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.

Calcaneal plate bridge reconstruction plate for acetabular fracture involving quadrilateral surface via modified Stoppa approach / 中国修复重建外科杂志

Objective: To explore the effectiveness of the calcaneal plate bridge reconstruction plate for acetabular fracture involving quadrilateral surface via modified Stoppa approach. Methods: Between January 2015 and December 2017, 18 patients with acetabular fracture involving quadrilateral surface were treated with the calcaneal plate bridge reconstruction plate via the modified Stoppa approach. There were 12 males and 6 females. The age ranged from 28 to 63 years (mean, 39 years). The cause of injury was traffic accident in 13 cases and falling from height in 5 cases. According to the Letournel-Judet classification, there were 10 cases of anterior and posterior column fractures, 6 cases of T-shaped fractures, and 2 cases of anterior column and posterior semi-transevere fractures. The interval from injury to operation was 6 to 24 days (mean, 8.6 days). The reduction quality was assessed by postoperative X-ray film and CT according to the criteria proposed by Matta. The hip joint function was assessed by the modified Merled'Aubigné-Postel score. Results: The operation time was 120-240 minutes (mean, 165 minutes) and the intraoperative blood loss was 600-1 400 mL (mean, 850 mL). All patients were followed up 18-30 months (mean, 24.5 months). There were 2 cases of the fat liquefaction of abdominal incisions, 3 cases of intraoperative injury of lateral femoral cutaneous nerve, 1 case of lower limb thrombosis, and 1 case of abdominal pain and hematuria due to intraoperative accidental bladder injury. According to the criteria proposed by Matta, the reduction quality rated as anatomic reduction in 12 cases, satisfactory reduction in 5 cases, and unsatisfied reduction in 1 case, and the satisfaction rate was 94.4%. All fractures healed with the healing time of 3-5 months (mean, 3.4 months). During follow-up, no internal fixator loosening, breakage, or fracture displacement occurred. At last follow-up, according to modified Merled'Aubigné-Postel score, hip joint functions rated as excellent in 11 cases, good in 4 cases, fair in 2 cases, and poor in 1 case. The excellent and good rate was 83.3%. Conclusion: Application of calcaneal plate bridge reconstruction plate via the modified Stoppa approach for the acetabular fracture involving the quadrilateral surface can obtain satisfactory effectiveness.

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.

Cerclage Clamping Using Cerclage Passer for Reduction of Anterior and Posterior Column Fracture / 대한정형외과학회잡지

PURPOSE: Both column and T-shaped acetabular fractures are frequently presented with difficulty in reduction. Incomplete reduction may cause traumatic arthritis in the hip joint, resulting in inferior clinical outcomes. The purpose of this study is to introduce our wiring technique and to report the clinical and radiological outcomes of such technique. MATERIALS AND METHODS: Eight patients who underwent our proposed technique for having acetabular fracture with displaced quadrilateral plate between March 2013 and December 2014 were enrolled. All patients were followed-up more than 1 year. The wire passer was set up from an anterolateral aspect of the iliac crest to the greater sciatic notch, between the abductor muscle and the periosteum. The quadrilateral plate of acetabular fracture was reduced with wiring. Internal fixation was added to the pelvic brim. An analysis of the clinical and radiological outcomes was performed. RESULTS: Reduction was performed within the 3 mm intra-articular step-off in all patients. The mean duration of union was 11.8 weeks (9-15 weeks). Five patients (62.5%) showed excellent results, and radiologically, three patients (37.5%) showed good results, and seven patients (87.5%) showed better than good results. CONCLUSION: The cerclage wiring fixation technique using a large cerclage passer instrument can be a useful and safe reduction method in some cases of acetabular fractures.

Effect of high ilioinguinal approach in the treatment of acetabular fractures involving quadrilateral plate / 局解手术学杂志

Objective To study effect of high ilioinguinal approach in treatment of acetabular fractures involving quadrilateral plate. Methods 28 cases of acetabular fractures were randomly divided into two groups according to admission time. 16 patients in the observation group were given high ilioinguinal approach operation. 12 patients in the control group were treated with traditional ilioinguinal approach op-eration. Operation condition, fracture reduction, the hip function recovery and postoperative complications of the two groups were compared. Results The amount of bleeding, the length of incision, operation time and operation conditions of the two groups had no significant differ-ence (P>0. 05). The satisfactory fracture reduction rate of observation group was higher than the control group (P0. 05). Conclusion High ilioinguinal approach can improve the fracture reduction effect, effectively improve the hip joint function in patients, and it has higher security which is a kind of ideal treatment approach for acetabular fractures involving quadrilateral plate.

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. .

