Courtland G. Lewis

Prosthetic component failures in hip arthroplasty surgery

A survey was conducted of the entire membership of the American Association of Hip and Knee Surgeons to determine their experience with total hip arthroplasty (THA) device-related failures. Forty-seven percent of the membership reviewed their preceding 5-year clinical experience and returned the survey instrument. The aggregate 5-year volume encompassed experience with more than 60,000 hip arthroplasties. The median 5-year experience per respondent was 200 metal-based sockets and 214 metal stems. The frequency distribution of the number of hip arthroplasties per respondent was skewed to the right, with fewer surgeons reporting the higher volumes of arthroplasties. In aggregate, 60,115 of the acetabular components used were metal backed. Nonmetal acetabular component usage totaled 3,219. Complete polyethylene failure was defined as fracture or complete wear through of the polyethylene portion of the component. Complete polyethylene failure was seen in 172 metal-backed sockets (29/10,000). Seventy-seven all-polyethylene sockets had complete polyethylene failure (239/10,100). A total of 87 THAs were revised for modular acetabular dissociations for a dissociation rate of 15/10,000. In aggregate, 64,483 metal-stemmed components were used. Femoral stem fractures occurred in 172 for a rate of 27/10,000. A total of 56,965 metallic femoral components were reported as being modular. Dissociation between the femoral head and neck was uncommonly seen (3/10,000). Use of ceramic femoral heads was low (5,023); however, a total of 11 ceramic head fractures were revised in the 5-year period for a failure rate of 22/10,000. The risks of catastrophic prosthetic THA failure are low but vary according to hip component and the manufacturer of the part.

American Academy of Orthopaedic Surgeons clinical practice guideline on: preventing venous thromboembolic disease in patients undergoing elective hip and knee arthroplasty.

AAOS Guideline on Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty Summary of Recommendations The following is a summary of the recommendations of the AAOS’ clinical practice guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty. This summary does not contain rationales that explain how and why these recommendations were developed, nor does it contain the evidence supporting these recommendations. All readers of this summary are strongly urged to consult the full guideline and evidence report for this information. We are confident that those who read the full guideline and evidence report will see that the recommendations were developed using systematic evidence-based processes designed to combat bias, enhance transparency, and promote reproducibility. This summary of recommendations is not intended to stand alone. Treatment decisions should be made in light of all circumstances presented by the patient. Treatments and procedures applicable to the individual patient rely on mutual communication between patient, physician, and other healthcare practitioners. We recommend against routine post-operative duplex ultrasonography screening of patients who undergo elective hip or knee arthroplasty. (Grade of Recommendation: Strong) Patients undergoing elective hip or knee arthroplasty are already at high risk for venous thromboembolism. The practitioner might further assess the risk of venous thromboembolism by determining whether these patients had a previous venous thromboembolism. (Grade of Recommendation: Weak) Current evidence is not clear about whether factors other than a history of previous venous thromboembolism increase the risk of venous thromboembolism in patients undergoing elective hip or knee arthroplasty and, therefore, we cannot recommend for or against routinely assessing these patients for these factors. (Grade of Recommendation: Inconclusive) Patients undergoing elective hip or knee arthroplasty are at risk for bleeding and bleeding-associated complications. In the absence of reliable evidence, it is the opinion of this work group that patients be assessed for known bleeding disorders like hemophilia and for the presence of active liver disease which further increase the risk for bleeding and bleeding-associated complications. (Grade of Recommendation: Consensus) Current evidence is not clear about whether factors other than the presence of a known bleeding disorder or active liver disease increase the chance of bleeding in these patients and, therefore, we are unable to recommend for or against using them to assess a patients risk of bleeding. (Grade of Recommendation: Inconclusive) We suggest that patients discontinue antiplatelet agents (e.g., aspirin, clopidogrel) before undergoing elective hip or knee arthroplasty. (Grade of Recommendation: Moderate) We suggest the use of pharmacologic agents and/or mechanical compressive devices for the prevention of venous thromboembolism in patients undergoing elective hip or knee arthroplasty, and who are not at elevated risk beyond that of the surgery itself for venous thromboembolism or bleeding. (Grade of Recommendation: Moderate) Current evidence is unclear about which prophylactic strategy (or strategies) is/are optimal or suboptimal. Therefore, we are unable to recommend for or against specific prophylactics in these patients. (Grade of Recommendation: Inconclusive) In the absence of reliable evidence about how long to employ these prophylactic strategies, it is the opinion of this work group that patients and physicians discuss the duration of prophylaxis. (Grade of Recommendation: Consensus) In the absence of reliable evidence, it is the opinion of this work group that patients undergoing elective hip or knee arthroplasty, and who have also had a previous venous thromboembolism, receive pharmacologic prophylaxis and mechanical compressive devices. (Grade of Recommendation: Consensus) In the absence of reliable evidence, it is the opinion of this work group that patients undergoing elective hip or knee arthroplasty, and who also have a known bleeding disorder (e.g., hemophilia) and/or active liver disease, use mechanical compressive devices for preventing venous thromboembolism. (Grade of Recommendation: Consensus) In the absence of reliable evidence, it is the opinion of this work group that patients undergo early mobilization following elective hip and knee arthroplasty. Early mobilization is of low cost, minimal risk to the patient, and consistent with current practice. (Grade of Recommendation: Consensus) We suggest the use of neuraxial (such as intrathecal, epidural, and spinal) anesthesia for patients undergoing elective hip or knee arthroplasty to help limit blood loss, even though evidence suggests that neuraxial anesthesia does not affect the occurrence of venous thromboembolic disease. (Grade of Recommendation: Moderate) Current evidence does not provide clear guidance about whether inferior vena cava (IVC) filters prevent pulmonary embolism in patients undergoing elective hip and knee arthroplasty who also have a contraindication to chemoprophylaxis and/or known residual venous thromboembolic disease. Therefore, we are unable to recommend for or against the use of such filters. (Grade of Recommendation: Inconclusive)

