Risk factors for tibial stress injuries: a case-control study.

OBJECTIVE: To identify physical and behavioral characteristics related to the incidence of tibial stress injuries (TSIs). DESIGN: Case-control study. No clinical care was conducted. SETTING: Research laboratories in the San Francisco (the United States) and Gold Coast (Australia) areas. PARTICIPANTS: Forty-eight patients (21 men and 27 women) with acute TSI, and 36 (16 men and 20 women) age-matched, sex-matched, height-matched, weight-matched, and activity-matched controls with no history of TSI. INDEPENDENT VARIABLES: Height, weight, body mass index, bone, lean and fat mass, lower limb alignment anomalies, foot type, orthotics, calcium, recent weight change, menstrual history, oral contraceptive use, medications, smoking, alcohol, sleep, training type, and intensity. Differences in continuous variables were tested using 1-way analysis of variance. Categorical variable comparisons were performed with Fisher exact test. MAIN OUTCOME MEASURE: Tibial stress injury. RESULTS: Tibial stress injury cases had 2.7% more fat (P < 0.001) and 2.6% less muscle (P < 0.001) as well as lower trochanteric bone mineral content (BMC) (P < 0.001), lumbar spine (LS) area (P < 0.001), femoral neck BMC (P < 0.001), length (P < 0.05), area (P < 0.001), cortical width (P < 0.01), cross-sectional moment of inertia (P < 0.001), and index of bending strength (P < 0.001) than controls. Controls had lower LS BMC (P < 0.01), length (P < 0.001), and broadband ultrasound attenuation (P < 0.001). The use of orthotic insoles was more prevalent in TSI cases than controls (25% vs 5.6%, respectively; P < 0.02), as were foot anomalies (56.3% vs 27.8%, respectively; P = 0.01). CONCLUSIONS: Tibial stress injury cases had lower lean and higher fat mass, a tendency for smaller bones, and for foot anomalies compared with uninjured matched controls. bone mineral density was normal for both groups. CLINICAL RELEVANCE: Enhancing lean mass and limiting gains in fat may provide some protection against TSI. Individuals with small skeletal frames are advised to increase training loads particularly gradually and to reduce training intensity at the first sign of pain in the shins.

Tibial stress injury: relationship of radiographic, nuclear medicine bone scanning, MR imaging, and CT Severity grades to clinical severity and time to healing.

PURPOSE: To examine the relationship between severity grade for radiography, triple-phase technetium 99m nuclear medicine bone scanning, magnetic resonance (MR) imaging, and computed tomography (CT); clinical severity; and recovery time from a tibial stress injury (TSI), as well as to evaluate interassessor grading reliability. MATERIALS AND METHODS: This protocol was approved by the Griffith University Human Research Ethics Committee, the Stanford University Panel on Human Subjects in Medical Research, the U.S. Army Human Subjects Research Review Board, and the Australian Defense Human Research Ethics Committee. Informed consent was obtained from all subjects. Forty subjects (17 men, 23 women; mean age, 26.2 years ± 6.9 [standard deviation]) with TSI were enrolled. Subjects were examined acutely with standard anteroposterior and lateral radiography, nuclear medicine scanning, MR imaging, and CT. Each modality was graded by four blinded clinicians. Mixed-effects models were used to examine associations between image severity, clinical severity, and time to healing, with adjustments for image modality and assessor. Grading reliability was evaluated with the Cronbach α coefficient. RESULTS: Image assessment reliability was high for all grading systems except radiography, which was moderate (α = 0.565-0.895). Clinical severity was negatively associated with MR imaging severity (P ≤ .001). There was no significant relationship between time to healing and severity score for any imaging modality, although a positive trend existed for MR imaging (P = .07). CONCLUSION: TSI clinical severity was negatively related to MR imaging severity. Radiographic, bone scan, and CT severity were not related to time to healing, but there was a positive trend for MR imaging.

The flexor hallucis longus: tenographic technique and correlation of imaging findings with surgery in 39 ankles.

