The rotator cuff refers to a group of 4 muscles and tendons enveloping the shoulder joint. A rotator cuff injury is one of the commonest reasons causing persistent pain of the shoulder (see rotator cuff tendinitis and tear).
Arthroscopic cuff repair is typically recommended in a few situations:
- acute traumatic complete full-thickness tears in a young active individual.
- large and retracted tears.
- tears that result in significant weakness and loss of function.
- tears that have resulted in persistent pain and disability for a long period of time.
Rotator cuff repair surgery is done in a minimally invasive manner. Dr Wee performs this surgery in a keyhole, arthroscopic fashion, and as a day surgery or a single overnight stay under general anaesthesia. Depending on the extent and pattern of the rotator cuff damage, a combination of 3 to 5 sub-centimetre keyholes will be utilized to perform the different steps of the procedure.
Performing rotator cuff repair using arthroscopic minimally invasive technique has the advantage of earlier recovery and less surgical trauma to the surrounding normal shoulder soft tissue. On top of that, the surgery is more accurate, and the surgical incisions cosmetically more pleasing.
Patient testimonial after arthroscopic cuff repair by Dr Andy Wee (available on google review of Pinnacle Orthopaedic Group Mount Elizabeth): > Dr Andy Wee’s patient testimonial
Despite most patients doing well with arthroscopic cuff repair, a minority (about 10%) of patients do not do as well in their post-surgery recovery. This is typically due to either a lack of physiotherapy or a recurrent tear of the repaired tendon (failed rotator cuff repair).
A rotator cuff repair can fail or re-tear for several reasons:
- poor surgical technique
- lack of or incorrect post-operative rehabilitation
- long-standing and large retracted rotator cuff tear (up to 50% failure despite a good surgical repair)
- re-injury of the repaired tendon
- presence of significant rotator cuff tendinosis (degeneration) or rotator cuff muscle atrophy of the repaired tendon
Recently, several advances have been made available to allow us to better treat rotator cuff related problems, so as to minimise our chance of re-tear during cuff repair.
Recent advances in arthroscopic cuff repair
1) Bio-inductive implant augmentation of cuff repair
At least half of the torn tendons that we surgically repair have underlying degeneration (tendinosis), which is the main reason why they tear in the first place. Tendinosis without a formal tear, if left untreated, can also progress to full thickness retracted tears.
Progression of rotator cuff tendinosis to a formal rotator cuff tear.
Until recently, all our surgical strategies in treating rotator cuff disorders have focused on repairing the torn tendon. But surgically repairing the tendon does not address the pre-existing tendinosis. Fortunately, we now have a Bio-inductive implant available to help us treat patients with painful and severe rotator cuff tendinosis or degeneration with no actual tear of the rotator cuff. The use of this bio-inductive implant allows us to halt the disease progression and slow down the progression to a full tear.
This newly available bio-inductive implant is inserted arthroscopically at the time of rotator cuff surgery and has been shown in several studies to stimulate new tendon growth in the degenerated tendon. What is even more amazing is the fact that this bio-inductive implant gradually gets completely absorbed by the body to leave a new layer of tendon tissue to augment the existing degenerated tendon. The overall result is that of a healthier tendon tissue.
Pictorial illustration showing the gradual resorption of the bio-inductive implant 6 months after arthroscopic surgical implantation, leaving a layer of new tendon like tissue to augment the existing rotator cuff tendon.
For patients who already have a formal tear, the use of this bio-inductive implant to augment the rotator cuff repair also results in an improvement in the quality of the repaired tendon, potentially minimising the risk of rotator cuff re-tears after surgery. The use of this Bio-inductive implant is also helpful and advantageous for revision (repeat) cuff repair surgery (in patients who have a failed rotator cuff repair).
As of 2020, Singapore is the only country in South East Asia that has access to this bio-inductive implant. Dr Wee has been the local pioneer surgeon in the use of this cutting-edge technique to address rotator cuff tendinosis and tears in Singapore since its launch in 2019.
2) Use of Biologics (Platelet Rich Plasma and Bone Marrow Aspirate Concentrate) to augment rotator cuff healing
The availability and the use of biologics like platelet rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) to augment rotator cuff healing is also gaining in popularity.
PRP is essentially obtained from a peripheral blood sample. Although blood is mainly a liquid (called plasma), it also contains small solid components (red cells, white cells, and platelets.) The platelets are best known for their importance in clotting blood. However, platelets also contain hundreds of proteins called growth factors which are especially important in the healing of injuries. Platelet Rich plasma (PRP) is plasma with a much higher concentration of platelets than what is typically found in blood. The concentration of platelets — and, thereby, the concentration of growth factors — can be 5 to 10 times greater (or richer) than usual.
