Subacromial InSpace Balloon Interposition for Massive Irreparable Rotator Cuff Tears

Abstract

Massive rotator cuff tears are a challenging problem for treatment. The best results we can still achieve with reconstruction. For treatment of massive rotator cuff tears when reconstruction is not possible, a new method has been developed recently: the implantation of the biodegradable balloon spacer/InSpace™ balloon/filled with the saline in the subacromial space. The main characteristic of this method is that to allow gliding of the humeral head against acromion without friction and to depress the humeral head for 2–3 mm. This depression is just enough that the humerus is in a better center of rotation that allows the deltoid muscle more strength—better vector forces for the deltoid muscle. This function of the balloon permits better deltoid activation and compensation through the arc of motion. Results of our first study and results of others show clinical safety and efficacy of the insertion of the InSpace™ balloon in a group of patients with massive irreparable rotator cuff tears. The insertion of this device shows significantly better early improvement, significant improvement in subjective pain scores, and a decrease in reported night pain. The measurement of the Total Constant score showed statistically significant improvement after insertion of the InSpace™ balloon at 5 years of follow-up. Generally, all studies show 75–80% of good results.

1. Introduction

• The deployment of an inflatable resorbable balloon into the subacromial space is indicated in patients with massive-irreparable rotator cuff tears [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15].

• Rotator cuff tears (RCTs) are among the commonest tendon injuries seen in orthopedic patients resulting in significant pain and disability [16, 17, 18, 19, 20, 21, 22].

• Irreparable RCTs are those where the rupture at least two tendons is present, tendons are retracted, atrophy of muscles and bigger degree of fatty degeneration are present [4, 23].

• In these situations, direct repair refixation of the tendon at the point of insertion is usually not possible despite extensive soft-tissue mobilization and release [24, 25, 26, 27].

• The InSpace ™ system is a biodegradable balloon that is made for arthroscopic insertion into the subacromial space following bursa excision. The pre-shaped balloon is produced from a copolymer of poly-L-lactide-co-ε-caprolactone in a 70: 30 ratio, which biodegrades over a period of 12 months. The insertion of this balloon into the subacromial space is a low-risk procedure [6, 7, 8, 9]. The aim of this is mainly to allow gliding of the humeral head against acromion without friction and to depress the humeral head for 2–3 mm. This depression is just enough that the humerus is in a better center of rotation that allows the deltoid muscle more strength—better vector forces for the deltoid muscle. This function of the balloon permits better deltoid activation and compensation through the arc of motion (Figure 1) [10].

• We have to be aware not to put the balloon into osteoarthritic joint—as such a joint balloon is not really effective [6, 8].

Figure 1.

Schematic representation of the InSpace ™ balloon deployment and inflation in the subacromial space.

2. Preoperative assessment

2.1 Clinical assessment

• Patients describe chronicity of the difficulties: chronic night pain, pain at motion, limited range of motion [28, 29].

• Examination assesses the location of pain [4, 13].

• Pain can limit the range of motion. The range of motion is usually limited under 90° of anteflexion and abduction [13].

• Muscle strength is usually diminished [4, 23].

• Atrophy of the m. supraspinatus and m. infraspinatus is usually visible [23].

2.2 Imaging assessment

2.2.1 Radiographs

• Anteroposterior and lateral views detect possible superior migration of the humeral head and osteoarthritic joint [23].

2.2.2 Ultra sound (US)

• US is useful for detecting the tear and size of the tear.

• We can see calcium depots and muscle atrophy [23].

2.2.3 Multi resonance imaging (MRI) arthrography

• MRI arthrography is nearly 100° accurate to show RC tear and size of the tear.

• We can determine tendon retraction.

• We can determine atrophy of the muscle and degree of fatty degeneration.

• We can detect osteoarthritic changes in the joint [4, 23].

3. Timing for surgery

• The mean duration of symptoms because of the RCT prior to surgery has to be at least 3 months at patients over 60 years of age with documented failure of conservative treatment. All younger, we operate earlier [7, 21, 23].

• At operation we always try to mobilize the cuff and make reconstruction or partial reconstruction. If this is not possible, then we decide on the implantation of the balloon [5].

4. Surgical preparation

4.1 Surgical equipment

• Complete arthroscopic set with a shaver and a high-frequency electrode.

• An arthroscopic pump.

