Rotator cuff tears

Introduction

Rotator cuff tears are a very common condition. Very few of these are acute traumatic tears. Most of them are chronic and in fact about 50% of people above 60 years of age would probably have a rotator cuff tear. By implication therefore, many of these do not need to be operated upon. Nevertheless, there are a number of symptoms that can be bothersome. Pain tends to be intractable and disturbs sleep. A small proportion of patients will respond to a steroid injection but if there is a physical spur in the area the relief tends to be short-lived. Weakness tends to be debilitating for overhead functions and face shaving or brushing one’s teeth. Finally, with repeated disuse, the shoulder can become stiff resulting in a frozen shoulder.


Figure 1. (a)While the rotator cuff is technically composed of 4 muscles, for all intents and purposes, the tears usually occur at the point of insertion of the supraspinatus tendon (arrowed). While this is fairly obvious on  (b), small tears can be difficult to visualize without an MR arthrogram (Figure 4 below). In arthroscopic repairs (c), small stab incisions are made in the back of the shoulder (eye) while the repair is done through a stab on the side of the shoulder (tool).

Anatomy

The rotator cuff technically is a cuff of 4 muscles around the upper humerus (Figure 1). These 4, the supraspinatus, infraspinatus, teres minor and subscapularis each can move the shoulder independently but together pull the head of the humerus into its cup or glenoid. The supraspinatus is the most commonly torn tendon and responsible for most symptoms although the subscapularis does tear especially in the elderly. The crux of the problem lies in the subacromial space (Figure 2a). This tight space houses the supraspinatus tendon and makes it relatively ischemic (a state of reduced blood supply). As such it is prone to undergoing wear and tear. The acromion and the clavicle by becoming diseased can add to this blockage.



Figure 2. The main area of contention in rotator cuff disease is the subacromial space (a). Because muscles have to slide in and out of the space they undergo degeneration and can develop calcium deposits. With time this progresses to tear (seen here in a historic picture of an open repair, c). Sometimes the acromioclavicular joint develops arthritis and can become large and press on the supraspinatus muscle causing the same effect (d). Arthroscopically, these tears can now be repaired due to the development of specialized shoulder equipment that was not available in the last century (e).

Treatment

When clinically indicated, injections probable manage a large proportion of these cases. Oral pain killers tend to have limited value due to the physical spurs that are in the shoulder (Figure 3). Imaging with an xray can be very useful and should be mandatory to rule out tumors, etc. MRI arthrograms may be necessary to confirm tears although an ultrasound scan can be sufficient with the right skill on hand (Figure 4).



Figure 3. This shoulder xray (a) shows calcification in the suprapinatus tendon which was localized during arthroscopy of the shoulder using a needle in the acromioclavicular joint (b). The procedure revealed a hidden tear in the suprapsinatus tendon (c) which communicated with the shoulder joint. In This case, there was a bony spur growing out of the acromion causing the problem (d). The spur was excised and the tear repaired (e). The pain disappeared immediately.

In the past, open surgeries done through a 3-4 cm incision were used. To this day they remain relevant for large tears with retraction (Figure 2c). The vast majority of small tears are however treated with arthroscopic repairs (Figure 1c). The procedure is relatively straightforward and apart from the initial discomfort, recovery is rapid with patients reaching full function in about three months.




Figure 4. Most patients with rotator cuff tears have normal xrays with the subtle change of sclerosis over the greater tuberosity (a,b). An MR arthogram may be necessary (c) where dye is injected into the joint confirming a tear if it leaks into the subacromial space (d). Arthroscopically this tear was of moderate size (e). A radio-frequency ablator is used to clean the edges (f) preparing the path for the awl (g). This in turn facilitates the passage of a suture anchor (h) to complete the repair (i). This entire process is performed through a 1 cm incision as opposed to open repairs through a 3 cm incision (Figure 2c).


Figure 5 (video). We present a useful little video that helps to explain a little bit more of what a rotator cuff repair is like. Do let us know what you think.