Safely Implementing the Direct Anterior Total Hip Arthroplasty: A Methodological Approach to Minimizing the Learning Curve.

INTRODUCTION: Orthopaedic surgeons often cite concern for a learning curve as a barrier to adopting the direct anterior approach (DAA) for total hip arthroplasty (THA) while transitioning from other approaches. Studies both assessing and describing a practical approach and strategy to safely accomplish this transition, as well as the effect on clinical outcomes, are not well described. METHODS: This prospective study compares a single surgeon's operative results and complications for the first consecutive 100 direct anterior THA to the last 100 consecutive posterior THA after 7 years in practice. The regimented and disciplined learning strategy used to implement the DAA is detailed in this study. The data were analyzed using univariate and multivariate regression models. RESULTS: Univariate analyses identified significant differences in sex, age, Asian race, and diagnostic cause for THA between the two cohorts. Multivariate analyses controlled for these differences and showed that relative to posterior THA, direct anterior THA cases were associated with 7-minute longer procedures (P = 0.002) and lengths of stay that were 0.7 days fewer (P = 0.013). No significant differences were present in the estimated blood loss, and importantly, no significant differences in death or surgical complication rates between cohorts. DISCUSSION: This study suggests that the DAA for THA can be safely implemented without the increased and adverse risk to the patient when a structured learning process is maintained and meticulously performed.

A Computer Model of Mid-Flexion Instability in a Balanced Total Knee Arthroplasty.

BACKGROUND: Some patients have mid-flexion instability despite stability at 0° and 90° of flexion. This study aims to determine the effects of total knee arthroplasty (TKA) stability while changing femur implant size and position. METHODS: A computational analysis was performed simulating knee flexion of posterior stabilized (PS) and cruciate retaining (CR) TKA designs. Deviations from the ideal TKA implant position were simulated by adjusting tibiofemoral proximal-distal position and femur anterior-posterior position as well as implant size. Forces in ligaments connecting the femur and tibia were collected. Total tibiofemoral ligament load for mid-knee flexion of 15°-75° was analyzed vs proximal-distal implant position, implant size, implant design, and knee flexion for PS and CR knees. Posterior cruciate ligament load was also analyzed for CR knees. RESULTS: Total tibiofemoral ligament load was significantly reduced by a more proximal tibiofemoral and anterior femur position (P < .001). Implant size did not have a significant effect on tibiofemoral ligament load (P > .1). Implant design and knee flexion significantly influenced total tibiofemoral ligament load (P < .001), but the interactions with implant proximal-distal position were not significant (P > .2), indicating that implant proximal-distal position had a similar effect across the 15°-75° knee flexion range for both studied PS and CR implant designs. CONCLUSION: PS and CR TKA can be well-balanced at 0° and 90° knee flexion and have instability in mid-flexion. Elevating the joint line and shifting the femur anteriorly can cause the knee to be too loose in mid-flexion.

Effect of Tranexamic Acid on Transfusion Rates Following Total Joint Arthroplasty: A Cost and Comparative Effectiveness Analysis.

Tranexamic acid (TXA) is used to reduce blood loss in orthopedic total joint arthroplasty (TJA). This study evaluates the effectiveness of TXA in reducing transfusions and hospital cost in TJA. Participants undergoing elective TJA were stratified into 2 cohorts: those not receiving and those receiving intravenous TXA. TXA decreased total hip arthroplasty (THA) transfusions from 22.7% to 11.9%, and total knee arthroplasty (TKA) from 19.4% to 7.0%. The average direct hospital cost reduction for THA and TKA was $3083 and $2582, respectively. Implementation of a TJA TXA protocol significantly reduced transfusions in a safe and cost-effective manner.

Cost Analysis of Total Joint Arthroplasty Readmissions in a Bundled Payment Care Improvement Initiative.

BACKGROUND: The Bundled Payment for Care Improvement (BPCI) Initiative is a Centers for Medicare and Medicaid Services program designed to promote coordinated and efficient care. This study seeks to report costs of readmissions within a 90-day episode of care for BPCI Initiative patients receiving total knee arthroplasty (TKA) or total hip arthroplasty (THA). METHODS: From January 2013 through December 2013, 1 urban, tertiary, academic orthopedic hospital admitted 664 patients undergoing either primary TKA or THA through the BPCI Initiative. All patients readmitted to our hospital or an outside hospital within 90-days from the index episode were identified. The diagnosis and cost for each readmission were analyzed. RESULTS: Eighty readmissions in 69 of 664 patients (10%) were identified within 90-days. There were 53 readmissions (45 patients) after THA and 27 readmissions (24 patients) after TKA. Surgical complications accounted for 54% of THA readmissions and 44% of TKA readmissions. These complications had an average cost of $36,038 (range, $6375-$60,137) for THA and $38,953 (range, $4790-$104,794) for TKA. Eliminating the TKA outlier of greater than $100,000 yields an average cost of $27,979. Medical complications of THA and TKA had an average cost of $22,775 (range, $5678-$82,940) for THA and $24,183 (range, $3306-$186,069) for TKA. Eliminating the TKA outlier of greater than $100,000 yields an average cost of $11,682. CONCLUSION: Hospital readmissions after THA and TKA are common and costly. Identifying the causes for readmission and assessing the cost will guide quality improvement efforts.

