Dissectional Orientation: Morphological Variations of Teres Minor Muscle and its Nerve Supply

SUMMARY: The teres minor is one of the rotator cuff muscles that comprise the superior margin of the quadrangular space. Quadrangular space syndrome (QSS) refers to the entrapment or compression of the axillary nerve and the posterior humeral circumflex artery in the quadrangular space, often caused by injuries, dislocation of the shoulder joint, etc. Patients who fail the primary conservative treatments and have persistent symptoms and no pain relief for at least six months would be considered for surgical interventions for QSS. This cadaveric study of 17 cadavers (males: 9 and females: 8) was conducted in the Gross Anatomy Laboratory at the Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University. The cadavers were preserved in a 10 % formaldehyde solution and obtained ethical approval by the ethical commission of the Siriraj Institutional Review Board. The morphology of the teres minor muscle-tendon junction, the bifurcation type of the axillary nerve, and the length and number of the terminal branches of the nerve to the teres minor were documented. Specimens with quadrangular space contents and surrounding muscles that had been destroyed were excluded from the study. The results showed that 47.06 % of the specimens had type A bifurcation, 47.06 % had type B bifurcation, and the remaining 5.88 % had type C bifurcation. It was observed that 58.82 % had nonclassic muscle-tendon morphology, while 41.18 % were classic. The average length of the terminal branches of the nerve to the teres minor in males was 1.13 cm, with the majority having two branches. For females, many showed one terminal branch with an average length of 0.97 cm. Understanding the differences in anatomical variations can allow for a personalized treatment plan prior to quadrangular space syndrome surgical procedures and improve the recovery of postsurgical interventions for patients.

El músculo redondo menor es uno de los músculos del manguito rotador que comprende el margen superior del espacio cuadrangular. El síndrome del espacio cuadrangular (QSS) se refiere al atrapamiento o compresión del nervio axilar y la arteria circunfleja humeral posterior en el espacio cuadrangular, a menudo causado por lesiones, dislocación de la articulación humeral, entre otros. En los pacientes en los que fracasan los tratamientos conservadores primarios y presentan síntomas persistentes y ningún alivio del dolor durante al menos seis meses se considerarían para intervenciones quirúrgicas para QSS. Este estudio cadavérico de 17 cadáveres (hombres: 9 y mujeres: 8) se llevó a cabo en el Laboratorio de Anatomía Macroscópica del Departamento de Anatomía de la Facultad de Medicina del Hospital Siriraj de la Universidad Mahidol. Los cadáveres se conservaron en una solución de formaldehído al 10 % y obtuvieron la aprobación ética de la comisión ética de la Junta de Revisión Institucional de Siriraj. Se documentó la morfología de la unión músculo-tendón del músculo redondo menor, el tipo de bifurcación del nervio axilar y la longitud y el número de las ramas terminales del nervio para el músculo redondo menor. Se excluyeron del estudio los especímenes con contenido de espacios cuadrangulares y músculos circundantes que habían sido destruidos. Los resultados mostraron que el 47,06 % de los especímenes presentó bifurcación tipo A, el 47,06 % una bifurcación tipo B y el 5,88 % restante una bifurcación tipo C. Se observó que el 58,82 % presentaba una morfología músculo-tendinosa no clásica, mientras que el 41,18 % era clásica. La longitud pmedia de los ramos terminales del nervio hasta el músculo redondo menor en los hombres era de 1,13 cm, y la mayoría tenía dos ramos. En el caso de las mujeres, mostraron un ramo terminal con una longitud promedio de 0,97 cm. Comprender las diferencias en las variaciones anatómicas puede permitir un plan de tratamiento personalizado antes de los procedimientos quirúrgicos del síndrome del espacio cuadrangular y mejorar la recupe- ración de las intervenciones posquirúrgicas de los pacientes.

Expanding the indications for calcaneal plates beyond foot fractures: a technical trick and case series.

Although non-locking calcaneal plates are designed to treat calcaneal fractures, they present some interesting characteristics that justify using them beyond their current application in fractures of the foot. Calcaneal plates are malleable, have an increased footprint area for fracture containment or buttressing, and present several hole options for screw placement in different trajectories, thereby providing proper fixation even in comminuted fracture patterns. The aim of this study is to describe the unconventional use of calcaneal plates in the orthopaedic trauma scenario.

Use of a stainless steel locking calcaneal plate for quadrilateral plate buttress in the treatment of acetabular fractures.

Operative fixation of acetabular fractures involving the quadrilateral surface presents a challenging clinical scenario. Classically, quadrilateral plate buttress was achieved via the use of a "seven" plate. More recently, the use of an anatomic, pre-contoured design has been gaining popularity due to its pre-contoured shape and larger footprint, allowing for a wider quadrilateral plate buttress. The current study presents using a stainless steel locking calcaneal plate to obtain similar surface area coverage as the modern pre-contoured quadrilateral plate, but at a lower cost.Level of evidence IV.

[Infrapectineal plate for repair with minimal invasion of quadrilateral blade acetabular fractures: description new implant and paramedial access]. / Placa infrapectínea para reparación con mínima invasión de fracturas de lámina cuadrilátera acetabular: descripción de un nuevo implante y acceso paramedial.

