Comparison of Quadriceps and Semitendinosus Grafts in ACL Reconstruction Using Data From the Danish Knee Ligament Reconstruction Registry (DKRR)

ACL Reconstruction With Quadriceps Tendon Graft vs. Quadrupled Semitendinosus Graft: A Comparison of Patients From the Danish National ACL Reconstruction Database

This study looks at two different types of tendon (tissue) used in knee surgery to repair a torn anterior cruciate ligament (ACL), which is a common injury in active people. The two types are taken from different muscles in the thigh: one from the front (quadriceps) and one from the back (semitendinosus). We will use information already collected in a national health registry to see how patients recover after surgery. The study will compare knee function, activity level, and how often patients need another operation.

This is a retrospective observational cohort study based on data from the Danish Knee Ligament Reconstruction Registry (DKRR). The study includes patients who underwent primary ACL reconstruction using either a quadriceps tendon graft (with or without a bone block) or a quadrupled semitendinosus tendon graft. The primary outcome measures are the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Tegner Activity Scale. Secondary outcomes include reoperation rates, postoperative complications, and patient satisfaction. All available demographic, operative, and patient-reported outcome data will be analyzed. Multivariable regression will be used to adjust for confounders such as age, sex, BMI, time from injury to surgery, and surgeon volume. The study is exempt from ethical approval under Danish law, and data will be handled in compliance with GDPR.

Inclusion Criteria:

• Primary ACL reconstruction registered in the Danish Knee Ligament Reconstruction Registry (DKRR)
• Known graft type: quadriceps tendon or semitendinosus tendon Minimum 1-year follow-up with completed patient-reported outcome measures (KOOS and/or Tegner score)
• Age between 15 and 50 years at the time of surgery (optional subgroup analysis)

Exclusion Criteria:

• Revision ACL reconstruction
• Multiligament knee reconstruction
• Missing or incomplete PROMs or key clinical data