Ceramic-Ceramic Hip Arthroplasty for Osteonecrosis: Average 5-year Follow-up in Patients Less Than 50 Years of Age.

INTRODUCTION: The optimal bearing surface for the young, active patient undergoing total hip arthroplasty (THA) is unknown. We sought to examine the clinical results of ceramic-on-ceramic (CoC) THA in patients under 50 years of age with a diagnosis of osteonecrosis. MATERIALS AND METHODS: Fifty-three hips underwent cementless THA with a CoC articulation. Clinical and functional outcomes, including preoperative and postoperative WOMAC and UCLA scores, were recorded. Serial radiographs were studied for component loosening or evidence of osteolysis. Revision surgery for any reason was the primary clinical endpoint. RESULTS: The average age at time of THA was 31.03 years (range: 15 to 50 years). Average follow-up was 64 months (range: 24 to 112 months). Average preoperative BMI was 25.3 (range: 20.1 to 39.4). WOMAC scores increased from a preoperative average of 37.1 (range: 3.9 to 70.2) to 89 (range: 11.7 to 100) at latest follow-up (p less than 0.05). UCLA scores improved from a preoperative average of 2.39 (range: 1 to 4) to 6.72 (range: 1 to 10) postoperatively (p less than 0.05). Forty-five percent of patients were highly active with UCLA scores between 8 and 10. There were no dislocations, deep infections, or ceramic component failures. One patient was revised for chronic pain at another institution, and one patient underwent revision for femoral component loosening. Three patients experienced squeaking, which did not affect quality of life. CONCLUSION: At mid-term follow-up, THA with CoC bearings affords high activity level with excellent clinical outcomes and component longevity in young, active patients with osteonecrosis.

Risk Factors for Infection Following Total Knee Arthroplasty: A Series of 3836 Cases from One Institution.

Higher PJI rates may be related to identifiable risk factors, which may or may not be modifiable. Identifying risk factors preoperatively provides opportunities for modification and potentially decreasing the incidence of PJI. The purposes of this study were to: (1) retrospectively identify and quantify risk factors for PJI following primary TKA, and (2) to classify those significant risk factors as either non-modifiable or modifiable for intervention prior to surgery. Optimization of modifiable risk factors such as Staphylococcus aureus colonization, and tobacco use prior to primary TKA may decrease the incidence of periprosthetic joint infection after primary TKA, thereby reducing morbidity and the costs associated with treating those infections.

Total hip arthroplasty with porous metal cups following acetabular fracture.

Total hip arthroplasty (THA) after acetabular fracture presents unique challenges, including acetabular fixation. Twelve patients with a history of acetabular fracture underwent THA with porous metal cups. The average age was 57 years (range 24-88). THA was performed at an average 20 months from initial fracture. Average follow-up was 39 months (range 24-49). Average WOMAC scores improved from 32 to 79; UCLA scores improved from 1.75 to 5.25. There was one case of acetabular loosening in a renal transplant patient with rheumatoid arthritis. No other patients showed progressive radiolucent lines. At average three-year follow-up, porous metal components afforded improved clinical and radiographic outcomes in the majority of patients. Longer follow-up will determine whether porous metal is a durable option in the management of prior acetabular fracture.

Delayed complete limb ischemia following a closed tibial shaft fracture.

We present a 19-year-old collegiate athlete who sustained a low-energy closed tibial shaft fracture. Following closed reduction, the dorsalis pedis and posterior tibial pulses were symmetric to the contralateral limb on physical examination. Angiography later confirmed triple vessel arterial disruption complicated by delayed ischemia requiring limb revascularization. Lower extremity triple vessel occlusion from a low-energy injury is rare, and delayed presentation requiring limb salvage is even more unusual. We review the literature, describe the diagnosis and treatment, and propose a strategy for post-fracture reduction management of vascular status.