From the Guidelines
The nerves involved in rotator cuff pain are the suprascapular nerve, axillary nerve, and those affected by an interscalene block.
Nerve Blocks for Rotator Cuff Pain
- Interscalene block: This is a regional analgesic technique that is recommended as a component of multimodal analgesia for rotator cuff repair surgery 1.
- Suprascapular nerve block: This block reduces pain scores and/or opioid use after surgery, but does not seem to have analgesic advantages over interscalene block 1.
- Axillary nerve block: This block can be used in combination with a suprascapular nerve block if an interscalene block is not possible 1.
Rationale for Nerve Involvement
The use of these nerve blocks is based on the anatomy of the rotator cuff and the innervation of the surrounding muscles and tissues. The suprascapular nerve innervates the supraspinatus and infraspinatus muscles, while the axillary nerve innervates the deltoid and teres minor muscles. An interscalene block affects the nerves that innervate the shoulder joint and surrounding muscles, providing effective pain relief for rotator cuff repair surgery 1.
Clinical Application
In clinical practice, the choice of nerve block will depend on the individual patient's needs and the surgical approach used. The evidence suggests that a combination of paracetamol, non-steroidal anti-inflammatory drugs, and a regional analgesic technique, such as an interscalene block or suprascapular nerve block with or without axillary nerve block, can provide effective pain relief for rotator cuff repair surgery 1.
From the Research
Nerves Involved in Rotator Cuff Pain
The nerves involved in rotator cuff pain include:
- Suprascapular nerve: This nerve has been associated with massive rotator cuff tears, although the study by 2 found no evidence to support the routine practice of suprascapular nerve release when rotator cuff repair is performed.
- Axillary nerve: This nerve is also commonly affected in rotator cuff injuries, with studies by 3, 4, and 5 reporting a high incidence of axillary nerve lesions in patients with rotator cuff tears.
- Musculocutaneous nerve: Although less common, this nerve can also be affected in rotator cuff injuries, as reported by 3.
Prevalence of Nerve Injuries
The prevalence of nerve injuries in rotator cuff tears is significant, with studies reporting:
- 12% of patients with massive rotator cuff tears having neurologic lesions, including suprascapular nerve neuropathy and axillary nerve palsy 2.
- 83.9% of patients with rotator cuff tear arthropathy having injuries to the axillary and/or suprascapular nerve 4.
- 31.5% of patients having acute postoperative nerve injuries after reverse shoulder arthroplasty 5.
Impact of Nerve Injuries on Outcomes
Nerve injuries can have a significant impact on outcomes, with studies reporting:
- Patients with preoperative neuropathy having lower functional results after surgery 4.
- Axillary nerve injuries being more likely to recover than suprascapular nerve injuries 5.
- Peripheral nerve stimulation being a potential treatment option for chronic shoulder pain due to rotator cuff pathology, targeting the suprascapular and axillary nerves 6.