title: Chronic medial knee pain without history of prior trauma: correlation of pain at rest and during exercise using bone scintigraphy and MR imaging.
abstract: OBJECTIVE
  The objective of this study was to correlate chronic medial knee pain at rest and during exercise with bone scintigraphic uptake, bone marrow edema pattern (BMEP), cartilage lesions, meniscal tears, and collateral ligament pathologies on magnetic resonance MR imaging (MRI).
  
  
  METHODS
  Fifty consecutive patients with chronic medial knee pain seen at our institute were included in our study. Pain level at rest and during exercise was assessed using a visual analog scale (VAS). On MR images, BMEP volume was measured, and the integrity of femoro-tibial cartilage, medial meniscus, and medial collateral ligament (MCL) were assessed. Semiquantitative scintigraphic tracer uptake was measured. Multivariate linear regression analysis was performed.
  
  
  RESULTS
  At the day of examination, 40 patients reported medial knee pain at rest, 49 when climbing stairs (at rest mean VAS 33 mm, range 0-80 mm; climbing stairs mean VAS, 60 mm, range 20-100 mm). Bone scintigraphy showed increased tracer uptake in 36 patients (uptake factor, average 3.7, range 2.4-18.0). MRI showed BMEP in 31 studies (mean volume, 4,070 mm(3); range, 1,200-39,200 mm(3)). All patients with BMEP had abnormal bone scintigraphy. Ten percent of patients with pain at rest and 8% of patients with pain during exercise showed no BMEP but tracer uptake in scintigraphy. Tracer uptake and signal change around MCL predicted pain at rest significantly (tracer uptake p = 0.004; MCL signal changes p = 0.002). Only MCL signal changes predicted pain during exercise significantly (p = 0.001).
  
  
  CONCLUSIONS
  In chronic medial knee pain, increased tracer uptake in bone scintigraphy is more sensitive for medial knee pain than BMEP on MRI. Pain levels at rest and during exercise correlate with signal changes in and around the MCL.
authors.affiliation: Department of Diagnostic Radiology and Nuclear Medicine, Lucerne Cantonal Hospital, Lucerne, Switzerland. florian.buck@gmail.com
authors.forename: Florian M
authors.initials: FM
authors.lastname: Buck
authors.forename: Alexander
authors.initials: A
authors.lastname: Hoffmann
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hofer
authors.forename: Christian W A
authors.initials: CW
authors.lastname: Pfirrmann
authors.forename: Bernhard
authors.initials: B
authors.lastname: Allgayer
mesh_terms: D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000000981:diagnostic imaging* / Q000473:pathology*; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000473:pathology; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D013669:Technetium Tc 99m Medronate
chemical_list: D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate