Intraoperative Femoral Head Dislodgement During Total Hip Arthroplasty: A Report of Four Cases

Dislodgment of trial femoral heads and migration into the pelvis during total hip arthroplasty is a rarely reported complication with limited published cases. There are three primary mechanisms of femoral head separation: dislodgement during reduction attempt, disassociation from anterior dislocation while assessing anterior stability, and during dislocation after implant trialing. If the trial femoral migrates beyond the pelvic brim, it is safer to finish the total hip arthroplasty and address the retained object after repositioning or in a planned second procedure with a general surgeon. We recommend operative retrieval since long-term complications from retention or clinical results are lacking

Total Hip Arthroplasty Dislocation after Cardioversion: A Case Report

New onset postoperative atrial fibrillation (AF) is the most common perioperative arrhythmia in the elderly. The incidence after total joint arthroplasty is much lower than other non-cardiac surgeries. Since postoperative atrial fibrillation can cause increased length of hospital stay, mortality, and healthcare costs, it is critical to focus on prevention and prompt management. New onset atrial fibrillation is treated with rhythm control for patients who demonstrate hemodynamic instability or refractory to rate control measures. Electrical cardioversion is an effective option for unstable patients with known complications. However, there is limited data on orthopedic problems after cardioversion. A unique case is reported presenting postoperative total hip arthroplasty (THA) dislocation after electrical cardioversion for new onset atrial fibrillation in the postanesthesia care unit (PACU)

Diagnosis and Management of Fungal Periprosthetic Joint Infections

Fungal periprosthetic joint infection (PJI) is a devastating complication because it can be difficult to diagnose, manage, and eradicate. Fungal PJI treatment requires a systematic approach. Increased awareness is essential when patients with painful arthroplasties present with immunosuppression, significant comorbidities, multiple surgeries, and history of drug use. Every suspected fungal PJI should be promptly diagnosed using readily available serum and synovial fluid markers. Surgical management involves débridement, antibiotics, and implant retention, one-stage exchange arthroplasty, prosthetic articulating spacers, and two-stage exchange arthroplasty. Because mycotic infections develop robust biofilms, the utility of débridement, antibiotics, and implant retention and one-stage revisions seem limited. A thorough irrigation and débridement is essential to decrease infection burden. Adjunctive local and systemic antifungal therapy is critical, although the agent choice and duration should be tailored appropriately. Future high-quality studies are needed to develop standardized guidelines for the management of fungal PJI

2018 John Charnley Award: Analysis of US Hip Replacement Bundled Payments: Physician-Initiated Episodes Outperform Hospital-Initiated Episodes

BACKGROUND: The Centers for Medicare & Medicaid Services (CMS) launched the Bundled Payment for Care Improvement (BPCI) initiative in 2013 to create incentives to improve outcomes and reduce costs in various clinical settings, including total hip arthroplasty (THA). This study seeks to quantify BPCI initiative outcomes for THA and to determine the optimal party (for example, hospital versus physician group practice [PGP]) to manage the program. QUESTIONS/PURPOSES: (1) Is BPCI associated with lower 90-day payments, readmissions, or mortality for elective THA? (2) Is there a difference in 90-day payments, readmissions, or mortality between episodes initiated by PGPs and episodes initiated by hospitals for elective THA? (3) Is BPCI associated with reduced total Elixhauser comorbidity index or age for elective THA? METHODS: We performed a retrospective analysis on the CMS Limited Data Set on all Medicare primary elective THAs without a major comorbidity performed in the United States (except Maryland) between January 2013 and March 2016, totaling more than USD 7.1 billion in expenditures. Episodes were grouped into hospital-run BPCI (n = 42,922), PGP-run BPCI (n = 44,662), and THA performed outside of BPCI (n = 284,002). All Medicare Part A payments were calculated over a 90-day period after surgery and adjusted for inflation and regional variation. For each episode, age, sex, race, geographic location, background trend, and Elixhauser comorbidities were determined to control for major confounding variables. Total payments, readmissions, and mortality were compared among the groups with logistic regression. RESULTS: When controlling for demographics, background trend, geographic variation, and total Elixhauser comorbidities in elective Diagnosis-Related Group 470 THA episodes, BPCI was associated with a 4.44% (95% confidence interval [CI], -4.58% to -4.30%; p \u3c 0.001) payment decrease for all participants (USD 1244 decrease from a baseline of USD 18,802); additionally, odds ratios (ORs) for 90-day mortality and readmissions were unchanged. PGP groups showed a 4.81% decrease in payments (95% CI, -5.01% to -4.61%; p \u3c 0.001) after enrolling in BPCI (USD 1335 decrease from a baseline of USD 17,841). Hospital groups showed a 4.04% decrease in payments (95% CI, -4.24% to 3.84%; p \u3c 0.01) after enrolling in BPCI (USD 1138 decrease from a baseline of USD 19,799). The decrease in payments of PGP-run episodes was greater compared with hospital-run episodes. ORs for 90-day mortality and readmission remained unchanged after BPCI for PGP- and hospital-run BPCI programs. Patient age and mean Elixhauser comorbidity index did not change after BPCI for PGP-run, hospital-run, or overall BPCI episodes. CONCLUSIONS: Even when controlling for decreasing costs in traditional fee-for-service care, BPCI is associated with payment reduction with no change in adverse events, and this is not because of the selection of younger patients or those with fewer comorbidities. Furthermore, physician group practices were associated with greater payment reduction than hospital programs with no difference in readmission or mortality from baseline for either. Physicians may be a more logical group than hospitals to manage payment reduction in future healthcare reform. LEVEL OF EVIDENCE: Level II, economic and decision analysis

