A Study to Compare Two Different Managements After Ankle Surgery: Immediate and Delayed Weight-bearing.

The investigators will compare two types of rehabilitation in patients who undergo a surgery for treatment of malleolar fractures: immediate complete weight-bearing and delayed weight-bearing.

The investigators want to evaluate if the immediate complete weight-bearing can improve and hasten the functional outcome of the ankle without increasing the risk of complications.

The study population corresponds to the patients who may benefit from a post-operative rehabilitation protocol with immediate weight-bearing. Eligible lateral malleolar fractures are limited to Weber A and Weber B fractures, since they have a higher stability, after open reduction and internal fixation, compared to Weber C and Maisonneuve fractures. This higher stability gives the possibility to evaluate the benefit of the immediate weight-bearing protocol without safety concerns.

A power analysis was performed to estimate the required sample size to detect a significant difference in the OMAS score at 6 weeks between groups: the number of patients needed is 42 patients per group (84 patients overall) but, considering the risk of drop-outs, the investigators plan to enroll 20% more patients for a total of 100 patients.

The surgical operation will be carried out following the AO Foundation general and specific rules concerning the surgical treatment of malleolar fractures . In particular,an anatomical open reduction and internal fixation with one or two compression screws sustained by a neutralization third-tubular plate for simple fractures or a bridging third-tubular locking compression plate for multi-fragmentary fractures will be performed.

Postoperatively, patients who still meet the eligibility criteria will be randomized in 2 groups: immediate post-operative complete weight-bearing and complete weight-bearing delayed for 6 weeks.Immediate complete weight-bearing consists in the possibility to undergo all the everyday activities without limiting weight-bearing and without the use of walking aids (patients will wear an ankle brace, this will ensure the safety of the early recovery phases, protecting from dangerous movements while allowing the mobilization in the healthy range of movement). Delayed weight-bearing consists in the limitation of the weight-bearing to 20-30% of patient's total weight using crutches for the first 6 weeks after surgery (also patients of the control group will wear the ankle brace).

Subsequent follow-up visits are scheduled at 2, 6, 12 and 24 weeks after surgery. Patients with a fracture non-union radiologically confirmed at week 24 will be followed up until 48 weeks after surgery. Clinical assessments will be performed using subjective, objective and radiological evaluations. Safety will be monitored throughout the study.

Overall study duration will be 2 years and 6 months (2 years to reach the expected sample size and 6 months to complete the follow-up):

Eligibility Criteria:
Inclusion Criteria:

* Male and female adults
* Age ranging from 18 to 70 years, included
* Signed Informed Consent
* Ankle fracture requiring surgical management classified as:1- Weber A fracture pattern (AO 44.A1, 44.A2, 44.A3) with or without association with a medial or posterior lesion/fracture or 2- Weber B fracture pattern (AO 44.B1, 44.B2, 44.B3) with or without association with a medial or posterior lesion/fracture
* Willingness and ability to participate in the trial

Exclusion Criteria:

* Weber C fracture pattern
* Bilateral fractures or fractures in other locations
* Maissoneauve associated lesion
* Body Mass Index \< 18.5 and ≥ 30
* Metabolic diseases influencing fracture healing processes
* Medical comorbidities precluding operative intervention
* Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, general physical problem of the participant, etc.
* Inability or contraindications to undergo the investigated intervention
* Other clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.)
* Pregnant women