Outcomes of Antibiotic-Impregnated Calcium Sulfate, Reamer-Irrigator-Aspirator, and Locked Intramedullary Static Spacer in the Treatment of Periprosthetic Joint Infection in the Multiply Revised and Infected Knee: A Single-Center Case Series.

Background: Periprosthetic joint infection after total knee arthroplasty is commonly treated via 2-stage revision utilizing either articulating or static antibiotic cement spacers. While recent literature exhibits a slight functional advantage in favor of articulating spacers, those patients with a history of recurrent infection/multiple revision procedures are frequently excluded from these studies. The purpose of this study was to report infection eradication rates and efficacy of utilizing antibiotic-loaded locked intramedullary nail for infection for the multiply revised, infected total knee arthroplasty. Methods: A retrospective review was performed of all consecutive patients receiving static spacers between 2017 and 2020 at an academic medical center. Surgical techniques for all patients included irrigation and debridement using a reamer-irrigator-aspirator, injection of antibiotic-loaded calcium sulfate into the intramedullary canal, and nail placement. Antibiotic-loaded cement is then used to create a spacer block in the joint space. A Cox proportional hazard regression was run to identify risk factors for reinfection. Results: Forty-two knees in 39 patients were identified meeting inclusion criteria. Overall, there was an 68.8% infection eradication rate at an average of 46.9 months following spacer placement. The only risk factors identified on cox regression were increasing number of previous spacers, a surrogate for previous infections (hazards ratio = 14.818, P value = .021), and increasing operative time during spacer placement (hazards ratio = 1.014, P value = .039). Conclusions: Use of static spacers, in conjunction with reamer-irrigator-aspirator and antibiotic-loaded calcium sulfate, can be effective in treating chronic, complex periprosthetic joint infections in the setting of bone loss and or soft-tissue compromise and produced similar results to more simple infection scenarios.

Risk Factors for Revision Surgery Following Revision Total Knee Arthroplasty Using a Hinged Knee Prosthesis for Septic and Aseptic Indications.

INTRODUCTION: The use of hinged knee replacements (HKRs) for limb salvage is a popular option for revision total knee arthroplasty (RTKA). Although recent literature focuses on the outcomes of HKR for septic and aseptic RTKAs, little is reported on the risk factors of returning to the operating room. The purpose of this study was to evaluate risk factors of revision surgery and revision after receiving HKR for septic versus aseptic etiology. METHODS: A multicenter, retrospective review was conducted on consecutive patients who received HKR from January 2010 to February 2020 with a minimum follow-up of 2 years. Patients were separated into two groups: septic and aseptic RTKAs. Demographic, comorbidity, perioperative, postoperative, and survivorship data were collected and compared between groups. Cox hazard regression was used to identify risk factors associated with revision surgery and revision. RESULTS: One-hundred fifty patients were included. Eighty-five patients received HKR because of prior infection, and 65 received HKR for aseptic revision. A larger proportion of septic RTKA returned to the OR versus aseptic RTKA (46% vs 25%, P = 0.01). Survival curves revealed superior revision surgery-free survival favoring the aseptic group ( P = 0.002). Regression analysis revealed that HKR with concomitant flap reconstruction was associated with a three-fold increased risk of revision surgery ( P < 0.0001). DISCUSSION: HKR implantation for aseptic revision is more reliable with a lower revision surgery rate. Concomitant flap reconstruction increased the risk of revision surgery, regardless of indication for RTKA using HKR. Although surgeons must educate patients about these risk factors, HKR remains a successful treatment option for RTKA when indicated. LEVEL OF EVIDENCE: prognostic, level III evidence.

A comparison of healing and complication rates between common flaps utilized in total knee arthroplasty: a review of the literature.

