JBJS | Rotation of the Clavicular Portion of the Pectoralis Major for Soft-Tissue Coverage of the Clavicle : An Anatomical Study and Case Report*

The Journal of Bone & Joint Surgery, Volume 82, Issue 12

Articles | December 01, 2000

Rotation of the Clavicular Portion of the Pectoralis Major for Soft-Tissue Coverage of the Clavicle : An Anatomical Study and Case Report*

G. R. Williams, M.D.†; K. Koffler, M.D.‡; M. Pepe, M.D.‡; K. Wong, M.D.‡; B. Chang, M.D.‡; d. M. Ramsey, M.D.

View Disclosures and Other Information

Investigation performed at the Shoulder and Elbow Service, Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.
†Penn Orthopaedic Institute, 1 Cupp Pavilion, Presbyterian Hospital, 39th and Market Streets, Philadelphia, Pennsylvania 19104.
‡Department of Orthopaedic Surgery (K. K., M. P., K. W., and M. R.) and Division of Plastic Surgery, Department of Surgery (B. C.), University of Pennsylvania School of Medicine, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.

The Journal of Bone & Joint Surgery. 2000; 82:1736-1736

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Article

Figures

References

text A A A

Abstract

Background: The purposes of this study were to describe the anatomical features of a rotational flap consisting of the clavicular portion of the pectoralis major and to report the surgical technique and the outcome of use of this flap in a patient with poor soft-tissue coverage following multiple operations for a clavicular fracture complicated by nonunion and infection.

Methods: Ten shoulders from five cadavera were dissected to isolate the clavicular portion of the pectoralis major. The vascular pedicle, thoracoacromial artery, and axillary artery were identified, and the length of the vascular pedicle from the axillary artery to the muscle was measured. The angle of rotation of the flap about its intact clavicular origin was measured before and after division of the acromial branch of the thoracoacromial artery. The clavicular origin was then incised, and the overall length, width, and thickness of the muscle as well as the distance from each end of the muscle to the vascular pedicle were measured.

Results: The average length of the vascular pedicle from the axillary artery to the pectoralis muscle belly was 5.3 centimeters (range, 3.7 to 6.5 centimeters). The average maximum angle of rotation with the clavicular origin intact was 60 degrees (range, 55 to 67 degrees) before division of the acromial branch and 73 degrees (range, 65 to 82 degrees) after division. The average total length of the clavicular head was 20.2 centimeters (range, 18.0 to 23.0 centimeters). The average width of the clavicular head was 2.9 centimeters (range, 2.0 to 4.0 centimeters), and the average thickness was 0.5 centimeter (range, 0.2 to 0.7 centimeter). The vascular pedicle entered the muscle an average of 8.7 centimeters (range, 5.2 to 10.7 centimeters) lateral to the most medial extent of the muscle and an average of 11.5 centimeters (range, 9.5 to 14.0 centimeters) medial to the most lateral extent of the muscle. The rotational flap was successfully used clinically to provide soft-tissue coverage after bone-grafting and internal fixation of a clavicular nonunion that had been complicated by infection.

Conclusions: The clavicular head of the pectoralis major may be used as a local rotational flap to cover soft-tissue deficiencies over the clavicle. It can be harvested with relative ease without damaging the sternocostal head.

Figures in this Article

Introduction

Pectoralis major flaps have been used extensively to reconstruct defects of the chest wall, axilla, and head and neck^2,8-12,16. Tobin described the morphology of the pectoralis major muscle as well as its segmental vascular supply, which is based upon the thoracoacromial artery²⁴. This segmental vascularity allows the pectoralis major muscle to be split into three specific, independently vascularized subunits; this gives it tremendous versatility for use in rotational flaps²⁵.

