Improving Cup Positioning Using a Mechanical Navigation Instrument

Abstract

Background Although surgical navigation reduces the rate of malpositioned acetabular cups in total hip arthroplasty (THA), its use has not been widely adopted. As a result of our perceived need for simple and efficient methods of navigation, we developed a mechanical navigation device for acetabular cup orientation. Questions/purposes We assessed accuracy of cup orientation (mean error of cup inclination and anteversion) of a novel mechanical navigation device, percentage of outliers, length of operation, and compared the results with a series of CT-based computer-assisted THAs.Methods Cup orientation of 70 THAs performed using the mechanical navigation device was compared with a historical control group of 146 THAs performed using CT-based computer navigation. Postoperative cup orientation was measured using a validated two-dimensional/ three-dimensional matching method. An outlier was defined outside a range of ± 10°from the planned inclination and/or anteversion. Results Using the mechanical navigation device, we observed a decrease in the errors of inclination (1.3°± 3.4°[ range, À6.6°to 8.2°] versus 3.5°± 4.2°[À12.7°to 6.9°]), errors of anteversion (1.0°± 4.1°[À8.8°to 9.5°] versus 3.0°± 5.8°[À11.8°to 19.6°]), percentages of outliers (0% versus 9.6%), and length of operation (112 ± 22 [78-184] minutes versus 132 ± 18 minutes) compared with CT-based navigation. Conclusions Compared with CT-based surgical navigation, navigation of acetabular cup orientation using a mechanical device can be performed in less time, lower mean errors, and minimal equipment.

Implementation of an accelerated mobilization protocol following primary total hip arthroplasty: impact on length of stay and disposition

“…All acetabular components were implanted using a patient-specific mechanical navigation device (Fig. 2, HipSextant, Surgical Planning Associates, Boston, MA) [5].…”

An Automated Pelvic Bone Geometrical Feature Measurement Utilities on Ct Scanning

“…For the last 10-15 years various concepts have been introduced to measure the orientation of the acetabular component. Recent inventions like mechanical guidance instruments [8], [9], many computer assisted strategies have been developed and successfully applied to THA's. The image based strategies either relay an preoperative CT scans [10]- [11] or on intra operative images fluoroscopy [12]- [13].And these strategies increased operative time and further both patient and surgical staff are exposed to radiations imageless strategies have developed.…”

The Learning Curve Associated With Robotic-Assisted Total Hip Arthroplasty

“…Improper femoral component placement may lead to leg length inequality, altered offset, and instability. Limb length inequality can be a source of patient dissatisfaction, and is the second most common cause of litigation in reconstructive surgery [8].Multiple techniques have been put forward over the last two decades to optimize component positioning including: computer navigation, mechanical navigation, intra-operative fluoroscopy, and robotic assistance [9][10][11][12]. Many of these guidance techniques have shown the ability to decrease component malposition; however, these techniques often present intra-operative challenges [11,13,14].…”

“…Many of these guidance techniques have shown the ability to decrease component malposition; however, these techniques often present intra-operative challenges [11,13,14]. Technical complexity, increased operating room time, and expense have been offered as reasons not to adopt navigation [15].…”