title: Pre-requisites for optimum centering of a tibiotalocalcaneal arthrodesis nail.
abstract: BACKGROUND
  Purpose of study was to compare nail alignment, incidence of stress riser and fracture with straight and curved nails of different lengths.
  
  
  METHODS
  We conducted a retrospective review of consecutive, initially 13 straight and subsequently 15 curved nails implanted in 17 men and 11 women. Angles of incidence and reflection subtended by nail tip with inner tibial cortex were measured. Cortical hypertrophy was assessed on follow-up radiographs.
  
  
  RESULTS
  Angles of incidence and reflection were greater with short straight nails, less with long straight nails and stayed close to zero with long curved nails. Stress fractures occurred in 2 patients with straight nails at the level of the proximalmost tibial screw. Cortical hypertrophy was present in 7 patients with straight nails and in only 1 patient with a curved nail (p=0.01).
  
  
  CONCLUSIONS
  Both nail length and inbuilt valgus contribute to better central positioning within the tibia. However, cortical stress reactions occur less frequently with curved nails.
authors.affiliation: Department of Trauma & Orthopaedics, Altnagelvin Hospital, Glenshane Road, Londonderry BT47 6SB, Northern Ireland, UK.
authors.forename: William
authors.initials: W
authors.lastname: Dominic Marley
authors.affiliation: Department of Trauma & Orthopaedics, Altnagelvin Hospital, Glenshane Road, Londonderry BT47 6SB, Northern Ireland, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Tucker
authors.affiliation: Department of Trauma & Orthopaedics, Altnagelvin Hospital, Glenshane Road, Londonderry BT47 6SB, Northern Ireland, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: McKenna
authors.affiliation: Department of Trauma & Orthopaedics, Altnagelvin Hospital, Glenshane Road, Londonderry BT47 6SB, Northern Ireland, UK. Electronic address: johnwong@doctors.org.uk.
authors.forename: John
authors.initials: J
authors.lastname: Wong-Chung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods*; D001858:Bone Nails; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013380:Subtalar Joint
keywords: Arthritis; Biomechanics; Hindfoot; Outcome studies; Tibiotalocalcaneal arthrodesis