Relative Acetabular Retroversion and Its Association With Earlier-Onset Symptomatic Osteoarthritis of the Hip.

Background: Hip osteoarthritis is associated with an aging population with the average total hip arthroplasty patient in the U.S. approximately 65 years of age. Although there is an association between femoroacetabular impingement and early arthritis, there is a paucity of data attributed to variation in native acetabular version and early onset osteoarthritis. We investigated that whether patients with relative acetabular retroversion are predisposed to earlier hip osteoarthritis. Methods: Five hundred sixteen charts of patients undergoing THA by a single surgeon between March 2018 and May 2022 were reviewed (221 male and 295 female subjects; mean age 66.7 years [standard deviation (SD) 9.8]). Patients with advanced dysplasia, who are post-traumatic, septic, have inflammatory arthritis, and osteonecrosis were excluded. Operative hip anteversion was measured using three-dimensional computed tomography. A univariate analysis was used to correlate the age of male and female subjects with anteversion angles of ≤15° and >15°. The effect of age and gender on version angle was studied using a multivariate linear regression model. Results: In patients with anteversion ≤15°, both male (P = .006) and female subjects (P = .015) presented at significantly lesser age (male: 98, avg. age: 63.7, SD: 8.7; female: 62, avg. age: 64.8, SD: 9.8) than those with anteversion >15° (male: 123, avg. age: 67.2, SD: 10.2; female: 233, avg. age: 68.2, SD: 9.8). Male subjects had lower anteversion than female subjects with age held constant (P < .001), and older patients had increased anteversion with gender held constant (P < .001). Conclusions: This study suggests that patients with a relatively decreased version angle (≤15°) are more likely to present with earlier-onset symptomatic hip osteoarthritis.

Reverse coronal deformity: use of robotic total knee arthroplasty for identification and correction.

BACKGROUND: Despite continued advances in techniques and implant designs, a population of patients who are dissatisfied after total knee arthroplasty (TKA) remains. During robotic-assisted arthroplasty, real-time intraoperative assessment of patient knee alignment is performed. Here, we assess the prevalence of an under-appreciated deformity, reverse coronal deformity (RCD), and the benefits of utilizing robotic-assisted knee arthroplasty to help correct this dynamic deformity. METHODS: A retrospective study evaluating patients undergoing robotic-assisted cruciate-retaining TKA was performed. Intraoperative measurements were obtained using tibial and femoral arrays to assess coronal plane deformity at full extension and at 90° flexion. RCD was defined as ≥ 2° varus in knee extension that reversed to ≥ 2° valgus in flexion, or vice-versa. Coronal plane deformity was then reassessed after robotic-assisted bony resection and implant placement. RESULTS: Of 204 patients that underwent TKA, 16 patients (7.8%) were found to have RCD, with 14 patients (87.5%) transitioning from varus in extension to valgus in flexion. The average coronal deformity was 7.75°, with a maximum of 12°. These improved to an average coronal change of 0.93° post-TKA. Final medial and lateral gaps were all balanced to within 1° in extension and flexion. Another 34 patients (16.7%) had ≥ 5° change in coronal plane deformity from extension to flexion (average 6.39°), however, did not experience a reversal of their coronal deformity. Outcomes were assessed with KOOS Jr. scores postoperatively. CONCLUSION: Computer and robotic assistance were utilized to demonstrate the prevalence of RCD. We also demonstrated accurate identification and successfully balancing of RCD utilizing robotic-assisted TKA. An increased awareness of these dynamic deformities could aid surgeons in proper gap balancing even in the absence of navigation and robotic-assisted surgery.

Transitioning a Practice to Robotic Total Knee Arthroplasty Is Correlated with Favorable Short-Term Clinical Outcomes-A Single Surgeon Experience.

