What is the recommended approach to physical therapy for a patient with bone metastases (bone mets)?

Physical Therapy for Bone Metastases Patients

Physical therapy and exercise are safe and feasible for patients with bone metastases when appropriately prescribed based on fracture risk assessment, with evidence demonstrating improved pain control, physical function, and quality of life without increased fracture incidence. 1, 2

Initial Risk Stratification Before Physical Therapy

Before initiating any physical therapy program, assess fracture and neurological risk using validated scoring systems 3, 4:

• For spinal lesions: Apply the Spinal Instability Neoplastic Score (SINS, range 0-18) 3, 4

  • Stable (≤6): Physical therapy can proceed with standard precautions
  • Potentially unstable (7-12): Requires modified approach with load restrictions
  • Unstable (≥13): Contraindication to weight-bearing exercises; requires surgical consultation first 3

• For long bone lesions: Use Mirels' score (range 4-12) 3, 4

  • Low risk (≤7): Exercise permitted with monitoring
  • Moderate risk (8): Restricted loading, non-weight-bearing exercises
  • High risk (≥9): Contraindication to resistance training; surgical stabilization needed first 3

• Evaluate cortical bone invasion throughout the entire affected bone, as this is essential for determining load-bearing capacity 3, 5

Contraindications to Physical Therapy

Absolute contraindications 5, 1:

• SINS ≥13 or Mirels' score ≥9 without surgical stabilization 3
• Acute spinal cord compression or cauda equina syndrome 3
• Severe hypercalcemia (>14 mg/dL) requiring urgent treatment 5
• Platelet count <50,000/μL (risk of bleeding with manual therapy) 5
• Uncontrolled severe pain (VAS >7/10) at rest 5, 1

Relative contraindications requiring modification 5, 1:

• Recent pathological fracture (<6 weeks post-surgical fixation) 3
• Active radiation therapy to weight-bearing bones (modify intensity) 2
• Severe bone marrow suppression in multiple myeloma patients 5

Evidence-Based Physical Therapy Interventions

Isometric Resistance Training (Preferred Initial Approach)

Isometric exercises for paravertebral muscles are safe and effective even during concurrent radiotherapy, with 83.3% feasibility and significant improvements in pain scores (p<0.001) and functional measures without fracture complications 2:

• Start with low-intensity isometric holds (5-10 seconds, 3-5 repetitions)
• Progress based on pain response and tolerance
• Focus on core stabilization and postural muscles 2
• No measurable adverse events or pathological fractures occurred in the intervention group 2

Progressive Exercise Programs

Exercise interventions demonstrate positive physical and self-reported outcomes with low fracture risk 1:

• Studies show no high fracture incidence with exercise compared to control groups 1
• No association found between exercise participation and fracture risk when appropriately prescribed 1
• Individualized prescription based on bone load-bearing capacity is essential 5, 1

Recommended Exercise Components

Aerobic exercise 3, 1:

• Low-impact activities: walking, stationary cycling, swimming
• Avoid high-impact activities (running, jumping) in all patients with bone metastases 5, 1
• Duration: Progress toward 150 minutes/week moderate intensity as tolerated 3

Resistance training 1, 2:

• Begin with isometric exercises before progressing to isotonic 2
• Avoid direct loading of affected skeletal structures 5
• Focus on maintaining muscle strength in unaffected areas 1
• Frequency: 2-3 sessions per week with adequate rest 3

Mobility and functional training 5, 6:

• Gait training with assistive devices as needed
• Transfer training to maintain independence
• Balance exercises to prevent falls (critical given fracture risk) 5, 6

Physical Modalities and Pain Management

Permitted modalities 5:

• Transcutaneous electrical nerve stimulation (TENS) for pain control 5
• Cold therapy for acute pain flares 5
• Gentle manual therapy away from tumor sites 5

Contraindicated modalities at tumor sites 5:

• Ultrasound therapy (increases local blood flow) 5
• Thermotherapy/heat application 5
• Deep tissue massage 5
• Various electrotherapy options that increase circulation 5

Multidisciplinary Integration

Physical therapy must be coordinated within a bone metastatic multidisciplinary tumor board 3, 4:

• Include medical oncology, radiation oncology, orthopedic surgery, interventional radiology, and rehabilitation specialists 3
• Reassess fracture risk before advancing exercise intensity 1
• Coordinate timing with radiation therapy and systemic treatments 5, 2

Outcomes and Safety Data

Rehabilitation of patients with bone metastases can be safely accomplished 6:

• Risk of producing pathological fractures by increasing mobility is low 6
• Satisfactory outcomes demonstrated in patients post-surgical repair of pathological fractures 6
• Improved pain control, physical function, and activities of daily living 5, 1, 2
• Enhanced quality of life even in palliative care settings 3

Critical Pitfalls to Avoid

• Never initiate weight-bearing exercises without fracture risk assessment using SINS or Mirels' scores 3, 4
• Do not apply heat or deep massage directly over metastatic lesions due to risk of tumor stimulation 5
• Avoid delaying surgical consultation for unstable lesions (SINS ≥13, Mirels' ≥9) 3
• Do not prescribe high-impact activities regardless of fracture risk scores 5, 1
• Monitor for new pain or neurological symptoms that may indicate disease progression requiring immediate re-evaluation 5, 1