Validation of Three Dimensional Topographical Scanning to Evaluate Deformity after Clavicle Fracture

Malcolm DeBaun MD, Cara Lai BS, Blake Schultz MD, Sean Campbell MD, Henry Goodnough MD, Julius Bishop MD, Michael Gardner MD
Department of Orthopaedic Surgery, Stanford University School of Medicine
PRESENTED AT:

 

BACKGROUND

  • Displaced clavicle fractures (DCF) have historically been treated nonoperatively, but Level 1 evidence has shifted paradigm toward more operative management
  • Degree of displacement, presence or absence of communinution, and amount of shortening are important in decision-making--but conventional radiographic measures of deformity are poor at characterizing complex three dimensional changes
  • White-light three-dimensional (3D) scanning is a relatively new technology designed to digitize objects of interest, and can potentially identify clinically relevant alterations in shoulder anatomy after DCF
  • Hypothesis: white-light 3D surface scanning of osseous shoulder landmarks is more sensitive than manual measurements to (1) identify clinically relevant deformity after DCF, (2) monitor restoration of anatomy after surgery or persistence of deformity among patients treated nonoperatively

METHODS

  • Shoulder deformity digitized with white-light 3D scanner
  • Measurements between osseous landmarks on the injured and uninjured shoulder are recorded

 

RESULTS

  • Midsternal notch-AC joint distance at presentation significantly shorter on injured shoulders after displaced clavicle fracture, measured with scanning (p<0.01)

 

  • Clavicle shortening had a weak and moderate positive correlation to radiographs (R=0.27) and manual measurements (R=0.53)

 

DISCUSSION

  • Differences in position between injured and uninjured shoulders found with digital but not manual measurements 
  • Moderately positive correlation between manual and digital measurements highlights the enhanced precision of the 3D scanner to measure linear distances between two points in space
  • Radiographic measurement of clavicle shortening only weakly correlated with the corresponding measurement on 3D scanning--likely because radiographs only provide a 2-dimensional representation of the bony anatomy that is disrupted after fracture

 

CONCLUSION

  • 3D surface scanning was more sensitive than manual measurements in identifying deformity after DCF and in monitoring restoration of anatomy after surgical fixation or persistence of deformity in nonoperative patients 
  • Typical natural history of shoulder ptosis after DCF: shortening of the midsternal notch/AC joint distance, C7/posterolateral acromion and posterolateral acromion/inferior angle of the scapula
  • Patients with surgical fixation of DCF had significant functional improvement from presentation at six (p<0.01) and twelve (p<0.01) weeks postoperative
  • Nonoperative patients had significant functional improvement by twelve weeks (p<0.01)

 

Aided by a grant from the Orthopaedic Trauma Association and by the Stanford Clinical and Translational Science Award (CTSA) to Spectrum (UL1 TR001085). The CTSA program is led by the National Center for Advancing Translational Sciences (NCATS) at the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.