Evaluating left atrial strain and left ventricular diastolic strain rate as markers for diastolic dysfunction in patients with mitral annular calcification

BACKGROUND

Mitral annular calcification (MAC) poses many challenges to the evaluation of diastolic function using standard echocardiography. Left atrial (LA) strain and left ventricular early diastolic strain rate (DSr) measured by speckle-tracking echocardiography (STE) are emerging techniques in the noninvasive evaluation of diastolic function. We aim to evaluate the utility of LA strain and early DSr in predicting elevated left ventricular filling pressures (LVFP) in patients with MAC and compare their effectiveness to ratio of mitral inflow velocity in early and late diastole (E/A).

METHODS

We included adult patients with MAC who presented between January 1 and December 31, 2014 and received a transthoracic echocardiogram (TTE) and cardiac catheterization with measurement of LVFP within a 24-h period. We used Spearman's rank correlation coefficient to assess associations of LA reservoir strain and average early DSr with LVFP. Receiver operating characteristic (ROC) curves were computed to assess the effectiveness of LA strain and DSr in discriminating elevated LVFP as a dichotomized variable and to compare their effectiveness with E/A ratio categorized according to grade of diastolic dysfunction.

RESULTS

Fifty-five patients were included. LA reservoir strain demonstrated poor correlation with LVFP (Spearman's rho = 0.03, p = 0.81) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.54, 95% CI 0.38-0.69). Categorical E/A ratio alone also demonstrated poor discriminatory ability (AUC = 0.53, 95% CI 0.39-0.67), and addition of LA reservoir strain did not significantly improve effectiveness (AUC = 0.58, 95% CI 0.42-0.74, p = 0.56). Average early DSr also demonstrated poor correlation with LVFP (Spearman's rho = -0.19, p = 0.16) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.59, 95% CI 0.44-0.75). Addition of average early DSr to categorical E/A ratio failed to improve effectiveness (AUC = 0.62, 95% CI 0.46-0.77 vs. AUC = 0.54, 95% CI 0.39-0.69, p = 0.38).

CONCLUSIONS

In our sample, LA reservoir strain and DSr do not accurately predict diastolic filling pressure. Further research is required before LA strain and early DSr can be routinely used in clinical practice to assess filling pressure in patients with MAC.

Waterproof Hip Spica Casts for Pediatric Femur Fractures

BACKGROUND

Hip spica casting is the treatment of choice for femur fractures in children ages 6 months to 5 years. Traditional spica (TS) casting utilizes cotton padding that precludes patient bathing. Waterproof (WP) casting has inherent advantages, including clearance for bathing and improved family satisfaction. This study examines the safety and efficacy of WP hip spica casting for the treatment of pediatric femur fractures.

METHODS

This is a retrospective, matched cohort study of patients ≤5 years with a femur fracture treated with hip spica casting. Patients with WP casts were matched to patients with TS casts by age, sex, and fracture type. TS casts utilize a Goretex liner and cotton padding, while WP spicas utilize fully WP materials and can be completely submerged in water.

RESULTS

Fifty patients were included (25 WP, 25 TS) without differences between cohorts in age, weight, or sex. There were no differences in operative time, length of stay, or length of time in cast. Patient charges were significantly lower in the WP group ($230 vs. $301, P <0.001). At cast-off, coronal/sagittal alignment and shortening were similar, while 9 TS patients had minor skin and/or cast complications that required outpatient repair versus only 1 WP patient ( P <0.001).

CONCLUSIONS

In a matched comparison, WP spica casting significantly reduces skin and cast complications traditionally associated with cotton-based spica casting, with significantly lower charges for WP cast materials. Fracture healing rate, alignment, and shortening at cast-off are similar in WP versus TS casts. WP spica casting is safe and efficacious for pediatric femur fractures, with the inherent advantage of clearance for bathing.

LEVEL OF EVIDENCE

Level 3.

Wrist Arthrotomy Saline Load Test

BACKGROUND

Failure to recognize a potential wrist arthrotomy may lead to missed septic arthritis and devastating sequelae. The saline load test is routinely used to recognize traumatic arthrotomies of other joints; however, there are limited data optimizing this test for the wrist. The purpose of this study was to investigate and perform saline load testing to identify traumatic arthrotomies of the wrist.

