Hyperextension may not impact retear rate after ACL reconstruction

ORLANDO, Fla. — There was no significant differences in stability and 5-year graft re-tear or failure rates between patients with equal to or greater than 6° of hyperextension who underwent ACL reconstruction using patellar tendon autograft and patients with equal to or less than 3° of hyperextension, according to data presented at the American Orthopaedic Society for Sports Medicine Annual Meeting, here.

“Patients with a high degree of knee hyperextension can be treated with an ACL reconstruction with a patella tendon autograft,” Rodney W. Benner, MD, said. “No increase in graft tears or failures was seen, and there was no difference in activity level, function, or subjective or objective stability.”

To determine the effect of higher degrees of hyperextension on stability and re-tear rates after ACL reconstruction, Benner and his colleagues prospectively collected 2-year minimum follow-up data on 278 patients with equal to or greater than 6° of hyperextension and 275 patients with less than or equal to 3° of hyperextension. All patients underwent ACL reconstruction performed by the senior study author.

Investigators used patient records and yearly patient surveys to document graft tears and failures, as well as defining failure as a mean maximum side-to-side difference of greater than 5 mm on the KT-1000. Additional outcomes included IKDC and Cincinnati knee scores, as well as measures on activity rating surveys. Overall, the study had a mean follow-up of 4.1 years and patients had an average age of 23 years.

Both groups showed around 2-mm side-to-side difference using the KT-1000, Benner said. Graft tear or failure rates within the first 5 years after surgery were 6.9% in the group with more hyperextension vs. 9.8% in the comparison group.

“Our study reveals there was no increase in ACL graft tear or failure in patients with high degrees of hyperextension. We also found no difference with objective stability, patient-reported stability or functional scores,” Benner said, noting there was no alteration in the ACL surgical technique or the postoperative rehabilitation based on the amount of knee hyperextension present in the normal knee. He added that postoperative immobilization was not used in any case and rehabilitation in both groups focused on immediate return of passive hyperextension, even on the day of surgery. – by Gina Brockenbrough, MA

Reference:

Benner RW, et al. Paper #7. Presented at: American Orthopaedic Society for Sports Medicine Annual Meeting; July 9-12, 2015; Orlando, Fla.

Disclosure: Benner has no relevant financial disclosures.