Nerve root compression due to lumbar spinal canal tophi: A case report and review of the literature

Abstract

Rationale: Gout in the spine and adnexa is rare in clinical practice and can also be easily misdiagnosed, we reported a patient with nerve root compression due to lumbar gout stones in the lumbar spinal canal.

Patient concerns: A 51-year-old male was admitted to the hospital with lumbar pain with numbness in the left lower limb for more than 6 months. The physical examination showed that tenderness and percussion pain were present at L4-S1 spinous process. Straight leg raise test: 50° on the left side were positive. Laboratory tests showed that the sUA was 669 μmol/L, MRI of the lumbar spine showed that cystic T1WI low signal and T2WI mixed high signal shadows were seen in the spinal canal at the level of L4-L5.

Diagnoses: Combining with lab examinations, imaging examinations, and histopathological results, the patient was diagnosed with lumbar spinal canal tophi.

Interventions: After active improvement of all examinations, the patient underwent surgical treatment with decompression and internal fixation of the L4-L5 segment.

Outcomes: After surgery, the patient's symptoms improved and muscle strength returned to normal. Among the 95 previously reported patients with lumbar gout, the ratio of men to women was 2.96:1, and the peak age group of incidence was 56 to 65 years. The onset of the disease was mainly in a single segment of the lumbar spine, with 34.41% of all cases occurring at the L4-L5 level. 61.05% of the patients had a history of gout attacks or hyperuricemia, and the most frequently involved site was the foot and ankle, followed by the wrist. Sixty-seven patients underwent surgical treatment, and 22 chose conservative treatment, with overall satisfactory results.

Lessons subsections: The incidence of lumbar gout is low and relatively rare in the clinic and pathological biopsy is still the gold standard. Vertebral plate incision and decompression are often selected for surgical treatment, and whether to perform fusion should be comprehensively considered for the destruction of vertebral bone by gout and the reasonable selection of the extent of surgical resection. Whether choosing surgical treatment or conservative therapy, the control of uric acid levels should be emphasized.

Figure 1.

The workflow diagram.

Figure 2.

X-ray of the lumbar spine with no significant abnormalities except for bone formation at the vertebral body margins (ortho and lateral views).

Figure 3.

Preoperative MRI sagittal and cross-sectional views of the lumbar spine showing an occupying lesion in the spinal canal at the L4-L5 level (shown by red arrows). Note: A cystic T1WI low signal and mixed T2WI high signal shadow is seen in the spinal canal at the L4-L5 level, with adjacent nerve fibers displaced by compression. MRI = magnetic resonance imaging.

Figure 4.

(A and B). Intraoperative cystic structure located at the dorsal aspect of the dura at the level of L4-L5 with an intact envelope that is adherent to the dura at its base and contains a yellow jelly-like substance and a plaster-like white granular substance filling the lateral crypt.

Figure 5.

(A–C). Intradural resection of fibrous, fatty and transverse muscle tissue, with some urate crystals in the fibrous tissue with giant cell reaction, consistent with gout pathology.

Figure 6.

Lumbar spine X-ray showing good internal fixation position at the L4-L5 level (orthogonal and lateral views). Note: The L4-L5 vertebrae are visible with metal internal fixation, some of the corresponding vertebral plates and spinous processes are absent, multiple vertebral marginal spurs are present, the vertebral space is as normal and the paravertebral soft tissue shadow is clear.

Figure 7.

Literature search flow chart.

Figure 8.

Number of case reports by country, the different colors represent the number of reports for each country.

Figure 9.

Number of reported cases of lumbar gout by year.

Figure 10.

(A and B). Graphical representation of gender and age groups.

Figure 11.

Diagram of incidence site of lumbar gout.