METHODS

This was a cadaveric study of 15 wrists. Traumatic arthrotomies were created using a blunt trocar through the 3-4 portal. A 3-mL syringe with 0.1 mL markings was used to inject methylene blue dyed saline into the wrist through the 1-2 portal. Once extravasation was visible from the atherectomized site, the volume was recorded.

RESULTS

The mean (range) volume injected to identify the arthrotomy of all wrists was 1.22 mL (range, 0.1-3.1 mL). Multivariate regression demonstrated that cadaver age, laterality, and extension range of motion were not significantly associated with the injected saline volume at extravasation (P > .05, each). Greater joint range of motion was independently associated with higher saline volume load for extravasation (odds ratio: 1.049; 95% confidence interval: 1.024-1.075; P = .003).

CONCLUSIONS

We found that 2.68 and 3.02 mL of methylene blue dyed saline offered 95% and 99% sensitivity, respectively, for diagnosing traumatic wrist arthrotomy. The maximum volume of saline needed to recognize an arthrotomy was 3.1 mL. We recommend this be the minimum volume used to evaluate a traumatic wrist arthrotomy.

Understanding Medical Optimization for Patients Undergoing Shoulder Arthroplasty

Many surgeons seek to optimize their patients' comorbid conditions preoperatively to reduce postoperative complications. To effectively optimize patients before total shoulder arthroplasty, the surgeon should be familiar with recognizing and treating common medical comorbidities found in an orthopedic patient including anemia, diabetes, malnutrition, cardiovascular conditions, and history of deep venous thrombosis. Screening for depression or other mental illness should also be conducted preoperatively and managed accordingly before surgery. Preoperative opioid use and smoking have significant effects on postoperative outcomes and should be addressed before surgery.

Priming Cardiac Function with Voluntary Respiratory Maneuvers and Effect on Early Exercise Oxygen Uptake

Oxygen uptake (V'O₂) at exercise onset is determined in part by acceleration of pulmonary blood flow (Q'p). Impairments in the Q'p response can decrease exercise tolerance. Prior research has shown that voluntary respiratory maneuvers can augment venous return, but the corollary impacts on cardiac function, Q'p and early-exercise V'O₂ remain uncertain. We examined a) the cardiovascular effects of 3 distinct respiratory maneuvers (abdominal, AB; rib cage, RC and deep breathing, DB) under resting conditions in healthy subjects (Protocol 1, n=13) and b) the impact of pre-exercise DB on pulmonary O₂ transfer during initiation of moderate intensity exercise (Protocol 2, n=8). In Protocol 1, echocardiographic analysis showed increased RV and LV cardiac output (RVCO and LVCO, respectively) following AB (by +23±13 and +18±15%, respectively, P<0.05), RC (+23±16; +14±15%, P<0.05) and DB (+27±21; +23±14%, P<0.05). In Protocol 2, DB performed for 12 breaths produced a pre-exercise increase in V'O₂ (+801±254 ml·min^-1 over ~ 6 s), presumably from increased Q'p followed by a reduction in pulmonary O₂ transfer during early phase exercise (first 20 s) compared to the control condition (149±51 vs 233±65 ml, P<0.05). We conclude that (1) respiratory maneuvers enhance RVCO and LVCO in healthy subjects under resting conditions, (2) AB, RC and DB have similar effects on RVCO and LVCO, and (3) DB can increase Q'p prior to exercise onset. These findings suggest that pre-exercise respiratory maneuvers may represent a promising strategy to prime V'O₂ kinetics and thereby to potentially improve exercise tolerance in patients with impaired cardiac function.

The "Fight Bite" Saline Joint Loading Test: Effectiveness in Detecting Simulated Traumatic Metacarpophalangeal Arthrotomies

