A comparison of conventional guidewire alignment jigs with imageless computer navigation in hip resurfacing arthroplasty.

BACKGROUND: Correct positioning of the initial femoral guidewire is vital in order to prepare the femoral head properly for hip resurfacing. The purpose of the present investigation was to determine the accuracy and precision of the placement of the initial femoral guidewire with use of conventional alignment jigs and to compare the results with those of imageless computer navigation. METHODS: Five commercially available jigs (two lateral pin jigs, two neck centering jigs, and one head planing jig) were obtained. Four surgeons used each jig and navigation three times to insert a guidewire in 10 degrees of relative valgus and neutral version into individual synthetic femora. A single surgeon then used each jig three times to align the initial guidewire in 10 degrees of relative valgus and neutral version in each of ten human cadaver femora. Radiographs of the synthetic and human femora were made to assess and compare guidewire inclination and version between conventional instrumentation and navigation. RESULTS: Navigation provided ranges of error in the coronal guidewire alignment of up to eight times less than the conventional jigs, but both methods provided similar ranges of error for version. In both arms of the study, there were significant differences in coronal alignment accuracy between the two neck centering jigs. Next to navigation, one lateral pin jig provided the most accurate coronal placement of the initial guidewire whereas one neck centering jig provided the most precise coronal placement of the guidewire. Navigation was similar to conventional jigs in terms of the accuracy and precision of guidewire version. CONCLUSIONS: In hip resurfacing arthroplasty, the choice of a femoral alignment device may influence the accuracy and precision of guidewire insertion, ultimately impacting femoral component placement. Imageless computer navigation can facilitate accurate and precise coronal alignment of the initial femoral guidewire, superior to that of conventional instrumentation. CLINICAL RELEVANCE: The results of this study may aid surgeons in the selection of alignment instruments for placement of the initial femoral guidewire during hip resurfacing.

Assessment of accuracy and reliability in preoperative templating for hip resurfacing arthroplasty.

The current study investigated the accuracy and reliability of hip resurfacing component selection based on digital preoperative templating. Four surgeons made a template of preoperative radiographs on 2 occasions for acetabular and femoral components in 50 randomly selected hip resurfacing patients. Component selection reliability was variable among surgeons (kappa = 0.16-0.73) and fair between surgeons (kappa = 0.23-0.32). The average percentage of agreement for the acetabular component was 47% (range, 32%-64%) and for the femoral component was 54% (range, 38%-70%). Surgeons tended to underestimate implant size if the correct implant was not chosen (acetabular, 29%; femoral, 32%). Selection of an undersized femoral component may lead to femoral neck notching or varus implant alignment. This study emphasizes the need for intraoperative verification of preoperative templating results to ensure optimal implant selection in hip resurfacing.

The accuracy of digital templating in uncemented total hip arthroplasty.

We analyzed the reproducibility and reliability of computer templating in primary uncemented total hip arthroplasties as compared to standard onlay templating techniques with hardcopy radiographs from a digital source. Digital templating showed good intraobserver and interoberserver reliability with intraclass correlation coefficient values greater than 0.7. Using computer templating, prediction of sizing to within 1 size was 85% accurate for femoral stem sizing and 80% accurate for acetabular sizing. Using onlay templating, prediction of sizing to within 1 size was 85% accurate for femoral sizing and 60% accurate for acetabular sizing. We conclude that the introduction of digital templating has significant benefits in preoperative planning for total hip arthroplasty over onlay templating.

Short-term outcomes of total hip arthroplasty after complications of open reduction internal fixation for hip fracture.

Failed open reduction internal fixation (ORIF) of the proximal femur can render patients severely disabled. This study analyzed the short-term functional results and complications of total hip arthroplasty (THA) for complications of ORIF after hip fracture. A retrospective arthroplasty database review identified 36 patients treated with a THA for complications of ORIF of the hip. These patients were matched to a cohort of 36 patients who underwent primary unilateral THA for osteoarthritis. Study results indicate that THA for failed ORIF of the hip is a successful procedure despite concerns of increased intraoperative difficulty and risk of fracture.