The burden of metastatic disease of the femur on the Medicare system.

BACKGROUND: In the United States, over 1,650,000 new cases of cancer are being diagnosed yearly with almost 50 % of them being the top five bone-seeking cancers. Since cancer risk increases with age, this suggests that orthopedic oncology services may be a strain on the Medicare system. The femur is the most common site of long bone metastases. Prophylactic fixation techniques prevent pathologic fractures, reduce morbidities, and enhance the quality of life of patients with femoral metastases. This study aims to assess the rate of metastatic disease to the skeleton and evaluate the use and financial burden of femoral prophylactic fixation techniques on the Medicare system. QUESTIONS/PURPOSES: (1) In the Medicare population, has the number of skeletal metastases increased? (2) In the Medicare population, has the use of prophylactic fixation techniques increased? (3) How has the financial burden of prophylactic fixation changed over the study period? METHODS: The Medicare database was searched between 2005 and 2014 with the assistance of PearlDiver Technologies Inc. and the RBRVS DataManager Online from the American Medical Association. Searches were completed by using International Classification of Disease-9 (ICD-9) and current procedural terminology (CPT) codes for secondary malignant neoplasms and prophylactic fixation techniques. Facility charges, Medicare reimbursement and length of hospital stay were extracted from the Medicare database. Simple linear regression was performed to test the significance of yearly changes and the coefficient of determination was used to assess the strength of the correlation. RESULTS: (1) In the Medicare population, has the number of skeletal metastases increased? While the number of Medicare patients with skeletal metastases has increased from 132,452 in 2005 to 155,819 in 2012 (p = 0.01, r2 = 0.72), the prevalence of skeletal metastases in this population remained constant at 30.66 cases per 10,000 Medicare patients in 2012 (p = 0.56, r2 = 0.06). (2) In the Medicare population, has the use of prophylactic fixation techniques increased? The number of prophylactic fixation techniques has not increased from 2005 to 2014 (p = 0.68, r2 = 0.02); however, the rate of prophylactic fixation among those diagnosed with skeletal metastases has significantly decreased from 94.6 per 10,000 in 2005 to 82.72 per 10,000 in 2012 (p = 0.006, r2 = 0.74). (3) How has the financial burden of prophylactic fixation changed over the study period? Both total and average hospital charges increased after adjusting for inflation in the total Medicare population; however, only the average Medicare reimbursement changed to reflect this. The total amount Medicare spent on prophylactic fixation techniques in 2012 was $20,245,957 after adjusting to 2014. Despite the increase in hospital charges and average Medicare reimbursement, the average length of hospital stay in the total Medicare population showed a significant decreased trend-down from 7.51 days in 2005 to 5.86 days in 2012 (p = 0.02, r2 = 0.81). CONCLUSIONS: Although the prevalence of metastatic disease to the skeleton remained stable between 2005 and 2012 in the Medicare population, prophylactic femoral fixation techniques declined in elderly adults between 2005 and 2014. This most likely signifies an increase in other treatment modalities that can prevent pathologic fractures such as prophylactic hemiarthroplasty, bisphosphonates, and/or radiation therapy. LEVEL OF EVIDENCE: Level IV, Cross-sectional Study.

Updated Outcomes of Prophylactic Femoral Fixation.

Despite an increasing number of patients with metastatic bone disease (MBD), minimal data exist regarding outcomes of patients undergoing prophylactic femoral fixation for MBD when compared with other frequently performed orthopedic operations, such as hemiarthroplasty of the femur. The authors performed a retrospective database review evaluating these procedures due to similar operative times and patient populations and also reviewed common comorbidities such as body mass index (BMI). The goal was to provide updated results of prophylactic femoral fixation and evaluate whether certain patient risk factors (eg, BMI) altered 30-day survival for patients with MBD. The authors reviewed 1849 patients with and without MBD treated by prophylactic fixation and hemiarthroplasty from 2006 to 2011 identified in the American College of Surgeons National Surgical Quality Improvement Program database. There were no significant differences in complications between patients undergoing surgical treatment for impending or actual femoral fracture. In addition, there were no differences between the 217 patients with MBD in either the hemiarthroplasty or prophylactic fixation groups because the rate of death within 30 days postoperatively was 5.56% and 3.30%, respectively (P=.526). When comparing BMI, obese patients had higher rates of wound infection, and underweight patients were more likely to develop pneumonia or die within 30 days postoperatively. Patients with impending femur fractures benefit from prophylactic fixation and perform as well in the short term as patients undergoing hemiarthroplasty. Certain BMI categories (underweight or obese) contributed to poorer outcomes. These findings provide updated information for discussing risks and benefits with surgical candidates.