BACKGROUND: This study sought to evaluate the patient experience and short-term clinical outcomes associated with the hospital stay of patients who underwent robotic arm-assisted total knee arthroplasty (TKA). These results were compared with a cohort of patients who underwent TKA without robotic assistance performed by the same surgeon prior to the introduction of this technology. MATERIALS AND METHODS: A cohort of consecutive patients undergoing primary TKA for the diagnosis of osteoarthritis by a single fellowship trained orthopaedic surgeon over a 39-month period was identified. Patients who underwent TKA during the year that this surgeon transitioned his entire knee arthroplasty practice to robotic assistance were excluded to eliminate selection bias and control for the learning curve. All patients received the same prosthesis and postoperative pain protocol. Patients that required intubation for failed spinal anesthetic were excluded. A final population of 492 TKAs was identified. Of these, 290 underwent TKA without robotic assistance and 202 underwent robotic arm-assisted TKA. Patient demographic characteristics and short-term clinical data were analyzed. RESULTS: Robotic arm-assisted TKA was associated with shorter length of stay (2.3 vs. 2.6 days, p < 0.001), a 50% reduction in morphine milligram equivalent utilization (from 214 to 103, p < 0.001), and a mean increase in procedure time of 9.3 minutes (p < 0.001). There was one superficial infection in the nonrobotic cohort and there were no deep postoperative infections in either cohort. There were no manipulations under anesthesia in the robotic cohort while there were six in the nonrobotic cohort. Additionally, there were no significant differences in emergency department visits, readmissions, or return to the operating room. CONCLUSION: This analysis corroborates existing literature suggesting that robotic arm-assisted TKA can be correlated with improved short-term clinical outcomes. This study reports on a single surgeon's experience with regard to analgesic requirements, length of stay, pain scores, and procedure time following a complete transition to robotic arm-assisted TKA. These results underscore the importance of continued evaluation of clinical outcomes as robotic arthroplasty technology continues to grow.

Stratifying Venous Thromboembolism Risk in Arthroplasty: Do High-Risk Patients Exist?

BACKGROUND: While there are many possible complications associated with total joint arthroplasty (TJA), venous thromboembolism (VTE) is both frequent and potentially severe. Despite this importance, there are inconsistent recommendations for prophylaxis based on patient risk factors. METHODS: A predictive model was constructed to compare low-molecular-weight heparin(LMWH) and aspirin (ASA) for prevention of VTE-associated complications following TJA.The model used risks from prior prophylaxis studies to estimate the risk of developing a symptomatic deep vein thrombosis, pulmonary embolism, thrombocytopenia, and operative or nonoperative site bleeding. We also evaluated the progression to 4 possible final health states: postphlebitis syndrome, intracranial hemorrhage, death, or baseline health. Within published ranges, we selected assumptions that were favorable to LMWH such that these analyses represent a best case scenario for LMWH or an alternative more aggressive low-molecular-weight heparin alternative (LMWHA). Events and outcomes were assigned quality-adjusted life-year (QALY) losses according to prior studies to determine the effect on patients' outcomes for ASA and LMWHA prophylaxis. RESULTS: Assessing VTE risk populations from 0.2% to 2% with life expectancies ranging from 5 to 40 years postoperatively, patients with a risk ratio less than 3.7 showed increased expected QALY with ASA compared to LMWHA. For patients with a baseline VTE risk of 1% and a 15 year life expectancy, a risk ratio of 13.4 was needed to identify patients that would benefit from LMWHA. With life expectancy increased to 30 years, the risk ratio needed to idetify these patients was 7.4. CONCLUSION: Patients undergoing TJA should receive ASA chemoprophylaxis in nearly all situations, unless the patient has a significantly increased VTE risk compared to the baseline population and a long life expectancy.

The 72-Hour Medicare Mandate After Total Joint Arthroplasty: Is This Medically Necessary?

