Introduction:

The risk for late periprosthetic fractures is higher in patients treated for a neck of femur fracture compared to those treated for osteoarthritis. It has been hypothesised that osteopenia and consequent decreased stiffness of the proximal femur are responsible for this. We investigated if a femoral component with a bigger body would increase the torque to failure in a biaxially loaded composite sawbone model.

Introduction:

In an attempt to reduce stress shielding in the proximal femur multiple new shorter stem design have become available. We investigated the load to fracture of a new polished tapered cemented short stem in comparison to the conventional polished tapered Exeter stem.

Introduction

We report our mid-term results and risk factors of a two-stage revision using impaction bone grafting for an infected hip replacement.

We used the D-dimer level as a measure for the early diagnosis of deep vein thrombosis (DVT), which can cause fatal pulmonary thromboembolism (PTE), following total hip arthroplasty (THA). Recently, we have performed anticoagulation therapy, in addition to the use of elastic stocking and intermittent pneumatic compression, for the prevention of DVT. In the present study, we examined the effect of administration of anticoagulation drugs on the changes in the D-dimer level.

Of 123 patients who had undergone THA between April 2003 and October 2007, 70 patients who were available for 3 or more measurements of the D-dimer level were included in this study. These 70 patients were divided into the following three groups: N group consisting of 30 patients who were not given anticoagulation drugs (4 males, 26 females; mean age 69 years (45–87 years); mean body mass index (BMI) 24.1 (15.8–28.5)), W group consisting of 23 patients who were administered dose-adjusted warfarin at a dose of 5 mg within 3 days after surgery and at 1–3 mg following 1-day rest (3 males, 20 females; mean age 62 years (48–83 years); mean BMI 24.1 (17.8–35.9)), and F group composed of 15 patients who were given fondaparinux (2.5 mg) between postoperative days 1 and 14 (6 males, 11 females; mean age 64 years (51–81 years); mean BMI 23.1 (18.2–31.6)). There was no significant difference in sex ratio and BMI between the three groups, while a significant difference in age was found between the N and F groups. The D-dimer level was measured on days 3, 7, 10, 14 and 21 and changes in the median D-dimer level were compared between groups.

In the N group, the D-dimer level was around 8 μg/ml between postoperative days 3 and 10 and exceeded 10 μg/ml on postoperative day 14. In the W group, the D-dimer level was around 8 μg/ml between postoperative days 3 and 14 and decreased thereafter.

In the F group, the D-dimer level was less than 3 μg/ ml on postoperative day 3, increased gradually thereafter until postoperative day 14, reaching the maximum level of approximately 8 μg/ml, and then decreased thereafter.

The D-dimer level was significantly different between the N and F groups and between the W and F groups on day 3, between the N and F groups and between the W and F groups on day 7, and between the N and W groups on day 21. With regard to hemorrhagic adverse events, neither major nor minor bleeding event was observed in either the W or F group.

The present study suggested that fondaparinux is effective for preventing DVT in an early postoperative period, with relatively low D-dimer levels observed between postoperative days 3 and 10.

We expect that various types of anticoagulation drugs will be used in the future.

Elucidating the effect of these drugs on the D-dimer level will help in the early diagnosis of DVT.

At the revision surgery of the cemented Total hip arthroplasty (THA), complete removal of an old cement mantle of the femur without loosening is very difficult. It can be associated with complications, such as femoral fracture, perforation and femoral bone loss. Cement-within-cement technique (CWCT) of femoral revision is very useful and advantageous without those complications for special cases.

We reviewed the experiential radiological outcomes using CWCT for the cemented femoral revision.

Between 1999 and 2006, we performed seventeen of revision THA using CWCT in 17 patients.

There were four men and 13 women, with an average age of 75 years (range 68 to 87), with an average follow up of 39 months (range 12 to 87).

The reasons for revision surgery were eleven for cup loosening, 5 for recurrent dislocation and one technical failure of stem insertion intra-operatively.

An original Charnley stem (Depuy, Leeds, England) was implanted in six cases, an Exeter femoral component (Stryker Benoist Girard, Herouville, Saint-Clair, France) was in 10 and another stem in one.

Posterolateral approach without trochanteric osteotmy was performing for all patients. After the femoral component was removed, the cement mantle was examined in detail, to confirm cement-bone interface and cement fracture.

The cement mantle was washed with a pulsatile lavage to clean and to be dried.

If necessary, the surface of the cement mantle was reamed. A double mix of Simplex P cement (Stryker Limerick, Limerick, Ireland) in liquid phase was inserted within the cement mantle by a cement gun with a thin nozzle(Stryker Instruments Kalamazoo, US). Thereafter suction and pressuriser were used, and a femoral component was inserted.

The results of this study were that the intra-operative complication was two fractures of the greater trochanter at the stem removed and was one shaft perforation at a new original Charnley stem inserted. The stem position was one valgus and 3 varus stem position of more than 2 degrees.

Radiographic outcomes showed no stem loosening, no radiolucent line at the bone-cement interface, nor any osteolysis in the patients at final follow-up.

We conclude that this cement-within-cement technique is good radiographic outcomes up to 87 months and this technique should be used with the thinner femoral component than the previous.