Trial to Evaluate the Effectiveness of Angular Stable Locking System (ASLS) in Patients With Distal Tibial Fractures

The primary aim of the present study is to evaluate the effectiveness of the Angular Stable Locking System (ASLS) in patients with distal tibial fractures treated with Expert Tibial Nails (ETN). In many cases, the existing locking bolts and screws in intramedullary nails do not provide sufficient stability. The play between screw and nail can result in loss of reduction and the instability due to the interfragmentary movement can result in malunions or nonunions. Therefore, an Angular Stable Locking System for Intramedullary Nails (ASLS) was developed to enhance axial and angular fracture stability. ASLS provides angular-stable fixation between nails and screws with resorbable sleeves used as dowels in the nail locking holes. Preliminary results of a pre-study show a trend towards reduced time to pain-free full weight bearing in patients being treated with ASLS. This hypothesis will be tested in the present randomized controlled study.

Inclusion criteria

• The patient is ≥ 18 years old
• The patient suffers from an acute distal third tibial fracture classified as:

AO 42 A1-A3, AO 42 B1-B3, AO 42 C1-C3, AO 43 A1-A3

• The fracture is fixed with an Expert Tibia Nail (ETN)
• The patient was able to walk without walking aid prior to the accident
• The patient is able to understand and read local language at elementary level
• The patient is willing and able to give written informed consent to participate in the study according to the CIP

Exclusion criteria

• The patient is legally incompetent
• Preexistent malunion or nonunion of the fracture under investigation
• Osteotomies
• The patient suffers from additional fractures of the lower extremities (Exception: ipsilateral fibular fracture)
• The patient suffers from a pathologic fracture
• The patient suffers from active malignancy
• The patient is pregnant, breast feeding or planning to get pregnant during the study period
• The patient suffers from a life-threatening condition
• The patient is affected by drug or alcohol abuse
• The patient has participated in any device related clinical trial affecting the lower extremities within the previous month
• The patient has participated in any drug related clinical trial affecting bone healing within the previous month