Surgical treatment of hip fractures is frequently associated with secondary fracture displacement, in part due to weak osteoporotic bone. So far, improvements have focused on new metal implants although an alternative could be to augment the bone that surrounds the implant. The aim of this thesis was to evaluate the use of calcium phosphate cement (Norian SRS) for augmentation of internally fixed hip fractures. Norian SRS is an injectable, biocompatible cement that hardens in situ without exothermic reaction. Over time it is remodeled and replaced by host bone. In a biomechanical study the holding characteristics for different implants was measured when inserted with or without augmentation. The study showed that conventional bone cement (PMMA) improved maximum torque and pull-out for almost all modalities while Norian SRS increased the holding power mainly in low-density bone. In a prospective and randomized study, patients with displaced femoral neck fractures were operated with internal fixation using screws alone or combined with Norian SRS for augmentation. The result showed improved stability when measured with radiostereometry (RSA) for the augmented fractures during the early rehabilitation period. The clinical evaluation of 118 patients included pain, walking aid, activities of daily living (ADLs), abductor muscle strength, mobility and range of motion. During the early course the augmented patients did better in some variables although over the total two-year study period there was no major difference between groups. Scintigraphic evaluation indicated that augmentation might compromise the circulation to the femoral head. The final part included unstable trochanteric fractures fixed with a sliding screw device alone or the same device combined with Norian SRS for augmentation. Using RSA it was shown that augmentation significantly improved the fracture stability until healing. In a randomized multicenter study including 112 patients, augmentation with Norian SRS reduced pain during early rehabilitation and improved quality of life until healing. In conclusion, augmentation with Norian SRS improved the early fracture stability in displaced femoral neck fractures while there was no major difference in clinical outcome. In unstable trochanteric fractures augmentation provided improved fracture stability and improved clinical course until healing.
|Publisher||Uppsala universitet, Institutionen för kirurgiska vetenskaper, Uppsala : Acta Universitatis Upsaliensis|
|Source Sets||DiVA Archive at Upsalla University|
|Type||Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text|
|Relation||Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, 1651-6206 ; 46|
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