INTRODUCTION: Currently, Medicare total joint arthroplasty patients are required to stay postoperatively 3 days in the hospital before discharge to a skilled nursing facility (SNF). We evaluated Medicare's mandated 3-night hospital stay rule to find out how many total joint arthroplastic patients are safe for discharge to SNFs on postoperative day 2 (POD2). METHODS: This is a retrospective case series analyzing Medicare primary total hip or total knee arthroplastic patients at a single hospital over 1 year. Patients meeting 15 separate criteria by POD2 were considered safe for discharge home rather than to a SNF. RESULTS: Of 259 patients, 47.88% met discharge criteria to SNF POD2. 31.66% did not meet 1, 13.13% did not meet 2, and 6.95% did not meet ≥3 criteria on POD2. Common criteria delaying discharge were blood pressure abnormalities, increasing or elevated white blood cell count, cardiac abnormalities, and fever. Thirty-day readmission rate for patients in the group safe for discharge POD2 was 1.75%. CONCLUSION: Of the total, 47.88% of patients required to stay by the Medicare 3-night stay rule were safe for discharge to SNF on POD2 without an increase in readmission rate at 30 days when compared to our institutional mean.

Radiographically Silent Loosening of the Acetabular Component in Hip Arthroplasty.

Polyethylene wear and subsequent osteolysis are major obstacles to the long-term success of total hip arthroplasty (THA). We conducted a study to determine the incidence of loose acetabular components that did not show frank signs of loosening on either plain radiography or computed tomography (CT), or radiographically silent loosening (RSL). In this retrospective study, we evaluated patients who underwent revision THA and were evaluated with plain radiography and CT between 2000 and 2012. Any patient with imaging that showed signs of component movement was excluded. Of the 104 patients who met the study inclusion criteria, 17 (16.3%) met the criteria for RSL of the acetabular shell. Patients with RSL presented at a similar age (P = .961) and with a similar sex profile (P = .185) compared with patients with stable acetabular components and were more likely to present with pain (P = .0487). Acetabular components may be loose even if there is no evidence of component migration on radiographic studies. Surgeons should be aware of the incidence of RSL and the potential of RSL to affect patient care and potential surgical options.

The Role of Potentially Retrievable Inferior Vena Cava Filters in High-Risk Patients Undergoing Joint Arthroplasty.

INTRODUCTION: Some patients undergoing total joint arthroplasty are at increased risk for venous thromboembolism (VTE). The aim of the present study was to evaluate the safety and efficacy of prIVCF in preventing PE in patients undergoing joint replacement surgery who are at high-risk for VTE. MATERIALS AND METHODS: In this prospective, IRB-approved study, prIVCF were placed in consecutive patients who met specific high-risk criteria (history of VTE or hypercoaguable state) prior to total joint arthroplasty. Patients were followed until the IVC filter was removed. Outcomes and complications were recorded per Society of Interventional Radiology guidelines. RESULTS: One hundred and nine potentially retrievable IVC filters were placed in 105 patients, who all subsequently underwent joint arthroplasty. One hundred eight IVC filters (98.9%) were retrieved successfully in a mean time of 44.1 days (range 13-183 days). There was 1 failed IVC filter retrieval attempt (0.9%) at 46 days post implantation. Two patients (1.9%) presented with recurrent PE and were successfully treated with anticoagulation prior to IVC filter retrieval. There were no fatalities from perioperative PE. In 1 patient (0.9%), a fractured filter leg had embolized during retrieval. CONCLUSION: Potentially retrievable IVC filters are safe and effective for prophylaxis against PE in patients at high-risk for VTE undergoing joint arthroplasty.

Understanding readmission after primary total hip and knee arthroplasty: who's at risk?

Readmission has been cited as an important quality measure in the Patient Protection and Affordable Care Act. We queried an electronic database for all patients who underwent Total Hip Arthroplasty or Total Knee Arthroplasty at our institution from 2006 to 2010 and identified those readmitted within 90 days of surgery, reviewed their demographic and clinical data, and performed a multivariable logistic regression analysis to determine significant risk factors. The overall 90-day readmission rate was 7.8%. The most common readmission diagnoses were related to infection and procedure-related complications. An increased likelihood of readmission was found with coronary artery disease, diabetes, increased LOS, underweight status, obese status, age (over 80 or under 50), and Medicare. Procedure-related complications and wound complications accounted for more readmissions than any single medical complication.