PURPOSE: To examine the use of tenography for evaluation of the flexor hallucis longus (FHL) sheath. MATERIALS AND METHODS: Institutional review board approval was waived, patient consent was obtained, and the study was HIPAA compliant. Retrospective review of 192 FHL tenograms and associated surgical records identified 39 ankles in 37 patients (17 male, 20 female; mean age +/- standard deviation, 38 years +/- 13.8; range, 14-68 years) in which both tenography and surgery had been performed. Two radiologists reviewed tenographic findings, including contrast agent extravasation, synovial irregularity, stenosis, fibrous bands, sheath outpouching, extent of opacification, and communications with adjacent structures. Alterations in pain after anesthesia of the tendon sheath were also recorded. Surgical reports were reviewed. RESULTS: Thirty-four of 39 tenograms were diagnostic. Some extravasation occurred in nine (45%) of 20 injections with an initial injection method and in two (11%) of 19 with a new injection technique. Synovial irregularity was present in all 34 studies (15 mild, 16 moderate, three severe). Stenoses were identified in 23 (68%) of 34 ankles, fibrous bands were seen in 16 (47%) of 34 ankles, and outpouching of the sheath above a stenosis was present in 13 (38%) of 34 ankles. Communication of the FHL sheath with the ankle, flexor digitorum longus, or subtalar joint occurred in half the cases. Most patients with pain reported relief; relief was complete (100% reduction from preprocedural pain) in eight of 27, moderate (50%-90% reduction) in nine of 27, and mild (<50% reduction) in eight of 27 patients. CONCLUSION: Tenography of the FHL sheath produced diagnostic images in almost all patients and effectively demonstrated abnormalities of the tendon sheath. Pain relief with anesthetic injection helped confirm the FHL sheath as the pain generator.

Asymptomatic tibial stress reactions: MRI detection and clinical follow-up in distance runners.

OBJECTIVE: The purpose of this study was twofold: to determine if asymptomatic elite distance runners exhibit stress reactions of the tibia on MR images and to determine if the presence of bone stress lesions predicts later development of symptomatic tibial stress injuries. CONCLUSION: Signs of a tibial stress reaction were found on MRI in 43% of the 21 asymptomatic college distance runners in this study. The presence of these changes was not found to be a predictor of future tibial stress reactions or stress fractures. Our findings underscore the importance of correlating MRI findings with clinical findings before making therapeutic decisions.

Interventional musculoskeletal procedures performed by using MR imaging guidance with a vertically open MR unit: assessment of techniques and applicability.

PURPOSE: To evaluate the safety of and time required for a broad range of musculoskeletal interventional procedures performed by using magnetic resonance (MR) imaging guidance with a vertically open 0.5-T unit. MATERIALS AND METHODS: Sixty-three MR imaging-guided procedures were performed. A vertically open MR unit equipped with in-room display monitors allowed interactive freehand MR guidance predominantly with fast spin-echo and gradient-echo sequences. Each procedure was classified in terms of the anatomic location, procedure type, and tissue type involved. The procedures were evaluated for success of needle placement, adequacy of tissue sampling, total procedural time, needle time, number of needle passes, and complications. RESULTS: Procedures consisted of tissue sampling with core-needle (n = 6) or fine-needle aspiration (n = 20) biopsy, corticosteroid or contrast agent injection (n = 19), joint cyst aspiration (n = 7), and drainage (n = 11). Successful needle placement was achieved in all 63 cases. Cytologic and histologic tissue samples were sufficient for pathologic diagnosis in 24 of 26 cases. In two cases, complications occurred: transient local bleeding and a brief vasovagal episode. The mean total procedural time was 64.8 minutes; the mean needle time, 26.2 minutes; and the mean number of needle passes per patient, 1.6. CONCLUSION: With use of a vertically open MR unit, MR-guided interventional procedures involving bone, soft tissue, intervertebral disks, and joints are safe and sufficiently rapid for use in clinical practice.