The comparative strength of laryngeal fracture fixation.

PURPOSE: To assess the fixation strength provided by miniplate fixation, wire-tube batten fixation, and wire fixation alone in repair of thyroid cartilage. MATERIALS AND METHODS: Segments 2.5-cm wide x 1-cm long were cut from three fresh, frozen, human cadaveric larynges from an 83-year-old man, a 58-year-old woman, and an unknown cadaver. A vertical fracture was induced and repaired with one of three randomly assigned fixation techniques (n=10 in each fixation group). The repaired cartilage was placed in an Instron Universal Testing Device (Boston, MA) and subjected to a three-point bending test. Load to failure was recorded on an analogue graph. RESULTS: All reconstruction techniques significantly differed from each other, with miniplate fixation providing a stronger repair than wire tube batten (P < .05), wire tube batten providing a stronger repair than wire alone (P < .01), and miniplate providing a stronger repair than wire alone (P < .001). CONCLUSION: In experimentally induced fractures of the human larynx, miniplate fixation consistently yielded the strongest repair. Although both miniplate and wire batten produced excellent anatomic reaction, we feel that miniplate fixation was easier to perform.

Hydroxyapatite cement in craniofacial skeletal reconstruction and its effects on the developing craniofacial skeleton.

OBJECTIVE: To assess the effects of hydroxyapatite cement (HAC) on the developing feline craniofacial skeleton. DESIGN: Fronto-orbital craniotomies were performed on 14 kittens and reconstructed by autograft or HAC. By design, animals in which the craniofacial skeleton was reconstructed with HAC also underwent obliteration of the left frontal sinus. After achievement of skeletal maturity, animals were sacrificed and compared by 11 standardized cranial measurements obtained by sliding caliper. Additional analyses included histological studies, histomorphometry, and computed tomography. SUBJECTS: Twenty-one 12-week-old female cats were divided into 3 groups, composed of 7 specimens. INTERVENTION: The control animals underwent periosteal elevation alone (group 1). The remaining animals underwent unilateral fronto-orbital craniotomy and subsequent reconstruction with orthotopic bone flap replacement (group 2) or HAC (group 3). RESULTS: All animals survived the study with no evidence of wound infection or implant failure. Gross morphological studies demonstrated excellent contour reconstruction in both experimental groups. Craniometric analysis detected 1 intergroup difference that consisted of a wider skull in group 3 on the reconstructed side. An intragroup difference in orbital height was also seen in group 3. Computed tomography demonstrated a solid appearance of the implant with obliteration of the left frontal sinus in group 3. Histological studies showed that HAC was osseointegrated to native bone, with areas of new bone interspersed throughout the implants. No significant inflammatory response or fibrous encapsulation was noted. Histomorphometry demonstrated that implants were replaced by osseous tissue in 44% to 50% of the animals within 5 months. CONCLUSION: Hydroxyapatite cement is safe and effective for craniofacial reconstruction in the developing feline and may be appropriate for similar applications in humans.

Polymeric implants in craniomaxillofacial reconstruction.

With advances in polymer chemistry, polymeric implants are becoming an increasingly attractive alternative to autogenous bone. Although polymeric implants were traditionally used to bridge bony defects and modify the overlying soft tissue envelope, new resorbable polymers may allow bony replacement and may be used as alternatives to metals in rigid fixation. This article contains an overview of polymeric implants from acrylics to modern resorbable polymers.