Surgical landmarks in revision total knee

Surgical Landmarks in Revision
Total Knee ArthroplastyDr. Mohamed A. Abdelsalam
Orthopedic department
Zagazig University

• The technical goal of primary and revision total knee arthroplasty (TKA) is to restore the
anatomical joint line .
• Failure to achieve this can lead to mid-flexion instability, a reduction in range of motion,
impingement of the patellar tendon against the tibial tray and gap imbalance.
• While in primary total knee arthroplasty matched resection is a reliable method for
restoration of the joint line level and gap balance, in revision surgery the use of matching
resection is impossible due to bone loss.
• Restoration of the joint line is a challenge and require a preoperative radiological (2004) and
intra-operative surgical landmarks.
Bellemans J (2004)

1. Femoral epicondyles
2. Fibular head
3. Inferior pole of patella
4. Tibial tubercle
5. Adductor tubercle
Surgical Landmarks in Revision total knee arthroplasty:

• The DMAD was 28.95 mm +/-3.3
• The PMAD was 28.57 mm +/-3.4
• The DLAD 23.97 mm +/- 3
• PLAD was 24.42 mm +/-3.
1- Femoral epicondyles

• The use of the epicondylar ratio is more
accurate method.
• DMAD = 0.35 X TEW
• DLAD= 0.28 X TEW
1- Femoral epicondyles

• The most proximal point of the fibular styloid is
chosen as a reference point.
• Fibular head joint line distance (FHJLD) is the
length of the perpendicular from the fibular
head to the tangent to tibial plateau, its length is
14.5mm +/-3
2- Fibular head

• The most proximal part of the slope of the
tibial tubercle.
• Tibial tubercle joint line distance (TTJLD) is
the perpendicular distance from the tibial
tubercle to the joint line. Its length is 32mm +/-
7 mm
3- The tibial tubercle

• The most inferior part of the patella
• Inferior pole of patella joint line distance
IPPJL is the distance between IPP and
distal Joint line and is 13.7 mm +/- 4.29
mm.
4- The inferior pole of patella

• The adductor tubercle (AT) is a bony
prominence located just proximal to the medial
condyle.
• The Adductor tubercle Joint line distance
(AAJL) is 48.7 ± 4.8. AAJL/FW is 0.52 and is a
constant value with no race or sex variation
5- Adductor tubercle

Reliability of the Surgical Landmarks in Revision TKA

Reliability of the Surgical Landmarks in Revision TKA
• Adductor tubercle distance/ Femoral width
ratio was found to be constant 0.52 and is the
most accurate surgical landmarks for joint
line position
• The usage of the ME and LE is less accurate
than the AT. Hence, ME and LE may serve as
second choices while AT is not available
• FH,TT, and IPP lower accuracy and marked
variability regarding sex, race and body mass
index

Use of Surgical landmarks in revision TKA
• Preoperative Planning:
Use landmarks to detect Joint line
malposition in failed TKA
Use contralateral knee to detect proper joint
line position

• Proper surgical exposure:
Extensile approaches
Medial parapatellar
Quadriceps snip
V-Y quadriceps turndown
Tibial tubersotiy osteotomy

• Component Removal:
• Management of bone loss:
Anderson Orthopaedic Research
Institute (AORI) bone defect
classification

1- Establishing a Stable tibial platform
- The tibia is a foundation on which the knee is
rebuilt.
-Managing of tibial defects according to AORI
-Sizing of tibial tray:
the old tibial tray.
The use of CT sizing of the healthy side and
through the use of patient specific
instrumentation system (PSI)
- Position of the tibial component : The tibial
component should be at or just above the level
of the fibular head. And should be in slight
external rotation.

2- Stabilizing the knee in flexion:
Critical step in revision TKA and include posterior femoral
augmentations applied to reconstruct the posterior femoral
offset. Appropriate tibia bearing was inserted to evaluate the
flexion gap and balance.
3- Stabilizing the knee in extension:
Then the extension gap was adjusted by distal or proximal
displacement of the femoral component with appropriate
distal femoral augments.

A- Re-establishing the joint line :
i. Placing marks on the bone proximal and distal to the failed implant prior
to its removal——Simple but not accurate.
ii. Using Surgical landmarks:
Several credos used to locate the JL intraoperatively.: two finger breadths
above the tibial tubercle (TT), 20 mm above the fibular head (FH) or one
finger width inferior to the inferior patellar pole (IPP) in extension—-Not
Accurate a lot of variations
Accurate method: Using Measurements from surgical landmarks

1- The use of the epicondyles landmarks
for detection of Joint line position:
The joint line should, ideally, be
approximately 30 mm distal to the medial
femoral epicondyle
25 mm distal to the lateral epicondyle
10 to 15 mm proximal to the fibular head,
with all three landmarks palpable during
rTKA

2- The use of Adductor tubercle for detection of
Joint line position:
- Measure femoral width intra-operatively
- Multiply femoral width with 0.52 to get ATJL
(roughly half of femoral width)
- Introduce intramedullary rod in canal and ATJL
distance plotted.
- Distal femoral cutting block is fixed at ATJL which
is plotted.
- Assess and select appropriate size of augments to
reconstruct joint line

3- Using the inferior pole of patella
-Patella Joint Line Gauge applied to
the anterior flange of the femoral
cutting guide—Inferior pole of
patella should lie between the two
“Normal” marks of the gauge.
- Joint line scale used to locate the
JL with respect to the TT and/or
IPP.

B- Sizing of the femoral component;
-Pre-operative templating of the contralateral side if
normal
- Use the size of the revised previous prosthesis
- Using intra-operative surgical landmarks:
transepicondylar width applied to special charts to
detect the proper size
- Using Intraoperative femoral sizing templates on
the Femoral Sizing Templates on the shaft of the
reamer or adapter until the appropriate size is found

C- Seating the femoral component in
external rotation;
- Use of the posterior femoral condyles—
However erosions of the posterior femoral
condyles —-Misleading internal rotation
- Use of the tibial shaft Axis —-inadequate
misleading
- Use epicondylar axis

D-Restoring the patellar height:
Inferior pole of patella about 13 mm from
the polyethylene insert “one finger width”
Avoid proximalization of Joint line
“pseudo patella baja”

D- Preoperative, intra-operative and post-
operative planning using landmarks

E- Post operative radiological evaluation :
Surgical landmarks can to asses proper
position of the implant ،restoration of the
joint line and patellar height

Summary:
Identifications and usage of surgical landmarks is essential to restore the normal joint line, femoral
component size and position in rTKA.
Furthermore, these landmarks can be used for preoperative planning and postoperative evaluation of the
surgery.

Surgical landmarks in revision total knee

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