title: TT-TG vs. modified lateral patellar edge for determination of tibial tubercle transfer distance in Fulkerson osteotomy procedures.
abstract: BACKGROUND
  Tibial tubercle-trochlear groove (TT-TG) distance is currently used at our institution to determine tibial tubercle medialization required in Fulkerson osteotomies. If the correlation between a modified lateral patellar edge (LPE) and the transfer distance was found to be stronger than its correlation with TT-TG, it would suggest that the best measurement to use is actually modified LPE.
  
  
  METHODS
  The electronic medical records of 32 patients who underwent Fulkerson osteotomy procedures with femoral nerve stimulation were reviewed and measured. For each patient, modified LPE was measured on quadriceps active hyperextension MRI, and TT-TG was measured on passive extension MRI. Correlation between both TT-TG and LPE and tibial tubercle transfer distance was then determined and analysed.
  
  
  RESULTS
  The correlation between TT-TG and actual intra-operative tibial tubercle transfer distance in Fulkerson osteotomy procedures with intra-operative femoral nerve stimulation was found to be weak at 0.436 (p<0.05). The correlation between modified LPE and actual intra-operative tibial tubercle transfer distance was found to be strong at 0.697 (p<0.001).
  
  
  CONCLUSIONS
  The correlation between modified LPE and actual intra-operative tibial tubercle transfer distance was stronger than the correlation between TT-TG and tibial tubercle transfer distance. This suggests that the modified LPE may actually be a better preoperative determinant than the currently-utilized TT-TG of the transfer distance required during Fulkerson osteotomy procedures.
  
  
  METHODS
  Level II, diagnostic study.
authors.affiliation: The University of Iowa, Department of Orthopaedics & Rehabilitation, 200 Hawkins Dr. #4802, Iowa City, IA 52240, United States.
authors.forename: Alan
authors.initials: A
authors.lastname: Edwards
authors.affiliation: The University of Iowa, Department of Orthopaedics & Rehabilitation, 200 Hawkins Dr. #4802, Iowa City, IA 52240, United States.
authors.forename: Evan
authors.initials: E
authors.lastname: Larson
authors.affiliation: The University of Iowa, Department of Orthopaedics & Rehabilitation, 200 Hawkins Dr. #4802, Iowa City, IA 52240, United States.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Beckert
authors.affiliation: The University of Iowa, Department of Orthopaedics & Rehabilitation, 200 Hawkins Dr. #4802, Iowa City, IA 52240, United States.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Sahai
authors.affiliation: The University of Iowa, Department of Orthopaedics & Rehabilitation, 200 Hawkins Dr. #4802, Iowa City, IA 52240, United States.
authors.forename: John P
authors.initials: JP
authors.lastname: Albright
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005267:Femoral Nerve / Q000503:physiopathology; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000601:surgery; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D010329:Patella / Q000000981:diagnostic imaging* / Q000601:surgery; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D013977:Tibia / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult
keywords: Fulkerson osteotomy; Patellar realignment; TT-TG