• Entire arthroscopic RC repair set includes anchor sutures or/and arthroscopic tunnel device.

• InSpaceTM resorbable balloons of three dimensions (Figure 2) with appropriate 20 ml syringe [6].

Figure 2.

InSpaceTM resorbable balloon—The ballon has been inflated already.

4.2 Equipment positioning

• The arthroscopic monitor faces the surgeon on the opposite side of the table at the level of the patient’s shoulder [2, 7].

4.3 Patient positioning

• We have to put the patient in the beach chair position or in lateral decubitus position with the arm in a special holder like at all other shoulder arthroscopic procedures. For the lateral decubitus position, we need a special holding device for the body of the patient [2, 7].

4.4 Further preparation

• Implantation of the material justify antibiotic prophylaxis [2, 7].

5. Surgical technique

• We perform all shoulder operations with the patient in a beach-chair position.

• Nowadays, we perform shoulder arthroscopic procedures mainly in regional anesthesia (scalene block). In only a few cases, we perform in general anesthesia [6, 7].

• We use three standard arthroscopic ports (anterior, lateral, posterior, or posterolateral).

• At surgery we remove first partially the subacromial bursa (Figure 3), then we debride the tear and release the tendon. After this, we try to draw the edge of the tendons with an arthroscopic clamp to the footprint region (Figure 4). A decision is made to insert the balloon when it is obvious that the RCT is irreparable [6, 7, 30].

• We usually perform tenotomy of the tendon of the long head of m. biceps brachii. But this is not necessary [28, 31].

• Measurement of the distance between the lateral border of the acromion and the superior rim of the glenoid and defining the extent of any tear extension (Figure 5) [17].

• Then we choose the balloon size (small, medium or large) according to measurements.

• Insertion of the proper balloon is aided by folding it into a cylindrical shape inside an insertion tube (Figure 6).

• Once positioned in the subacromial space, the balloon is inflated with saline permitting frictionless gliding of the humeral head against the acromion. For each size we have to fill with the proper amount of the saline—it is written on the package (Figures 7 and 8) [6, 7].

• Then we simply turn around the green ring on the handle holder and cut of insertion device from the balloon.

• After this we can move the arm and suture the ports.

Figure 3.

Debridement of the subacromial space.

Figure 4.

Grasping the edges of the tendons with an arthroscopic clamp in an attempt to draw it to the footprint region.

Figure 5.

Measurement of the distance between the lateral border of the acromion and the superior rim of the glenoid.

Figure 6.

Insertion of the proper balloon (cylindrical shape, insertion tube is removed from the joint).

Figure 7.

Inflation of the balloon in the subacromial space.

Figure 8.

Balloon is inflated in the subacromial space, we can see that humeral head is pushed down.

6. Postoperative course

6.1 Postoperative regime

• Medications: pain killer, nonsteroidal anti-inflammatory drugs (NSAI).

• 5–7 days of immobilization of the arm during walking with broad arm sling.

• Immediate mobilization without limitations.

• Further physiotherapy.

• Outpatient visit at day 7 and 21 to check movement [6, 7].

6.2 Early phase postoperative complications

• Swelling of the shoulder

• There may be an obvious swelling in the arm caused by the contracted biceps muscle (“Popeye sign”)—this sometimes develops due to tenotomy of the long head of the biceps brachii muscle [28, 31].

7. Conclusion

• Our first study and results of other studies show clinical safety and efficacy of the insertion of the InSpace™ balloon in a group of patients with massive irreparable rotator cuff tears [6, 7].

• The insertion of this device shows significantly better early improvement, significant improvement in subjective pain scores, and a decrease in reported night pain. The measurement of the Total Constant score showed statistically significant improvement after insertion of the InSpace™ balloon at 5 years of follow-up. Generally, all studies show 75–80% of good results. (Figure 9) [6, 11, 12, 13].

Figure 9.

(a) graphical presentation of constant variables following biodegradable spacer insertion. TCS—total constant score, pain score, ADL—Activity of daily living, ROM—Range of motion, power. Figure presents change in score from baseline to 5 years following insertion. Values are presented as means ±SD. (b)-graphical presentation of range of motion scores variables during 5 years follow-up. Active, pain-free range of elevation: 2 points per 30°; 0 = worst, 10 = best; position of hand:0 = worst, 10 = best. Values are presented as means.