Músculo Esternal Bilateral, Descripción de un Caso e Implicancias Clínicas / Bilateral Sternal Muscle, Description of a Case and Clinical Implications

El músculo esternal corresponde a una variante muscular supernumeraria de la musculatura torácica, cuya descripción más antigua se remonta al año 1604. A lo largo de la historia ha sido denominado músculo "epiesternal", "preesternal", "recto torácico" o "recto esternal". Se ubica entre la fascia superficial y el músculo pectoral mayor, tiene una prevalencia de entre 3 % y 8 % en la población general, se presenta de forma unilateral o bilateral exhibiendo una alta variabilidad interracial y puede ser motivo de dilemas diagnósticos durante cirugías y exámenes de imagen. Disección en un cadáver adulto de sexo masculino. Se encontraron dos músculos esternales conectados superiormente por un tendón central. El músculo esternal derecho se extendía desde el manubrio esternal hasta el séptimo cartílago costal derecho. El músculo esternal izquierdo se extendía desde el manubrio esternal hasta el sexto cartílago costal izquierdo. Su inervación estaba dada por ramos cutáneos anteriores de los nervios intercostales y su vascularización por ramas perforantes provenientes de los vasos torácicos internos. El músculo esternal presenta una alta variabilidad morfológica y su prevalencia se ve influenciada por factores raciales. Conocer esta variación muscular enriquece la capacidad diagnóstica y quirúrgica reduciendo la posibilidad de iatrogenia.

SUMMARY: The sternal muscle corresponds to a supernumerary muscle variant of the thoracic musculature, whose oldest description dates to 1604. Throughout history it has been called the "episternal", "presternal", "rectus thoracis" or "rectus sternalis" muscle. It is located between the superficial fascia and the pectoralis major muscle, has a prevalence of between 3 % and 8 % in the general population, presents unilaterally or bilaterally, exhibits a high interracial variability and can be the cause of diagnostic dilemmas during surgery and imaging examinations. Dissection in an adult male cadaver. Two sternal muscles were found connected superiorly by a central tendon. The right sternal muscle extended from the sternal manubrium to the right seventh costal cartilage. The left sternal muscle extended from the sternal manubrium to the left sixth costal cartilage. The innervation was given by anterior cutaneous branches of the intercostal nerves and the vascularization by perforating branches coming from the internal thoracic vessels. The sternal muscle presents a high morphological variability and the prevalence is influenced by racial factors. Knowing this muscle variation enriches the diagnostic and surgical capacity, reducing the possibility of iatrogenesis.

Delayed periprosthetic seroma in a male Poland syndrome patient: A case report.

RATIONALE: Custom-made implant is an accepted treatment option for treatment of chest deformity in Poland syndrome. Unlike the raised concerns and awareness for the long-term consequences of breast implants, the long-term complications of customized implants for special purposes like Poland syndrome has not been reported in the literature. PATIENT CONCERNS: A 44-year-old male with Poland syndrome presented to our institution complaining of a large bulge and fluctuation on the right chest wall. This occurred after 14 years from the initial implant surgery for correction of chest wall deformity. Upon failure of resolution by multiple aspirations, workup was carried out under suspicion of implant associated malignancy. INTERVENTION: Total Capsulectomy and implant removal was done. OUTCOMES: Histology revealed chronic inflammation with fibrosis. Implant-associated malignancy was not found. He is being followed up with no signs of recurrence. LESSONS: For rare cases of implant insertion such as Poland syndrome, awareness of delayed complications and workups based on suspicion of implant-associated malignancy is needed. Surgeon awareness and patient education is required.

Prevalence of anomalous or ectopic insertion of pectoralis minor: a systematic review and meta-analysis of 4146 shoulders.

