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Good news, bad news on ACL reconstruction

By: Annie Hayashi

By Annie Hayashi

Associated meniscal lesions affect OA development
According to a study presented at the 75th Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS), 90 percent of patients who underwent anterior cruciate ligament (ACL) reconstruction surgery to restore knee stability showed favorable initial results. Osteoarthritis (OA) was more likely to develop in patients who required meniscectomies in addition to the reconstructive surgery.

“Osteoarthritis radiographic changes at 12-year follow-up of ACL reconstruction of the knee” was a retrospective study conducted by Matias Costa-Paz, MD; Miguel Angel Ayerza, MD; Arturo Roberto Makino, MD; Miguel Puigdevall, MD, and Domingo Luis Muscolo, MD.

Study participant demographics
Between 1986 and 1991, a total of 220 patients had ACL arthroscopic reconstruction using a two-incision technique and an autologous patellar tendon graft. Of those patients, 47 (35 males and 12 females, ranging in age from 25 to 59 years) qualified for the retrospective evaluation. Patients who had additional knee ligament surgery, previous knee ligament surgery, revision surgery, contralateral ligament injuries, or degenerative changes were excluded.

Within the study group, 12 patients (26 percent) had “early reconstruction”—within 3 months of the ACL rupture—and 35 (74 percent) had “late reconstruction”—3 months or more after the initial injury.

Partial medial meniscectomies were performed on 62 percent of the patients and 32 percent had undergone partial lateral meniscectomies either prior to or during the ACL reconstruction surgery.

Knee stability still strong
The average postoperative follow-up was 12 years (range, 10 to 14 years). The research team performed a number of tests to determine stability of the knee; they also made radiographic comparisons between the uninjured knee and the surgically treated knee.

Knee stability was measured using the Lysholm scale, which includes pain, subjective instability, use of a walking device, articular blocking, effusion and claudication when walking, ability to climb stairs, and difficulty in kneeling.

Based on the Lysholm point system (excellent, 95 to 100; good, 94 to 84; regular, 83 to 65), 65 percent of patients had excellent results, 24 percent had good results, and 11 percent had regular results.

The International Knee Documentation Committee (IKDC) form was also used to evaluate the clinical outcome of the ACL reconstruction. The IKDC considers the subjective evaluation of the patient, presence of symptoms, passive motion deficit, ligament examination, compartment findings, harvest site pathology, radiologic findings, and a function test.

According to the IKDC evaluation, 57.5 percent of patients rated their knee as “normal,” 32 percent as “near normal,” 8.5 percent as “abnormal,” and 2 percent as “severely abnormal.”

Radiographs show degenerative changes
Radiographs of both knees included anteroposterior views in full extension standing and in 35 degrees of flexion, and lateral and Merchant views of the patella.

A negative pivot shift was evident in 85 percent of the patients. In addition, radiographic evaluation showed degenerative changes in 81 percent of the operated knees—62 percent were classified as mild changes (Grade B), 17 percent as moderate changes (Grade C), and 2 percent as severe changes (Grade D).

Among patients who had early reconstruction, 2 had normal menisci and 10 had meniscectomies. Of the latter group, three patients showed no signs of degenerative changes, six had mild changes, and one had moderate changes.

Among patients who had late reconstruction, nine had normal menisci; two showed no changes and seven showed only minor degenerative changes. Among the 26 patients who underwent meniscectomies, however, only 2 showed no degenerative changes; 16 showed minor changes, 8 showed moderate changes, and 1 showed severe changes.

Late reconstructions, meniscal lesions, and OA
Researchers found evidence of OA in 74 percent of the knees that had late reconstructions. “Our series found a correlation between patients with chronic ACL with late reconstruction and the presence of these associated meniscal lesions and the development of degenerative changes,” said Dr. Costa-Paz. “However, these degenerative changes had no correlation with knee stability.”

“Arthroscopic ACL reconstruction with the patellar tendon stabilizes the knee and permits a return to sports in a high percentage of patients, he said. “Progression of degenerative osteoarthritis, particularly in patients with meniscectomies, seems to be an unsolved problem.” The authors report no conflicts of interest.

Annie Hayashi is the senior science writer for AAOS Now.

She can be reached at hayashi@aaos.org

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