Temporary Internal Fixation for Ligamentous and Osseous Lisfranc Injuries: Outcome and Technical Tip

BACKGROUND Open rather than closed reduction and internal fixation as well as primary definitive arthrodesis are well accepted for ligamentous and osseous Lisfranc injuries. For ligamentous injuries, a better outcome after primary definitive partial arthrodesis has been published. METHODS Of 135 Lisfranc injuries that were treated from 1998 to 2012 with open reduction, temporary internal fixation by screws and plates, and restricted weight bearing in a lower leg cast for 3 months followed by an arch support for another 4 to 6 weeks, 29 ligamentous Lisfranc injuries were available for follow-up. They were compared with 29 osseous Lisfranc injuries matched in age and gender. RESULTS Between the groups, there were no significant differences in average age (39.9 vs 38 years) or in average follow-up time (8.3 vs 9.1 years). Also, no significant differences were seen in the AOFAS midfoot score (84 vs 85.3 points), the FFI pain scale (9.9 vs 14.9 points), SF 36 physical component (56.2 vs 53.9 points), SF 36 mental component (57 vs 56.4 points), or VAS for pain (1.6 vs 1.5 points). The FFI function scale was significantly lower in the ligamentous group (11.6 vs 19.5 points). Radiographically, loss of reduction was recorded 3 times in the ligamentous injuries and 4 times in the osseous injuries. Arthritis was mild/moderate/severe in 5/3/0 ligamentous injuries and in 7/2/1 osseous injuries, requiring 1 definitive secondary Lisfranc arthrodesis in each group. CONCLUSION With longer and conservative postoperative management, open reduction and temporary internal fixation in ligamentous and osseous Lisfranc injuries led to equal medium-term outcome. Inferior outcome in ligamentous injuries was not found. LEVEL OF EVIDENCE Level III, retrospective comparative cohort study.

Cheek Tooth Extraction Via a Minimally Invasive Transbuccal Approach and Intradental Screw Placement in 54 Equids

OBJECTIVE: To describe (1) preoperative findings and surgical technique, (2) intraoperative difficulties, and (3) postoperative complications and long-term outcome of equine cheek tooth extraction using a minimally invasive transbuccal screw extraction (MITSE) technique. STUDY DESIGN: Retrospective case series. ANIMALS: Fifty-four equids; 50 horses, 3 ponies, and 1 mule. METHODS: Fifty-eight MITSE procedures were performed to extract cheek teeth in 54 equids. Peri- and intraoperative difficulties, as well as short- (<1 month) and long-term (>6 months) postoperative complications were recorded. Followup information was obtained through telephone interviews, making specific inquiries about nasal discharge, facial asymmetry, and findings consistent with surgical site infection. RESULTS: Preoperative findings that prompted exodontia included 50 cheek teeth with apical infections, 48 fractures, 4 neoplasia, 2 displacements, and 1 supernumerary tooth. Previous oral extraction was attempted but had failed in 55/58 (95%) animals because of cheek tooth fracture in 28, or insufficient clinical crown for extraction with forceps in 27. MITSE was successful in removing the entire targeted dental structure in 47/58 (81%) procedures. However, MITSE failed to remove the entire targeted dental structure in 11/58 (19%) procedures and was followed by repulsion in 10/11 (91%). Short-term postoperative complications included bleeding (4/58 procedures, 7%) and transient facial nerve paralysis (4/58 procedures, 7%). Owners were satisfied with the functional and cosmetic outcome for 40/41 (98%) animals with followup. CONCLUSION: MITSE offers an alternate for cheek tooth extraction in equids, where conventional oral extraction is not possible or has failed. Overall, there was low morbidity, which compares favorably with invasive buccotomy or repulsion techniques

In vivo degradation of magnesium plate/screw osteosynthesis implant systems: Soft and hard tissue response in a calvarial model in miniature pigs.

