1. Imaging Findings

According to the provided pelvic and lumbosacral CT images, multiple fracture lines are visible in the sacrum. The specific findings are as follows:

• On axial (transverse) and coronal reconstructed images, fracture lines can be seen in both sacral ala regions, near the sacral canal, with some fracture lines passing through the areas of the sacral foramina (i.e., medial portion of the sacral ala).
• The sagittal reconstruction shows that the course of the fracture involves parts of the posterior structures of the sacral vertebral bodies, but there is no clear forward displacement or large-scale collapse.
• No obvious concomitant fractures in the pubis, ilium, or ischium were seen, indicating that the integrity of the pelvic ring appears relatively maintained.
• No significant large hematoma was observed in the surrounding soft tissues, and no evident signs of sacral nerve root compression on imaging. However, clinical neurological examination is necessary to rule out possible nerve injury.

2. Possible Diagnoses

Based on the patient’s advanced age, history of trauma (a sudden brake on a bus or a fall), and imaging findings, the following possibilities are considered:

1. Traumatic Sacral Fracture (Primarily Denis Zone 2)
   • The fracture mainly involves the sacral ala and the region near the sacral foramina, consistent with the typical presentation of Denis Zone 2.
   • This region could be fractured due to direct impact or transmitted stress; in some patients with osteoporosis, relatively minor trauma may result in fracture.
2. Sacral Insufficiency Fracture (on the background of osteoporosis)
   • In elderly females with osteoporosis, low-energy injuries such as a simple fall can also lead to sacral fractures.
   • However, this patient has a clear acute traumatic event, making a traumatic fracture more likely, though chronic stress or osteoporotic factors may be overlapping concerns.
3. Concurrent or Potential Sacral Nerve Root Injury
   • Although no obvious nerve root compression is seen on imaging, the fracture lines passing through the foramina region raise the possibility of unilateral or bilateral sacral nerve root compromise.
   • Neurological examination and possibly electrophysiological evaluations are required.

3. Final Diagnosis

Considering the patient’s old age, history of falling trauma, and CT imaging showing multiple sacral fracture lines, the diagnosis most consistent with these findings is:

• Multiple traumatic sacral fractures, primarily located in Denis Zone 2, with no indication of pelvic ring fracture.

Additionally, given that the fractures involve sacral foramina and are near the sacroiliac joint and L5-S1 facet joints, Isler classification may be used for further subclassification. From the images, the fractures appear mostly lateral to or close to the facet joint area, suggesting a possible Isler Type A or Type B classification (a detailed three-dimensional reconstruction and clinical biomechanical assessment would be necessary for final confirmation).

4. Treatment Plan and Rehabilitation Strategy

4.1 Treatment Strategy Overview

• Conservative Treatment: Suitable for stable fractures with no significant displacement and mild or no neurological deficit. This includes bed rest, wearing a lumbosacral brace, analgesics, and management of osteoporosis (for example, calcium and vitamin D supplements, bisphosphonates, or calcitonin).
• Surgical Treatment: If significant fracture displacement, severe neurological symptoms, or instability (e.g., Isler Type B or C with marked facet involvement) are present, percutaneous screw fixation, sacroiliac screw fixation, or other individualized surgical interventions may be considered.
• Neurological Assessment: If any symptoms such as sensory changes, decreased muscle strength, or bowel/bladder dysfunction are noted or suspected, electrophysiologic studies and MRI may be indicated. In cases of acute nerve compression or progressively worsening neurological deficits, prompt surgical decompression is necessary.

4.2 Rehabilitation/Exercise Prescription Recommendations

Considering the patient’s advanced age, osteoporosis, and existing risk of sacral fracture, an individualized, gradual, and safety-oriented approach should be adopted:

1. Early Recovery (Acute Fracture Phase: 2-4 weeks)
   • Focus on protective immobilization and pain management; a lumbosacral support brace can be used depending on pain levels.
   • Encourage gentle lower limb activity: ankle pumps and knee flexion/extensions in sitting or lying positions to prevent lower-limb thrombosis.
   • Use assistive devices (walker or cane) for short indoor ambulation; permit mild weight bearing as tolerated, ensuring patient safety.
2. Intermediate Functional Recovery (about 4-8 weeks)
   • Gradually increase weight-bearing as pain allows, such as short-distance walking a few times a day (2-3 sessions of 10-15 minutes each), while avoiding prolonged standing or sitting.
   • Begin core muscle strengthening exercises: supine bridge (hip lift) or simplified lumbar/back muscle training, executed gently and slowly.
   • Closely monitor pain and neurological symptoms; adjust or reduce exercise if symptoms worsen.
3. Late-Stage Reinforcement (about 8-12 weeks and beyond)
   • Progressively resume normal daily activities; incorporate lumbar and core stabilization exercises. If conditions allow, balance training such as partial squats or use of a balance board can be introduced.
   • Gradually increase walking duration and frequency; for instance, add 5-10 minutes per week, monitoring for fatigue and joint stress.
   • After fracture healing is confirmed and if cardiopulmonary function permits, consider low-impact aerobic activities such as stationary cycling or swimming.

Throughout the rehabilitation process, adherence to the FITT-VP principle (Frequency, Intensity, Time, Type, Volume, Progression) and individualization is emphasized, adjusting interventions based on bone density and pain tolerance.

Disclaimer: This report is provided as a reference based on current imaging findings and the patient’s history and does not replace an in-person consultation or professional medical advice. If you have any concerns or if symptoms worsen, please seek medical attention promptly for further evaluation or treatment.