1. leg length discrepancy after THA
Luc Kerboull

2. ? introduction Is it a true concern ? depends on :
value
Origin
preoperative status
patient expectation.
surgeon priority
Arthroplasty of the hip. Leg length is not important.
JBJS Br Apr;84(3):335-8. 
White TO, Dougall TW
But an actual problem for the surgeon and his patient ?

3. introduction frequency anatomical basis diagnosis causes consequences
treatment
how to prevent LLD

4. frequency frequent under 10 mm in the literature Revision >primary
Prevalence and functional impact of patient-perceived leg length discrepancy after hip replacement.
Int Orthop Apr 25
Wylde V, Whitehouse SL : 30% (1114 hips)
Revision >primary
personal experience
2 LLD > 10 mm in revision cases
None case during primary surgery
usual accuracy < 5 mm in 90% of cases
more often lengthening than shortening

5. anatomical basis True segmental LLD False segmental LLD
acetabular side
femoral side
False segmental LLD
Spinal origin (fixed deformity with pelvic obliquity)
other length discrepancy in the bone segments or joints under the hip
In all cases, a mistake for the patient

6. diagnosis clinical examination: radiological examination
limb length measurement
range of motion
stiffness
fixed abduction
radiological examination
Pelvic AP radiograph in a standing position
long standing view in a standing position

7. causes Preoperative causes intraoperative causes
lack or bad preoperative planning
bad assessment of other parameters (spine, bone segments)
intraoperative causes
acetabular side
high position
too horizontal inclination
lack of impaction : lateralization
femoral side
neck resection level
choice of the prosthesis neck length

8. consequences lateral hip pain, trochanteric pain
muscle weakness or tightness (lack of motion)
Limping
back pain
knee pain (homo or contra lateral)
limb nerve damage : pain, palsy
radiculopathy
loosening
The role of overlength of the leg in aseptic loosening after total hip arthroplasty.
Ital J Orthop Traumatol. 1993;19(1):
Visuri T, Lindholm TS, Antti-Poika I, Koskenvuo M

9. Treatment Shoe lift femoral diaphysis shortening Revision
uni or bipolar
be careful , shortening expose to postoperative instability, lowering of the greater trochanter helps to prevent it

10. How to prevent LLD preoperative planning PO
standard templating
Magnification is the problem

11. How to prevent LLD preoperative planning PO
standard templating : complex cases

12. How to prevent LLD preoperative planning PO
digitalized planning (Bfits Biomet)
if preoperative discrepancy, it must be calculated on a standard planning

13. How to prevent LLD Anatomical references acetabular inferior margin
lesser trochanter
Great trochanter summit
Soft tissue tension
contra lateral limb
????

14. How to prevent LLD Intraoperative measurement
superposition of the trial femoral prosthesis with the femoral neck along with the femoral axis and according to the preoperative planning

15. How to prevent LLD Intraoperative measurement
Measurement of the resected neck according to the PO
Calliper and Carpenter Level
P Chiron

16. How to prevent LLD Intraoperative measurement
Measurement of the trochanteric-iliac distance
Calliper and Carpenter Level

17. How to prevent LLD Intraoperative measurement
ultrasonographic measurement
intraoperative radioscopy

18. How to prevent LLD Computer Assisted Surgery
LLD /- 3 mm (range -5 to 10 mm)
[Computer-assisted positioning of the acetabular cup for total hip arthroplasty based on joint kinematics without prior imaging: preliminary results with computed tomographic assessment]
RCO Jun;92(4):
Laffargue P, Pinoit Y, Tabutin J, Giraud F, Puget J, Migaud H.

19. conclusion
frequent but often well tolerated after 6 months if less than 1 cm
Acute preoperative planning (PP) still is the simplest way to avoid major LLD (digitalized PP is more reliable)
Intraoperative references may help to check the data coming from the PP, but can not replace it
CAS definitely helps to minimize LLD to a very low level
Do not forget to inform the patient (before and ….after surgery)
I still need to paid attention to this issue even after several thoousand THA

20. Thank you
for
your attention