Volume VII, Number 1 | April 2023

A Case of Gout Masquerading as Flexor Tenosynovitis of the Hand

Authors

1. Jordan Grilliot DO – Aultman Heath Foundation/ Aultman Hospital
2. Jeffrey Dulik DO – Aultman Heath Foundation/ Aultman Hospital
3. Jeffrey Cochran DO – Aultman Heath Foundation/ Aultman Hospital

 

Abstract

Case Description: A 58 year old male presented to the hospital with a 5 day history of atraumatic left hand swelling and pain. Based upon clinical and physical exam findings, he was diagnosed with flexor tenosynovitis. Routine laboratory and imaging studies were performed. He was taken urgently to the operative suite for formal irrigation and debridement. Unexpected intra-operative findings were encountered.  Incision of the tendon sheath exposed chalky, sedimented material. Post-operatively, the patient was admitted for antibiotics and monitoring of laboratory data. Crystal analysis was consistent with gouty tophus and cultures demonstrated no growth.  Antibiotics were discontinued and a course of corticosteroids and non-steroidal anti-inflammatory medication was started. He was ultimately discharged home after his symptoms resolved.

Discussion: This case illustrates a rare cause of flexor tenosynovitis. When patients present with suspicion of flexor tenosynovitis, the differential diagnosis should consider gout, even if the patient has no history of gout. This clinical presentation was consistent with pyogenic flexor tenosynovitis and necessitated urgent surgical intervention. Expedient diagnosis helped to tailor appropriate medical therapy once the diagnosis was confirmed.

Keywords: Gout, flexor tenosynovitis, flexor tendon pathology, hand surgery

Introduction: Gout is a common cause of pain and disability in western countries. The most frequent complaints associated with this condition include joint pain, erythema, and swelling. Gout is frequently found in the great toe but can affect any of numerous joints of the body. Risk factors for this condition include alcohol intake, age>50, male sex, excessive red meat consumption, diabetes mellitus, hypertension, and hyperlipidemia.1 Pathologically, gout is thought to be a multifactorial condition with an underlying imbalance of uric acid production and excretion. Purines found in the body are thought to be the cause of uric acid formation. Purines perform many important functions in the cell including forming precursors to DNA and RNA, regulation of signal transduction and energy metabolism, and performance of physiologic functions involved in muscle tissue, platelets, and nerves.2 The ultimate catabolic products of purine metabolism produce uric acid, which could lead to gout if produced in excess. The pain and other clinical manifestations can be traced to monosodium urate (MSU) crystal formation and the subsequent cytokine release. MSU crystal formation leads to the release of IL-1 beta in the presence of free fatty acids. This is thought to lead to the development of inflammation and erythema that is characteristic during a gout flare.

Gout’s clinical presentation is often confused with soft tissue infection or septic arthritis, which is why orthopedic services are often consulted during the differential diagnosis. An expedient diagnosis is important to properly treat this condition and prevent complications or recurrences. Orthopedic surgeons should have a thorough understanding of this condition and the typical and atypical presentations. It is also critical to understand the gout’s pathophysiology to make accurate and medically sound treatment recommendations as part of a team-based approach to patient care. In some rare cases, manifestations of gout require orthopedic surgical intervention. The following case report describes a rare presentation of gout that initially appeared to be pyogenic flexor tenosynovitis.

