Figure 1 - uploaded by George Robert Matcuk
Content may be subject to copyright.
Normal anatomy of the pectoralis major muscle. (a) The pectoralis major consists of a clavicular head (CH) and several sternal head segments (s1-s6). The proximal clavicular head attaches to the medial half of the clavicle, whereas the sternal head segments attach to the sternum, second to sixth costal cartilages, and aponeurosis of the external oblique muscle. The clavicular and sternal head tendons combine to form a U-shaped tendon laterally; this tendon consists of an anterior layer (AT) and posterior layer (PT). This common tendon inserts onto the humerus at the lateral lip of the bicipital groove. (b) Coronal T1-weighted MR image shows the clavicular (C) and sternal (S) heads and the deltopectoral groove (arrow). (c) Axial proton-density-weighted fat-saturated MR image shows the pectoralis major tendon attaching to the humerus (arrowheads). The cephalic vein is seen within the deltopectoral groove (arrow), and the pectoralis major muscle belly (PM) is seen in relation to the long head of the biceps tendon (LHB); short head of the biceps tendon (SHB); and deltoid (D), coracobrachialis (CB), pectoralis minor (PMin), teres major (TM), and serratus anterior (SA) muscles. 

Normal anatomy of the pectoralis major muscle. (a) The pectoralis major consists of a clavicular head (CH) and several sternal head segments (s1-s6). The proximal clavicular head attaches to the medial half of the clavicle, whereas the sternal head segments attach to the sternum, second to sixth costal cartilages, and aponeurosis of the external oblique muscle. The clavicular and sternal head tendons combine to form a U-shaped tendon laterally; this tendon consists of an anterior layer (AT) and posterior layer (PT). This common tendon inserts onto the humerus at the lateral lip of the bicipital groove. (b) Coronal T1-weighted MR image shows the clavicular (C) and sternal (S) heads and the deltopectoral groove (arrow). (c) Axial proton-density-weighted fat-saturated MR image shows the pectoralis major tendon attaching to the humerus (arrowheads). The cephalic vein is seen within the deltopectoral groove (arrow), and the pectoralis major muscle belly (PM) is seen in relation to the long head of the biceps tendon (LHB); short head of the biceps tendon (SHB); and deltoid (D), coracobrachialis (CB), pectoralis minor (PMin), teres major (TM), and serratus anterior (SA) muscles. 

Source publication
Article
Full-text available
During the past 2 decades, the frequency of pectoralis major muscle injuries has increased in association with the increased popularity of bench press exercises. Injury of the pectoralis major can occur at the muscle origin, muscle belly, musculotendinous junction, intratendinous region, and/or humeral insertion—with or without bone avulsion. The e...

Contexts in source publication

Context 1
... pectoralis major muscle consists of clavicular and sternal heads (Fig 1) and variable contribu- tions from the costal attachments inferior to the sternum, which are sometimes considered to be an "abdominal" head. The clavicular head is the most superior unit of the pectoralis major and is a single architectural segment that cannot be further divided. The clavicular head is within the clavicular lamina and arises from the medial half of the clavicle. In contrast to the clavicular head, the sternal head can be subdivided into six to seven segments along individual fascial planes. The sternal head segments are within the ab- dominal and manubrial laminae and arise from the anterior manubrium, sternum, and second to sixth costal cartilages. The sternal head consti- tutes approximately 80% of the pectoralis major volume and is more commonly torn (2). The muscle fibers of the clavicular head and sternal heads insert into a common tendon mea- suring approximately 5 cm in mediolateral length and 4 cm in craniocaudal width (2). The com- mon tendon of the pectoralis major has a char- acteristic U shape, with anterior and posterior layers that are continuous inferiorly (Fig 2) (2). The anterior tendon layer consists of the clavicu- lar head and the three to five most superior ster- nal segments, whereas the posterior tendon layer consists of the two to three most inferior sternal segments. According to recent cadaveric dissec- tion study data, the individual sternal segments overlap each other and form a pattern similar to that of an unfolded Chinese fan (2). The two lay- ers of the tendon fuse and traverse anterior to the coracobrachialis muscle and the tendons of the short and long heads of the biceps brachii before inserting at the lateral lip of the bicipital groove onto the proximal humerus. The attachment of the pectoralis major tendon onto the humerus occurs at the same level that the latissimus dorsi, teres major, and lateral head of the triceps muscles attach to the ...
