The Use of Fluoroscopy During Direct Anterior Hip Arthroplasty: Powerful or Misleading?

BACKGROUND: Direct anterior approach total hip arthroplasty (THA) with fluoroscopic assistance is growing in popularity. Variables such as pelvic tilt, c-arm technique, and patient positioning can affect the perceived fluoroscopic view. This study evaluates the effect of these variables on the position of the acetabular component. METHODS: Forty-one hips in 40 patients undergoing direct anterior arthroplasty THA with fluoroscopic assistance underwent routine postoperative radiographs and postoperative pelvic computed tomography scan. The acetabular component position as defined by a 3-dimensional reconstruction was compared to the surgeon's intraoperative perception of the component's position and compared to routine postoperative plain radiograph measurements. RESULTS: Although fluoroscopy was used to create an anteroposterior pelvic radiograph utilizing the coccyx to pubis symphysis distance, a 3D reconstruction created in the same pelvic orientation as the fluoroscopic images confirmed that 39/41 hips were placed with unrecognized excess of anteversion and inclination secondary to imaging the pelvis in extension. CONCLUSION: Intraoperative imaging during supine direct anterior arthroplasty THA confirms appropriate component placement. Pelvic tilt can greatly affect the perceived position of the acetabular component and cannot be accurately compensated for by assessing the relationship between the coccyx and pubic symphysis due to morphologic variation and orientation. We recommend positioning the c-arm so that the size and shape of the obturator foramen matches the standing preoperative anteroposterior pelvis image. This technique allows for the native standing pelvic tilt to be accounted for intraoperatively and will result in the least variation in intraoperative and postoperative standing acetabular component orientation.

Novel Technique: Knee Arthrodesis Using Trabecular Metal Cones with Intramedullary Nailing and Intramedullary Autograft.

The failed total knee arthroplasty is a challenge to the surgeon and the patient. Infection, bone loss, and instability lead to a chronically painful and dysfunctional limb. Two-stage revision arthroplasty has been successful in clearing a majority of periprosthetic joint infections. However, there are many cases when the multiply revised and infected total knee arthroplasty cannot be salvaged. We report, a review of knee arthrodesis and a novel technique to manage significant bone loss. The use of trabecular metal cones and a long intramedullary nail can be used in concert with an autologous intramedullary bone graft to provide a stable, length restoring construct with sufficient biology to heal very large bone voids. With this technique we have successfully restored function and stability in the failed knee arthroplasty.

Orthopedic Trauma and Aging: It Isn't Just About Mortality.

The elderly (age 70+) patient with orthopedic trauma is a rapidly growing subset of patients in the United States. Due to increased medical comorbidities and decreased physiological reserve, morbidity and mortality after trauma may significantly differ from those patients younger than 70 years old. A retrospective review was performed to investigate the effect of age on orthopedic trauma. A total of 870 records of patients with orthopedic trauma from 2006 to 2009 at our Level One trauma center were reviewed. A database was created to include demographics, type and number of comorbid conditions at presentation, injuries, intensive care unit (ICU) and hospital length of stay, and description of the fracture. Patients aged 70 years and older had an increased number of comorbidities per person (3.3214-P < .0001). Length of stay in patients aged 70 years and older was not significantly greater than that of the younger patients. They spent an average of 14.76 days in the hospital compared to 13.42 days for the combined younger patients (P = .45), but they spent significantly (P < .0001) more of their stay in the ICU (52.74% vs 34.9% for the younger cohorts). The number of fractures per patient was lower (1.66) in the 70 and older age-group when compared to younger populations (P < .0001). The 70 and older group was more likely to have their injury due to a fall and less likely to have solid organ injuries. As the number of elderly patients increase, continued research in the management of elderly patients with trauma can lead to protocols and practice guidelines to improve outcomes.

Acute, recurrent total knee dislocation: Polyethylene dislocation and malreduction.

A 62-year-old man underwent total knee arthroplasty using a mobile-bearing prosthesis. Four days post-operatively the patient experienced the first of several acute knee dislocations. Closed reduction was performed at an outside hospital a total of three times prior to presentation at this institution. A two-stage exchange of the TKA was recommended due to the clinical suspicion for an infected prosthesis. Upon surgical exploration, it was discovered that the polyethylene insert had spun out completely to 180°. Closed reduction attempts of a posterior dislocation of a mobile-bearing knee prosthesis may contribute to complete 180° spinout of the polyethylene insert.