THE EFFECT OF COMORBIDITY AND DURATION OF NONUNION ON OUTCOME AFTER SURGICAL-TREATMENT FOR NONUNION OF THE HUMERUS

The purpose of our study was to assess the effect of comorbidity and d uration of nonunion on the general health status and joint-specific ou tcome of a group of patients treated for nonunion of the humeral shaft . We identified 25 consecutive patients with nonunion of the humeral s haft, all treated with compression plating and bone grafting. Twenty-o ne patients returned For a comprehensive assessment including completi on of the SF 36 Health Status Survey and determination of the Constant shoulder and Morrey elbow scores. Thirteen patients had greater than or equal to 1 comorbid conditions. Eleven patients had a nonunion of > 8 months' duration, and 10 had a nonunion of < 8 months' duration. Fo llow-up at a mean of 42 months (range 12 to 99 months) revealed that a ll nonunions united an average of 5 months offer surgery. The mean Mor rey elbow score was 94, Constant shoulder score 82, and ''global'' SF 36 score 59.4. The physical portion of the SF 36 score correlated well with the Constant and Morrey scores (p = 0.047 and p = 0.027 respecti vely). The presence of comorbid factors had a significant negative eff ect on the SF 36 scores (p = 0.001) but no effect on joint-specific Mo rrey or Constant scores. The duration of nonunion had no effect on SF 36 or joint-specific scores. Although the reliability of the SF 36 is illustrated by the close correlation between its ''physical function'' portion and standard (joint-specific) outcome measures, comorbidity h as a significant negative effect on overall scores. This must be consi dered when such tools are used for assessment of orthopaedic intervent ion.