Tobin^24,25 reported thirty-six cases in which he used a segmentally split pectoralis major flap. Although most cases involved transposition of the sternocostal portion of the pectoralis major, one case involved rotation of the clavicular segment to cover a lateral acromioclavicular defect^24,25. We treated a patient who had soft-tissue compromise overlying the midpart of the shaft of the clavicle after a fracture that subsequently required multiple surgical procedures because of nonunion and infection. In order to determine the feasibility of using the clavicular head of the pectoralis major as a rotational flap, a cadaveric anatomical investigation was performed. Open reduction, internal fixation, and bone-grafting was then performed in combination with a rotational flap consisting of the clavicular head of the pectoralis major in this patient.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1:: Cadaveric anatomical dissection showing the rotated flap (arrows), with the origin intact, prior to division of the acromial branch of the thoracoacromial trunk.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 2:: Radiograph showing a midshaft clavicular nonunion with atrophic medial and lateral fragments. A portion of a broken screw is present in the lateral segment.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-A:: Figs. 3-A, 3-B, and 3-C: Illustrations showing the surgical technique for use of a rotational pectoralis major flap.
Fig. 3-A: The interval between the sternocostal and clavicular heads is identified and dissected distally and laterally.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-B:: A separate skin incision is made over the humeral insertion, and the tendon of the clavicular head is identified and incised.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 3-C:: The vascular pedicle becomes more superficial with rotation of the flap. The muscle belly is rotated on its intact clavicular origin over the nonunion site, and the tendinous insertion is sutured to the fascia over the distal portion of the scapular spine.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 4:: Clinical photograph showing the healed clavicular incision and the contouring flap.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 5:: Radiograph made twenty-one months postoperatively, showing a healed nonunion of the clavicle.

Materials and Methods

Five fresh-frozen cadavera were thawed to room temperature for dissection. Three of the cadavera were male and two were female, and the average age at the time of death was sixty-two years (range, forty-eight to eighty-seven years). The cadavera were positioned supine on a dissecting table, and the skin, subcutaneous tissue, and deep fascia were excised from the superior aspect of both shoulders and from both hemithoraces. Dissections were performed on both shoulders to yield data from ten paired shoulder specimens.

The interval between the clavicular and sternocostal portions of the pectoralis major muscle was easily identified, and the muscle was split distally and laterally in line with its fibers. This interval was developed laterally to the insertion of the pectoralis major on the lateral lip of the bicipital groove. The insertion of the clavicular head was carefully separated from the deeper insertion of the sternocostal head and was transected. The superior border of the muscle was then separated from the medial border of the anterior part of the deltoid by dissecting the deltopectoral interval, leaving only the origin of the clavicular head intact.

The deep surface of the clavicular head of the pectoralis major was then dissected from lateral to medial to identify its vascular pedicle and the thoracoacromial artery. The pedicle and artery were dissected proximally to the origin of the thoracoacromial artery from the second portion of the axillary artery. This required reflection of the pectoralis minor tendon from its insertion on the coracoid process. The combined length of the vascular pedicle and the thoracoacromial artery from the axillary artery to the deep surface of the clavicular head of the pectoralis major was measured. Variations in the number and course of the vascular branches were also noted.

The muscle was then rotated superiorly about its long axis so that the deep surface was superficial and the insertion was as far posterior and superior as the pedicle would allow (Fig. 1). The angle subtended by the original and final positions of the inferior border of the muscle was measured with use of a handheld goniometer. Subsequent division of the acromial branch of the thoracoacromial artery allowed further rotation of the muscle. The angle subtended by the original position and this second, final position was also measured with a handheld goniometer.

The muscle was derotated back to its original position, and the origin was detached from the medial third of the clavicle. With use of manual calipers, the length, width, and thickness of the clavicular head were measured. The distances from the most medial extent of the muscle origin and from the most lateral extent of the muscle insertion to the entrance of the vascular pedicle into the midportion of the muscle were also recorded.

