1. Step by step guide: Planning total hip arthroplasty
Lecture
AORecon Course—Principles of Total Hip and Knee Arthroplasty

2. Preoperative planning—introduction
Detailed clinical and x-ray examination
To prevent:
Component malposition
Increased rate of aseptic loosening
Increased rate of dislocation
Bad functional results
Preoperative planning is important in order to prevent

3. Preoperative planning—goals
To accurately implant the components:
Type
Size
Positioning
To avoid problems:
Complications
Patient dissatisfaction

4. Restoration of the center of rotation
BW-LA[m]
GMV[ccm]
BW [N]
Adductionmoment
Muscle lever arm
Joint reaction forces
Range of motion
Impingement
Instability
The crucial part in restoration hip biomechanics is the center of rotation
Reference:
Preininger B, Schmorl K, von Roth P, et al. A formula to predict patients' gluteus medius muscle volume from hip joint geometry. Man Ther Oct;16(5):
Preininger et al. (Man Ther 2011;Oct;16(5):

5. Restoration of the center of rotation
BW-LA[m]
GMV[ccm]
BW [N]
Adductionmoment
Muscle lever arm
Joint reaction forces
Range of motion
Impingement
Instability
The crucial part in restoration hip biomechanics is the center of rotation
Reference:
Preininger B, Schmorl K, von Roth P, et al. A formula to predict patients' gluteus medius muscle volume from hip joint geometry. Man Ther Oct;16(5):
Preininger et al. (Man Ther 2011;Oct;16(5):

6. Planning total hip arthroplasty

7. Radiographic evaluation
10–15° internal rotation (compensates for femoral neck anteversion  offset)
True lateral:
Osteophytes

8. Radiographic evaluation
10–15° internal rotation (compensates for femoral neck anteversion  offset)
True lateral:
Osteophytes
Reference:
Scheerlinck T. Primary hip arthroplasty templating on standard radiographs A stepwise approach. Acta Orthop. Belg., 2010, 76, 432–442.
Scheerlinck (Acta Orthop. Belg., 2010, 76, 432–442)

9. Radiographic evaluation
10–15° internal rotation (compensates for femoral neck anteversion  offset)
True lateral:
Osteophytes

10. Step 1: Magnification External markers
In step 1 the magnification should be verified via external markers as depicted.
References:
Davila JA, Kransdorf MJ, Duffy GP. Surgical planning of total hip arthroplasty: accuracy of computer-assisted EndoMap software in predicting component size. Skeletal Radiol Jun;35(6):390–393.
Bono JV. Digital templating in total hip arthroplasty. J Bone Joint Surg Am. 2004;86-A Suppl 2:118–22.
Davila et al (Skeletal Radiol Jun;35(6):390–393)
Bono (J Bone Joint Surg Am. 2004;86-A Suppl 2:118–22)

11. Step 2: Identify x-ray landmarks
Tear drop—inferomedial acetabulum
Placement of inferior edge of the cup
Reference:
Gonzales et al. JOA 2005
Gonzales et al (JOA 2005)

12. Step 2: Identify x-ray landmarks
Tear drop—inferomedial acetabulum
Placement of inferior edge of the cup
Ilioischial line
Reference:
Gonzales et al. JOA 2005
Gonzales et al (JOA 2005)

13. Step 2: Identify x-ray landmarks
Tear drop—inferomedial acetabulum
Placement of inferior edge of the cup
Ilioischial line
Superior acetabular edge
Reference:
Gonzales et al. JOA 2005
Gonzales et al (JOA 2005)

14. Step 2: Identify x-ray landmarks
Femoral shaft
Greater trochanter
Lesser trochanter
Reference:
Scheerlinck T. Primary hip arthroplasty templating on standard radiographs A stepwise approach. Acta Orthop. Belg., 2010;76:432–442.
Scheerlinck (Acta Orthop. Belg., 2010;76:432–442)

15. Step 2: Identify x-ray landmarks
Femoral shaft
Greater trochanter
Lesser trochanter
Quality control: Foramen obturatum, distance between symphysis and sacrococcygeal joint women: 32 mm (range: 8–50 mm); men: 47 mm (range: 15–72 mm)
Referemce_
Scheerlinck T. Primary hip arthroplasty templating on standard radiographs A stepwise approach. Acta Orthop. Belg., 2010, 76, 432–442.
Scheerlinck (Acta Orthop. Belg., 2010, 76, 432–442)

16. Step 3: Assess leg length
Clinical examination
Interteardrop line
Keep in mind causes of leg-length differences distal to the hip (eg, tibial trauma)

17. Step 4: Identify areas of deformity
Excessive version
Dysplasia
Retained hardware
Previous surgery (eg, osteotomy)
Template the contralateral side

18. Step 5: Template the acetabulum
Define the center of rotation (COR)
Inferior edge at the tear drop
Touch the ilioischial line
45°of inclination
Define implant size
Reference:
Mabry T, in Surgery of the Hip, Ed. 2013
Mabry T, in Surgery of the Hip, Ed. 2013

19. Step 6: Template the femur
Assess offset

20. Step 6: Template the femur
Assess offset
Verify leg length

21. Step 6: Template the femur
Greater trochanter
Trochanteric fossa
Lesser trochanter @
Preliminary neck cut
Assess offset
Verify leg length
Define the femoral osteotomy

22. Step 6: Template the femur
Assess offset
Verify leg length
Define the femoral osteotomy
Assess the configuration of the meta- and diaphysis

23. Take-home messages Planning helps to:
Note osseous deformities and landmarks
Determine the implant size
Correctly restore biomechanics of the joint

24. Take-home messages Planning helps to:
Note osseous deformities and landmarks
Determine the implant size
Correctly restore biomechanics of the joint
 Rehearse the procedure