Radiological Findings

Based on the provided X-ray images, the following features are observed:

• Diffuse thickening of bone tissue, showing a “sclerotic” appearance with generally increased density.
• Thickened cortical bone with narrowing of the medullary cavity, suggesting compression or reduced space in the marrow.
• Typical “bone within bone” sign and “sandwich vertebrae” appearance (presence of dense bands in the vertebrae).
• Possible “Erlenmeyer flask” deformity at the metaphyses, i.e., flask-shaped expansion.
• Multiple transverse (horizontal) fracture lines, with clearly visible fracture ends and abundant callus formation.

Potential Diagnosis

Taking into account the patient’s age, clinical presentation (multiple transverse fractures), and radiographic findings, the following diagnoses or differential diagnoses may be considered:

1. Osteopetrosis (“marble bone disease”)
   Characteristically presents with diffuse sclerosis, increased bone fragility, a tendency for transverse fractures, and involvement of the bone marrow cavity, consistent with the imaging findings.
2. Paget’s disease
   Commonly seen in older patients. On imaging, there is disordered bone architecture with thickening or deformity, often localized lesions rather than generalized “sclerosis,” and the patient’s age does not typically match classic cases.
3. Other sclerosing bone disorders (e.g., osteosclerosis)
   Certain other conditions leading to increased bone density may present similarly, but classic signs such as “bone within bone” and Erlenmeyer flask deformity may be lacking.

Final Diagnosis

Considering the patient is an 18-year-old male with multiple transverse fractures, imaging suggestive of diffuse osteosclerosis, narrowing of the medullary cavity, and the “bone within bone” sign as core features, along with the possibility of a hereditary background, the most likely diagnosis is:

Osteopetrosis tarda (benign form of marble bone disease)

This form typically presents in adulthood with increased fracture risk, generally favorable prognosis, and about half of the patients may be asymptomatic. The fact that this patient’s main complaint is fracture aligns with the characteristics of this benign type.

Treatment Plan and Rehabilitation

Treatment Strategies

• Fracture Management: Provide standard fracture fixation and rehabilitation (e.g., casting or surgical internal fixation). Pay attention to fracture alignment and callus formation. Although the fracture healing process is similar to that of healthy individuals, patient monitoring is essential.
• Supportive Therapy: Currently, there is no specific pharmacological treatment for benign osteopetrosis (Osteopetrosis tarda). Management mainly involves symptomatic and supportive care. In the absence of severe complications, no special intervention is necessary.
• Bone Marrow Transplantation: Primarily indicated for the malignant (congenital) form of osteopetrosis; typically not required in the benign form.
• Monitoring Complications: Particularly anemia or bone marrow dysfunction. If there are any abnormalities in the blood count, timely management is needed.

Rehabilitation and Exercise Prescription

In rehabilitation training, individualized plans and safety are paramount. Given the fragile bones and risk of fracture, a low-to-high, gradual exercise approach is recommended, focusing on maintaining muscle strength and joint mobility while minimizing fall risk.

• Type of Exercise:
  Prioritize low-impact or non-weight-bearing activities such as swimming, light lower-limb resistance exercises (e.g., resistance band training), and simple core exercises. Avoid high-impact and contact sports.
• Frequency:
  3–4 times per week, adjusted according to the stage of fracture healing.
• Intensity:
  Keep heart rate at 40%–60% of maximum heart rate. Start resistance training with very light loads or resistance bands to avoid additional fracture risk.
• Time:
  20–30 minutes per session, including joint range-of-motion exercises and muscle-strengthening routines.
• Type (Specifics):
  Begin with gentle aerobic exercises, supplemented by flexibility (stretching, joint mobilization) and low-intensity resistance work. As fractures heal, gradually increase resistance and weight-bearing.
• Progression:
  Once fractures have healed and with medical clearance, gradually increase resistance training intensity, extend exercise duration, and progressively introduce light weight-bearing daily activities (e.g., walking on inclines).

Throughout the rehabilitation process, monitor for joint pain, swelling, and neurovascular symptoms. In the event of any discomfort or new symptoms, promptly seek medical evaluation.