Midterm follow-up of elderly patients with fragility fractures of the pelvis: A prospective cohort-study comparing operative and non-operative treatment according to a therapeutic algorithm.

INTRODUCTION: The treatment of fragility fractures of the pelvis (FFP) is a challenge. The variations of non-operative- and of operative treatment are manifold and a structured treatment algorithm is lacking. The purpose of this study was to evaluate the outcome of elderly patients with a FFP who were treated with a therapeutic algorithm based on the FFP-classification. PATIENTS AND METHODS: In a prospective cohort study 154 patients (mean age: 81.8 ±.61 (65-96); female: (86.8%; 131/154). BMI: 23.7 ±.34 (15-43)) with a FFP after inadequate mono trauma were treated according to a strict therapeutic algorithm between 04/2016 and 12/2018. According to a classification based on CT-scans either a standardized operative treatment or conservative therapy was induced and the outcome regarding objective measurements of mobility, pain, need for analgesics and mortality during hospital stay and after one year was analyzed. RESULTS: 82/154 participants (53.2%) were assigned to the conservative treatment group and 72 participants (46.8%) to the operative treatment group. The overall one-year survival rate was 78.1% (118/151). The survival of the operative treatment group was 90.7% (49/54) and significantly higher than the survival of the conservative treatment group (74.7%; 56/75; p=.023). The one-year follow up showed a high dispersion of the pain level in the operatively treated patients and a significantly higher mean in comparison to conservatively treated patients. Both treatment groups showed increasing numbers of patients with unlimited mobilization but also immobile patients. Overall in 31.0% (18/58) of the operative participants and in 14.9% (14/93) of the non-operatively treated participants complications occurred (p=.04). CONCLUSION: The strict compliance to the presented treatment algorithm of FFP with an operative strategy starting from FFP IIc leads to a significantly lower mortality within one year in comparison to the conservatively treated patients. The worst outcome and the highest mortality was seen in patients who refused the recommendation of operative stabilization. The results of this study justify to proceed with the strict classification dependent treatment algorithm and also support the early switch-over to operative treatment of patients with failed conservative therapy in FFP I to FFP IIb.

Biomechanical testing to evaluate the cut-through resistance of intramedullary nails for the proximal humerus.

Intramedullary nailing for stabilization of proximal humeral fractures is well-established. Complications as part of a cut-through, such as backing out of locking screws, loss of reduction, and perforation of the screws into the glenoid, are equally well-known. The test bench presented in this study enables testing of the cut-through behavior of multiple intramedullary implants on a simulated osteoporotic three-part fracture configuration with three different loading circumstances (A, B and C). In situation A, the glenohumeral dynamic force with progressive loadings entered at an angle of 15° to the humeral shaft. In situation B the force entered at an angle of 35° and in situation C the angle measured 55°. Three different types of nails were tested: the Targon PH with the optimal proximal screw length (T) and with all four proximal screws shortened (Tshort), the Synthes MultiLoc PHN with (S5) and without (S4) the additional calcar screw and, lastly, the PolyAxNail PH, a polyaxial intramedullary nail, in a neutral screw configuration (PAN) and a version with diametrically opposed crossed first and fourth locking screws (PAN10). Significant differences in the three cases were found with the evaluation of the failure load, which represents the cut-through resistance. Case A: Tshort (245.4 ± 18.7 N) - S4 (346.8 ± 18.0 N) (adjusted p = 0.002); Tshort (245.4 ± 18.7 N) - S5 (368.5 ± 12.0 N) (adjusted p = < 0.001); Tshort (245.4 ± 18.7 N) - T (323.5 ± 38.2 N) (p = 0.004); Case B: no significant differences between the study groups (adjusted significance). Case C: PAN (412.5 ± 16.0 N) - S5 (471.5 ± 21.5 N) (adjusted p = 0.007); T (414.0 ± 33.5 N) - S5 (471.5 ± 21.5 N) (adjusted p = 0.008). The optimal screw length has a strong influence on the failure load. Choosing proximal screws that are too short, produces a negative impact on the cut-through resistance. The additional calcar screw of the MultiLoc PHN and the polyaxiality of the PolyAxNail showed a positive effect with regard to the failure load reached.