title: MRI evaluation of rotational alignment and synovitis in patients with pain after total knee replacement.
abstract: Component malalignment can be associated with   pain following total knee replacement (TKR). Using MRI, we reviewed   50 patients with painful TKRs and compared them with a group of   16 asymptomatic controls to determine the feasibility of using MRI   in evaluating the rotational alignment of the components. Using   the additional soft-tissue detail provided by this modality, we   also evaluated the extent of synovitis within these two groups.   Angular measurements were based on the femoral transepicondylar   axis and tibial tubercle. Between two observers, there was very   high interobserver agreement in the measurements of all values.   Patients with painful TKRs demonstrated statistically significant   relative internal rotation of the femoral component (p = 0.030).   There was relative internal rotation of the tibial to femoral component   and combined excessive internal rotation of the components in symptomatic   knees, although these results were significant only with one of   the observers (p = 0.031). There was a statistically significant   association between the presence and severity of synovitis and painful   TKR (p < 0.001). MRI is an effective modality in evaluating component rotational   alignment.
authors.affiliation: Boston University School of Medicine, Department of Radiology, 820 Harrison Avenue, FGH Building, 3rd Floor, Boston, Massachusetts 02118, USA. akira.murakami@bmc.org
authors.forename: A M
authors.initials: AM
authors.lastname: Murakami
authors.forename: T W
authors.initials: TW
authors.lastname: Hash
authors.forename: M S
authors.initials: MS
authors.lastname: Hepinstall
authors.forename: S
authors.initials: S
authors.lastname: Lyman
authors.forename: B J
authors.initials: BJ
authors.lastname: Nestor
authors.forename: H G
authors.initials: HG
authors.lastname: Potter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000209:etiology*; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012399:Rotation; D013585:Synovitis / Q000175:diagnosis* / Q000209:etiology*