SAEM Clinical Images Series: Weird Flex

tenosynovitis

A 29-year-old female with a history of depression, anxiety, and tobacco use disorder presented with worsening right index finger pain, swelling, and redness for the previous three days. Additionally, she reported that she was unable to further flex or extend her finger. She denied fevers, chills, rashes, or recent illness. There was no history of trauma, aquatic or other environmental exposures, insect bites, or intravenous drug use. She did note that she uses a copper brillo pad to clean her dishes at home which often causes small abrasions to her fingers.

Physical Exam

Vitals: BP 160/112; PR 73; Temp 36.4°C; RR 18; SpO2 100% on RA

General: Well-appearing, no acute distress.

Cardiovascular: Right index finger capillary refill <2 sec.

Skin: Right index finger uniformly edematous and erythematous with tenderness to palpation along the tendon sheath; small healed abrasions over distal palmar aspect of the digit; no focal area of fluctuance.

MSK: right index finger held in flexion, pain with passive extension.

Laboratory Data

WBC: 8.6

ESR: 129

CRP: 105.5

Case Question: What is this patient's diagnosis?

This patient has flexor tenosynovitis, an infection of the synovial sheath surrounding the flexor tendon of the hand. The condition is usually caused by local inoculation from penetrating trauma although can also result from hematogenous spread. Flexor tenosynovitis is considered a surgical emergency, as delayed intervention can lead to significant morbidity including tendon rupture, deep space infection, abscess development, soft tissue necrosis, amputation, and/or chronically compromised hand function. Diagnosis is usually clinical, based on history and physical exam findings; however, laboratory evaluation may reveal leukocytosis and/or elevated inflammatory markers. If there is a history of penetrating trauma, x-rays of the affected digit are recommended to rule out retained foreign body. Management in the ED includes prompt surgical consultation and broad-spectrum antibiotics against common cutaneous pathogens. Antibiotic coverage should be broadened in patients with a history of marine exposure or Pseudomonal risk factors including immunocompromised status.

Case Question:What is the tetrad of physical exam findings found in this condition?

Flexor tenosynovitis presents with four classic exam findings called “Kanavel Signs.” Kanavel Signs include (1) flexion of the involved digit, (2) tenderness to palpation over the tendon sheath, (3) pain with passive extension, and (4) uniform swelling of the finger. The presence of all four Signs has a sensitivity for flexor tenosynovitis as high as 97.1%, although early in the course of infection, pain with passive extension may be the only finding.

Case Discussion

Take-Home Points

Flexor tenosynovitis is an infection of the flexor tendon sheath of the hand and a history of trauma or penetrating injury to the area should raise suspicion.
Flexor tenosynovitis is a “can’t miss” clinical diagnosis in the ED as there is a risk of significant complications with delayed antibiotics and surgical intervention.
Infection can reliably be identified by the presence of the four Kanavel Signs on physical exam.

References

Chan E, Robertson BF, Johnson SM. Kanavel signs of flexor sheath infection: a cautionary tale. Br J Gen Pract. 2019 Jun;69(683):315-316. doi: 10.3399/bjgp19X704081. PMID: 31147342; PMCID: PMC6532803.
Chapman T, Ilyas AM. Pyogenic Flexor Tenosynovitis: Evaluation and Treatment Strategies. J Hand Microsurg. 2019 Dec;11(3):121-126. doi: 10.1055/s-0039-1700370. Epub 2019 Nov 2. PMID: 31814662; PMCID: PMC6894957.
Hermena S, Tiwari V. Pyogenic Flexor Tenosynovitis. In: StatPearls. StatPearls Publishing; 2022.
Kennedy CD, Huang JI, Hanel DP. In Brief: Kanavel’s Signs and Pyogenic Flexor Tenosynovitis. Clin Orthop Relat Res. 2016 Jan;474(1):280-4. doi: 10.1007/s11999-015-4367-x. Epub 2015 May 29. PMID: 26022113; PMCID: PMC4686527.

Copyright

Images and cases from the Society of Academic Emergency Medicine (SAEM) Clinical Images Exhibit at the 2023 SAEM Annual Meeting | Copyrighted by SAEM 2023 – all rights reserved. View other cases from this Clinical Image Series on ALiEM.