Opening wedge high tibial osteotomy: navigation system compared to the conventional technique in a controlled clinical study.
OBJECTIVE
This study aimed to verify if the navigation system used in high tibial osteotomy (HTO) adds precision to the procedure regarding mechanical axis correction and prevention of tibial slope increases.


METHODS
In this historically controlled study, patients with medial osteoarthrosis and genuvarum underwent HTO between 2004 and 2012; the first 20 were operated with the conventional technique, using pre-planning correction by the Dugdale method and 18 further patients were operated with the navigation system introduced in our hospital.


RESULTS
The two groups were similar for pre-operative mechanical axis (mean 8.10 ± 3.14 for the control and 6.60 ± 2.50 for the navigated group), pre-operative tibial slope (mean 8.95 ± 3.47 versus 8.17 ± 3.11, respectively) and Lyshom score (40.85 ± 15.46 and 44.83 ± 16.86). After surgery, the control group presented mean mechanical axis of 3.35 ± 3.27, tibial slope of 13.75 ± 3.75 and Lyshom score of 87.60 ± 11.12. The navigated group showed a postoperative mechanical axis mean of 3.06 ± 1.70, tibial slope of 10.11 ± 0.18 and Lyshom score of 91.94 ± 11.61.


CONCLUSIONS
The navigation system allowed a significantly better control of tibial slope. Patients operated with the navigation system had significantly better Lysholm scores.
Knee Surgery Division, Department of Orthopedics and Traumatology, Santa Casa de Misericórdia de São Paulo (FCMSCSP), São Paulo, Brazil, alelorenti@yahoo.com.br.
Cristiano Hossri
CH
Ribeiro
Nilson Roberto
NR
Severino
Patricia Maria
PM
Moraes de Barros Fucs
D000328:Adult; D001696:Biomechanical Phenomena; D017760:Bone Malalignment / Q000517:prevention & control; D005260:Female; D056305:Genu Varum / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D010149:Postoperative Pain / Q000453:epidemiology; D015995:Prevalence; D011859:Radiography; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome