Comparison of canine femoral implant templating for total hip arthroplasty on 25 sets of craniocaudal extended and caudocranial flexed hip radiographs
🔍 Key Findings
- Hip-flexed and hip-extended radiographs produced significantly different femoral stem template sizes, confirming the techniques are not interchangeable (p < .0001).
- Hip-extended templating underestimated implanted stem size (mean difference −0.54), whereas hip-flexed templating overestimated implanted size (mean difference +0.30).
- Neither radiographic method consistently predicted the actual implanted femoral stem, emphasizing the importance of intraoperative assessment.
- Flexed projections generated larger template sizes (median stem size 9) than extended projections (median stem size 8).
- Canal flare index (CFI) was significantly higher on flexed views (1.89 vs 1.61; p < .0001), reducing apparent "stovepipe" morphology.
- 88% of extended projections were classified as stovepipe femora versus 44% of flexed projections (p = .0027), suggesting substantial projection-related morphologic distortion.
- Femoral length appeared significantly longer on flexed radiographs (204.8 mm vs 189.3 mm; p < .001), supporting the presence of foreshortening on extended views.
- Hip-flexed radiographs may be a practical alternative when hip extension is not possible, especially in severe OA, but implant selection should remain guided by intraoperative findings.
Simini Surgery Review Podcast
🔍 Key Findings
- Hip-flexed and hip-extended radiographs produced significantly different femoral stem template sizes, confirming the techniques are not interchangeable (p < .0001).
- Hip-extended templating underestimated implanted stem size (mean difference −0.54), whereas hip-flexed templating overestimated implanted size (mean difference +0.30).
- Neither radiographic method consistently predicted the actual implanted femoral stem, emphasizing the importance of intraoperative assessment.
- Flexed projections generated larger template sizes (median stem size 9) than extended projections (median stem size 8).
- Canal flare index (CFI) was significantly higher on flexed views (1.89 vs 1.61; p < .0001), reducing apparent "stovepipe" morphology.
- 88% of extended projections were classified as stovepipe femora versus 44% of flexed projections (p = .0027), suggesting substantial projection-related morphologic distortion.
- Femoral length appeared significantly longer on flexed radiographs (204.8 mm vs 189.3 mm; p < .001), supporting the presence of foreshortening on extended views.
- Hip-flexed radiographs may be a practical alternative when hip extension is not possible, especially in severe OA, but implant selection should remain guided by intraoperative findings.
Simini Surgery Review Podcast
Know What Matters in the Literature - and Why
We distill peer-reviewed surgical studies into clinically relevant summaries and
exam-style questions, so you can make informed decisions with confidence.
Free Access. No Spam. Just Smarter Surgical Learning
Multiple Choice Questions on this study
Access the full library of surgical summaries and exam-style questions.
Educational content developed independently and supported by Simini.
The maker of Simini Protect Lavage.