Management and Prevention of Intraoperative Acetabular Fracture in Primary Total Hip Arthroplasty.

Intraoperative acetabular fracture (IAF) is a rare complication of primary total hip arthroplasty (THA). Known risk factors include poor bone stock, underreaming of the acetabular bed, and use of elliptic components. There is a paucity of literature on risk factors, treatment strategies, and outcomes of this potentially devastating complication. We studied the incidence of IAF in primary THA at our high-volume institution. We reviewed 21,519 primary THA cases and identified 16 patients (16 hips) with IAFs. Mean follow-up was 4 years (range, 0-10 years). Implant data were recorded, and acetabular components were identified as elliptic modular or hemispheric modular. The institution\u27s IAF rate was 0.0007%. All IAFs were associated with uncemented acetabular components. Sixty-nine percent of the fractures were not appreciated during surgery. All posterior column fractures required operative intervention in the immediate or early (\u3c3 \u3emonths) postoperative period. Compared with anterior column fractures, posterior column fractures were associated with acetabular component instability and need for additional surgery. In this article, we also present strategies for managing and preventing IAF in primary THA. This rare fracture requires prompt recognition and often necessitates aggressive management. More study is needed to determine how to better manage IAFs

Intraoperative Proximal Tibia Periprosthetic Fractures in Primary Total Knee Arthroplasty.

Intraoperative fracture of the proximal tibia is a rare complication of total knee arthroplasty (TKA) with few studies available reporting risk factors or prognosis. A review of our prospective joint registry was performed to determine the incidence and associated risk factors of intraoperative tibia fractures during primary TKA; 14,966 TKAs of all manufacturers were performed with 9 intraoperative tibia fractures. All fractures occurred in a single TKA design. There were 8,155 TKAs of this design performed with a fracture incidence of 0.110%. All but one fracture occurred on the medial tibial plateau, and all but one occurred during preparation of the tibia with keel punching. A control group of 75 patients (80 knees) with the same TKA design were randomly selected. Baseplates size 3 or smaller were less likely to experience an intraoperative fracture (odds ratio [OR]: 0.864, 95% confidence interval [CI]: 0.785-0.951), as were knees with a polyethylene insert thickness of 13 mm or larger (OR: 0.882, 95% CI: 0.812-0.957). Fractures were treated with a variety of different methods, but every patient had at least one screw placed and most (67%) had postoperative weight-bearing restrictions. At final follow-up, there were no cases of nonunion, component subsidence, or need for reoperation. Intraoperative tibia fractures are a rare complication of this TKA design at 0.11%. Knees with baseplates of size ≤3 and polyethylene thickness ≥13 mm were less likely to experience intraoperative fracture. These findings may be related to the depth of tibial resection, requiring the use of a thicker polyethylene insert, and a change in the keel width in implants size 4 or larger. No fracture patients required reoperation

Proximal tibial trabecular bone mineral density is related to pain in patients with osteoarthritis

