Continuous Suprainguinal Fascia Iliaca Block for Postoperative Analgesia in a Patient with Alkaptonuria: A Case Report

INTRODUCTION

Alkaptonuria is a rare autosomal recessive disorder of tyrosine metabolism, with an estimated prevalence of 1 in 2,50,00 live births.¹ It results from a deficiency of homogentisate 1,2-dioxygenase enzyme, leading to accumulation of homogentisic acid (HGA) in the connective tissues. The classical triad includes homogentisic aciduria, ochronosis, and arthritis.² Ochronotic arthropathy is the most common clinical manifestation, caused by polymer deposition that activates an inflammatory response and calcium deposition in synovial and intervertebral joints.²

The disease commonly affects multiple systems, including the musculoskeletal, respiratory, airway, cardiovascular, genitourinary, cutaneous, and ocular systems. Total hip arthroplasty (THA) is associated with severe pain during the perioperative period. Hence, effective analgesia is essential to facilitate early mobilization, thus reducing hospital stay and lowering medical costs related to THA.^3-5

CASE REPORT

A 71-year-old male presented with left hip pain following a fall at home, along with a one-year history of low backache and difficulty in walking. He was a known case of alkaptonuria since childhood, and had a history of hypertension for two years, controlled with the tablet bisoprolol 2.5 mg once daily. He had also been diagnosed with atrial fibrillation six months earlier. He was maintained on tablet diltiazem SR 90 mg twice daily, tablet dabigatran 110 mg twice daily, and tablet ecosprin. The patient reported allergies to ibuprofen, ciprofloxacin, nimesulide, and amoxycillin/clavulanic acid.

He had undergone bilateral total knee replacement 12 years earlier, under combined spinal-epidural anesthesia, which he described as traumatic due to multiple attempts, severe back pain, and a post-dural puncture headache. Subsequently, he underwent transurethral resection of the prostate and right knee medial meniscus repair under general anesthesia without complications.

On examination, vital signs were stable with a heart rate of 82 beats/min and a blood pressure of 130/80 mmHg. Airway assessment revealed Mallampati Class II, adequate mouth opening, thyromental distance > 6.5 cm, and unrestricted neck movements. Spinal examination revealed narrowed, calcified intervertebral spaces. Laboratory investigations, including hemoglobin, Chest X-ray, ECG, and echocardiography, were within normal limits. X-ray of the lumbosacral spine showed scoliosis with narrowing of all disc spaces. A diagnosis of left hip ochronosis with severe secondary osteoarthritis was made, and a cemented left-sided THA was planned.

Given the patient’s refusal of neuraxial anesthesia, general anesthesia with controlled ventilation was planned. Dabigatran and ecosprin were discontinued seven days before surgery, while antihypertensives were continued till the morning of surgery. After adequate fasting and written informed consent, standard monitoring was instituted in the operating room. Following preoxygenation, anaesthesia was induced with fentanyl, propofol, and rocuronium after confirming mask ventilation. The trachea was intubated successfully with an 8.0 mm cuffed endotracheal tube (Cormack-Lehane Grade II). Anesthesia was maintained with sevoflurane in an oxygen-nitrous oxide mixture, and rocuronium was used as the muscle relaxant. An ultrasound-guided left femoral nerve block was administered before positioning the patient for surgery. The drug used was 12 mL of 1% xylocaine adrenaline. The surgery lasted 3 h.

An ultrasound-guided supra-inguinal fascia iliaca block with continuous catheter placement was performed before extubation for posoperative analgesia. A high-frequency, linear probe was placed longitudinally just medial to the anterior superior iliac spine (ASIS) [Figure 1]. The iliacus muscle over the iliac blade was identified, producing the characteristic “bow-tie” appearance, with the ASIS at the center of the bow, internal oblique cephalad, and sartorius caudad [Figure 1]. The deep circumflex artery was identified superficial to the fascia iliaca and the internal oblique and confirmed using color Doppler.

