Nonunited humerus shaft fractures treated by external fixator augmented by intramedullary rod

Nonunion of humeral shaft fractures after previously failed surgical treatment presents a challenging therapeutic problem especially in the presence of osteoporosis, bone defect, and joint stiffness. It would be beneficial to combine the use of external fixation technique and intramedullary rod in the treatment of such cases. The present study evaluates the results of using external fixator augmented by intramedullary rod and autogenous iliac crest bone grafting (ICBG) for the treatment of humerus shaft nonunion following previously failed surgical treatment.

Eighteen patients with atrophic nonunion of the humeral shaft following previous implant surgery with no active infection were included in the present study. The procedure included exploration of the nonunion, insertion of intramedullary rod (IM rod), autogenous ICBG and application of external fixator for compression. Ilizarov fixator was used in eight cases and monolateral fixator in ten cases. The monolateral fixator was preferred for females and obese patients to avoid abutment against the breast or chest wall following the use of Ilizarov fixator. The fixator was removed after clinical and radiological healing of the nonunion, but the IM rod was left indefinitely. The evaluation of results included both bone results (union rate, angular deformity and limb shortening) and functional outcome using the University of California, Los Angeles (UCLA) rating scale.

The mean follow-up was 35 months (range 24 to 52 months). Bone union was obtained in all cases. The functional outcome was satisfactory in 15 cases (83%) and unsatisfactory in 3 cases (17%) due to joint stiffness. The time to bone healing averaged 4.2 months (range 3 to 7 months). The external fixator time averaged 4.5 months (range 3.2 to 8 months). Superficial pin tract infection occurred in 39% (28/72) of the pins. No cases of nerve palsy, refracture, or deep infection were encountered.

The proposed technique is effective in treating humeral nonunion especially in the presence of osteoporosis and short bone segments. The inclusion of intramedullary rod as internal splint improves stability of fixation and prevents refracture after fixator removal.