Background: The saline load test is routinely used to recognize other joints' traumatic arthrotomies; however, there are currently no studies evaluating the novelty of this test for metacarpophalangeal joints (MCPJs). This study aimed to investigate the effectiveness and sensitivity of saline load testing in identifying the traumatic arthrotomies of the MCPJs using human cadavers. Methods: This was a cadaveric study of 16 hands (79 MCPJs). Traumatic arthrotomies were created using 11-blade stab-incisions, followed by blunt probing into the joint on the radial or ulnar side of the flexed MCPJs. A 3-mL syringe was used to inject intra-articular methylene-blue-dyed saline from the contralateral side. The volume at saline extravasation was recorded. Test sensitivity and factors influencing extravasation volume were assessed. Results: The mean (range) volume injected to identify arthrotomy of all MCPJs was 0.18 mL (0.1-0.4 mL). The mean volume to identify MCPJ arthrotomy of the thumb, index, long, ring, and small fingers was 0.16 mL (0.1-0.3 mL), 0.19 mL (0.1-0.3 mL), 0.21 mL (0.1-0.4 mL), 0.17 mL (0.1-0.3 mL), and 0.16 mL (0.1-0.3 mL), respectively. Cadaver age, laterality, and joint range of motion were not significantly associated with the injected volume at extravasation(P > .05, each). Injection volumes of 0.3 and 0.32 mL were required to detect arthrotomies at 95% and 99% sensitivities across all MCPJs. None of the MCPJs required > 0.4 mL to detect arthrotomy. Conclusions: Saline joint loading volumes to detect traumatic arthrotomy were similar for all MCPJs. Injection volumes of 0.32 mL is suggested for 99% sensitivity. Our findings provide the first report, to our knowledge, on intra-articular injection volumes expected to detect an arthrotomy of MCPJ. This is critical for further validation using in vivo clinical studies.

The Effectiveness of Saline Load Test in Detecting Simulated Traumatic Elbow Arthrotomies: A Cadaveric Investigation

Background

The saline load test has not been well explored in the elbow. We aimed to determine 1) the saline infusion volume needed for 90%, 95%, and 99% sensitivity in detecting elbow arthrotomy; and 2) factors associated with higher volume at detection using sixteen forequarter upper extremity amputation cadavers.

Methods

Sixteen fresh-frozen forequarter upper extremity amputations were procured, and demographic data, including age, body mass index (BMI), and laterality, were recorded. The olecranon process, radial head, and the lateral epicondyle were palpated, and elbow arthrotomy was consistently performed at the direct lateral arthroscopic portal site. The elbow joint was loaded with saline mixed with methylene blue (concentration: 2 mg/300 mL) using an 18-gauge needle inserted just medial to the triceps tendon 2 cm superior to the olecranon.

Results

Mean volume for extravasation was 12.2 mL ±6.26. Volume needed for 90%, 95%, and 99% sensitivities were 21 mL, 23 mL, and 25.4 mL. Linear regression demonstrated that increasing age was associated with lower volume to extravasation (OR: 0.67; 95% CI: 0.48-0.932; p=0.037), while BMI (p=0.571) and extremity laterality (p=0.747) did not affect the volume.

Conclusions

The saline load test can be effective in diagnosing the violation of the elbow joint in traumatic injuries. This test should be used in conjunction with the clinical examination and radiographs before operative decisions are made. We recommend using ≥26 mL to rule out traumatic elbow arthrotomy.

The Association of International Normalized Ratio with Postoperative Complications in Revision Total Knee Arthroplasty

The purpose of this study was to examine the relationship between elevated preoperative international normalized ratio (INR) and (1) mortality, (2) postoperative bleeding, and (3) other postoperative complications in a national cohort of patients who underwent revision total knee arthroplasty (rTKA). The American College of Surgeons National Surgical Quality Improvement Program was queried for rTKA procedures conducted between 2006 and 2017. Cohorts were based on INR ranges: <1, 1 < INR ≤ 1.25, 1.25 < INR ≤ 1.5, and >1.5. Univariate/multivariate statistics were calculated to analyze associations between INR value and designated covariates. These statistics were additionally applied to optimal cutoff values of INR calculated using a receiver operating characteristics curve. The final cohort consisted of 1,676 patients. Progressively higher INR values were associated with an increased risk of mortality within 30 days (p < 0.006), bleeding requiring transfusion (p < 0.001), sepsis (p < 0.001), return to the operating room (Odds Ratio [OR], p = 0.011), reintubation (p < 0.001), pneumonia (p < 0.001), failure to wean from mechanical ventilation ≤48 hours (p < 0.001), acute renal failure (p = 0.001), and hospital length of stay (LOS). Statistically significant associations were similarly seen when calculated optimal INR values were used. Optimal INR turn point was found to be associated with a significant increased risk of long LOS (optimal INR = 1.03, OR: 1.7, 95% confidence interval [CI]: 1.33-2.18; p < 0.001) and a significant decreased risk of bleeding requiring transfusion (INR = 1.005, OR: 0.732, 95% CI: 0.681-0.786; p < 0.001). High preoperative INR values were independently and significantly associated with an increased risk of multiple postoperative complications. Current guidelines for INR <1.5 should be reassessed for patients undergoing rTKA.

