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Explore the efficacy, ideal candidates, complications, and long-term results of High Tibial Osteotomy (HTO) surgery for medial osteoarthritis knees in the lecture by Dr. Kazunori Yasuda.
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6 yrs. 12 yrs. Preop Knee lecture course, Prague 2007 Evidence-based considerations on a role of HTO for medial OA knees Kazunori Yasuda, MD, PhD Department of Sports Medicine & Joint Surgery Hokkaido University School of Medicine, Sapporo, Japan
Hokkaido Sapporo Tokyo Japan Kazunori Yasuda, MD, PhD Department of Sports Medicine & Joint reconstruction Surgery Hokkaido University School of Medicine, Sapporo, Japan
High Tibial Osteotomy (HTO) • Biological joint-preserving surgery for Medial OA • Efficacy of HTO has been established in the 1970’s • Jackson and Waugh: JBJS-Br, 1961 • Coventry: JBJS-Am, 1965 and 1973 • Insall et al: JBJS-Am, 1979 • Currently, the popularity of TKA has increased due to various social reasons • However, HTO remains a significant surgical procedure for Medial OA
3 Topics in my talk • Current consensus about basic issues on HTO • Evidence-based considerations • Current role of HTO • The best procedure selection to perform HTO
3 Topics in my talk • Current consensus about basic issues on HTO • Evidence-based considerations • Current role of HTO • The best procedure selection to perform HTO
FTA=170 deg FTA=165 deg FTA=185 deg Pain relief mechanism of HTO • 2 possible mechanisms • HTO changes load distribution in the knee joint due to an alignment correction • HTO reduces intra-osseous venous pressure in the tibia • The first mechanism is more essential • Insufficient correction of alignment does not have long-term effects for pain relief
The most ideal candidate for HTO • Younger than 60 years • Wishes to maintain an active life style • Purely medial OA knee • Varus deformity of less than 15 degrees
Contra-indications of HTO • Bi- or tri-compartmental joint destruction • Lateral OA (clinical results are not predictable) • Flexion contracture exceeding 10 degrees • Overall ROM of less than 90 degrees • Varus deformation of more than 15 degrees
Complications during and after HTO • Intra-operative complications • Peroneal nerve palsy • Anterior tibial or peroneal artery injury • Intraarticular fracture • Post-operative complications • Nonunion / delayed union • Infection
Deep peroneal nerve Incorrect direction Correct direction Superficial peroneal nerve Peroneal nerve palsy • Insall (1993): 56/ 804 ( 7.0%) • Surgeons should have precise anatomical knowledge about 3-dimensional location of nerve and arteries
Topics in my talk • Current consensus about basic issues on HTO • Evidence-based considerations • Current role of HTO • The best procedure selection to perform HTO Is HTO a curative surgery, or a temporary surgery before TKA?
Preop 172 deg 7 yrs. 13 yrs. Long-term results of HTO • Hernigou et al: JBJS-Am, 1987 • “Good” evaluation • 90% at 5 years • 45% at 10 years • Yasuda, et al: Clin Orthop, 1992 • “Good” evaluation • 85% at 5 years • 63% at 10 years • The results of HTO gradually degrades after the 5-year period
The survival rate of HTO • If the patients who have undergone HTO complain of severe knee pain, TKA must be chosen as a revision surgery • The survival rate of HTO • Aglietti et al: Clin Orthop 2003 • 78% at 10 years and 57% at 15 years • Nagi et al: JBJS-Am 2007 • 92% at 10 years and 58% at 20 years
Is HTO a curative surgery, or a temporary surgery? • Remember! • HTO is commonly recommended for relatively younger patients with medial OA • Currently, the average life expectancy is getting longer and longer in advanced nations • Thus, HTO is a temporary surgery until TKA
HTO is a temporary surgery until TKA • This has not a negative meaning • If the temporary surgery provides pain relief of more than 10 years, then it can provide many benefits to patients • We should make effort in surgery to obtain good 10-year results • How should we do?