A Comparison of Single Shot Adductor Canal Block Versus Femoral Nerve Catheter for Total Knee Arthroplasty.

The aim of this study was to compare perioperative analgesia provided by single-injection adductor canal block (ACB) to continuous femoral nerve catheter (FNC) when used in a multimodal pain protocol for total knee arthroplasty (TKA). A retrospective cohort study compared outcome data for 148 patients receiving a single-injection ACB to 149 patients receiving an FNC. The mean length of stay (LOS) in the ACB group was 2.67 (±0.56) and 3.01 days (±0.57) in the FNC group (P<0.0001). The median ambulatory distances for the adductor group were further than the femoral group for postoperative days 1 (P<0.0001) and 2 (P=0.01). Single-injection ACB offered similar pain control and earlier discharge compared to continuous FNC in patients undergoing TKA.

Low rates of heterotopic ossification after resurfacing hip arthroplasty with use of prophylactic radiotherapy in select patients.

Recent reports have noted higher rates of heterotopic ossification (HO) with surface replacement arthroplasty (SRA) than with traditional total hip arthroplasty in the absence of postoperative HO prophylaxis. This study reports rates and grades of HO in 44 SRA patients with at least 1 year of follow-up. Heterotopic ossification prophylaxis was used in 32 (73%) of 44 cases. Heterotopic ossification prophylaxis consisted of radiotherapy (22/32), nonsteroidal anti-inflammatory drugs (8/32), or both (2/32). One case of clinically significant HO was documented in the no-prophylaxis group. This strategy of selective HO prophylaxis in patients felt by orthopedic surgeons to be at high risk of HO resulted in low rates of clinically relevant HO after SRA (1/44, 2.3%). Further study is needed to establish optimal selection criteria for HO prophylaxis after SRA.

Large-head metal-on-metal total hip arthroplasty using the Durom acetabular component at minimum 1-year interval.

Large-head metal-on-metal total hip arthroplasty represents novel technology, and outcome data are lacking. We prospectively compared the performance of a nonmodular metal-on-metal acetabular component (Durom; Zimmer, Warsaw, IN) with a modular titanium component (Trilogy, Zimmer). All Durom components placed at our institution with minimum 1-year follow up (n = 63) were compared with an age- and sex-matched Trilogy control group (n = 100). Failure defined as revision or persistent moderate/severe groin pain was significantly higher for the Durom (11.1%) compared with the Trilogy group (0%) (P = .002). Although all acetabular components in both groups appeared radiographically stable, no significant bone ingrowth was noted at the time of Durom revisions. We could not identify any patient/surgical-related factors predictive of failure. Further study is needed to determine the scientific basis for these observations.

Radiotherapy to bone has utility in multifocal metastatic renal carcinoma.

Renal cell carcinoma metastases to bone are classically considered radioresistant. We reviewed 28 patients who underwent irradiation for metastatic renal cell carcinomas to bone to test the hypothesis that irradiation of renal metastases to bone provides adequate palliation in carefully selected patients. Metastases were multifocal in all patients. All patients were followed until death. Overall, 36 index radiotherapy treatments were given as palliative initial treatment for 36 osseous metastatic sites. Twenty-five of 36 sites (69.5%) had no subsequent radiotherapy. Eight sites (22.2%) underwent repeat radiotherapy at a mean 28.9 weeks after treatment. Two (5.6%) additional sites underwent surgery at the site at an average 74 weeks later, and a pathologic fracture occurred at one (2.8%) site 3 weeks after irradiation. Overall, 33 of 36 (91.7%) sites had only radiotherapy as their source of palliation. Median times to return to pretreatment pain and functional levels, however, were 2 months and 1 month, respectively. Radiotherapy to osseous sites appears to control pain for the short term and generally prevents fractures and avoids the need for surgery in renal cell carcinoma patients with multiple bone metastases.

Gluteal muscle attachment during proximal femoral reconstruction in a canine model.

