Clinical pathways for fragility fractures of the pelvic ring: personal experience and review of the literature.

Fragility fractures of the pelvic ring (FFP) are increasing in frequency and require challenging treatment. A new comprehensive classification considers both fracture morphology and degree of instability. The classification system also provides recommendations for type and invasiveness of treatment. In this article, a literature review of treatment alternatives is presented and compared with our own experiences. Whereas FFP Type I lesions can be treated conservatively, FFP Types III and IV require surgical treatment. For FFP Type II lessions, percutaneous fixation techniques should be considered after a trial of conservative treatment. FFP Type III lesions need open reduction and internal fixation, whereas FFP Type IV lesions require bilateral fixation. The respective advantages and limitations of dorsal (sacroiliac screw fixation, sacroplasty, bridging plate fixation, transsacral positioning bar placement, angular stable plate) and anterior (external fixation, angular stable plate fixation, retrograde transpubic screw fixation) pelvic fixations are described.

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

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.

The Retrograde Tibial Nail: presentation and biomechanical evaluation of a new concept in the treatment of distal tibia fractures.

Displaced distal tibia fractures require stable fixation while minimizing secondary damage to the soft tissues by the surgical approach and implants. Antegrade intramedullary nailing has become an alternative to plate osteosynthesis for the treatment of distal metaphyseal fractures over the past two decades. While retrograde intramedullary nailing is a standard procedure in other long bone fractures, only few attempts have been made on retrograde nailing of tibial fractures. The main reasons are difficulties of finding an ideal entry portal and the lack of an ideal implant for retrograde insertion. The Retrograde Tibial Nail (RTN) is a prototype intramedullary implant developed by our group. The implant offers double proximal and triple distal interlocking with an end cap leading to an angle-stable screw-nail construct of the most distal interlocking screw. Its design meets the requirements of a minimally invasive surgical approach, with a stable fracture fixation by multiple locking options. The 8mm diameter curved nail, with a length of 120 mm, is introduced through an entry portal at the medial malleolus. We see possible indications for the RTN in far distal tibial shaft fractures, distal extraarticular metaphyseal tibial fractures and in distal tibia fractures with simple extension into the ankle joint when the nail is combined lag screw fixation. A biomechanical comparison of the current RTN prototype against antegrade nailing (Expert Tibial Nail, Synthes(®), ETN) was performed. Both implants were fixed with double proximal and triple distal interlocking. Seven biomechanical composite tibiae were treated with either osteosynthesis techniques. A 10mm defect osteotomy 40 mm proximal to the joint line served as an AO 43-A3 type distal tibial fracture model. The stiffness of the implant-bone constructs was measured under low and high extra-axial compression (350 and 600 N) and under torsional load (8 Nm). Results show a comparable stability during axial loading for the two implant types with slightly higher stability in the RTN group. Rotational stability was superior for the RTN. Statistical analysis proved a significant difference (p<0.05) between the ETN and RTN for rotational stability. This study suggests that retrograde tibia nailing with the RTN is a promising new concept for the treatment of distal tibia fractures.

Retrograde tibial nailing: a minimally invasive and biomechanically superior alternative to angle-stable plate osteosynthesis in distal tibia fractures.

BACKGROUND: Currently, antegrade intramedullary nailing and minimally invasive plate osteosynthesis (MIPO) represent the main surgical alternatives in distal tibial fractures. However, neither choice is optimal for all bony and soft tissue injuries. The Retrograde Tibial Nail (RTN) is a small-caliber prototype implant, which is introduced through a 2-cm-long incision at the tip of the medial malleolus with stab incisions sufficient for interlocking. During this project, we investigated the feasibility of retrograde tibial nailing in a cadaver model and conducted biomechanical testing. METHODS: Anatomical implantations of the RTN were carried out in AO/OTA 43 A1-3 fracture types in three cadaveric lower limbs. Biomechanical testing was conducted in an AO/OTA 43 A3 fracture model for extra-axial compression, torsion, and destructive extra-axial compression. Sixteen composite tibiae were used to compare the RTN against an angle-stable plate osteosynthesis (Medial Distal Tibial Plate, Synthes®). Statistical analysis was performed by Student's t test. RESULTS: Retrograde intramedullary nailing is feasible in simple fracture types by closed manual reduction and percutaneous reduction forceps, while in highly comminuted fractures, the use of a large distractor can aid the reduction. Biomechanical testing shows a statistically superior stability (p < 0.001) of the RTN during non-destructive axial loading and torsion. Destructive extra-axial compression testing resulted in failure of all plate constructs, while all RTN specimens survived the maximal load of 1,200 N. CONCLUSIONS: The prototype retrograde tibial nail meets the requirements of maximum soft tissue protection by a minimally invasive surgical approach with the ability of secure fracture fixation by multiple locking options. Retrograde tibial nailing with the RTN is a promising concept in the treatment of distal tibia fractures.