Preventing venous thromboembolic disease in patients undergoing elective hip and knee arthroplasty.

This guideline supersedes a prior one from 2007 on a similar topic. The work group evaluated the available literature concerning various aspects of patient screening, risk factor assessment, and prophylactic treatment against venous thromboembolic disease (VTED), as well as the use of postoperative mobilization, neuraxial agents, and vena cava filters. The group recommended further assessment of patients who have had a previous venous thromboembolism but not for other potential risk factors. Patients should be assessed for known bleeding disorders, such as hemophilia, and for the presence of active liver disease. Patients who are not at elevated risk of VTED or for bleeding should receive pharmacologic prophylaxis and mechanical compressive devices for the prevention of VTED. The group did not recommend specific pharmacologic agents and/or mechanical devices. The work group recommends, by consensus opinion, early mobilization for patients following elective hip and knee arthroplasty. The use of neuraxial anesthesia can help limit blood loss but was not found to affect the occurrence of VTED. No clear evidence was established regarding whether inferior vena cava filters can prevent pulmonary embolism in patients who have a contraindication to chemoprophylaxis and/or known VTED.

Risk stratification algorithm for management of patients with metal-on-metal hip arthroplasty: consensus statement of the American Association of Hip and Knee Surgeons, the American Academy of Orthopaedic Surgeons, and the Hip Society.

There should be a low threshold to perform a systematic evaluation of patients with MoM hip arthroplasty as early recognition and diagnosis will facilitate the initiation of appropriate treatment prior to significant adverse biological reactions. A painful MoM hip arthroplasty has various intrinsic and extrinsic causes, and a systematic treatment approach based on the currently available data is presented to optimize management of MoM patients. The risk stratification algorithm presented will continue to develop as further evidence becomes available providing additional insights. While specialized tests such as metal ion analysis are useful modalities for assessing MoM hip arthroplasty, over-reliance on any single investigative tool in the clinical decision-making process should be avoided. Future research focusing on validation of the current diagnostic tools for detecting adverse local tissue reactions as well as optimization of MoM bearings and modular connections to further diminish wear and corrosion is warranted.

The effects of patient age on human osteoblasts’ response to Ti–6Al–4V implants in vitro