In this 18 month in vivo canine study we compared three methods of attaching the gluteal muscles to the proximal femur during hip reconstruction with an allograft-prosthesis composite (APC). All three methods are commonly practiced in human hip revision surgery and data on their effectiveness in dogs is directly relevant to human treatment. The methods compared were host gluteal tendon sutured to allograft tendon, host greater trochanter apposed to allograft using a cable grip system, and host cortical bone shells around the allograft secured with cerclage wires. For each method, we assessed changes in allograft-host bone fusion, weight bearing, gluteal muscle mass, and structural properties through qualitative radiography, gait analysis, histology, and biomechanical testing. Hip reconstruction using the WRAP method resulted in the greatest limb use with complete resolution of gluteal muscle atrophy 18 months after surgery. This method yielded a stronger, more stable hip joint that allowed for more normal limb function. These hips had the more rapid rate of bony union at the host bone-allograft junction and little resorption of the graft. The increased limb use and resultant larger gluteal muscle mass conferred to the WRAP hip composites the greatest tensile strength and stiffness when tested 18 months after reconstruction. There was a large amount of new bone formation on the periosteal surface where the WRAP reconstructions had an overlay of live bone that resulted in a more rapid union and increased cortical width at the level of the osteotomy. New bone also penetrated into the allograft a greater distance from the osteotomy in the WRAP group.

Prospective analysis of a novel long-acting oral opioid analgesic regimen for pain control after total hip and knee arthroplasty.

Parenteral opioid use after total knee (TKA) and hip (THA) arthroplasty often results in substantial functional interference and side effects. This prospective study compared use of traditional intravenous patient-controlled analgesia (IV PCA) with a novel oral regimen after TKA and THA. Sixty-two patients received IV PCA and 62 received scheduled long-acting and, as needed, short-acting oral opioids postoperatively. Surveys and chart audits documented functional interference, pain scores, opioid-related side effects, and opioid consumption. Patients who received the oral regimen had significantly less opioid consumption (P < .05) and experienced less functional interference (P < .05) than the IV PCA group. Both groups had similar pain scores and incidence of opioid side effects. This study demonstrates some significant advantages of an oral analgesic regimen compared with IV PCA after TKA and THA.

The diagnostic and predictive value of hip anesthetic arthrograms in selected patients before total hip arthroplasty.

Concurrent osteoarthritis of the hip and lumbar spine occurs frequently. Our study tests the hypothesis that hip anesthetic arthrograms can be used as predictive diagnostic tool before total hip arthroplasty when standard evaluation techniques fail to provide convincing evidence of the source of pain. Thirty-four consecutive hip anesthetic arthrograms were reviewed retrospectively. Quantified outcome measures included Visual Analog Pain Score, Harris Hip Score, and patient satisfaction. The pain relief after hip anesthetic arthrogram accurately predicted pain relief after hip arthroplasty (positive predictive value = 95.23%, negative predictive value = 87.5%). Our study supports the selected use of hip anesthetic arthrograms in the preoperative assessment of patients with concurrent hip and lumbar spine osteoarthritis associated with nondiagnostic history and physical examinations.

Inflammatory changes in ruptured canine cranial and human anterior cruciate ligaments.

OBJECTIVE: To compare expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K and histologic changes in canine cranial cruciate ligaments (CCLs) and human anterior cruciate ligaments (ACLs). STUDY POPULATION: Sections of cruciate ligaments from 15 dogs with ruptured CCLs, 8 aged dogs with intact CCLs, 14 human beings with ruptured ACLs, and 11 aged human beings with intact ACLs. PROCEDURE: The CCLs and ACLs were evaluated histologically, and cells containing TRAP and cathepsin K were identified histochemically and immunohistochemically, respectively. RESULTS: The proportion of ruptured CCLs that contained TRAP+ cells was significantly higher than the proportion of intact ACLs that did but similar to proportions of intact CCLs and ruptured ACLs that did. The proportion of ruptured CCLs that contained cathepsin K+ cells was significantly increased, compared with all other groups. Numbers of TRAP+ and cathepsin K+ cells were significantly increased in ruptured CCLs, compared with intact ACLs. The presence of TRAP+ cells was correlated with inflammatory changes, which were most prominent in ruptured CCLs. CONCLUSION AND CLINICAL RELEVANCE: Results suggest that synovial macrophage-like cells that produce TRAP are an important feature of the inflammation associated with CCL rupture in dogs. Identification of TRAP and cathepsin K in intact CCLs and ACLs from aged dogs suggests that these enzymes have a functional role in cruciate ligament remodeling and repair. We hypothesize that recruitment and activation of TRAP+ macrophage-like cells into the stifle joint synovium and CCL epiligament are critical features of the inflammatory arthritis that promotes progressive degradation and eventual rupture of the CCL in dogs.

Hybrid total knee arthroplasty: a retrospective analysis of clinical and radiographic outcomes at average 10 years follow-up.