BACKGROUND: Flap reconstruction with perforator, fasciocutaneous, muscular, and/or free microvascular flaps is utilized to cover wound defects and improve vascularization and antibiotic/nutrient delivery. Flap use in revision procedures for total knee arthroplasty has been explored previously; however, current data are limited and studies comparing healing and complication rates between different flap types are lacking. METHODS: A literature review was performed using PubMed on 13 January 2022. Studies were included if they reported healing and complication rates for either gastrocnemius, rectus abdominis, latissimus dorsi, fasciocutaneous, chimeric, or gracilis flaps in the setting of revision total knee arthroplasty (TKA). RESULTS: The final cohort included gastrocnemius (n = 421, healing rate 73.8%, complication rate 59.9%), gracilis (n = 9, healing rate 93%, complication rate 55.6%), latissimus dorsi (n = 41, healing rate 67%, complication rate 46.3%), rectus abdominis (n = 3, healing rate 100%, complication rate 0%), fasciocutaneous (n = 78, healing rate 70%, complication rate 19.2%), and chimeric flaps (n = 4, healing rate 100%, complication rate 25%). There was no significant difference when comparing healing rates across flap types (p = 0.39). There was a significant difference when comparing complication rates across flap types (p < 0.0001), with a significant difference being noted between gastrocnemius and fasciocutaneous complication rates (p < 0.0001). All other comparisons between flap types by complication rate were not significantly different. CONCLUSIONS: Gastrocnemius flaps are the workhorse flap in the setting of revision TKA, as evidenced by this review. Healing rates did not vary significantly across flap types, which suggests that determining the appropriate flap for coverage of soft-tissue defects in revision TKA should be driven by defect size and location as well as physician experience and patient tolerance.

Esophagopharyngeal perforation and prevertebral abscess after anterior cervical discectomy and fusion: a case report.

Anterior cervical discectomy and fusion (ACDF) represents one of the most commonly performed spine surgeries. Dysphagia secondary to esophageal injury during retraction is one of the most common complications, and usually leads to self-limiting dysphagia. However, actual perforation and violation of the esophageal tissue is much rarer and can lead to delayed deep infections. Prevertebral abscess' are one of the most feared complications after ACDF, as they can lead to severe tissue swelling, osteomyelitis, hardware failure, and even death. Due to their rarity, a gold standard of workup and treatment is still unknown. A healthy 47-year-old female presents 9 months after a C4-C7 ACDF done at an outside institution with a large prevertebral abscess, osteomyelitis, hardware failure, and pseudoarthrosis secondary to esophagopharyngeal defect and prominent hardware. Overall, the patient underwent eight surgeries, and required an extended course of intravenous (IV) antibiotics, multiple diagnostic procedures, and complex soft tissue coverage using an anterolateral thigh free flap. Currently, the patient is doing well 6 months from her last procedure without any complications or plan for future surgery. This was an extremely rare case of a late occurring prevertebral abscess after ACDF. Dysphagia in the late postoperative setting should be evaluated carefully and thoroughly for any esophageal perforation and deep infection. As exemplified in this case, even partial thickness injuries to the esophageal-pharyngeal anatomy due to hardware irrigation can lead to catastrophic complications over time. Safe removal of all hardware anteriorly to avoid continued irritation of the esophagopharyngeal mucosa should be prioritized. If anterior hardware is necessary for stability, implants with the smallest footprint should be utilized. Early collaboration with ENT colleagues should be a priority and can provide crucial diagnostic and therapeutic interventions. Complex closure with a free flap was shown to be an effective way to provide successful definitive soft tissue coverage.

Updated Analysis of the Oncology Section of the OITE from 2007 to 2019.

The Orthopaedic In-Training Exam (OITE) is administered annually to orthopedic surgery residents to assess their medical knowledge. The authors provide a comprehensive review of the orthopedic oncology portion of the exam in order to aid residents in preparation for future in-training and licensing examinations as well as to help guide oncology residency education curriculum. All of the orthopedic oncology questions on the OITE from 2007 to 2019 were reviewed. Analysis included (1) the number of oncology questions each year, (2) question topic, (3) question taxonomy (knowledge versus interpretation), (4) the type of imaging modalities (radiological, histological), (5) most commonly cited references, and (6) level of evidence. Descriptive statistics were utilized to compare means between variables. From 2007 to 2019, there was a total of 292 tumor-related questions with a mean of 22.5 tumor-related questions (range 19-28) per year. Of the questions, 54.8% pertained to malignant tumors and 45.2% to benign tumors. Assessment of question taxonomy showed that 79.8% of questions required interpretation of imaging and analysis of the information provided versus 20.2% of questions being knowledge recall type. Of the questions, 76.7% required interpretation of radiological images, pathological images, or both. Orthopaedic Knowledge Update, Journal of the American Academy of Orthopaedic Surgeons, and Journal of Bone and Joint Surgery were the three most commonly cited question sources. Only 29 (9.84%) oncology questions over the past 13 years have been supported by level I or II sources of evidence. Better understanding of the OITE make-up, question distribution, and number and style of question, reference sources can improve an orthopedic residents' performance as well as better guide educational curriculum to prepare residents in their orthopedic oncology education.

