Arthroscopic Bursal Acromial Reconstruction With a Porcine Extracellular Matrix Graft

Abstract

Reinsertion of superior or posterosuperior rotator cuff ruptures in the elderly is often not possible. Patients can be left with symptoms of pain, loss of strength, and active range of motion. Bursal acromial reconstruction is an anchorless operative treatment method for painful, irreparable superior or posterosuperior rotator cuff ruptures in the elderly with a functional range of motion. This article describes our bursal acromial reconstruction technique using a porcine dermal xenograft.

Chronic irreparable superior rotator cuff tears can lead to an unstable and superiorly displaced glenohumeral fulcrum resulting in painful collision of the humeral head against the undersurface of the acromion during shoulder abduction. ¹ , ² Often, surgical reinsertion of such defects is impossible. These patients are left with symptoms of pain, loss of strength, and a full active range of motion.

Some patients over the age of 70 years achieve less satisfying results with physiotherapy. ¹ , ² , ³ , ⁴ , ⁵ Surgical options are debridement and subacromial decompression without violating the coracoacromial ligament, tenotomy of the long head of the biceps, or partial rotator cuff repair. A reverse shoulder arthroplasty is an often used technique, too. ² , ⁴ , ⁶ , ⁷ , ⁸ , ⁹ Superior capsular reconstruction is possibly not an optimal choice for the elderly patient because of expected osteopenic bone which might not yield proper fixation over several anchors which are necessary with that technique. ⁹ , ¹⁰ , ¹¹ , ¹² , ¹³

For elderly patients with no or modest glenohumeral cartilage breakdown, a new operative technique, bursal acromial reconstruction (BAR), has been developed using a human dermal allograft. ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷ With this technique, an artificial interpositional graft is fixed to the underside of the acromion without the use of anchors. The graft is a substitute for the upper glenohumeral capsule, the supraspinatus tendon, and its overlying subacromial bursa. The graft functions as a passive, stationary interpositional subacromial arthroplasty that is thought to relieve painful impaction between the humeral head and the inferior acromion when the arm is elevated. ¹⁴ , ¹⁸ , ¹⁹ We describe a modified BAR technique using a porcine dermal xenograft.

SURGICAL TECHNIQUE

The operation is performed entirely arthroscopically under general anesthesia in the beach‐chair position. The operated arm is draped and fixed in a Trimano Support Arm system (Arthrex, Naples, FL) adjacent to the torso. At first, a posterior portal is established. Tendon remnants are released from adhesions (Video 1), and it is examined whether a tension‐free tendon reinsertion can be performed. If not, a porcine xenograft is implanted. All defect tendon and bursal remnants are debrided. Then, a gentle subacromial decompression is performed to obtain smooth bleeding bone but not to correct any acromial natural curvation. The coracoacromial ligament is preserved. Next, a small acromioclavicular joint resection for suture passage is performed (Figure 1). The covered graft area spans from the anterior acromion to posteriorly at the level of the scapular spine and from lateral to medial across the acromion. The area is approximately 25 (width) × 35 (length) mm (Video 1).

VIDEO 1.

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The operation is executed under general anesthesia in the beach‐chair position and entirely arthroscopically on the left shoulder. Nine portals are used: 1 anterior, 1 primary posterior, 1 midlateral, 3 medial, and 3 lateral portals. All adhesions are removed from the remaining superior rotator cuff and from the subacromial space. If the tendon defect cannot be repaired, a gentle subacromial decompression is performed, preserving the coracoclavicular ligament. An acromioclavicular joint resection is performed, only on the clavicular side except for any larger acromial‐side osteophytes that are also removed, too. The debrided acromial bone is measured in 2 planes, and 2 pieces of porcine graft material are cut and glued together. A looped FiberLink Suture Tape is placed in each corner, and 2 further FiberLink Suture Tapes are placed in the middle of each long side of the graft. The graft is introduced by pulling the 3 medial SutureLink Suture Tapes through the Gemini working cannula and the Neviaser portal with a separate looped SutureLink Suture Tape. The anteromedial and medial sutures are then shuttled through the anterior and midacromioclavicular portals. The 3 lateral sutures are shuttled through 3 separate lateral portals. The medial sutures are retrieved submuscularly directly across the acromion through the lateral portals and tied statically to the lateral acromial bone border with a knot pusher. Suture ends are cut and the 9 portals are sutured. Video content can be viewed at https://doi.org/10.1002/atn2.70341.

