title: Femoral pinless length and offset measurements during computer-assisted, minimally invasive total hip arthroplasty.
abstract: We asked whether the intraoperative assessment of leg length (LL) and offset (OS) change would be accurate using a novel pinless femoral reference system during unilateral minimally invasive THA in 50 patients with a mean age of 60 years (48-79). LL and OS change measured at surgery was compared with LL/OS change as measured on magnification-corrected preoperative and postoperative radiographs by two blinded examiners. The radiographic evaluation showed a high inter-rater reliability (r > 0.80 for all assessments). The mean differences (± 95% limits of agreement) between navigation and radiographic measurements on the treated side were +0.4mm (± 3.6) for LL and -1.0 mm (± 3.9) for OS. Femoral pinless navigation technology represents a feasible assistance in THA.
authors.affiliation: Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Renkawitz
authors.affiliation: Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: Sendtner
authors.affiliation: Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.affiliation: Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Weber
authors.affiliation: Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.affiliation: Department of Orthopaedic Surgery, Regensburg University Medical Center, Bad Abbach, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Woerner
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods*; D017760:Bone Malalignment / Q000209:etiology / Q000517:prevention & control; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery*; D006621:Hip Joint; D006801:Humans; D007870:Leg Length Inequality / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D011859:Radiography; D025321:Surgery, Computer-Assisted
keywords: biomechanics; leg length inequality; navigation; total hip arthroplasty