title: Bone impregnated hip screw in femoral neck fracture: Clinicoradiological results.
abstract: BACKGROUND
  Femoral neck fractures are treated either by internal fixation or arthroplasty. Usually, cannulated cancellous screws are used for osteosynthesis of fracture neck of femur. The bone impregnated hip screw (BIHS) is an alternative implant, where osteosyntehsis is required in femoral neck fracture.
  
  
  METHODS
  The BIHS is a hollow screw with thread diameter 8.3 mm, shank diameter 6.5 mm and wall thickness 2.2 mm and holes in the shaft of the screw with diameter 2 mm, placed in a staggered fashion. Biomechanical and animal experimental studies were done. Clinical study was done in two phases: Phase 1 in a group of volunteers, only with BIHS was used in a pilot study and phase 2 comparative study was done in a group with AO cannulated screws and the other group treated with BIHS.
  
  
  RESULTS
  In the phase 1 study, out of 15 patients, only one patient had delayed union. In phase 2, there were 78 patients, 44 patients in BIHS showed early union, compared to the rest 34 cases of AO cannulated screws Out of 44 patients with BIHS, 41 patients had an excellent outcome, 2 had nonunions and one implant breakage was noted.
  
  
  CONCLUSIONS
  Bone impregnated hip screw has shown to provide early solid union since it incorporates the biomechanical principles and also increases the osteogenic potential and hence, found superior to conventional cannulated cancellous screw.
authors.affiliation: Department of Orthopedics, Government Medical College, Thiruvananthapuram, Kerala, India ; Department of Orthopedics, Azeezia Medical College, Kollam, Kerala, India.
authors.forename: P K
authors.initials: PK
authors.lastname: Sundar Raj
authors.affiliation: Department of Orthopedics, Government Taluk Headquarter's Hospital, Chirayinkeezhu, Thiruvananthapuram, Kerala, India.
authors.forename: Jiju A
authors.initials: JA
authors.lastname: Nuuman
authors.affiliation: Department of Orthopedics, Azeezia Medical College, Kollam, Kerala, India.
authors.forename: Amish Sunder
authors.initials: AS
authors.lastname: Pattathil
keywords: Bone impregnated hip screw; Femoral neck fractures; bone; bone screws; cannulated cancellous screws; femoral neck fracture; grafting; osteogenic