Bankart Lesion

Bankart Lesions are seen in anterior shoulder instability, it’s either a detachment of the anteroinferior capsulolabral glenoid complex or a bony Bankart which is a fracture of the anteroinferior glenoid rim of the shoulder.

Bankart lesion

Detachment of the anteroinferior glenoid labrum (also known as a Bankart lesion) is thought to occur in up to 90 % of cases of traumatic anterior instability and has traditionally been referred to as the “essential lesion” of traumatic shoulder dislocation. When the soft tissue defect is associated with periosteal stripping of the glenoid neck without medial displacement of the labral tissue, it is typically referred to as a “Perthes lesion”.

Despite its near-universal presence in cases of traumatic instability, soft-tissue Bankart lesions alone are not a frequent cause recurrent instability. Rather, the underlying cause is most often multifactorial with particular focus on redundancy and plastic deformation of the IGHL complex.

See Also: Anterior Shoulder Instability

Bony Bankart Lesion

Anterior shoulder dislocations can also create fractures of the anteroinferior glenoid rim (bony Bankart lesions). These fractures can range in morphology and size depending on the direction of load transmission.

Loss of bone from the anterior glenoid from any cause decreases glenoid concavity and increases the potential for recurrent dislocations. In general, as the size of the lesion increases, glenohumeral stability decreases.

Several biomechanical studies have shown that defects measuring more than one half of the glenoid length decrease joint stability by up to 30 %. Others have shown that soft tissue Bankart repair is not adequate for defects involving at least 20–25 % of the inferior glenoid diameter.

The bone fragment in a bony Bankart lesion has been shown to undergo rapid absorption within 1 year of the primary injury

See Also: Shoulder SLAP Lesion

Reversed Bankart Lesion

Reversed Bankart Lesion occurs in posterior shoulder instability, it is a posteroinferior labrum detachment with avulsion of posterior capsular periosteum.

References

1. Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy. 2000 Oct;16(7):677-94. doi: 10.1053/jars.2000.17715. PMID: 11027751.
2. Wischer TK, Bredella MA, Genant HK, Stoller DW, Bost FW, Tirman PF. Perthes lesion (a variant of the Bankart lesion): MR imaging and MR arthrographic findings with surgical correlation. AJR Am J Roentgenol. 2002;178(1):233–7.
3. Baker CL, Uribe JW, Whitman C. Arthroscopic evaluation of acute initial anterior shoulder dislocations. Am J Sports Med. 1990;18(1):25–8.
4. Taylor DC, Arciero RA. Pathologic changes associated with shoulder dislocations. Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations. Am J Sports Med. 1997;25(3):306–11.
5. Speer KP, Deng X, Borrero S, Torzilli PA, Altchek DA, Warren RF. Biomechanical evaluation of a simulated Bankart lesion. J Bone Joint Surg Am. 1994;76(12):1819–26.
6. Boileau P, Villalba M, Héry JT, Balg F, Ahrens P, Neyton L. Risk factors for recurrence of shoulder instability after arthroscopic Bankart repair. J Bone Joint Surg Am. 2006;88(8):1755–63.
7. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. J Bone Joint Surg Am. 2000;82(1):35–46.
8. Yamamoto N, Itoi E, Abe H, Kikuchi K, Seki N, Minagawa H, Tuoheti Y. Effect of an anterior glenoid defect on anterior shoulder stability: a cadaveric study. Am J Sports Med. 2009;37(5):949–54.