INTRODUCTION: The proximal insertion beyond coracoid process of pectoralis minor is considered as hidden culprit of rotator cuff disorders. The ectopic insertion is also associated with thoracic outlet syndrome. The current review was conducted to provide a comprehensive evidence-based assessment of the anatomical characteristics of ectopic insertion of pectoralis minor. MATERIALS AND METHODS: A through systematic search was conducted on the major electronic database, PubMed, EMBASE, Google Scholar and Journals of Anatomy, orthopedics, plastic surgery, sports medicine. The primary outcome was to measure the prevalence of ectopic insertion of pectoralis minor tendons. The data extraction was conducted for pooled estimation and metanalysis. RESULTS: A total of 25 studies were included for systematic review. The overall pooled estimate of ectopic insertion of Pectoralis Minor was 19.27% (95% CI 15-24%). The prevalence rate in dissected specimen was 21% (CI 15-28%) and in arthroscopic evaluation was 22% (95% CI 5-59%) which was marginally higher with wide confidence interval due small sample size. The prevalence rate in MRI and USG were 15 and 12%, because MRI and USG have almost similar sensitivity in the detection of anomalous insertion of Pectoralis Minor. The distribution of subtypes of anomalous or ectopic insertion based on Le Double classification was 34% for type I, 42 and 9% for Type III. The incidence of ectopic insertion of pectoralis minor was highest in Japanese population. The female and left side have slightly higher incidence at insignificant level. CONCLUSION: The preoperative MRI or at least USG evaluation of shoulder joint must be conducted for appropriate surgical planning, because the prevalence of ectopic insertion is around 20%. The preoperative detection of anomalous insertion of pectoralis minor can be crucial in minimizing the incidences of iatrogenic injuries of tendon or post-operative complications.

Concomitant aortic root and pectus deformity repair in Marfan syndrome patients.

The role of concomitant aortic and pectus repair in Marfan patients remains controversial. We present our surgical technique for concomitant aortic repair of aortic root pathology and pectus correction. The concomitant surgery can be safely achieved in Marfan patients, thus, avoiding the need for a risky second stage operation.

Nonsyndromic Congenital Absence of the Pectoralis Muscles.

The congenital absence of the pectoralis muscle is usually a manifestation of Poland syndrome. However, a nonsyndromic congenital absence of this muscle is rare, and such absences are usually partial and unilateral. A complete or bilateral absence is even rarer. Two young men presented to our outpatient clinic with incidentally noted unilateral flat chest walls. By chest computed tomography, they were diagnosed with a congenital unilateral absence of the pectoralis muscles. They did not show any functional disability of the arms. As the congenital absence of the pectoralis muscles is often associated with leukemia and genitourinary anomalies, it is advised that hematological testing and renal ultrasonography be performed, even in nonsyndromic cases.

Poland syndrome accompanied by internal iliac artery supply disruption sequence: a case report.

BACKGROUND: Poland syndrome is a congenital malformation characterized by ipsilateral hand and chest wall depression, including an absence or hypoplasia of the breast and pectoral muscles. These hypoplastic defects are reportedly caused by a subclavian artery supply disruption sequence. CASE PRESENTATION: A 45-year-old Japanese woman, an out-patient, underwent an emergency examination for intense left lower abdominal pain. Computed tomography images revealed a hydronephrotic left kidney and dilatation of the left ureter. No ureteral calculus or neoplasm was found. In addition, no abnormalities connected to her left abdominal pain were found. Nephritis was diagnosed based on the results of urine analysis, and a course of antibiotics was administered. Computed tomography images also revealed a history of breast reconstruction with a custom-made silicone implant in her right breast. The present case showed symptoms of Poland syndrome, which were absence of the sternal head of the right pectoralis major and asymmetrical malformation of the chest wall due to hypoplasia of the right rib cage. In addition to typical Poland syndrome symptoms, she had hypoplasia of her right kidney, hypoplasia of the right gluteus minimus muscle, right-sided pelvic hypoplasia, spinal curvature to the right, and a cystic mass in her right ovary. CONCLUSIONS: In the present case of Poland syndrome, computed tomography images revealed malformation of the chest wall, absence of the pectoral muscle, and hypoplasia of a left kidney. Unilateral visceral hypoplasia is reported to be caused by a subclavian artery supply disruption sequence that occurs around 7 to 8 weeks of gestation. The present case can be considered a rare atypical phenotype of Poland syndrome with possible subclavian artery supply disruption sequence with internal iliac artery supply disruption.

