Quadratus lumborum is one of the common sources of low back pain and one that is easily missed or ignored. Quadratus lumborum pain syndrome is part of the myofascial pain syndrome, which is defined as regional pain referred from trigger points and associated with dysfunction. A trigger point is a hyperirritable spot usually within a taut band of skeletal muscle or in the muscle fascia, that is painful on compression and can give rise to characteristic referred pain, localized tenderness and autonomic phenomena.
Quadratus lumborum muscle can be an important source of low back pain. It is commonly over looked and can result in persistent low back pain. Quadratus lumborum injection can be of diagnostic benefit and therapeutic value in patients with chronic low back pain. Botox injection in to the quadratus lumborum muscle can provide sustained pain relief in some patients. However it is important to note that in some cases injection treatment may not provide the desired results or the pain relief may not be sustained. At Pain Spa, Dr Krishna is very experienced in interventional treatments and performs quadratus lumborum injections under ultrasound guidance for greater accuracy and safety.
At Pain Spa, Dr Krishna is very experienced in interventional treatments and performs trigger point injections under ultrasound guidance. Quadratus lumborum muscle can be accurately localised under ultrasound guidance.
The quadratus lumborum muscle is a muscle of the posterior abdominal wall lying deep inside the abdomen and dorsal to the iliopsoas. The quadratus lumborum muscle can be palpated above the posterior iliac crest. The muscle runs craniomedially from the iliac crest and attaches to the 12th rib and the transverse processes of the 1st to 4th lumbar vertebrae. The fibers together give the muscle a rectangular appearance. It is innervated by the subcostal nerves and the branches of the lumbar plexus.
The quadratus lumborum muscle contributes to the stabilization and movement of the spine and the pelvis. Bilateral contraction leads to extension of the lumbar spine. Unilateral contraction of the muscle leads to ipsilateral flexion, so the trunk is bent towards the same direction. In addition, the muscle fixes the 12th rib during movements of the thoracic cage and thus supports expiration (accessory muscle of expiration).
Overuse and strain of the quadratus lumborum is one of the major causes for chronic pain in the lower back. Typical cause includes the habit of sitting at the desk using a reclining seat, which relaxes the intrinsic back muscles and weakens them in the long term. The weak back muscles are compensated by the quadratus lumborum, leading to painful tension and stiffening of the muscle. Other causes can be direct damage or any type of imbalance of the pelvis or spine, which forces the quadratus lumborum to stabilize them.
The trigger points in quadratus lumborum muscle can be accurately targeted under ultrasound guidance. The procedure is usually done on an outpatient basis. Patients need to be aware that the outcome of the procedure is variable and they may not receive the desired benefits. Similarly, they must be aware of the transient nature of the therapeutic benefits and that there may need repeated injections.
Generally a mixture of local anaesthetic and steroid is injected. The local anaesthetic agent within the injectate may act on the nociceptive fibres in the muscle, whereas corticosteroids may reduce inflammation. The anaesthetic is probably responsible for immediate pain relief, whereas steroids are believed to be responsible for pain relief 2–6 days after their administration.
Botox may be injected in to the quadratus lumborum muscle to help with the myofascial pain. It is recommended for patients who get short-term benefit from local anaesthetic and steroid injection.
Injections are generally avoided in patients with systemic infection or skin infection over puncture site, bleeding disorders or coagulopathy, allergy to local anaesthetics or any of the medications to be administered.
Complications are rare, particularly if injections are performed using a precise needle-positioning technique and imaging guidance. Severe allergic reactions to local anaesthetics are uncommon. Steroid injections may produce local reactions, occurring most often immediately after injection. These local reactions last for 24 to 48 hours, and are relieved by application of ice packs. Post-procedural pain flare-up may occasionally occur, and may be treated with painkillers. Infection can occur but can be avoided with aseptic technique.