25 YEARS POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: THE BEST, THE WORST AND THE REASONS WHY. A PROSPECTIVE STUDY

S. Keays¹, P. Newcombe², A. Keays³, J. Bullock-Saxton⁴, N. Collins⁵, H. Mohamed⁶

¹Private Practice and The University of the Sunshine Coast, School of Health and Behavioral Sciences, Sunshine Coast, Australia, ²The University of Queensland, School of Psychology, Brisbane, Australia, ³Private Orthopaedic Practice, Sunshine Coast, Australia, ⁴Active Rehabilitation Physiotherapy, Brisbane, Australia, ⁵The University of Queensland, School of Health and Rehabilitation Sciences, Brisbane, Australia, ⁶Private Physiotherapy Practice, Sunshine Coast, Queensland, Australia

Background: Numerous short and medium-term anterior cruciate ligament reconstruction (ACLR) studies have been reported, but very few 25-year prospective studies exist and long-term outcomes are largely unknown. With the current trend towards non-surgical treatment for ACL rupture, it is important to investigate long-term outcomes of surgery and explore factors, especially those that are modifiable, that explain any differences in outcome.

Purpose: This study aimed to describe outcomes 25 years post-ACLR and relate the best and the worst outcomes to patient and surgical variables.

Methods: Sixty-two patients (44 males) participating in a long-term study were assessed pre-surgery, at 6 months and 6 years post-ACLR.At study onset, patients with a unilateral ACL rupture confirmed by a definite positive pivot shift test together with functional instability, were included (mean age 27±6 years). All patients were treated by the same surgeon and physiotherapist, and were followed-up 25 years post-surgery. Outcome measures included: strength (Cybex 11); stability (clinical and KT 1000); function (5 agility and hop tests); subjective outcome (5 PROMs); 4-view bilateral radiographs; and return to sport scores. The 10 highest and lowest subjective scores as assessed on the combined KOOS and Modified Cincinnati scores determined best and worst outcome subgroups. These two subgroups were compared on the following patient variables: quadriceps and hamstring strength; residual instability; post-surgery weight gain; post-surgery sports history; radiographic severity of tibiofemoral and patellofemoral osteoarthritis. The following injury/surgical variables were also compared: age at the time of surgery; time delay before surgery; meniscal injuries; graft type; graft failure; subsequent injuries and subsequent surgery.

Results: To date, 33 patients (23 males) have been assessed 25 years post-surgery (mean age 51±6.1 years). Fourteen patients received bone-patellar tendon-bone and 19 received semitendinosus/gracilis grafts. Four patients ruptured their ACL grafts, 7 ruptured the contralateral ACL, 4 had subsequent meniscal injuries, one had a tibial osteotomy, and 3 had bilateral knee replacements. Seven patients continued to play competitive sports (including pivoting sports at National Masters level), and an additional 17 patients had participated in competitive pivoting sports for 5-20 years post-ACLR. The overall mean (±SD) KOOS score was 79(±21) and Modified Cincinnati score was 81(±17). Two divergent subgroups were identified with the combined mean score for the best 10 patient scores being 99(±2), and for the worst 10 patient scores 45(±12). The best and worst subgroups were compared and their outcomes related to patient and surgical variables to determine which factors may differentiate the best from the worst outcomes 25 years after ACLR.

Conclusions: Surgical outcomes 25 years after ACLR vary widely as numerous factors interact over time. This study provides new insights into possible reasons accounting for varied long-term outcomes between patients, focusing on modifiable factors.

Implications: The role of surgery for this common sporting knee injury remains controversial. The knowledge gained from prospective long-term studies is critical in determining what is realistically possible long after ACL surgery and how this can best be achieved.

Funding acknowledgements: Nil

Keywords:
Anterior cruciate ligament
Long-term
Reconstruction

Topics:
Sport & sports injuries
Musculoskeletal: lower limb
Orthopaedics

Did this work require ethics approval? Yes

Institution: The University of Queensland

Committee: Medical Ethics Commitee

Ethics number: 2020000921