title: Conservative treatment of spontaneous osteonecrosis of the knee in the early stage: pulsed electromagnetic fields therapy.
abstract: BACKGROUND
  
  
  
  OBJECTIVE
  pulsed electromagnetic fields treatment might improve symptoms in the early stage of spontaneous osteonecrosis of the knee.
  
  
  METHODS
  Twenty-eight patients (19M/9F, age 49.8±16.4 years) suffering from symptomatic (pain) Koshino stage I spontaneous osteonecrosis of the knee, confirmed by magnetic resonance imaging (MRI) were treated with local pulsed electromagnetic fields therapy (6 h daily for 90 days). Clinical evaluation: baseline, 6- and 24-month follow-up by VAS for pain, knee society score (KSS), Tegner and EQ-5D scales. MRI evaluation: baseline and 6-month follow-up, measuring bone marrow lesion's areas and grading these lesions by WORMS score. Failures: patients undergoing knee arthroplasty.
  
  
  RESULTS
  Pain significantly reduced at 6 months (from 73.2±20.7 to 29.6±21.3, p<0.0001), which remained almost unchanged at final follow-up (27.0±25.1). KSS significantly increased in first 6 months (from 34.0±13.3 to 76.1±15.9, p<0.0001) and was slightly reduced at final follow-up (72.5±13.5, p=0.0044). Tegner median level increased from baseline to 6-month follow-up (1(1-1) and 3(3-4), respectively, p<0.0001) and remained stable. EQ-5D improved significantly throughout the 24 months (0.32±0.33, baseline; 0.74±0.23, 6-month follow-up (p<0.0001); 0.86±0.15, 24-month follow-up (p=0.0071)). MRI evaluation: significant reduction of total WORMS mean score (p<0.0001) and mean femoral bone marrow lesion's area (p<0.05). This area reduction was present in 85% and was correlated to WORMS grading both for femur, tibia and total joint (p<0.05). Four failures (14.3%) at 24-month follow-up.
  
  
  CONCLUSIONS
  Pulsed electromagnetic fields stimulation significantly reduced knee pain and necrosis area in Koshino stage I spontaneous osteonecrosis of the knee already in the first 6 months, preserving 86% of knees from prosthetic surgery at 24-month follow-up. No correlation was found between MRI and clinical scores.
  
  
  METHODS
  Level IV; case series.
authors.affiliation: Isituto Ortopedico Rizzoli, University of Bologna, III Orthopaedic and Traumatologic Clinic and Biomechanics Laboratory Via di Barbiano, 1/10, 40136 Bologna (BO), Italy. marcheggianimuccioli@me.com
authors.forename: G M
authors.initials: GM
authors.lastname: Marcheggiani Muccioli
authors.forename: A
authors.initials: A
authors.lastname: Grassi
authors.forename: S
authors.initials: S
authors.lastname: Setti
authors.forename: G
authors.initials: G
authors.lastname: Filardo
authors.forename: L
authors.initials: L
authors.lastname: Zambelli
authors.forename: T
authors.initials: T
authors.lastname: Bonanzinga
authors.forename: E
authors.initials: E
authors.lastname: Rimondi
authors.forename: M
authors.initials: M
authors.lastname: Busacca
authors.forename: S
authors.initials: S
authors.lastname: Zaffagnini
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D061208:Pulsed Radiofrequency Treatment / Q000379:methods*; D016896:Treatment Outcome