• Home
• Journal Club
• 2010

Journal Club

March 2010

Results of Internal Fixation of Pauwels Type-3 Vertical Femoral Neck Fractures

Author

Institution

• Multicentre
• North Jersey Orthopaedic institute, Orthopaedic Specialty Associates Fort Worth, Florida Orthopaedic institute

Journal

• Study type
  • Retrospective cohort study 
• Level IV.  (Level III evidence)
• Non-funded

 

Introduction

• Aim
• To evaluate a large consecutive series of Pauwels type-3 femoral neck fractures
  • learn more about the outcomes and complications associated with the treatment of these fractures
  • To assess the performance of various internal fixation devices
• Hypothesis
• Fractures with a higher ‘‘shear angle’’ are more unstable and,
• Therefore have a higher nonunion rate
• Inclusion/Exclusion criteria
• Inclusion
  • Pauwels’ 3 femoral neck fractures
  • > 70 deg verticality
  • Transcervical
  • At least 1cm superior to medial aspect of GT
• Exclusion
  • Basicervical fractures
• Outcome parameters
• Quality of reduction
  • Haidukewych method
    • Excellent : <2 mm displacement, <5deg angulation
    • Good: 2 to 5 mm displacement, 5 to 10 deg  angulation
    • Fair: >5 to 10 mm displacemnt, >10 to 20 deg of angulation
    • Poor: >10 mm of displacement, >20 of angulation, or any varus.
• Osteonecrosis
  • radiographically with Ficat classification.
• Union
  • No system documented

Methodology

• X rays reviewed and fracture verticality measured
  • Preoperative radiographs, intraoperative fluoroscopic images and immediate postoperative radiographs
• All surgery within twenty-four hours after presentation.
• Choice of fixation device, the operative approach, and the need for capsulotomy  determined by the treating surgeon.
• No method documented for measurement of union
• Ficat classification for osteonecrosis

Results

• Overall 74% united with no osteonecrosis
  • ON in 11%,
  • Non-union in 16%
  • 1 infected non-union
• Fixation
  • Screws. 19% Non-union. 14% ON
  • Fixed angle. 8% Non-union. 8% ON
  • Parallel screw 12% failure, Cross screw 60% failure.
• Displacement
  • 100% union in non displaced
  • 16% non-union,
  • 12% ON if displaced
  • Good-excellent reduction: 14% non union, 12% ON
  • Fair reduction: 2/3 non union
• Capsulotomy
  • 14% osteonecrosis (2/14) if capsulotomy performed
  • 10% osteonecoris if no capsulotomy
• Revision Surgery
  • 5 THR for ON, 3 THR for non-union, 2 Hemiarthroplasties
  • 3 screws revised to fixed angle device

Discussion

• In this series, contemporary internal fixation methods for Pauwels type-3 vertical femoral neck fractures had a reasonable union rate (84%) with a low prevalence of osteonecrosis (11%).
  • Still demonstrates that as a group the incidence of these outcomes is high.
• Quality of the reduction and indicator of potential for ON or non-union
• Effect of capsulotomy not ascertained
• Type of fixation device not ascertained
• Higher non-union rate than for other studies which did not select Pauwel 3 fractures
  • Vertical shear predisposes to varus and shortening

Pros of Study

• Defines the outcome of a rare fracture pattern
• Compared various treatment options
• Used a clear method for identifying reduction and osteonecrosis
• Follow up of 2 years

Cons of Study

• Retrospective study
• Inclusion criteria unclear
  • Some patients included pre or post operatively
• Poor exclusion criteria
  • Smoking, DM, steroid use, metabolic or endocrine disorders.
• Outcome parameters poorly defined
  • No description of method of assessing union, which clinicians doing assesment.
• No documentation in method of post-operative plans, weight bearing status
• Loss to follow up patients not included in results intention to treat
• Difficult to draw real conclusions from the results