Results

The average total length of the clavicular head was 20.2 centimeters (range, 18.0 to 23.0 centimeters). An average of 11.5 centimeters (range, 9.5 to 14.0 centimeters) of this length was lateral to the vascular pedicle, and an average of 8.7 centimeters (range, 5.2 to 10.7 centimeters) was medial to it. The average width of the muscle was 2.9 centimeters (range, 2.0 to 4.0 centimeters), and the thickness averaged 0.5 centimeter (range, 0.2 to 0.7 centimeter). The average angle of rotation of the muscle with the clavicular origin intact was 60 degrees (range, 55 to 67 degrees). This increased to 73 degrees (range, 65 to 82 degrees) after division of the acromial branch of the thoracoacromial artery. The vascular pedicle measured an average of 5.3 centimeters (range, 3.7 to 6.5 centimeters) from the axillary artery to the clavicular head.

Anatomical variations were noted in two cadavera and were present in only one shoulder of each. In one, a common arterial branch from the thoracoacromial artery gave rise to two branches: one branch that formed the pedicle to the clavicular head and one branch that entered the superior border of the sternocostal head. The branch to the sternocostal head did not appear to hinder rotation of the flap. In the other specimen, there were two separate arterial branches to the clavicular head and a more medial takeoff of the thoracoacromial trunk from the axillary artery. The two branches to the clavicular head were approximately one centimeter apart, and the lateral branch was much smaller than the more medial branch. The more prominent medial branch was used for measurements.

Case Report

A forty-year-old man sustained a clavicular fracture on his left, nondominant side in a work-related injury. Three months after the fracture, the patient underwent open reduction and internal fixation with iliac crest bone-grafting and use of a 3.5-millimeter dynamic compression plate. A nonunion of the clavicle developed with infection with methicillin-resistant coagulase-negative Staphylococcus. The loose hardware was removed, and the wound was irrigated and debrided. The patient was treated with oral ciprofloxacin for six weeks and presented to our shoulder clinic two months after hardware removal.

The patient complained of pain in the left shoulder as well as numbness and paresthesias in all of the fingers of the left hand. The left shoulder drooped, and there was palpable false motion at the midpart of the shaft of the left clavicle. Motor function was intact. The skin was healed but was thin and discolored and adherent to the underlying clavicle. Radiographs revealed a midshaft clavicular nonunion with atrophic medial and lateral fragments (Fig. 2).

A bone scan with delayed images indicated preservation of blood flow to both fragments^1,15,21. An indium scan revealed no abnormal activity in the region of the left clavicle consistent with acute or chronic infection^5,6,14,18,27.

Open reduction, internal fixation, and bone-grafting were performed through the previous incision, which paralleled the long axis of the clavicle. The skin was adherent to the nonunion site and to the medial and lateral clavicular fragments for a distance of three centimeters on either side of the nonunion. There was no subcutaneous tissue associated with the skin flap. The edges of the skin showed few areas of visible bleeding and were debrided to normal-appearing skin margins.

The nonunion site was identified, and the intervening soft tissue was excised along with a small, atrophic intercalary fragment of bone. The remaining medial and lateral fragments were thin and revealed almost no superficial areas of punctate bleeding. Multiple areas of punctate bleeding were observed on the endosteal surfaces of both fragments after curettage. Intramedullary fixation of the fragments was obtained by insertion of a four-millimeter threaded pin into the distal fragment, just posterior to the acromioclavicular joint, and advancement of the pin across the nonunion site into the proximal fragment. Strips of autogenous cancellous and corticocancellous graft obtained from the left iliac crest were applied to the nonunion site.

The bone-grafted nonunion site was then covered with a rotational flap consisting of the clavicular head of the pectoralis major (Fig. 3-A, Fig. 3-B, and Fig. 3-C). The skin was closed over the flap without grafting. The patient was placed in an abduction pillow before he was taken from the operating room. He was treated postoperatively with three weeks of intravenous vancomycin followed by three weeks of oral ciprofloxacin.

