Stryker InSpace Balloon Spacer

What is Stryker InSpace for Rotator Cuff Tears?

Stryker’s InSpace is a minimally invasive, subacromial spacer for arthroscopic treatment of massive, irreparable rotator cuff tears (MIRCTs). It involves implantation of a balloon spacer made of a biodegradable polymer into the subacromial space of the shoulder arthroscopically. The subacromial space is the space between the acromion and the top surface of the humeral head. This space houses several soft tissue structures such as the rotator cuff, bicep tendon, and bursa, which are instrumental in the proper functioning of the shoulder.

The InSpace balloon implant or spacer acts as a substitute for the fluid-filled sac called a bursa that protects and cushions your shoulder joints. The bursa usually becomes inflamed and causes pain when the rotator cuff muscles rupture. The InSpace subacromial spacer creates adequate room between the shoulder and the scapula, acromion, and humerus bones thereby providing pain-free and friction-free shoulder motion.

The purpose of Stryker’s InSpace biodegradable implantable balloon (spacer) is to help heal ruptured or torn rotator cuff muscles following rotator cuff repair and to decrease friction between the acromion and the humeral head or rotator cuff to enable smooth movement of the humeral head against the acromion. Stryker’s InSpace implant is designed to restore the subacromial space without needing fixation devices or sutures.

Anatomy of the Shoulder

The shoulder joint is made up of a ball and socket joint, where the head of the humerus (upper arm bone) articulates with the socket of the scapula (shoulder blade), which is called the glenoid. The scapula has four bony processes - acromion, spine, coracoid and glenoid cavity. The acromion and coracoid processes serve as places for attachment of the ligaments and tendons. A rotator cuff is a group of four tendons that join the head of the humerus to the deeper shoulder muscles to provide stability and mobility to the shoulder joint. Major injury to these tendons may result in a condition called rotator cuff tear. The tear results in symptoms such as severe pain, swelling, stiffness,  weakness of the arm, and loss of joint motion. 

Indications for Stryker InSpace for Rotator Cuff Tears

The main indication for the Stryker InSpace balloon implant is to treat MIRCTs caused by trauma. Your surgeon may also recommend an InSpace spacer implant in the following scenarios, including:

• For individuals who are not suitable candidates for standard tendon transfer treatment for rotator cuff repair
• In patients who manifest proximal humeral migration secondary to massive full-thickness rotator cuff tears
• In seniors suffering rotator cuff tendon degradation with mild to moderate glenohumeral osteoarthritis
• In patients with multiple comorbidities and who are contraindicated to undergo general anesthesia or open surgery

Preparation for Stryker InSpace for Rotator Cuff Tears

Preoperative preparation for Stryker InSpace implant for rotator cuff tears may involve the following steps:

• A review of your medical history and a thorough examination is performed by your doctor to check for any medical issues that need to be addressed prior to surgery.
• Depending on your medical history, social history, and age, you may need to undergo tests such as bloodwork and imaging to screen for any abnormalities that could compromise the safety of the procedure.
• You will be asked if you have allergies to medications, anesthesia, polymers, or latex.
• You should inform your doctor of any medications or supplements you are taking or any conditions you have such as heart or lung disease.
• You may be asked to stop taking certain medications, such as blood thinners, anti-inflammatories, aspirin, or other supplements for a week or two.
• You should refrain from alcohol and tobacco at least a few days prior to surgery and several weeks after, as it can hinder the healing process.
• You should not consume solids or liquids at least 8 hours prior to surgery.
• You should arrange for someone to drive you home after surgery.
• A signed informed consent form will be obtained from you after the pros and cons of the surgery have been explained.

Procedure for Stryker InSpace Placement for Rotator Cuff Tears

The Stryker InSpace spacer implant procedure is similar to other standard rotator cuff operations and is commonly performed as a minimally invasive arthroscopic technique under local anesthesia. The procedure generally involves the following steps:

• After cleaning the skin over the shoulder area, your surgeon makes a few small entry points known as keyhole incisions in your shoulder joint.
• An arthroscope, a slender tubular device attached with a light and a small camera at the end is inserted through one of the incisions into your shoulder joint.
• The camera transmits the image of the inside of your shoulder joint onto a monitor for your surgeon to view.
• Your surgeon then guides miniature surgical instruments through the other tiny incisions to perform surgical debridement of the joint area (removal of damaged tissue). Care is taken to prevent damage to healthy tissue.
• After adequate repair of the torn rotator cuff, the InSpace balloon spacer is implanted between the humeral head and the acromion and is inflated with a normal saline solution. The balloon spacer degrades within six to twelve months.
• The inflated balloon spacer decreases subacromial friction, maintains the structure and function of the repaired cuff, and creates more space between the humeral head and coracoacromial arch to allow frictionless and smooth gliding between the shoulder bones.

Postoperative Care Instructions and Recovery

In general, postoperative care instructions and recovery after Stryker InSpace spacer placement will involve the following steps:

• You will be transferred to the recovery area where your nurse will closely observe you for any allergic or anesthetic reactions and monitor your vital signs as you recover.
• Your shoulder will be wrapped with dressings and immobilized in a sling for a few weeks to promote healing and to rest the shoulder.
• Instructions will be given on how to remove the sling and perform a gentle range of motion exercises soon after the surgery.
• You may experience pain, swelling, and discomfort in the shoulder area. Pain and anti-inflammatory medications are provided as needed to keep you comfortable.
• Antibiotics are also prescribed to prevent the risk of surgery-related infection.
• You may also apply ice packs on the shoulder to help reduce swelling and pain.
• Instructions on surgical site care and bathing will be provided to keep the wound clean and dry.
• Refrain from strenuous activities and lifting heavy weights for a defined period. A gradual increase in activities over a period of time is recommended.
• An individualized physical therapy protocol will be designed to help strengthen your shoulder muscles and optimize shoulder function.
• You will be able to resume your normal activities in a couple of weeks, but with certain activity restrictions. Return to sports may take at least 6 months or longer.
• Refrain from driving until you are fully fit and receive your doctor’s consent.
• A periodic follow-up appointment will be scheduled to monitor your progress.

Benefits of Stryker InSpace Implant for Rotator Cuff Tears

Some of the benefits of InSpace subacromial balloon spacer include:

• Improved shoulder range of motion
• Safe and low risk of complications
• Minimal postoperative pain
• Minimal damage to muscles
• Quick rehabilitation
• Minimal technical demands
• Shorter operative duration
• Cost-effective

Risks and Complications

Stryker InSpace placement is a relatively safe procedure; however, as with any surgery, some risks and complications may occur, such as:

• Infection
• Bleeding
• Inflammation
• Implant migration
• Foreign body response
• Irritation at the wound site
• Tissue necrosis