Introduction

The volume of intraoperative blood loss is measured and reported by OR nurses in many hospitals and doctors do not usually measure it by themselves. To measure intraoperative blood loss accurately is such a difficult task that many measurement errors occur due to various factors. However, it is important to obtain a more correct measurement for performing a safe operation and stable anesthesia control.

Dislocation following total hip arthroplasty is one of the most common complications, occurring in 1% to 5% of all cases. Several causes for dislocation have been suggested that

Mismatching of cup positioning and stem anteversion

Most often positioning of the stem is anatomically predetermined, while the orientation of the cup is much more flexible. Since July 2005, stem first method has been applied for all cases. During this method, canal preparation and stem trial was done first, and then cup orientation was determined according to the stem direction and impingement. For the bigger cups 34mm or 38mm heads were applied in this series. In the present study dislocation ratio was compared to cup first method.

In the stem fist group (SF), the following procedures were done consequently.

Canal was prepared for the stem. Revelation lateral flare high proximal load transfer stem (DJO) was mainly selected. But for the case with high anteversion over 50 degrees, Modulas; conical distal load transfer stem with modular neck (Lima) was selected.

From October 2002 to July 2008, there were 191 THA cases. There were 81 hips in Standard group and 109 hips in SF group. There were 63 females and 18 males in Standard group and 90 females and 19 males in SF group (p=0.41). Average age was 61.0(22–81) in Standard group and 60.2(29–89) in SF group (p=0.53). In Standard group, 64 were replaced for osteoarthritis, 15 for rheumatoid arthritis and two for avascular necrosis. In SF group, 86 were replaced for osteoarthritis, 17 for rheumatoid arthritis and six for avascular necrosis (p=0.53). As for Crowe’s classification, 61 type I, 18 type II and 2 type III were included in Standard group. And 88 type I, 15type II, 4 type III and 2 type IV were included in SF group (p=0.29). Average anteversion of femoral neck were 23.1(−2 to 70) degree in Standard group and 26.2(−4 to 65) degree in SF group measured with CAT scan (p=0.274). MoM bearing surfaces were used with 71 hips (87.7%) in Standard group and 100 hips (91.7%) in SF group (p=0.35). Only in SF group, big metal head were used in 24hips(22%) with 34mm and in 12hips(11%) as 38mm diameter. Average leg length difference between pre and post operation was 11.5mm(0 to 36) in Standard group and 8.0mm(−18 to 30) in SF group (p< 0.05). Average cup inclination was 43.2(25 to 84) degree in Standard group and 40.9 (22 to 66) degree in SF group (p< 0.05). Average cup anteversion was 8.2 degree (0 to 22.8) in Standard group and 7.1 degree (−12 to 30.5) in SF group (p< 0.05). Average operating time was 111.9min (67–150) in Standard group and 97.5min(60–162) in SF group (p< 0.05). Average intra operative hemorrhage was 744ml(10–2757) in Standard group and 487ml(10–1374) in SF group (p< 0.05). The dislocation rate was decreased from 3.7% (3/81 cases) in Standard group to 0.0% (0/109) in SF group.

In conclusion our study suggested that Stem first method and utilization of big metal head would decrease the dislocation rate in primary cases. More bleeding from canal during accetabular reaming was expected. However less bleeding was observed in SF group.

Introduction: For longer lasting and bone conserving cementless stem fixation, stable and physiological proximal load transfer from the stem to the canal should be one of the most essential factors. According to this understanding, we have been developing a custom stem system with lateral flare and an off-the-shelf (OTS) lateral flare stem system was added to the series. On the other hand, dysplastic hips are often understood that they have larger neck shaft angle as well as larger anteversion. In other words they are in the status called “coxa valga.” From this point of view we had been mainly using custom stems for the dysplastic cases before. After off-the-shelf lateral flare stem system; which is designed to have very high proximal fit and fill to normal femora; was added, we have been using 3D preoperative planning system to determine custom or OTS. Then in most of the cases, OTS stem were suitably selected. Our pilot study of virtual insertion of OTS lateral flare stem into 38 dysplastic femora has shown very tight fit in all 38 cases. The reason was analyzed that the excessive anteversion is twist of proximal part over the distal part and the proximal part has almost normal geometry. In the present study, 59 femora were examined by the 3D preoperative planning system how the excessive anteversion effect to the coxa valga status.

