Shelbourne Knee Center has only used the patellar tendon as the primary graft choice when doing ACL reconstructions. The patellar tendon is considered the “gold standard” of graft choices; however, many surgeons do not like to use this tendon due to the difficulty of the rehabilitation. When Dr. Shelbourne started practice, he took the patellar tendon from the same knee (ipsilateral) as the knee with the ACL tear. He learned, inadvertently, that taking the patellar tendon from the opposite knee (contralateral) has a more predictable outcome and was easier for patients to rehab and return to sport. There have been studies that have suggested a link between patellar tendon graft harvest (taking a section of the patellar tendon) and increased incidence of patellofemoral osteoarthritis (increased joint space narrowing). One of our physical therapists and our research staff decided to look at our own data to see if this was true among our patient population since we have a large database of ACL patients using both ipsilateral and contralateral patellar tendon graft.
When the graft harvest occurs on the same knee as the ACL reconstructed knee, it is difficult to conclude that the association of patellofemoral osteoarthritis is directly related to the harvesting of the patellar tendon graft as opposed to other factors. This study looked at 193 patients and compared patellofemoral osteoarthritis between contralateral versus ipsilateral graft harvest for ACL reconstruction. Patients were excluded if they had a revision ACL, bilateral ACL involvement, subsequent graft tear or contralateral ACL tear, patellofemoral chondral wear seen at the time of surgery, preoperative or subsequent surgery to either knee, or the presence of preoperative patellofemoral osteoarthritis. Patients who had X-rays between minimum 15 and maximum 25 years postop were included and then separated into four groups based on ipsilateral (95) or contralateral (98) patellar tendon harvest. The standard merchant’s radiographs were graded based on joint space narrowing as none, mild (up to 50%), moderate (50-99%) or severe (100%) patellofemoral osteoarthritis and compared between groups.
The patellofemoral osteoarthritis of any grade within the ipsilateral graft group was present in 20% of the involved ACL reconstructed knees and 9.5% of the uninvolved normal knee which was a statistically significant difference (p=.041). The patellofemoral osteoarthritis in the contralateral graft group was 10.2% in the ACL reconstructed knee and 13.3% in the contralateral donor knees (p=.506). Any grade of patellofemoral osteoarthritis was present in 14.7% of all knees in the ipsilateral group and 11.7% of all knees in the contralateral groups (p=.348). There is no statistically significant difference in the patellofemoral osteoarthritis rates of any grade when comparing the uninvolved normal knee from the ipsilateral group to the contralateral graft donor knee of the contralateral group (9.5% vs 13.3%). The ACL reconstructed knee in the ipsilateral group exhibited patellofemoral osteoarthritis in 20.0% and 10.2% in the contralateral group (p=.057). Rates of moderate to severe patellofemoral osteoarthritis between the two groups were not statistically significant.
Based on this study looking at our own database, the rates of patellofemoral osteoarthritis are not higher when a contralateral patellar tendon graft is used during ACL reconstruction compared to a normal knee and is one more benefit towards the use of a contralateral patellar tendon graft. However, the use of an ipsilateral patellar tendon graft for ACL reconstruction was found to be 2.4 times more likely versus the uninvolved normal knee. Although there was not a statistically significant difference in these graft choices, overall utilizing the patellar tendon as a primary graft choice does not lead to increased risk of patellofemoral osteoarthritis.