Chronic hip pain.
The patient presented with chronic pain in the right hip. A frontal radiogram of the pelvis was performed.
The X-ray revealed marked prominence of the bone trabeculae of the right ilium, ischium and pubic bones with cortical thickening, coarse trabeculae and marked sclerosis, a thickening of the pelvic rim (the "rim sign") and involvement of the right coxo-femoral articulation with narrowing of the hip joint and medial migration of the femoral head. There were also arthrosic changes of the pubis.
The most probable diagnosis is Pagetic involvement of the pelvic bones.
Paget's disease (PD) is a relatively common disease occuring in approximately 3-4% of people over 40 years of age. Most patients are mildly symptomatic or asymptomatic. No clear aetiology is known.
Pathologically, the disease occurs in three phases. Initially, bone is resorbed secondary to increased osteoclastic activity. Osteoblasts then form abnormal new bone. The primitive woven bone production is disorganised, contains increased vascularity and connective tissue, and does not contain Haversian systems. These two phases are repeated until the osteoclastic activity subsides. The final, or inactive phase is reached when there is a cessation of osteoblastic activity. The disease usually involves more than one bone although 10-35% of patients have monostotic disease.
The three distinct radiographic phases (lytic, mixed and sclerotic) correspond to the pathological phases. In the lytic phase, most commonly recognised in the skull as osteoporosis circumscripta and in long bones, a purely lucent defect is noted. As the disease progresses, through the mixed, to the inactive sclerotic phase, new pagetoid bone enlarges the bone predominantly through cortical apposition. Coarse and thickened trabeculae are also noted and in the skull a "cotton wool" appearance may be seen. In the inactive or sclerotic phase, a diffuse increase in bone density as well as bone enlargement is noted.
The pelvis is involved in about 60-70% of cases, usually in the combined phase. Involvement may be localised to a small area, may involve one side of the pelvis or may be a generalised process. -X-rays generally demonstrate sclerosis, particularly along the iliopubic and ischial lines, a coarsening of the trabecular pattern, thickening of the pelvic rim (also called the "rim sign"), and narrowing of the hip joint. Patchy areas of lucency and sclerosis may be seen. Protrusio acetabuli is a common late finding.
Most difficulty in diagnosis will occur in the mixed phase, when patchy areas of sclerosis are present with minimal or no bone enlargement. The main differential diagnoses are metastasis to the bone; fibrous dysplasia, if the facial bones are involved; myelofibrosis; fluorosis; renal osteodystrophy; and haemolytic anemias. The clinical context and biological and haematological tests lead usually to the correct diagnosis of Paget's disease.
Pagetic involvment of the pelvic bones.
Based on the patient’s anteroposterior pelvic X-ray, the following major features can be observed:
1. Sclerosis around the iliopectineal and ischiopubic lines: Localized areas of increased density (sclerosis) around the acetabulum of the pelvis, showing noticeably increased bone density compared to normal bone.
2. Disorganized and thickened trabeculae: The trabeculae are arranged in a clearly coarse and disordered manner, and in some areas, patchy lucent areas interlace with sclerotic regions.
3. Thickened bone margins and widened pelvic rim: Noticeable bone thickening seen at the lateral edge of the ilium or the pelvic rim, suggesting active bone remodeling.
4. Changes in the hip joint space: There is some degree of joint space narrowing, indicating that the joint may be affected during the chronic course.
5. Others: No obvious signs of a new fracture or marked soft tissue abnormalities are observed; the hip morphology mainly shows degenerative and abnormal bone structure changes.
Considering the above imaging findings and the patient’s age of 76 years with a history of chronic hip pain, the following differential diagnoses should be taken into account:
1. Paget’s disease (osteitis deformans): Commonly seen in individuals over 40 years old, often characterized by bone overgrowth, thickened trabeculae, and patchy areas of increased and decreased density, with possible bone deformities.
2. Metastatic bone disease: More common in elderly patients, may present with patchy areas of bone destruction or sclerosis; requires correlation with known tumor history and tumor marker tests to rule this out.
3. Fibrous dysplasia: Often seen in the long bones or craniofacial bones, typically appearing as a “ground-glass” change in the bone, but can also present with localized thickening and irregular sclerosis.
4. Other metabolic bone diseases (renal osteodystrophy, fluorosis, etc.): Generally associated with systemic metabolic or environmental factors; laboratory tests (e.g., serum calcium, phosphate, alkaline phosphatase) are needed to confirm.
5. Other hematological diseases (e.g., myelofibrosis, hemolytic anemia) causing bone changes: Must be ruled out with relevant hematological examinations.
Considering the patient’s age, chronic hip pain, the common site involvement (about 60%-70% of Paget’s disease cases involve the pelvis), and imaging findings such as bone thickening, sclerosis, and patchy lesions, the most likely diagnosis is Paget’s disease.
If there is still doubt, further laboratory tests (for example, serum alkaline phosphatase) and nuclear medicine scans (bone scintigraphy) may be performed to confirm the diagnosis; bone biopsy might be considered if a malignant process is suspected.
1. Pharmacotherapy:
• Bisphosphonates (e.g., alendronate, risedronate) can be used to inhibit excessive bone resorption, thus improving bone remodeling processes and relieving bone pain.
• Analgesics: Appropriate use of non-steroidal anti-inflammatory drugs (NSAIDs) or other pain relievers to help alleviate hip or pelvic pain.
2. Surgical Treatment:
• In cases of pathological fractures, severe joint deformities, or significant functional impairment, surgical fixation or joint replacement may be considered.
3. Other Supportive Therapy:
• Supplementation with calcium and vitamin D (under medical guidance) to maintain a healthy bone metabolism environment.
• Physical therapy and other supportive measures to reduce pain and promote joint flexibility.
Given the advanced age of the patient and chronic pain history, exercise should follow the principles of gradual progression and individualization, formulated according to the FITT-VP components (Frequency, Intensity, Time, Type, Progression, and Personalization):
• Frequency (F): Start at 2-3 sessions per week and gradually increase to 3-5 sessions per week as tolerated.
• Intensity (I): Begin with low-intensity activities (e.g., daily walking, gentle flexibility exercises), avoiding heavy loads or vigorous twisting motions. Increase intensity gradually after symptom relief.
• Time (T): 20-30 minutes per session, adjusted based on endurance and joint pain levels, either shortening or increasing the duration as necessary.
• Type (T):
1) Low-impact aerobic exercises: Such as walking on flat ground, stationary cycling, swimming, or water-based aerobic exercise to minimize stress on the hip joints.
2) Range of motion and strength training: Focus on strengthening key muscle groups in the lower extremities, such as the quadriceps and hip abductor muscles (preferably under the guidance of a physical therapist).
• Progression (P): As symptoms improve and strength increases, add more sessions or extend duration. Consider mildly increasing the load with light resistance bands when the joint is stable.
• Personalization (P): In cases of comorbid conditions (e.g., impaired cardiopulmonary function, significantly reduced bone density), consult relevant specialists to ensure maximum safety.
This report is based on the current imaging data and medical history for analysis and is provided solely for medical learning and reference purposes. It is not a substitute for an in-person consultation or professional medical advice. Patients should consider their own individual circumstances and consult with a specialist to develop an individualized treatment plan.
Pagetic involvment of the pelvic bones.
