Bone cement filling in morrow cavity following high-pressure washing can reduce prosthesis loosening:CT scanning and gross observation

Xuanhe SONG; Changdong FAN

ABSTRACT

BACKGROUND:

Better fusion of bone cement and bone interface can reduce prosthesis loosening rate.Marrow cavity is the place where bone cement fusion takes place,so its preparation is important to improve bone cement filling quality.

OBJECTIVE:

To evaluate bone cement-bone interface fusion in marrow cavity washed with high-pressure pulsed water syringe versus marrow cavity brushing.DESIGN,TIME AND

SETTING:

The comparative observation was performed at Animal Laboratory and Orthopaedic Laboratory of the First Hospital of Harbin Medical University from July 2002 to June 2003.MATERIALSForty fresh horse ulnas were randomly divided into 2 groups(n=20)washing group and control group.

METHODS:

The articular surfaces of the proximal ulna and cortex of horse ulnas were sawn to expose the trabecular bone,and only 15 cm proximal ulna was retained.The marrow cavity was opened with marrow cavity drilling and marrow cavity file along the line parallel to the longitudinal axis,proximal diameter 1.5 cm,5.5 cm deep,and self-developed marrow cavity bolt was put into the cavity until 5 cm deep.The marrow cavity of washing group was treated with high-pressure washing,1 000 mL fluid for each model,and the cavity was brushed once after washing with every 300 mL fluid for a total of 3 times.At the last time,100 mL water was used to clean the cavity following by wiping until the cavity was dry.The control group was not given any treatment.Both groups were infused with bone cement by the same method,and the models of each group were scanned by CT(interval 4 mm).MAIN OUTCOME

MEASURES:

Number of trabecular bone closely or not closely connected by bone cement section surrounding to calculate the rate of combination;condition of surfaces of marrow cavity and bone cement in the column by amplifier.

RESULTS:

CT scanning showed that interface connection rate of washing group was 64.47%,while the control group was 26.67%;the differences were statistically significant(P