[Medical Q&A] Why does the upper limb become shorter after a fracture?

Planner: Chinese Medical Association

Reviewer: Shao Zengwu, Chief Physician and Professor of Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology

Postfracture shortening of the upper limb is commonly seen in humeral shaft fractures.

Typical manifestations of humeral shaft fractures include local pain, swelling, deformity, abnormal movement, and limb shortening. The ulnar and radial artery pulses of the affected limb should be checked and compared with the healthy limb, and vascular color Doppler ultrasound should be performed if necessary. Check the skin sensation of the base of the hand and the dorsiflexion of the wrist and thumb to determine whether there is radial nerve injury. Humeral shaft fractures should be suspected if there is deformity of the upper arm appearance, local tenderness, and abnormal movement after trauma. Some patients with combined radial nerve or vascular injury will have motor sensation and blood supply disorders in the affected limb, which can be confirmed by physical examination and imaging examinations.

Treatment mainly includes non-surgical treatment and surgical treatment. After humeral shaft fracture, the surrounding muscles are rich, the blood supply is good, and there is a certain degree of angulation. Rotational shortening can be compensated by joint movement. Therefore, most humeral shaft fractures can achieve good results through non-surgical treatment. Non-surgical treatment uses manual reduction and auxiliary supra-articular long-arm plaster fixation. If there is a fracture that is difficult to reduce or difficult to maintain after reduction, shortening> 3cm, rotational deformity> 30°, angular deformity> 20°, humeral shaft fractures with vascular and nerve damage, floating shoulder, floating elbow, pathological fractures, etc., surgical treatment should be performed.