Evidence-based considerations on a role of HTO for medial OA knees Kazunori Yasuda, MD, PhD...
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Transcript of Evidence-based considerations on a role of HTO for medial OA knees Kazunori Yasuda, MD, PhD...
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
Knee lecture course, Prague 2007
12 yrs.6 yrs.Preop
Kazunori Yasuda, MD, PhDDepartment of Sports Medicine & Joint reconstruction Surgery
Hokkaido University School of Medicine,Sapporo, Japan
Japan
Tokyo
Hokkaido
Sapporo
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 procedur
e 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
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
FTA=185 deg FTA=170 deg FTA=165 deg
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
Peroneal nerve palsy
Insall (1993): 56/ 804 ( 7.0%) Surgeons should have precise anatomical knowledge about
3-dimensional location of nerve and arteries
Superficial peroneal nerve
Deep peroneal nerveIncorrect direction Correct direction
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?
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
13 yrs.7 yrs.Preop 172 deg
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
The effect of the preoperative age
Insall (JBJS-Am,1984) The results of HTO was worse in the aged patients of m
ore 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
Age Good Fair Poor
60 - 69 6 14 16
50 - 59 8 24 14
X2 tests: NS.
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 H
TO• The results were worse in stage IV than in stages II a
nd III
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 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
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
FTA
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 degre
es The mechanical must pass at the center of the lateral plat
eau
11 yrs.5 yrs.Preop 167 degOsteotomy
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