The value of full-body skin examination: Poland syndrome diagnosed as an incidental finding.

Poland syndrome is a rare congenital disorder characterized by agenesis of the pectoralis major muscle. It is generally unilateral, right-sided, and can be associated with a myriad of thoracic and upper limb defects. Knowledge of this disorder can lead the astute clinician to prompt diagnosis and referral to surgical specialists for further workup. Surgery is often performed for either esthetic or functional concerns.

Serie de Casos: Síndrome de Poland Completo vs. Incompleto. Resolución Quirúrgica / Case Series: Poland Syndrome Complete vs Incomplete. Surgical Resolution

INTRODUCCIÓN: El síndrome de Poland es una enfermedad congénita polimalformativa extremadamente rara, su etiología es aún desconocida, afectando principalmente el desarrollo del músculo pectoral mayor; se acompañan frecuentemente de malformaciones de la mano, mama, complejo areola-pezón, pectoral menor ipsilateral y otras malformaciones asociadas. Su diagnóstico se basa en un correcto examen clínico junto con una tomografía axial computarizada con reconstrucción en 3D. El tratamiento quirúrgico final es individualizado y dependerá de la existencia de una o más malformaciones. CASOS CLÍNICOS: Se trató de cuatro pacientes con cuadro clínico compatible con síndrome de Poland, siendo común el subdesarrollo o ausencia del músculo pectoral mayor. EVOLUCIÓN: Se realizó a cada paciente una tomografía axial computarizada con reconstrucción en 3D para confirmar su diagnóstico y realizar un tratamiento quirúrgico según la necesidad de cada paciente, después del procedimiento se dio seguimiento a los pacientes con una respuesta favorable y sin complicaciones. CONCLUSIONES: El síndrome de Poland se caracteriza por un cuadro clínico variable, con la ausencia o subdesarrollo del músculo pectoral mayor, el tratamiento quirurgico fue personalizado para cada paciente. Las técnicas quirúrgicas incluyeron reconstrucción de la pared torácica mediante osteosíntesis en los casos graves independientemente del sexo del paciente; rotación de colgajos del músculo dorsal ancho, colocación de expansores tisulares y prótesis mamarias en el caso de las pacientes femeninas y colocación de prótesis preformadas mediante estereolitografía en el caso de los pacientes masculinos.

BACKGROUND: The Poland syndrome is an extremely rare polymalformative congenital disease, the etiology is still unknown, mainly affecting the development of the pectoralis major muscle; they are frequently accompanied by malformations of the hand, breast, nipple-areola complex, ipsilateral minor pectoral and other associated malformations. The diagnosis is based on a correct clinical examination together with a computerized axial tomography with 3D reconstruction. The final surgical treatment is individualized and will depend on the existence of one or more malformations. CASE REPORTS: Four patients with a clinical picture compatible with the Poland syndrome were treated, with underdevelopment or absence of the pectoralis major muscle being common. EVOLUTION: Each patient underwent a computerized axial tomography with 3D reconstruction to confirm their diagnosis and perform a surgical treatment according to the needs of each patient; after the procedure, patients were followed up with a favorable response and without complications. CONCLUSIONS: The Poland syndrome is characterized by a variable clinical picture, with the absence or underdevelopment of the pectoralis major muscle, the surgical treatment was customized for each patient. Surgical techniques included reconstruction of the chest wall by osteosynthesis in severe cases regardless of the sex of the patient; rotation of flaps of the latissimus dorsi muscle, placement of tissue expanders and mammary prosthesis in the case of female patients and placement of preformed prostheses by stereolithography in the case male patients.

Controversies in Poland Syndrome: Alternative Diagnoses in Patients With Congenital Pectoral Muscle Deficiency.