INTRODUCTION: Quadrilateral plate fractures are the most difficult to reduce and fix. Different techniques have been developed for quadrilateral plate osteosynthesis. The objective of this work was to create an implant and a novel approach to simplify and improve acetabular fracture osteosynthesis. MATERIAL AND METHODS: A total of 83 patients were studied. Pelvic CT scan images of both acetabula were measured at the proximal and distal posterior column. Implant length, diameters and morphological characteristics were determined. The anatomical features of a novel surgical approach are described. The paramedian approach was performed on a cadaveric specimen to determine its anatomical safety. RESULTS: The screws measured 20 × 6 × 8 mm (length × core diameter x head diameter), with internal threads of 4.5 mm. The Kolmogorov-Smirnov (Lilliefors) test was used, where p had to be 0.05. Plates were previously determined to be 10 mm wide and 3 mm thick, of variable length. Instruments were developed to surmount difficulties. DISCUSSION: This new procedure and implant could make the repair of acetabular fractures easier and offers several advantages. Clinical trials are needed to assess the benefits of this proposal. The newly described method can allow acetabular fracture osteosynthesis to be performed safely, avoid iatrogenic injury to anatomical structures and achieve better results.

INTRODUCCIÓN: Las fracturas de la lámina cuadrilátera del acetábulo son las más difíciles de reducir y fijar. Se han desarrollado diferentes técnicas para la osteosíntesis de la lámina cuadrilátera. El objetivo de este trabajo fue crear implantes y un nuevo acceso quirúrgico para simplificar y mejorar la osteosíntesis de fracturas del acetábulo. MATERIAL Y MÉTODOS: Un total de 83 pacientes fueron estudiados mediante la tomografía axial computarizada de ambos acetábulos, siendo medidos a nivel de columna posterior alta y baja con el fin de determinar longitud y diámetro de los implantes, a través del análisis de normalidad de variables, dónde p es 0.05, usando la prueba Kolmogorov-Smirnov (Lilliefors). Las características anatómicas del nuevo acceso quirúrgico también se describen. La incisión se practicó en espécimen cadavérico para determinar la seguridad de todo el acceso. RESULTADOS: El par de tornillos macho-hembra midió 20 x 6 x 8 mm (longitud, diámetro interno y de la cabeza), mientras que las placas fueron de 10 mm de ancho y 3 mm de espesor, con longitud correspondiente al número de orificios. Se desarrollaron instrumentos apropiados para su aplicación. DISCUSIÓN: Este método puede facilitar la osteosíntesis del acetábulo. Se requieren estudios cadavéricos y clínicos para corroborarlo. Puede ser que se mejoren los resultados de osteosíntesis del acetábulo, con menor riesgo.

Placa infrapectínea para reparación con mínima invasión de fracturas de lámina cuadrilátera acetabular: descripción de un nuevo implante y acceso paramedial / Infrapectineal Plate for repair with minimal invasion of quadrilateral blade acetabular fractures: description new implant and paramedial access

Resumen: Introducción: Las fracturas de la lámina cuadrilátera del acetábulo son las más difíciles de reducir y fijar. Se han desarrollado diferentes técnicas para la osteosíntesis de la lámina cuadrilátera. El objetivo de este trabajo fue crear implantes y un nuevo acceso quirúrgico para simplificar y mejorar la osteosíntesis de fracturas del acetábulo. Material y métodos: Un total de 83 pacientes fueron estudiados mediante la tomografía axial computarizada de ambos acetábulos, siendo medidos a nivel de columna posterior alta y baja con el fin de determinar longitud y diámetro de los implantes, a través del análisis de normalidad de variables, dónde p es > 0.05, usando la prueba Kolmogorov-Smirnov (Lilliefors). Las características anatómicas del nuevo acceso quirúrgico también se describen. La incisión se practicó en espécimen cadavérico para determinar la seguridad de todo el acceso. Resultados: El par de tornillos macho-hembra midió 20 x 6 x 8 mm (longitud, diámetro interno y de la cabeza), mientras que las placas fueron de 10 mm de ancho y 3 mm de espesor, con longitud correspondiente al número de orificios. Se desarrollaron instrumentos apropiados para su aplicación. Discusión: Este método puede facilitar la osteosíntesis del acetábulo. Se requieren estudios cadavéricos y clínicos para corroborarlo. Puede ser que se mejoren los resultados de osteosíntesis del acetábulo, con menor riesgo.

Abstract: Introduction: Quadrilateral plate fractures are the most difficult to reduce and fix. Different techniques have been developed for quadrilateral plate osteosynthesis. The objective of this work was to create an implant and a novel approach to simplify and improve acetabular fracture osteosynthesis. Material and methods: A total of 83 patients were studied. Pelvic CT scan images of both acetabula were measured at the proximal and distal posterior column. Implant length, diameters and morphological characteristics were determined. The anatomical features of a novel surgical approach are described. The paramedian approach was performed on a cadaveric specimen to determine its anatomical safety. Results: The screws measured 20 × 6 × 8 mm (length × core diameter x head diameter), with internal threads of 4.5 mm. The Kolmogorov-Smirnov (Lilliefors) test was used, where p had to be > 0.05. Plates were previously determined to be 10 mm wide and 3 mm thick, of variable length. Instruments were developed to surmount difficulties. Discussion: This new procedure and implant could make the repair of acetabular fractures easier and offers several advantages. Clinical trials are needed to assess the benefits of this proposal. The newly described method can allow acetabular fracture osteosynthesis to be performed safely, avoid iatrogenic injury to anatomical structures and achieve better results.

Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?

OBJECTIVE: The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area. METHODS: A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations. RESULTS: As the load was added, the displacements were A<B, increasing in line. In the 600 N physiological loading, the differences were significant (standing position: p = 0.013; sitting position: p = 0.009) between groups A and B. CONCLUSION: The anterior construct plate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting. .