Predictors of lower knee function improvement two years after anterior cruciate ligament reconstruction

ABSTRACT

Objectives

The extent to which knee functions improve after anterior cruciate ligament reconstruction (ACLR) varies. This study aimed to determine the factors that affect lower knee function improvement after two years of ACLR.

Methods

The study included 159 patients who underwent ACLR in the Indonesian ACL community between August 2018 and April 2020. The concomitant injury and graft types of ACLR were determined using patients’ pre-surgical MRI and medical records. The five subscales of the knee injury and osteoarthritis outcome score (KOOS) were used to evaluate the patient at baseline, first year, and second year following ACLR. A linear mixed-effect model (LMEM) was used to predict the longitudinal improvement models for the five-subscales KOOS score after ACLR.

Results

The LMEM predicted lower KOOS subscales scores improvements by 0.5 for QOL, 0.1 for symptom, ADL, and QOL, and 0.2 for sports/recreation, respectively, for a one score increase of age and time from injury to surgery. Male patients had higher KOOS subscale scores with the improvement of pain, symptom, and ADL by 5.7, 5.9, and 6.3 compared to female patients, respectively, while patients with patellar tendon grafts had lower improvement of KOOS score pain by 6.5 compared to hamstring tendon grafts.

Conclusion

As the age and time from injury to surgery increased, the KOOS subscales scores of QOL and symptoms, ADL, sports/recreation, and QOL decreased. Male patients reported higher KOOS subscales scores for pain, symptoms, and ADL, while patients with patella tendon grafts had a lower improvement in pain score.

KEYWORDS:

• anterior cruciate ligament reconstruction
• knee functions
• KOOS
• osteoarthritis
• quality of life

Disclosure statement

No commercial entity with a direct or indirect interest in this study will offer anything of value to the authors or any affiliated organization.

Contributions of the authors

IPGSA conceived and carried out the study design, data collection, analysis, and drafted the manuscript; AW participated in data collection, drafted the manuscript, and data interpretation; IGNWA conducted the data collection, drafted and revised the manuscript; LS performed the data analysis and drafted the manuscript; IK participated in literature search, and manuscript revision; IDGAK participated in literature search and manuscript revision; GPK participated in literature search and manuscript revision. All authors read and approved the final version of the manuscript and agreed with the order of presentation of the authors.

Additional information

Funding

The authors are grateful to the Research and Community Service Institutions, Universitas Udayana, Bali, Indonesia (B/1.513/UN14.4.A/PT.01.03/2023) for the support rendered.