In 2007, we developed a new surgical treatment, ?superior capsule reconstruction (SCR),? to restore superior stability and muscle balance in the shoulder joint without repairing supraspinatus and infraspinatus tendon tears, consequently improving shoulder function?particularly deltoid muscle function?and relieving pain. The presence of indications for SCR is determined by preoperative magnetic resonance imaging. Goutallier grades 3 and 4 (fatty infiltration equal to, or more than, the muscle volume) are absolute indications. Moreover, in Goutallier grade 2, if the torn tendon is severely atrophied, degenerated, and thin, we recommend SCR. Irreparable rotator cuff tears of Hamada grades 1 to 3 are an absolute indication for ?fascia lata? SCR. Factors prognostic of clinical outcome are the degree of graft healing and the level of deltoid function. To decrease the rate of graft tear, a ?thick? and ?stiff? graft (6 to 8 mm thick) should be made by carefully determining the correct graft size. Concomitant cervical spinal (C5) palsy or axillary nerve palsy worsens clinical outcomes after surgery, resulting in poor shoulder function despite graft healing.
Keywords: autograft, fascia lata, irreparable, reconstruction, rotator cuff, shoulder, superior capsule, tear
Preoperative preparation for superior capsular reconstruction (SCR) is the same as for rotator cuff repair. The surgery can be performed either arthroscopically or by an open approach, and both the lateral decubitus position and the beach chair position are suitable. In my surgery, all procedures are performed under general anesthesia in the lateral decubitus position.
Three portals are typically required for arthroscopic SCR. An arthroscope (viewing portal) is placed in a posterior portal from beginning to end. An anterior portal and lateral portal are used as the working portal. For each suture anchor placement, its own small portal (4?5 mm) is created to make the best direction for anchor insertion, which decreases risk of anchor pullout. The graft is inserted though the lateral portal.
Subacromial bursal tissue around the torn tendons is completely removed before measurement of the defect size. The defect is then measured in the mediolateral (5 to 6 cm in most cases: from ?the superior glenoid,? not the edge of the torn tendon, to the lateral edge of the greater tuberosity) and anteroposterior (from the anterior edge to the posterior edge of the torn tendon) directions. Partial repair of the torn tendons makes the defect size decrease. However, the partial repair may cause inconsistent clinical results because of overtightening or possible re-tear of the repaired tendon.1 Therefore, the defect size should be measured without partial repair (? Video 21.1).
Fig. 21.1 Measurement of defect size and deciding on graft size. The size of the defect is measured in the mediolateral (from the superior glenoid to the lateral edge of the greater tuberosity) and anteroposterior (from the anterior edge to the posterior edge of the torn tendon) directions. The graft length in the anteroposterior direction is determined to be exactly the same as the length of the defect without partial repair of the torn tendon. In the mediolateral direction, the graft should be 15 mm longer than the distance from the superior glenoid to the lateral edge of the greater tuberosity to make a 10 mm footprint on the superior glenoid and allow for 5 mm of latitude in graft size.
The graft length in the anteroposterior direction is determined to be exactly the same as the length of the defect without partial repair of the torn tendon. In the mediolateral direction, the graft should be 15 mm longer than the distance from the superior glenoid to the lateral edge of the greater tuberosity to make a 10 mm footprint on the superior glenoid and allow for 5 mm of latitude in graft size. A biomechanical study has indicated that the appropriate graft thickness for SCR using the fascia lata is 6 to 8 mm.2 Therefore, the amount of fascia lata that we need to harvest will be at least double the estimated graft length or width.
Fascia lata is harvested beginning at the tip of the greater trochanter, with care to include the posterior, thicker tissue. The average thickness of a single layer of autologous fascia lata is 1 to 3 mm. Therefore, a graft thickness of 6 to 8 mm is achieved by folding the fascia lata two or three times. Also, the fascia lata includes an intermuscular septum that consists of the tissues of two tendons and connects the fascia lata to the femur. To make a thicker graft, this intermuscular septum should be included in the graft. The fascia lata is mostly thinner at its anterior aspect than posteriorly; therefore, to make a flat graft of even thickness, the intermuscular septum is usually sutured to the anterior surface of the fascia lata after being completely detached from it. All fatty tissue should be removed from the graft. Finally, the layers of fascia lata are united very closely with nonabsorbable sutures to prevent delamination after surgery.
