title: Persistence and Recurrence Following Femoral Derotational Osteotomy in Ambulatory Children With Cerebral Palsy.
abstract: BACKGROUND
  Excessive hip internal rotation is frequently seen in children with cerebral palsy (CP). Femoral derotational osteotomy (FDO) is effective in the short term, but factors associated with long-term correction remain unclear. The purposes of this study were to define the incidence of persistence and recurrence of hip internal rotation following FDO in ambulatory children with CP and to evaluate factors that influence outcome.
  
  
  METHODS
  Following IRB approval, kinematic and passive range of motion (PROM) variables were retrospectively evaluated in children with spastic CP who had FDO to correct hip internal rotation as part of clinical care at a children's specialty hospital. Children included had a preoperative evaluation (Vpre), a short-term postoperative evaluation (Vshort, 1 to 3 y post), and, in some cases, a long-term postoperative evaluation (Vlong, ≥5 y post). Age at surgery, physical exam measures, and kinematics variables were evaluated as predictors for dynamic and static recurrence.
  
  
  RESULTS
  Kinematic hip rotation improved from 14±12 degrees (Vpre; internal positive) to 4±13 degrees (Vshort) and relapsed to 9±15 degrees long term (P<0.05 Vpre/Vshort/Vlong; 99 limbs). Hip PROM midpoint improved from 23±9 degrees (Vpre) to 8±11 degrees (Vshort) and relapsed to 14±13 degrees (P<0.01 Vpre/Vshort/Vlong). Persistent hip internal rotation was noted in 41% (kinematics) and 18% (PROM) of limbs at Vshort (105 children, 178 limbs). Of limbs that showed initial improvement at Vshort (62 children, 95 limbs), recurrence was seen in 40% (kinematic hip rotation) and 39% (hip midpoint) at Vlong. Comparing children who had recurrent hip internal rotation and those who maintained long-term correction, we saw higher levels of spasticity and lower gait velocity in the recurrent group (P<0.05).
  
  
  CONCLUSIONS
  Although FDO is an accepted treatment in children with CP, persistence and recurrence of hip internal rotation can occur. Recurrence is associated with spasticity and slower gait velocity. Predictor variables may be useful for surgeons during preoperative discussions of expected outcome with families of FDO candidates.
  
  
  METHODS
  Level III.
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE.
authors.forename: Chris
authors.initials: C
authors.lastname: Church
authors.forename: Nancy
authors.initials: N
authors.lastname: Lennon
authors.forename: Kevin
authors.initials: K
authors.lastname: Pineault
authors.forename: Oussama
authors.initials: O
authors.lastname: Abousamra
authors.forename: Tim
authors.initials: T
authors.lastname: Niiler
authors.forename: John
authors.initials: J
authors.lastname: Henley
authors.forename: Kirk
authors.initials: K
authors.lastname: Dabney
authors.forename: Freeman
authors.initials: F
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D002547:Cerebral Palsy / Q000150:complications*; D002648:Child; D005260:Female; D005269:Femur / Q000002:abnormalities*; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008297:Male; D009128:Muscle Spasticity / Q000150:complications; D010027:Osteotomy / Q000379:methods*; D011184:Postoperative Period; D016059:Range of Motion, Articular; D012008:Recurrence; D012189:Retrospective Studies; D014102:Torsion Abnormality / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome