A Comparative Study on Functional Outcomes of Fixed Versus Adjustable Length-Loop Device for Femoral Fixation of Graft in Anterior Cruciate Ligament Reconstruction
Authors: Nag Dharmaraj 
Published: November 2022

Background: ACL injury is one of the most common injuries of knee among high level athletes and also common in young and non-sports people. Intra-articular anatomical ACL reconstruction (ACLR) with a biologic graft has become the gold standard for the treatment of ACL tear. The use of the semitendinosus and gracilis (STG) tendons is becoming the choice method in anterior cruciate ligament (ACL) reconstruction. Cortical suspensory fixation is the current preferred Femoral fixation method & is in wide-spread use. Cortical suspension device available in two varieties – 1. Fixed Loop-Length device (FLD) e.g. Endobutton; 2. Adjustable Loop-Length device (ALD) e.g. Tightrope, Toggleloc, ZipLoop. We conducted this prospective study to find out which device fared better in terms of functional outcomes and laxity measurements at a final follow up of 1 year. Study design: prospective study Material and methods: This is prospective study conducted in the PG Department of Orthopaedics in S.C.B medical college & hospital from June 2018 to February 2020. There were 53 patients included in our study. All patients presenting with history of trauma to the knee in the Orthopaedics emergency and outpatient departments in SCB Medical College were evaluated by a thorough general and local examination of the knee. Routine radiographs in antero-posterior view and lateral view of the affected knee were taken. MRI of the knee was done in all suspected ACL torn cases for confirmation. Patients who have chosen to undergo ACL repair surgery are then randomly selected and allocated to two groups, group 1 are the patients operated with fixed loop suspension devices and group 2 patients are operated with adjustable loop suspension devices. All patients underwent ACLR with 4 strand, autologous hamstring grafts and fixed in the tibial side with a bio-degradable interference screw. Study center: SCB medical college &hospital, Cuttack between June 2018- February 2020. Results: Tegner Lysholm Score shows no difference between both the groups at any point of time. At last follow up of 12 months the Tegner Lysholm score was 93.05±4.04 in Fixed loop group and 92.81±2.96 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.726, 0.572 and 0.805 respectively. KOOS Score for pain shows no difference between both the groups at any point of time. At last follow up of 12 months the KOOS score for pain was 91.86±3.73 in Fixed loop group and 91.79±3.46 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.545, 0.490 and 0.949 respectively. KOOS Score for symptoms shows no difference between both the groups at any point of time. At last follow up of 12 months the KOOS score for symptoms was 95.90±3.73 in Fixed loop group and 96.16±3.46 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.968, 0.626 and 0.797 respectively. KOOS Score for Activities for Daily Living shows no difference between both the groups at any point of time. At last follow up of 12 months the KOOS score for activities for daily living was 91.59±2.49 in Fixed loop group and 91.22±1.99 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.757, 0.566 and 0.549 respectively. KOOS Score for sports and recreations shows no difference between both the groups at any point of time. At last follow up of 12 months the KOOS score for pain was 85.00±6.54 in Fixed loop group and 85.65±7.15 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.545, 0.781 and 0.739 respectively. KOOS Score for quality of life shows no difference between both the groups at any point of time. At last follow up of 12 months the KOOS score for pain was 86.64±9. 10 in Fixed loop group and 88.30±7.17 in Adjustable Loop group. The difference is not significant at 3 months, 6 months and 12 months with p values 0.876, 0.790 and 0.462 respectively. Conclusions: Arthroscopic ACL reconstruction using fixed loop or adjustable loop suspensory devices are equally effective fixation alternatives. It gives equal functional outcome in both cases, in terms of Tegner-Lysholm score & Knee-injury & Osteoarthritis Outcomes Score. Proper technique with appropriate tunnel positioning are the main factors of ACL reconstruction. Although many in vitro studies have shown that adjustable loop devices are biomechanically inferior to fixed loop devices, previous clinical studies as well as our study fail to corroborate this. The logical step forward would be to conduct well designed Randomized Control Trials comparing the two devices. Until further evidence clearly shows the superiority of one device over the other, it can be expected to yield similar results. Keywords: ACL reconstruction, Adjustable length loop device, Fixed loop device