The value of artificial neural networks for predicting length of stay, discharge disposition, and inpatient costs after anatomic and reverse shoulder arthroplasty

HYPOTHESIS/PURPOSE

The objective is to develop and validate an artificial intelligence model, specifically an artificial neural network (ANN), to predict length of stay (LOS), discharge disposition, and inpatient charges for primary anatomic total (aTSA), reverse total (rTSA), and hemi- (HSA) shoulder arthroplasty to establish internal validity in predicting patient-specific value metrics.

METHODS

Using data from the National Inpatient Sample between 2003 and 2014, 4 different ANN models to predict LOS, discharge disposition, and inpatient costs using 39 preoperative variables were developed based on diagnosis and arthroplasty type: primary chronic/degenerative aTSA, primary chronic/degenerative rTSA, primary traumatic/acute rTSA, and primary acute/traumatic HSA. Models were also combined into diagnosis type only. Outcome metrics included accuracy and area under the curve (AUC) for a receiver operating characteristic curve.

RESULTS

A total of 111,147 patients undergoing primary shoulder replacement were included. The machine learning algorithm predicting the overall chronic/degenerative conditions model (aTSA, rTSA) achieved accuracies of 76.5%, 91.8%, and 73.1% for total cost, LOS, and disposition, respectively; AUCs were 0.75, 0.89, and 0.77 for total cost, LOS, and disposition, respectively. The overall acute/traumatic conditions model (rTSA, HSA) had accuracies of 70.3%, 79.1%, and 72.0% and AUCs of 0.72, 0.78, and 0.79 for total cost, LOS, and discharge disposition, respectively.

CONCLUSION

Our ANN demonstrated fair to good accuracy and reliability for predicting inpatient cost, LOS, and discharge disposition in shoulder arthroplasty for both chronic/degenerative and acute/traumatic conditions. Machine learning has the potential to preoperatively predict costs, LOS, and disposition using patient-specific data for expectation management between health care providers, patients, and payers.

The tricuspid valve in review: anatomy, pathophysiology and echocardiographic assessment with focus on functional tricuspid regurgitation

The tricuspid valve (TV) is a complex anatomical structure that incorporates a saddle-shaped annulus, asymmetric leaflets, the subvalvular apparatus and the right ventricle and its loading conditions. In this paper, an appreciation of the normal anatomy and physiology of the TV is reviewed before discussing functional tricuspid regurgitation (TR), a disease that has garnered renewed interest due to increased awareness of adverse outcomes and novel transcatheter therapeutic options. Two and three-dimensional echocardiographic imaging of the TV using transthoracic and transesophageal windows are subsequently discussed. The future of cardiovascular medicine will have more to offer the “forgotten” right-sided chambers and valves, and this review aims to refresh knowledge and enthusiasm around the forgotten but crucially important TV.

A Case Series of Successful Repair of Articular Cartilage Fragments in the Knee

BACKGROUND

It is unclear whether chondral fragments without bone have the potential to heal after fixation. Controversy exists and opinions differ regarding the optimal treatment of chondral defects after pure chondral fracture.

PURPOSE

To determine clinical and radiographic outcomes after internal fixation of traumatic chondral fragments repaired to bone in the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective clinical and radiographic evaluation of 10 male patients with a mean age of 14.6 years (range, 10-25 years) at the time of surgery was performed. Eight of 10 patients were skeletally immature. Patients were selected by operating surgeons per the presence of a large displaced pure chondral fragment on magnetic resonance imaging and confirmed on intraoperative inspection. All patients had a diagnosed traumatic displaced pure chondral fracture of the knee (without bone) and underwent internal fixation with minimum 1-year follow-up. Validated patient-reported and surgeon-measured outcomes were collected pre- and postoperatively. All patients were evaluated at a mean 56 months postoperatively.

RESULTS

At surgery, the mean defect size that was primarily repaired with the displaced chondral fragment was 1.9 × 2.0 cm. With minimum 1-year follow-up, there were no clinical failures. All 8 patients who had subsequent magnetic resonance imaging follow-up had radiographic evidence of complete healing of the chondral fragment back to bone. At a mean follow-up of 56 months (range, 13-171 months; median, 36 months), patients had a mean International Knee Documentation Committee score of 94.74 (range, 87.4-100), a mean Marx Activity Scale score of 14.4 (range, 8-16), and a mean Tegner Activity Scale score of 7 (range, 5-9). At final follow-up, all patients except 1 returned to sports.

