We have reviewed 183 patients (215 knees) assessing results and indications of High Tibial Osteotomies in medial gonarthrosis.

Material: 128 females and 55 males. Follow up is 11.5 years, 120 cases with average varus angle 13° had opening ; 95 cases with average varus angle 10° had closing wedges. Ahlback classification showed stages I: 54, II: 71, III: 66 and IV: 24. H.S.S. scoring was 61 for opening and 68 for closing wedge.

Results: 27 re-operations and 13 other complications.

Healing delay was 55 days for closing and 70 for opening. R.O.M. was 125°.

25 knees are painful.

1/After opening, scoring is 77 and valgus angle is 3°.

2/After closing, scoring is 80 and valgus angle is 5°.

3/Global results: very good: 26%, good: 33%, medium: 28% and poor: 13%.

Discussion: H.T.O. decreases stresses on medial compartment and widens joint space. No significant aggravation is observed at follow up.

Clinical results are satisfying in early surgery. Reaxation is good for delaying or managing arthritis.

The average of 5° mechanical valgus at osteotomy seems to be effective.

Conclusions: -Opening wedge for medium severity and wide varus angle, till the age of 70.

-Closing wedge for medium varus in younger patients.

H.T.O. allows quite pain-free knees, restores axes and avoids or delays T.K.R.

H.T.O. gives satisfactory results and should be then considered the best choice for early prevention and treatment of varus knee arthritis.