Early Predictors of Recovery From Nonoperatively Treated Achilles Tendon Rupture: 1 Year Follow‐Up Study

• DOI: 10.1111/sms.14700
• Publication Date: 2024-07-16T05:28:54Z
• Authors: Maria Sukanen; Ra’ad M. Khair; Aleksi Reito; Ville Ponkilainen; Juha Paloneva; Neil Cronin; Arto J. Hautala; Taija Finni
• Keywords: Adult; Male; 3126; 610; Achilles tendon resting angle; tendon nonuniformity; toipuminen; Achilles Tendon; Tendon Injuries; Isometric Contraction; Hyvinvoinnin tutkimuksen yhteisö; Humans; Biomechanics; Muscle Strength; Prospective Studies; strength deficit; Muscle, Skeletal; shear wave elastography; School of Wellbeing; Rupture; ultrasonography; Recovery of Function; Middle Aged; ultraäänitutkimus; Biomekaniikka; Female; seurantatutkimus; kantajänne; vammat; lihasvoima; Follow-Up Studies

ABSTRACTPurposeTo investigate early structural and mechanical predictors of plantarflexor muscle strength and the magnitude of Achilles tendon (AT) nonuniform displacement at 6 and 12 months after AT rupture.MethodsThirty‐five participants (28 males and 7 females; mean ± SD age 41.7 ± 11.1 years) were assessed for isometric plantarflexion maximal voluntary contraction (MVC) and AT nonuniformity at 6 and 12 months after rupture. Structural and mechanical AT and plantarflexor muscle properties were measured at 2 months. Limb asymmetry index (LSI) was calculated for all variables. Multiple linear regression was used with the 6 and 12 month MVC LSI and 12 month AT nonuniformity LSI as dependent variables and AT and plantarflexor muscle properties at 2 months as independent variables. The level of pre‐ and post‐injury sports participation was inquired using Tegner score at 2 and 12 months (scale 0–10, 10 = best possible score). Subjective perception of recovery was assessed with Achilles tendon total rupture score (ATRS) at 12 months (scale 0–100, 100=best possible score).ResultsAchilles tendon resting angle (ATRA) symmetry at 2 months predicted MVC symmetry at 6 and 12 months after rupture (β = 2.530, 95% CI 1.041–4.018, adjusted R2 = 0.416, p = 0.002; β = 1.659, 95% CI 0.330–2.988, adjusted R2 = 0.418, p = 0.016, respectively). At 12 months, participants had recovered their pre‐injury level of sports participation (Tegner 6 ± 2 points). The median (IQR) ATRS score was 92 (7) points at 12 months.ConclusionGreater asymmetry of ATRA in the early recovery phase may be a predictor of plantarflexor muscle strength deficits up to 1 year after rupture.Trial Registration: This research is a part of “nonoperative treatment of Achilles tendon rupture in Central Finland: a prospective cohort study” that has been registered in ClinicalTrials.gov (NCT03704532)