Surgery versus non-operative treatment for ER-stress unstable Weber-B unimalleolar fractures: a study protocol for a prospective randomized non-inferiority (Super-Fin) trial

Abstract

Roughly two-thirds of ankle fractures are unimalleolar injuries, the Weber B-type fibula fracture being by far the most common type. Depending on the trauma and the accompanying soft-tissue injury, these fractures are either stable or unstable. Current clinical practice guidelines recommend surgical treatment for unstable Weber B-type fibula fractures. An ongoing randomized, parallel group, non-inferiority trial comparing surgery and non-operative treatment for unstable Weber B-type ankle fractures with allocation ratio 1:1. The rationale for non-inferiority design is as follows: By being able to prove non-inferiority of non-operative treatment, we would be able to avoid complications related to surgery. However, the primary concern related to non-operative treatment is increased risks of ankle mortise incongruency, leading to secondary surgery, early post-traumatic osteoarthritis and poor function. After providing informed consent, 126 patients aged 16 years or older with an unimalleolar Weber B-type unstable fibula fracture were randomly assigned to surgery (open reduction and internal fixation) or non-operative treatment (6-week cast immobilization). We have completed the patient enrolment and are currently in the final stages of the 2-year follow-up. The primary, non-inferiority outcome is the Olerud-Molander Ankle Score (OMAS) at 2 years (primary time point). The predefined non-inferiority margin is set at 8 OMAS points. Secondary outcomes include the Foot and Ankle Score, a 100 mm Visual Analogue Scale for function and pain, the RAND-36-Item Health Survey for health-related quality-of-life, the range-of-motion of the injured ankle, malunion (ankle joint incongruity) and fracture union. Treatment-related complications and harms; symptomatic non-unions, loss of congruity of the ankle joint, reoperations and wound infections will also be recorded. We hypothesize that non-operative treatment yields non-inferior functional outcome to surgery, the current standard treatment, with no increased risk of harms.

Assessment of articular cartilage of ankle joint in stable and unstable unilateral weber type-B/SER-type ankle fractures shortly after trauma using T2 relaxation time

“…Consecutive patients with an isolated Weber B/SER-type lateral malleolar fracture and congruent ankle mortise (MCS <4 mm and ≤1 mm wider than the superior clear space) were initially enrolled for pragmatic randomized controlled trials (RCT). 28 , 29 All patients gave written informed consent. A total of 87 study participants were gathered in the previous study 16 of which 26 could not be included due to variety of reasons reported previously 16 ; five were omitted due to severe metal artifacts, three due to subpar quality of MR images, and two because T2 maps were not acquired.…”

“…The final study group contained 51 subjects (23 female and 28 male; mean age 45 years, standard deviation (SD) 18 years; age range 16 to 82 years). The study group was split into two RCTs 28 , 29 based on the external-rotation stress test: stable fractures ( n = 28; 12 female, 16 male; mean age 42 years, SD 18 years; mean BMI 26.7 kg/m 2 , SD 4.9 kg/m 2 ) and unstable fractures ( n = 23; 11 female, 12 male; mean age 48 years, SD 19 years; mean BMI 26.9 kg/m 2 , SD 4.2 kg/m 2 ). Demographics are presented in Table 1 .…”

“…The final study group contained 51 subjects (23 female and 28 male; mean age 45 years, standard deviation (SD) 18 years; age range 16 to 82 years). The study group was split into two RCTs 28,29 A control group of healthy young medical students was gathered for our conducted qMRI study. The recruitment of volunteers was conducted via email among medical students.…”