PREOPERATIVE CONSIDERATIONS

Bone loss is frequently associated with chronic traumatic glenohumeral instability on the glenoid side or humeral side.^1–4 Significant bone loss, often characterized by an inverted pear glenoid or engaging Hill-Sachs lesion, is believed to be a main cause of failure after arthroscopic stabilization.^5–7

According to a three-dimensionally reconstructed computed tomography (CT) study with the humeral head digitally subtracted, the prevalence of glenoid bone defect has been reported as high as 90% in shoulders with chronic recurrent traumatic anterior instability.⁸ In addition, a bony fragment is present at the anteroinferior portion of the glenoid neck in about half of shoulders with glenoid bone loss.⁸ Furthermore, bone loss in shoulders associated with a bony fragment is relatively significant compared with that in shoulders with attritional glenoid loss without a bony fragment.^8,9

ANATOMY AND PATHOANATOMY

Lo and colleagues⁷ and Burkhart and associates¹⁰ have defined the inverted pear glenoid as more than 25% to 30% loss of diameter in the inferior glenoid circle. Burkhart and DeBeer⁵ have recommended a bone grafting procedure for these shoulders based on their clinical outcome after arthroscopic soft tissue repair.

We have investigated a consecutive series of 121 glenoids in shoulders with chronic recurrent traumatic anterior instability, including 97 males and 24 females with an average age of 24 years (range, 13 to 54 years), using three-dimensional CT.¹¹ The percentage defect of the glenoid was defined as a ratio of defect width against the diameter of the assumed circle based on the inferior portion of each glenoid (Fig. 14-1).⁹ The results demonstrated that 19 out of 121 glenoids (15.7%) were measured and showed more than 25% bone loss, with a mean percentage defect of 30.2% (range, 25.0% to 43.8%). Interestingly, a bone fragment was confirmed in 18 out of 19 glenoids in these shoulders (94.7%). Furthermore, in 9 glenoids (7.4%) that were measured and demonstrated more than 30% bone loss with 35.6% mean percentage defect (range, 30.6% to 43.8%), a bone fragment was confirmed in all shoulders. Therefore, it was concluded that most shoulders with a large glenoid bone defect, which corresponds to the so-called inverted pear glenoid,⁷ retain an associated bone fragment (Table 14-1).¹¹

FIGURE 14-1 Quantifying method of the glenoid bone loss. The percentage defect of the glenoid is defined as a ratio of defect width against the diameter of the assumed inferior circle of the glenoid (b/A).

(From Sugaya H, Moriishi J, Kanisawa I, Tsuchiya A. Arthroscopic osseous Bankart repair for chronic recurrent traumatic anterior glenohumeral instability. J Bone Joint Surg Am. 2005;87:1752-1760.)

TABLE 14-1 Presence of Bone Fragment in Large Glenoid Bone Defect

* The values are given as the number of glenoids, with percentage in parenthesis.

HISTORY AND PHYSICAL EXAMINATION

The diagnosis of recurrent traumatic anterior glenohumeral instability is usually made easily on the basis of the history of distinct dislocation or subluxation and the positive apprehension sign. However, when collision athletes are seen, care should be taken because they may not experience clear dislocation or subluxation and only complain of pain or weakness when they bring their arm to maximum external rotation in abduction. In addition, many collision athletes do have a minimally displaced bony Bankart lesion, often without a concomitant Hill-Sachs lesion, in which the arthroscopic finding demonstrates clear evidence of anteroinferior instability, but without dislocation or subluxation (Fig. 14-2).

FIGURE 14-2 Minimally displaced bony Bankart lesion seen in a collision athlete. The patient did not experience clear dislocation or subluxation but complained of pain and weakness at a certain arm position. A, En face view of the glenoid. B, Oblique view of the glenoid. C, Arthroscopic finding.

The anterior apprehension test is done with the patient in the supine position. In this test, the shoulder is moved passively into maximum external rotation with the arm at the side in 30, 60, 90, 120, and 150 degrees of abduction and maximum flexion. At the same time, the posterior apprehension test is done, with the arm at maximum internal rotation in 90 degrees of abduction. The feeling of apprehension is reported in each arm position. However, the most important and reliable physical examination can usually be done with the patient under anesthesia, comparing stability testing with the contralateral extremity (Fig. 14-3).

FIGURE 14-3 Examination under general anesthesia (EUA). In the beach chair position, EUA is easily done on both sides. The humeral head translation is evaluated with shoulder in 90 degrees of abduction in neutral rotation. A, View from the side. B, View from the top.

