FGF gene expression in injured tendons as a prognostic biomarker of 1-year patient outcome after Achilles tendon repair

Abstract

Purpose Healing outcome after Achilles Tendon Rupture (ATR) is variable and unsatisfactory. Many ATR patients still exhibit pain, functional deficits and limitations in walking one-year post-surgery. The present study was designed to investigate the association between the expression of healing biomarkers and patient outcome after ATR. Methods Tendon biopsies were collected from 25 ATR patients during surgery. At 1-year post surgery, all patients completed questionnaires; Achilles tendon Total Rupture Score (ATRS) and Foot and Ankle Outcome Score (FAOS), and were tested for functional outcomes by heel-rise test. In biopsies, FGF, COL III, FN, COL I and MMP-9 mRNA levels were assessed by quantitative RT-PCR while protein expression was studied by immunohistochemistry (IHC). Results Our analysis confirmed the presence of FGF, COL III, FN, COL I and MMP-9 at mRNA and protein levels in tendon biopsies. FGF gene expression associated positively with improved total ATRS and better functional outcomes. Additionally, FGF mRNA levels were associated with less pain, less running limitations and less loss in physical activity. In addition, higher COL III mRNA expression was associated with more tendon strength. Conclusion Our findings indicate that FGF gene expression is associated with improved patient-reported outcome. FGF expression in surgical biopsies could potentially be used to assist the prognostic evaluation of patient outcome and may be used as a predictor for healing. However, further studies are needed to evaluate the role of FGF in Achilles tendon healing. Level of evidence II

eEF2 improves dense connective tissue repair and healing outcome by regulating cellular death, autophagy, apoptosis, proliferation and migration

“…Patients were randomly selected from a patient cohort who participated in randomized control trials at the hospital. All the participants received the same anesthetic and surgical procedure to repair mid-substance tears within 2-7 days of injury and followed exclusion criteria as reported previously (Chen et al, 2021, Alim et al, 2016).…”

“…The patient-reported outcomes were evaluated 1-year postoperatively using validated questionnaires: Achilles Tendon Total Rupture Score (ATRS), Foot and Ankle Outcome Score (FAOS) and functional outcome was measured using the Heel-rise Test (HRT). All the methodology, rules and regulations of patient outcome measurement followed the same description as in our previous studies (Svedman et al, 2018, Alim et al, 2016, Abdul Alim et al, 2018, Chen et al, 2021).…”

“…Outcome Score (FAOS) and functional outcome was measured using the Heel-rise Test (HRT). All the methodology, rules and regulations of patient outcome measurement followed the same description as in our previous studies (Svedman et al, 2018, Alim et al, 2016, Abdul Alim et al, 2018, Chen et al, 2021.…”

“…Such variations often result in compromised function, chronic pain and degenerative musculoskeletal diseases for many patients. Knowledge of the regulatory mechanisms responsible for such variability in regenerative outcomes, as well as identification of validated biomarkers that can be used as predictors of DCT healing are still mostly lacking (Abdul Alim et al, 2018, Baranzini et al, 2021, Chen et al, 2021, Grol et al, 2021).…”

Optimizing repair of tendon ruptures and chronic tendinopathies: Integrating the use of biomarkers with biological interventions to improve patient outcomes and clinical trial design

“…Endogenous repair following either conservative care (no surgery) or following surgery leads to scar formation with the risk for functional compromise due to the inferior biochemical and biomechanical properties of the scar tissue (84, 85, 92). However, recently Chen et al (23,93) have reported that some patients who have had their Achilles tendon ruptures surgically repaired had very good functional outcomes by 1-year post-surgery while others had less optimal outcomes. Therefore, outcomes following tendon rupture can be variable, possibly due to the quality of the product of the healing process.…”