Elbow Instability

Abstract

The stability of the elbow is based on a combination of primary (static) and secondary stabilizers (dynamic). In varus stress, the bony structures and the lateral ulnar collateral ligament (LUCL) are the primary stabilizers, and in valgus stress, the ulnar collateral ligament (UCL) is the primary stabilizer. The flexor and extensor tendons crossing the elbow joint act as secondary stabilizers. Elbow instability is commonly divided into acute traumatic and chronic instability. Instability of the elbow is a continuum, with complete dislocation as its most severe form.

Posterolateral rotatory instability is the most common elbow instability and can be detected at imaging both in the acute as well as the chronic phase. Imaging of suspected elbow instability starts with radiographs. Depending on the type of injury suspected, it is followed by magnetic resonance imaging (MRI) or computed tomography evaluation for depiction of a range of soft tissue and osseous injures. The most common soft tissue injuries are tears of the LUCL and the radial collateral ligament; the most common osseous injuries are an osseous LUCL avulsion, a fracture of the coronoid process, and a radial head fracture.

Valgus instability is the second most common instability and mostly detected in the chronic phase, with valgus extension overload the dominant pattern of injury. The anterior part of the UCL is insufficient in valgus extension overload due to repetitive medial tension seen in many overhead throwing sports, with UCL damage readily seen at MRI.

Keywords

posterolateral instability - valgus extension overload

Publikationsverlauf

Artikel online veröffentlicht:
27. Oktober 2021

• References

• 1 Sutter R. MRI of the Elbow. ESSR Sports Imaging Subcommittee. Horn, Austria: Breitenseher; 2018: 144
• 2 Morrey BF, Askew LJ, Chao EY. A biomechanical study of normal functional elbow motion. J Bone Joint Surg Am 1981; 63 (06) 872-877
• 3 King GJ, Morrey BF, An KN. Stabilizers of the elbow. J Shoulder Elbow Surg 1993; 2 (03) 165-174
• 4 Karbach LE, Elfar J. Elbow instability: anatomy, biomechanics, diagnostic maneuvers, and testing. J Hand Surg Am 2017; 42 (02) 118-126
• 5 Hildebrand KA, Patterson SD, King GJ. Acute elbow dislocations: simple and complex. Orthop Clin North Am 1999; 30 (01) 63-79
• 6 Stoneback JW, Owens BD, Sykes J, Athwal GS, Pointer L, Wolf JM. Incidence of elbow dislocations in the United States population. J Bone Joint Surg Am 2012; 94 (03) 240-245
• 7 Marinelli A, Guerra E, Rotini R. Elbow instability: are we able to classify it? Review of the literature and proposal of an all-inclusive classification system. Musculoskelet Surg 2016; 100 (Suppl. 01) 61-71
• 8 Husarik DB, Saupe N, Pfirrmann CW, Jost B, Hodler J, Zanetti M. Elbow nerves: MR findings in 60 asymptomatic subjects—normal anatomy, variants, and pitfalls. Radiology 2009; 252 (01) 148-156
• 9 Kälicke T, Muhr G, Frangen TM. Dislocation of the elbow with fractures of the coronoid process and radial head. Arch Orthop Trauma Surg 2007; 127 (10) 925-931
• 10 Cohen MS, Hastings II H. Acute elbow dislocation: evaluation and management. J Am Acad Orthop Surg 1998; 6 (01) 15-23
• 11 Kuhn MA, Ross G. Acute elbow dislocations. Orthop Clin North Am 2008; 39 (02) 155-161 , v
• 12 O'Driscoll SW, Bell DF, Morrey BF. Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991; 73 (03) 440-446
• 13 O'Driscoll SW. Classification and evaluation of recurrent instability of the elbow. Clin Orthop Relat Res 2000; (370) 34-43
• 14 Cohen MS, Hastings II H. Rotatory instability of the elbow. The anatomy and role of the lateral stabilizers. J Bone Joint Surg Am 1997; 79 (02) 225-233
• 15 McAdams TR, Masters GW, Srivastava S. The effect of arthroscopic sectioning of the lateral ligament complex of the elbow on posterolateral rotatory stability. J Shoulder Elbow Surg 2005; 14 (03) 298-301
• 16 Dunning CE, Zarzour ZD, Patterson SD, Johnson JA, King GJ. Ligamentous stabilizers against posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 2001; 83 (12) 1823-1828
• 17 Hyman J, Breazeale NM, Altchek DW. Valgus instability of the elbow in athletes. Clin Sports Med 2001; 20 (01) 25-45 , viii
• 18 Jobe FW, Bradley JP. The diagnosis and nonoperative treatment of shoulder injuries in athletes. Clin Sports Med 1989; 8 (03) 419-438
• 19 Conway JE, Jobe FW, Glousman RE, Pink M. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 1992; 74 (01) 67-83
• 20 Nardi NM, Schaefer TJ. Nursemaid Elbow. Treasure Island. FL: StatPearls Publishing; 2020
• 21 Jeon IH, Micic ID, Yamamoto N, Morrey BF. Osborne-Cotterill lesion: an osseous defect of the capitellum associated with instability of the elbow. AJR Am J Roentgenol 2008; 191 (03) 727-729
• 22 Osborne G, Cotterill P. Recurrent dislocation of the elbow. J Bone Joint Surg Br 1966; 48 (02) 340-346
• 23 Chen NC, Ring D. Terrible triad injuries of the elbow. J Hand Surg Am 2015; 40 (11) 2297-2303
• 24 Dugas JR. Valgus extension overload: diagnosis and treatment. Clin Sports Med 2010; 29 (04) 645-654
• 25 Lian J, Mohamadi A, Chan JJ. et al. Comparative efficacy and safety of nonsurgical treatment options for enthesopathy of the extensor carpi radialis brevis: a systematic review and meta-analysis of randomized placebo-controlled trials. Am J Sports Med 2019; 47 (12) 3019-3029
• 26 Erickson BJ, Harris JD, Chalmers PN. et al. Ulnar collateral ligament reconstruction: anatomy, indications, techniques, and outcomes. Sports Health 2015; 7 (06) 511-517
• 27 Zubler V, Saupe N, Jost B, Pfirrmann CW, Hodler J, Zanetti M. Elbow stiffness: effectiveness of conventional radiography and CT to explain osseous causes. AJR Am J Roentgenol 2010; 194 (06) W515-W520