Whole Blood Metal Levels in the Setting of an Oncologic Endoprosthesis: Is There Cause for Concern?

BACKGROUND: Massive modular endoprostheses have become a primary means of reconstruction after oncologic resection of a lower extremity tumor. These implants are commonly made with cobalt-chromium alloys that can undergo wear and corrosion, releasing cobalt and chromium ions into the surrounding tissue and blood. However, there are few studies about the blood metal levels in these patients. QUESTION/PURPOSE: What is the whole blood cobalt and chromium ion level in patients with massive modular endoprostheses? METHODS: We performed a cross-sectional study of our total joints registry to identify patients with a history of an endoprosthetic reconstruction performed at our institution. Patients who were alive at the time of our review in addition to those undergoing an endoprosthetic reconstruction after an oncologic resection were included. Whole blood samples were obtained from 27 (14 male and 13 female) patients with a history of a lower extremity oncologic endoprosthesis. The median time from surgery to blood collection was 8 years (range 6 months to 32 years). Blood samples were collected and stored in metal-free ethylenediaminetetraacetic acid tubes. Samples were analyzed on an inductively coupled plasma mass spectrometer in an International Organization for Standardization seven-class clean room using polytetrafluoroethylene-coated instruments to reduce the risk of metal contamination. The analytical measuring range was 1 to 200 ng/mL for chromium and cobalt. Cobalt and chromium levels were considered elevated when the blood level was ≥ 1 ppb. RESULTS: Cobalt levels were elevated in 59% (16 of 27) of patients, and chromium levels were elevated in 26% (seven of 27). In patients with elevated metal ion values, 15 of 17 patients had a reconstruction using a Stryker/Howmedica Global Modular Replacement System implant. CONCLUSION: Blood metal levels were elevated in patients who received reconstructions using modular oncology endoprostheses Future work is needed to establish appropriate follow-up routines and determine whether and when systemic complications occur because of elevated metal levels and how to potentially address these elevated levels when complications occur. Prospective and retrospective collaboration between multiple centers and specialty societies will be necessary to address these unknown questions in this potentially vulnerable patient group. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Long-term outcome of total hip arthroplasty in patients with multiple hereditary exostosis.

BACKGROUND: Multiple hereditary exostosis (MHE) is a rare autosomal dominant disorder characterized by multiple osteochondromas. There is a paucity of literature concerning total hip arthroplasty (THA) in patients with MHE. The aim of this study is to report long-term outcomes of THA in patients with MHE. METHODS: Fourteen patients undergoing 15 THA's for the treatment of osteoarthritis in the presence of osteochondromas and proximal femoral deformity secondary to MHE were reviewed. Mean age at the time of surgery and follow-up was 56 and 12 years. Seven (47%) had uncemented femoral components. Eleven hips had coxa valga on preoperative imaging. Clinical outcomes were assessed with both Harris hip scores (HHS) and Musculoskeletal Tumor Society Scores (MSTS). RESULTS: Following surgery, there was an improvement in the HHS (48-82, p < 0.01) and MSTS scores (41-70%, p < 0.01). Complications occurred in 5 patients leading to reoperation in 3 patients, of which 2 patients underwent a revision procedure at 19 and 20-years postoperative. The 10-year revision free survival was 100%. CONCLUSIONS: THA in the setting of MHE reliably improves patient function. One in three patients will have a postoperative complication; however, the long-term incidence of revision is low.

Midterm outcomes of total hip arthroplasty after internal hemipelvectomy and iliofemoral arthrodesis.

BACKGROUND AND OBJECTIVES: Recent studies have reported acceptable outcomes after arthrodesis takedown and conversion to total hip arthroplasty (THA); however, there are no reports on outcomes after oncologic resection, which are inherently complex and may portend poorer outcomes. The purpose of this study was to examine the surgical and functional outcomes of patients who underwent prior hemipelvectomy for tumor resection and were later converted to THA. METHODS: All patients who had prior iliofemoral arthrodesis after oncologic resection that were later converted to THA at a single institution were examined. Charts were reviewed for demographic information, operative information, functional outcomes, and complications/reoperations. RESULTS: All three patients in this study were males who underwent internal hemipelvectomies for chondrosarcoma. Patients were converted to THA at a mean of 26 years after arthrodesis. Mean follow-up after conversion to THA was 7.4 years. During this follow-up period, two of the three patients required revision surgery. At last follow-up, the mean Harris Hip Score was 81 and the mean Mayo Hip Score was 67, and all patients were ambulatory without significant pain. CONCLUSIONS: Overall, patients who undergo iliofemoral arthrodesis after oncologic hemipelvectomy and are later converted to THA can expect to have a reasonable outcome, despite a high rate of complications and revision surgery.

