In the JournalsPerspective

Bridge-enhanced ACL repair may restore tissue quality, quantity

At 2-year follow-up, bridge-enhanced ACL repair yielded a cross-sectional area, signal intensity and sagittal orientation similar to the contralateral native ACL, according to published results.

Ata M. Kiapour , PhD, MMSc , and colleagues analyzed the MRIs of patients with a complete midsubstance ACL tear treated with either bridge-enhanced ACL repair (BEAR; n=10) or ACL reconstruction with hamstring autograft (n=10) at 3, 6, 12 and 24 months after surgery to determine the average cross-sectional area and signal intensity of the ACL or graft. Researchers also assessed ACL orientation, stump length and bony anatomy.

At all time points, results showed the ACL reconstruction group had a 48% to 98% larger mean cross-sectional area compared with the contralateral intact ACLs. Although BEAR ACLs had a 23% to 28% greater cross-sectional area vs. the contralateral intact ACLs at 3 and 6 months, researchers found these were similar at 12 and 24 months. The BEAR ACLs and contralateral ACLs had similar sagittal orientation compared with the grafts in the ACL reconstruction group, which were 6.5° more vertical.

Researchers noted a correlation between a bigger notch and a bigger cross-sectional area, while high signal intensity was associated with shorter ACL femoral stump, steeper lateral tibial slope and shallower medial tibial depth for BEAR ACLs. Results showed an increased ACL cross-sectional area after the BEAR procedure resulted from performance of notchplasty. ACL graft size or signal intensity were not correlated with any anatomic features.

Kiapour and colleagues noted use of BEAR may lead to a significant impact on the clinical care of patients with ACL injuries.

“These results suggest that BEAR procedure can offer a subject-specific treatment to ACL injury, which is a major breakthrough considering the biological variations in ACL tissue quality and anatomy between different subjects,” Kiapour told Healio.com/Orthopedics. “The observed 2-year changes in the repaired ACL, as well as the associations between knee anatomy and repaired ACL properties, are very informative and justify the need for future studies to further improve the outcomes of the BEAR procedure.” – by Casey Tingle

Disclosures: Kiapour reports he received research grants from the NIH and the National Football League Players Association through the Harvard Catalyst’s Football Players Health Study. Please see the full study for a list of all other authors’ relevant financial disclosures.

At 2-year follow-up, bridge-enhanced ACL repair yielded a cross-sectional area, signal intensity and sagittal orientation similar to the contralateral native ACL, according to published results.

Ata M. Kiapour , PhD, MMSc , and colleagues analyzed the MRIs of patients with a complete midsubstance ACL tear treated with either bridge-enhanced ACL repair (BEAR; n=10) or ACL reconstruction with hamstring autograft (n=10) at 3, 6, 12 and 24 months after surgery to determine the average cross-sectional area and signal intensity of the ACL or graft. Researchers also assessed ACL orientation, stump length and bony anatomy.

At all time points, results showed the ACL reconstruction group had a 48% to 98% larger mean cross-sectional area compared with the contralateral intact ACLs. Although BEAR ACLs had a 23% to 28% greater cross-sectional area vs. the contralateral intact ACLs at 3 and 6 months, researchers found these were similar at 12 and 24 months. The BEAR ACLs and contralateral ACLs had similar sagittal orientation compared with the grafts in the ACL reconstruction group, which were 6.5° more vertical.

Researchers noted a correlation between a bigger notch and a bigger cross-sectional area, while high signal intensity was associated with shorter ACL femoral stump, steeper lateral tibial slope and shallower medial tibial depth for BEAR ACLs. Results showed an increased ACL cross-sectional area after the BEAR procedure resulted from performance of notchplasty. ACL graft size or signal intensity were not correlated with any anatomic features.

Kiapour and colleagues noted use of BEAR may lead to a significant impact on the clinical care of patients with ACL injuries.

“These results suggest that BEAR procedure can offer a subject-specific treatment to ACL injury, which is a major breakthrough considering the biological variations in ACL tissue quality and anatomy between different subjects,” Kiapour told Healio.com/Orthopedics. “The observed 2-year changes in the repaired ACL, as well as the associations between knee anatomy and repaired ACL properties, are very informative and justify the need for future studies to further improve the outcomes of the BEAR procedure.” – by Casey Tingle

Disclosures: Kiapour reports he received research grants from the NIH and the National Football League Players Association through the Harvard Catalyst’s Football Players Health Study. Please see the full study for a list of all other authors’ relevant financial disclosures.

    Perspective

    Reconstruction of the ACL has been the standard treatment for patients who opt for surgical treatment of their ACL tear. There has also been interest in ACL repair, specifically using the BEAR technique. In assessing ACL integrity post-surgery, physical examination and patient-reported outcomes are typically used. However, these results can be influenced by factors not directly related to the structural integrity of the ACL. In their study, Ata M. Kiapour, PhD, MMSc, and colleagues used MRI imaging to directly assess the graft or repaired ligament for tissue quantity (graft size measured by average cross-sectional area) and quality (normalized signal intensity). At 24 months after surgery, BEAR ACLs had a cross-sectional area, signal intensity and sagittal orientation similar to the contralateral ACL vs. ACL reconstructions, which were larger in cross-sectional area and more vertically oriented. Although larger and longer-term studies are needed, this is certainly promising data on the benefits of ACL repair in restoring native anatomy. I look forward to seeing more studies involving the BEAR technique in the future.

    • Alexis C. Colvin, MD
    • Associate professor of orthopedics
      Icahn School of Medicine at Mount Sinai
      New York

    Disclosures: Colvin reports no relevant financial disclosures.