**6.4.1 Malondialdehyde determination in periprosthetic tissues**

Determination of oxidative stress assessed by level of lipid peroxidation product MDA in periprosthetic tissues obtained from 40 primary THA, revised for loosening or high rate of wear, showed higher oxidative stress in the two groups. The mean MDA value of the 28 patients in Group I was 0.052 nmol/mg (±0.09 SD), and of the 12 patients with high rate of wear and osteolysis in Group II, 0.031 nmol/mg (±0.014 SD) (p=0.74). MDA levels in the control tissues (0.009 nmol/mg, ±0.0093 SD) were significantly lower than those in Group I (p<0.0001) and Group II (p<0.0001). Figure 5 shows the comparisons between the two groups and controls in graphical form.

306 Recent Advances in Arthroplasty

abundance compared to control samples taken from fascia lata supported the proposal that these findings were a result of ROS damage (Fig. 3). Wear debris inclusions were

Fig. 4. Electron micrograph (x12 000) showing giant cell with ingested polyethylene (open

Level of reduced and oxidized glutathione was elevated in both groups compared to controls. However, a lower statistically significant GSH/GSSG ratio was detected only in Group II compared to Group I and controls (p=0.005 and p=0.024, respectively). GSH and GSSG concentrations and GSH/GSSG ratio in the two groups and controls are given in

Analyzed parameter *Group I* (N 28) *Group II* (N 12) *Controls* (N 16)

GSH 74.1 67.3 \* 58.7 35 \* 18.9 20.9

GSSG 19.3 26.4 \* 21.8 12.6 \*'\*\*\* 4.3 4.4

GSH/GSSG 5.4 3.6 3.1 1.4 \*\*'\*\*\*\* 4.4 1.5

\* p<0.0001, \*\* p<0.024 versus the control group; \*\*\* p<0.045, \*\*\*\* p<0.005 versus Group I

**6.4.1 Malondialdehyde determination in periprosthetic tissues** 

Table 1. The levels of GSH, GSSG, as well as GSH/GSSG ratio in periprosthetic tissues and controls. Values measured in µmol/mg hydroxyproline. Data represented as mean SD.

Determination of oxidative stress assessed by level of lipid peroxidation product MDA in periprosthetic tissues obtained from 40 primary THA, revised for loosening or high rate of

demonstrated in the various cells (Fig. 4).

arrow) and metal (black arrow) particles.

**6.3 Glutathione determination** 

**6.4 Malondialdehyde determination** 

Table 1.

Fig. 5. The concentration of lipid peroxidation product, malondialdehyde (MDA), in periprosthetic tissues and controls. Values were measured in nmol/mg hydroxyproline. The lower and upper lines in the boxes represent the 25th and 75th percentiles, respectively, with the median marked in the box.