Osseointegrated implants are a common therapy for the elderly population as lifespan increases. Understanding the effects of age and sex on osseointegration is important for successful implant therapy. Therefore, the response of primary human osteoblasts (HOB) to implant materials was studied. HOBs were obtained by outgrowth of cells from bone from orthopaedic procedures and categorized as Young (Y), < 15; Middle (M), 30–50; and Old (O), > 60 years old. Initially the HOB phenotype was determined on tissue culture plastic. Alkaline phosphatase (ALP) staining and activity were significantly increased in HOBs from older patients. Message levels of type I collagen (COL), bone sialoprotein (BSP) and ALP were significantly higher (from 2.3‐ to 3.8‐fold) in Y subjects compared to M and O patients at 2 weeks. Studies of the response of HOBs to implant materials were undertaken using Ti–6A1–4V disks prepared in a manner similar to orthopaedic implants. A 1.4‐fold (p < 0.05) increase in cell attachment was found in HOBs from Y compared with O in female subjects but not in male subjects. Cell proliferation at 24 h was not significantly different by age or sex, nor was DNA content different at 2 and 4 weeks. Mineralization in HOB‐implant cultures was 2.3‐fold higher in Y than in O, and 1.7‐fold higher in Y compared to M HOBs from female but not male subjects at 4 weeks. Northern blot and RT‐PCR analysis at 2 weeks of culture showed significantly higher levels (1.6–2.3‐fold) of COL, BSP, and osteocalcin (OC) mRNAs in Y HOBs compared to M and O HOBs from female subjects. We conclude that human osteoblasts from older female patients have a decreased ability to form bone on implants.

Focused Risk Analysis: Regression Model Based on 5,314 Total Hip and Knee Arthroplasty Patients from a Single Institution

We aimed to identify significant demographic, preoperative comorbidity and surgical predictors for major complications for use in the development of a risk prediction tool for a well-defined population as Total Joint Arthroplasty (TJA) patients. Data on 5314 consecutive patients who underwent primary total hip or knee arthroplasty from October 1, 2008 through September 30, 2011 at a single institution were used in a multivariate regression analysis. The overall incidence of a primary endpoint (reoperation during same admission, extended length of stay, and 30-day readmission) was 3.8%. Significant predictors include certain preexisting genitourinary, circulatory and respiratory conditions; ASA>2; advanced age and prolonged operating time. Mental health conditions demonstrate a strong predictive effect for subsequent serious complication(s) in TJA patients and should be included in a risk-adjustment tool.

Bone demineralization induced by cementless alumina-coated femoral stems

The biologic compatibility of ceramic materials has been widely demonstrated, and alumina (Al2O3) has been used extensively in clinical applications for nearly 20 years. The authors examined the behavior of bone tissue adjacent to the alumina coating in eight cementless hip prosthetic stems that appeared radiologically stable and were explanted because of pain. Histologic evaluation demonstrated the presence of a consistent layer of decalcified bone tissue in continuity with and parallel to the prosthetic interface. Based on laboratory findings, the authors attribute this demineralization phenomenon to a high local concentration of aluminum ions with metabolic bone disease, which is histologically comparable to the osteomalacic osteodystrophy described in dialysis patients. These findings must be carefully considered given the potential long-term implications for alumina-coated implants.

Local infiltration analgesia followed by continuous infusion of local anesthetic solution for total hip arthroplasty: a prospective, randomized, double-blind, placebo-controlled study.

BACKGROUND We studied the efficacy of local infiltration analgesia in surgical wounds with 0.2% ropivacaine (50 mL), ketorolac (15 mg), and adrenaline (0.5 mg) compared with that of local infiltration analgesia combined with continuous infusion of 0.2% ropivacaine as a method of pain control after total hip arthroplasty. We hypothesized that as a component of multimodal analgesia, local infiltration analgesia followed by continuous infusion of ropivacaine would result in reduced postoperative opioid consumption and lower pain scores compared with infiltration alone, and that both of these techniques would be superior to placebo. METHODS In this prospective, double-blind, placebo-controlled study, 105 patients were randomized into three groups: Group I, in which patients received infiltration with ropivacaine, ketorolac, and adrenaline followed by continuous infusion of 0.2% ropivacaine at 5 mL/hr; Group II, in which patients received infiltration with ropivacaine, ketorolac, and adrenaline followed by continuous infusion of saline solution at 5 mL/hr; and Group III, in which patients received infiltration with saline solution followed by continuous infusion of saline solution at 5 mL/hr.All patients received celecoxib, pregabalin, and acetaminophen perioperatively and patient-controlled analgesia; surgery was performed under general anesthesia. Before wound closure, the tissues and periarticular space were infiltrated with ropivacaine, ketorolac, and adrenaline or saline solution and a fenestrated catheter was placed. The catheter was attached to a pump prefilled with either 0.2% ropivacaine or saline solution set to infuse at 5 mL/hr.The primary outcome measure was postoperative opioid consumption and the secondary outcome measures were pain scores, adverse side effects, and patient satisfaction. RESULTS There were no differences between groups in the administration of opioids in the operating room, in the recovery room, or on the surgical floor. The pain scores on recovery room admission and discharge and the floor were low and similar between groups. There were no differences in the incidence of adverse side effects among groups. Patient satisfaction with pain management was similar in all groups. CONCLUSIONS Local infiltration analgesia alone or followed by continuous infusion of ropivacaine as part of multimodal analgesia provides no additional analgesic benefit or reduction in opioid consumption compared with placebo following total hip arthroplasty. LEVEL OF EVIDENCE Therapeutic level I. See Instructions for Authors for a complete description of levels of evidence.