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Figure 1:

(a) Bow-tie appearance of the iliacus over the anterior superior iliac spine (ASIS), S- sartorius, IO- internal oblique, black arrow depicts the direction of needle from caudad to cephalad, (b) deep circumflex iliac artery (DCIA) on color Doppler, square box- delineates the area where color Doppler was used to locate vessels, (c) catheter over the suprainguinal fascia iliaca plane depicted by white arrow, (d) tunneling of the catheter done to reduce displacement and fixed on the lower abdomen.

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An in-plane approach was used from caudad to cephalad under real-time ultrasound guidance. As the needle pierced the fascia iliaca, a characteristic “pop” was appreciated. Correct needle placement was confirmed with incremental injections of 0.5–1 mL of 0.2% ropivacaine, demonstrating appropriate spread above the iliacus muscle. The needle was advanced cautiously to avoid vascular puncture. Needling was done with caution to avoid vascular puncture. The catheter was then inserted and fixed 3 cm beyond the needle tip to prevent kinking or displacement. A total of 40 mL of 0.2% ropivacaine was injected above the iliacus muscle, and the catheter was subcutaneously tunneled. Neuromuscular blockade was reversed with neostigmine and glycopyrrolate, and the patient was extubated once fully conscious. A continuous infusion of 0.1% ropivacaine at 5 mL/h was initiated through the catheter. A 15 mL bolus of 0.1% ropivacaine was administered through the catheter 6 h after surgery, before ambulation. The patient reported excellent analgesia (i.e., Visual Analog Scale (VAS) 1 at rest and during ambulation), requiring no rescue analgesia, and the catheter was removed 48 h after surgery.

DISCUSSION

Alkaptonuria is an autosomal recessive disorder of tyrosine metabolism caused by a deficiency of the enzyme HGA oxidase, leading to HGA accumulation and deposition of ochre-colored pigment in cartilage and collagenous tissues (endogenous ochronosis).¹ This results in progressive degenerative changes, particularly involving the spine, including disc calcification and narrowing of intervertebral disc spaces, as observed in our patient.^1,2,6

Difficulty in performing a central neuraxial block was anticipated in this patient based on spinal radiographic findings, and the patient’s unpleasant experience further precluded this option; hence, general anesthesia was planned.

Multiple regional analgesic techniques have been described for post-operative pain management following THA, all with varying success.^1,2 The various options include femoral nerve block, fascia iliaca nerve block, pericapsular nerve group block, anterior quadratus lumborum block, and the obturator nerve block. Conventional infrainguinal fascia iliaca block -demonstrates variable lateral femoral cutaneous nerve (LFCN) blockade, with reported failure rates of 10–37%.^3-5 This variability is attributed to inconsistent distribution and branching of LFCN distal to the inguinal ligament. In contrast, its course is more predictable proximally beneath the fascia iliaca within the pelvis.^6-8 Hebbard et al. demonstrated improved LFCN coverage using a suprainguinal approach by injecting the drug proximal to the inguinal ligament.⁹ Despite the advantages of the suprainguinal approach, the long needle path and the body mass of obese patients can make this approach challenging.

Ultrasound-guided suprainguinal fascial iliaca (SIFI) block offers a more consistent spread toward the lumbar plexus compared with the infrainguinal approach, resulting in reliable blockade of the femoral nerve and LFCN with partial obturator nerve involvement.^7,8 Continuous catheter placement further prolongs analgesia and facilitates early mobilization. Advancing the catheter 2–3 cm beyond the needle tip minimizes the risk of kinking, and ultrasound confirmation of catheter position enhances accuracy.

CONCLUSION

Multisystem involvement in alkaptonuria, patient refusal of neuraxial techniques and allergies to analgesics necessitates a careful selection of anesthetic techniques in major hip surgery. Combination of general anesthesia and regional analgesic techniques provide suitable alternatives to neuraxial techniques in hip surgery. SIFI block is a simple, safe, and effective regional analgesic technique for providing postoperative analgesia in major hip surgery. Continuous analgesia via an indwelling catheter, combined with multimodal analgesia, facilitates early mobilization and contributes to improved recovery.