High tibial osteotomy (HTO) is a common and widely accepted procedure in orthopaedic surgery. In the literature, we find descriptions of the technique dating back to the 50s, with Jackson (Jackson, 1958). However, it was not until the 70s, with the publications of Conventry (Coventry, 1969 and 1973) and Insall (Insall, 1975), that proximal tibial osteotomy became common practice as a treatment option for medial compartment osteoarthritis of the knee usually associated to varus deformity. At that time, closing wedge osteotomies were performed, despite the greater technical difficulty and risks involved, as there were no fixation materials available that could enable opening wedge osteotomy. Only after the development of medial wedge plate fixation that opening wedge osteotomy became applicable (Puddu, 2004).
The goals of HTO are:
1. To reduce knee pain by transferring weight-bearing loads to the relatively unaffected compartment;
2. To increase the life span of the knee joint, by slowing or stopping the destruction of the medial joint compartment. This could delay the need of a joint replacement.
8. • Fujisawa point
• Cartilage height
Correction angle calculation
…Jakob and Jacobi
9. • Method of Bauer, Insall
& Koshino
1° = 1 mm base of wedge
(57mm)
• W = diameter × 0.02 ×
angle
• Full-length near actual
size, standing AP x-ray
Wedge Amount
10. • Lateral closing wedge
• Medial opening wedge
• Dome osteotomy
• Medial opening hemicallotasis
Types of Osteotomies
11. • Coventry & Insall
• Proximal to tibial tubercle
• Rapid bone union
• Limitation- size of wedge
• Correction in one plane (frontal)
Lateral Closing Wedge Osteotomy
13. • Near the deformity
• Cancellous bone-heals rapidly
• No need for bone grafting
• Rigid fixation
• Early Wt bearing & rehab
• Knee exploration through
same incision
Advantages Disadvantages
• Fibular osteotomy/release of
PTF joint
• Peroneal nerve injury
• Correction in one plane
• Leg shortening
• loss of bone stock
14. • Hernigou et al.
• Precise & exact correction
• Use of jig & rigid fixation
recommended
• Autograft/hydroxyapatite
• Extremity ≥ 2 cm shorter
Medial opening wedge osteotomy
16. • Correction in two plane:
coronal & sagittal
• Adjust amount of correction
intraoperatively
• No need for fibular osteotomy
• No bone loss
Advantages Disadvantages
• Need for bone graft
• Risk of delayed or non-union
• Longer wt-bearing restriction
• Decreased patella height
• ↑ses posterior tibial slope
17. Dome osteotomy
• Maquet - “barrel vault” or dome
• Inverted U
• Indication: 18-20 mm / ≥20°
• Cast/ Plate-screw/ ex fix
18. • Better bony contact
• No bone graft required
• No change in patellar height
• Stable: int. fixation optional
• Post op adjustment in cast
• Large degree of correction
Advantages Disadvantages
• Technical difficulty
• Divide fibula
• Intraarticular fracture
• Scarring - PF extensor
mechanism
19. • Progressive callus distraction
+ opening wedge osteotomy
• Distraction -7th POD (1mm/D)
• Distal to tibial tubercle
• Axial / ring fixator
• Large degree of correction
Opening wedge hemicallotasis
20. • No change in patellar height
• Post op adjustment
• Immediate wt bearing: ilizarov
• Large degree of correction
Advantages Disadvantages
• Poor patient compliance
• Lateral cortex #
• Pin loosening
• Pin site infection
Decompression of the Subchondral Hypertension hence any osteotomy even if undercorrected or ill performed will offer pain relief
The combination of varus malalignment with chronic posterolateral instability was defined as triple varus by Noyes and Simon (Noyes & Simon, 1994).
ROM <120°
Mechanical axis (line from the centre of the femoral head to the centre of the knee), anatomical axis (a line from the piriformis fossa to the centre of the knee joint and a line through the long axis of the tibia), and weight bearing axis (line drawn from the centre of the femoral head to the centre of ankle joint) are measured on the alignment view, where the location, type, and amount of corrective osteotomy is determined.
Tunnel views PA with 40 deg flexion & Rosenberg views-PA with 45 deg flexion
Jakob and Jacobi17 suggested that correction of the mechanical axis depends on the thickness of the cartilage in the medial compartment: if one third of the medial cartilage is lost, the mechanical axis should pass 10-15% lateral from the center of the tibial plateau; if two thirds of the cartilage is lost, the axis should pass 20-25% lateral; and if all is lost, the axis should pass 30-35% lateral.
