Ulnar lengthening using a half-ring sulcated external fixator for ulnar longitudinal deficiency: a case report

Area of Science:

• Orthopedic Surgery
• Pediatric Orthopedics
• Limb Deformity Reconstruction

Background:

• Ulnar longitudinal deficiency (ULD) is a rare upper limb condition.
• Existing treatments focus on radial longitudinal deficiency (RLD), with limited options for ULD without RLD.
• Surgical lengthening for ULD without concurrent RLD or hand deformities remains largely unreported.

Observation:

• A case report details the treatment of an 11-year-old boy with Bayne type II ULD.
• A half-ring sulcated external fixator was employed for ulnar distraction lengthening and radial head reduction.
• The procedure involved transverse osteotomy in the mid-ulna, with distraction at 1 mm/day over 95 days.

Findings:

• Achieved 81 mm of ulnar lengthening (62% gain) one year post-surgery.
• Maintained elbow range of motion (>40°) and forearm rotation at two years.
• Preserved wrist extension/flexion with no reported pain.

Implications:

• Ulnar distraction lengthening offers a viable solution for ULD.
• Gradual radial head reduction can be effectively managed with external fixation.
• This technique significantly improves limb appearance and patient-reported outcomes in ULD cases.