Cracking Sound in Knees May Signal Early Cartilage Damage After ACL Surgery, Study Finds
Australia: A recent study published in Arthritis Care & Research has examined the role of knee crepitus—commonly described as a grinding or crackling sound—after anterior cruciate ligament reconstruction (ACLR) and its link with osteoarthritis (OA) features in young adults. The research, led by Jamon L. Couch, BHlthSc, from the Australian IOC Research Centre, Melbourne, sheds light on whether this symptom signals structural deterioration or worsening joint health following traumatic knee injuries.
The study analyzed 112 participants (41 women, median age 28 years) one year after ACLR. Researchers recorded self-reported knee crepitus using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Magnetic resonance imaging (MRI) scans evaluated patellofemoral and tibiofemoral OA-related features—including cartilage lesions, osteophytes, and bone marrow lesions—at one and five years post-surgery. Patient-reported outcomes such as pain, knee-related quality of life (QoL), and function were assessed using KOOS subscales and the International Knee Documentation Committee subjective evaluation form.
The study led to the following notable findings:
- There was a notable association between self-reported knee crepitus and full-thickness cartilage lesions in the patellofemoral joint one year after ACLR.
- Individuals experiencing crepitus had a 2.7 times higher likelihood of these cartilage defects compared to those without crepitus (prevalence ratio 2.70).
- Knee crepitus did not predict worsening OA features such as cartilage loss, osteophyte growth, or bone marrow lesions over the four-year follow-up period.
- The presence of crepitus correlated with significantly worse pain, poorer QoL, and reduced function at one year post-surgery.
- Statistical analysis showed a negative impact on pain (β -6.42), QoL (β -10.39), and functional ability (β -5.49).
- Between years one and five, individuals with crepitus experienced greater improvements in pain and function compared to those without crepitus.
- Crepitus itself did not indicate accelerated joint deterioration over time.
The researchers concluded that while knee crepitus may serve as an early indicator of cartilage damage in the patellofemoral compartment, it does not appear to predict long-term structural progression of OA features after ACL injury and reconstruction. Instead, its clinical significance lies in its association with poorer short-term symptoms and reduced quality of life during the early recovery period.
"These findings emphasize the need for clinicians to recognize crepitus as a symptom that may reflect underlying cartilage changes and impact patient-perceived outcomes, rather than as a marker for future OA progression. Early interventions aimed at managing pain and improving function could help address these concerns without unnecessary alarm about worsening structural damage," the authors concluded.
Reference:
Couch, J. L., Patterson, B. E., Crossley, K. M., Guermazi, A., King, M. G., Oliveira Silva, D. D., Whittaker, J. L., Girdwood, M. A., & Culvenor, A. G. Knee crepitus and osteoarthritis features in young adults following traumatic knee injury. Arthritis Care & Research. https://doi.org/10.1002/acr.25637
Next Story