Cemented total knee arthroplasty has demonstrated high success rates at 10-12 years. Although many cementless designs have demonstrated inferior outcomes, hybrid fixation has not been studied in detail. We retrospectively reviewed 112 hybrid total knee arthroplasties (PCA-67 and Duracon-45) after clinical and radiographic review using the SF-12 and Knee Society Scores at an average 10-year follow-up. The revision rate was 4.5%: 4 occurred in patients with metal-backed patellae and 1 in a patient with infection. No revisions were performed for aseptic loosening of the femoral component. Hybrid total knee arthroplasty with these designs provided excellent clinical and radiographic performance at 10 years comparable to cemented series. Aseptic loosening and radiographic failure rates were 0% if patients with metal-backed patellae were excluded. The durability of hybrid fixation beyond 10 years deserves further study.

Critical evaluation of Mirels' rating system for impending pathologic fractures.

This project examined the hypothesis that Mirels' rating system for impending pathologic fractures is reproducible, valid, and applicable across various experience levels and training backgrounds. Twelve true clinical histories and corresponding radiographs for patients with femoral metastatic lesions were reviewed by 53 participants from five experience levels: orthopaedic residents, musculoskeletal radiologists, orthopaedic attendings, fellowship-trained practicing orthopaedic oncologists, and radiation or medical oncologists. Each examiner provided individual and total Mirels' scores and independent determination of impending fracture using clinical judgment. A subset of seven histories without prophylactic fixation provided a natural history group. There was highly significant agreement across experience categories for overall Kappa and for the concordance for individual and overall scores. Kappa analysis showed good agreement for site, moderate agreement for type, and fair agreement for size and pain. There was no significant difference in overall scores across experience levels. The pooled odds ratio favored Mirels rating system over clinical judgment regardless of experience level. Overall sensitivity was 91% and specificity was 35%. Mirels' system seems to be reproducible, valid, and more sensitive than clinical judgment across experience levels. However, although the system is a valuable screening tool, more specific parameters are needed.

Thermal chondroplasty with bipolar and monopolar radiofrequency energy: effect of treatment time on chondrocyte death and surface contouring.

PURPOSE: The purpose of this study was to evaluate chondrocyte viability and surface contouring of articular cartilage using confocal laser microscopy (CLM) and scanning electron microscopy (SEM), respectively, during different treatment time intervals with monopolar and bipolar radiofrequency energy (RFE). TYPE OF STUDY: In vitro analysis using chondromalacic human cartilage. METHODS: Forty-two fresh osteochondral sections from patients undergoing partial or total knee arthroplasties were used to complete this study. Each of 36 sections was divided into 2 distinct 1-cm(2) regions that were treated with either bipolar or monopolar RFE. Six sections were maintained as untreated controls. Six RF treatment time intervals were evaluated: 5, 10, 15, 20, 30, and 40 seconds (6 specimens per time interval per group). After treatment, each specimen was processed for CLM and SEM. RESULTS: CLM demonstrated that the depth of chondrocyte death in the monopolar RFE treatment group was significantly less than the bipolar group at each of the same time intervals (P <.05). SEM showed that each RFE device began to contour and smooth the articular surface after 15 seconds of treatment. CONCLUSIONS: When applying thermal chondroplasty, a broad treatment time range could result in variable degrees of cartilage smoothness and significant chondrocyte death.

Adverse clinical events during cemented long-stem femoral arthroplasty.

The occurrence and risk factors for adverse clinical events associated with cemented long-stem femoral arthroplasty were studied. The hypothesis was that patients with femoral metastatic disease and previously uninstrumented canals were at higher risk for such adverse events. Fifty-five consecutive patients requiring long-stem femoral arthroplasty at two institutions were retrospectively reviewed. Adverse clinical events including hypotension, sympathomimetic administration, and O 2 desaturation were subclassified according to the timing of their occurrence. Adverse events occurred in 34 of 55 patients (62%), including coma in two patients and death in a third patient. The three catastrophic events occurred in patients with metastatic disease involving previously uninstrumented femoral canals. Desaturation was more frequent in patients with metastatic disease and previously uninstrumented canals compared with patients who had revision arthroplasty and patients with previously instrumented femoral canals. Preexisting medical illness was a significant risk factor in total adverse clinical events that included cement-associated adverse clinical events and cement-associated and postoperative hypotension. In long-stem cemented femoral components risk factors for adverse clinical events included metastatic disease, uninstrumented femoral canals, and preexisting medical conditions. These findings underscore the importance of appropriate patient selection, patient and family education, and anesthesia preparation before long-stem cemented femoral arthroplasty.