Circumferential Rim Augmentation Suture Around the Perimeniscal Capsule Decreases Meniscal Extrusion and Progression of Osteoarthritis in Rabbit Meniscus Root Tear Model.

BACKGROUND: We recently analyzed the joint capsule adjacent to the medial meniscus and found that the perimeniscal joint capsule has collagen fiber orientation similar to that of circumferential meniscal fibers, potentially playing a role in preventing extrusion. PURPOSE: To analyze the meniscal extrusion prevention potential of the circumferential rim augmentation suture around the perimeniscal capsule in a rabbit root tear model and analyze the biomechanical function in a porcine cadaveric knee. STUDY DESIGN: Controlled laboratory study. METHODS: Rabbit medial meniscus root tear models were divided into 3 experimental groups: root tear, root tear and suture repair, and root tear and circumferential rim augmentation suture. As for the circumferential rim augmentation suture procedure, a suture was placed to circumscribe the outer rim of the medial meniscus and passed through bone tunnels located at the tibial insertion of each root. After 4 and 8 weeks, meniscal extrusion was analyzed by micro-computed tomography, gross morphology, and histologic analysis of the medial femoral cartilage. For biomechanical analysis, porcine knees were divided into groups similar to rabbit experiments. Tibiofemoral contact parameters were assessed using a pressure mapping sensor system after applying a load of 200 N on the knee joint. RESULTS: The root tear and circumferential rim augmentation suture group showed less meniscal extrusion, less gap within the tear site, and less cartilage degeneration compared with other groups after 4 and 8 weeks of surgery in the rabbit root tear model. Biomechanical analysis showed the root tear and circumferential rim augmentation suture group had larger contact area and lower peak contact pressure compared with root tear and root tear and suture repair groups. CONCLUSION: The circumferential rim augmentation suture reduced the degree of meniscal extrusion while restoring meniscal function, potentially preventing progression of arthritis in a rabbit root tear model and porcine knee biomechanical analysis. CLINICAL RELEVANCE: The circumferential rim augmentation suture may be a novel augmentation option during root tear treatment.

Muscle transposition for the treatment of paralytic strabismus. Retrospective review of 23 cases / Transposição muscular para o tratamento do estrabismo paralítico. Revisão retrospectiva de 23 casos

Abstract Introduction: Muscular transposition procedures are used when there is no ocular rotation in a particular direction due to alterations of the extraocular muscles such as paralysis, agenesis or congenital anomalies. The objective of this study is to characterize the patients treated with this procedure and determine the percentage of correction of the deviation angle obtained after surgery in the Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology Unit. "Dra. Ana María Illescas Putzeys", Hospital de ojos y oídos "Dr. Rodolfo Robles V. Methods: A retrospective, descriptive, observational study was conducted with review of records of patients operated on muscle transposition during the years 1999 to 2016. Results: Twenty-three rectus muscle transposition procedures were performed. Thirteen were male (56.5%). The mean age was 42 years. In our series, an average correction of 42 PD (82%) was obtained regardless of the type of paralysis or the surgical procedure performed. Conclusion: In selected cases of paralytic strabismus, the main approach may be only muscle transposition with augmentation (posterior intermuscular fixation suture), with good results, similar to those obtained with muscle transposition using adjuvants such as botulinum toxin treatment.

Resumo Introdução: Os procedimentos de transposição muscular são utilizados quando não há rotação ocular em nenhuma direção determinada devido a alterações dos músculos extraoculares, como paralisia, agenesia ou anomalias congênitas. O objetivo deste estudo é caracterizar os pacientes tratados com este procedimento e determinar a porcentagem de correção do ângulo de desvio obtida após a cirurgia na Unidade Pediátrica de Oftalmologia, Estrabismo e Neuro-Oftalmologia. "Dra. Ana María Illescas Putzeys", Hospital de ojos y oídos "Dr. Rodolfo Robles V. Métodos: Foi realizado um estudo retrospectivo, descritivo, observacional, com revisão dos registros de pacientes operados para transposição muscular nos anos de 1999 a 2016. Resultados: Foram realizados vinte e três procedimentos de transposição do músculo reto. Treze pacientes eram homens (56,5%). A idade média foi de 42 anos. Em nossa série, foi obtida uma correção média de 42 PD (82%), independente do tipo de paralisia ou do procedimento cirúrgico realizado. Conclusão: Em casos selecionados de estrabismo paralítico, a principal abordagem pode ser apenas a transposição muscular com aumento (sutura de fixação intermuscular posterior), com bons resultados semelhantes aos obtidos com a transposição muscular com a utilização de adjuvantes como o tratamento com toxina botulínica.