DIAGNOSTIC IMAGING

X-ray images are sometimes helpful for detecting the Hill-Sachs lesion and the anterior glenoid rim lesion,³ especially during the first patient visit. Bernageau¹² has described a unique method for detecting an anterior glenoid rim lesion with the patient in the standing position. However, this technique requires fluoroscopic control to obtain optimal diagnosable images and, therefore, radiation exposure is an issue that cannot be ignored.¹³ Our group has developed a modified Bernageau method with the patient lying on the axilla in the most relaxed position (Fig. 14-4). In this method, clear x-ray images can be obtained more easily with a high probability of ascertaining bony pathology without using fluoroscopic imaging (Fig. 14-5).

FIGURE 14-4 Modified Bernageau method. The patient lies on his or her axilla in the most relaxed position. A, In this position, the scapula needs to incline 5 degrees to the vertical line. B, Then the incident x-ray needs to be aimed craniocaudally with15 to 20 degrees of inclination to the vertical line.

FIGURE 14-5 X-ray images obtained by the modified Bernageau method. A, Normal glenoid. B, Attritional glenoid. C, Bony Bankart.

Although plain magnetic resonance imaging (MRI) provides only limited information, MR arthrography is helpful when detecting a soft tissue lesion such as a Bankart lesion, capsular pathology, and/or a HAGL (humeral avulsion of the glenohumeral ligament) lesion.¹⁴ However the final diagnosis of soft tissue pathology can be made most accurately through diagnostic arthroscopy.

Three-dimensional CT is the most important imaging study for assessing glenoid morphology accurately.⁸ The arthroscopic glenoid view sometimes makes surgeons overestimate the bone defect because normally the cartilage damage is more extensive than the bony lesion (Fig. 14-6). Furthermore, in a shoulder with a bony Bankart lesion, detecting accurate configuration of the bony fragment is not easy because the bone fragment is covered by the surrounding soft tissue. Through preoperative three-dimensional CT, surgeons can determine whether the glenoid is attritional or if a bony Bankart lesion is present. They can also quantify bone loss with attritional glenoids and detect the size and shape of the bony fragment in shoulders with a bony Bankart lesion.^8,9,11,15

FIGURE 14-6 An arthroscopic view sometimes makes surgeons overestimate glenoid bone loss. A, Arthroscopic view from the anterior portal. B, Three-dimensional CT scan of the same shoulder.

INDICATIONS AND CONTRAINDICATIONS

Surgery is indicated for all patients who want to recover a stable shoulder. Patients with uncontrolled epilepsy or who are noncompliant are not candidates for arthroscopic stabilization. Although bony Bankart lesions are often observed in collision or contact athletes, these lesions can be treated arthroscopically, regardless of the fragment size or age of the patient.

TREATMENT OPTIONS

Arthroscopic Treatment

If a bone fragment is present with three-dimensional CT, an arthroscopic bony Bankart repair, in which the fragment is incorporated into the Bankart repair, is indicated, regardless of the severity of bone loss.^9,16,17 Therefore, most shoulders with a large glenoid bone loss can be treated arthroscopically using this technique.¹¹ For shoulders with significant bone loss associated with the attritional glenoids in young and active patients, although the number of such patients is limited, open or arthroscopic bone grafting procedures are indicated. My preference is an arthroscopic iliac bone grafting in combination with an anterior-inferior capsulolabral repair (see later).^18–20

Arthroscopic Bony Bankart Repair

Most bony Bankart lesions are displaced and represent a partly malunited chronic avulsion–type fracture, and the bony fragment is firmly connected to the adjacent labrum or soft tissue. These characteristics of chronic bony Bankart lesions make arthroscopic bony reconstruction feasible.^9,16 Normally, bony Bankart lesions are never completely healed to the glenoid neck because the fragment is displaced from its original location while the adjacent glenohumeral ligament is not functioning. Therefore, most of the bony fragments associated with a bony Bankart lesion can be easily separated from the glenoid neck using a standard straight rasp. The gap between the fragment and original glenoid is usually well demarcated in most shoulders, but if this is not the case, careful palpation or information from a preoperative three-dimensional CT scan can assist in delineating the gap.

Setup and Arthroscopic Evaluation.

All patients are seated in the beach chair position under general anesthesia and joint laxity is assessed by examination of both shoulders prior to surgical intervention. A 4-mm arthroscope is introduced through a standard posterior portal and a diagnostic arthroscopy is performed. I then create an anterior portal just superior to the subscapularis tendon and lateral to the conjoined tendon using an outside-in technique to facilitate instrument insertion without cannulas.²¹ Inserting the arthroscope through the anterior portal can also help confirm a bony Bankart lesion (Fig. 14-7).