Radiographic Accuracy of Malseated Dual-Mobility Liners Varies Based on Implant Design.

BACKGROUND: Dual-mobility constructs have gained popularity to mitigate dislocations after high-risk primary and revision total hip arthroplasties. Contemporary data have indicated that malseating of modular dual-mobility liners occurs in up to 6% of cases. The purpose of this cadaveric-based radiographic study was to determine the ability to accurately determine if modular dual-mobility liners were seated. METHODS: There were 10 hips (5 cadaveric pelvic specimens) used to implant modular dual-mobility liners of 2 designs. One had a liner that seated flush and the other had an extended rim. There were 20 constructs that were well-seated and 20 constructs were intentionally malseated. A comprehensive series of radiographs was reviewed by 2 blinded surgeons. Statistical analyses included Chi-squared testing, logistic regressions, and kappa statistics. RESULTS: Radiographic assessment of liner malseating was not accurate with an elevated rim design with misdiagnosis in 40% (16 of 40). The flush design had diagnostic errors in 5% (2 of 40; P = .0002). Logistic regressions demonstrated a significantly higher risk of misdiagnosing a malseated liner in the elevated rim group (odds ratio 13). There were 12 of 16 misdiagnoses in the elevated rim group failing to recognize a malseated liner. Each surgeon had almost perfect agreement for intraobserver reliability for flush designs (k 0.90) and fair agreement in the elevated rim design (k 0.35). CONCLUSION: A comprehensive series of plain radiographs can reliably detect a malseated modular dual-mobility liner with a flush rim design in 95% of cases. However, elevated rim designs are more difficult to accurately identify malseating on plain radiographs.

Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies Project - Phase III Outcomes.

BACKGROUND: Our institution initiated the Orthopedic Surgery and Anesthesiology Surgical Improvement Strategies (OASIS) project in 2017 to improve the quality and efficiency for hip and knee arthroplasties. Phase III of this project aimed to: 1) increase same-day discharge (SDD) of primary total joint arthroplasties (TJAs) to 20%; 2) maintain or improve 30-day readmission rates; and 3) realize cost savings and revenue increases. METHODS: All primary TJAs performed between 2021 and 2022 represented our study cohort, with those in 2019 (prepandemic) establishing the baseline cohort. A multidisciplinary team met weekly to track project tactics and metrics through the entire episode of care from preoperative surgical visit through 30 days postoperatively. RESULTS: The SDD rate increased from 4% at baseline to 37%, with mean lengths of stay (LOS) decreasing from 1.5 to 0.9 days for all primary TJAs. The 30-day readmission rate decreased to 1.2 from 1.3%. Composite changes in surgical volume and cost reductions equaled $5 million. CONCLUSION: Application of a multidisciplinary team with health systems engineering tools and methods allowed SDD to increase from 4 to 37% with a mean LOS <1 day, resulting in a $5 million incremental gain in profit at a major academic medical center. Importantly, patient safety was not compromised as 30-day readmission rates remained stable. LEVEL OF EVIDENCE: III Therapeutic.

Frank Stinchfield Award: Does Bariatric Surgery Prior to Primary Total Hip Arthroplasty Really Improve Outcomes?

BACKGROUND: Optimal management of morbid obesity before total hip arthroplasty (THA) remains debated. Recently, bariatric procedures have become more common with advancements in surgical techniques. We hypothesized that bariatric surgery prior to primary THA would mitigate acute postoperative complications and improve implant survivorship. METHODS: A retrospective review from 1995 to 2020 identified 88 primary THA procedures in 71 unique patients who previously underwent bariatric surgery (73% Roux-en-Y). This cohort was matched 1:1:1 for age, gender, surgical year, American Society of Anesthesiologists score, and Charlson Comorbidity Index to cohorts of patients with body mass index (BMI) <40 kg/m2 and BMI ≥40 kg/m2. Revisions, reoperations, and acute complications were compared. Subgroup analysis then evaluated historical (pre-2012) relative to contemporary (2012 and after) bariatric procedures. RESULTS: Revision rates for bariatric patients were higher relative to controls with low (hazard ratio [HR] 19, P < .01) and high BMI (HR 8, P < .01). Reoperation rates showed a similar increase for bariatric patients when compared to low (HR 9, P < .01) and high BMI (HR 4, P = .01) patients. Moreover, bariatric patients had an increased dislocation risk compared to the low (HR 7, P = .03) and high BMI (HR 17, P < .01) patients. Contemporary bariatric techniques had similar complications, revisions, and reoperations relative to historical procedures. CONCLUSION: Morbidly obese patients undergoing THA have increased risks of certain complications, but it is unclear if bariatric surgery improves this risk. This study found that patients undergoing bariatric surgery have worse implant survivorship and higher dislocation rates compared to patients with naturally low and high BMIs. Further investigation into the post-bariatric metabolic state is warranted. LEVEL OF EVIDENCE: Prognostic Level IV.

