Magnetic resonance imaging-based observations of ligamentization and tunnel widening in relation to functional outcomes after all-inside anterior cruciate ligament reconstruction: A pilot case series

Objectives: Anterior cruciate ligament (ACL) injuries are common among athletes, potentially leading to knee instability, meniscal injuries, and early-onset osteoarthritis if untreated. The all-inside ACL reconstruction technique is increasingly favored for its minimally invasive nature, reduced post-operative pain, and enhanced graft integration. This case series aimed to observe functional outcomes (Lysholm and Tegner scores) and magnetic resonance imaging (MRI) findings (graft ligamentization and tunnel widening) after all-inside ACL reconstruction. Methods: A retrospective pilot review was conducted at Prof. Dr. R. Soeharso Orthopedic Hospital, Indonesia, from January 2020 to July 2024. Patients aged 18 years and older who underwent ACL reconstruction using the all-inside technique and had a minimum 12-month follow-up were included. Functional outcomes were assessed using the Lysholm knee scoring and Tegner activity scale. Graft ligamentization was evaluated using the Figueroa scoring system, and tunnel widening was measured using MRI. Results: Twelve patients met the inclusion criteria. The mean Lysholm score was 80.67 ± 17.77, and the mean Tegner score was 5.33 ± 1.72. The average Figueroa score was 3.33 ± 0.98. Tibial and femoral tunnel widening measured 2.25 ± 1.49 mm and 1.81 ± 1.66 mm, respectively. One patient developed knee stiffness, which was treated with range of motion manipulation under anesthesia. No infections or graft failures occurred. Conclusion: This pilot case series observed favorable functional outcomes despite variable MRI findings of graft ligamentization and tunnel widening after all-inside ACL reconstruction. Functional recovery may depend more on rehabilitation and neuromuscular factors than on MRI findings, suggesting the need for comprehensive clinical assessments.