title: Multiple Nonspecific Sites of Joint Pain Outside the Knees Develop in Persons With Knee Pain.
abstract: Many persons with knee pain have joint pain outside the knee, but despite the impact and high frequency of this pain, its distribution and causes have not been studied. We undertook this study to test the hypothesis of those studying gait abnormalities who have suggested that knee pain causes pain in adjacent joints but that pain adaptation strategies are highly individualized.
  
  
  
  We studied persons ages 50-79 years with or at high risk of knee osteoarthritis who were recruited from 2 community-based cohorts, the Multicenter Osteoarthritis Study and the Osteoarthritis Initiative, and we followed them up for 5-7 years. We excluded those with knee pain at baseline and compared those who had developed knee pain at the first follow-up examination (the index visit) with those who had not. We examined pain on most days at joint regions outside the knee in examinations after the index visit. Logistic regression analyses examined the risk of joint-specific pain adjusted for age, sex, body mass index, and symptoms of depression, and we performed sensitivity analyses excluding those with widespread pain.
  
  
  
  In the combined cohorts, 693 persons had knee pain at the index visit and 2,793 did not. A total of 79.6% of those with bilateral knee pain and 63.8% of those with unilateral knee pain had pain during follow-up in a joint region outside the knee, compared with 49.9% of those without knee pain. There was an increased risk of pain at most extremity joint sites, without a predilection for specific sites. Results were unchanged when those with widespread pain were excluded.
  
  
  
  Persons with chronic knee pain are at increased risk of pain in multiple joints in no specific pattern.
authors: Boston University School of Medicine, Boston, Massachusetts, and University of Manchester and Central Manchester NHS Foundation Trust, Manchester, UK.
authors: David T
authors: DT
authors: Felson
authors: Boston University School of Medicine, Boston, Massachusetts.
authors: Jingbo
authors: J
authors: Niu
authors: Boston University School of Public Health, Boston, Massachusetts.
authors: Emily K
authors: EK
authors: Quinn
authors: Boston University School of Medicine, Boston, Massachusetts.
authors: Tuhina
authors: T
authors: Neogi
authors: Boston University School of Medicine, Boston, Massachusetts.
authors: Cara L
authors: 0000-0002-9888-4902
authors: CL
authors: Lewis
authors: University of Alabama School of Medicine, Birmingham.
authors: Cora E
authors: CE
authors: Lewis
authors: University of Iowa, Iowa City.
authors: Laura
authors: L
authors: Frey Law
authors: University of California, San Francisco.
authors: Chuck
authors: C
authors: McCulloch
authors: University of California, San Francisco.
authors: Michael
authors: M
authors: Nevitt
authors: Boston University School of Public Health, Boston, Massachusetts.
authors: Michael
authors: 0000-0002-8488-5170
authors: M
authors: LaValley
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000150:complications* / Q000209:etiology; D059350:Chronic Pain / Q000150:complications* / Q000209:etiology; D005260:Female; D006801:Humans; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications