KOOS pain as a marker for significant knee pain two and six years after primary ACL reconstruction: a Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort study.


Journal Article

OBJECTIVE: The prevalence of radiographic osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) approaches 50%, yet the prevalence of significant knee pain is unknown. We applied three different models of Knee injury and Osteoarthritis Outcome Score (KOOS) thresholds for significant knee pain to an ACLR cohort to identify prevalence and risk factors. DESIGN: Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort patients with a unilateral primary ACLR and normal contralateral knee were assessed at 2 and 6 years. Independent variables included patient demographics, validated Patient Reported Outcomes (PRO; Marx activity score, KOOS), and surgical characteristics. Models included: (1) KOOS criteria for a painful knee = quality of life subscale <87.5 and ≥2 of: KOOSpain <86.1, KOOSsymptoms <85.7, KOOSADL <86.8, or KOOSsports/rec <85.0; (2) KOOSpain subscale score ≤72 (≥2 standard deviations below population mean); (3) 10-point KOOSpain drop from 2 to 6 years. Proportional odds models (alpha ≤ 0.05) were used. RESULTS: 1761 patients of median age 23 years, median body mass index (BMI) 24.8 kg/m(2) and 56% male met inclusion, with 87% (1530/1761) and 86% (1506/1761) follow-up at 2 and 6 years, respectively. At 6 years, n = 592 (39%), n = 131 (9%) and n = 169 (12%) met criteria for models #1 through #3, respectively. The most consistent and strongest independent risk factor at both time-points was subsequent ipsilateral knee surgery. Low 2-year Marx activity score increased the odds of a painful knee at 6 years. CONCLUSIONS: Significant knee pain is prevalent after ACLR; with those who undergo subsequent ipsilateral surgery at greatest risk. The relationship between pain and structural OA warrants further study.

Full Text

Duke Authors

Cited Authors

  • Wasserstein, D; Huston, LJ; Nwosu, S; MOON Group, ; Kaeding, CC; Parker, RD; Wright, RW; Andrish, JT; Marx, RG; Amendola, A; Wolf, BR; McCarty, EC; Wolcott, M; Dunn, WR; Spindler, KP

Published Date

  • October 2015

Published In

Volume / Issue

  • 23 / 10

Start / End Page

  • 1674 - 1684

PubMed ID

  • 26072385

Pubmed Central ID

  • 26072385

Electronic International Standard Serial Number (EISSN)

  • 1522-9653

Digital Object Identifier (DOI)

  • 10.1016/j.joca.2015.05.025


  • eng

Conference Location

  • England