Aim for 10°valgus-- Anatomical Axis Aim for 3-6 valgus --Mechanical Axis
historic approach and is more familiar to some surgeons.
limitation in the amount of correction from a valgus osteotomy is the size of the bone wedge that can be taken proximal to the patellar tendon.
1° = 1 mm @ base of wedge W = diameter × 0.02 × angle or tangent tables
Gerdy’s tubercle and fibular head determines the radius of a 100° arc, that represents an anatomical safe area
Precise & exact correction intraoperatively
Precise & exact correction intraoperatively
the normal anatomical tibial bone shape is maintained after the procedure, which allows for conversion to knee replacement.
MCL becomes slightly tight
posterior tibial slope, patella height and patellofemoral compartment pressure
indicated when a large degree of correction involving 18-20 mm opening or closing or ≥20 degrees angular correction is necessary for traumatic varus deformity or Blount disease. the center of the dome is located at the center of rotation of angulation (CORA)
technical difficulty,
intraarticular fracture
Scarring - PF extensor mechanism
the normal anatomical tibial bone shape is maintained after the procedure, which allows for conversion to knee replacement.
MCL becomes slightly tight
posterior tibial slope, patella height and patellofemoral compartment pressure
the normal anatomical tibial bone shape is maintained after the procedure, which allows for conversion to knee replacement.
MCL becomes slightly tight
posterior tibial slope, patella height and patellofemoral compartment pressure
Opening wedge tibial osteotomy enables this slope to be altered. In the vast majority ofcases, we see an undesirable increase in tibial slope, which causes a loss of knee extension,
Care should be taken not to cause the posterior tibial slope to be ≥10o because the load on the ACL is increased by more than 3 times in this case
and also an overload in the anterior cruciate ligament (Song et al., 2007). Patients who
present insufficiency of this ligament evolve with worsening instability (Song et al., 2007).
The best way to control the tibial slope is through observation of the osteotomy wedge
opening. This should present an anterior opening of two thirds of the size of the posterior
(Song et al., 2007), forming a trapezoidal opening wedge at the medial border of the tibia
(Fig. 6). The navigation system is of great help in controlling the mechanical axis and also
the tibial slope (Hart et al., 2007).
Opening wedge tibial osteotomy enables this slope to be altered. In the vast majority ofcases, we see an undesirable increase in tibial slope, which causes a loss of knee extension,
Care should be taken not to cause the posterior tibial slope to be ≥10o because the load on the ACL is increased by more than 3 times in this case
and also an overload in the anterior cruciate ligament (Song et al., 2007). Patients who
present insufficiency of this ligament evolve with worsening instability (Song et al., 2007).
The best way to control the tibial slope is through observation of the osteotomy wedge
opening. This should present an anterior opening of two thirds of the size of the posterior
(Song et al., 2007), forming a trapezoidal opening wedge at the medial border of the tibia
(Fig. 6). The navigation system is of great help in controlling the mechanical axis and also
the tibial slope (Hart et al., 2007).
Following high tibial osteotomy, osteosclerosis in the medial compartment of the arthritic knee
is significantly reduced, and the degenerated portions of the articular surface are completely
covered by a fibrocartilagenous layer (Akamatsu et al., 1997; Fujisawa et al., 1979; Koshino, &
Tsuchiya, 1979; Koshino, 2010; Odenbring et al. 1992; Takahashi et al. 2002-2003).
Autologous chondrocyte implantation(ACI)
Osteochondral autograft transfer system(OATS)
it has been reported that the decreased distance between the patella and the tibiofemoral joint line following medial oWHto is a function of joint line
elevation, and that the high incidence of patella infera following medial oWHto may have deleterious effects on patellofemoral biomechanics or may complicate
The operative technique of total knee arthroplasty can be complicated by several factors in patients with proximal tibial osteotomies. Obtaining adequate exposure is the most frequently encountered technical difficulty. Lateral ligamentous laxity can occur because of proximal “riding” of the fibula, and maintaining continuity of the medial soft tissue sleeve during exposure can be difficult because scarring at the level of the osteotomy causes laxity of the medial collateral ligament. The posterior cruciate ligament usually is scarred, making posterior cruciate ligament substitution necessary. The lateral tibial plateau usually is the more deficient side and may require bone grafting or metal block augmentation. Offset of the proximal fragment laterally or posteriorly can make stem placement difficult. Patella infera may require tibial tubercle osteotomy
subsequent total knee arthroplasty
hardware removal, joint exposition, tibial deformities due to previous osteotomy, and managing soft tissue mismatches.
Very accurate measurement of mechanical axis of tibial slope during the surgical procedure
