A 26-year-old female patient presented at the Emergency Department of our institution with complaints of severe pain on the dorsal face of the wrist due to a fall while performing Crossfit. On observation, there was significant oedema and haematoma. A wrist radiograph and, two weeks later, a wrist MR were performed for further clarification.
The wrist radiograph revealed correct alignment of bone structures, with no evidence of fracture lines (Fig. 1). Considering the persistent oedema and haematoma on the dorsal aspect of the wrist, an MR was performed and revealed a horizontal, non-displaced fracture line of the distal radius with significant bone marrow oedema, especially on its dorsal surface near Lister’s tubercle (Fig. 2a, b). Additionally, there was soft tissue swelling and distension of the synovial sheath of the tendon of the Extensor Pollicis Longus (EPL) with T1-hyperintense content, compatible with blood (Fig. 3), without evidence of tendon rupture. Distally, at the crossing with the extensor carpi radialis longus and brevis (ECRL; ECRB), there was exuberant distension of the sheath of the second compartment that was filled with similar content (Fig. 4). The extensor retinaculum was intact (Fig. 4).
The second extensor compartment is composed of ECRB and ECRL, and lies between the first compartment and Lister’s tubercle. The second and third compartment tendon sheaths communicate through a foramen and, for that reason, tenosynovitis can affect both, as it occurred on our case. The third compartment, composed solely of the EPL, should be recognised as being particularly prone to lesions due to its superficial location [2]. EPL tendon rupture is a well-known complication in fractures without misalignment of the distal radius [1]. In these fractures, the extensor retinaculum is usually intact [3], which is in line with the case we present. The mechanism of injury occurs when fluid and blood accumulate and cause irritation in the third extensor compartment [4]. This accumulation results in an increase in pressure and friction over the bone, leading to a possible delayed rupture of the tendon of the EPL that usually occurs between 3 weeks to 3 months after the traumatic event [1, 4]. This does not usually occur on displaced radial fractures since the retinaculum is ruptured and, for this reason, intracompartment pressure does not rise significantly. The MR was performed 13 days after the initial injury. This fact explains, at least in part, why the tendon is intact. The timely recognition of this type of lesions is of a higher degree of importance since this tendon, in the region of Lister's tubercle, has very poor vascularisation, known as a critical zone [5]. In the context of high intracompartmental pressure, this critical zone is even at a higher risk, leading to an increased potential for rupture or necrosis [1]. Treatment in this case should be focused on decompression of the sheaths, thus avoiding a possible delayed tendon rupture.
As far as the authors know, this is one of the few cases that clearly depicts the presence of acute haemorrhage in the wrist extensor tendon sheaths on MR. This may be because there are not many cases that go through an MR in such an acute setting.
The key to a correct diagnosis and thoughtful clinical guidance, in this case, should focus on three aspects:
1. Knowledge of the injury mechanism and non-displaced radial fracture possible complications
2. Anatomical specificities of the second or third extensor compartment
3. Observing the distension of the synovial sheaths with hyperintense content on T1-weighted images, corresponding to haemorrhage, very rarely documented on MR.
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Occult radius fracture with acute haemorrhagic tenosynovitis of extensor compartments
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Based on the provided anteroposterior radiograph of the wrist, there is no obvious displacement or only minimal displacement of the distal radius fracture. The fracture fragments appear relatively well-aligned, and the articular surface is generally smooth. Slight swelling or increased soft tissue density can be observed on the dorsal side of the wrist, suggesting local hematoma or soft tissue edema.
Subsequent MRI findings (including axial and sagittal sequences) reveal T1 hyperintense fluid or linear signals within the second and third extensor compartments, suggesting acute hemorrhage. Corresponding synovial sheath appears distended, and noticeable synovial cystic expansion is present. No definitive interruption indicating complete tendon rupture is observed; however, there are signs of tendon sheath involvement and hematoma surrounding the tendons. The distal radius itself does not exhibit any notable displacement, which, along with clinical evaluation, supports a diagnosis of a non-displaced distal radius fracture.
Taking into account the patient’s history of injury from a fall, clinical presentation, and imaging findings, the most likely final diagnosis is:
“Right wrist non-displaced distal radius fracture with acute hemorrhagic changes in the second and third extensor compartments, carrying a risk of delayed EPL tendon injury.”
Particular attention is required for potential delayed rupture of the extensor pollicis longus tendon in these types of fractures (with minimal displacement and extensor compartment compression). Regular imaging follow-up (ultrasound or MRI) is recommended to monitor tendon integrity.
(1) Early Rehabilitation (Weeks 1–2):
(2) Mid Rehabilitation (Weeks 3–6):
(3) Late Rehabilitation (6 Weeks and Beyond):
This report is based on the current imaging and clinical information available and is intended as a reference opinion, not a substitute for in-person consultation or professional medical advice. Patients should seek timely medical evaluation and follow the recommendations of qualified healthcare providers. If the condition changes or new symptoms arise, please seek medical attention immediately.
Occult radius fracture with acute haemorrhagic tenosynovitis of extensor compartments
