Page 44 - ISAKOS 2020 Newsletter Volume 2

CURRENT CONCEPTS
Quadriceps Autograft in Primary ACL Reconstruction:
An Evidence-Based Synthesis
From a research perspective, as mentioned previously, the QT can be harvested with or without a patellar bone block. While the pros and cons of each method are beyond the scope of this article, our group has examined this topic in a systematic review of the literature that is currently under review. Our findings point to the utility of an all-soft-tissue QT autograft in the setting of primary ACL reconstruction: across 32 studies involving 2001 patients with a mean age of 29.1 years (range, 15 – 59 years) and a mean duration of follow-up of 35.7 months, knee outcome scores and return- to-sport rates were similar between patients who underwent reconstruction with both QT preparations (unpublished data). Although the use of a bone block theoretically potentiates faster healing and graft integration, these proposed advantages are not captured in any clinically meaningful way as all patients initiate immediate weight-bearing and range- of-motion protocols and are not necessarily cleared for return to sport sooner. We employ a bone block-QT graft in specific scenarios, such as cases in which the length of an all-soft- tissue graft is inadequate (rare) or cases in which bone is required in the revision setting. Graft integration is facilitated with the all-soft-tissue option by reaming tunnels 0.5 cm less than the graft diameter, and subsequently dilating to the graft diameter, to ensure complete socket fill and interference fit.
In another systematic review, our group investigated types of QT graft fixation with either suspensory or aperture technologies. That review demonstrated that, following primary ACL reconstruction, QT grafts appear to have a short-term failure rate of 3%, independent of fixation method, which is on-par with other graft re-rupture rates. It would appear that suspensory or aperture fixation for both the femoral and tibial tunnels are equally effective.
Moreover, our group not only highlighted that all dimensions of the QT graft can be easily predicted from preoperative MRI studies—an important consideration for those who value graft diameter as a predictive factor for success — but also demonstrated, in yet another systematic review of 20 studies involving 1,212 patients, that there were no differences between full-thickness and partial-thickness grafts in terms of outcomes or complications.
From a rehabilitation perspective, functional targets exist, especially early, to ensure optimal recovery and performance. Hindrances to achieving these milestones include, but are not limited to, perceived pain, the presence of edema, muscle inhibition, and movement limitations. It has been our experience that patients managed with QT grafts receive the “best of both worlds,” experiencing less morbidity (i.e., anterior knee pain) while achieving both functional milestones and recovery of quadriceps strength quickly (Fig. 3). While we are currently studying this topic from a kinesiographic perspective, we are encouraged that our experience has also been echoed in the literature.
03 Range-of-motion and extension testing 4 weeks after ACL reconstruction with an all-soft-tissue QT autograft.
03A Maximum extension.
03B Maximum flexion.
03C Extension testing demonstrating no extensor lag.
A recent study from the Danish Knee Ligament Registry showed higher revision rates following primary ACL reconstructions performed with use of QT autograft as compared with BPTB and HT4. In that study, fewer ACL reconstructions were performed with QT than with either BPTB or HT (531, 1,835, and 14,213 procedures, respectively). In view of those numbers, the issue of a learning curve must be considered both by those who use this graft option as well as those who review the literature.
As orthopaedic surgeons, we must answer the call to work collaboratively and address key controversies with high- powered, well-designed, blinded, global randomized-control trials (RCTs) with long-term follow-up and intention-to-treat analyses. Indeed, it is largely through these efforts that causative inferences can be made regarding the effect of a treatment on a particular outcome.
To this end, we are encouraged by the recent findings of Professor Lind’s prospective RCT, published in February 2020, which concluded that “The QT graft could be a better graft choice for ACLR”5, and we eagerly anticipate the results from the STABILITY 2 RCT in adult ACL patients. We have no doubt that the aforementioned studies will continue to provide some insight into important unanswered questions in the young adult population undergoing ACL reconstruction.
42 ISAKOS NEWSLETTER 2020: VOLUME II