Biodegradable magnesium plate/screw osteosynthesis systems were implanted on the frontal bone of adult miniature pigs. The chosen implant geometries were based on existing titanium systems used for the treatment of facial fractures. The aim of this study was to evaluate the in vivo degradation and tissue response of the magnesium alloy WE43 with and without a plasma electrolytic surface coating. Of 14 animals, 6 received magnesium implants with surface modification (coated), 6 without surface modification (uncoated), and 2 titanium implants. Radiological examination of the skull was performed at 1, 4, and 8 weeks post-implantation. After euthanasia at 12 and 24 weeks, X-ray, computed tomography, and microfocus computed tomography analyses and histological and histomorphological examinations of the bone/implant blocks were performed. The results showed a good tolerance of the plate/screw system without wound healing disturbance. In the radiological examination, gas pocket formation was found mainly around the uncoated plates 4 weeks after surgery. The micro-CT and histological analyses showed significantly lower corrosion rates and increased bone density and bone implant contact area around the coated screws compared to the uncoated screws at both endpoints. This study shows promising results for the further development of coated magnesium implants for the osteosynthesis of the facial skeleton.

Stability of Le Fort I maxillary inferior repositioning surgery with rigid internal fixation: a systematic review

The aim of this study was to evaluate the stability of Le Fort I maxillary inferior repositioning surgery in patients with a vertical maxillary deficiency at least 6 months after surgery. The electronic databases were searched to identify all articles reporting the long-term effects of one-piece maxillary inferior repositioning with rigid fixation. Methodological quality was evaluated according to 15 criteria related to study design, measurements, and statistical analysis. Two articles were identified, with a total of 22 patients. The maxilla was repositioned inferiorly from a mean 3.2 to 4.5mm in the anterior part and from a mean 0.1 to 1.8mm in the posterior part. At 6 months post-treatment, absolute relapse of a mean 1.6mm was measured for the anterior part of the maxilla and 0.3mm for the posterior part of the maxilla. The stability of maxillary inferior repositioning surgery could not be confirmed due to the small sample size, unclear diagnosis, and potential confounding factors.

Zirconia-Based Screw-Retained Prostheses Supported by Implants: A Retrospective Study on Technical Complications and Failures

BACKGROUND Little information is yet available on zirconia-based prostheses supported by implants. PURPOSE To evaluate technical problems and failures of implant-supported zirconia-based prostheses with exclusive screw-retention. MATERIAL AND METHODS Consecutive patients received screw-retained zirconia-based prostheses supported by implants and were followed over a time period of 5 years. The implant placement and prosthetic rehabilitation were performed in one clinical setting, and all patients participated in the maintenance program. The treatment comprised single crowns (SCs) and fixed dental prostheses (FDPs) of three to 12 units. Screw-retention of the CAD/CAM-fabricated SCs and FDPs was performed with direct connection at the implant level. The primary outcome was the complete failure of zirconia-based prostheses; outcome measures were fracture of the framework or extensive chipping resulting in the need for refabrication. A life table analysis was performed, the cumulative survival rate (CSR) calculated, and a Kaplan-Meier curve drawn. RESULTS Two hundred and ninety-four implants supported 156 zirconia-based prostheses in 95 patients (52 men, 43 women, average age 59.1 ± 11.7 years). Sixty-five SCs and 91 FDPs were identified, comprising a total of 441 units. Fractures of the zirconia framework and extensive chipping resulted in refabrication of nine prostheses. Nearly all the prostheses (94.2%) remained in situ during the observation period. The 5-year CSR was 90.5%, and 41 prostheses (14 SCs, 27 FDPs) comprising 113 units survived for an observation time of more than 5 years. Six SCs exhibited screw loosening, and polishing of minor chipping was required for five prostheses. CONCLUSIONS This study shows that zirconia-based implant-supported fixed prostheses exhibit satisfactory treatment outcomes and that screw-retention directly at the implant level is feasible.