Fractures of the proximal part of the humerus have a large remodeling capacity in the growing skeleton because 80% of humeral growth comes from proximal physis. This physis remains open in girls until 14 years of age and in boys until 16 years of age. There has always been a controversy as to how much angulation and displacement is acceptable. Certainly as a child ages, the amount of anticipated remodeling decreases. A previous study had noted that angulation more than 20° in patients older than 11 years only partially corrected by humeral remodeling.
Germany has established national guidelines aimed to support a more age and deformity focused intervention scheme. The goal is to achieve a stable anatomic reduction of the fracture and healing without any residual deformity. This guideline has been applied to proximal humerus fractures, and the authors thought to investigate its usage and possible reasons for failed close reduction.
The German National Guidelines state that non-operative treatment is performed in patients younger than 10 years of age, with a total angulation of less 60° and less than 10° of valgus deformity. In adolescent patients older than 10 years, fractures with a displacement of less than 30° and a valgus deformity of less than 10° are also treated without surgery. The authors applied these principles to a cohort of patients seen between 1997 and 2006. Forty-three patients were included in the cohort. Overall, 10 patients were treated non-operatively and 33 patients underwent close reduction or open reduction with internal fixation using Kirschner wires. Close reduction was performed using standard techniques, and open reduction was performed using a deltopectoral incision with percutaneous K-wire placement. Outcome was based upon clinical and radiographic follow-up. The Constant score was used to assess subjective outcome. Active range of motion was also recorded.
At follow-up, of the 33 patients treated with surgery, 16 of the fractures were treated with close reduction and K-wire fixation. Seventeen patients failed close reduction and required open reduction. Within the subgroup, close reduction was not possible because of entrapment of the periosteum (2), and the biceps tendon including parts of the periosteum (7). There was no loss of reduction in the healing period and the k-wires were removed after healing was established. All had a perfect score according to the Constant scale.
This study has multiple interesting points. The authors do show that when a proximal humerus fracture is irreducible; the most common structure preventing reduction is the biceps tendon and/or the periosteum. Within the authors’ discussion, they tend to infer superior outcomes based upon these treatment guidelines and lack of residual deformity. However, another interpretation is that the treatment guidelines are too aggressive with regards to surgery. The inordinately high surgical rate may infer that the parameters are too strict for accepting a close reduction. Since we have no retrospective cohort of patients treated with more generous non-operative conclusion criteria, the exact amount of acceptable reduction still remains unclear.