The primary wound healed without a problem, and the flap contoured well (Fig. 4). However, the fracture failed to heal. Seven months following the initial intramedullary fixation and bone-grafting, the patient underwent pin removal and repeat open reduction, internal fixation with a low-contact dynamic compression plate, and bone-grafting.

During the repeat fixation and bone-grafting, the pectoralis flap was reflected carefully from the scapular spine, clavicular shaft, and nonunion site. It appeared healthy. Moreover, the vascularity of the underlying clavicle appeared to be increased compared with that seen at the initial surgery. Ten months following the repeat fixation and bone-grafting, radiographs revealed no sign of hardware failure and the graft appeared to be incorporating well. The fracture also appeared to be healed on tomograms made at this time. Twenty-one months postoperatively, radiographs showed almost complete obliteration of the fracture site and no evidence of hardware loosening (Fig. 5). Unfortunately, the patient continued to have substantial pain and had not returned to work.

Discussion

Clavicular fractures are common injuries. However, less than 2 percent of these fractures fail to unite^3,17,20,26. Infection at the site of a nonunion of the clavicle (especially one associated with soft-tissue deficiency) is even more rare, and the literature on this subject is scarce. Much has been written about the successful use of local rotational muscle flaps for the treatment of osteomyelitis and nonunion of other fractures, especially those of the tibia^4,7,9,13,22. Muscle may be transposed as a local rotational flap or transplanted by microvascular techniques. The segmental anatomy of the pectoralis major makes it an ideal muscle for local transposition. The three major segmental subunits include the clavicular segment, the sternocostal segment, and an external segment²⁴. Each has a unique origin, and the three segments insert on the humerus as a single fused tendon with a constant relationship. The tendon has a u-shaped insertion on the humerus; the clavicular segment tendon is the ventral limb, the sternocostal segment tendon is the inferior cup, and the external segment tendon is the dorsal limb²⁴.

The clavicular muscle segment is the most superior segmental subunit, and it originates on the medial half of the clavicle. It is separated from the sternocostal segment by an intramuscular septum of connective tissue that is easily identifed. In Tobin's study²⁴ of 105 human cadaveric pectoralis major muscles, the clavicular segment was always segmentally innervated by one or more lateral pectoral nerve branches and was always supplied by the superior, or deltoid, branch of the thoracoacromial trunk.

While the literature describing use of the sternocostal portion of the pectoralis major is substantial, very little has been written about use of the clavicular head. Tobin²⁴ mentioned use of the clavicular head to cover the acromioclavicular joint in one patient. Reid et al.¹⁹ described use of the clavicular head as a musculocutaneous free flap for intraoral reconstructions. We found no information regarding soft-tissue coverage for clavicular nonunion except for a description of an adipofascial turnover flap by Tarar and Quaba²³. Although the clavicular head may be too small for coverage of large defects in the chest wall, head, or neck, it is very suitable for soft-tissue defects around the shoulder, where bulk is often less desirable.

We carried out anatomical dissections of the clavicular head in order to characterize its dimensions and vasculature and to predict which areas of the shoulder could be covered with this rotational flap. The anatomy is quite consistent. The intramuscular septum between the clavicular and sternocostal segments is very easy to identify and to dissect. The vascular pedicle is usually in the middle of the flap or slightly medial to midline. The length of the pedicle averaged 5.3 centimeters in our study, which is consistent with other reported results¹⁵.

The muscle dimensions were sufficient to easily cover the front of the shoulder, the clavicle, the lateral aspect of the acromion, and the sternoclavicular joint without excess bulk. If the clavicular origin of the muscle was dissected, the flap was able to cover the posterior aspect of the acromion and the scapular spine. Division of the lateral pectoral nerve branches to the clavicular head will cause some additional atrophy, which may result in a better contour of the flap¹⁰. Since the sternocostal portion of the pectoralis major is left intact, its form and function are preserved^16,24,25.