Context 2
... of the pectoralis major can also be categorized according to their location: muscle origin or belly, musculotendinous junction, intratendinous region, humeral insertion, or area of bone avulsion at the humeral attachment ( Fig 14). Patients with injuries at the muscle origin or belly, including contusions and strains, usually are treated conservatively. Although injuries that occur at the musculotendinous junction, intratendinous region, or humeral insertion are difficult to dif- ferentiate on images, they are assigned to the same category because they are managed essentially the same: with suturing or bone-tunneling techniques. The majority of pectoralis major injuries occur at the humeral insertion (59%) and musculotendi- nous junction (24%) (24). Injuries involving bone avulsion at the humeral attachment are differenti- ated from those that occur at the other locations because patients with these injuries may benefit more from a primary fracture ...
Context 3
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 4
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 5
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 6
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 7
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 8
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 9
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 10
... repair of tears, as compared with nonsurgical management, has been shown to restore the patient's function to a near-baseline level (24). A distinction is made between acute and chronic tears because with chronic inju- ries, a delay in surgery of a few weeks to a few months is associated with the development of adhesions, muscular contraction, atrophy, and worsened functional outcome (5,25,(34)(35)(36)(37)(38)(39). MR imaging findings will parallel the patho- logic changes, showing hemorrhage and edema within 1-2 weeks after an acute pectoralis major injury but later showing the development of fi- brosis and scarring with chronic injury (40,41). Although according to the current injury clas- sification system, the distinction between acute and chronic tears is based on the time of the injury in relation to a 6-week interval, the find- ings of a number of authors suggest that a dis- tinction could be made on the basis of an even earlier time interval. Some authors have noted tendon retraction as early as 3 weeks after the injury (4). Other authors have found that the administration of treatment within 3 weeks after the injury resulted in better outcomes (25,34). Surgical treatments of acute tendon tears include bone trough, suture-anchoring, and cortical button techniques (Fig 19) (24). With chronic tears, muscle retraction may prevent primary repair; in such cases, reconstruction is performed by using grafts from the Achilles tendon, bone-patellar tendon, hamstrings, or fascia lata ...
Context 11
... the different types of anomalies that can involve the pectoralis major, trauma-related tears have increased in frequency during the past 20 years, with indirect injury being the most common cause (83% of all cases) accord- ing to a 2012 systematic review of 365 pecto- ralis major injuries reported between the years 1822 and 2010 (1). This trend is due in large part to the increase in sports-related injuries, with 48% of these injuries resulting from bench pressing. Other physically demanding activities that have been reported as a cause of pectoralis major injuries include rugby, wrestling, jujitsu, gymnastics, and boxing (4,24,25). Pectoralis major injuries occur when there is an overloaded and extended humerus, such as during the ec- centric contraction portion of the bench press exercise, when the muscle fibers of the lower sternal heads are disproportionately stressed (5). These injuries are commonly seen in active male individuals aged 20-40 years (1). Symptoms of pectoralis major tears include immediate pain, weakness with arm adduction, thinning of the axillary fold, ecchymosis of the anterior and lateral axillae, and a palpable defect, depending on the severity of injury (Fig 10) ...
Context 12
... pectoralis major muscle consists of clavicular and sternal heads (Fig 1) and variable contribu- tions from the costal attachments inferior to the sternum, which are sometimes considered to be an "abdominal" head. The clavicular head is the most superior unit of the pectoralis major and is a single architectural segment that cannot be further divided. The clavicular head is within the clavicular lamina and arises from the medial half of the clavicle. In contrast to the clavicular head, the sternal head can be subdivided into six to seven segments along individual fascial planes. The sternal head segments are within the ab- dominal and manubrial laminae and arise from the anterior manubrium, sternum, and second to sixth costal cartilages. The sternal head consti- tutes approximately 80% of the pectoralis major volume and is more commonly torn (2). The muscle fibers of the clavicular head and sternal heads insert into a common tendon mea- suring approximately 5 cm in mediolateral length and 4 cm in craniocaudal width (2). The com- mon tendon of the pectoralis major has a char- acteristic U shape, with anterior and posterior layers that are continuous inferiorly (Fig 2) (2). The anterior tendon layer consists of the clavicu- lar head and the three to five most superior ster- nal segments, whereas the posterior tendon layer consists of the two to three most inferior sternal segments. According to recent cadaveric dissec- tion study data, the individual sternal segments overlap each other and form a pattern similar to that of an unfolded Chinese fan (2). The two lay- ers of the tendon fuse and traverse anterior to the coracobrachialis muscle and the tendons of the short and long heads of the biceps brachii before inserting at the lateral lip of the bicipital groove onto the proximal humerus. The attachment of the pectoralis major tendon onto the humerus occurs at the same level that the latissimus dorsi, teres major, and lateral head of the triceps muscles attach to the ...
