[Comparative study on clinical effect of bone cement-strengthened screw fixation in the correction of Kümmell's disease with kyphosis].

Abstract

Objective: To explore clinical effect of bone cement-strengthened pedicle screw technique in the correction of stage Ⅲ asymptomatic Kümmell disease with kyphosis.

Methods: A retrospective analysis was conducted on clinical data of 40 asymptomatic stage Ⅲ Kümmell disease patients admitted between March 2019 and December 2021, including 15 males and 25 females, aged from 61 to 81 years old with an average of (67.4±5.2) years old;according to different surgical methods, they were divided into percutaneous kyphoplasty group (PKP) and reinforced screw group. There were 18 patients in PKP group, including 7 males and 11 females, aged from 61 to 78 years old with an average of (66.2±5.5) years old;the courses of disease ranged from 5 to 12 months with an average of (7.33±1.78) months;bone mineral density(BMD) T values ranged from -2.45 to -4.00 with an average of (-3.08±0.46);2 patients with T₈-T₉, 10 patients with T₁₀-T₁₂, and 6 patients with L₁-L₂;treated with PKP. There were 22 patients in reinforced screw group, including 8 males and 14 females, aged from 65 to 81 years old with an average of (68.5±3.8) years old;the courses of disease ranged from 4 to 15 months with an average of (7.86±2.73)months;bone mineral density(BMD) T values ranged from -2.40 to -4.50 with an average of (-3.18±0.54);3 patients with T₈-T₉, 12 patients with T₁₀-T₁₂, and 7 patients with L₁-L₂;treated with bone cement reinforced pedicle screw internal fixation combined with kyphoplasty. Cobb angle and anterior margin height of the injured vertebra were compared before operation, 3 d and 12 months after operation. Visual analogue scale (VAS) and Oswestry disability index (ODI) were compared between two groups before operation and 12 months after operation. The incidence of postoperative complications was compared between two groups.

Results: All patients were followed up, PKP group followed up for 11 to 14 months with an average of (11.97±0.96) months and 10 to 14 months with an average of (12.05±1.09) months in reinforced screw group;there was no significant difference between two groups (P>0.05). Postoperative Cobb angle at 3 days and 12 months in reinforced screw group were (7.34±2.26) ° and (18.86±1.96) °, while in PKP group were (18.88±1.89) ° and (23.28±1.90) °;there were statistical difference between two groups (P<0.05). The anterior margin height of the injured vertebra in reinforced screw group were (25.28±1.33) mm and (19.62±2.22) mm at 3 days and 12 months after operation, while in PKP group were (18.61±2.16) mm and(15.93±1.34) mm;there were statistical difference between two groups (P<0.05). Cobb angle and the anterior margin height of the injured vertebra were significantly improved at 3 days and 12 months after operation between two groups (P<0.05). Postoperative VAS and ODI at 12 months in PKP group were (2.00±0.69) score and (13.44±4.02)%, while in reinforced screw group were(1.91±0.61) score and (10.18±4.26)%;which were significantly lower than (6.89±0.76) score and (36.33±3.40)% in PKP group, (7.23±0.75) score and (37.09±3.73) % in reinforced screw group before operation. There were no difference in postoperative VAS between two groups at 12 months (P>0.05);postoperative ODI in reinforced screw group at 12 months was lower than that in PKP group(P<0.05). There was no significant difference in complications between two groups (χ²=0.071, P>0.05).

Conclusion: PKP and bone cement reinforced nail combined with PKP could improve kyphotic deformity and postoperative function, and relieve pain. The application of bone cement-reinforced nail fixation technology could provide a more stable support, more obvious functional recovery, lower the risk of re-collapse of the injured vertebra, and maintain the long-term stability of spine.