t h e s u r g e o n 8 ( 2 0 1 0 ) 1 1 9 – 1 2 1

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The Surgeon, Journal of the Royal Collegesof Surgeons of Edinburgh and Ireland

www.thesurgeon.net

Correspondence: Surgical Technique

A simple intraoperative technique to avoid limb lengthdiscrepancy in total hip arthroplasty

Keywords

Limb length discrepancy

Total hip arthroplasty

Sir,

Introduction

Limb length discrepancy (LLD) following total hip arthroplasty

(THA) is a well-known and documented complication. LLD can

pose a substantial problem for both the patient and the

surgeon. Patient dissatisfaction with LLD after THA is the

most common reason for litigation against orthopaedic

surgeons.1,2 Failure to restore limb length may lead to an

unstable hip, whereas over-lengthening may cause low back

pain, sciatic nerve palsy and early mechanical loosening.3

Several intraoperative techniques both invasive and non-

invasive have been reported in the literature to overcome LLD

during THA.2,4–10 The accuracy of all the methods that measure

from pinsanchored intopelvis to point onthe greater trochanter

may be affected by the inherent variability of the leg position

when measurements are made. Bending or dislodging the pins

and using of calliper devices can be cumbersome during the

THA surgery and can compromise the measurements.

Hence we describe a simple, safe and reliable intra-

operative technique, which can be easily used in THA surgery

done by posterior approach without any additional equip-

ment, incision and radiographs.

Fig. 1 – Judd pin with thread and knot-marking the

reference point.

Materials and methods

Operative technique

The patient is placed in the lateral position and a posterior

approach to the hip used. Prior to dislocation of the hip, a Judd

pin (Judd Medical, Braintree, Essex, U.K.) or any other stout

retractor pin is inserted into the pelvis just superior to the

acetabulum into the ileum to retract the abductors anteriorly

from the operative site. This forms the stable pelvic reference

point. A thread/suture (normally no. 5 ethibond, but any stout

braided material can be used) is then securely tied to this pin,

and a knot tied into the suture at a length of roughly 10 cm.

The operated leg is placed exactly over the top of the contra-

lateral leg, which should be palpable through the drapes by

lining up the heels which, is the easy way to reproduce the

same attitude of hip flexion as the contralateral leg i.e.

contralateral hip in 45� flexion and knee in 90� flexion which

makes it easy to place the operating leg over the non-operated

leg. Once satisfied that the hip is in this position, a mark is

made using diathermy on the greater trochanter to the long

axis of the femur, at a point corresponding to the knot in the

suture (Fig. 1). This mark is the preoperative leg length, which

can then be used as guide intraoperatively to either lengthen

or maintain the same length based on preoperative templat-

ing/planning. The pin in the ileum is left in place throughout

Fig. 2 – Level of the mark proximal to the knot-limb

shortened.

Fig. 3 – Level of mark distal to the knot-limb lengthened.

Fig. 4 – Level of the mark at the knot-limb length

maintained.

Fig. 5 – Intraoperative photograph showing the level of the

mark at the knot-limb length maintained.

t h e s u r g e o n 8 ( 2 0 1 0 ) 1 1 9 – 1 2 1120

the operation and the suture/thread left attached. The suture

is rested away from the hip joint.

The hip is then dislocated and the arthroplasty performed in

the usual way. With the trial components in place, the limb is

again placed in the position as described above. The suture

attached to the Judd pin is then utilised i.e. the knot is compared

to the mark made in the greater trochanter. The level of the

mark on the greater trochanter distal or proximal to the knot

gives an indication of lengthening or shortening (Figs. 2 and 3).

Adjustments can then be made to optimise the leg length i.e. if

shortening is noted pre-operatively then one can aim to achieve

length by this mark (Figs. 4 and 5). The final distance between

the knot and the mark is recorded as the indication of LLD.

The technique is dependant on two factors as described by

Bose WJ2 i.e.

1) Ensuring that the Judd pin stays in its original point in the

pelvis and is stable.

2) The attitude of the leg when measuring i.e. ensuring that

it stays in the same position.

Discussion

It is widely accepted that surgeons performing THA should

aim to minimize LLD, and therefore should adopt a reliable

method of doing so. The use of a stable pelvic reference,

combined with a method for accurately positioning the leg

during measurements, provides the surgeon a practical

method for measuring leg length during arthroplasty.11

The risk of introducing error in leg length measurement

by bending or loosening of the pin in the ileum can be defi-

nitely overcome by this simple and reliable technique using

a stout Judd pin. Utilising the routine incision for the poste-

rior approach to the hip, this technique can be easily carried

out in primary THA surgery as compared to other techniques

used to avoid LLD, which require further incision, and spe-

cialised equipment which are time consuming, cumbersome

and may not be very secure. This technique of using a suture

mark over the Judd pin is simple, inexpensive and easily

adaptable.

r e f e r e n c e s

1. Hofmann AA, Skrzynski MC. Leg-length inequality and nervepalsy in total hip arthroplasty: a lawyer awaits! Orthopedics2000;23(9):943–4.

2. Bose WJ. Accurate limb-length equalization during total hiparthroplasty. Orthopedics 2000;23(5):433–6.

3. Amstuz SM, Jinnah RH, Mai L. Revision of aseptic loose totalhip arthroplasties. Clin Orthop 1982;170:21–3.

t h e s u r g e o n 8 ( 2 0 1 0 ) 1 1 9 – 1 2 1 121

4. Charnley J. Low friction arthroplasty of the hip. Berlin, Germany:Springer-Verlag; 1979.

5. Mihalko WM, Phillips MJ, Krackow KA. Acute sciatic andfemoral neuritis following total hip arthroplasty: a case report.J Bone Joint Surg Am 2001;83:589–92.

6. Mcgee HMJ, Scott JHS. A simple method of obtaining equal leglength in total hip arthroplasty. Clin Orthop 1985;194:269–70.

7. Bal BS. A technique for comparison of leg lengths during totalhip replacement. Am J Orthop 1996;25:61–2.

8. Huddleston HD. An accurate method for measuring leg lengthand hip offset in hip arthroplasty. Orthopedics 1997;20:331–2.

9. Naito M, Ogata K, Asayama I. Intraoperative limb lengthmeasurement in total hip arthroplasty. Int Orthop 1999;23:31–3.

10. Takigami I, Itokazu M, Itoh Y, Matsumoto K, Yamamoto T,Shimizu K. Limb-length measurement in total hiparthroplasty using a calipers dual pin retractor. Bull NYU HospJt Dis 2008;66(2):107–10.

11. Clark CR, Huddleston HD, Schoch EP, Thomas BJ. Leg-lengthdiscrepancy after total hip arthroplasty. J Am Acad Orthop Surg2006;14:38–45.

Aravind Desai*, Bilal Barkatali, Asterios Dramis,

Timothy N. Board

Centre for Hip Surgery, Wrightington Hospital, Wigan, UK

*Correspondence to: Aravind Desai, 297 Lovely Lane,

Warrington WA5 0AF, UK. Tel.: þ44 07885994545;

fax: þ44 01257253853.

E-mail address: desaiaravind@yahoo.co.uk (A. Desai)

Available online xxx

1479-666X/$ – see front matterª 2009 Royal College of Surgeons of Edinburgh (Scottish charity

number SC005317) and Royal College of Surgeons in Ireland.Published by Elsevier Ltd. All rights reserved.

doi:10.1016/j.surge.2009.10.023