introductionIs it a true concern ? depends on :valueOriginpreoperative statuspatient expectation.surgeon priorityArthroplasty of the hip. Leg length is not important.JBJS Br. 2002 Apr;84(3):335-8.White TO, Dougall TW

But an actual problem for the surgeon and his patient ?

introduction

frequencyfrequent under 10 mm in the literaturePrevalence and functional impact of patient-perceived leg length discrepancy after hip replacement.Int Orthop. 2008 Apr 25Wylde V, Whitehouse SL : 30% (1114 hips)Revision >primarypersonal experience2 LLD > 10 mm in revision casesNone case during primary surgeryusual accuracy < 5 mm in 90% of casesmore often lengthening than shortening

anatomical basisTrue segmental LLDacetabular sidefemoral sideFalse segmental LLDSpinal 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

diagnosisclinical examination:limb length measurement range of motionstiffnessfixed abduction

radiological examinationPelvic AP radiograph in a standing positionlong standing view in a standing position

causesPreoperative causeslack or bad preoperative planningbad assessment of other parameters (spine, bone segments)intraoperative causesacetabular sidehigh positiontoo horizontal inclinationlack of impaction : lateralizationfemoral side neck resection levelchoice of the prosthesis neck length

consequenceslateral hip pain, trochanteric painmuscle weakness or tightness (lack of motion) Limpingback painknee pain (homo or contra lateral)limb nerve damage : pain, palsyradiculopathyloosening The role of overlength of the leg in aseptic loosening after total hip arthroplasty.Ital J Orthop Traumatol. 1993;19(1):107-11.Visuri T, Lindholm TS, Antti-Poika I, Koskenvuo M

TreatmentShoe lift

femoral diaphysis shorteningRevisionuni or bipolarbe careful , shortening expose to postoperative instability, lowering of the greater trochanter helps to prevent it

How to prevent LLDpreoperative planning POstandard templating

Magnification is the problem

How to prevent LLDpreoperative planning POstandard templating : complex cases

How to prevent LLDpreoperative planning POdigitalized planning (Bfits Biomet)

if preoperative discrepancy, it must be calculated on a standard planning

How to prevent LLDAnatomical referencesacetabular inferior marginlesser trochanter

Great trochanter summitSoft tissue tensioncontra lateral limb

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How to prevent LLDIntraoperative measurementsuperposition of the trial femoral prosthesis with the femoral neck along with the femoral axis and according to the preoperative planning

How to prevent LLDIntraoperative measurementMeasurement of the resected neck according to the POCalliper and Carpenter LevelP Chiron

How to prevent LLDIntraoperative measurementMeasurement of the trochanteric-iliac distanceCalliper and Carpenter Level

How to prevent LLDIntraoperative measurementultrasonographic measurementintraoperative radioscopy

How to prevent LLDComputer Assisted Surgery LLD 0.6 +/- 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. 2006 Jun;92(4):316-25.Laffargue P, Pinoit Y, Tabutin J, Giraud F, Puget J, Migaud H.

conclusionfrequent but often well tolerated after 6 months if less than 1 cmAcute 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 itCAS definitely helps to minimize LLD to a very low levelDo not forget to inform the patient (before and .after surgery)I still need to paid attention to this issue even after several thoousand THA

Thank you for your attention