CONCLUSION

The treatment of large traumatic chondral fragments is controversial. In this select series of 10 young patients who underwent primary repair with internal fixation, there were no failures clinically. Patients demonstrated excellent short-term clinical and radiographic results after fixation of these relatively large chondral fragments in the knee.

The Effect of Body Mass Index on 30-day Complications After Revision Total Hip and Knee Arthroplasty

BACKGROUND

We aimed to explore the effect of body mass index (BMI) on 30-day complications after aseptic revision total knee arthroplasty (rTKA) and aseptic revision total hip arthroplasty (rTHA), considering BMI as both a categorical and continuous variable.

METHODS

A total of 18,866 patients (9093 rTHA and 9773 rTKA) patients were included for analysis using the American College of Surgeons National Surgical Quality Improvement Project database. Thirty-day rates of readmissions, reoperations, and major and minor complications were compared between different weight categories (overweight: BMI >25 and ≤30 kg/m²; obese: BMI >30 and ≤40 kg/m²; morbidly obese: BMI >40 kg/m²) and the normal weight category (BMI >18.5 and ≤25 kg/m²) using multivariate regression models. Spline regression models were created to study BMI as a continuous variable.

RESULTS

Both readmission rates and reoperation rates increased for rTKA as BMI increased (P < .005). There was a linear relationship between BMI and readmission rates for rTKA. Morbid obesity was associated with an increased reoperation rate for rTHA on univariate analysis (P = .022); however, multivariate analysis showed no statistically significant increase in readmission or reoperation rates as BMI increased for rTHA.

CONCLUSIONS

The relationship between BMI and complications after revision total joint arthroplasty is a J-shaped curve with the lowest rates of complications occurring around a BMI of 30 kg/m². The relationship between BMI and perioperative complications is stronger for revision TKA as opposed to revision THA.

Metabolic syndrome and hip fracture: Epidemiology and perioperative outcomes

INTRODUCTION

Hip fractures and metabolic syndrome (MetS) are becoming major global healthcare burdens as populations age. This study sought to determine the impact of MetS in hip fracture patients on perioperative outcomes following operative fixation or arthroplasty.

METHODS

Data from the 2004-2014 Nationwide Inpatient Sample was used to select 3,348,207 discharges with hip fracture. MetS patients were identified by having at least 3 of 4 component comorbidities: hypertension, dyslipidemia, obesity, and diabetes. Logistic regression was used to estimate odds ratios for the association between MetS and perioperative outcomes adjusted for age, gender, race, payer status, and comorbidities.

RESULTS

Overall, 32% of hip fracture patients were treated with open reduction internal fixation (ORIF), 28% hemiarthroplasty (HA), 18% closed reduction with internal fixation (CRPP), and 3% primary total hip arthroplasty (THA). The remaining 19% of cases were either treated via unspecified procedure of hip repair (9%), managed non-operatively (2%), underwent multiple procedures during the hospital stay (6%), or the surgical procedure data was missing (2%) and were excluded from procedural analyses. The prevalence of MetS was 7.9% and increased among minorities, patients treated at urban hospitals, with comorbidities (heart failure, kidney disease, peripheral vascular disease), and with Medicare coverage. MetS was associated with increased odds of any adverse event (p < 0.0001), specifically: acute renal failure, myocardial infarction, acute posthemorrhagic anemia. MetS was also associated with increased LOS (p < 0.0001) and increased total charges (p < 0.0001). However, MetS was associated with reduced odds of postoperative pneumonia, deep vein thrombosis and pulmonary embolism, surgical site infection, septicemia, and in-hospital mortality (p < 0.0001). The above associations were maintained for MetS patients stratified according to their treatment groups: HA, CRPP, and ORIF.

CONCLUSIONS

MetS is associated with increased odds of complications in hip fracture patients but decreased odds of in-hospital mortality. This may be related to patients' nutritional status and catabolic states in the perioperative period.