PURPOSE: Poland syndrome was first described as a deficiency of the pectoral muscle with ipsilateral symbrachydactyly. Currently, numerous case reports describe variations of Poland syndrome in which pectoral muscle deficiency is often used as the only defining criterion. However, more syndromes can present with pectoral muscle deficiency. The aim of this review is to illustrate the diversity of the phenotypic spectrum of Poland syndrome and to create more awareness for alternative diagnoses in pectoral muscle deficiency. METHODS: A systematic literature search was performed. Articles containing phenotypical descriptions of Poland syndrome were included. Data extraction included number of patients, sex, familial occurrence, and the definition of Poland syndrome used. In addition, hand deformities, thoracic deformities, and other deformities in each patient were recorded. Alternative syndrome diagnoses were identified in patients with a combination of hand, thorax, and other deformities. RESULTS: One hundred-and-thirty-six articles were included, describing 627 patients. Ten different definitions of Poland syndrome were utilized. In 58% of the cases, an upper extremity deformity was found and 43% of the cases had an associated deformity. Classic Poland syndrome was seen in 29%. Fifty-seven percent of the patients with a pectoral malformation, a hand malformation, and another deformity had at least 1feature that matched an alternative syndrome. CONCLUSIONS: Pectoral muscle hypoplasia is not distinctive for Poland syndrome alone but is also present in syndromes with other associated anomalies with a recognized genetic cause. Therefore, in patients with an atypical phenotype, we recommend considering other diagnoses and/or syndromes before diagnosing a patient with Poland syndrome. This can prevent diagnostic and prognostic errors. CLINICAL RELEVANCE: Differentiating Poland syndrome from the alternative diagnoses has serious consequences for the patient and their family in terms of inheritance and possible related anomalies.

Modified Ravitch Procedure for Left Poland Syndrome Combined With Pectus Excavatum.

Poland Syndrome is a rare disease with an incidence of 1 in 30,000. This disease is characterized by agenesis of the pectoralis major, hypoplasia of mammarian tissue and the nipple complex, and limb abnormalities. The severe form of this disease can be associated with rib and sternal malformations like pectus excavatum. A 19-year-old man with severe Poland syndrome with cardiac extrasystoles and restrictive ventilation as shown by a spirometry test is presented. A total sternal reconstruction with partial osteotomies and bilateral resection of cartilage was performed. The sternum was stabilized with underlying titanium bars and clips. The cosmetic result was satisfactory.

Abordagem vertical do peitoral maior nas inclusões mamárias / Vertical approach to the pectoralis major in breast implant insertion

INTRODUÇÃO: O trabalho demonstra uma abordagem alternativa para ampliarmos a escolha do espaço retromuscular e evitarmos os efeitos indesejáveis nas inclusões de próteses mamárias neste plano. MÉTODOS: Foram avaliados 328 pacientes do sexo feminino, com idade entre 17 e 62 anos, com queixa de hipomastia e certo grau de ptose mamária bilateral. Todas as pacientes foram submetidas à inclusão de próteses bilaterais e incisão vertical no músculo peitoral maior. A avaliação foi realizada com um período mínimo de 6 meses. RESULTADOS: A tática cirúrgica de incisão vertical no músculo peitoral maior nos permitiu ampliar a indicação do espaço retromuscular nas cirurgias de inclusão de próteses de mamas, conseguindo alcançar com êxito o posicionamento adequado da prótese e do tecido mamário, evitando cicatrizes adicionais. CONCLUSÕES: A técnica mostrou-se eficaz na sua propositura, evitando cicatrizes e o efeito de dupla-bolha e ampliando a indicação do espaço retromuscular.

INTRODUCTION: This study demonstrates an alternative method to access the retromuscular space and avoid undesirable effects caused by breast implant insertion in this space. METHODS: We evaluated 328 female patients, aged 17 to 62 years, with complaints of micromastia and bilateral ptosis. All patients underwent insertion of bilateral implants using a vertical incision in the pectoralis major. Follow-up was performed for at least 6 months. RESULTS: The technique of vertical incision in the pectoralis major increases the options for access to the retromuscular space in breast implant insertion. This method successfully achieves appropriate positioning of the implant and avoids additional scars. CONCLUSIONS: The technique proved to be effective, avoiding scars and the double-bubble effect, and increases the options for access to the retromuscular space.