Combination Lower Extremity Nerve Blocks and Their Effect on Postoperative Pain and Opioid Consumption: A Systematic Review.

The purpose of this study was to perform a systematic review of the literature examining postoperative outcomes following single site and combined peripheral nerve blocks (PNBs), including (1) sciatic and femoral nerve, (2) popliteal and saphenous nerve, and (3) popliteal and ankle nerve, during elective foot and ankle surgery. We hypothesized that combination blocks would decrease postoperative narcotic consumption and afford more effective postoperative pain control as compared to general anesthesia, spinal anesthesia, or single site PNBs. A review of the literature was performed according to the PRISMA guidelines. Medline, EMBASE, and the Cochrane Library were searched from January 2009 to October 2019. We identified studies by using synonyms for "foot," "ankle" "pain management," "opioid," and "nerve block." Included articles explicitly focused on elective foot and ankle procedures performed under general anesthesia, spinal anesthesia, PNB, or with some combination of these techniques. PNB techniques included femoral, adductor canal, sciatic, popliteal, saphenous, and ankle blocks, as well as blocks that combined multiple anatomic sites. Outcomes measured included postoperative narcotic consumption as well as patient-reported efficacy of pain control. Twenty-eight studies encompassing 6703 patients were included. Of the included studies, 57% were randomized controlled trials, 18% were prospective comparison studies, and 25% were retrospective comparison studies. Postoperative opioid consumption and postoperative pain levels were reduced over the first 24 to 48 hours with the use of combined PNBs when compared with single site PNBs, both when used as primary anesthesia or when used in concert with general anesthesia either alone or combined with systemic/local anesthesia in the first 24 to 48 hours following surgery. Studies demonstrated higher reported patient satisfaction of postoperative pain control in patients who received combined PNB. Nine of 14 (64%) studies reported no neurologic related complications with an overall reported rate among all studies ranging from 0% to 41%. Our study identified substantial improvement in postoperative pain levels, postoperative opioid consumption, and patient satisfaction in patients receiving PNB when compared with patients who did not receive PNB. Published data also demonstrated that combination PNB are more effective than single-site PNB for all data points. Notably, the addition of a femoral nerve block to a popliteal nerve block during use of a thigh tourniquet, as well as addition of either saphenous or ankle blockade to popliteal nerve block during use of calf tourniquet, may increase overall block effectiveness. Serious complications including neurologic damage following PNB administration are rare but do exist.

Temporary External Fixation to Table as a Traction Reduction Aide in the Treatment of Unstable Pelvic Ring Injuries: A Technical Note.

Displaced pelvic ring injuries can be challenging to even the experienced orthopedic traumatologist. A temporary external fixation to table construct provides a quick, simple, and accessible means of external skeletal fixation to reliably obtain and maintain stable hemipelvis reduction on the operating room table. The contralateral hemipelvis can be stabilized to the table by use of Steinman pins safely inserted into the subtrochanteric and anterior column regions and later connected to external fixator bars attached to the table. With rigid stabilization, the displaced contralateral pelvic fragment(s) can be reduced in a more vector intentional manner with greater force than the traditional means of pelvic reduction can allow. The skeletal-table fixation technique is presented along with two cases, a combined pelvic-acetabular injury and an isolated pelvic ring injury.

The Utility and Cost Effectiveness of Immediate Postoperative Laboratory Studies in Hip and Knee Arthroplasty.

BACKGROUND: Routine immediate postoperative laboratory studies, including metabolic panels and hematologic profiles, are commonly ordered after arthroplasty procedures. However, their values only occasionally influence management. This study investigated the clinical utility and value of these tests. METHODS: A large retrospective cohort study of 18,935 patients spanning a 6-year period from 2008 to 2013 from a single high-volume institution was evaluated. Only immediate postoperative labs drawn on postoperative day 0 in the recovery room were included in the study. Complete blood counts (CBC) and basic metabolic panels (BMP) were reviewed, and ranges of abnormal were set for each lab test based on values significant enough to impact patient management. Cost effectiveness calculations were made based on current cost of the laboratory tests. RESULTS: Actionably low hemoglobin values ( < 8 g/dL) were found in 1.44% of the overall cohort. Unilateral primary total knee arthroplasty was associated with the fewest hemoglobin abnormalities at 0.59%. Primary unilateral total hip arthroplasty was associated with abnormal hemoglobin values in 1.81% of cases. Significant electrolyte abnormalities were far less common, with hyperkalemia (> 6.5 mEq/L) in 0.19%, hyponatremia ( < 120 mEq/L) in 0.01% and elevated creatinine (> 2.0 mg/dL) was found in 0.25%. Hemoglobin values were calculated at a cost of $1,710 to detect a single significantly abnormal result. The cost to detect a single actionably abnormal BMP value was $1,000. CONCLUSIONS: Routine immediate postoperative laboratory tests represent a high institutional cost and are seldom abnormal enough to warrant a change in patient management. The routine use of these tests can likely be safely eliminated in uncomplicated primary unilateral arthroplasty procedures.