FIGURE 14-7 A, Bony Bankart lesion in three-dimensional CT images. B, C, Arthroscopic appearance of the bony Bankart lesion in the same shoulder viewed from the posterior (B) and anterior portals (C). The tip of the probe indicate the bony fragment embedded in the surrounding soft tissue. G, glenoid, H, humeral head.

Mobilization of the Complex.

After inspection from the anterior portal, separation and mobilization of the labroligamentous complex, together with the bony fragment from the glenoid neck, is performed using an elevator, straight and curved rasps, scissors, shavers, and a radiofrequency instrument through a cannula-less anterior portal. This step is a vital part of this procedure. First, a straight rasp is inserted from the anterior portal and placed in the small gap between the fragment and glenoid neck. Then, the gap is expanded by tapping the handle of the rasp. After separating the fragment from the glenoid neck, the mobilization of the labroligamentous complex is performed up to the 7:30 o’clock position in the right shoulder until the complex and fragment become completely free. This is done in the same way as one would mobilize a Bankart lesion without a bony fragment using the instruments described. Once mobilization of the fragment and complex are completed, the glenoid is prepared by removing scar tissue from the glenoid neck and exposing the bony surface using a shaver and abrader. Articular cartilage on the edge of the glenoid is also removed to promote tissue healing after repair (Fig. 14-8). Normally, the separation of the fragment from the neck can be readily accomplished using only elevators and rasps. If the separation of the fragment is difficult and the fragment is united firmly, a small chisel can be introduced from the anterior portal to separate it from the glenoid neck. An anterosuperior portal is established at the anterosuperior margin of the rotator interval using an outside-in technique. This becomes the second working portal. In shoulders with superior labral detachment, a lateral acromial portal, established just lateral to the midpoint of the acromion through the muscle-tendon junction of the infraspinatus, is used instead of the anterosuperior portal.²²

FIGURE 14-8 Separation and mobilization of a bony fragment and labroligamentous complex. A, Schematic drawing after completion of this procedure. The dotted area on the glenoid indicates the area where articular cartilage is removed. The dotted area on the labrum side indicates a bony fragment inside the soft tissue. B, Arthroscopic view after complete separation and mobilization of the complex, viewed from the anterior portal. The asterisk indicates the area where articular cartilage is removed. G, glenoid.

Repair of Inferior Labrum Adjacent to the Osseous Fragment.

In total, four bioabsorbable suture anchors loaded with no. 2 high-strength suture are inserted on the surface of the glenoid at the 6 o’clock position using a drill guide introduced through the anterior portal. Because this portal has no cannula, the angle of approach of the guide can be adjusted, easily allowing optimization of the angle to the glenoid.²¹ After the first anchor insertion, a looped 2-0 nylon suture is placed into the labrum at the 6:30 o’clock position using a low profile 7-mm punch or a suture hook. A suture relay is then performed intra-articularly.²¹ The second anchor in inserted into the face of the glenoid at the 4:40 o’clock position, followed by suture placement in the labrum adjacent to the inferior side of the bony fragment using the same technique. After completion of the suture placement of the inferior two anchors, knot tying is performed using a self-locking sliding knot through a 5-mm cannula inserted through the anterior portal. To accomplish secure knot tying, the complex, together with the fragment, is held upward and laterally on the glenoid surface by a grasper introduced through the anterosuperior portal to reduce tensile force on the suture.

Osseous Fragment and Superior Labrum Repair.

The next step is the suturing of the osseous fragment itself by passing the suture through the fragment or by penetrating it using a bone-penetrating tool, such as a Suture Leader (DePuy Mitek, Raynham, Mass), Ideal Suture Grasper (DePuy Mitek), an originally developed bone penetrator with a stiff shaft and large handle, a Bone Stitcher (Smith & Nephew, Andover, Mass), or by passing suture around the fragment using a suture hook (Conmed Linvatec, Largo, Fla) or Suture Leader.^16,23,24 It is very important to characterize the fragment shape and size preoperatively by three-dimensional CT evaluation to decide whether passing through or passing around the fragment is most appropriate.¹⁶ This procedure is facilitated when the bony fragment is reduced and stabilized by grasping the labrum adjacent to the superior portion of the fragment with a grasper while the first knot is tied (see earlier). Although the number of suture anchors used is dependent on the size and shape of the osseous fragment, normally one or two suture anchors are used for this part of the stabilization procedure (Fig. 14-9).¹⁶ Knot tying is performed after placing the sutures through the fragment. The final step is to suture the labrum adjacent to the superior side of fragment to augment the stability of the entire complex. Normally, four suture anchors with simple sutures are used to reconstruct the entire labroligamentous complex (Fig. 14-10).