Context 13
... of the pectoralis major can also be categorized according to their location: muscle origin or belly, musculotendinous junction, intratendinous region, humeral insertion, or area of bone avulsion at the humeral attachment ( Fig 14). Patients with injuries at the muscle origin or belly, including contusions and strains, usually are treated conservatively. Although injuries that occur at the musculotendinous junction, intratendinous region, or humeral insertion are difficult to dif- ferentiate on images, they are assigned to the same category because they are managed essentially the same: with suturing or bone-tunneling techniques. The majority of pectoralis major injuries occur at the humeral insertion (59%) and musculotendi- nous junction (24%) (24). Injuries involving bone avulsion at the humeral attachment are differenti- ated from those that occur at the other locations because patients with these injuries may benefit more from a primary fracture ...
Context 14
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 15
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 16
... ( Note.-FOV = field of view, TE = echo time, TR = repetition time. A normal pectoralis major tendon should have uniform low signal intensity at MR imaging. Similar to findings at US, tears of the pectoralis major tendon seen at MR imaging exhibit differ- ent degrees of tendon abnormality, depending on the degree of injury. A grade I strain of the muscle belly will have feathery intramuscular fluid-sensi- tive signal intensity, which represents edema and/ or hemorrhage (Fig 11). A grade II injury will appear as a partial tear with an intramuscular he- matoma (Fig 12). A grade III injury will appear as a complete tear with possible retraction (Fig 13). In particular, with a partial tear involving only the posterior sternal segments, the anterior clavicular head and tendon will be intact, with the long head of the biceps tendon in place. With complete tears involving both the sternal head and the clavicular head, however, there will be disruption of the en- tire tendon, with anterior displacement of the long head of the biceps ...
Context 17
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 18
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 19
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 20
... extent of injury along the tendon is an- other factor that may have clinical ramifications. The extent of the tear can be described in terms of the thickness and width of tendon involvement; Figure 11. Grade I pectoralis major muscle strain. Axial STIR MR image (left) and corresponding illustration (right) show edema (arrowhead) in the pecto- ralis major muscle belly (PM), consistent with a grade I strain. The pectoralis major tendon (arrow) is intact. this is similar to the way rotator cuff tears of the shoulder are described. The thickness of the tear is the degree of anteroposterior involvement of the two layers of the tendon, and the width of the tear is the craniocaudal extent of each of the tendon layers (Fig 15). With use of this scheme, a partial- thickness partial-width injury is a tear involving the partial craniocaudal extent of a single tendon layer. A partial-thickness full-width injury is a tear involving the entire craniocaudal extent of a single layer of the tendon. A full-thickness partial-width injury is a tear of both tendon layers that involves the partial craniocaudal extent of one of the layers. A full-thickness full-width injury is a complete tear of both tendon layers that results in the disruption of the entire tendon (Figs 16-18) (1). Tears of the tendon occur in a predictable sequential pattern, with the most inferior segment of the sternal head (segment 7) rupturing first, as the greatest strain is placed at this location during eccentric contrac- tion with the humerus in extension. In this setting, when there is a partial tear of only the posterior layer, the injury is classified as a partial-thickness partial-width tear. With increasing mechanical load, the remaining inferior sternal segments (segments 6 and 5) of the entire posterior layer will rupture (33). The resultant complete tear of the entire posterior layer of the tendon is classi- fied as a partial-thickness full-width injury. As the mechanical load increases, the anterior layer of the Figure 14. Illustrations of pectoralis major injuries categorized, according to injury location, into those for which surgical treatment is required and those for which nonsurgical treatment is required. "Nonsurgical" injuries at the origin (a) and muscle belly (b) usu- ally are the result of direct trauma, and the affected patient will benefit from conservative management. "Surgical" injuries at the musculotendinous junction (c), intratendinous region (d), and humeral insertion (e) may be difficult to differentiate from each other on images; however, they are classified and addressed similarly: with suturing or bone anchor techniques. (f) Humeral bone avulsion, another surgical injury, is addressed with fixation of the fracture ...
