Dr. Bottoni implants a hamstring graft during an arthroscopic ACL procedure.


Published 10/1/2007
Annie Hayashi

The case for early reconstruction of the ACL

A new study finds comparable results in early and delayed surgeries

“Excellent clinical results can be achieved following anterior cruciate ligament (ACL) reconstructions performed soon after injury using autograft hamstrings,” according to Craig R. Bottoni, MD, who received the O’Donoghue Sports Injury Research Award during the American Orthopaedic Society for Sports Medicine annual meeting.

The results from Dr. Bottoni’s prospective, randomized clinical trial contradict a longstanding belief that surgical reconstruction of an acutely torn ACL should be delayed for at least three weeks.1

“We found that those patients who had early reconstruction surgery quickly regained their pre-injury range of motion and felt much better,” explained Dr. Bottoni. “If the surgery is performed shortly after the injury, the body has to heal from just one ‘trauma.’ When the surgery is delayed, the knee recovers from the first injury. The hemarthrosis resolves and motion is restored. The subsequent surgery is perceived by the body as a ‘second hit’ that requires healing to commence again.”

Timing of reconstruction: A hotly debated issue
Since Shelbourne’s study of arthrofibrosis in acute ACL reconstruction in the early 1990s, the standard treatment of an acute ACL tear has been to delay reconstruction for at least 21 days following the injury.2 Although several other studies support delayed surgery, timing remains an issue.

Dr. Bottoni and his colleagues conducted a prospective, randomized study that compared postoperative range of motion, stability, and early clinical results in a group of 69 young (average age: 27 years old), active duty military personnel with acute ACL tears. Patients were prospectively randomized into early or delayed surgical reconstruction.

All reconstructions were done using autograft hamstrings. The 34 patients in the early group had their procedures performed within 21 days of their injuries; the average time from injury to surgery was just 9 days. The 35 patients in the delayed group did not have surgery until at least 6 weeks following their injury (average of 85 days from injury to surgery).

“We didn’t choose patients who were in optimal condition for knee surgery,” said Dr. Bottoni. “We wanted to determine whether reconstructing the ACL in patients with acutely injured knees would affect their postoperative motion or any of the clinical outcomes.”

All patients in the first group were scheduled for surgery at the earliest possible date regardless of pain, swelling, or limitations in knee motion. Those in the delayed group were prescribed comprehensive physical therapy that emphasized quadriceps strengthening and restoration of full range of motion. They were not allowed to return to full active military duty or sports activities during their physical therapy program or before their surgery.

Comparing the results
Postoperative evaluations on all patients were conducted at 3 days, 2 weeks, monthly for the first 6 months and every 6 months thereafter during the study period. Based on standardized outcome measures, the early group either fared better than or equal to the delayed group in every category. No statistical differences between the two groups were found when flexion and extension deficits for the reconstructed knee were compared to those for the contralateral knee. A knee ligament arthrometer designed to quantify the sagittal plane motions of the tibia relative to the femur also found no appreciable differences between the two groups.

The two groups also had comparable clinical outcome scores, although based on Tegner activity scores, the patients in the early group rated their activity level almost a full level higher than the patients in the delayed group.

Early reconstruction may also be beneficial in treating concurrent injuries. More than 90 percent of patients in the early group had meniscal tears, and more than half of these tears (57 percent) could be repaired during the surgery. Of the 69 percent of patients in the delayed group with meniscal tears, surgeons were able to repair less than a third (27 percent) of the tears.

Dr. Bottoni implants a hamstring graft during an arthroscopic ACL procedure.
Dr. Bottoni harvests a hamstring graft.

A similar number of patients in both groups sustained medial meniscal tears (14 vs. 15), but twice as many patients in the early group had tears that were reparable. “The delay in surgery and probably an increase in trauma sustained by the meniscus could account for the inability to repair these meniscal tears,” explains Dr. Bottoni.

He also notes that a patient who takes advantage of an early reconstruction can avoid further meniscal or chondral injuries. He cites a study by Wasilewski that found a higher incidence of chondral knee injuries among patients who delayed ACL reconstruction rather than having it done acutely.3

Advantages to early reconstruction
Performing early ACL reconstruction does not result in any clinical differences in postoperative range of motion, stability, or early subjective outcome measures, and may have some advantages. Patients in this study who had early surgery had higher Tegner activity scores than those in the delayed group. Evidence also exists that early ACL reconstruction can help patients avoid additional meniscal and chondral injuries. Early reconstruction also increases the likelihood of repairing medial meniscal tears.

“Our study demonstrates that surgery doesn’t need be delayed to obtain satisfactory clinical results” says Dr. Bottoni, “We believe it is permissible to proceed with an ACL reconstruction soon after injury and delaying the surgery for some arbitrary period of time is not necessary.”

CPT Travis R. Liddell, MD; LCDR Timothy J. Trainor, MD; and LTC Kenneth K. Liddell, MD, were members of this research team.

Annie Hayashi is the senior science writer for AAOS Now. She can be reached at hayashi@aaos.org.

Is early really better?
Kenneth D. Shelbourne, MD, offers another viewpoint on the topic

Although the prospective, randomized study conducted by Craig R. Bottoni, MD, found excellent clinical results with early reconstruction of an acutely torn anterior cruciate ligament (ACL), not all surgeons agree that early is better. Kenneth D. Shelbourne, MD, contends that “acute surgery can be performed safely in most patients, but can that approach assure that all patients achieve full range of motion?”

Dr. Shelbourne, author of a study published in 1991, notes that at that time, “we were trying to eliminate the problem of motion loss after surgery.” Dr. Shelbourne’s study included three patient groups, based on time from injury to surgery (0-7 days, 8-21 days, and 21-56 days). “The incidence of patients who had extension loss of at least 5 degrees was 55 percent in the first group, 17 percent in the second group, and 0 percent in the third group,” he recalls.

“Since that study, we have learned that it is not so much the timing of the surgery, but the condition of the knee before surgery that is important,” Dr. Shelbourne says. “The goals of preoperative rehabilitation are to restore normal knee range of motion, eliminate swelling, and regain leg control. These goals can be accomplished quickly in some patients and these patients can undergo surgery before the arbitrary time of 21 days after the injury. Since using this approach, we have improved the percentage of patients with extension loss to less than 1 percent.”

Dr. Shelbourne does use the “delayed approach” with some patients so they will not have postoperative range of motion problems. “We and others have shown the importance of performing at least subacute surgery for an ACL injury to prevent meniscus tears and chondral damage. Our goal is for patients to undergo surgery at a time when they are mentally and physically prepared for surgery and before additional meniscal and chondral damage occurs.”


  1. Bottoni, CR. Anterior cruciate ligament reconstructions in active duty military personnel. Oper Tech Sports Med July 2005;13(3):169-175.
  2. Shelbourne KD, Wilckens JH, Mollabashy A. Arthrofibrosis in acute anterior cruciate ligament reconstruction: The effect of timing of reconstruction and rehabilitation. Am J Sports Med.1991;19:332-6.
  3. Wasilewski SA, Covall DJ, Cohen S: Effect of surgical timing on recovery and associated injuries after anterior cruciate ligament reconstruction. Am J Sports Med.1993; 21:338-342 (http://ajs.sagepub.com/cgi/content/abstract/21/3/338; accessed 9/7/07)