Matched case study finds similar outcomes
“Anterior cruciate ligament (ACL) injuries are increasingly common,” stated Eric Kropf, MD, at the annual meeting of the Arthroscopy Association of North America. “Historically, young athletes have been treated with bone-patellar tendon-bone autografts. Hamstring autograft is finding increased acceptance, but whether either graft consistently returns athletes to pre-injury levels of play is unclear.”
Dr. Kropf and his colleagues conducted a matched pair case-control analysis of 46 patients who underwent either patellar tendon (PT) or hamstring (HS) autografts for ACL reconstruction.
A null hypothesis
“We wanted to retrospectively compare objective, patient-reported, and return-to-sport outcomes,” he explained. “Our null hypothesis was that there would be no significant differences between the two groups.”
Patients were matched into pairs based on age, gender, length of follow-up, and treating surgeon. In each pair, one patient had a PT autograft and the other patient had an HS autograft; both patients had the same treating surgeon. Patients were 25 years of age or younger, with a minimum 2-year follow-up; all patients self-reported participating in strenuous athletics at least four times per week prior to the injury.
Patients who had significant collateral or corner injuries or any articular cartilage injury greater than grade I on the modified Outerbridge classification were excluded, as were patients who had undergone any previous knee surgery.
“Our operative technique was single-bundle ACL reconstruction,” said Dr. Kropf. “Tunnel preparation was identical across all patients. PT grafts were fixed with interference screws, and HS grafts were fixed with cortical fixation devices. The two treating surgeons were Freddie H. Fu, MD, DSc, and Christopher D. Harner, MD.”
Few differences found
At final follow-up, 18 (78.3 percent) of the PT patients and 19 (82.6 percent) of the HS patients reported that they were able to participate in “strenuous” or “very strenuous” sporting activity, but only 13 (56.5 percent) of the PT patients and 10 (43.5 percent) of the HS patients indicated that they had returned to pre-injury levels in terms of frequency and type of sport. The patients who had undergone the HS procedure showed higher Activities of Daily Living scores (p < 0.01), Sports Activity Scale scores (p < 0.01), and better restoration of extension (p < 0.05).
“No radiographic differences were found in the medial compartments in either group,” said Dr. Kropf. “Interestingly, we did see a greater increase in degenerative changes in both the patellofemoral and the lateral compartment in the PT group compared to the HS group.”
In conclusion, Dr. Kropf pointed out that the PT group had a slightly higher rate of return to sports, but the HS group had higher patient-reported outcomes and less loss of extension.
Dr. Kropf’s coauthors included Dr. Fu; Dr. Harner; Randy Mascarenhas, MD; Michael Tranovich, BA; and James J. Irrgang, PT, PhD, ATC, FAPTA. Disclosure information: Dr. Fu—Arthrocare, Stryker, DePuy, Breg, Smith & Nephew, DonJoy, Synthes, Johnson & Johnson; Dr. Harner—Smith & Nephew, Breg. The other authors reported no conflicts.
Peter Pollack is a staff writer for AAOS Now. He can be reached at email@example.com
• This is a matched-pair, case-control analysis of 46 patients who received either a patellar tendon or a hamstring autograft ACL reconstruction.
• Researchers found no differences in return to sports based on the autograft used.
• Across the study, only about half of patients returned to pre-injury levels of participation.