Groundbreaking Research on ACL Outcomes

After anterior cruciate ligament (ACL) reconstruction, limitations in range of motion (ROM) reduce the ability of patients to return to sports and function normally, and increase symptoms such as pain. Even a small loss of knee extension—3° to 5°—has a negative impact,1 according to groundbreaking research conducted at Shelbourne Knee Center.

“Loss of range of motion is a huge variable in surgical outcome,” says K. Donald Shelbourne, MD, an orthopedic surgeon at Shelbourne Knee Center. “Most orthopedic surgeons don’t know that having less than full range of motion after surgery is bad.”

Award-Winning Research 

The study that identified the importance of normal ROM after ACL reconstruction followed 502 patients who had this procedure with an ipsilateral autogenous patellar tendon graft at Shelbourne Knee Center between 1982 and 1994. As part of the ACL reconstruction process, patients completed the center’s ACL rehabilitation program, which focuses on improving ROM before strengthening. During the study period, rehabilitation was slightly different before and after 1986. Starting in 1987, the center introduced the accelerated ACL rehabilitation program.

Dr. Shelbourne and Tinker Gray, MA, published their findings in the article “Minimum 10-Year Results After Anterior Cruciate Ligament Reconstruction: How the Loss of Normal Knee Motion Compounds Other Factors Related to the Development of Osteoarthritis After Surgery” in the American Journal of Sports Medicine in 2009. Gray is a research manager and medical writer at Shelbourne Knee Center.

In 2010, Dr. Shelbourne and Gray received the Hughston award from the American Orthopedic Society for Sports Medicine.1 The award recognizes the most outstanding paper published in the American Journal of Sports Medicine each year.

Objective and Subjective Methods

The researchers prospectively evaluated patients using both objective and subjective methods at >10 years post-surgery, with a mean of 14.1 years. Objective evaluations were a key component of the study. “Loss of motion can’t be evaluated by a questionnaire. It has to be examined,” says Dr. Shelbourne.

The objective evaluations were performed at 2, 5, 10, 15 and 20 years after surgery during research visits to Shelbourne Knee Center, using the International Knee Documentation Committee (IKDC) criteria. Normal knee motion was defined as being within 2° of extension (including hyperextension) and 5° of flexion compared with the uninvolved knee.

Patients also completed questionnaires annually: a modified Noyes subjective questionnaire and, starting in 2000, also the International Knee Documentation Committee knee evaluation form. These questionnaires covered symptoms, sports activity and knee function.

Lack of ROM Impacts Function

Results showed that lack of normal knee extension was the most statistically significant factor related to lower subjective scores. Loss of normal flexion was also significantly related to lower scores.

Patients who had undergone meniscectomy or had articular cartilage damage had statistically significantly lower subjective scores if they also had less than normal range of motion. Almost all patients with intact menisci and normal articular cartilage—98%—had normal radiographs. The researchers reported less than normal radiographs for:

  • 29% of patients with normal motion
  • 71% of patients who had less than normal motion.

The overall International Knee Documentation Committee objective grade was:

  • Normal: 48% of patients
  • Nearly normal: 42% of patients
  • Abnormal: 9% of patients
  • Severely abnormal: 0.5% of patients.

The researchers concluded that “even 3° to 5° of knee extension loss compared with the opposite knee, to include loss of hyperextension, adversely affected the subjective and objective results after surgery, especially when coupled with meniscectomy and articular cartilage damage.”

“In no other joint in the body does it matter to have equal ROM,” says Dr. Shelbourne.

Shelbourne Knee Center continues to track ROM and other patient outcomes. The research program currently has more than 38 years of data on more than 13,000 patients. Findings are used to continuously improve treatment for ACL tears and other knee problems.

Second Hughston Award

The 2010 Hughston Award was the second given to Dr. Shelbourne. In 2000, he received the same award for “The Natural History of Acute, Isolated, Nonoperatively Treated Posterior Cruciate Ligament Injuries,” co-authored with Thorp J. Davis, MD, and Dipak V. Patel, MD.2

This article showed that non-operative treatment works best for isolate posterior cruciate ligament (PCL) tears and that some laxity does not reduce activity, strength or range of motion. Also, the incidence of moderate to severe osteoarthritis is the same for non-operative treatment and PCL reconstruction.

For more information about ACL reconstruction at Shelbourne Knee Center, call 888-FIX-KNEE or email


  1. Shelbourne KD, Gray T. Minimum 10-Year Results After Anterior Cruciate Ligament Reconstruction: How the Loss of Normal Knee Motion Compounds Other Factors Related to the Development of Osteoarthritis After Surgery. Am J Sports Med. 2009;41(7):1526-1533.
  2. Shelbourne KD, Davis TJ, Patel DV. The natural history of acute, isolated, nonoperatively treated posterior cruciate ligament injuries. A prospective studyAm J Sports Med. May-Jun 1999;27(3):276-83.