Knee Surg Relat Res.  2017 Jun;29(2):110-114. 10.5792/ksrr.17.003.

The Effect of Sagittal Knee Deformity on Preoperative Measurement of Coronal Mechanical Alignment during Total Knee Arthroplasty

• Shetty GM
• Mullaji A
• Khalifa AA
• Ray A
• Nikumbha V

• KMID: 2379434
• DOI: http://doi.org/10.5792/ksrr.17.003

Abstract

PURPOSE
The purpose of this prospective study was to determine correlation between coronal mechanical alignment measured on preoperative standing full-length radiographs and navigation during total knee arthroplasty (TKA) in the presence of an associated sagittal deformity (hyperextension and flexion deformity).
MATERIALS AND METHODS
Coronal mechanical alignment measured on preoperative, standing, full-length, hip-to-ankle anteroposterior radiographs was compared with intraoperative measurements recorded with computer navigation in 200 primary navigated TKAs.
RESULTS
The mean difference in mechanical alignment between the two techniques was significantly greater (p=0.001) in patients with an associated flexion deformity >10° when compared to knees with associated flexion deformity ≤10°; 48% of knees with a flexion deformity >10° had a difference of ≥3° between the full-length radiograph and navigation alignment measurements. There was a strong correlation between the radiographic and navigation measurement techniques.
CONCLUSIONS
The mean difference in coronal mechanical alignment between the two techniques was significantly higher in patients with an associated flexion deformity >10°. Hence, surgeons should take caution when relying on preoperative full-length radiographs for determining coronal mechanical alignment in patients with an associated flexion deformity >10° where using navigation may be more reliable.

Keyword

Knee; Arthroplasty; Computer-assisted surgery; Sagittal deformity; Alignment

MeSH Terms

Arthroplasty
Arthroplasty, Replacement, Knee*
Congenital Abnormalities*
Humans
Knee*
Prospective Studies
Surgeons
Surgery, Computer-Assisted