ROM loss after ACL reconstruction linked to arthritis

This year’s Best Poster Award went to a study on the link between the loss of normal knee range of motion (ROM) after reconstruction of the anterior cruciate ligament (ACL) and the incidence of arthritic changes observed on radiographs. The authors found that patients who were able to obtain and maintain normal knee motion had a lower incidence of such changes than patients who lost knee motion.

Scott E. Urch, MD, with the winning poster.

A few studies have examined the association between ROM loss and arthritic changes on radiographs. One found that flexion contractures were associated with osteoarthritis (OA) at 7 and 13 years after surgery. Another study found that 15 years after surgery, 43 percent of those patients who had radiographic evidence of OA had loss of ROM versus only 14 percent of those with normal radiographs. Several studies have established that meniscectomy and articular cartilage damage are major risk factors for OA development.

The poster authors prospectively followed 780 patients who had ACL reconstruction a minimum of 5 years ago. Among patients with normal extension and flexion, 71 percent had normal radiographs. Among patients who had any deficit in ROM, only 55 percent had normal radiographs (p < 0.001). Among patients with intact menisci, 77 percent of those with normal motion had normal radiographs, while 67 percent of those who lacked normal motion had normal radiographs (p = 0.19).

Among patients who had medial meniscectomy and retained normal motion, 56 percent had normal radiographs. Among those who had medial meniscectomy without normal motion, only 38 percent had normal radiographs (p = 0.035). Similar statistical significance was found for patients with lateral meniscectomy or both menisci removed.

Criteria for the study were

  • Unilateral ACL injury
  • No pre-existing evidence of OA before surgery
  • No ACL graft tear after surgery.

The obtained radiographs were bilateral knee views with a 45-degree posterior weight-bearing view, Merchant view, and lateral view.

Among the patients in this study, 92 percent had hyperextension in their knees, with the average being 5-degrees (range, 1 degree to 14 degrees). The authors note that subtle degrees of difference between knees can be evaluated by holding the thigh in place with one hand and using the other hand to hold the ball of the foot to lift the heel off the examination table. “This evaluation of passive knee extension should be compared to the other knee to feel subtle differences in extension,” the researchers observed.

The authors concluded: “The data in this study confirm the importance of achieving and maintaining full and symmetricknee ROM, in order to lower the incidence of OA in the long term after surgery.”

Poster presenter Scott E. Urch, MD, said the take-home message is that “something as simple as symmetric ROM correlates very well with having normal radiographs at 10-year follow-up. Regardless of the status of the meniscus at the time of surgery, better motion—particularly extension—was associated with better radiographs long term. Motion is a simple but very important concept that often gets overlooked.”

Poster 410, “Loss of Knee Motion After ACL Reconstruction Is Associated with Arthritic Changes After Surgery,” was authored by K. Donald Shelbourne, MD; Tinker Gray, MA, ELS; Heather Freeman, PT; and Scott E. Urch, MD.

Prepared by Terry Stanton, senior science writer for AAOS Now.