M. Rosenwasser (New York) (FOT: AIOD USA)
Diaphyseal osteosynthesis of the humerus. Complications and their treatments
Humerus fracture nonunions are uncommon complications of humeral diaphyseal fractures with reported rates of between 1 and 15%. When treating a humerus nonunion, most authors recommend plate and screw fixation with autologous iliac crest bone grafting (ICBG), especially when the nonunion is considered atrophic.
The goal of autologous bone graft from the iliac crest is to provide the nonounion site with osteoconductive, osteoinductive, and osteogenic factors to promote bone healing and to fill bone defects. However, the risks of ICBG harvesting have been well documented and include infection, nerve injury, fracture, and most commonly pain (38% of patients). An alternative to autogenous bone graft is freeze-dried, irradiated, human cancellous bone allograft and demineralized bone matrix (DBM). The cancellous allograft (CA) provides a scaffold for osteoconduction, fills bone defects, and can be impacted. DBM has proved to be highly osteoinductive and readily osteoconductive.
We retrospectively evaluated 11 patients (mean age 62 years; 5 males and 6 females) with humeral nonunions who were treated with cancellous allograft, demineralized bone matrix, and plate fixation to determine their clinical outcome. Patients were evaluated preoperatively, postoperatively, and at follow-up with a standard upper extremity physical exam and radiographs of the humerus. At follow-up, patients completed the Disabilities of the Arm, Shoulder, and Hand Questionnaire (D.A.S.H.) to evaluate subjective outcome.
The mean duration of the nonunion preoperatively was 24 months (range, 4 – 120 months). Five of the nonunions were mid-shaft, three distal one-third, and two proximal one-third. At a mean follow-up of 33 months (range, 25 -42 months; minimum 2 years) 10 of the 11 nonunions (91%) had healed. One patient required a second operation with a longer plate to gain union. The nonunion that failed to heal was proximal and eventually required a hemiarthroplasty, secondary to blade plate cut out of the humeral head. The D.A.S.H. score demonstrated 4 excellent, 5 good, 2 fair, and no poor results at follow-up examination. All patients had functional shoulder and elbow motion.
These results show that cancellous allograft and demineralized bone matrix can be a useful adjunct to plate fixation in the treatment of humeral nonunions. Complications of autograft harvest are avoided, anesthesia time can be shortened, and the union rate is comparable to past studies of humeral nonunions utilizing autologous bone graft.