A dose-ranging study of 0.5% bupivacaine or ropivacaine on the success and duration of the ultrasound-guided, nerve-stimulator-assisted sciatic nerve block: a double-blind, randomized clinical trial.

BACKGROUND AND OBJECTIVES: Before bifurcation, the sciatic nerve is composed of 2 component nerves encased in a common investing extraneural layer (CIEL). We examined the effect of various volumes injected beneath the CIEL on the success and duration of sciatic nerve block. METHODS: Ultrasound-guided nerve-stimulator-assisted sciatic nerve blocks were performed on 142 subjects. Subjects were randomized into 14 groups (0.5% ropivacaine or bupivacaine) with epinephrine 1:300,000 in volumes ranging from 2.5 to 30 mL. Successful block was defined as a complete sensory and motor block at 60 minutes. The minimum threshold current, time to complete block, duration of sensory and motor block, postoperative pain, and analgesic requirements were recorded. RESULTS: The mean threshold current external to the CIEL was 0.52 (0.15) mA compared to 0.19 (0.09) mA beneath the CIEL (P < 0.001). Successful block was achieved in 30 of 40 subjects that received 5 mL or less of ropivacaine or bupivacaine compared with 97 of 99 that received 10 mL or greater volume (P = 0.006). Injection volumes greater than or equal to 10 mL produced complete sensory and motor block within 30 minutes. Volumes greater than 10 mL did not extend the duration of the sensory or motor block. Injection volumes of 2.5 and 5 mL were associated with delayed onset and decreased block duration and a greater fraction of subjects experiencing pain behind the knee. CONCLUSIONS: Injecting 10 mL of 0.5% bupivacaine or ropivacaine below the CIEL produces comparable onset and duration of sensory and motor blockade as volumes as large as 30 mL.

Impact of preoperative myocardial infarction on surgical outcomes in inpatient orthopaedic surgery.

PURPOSE: The purpose of this study was to evaluate the impact of a preoperative myocardial infarction (MI) on outcomes of inpatient orthopaedic operations. METHODS: The National Surgical Quality Improvement Program database was used to identify patients who underwent common orthopaedic operations from 2006 to 2010. Patient demographic data, comorbidities, complications, and lengths of stay were collected. Multivariate logistic regression and linear regression models were used to compare outcomes for patients with and without a history of MI in the six months prior to surgery. RESULTS: Of the 32,462 patients identified, 86 had sustained an MI in the six months prior to surgery. The MI cohort had no cardiac complications but had increased incidences of superficial surgical site infection, unplanned re-intubation, ventilator-assisted respiration for more than 48 hours, pneumonia, sepsis or septic shock, and postoperative mortality within 30 days of surgery, as well as prolonged lengths of stay. Following logistic regression to adjust for baseline differences, a history of MI showed no association with cardiac complications and was significantly associated with superficial surgical site infection (OR 3.6, 95% CI 1.1-11.8), ventilator dependence for over 48 hours (OR 4.0, 95% CI 1.1-14.0), and extended length of stay (median with interquartile range 4 [4-4] vs. 5 [5-5] days). CONCLUSIONS: A myocardial infarction within six months prior to orthopaedic surgery is not associated with a higher risk of 30-day perioperative cardiac complications; however, it is associated with increased rates of surgical site infection, prolonged ventilator dependence, and longer hospital stay.

How accurately are we coding readmission diagnoses after total joint arthroplasty?

