Grade 3 Tibial Stress Fracture

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The tibia is the most common site of stress-related injury in runners [6,8]. Leg pain is common in runners, and may be caused by a number of etiologies,

Medial Malleolus Stress Fracture

Fig. 5. Navicular stress fracture. (A) Twenty-seven-year-old female tennis pro with pain and tenderness along the medial aspect of the navicular. Axial T2 SE image shows increased signal intensity within the navicular consistent with bone marrow edema, with a low-signal vertical line interrupting the dorsal cortex, consistent with a stress fracture (straight arrow). (B) Same patient. Coronal oblique T2 SE image shows increased signal intensity within the navicular, consistent with bone marrow edema (curved arrow), with a low-signal vertical line interrupting the dorsal cortex consistent with a stress fracture (straight arrow).

Fig. 5. Navicular stress fracture. (A) Twenty-seven-year-old female tennis pro with pain and tenderness along the medial aspect of the navicular. Axial T2 SE image shows increased signal intensity within the navicular consistent with bone marrow edema, with a low-signal vertical line interrupting the dorsal cortex, consistent with a stress fracture (straight arrow). (B) Same patient. Coronal oblique T2 SE image shows increased signal intensity within the navicular, consistent with bone marrow edema (curved arrow), with a low-signal vertical line interrupting the dorsal cortex consistent with a stress fracture (straight arrow).

Naviculare Fatigue Fracture
Fig. 6. Calcaneal stress fracture. Sagittal STIR image showing linear low signal fracture line (arrow) and extensive bone marrow edema in a long distance runner with heel pain and tenderness.

including: tibial periostitis (shin splints), stress reaction, stress fractures, muscle/ tendon injuries, and compartment syndromes. Tibial stress reaction and stress fractures most commonly present with pain and tenderness along the medial shaft of the tibia, precipitated by exercise.

There is usually focal tenderness to palpation and percussion along the medial tibia. Tibial stress fractures can involve the diaphysis, metaphysis, and mal-leoli, and can be transverse, longitudinal, or spiral (Fig. 7) [16,49,50].

Stress fractures of the tibial diaphysis are common among runners. The proximal tibial metaphysis is a relatively unusual site of stress fracture, and can mimic internal derangement of the knee. It has been suggested from research on bone geometry that runners with significantly smaller tibial cross-sectional dimensions and area as determined by CT and dual energy x-ray absorptionmetry (DXA) are at greater risk for the development of tibial stress fractures [51].

Mri Tibula Stress Fracture
Fig. 7. Bilateral distal tibial metaphyseal stress fractures (arrows). 64-year-old female vacationing in Hawaii and hula dancing for 2 weeks developed bilateral ankle pain.

Diagnosis is commonly made clinically. An early radiographic sign of stress fracture termed the ''gray cortex'' has been described in initial conventional radiographs [52], but most plain films are normal in the setting of stress injuries [53]. Bone scintigraphy may show longitudinal uptake of radiotracer along the posteriomedial tibial diaphysis, at the attachment of the soleus in shin splints. Transverse tibial stress fractures of the diaphysis manifest as focal elliptical or fusiform cortically based radiotracer activity on the delayed bone scan imaging (Fig. 8) [54].

A recent study comparing MRI, CT, and bone scintigraphy described MRI as the single best technique to assess suspected tibial stress injuries [53]. The sensitivities of MRI, CT, and bone scintigraphy were 88%, 42%, and 74% respectively. The specificity, accuracy, and positive and negative predicted values were 100%, 90%, 100%, and 62% respectively for MRI and 100%, 52%, 100%, and 26% respectively for CT [53]. Using MRI, the transverse plane has been determined to be the best in the detection of tibial shaft stress injuries. Axial MR images may show endosteal marrow edema, subtle periosteal edema, and a thickened detached periosteum manifested as a thin line of signal void [53,55]. CT can show osteopenia in the tibial cortex, which is the earliest finding in cortical bone fatigue injury. CT may also show subperiosteal irregularity and cortical resorptive change [53].

Longitudinal stress fractures are an unusual but recognized injury in runners [16]. Longitudinal tibial stress fractures present as elongated, diffuse, increased radiotracer activity extending from the tibiotalar area proximally. This may be suggested on the soft-tissue blood pool phase of the triple-phase bone scan, but is best seen on the 3-hour delayed imaging [50]. Plain films are most often negative, and reports of negative bone scans in longitudinal tibial stress fractures

Fig. 8. Tibial stress fracture. Delayed nuclear scintigraphy shows focal fusiform uptake of radiotracer activity in the proximal tibial diaphysis consistent with a stress fracture (arrow).

have been noted [16]. MRI diagnosis of longitudinal fractures may be challenging in that findings may consist only of longitudinal, intramedullary, hyperin-tense signal intensity seen with STIR sequences. T1-weighted sequences may show corresponding less obvious decreased signal intensity. An actual fracture line may not be seen on MRI in longitudinal stress fractures of the tibia. In these cases, CT with thin section reformats may reveal an intracortical longitudinal fracture line, confirming the diagnosis [16].