Arthroscopic stabilisation of an acute acromioclavicular dislocation grade III in a patient with ectopic insertion of the pectoralis minor: technical considerations.

The different approaches used in arthroscopic stabilisation of the acromioclavicular joint are well known. However, and despite a great incidence of ectopic pectoralis minor insertion, an alternative choice for the use of arthroscopic portal has not being sufficiently described. Here, we describe a case of acute acromioclavicular dislocation grade III. The arthroscopic stabilisation was achieved using the TightRope (Arthrex, Naples, USA) implant. Through this technique, the approach to the articular portion of the coracoid process can be made intra-articularly or from the subacromial space. We accessed intra-articularly, by opening the rotator interval to reach the coracoid process from the joint cavity. After opening the rotator interval, an ectopic insertion of the pectoralis minor was observed. The choice of approach of the coracoid process from the subacromial space would have complicated the intervention, making it necessary to sever the ectopic tendon to complete the technique, lengthening the surgical time and increasing the chance of complications. For this reason, the use of a standard posterior portal providing intra-articular arthroscopic access through the rotator interval is recommended since the aforementioned anatomical variation is not infrequent. Level of evidence Therapeutic studies-investigating the results of treatment, Level V.

Bipolar Latissimus Dorsi Transfer for Restoration of Pectoralis Major Function in Poland Syndrome.

BACKGROUND: Poland syndrome typically presents as a unilateral congenital complete or partial absence of the pectoralis major muscle, variably with other associated anomalies. Reconstruction of the defect typically concentrates on aesthetic restoration with functional outcomes being unsuccessful or limited. We present an innovative means of true muscle transfer that provided functional benefit to increase upper extremity strength. CASE REPORT: A 16-year-old adolescent boy with Poland syndrome manifesting as left pectoralis major muscle agenesis wished to undergo functional reconstruction. He wanted to play on his high school football team, but could not meet the minimum weightlifting requirements. An ipsilateral latissimus dorsi muscle bipolar functional transfer was done with bone-anchored inset into the sternum and humerus so that muscle flexion would replace the absent pectoralis major. A progressive weight training program was then instituted postoperatively. At 9 months, a significant increase in left upper extremity strength was confirmed. The patient ultimately was able to surpass the weightlifting requirements for his high school football team, and joined the team. CONCLUSIONS: Our highlighted procedure restored functional outcome using both plastic surgical principles and orthopedic techniques for muscle and tendon repair: bipolar muscle transfer and load-bearing muscle inset. Heretofore, transfer of the latissimus for provision of pectoralis major function has not been reported. Functional reconstruction was possible due to stable, bipolar muscle transfer with load-bearing muscle attachments into cortical bone of the anterior sternum and anteromedial aspect of the humerus. The techniques described should be within the skill set of most plastic surgeons, so that functional restoration for those with Poland syndrome is possible and accessible.

The Chondroepitrochlearis Muscle: A Rare Cause of Axillary Vein Thrombosis and Lymphedema.

The chondroepitrochlearis muscle is a rare anomaly of the pectoralis major crossing over the neurovascular bundle in the axilla. Often associated with other supernumerary muscles like the arch of Langer, it has been reported in the past as a cause of restriction of arm abduction, cosmetic defects and compression of the ulnary nerve. This case report describes the first known vascular complication due to a chondroepitrochlearis muscle, causing intermittent compression of the axillary vein and thrombosis, associated with pain, upper limb lymphedema, and impaired movements. The diagnosis was suspected from the medical history and confirmed by palpation and dynamic ultrasonography. Surgery was performed to divide the muscle slip with the help of lymphofluoroscopy to prevent damage to the lymphatic structures. Pain and impairment of movement disappeared within a few days after surgery and lymphedema decreased significantly.

Pectoralis minor tendon in the rotator interval: arthroscopic, magnetic resonance imaging findings, and clinical significance.