Context 21
... repair of tears, as compared with nonsurgical management, has been shown to restore the patient's function to a near-baseline level (24). A distinction is made between acute and chronic tears because with chronic inju- ries, a delay in surgery of a few weeks to a few months is associated with the development of adhesions, muscular contraction, atrophy, and worsened functional outcome (5,25,(34)(35)(36)(37)(38)(39). MR imaging findings will parallel the patho- logic changes, showing hemorrhage and edema within 1-2 weeks after an acute pectoralis major injury but later showing the development of fi- brosis and scarring with chronic injury (40,41). Although according to the current injury clas- sification system, the distinction between acute and chronic tears is based on the time of the injury in relation to a 6-week interval, the find- ings of a number of authors suggest that a dis- tinction could be made on the basis of an even earlier time interval. Some authors have noted tendon retraction as early as 3 weeks after the injury (4). Other authors have found that the administration of treatment within 3 weeks after the injury resulted in better outcomes (25,34). Surgical treatments of acute tendon tears include bone trough, suture-anchoring, and cortical button techniques (Fig 19) (24). With chronic tears, muscle retraction may prevent primary repair; in such cases, reconstruction is performed by using grafts from the Achilles tendon, bone-patellar tendon, hamstrings, or fascia lata ...
Context 22
... the different types of anomalies that can involve the pectoralis major, trauma-related tears have increased in frequency during the past 20 years, with indirect injury being the most common cause (83% of all cases) accord- ing to a 2012 systematic review of 365 pecto- ralis major injuries reported between the years 1822 and 2010 (1). This trend is due in large part to the increase in sports-related injuries, with 48% of these injuries resulting from bench pressing. Other physically demanding activities that have been reported as a cause of pectoralis major injuries include rugby, wrestling, jujitsu, gymnastics, and boxing (4,24,25). Pectoralis major injuries occur when there is an overloaded and extended humerus, such as during the ec- centric contraction portion of the bench press exercise, when the muscle fibers of the lower sternal heads are disproportionately stressed (5). These injuries are commonly seen in active male individuals aged 20-40 years (1). Symptoms of pectoralis major tears include immediate pain, weakness with arm adduction, thinning of the axillary fold, ecchymosis of the anterior and lateral axillae, and a palpable defect, depending on the severity of injury (Fig 10) ...

Citations

... In this study, one patient who underwent implant breast augmentation 6 months after autologous fat grafting allowed us to access a human sample of fat grafts. Because there is no fat on the surface of (retromammary) or beneath (retropectoral) the pectoralismajor under normal conditions (27,28), the retromammary and retropectoral spaces were selected to be sampled in this study. Therefore, we harvested the surviving faton the surface of and beneath the pectoralis major. ...
Article
Full-text available
Background Autologous fat transfer is common in breast augmentationor reconstruction. However, AFG recipient site in the breast for fat grafting has not been carefully investigated. Methods Forty female patients requiring breast augmentation with fat grafting were randomly assigned into two groups. The retromammary group received 2/3 fat into the retromammary space and the other 1/3 into the subcutaneous and retropectoral planes. The retropectoral group received 2/3 fat into the retropectoral plane and the other 1/3 into the subcutaneous and retromammary planes. The fat grafting result at 6 months was assessed by 3D laser surface scanning and then ultrasound. Any complications were recorded during follow-up. Samples from a patient who underwent fat grafting for 6 months was obtained and histological examination was conducted. Results No significant difference in the retention rate after 6 months was observed between the two groups (retromammary group: 35.9% ± 6.6; retropectoral group: 39.3% ± 5.1, p = 0.1076). The retromammary grouphad a higher incidence of oil cyst formation than the retropectoral group. Histological examination showed that there were more oil cysts and mac2 positive macrophage infiltration in the fat cells in retromammary group, while retropectoral group had more small-size adipocytes. Conclusion Although fat grafting into the retropectoral plane did not provide a superior fat graft retention rate, it did lower the incidence of complications. The retropectoral space show great potential to become a favorable recipient site.
... Describing imaging patterns involving PM tears in imaging studies may improve management and lead to improved functional outcomes. Notably, MR imaging features of PM tendon and MTJ tears have been previously described [15]; One-sided PM lesion during exercises such as bench-press suggests the effect of weightlifting at subject's individual maximal load; however, findings of the contralateral noninjured side and potential significance remain unknown. ...