Does Bariatric Surgery Prior to Primary Total Knee Arthroplasty Improve Outcomes?

BACKGROUND: Recent advancements in bariatric surgical techniques have increased its utilization for the management of morbid obesity prior to total knee arthroplasty (TKA). We hypothesized that bariatric surgery prior to primary TKA would mitigate postoperative complications and improve implant survivorship. METHODS: A retrospective review from 1992-2020 identified 205 bariatric surgery patients with subsequent primary TKA. This cohort was matched 1:1:1 to patients without bariatric surgery and with BMI <40 kg/m2 and BMI ≥40 kg/m2. Revisions, reoperations, and 90-day complications were evaluated. Subgroup analysis evaluated bariatric patients with BMI >40 kg/m2 at TKA, the time between surgeries, and compared historical to contemporary bariatric techniques. RESULTS: Bariatric patients demonstrated higher revision rates than low (HR 4, P < .01) and high BMI (HR 9, P < .01) controls, and increased reoperations when compared to the low (HR 2, P < .01) and high BMI (HR 6, P < .01) groups. Reoperation for instability was more common in bariatric patients than low (HR 15, P = .01) and high BMI (HR 17, P < .01) groups. Reoperation for infection was higher in bariatric patients relative to the high BMI (HR 6, P = .03), but not the low BMI cohort (HR 3, P = .06). There was no difference in 90-day complications (P = .33). Bariatric patients with high BMI and contemporary bariatric procedures did not significantly impact complications or survivorship, but bariatric surgery >2 years before TKA was associated with higher revision rates (P = .01). CONCLUSION: This study found that bariatric surgery patients who undergo primary TKA have worse implant survivorship, mostly related to infection and instability. Further investigation into perioperative optimization is warranted. LEVEL OF EVIDENCE: Prognostic Level IV.

The ACS-NSQIP surgical risk calculator is a poor predictor of postoperative complications in patients undergoing oncologic distal femoral replacement.

BACKGROUND: Distal femur replacement (DFR) has become a preferred reconstruction for tumors involving the femur but is associated with known complications. The ACS-NSQIP surgical risk calculator is an online tool developed to estimate postoperative complications in the first 30-days, however, has not been used in patients undergoing DFR. The purpose of this study was determining the utility of the ACS-NSQIP calculator to predict postoperative complications. METHODS: 56 (30 male, 26 female) patients who underwent DFR were analyzed using the CPT codes: 27,365 (Under Excision Procedures on the Femur and Knee Joint), 27,447 (Arthroplasty, knee, condyle and plateau), 27,486 (Revision of total knee arthroplasty, with or without allograft), 27,487 (Revision of total knee arthroplasty, with or without allograft) and 27,488 (Repair, Revision, and/or Reconstruction Procedures on the Femur [Thigh Region] and Knee Joint). The predicted rates of complications were compared to the observed rates. RESULTS: Complications were noted in 30 (54%) of patients. The predicted risk of complications based off the CPT codes were: 27,356 (14%); 27,447 (5%); 27,486 (7%); 27,487 (8%) and 27,488 (12%). Based on ROC curves, the use of the ACS-NSQIP score were poor predictors of complications (27356, AUC 0.54); (27447, AUC 0.45); (27486, AUC 0.45); (27487, AUC 0.46); (27488, AUC 0.46). CONCLUSIONS: Distal femur arthroplasty performed in the setting of oncologic orthopedics is a complex procedure in a "high risk" surgical group. The ACS-NSQIP does not adequately predict the incidence of complications in these patients and cannot be reliably used in the shared decision-making process.

Utility of the ACS-NSQIP surgical risk calculator in predicting postoperative complications in patients undergoing oncologic proximal femoral replacement.