FIGURE 14-9 Final appearance before (A) and after knot tying (B) during the repair. The dotted area on the glenoid indicates the area where articular cartilage is removed. The dotted area on the labrum side indicates a bony fragment inside the soft tissue.

FIGURE 14-10 Arthroscopic appearance after completing bony Bankart repair, viewed from the posterior (A) and anterior portals (B). G, glenoid, H, humeral head.

Management of the Associated Pathology.

In shoulders with a capsular tear, a capsular repair using two to three side to side stitches is performed prior to the bony Bankart repair. Furthermore, in shoulders with a superior labral detachment, arthroscopic reattachment is performed after the Bony Bankart repair is completed, using a lateral acromial portal instead of the anterosuperior portal.²²

Rotator Interval Closure.

The rotator interval closure is performed as an augmentation in patients with relatively high-risk shoulders, such as contact athletes, young individuals with joint laxity, and those with a large Hill-Sachs lesion (Rowe²⁵ grade III). ^26-28 In these patients, the rotator interval is closed by suturing the superior margin of the subscapularis tendon to the superior glenohumeral ligament with the arm held at the side and in maximum external rotation using no. 2 high-strength sutures.²⁹

PEARLS& PITFALLS

• Recognize the size, shape, and location of the bony fragment using preoperative three-dimensional CT prior to surgery.

• Clearly define the gap between the fragment and glenoid neck using a radiofrequency instrument before inserting a rasp.

• Apply the rasp firmly to the glenoid neck when separating the bony fragment together with the adjacent labrum.

• Aim the blade of the bone-penetrating tool perpendicular to the fragment when penetrating the bony fragment to avoid bone comminution or instrument breakage.

• After catching the bony fragment by the tip of the penetrating instrument, push the fragment to the neck of the glenoid and then penetrate it by rotating the bone penetrator with a force perpendicular to the glenoid neck.

• Use two high-strength sutures per anchor for a large fragment to achieve a solid construct.

Arthroscopic Iliac Bone Grafting

For shoulders with significant bone loss in the attritional glenoid category, many surgeons prefer to use the coracoid transfer procedure.^5,15,30 I believe that the coracoid process should be preserved because it plays an important role in shoulder function. In addition, an arthroscopic coracoid transfer normally requires an anterior capsular resection despite the fact that the capsule is important for proprioception of the glenohumeral joint.^31–33 Therefore, I prefer an arthroscopic technique using a tricortical bone graft, which is harvested from the iliac crest, in combination with an anterior-inferior capsulolabral repair.

Harvesting the Iliac Bone Graft.

An iliac tricortical bone graft 20 mm in length and 10 mm in depth is harvested from the iliac crest with the patient in the supine position prior to arthroscopy. The graft is then prepared for insertion to fit the configuration of the anteroinferior portion of the native glenoid demonstrated by preoperative three-dimensional CT. Two drill holes are created to accommodate a 3-mm cannulated screw inserted into the graft; another two small holes are also created in the center of the graft for sutures from the suture anchor for temporary graft fixation (Fig. 14-11).

FIGURE 14-11 A, Iliac tricortical bone is harvested from the iliac crest. The graft is prepared for insertion to fit the configuration of the anteroinferior portion of the native glenoid. B, Two large drill holes are created in advance for 3-mm cannulated screws.

Arthroscopic Evaluation and Mobilization of the Complex.

All patients are seated in the beach chair position under general anesthesia and joint laxity is assessed prior to surgery. A 4-mm arthroscope is introduced through a standard posterior portal and a diagnostic arthroscopy is performed. I then create an anterior portal in the same manner as that for a bony Bankart repair. After inspection from the anterior portal, separation and mobilization of the labroligamentous complex from the glenoid neck are performed up to the 7:30 o’clock position in the right shoulder until the complex becomes completely free. Then, an anterosuperior portal is established at the anterosuperior margin of the rotator interval as the second working portal.

Introduction of the Bone Graft.

First, the rotator interval capsule is removed to insert a large syringe cannula created from an outer sheath of a disposable 10-mL plastic syringe through the anterior portal to assist in graft insertion. A bioabsorbable suture anchor loaded with no. 2 high strength suture, is inserted at the 3:30 o’clock position of the edge of the glenoid through this syringe cannula. Both suture limbs are passed through the holes of the graft, which are created in advance in the center of the graft. The graft is maneuvered into the glenohumeral joint through the syringe cannula by pulling on these suture limbs. The graft is then fixed temporarily by these sutures and the syringe cannula is removed.