Materials and Methods: Fifty-nine femoral geometry data were examined by the 3D preoperative planning system. Thirty-three hip arithritis, 3 RA, 2 metastatic bone tumours, 5 AVN, 1 knee arthritis, 12 injuries, and 3 normal candidates were included. Among them one arthritic Caucasian and one AVN South American were included. The direction of the femoral landmarks; centre of femoral head (CFH), lesser trochanter (LTR), and asperas in 3 levels (just below LTR, upper 1/3, mid femur; A1-3); were assessed as the angle from knee posterior condylar (PC) line. Neck shaft angle of each case was assessed from the view perpendicular to PC line and neck shaft angle form the view perpendicular to CFH and femoral shaft (i.e. actual neck shaft angle).

Results: Average anteversion was 34.4 +/−9.9 degree. CFH and LTR correlated well (i.e. they rotate together). A1, A2, A3 correlated well (i.e. they rotate together). LTR and A1 correlate just a little, LTR and A2 were independent each other. So the twist existed around A1. Neck shaft angle was 138.7+/−6.6 in PC line view and in actual view 130.3+/−4.4. No excessive neck shaft angle was observed in actual view. Even the case that has the largest actual neck shaft angle (140.4), the virtual insertion showed good fit and fill with the lateral flare stem.

Conclusion: In many high anteversion cases, coxa valga is a product of the observation from non perpendicular direction to CFH-shaft plane. Selection or designation of the stem for high anteversion cases should be carefully determined by 3D observation.

Elderly femoral neck fractures are often treated with cemented stems according to the reason that bone quality of the patients is not good enough to obtain the initial stability for supporting press fit cementless stem. Some elderly patients also have medullary expanding so called stovepipe canals which make initial stability of press fit stems difficult. Stems with lateral flare have some mechanical advantages to obtain proximal fixation compare to the straight stems without lateral flare. Concerning to initial stability, their vertical loads can be supported not only by proximal medial cortex but also by proximal lateral cortex. The stems also have rotational stability because of the proximal high fit and fill. As lateral flare is a transverse extension in axial section, the stem occupies the proximal canal widely. So it provides strong rotational stability. The purpose of this study was to evaluate the outcome of press fit cementless stem with lateral flare for elderly femoral neck fractures with poor bone quality and with medullary expanding.

We performed a retrospective review of the clinical records and radiograghs of consecutive 42 patients (42 hips) of femoral neck fracture operated with cement-less stems with lateral flare in 2005 and 2006. In this period, all displaced femoral neck fractures were operated using cementless stems with lateral flare (Revelation Hip System, DJO, USA) in our hospital. We could follow 24 patients for over one year. 12 of 24 patients had so called stovepipe canals according to Canal Flare Index< 3.0 (Noble et al). Minimum follow up duration was one year. The mean age of the patients at the time of operation was 78.2 years. The mean duration of follow-up was one year and three month. At the time of final follow-up, stem subsidence, stem fixation, spot welds and demarcation line at distal part of stem are assessed on radiograph. And operation time, blood loss at operation and complaint of thigh pain through all the follow up period are also investigated on clinical record.

There was no stem subsidence over 2mm and demarcation line in two cases. All stems were assessed bone-grown fixation. We could find at least one spot welds in all patients around porous coated part of the stem. The mean operation time was 60.1 min. and mean blood loss was 240.5 ml. There was no patient who complaints of thigh pain after operation.

Cementless stems with lateral flare were seemed to obtain good initial stem fixation for elderly femoral neck fracture patients even they have poor bone quality and medullary expanding.