Mechanical failure of a femoral lengthening nail: a case report

Abstract

Background: This case report describes the mechanical failure of a femoral lengthening nail in order to allow early recognition and prevent its occurrence.

Case presentation: A femoral lengthening nail was used to achieve goal distraction length over eight weeks and sustained a mechanical failure during progressive weightbearing. Re-distraction was attempted with subsequent non-weight-bearing status. Although the patient was not able to attain the original goal length, radiographs demonstrated stable shortening of the patient's right lower extremity along with early signs of incomplete regenerate bone. She eventually received exchange nailing with bone graft.

Conclusion: Post-operative protocol and weight-bearing status should be further researched and standardized after re-evaluating the mechanical stiffness of the intramedullary nail construct.

Keywords: Distraction osteogenesis; Femoral lengthening nail; Nonunion.

Fig. 1

Initial clinical presentation and long leg alignment films demonstrating a 3 cm leg-length discrepancy

Fig. 2

Post-operative portable films of right femur with PRECICE® nail

Fig. 3

Long leg weight-bearing plain films demonstrating femur after one week of lengthening

Fig. 4

Long leg weight-bearing plain films demonstrating femur after four weeks of lengthening

Fig. 5

Long leg weight-bearing plain films demonstrating femur at eight weeks after lengthening with mechanical shortening of nail

Fig. 6

Enhanced view of distal nail, with a red circle demonstrating flaring of the nail flange that was not present in previous films

Fig. 7

Long leg weight-bearing plain films demonstrating femur at ten weeks after restarting lengthening

Fig. 8

Final construct after exchange nailing. Most recent films from January 2016