Current Controversies in Reverse Total Shoulder Arthroplasty

Reverse total shoulder arthroplasty can restore forward elevation in pseudoparalytic shoulders, can reduce pain, and can increase quality of life for patients; however, there are a number of issues with regard to the design and ideal implantation technique of reverse total shoulder arthroplasties that remain controversial. Glenospheres with a Grammont, medialized center of rotation and designs with a more lateralized center of rotation have specific pros and cons. Medialized designs have historically decreased glenosphere loosening but increase scapular notching, and lateralized designs decrease notching and improve range of motion but historically have resulted in increased baseplate failure. As such, a concrete conclusion with regard to medialization or lateralization of the glenosphere cannot be made at this time. Caudal, inferior placement of the glenosphere increases internal rotation, external rotation, abduction, and adduction while reducing notching. Superior baseplate positioning and tilt are correlated with baseplate failure and therefore should be avoided. It remains unclear whether neutral or slightly inferior tilt is preferred. The ideal humerosocket inclination angle remains unclear. The 135[degrees] designs appear to have a lower rate of scapular notching than the Grammont-style 155[degrees] humerosockets. The implications of this angle for instability remain unclear as, to our knowledge, there have been no randomized comparisons and the largest meta-analysis was confounded by other implant variables.

Gap-Balancing versus Measured Resection Technique in Total Knee Arthroplasty: A Comparison Study

Proper femoral component alignment in the axial plane during total knee arthroplasty (TKA) depends on accurate bone cuts and soft tissue balancing. Two methods that are used to achieve this are "measured resection" and "gap balancing." However, a controversy exists as to which method is more accurate and leads to better outcomes. Therefore, the purpose of this study was to evaluate: (1) implant survivorship, (2) patient outcomes, (3) complications, and (4) radiographic analysis comparing patients who underwent TKA with either gap-balancing or measured resection techniques. A total of 214 consecutive patients (221 knees) underwent primary TKA by a single surgeon between 2011 and 2012. Component alignment was achieved by using measured resection in 116 knees and gap balancing was used in 105 knees. The patients had a mean age of 66 years (range, 44-86 years) and a mean body mass index of 32 kg/m² (range, 22-52 kg/m²). Patient range-of-motion (ROM) and Knee Society (KS) function and pain scores, and radiographic assessment, were assessed preoperatively and postoperatively at ∼6 weeks, 3 months, 1 year, and then annually. The mean follow-up time was 3 years. A Kaplan-Meier's analysis was performed to calculate the survivorship. The aseptic survivorship was 98% in both the measured resection and gap-balancing groups. The mean ROM was not significantly different between the measured resection and gap-balancing groups (123 vs. 123 degrees, p = 0.990). There were no significant differences between the two groups in terms of the KS function scores (86 vs. 85 points, p = 0.829) or the KS pain scores (93 vs. 92 points, p = 0.425). Otherwise, the radiographic evaluation at latest follow-up did not demonstrate any evidence of progressive radiolucencies or loosening, of any prosthesis. The results of this study found that at a mean follow-up of 3 years, both the measured resection and gap-balancing techniques achieved excellent survivorship and postoperative outcomes. This demonstrates that both methods can be used to achieve accurate femoral component alignment with similar short-term outcomes.

Total knee arthroplasty fibrosis following arthroscopic intervention

Background

Although arthroscopy is generally considered to be a relatively benign procedure with limited trauma to periarticular soft tissues, post-arthroscopic bleeding as well as osmolality differences between the normal saline used to irrigate and the native synovial fluid (282 vs. 420 mOs) can lead to capsular reactions. Therefore, the purpose of this study was to evaluate whether capsular reaction occurred after knee arthroscopy, by comparing a matched cohort of patients who either did or did not undergo prior arthroscopic surgery. Specifically, we compared histological features such as: (I) synovial thickness; (II) cellularity; and (III) the amount of fibrous tissue for each cohort.

Methods

Prior to their total knee arthroplasty (TKA), 40 consecutive patients who had previously undergone arthroscopy were matched to 40 consecutive patients who had not. During each patient's TKA, a biopsy of the capsule and fat pad was taken and formalin sections were sent to pathology to assess for synovial thickness, cellularity, and the amount of fibrous tissue. The pathologist was blinded to the groupings. Findings for all histologic features were classified as equivocal, slight to moderate, and moderate to severe.