It is impossible to know how important the flap was in the management of our patient. Although twenty-one-month follow-up radiographs revealed consolidation of the fracture and no hardware failure, radiographic union is difficult to prove clinically. Moreover, the nonunion did not heal after the initial treatment. Rigid fixation with plates and screws appears to have resulted in union and may have accomplished the same result without the flap. However, a control population of patients with an infected clavicular nonunion and soft-tissue compromise was not available. Furthermore, the poor soft-tissue envelope in this patient was likely to have compromised fracture-healing and the control of the infection.

Certainly, the indications for use of this flap have yet to be completely outlined. However, once the need for soft-tissue coverage has been established, the clavicular segment of the pectoralis major is available for use as a local rotational flap to cover the clavicular shaft; the acromioclavicular joint; and, with release of the origin of the clavicular head, the posterior aspect of the acromion and the lateral part of the scapular spine. Soft-tissue defects over the posterior aspect of the glenohumeral joint probably cannot be covered adequately with this flap. Small anterior glenohumeral defects can be covered by releasing both the origin and the insertion of the clavicular head and advancing the muscle belly into the defect. Larger anterior glenohumeral defects may require similar advancement of the entire pectoralis major or the larger sternocostal segment.

References

Alazraki, N. P. and Mishkin, F. [editors]: Fundamentals of Nuclear Medicine, pp. 112-122. New York, Society of Nuclear Medicine, 1988.

Baek, S. M.; Lawson, W.; and Biller, H. F.: An analysis of 133 pectoralis major myocutaneous flaps. Plast. and Reconstr. Surg.,69: 460-469, 1982.69460 1982

Boehme, D.; Curtis, R. J. Jr.; DeHaan, J. T.; Kay, S. P.; Young, D. C.; and Rockwood, C. A. Jr.: The treatment of nonunion fractures of the midshaft of the clavicle with an intramedullary Hagie pin and autogenous bone graft. In Instructional Course Lectures, American Academy of Orthopaedic Sugeons. Vol. 42, pp. 283-290. Rosemont, Illinois, American Academy of Orthopaedic Surgeons, 1993.

Cierny, G. III: The classification and treatment of adult osteomyelitis. In Surgery of the Musculoskeletal System, edited by C. McC. Evarts. Vol. 5, pp. 4337-4379. New York, Churchill Livingstone, 1990.

Esterhai, J. L. Jr.; Goll, S. R.; McCarthy, K. E.; Velchik, M.; Alavi, A.; Brighton, C. T.; and Heppenstall, R. B.: Indium-111 leukocyte scintigraphic detection of subclinical osteomyelitis complicating delayed and nonunion long bone fractures: a prospective study. J. Orthop. Res.,5: 1-6, 1987.51 1987 [PubMed]

Esterhai, J. L. Jr.; Silfen, D.; and Alavi, A.: The indium white blood cell scan in the evaluation of osteomyelitis. J. Nucl. Med.,31: 2029-2033, 1990.312029 1990 [PubMed]

Fitzgerald, R. H. Jr.; Ruttle, P. E.; Arnold, P. G.; Kelly, P. J.; and Irons, G. B.: Local muscle flaps in the treatment of chronic osteomyelitis. J. Bone and Joint Surg.,67-A: 175-185, Feb 1985.67-A175 1985

Freeman, J. L.; Walker, E. P.; Wilson, J. S.; and Shaw, H. J.: The vascular anatomy of the pectoralis major myocutaneous flap. British J. Plast. Surg.,34: 3-10, 1981.343 1981

Ger, R.: Muscle transposition for treatment and prevention of chronic post-traumatic osteomyelitis of the tibia. J. Bone and Joint Surg.,59-A: 784-791, Sept 1977.59-A784 1977

Hoffman, G. W., and Elliott, L. F.: The anatomy of the pectoral nerves and its significance to the general and plastic surgeon. Ann. Surg.,205: 504-507, 1987.205504 1987 [PubMed]

