TY - JOUR
T1 - Importance of the posterior bundle of the medial ulnar collateral ligament
AU - Shukla, Dave R.
AU - Golan, Elan
AU - Nasser, Philip
AU - Culbertson, Maya
AU - Hausman, Michael
N1 - Publisher Copyright:
© 2016 Journal of Shoulder and Elbow Surgery Board of Trustees
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Background There has been a renewed interest in the pathomechanics of elbow dislocation, with recent literature having suggested that the medial ulnar collateral ligament is more often disrupted in dislocations than the lateral ligamentous complex. The purpose of this serial sectioning study was to determine the influence of the posterior bundle of the medial ulnar collateral ligament (pMUCL) as a stabilizer against elbow dislocation. Methods An elbow dislocation was simulated in 5 cadaveric elbows by mechanically applying an external rotation moment and valgus force. Medial ulnohumeral joint gapping was measured at 30°, 60°, and 90° of flexion in an intact elbow after sectioning of the medial collateral ligament's anterior bundle (aMUCL) and then after sectioning of the pMUCL as well. Results After sectioning of the aMUCL, the pMUCL was able to stabilize the joint against dislocation. After aMUCL sectioning, the proximal joint space significantly increased by 4.2 ± 0.6 mm at 30° of flexion and 2.6 ± 0.3 mm at 60° of flexion, although it did not dislocate. The gapping increase of 0.9 ± 0.6 at 90° of flexion did not reach significance. After sectioning of the pMUCL (after having already sectioned the aMUCL), all of the specimens frankly dislocated at all flexion angles. Conclusions An intact pMUCL can prevent elbow dislocation and limited joint subluxation to within 6.6 mm. Our findings indicate that repair or reconstruction may be warranted in certain circumstances (ie, residual instability after operative management of a terrible triad injury or after aMUCL reconstruction).
AB - Background There has been a renewed interest in the pathomechanics of elbow dislocation, with recent literature having suggested that the medial ulnar collateral ligament is more often disrupted in dislocations than the lateral ligamentous complex. The purpose of this serial sectioning study was to determine the influence of the posterior bundle of the medial ulnar collateral ligament (pMUCL) as a stabilizer against elbow dislocation. Methods An elbow dislocation was simulated in 5 cadaveric elbows by mechanically applying an external rotation moment and valgus force. Medial ulnohumeral joint gapping was measured at 30°, 60°, and 90° of flexion in an intact elbow after sectioning of the medial collateral ligament's anterior bundle (aMUCL) and then after sectioning of the pMUCL as well. Results After sectioning of the aMUCL, the pMUCL was able to stabilize the joint against dislocation. After aMUCL sectioning, the proximal joint space significantly increased by 4.2 ± 0.6 mm at 30° of flexion and 2.6 ± 0.3 mm at 60° of flexion, although it did not dislocate. The gapping increase of 0.9 ± 0.6 at 90° of flexion did not reach significance. After sectioning of the pMUCL (after having already sectioned the aMUCL), all of the specimens frankly dislocated at all flexion angles. Conclusions An intact pMUCL can prevent elbow dislocation and limited joint subluxation to within 6.6 mm. Our findings indicate that repair or reconstruction may be warranted in certain circumstances (ie, residual instability after operative management of a terrible triad injury or after aMUCL reconstruction).
KW - Elbow instability
KW - elbow dislocation
KW - elbow trauma
KW - medial collateral ligament posterior bundle
KW - posterolateral rotatory instability
KW - recurrent elbow instability
UR - http://www.scopus.com/inward/record.url?scp=84973526717&partnerID=8YFLogxK
U2 - 10.1016/j.jse.2016.04.008
DO - 10.1016/j.jse.2016.04.008
M3 - Article
C2 - 27282737
AN - SCOPUS:84973526717
SN - 1058-2746
VL - 25
SP - 1868
EP - 1873
JO - Journal of Shoulder and Elbow Surgery
JF - Journal of Shoulder and Elbow Surgery
IS - 11
ER -