Results

Baseline demographic and injury characteristics

Forty-six patients met the inclusion criteria. The mean age was 30.8±8.8 years (range, 18-50 years); 28 (60.9%) were female, giving a female-to-male ratio of 1.55:1. The most common mechanism of injury was a fall from height (30; 65.2%), followed by falls from stairs (9; 19.6%) and road traffic accidents (7; 15.2%), representing high-energy trauma. The most frequently involved level was L2 (25; 54.3%), and all fractures were AO type A3 (20; 43.5%) or A4 (26; 56.5%); no type B injuries occurred during the study period. Calcaneal fractures coexisted in 13 patients (28.3%), of whom nine had bilateral fractures. Baseline characteristics are summarized in Table 1.

Characteristics | Category | n (%)
Age group (years) | ≤20 | 5 (10.9)
 | 21-30 | 19 (41.3)
 | 31-40 | 15 (32.6)
 | 41-50 | 7 (15.2)
Sex | Female | 28 (60.9)
 | Male | 18 (39.1)
Mechanism | Fall from height | 30 (65.2)
 | Fall from stairs | 9 (19.6)
 | Road traffic accident | 7 (15.2)
Fracture level | D12 | 4 (8.7)
 | L1 | 13 (28.3)
 | L2 | 25 (54.3)
 | L3 | 4 (8.7)
AO type | A3 | 20 (43.5)
 | A4 | 26 (56.5)
Associated injury | Bilateral calcaneal# | 9 (19.6)
 | Unilateral calcaneal# | 4 (8.7)
 | None | 33 (71.7)

Perioperative outcomes

Mean operative time was 108.2±12.1 minutes (range, 90-150), and mean intraoperative blood loss was 102.6±16.1 mL (range, 70-150). Mean length of hospital stay was 2.6±0.7 days (range, 2-4). Mean VAS pain score decreased from 4.4±0.6 on the day of surgery to 2.6±0.7 on postoperative day 3 (Table 2).

Parameter | Mean±SD | Range
Operative time (min) | 108.2±12.1 | 90-150
Intraoperative blood loss (mL) | 102.6±16.1 | 70-150
VAS, day of surgery | 4.4±0.6 | 4-6
VAS, postoperative day 3 | 2.6±0.7 | 2-4
Length of stay (days) | 2.6±0.7 | 2-4

Radiographic correction

The sagittal Cobb angle improved from a preoperative mean of 18.9±5.9° to a postoperative mean of 8.7±5.9°, representing a mean correction of 10.2±4.2°. AVBH increased from 55.3±11.0% to 74.3±10.4% of normal, representing a mean restoration of 18.9±7.5%. Both changes were statistically significant (p<0.01) (Table 3). These measurements reflect the immediate postoperative period.

Parameter | Preoperative (mean±SD) | Postoperative (mean±SD) | Mean difference±SD | Paired t-value | df | P-value
Cobb angle (°) | 18.9±5.9 | 8.7±5.9 | 10.2±4.2 | 16.47 | 45 | <0.01
Anterior VBH (% normal) | 55.3±11.0 | 74.3±10.4 | 18.9±7.5 | 17.10 | 45 | <0.01

Screw placement accuracy

A total of 184 screws were placed (92 on each side). On postoperative CT, 173 screws (94.0%) were classified as Gertzbein-Robbins grade A (fully contained). Eleven screws (6.0%) were malpositioned: nine (4.9%) were grade B, one (0.5%) was grade C, and one (0.5%) was grade D, distributed between D12 and L3. No malpositioned screw caused neurovascular injury, and no screw required revision (Table 4).

Grade (breach) | Screws, n | %
A (contained) | 173 | 94.0
B (0-2 mm) | 9 | 4.9
C (2-4 mm) | 1 | 0.5
D (4-6 mm) | 1 | 0.5
Total | 184 | 100.0

Complications

No patient developed a new neurological deficit, surgical-site infection, or implant failure during the study period, and no screw revision was performed.