Subscapularis tears should be repaired. Treatment of biceps is not necessary when SCR is performed. Preoperative biceps symptom is completely relieved without tenodesis or tenotomy after SCR. In my clinical experience, more than 95% of SCR were performed without biceps tenodesis or tenotomy and provided satisfactory results after surgery. In case of biceps dislocation, biceps tenodesis was performed.
Acromioplasty makes improved visualization during SCR, improved control of bleeding in the subacromial space, and increased concentrations of growth factors in the subacromial space, potentially improving tendon healing.3,4,5 The coracoacromial ligament and spurs on the anterior, lateral, or medial side should be resected to prevent subacromial impingement after surgery. Also, the inferior surface of the acromion is usually made flat. A biomechanical study showed that acromioplasty decreased contact area between the graft and undersurface of acromion, suggesting that acromioplasty may help to decrease the postoperative risk of abrasion and tearing of the graft beneath the acromion when SCR is performed for irreparable rotator cuff tears.6 Although acromioplasty is performed in all cases of SCR, we have had no cases of postoperative superior dislocation of the humeral head (? Video 21.2).
All soft tissue on the footprint of the superior glenoid should be removed to give a good bone bed before insertion of the suture anchors. Excessive resection of the cortical bone may lead to anchor pullout after surgery. Two 4.5-mm Corkscrew FT (Arthrex, Naples, FL) anchors are inserted, at the 10 or 11o?clock and 11 or 12o?clock positions on the glenoid of the right shoulder, and at the 12 or 1o?clock and 1 or 2o?clock positions on the left shoulder. Even for massive rotator cuff tears, two 4.5 mm Corkscrews are enough to prevent suture anchor pullout or graft tear on the glenoid (? Video 21.3).
Fig. 21.2 Harvesting the fascia lata. (a) Fascia lata is harvested beginning at the tip of the greater trochanter. (b) Fascia lata is cut along the proximal, anterior, and distal marks. (c) After that, the fascia lata is flipped over. The fascia lata includes an intermuscular septum (asterisk) that consists of the tissues of two tendons and connects the fascia lata and the femur. To make a thicker graft, this intermuscular septum should be included in the graft.
Fig. 21.3 (a) The reverse side of the harvested fascia lata. The fascia lata tends to be thinner anteriorly. (b, c) Therefore, to make a flat graft of even thickness, the intermuscular septum (asterisk) is usually sutured to the anterior surface of the fascia lata after being detached from it. Then the fascia lata is folded. (d) Finally, the layers of fascia lata are united by using nonabsorbable sutures.
Fig. 21.4 Superior capsule reconstruction.The graft is attached medially to the superior glenoid and laterally to the greater tuberosity. This is followed by side-to-side suturing between the graft and the infraspinatus or teres minor tendon. (a) Compression double-row repair technique, and (b) SpeedBridge (Arthrex, Naples, FL) repair technique.
All soft tissue on the footprint of the greater tuberosity should be removed. Excessive resection of the cortical bone, which may lead to anchor pullout after surgery, is not recommended for SCR. Two 4.75-mm SwiveLock (Arthrex) anchors with Fiber-Tape (Arthrex) are inserted on the medial footprint of the greater tuberosity to make a SpeedBridge (Arthrex) (? Fig. 21.4). Alternatively, when we fix the graft to the greater tuberosity by using a compression double-row repair technique, two 4.5-mm Corkscrew FT anchors are inserted on the medial footprint (? Fig. 21.4, ? Video 21.4).
A 10 cc syringe is used as a cannula. FiberWire (Arthrex) from the superior glenoid suture anchors is placed through the fascia lata in a mattress fashion when the graft is still outside the body. After all FiberWires have been placed through the fascia lata, the graft is inserted in its appropriate place on the glenoid. All sutures are then tied in the subacromial space (? Video 21.5).