FIGURE 1.

A left shoulder. With the arthroscope viewing from the posterior portal, a gentle subacromial decompression to achieve bleeding bone is performed with the burr from the lateral portal. An acromioclavicular resection is performed to obtain room for suture passage. Only the cartilaginous clavicular side of the joint is resected to avoid a potential acromion fracture (arrow).

Two rectangular pieces of the 1.5‐mm‐thick xenograft are cut and glued together with a Leukosan tissue adhesive glue (Essity Medical Solutions, Germany). An arrow is drawn on the underside of the graft to assist in pointing the graft toward the anterior acromion. Six FiberLink Suture Tapes (Arthrex) are pierced through the perimeter of the graft: one in each corner, one on the midst of the lateral side and one on the midst of the medial side, and the suture tapes are then locked on their own loop (Figure 2). No suture material is passed across the graft to avoid any cutting of suture thread into the humeral head.

FIGURE 2.

The xenograft is prepared on a side table. The porcine graft material is 1.5 mm thick. After measurement, 2 rectangular pieces are cut, typically 35 mm in length by 25 mm in width. The 2 layers are glued together, making the xenograft patch 3 mm thick. Six FiberLink Suture Tapes are pierced through the perimeter of the graft (arrow) with a Scorpion (Arthrex) antegrade suture passer. Different colors of suture tape can be used to make it easier to identify the correct tapes in the subacromial space. The glue dries in approximately 5 minutes, and the graft is ready for introduction in to the shoulder.

Next, 3 medial portals are established. One is at the anterior border of the acromioclavicular joint, one in the middle of the acromioclavicular joint, and the third is the Neviaser portal. A lateral portal is established, a Gemini cannula (Arthrex) is inserted, and the 3 medial sutures are passed together into the joint using a FiberLink suture loop from the Neviaser portal where there is particularly little subacromial space. The graft is rolled and passed through the cannula without its inner transparent sleeve. The graft is then unfolded with a grasper in the subacromial space with the arrow pointing anteriorly. Then, the lateral sutures are pulled out through 3 separately established portals, an anterolateral, a midlateral, and a posterolateral portal. The 2 anterior medial sutures are pulled through the 2 corresponding anterior medial portal sites. The graft is positioned with its contour matching the acromion (Figure 3). Through the lateral portals, the corresponding medial sutures are retrieved transversely with a grasper superior to the acromion and through the deltoid muscle adjacent to the superior acromial bone, pulled through the lateral portals and tied at the lateral acromial bone border with 3 static knots (Figure 4). Hence, the graft is fixed to the underside of the acromion (Figure 5). No tuberoplasty is performed.

FIGURE 3.

Seen with the arthroscope in the posterior portal, the graft has been introduced to the subacromial space through a Gemini working portal (Arthrex) and positioned with its contour matching the acromion (arrow). An arrow is drawn on the inferior side of the graft pointing toward its anterior end to help with orientation and correct placement of the graft in the subacromial space.

FIGURE 4.

The patient is seen in the beach‐chair position. Through the lateral portals, the medial sutures are retrieved supra‐acromially and tied to the lateral sutures at the lateral acromial border. The 3 lateral portals have been placed a little higher than conventionally to facilitate easier retrieval of the medial sutures over the acromion (arrow). In this way, the medial sutures are harvested submuscularly through the deltoid muscle with a Kingfisher grasper (Arthrex). The lateral sutures are retrieved from the subacromial space from the same lateral portals. The lateral and medial sutures are then tied with 3 static knots using a knot pusher, anterolateral suture to anteromedial suture, midlateral suture to midmedial suture, and posterolateral suture to posteromedial suture. Thus, each suture set is tied directly across the acromion in a 90° orientation to the long side of the graft and acromion, not diagonally. Care is taken not to shift the graft away from the debrided acromial bone site when the first and second suture sets are tied.

