Segmental Cobb angles were measured using the superior endplate of the rostral vertebral body and inferior endplate of the caudal vertebral body. By using this find protocol method, measurements of the true angle can be obtained as opposed to a measurement of what may represent the lordosis of the cage. The mean disc height was taken as the mean of the anterior and posterior disc heights. Figure 2Representative lordosis and disc height measurements. Regional Cobb angles are based on the superior endplate of L1 and the superior endplate of S1 to measure regional lumbar lordosis. Segmental Cobb angles are based on the superior endplate of the rostral …All measurements were collected and organized using an excel spreadsheet (Microsoft, Redmond, WA, USA).

Of the total, a hypolordosis subgroup (preoperative regional Cobb angle of <42��) and a normolordosis group (preoperative regional Cobb angle of ��42��) were then analyzed for the above endpoints. Statistical analysis was carried out with IBM SPSS 19.0 using the paired t-test and nonparametric Wilcoxon Signed Ranks test.3. ResultsThirty-five patients were included, of which 7 were hypolordotic and 28 were normolordotic based on preoperative lateral radiographs. The mean follow-up period was 13.3 months. Fifty total levels were fused giving a mean of 1.42 levels fused per patient. The mean segmental Cobb angle increased from 11.10�� �� 9.29 to 13.61�� �� 8.46 (P < 0.001) (Figure 3). The mean regional Cobb angle increased from 52.47�� �� 10.55 to 53.45�� �� 11.90 (P = 0.392) (Figure 4). The mean disc height increased from 6.50mm �� 2.

51 to 10.04mm �� 2.75 (P < 0.001) (Figure 5). Figure 3Segmental lumbar lordosis changes after MIS LIF. Statistically significant increases were observed at each measured level as well as in aggregate. (* = P < 0.05,** = P < 0.01,*** = P < 0.001).Figure 4: Regional lumbar lordosis changes after MIS LIF. No statistically significant increases were observed.Figure 5Disc height changes after MIS LIF. Statistically significant increases were observed at each measured level as well as in aggregate. (* = P < 0.05,** = P < 0.01,*** = P < 0.001).The proportional increase in mean segmental Cobb angle was 22.6% for all levels. Proportional gains in segmental Cobb angles progressively declined with more caudal lumbar segments, with 157.8%, 13.9%, and 8.7% increases for L2-3, L3-4, and L4-5, respectively.

The proportional increase in mean preoperative disc heights was 54.5% for all levels. A proportional increase in mean preoperative disc heights of 58.6%, 44.7%, and 61.0% was observed for L2-3, L3-4, and L4-5, respectively. For the hypolordotic subgroup, the mean segmental Cobb angle increased Anacetrapib from 2.38�� �� 8.61 to 5.90�� �� 7.06 (P = 0.051). The mean regional Cobb angle increased from 37.74�� �� 2.74 to 39.39�� �� 10.53 (P = 0.