Article
Objective: To evaluate magnetic resonance imaging (MRI) features of the contralateral side in weightlifting athletes with pectoralis major (PM) tears. We hypothesized that MRI of the non-injured side may present increased pectoralis major tendon (PMT) length and thickness and greater pectoralis major muscle (PMM) volume and cross-sectional area when compared with the control group. Methods: We retrospectively identified MRI cases with unilateral PM injury and reviewed imaging findings of the contralateral side. Also, we evaluated MRI from ten asymptomatic control weightlifting athletes, with PM imaging from both sides. Two musculoskeletal radiologists independently reviewed MRI and measured PMT length, PMT thickness, PMM volume (PMM-vol) and PMM cross-sectional area (PMM-CSA), as well as humeral shaft cross-sectional area (Hum-CSA) and the ratio between PMM-CSA and Hum-CSA (PMM-CSA/Hum-CSA). Data were compared between the non-injured side and controls. The MRI protocol from both groups was the same and included T1 FSE and T2 FATSAT axial, coronal, and sagittal images, one side at a time. Results: We identified 36 male subjects with unilateral PM injury with mean age 35.7 ± 8 years and 10 age- and gender-matched controls (p = 0.45). A total of 36 PM MRI with non-injured PM and 20 PM MRI studies were included in this study. PMT length and PMT thickness were significantly higher in contralateral PM injury versus control subjects (both P < 0.001). Also, PM-CSA and Hum-CSA were greater in the contralateral PM injury group (P = 0.032 and P < 0.001, respectively). PMT thickness > 2.95 mm had 80.6% sensitivity and 90.0% specificity to differentiate the non-injured PM group from controls. Conclusion: Non-injured side MR imaging of patients with previous contralateral PM lesion demonstrates greater PMT thickness and length as well as PM-CSA and Hum-CSA than controls.
... When scanning the tendon of the PM, the arm of the patient should be externally rotated in the same posture as scanning the SSC tendon. The transducer should be moved down along the bicipital groove from the level of the SSC tendon to locate the tendon of the PM, which is visualized as an echogenic linear structure superficial to the muscle belly of the biceps and attached onto the lateral lip of the bicipital groove [18] (Figure 5). ...
... The muscle fibers fuse to form a common tendon, which travels laterally and runs anterior to the biceps and coracobrachialis muscle belly. It finally inserts into the lateral lip of the bicipital groove [17,18]. The common tendon of the PM has a characteristic U shape with anterior and posterior layers that are inferiorly continuous [19]. ...
Article
Full-text available
The long head of the biceps tendon (LHBT) has been recognized as an important generator of anterior shoulder pain, causing a significant reduction in the shoulder flexion range. Various tendinous and ligamentous structures form the anchoring apparatus of the LHBT along its course to maintain its appropriate location during shoulder movements, including the coracohumeral ligament (CHL), superior glenohumeral ligament (SGHL), subscapularis (SSC) tendon and supraspinatus (SSP) tendon as well as the less recognized tendons of pectoralis major (PM), latissimus dorsi (LD) and teres major (TM). Lesions of this stabilizing apparatus may lead to an instability of the LHBT, resulting in pain at the anterior shoulder. Ultrasonography (US) has been increasingly used in the assessment of shoulder injuries, including the anchoring apparatus of the LHBT. An accurate diagnosis of these injuries is often challenging, given the complex anatomy and wide spectrum of pathologies. In this review article, US anatomy and common pathologic conditions that affect the anchoring apparatus of the LHBT are discussed, including biceps pulley lesions, adhesive capsulitis, chronic pathology of SSC and SSP tendons, tears in the PM tendon and injuries to the LD and TM. Knowledge of a normal anatomy, an appropriate scanning technique and US findings of common pathologic conditions are the keys to accurate diagnoses.
... Specifically, the image acquisition unit consisted of a customized ultrasound probe (4.5 3 0.7 cm), a signal cable, and a control box (15.6 3 6 3 2 cm). The ultrasound frequency of the probe was 7.5 MHz (35% bandwidth), which is suitable for superficial muscle imaging according to earlier studies (15). The control box contained the components for signal processing and data transmission. ...
