A new angle stable nailing concept for the treatment of distal tibia fractures

Abstract

Purpose Surgical treatment of distal tibial fractures demands a stable fracture fixation while minimizing the irritation to the soft tissues by approach and implant. Biomechanical studies have demonstrated superior performance for angular-stable locked nails over standard locked nails in distal tibial fractures. The experimental Retrograde Tibial Nail (RTN) is a minimally invasive local intramedullary osteosynthesis, which has been under design by our group. We conducted a biomechanical comparison in composite tibiae of the Retrograde Tibial Nail against the Expert Tibial Nail (Synthes®). Our hypothesis was that the RTN would provide equivalent biomechanical stability with respect to extra-axial compression, torsion and load to failure testing, in an extra-articular distal tibia fracture model. Methods Biomechanical composite bone testing was conducted in 14 biomechanical composite tibiae in an AO 43 A3 fracture model. In both groups, triple angle stable interlocking was performed in the distal fragment. Results Results show a statistically non-significant higher stability of the ETN during the axial loading tests. Torsional stability testing resulted in a statistically superior performance for the RTN (p=0.018).Destructive extra-axial compression resulted in failure of six ETN constructs, while all RTN specimens survived the maximal load. Conclusions The experimental Retrograde Tibial Nail provides the key features for the treatment of distal tibial fractures. It combines a minimally invasive local intramedullary osteosynthesis with the ability to securely fix the fracture by multiple angle stable locking options.

Intramedullary nail versus plate treatments for distal tibial fractures: A meta-analysis

“…We should note that, the subgroup analysis stratified by region showed that, in non-Asian region, no significant difference between the two approaches in terms of SI was observed, implying that region might be another factor that would affect the pooled results. Despite these desirable results of IMN in above assessment indexes, IMN could also cause some unsatisfactory effects because IMN allows micro-motion, which induces callus formation [32]. Biomechanically, even reamed IMN could not match well to the lenient medullary canal of the tibia metaphysic, and the lack of adequate purchase of locking screws is apt to result in the failure to gain or maintain the tibial alignment [36].…”

“…nonunion in tibia fracture in feline than in canine [31]. IMN treatment could benefit the distal tibial fracture for it preserves the integrity of the surrounding soft-tissue and vascular supply [32], and thus promotes the biological bone healing [33]. For this account, in the management of distal tibial fractures, IMN might possess the advantages of saving OT, UT and HT, as well as reducing the incidence of infections.…”

Recent developments on intramedullary nailing: a biomechanical perspective

“…When the sleeve–screw combination is inserted into the nail, the sleeve expands in the nail hole, resulting in a tight fit that prevents toggling between nail and screw. Additionally, the angular stable locking nail has a more even load distribution over the nail, thus decreasing individual stress raisers and reducing loosening of locking screws . When introduced, the ASLS used PEEK.…”

“…When introduced, the ASLS used PEEK. This was gradually replaced by a more biodegradable material: 70:30 poly( l ‐lactide‐co‐ d,l ‐lactide) dowels . The latter has resorbable properties that may lead to an intrinsic dynamization.…”

“…Additionally, the angular stable locking nail has a more even load distribution over the nail, thus decreasing individual stress raisers and reducing loosening of locking screws. 94,98 When introduced, the ASLS used PEEK. This was gradually replaced by a more biodegradable material: 70:30 poly(l-lactideco-d,l-lactide) dowels.…”