Blog Written by: Kyle Harris
Reviewed by: Jeffrey Driban
Clinical Results and Risk Factors for Reinjury 15 Years After Anterior Cruciate Ligament Reconstruction: A Prospective Study of Hamstring and Patellar Tendon Grafts
Leys T, Salmon L, Waller A, Linklater J, and Pinczewski L. Am J Sports Med. 2012; 40 (3). 595-605. (link to abstract)
Commonly seen in young athletes, anterior cruciate ligament (ACL) rupture is often treated by surgical reconstruction of the ligament. The aims of this surgery are to restore the joint kinematics, limit episodes of instability, and return the patient to preinjury levels of activity. While the aims of ACL reconstructions are the same, the optimal graft type used in this reconstruction, is still a debated issue. Therefore, Leys and colleagues conducted a prospective cohort study to compare the outcomes of patellar tendon (PT) and hamstring tendon (HT) autografts assessed at 2, 5, 7, 10, and 15 years post-surgery. A total of 180 patients (90 consecutive patients in each group) were initially included in the study. At the 15-year follow-up visit, 51 patients with HT were available and 43 patients with PT were available for full assessment (subjective and clinical review, over 70 patients/group were available for just a subjective review at 15 years). The decision of which graft would be used was based on what time period (mid-October 1993: HT autograft, Oct 1993-Nov 1994: PT autograft) the patient’s initial consultation took place, with all surgeries being performed by one surgeon. The follow-up assessments included the International Knee Documentation Committee (IKDC) knee ligament evaluation (assesses signs and symptoms as well as knee function), Lysholm knee score (assesses knee function), clinical assessment (Lachman, anterior drawer, etc.), instrumented laxity testing, range of motion, kneeling pain using a visual analog scale, and single-legged hop test. Radiographs were also taken at each follow-up visit. Patients who received a HT autograft had superior outcomes at 15-years post-surgery compared to patients with PT autografts with respect to IKDC score, activity level (based on patient reports:, strenuous vs. moderate vs. light), kneeling pain, range of motion, single-legged hop test, and radiologic changes (using IKDC grading system). Since the 10-year follow-up visit, more patients with PT autografts may have developed extension deficits and patients with PT autografts experienced a decline in single-leg hop performance. Interestingly, the PT autograft was found to have better results with respect to clinical ligament stability measurements at 15 years post-surgery follow-up.
Overall, this study presents interesting insight into the long-term results comparing both HT and PT autografts. While the results of this study showed patient with HT autografts had significantly better results in function, pain levels, activity levels, and radiologic changes, the authors note that this change was seen primarily between 10 and 15 year follow-up. The authors suggest that these differences after long-term follow-up could be in part related to the onset and progression of osteoarthritis. Clinically, this study presents and interesting case for patients who are concerned about long-term knee outcomes to receive HT autografts as they appear to have less degenerative change and better functional outcomes at a 15 year follow-up. While this may be true, the PT autograft did show better performance (although not statistically significant) with respect to instrumental stability measures (once again showing a discordance between knee stability measures and other outcomes). How does this information change your current counseling strategy? Would you be more inclined to suggest a HT graft knowing that the long-term functional outcomes appear to be better?