[High bone consolidation rates after humeral head-preserving revision surgery in non-unions of the proximal humerus].

BACKGROUND

Fractures of the subcapital and proximal humerus shaft region are common fractures of the human skeleton. Their treatment should provide an early functional after-care of the shoulder joint, that is prone to arthrofibrosis. Although the upper extremity is not weight-bearing the occurrence of proximal humerus non-unions leads to severe impairment with inability to work and restrictions of activity of daily life. The aim of this study was to investigate whether an operative revision of proximal humerus non-unions with reosteosynthesis and application of distant autologous bone grafts can lead to sufficient bone healing. The second aim was to find out whether patients achieved an acceptable functional outcome, as alternatively patients could be treated by reconstruction with a shoulder prosthesis.

PATIENTS AND METHODS

27 patients (female = 15, male = 12) with reosteosynthesis of the proximal humerus and proximal humeral shaft due to non-union after initially operative fracture treatment were included between 2008 and 2014. Average age of patients was 56 years (23-87), 48% had no comorbidities, while 52% of the patients had at least 1 comorbidity such as diabetes, hypertension or nicotine abusus. The mean number of prior surgical intervention was 1.2 (1-3). The mean time between initial surgery and re-osteosynthesis was 12.3 months. Patients with signs of infection pseudarthrosis were excluded. The initial type of osteosynthesis was with plates (n = 16; thereof PHILOS Plate n = 14), and intramedullary nails (T2, Targon Nail, PHN, Seidel Nail; n = 11). Revision surgery was done with plate osteosynthesis (n = 26; thereof PHILOS Plate n = 4; LC Plate n = 10; angle plate n = 12). In 23 patients (89%) a distant bone transplantation was done from the iliac crest, and 1 patient received allogenous bone. Three patients (11%) received bone morphogenetic protein 7 (BMP 7) in combination with distant bone graft. Intraoperative swabs from the pseudarthrosis area showed no bacterial pathogen after 14 days of incubation. DASH score and Constant score were used to evaluate the functional outcome after revision surgery. Bone healing was determined by standard X-rays and evaluated by a modified radiological score.

RESULTS

89% of the patients could be followed for an average of 28 months and the radiological follow-up was at 9 months. The radiological score showed very good (50%), or good results, and a sufficient bone healing was shown in 25 of 27 patients (93%). The pseudarthrosis revision surgery failed in two cases (n = 1 persisting non-union; n = 1 humeral head necrosis after re-operation with angle plate). DASH scores provided a mean of 40 ± 28.8 with a range from 0-97 points, and the results from the Constant score provided 45 ± 25.4. The analysis with variation of age showed a trend for better results in female patients < 60 years of age. As complications after bone graft 3 patients had persistent local dysesthesia (11%), in one case fracture of the iliac bone occurred that healed with conservative treatment.

CONCLUSION

The pseudarthrosis revision surgery with humeral head preserving re-osteosynthesis with bone transplantation is an effective treatment for non-unions of the proximal humerus and the proximal humeral shaft and the current results showed high bone consolidation rates. As the functional results remained limited after revision an individual treatment decision should be made concerning the most appropriate therapy. While a shoulder prosthesis may be considered in the aged patient, a revision strategy with reosteosynthesis should be considered particularly in younger patients.