CT Scans are Essential: You will Fail Otherwise J. W . W. . - PowerPoint PPT Presentation

CT Scans are Essential: You will Fail Otherwise J. W . W. . Thomas By Byrd, MD MD Mini-Pane Min nel: Imaging ng S Showdow own n Orthop thopae aedic S c Summit 2 t 2017 17 - Evolving ng T Techni hniques ues Las V Vegas as, N Nevad ada Decem cember er 8 th th , 201 2017

• Don’ Don’t g get a et a CT CT scan can on on ev ever eryone • Rare rely n necessary t to ma make decis ision a on about ut s surg rgery ery – Tha hat’s b based on on nume numerou ous ot othe her fact actors… s…

• Once d e decis ision f ion for surg rgery ery h has been ma made, C CT helpf lpful f for: r: – Sus Suspected c cont ontribut ution of n of FA FAI ( Most c ases ) t cas – Occa casi sionally, y, t to rule o e out/asse assess ss componen ent o of dysp splasi asia t a that at m might contraindicat cate a e arthrosc scopy

• Ample l le literat rature t ure to support: ort: – Inad adequac acy y of plai ain r rad adiography i y in asse sessi ssing c complex ex t three ee dime mens nsional ana natom omy of of FA FAI – Superio iority ity o of CT im imagin ing ( ( 3D r econs ) D rec

Clin Orthop Rel Res 2013; 471(8)2463-2470 . The Crossover Sign Overestimates Acetabular Retroversion Zaltz I, Kelly BT, Hetsroni I, Bedi A

J Orthop Res 2012; Sep:1369-1376 . Standardized AP Radiographs Do Not Provide Reliable Diagnostic Measures for the Assessment of Acetabular Retroversion Wassilew GI, Heller MO, Diederichs G, Janz V, Wenzl M, Perka C

Clin Orthop Rel Res 2013;471:2484-2491. Novel CT-based 3-Dimensional Software Improves the Characterization of Cam Morphology Milone MT, Bedi A, Poultsides L, Magennia E, Byrd JWT, Larson CM, Kelly BT

• Few a art rtic icles t try ry t to imp imply c compa mpara rable ro role le f for p r pla lain in ra radiogr graph phy: – Methodology w y weak eak – Clinical al r relev evan ance ce marginal

Knee Surg Sports Traumatol Arthrosc. 2014;published online September 26. Inter- and Intra-observer Agreement of FAI Parameters Comparing Plain Radiographs and Advanced, 3D CT-generated Hip Models in a Surgical Patient Cohort Cadet ER, Babatunde OM, Gorroochurn P, Chan AK, et al.

Clin Orthop Rel Res 2012; 470: 3313-3320. Do Plain Radiographs Correlate with CT for Imaging of Cam-Type FAI? Nepple JJ, Martel JM, Kim YJ, Zaltz I, Clohisy JC, ANCHOR Study Group

• At le least a as enli ligh ghtening in g in seeming ngly ly s straig aight htforw orward ard c cases es as compl mplex c cases – Pr Prob obably mor more so o wi with wha h what l look ooks to o be s straightforwar ard, s since y ce you w would other erwise se r remai ain u unsusp specting

• Primi rimitive 2 2D in indices t try rying t g to in interpr pret c comp mplex 3 3D anatomy my

• Move t towards ds mo more re me meaningf gful 3 3D param ameters eters

Clin Orthop Rel Res 2013;471:358-362. Emerging Ideas: Novel 3D Quantification and Classification of Cam Lesions in Patients with Femoroacetabular Impingement Kang RW, Yanke AB, Orias AE, Inous N, Nho S

Clin Orthop Rel Res, pub pending. A Novel Method for Defining Normal Acetabular Coverage: A CT-Based Study of Asymptomatic Hips and Correlation with Conventional Radiographic Measures of Acetabular Deformity Larson CM, Moreau-Gaudry A, Kelly BT, Byrd JWT, Tonetti J, Lavallee S, Chabanas L, Barrier G, Bedi A

Radiation?

Radiati tion? • Low Low-dos ose r e radiatio iation p n protoc tocol ol – Les ess t than an 5 5 film h hip ser series • Best e t esti timate ate • Not i t inconsequ quen ential

Radiati tion? • CT r radiation ation o offset b t by o other r advant antag ages es: – Min Minim imiz izes p pla lain in r radiographs • Reasonabl bly c cente tered d AP pelvis • Frog l g late teral a affect cted d hip • Eas asy to g to get r et rep eproducible v view ew • Occ ccasionally f fal alse e profi file • Asse ssessi sing d dysp ysplasi sia • Discer cern o n occul cult a t anter erior or o or p poster terior or j joint nt space n ce narrow owing ng t that m at might c ht contr ntrai aind ndicate cate arthr thros oscop copy

Radiati tion? • CT r radiation ation o offset b t by o other r advant antag ages es: – Eliminat ates n s need ed for r rep epea eating radiograp aphs s to get p proper o orien entat ation • Pr Proverbi bial p prope perly c cen ente tered d AP P pel elvis, Dunn v Du view, w, etc tc. • Ev Everyone e emphasizes es i importance of prope perly o oriente ted r d radiogr graph phs; b but h t how w do y o you ou cor orrect w whe hen you d ou don on’t? • Keep ep s shooti oting ng?

Radiati tion? • CT r radiation ation o offset b t by o other r advant antag ages es: – Lessen ssens n s need ed f for intrao aoperative ve fluorosco scopy • Ev Everyone g gets ts wet wet

Summary

Summary ary • Need d to be min mindful in in y your decis ision t on to order a er a CT scan an – Onl nly wi with a h a pur urpos ose • Cle learl rly g giv ives y you a a better interp rpretat retation o ion of comple lex t x three e dimens ensional a onal anatom omy o of FAI p problem lems wit ith w whic ich w we are re challe lenged

Summary ary • Peop People who ho say ay they they don’ on’t need it, I q ques estion ion whether her they s they simply d don’ on’t k know now w what hat they they are re n not seeing • Freque uently ntly s surp rpris ised ed b by i inform rmation ation gleaned aned f from C CT t that s substan tantial tially ly alt lters o or r sharpe pens my my surgi gical strateg ategy – Hard t to pred edict ct w which cases t ases those se are e goi oing ng t to o be…

Summary ary • Goo Good Luc Luck!...

“No No one one want ants an an unl unluc ucky s sur urgeon…”