Tenodesis Effect Mimicked by Flexor Tendon Entrapment in a Paediatric Midshaft Forearm Fracture: a Case Report and Review of the Literature

Abstract

Entrapment of the flexor digitorum profundus (FDP) tendon following radius and ulna midshaft paediatric forearm fractures has been reported rarely in the literature. To date, 19 cases have been described. A characteristic fracture pattern, persistent cortical defect at the fracture site and flexion contracture not responsive to hand therapy are all hallmarks of the condition. We present a case along with a review of the literature. A 12-year-old boy underwent exploration of a primary right open radius and ulna fracture site 22 months following initial open reduction and titanium elastic nail system (TENS) fixation. The little finger FDP tendon was found interposed between the ulna bone with a significant defect in the cortical surface of the ulna, correlating with a lucency identified on plain radiograph preoperatively. Removal of all interposed tissue, debridement of the bone edges and Pulvertaft tendon weave of the FDP of the little finger to the ring finger were performed. The patient recovered full upper limb function. Clinicians should be vigilant to identify this complication when managing patients with forearm fractures. A thorough clinical examination pre-and post-open or closed forearm fracture reduction should be performed to ensure early recognition of this rare complication. If the tenodesis effect and post-operative adhesions cannot be adequately released by therapy, interposition of the tendon at the fracture site should be considered as a differential diagnosis. If the complication is suspected, early operative intervention should be performed to ensure optimal fracture healing and restoration of function.

<p>Flexor Tendon Entrapment of the Index Finger After Monteggia Fracture in a Pediatric Patient</p>

“…The period from injury to FDP release surgery ranged from 2 days to 16 years. 1 A previous study suggested that two mechanisms underlie entrapment. 2 In the first mechanism, the muscle belly becomes directly sandwiched between the fractured areas.…”

“…Twenty-one similar cases have been found to date. 1 Surgical treatment was performed in all cases, and the fractured part was deployed openly to prevent the detachment of muscles and tendons. All subjects were aged between 5 and 17 years old.…”

“…Page et al also reported that FDP entrapment commonly allows for increased finger extension and decreased pain when the wrist is flexed or neutral compared to when the wrist is extended. 1 In addition to clinical findings, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound sonography (US) are also effective diagnostic tools. 4 Preoperative ultrasound may serve as an alternative to MRI, especially in pediatric patients because it is non-invasive, cost-effective, and less time-consuming.…”

Treatment of a neglected flexor digitorum profundus entrapment after closed reduction of both bone forearm fracture: A case report

“…[14] Review of the literature reveals 31 cases (both children and adults) of FTE after forearm fractures. [2][3][4][5][6][7][8][9]12,13] In 13 of previous 31 cases, only one finger was affected, while two or more fingers were affected in 18 cases. [2][3][4][5][6][7][8][9]12,13] The average age of patients is 11.6 years ranging from 4 to 28.…”

“…[2] Nerve and tendon entrapment in the fracture line after reduction are rarely reported complication of these fractures. [3][4][5][6][7][8][9][10][11][12][13] Flexor tendon entrapment (FTE) is a rare and usually lately diagnosed complication of pediatric forearm fractures. In this case report, we present a case of a neglected ring and little finger flexor digitorum profundus (FDP) entrapment after closed reduction of both bone forearm fracture and treated five years later due to late diagnosis.…”