Background: Our objective was to examine the relationships between proximal tibial trabecular (epiphyseal and metaphyseal) bone mineral density (BMD) and osteoarthritis (OA)-related pain in patients with severe knee OA. Methods: The knee was scanned preoperatively using quantitative computed tomography (QCT) in 42 patients undergoing knee arthroplasty. OA severity was classified using radiographic Kellgren-Lawrence scoring and pain was measured using the pain subsection of the Western Ontario and McMaster Universities Arthritis Index (WOMAC). We used three-dimensional image processing techniques to assess tibial epiphyseal trabecular BMD between the epiphyseal line and 7.5 mm from the subchondral surface and tibial metaphyseal trabecular BMD 10 mm distal from the epiphyseal line. Regional analysis included the total epiphyseal and metaphyseal region, and the medial and lateral epiphyseal compartments. The association between total WOMAC pain scores and BMD measurements was assessed using hierarchical multiple regression with age, sex, and body mass index (BMI) as covariates. Statistical significance was set at p < 0.05. Results: Total WOMAC pain was associated with total epiphyseal BMD adjusted for age, sex, and BMI (p = 0.013) and total metaphyseal BMD (p = 0.017). Regionally, total WOMAC pain was associated with medial epiphyseal BMD adjusted for age, sex, and BMI (p = 0.006). Conclusion: These findings suggest that low proximal tibial trabecular BMD may have a role in OA-related pain pathogenesis.Other UBCNon UBCReviewedFacult

Knee osteoarthritis patients with more subchondral cysts have altered tibial subchondral bone mineral density

Background: Subchondral bone cysts are a widely observed, but poorly understood, feature in patients with knee osteoarthritis (OA). Clinical quantitative computed tomography (QCT) has the potential to characterize cysts in vivo but it is unclear which specific cyst parameters (e.g., number, size) are associated with clinical signs of OA, such as disease severity or pain. The objective of this study was to use QCT-based image-processing techniques to characterize subchondral tibial cysts in patients with knee OA and to explore relationships between proximal tibial subchondral cyst parameters and subchondral bone density as well as clinical characteristics of OA (alignment, joint space narrowing (JSN), OA severity, pain) in patients with knee OA. Methods: The preoperative knee of 42 knee arthroplasty patients was scanned using QCT. Patient characteristics were obtained, including OA severity, knee pain, JSN, and alignment. We used 3D image processing techniques to obtain cyst parameters including: cyst number, cyst number per proximal tibial volume, cyst volume per proximal tibial volume, as well as maximum and average cyst volume across the proximal tibia, as well as regional bone mineral density (BMD) excluding cysts. We used Spearman’s correlation coefficients to explore associations between patient characteristics and cyst parameters. Results: At both the medial and lateral compartments of the proximal tibia, greater cyst number and volume were associated with higher BMD. At the lateral region, cyst number and volume were also associated with lateral OA severity, lateral JSN, alignment and sex. Pain was not associated with any cyst parameters at any region. Conclusion: Cyst number and volume were associated with BMD at both the medial and lateral compartments. Lateral cyst number and volume were also associated with joint alignment, OA severity, JSN and sex. This is the first study to use clinical QCT to explore subchondral tibial cysts in patients with knee OA and provides further evidence of the relationships between subchondral cysts and clinical OA characteristics.Other UBCNon UBCReviewedFacult

Intramedullary Arthrodesis of the Knee in the Treatment of Sepsis After TKR

Infection is a devastating complication following total knee replacement (TKR). In the majority of cases, single- or two-stage revision has excellent results in eradicating infection and restoring function. Rarely, recurrent infection requires alternative treatments such as resection, amputation, or arthrodesis. A review of infections following TKR treated at two joint replacement centers identified 29 cases of resistant knee sepsis treated with a long intramedullary fusion nail. Clinical outcome and radiographs were reviewed at an average follow-up of 48 months (13–114). After the initial intramedullary arthrodesis union occurred in 24 of 29 patients (83%). The average time to fusion was 6 months (3–18 months). Failures included two cases of nail breakage, one of which subsequently achieved fusion following revision nailing, and three cases of recurrent infection requiring nail removal and permanent resection. At a minimum 2-year follow-up, 28% of the patients that achieved fusion complained of pain in the fused knee, 28% complained of ipsilateral hip pain, and two patients complained of contralateral knee pain. Four of the 25 fused patients (16%) remained nonambulatory after fusion, 17 required walking aids (68%) and only four ambulated unassisted. There was no association between age, number of previous procedures, the use of two-stage versus single stage technique, or infecting organism and failure of arthrodesis. Intramedullary arthrodesis is a viable treatment for refractory infection after TKR. Patients undergoing fusion should be informed of the potential for nonunion, recurrence of infection, pain in the ipsilateral extremity, and the long-term need for walking aids