Pre-Operative Imaging and Bone Quality Assessment

Imaging Is Chosen to Answer a Clinical Question

A pre-operative workup should establish limb length, mechanical alignment, joint orientation, bone anatomy, and implant fit. It does not require every patient to receive every available scan. Additional imaging and laboratory tests should be driven by the history, examination, proposed device, and local protocol.

Full-Length Standing Radiographs

A calibrated, weight-bearing image from hip to ankle is commonly used to measure anatomic limb length and evaluate the mechanical axis and joint orientation. A 2021 systematic review found full-length standing anteroposterior radiography to be the most valid and reliable imaging method among the evaluated options for anatomic leg-length discrepancy, while also noting limitations in the underlying evidence. ^[1]

When Additional Imaging May Be Useful

• CT or low-dose cross-sectional imaging may be selected when rotational deformity, complex anatomy, flexion deformity, prior hardware, or precise canal geometry cannot be answered adequately by standing radiographs.
• MRI or vascular studies may be used for a specific soft-tissue, tumor, infection, nerve, or blood-supply question. They are not universal screening tests for uncomplicated candidates.
• Skeletal maturity may be assessed from clinical history and appropriate imaging when it is relevant to the indication and implant. Elective adult stature lengthening and pediatric reconstruction should not be treated as the same pathway.

Implant Fit Uses Current Device Information

Canal diameter, bone length, curvature, entry point, and planned osteotomy all affect whether a particular implant can be used. Do not rely on a generic canal-diameter or BMI cutoff from a different device or center. The surgeon should match the measurements to the current instructions for use for the exact model and diameter. ^[2]

DEXA Is Not a Universal Limb-Lengthening Screen

DEXA may be reasonable when age, fracture history, medication exposure, endocrine disease, or another risk factor raises concern about bone mineral density. Older studies also evaluated DEXA for monitoring regenerate during external fixation. Those monitoring thresholds should not be presented as universal pre-operative eligibility rules for modern internal nails. ^[3]

Laboratory Testing Is Risk-Based

Pre-operative blood tests are determined by the planned operation, anesthesia requirements, medical history, nutrition or endocrine concerns, and facility policy. Abnormal results require clinical interpretation; they do not justify self-treatment with supplements or prescription drugs.

Ask How Measurements Will Be Repeated

The useful question is not only which images are taken before surgery, but how the same alignment, length, regenerate, and device measurements will be repeated during distraction and consolidation, who reviews them, and how quickly the plan changes when findings are concerning.