SURGICAL TECHNIQUE – ARTHROSCOPIC DISTAL CLAVICLE RESECTION – MUMFORD
Subacromial Approach Technique: Patients with Associated Subacromial Symptoms
1. Perform arthroscopic glenohumeral exam through standard posterior and high anterior portal. Address any intra-articular pathology.
2. Perform subacromial exam utilizing the same anterior and posterior skin incisions and a lateral portal 2.5-3.0 cm lateral and slightly anterior to the midpoint of the acromion.
3. Utilize posterior portal as viewing portal initially. Utilize same anterior portal as outflow cannula. Lateral portal for shaver/burr. (Figure 1)
|Figure 1. Portal position for right shoulder glenohumeral exam, subacromial decompression and distal clavicle resection. Scope posteriorly; gray cannula in lateral portal; blue cannula in anterior superior portal; needle at anterior AC portal|
4. Perform a bursectomy and coracoacromial ligament release and/or subacromial decompression as indicated from preoperative evaluation and arthroscopic exam.
5. If decompression indicated, utilize a two-portal cutting block technique except in a very thin, broad anterior hooked acromion for which a limited anterior hook resection is performed from a lateral portal while visualizing from posterior. (Figure 2A, 2B)
|Figure 2A. Posterior view of debrided undersurface of right acromion with shaver tip on coracoacromial ligament. Anterior lateral corner of acromion to right.
|Figure 2B. Posterior view: Small amount of anterior and lateral acromial bone resection with burr on lateral edge of CA ligament.
6. View from lateral portal as bring burr brought forward from posterior to anterior converting curved acromion to flat type 1 surface. (Figure 3A-C)
|Figure 3A. Subacromial lateral view of planing from posterior (left) to anterior (right).
|Figure 3B. Further planing with tip of clavicle
visible under tip of burr.
|Figure 3C. Completed decompression with inferior clavicle partially resected – lateral view.
7. With burr or cautery/ablation device in the posterior portal, sweep medially from the anterior ½ of acromion to resect/ablate the inferior A-C joint capsule. Expose the tip of the distal clavicle. (Figure 3C)
8. Resect the inferior 1/3 or ½ of clavicle with the burr from posterior. Keep burr opening directed toward the center of the clavicle and move from posterior to anterior and medially approximately 1.0-1.5 cm.
9. Manual pressure from superiorly downward on the clavicle delivers more of the remaining clavicle for resection.
10. Fashion an anterior angle of the resected vertical clavicle wall and the unresected remaining horizontal line of superior clavicle (Figure 4)
|Figure 4. Posterior view of undersurface of
acromion (right), AC line, and
clavicle (left) with inferior half of clavicle resected.
11. Introduce a percutaneous 18 gauge needle at the apex of the angle, incise skin , then bring in a burr from this anterior A-C portal. (Figure 5)
12. Place scope in the posterior portal and rotate scope upward to view the remaining superior clavicle and A-C gap. (Figure 5)
|Figure 5. Scope is placed posteriorly with
burr introduced from anterior-inferior AC portal.
13. With burr anterior, resect the remaining superior clavicle from anterior to posterior. Direct burr from anterior to superior and lateral to medial and proceed posteriorly. (Figure 6)
|Figure 6. Burr from anterior resecting remaining
14. Remove the remaining superior cortical shell of bone. (Figure 7)
|Figure 7. Superior clavicle resected
exposing superior capsule.
15. Rotate the scope from superior to medial. This exposes the posterior cortex and posterior-superior capsule. Make sure posterior bone is resected evenly and that the gap of resection is even from front to back. (Figure 8)
|Figure 8. Scope rotated medially to view completed
clavicle resection. Posterior superior capsule intact.
16. If bursa tissue compromises visualization, either debride or insert scope through lateral portal. If superior visualization is poor, use a 70-degree scope.
|Patients with Isolated AC Disease and No Subacromial Symptoms|
17. If the glenohumeral joint looks pristine, one can complete the 15 point exam from the posterior portal using a 70 degree scope and not utilize an anterior-superior portal.
18. Redirect the scope into the subacromial bursa from the posterior portal.
19. Direct the cautery/ablation tip medially from a lateral portal 2.5-3.0 cm lateral to the midpoint of the acromion. Resect the inferior A-C capsule. Once the AC joint has been exposed, introduce the burr from the lateral portal.
20. Resect the inferior 1.0-1.5 cm of inferior clavicle. Scope can be inserted through the lateral portal for visualization of the posterior clavicle if needed.
21. Place scope in the posterior portal and make an anterior A-C portal as before with the aid of an 18 gauge needle. Resect the remaining superior clavicle from anterior to posterior as noted above keeping the gap even.
22. Three portals rather than four are thus utilized for isolated AC joint disease.
|With or Without Subacromial Decompression|
23. Exam A-C gap.
24. Make sure all cortical bone superiorly is removed. Make sure the resection is even from anterior to posterior.
25. Measure the width of the gap with two superior percutaneous18 gauge needles. (Figure 9) With any previous AC instability, resect 10-15mm of bone. (Figure 10A and 10B)
|Figure 9. Needles placed percutaneously in a parallel fashion to measure the amount of distal clavicle resection.|
|Figure 10A. Arthroscopic view of gap with needles.|
|Figure 10B. Lateral view of acromion (posterior to left) and resected end of clavicle.|
26. Reduce pump pressure.
27. Use electrocautery device to obtain hemostasis of larger vessels.
28. No immobilization is necessary unless an associated rotator cuff repair is performed.