Meniscus treatment and age associated with narrower radiographic joint space width 2-3 years after ACL reconstruction: data from the MOON onsite cohort

Osteoarthritis Cartilage. 2015 Apr;23(4):581-8. doi: 10.1016/j.joca.2014.12.018. Epub 2015 Jan 3.


Objective: To identify risk factors for radiographic signs of post-traumatic osteoarthritis (OA) 2-3 years after anterior cruciate ligament (ACL) reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort.

Methods: A nested cohort within the Multicenter Orthopaedic Outcomes Network (MOON) cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors.

Results: Unexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96-5.15 mm) vs 4.71 mm (95% CI 4.62-4.80 mm), P < 0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38-0.90 mm) (P < 0.001). Age (P < 0.001) and meniscus repair (P = 0.001) were also significantly associated with mJSW difference.

Conclusion: Semi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2-3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study.

Keywords: ACL reconstruction; Joint space narrowing; Knee; Meniscus; Post-traumatic osteoarthritis; Radiographs.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Anterior Cruciate Ligament Reconstruction*
  • Athletic Injuries / complications
  • Athletic Injuries / surgery*
  • Child
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Knee Injuries / complications
  • Knee Injuries / surgery*
  • Knee Joint / diagnostic imaging*
  • Knee Joint / surgery
  • Linear Models
  • Longitudinal Studies
  • Male
  • Menisci, Tibial / diagnostic imaging
  • Menisci, Tibial / surgery*
  • Osteoarthritis, Knee / epidemiology
  • Radiography
  • Risk Factors
  • Treatment Outcome
  • Young Adult