What is the best approach to manage pain in a patient with an orthopedic prosthesis and multiple comorbidities, including post-traumatic osteoarthritis, major depressive disorder, type 2 diabetes mellitus, prior cerebral infarction, essential hypertension, hyperlipidemia, chronic pain, primary insomnia, protein-calorie malnutrition, hypothyroidism, gait abnormality, and generalized muscle weakness?

Pain Management in Orthopedic Prosthesis with Multiple Comorbidities

This patient requires a multidisciplinary stepped-care approach starting with patient education, physical therapy with graded exercise, psychological intervention for depression, sleep hygiene for insomnia, and pharmacological management prioritizing duloxetine (which addresses both chronic pain and depression), with careful attention to nutritional status and glucose control. 1

Immediate Assessment Priorities

Before initiating treatment, assess the following pain-related factors 1:

• Nature and extent of pain-related disability - specifically how prosthesis pain limits daily activities 1
• Beliefs and emotions about pain - particularly important given the major depressive disorder 1
• Sleep disturbance patterns - critical with documented primary insomnia 1
• Nutritional status - protein-calorie malnutrition will impair healing and muscle function 1
• Current glucose control - the reported discrepancy between home glucose (well-maintained) and hospital values (44 units insulin but glucose 25) suggests either measurement error, medication error, or acute stress response requiring immediate correction 1

Stepped-Care Treatment Algorithm

Step 1: Foundation (All Patients)

Education and Self-Management 1

• Provide educational materials about staying active despite prosthesis pain 1
• Psychoeducation addressing the relationship between depression, sleep, pain, and function 1
• Sleep hygiene guidelines (see below) 1

Physical Activity and Exercise 1

• Refer to physiotherapist immediately for individually tailored graded exercise program 1
• Physical activity showed the most uniformly positive effects on pain across all osteoarthritis studies 1
• Given generalized muscle weakness and gait abnormality, supervised strength training is essential 1
• Address fear of movement through cognitive-behavioral approaches if patient is reluctant 1

Orthotics and Assistive Devices 1

• Refer to occupational therapist for assessment of assistive devices (cane, rollator) to reduce prosthesis loading 1
• Consider custom insoles or bracing for the contralateral limb to address gait abnormality 1
• Ergonomic adaptations at home to reduce pain during daily activities 1

Step 2: Targeted Interventions

Psychological Intervention (High Priority) 1

• Refer to psychologist or CBT program immediately given major depressive disorder in partial remission 1
• Psychological interventions showed uniform positive effects on pain in osteoarthritis 1
• Depression interferes with effective pain management and must be addressed concurrently 1
• CBT can address both pain catastrophizing and depressive cognitions 1

Sleep Intervention 1

• Inquire about specific causes: prosthesis pain at night, persistent worrying related to depression, poor sleep habits 1
• Provide basic sleep hygiene education: consistent sleep schedule, avoid caffeine after noon, dark quiet room 1
• If insomnia persists after 2-4 weeks, refer to specialized sleep clinic 1
• Sleep interventions showed small but consistent effects on pain in chronic conditions 1

Nutritional Optimization 1

• Refer to dietitian urgently for protein-calorie malnutrition management 1
• Malnutrition impairs wound healing, muscle strength, and functional recovery 1
• Adequate protein intake (1.2-1.5 g/kg/day) essential for muscle strengthening exercises 1

Pharmacological Management 1

First-line: Duloxetine 60 mg daily 2

• This is the optimal choice as it addresses both chronic musculoskeletal pain AND major depressive disorder 2
• FDA-approved for chronic musculoskeletal pain with demonstrated efficacy 2
• Start at 30 mg daily for one week, then increase to 60 mg daily 2
• Patients experienced pain decrease as early as week 1 2
• Do not increase to 120 mg - no additional benefit demonstrated and higher adverse effects 2
• Monitor for serotonin syndrome given potential drug interactions 2

Adjunctive analgesics (as needed):

• Paracetamol (acetaminophen) 1000 mg three times daily for baseline analgesia 1
• NSAIDs or COX-2 inhibitors if not contraindicated by cardiovascular history (prior stroke) - use with extreme caution or avoid 1
• Avoid chronic opioid use - only for rescue analgesia if severe breakthrough pain 1, 3

Critical Medication Considerations:

• Review all current medications for safe dosing and potential over-medication 1
• Given prior cerebral infarction, NSAIDs carry increased cardiovascular risk 1
• Hypothyroidism must be optimally treated as it can worsen depression and pain 1
• Urgent endocrinology consultation for glucose management discrepancy 1

Step 3: Multidisciplinary Treatment (If Steps 1-2 Insufficient)

Initiate formal multidisciplinary pain program if: 1

• Multiple treatment modalities needed simultaneously 1
• Psychological distress combined with sedentary lifestyle persists 1
• Monotherapy approaches have failed after 8-12 weeks 1

Team should include: 1

• Pain medicine physician
• Physiotherapist
• Psychologist
• Occupational therapist
• Dietitian
• Primary care physician for comorbidity management

Critical Pitfalls to Avoid

Glucose Management Crisis 1

• The reported insulin dose (44 units) with glucose of 25 mg/dL represents severe hypoglycemia requiring immediate correction 1
• Do not attribute pain or weakness to prosthesis alone - hypoglycemia causes weakness and altered mental status 1
• Coordinate with endocrinology before discharge to prevent recurrent hypoglycemia 1

Opioid Trap 3

• Establish opioid weaning plan if currently prescribed 3
• Only 8% of patients in specialized orthopedic pain clinics appropriately continue opioids 3
• Opioids worsen depression and do not improve long-term function 3

Neglecting Depression 1

• Pain management will fail if depression remains untreated 1
• Depression and chronic pain create a vicious cycle requiring simultaneous treatment 1

Immobility 1

• Despite pain, immobility worsens outcomes 1
• Graded exercise is essential even if initially painful 1
• Fear of movement must be addressed through CBT if present 1

Timeline and Follow-up

• Week 1-2: Education, duloxetine initiation (30 mg), PT/OT referrals, glucose stabilization 1, 2
• Week 2-4: Increase duloxetine to 60 mg, begin graded exercise, psychology referral 1, 2
• Week 4-8: Assess response; if <30% pain reduction, proceed to Step 3 multidisciplinary care 1, 2
• Week 8-12: Reassess all interventions; adjust based on documented pain levels and functional improvement 1

Document pain as the fifth vital sign at every encounter to guide treatment adjustments 4