Anterior cruciate ligament injury and radiologic progression of
knee osteoarthritis: a systematic review and meta-analysis

Ajuied A, Wong F, Smith C,
Norris M, Earnshaw P, Back D, And Davies A. Am J Sports Med. 2013; [Epub
ahead of print].

Home Message: Sustaining an ACL rupture increases the likelihood of knee
osteoarthritis in a 10-year follow-up period.

The current gold-standard for treating an anterior
cruciate ligament (ACL) deficient knee is an ACL reconstruction, which attempts
to restore basic biomechanical function and thus delaying knee osteoarthritis
(OA). Unfortunately, the prevalence of knee OA after an ACL injury and the efficacy
of an ACL reconstruction at preventing knee OA are still unclear. Therefore,
Ajuied and colleagues completed a meta-analysis to assess the development and progression
of OA at a minimum of 10 years after an ACL injury. They focused on studies
that used the Kellgren & Lawrence grading system, which is a commonly
used assessment of radiographic OA severity. Relevant articles were identified via the PubMed, Medline, EMBASE, and
AMED databases. Two independent reviewers screened the articles for the
inclusion criteria, which included surgically and non-surgically treated ACL
rupture patients, patients with isolated ACL injuries or in combination with
meniscal and/or medial collateral ligament injury, and radiological assessment with
the Kellgren & Lawrence grade. The authors identified 9 articles for the
systematic review and 6 articles for the meta-analysis. The 9 articles included
615 patients (422 male, 222 female), which included 228 (37%) patients with a
known meniscal injury and 520 (85%) patients who received an ACL reconstruction
(typically a bone-patellar tendon-bone autograft). At follow-up 309 (52%) out
of 596 knees with a history of an ACL injury had radiographic OA
(Kellgren-Lawrence Grade > 2). A knee with a prior ACL injury was
almost 4 times as likely to have knee OA compared with a contralateral knee that
had no ACL injury. Regardless of whether the knee had an ACL reconstruction or
not they were 3 to 5 more likely to have knee OA compared with the
contralateral uninjured knee.

This study provides clinicians with information supporting the concept
that sustaining an ACL rupture increases the risk of OA later in life.
Furthermore, performing an ACL reconstruction to restore normal knee mechanics
may still leave the knee at greater risk for OA. However, clinicians must
cautiously interpret these results because the meta-analysis focused on the contralateral
knee as the control knee for comparison and excluded the study with radiographs
of the ipsilateral joint at baseline. By excluding this study, the author
eliminated the only study able to assess the true risk of disease progression. Meniscal
injuries were also not accounted for, which prevents clinicians from truly
understanding the long-term implications of an ACL rupture or ACL
reconstruction because the meniscus has been shown to play a vital role in the
long-term health of the knee joint. Regardless of these limitations this study
highlights that despite an ACL reconstruction our patients may still be more
likely to have knee OA later in life, which should cause all of us to pause and
wonder how we can improve our current treatment strategies to protect the
long-term health of the joint.

Questions for Discussion: Do you think the research needs to separate the influence of a meniscal tear with an ACL injury to make the findings more applicable to you?

Written by: Kyle Harris
Reviewed by: Jeffrey Driban

Related Posts:

Ajuied A, Wong F, Smith C, Norris M, Earnshaw P, Back D, & Davies A (2013). Anterior Cruciate Ligament Injury and Radiologic Progression of Knee Osteoarthritis: A Systematic Review and Meta-analysis. The American Journal of Sports Medicine PMID: 24214929