title: Intraoperative femur fracture is associated with stem and instrument design in primary total hip arthroplasty.
abstract: BACKGROUND
  Intraoperative proximal femoral fracture is a risk in total hip arthroplasty (THA) with cementless stems with reported rates of 1.5-27.8%. Certain designs or designs associated with certain types of instrumentation may have higher rates.
  
  
  OBJECTIVE
  We compared the incidence of proximal femoral fracture with two stem and instrument design systems.
  
  
  METHODS
  We retrospectively reviewed 425 patients (457 hips) undergoing primary THAs using a supine, muscle-sparing approach between February 2007 and April 2009. In 439 cases, a monoblock, broach-only, tapered wedge design stem was used with a single low-profile cutting blade (cutting) calcar mill. Eighteen proximally modular, broach-only, tapered wedge design stems were used with a calcar mill with multiple deep cutting teeth (toothed).
  
  
  RESULTS
  There were no proximal femoral fractures among the 439 hips using the cutting mill and two intraoperative proximal femur fractures in 18 hips using the toothed mill. Both fractures occurred during calcar milling when the cutting teeth engaged the bone, resulting in a torque of the broach.
  
  
  CONCLUSIONS
  Given the high intraoperative proximal femur fracture rate using the toothed design, and the absence of fractures using the cutting design, we caution against the use of the toothed style. The overall rate using a flat, wedge, tapered design (two of 457 hips or 0.4%) is lower than that associated with previously published designs. Fracture appears directly related to instrumentation.
  
  
  METHODS
  Level III, retrospective comparison study. See Guidelines for Authors for a complete description of Levels of Evidence.
authors.affiliation: Joint Implant Surgeons, Inc, 7277 Smith's Mill Road, Suite 200, New Albany, OH 43054, USA. berendkr@joint-surgeons.com
authors.forename: Keith R
authors.initials: KR
authors.lastname: Berend
authors.forename: Adolph V
authors.initials: AV
authors.lastname: Lombardi
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation*; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D015994:Incidence; D007432:Intraoperative Period; D011474:Prosthesis Design; D011859:Radiography; D012189:Retrospective Studies
references.citation: J Bone Joint Surg Am. 1989 Sep;71(8):1135-42
references.pmid: 2777839
references.citation: Orthopedics. 1998 Sep;21(9):982-4
references.pmid: 9769041
references.citation: Oper Orthop Traumatol. 2006 Oct;18(4):317-29
references.pmid: 17103130
references.citation: J Bone Joint Surg Am. 2002;84-A Suppl 2:81-9
references.pmid: 12479343
references.citation: J Arthroplasty. 2001 Dec;16(8 Suppl 1):49-54
references.pmid: 11742451
references.citation: Clin Orthop Relat Res. 1988 Oct;(235):61-6
references.pmid: 3416542
references.citation: J Arthroplasty. 2004 Oct;19(7 Suppl 2):17-21
references.pmid: 15457413
references.citation: Acta Orthop Belg. 1994;60(1):43-54
references.pmid: 8171987
references.citation: Instr Course Lect. 2003;52:309-22
references.pmid: 12690859
references.citation: Orthop Clin North Am. 2002 Jan;33(1):143-52, ix
references.pmid: 11832318
references.citation: Orthopedics. 1992 Feb;15(2):143-6
references.pmid: 1738716
references.citation: Clin Orthop Relat Res. 2008 Mar;466(3):749-53
references.pmid: 18196363
references.citation: Orthopedics. 1997 Sep;20(9):798-800
references.pmid: 9306457
references.citation: J Arthroplasty. 2002 Jun;17(4 Suppl 1):11-3
references.pmid: 12068395
references.citation: J Arthroplasty. 2006 Oct;21(7):1064-7
references.pmid: 17027552
references.citation: Instr Course Lect. 1995;44:293-304
references.pmid: 7797866
references.citation: J Bone Joint Surg Am. 1975 Jun;57(4):494-501
references.pmid: 1141259
references.citation: Orthop Rev. 1992 Mar;21(3):337-42
references.pmid: 1565523
references.citation: Clin Orthop Relat Res. 1991 Nov;(272):175-80
references.pmid: 1934730
references.citation: J Arthroplasty. 1995 Dec;10(6):823-9
references.pmid: 8749768
references.citation: Ann Chir Gynaecol. 2000;89(2):113-8
references.pmid: 10905677