Fredericson and colleagues [56] have proposed an MRI grading system as a method of describing a continuum of stress injuries of the tibia. Grade 1 injury consists of only periosteal edema on T2-weighted, fat-suppressed images without marrow or cortical signal abnormality. Grade 2 shows both periosteal edema and marrow edema on fat-suppressed, T2-weighted images, but no corresponding decreased signal on the T1-weighted images. Grade 3 injuries show moderate to severe edema of both the periosteum and of the marrow on both the fat-suppressed T2 and the T1-weighted sequences. Grade 4 injury shows grade 3 signal changes, with the addition of the actual cortical fracture line being visible. Fredericson and colleagues recommended MRI over bone scintigra-phy as a more informative and accurate test to determine the extent of underlying bone injury, which allows better recommendations for clinical management without the exposure to ionizing radiation characterized by bone scintigraphy, along with significantly reduced imaging times [56]. MRI results must be correlated with the clinical setting, however, because signal changes suggestive of tibial stress reaction may be seen in asymptomatic long distance runners. Bergman and coworkers [57] followed 21 asymptomatic collegiate long distance runners, and reported that 67% were normal, but that the other 43% of asymptomatic long distance runners showed grade 1 to grade 3 signal changes. No asymptomatic subjects were found to have grade 4 injuries. All subjects remained asymptomatic for a 2-year follow-up time period [57]. This demonstrates the importance of correlating imaging findings with clinical findings before management decisions. Treatment consists of activity restriction and modification in milder cases and non-weight bearing or immobilization in more severe cases.

Tibial stress fractures in runners may occur less commonly in locations such as the medial tibial condyle and medial malleolus. These injuries are particularly difficult to diagnose clinically because they may mimic other regional injuries such as meniscal tears, ligamentous, or cartilaginous pathology [8,58]. Stress fractures may result in a large amount of bone marrow signal alteration that may be mistaken for malignant tumors, resulting in unnecessary biopsy [8]. Meniscal tears may be associated with adjacent bone marrow edema as a stress response to the meniscal tear, or may be an asymptomatic incidental finding in the setting of a symptomatic stress fracture of the proximal tibia. Patterns of signal alteration and clinical correlation are important discriminators of these injuries (Figs. 9, 10).

Medial malleolus stress fractures are rare. They most commonly present with subacute or chronic pain and tenderness over the medial malleolus, or i m

if tSii

Fig. 9. Tibial metaphyseal stress response. Coronal T2 FSE FS image. Thirty-two-year-old male long distance runner with pain and tenderness just distal to the medial joint line. Medial proximal tibial metaphyseal bone marrow edema (arrow) without fracture line consistent with stress response.

medial ankle pain with a history of running. An ankle effusion may be present [59,60]. Plain films are most often normal. Bone scan normally shows uptake of radiotracer in the medial malleolus. [59-61]. CT may show the presence of subtle fissures at the junction of the medial malleolus and tibial plafond, and circumscribed lytic lesions have been reported with medial malleolus stress fractures [61]. These patients may be treated conservatively or operatively, depending on the severity of the injury and its radiographic appearance, or lack of response to conservative treatment [59,60,62]. It has been suggested that stress fractures in athletes desiring an early return to full activities that are visible by plain film should be treated by open reduction and internal fixation with can-cellous screws. Patients who have bone scan or MRI evidence of medial mal-leolus stress fracture that are not evident on plain film may be treated conservatively with casting and immobilization [60].

Fig. 10. Transverse tibial metaphyseal stress fracture. Coronal T1, contrast-enhanced FS. Long distance runner with pain and tenderness just distal to the medial joint line. Low signal intensity transverse fracture line is visible (curved arroW) with surrounding enhancing bone marrow edema (straight arrow).

A study measuring in vivo tibial strain rates found that strain rates were 48% to 285% higher during overground running in comparison with treadmill running [63]. The authors in the study suggest that treadmill runners are at a lower risk of developing tibial stress fracture, but less likely to achieve tibial bone strengthening than over-ground runners [63].

Stress fractures of the anterior tibial midshaft cortex are injuries that require particular attention, because they are prone to delayed healing and nonunion. Rest and external electric stimulation for 3 to 6 months have been suggested as initial management in these patients before surgical intervention. In one study, the average time to return to competitive activity was 12.5 months using this management [64]. Chronic, recurrent, or recalcitrant stress fractures of the tibia that do not heal with nonoperative therapy may benefit from intramedullary tibial nailing [65].

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  • CHARLES
    What is a grade three stress fracture?
    8 years ago
  • laila
    What is a grade three midshaft tibial stress fracture?
    8 years ago
  • keith
    What is the highest grade of stress fractures?
    7 years ago
  • bisirat
    Is a grade 4b tibial stress injury an actual stress fracture?
    3 years ago
  • milena
    What is a grade 3 tibia fracture?
    3 years ago
  • claudia
    What is grade 2 fibrillation of the distal tibial plafond?
    3 years ago
  • KIBRA RUSSOM
    WHAT DOES GRADE 1 STRESS REACTION OF THE TIBIAL DIAPHYSIS MENA?
    2 years ago
  • Stephanie
    Can tibial stress reactions be mistaaken for metastases?
    1 year ago
  • leonie
    How common are posterior medial stress fractures?
    10 months ago
  • Charlie
    How long does it take for a grade 3 stress fracture to heal completley?
    8 months ago
  • MIRRIN
    What are grade 3 fracture of the bone?
    4 months ago
  • anne
    Is proximal medial tibial metaphysis a low risk stress fracture?
    10 days ago

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