Microanatomy and histological study of the fascicular group to deltoid muscle in axillary nerve at the level of quadrilateral zone / 中华创伤骨科杂志

Objective To observe and study the distribution and histological feature of the fascicular groups to deltoid muscle in axillary nerve at the level of quadrilateral zone. Methods 12 adult human cadavers (24 upper limbs)embalmed by formalin were used,, and microsurgical longitudinal contradissection of the axillary nerves by tracing their terminal branches were processed. At the level of quadrilateral zone,distrabution of the fscicular groups to deltoid muscle in the never trunk were recorded and their diameters were measured;Another 6 upper extremities (3 right and 3 left) of fresh-frozen human cadavers were obtained.Axillary nerves and their fascicular groups were exposured, and the segments at the level of qusdrilateral zone gotten, then histological cross section was done, acetycholinesterase (ACHE) stained with the method of Karnovsky Roots and myelin stained with the method of Loyezs. Defferent never fibres were distinguished under microscope and the fiber number was counted with IAS . Results At the level of quadrilateral zone,fasciculars were divided into two groups.The fascicular group of anterior branch to deltoid muscle was in the lateral of the nerve trunk . Its cross sectional area was (2.449?1.327)mm2 ,occupied 55.4%?9.3%of the axillary nerve trunk ;Its most fibers were motor fibers;The number of fibers is (2112?631), occupied 45.6 %?1.1%of all fibers of axillary nerve . Conclusions In the treatment of root avulsion of brachial plexus injury, selective suture donor nerve with the lateral fascicular group should be processed to repair the function of shoulder abduction,fibers loss would be reduced and rate of functional restoration improved .

Branching pattern and morphometry of the axillary nerve / 대한해부학회지

The branches of the axillary nerve and branching pattern of the posterior cord of the brachial plexus are not fully described in the anatomy textbooks. The branching pattern of the axillary nerve is needed to understand various symptoms of quadrilateral space syndrome. We studied on the branching patterns and variation of the axillary nerve and posterior cord of brachial plexus in 127 adult cadaver arms. The axillary, radial and thoracodorsal nerves arising from the posterior cord of the brachial plexus were classified into 4 types according to the position of the thoracodorsal nerve. The most common type (42.5%) was that the three nerves directly arising from the posterior cord. The thoracodorsal nerve branched from the axillary nerve in 27.6%. The posterior branches of the axillary nerve were divided into 6 types by the arising point of the nerve to teres minor muscle. The deltoid branch and lateral superior brachial cutaneous nerve were divided after branching of nerve to teres minor muscle in 50.8%. The lower subscapular nerve was branched from the axillary nerve in 70.9%. We measured the distances from the branching point of the axillary nerve to the inferior border of the subscapularis in the quadriangular space and from the coracoid process to the axillary nerve. The length and motor point of the teres minor muscle were measured. The relationship of the axillary nerve and posterior circumflex humeral artery was observed. The axillary nerve was always medial to the artery and their superoinferior relationship was variable. The clinical significance of the branching pattern of the axillary nerve was discussed.

Supracondylar Quadrilateral Displacement Osteotomy for Cubitus Varus Deformity: New Operative Technique / 대한정형외과학회잡지

Cubitus varus deformity is the late complication of the supracondylar fracture of humerus which is common in growing children. If the deformity is severe it causes tunctional problems as well as cosmetic ones necessitating conective osteotomy. Though many authors devised different methods of corrective osteotomy, the cosmetic results are not always satisfactory because of the development of the lazy S deformity hy the lateral prominence. Technically. the initial stahility of the osteotomy is also poor due to the poor contact of the osteotomy site. So we have devised a new quadrilateral displacement osteotomy to increase the initial stability of the osteotomy by creating a wedge on the osteotomy site & also to prevent the development of the lazy S deformity hy elimination of the Interal prominence. We treated 9 cases of cubitus varus deformity with the new quadrilateral displacement osteotomy. The correction technique was not difficult & the initial stahility of the osteotomy is rather good & the osteotomy is fixed by the conventional methods, & all of the cases were healed uneventfully. There developed no the lazy & deformity after osteotomy. We would like to report the details ot the supracondylnrquadrilateral displacemenl osteotomy.

Surgical Correction of the Blepharophimosis Syndorome

During the past decade the syndorome of blepharoptosis, blepharophimosis, epicanthus inversus and telecanthus(blepharophimosis syndrome)have become recognized as a distinct tetrad based upon clinical and hereditary characteristics. Early surgery is recommended to minimize being teased at school altough the final results surgical correction may be better in older children and in adults. We treated nine patients with epicanthus by Mustarde's quadrilateral flap or Y to V flap Medial canthal tendon is shortened by tucking for telecanthus. Blepharoptosis is corrected by frontalis suspension using preserved dura or preserved fascia lata as a sling material. We experience satisfactory results in nine patients by this technique without serious postoperative complications.