Article
Full-text available
Huang, Z-H, Ma, CZ-H, Wang, L-K, Wang, X-Y, Fu, S-N, and Zheng, Y-P. Real-time visual biofeedback via wearable ultrasound imaging can enhance the muscle contraction training outcome of young adults. J Strength Cond Res 36(4): 941-947, 2022-Real-time ultrasound imaging (RUSI) can serve as visual biofeedback to train deep muscle contraction in clinical rehabilitative settings. However, its effectiveness in resistance training in sports/fitness fields remains unexplored. This article introduced a newly developed wearable RUSI system that provided visual biofeedback of muscle thickening and movement and reported its effectiveness in improving the training outcomes of muscle thickness change (%) during dynamic contraction. Twenty-five healthy young men participated and performed pec fly exercise both with and without RUSI biofeedback. Statistical analysis was conducted to examine the reliability of the measurements and the immediate effects of (a) RUSI biofeedback of muscle contraction and (b) training intensity (50 vs. 80% of 1-repetition maximum [1RM]) on the pectoralis major (PMaj) thickness change measured by ultrasound images. In addition to significantly high inter-contraction reliability (ICC3,1 > 0.97), we observed significantly increased PMaj thickness change for both training intensities upon receiving biofeedback in subjects, compared with without biofeedback (p < 0.001). We also observed significantly larger PMaj thickness change at 80% of 1RM compared with 50% of 1RM (p = 0.023). The provision of visual biofeedback using RUSI significantly enlarged the magnitude of PMaj thickness change during pec fly exercises, potentially indicating that RUSI biofeedback could improve the ability of targeted muscle contraction of PMaj in healthy young adults. To our knowledge, this study has pioneered in applying RUSI as a form of biofeedback during weight training and observed positive effectiveness. Future iterations of the technique will benefit more subject groups, such as athletes and patients with neuromuscular disorders.
... 1,19 Although physical examination may be sufficient to identify large PM ruptures, confirmation and assessment of the extent of PM injuries typically involve ultrasonography and magnetic resonance imaging, with the latter providing a more comprehensive assessment of the entire PM muscle and tendon. 25 Current evidence favors surgical repair of some partial (grade II) and most complete (grade III) PM injuries at the tendinous insertion or musculotendinous junction or when the patient is unable to accept the resulting deformity or weakness. 2,6,26,27 In the NFL, PM injuries are infrequently reported. ...
Article
Full-text available
Purpose The purpose of this study was to determine return-to-play (RTP), performance and career survivorship for National Football League (NFL) athletes sustaining pectoralis major (PM) injuries with comparison among grades of injury and between nonoperative and operative management. Methods Publicly available data from the 1998–2020 NFL seasons were reviewed to identify athletes with PM injuries. Athlete characteristics were collected 1 season before and 2 seasons after injury. Percent of total games played in a season, player efficiency rating (PER), and Pro Football Focus (PFF) grades were compared for the preinjury season and 2 postinjury seasons. Kaplan-Meier survivorship plots were computed for RTP and postinjury career length, whereas a log-rank test was used to compare survivorship differences. Results In total, 258 PM injuries were reported at a mean age of 27.1 ± 3.3 years. A total of 126 surgical repairs occurred in 48.8% (n = 126) of injuries, with athletes undergoing repair possessing a lower RTP rate and longer time to RTP compared to athletes treated conservatively (P < .001). Survival analysis revealed shorter career length for athletes sustaining PM tears compared to strains (P < .001), although no difference in career length was appreciated on the basis of injury management (P = .980). Defensive linemen and wide receivers had lower PER during their second postinjury seasons (P = .019 and .030, respectively), whereas defensive linemen had lower PFF grades during their second post-injury seasons (P = .044). Conclusion NFL athletes requiring PM repair may experience a lower likelihood of RTP, and longer RTP timing, likely because of higher-grade injuries. Defensive linemen and wide receivers experiencing PM injuries are at risk for diminished performance post-injury. Career length does not appear to be affected based on injury management. Level of Evidence Level III, cohort study.
... Pectoralis major injuries were rare, typically occurring in active individuals participating in manual labour or sports. During the past two decades, the frequency of pectoralis major muscle injuries has increased in association with the increased popularity of bench press exercises (Lee et al. 2017). Diagnosis can usually be made based on a patient's history and physical examination. ...
... Ultrasound and magnetic resonance imaging grading and characterization are helpful for treatment planning, conservative or surgical (Figs. 5 and 6). US may be useful for the initial screening of injuries, but MR imaging should be used invariably for patients in whom surgery is being considered and a more thorough evaluation is required (Lee et al. 2017). A thorough understanding of the complex anatomy of the pectoralis major is crucial. ...
... Distal lesions with bony avulsion also exist and might need primary fracture fixation. A distinction is made between acute and chronic tears because with chronic injuries, a delay in a c b surgery of a few weeks to a few months is associated with the development of adhesions, muscular contraction, atrophy and worsened functional outcome (Lee et al. 2017). Distal pectoralis major lesions have to be discriminated from distal acute and chronic overuse and elongation lesions to the latissimus dorsi and teres major; these lesions are also the result of forceful resisted arm adduction. ...
