Case report: Neuropathic arthropathy of the hip as a sequela of undiagnosed tertiary syphilis

Abstract

Background: Neuropathic arthropathy is characterized by rapidly progressive bone destruction in the setting of impaired nociceptive and proprioceptive innervation to the involved joint. It is seen most commonly in the foot and ankle, secondary to peripheral neuropathy in patients with diabetes mellitus. Other less common sites of involvement may include the knee, hip, shoulder, and spine, depending on the underlying etiology. Neuropathic arthropathy can be associated with tabes dorsalis, a unique manifestation of late, tertiary neurosyphilis that may arise in individuals with untreated syphilis many years after initial infection, and usually involves the knee, or less commonly, the hip.

Case report: We report the case of a 73-year-old man with neuropathic arthropathy of the hip and tabes dorsalis attributable to previously undiagnosed tertiary syphilis. There was considerable delay in the diagnosis and unnecessary diagnostic testing owing to failure to consider syphilis as the cause.

Literature review: With the advent of effective antimicrobial therapy and public health campaigns, the relationship between untreated syphilis and neuropathic arthropathy has been primarily a historic point of interest. However, current epidemiologic research suggests a resurgence of syphilis in the United States, with an increased incidence of patients presenting with manifestations of tertiary syphilis from unidentified and untreated primary infections. Treatment options for neuropathic arthropathy of the hip are limited. Arthrodesis has had poor success and treatment with THA has had high complication rates.

Conclusions: Syphilis is not merely a historic cause of neuropathic arthropathy. Neurosyphilis and tabes dorsalis should be considered in the differential diagnosis for patients presenting with rapid joint destruction consistent with Charcot arthropathy and no other apparent cause.

Fig. 1

A radiograph of the left hip shows extensive bone resorption of the femoral head and neck, along with superolateral subluxation of the hip and periarticular osseous debris.

Fig. 2A–B

Axial CT images with (A) soft tissue and (B) bone windows show destruction of the left hip with fluid and soft tissue densities in the joint space, extensive resorption of bone from the left acetabulum and left femoral head, and foci of osseous debris about the joint.

Fig. 3

A coronal T1-weighted MR image of the pelvis shows extensive destruction of the left hip with bone resorption.

Fig. 4

A low-power photomicrograph shows fragments of necrotic bone embedded in fibrous tissue (Stain, hematoxylin and eosin; original magnification, ×40).