What factors affect the 10-year results after HTO? • Possible factors • Preoperative age • Preoperative grade of TF and PF OA • Postoperative FTA
Total Score Age Good Fair Poor 60 - 69 6 14 16 50 - 59 8 24 14 X2 tests: NS. The effect of the preoperative age • Insall (JBJS-Am,1984) • The results of HTO was worse in the aged patients of more than 60 years than the other younger patients • Yasuda, et al (Clin Orthop, 1992) • There were no difference between the aged patients of more than 60 years in the 10-year results than the other younger patients
Total Score vs. OA Stage Total Score Stage Good Fair Poor II 2 2 1 III 5 6 5 IV 0 4 4 The effect of the preoperative grade of TF and PF OA • Yasuda, et al (Clin Orthop, 1992) • Significantly affected the 10 or more-year results after HTO • The results were worse in stage IV than in stages II and III
The effect of the postoperative FTA • Yasuda, et al (Clin Orthop, 1992) • Significantly affected the 10 or more-year results after HTO • In the range of FTA between 160 and 180, • the more valgus correction, the better in the improvement of the evaluation score • The post-operative FTA is extremely important • because it is a factor decided by the operator of each surgery
My philosophy on HTO • HTO is not a minor surgery • Surgical viewpoint • Economical viewpoint • Social viewpoint • Surgeons should make planning the HTO so that the pain-relief time maintains for 10 years or more for common OA patients • Surgeons should select a procedure that can precisely correct the FTA to 167 to 169 degrees in every patient
FTA How to make preoperative planning • Precise physical examinations • Standing full-length A-P radiogram • Draw 3 lines, • Mechanical axis • Femoral axis • Tibial axis • Measure the FTA (femoro-tibial angle) • Normal value: 173 to 175 degrees
Osteotomy Preop 167 deg 5 yrs. 11 yrs. How to make preoperative planning • To obtain favorable 10-year results, surgeons should decide a tibial correction angle • So that the the FTA will be corrected to 167 to 169 degrees • The mechanical must pass at the center of the lateral plateau
Topics in my talk • Current consensus about basic issues on HTO • Evidence-based considerations • Current role of HTO • The best procedure selection to perform HTO
What procedure is the best for HTO? • Many procedures and fixation devises to perform HTO • Surgeons consider the best combination among them • Taking the followings into account • Precise alignment correction • Rigid fixation • Ease of possible TKA
A problem in possible TKA • These knees have remarkable deformation and bone stock loss of the proximal tibia due to HTO • Revision TKA is difficult to be performed After closed wedge osteotomy After dome-shaped osteotomy
My preference • Hemi-closed hemi-open wedge osteotomy • Aoki, Yasuda, et al (Clin Orthop, 2006) • The 10-year results of this osteotomy were significantly better than the closed wedge osteotomy • Deformation of the proximal tibia is minimal • Bone stock is completely preserved • Possible TKA may be easy to be performed Bone graft
Many combinations available • Many procedures • Closed wedge osteotomy • Dome-shaped osteotomy • Hemi-closed/Hemi-open wedge osteotomy • Open wedge osteotomy • Many fixation devices and implants • Staples • External fixator • Blade plate and screws • Plate and screws
What combination is the best? • No definite answer to this question • When you will consider it, you should take long-term benefits for patients into account • Ease to precisely correct the FTA to the targeted angle • Less invasiveness • Lower rate of complications • Comfortableness after surgery • Early return to daily life • Lower rate of delayed/non-union • Economical treatment costs • Ease of revision TKA for the worst case scenario
Conclusion • The results of HTO gradually degrades after the 5-year period • HTO is a temporary surgery until TKA • Surgeons should make effort in surgery so that the good results maintain 10 years or more • To obtain good 10-year results, surgeons should precisely correct the FTA to 167 to 169 degrees in every patient • When surgeons consider the surgical procedure and devises, they should take long-term benefits for patients as well as revision TKA for the worst case scenario into account
Acknowledgement Thank you