Chapter
Specific imaging literature on abdominal and thoracic wall injuries is relatively uncommon compared to the overall incidence in sports medicine. However radiological grading and follow-up of musculotendinous unit (MTU) elongation may be significant in athletes. Moreover radiological diagnosis is relevant in specific circumstances. During the past two decades, the frequency of pectoralis major muscle injuries has increased. Ultrasound and magnetic resonance imaging are helpful for treatment planning. A thorough understanding of the complex anatomy of the pectoralis major is crucial. Rectus abdominis sheath haematoma has to be excluded in cases of muscular tear as it might not self-tamponade. Clinical diagnosis of groin lesions is difficult and therefore radiological procedures may be of additional help in the diagnosis of groin lesions. An in-depth knowledge of the anatomy and biomechanics of the thoracic and abdominal wall is a prerequisite for understanding the pathological conditions of this area. Handlebar injuries are a significant cause of both blunt abdominal trauma and lacerations to the contact area in children. The high proportion of lacerations observed in this type of trauma result from the sharp metallic end of the handlebar cutting through the soft rubber handle. Arterial endofibrosis at the external iliac artery is found in cyclists. It is characterized by thickening of the intima and/or adventitia. Angiographic examination demonstrates tapering of the arterial lumen with elongation of the artery.
... different treatments may be prescribed. 19 Our results confirm that the PM myotendinous junction is quite variable, being as close as 6 mm to the humerus for the clavicular head and as far as 75 mm from the humerus for the sternal head. In the cases where a short PM tendon exists, it is conceivable that a tear at the muscle or myotendinous junction may be misinterpreted as a distal tendon or enthesis tear. ...
Article
Full-text available
Background This study evaluates the pectoralis major (PM) tendon humeral insertion, using imaging and histologic assessment in cadaveric specimens. Current descriptions of the pectoralis major tendon depict a bilaminar enthesis, and clarification of the anatomy is important for diagnostic and surgical considerations. Materials and Methods Fourteen fresh-frozen whole upper extremity specimens were used in this study. Magnetic resonance (MRI) and ultrasonographic (US) imaging of the PM muscles, tendons, and entheses were performed, followed by anatomic dissection and inspection. Morphology of the lateral tendon and entheses were evaluated, focused on the presence of layers. In 11 specimens, the lateral 3 cm of the PM tendon was carefully dissected from the footprint, whereas in 3 specimens, the tendon and humeral insertion were preserved and removed en bloc. Histology was performed in axial slabs along the medial-lateral length of the tendon and also evaluated for the presence of layers. Results The superior-inferior and medial-lateral lengths of the PM footprint were 75 ± 9 mm and 7 ± 1 mm respectively. In all specimens, the clavicular and sternal head muscles and tendons were identified, with the clavicular head tendon generally being shorter. The medial-lateral length of the clavicular head tendon measured 19 ± 8 mm superiorly and 9 ± 3 mm inferiorly. The medial-lateral length of the sternal head tendon measured 38 ± 8 superiorly and 41 ± 18 mm inferiorly. All specimens demonstrated a unilaminar, not bilaminar, enthesis with abundant fibrocartilage on histology. Three specimens demonstrated interspersed entheseal fat and loose connective tissue at the enthesis on MRI and histology. Conclusion The PM tendon humeral insertion consists of a unilaminar fibrocartilaginous enthesis. US, MRI, and histology failed to identify true tendon layers at the enthesis. Delaminating injuries reported in the literature may originate from a location other than the enthesis.
... The PM plays an important role in the upper limb movements, especially during adduction and the medial rotation of the arm [3][4][5]. Due to its relationship to the chest wall and breast, the PM can be considered as one of the key anatomical structures in plastic and reconstructive surgery [6][7][8]. The importance of PM in orthopedic surgery refers, among others, to the deltopectoral approach [9][10][11][12] or to the repair of PM injuries [6,[13][14][15]. ...
... The importance of PM in orthopedic surgery refers, among others, to the deltopectoral approach [9][10][11][12] or to the repair of PM injuries [6,[13][14][15]. At the same time, the PM belongs to muscles demonstrating high anatomical variability, which may affect performing imaging-based evaluation and understanding the injury findings [4,16]. Moreover, anatomical variations (especially those related to attachments 2 BioMed Research International or unusual muscle morphology) may affect significantly the course of surgical procedures [13,17]. ...