To develop a PRP preparation, blood must first be drawn from a peripheral vein of the patient. The platelets are then separated from other blood cells and their concentration is increased during a process called centrifugation.
Bone Marrow Aspirate Concentrate, or BMAC, is similar to PRP, except that the ‘blood’ sample is drawn from the bone marrow instead of a peripheral vein. Typical sites where we harvest BMAC from include the tip of a patient’s pelvic bone (iliac crest), and the shin bone (proximal tibia). The advantage of BMAC over PRP is that on top of the presence of numerous growth factors, a sample of bone marrow aspirate also contains a small but important proportion of mesenchymal stem cells within it, which is subsequently increased by concentrating/centrifuging it to form BMAC. Mesenchymal stem cells have been shown by various in-vitro as well as clinical studies to aid in healing of musculoskeletal tissues (including tendon, cartilage, muscle, ligament, and bone).
The main drawback of using BMAC instead of PRP to augment healing is that obtaining a sample of bone marrow aspirate is usually done under general anaesthesia at the time of surgery, as compared to PRP which can be obtained just from a simple blood taking procedure in an office setting. For this reason, when biologics are currently used to augment rotator cuff healing, Dr Wee prefers to use PRP when treating a rotator cuff problem non-operatively in the clinic setting, and BMAC when augmenting rotator cuff repair surgery in the operating room. He generally recommends the use of BMAC as an augment during revision rotator cuff repairs.
When PRP is being used to augment cuff healing non-operatively, we tend to inject PRP around the area of the tendon tear or tendinosis under ultrasound guidance in the clinic. BMAC is typically mixed with a clotting medium and applied around the rotator cuff repair site under arthroscopic view during surgery.
3) Latest surgical options for irreparable cuff tears
Not all rotator cuff tears can be successfully repaired. About 10% of all cuff tears will not be amenable to repair, typically the large and retracted tears. In such situations, several alternatives are now available to help us manage an irreparable tear.
A) Superior capsule reconstruction (Arthroscopy)
Superior capsule reconstruction is a procedure that can now be performed in an arthroscopic key-hole fashion, and it is typically performed for cuff tears that cannot be repaired. A donor tissue (dermal allograft or fascia allograft) is used to fill the tendon defect/void that results from an irreparable cuff tear. The allograft is attached to the glenoid rim and humeral head using suture anchors, and this helps to replace and take over the role of the irreparable torn tendon in preventing upward migration of the humeral head and hence maintaining functional pain-free movement of the shoulder.
B) Tendon transfer
Tendon transfer is a procedure that is reserved for young and high demand patients with cuff tears that cannot be repaired. A neighbouring tendon (usually the latissimus dorsi tendon) is re-routed and attached to the humeral head, where the torn retracted irreparable tendon originally inserts. Like a superior capsule reconstruction, the re-routed tendon replaces and takes over the role of the irreparable torn tendon, and preventing upward migration of the humeral head, which in turn enable functional movement of the shoulder. Compared to superior capsular reconstruction, the re-routed musculotendinous transfer also theoretically offers the high demand patient greater strength and ability compared to other procedures done for an irreparable cuff tear.
C) Reverse shoulder arthroplasty
The use of Reverse shoulder arthroplasty, a form of shoulder joint replacement, is the most suitable solution for elderly patients with long standing and large irreparable tears that has resulted in arthritis or degeneration of the shoulder joint. In such patients, the shoulder joint has already undergone significant degeneration and upward migration or subluxation due to the progressive retraction and long-term absence of the torn rotator cuff, also called rotator cuff arthritis or arthropathy. Reverse shoulder replacement offers the most predictable outcome in terms of pain relief and regain of shoulder function for this condition in those above 65 years old.
D) InSpace Balloon insertion (arthroscopy)
The InSpace balloon is a new innovative solution that is currently available for use in Singapore. The balloon can be introduced arthroscopically and deployed in the subacromial space, and like the superior capsule reconstruction and tendon transfer, it aims to maintain and prevent the humeral head from migrating superiorly, thereby minimising pain and dysfunction from a large and irreparable cuff tear, without having to actually repair the tendon or replace the torn tendon with a more tedious procedure like a superior capsule reconstruction or tendon transfer.
The use of the InSpace balloon for irreparable cuff tears has the advantage of an extremely easy and efficient introduction, with no need for subsequent removal of the balloon. Dr Wee tends to recommend this procedure for lower demand patients with failed rotator cuff repairs who are not suitable for a formal revision superior capsule reconstruction surgery.