Impingement-free range of movement, acetabular component cover and early clinical results comparing ‘femur-first’ navigation and ‘conventional’ minimally invasive total hip arthroplasty

Abstract

We report the kinematic and early clinical results of a patient- and observer-blinded randomised controlled trial in which CT scans were used to compare potential impingement-free range of movement (ROM) and acetabular component cover between patients treated with either the navigated 'femur-first' total hip arthroplasty (THA) method (n = 66; male/female 29/37, mean age 62.5 years; 50 to 74) or conventional THA (n = 69; male/female 35/34, mean age 62.9 years; 50 to 75). The Hip Osteoarthritis Outcome Score, the Harris hip score, the Euro-Qol-5D and the Mancuso THA patient expectations score were assessed at six weeks, six months and one year after surgery. A total of 48 of the patients (84%) in the navigated 'femur-first' group and 43 (65%) in the conventional group reached all the desirable potential ROM boundaries without prosthetic impingement for activities of daily living (ADL) in flexion, extension, abduction, adduction and rotation (p = 0.016). Acetabular component cover and surface contact with the host bone were > 87% in both groups. There was a significant difference between the navigated and the conventional groups' Harris hip scores six weeks after surgery (p = 0.010). There were no significant differences with respect to any clinical outcome at six months and one year of follow-up. The navigated 'femur-first' technique improves the potential ROM for ADL without prosthetic impingement, although there was no observed clinical difference between the two treatment groups.

Navigation is Equal to Estimation by Eye and Palpation in Preventing Psoas Impingement in THA

“…According to the main study, patients were randomized to with or without the use of imageless navigation [19]. The investigation was approved by the local ethics commission.…”

“…In contrast, imageless navigation systems without the need for preoperative or intraoperative image acquisition and exposure to radiation have been reported to increase precision in positioning the acetabular component, achieve leg length and offset reconstruction, and prevent impingement [19,24]. The current study is a reanalysis of data from a randomized controlled trial [19]. The primary study dealt with ROM improvement by computer-assisted, functional optimization of cup position and containment.…”

Correction of Pelvic Tilt and Pelvic Rotation in Cup Measurement after THA – An Experimental Study

“…Assessment of cup orientation in the APP is necessary when computer navigation is used for improving the range of motion in THA [2]. Babisch used normograms to convert values of cup position from the APP to the coronal plane [22].…”

“…Inaccurate placement of femoral and acetabular components is associated with dislocation [1], a decreased range of motion [2,3], periprosthetic impingement [2], and component wear [4]. For orientation of the femoral component, stem torsion can be assessed by means of the neck-shaft angle (NSA) [5].…”

Measuring Acetabular Cup Orientation on Antero-Posterior Radiographs of the Hip after Total Hip Arthroplasty with a Vector Arithmetic Radiological Method. Is It Valid and Verified for Daily Clinical Practice?

“…This investigation was approved by the local ethics commission. The current study is a secondary analysis from this cohort [2,15]. A consecutive series of 135 patients were enrolled in this single center study, 12 of whom had to be withdrawn.…”