Does Fluoroscopy Improve Acetabular Component Placement in Total Hip Arthroplasty?

Abstract

Background The success of THA largely depends on correct placement of the individual components. Traditionally, these have been placed freehand using anatomic landmarks, but studies have shown poor accuracy with this method. Questions/purposes Specifically, we asked (1) does using fluoroscopy lead to more accurate and greater likelihood of cup placement with the Lewinnek safe zone than does freehand cup placement; (2) is there a learning curve associated with the use of fluoroscopy for cup placement; (3) does the use of fluoroscopy increase operative time; and (4) is there a difference in leg length discrepancy between freehand and fluoroscopic techniques? Methods This series consisted of 109 consecutive patients undergoing primary THA, conversion of a previous hip surgery to THA, and revision THA during a 24-month period. No patients were excluded from analysis during this time. The first 52 patients had cups placed freehand, and then the next 57 patients had acetabular components placed using fluoroscopy; the analysis began with the first patient treated using fluoroscopy, to include our initial experience with the technique. The abduction, version, and limb length discrepancy were measured on 6-week postoperative pelvic radiographs obtained with the patient in the supine position. Operative time, sex, age, BMI, diagnosis, operative side, and femoral head size were recorded as possible confounders. Results Cups inserted freehand were placed in the ideal range of abduction (30°-45°) and anteversion (5°-25°) 44% of the time. With fluoroscopy, placement in the Lewinnek safe zone for both measures significantly increased to 65%. The odds of placing the cup in the Lewinnek safe zone for abduction and version were 2.3 times greater with the use of fluoroscopy (95% CI, 1.2-5.0; p = 0.03). Patients undergoing primary THAs (32 freehand, 35 C-arm) had cup placement in the safe zone for abduction and version 44% of the time freehand and 57% of the time with fluoroscopy, which failed to reach statistical significance. There was no difference in operative time, patient age, sex, operative side, diagnosis, limb length discrepancy, or femoral head size between the two groups. Conclusions The use of fluoroscopy to directly observe pelvic position and acetabular component placement increased the success of placement in the Lewinnek safe zone in this cohort of patients having complex and primary THAs. This is a simple, low-cost, and quick method for increasing successful acetabular component alignment. The study population included a large proportion of patients

A Comparison of Radiographic Outcomes After Total Hip Arthroplasty Between the Posterior Approach and Direct Anterior Approach With Intraoperative Fluoroscopy

“…Intra-operative fluoroscopy allows real-time assessment of implant positioning and has been shown to improve component positioning when compared to freehand techniques. 15 Poor component positioning has been associated with increased risk of dislocation, decreased range of motion, increased concentration of metal ions after resurfacing, and increased risk of polyethylene wear. 16–19 Other studies have compared post-operative acetabular inclination and acetabular anteversion between the DAA with intra-operative fluoroscopy and the posterior approach.…”

Fluoroscopy assessment during anterior minimally invasive hip replacement is more accurate than with the posterior approach

“…Multiple techniques have been promoted to enhance the accuracy of component positioning, including the use of fluoroscopy [1,2,24], computer navigation [31,32], and robotic assistance [5,6]. Of these three, fluoroscopy is the most widely available and least expensive to adopt.…”

“…It's unclear if the improvement in that sense was due to the use of fluoroscopy or the change in approach. Beemer et al [2] demonstrated that the use of fluoroscopy can improve component position in the posterior approach. Our results demonstrate that when using fluoroscopy in the anterior approach, we achieved better results than when used in the posterior approach (Fig.…”

“…Methods are available to help ensure accurate component positioning including fluoroscopy [1,2], computer navigation [3,4], and robotics [5,6]. This study focuses on the use of fluoroscopy to help assure correct acetabular component orientation.…”

“…Another study by Beemer et al [2] suggested that the use of fluoroscopy with posterior hip arthroplasty may increase accurate placement of acetabular components for surgeons performing a mix of primary, revision, and complicated total joint arthroplasties. From previous studies, it is unclear if the value of fluoroscopy is similar when used in the posterior approach as compared to the anterior approach.…”