Pectoralis minor syndrome

Pectoralis minor syndrome (PMS) is a condition related to thoracic outlet syndrome (TOS) that results from the pectoralis minor muscle being too tight.[1] PMS results from the brachial plexus being compressed under the pectoralis minor[2] while TOS involves compression of the bundle above the clavicle. In most patients, the nerves are constricted resulting in neurogenic PMS, but venous compression (venous PMS) can also occur.[3]

PMS and TOS often, but not always, occur together. They share similar symptoms including tingling, pain, or weakness in the hand and arm, but in PMS there is also pain or tenderness in the chest wall where the pectoralis minor attaches to the scapula as well as in the armpit.[1] One study of 100 patients diagnosed with neurogenic TOS found that 75 percent also had neurogenic PMS and 30 percent in fact had PMS without TOS.[4]

PMS is often caused by injury to the neck, excessive stretching of the shoulder, or certain sports that involve overhead throwing.[1] Confirmation of the diagnosis can be done by blocking the pectoralis minor muscle or injecting botulinium.[5] First-line treatment for patients with PMS but without TOS is self-stretching of the pectoralis minor muscle.[6] Other treatments include injection of botulinium, or surgery that cuts the pectoralis minor tendon.[7][8][2]

For patients with PMS but without TOS, one study found that surgery resulted in a good or excellent outcome in 90 percent of cases.[4] Another study in ten patients with PMS substantially resolved symptoms in all but one case.[9]

PMS was first described in 1945.[10]

  1. ^ a b c Sencen, Lisa. "Thoracic Outlet Syndrome". NORD (National Organization for Rare Disorders). Retrieved 25 August 2022.
  2. ^ a b Howard, Matthew; Jones, Michael; Clarkson, Richard; Donaldson, Oliver (2022). "Pectoralis minor syndrome: diagnosis with Botulinum injection and treatment with tenotomy – a prospective case series". Shoulder & Elbow. 14 (2): 157–161. doi:10.1177/1758573220968454. PMC 8899325. PMID 35265181.
  3. ^ Sanders, Richard J.; Annest, Stephen J. (2014). "Thoracic outlet and pectoralis minor syndromes". Seminars in Vascular Surgery. 27 (2): 86–117. doi:10.1053/j.semvascsurg.2015.02.001. PMID 25868762.
  4. ^ a b Sanders, Richard J.; Rao, Neal M. (2010). "The Forgotten Pectoralis Minor Syndrome: 100 Operations for Pectoralis Minor Syndrome Alone or Accompanied by Neurogenic Thoracic Outlet Syndrome". Annals of Vascular Surgery. 24 (6): 701–708. doi:10.1016/j.avsg.2010.02.022. PMID 20471786.
  5. ^ Pietramaggiori, Giorgio; Scherer, Saja (2020). "Diagnosis and Treatment of Pectoralis Minor Syndrome (Neurogenic Thoracic Outlet)". Minimally Invasive Surgery for Chronic Pain Management: An Evidence-Based Approach. Springer International Publishing. pp. 47–52. ISBN 978-3-030-50188-4.
  6. ^ Sanders, Richard J. (2013). "Pectoralis Minor Syndrome". Thoracic Outlet Syndrome. Springer. pp. 93–100. ISBN 978-1-4471-4366-6.
  7. ^ Martinez Del Carmen, Dorelly Tanayra; Martí Mestre, Francisco Xavier; Tripodi, Paolo; Macia Vidueira, Ivan; Ramos Izquierdo, Ricard; Romera Villegas, Antonio (2022). "Role of Botulinum Toxin in Pectoralis Minor Syndrome". Annals of Vascular Surgery. 81: 225–231. doi:10.1016/j.avsg.2021.09.032. PMID 34775010. S2CID 244070486.
  8. ^ Aktas, Ilknur; Kaya, Ezgi; Akpinar, Pinar; Atici, Arzu; Unlu Ozkan, Feyza; Palamar, Deniz; Akgun, Kenan (2020). "Spasticity-induced Pectoralis minor syndrome: a case-report". Topics in Stroke Rehabilitation. 27 (4): 316–319. doi:10.1080/10749357.2019.1691807. PMID 31774031. S2CID 208319300.
  9. ^ Haeni, David; Martinez-Catalan, Natalia; Esper, Ronda N.; Wagner, Eric R.; El Hassan, Bassem T.; Sanchez-Sotelo, Joaquin (2022). "Arthroscopic release of the pectoralis minor tendon from the coracoid for pectoralis minor syndrome". Journal of Experimental Orthopaedics. 9 (1): 57. doi:10.1186/s40634-022-00491-x. PMC 9206061. PMID 35713735. S2CID 249713897.
  10. ^ Sanders, Richard J.; Rao, Neal M. (2009). "PP30. The Forgotten Pectoralis Minor Syndrome: Report of 100 Operations". Journal of Vascular Surgery. 49 (5): S23. doi:10.1016/j.jvs.2009.02.060.