Results

There were a significantly higher proportion of patients who had increased synovial thickness in the prior arthroscopy group as compared to the no-prior arthroscopy group (97.5% vs. 0%, P<0.001). Additionally, there were a significantly higher proportion of patients who had increased cellularity in the prior arthroscopy group as compared to the no-prior arthroscopy group (60.0% vs. 0%, P<0.001). There were also a significantly higher proportion of patients who had increased fibrous tissue in the prior arthroscopy group as compared to the no-prior arthroscopy group (95% vs. 62.5%, P<0.001).

Conclusions

Arthroscopic surgery may have long-term effects on capsular tissue as surgical observations of patients with prior arthroscopic surgery from this study found that the capsule is thicker and denser. Histologic assessment confirms there may be increased synovial thickness, increased cellularity, as well as thickening of fibrous tissue. This preliminary study and further evaluation are required. This suggests that arthroscopic surgery may have long-lasting effects on periarticular tissue especially the capsular tissue which may have implications for pain and functional recovery.

Comparing ε-Aminocaproic Acid and Tranexamic Acid in Reducing Postoperative Transfusions in Total Knee Arthroplasty

Multiple studies have shown tranexamic acid (TXA) to reduce blood loss and transfusion rates in patients undergoing total knee arthroplasty (TKA). Accordingly, TXA has become a routine blood conservation agent for TKA. In contrast, ε-aminocaproic acid (EACA), a similar acting antifibrinolytic to TXA, has been less frequently used. This study evaluated whether EACA is as efficacious as TXA in reducing postoperative blood transfusion rates and compared the cost per surgery between agents. A multicenter retrospective chart review of elective unilateral TKA from April 2012 through December 2014 was performed. Five hospitals within a health care system participated. Data collected included age, gender, severity of illness score, use of antifibrinolytic and dose, red blood cell (RBC) transfusions and the number of units, and preadmission and discharge hemoglobin (Hb). Dosing of the antifibrinolytic differed based on the agent used, 5 or 10 g (based on weight) for EACA versus 1 g for TXA. The institutional acquisition cost of each antifibrinolytic was obtained and averaged over the study period. Of 2,922 primary unilateral TKA cases, 820 patients received EACA, 610 patients received TXA, and 1,492 patients received no antifibrinolytic (control group). Compared with the control group both EACA and TXA groups had significantly fewer patients transfused (EACA 2.8% [p < 0.0001], TXA 3.2% [p < 0.0001] vs. control 10.8%) and lower mean RBC units transfused per patient (EACA 0.05 units/patient [pt] [p < 0.0001], TXA 0.05 units/pt [p < 0.0001] vs. control 0.19 units/pt]. There was no difference in mean RBC units transfused per patient, percentage of patients transfused, and discharge Hb levels between the EACA and TXA groups (p = 0.822, 0.236, and 0.322, respectively). Medication acquisition cost for EACA averaged $2.23 per surgery compared with TXA at $39.58 per surgery. Administration of EACA or TXA significantly decreased postoperative transfusion rates compared with no antifibrinolytic therapy. Utilization of EACA for unilateral TKA proved to be comparable to TXA in all studied aspects at a lower cost. The level of evidence for the study is Level 3.

Using Aminocaproic Acid to Reduce Blood Loss After Primary Unilateral Total Knee Arthroplasty

xtensive blood loss after total knee arthroplasty (TKA) is common, and affected patients often require blood transfusions. Studies suggest that antifibrinolytic agents such as aminocaproic acid (ACA) reduce blood loss and blood transfusion rates in patients undergoing TKA. We conducted a study to evaluate whether a single intravenous 10-g dose of ACA given during primary unilateral TKA would decrease perioperative blood loss, raise postoperative hemoglobin levels, and reduce postoperative blood transfusion rates. We retrospectively reviewed the charts of 50 comparable cemented primary unilateral TKAs. Twenty-five patients had been given a single intraoperative 10-g dose of ACA (antifibrinolytic group), and the other 25 had not been given ACA (control group). Postoperative drain output was decreased significantly (P < .0001) in the antifibrinolytic group (155 mL) compared with the control group (410 mL), as was the number of units of blood transfused after surgery (antifibrinolytic group, 0 units; control group, 10 units; P < .002). There were no adverse events in the antifibrinolytic group. In TKA, perioperative blood loss and blood transfusion rates were reduced significantly in patients given a single intraoperative intravenous 10-g dose of ACA compared with patients not given antifibrinolytics. The positive effects of ACA were obtained without adverse events or complications.