Pilot study using novel technique for restoring the limb length in patients undergoing bipolar cemented hemiarthroplasty, using preoperative scaled radiographs of the normal side

Fracture around proximal femur are a commonlyencountered fracture in the older population with a globally increasingincidence. The incidence of the fracture around proximal femur also riseswith age. Among the fractures ofproximal femur the incidence of intertrochanteric fracture is around 55 % fractureneck of femur is around 32%.

Fractures around the hip are associated withincreased mortality rate, incidence being around 8-11% at the end of 30 daysand 20-30% at the end of 01 year. A delay in surgery is due to variousfactors  such as associatedco-morbidities requiring pre-operative optimization  in these group of patients and subsequentsurgery readiness and resource availability factors such as high volume ofcases.

In order to achieve the goals of fracturemanagement the options are primarily surgical with options including reductionand internal fixation or arthroplasty. Arthroplasty can be either Hemi-replacementArthroplasty (HRA) or Total Hip Arthroplasty (THA). HRA in current practice isof two types: unipolar and bipolar. HRA is generally indicated in olderpatients with a aim to regain early mobilization and better functional results.HRA prevents the bed ridden state and thus avoids the complications associatedwith recumbency.

In order to achieve better functional resultsfollowing HRA the hip biomechanics need to be restored to its native state. Thefemoral offsets and limb length are the factors that decide the biomechanics ofthe operated hip. Inability to restore the leg length has shown to beassociated with back pain, gait abnormalities, dislocation,prosthesis loosening and poor functional capacity.

Incidence of limb length discrepancy followinga HRA with a unipolar prosthesis is as high as 50% when the difference isminimum 10 mm. whereas in bipolar Arthroplasty the incidence decreases butis more when compared to THA

There are various means of reducing theincidence of LLD described in literature in patients undergoing Total HipArthroplasty. These methods were broadly classified by Khanduja et al  into 03 groups a) those which rely on preoperative templating and determinationof the osteotomy site with intra-operative determination of the osteotomy sitein relation to the lesser trochanter; b) those using intra-operative pelvic andfemoral markers for reference and; c) experimental methods which employ complexmathematical calculations and ultrasound probes to measure leg lengthsaccurately.

However there is limited available literatureon methods of reduction of limb length discrepancy in patients of proximalfemur fracture undergoing Hemi-replacement Arthroplasty. Methods used aretaking reference of the greater trochanter in relation to head of femur onnormal side and pre-operative templating and estimating the size of prosthesis

This study will be undertaken at a tertiarycare center in western part of India in patients of fracture of proximal femurundergoing Hemi-replacement Arthroplasty and wherein Pre-operative ScaledRadiograph shall be taken and a novel technique using fixed accessiblelandmarks will be used to assess the level of cuts intraoperatively with a aimto achieve equal limb length or minimize limb- length discrepancy.