(4):e800-e805.].

Patient-Reported Outcomes Following Total Hip Arthroplasty Stratified by Body Mass Index.

Obese patients undergoing total hip arthroplasty have been shown to have less functional recovery. This study prospectively compared temporal trends in patient-reported outcomes and activity levels between patients with a body mass index (BMI) of less than 30, 30 to 35, and 35 to 40 kg/m(2) after total hip arthroplasty. Patients were evaluated via the Harris Hip Score, Lower Extremity Activity Scale, and Short Form-12 physical and mental components. The results suggest that patients with BMIs of 35 to 40 kg/m(2) might have poorer functional outcomes preoperatively, with function returning more slowly or poor function being sustained and their not reaching other cohorts' levels. Surgeons must counsel these patients regarding functional expectations and the potential for slower functional returns. [Orthopedics. 2016; 39(3):e572-e577.].

Inferomedial or Inferolateral Intra-articular Injections of the Knee to Minimize Pain Intensity.

Pain levels of 3 knee intra-articular corticosteroid injection sites were assessed to determine if an optimal site exists. Patients were stratified by site, demographic, and disease characteristics. All injections were performed by 1 surgeon using a uniform technique. Pain severity was assessed before, 1 minute after, and 5 minutes after injection using a visual analog scale. Mean visual analog scale scores for the lateral suprapatellar, medial infrapatellar, and lateral infrapatellar injection sites were 7, 4, and 2 points, respectively, but this was not statistically significant. These results suggest intra-articular injections should be administered from an inferomedial or inferolateral site to minimize pain intensity. [Orthopedics. 2016; 39(3):e578-e581.].

A Meta-Analysis of Transcutaneous Electrical Nerve Stimulation for Chronic Low Back Pain.

OBJECTIVE: Transcutaneous electrical nerve stimulation (TENS) may provide a safe alternative to current side-effect-heavy narcotics and anti-inflammatories utilized in chronic low back pain. Therefore, we performed a meta-analysis to evaluate the efficacy of TENS for the treatment of chronic low back pain. MATERIALS AND METHODS: We included randomized controlled trials (RCTs), cohort studies, and randomized crossover studies on TENS for the management of low back pain. We utilized a visual analogue scale (VAS) for pain as our primary outcome. Effectiveness of treatment was quantified using improvement in outcome scores for each study. Of the studies that met the criteria, 13 allowed for calculation of weighted mean differences in pain reduction. We used a random model effect to evaluate changes in pain produced by the intervention. RESULTS: Included were nine level I and four level II, encompassing 267 patients (39% male) who had a mean follow-up of seven weeks (range; 2 to 24 weeks). The mean duration of treatment was six weeks (range; 2 to 24 weeks). The standardized mean difference in pain from pre- to post-treatment for TENS was 0.844, which demonstrated significant improvement of TENS on pain reduction. When subdividing treatment duration, patients that were treated for < 5 weeks had significant effects on pain, while those treated for > 5 weeks did not. CONCLUSION: Treatment of chronic low back pain with TENS demonstrated significant pain reduction. The application of TENS may lead to less pain medication usage and should be incorporated into the treatment armamentarium for chronic low back pain.

Prospective, Longitudinal Evaluation of Gender Differences After Total Hip Arthroplasty.

Temporal trends in survivorship, patient-reported outcomes, and activity levels following total hip arthroplasty were compared between 61 men and 127 women. Overall implant survivorship was excellent for both genders. Similar functional improvements were found between men and women out until 5 years. Some gender differences were observed: men had a faster time to functional recovery and higher preoperative Short-Form 12-item survey mental component scores, whereas women had a significant improvement in Short-Form 12-item survey mental component scores. Increased understanding of these differences by patients and surgeons, combined with gender-based interventions, may further advance outcomes for these patients.

Bilateral Symmetrical Comparison of Femoral and Tibial Anatomic Features.

BACKGROUND: Variability in morphologic features of the human lower extremity within and across populations has been reported, but limb asymmetry within individuals is often overlooked. For example, in 19 studies of version of the lower extremity in the literature, 6 document asymmetry in the population, but none of these reports document asymmetry in an individual. The aim of this study was to identify the (a)symmetry and quantify variability in the tibiae and femora of matched pairs of limbs. More specifically, using a computed tomography scan database tool, we (1) identified (a)symmetry between paired left and right legs for angulation, version, and alignment features and (2) calculated the percentage of paired limbs with >1° of (a)symmetry for each evaluated parameter. METHODS: Computerized axial tomographic scans (<1.0 mm slices) from bilateral lower limbs of 361 skeletally mature subjects without bone pathology were prospectively acquired. Bones were segmented and morphologic features were measured. RESULTS: Angular features are symmetric left to right, but rotational features are not, with 7° of mean asymmetry in femoral anteversion (range: 0°-23°) and 3° of asymmetry in tibial version (range: 0°-8°). CONCLUSIONS: This study disproves the hypothesis that human limbs are absolutely symmetric, confirming instead that there is asymmetry in version between left and right paired limbs. Surgeons strive for symmetry in lower extremity reconstruction, and they often compare side to side in outcome studies, believing that normal limbs are absolutely symmetric when this is not necessarily true. These assumptions concerning lower extremity symmetry need to be reassessed.

The Economic Impact of Periprosthetic Infections After Total Hip Arthroplasty at a Specialized Tertiary-Care Center.

BACKGROUND: Periprosthetic infections after total hip arthroplasty represent an increased risk for patient morbidity and mortality, and an increased economic burden. The purpose of this study was to compare a group of patients who had periprosthetic infections after total hip arthroplasty to a matched group of patients who underwent primary total hip arthroplasty in terms of the associated costs, length of hospitalization, and number of readmissions (within 1 year). METHODS: Between 2007 and 2011, 16 consecutive infected patients were matched to 32 noninfected patients (1:2 ratio). RESULTS: The mean episode cost, length of hospitalization, and median readmissions was significantly higher in the infected group when compared to the matched cohort: $88,623 vs $25,659, 7.6 vs 3.29 days, and 2 vs 0, respectively. CONCLUSION: Periprosthetic infections after THA resulted in an increased episode cost by approximately 3-fold, mean hospitalization period 2-fold, and led to a higher median number of readmissions.