A total of 20 eligible patients with osteoporotic per trochanteric fractures, that are treated with proximal femoral nail (PFN), will be included in the study after informed and approved consent and will be randomized into two groups. Randomization will be performed by the principal investigator, by sealed envelopes, after determining if the patient fulfills the inclusion criteria.
Following randomization, all patients will be operated with PFN. The control group will receive a standard surgical procedure without augmentation of the helical blade. The study group will also receive 2-3 mL of CERAMENT™ BONE VOID FILLER (510(k) Number K201535) delivered using an introducer needle inserted through the helical blade of the PFN inserted in the femoral head, away from the fracture site, with an intent to increase bone-implant anchorage.
Routine procedure for anesthesia and infection prophylaxis according to written instructions will be followed in every patient. For infection infection prophylaxis, 2g cefazolin will be administered 1 hour preoperatively as well as 100 mg doyxcycline 2 hours preoperatively and 6 hours postoperatively. The patient will be operated supine with the fractured leg positioned in traction table. In the standard protocol, fluoroscopy is used to get AP and lateral view during surgery. The hip region is scrubbed and dressed in sterile drapes. Using standard technique, a nail is inserted into the intramedullary canal after fracture reduction. To insert the helical blade in the femoral neck, 2.0 mm diameter guide wire is first placed in the femoral neck, checking the fluoroscopic AP and lateral views. The canal is opened using a 10 mm drill bit and the length of helical blade is measured.
In addition to the standard surgical procedure, in the study group, after creating the canal with 10 mm drill bit and partly insertion of the helical blade, the synthetic bone void filler Calcium Sulphate/Hydroxyapatite (CaS/HA) will be injected.
After the pilot hole is created for the helical blade placement, the hollow helical blade will be inserted partially with gentle blows with a hammer, 2.5 cm from its final intended position. At this point, the injectable CaS/HA biomaterial will be mixed as per the manufacturer guidelines and the paste will be transferred into an injection syringe. At t = 2.5 min from the start of mixing, 2-3 mL of bone void filler (BVF) paste will be injected by a CE marked Introducer Needle connected to the injection syringe, through the hollow helical blade. Under fluoroscopic guidance, injection will start proximal and continue while the cannula is slowly retracted towards the tip of the helical blade until the drilled space in front of the lag screw and the surrounding cancellous bone is filled with 2-3 mL of the material. Finally, the helical blade will be inserted to its end position with gentle blows with a hammer. Remaining material approximately 2 mL still being moldable will be manually deposited in the trochanteric fracture void. A very similar injection technique for application in a dynamic hip screw (DHS) in trochanteric fractures is described in a recently published scientific article.
Patients with an osteoporotic trochanteric femoral fracture that have no contraindications should receive secondary fracture prevention with a bisphosphonate. In this study, all patients will receive systemic (Intravenous) Zoledronic acid (ZA) as routine. All patients included in the study without any contraindication for ZA, therefore will receive 5mg/100ml ZA intravenously day 5 after surgery, during hospitalization. ZA has been shown to significantly reduce the risk of hip fracture in post-menopausal women.
