A Comparison of Conventional Guidewire Alignment Jigs with Imageless Computer Navigation in Hip Resurfacing Arthroplasty

et al. 2013

IJOO

Self Cite

Background:The use of computer navigation has been shown to improve the accuracy of femoral component placement compared to conventional instrumentation in hip resurfacing. Whether exposure to computer navigation improves accuracy when the procedure is subsequently performed with conventional instrumentation without navigation has not been explored. We examined whether femoral component alignment utilizing a conventional jig improves following experience with the use of imageless computer navigation for hip resurfacing.Materials and Methods:Between December 2004 and December 2008, 213 consecutive hip resurfacings were performed by a single surgeon. The first 17 (Cohort 1) and the last 9 (Cohort 2) hip resurfacings were performed using a conventional guidewire alignment jig. In 187 cases, the femoral component was implanted using the imageless computer navigation. Cohorts 1 and 2 were compared for femoral component alignment accuracy.Results:All components in Cohort 2 achieved the position determined by the preoperative plan. The mean deviation of the stem–shaft angle (SSA) from the preoperatively planned target position was 2.2° in Cohort 2 and 5.6° in Cohort 1 (P = 0.01). Four implants in Cohort 1 were positioned at least 10° varus compared to the target SSA position and another four were retroverted.Conclusions:Femoral component placement utilizing conventional instrumentation may be more accurate following experience using imageless computer navigation.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Computer navigation experience in hip resurfacing improves femoral component alignment using a conventional jig

Morison

Mehra

et al. 2013

IJOO

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“…7,8 Synthetic femurs were prepared according to the manufacturer's standard surgical protocol. Implant alignment for MHR-implanted femurs was verified within 61°by plain digital radiographs using previously described measurement techniques, 9,10 with no evidence of post-implantation fracture visible upon radiographic examination. MHR-implanted femurs were tested using a mechanical testing system (Model 8874; Instron, Norwood, MA, USA), which had a 625 kN capacity, a 0.1 N resolution, and a 60.5% accuracy.…”

Section: Methodsmentioning

confidence: 99%

The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty

Saied

Morison

et al. 2014

Proc Inst Mech Eng H

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Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120° and 18 femurs with a valgus NSA of 135° were each implanted with a mid-head resection prosthesis. Femurs within the two different femoral morphology groups were divided into three equal coronal implant alignment groups: 10° valgus, 10° varus or neutral alignment. Prepared femurs were tested for stiffness and to failure in axial compression. There was no significant difference in stiffness nor failure load between femurs implanted with valgus-, varus- or neutrally aligned implants in femurs with a NSA of 120° (p = 0.396, p = 0.111, respectively). Femurs implanted in valgus orientation were significantly stiffer and failed at significantly higher loads than those implanted in varus alignment in femurs with a NSA of 135° (p = 0.001, p = 0.007, respectively). A mid-head resection short-stem hip arthroplasty seems less sensitive to clinically relevant variations of coronal implant alignment and may be more forgiving upon implantation in some femoral morphologies, however, a relative valgus component alignment is recommended.

“…Component version was evaluated at latest followup using digital crosstable lateral hip radiographs. The stem-neck angle (SNA) was defined as the angle subtended by the neck and component stem axes [23] and was considered neutral if the anteversion or retroversion value was less than 10° [1]. Femoral fixation was evaluated using the grading scale devised by Amstutz et al [1].…”

Section: Methodsmentioning

confidence: 99%

Avoiding Short-term Femoral Neck Fracture With Imageless Computer Navigation for Hip Resurfacing

Clinical Orthopaedics &Amp; Related Research

Schemitsch

2011

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Background Femoral neck fracture in hip resurfacing has been attributed to technical error during femoral head preparation. In the absence of fracture, several radiographic findings have been speculated to increase the risk of femoral component failure. Questions/purposes We examined whether (1) the use of navigation to reduce technical errors during femoral head preparation reduces the incidence of femoral neck fractures in the short-term followup period; and (2) alignment of the femoral component with the use of computer navigation reduces the incidence of femoral neck thinning, femoral stem radiolucencies, and stem migration. Methods We retrospectively reviewed the first 100 Birmingham Hip Resurfacings performed in 94 prospectively followed patients between October 2005 and November 2007. We examined all radiographs on last followup. Eighty-six patients of the 94 patients had a minimum followup of 2 years (mean, 2.5 years; range, 2-4.1 years).