Hip Joint & RA Flashcards
What is the innervation of the hip joint capsule?
Articular branches of the anterior hip capsule:
- Femoral nerve articular branches (L2-4)
- Obturator nerve (L2-4)
- Accessory obturator nerve (L2-5)
Articular branches of posterior hip capsule:
Branches from sacral plexus:
1. Sciatic nerve (L4-S3)
2. Nerve to quadratus femoris (L4-S1)
3. Superior gluteal nerve (L4-S1)
4. Inferior gluteal nerve (L5-S2)
Describe anatomy of femoral nerve
FN can be identified as a flat, hyperechoic structure that lies deep to the fascia iliaca laterally to femoral artery in the femoral triangle at the inguinal crease by US.
What are the advantages of Femoral Nerve block (FNB)?
- FNB facilitates positioning and reduces the time required for central neuraxial anaesthesia.
- A single-shot FNB as an adjunct to GA during THA enables:
(i) earlier discharge from PACU
(ii) improves lung function
(iii) lowers pain scores within 24 h after the procedure
What are risks of FNB?
- Quadriceps weakness
- Inadvertent neural injury can occur.
FICB is recommended as it reduces the risk of nerve damage.
What is the 3-in-1 block?
The ‘3-in-1’ block is an inguinal perivascular injection technique carried out at the inguinal level.
Blocks 3 nerves of the lumbar plexus with a single injection:
1. Femoral Nerve
2. Obturator Nerve
3. Lateral Femoral Cutaneous Nerve
Describe Fascia Iliaca Compartment block
Fascia iliaca compartment is a virtual space formed by the fascia iliaca and the underlying iliopsoas muscle.
The lateral margin is where the fascia iliaca attaches to the iliac crest and the medial margin is the fascia overlying the psoas muscle.
40-ml injectate provides the most optimal spread.
FIB is recommended for postoperative analgesia after THA because it is more effective than the lumbar plexus block and has fewer risks.
Technique has been incorporated in the PROSPECT guidelines by ESRA
What are the advantages of PENG Pericapsular nerve group block in THA surgery?
PENG block targets branches of targets of the ON, FN and AON.
- Can be performed in the supine position, avoids positioning-related pain.
- Opioid consumption is significantly reduced with the PENG block compared with the FICB within first 24 hours
- Largely motor-sparing. Decreased incidence of quadriceps weakness after hip surgeries compared with FNB and FIB.
Disadvantages:
PENG block cannot routinely provide cutaneous anaesthesia, which makes it unsuitable as the sole anaesthetic block.
What are the challenges with an iliopsoas block in THA surgery?
The iliopsoas plane is formed by the space between the iliofemoral ligament and the iliopsoas muscle lateral to the rectus femoris and medial to the iliopsoas tendon.
Can be challenging to be identify clearly in patients with significant periarticular haematoma after hip # or with soft tissue oedema right after hip surgery.
What is hip joint denervation?
Hip joint denervation can be accomplished by radiofrequency ablation, chemical neurolysis and cryoablation, traditionally targeting the articular branches of femoral and obturator nerves.
It has been used for palliative analgesia in patients with hip joint metastases and more recently for patients with inoperable hip fracture and advanced hip osteoarthritis
What is chemical neurolysis?
Primarily considered in palliative care, especially when radiofrequency or cryoablation is contraindicated or inaccessible. The anterior hip capsule is the main target.
Both absolute alcohol (100%) and phenol (6-10%) can be used as the neurolytic agent.
Systemic adverse effects:
Tachyarrhythmias
Transient hypotension.
Have vasopressor drugs available, along with careful rehydration
What are complications of radiofrequency ablation and cryoablation?
Radiofrequency ablation of the hip articular branches has been reported to reduce pain by 30-80% for at least 6 months, with a duration of up to 36 months reported.
Functional improvement is also generally seen.
Complications:
1. Transient paraesthesia
2. Femoral neuropathy with quadricep paralysis.
