Abstract
Background
Limb length discrepancy after total hip replacement is one of the possible complications of suboptimal positioning of the implant and cause of patients dissatisfaction.
Computer assisted navigation become affirmed in last years for total hip replacement surgery and it is also used for the evaluation of the intra-operative limb length discrepancy.
The purpose of this study is to verify the reliability of a navigation system with a dedicated software in intraoperative evaluation of limb lengthening and offset as compared with manual technique.
Methods
Forty patients who underwent a Total Hip Arthroplasty in our institution were entrolled in this study. Twenty patients were evaluated with pre operative manual planning (group A) and treated with hand positioning of femoral stem. Twenty Patient were evaluated with preoperative manual planning and treated with Computer assisted navigation of Stem (group B).
Mean operating time and blood loss were analyzed. Radiological and clinical follow up was made at 1, 3, 6 and 12 months postoperative to assess any mismatch of implant, complications and clinical results that was measured with Harris Hip Score.
Results
In the evaluation of the limb length and offset in group A there wasn't significance difference between pre and postoperative measurements obtained with manual planning. Also in group B there wasn't a significance difference between the measurement obtained intraoperative with computer assisted navigation and the one obtainedafter surgery and preoperative with manual planning. In any case we noted a limb length discrepancy in this series. No statistically significance difference was noted between the two groups in relations to the others parameters investigated.
Conclusions
Based on our study the computer navigation system is a simple and reliable for the evaluation of limb length discrepancy and offset in total hip replacement. This Navigation system can offer to the surgeon a valid intraoperative information that can reduce possible errors in stem positioning and can reduce rate of length discrepancy.