Iliac Graft Fixation.

An anteroinferior portal is then created 3 cm inferior and 1cm medial to the anterior portal with a 2-cm longitudinal skin incision. The conjoined tendon and coracoid process are palpated manually with the index finger, and the conjoined tendon retractor, inserted from the anteroinferior portal, is placed lateral to the tendon at a point 2 to 3 cm below the coracoid process. The conjoined tendon is then retracted medially to obtain an optimal angle to the glenoid. Next, a cannulated guidewire inserter is introduced from the anteroinferior portal into the joint by penetrating the subscapularis muscle to line up the drill hole created in the graft in advance (Fig. 14-12). A guidewire is inserted through this cannulated guide and drilled to the optimal position of the glenoid neck. The cannulated guide is then replaced by one with a larger diameter to fit the cannulated drill and screw (Fig. 14-13). After drilling, a 3-mm diameter cannulated cancellous screw, 30 mm long (Synthes, West Chester, Pa), is inserted through this cannula to the superior portion of the graft. The same procedure is then repeated to insert another screw into the inferior portion of the graft. The guidewire, cannulated guide, and conjoined tendon retractor are then removed (Fig. 14-14).

FIGURE 14-12 The conjoined tendon is retracted medially by the conjoined tendon retractor, inserted from the anteroinferior portal, to obtain an optimal angle to the glenoid. A cannulated guidewire inserter is introduced from this portal.

FIGURE 14-13 A, Step cannulation system: a drill with a long blade, a driver with a long shaft, and the conjoined tendon retractor. B, Close look of the step cannulation system. Shown are a guidewire inside the cannulated guides (top), cannulated drill with the guide sheath for the drill (middle), and screwdriver with the guide sheath for the driver (bottom).

FIGURE 14-14 Arthroscopic view after completing the graft fixation. A, View from the posterior portal. B, View from the anterior portal. Gl, glenoid, Gr, graft.

Anteroinferior Capsulolabral Repair.

The capsulolabral complex, which was previously mobilized, is then reattached to the native glenoid using another three to four bioabsorbable suture anchors loaded with no. 2 high-strength suture in the same manner as a Bankart repair (Fig. 14-15).

FIGURE 14-15 Final appearance of completed iliac bone grafting and capsulolabral repair. The graft is located totally outside the glenohumeral joint and is working as a platform for the humeral head. A, View from the posterior portal. B, View from the anterior portal. G, glenoid, H, humeral head.

PEARLS& PITFALLS

• Recognize the configuration of the anteroinferior portion of the glenoid using preoperative three-dimensional CT and trim the graft to fit the native glenoid.

• Create larger holes in the graft for screw fixation in advance; otherwise, guidewire insertion to the graft can be difficult.

• Retract the released capsulolabral complex using sutures or instruments to keep enough working space during the graft fixation.

• Do not retract the conjoined tendon aggressively or persistently, or nerve injury may occur.

• Insert a guidewire to the optimal position on the anterior portion of the glenoid neck. A 70- degree arthroscope is sometimes helpful.

• Use a cannulated guide when drilling or screwing to protect the surrounding neurovascular structures and muscles.

• Take care not to damage the screw used in the graft fixation while drilling for anchor insertion for the capsulolabral repair.

Treatment for the Engaging Hill-Sachs Lesion

A Hill-Sachs lesion should be considered in conjunction with the glenoid bone defect.² I believe that if the bone loss on the glenoid side is addressed by the bony Bankart repair or the iliac bone graft procedure, surgeons can ignore the Hill-Sachs lesion. In shoulders with a large engaging Hill-Sachs lesion associated with minimum glenoid bone loss, a Hill-Sachs remplissage technique can be useful.³⁴

POSTOPERATIVE REHABILITATION PROTOCOL

The shoulders are immobilized for 3 weeks using a sling (UltraSling II, Donjoy, Carlsbad, Calif). After immobilization, passive and assisted-active exercises are initiated for forward flexion and external rotation, avoiding pain. After 6 weeks, patients begin strengthening exercises of the rotator cuff and scapular stabilizers. Three months after the operation, they are permitted to practice noncontact sports. Full return to throwing or contact sports is allowed after 6 months according to each individual’s functional recovery. The same postoperative protocol is used after the bony Bankart repair and the iliac bone grafting.