Hueston, J. T., and McConchie, I. H.: A compound pectoral flap. Australian and New Zealand J. Surg.,38: 61-63, 1968.3861 1968

Manktelow, R. T.; McKee, N. H.; and Vettese, T.: An anatomical study of the pectoralis major muscle as related to functioning free muscle transplantation. Plast. and Reconstr. Surg.,65: 610-615, 1980.65610 1980

Mathes, S. J.; Alpert, B. S.; and Chang, N.: Use of the muscle flap in chronic osteomyelitis: experimental and clinical correlation. Plast. and Reconstr. Surg.,69: 815-829, 1982.69815 1982

Merkel, K. D.; Brown, M. L.; Dewanjee, M. K.; and Fitzgerald, R. H. Jr.: Comparison of indium-labeled-leukocyte imaging with sequential technetium-gallium scanning in the diagnosis of low-grade musculoskeletal sepsis. A prospective study. J. Bone and Joint Surg.,67-A: 465-476, March 1985.67-A465 1985

Mettler, F. A. and Guiberteau, M. J.: Bone scanning. In Essentials of Nuclear Medicine Imaging. Ed. 2, pp. 247-283. New York, Grune and Stratton, 1986.

Morain, W. D.; Colen, L. B.; and Hutchings, J. C.: The segmental pectoralis major muscle flap: a function-preserving procedure. Plast. and Reconstr. Surg.,75: 825-830, 1985.75825 1985

Neer, C. S. II: Nonunion of the clavicle. J. Am. Med. Assn.,172: 1006-1011, 1960.1721006 1960

Nepola, J. V.; Seabold, J. E.; Marsh, J. L.; Kirchner, P. T.; and el-Khoury, G. Y.: Diagnosis of infection in ununited fractures. Combined imaging with indium-111-labeled leukocytes and technetium-99m methylene diphosphonate. J. Bone and Joint Surg.,75-A: 1816-1822, Dec 1993.75-A1816 1993

Reid, C. D.; Taylor, G. I.; and Waterhouse, N.: The clavicular head of pectoralis major musculocutaneous free flap. British J. Plast. Surg.,39: 57-65, 1986.3957 1986

Rowe, C. R.: An atlas of anatomy and treatment of midclavicular fractures. Clin. Orthop.,58: 29-42, 1968.5829 1968 [PubMed]

Sandler, M. P. [editor]: Diagnostic Nuclear Medicine, pp. 680-684. Baltimore, Williams and Wilkins, 1996.

Stark, W. J.: The use of pedicled muscle flaps in the surgical treatment of chronic osteomyelitis resulting from compound fractures. J. Bone and Joint Surg.,28: 343-350, April 1946.28343 1946

Tarar, M. N., and Quaba, A. A.: An adipofascial turnover flap for soft tissue cover around the clavicle. British J. Plast. Surg.,48: 161-164, 1995.48161 1995

Tobin, G. R.: Pectoralis major segmental anatomy and segmentally split pectoralis major flaps. Plast. and Reconstr. Surg.,75: 814-824, 1985.75814 1985

Tobin, G. R.: Pectoralis major muscle-myocutaneous flap for chest-wall reconstruction. Surg. Clin. North America,69: 991-1006, 1989.69991 1989

Wilkins, R. M., and Johnston, R. M.: Ununited fractures of the clavicle. J. Bone and Joint Surg.,65-A: 773-778, July 1983.65-A773 1983

Wukich, D. K.; Abreu, S. H.; Callaghan, J. J.; Van Nostrand, D.; Savory, C. G.; Eggli, D. F.; Garcia, J. E.; and Berrey, B. H.: Diagnosis of infection by preoperative scintigraphy with indium-labeled white blood cells. J. Bone and Joint Surg.,69-A: 1353-1360, Dec 1987.69-A1353 1987

Topics