Case Description: The patient was a 58-year-old left hand dominant male with no past history of gout who presented to the Emergency Department with complaints of left hand and pain and swelling for 5 days prior to evaluation. He denied any trauma to the hand but had been performing manual labor earlier in the week and felt he may have “tweaked” his hand. He noticed only mild pain initially but then progressively began to develop increasing erythema and pain. The patient was evaluated by emergency department staff and had laboratory and imaging studies performed. He was found to have no leukocytosis but did have elevations in both his Erythrocyte Sedimentation Rate (ESR) and C-reactive Protein (CRP) levels (61 mm/hr and 10.8 mg/dL respectively). He was also having intermittent fevers in the emergency department with Tmax of 38.2 degrees Celsius. He underwent imaging studies prior to consultation, including radiographs and CT scanning of the hand. Radiographs demonstrated diffuse soft tissue swelling about the left hand with no bony findings. CT scanning demonstrated an incidental fluid collection overlying the volar triquetrum. These findings are shown in figure 1. Orthopedics was consulted for concern for left hand infection. Physical exam was pertinent for localized erythema and swelling overlying the volar aspect of the MCP joint and distal palm of the left hand little finger. There was exquisite tenderness to palpation noted over the A1 pulley. Further physical exam demonstrated tenderness over the course of the flexor tendon sheath as well as resting flexed posturing of the left small finger and pain with passive extension. The combination of laboratory data and the physical exam findings led to a presumptive diagnosis of pyogenic flexor tenosynovitis. The patient was subsequently admitted to the hospital and underwent surgical irrigation and debridement the same day. A limited bruner incision was performed centered over the A1 pulley and extended distal to the MCP flexion crease. This exposure was chosen due to the delay in presentation, and to improve exposure should more extensive debridement be required. The A1 pulley was identified and incised longitudinally, which exposed copious amounts of chalky material. This did not appear purulent on initial examination nor was there any subcutaneous purulence on initial exposure. The fluid was sent for gram stain, cultures, and crystal analysis due to the suspicious nature of its appearance.  The patient’s tendon quality was excellent with no evidence of impending rupture or signs of tendinosis. Post operatively the patient was placed on empiric antibiotics. Infectious disease consultation was obtained to manage his antibiotic regimen. On post-operative day two crystal analysis demonstrated monosodium urate crystals consistent with a diagnosis of gout. His gram stain and cultures were negative at that time and remained negative until finalized. Therefore, antibiotics were discontinued and he was placed on ibuprofen and a brief course of oral corticosteroids. He improved rapidly after initiation of the medical therapy and was discharged home post op day 3. The patient was discharged with follow up instructions for both a primary care physician as well as orthopedics. The patient was evaluated at two weeks post op and was then lost to follow up as the patient relocated soon after surgery. He also did not obtain follow up with a local primary care physician and was not placed on long term therapy for gout.

Outcome: One year post operatively the patient was contacted via telephone to undergo a questionnaire. The Michigan Hand Outcomes Questionnaire (MHOQ) was administered at that time. This outcome score is a validated, reliable score that evaluates the overall function of the hand with regards to six domains (ADL’s, work, pain, function, appearance, overall satisfaction.)3 Because gout rarely presents as flexor tenosynovitis, there is a scarcity of literature using this outcome score for this condition. However, given the validation and high reliability of this score, it was applied to this clinical situation. The minimum clinically important difference for the MHOQ has been found to range from 3-23 points.4 This patient’s scores can be found in table 1.  Overall, the patient was quite satisfied with the function and appearance of his hand. He reported no residual pain in the left hand or little finger and felt it functioned as well as the right. The patient denied any complications including recurrent gout, infection, wound dehiscence, or stiffness in the hand.

Discussion and Significance: Gout of the flexor tendon sheath is a rare entity. There are very few case reports and no large-scale case series that have been presented. Upon literature review, the largest case series consisted of three patients who underwent surgical treatment for this condition.5 Because this condition is so rare, when a patient presents with suspicion for pyogenic flexor tenosynovitis, gouty involvement of the tendon sheath may not be considered during the work up. However, gouty flexor tenosynovitis can be devastating, with large tophus deposition leading to tendon rupture in chronic or uncontrolled cases. An example of tophus formation about flexor tendons can be seen in figure 2.6 Prompt surgical treatment is necessary to prevent these complications and optimize function. Treatment of this pathology also requires a multidisciplinary approach from medical and surgical services. These patients will require medical evaluation to address potential underlying causes of hyperuricemia as well as long-term prophylaxis against the recurrence of gout. This patient had a good outcome with no significant loss of function through a combination of prompt surgical treatment and medical therapy for the resulting acute inflammatory process. To establish a complete pre-operative differential diagnosis in patients who have signs and symptoms of flexor tenosynovitis, a thorough history is imperative.  Lastly, this case illustrates the importance of intra-operative decision making in the face of unexpected findings. When confronted with peculiar intra-operative findings, obtaining a broad laboratory work up that includes crystal analysis, is prudent as gout, although rare, can precipitate in the tendon sheath.

References

  1. Gonzalez EB. An update on the pathology and clinical management of gouty arthritis. Clin Rheumatol. 2012; 31(1): 13-21.
  2. Maiuolo J et al. Regulation of uric acid metabolism and excretion. Int. J. Card. 2016; 213(1): 8-14.
  3. Chung KC, et al. Reliability and validity testing of the Michigan Hand Outcomes Questionnaire. J Hand Surg Am. 1998; 23(4): 575-87.
  4. Shauver MJ, Chung KC. The minimal clinically important difference of the Michigan Hand Outcomes Questionnaire. 2009; 34(3): 509-514.
  5. Weniger FG, et al. Gouty flexor tenosynovitis of the digits: report of three cases. J Hand Surg Am. 2003; 28(4): 669-672.
  6. Meyer G, Dahmam A. Hand involvement in gout. Hand Surg Rehabil. 2018; 37: 197-201.
The Journal of the American Osteopathic Academy of Orthopedics

Steven J. Heithoff, DO, FAOAO
Editor-in-Chief

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