Search

OBJECTIVES: High energy long bone fractures with critical bone loss are at risk for nonunion without strategic intervention. We hypothesize that a synthetic membrane implanted at a single stage improves bone healing in a preclinical nonunion model. METHODS: Using standard laboratory techniques, microspheres encapsulating bone morphogenic protein-2 (BMP2) or platelet derived growth factor (PDGF) were designed and coupled to a type 1 collagen sheet. Critical femoral defects were created in rats and stabilized by locked retrograde intramedullary nailing. The negative control group had an empty defect. The induced membrane group (positive control) had a polymethylmethacrylate spacer inserted into the defect for four weeks and replaced with a bare polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold at a second stage. For the experimental groups, a bioactive synthetic membrane embedded with BMP2, PDGF or both enveloped a PCL/β-TCP scaffold was implanted in a single stage. Serial radiographs were taken at 1, 4, 8, and 12 weeks postoperatively from the definitive procedure and evaluated by two blinded observers using a previously described scoring system to judge union as primary outcome. RESULTS: All experimental groups demonstrated better union than the negative control (p=0.01). The groups with BMP2 incorporated into the membrane demonstrated higher average union Mehta scores than the other groups (p=0.01). The induced membrane group performed similarly to the PDGF group. Complete union was only demonstrated in groups with BMP2-eluting membranes. CONCLUSIONS: A synthetic membrane comprised of type 1 collagen embedded with controlled release BMP2 improved union of critical bone defects in a preclinical nonunion model.

To determine the short-term results of surgical treatment with dual posterolateral and posteromedial approaches for fractures of the entire posterior tibial plafond and secondarily to identify common fracture characteristics.Retrospective.Single academic Level 1 trauma center.Thirty-five patients with posterior pilon fractures followed until fracture union (minimum 3 months).Surgical treatment using simultaneous combined posterolateral and posteromedial exposures for fracture reduction and internal fixation.(1) Surgical outcomes including rate of wound complications and accuracy of the articular reduction. (2) Fracture characteristics including the incidence of articular impaction, comminution interfering with reduction, syndesmosis injury, and the type of fibula fracture.The rate of wound problems was low (6%), and 94% of patients had an articular reduction with less than 1 mm of step or gap. There were high rates of articular comminution (83%) and posteromedial articular impaction (63%) and a 17% rate of syndesmosis injury requiring repair.Surgical fixation using simultaneous, combined posterolateral and posteromedial approaches for posterior pilon fractures had a low rate of wound complications and was an effective strategy for obtaining an accurate reduction. The rate of syndesmotic instability requiring fixation was lower than previous work reporting on fixation using a single approach. This may be a useful technique for surgeons who treat these injuries. Careful assessment of the preoperative imaging is required in patients with posterior pilon fractures.Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

To evaluate whether a single proximal interlocking bolt was sufficient during the treatment of extra-articular femur fractures with retrograde medullary nailing.Retrospective comparative study.Academic Level 1 trauma center.The study included 136 patients with extra-articular femur fractures treated with retrograde medullary nailing who met inclusion and follow-up criteria.The intervention included surgical treatment for a femur fracture with retrograde medullary nailing, with comparisons made between those treated with a single proximal interlocking (1 IL) bolt and those treated with 2 proximal interlocking bolts (2 IL).The main outcome measurements were as follows: (1) rate of nonunion and (2) rate of catastrophic implant failure.There was no difference in the rate of nonunion requiring surgical intervention between the 2 groups. There were no catastrophic failures in either group.A single proximal interlocking bolt may be sufficient when using retrograde nailing for the treatment of extra-articular femur fractures.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.