title: Evaluating the Native Length-Tension Relationship in Arthroscopic Suprapectoral Biceps Tenodesis: An MRI Assessment of Contralateral Shoulders.
abstract: BACKGROUND
  Successful tenodesis of the proximal biceps relies on accurate reproduction of the native length-tension relationship of the long head of the biceps (LHB). While open tenodesis procedures can reproduce this relationship by referencing the position of the LHB musculotendinous junction (MTJ) to a visible anatomic landmark, arthroscopic suprapectoral tenodesis does not afford such advantage because the MTJ is usually not visible. No studies to date have evaluated the position of the MTJ of the LHB following arthroscopic suprapectoral biceps tenodesis.
  
  
  METHODS
  Patients undergoing arthroscopic suprapectoral biceps tenodesis between January 2013 and May 2014 at one center were evaluated for inclusion. Patients included in the study underwent a postoperative MRI of bilateral shoulders. The distance from the superior portion of the humeral head to the LHB MTJ was measured bilaterally. The measurements from each matched pair were compared using a paired t-test to determine if arthroscopic suprapectoral biceps tenodesis anatomically restored the LHB length-tension relationship.
  
  
  RESULTS
  A total of 17 patients met the inclusion criteria. Fourteen of the seventeen patients underwent a postoperative MRI of bilateral shoulders. The distance from the superior portion of the humeral head to the LHB musculotendinous junction was significantly larger on the operative side when compared to the nonsurgical side (operative side mean 98.34 mm, standard deviation 13.38 mm; nonsurgical mean 87.26 mm, standard deviation 9.09; mean difference 11.08 mm; p=0.0105).
  
  
  CONCLUSIONS
  The musculotendinous junction of the LHB in patients who underwent arthroscopic suprapectoral biceps tenodesis was located significantly more distal than the contralateral control, as measured on MRI.
authors.affiliation: Department of Orthopedic Surgery, Drexel University College of Medicine/Hahnemann University Hospital, Philadelphia, Pennsylvania.
authors.forename: John
authors.initials: J
authors.lastname: Prodromo
authors.affiliation: Department of Orthopedic Surgery, Drexel University College of Medicine/Hahnemann University Hospital, Philadelphia, Pennsylvania.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Mulcahey
authors.affiliation: Radiology Department, San Diego Imaging, San Diego, California.
authors.forename: Raymond
authors.initials: R
authors.lastname: Hong
authors.affiliation: Department of Orthopedic Surgery, San Diego Arthroscopy and Sports Medicine, San Diego, California.
authors.forename: Tal S
authors.initials: TS
authors.lastname: David
mesh_terms: D001182:Arthroscopy; D006801:Humans; D058430:Humeral Head / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D009129:Muscle Tonus / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D019651:Plastic Surgery Procedures; D012782:Shoulder / Q000502:physiology*; D013710:Tendons / Q000502:physiology / Q000601:surgery*; D053656:Tenodesis / Q000379:methods*