Invention technique and clinical results of Lampang cement injection gun used in hip hemiarthroplasty.

BACKGROUND

Cemented hemiarthroplasty is the common treatment of femoral neck fracture in elderly patients. The authors had invented Lampang cement gun (LCG) from a caulking gun to improve cementing technique. There was no previous study about LCG in clinical use.

OBJECTIVE

To describe invention technique and evaluate clinical result of using LCG for cemented hemiarthroplasty in elderly patients with femoral neck fracture.

MATERIAL AND METHOD

A retrospective study was conducted on 96 elderly patients who underwent cemented hemiarthroplasty (58 Austin Moore, 14 Thompson, 24 bipolar) in Lampang Hospital between October 2003 and April 2008. The femoral canal was filled with cement by using LCG Clinical outcome was assessed by Harris hip score (HHS). Radiographic quality of cementing technique was evaluated by Barrack's grading system.

RESULTS

The mean age of the patients was 76 years (range, 62-96) and follow-up period was 39 months (range, 12-66). Twenty-four patients died and five were lost to follow-up. The mean HHS in bipolar group was higher than Thompson and Austin Moore groups (83.2, 78.3 and 76.9 respectively). Excellent and good scores were found in 90.9% of bipolar hips compared with 46.7% in unipolar hips. Less than 10% of the patients had poor clinical result. Cement mantles was grade A 37.3%, B 32.8%, C 20.9% and D 9%. Probably loose was found in one grade-D hip. Two grade-D hips were removed due to infection and dislocation. One grade-C hip was revised due to periprosthetic fracture. The mortality rate at 36 months was 20.8% in unipolar and 8.3% in bipolar group.

CONCLUSION

The use of LCG for cemented hemiarthroplasties in elderly patients with femoral neck fracture provided satisfactory clinical outcome. LCG could be used to improve cementing technique and save the operative cost.