What strength characteristic is associated with interference screws in ACL fixation?

The choice highlighting that interference screws are the strongest for bone-patellar tendon-bone (BPTB) grafts is accurate because of the unique properties of the BPTB graft structure and how it interacts with the interference screw fixation method. BPTB grafts contain bone blocks at each end, which allow effective integration with the interference screws, providing higher pull-out strength due to the screw's ability to compress the bone tightly. This mechanical advantage ensures a secure grip and optimal fixation strength during the healing process.

The design of interference screws allows for compression of the graft into the bone tunnel, and the BPTB graft's inherent structure makes it particularly effective at this. When using interference screws with BPTB grafts, the fixation primarily relies on bone-to-bone contact, which is generally stronger than soft tissue-to-bone contact seen with some other graft options. This quality is pivotal in the early stages of rehabilitation, where maintaining graft stability is crucial to the success of the surgical procedure and the patient's recovery trajectory.

Understanding this strength characteristic emphasizes the importance of selecting the appropriate graft type, as it directly influences the success of ACL reconstruction through the effectiveness of the fixation method.