- Discussion:
- serratus anterior arises from upper eight ribs, inserts on vertebral border of scapula, is innervated by
long thoracic nerve,
and functions to draw scapula forward in sports such as a jab in boxing;
- paralysis produces characteristic prominence ("medial winging") of vertebral border of the scapula;
- this is in contrast to paralysis of the
trapezius which is associated w/ lateral winging;
- origin:
- superior lateral surfaces of upper 8 or 9 ribes at the side of chest;
- arises from the upper 8 ribs, inserts on vertbral border of scapula;
- insertion:
- costal surface of vertebral border along inferior angle of scapula;
- paralysis produces winging of the vertbral border of the scapula;
- action:
- functions to draw scapula forward;
- abducts scapula and rotates it to point glenoid cavity superior;
- stabilizes vertebral border of scapla to thoracic cage, along with
rhomboids
and middle
trapezius;
- nerve supply: long thoracic,
C5,
C6,
C7;
- Serratus Anterior Flaps:
- inferior three slips of serratus anterior may be used for free tissue transfer for coverage of dorsal & palmar defects in the hand;
- there are three separate slips that are easily divisible for contouring;
- this flap has low donor site morbidity;
- free scapular fascial flap resurfaced with skin graft provides less bulk than cutaneous scapular flap;
- Vascular Supply:
- it is supplied by circumflex scapular artery, which emerges at lateral border of scapula and divides into cutaneous
scapular & periscapular arteries;
- it has the advantage of a constant vascular pedicle and a well- hidden donor site, although the scar does spread;
- Management of Serratus Paralysis:
- paralysis may be traumatic (sports, MVA ect..), atraumatic (post-infectious neuritits, allergic rxns), or iatrogenic (mastectomy, thoracotomy);
- patients will note weakened forward flexion;
- in most cases, serratus paralysis will resolve over 6 months;
- diff dx: paralysis of the trapezius may also cause winging of the scapula;
- on physical exam, manually fix the inferior scapula to the chest wall in about of 35 deg of rotation, and note effect on forward flexion;
- slightly more or less rotation may improve forward flexion;
-
treatment: (from Vukov et al 1996)
- if physical exam demonstrates that manual fixation of the scapula will improve forward flexion, then a loose
spaculopexy (opposition of the scapula to the chest wall) may improve function;
- incision is made along the inferomedial border of the scapula;
- the infero-medial border of the scapula is defined;
- the scapula is oppose to the chest wall in the appropriate degree of rotation;
- the nearest distal rib is cleared of soft tissue;
- w/ appropriate retractors in place, a small drill hole is made in both the tip of the scapula and the adjacent rib;
- a Vicry ribbon (or similar material) is then passed circumferentially
around the rib and thru then thru the holes in the rib and scapula;
Serratus anterior paralysis in the young athlete.
The serratus anterior free-muscle transplant for reconstruction of the injured hand: an analysis of the donor and recipient sites.
Isolated Serratus Anterior Paralysis: A Simple Surgical Procedure to Reestablish Scapulo-humeral Dynamics.
V. Vukov, D. Ukropina, M. Bumbasirevic, G. Pecotic, M. Zdravkovic, and M. Ille.
J Orthop Trauma, Vol. 10. No. 5. 1996;
Pectoralis major transfer for serratus anterior paralysis