FIGURE 5.

Seen with the arthroscope in the posterior portal, the graft is now fixed to the underside of the acromion with the arrow pointing anteriorly (arrow).

Postoperatively, a sling is used for 3 to 6 weeks. The arm is only fixed to the abdomen during nighttime in the first 3 weeks. The shoulder is passively mobilized during the first week. Thereafter, the patient starts with an active range of movement to 60° of scaption for 1 week. After this, there are no restrictions to the range of motion. The intact rotator cuff tendons are activated and open‐chain exercises performed. From week 7, the posterior capsule is stretched, and light external loading of the shoulder is allowed. The graft should be healed to bone within 3 months, and the shoulder can then be loaded freely as long as this is pain free. ¹⁵

DISCUSSION

The indication for BAR is an irreparable painful single tendon supraspinatus tendon defect or larger to massive posterosuperior tendon defects in patients with a functional range of motion. ¹⁴ , ¹⁵ The presented BAR technique likely functions as a static 3‐mm‐thick subacromial interpositional cushion between the inferior acromion and superior humeral head to minimize collision pain and secondarily to improve active elevation over the joint with the remaining intact cuff tissue. ² , ⁴ , ²⁰

There are no diagonal sutures crossing the graft in the subacromial space which could otherwise cut into the upper humeral head, possibly leading to pain (Table 1). The xenograft used in this study is 3 mm thick at the time of implantation. Because the graft probably functions as a cushion in the subacromial space, increased graft thickness might yield better results because of pressure absorption and possibly yield more stability (Table 2). However, the use of a thicker graft could carry the risk of increased rates of graft tearing and possible erosion of the greater tubercle. ¹³ , ²¹

TABLE 1.

Pearls and Pitfalls of Our Technique

Pearls	Pitfalls
Differently colored suture tapes and a drawn arrow on the xenograft help in subacromial orientation	Suture management can be technically challenging because of the number of sutures and portals
An acromioclavicular joint resection allows for easier medial suture passage	Portals must be placed precisely to achieve uniform expansion of the graft under the acromion
Medial sutures are initially passed through the Neviaser portal where space is most limited	The minimal subacromial space after the graft has been introduced challenges arthroscopic orientation

TABLE 2.

Advantages and Disadvantages

Advantages	Disadvantages
100% arthroscopic procedure	Learning curve when initially performing the technique
Equipment cost‐efficient salvage operation with no use of anchors or special introducer equipment	No mid‐ to long‐term results exist
Compared with RSA, time costs are lower by BAR being an outpatient procedure	Unknown rate of revision
Compared with RSA, salary costs could be lower with BAR because it could be performed without additional operating personnel	A limited number of surgeons will be able to offer the procedure
There is no donor‐site morbidity involved because the graft is a xenograft	The price of the procedure is higher using a xenograft compared with using an autograft
No tendon is cut to implant the BAR xenograft
Potentially lesser accumulated rate of infection compared with RSA in which case long‐term costs could be minimized with BAR

BAR, bursal acromial reconstruction; RSA, reverse shoulder arthroplasty.

BAR is relatively low in cost because no anchors are used, only sutures and the graft. The xenograft is cheaper than a human dermal allograft. The porcine graft probably does not have any superior mechanical or histological properties compared with human allografts or autografts. Choosing an autograft could lead to donor site morbidity in the form of infection, excessive scar formation or chronic harvest site pain. ²² BAR is a relatively technically demanding procedure. A stable fixation of the graft is mandatory. Other critical factors for a good result are patient compliance and the quality of rehabilitation. Also, should the BAR fail or any severe arthropathy symptoms develop, a reverse shoulder arthroplasty can be offered. BAR can be performed arthroscopically in a minimally invasive fashion which has potential benefits for postoperative rehabilitation. ²³ , ²⁴ Clinical studies are needed to investigate the clinical and structural impact that the presented BAR xenograft technique yields regarding graft integrity, differences in results for patients who had traumatic tendon defects compared with degenerative defects, and improvements in function and pain levels.

DISCLOSURES

The authors (A.U., C.S.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.