Remplissage Procedure: When and How?

Hill-Sachs lesions were first described in 1940 as grooved defect in the posterior aspect of the humeral head associated with traumatic anterior glenohumeral dislocation. The reported incidence of Hill-Sachs lesions following traumatic anterior instability events ranges from 60% to 90%. Despite recognition of the Hill-Sachs lesion for more than 75 years, most shoulder stabilization procedures have focused on repairing or augmenting the torn or deficient anterior soft tissues and glenoid bone in hopes of preventing engagement of the posterior humeral head defect. To help identify lesions that are important causes of instability, both Palmer and Widen and Burkhart and De Beer described the ‘‘engaging’’ Hill-Sachs lesion, which refers to one that engages the rim of the glenoid when the shoulder is physiologically abducted and externally rotated. Engaging Hill-Sachs lesions lead to recurrent instability, and a high rate of failure when treated with arthroscopic Bankart repair alone. There are two methods to assess the Hill-Sachs lesion related with surgical decision making for concomitant remplissage procedure. One method is dynamic examination. During arthroscopic surgery, the relative relationship between the Hill-Sachs lesion and the glenoid can be assessed. The important thing is that this dynamic examination should be performed after the Bankart repair. The disadvantage of this method is that there is a risk of damaging the repair during the dynamic examination. The second method is to use the ‘glenoid track’ concept. The width of the glenoid track, defined as the distance between the medial margin of the glenoid track and the medial margin of the footprint of the rotator cuff was 83% of the glenoid width when the arm was at 90° of abduction in live shoulders. Our institution use en face views of both glenoids and the posterior view of the involved humeral head on 3D CT. First, we measure the width of the intact glenoid and calculate 83% of the glenoid width(0.83D). Then, this 83% value (0.83D) is applied to the involved glenoid en face view. If there is a bony defect of the glenoid, the defect width ‘d’ needs to be subtracted from the 83% value (0.83D) to obtain the true width of the glenoid track (0.83D - d). We apply this width (0.83D - d) to the posterior view of the humeral head. If the medial margin of the Hill-Sachs le stays within the glenoid track, there is no risk that this Hill-Sachs lesion engages with the anterior rim of the glenoid. If the Hill-Sachs lesion extends more medially over the medial margin of the glenoid track, there is a risk of engagement and dislocation. The former used to be called ‘on-track HSL’ and the latter ‘off-track Hill-Sachs lesion’. Based on the on-track/off-track concept, treatment strategy is as follows. For shoulders with on-track Hill-Sachs lesion and glenoid bone loss of < 25%, Bankart repair alone is sufficient. With on-track Hill-Sachs lesion and glenoid bone loss of ≥ 25%, the glenoid bone loss needs to be fixed, for example by the Latarjet procedure. With off-track Hill-Sachs lesion and the glenoid bone loss of < 25%, Bankart repair plus remplissage is needed. In addressing recurrent anterior shoulder instability, surgical decision making for additional remplissage procedure is inevitable. There are two methods: one is glenoid track method which can be employed in preoperative evaluation. The other is assessment of engaged Hill-Sachs lesion during arthroscopic evaluation. Which one do you prefer? REFERENCES: 1. Hill, H.A. and M.D. Sachs, The grooved defect of the humeral head: a frequently unrecognized complication of dislocations of the shoulder joint. Radiology, 1940. 35(6): p. 690-700. 2. Burkhart, S.S. and J.F. De Beer, 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: The Journal of Arthroscopic & Related Surgery, 2000. 16(7): p. 677-694. 3. Flatow, E.L. and J.J. Warner, Instability of the shoulder: Complex problems and failed repairs: Part 1. Relevant biomechanics, multidirectional instability, and severe loss of glenoid and humeral bone. Journal of Bone and Joint Surgery, 1998. 80(1): p. 122. 4. Lynch, J.R., et al., Treatment of osseous defects associated with anterior shoulder instability. Journal of shoulder and elbow surgery, 2009. 18(2): p. 317-328. 5. Buza, J.A., 3 rd, et al., Arthroscopic Hill-Sachs remplissage: a systematic review. J Bone Joint Surg Am, 2014. 96(7): p. 549-55. 6. Spatschil, A., et al., Posttraumatic anterior-inferior instability of the shoulder: arthroscopic findings and clinical correlations. Archives of orthopaedic and trauma surgery, 2006. 126(4): p. 217-222. 7. Yiannakopoulos, C.K., E. Mataragas, and E. Antonogiannakis, A comparison of the spectrum of intra-articular lesions in acute and chronic anterior shoulder instability. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2007. 23(9): p. 985-990. 8. Itoi, E., ‘On-track’ and ‘off-track’ shoulder lesions. EFORT Open Rev, 2017. 2(8): p. 343-351. 9. Parke, C., et al. Arthroscopic remplissage for humeral defect in anterior shoulder instability: is it needed. in 39th annual meeting of Japan Shoulder Society, Tokyo. 2012. 10. Yamamoto, N., et al., Contact between the glenoid and the humeral head in abduction, external rotation, and horizontal extension: a new concept of glenoid track. Journal of shoulder and elbow surgery, 2007. 16(5): p. 649-656. 11. Omori, Y., et al., Measurement of the glenoid track in vivo as investigated by 3-dimensional motion analysis using open MRI. The American journal of sports medicine, 2014. 42(6): p. 1290-1295. 12. Di Giacomo, G., E. Itoi, and S.S. Burkhart, Evolving concept of bipolar bone loss and the Hill-Sachs lesion: from “engaging/non-engaging” lesion to ”on-track/off-track” lesion. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2014. 30(1): p. 90-98. 13. Locher, J., et al., Hill-Sachs off-track lesions as risk factor for recurrence of instability after arthroscopic Bankart repair. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2016. 32(10): p. 1993-1999. 14. Shaha, J.S., et al., Clinical validation of the glenoid track concept in anterior glenohumeral instability. JBJS, 2016. 98(22): p. 1918-1923. 15. Yamamoto, N., et al., The stabilizing mechanism of the Latarjet procedure: a cadaveric study. JBJS, 2013. 95(15): p. 1390-1397. 16. Connolly, J., Humeral head defects associated with shoulder dislocation: their diagnostic and surgical significance. Instr. Course Lect., 1972. 2: p. 210-218. 17. Purchase, R.J., et al., Hill-Sachs “remplissage”: an arthroscopic solution for the engaging Hill-Sachs lesion. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2008. 24(6): p. 723-726. 18. Boileau, P., et al., Arthroscopic Hill-Sachs Remplissage with Bankart Repair: Strategy and Technique. JBJS Essent Surg Tech, 2014. 4(1): p. e4.