Factors that influence provider selection for elective total joint arthroplasty.

BackgroundThe growth of consumer-directed health plans has sparked increased demand for information regarding the cost and quality of healthcare services, including total joint arthroplasty (TJA). However, the factors that influence patients’ choice of provider when pursuing elective orthopaedic care, such as TJA, are poorly understood.Questions/purposesWe evaluated the factors patients consider when selecting an orthopaedic surgeon and hospital for TJA.MethodsTwo hundred fifty-one patients who sought treatment from either an academic or community-based orthopaedic practice for primary TJA completed a 37-item survey using a 5-point Likert scale rating (“unimportant” to “very important”) regarding seven established clinical and nonclinical dimensions of care patients considered when selecting a provider and hospital.ResultPatients rated physician manner (average Likert, 4.7) and physician quality (eg, outcomes) (average Likert, 4.6) as most important in their selection of surgeon and hospital for TJA. Despite the expressed importance of surgeon and hospital quality, only 46% of patients were able to find useful information to compare outcomes among surgeons, and 47% for hospitals that perform TJA.ConclusionsOur findings suggest physician manner and surgical outcomes are the most important considerations for patients when choosing a provider for elective TJA. Cost sharing is the least important criterion patients considered. Patients expressed high motivation to seek out provider quality information but indicated accessible and actionable sources of information are lacking. Future efforts should be directed at developing clinically relevant, easily interpretable, objective, risk-adjusted measures of physician and hospital quality.

Evaluation of the first-generation AAOS clinical guidelines on the prophylaxis of venous thromboembolic events in patients undergoing total joint arthroplasty: experience with 3289 patients from a single institution.

BACKGROUND Patients undergoing total hip or total knee arthroplasty have risks that include venous thromboembolism. The American Academy of Orthopaedic Surgeons has promulgated guidelines for the preoperative assessment of patients with the primary objective of preventing pulmonary embolism. We aimed to evaluate and establish the utility of the first-generation American Academy of Orthopaedic Surgeons guidelines for the prophylaxis of venous thromboembolism in patients undergoing total joint arthroplasty at a single institution. METHODS A prospective analysis of 3289 consecutive patients managed with total hip or total knee arthroplasty at the Connecticut Joint Replacement Institute between June 1, 2009, and April 30, 2011, was conducted. Data on age, sex, body mass index, American Society of Anesthesiologists classification, and a personal or family history of blood clots requiring long-term warfarin use were analyzed, as were data on a personal history of a malignant tumor, a bleeding disorder, gastrointestinal bleeding, or a hemorrhagic cerebrovascular accident. All patients were managed prophylactically with a specific algorithm based on the American Academy of Orthopaedic Surgeons guidelines. All of the patients were mobilized on postoperative day one, and pneumatic foot-pump compression was used for the duration of the hospitalization. RESULTS Thirty-six major venous thromboembolic events were documented with Doppler ultrasound or computed tomography angiography, for a ninety-day incidence of 1.1% (95% confidence interval, 0.8% to 1.5%). A personal history of blood clots was significantly associated with a blood clot in the proximal part of the thigh or a pulmonary embolism, but a family history of blood clots and a personal history of a malignant tumor did not show a significant relationship with venous thromboembolism. The ninety-day incidence of venous thromboembolism was significantly different between total hip arthroplasty patients (0.56%; 95% confidence interval, 0.30% to 1.15%) and total knee arthroplasty patients (1.46%; 95% confidence interval, 1.01% to 2.10%). The risk was greater in high-risk total knee arthroplasty patients compared with high-risk total hip arthroplasty patients despite comparable prophylaxis with enoxaparin sodium for twenty-eight days. CONCLUSIONS The prospective use of the first-generation American Academy of Orthopaedic Surgeons guidelines resulted in a low incidence of clinically important thromboembolic events in total hip and total knee arthroplasty patients. When properly used in these patients, the guidelines to minimize adverse outcomes are executable and effective. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.