Readmission rates have been cited as an important quality measure in the Affordable Care Act. Accordingly, understanding and accurately tracking the causes for readmission will be increasingly important. We queried an electronic database for all patients who underwent primary THA or TKA at our institution from 2006 through 2010. We identified those readmitted within 90 days of surgery and analyzed 87 random de-identified medical records. We then assigned a clinical diagnosis for each readmission, which was then compared with the coder-derived diagnosis by ICD-9 code. The overall 90-day readmission rate was 7.9%. We identified 22 of 87 patients for whom there was disagreement (25.3%, 95% CI=16.6-35.8%). The most common were procedure-related complications. Coded diagnoses frequently did not correlate with the physician-derived diagnoses. The unverified use of coded readmission diagnoses in calculating quality measures may not be clinically relevant.

Demonstration of saw blade accuracy and excursion: a cadaveric comparison study of blade types used in total knee arthroplasty.

In total knee arthroplasty, outcomes partly depend on accurate osteotomies and integrity of stabilizing structures. We compared accuracy and excursion between a conventional and an oscillating tip saw blade. Two sets of osteotomies were made on cadaveric knees. Bi-planar accuracy was compared using computer navigation, and excursion was compared using methylene blue. Wilcoxon-Mann-Whitney testing demonstrated no significant difference in blade accuracy (p=0.35). Blades were within 0.5 degrees of neutral coronally and 2.0 degrees sagittally. The oscillating tip blade demonstrated less dye markings on the surrounding tissues. Accurate osteotomies and soft tissue protection are critical to successful arthroplasties. Although comparative accuracy was equal, the oscillating tip blade exhibited less excursion displaying potential for less iatrogenic soft tissue injuries leading to catastrophic failure.

Single-use instrumentation, cutting blocks, and trials decrease contamination during total knee arthroplasty: a prospective comparison of navigated and nonnavigated cases.

The purpose of this prospective controlled trial was to determine whether decrease in contamination could be achieved in nonnavigated and navigated total knee arthroplasties by replacing traditional saws, cutting blocks, and trials with specialized saws and single-use cutting blocks and trials. Various tray wrapping metrics during total knee arthroplasty were measured in 400 procedures performed by 8 different surgeons at 6 institutions. Instrumentation contamination was determined by counting the number of tray sterility indicators, pans, and instruments that were compromised. The results show that a decrease in contamination was evident in 57% (nonnavigated) and 32% (navigated) fewer compromises of tray sterility indicators, pans, and instruments. Single-use instruments show promising benefits, but further study is needed to confirm safety and efficacy before they can be widely adopted. The authors believe that the use of single-use instruments, cutting guides, and trial implants for total knee arthroplasty will play an increasing role in decreasing operating room contamination and potential deep infections.

Computer-assisted total knee arthroplasty for significant tibial deformities.

Computer-assisted total knee arthroplasty has been demonstrated to provide reproducible limb mechanical alignment within 3° from the neutral mechanical axis. However, restoring proper implant and extremity alignment remains a significant challenge with proximal tibial deficiencies. In this prospective study, we describe the use of computer navigation to quantify the amount of bone loss on the medial or lateral tibial plateau and the use of these data to assess the need for augmentation with metallic tibial wedges. In this study, we demonstrate that computer-assisted total knee arthroplasty in patients with significant tibial deformities can accurately measure severe tibial deformities, predict tibial augment thickness, and provide excellent mechanical alignment and restore the joint line without excessive bony resection, repeated osteotomies, and repeated augment trialing.

Wound complications in joint arthroplasty: comparing traditional and modern methods of skin closure.

