Meniscectomy of the sternoclavicular joint: A report of two cases Demetris Delos, MD a, *, Michael K. Shindle, MD a , Douglas N. Mintz, MD b , Russell F. Warren, MD a a Department of Orthopedic Surgery, New York, NY b Radiology, Hospital for Special Surgery, New York, NY The sternoclavicular joint (SCJ) is the only true articu- lation between the axial and appendicular skeleton. It is a saddle-type, diarthrodial joint where less than half of the clavicle articulates with the sternum 26 ; sprains, fractures, or dislocations, especially from indirect forces, are often attributed to this relatively bony incongruity. 20 Its location close to the center of the body and its strong ligamentous restraints, however, limit the frequency of injury to this joint. 9,25 Biomechanically, the SCJ is characterized by approximately 30  to 35  of forward elevation and 35  of flexion/extension during normal shoulder range of motion (ROM), with 4  of sternoclavicular motion for every 10  of shoulder elevation. 25 Although injuries to the SCJ are rare, they can some- times result in chronic pain and instability. Traumatic SCJ dislocation is most frequent after motor vehicle collision or sports-related injury, 5,7,29 and it has been associated with chronic disability that may require operative intervention. Spontaneous dislocation has also been known to occur, though less frequently, in patients with generalized liga- mentous laxity or congenital deformity. 6,10,11,19,29 Injuries to the SCJ intra-articular disk (meniscal homologue) are common after trauma and may also play a role in chronic SCJ symptomatology. A recent magnetic resonance imaging (MRI) study from our institution found that 80% of patients with SCJ pain due to trauma had intra-articular disk injuries. 4 The intra-articular disk has been described as analogous to the knee meniscus, and tears can present with mechanical symptoms similar to meniscal tears of the knee. 13 The exact role of the SCJ disk in recurrent SCJ pain and instability has been poorly defined. It is known that osteoarthritis of the SCJ is common, especially in individ- uals aged over 40 years, with up to 90% of persons affected after the age of 60 years, although the majority are asymptomatic. 1,16,27 Anatomically, the intra-articular disk functions in dividing the articular cavity via its attachments to the joint capsule anteriorly and posteriorly; it also increases joint congruency and helps in restraining medial translation of the clavicle over the sternum. 13 With the use of higher-resolution studies, such as computed tomography (CT) and MRI, 15 clinicians can now better define the pathoanatomy of the joint and the soft tissues, including the intra-articular disk, allowing for more precise diagnosis and treatment plans (Figures 1 and 2). The literature regarding SCJ pathology and treatment is limited, and references specific to pathology stemming from the SCJ disk are even less common. One of the earliest reports describing SCJ pain and disability attributable to a dysfunc- tional disk was that of Duggan 14 in 1931, who performed surgical excision of the disk and capsular repair with successful relief of pain. However, follow-up was limited to 3 months, and no other cases were reported. 14 The only series published, to our knowledge, was that of Pierce 22 in 1979, who reported on the results of 4 patients with SCJ disk injuries, 3 of whom underwent simple disk excision. Follow- up was limited to 8 months maximum postoperatively. In this series we report the results of 2 patients who underwent intra-articular disk excision for chronic SCJ pain, with follow-up of 17 years and 1 year, respectively. *Reprint requests: Demetris Delos, MD, Department of Orthopedic Surgery, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021. E-mail address: delosd@hss.edu (D. Delos). J Shoulder Elbow Surg (2010) 19, e9-e12 www.elsevier.com/locate/ymse 1058-2746/2010/$36.00 - see front matter Ó 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. doi:10.1016/j.jse.2009.11.051