Plain Films are Still the Answer : The Right Views Everytime - - PowerPoint PPT Presentation

Hinsdale Orthopaedics

Plain Films are Still the Answer:

The Right Views Everytime

Benjamin G. Domb, M.D.

Medical Director, American Hip Institute Director of Orthopedics, Adventist Hinsdale Hospital

David Maldonado, M.D.

Fellow, American Hip Institute

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Disclosures

• American Hip Institutea, AANA Learning

Center Committeea, Adventist Hinsdale Hospitalc, Arthroscopy Journala, Amplitudec, Arthrexb,c,d, DJO Globald, Medactab,c, Orthomericad, Strykerb,c

• a – boardmember; b – research support; c – consulting; d – royalty; e - stockholder

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My Experience

• Used CT w 3D recons

for >500 cases

• I realized I was no

longer gaining any info from CT

• Why?
• My brain adapted to

build a 3D model in my mind from the x-rays

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Our Protocol: What are we looking for?

• AP pelvis
• Supine
• Standing
• Bilateral Dunn view
• False Profile
• Osteoarthritis:

 Early signs od OA.  Tӧnnis grade, joint space

• Coverage:

 LCEA,Tӧnnis angle, ACEA

• Acetabular architecture:

 Cross-over sign  Retroversion signs

• Neck-Head junction:

 Alpha angle  Off-set

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Early Signs of OA

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Joint space, not only in AP but False Profile View

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LCE angle of Wiberg with Ogata modification*

*Ogata S et al, J Bone Joint Surg Br. 1990

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Tӧnnis angle

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Ischial, Cross-over, and Posterior Wall signs

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Alpha angle and Off-set

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ACE angle

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By the end, just with X-rays...

AP pelvis (S & U) Dunn view False Profile

Sphericity Coverage Cam Retroversion Dysplasia Joint space Early OA Acetabular version Joint space Coverage “Normal” Overcovered True Dysplasia “Borderline” Dysplasia Anterior

• vercoverage

Posterior deficiency Space≥2mm Yes No Yes No Yes No Early OA Yes No Dysplasia Yes No Yes Yes Yes No No No

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What are we missing?

• Femoral version
• Can we obtained it without CT?

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MRI for Femoral Version

Schneider B, Laubenberger J, Jemlich S, Groene K, Weber HM, Langer M. Measurement of femoral antetorsion and tibial torsion by magnetic resonance imaging. Br J Radiol. 1997;70(834):575–579. Botser IB, Ozoude GC, Martin DE, Siddiqi AJ, Kuppuswami S, Domb BG. Femoral Anteversion in the Hip: Comparison of Measurement by Computed Tomography, Magnetic Resonance Imaging, and Physical Examination Arthroscopy. 2012 May;28(5):619-27

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Still thinking in CT for everybody...

Computed Tomography Scans in Patients With Young Adult Hip Pain Carry a Lifetime Risk of

• Malignancy. Wylie JD et al. Arthroscopy 2017

“Protocols with CT scans of the hip/pelvis pose (...) a large relative risk (5-17 times) of cancer compared with radiographs alone in the imaging evaluation for hip pain that decreases with increasing age”. The use of computed tomography in pediatrics and the associated radiation exposure and estimated cancer risk. Miglioretti DL et al. JAMA Pediatr 2013 “Nationally, 4 million pediatric CT scans of the head, abdomen/pelvis, chest, or spine performed each year are projected to cause 4870 future cancers”. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Smith-Bindman et al. Arch Intern Med 2009 Radiation doses from commonly performed diagnostic CT examinations were higher and more variable than generally quoted. Benefits of CT imaging must be balanced against the potential harm from its associated radiation.

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Low dose CT

Biswas D., Bible JE., Bohan M., Simpson AK., Whang PG., Grauer JN., Radiation exposure from musculoskeletal computerized tomographic scans, J Bone Joint Surg Am., August 2009, 91(8):1882-9

In fact is 50% less that standard CT, but safe enough ?

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Radiation Facts

• Background Radiation dose from natural sources is

approximately 3 mSv per year.

• Round-trip flight from New York to London is 0.1 mSv.
• CT = 3½ years of background radiation or 108 round-trip

flights from New York to London.

• What about just 1 lower-dose CT scan preoperatively ???
• 1 to 2 years of background radiation and 35 to 57 round-trip

flights from New York to London

Computed Tomography Scans in Patients With Young Adult Hip Pain Carry a Lifetime Risk of

• Malignancy. Wylie JD et al. Arthroscopy 2017

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Conclusion

1) Consider getting CT in your first 300 hip arthroscopies. After that, you likely won’t gain any information from it. 2) Remember: “Do no harm...” 3) Downsides is cancer 4) The experienced hip surgeon can get all

the info we need from X-rays, complement with MRA and avoid the downsides of CT.

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Thank You

www.AmericanHipInstitute.org

Benjamin G. Domb, M.D.

Medical Director, American Hip Institute Director of Orthopedics, Adventist Hinsdale Hospital