BACKGROUND: Although insertional variation of the pectoralis minor on the rotator interval has been reported, more detailed characteristics as seen on magnetic resonance imaging (MRI) or arthroscopy and clinical significance have been rarely discussed. This study evaluated the prevalence of tendinous insertion of the pectoralis minor by arthroscopy and diagnostic performances of MRI and suggests its clinical implication in rotator cuff repair. MATERIALS AND METHODS: The study prospectively recruited 99 consecutive patients for arthroscopic exploration of pectoralis minor insertion. Preoperative MRIs were evaluated to detect tendinous insertion of the pectoralis minor by 2 independent, blinded observers, and these results were correlated with arthroscopy as the gold standard. During arthroscopy, the effect of this variation on supraspinatus tendon tear and repair was evaluated. RESULTS: Tendinous insertion of the pectoralis minor was found in 11 patients (11%) at arthroscopy. The sensitivity and specificity of MRI were 64% (95% confidence interval [CI], 31%-89%), the specificity was 82% (95% CI, 72%-89%), and the accuracy was 80% (95% CI, 72%-88%). Intraobserver and interobserver reliability tests showed moderate agreements. In 7 patients, it tethered the retracted supraspinatus tendon from mobilization and gave rise to tension on the repaired cuff, which warranted complete resection of the pectoralis minor tendon for a tension-free cuff repair. CONCLUSIONS: Tendinous insertion of the pectoralis minor existed with 11% prevalence in our series and could be preoperatively detected on MRI. During arthroscopic rotator cuff repair, it can be an obstacle to supraspinatus tendon mobilization and repair.

Eight patients with multiple bilateral thoracic anomalies: a new syndrome or bilateral Poland's syndrome?

BACKGROUND: Poland's syndrome is a rare congenital anomaly characterized by an absence or hypoplasia of the greater and smaller pectoral muscles, breast or nipple anomalies, hypoplasia of subcutaneous tissue, chest wall deformities, pectoral and axillary alopecia, and hand anomalies. Poland's syndrome is usually unilateral. We present 8 patients with multiple bilateral thoracic anomalies. METHODS: Eight patients were admitted to our clinic with an abnormal thoracic appearance and restriction of shoulder mobilization. Bilateral multiple muscles, including the greater pectoral muscle and some other thoracic muscles, could not be palpated during physical examination. All patients were evaluated, with a preliminary diagnosis of bilateral Poland's syndrome. RESULTS: All patients exhibited partial or complete absence of bilateral greater pectoral muscles, absence or hypoplasia of bilateral smaller pectoral muscles, bilateral shoulder protrusion to the front, limited abduction of both shoulders, absence or hypoplasia of other bilateral thoracic muscles (serratus anterior, latissimus dorsi, and trapezius muscles), and scapula alata. CONCLUSIONS: All patients with Poland's syndrome have unilateral hypoplasia or absence of the greater pectoral muscle as the main feature. Poland's syndrome is routinely described as a unilateral syndrome. Cases of Poland's syndrome are typically sporadic. Our patients had different additional bilateral anomalies. In particular, the main problems our patients had were the position of the shoulders and limited abduction of both upper extremities. In contrast to patients with Poland's syndrome, half of our cases were familial. We consider our patients important examples in that they either present a new syndrome or show that Poland's syndrome can be bilateral.

Thoracic outlet and pectoralis minor syndromes.

Compression of the neurovascular bundle to the upper extremity can occur above or below the clavicle; thoracic outlet syndrome (TOS) is above the clavicle and pectoralis minor syndrome is below. More than 90% of cases involve the brachial plexus, 5% involve venous obstruction, and 1% are associate with arterial obstruction. The clinical presentation, including symptoms, physical examination, pathology, etiology, and treatment differences among neurogenic, venous, and arterial TOS syndromes. This review details the diagnostic testing required to differentiate among the associated conditions and recommends appropriate medical or surgical treatment for each compression syndrome. The long-term outcomes of patients with TOS and pectoralis minor syndrome also vary and depend on duration of symptoms before initiation of physical therapy and surgical intervention. Overall, it can be expected that >80% of patients with these compression syndromes can experience functional improvement of their upper extremity; higher for arterial and venous TOS than for neurogenic compression.