Patient-reported knee symptoms (grinding/clicking, catching/locking, and/or pivot pain) are traditionally presumed to be due to a meniscal tear. However, researchers at Brigham and Women’s Hospital recently found these patient-reported knee symptoms are more strongly associated with the number of compartments with cartilage damage and the severity of cartilage damage in those compartments than with meniscal tears. Moreover, meniscal tear and cartilage damage often coexisted in symptomatic knees.

Elizabeth G. Matzkin, MD, surgical director for women’s musculoskeletal health and chief of the Women’s Sports Medicine Program in the Department of Orthopaedic Surgery, Eli T. Sayegh, MD, orthopaedic sports medicine fellow, and colleagues went on to study the benefit of arthroscopy for individual knee symptoms. In Arthroscopy, they report two-thirds of patients experienced resolution of grinding/clicking and pivot pain, and nearly half reported resolution of catching/locking.

Methods

This retrospective study analyzed prospectively collected registry data on 584 patients who underwent knee arthroscopy by Dr. Matzkin between August 2012 and December 2019. Eligible patients presented with a symptomatic suspected meniscal tear, had at least three months of nonoperative treatment before arthroscopy, and had at least one year of follow-up. The mean age was 47, and 61% were female.

Subjects completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire before surgery and at the one- and two-year follow-up visits. Two-year follow-up data were available for 408 subjects.

Symptom Resolution

66% of patients with grinding/clicking and 68% with pivot pain experienced symptom resolution, and 44% had a resolution of catching/locking.

One explanation for the relatively refractory nature of catching/locking might be that patients with this symptom present with more advanced underlying osteoarthritis. Alternatively, catching/locking may be least associated with an underlying meniscal tear that would otherwise respond to arthroscopic intervention.

Symptom Burden

Clinically meaningful improvements (>8 points on a 100-point scale) were noted postoperatively in KOOS Pain, Activities of Daily Living, and Quality of Life subscale scores (87%, 81%, and 83% of patients, respectively).

Individuals with symptom resolution exhibited a two-fold improvement in scores compared with those whose symptoms persisted. However, even patients with persistent symptoms demonstrated clinically important improvements in all three KOOS subscales.

Persistence of pivot pain was associated with the least improvement in all three subscales.

Predictors of Symptom Persistence

Several factors made symptom resolution less likely:

• Absence of meniscal tear—associated with less likelihood of resolution of grinding/clicking, but not other symptoms, two years postoperatively (adjusted OR [aOR], 0.27; 95% CI, 0.11–0.64)

• Focal cartilage lesions in all three compartments—Less likelihood of resolution of grinding/clicking at two years (aOR, 0.12; 95% CI, 0.03–0.045)

• Smoking—Less likelihood of resolution of pivot pain at one year (aOR, 0.39; 95% CI, 0.19–0.78)

• Overweight—Less likelihood of resolution of pivot pain at two years (aOR, 0.39; 95% CI, 0.16–0.98)

• Obesity—Less likelihood of resolution of pivot pain at two years (aOR, 0.40; 95% CI, 0.17–0.97)

Considerations for Surgeons

The American Academy of Orthopaedic Surgeons guidelines for treating knee osteoarthritis contain no definitive recommendation about using arthroscopic partial meniscectomy in patients with concomitant meniscal tear and symptomatic knee osteoarthritis.

This study suggests knee arthroscopy in appropriately indicated patients could result in clinically important improvements in patient-reported symptoms but may require further discussion for patients presenting with a greater burden of osteoarthritis.