Various methods of skin closure exist in joint replacement surgery. Although subcuticular skin closure techniques offer an aesthetic advantage over conventional skin stapling, no measurable differences have been reported. Furthermore, newer barbed sutures, such as the V-Loc absorbable suture (Covidien, Mansfield, Massachusetts), theoretically distribute tension evenly through the wound and help decrease knot-related complications. The purpose of this study was to evaluate whether wound complication rates were (1) lower in V-Loc closure cases as theoretically suggested, (2) lower for subcuticular closure vs staples, and (3) significantly different for knee and hip joint reconstruction.A retrospective chart review was conducted of 278 consecutive cases of primary joint reconstruction performed by a single surgeon (L.P.). The study group comprised 106 men and 161 women. Average patient age at surgery was 63 years (range, 18-92 years), and average body mass index of the cohort was 33.7 kg/m(2) (range, 25-51 kg/m(2)). Skin was closed via staple gun or subcuticular stitch (3-0 Biosyn [Covidien] vs V-Loc). Seven (3.9%) wound complications occurred in 181 cases closed with staples. Four (7.8%) wound complications occurred in 51 cases closed via subcuticular Biosyn suture. Six (13.0%) wound complications occurred in 46 cases closed with V-Loc suture. The staple group had a lower rate of complications when compared with the suture group as a whole (P=.033) and when compared specifically with the V-Loc suture group (P=.017).

Complications of femoral nerve blockade in total knee arthroplasty and strategies to reduce patient risk.

Femoral nerve catheters are widely used for analgesia in total knee arthroplasty. Although evidence suggests that catheters improve pain control and may facilitate short-term rehabilitation, few reports exist regarding their complications. This case series explores the experience of femoral nerve catheter use at high-volume orthopedic specialty hospitals. Serious complications including compartment syndrome, periprosthetic fracture, and vascular injury are reported. The authors support femoral nerve catheter use with appropriate precautions taken to reduce risk of patient falls, vascular injury, and wrong-site surgery.

The lateral compartment in knees with isolated medial and patellofemoral osteoarthritis: a histologic analysis of articular cartilage.

The purpose of this study was to examine, at a histologic level, the articular cartilage of the radiographically normal lateral compartment in knees with isolated medial and possibly patellofemoral osteoarthritis. Twenty patients with radiographic evidence of medial compartment osteoarthritis and a radiographically osteoarthritis-free lateral compartment underwent a tricompartmental total knee arthroplasty. The resected lateral femoral condyle and lateral tibial plateau were evaluated by a fellowship-trained musculoskeletal pathologist for the presence, or lack thereof, of osteoarthritis at a microscopic level. Both the tibia and femur showed evidence of mild osteoarthritis at a microscopic level. This study shows that in patients with radiographic evidence of medial osteoarthritis and a radiographically normal lateral compartment, there is mild osteoarthritis in the lateral compartment.

Productivity and cost implications of implementing electronic medical records into an ambulatory surgical subspecialty clinic.

OBJECTIVES: Electronic medical records (EMRs) have been proposed as technology through which the quality of healthcare could be improved. We present an analysis of the cost and productivity implications associated with the transition from transcription to an EMR system in an ambulatory setting. METHODS: Data were collected from eight consecutive fiscal years from 1998 to 2005. Transcription was used in the first 4-year period, and EMR was implemented and used in the later 4-year period. Productivity was defined as ambulatory revenue and the number of patient encounters. All costs related to transcription and EMR implementation were calculated. All data were adjusted for inflation. RESULTS: Within the transcription era, the transcription costs were $395,404, total revenue was $18,137,945, and patient encounters numbered 52,027. The average transcription cost per encounter was $7.60, average revenue per encounter was $348.63, and average revenue per provider was $505,615. Within the EMR era, the EMR-related costs were $293,406, total revenue was $30,370,647 and patient encounters numbered 65,102. The average documentation cost per encounter was $4.51, average revenue per encounter was $466.51, and average revenue per provider was $690,242. The startup costs of initial EMR implementation were $10,329 per physician provider. CONCLUSIONS: The results of our study have shown that the implementation of an EMR system when an economy of scale exists coincides with an increase in the revenue per encounter and per provider compared with transcription. The advantage of the fixed costs of an EMR system compared with the variable costs of a transcription-based system is the allowance of cash savings in an ambulatory surgical subspecialty practice.