INTRODUCTION: Proximal femur replacement (PFR) in the setting of tumor resection is associated with a high rate of postoperative complication. The online American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator is approved by the Center of Medicare and Medicaid services to estimate 30-day postoperative complications. This study was to determine if the ACS-NSQIP can predict postoperative complications following PFR. METHODS: We reviewed 103 (61 male and 42 female) patients undergoing PFR using the Current Procedural Terminology (CPT) codes available in the calculator: 27125 (hemiarthroplasty), 27130 (total hip), 27132 (conversion to total hip), 27134 (revision total hip), 27137 (revision acetabulum), 27138 (revision femur), and 27365 (excision tumor hip). The predicted rates of complications were compared with the observed rates. RESULTS: Complications occurred in 54 (52%) of patients, with the predicted risk based on CPT codes: 27125 (21.5%); 27130 (7.8%); 27132 (16.6%), 27134 (17.8%), 27137 (14.4%), 274138 (22.7%), and 27365 (16.2%). The calculator was a poor predictor of complications (27125, area under the curve [AUC] 0.576); (27130, AUC 0.489); (27132, AUC 0.490); (27134, AUC 00.489); (27137, AUC 0.489); (27138, AUC 0.471); and (27365, AUC 0.538). CONCLUSION: Oncologic PFR is known for complications. The ACS-NSQIP does not adequately predict the incidence of complications, and therefore cannot reliably be used in their shared decision-making process preoperative.

Contemporary Porous Titanium Acetabular Components for Total Hip Arthroplasty After Pelvic Radiation.

BACKGROUND: Patients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study is to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, porous titanium acetabular components in the setting of prior pelvic radiation. METHODS: We retrospectively reviewed 33 patients (38 hips) with prior pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (DePuy Synthes) in 76%. Eight-seven percent of cups were fixed with screws. The mean age at primary THA was 74 years, 76% were male, and the mean body mass index was 30 kg/m2. Mean follow-up was 5 years. RESULTS: The 10-year survivorship free of revision for aseptic loosening, free of any revision, and free of any reoperation were 100%, 89%, and 89%, respectively, when accounting for death as a competing risk. There were 3 revisions; one each for taper corrosion, recurrent dislocation, and infection. Radiographically, all cups had evidence of osteointegration and none had radiographic evidence of loosening. The mean Harris Hip Score improved from 50 to 84 postoperatively (P < .0001). CONCLUSION: Contemporary porous titanium acetabular components with supplemental screws provided excellent implant fixation in patients with prior therapeutic pelvic radiation. At 10 years, 100% of these components were free of revision for aseptic loosening and 100% were radiographically well-fixed. LEVEL OF EVIDENCE: Level IV, Therapeutic.

Safe Positioning for Sexual Intercourse After Proximal Femoral Replacement.

Hip arthroplasty is a common procedure used for the treatment of fractures and degenerative processes affecting the hip. Proximal femoral replacement is an uncommon type of hip arthroplasty used for reconstruction after extensive bone loss. Proximal femoral replacement is used most commonly after the resection of the proximal femur for malignancies and for extensive bone loss encountered in revision hip arthroplasty and occasionally for extensive bone loss after fractures. The authors present a case of a female patient who sustained a prosthetic dislocation of her proximal femoral replacement during sexual intercourse. Standard hip arthroplasty itself can pose a risk factor for dislocation associated with certain sexual positions. Proximal femoral replacement surgery likely carries an increased risk for dislocation, given the magnitude of soft tissue loss at the time of resection. The authors believe that routine perioperative conversations for sexually active patients with proximal femur replacements should include this potential risk and discuss appropriate positioning to prevent a potential dislocation. [Orthopedics. 2018; 41(2):e292-e294.].

Readability of Patient Education Materials in Hand Surgery and Health Literacy Best Practices for Improvement.

PURPOSE: This study aimed to update a portion of a 2008 study of patient education materials from the American Society for Surgery of the Hand Web site with new readability results, to compare the results to health literacy best practices, and to make recommendations to the field for improvement. METHODS: A sample of 77 patient education documents were downloaded from the American Society for Surgery of the Hand Web site, handcare.org, and assessed for readability using 4 readability tools. Mean readability grade-level scores were derived. Best practices for plain language for written health materials were compiled from 3 government agency sources. RESULTS: The mean readability of the 77 patient education documents in the study was 9.3 grade level. This reading level is reduced from the previous study in 2008 in which the overall mean was 10.6; however, the current sample grade level still exceeds recommended readability according to best practices. CONCLUSIONS: Despite a small body of literature on the readability of patient education materials related to hand surgery and other orthopedic issues over the last 7 years, readability was not dramatically improved in our current sample. Using health literacy as a framework, improvements in hand surgery patient education may result in better understanding and better outcomes for patients seeing hand surgeons. CLINICAL RELEVANCE: Improved understanding of patient education materials related to hand surgery may improve preventable negative outcomes that are clinically significant as well as contribute to improved quality of life for patients.