Overexpression of tissue-nonspecific alkaline phosphatase (TNAP) in endothelial cells accelerates coronary artery disease in a mouse model of familial hypercholesterolemia.

OBJECTIVE: Overexpression of tissue-nonspecific alkaline phosphatase (TNAP) in endothelium leads to arterial calcification in mice. The purpose of this study was to examine the effect of elevated endothelial TNAP on coronary atherosclerosis. In addition, we aimed to examine endogenous TNAP activity in human myocardium. APPROACH AND RESULTS: A vascular pattern of TNAP activity was observed in human non-failing, ischemic, and idiopathic dilated hearts (5 per group); no differences were noted between groups in this study. Endothelial overexpression of TNAP was achieved in mice harboring a homozygous recessive mutation in the low density lipoprotein receptor (whc allele) utilizing a Tie2-cre recombinase (WHC-eTNAP mice). WHC-eTNAP developed significant coronary artery calcification at baseline compared WHC controls (4312 vs 0µm2 alizarin red area, p<0.001). Eight weeks after induction of atherosclerosis, lipid deposition in the coronary arteries of WHC-eTNAP was increased compared to WHC controls (121633 vs 9330µm2 oil red O area, p<0.05). Coronary lesions in WHC-eTNAP mice exhibited intimal thickening, calcifications, foam cells, and necrotic cores. This was accompanied by the reduction in body weight and left ventricular ejection fraction (19.5 vs. 23.6g, p<0.01; 35% vs. 47%, p<0.05). In a placebo-controlled experiment under atherogenic conditions, pharmacological inhibition of TNAP in WHC-eTNAP mice by a specific inhibitor SBI-425 (30mg*kg-1*d-1, for 5 weeks) reduced coronary calcium (78838 vs.144622µm2) and lipids (30754 vs. 77317µm2); improved body weight (22.4 vs.18.8g) and ejection fraction (59 vs. 47%). The effects of SBI-425 were significant in the direct comparisons with placebo but disappeared after TNAP-negative placebo-treated group was included in the models as healthy controls. CONCLUSIONS: Endogenous TNAP activity is present in human cardiac tissues. TNAP overexpression in vascular endothelium in mice leads to an unusual course of coronary atherosclerosis, in which calcification precedes lipid deposition. The prevalence and significance of this mechanism in human atherosclerosis requires further investigations.

ICG angiography predicts burn scarring within 48 h of injury in a porcine vertical progression burn model.

The current standard of care in determining the need to excise and graft a burn remains with the burn surgeon, whose clinical judgment is often variable. Prior work suggests that minimally invasive perfusion technologies are useful in burn prognostication. Here we test the predictive capabilities of Laser Doppler Imaging (LDI) and indocyanine green dye (ICG) angiography in the prediction of burn scarring 28 days after injury using a previously validated porcine burn model that shows vertical progression injury. Twelve female Yorkshire swine were burned using a 2.5 × 2.5 cm metal bar at variable temperature and application times to create distinct burn depths. Six animals (48 injuries total) each were analyzed with LDI or ICG angiography at 1, 24, 48, and 72 h following injury. A linear regression was then performed correlating perfusion measurements against wound contraction at 28 days after injury. ICG angiography showed a peak linear correlate (r(2)) of .63 (95% CI .34 to .92) at 48 h after burn. This was significantly different from the LDI linear regression (p < .05), which was measured at r(2) of .20 (95% CI .02 to .39). ICG angiography linear regression was superior to LDI at all timepoints. Findings suggest that ICG angiography may have significant potential in the prediction of long-term burn outcomes.