Article
Full-text available
Background: The presented study attempts to classify individual anatomical variants of the pectoralis major muscle (PM), including rare and unusual findings. Rare cases of muscular anomalies involving the PM or its tendon have been presented. An attempt has also been made to determine whether anatomical variations of the PM may affect the innervation pattern of the lateral and medial pectoral nerves. Material and methods: The research was carried out on 40 cadavers of both sexes (22 males, 18 females), owing to which 80 PM specimens were examined. Results: Typical PM structure was observed in 63.75% of specimens. The most frequently observed variation was a separate clavicular portion of the PM. In one female cadaver (2.5% of specimens) the hypotrophy of the clavicular portion of the PM was noticed. In two male cadavers (5% of specimens) the fusion between the clavicular portion of the PM and the deltoid muscle was observed. In one of those cadavers, small sub-branches of the lateral pectoral nerve bilaterally joined the clavicular portion of the deltoid muscle. The detailed intramuscular distribution of certain nerve sub-branches was visualized by Sihler's stain. PM is mainly innervated by the lateral pectoral nerve. In all specimens stained by Sihler's technique, the contribution of the intercostal nerves in PM innervation was confirmed. Conclusions: Surgeons should be aware of anatomic variations of the PM both in planning and in conducting surgeries of the pectoral region.
... Injuries of the pectoralis major can be categorized according to their location: muscle origin or belly, musculotendinous junction, intratendinous region, humeral insertion, or area of bone avulsion at the humeral attachment. Most of pectoralis major injuries occur at the humeral insertion (59%) and musculotendinous junction (24%) (32). Patients with injuries at the muscle origin or belly, including contusions and strains, usually are treated conservatively. ...
... However, radiologists must be aware of unnecessarily MDCT scans expose patients to potentially harmful ionizing radiation (5,6). In front of subtle rib fractures and muscle-tendinous tears, complementary techniques such as US and MRI may improve the diagnostic accuracy (19,20,32,35,38,42). All these imaging methods have an important role in quantifying the severity of chest wall trauma. ...
Article
Full-text available
Blunt injuries to the chest wall are an important chapter on emergency room (ER) departments, being the third most common injuries in trauma patients which ominous complications could appear. This article describes different types of traumatic events affecting the chest wall, which maybe misdiagnosed with conventional X-ray. Special emphasis has been done in computed tomography (CT) and multidetector CT (MDCT) imaging. This technique is considered the "gold-standard" for those traumatic patients, due to its fast acquisition covering the whole area of interest in axial plane, reconstructing multiplanar (2D, 3D) volume-rendered images with a superb quality and angiographic CT capabilities for evaluating vascular damage. Complementary techniques such as ultrasonography (US) and magnetic resonance imaging (MRI) may improve the diagnostic accuracy due to its great capacity in visualising soft-tissue trauma (muscle-tendinous tears) and subtle fractures. All these imaging methods have an important role in quantifying the severity of chest wall trauma. The findings of this study have been exposed with cases of our archives in a didactic way. © Quantitative Imaging in Medicine and Surgery. All rights reserved.
... Protocols should include T1, fluid sensitive (T2, inversion recovery), and proton density axial and coronal oblique slices that extend visualization from the deltoid insertion inferiorly to the quadrilateral space superiorly [20, 35, 41 •• , 48]. With MRI, tear location (bony avulsion, humeral insertion, intratendinous, myotendinous junction, intramuscular, muscular origin) and degree of injury (complete vs. high partial vs. low partial) can be determined as well as assessment of the extent of tendon retraction if present [48,49]. Acute tears can demonstrate high signal intensity at the myotendinous junction with muscle retraction or tendon-bone discontinuity [35, 41 •• ]. ...
... Surgical complications include infection, stiffness, rerupture, hypertrophic scar, and injury to the long head biceps tendon and medial and lateral pectoral nerves [1]. Most authors recommend surgical intervention within 6-8 weeks of injury, with some advocating even earlier intervention by 3 weeks given concern for possible muscle belly retraction by this time [3,4,6,18,48]. Due to potential scarring, adhesions, and muscle retraction, chronic tears (defined as greater than 6 weeks) may require increased surgical exposure and dissection. ...
Article
Full-text available
Purpose of Review The aim of this review is to present the most recent evidence for the assessment and treatment of pectoralis major (PM) tears and to provide the reader with practical guide for returning the athlete to play. Recent Findings The latest research supports the use of MRI in accurately classifying PM injury location and severity and informing appropriate surgical indications. Ultrasound evaluation can be a valuable modality in assessment but has limitations. Recent studies further support operative management of complete tears. Summary MRI is the diagnostic imaging of choice. Non-operative management is recommended for low-grade partial tears. Operative repair is recommended for complete PM tears in athletes and young active individuals and can provide excellent results and full return to play at about 6 months, but may be earlier in certain cases.