What are the next steps for an elderly patient with hip pain post (after) TENEX procedure who was last trialed on methocarbamol (Robaxin) 500 mg twice a day (BID)?

Management of Hip Pain Post-TENEX Procedure in Elderly Patient

For an elderly patient with persistent hip pain after TENEX procedure who has trialed methocarbamol 500 mg BID, escalate to the full therapeutic dose of methocarbamol (6-8 grams daily for 48-72 hours, then 4 grams daily maintenance) and implement a multimodal analgesic regimen with scheduled acetaminophen plus NSAIDs (if not contraindicated), reserving opioids only for breakthrough pain. 1, 2

Optimize Current Muscle Relaxant Therapy

• Increase methocarbamol to therapeutic dosing: The current 500 mg BID (1 gram daily) is substantially below the FDA-recommended initial dosage of 6 grams daily for the first 48-72 hours, with up to 8 grams daily for severe conditions 1
• After the initial 48-72 hour period, reduce to maintenance dosing of approximately 4 grams daily (e.g., 750 mg QID or 1000 mg TID-QID) 1
• This represents a critical dosing error that should be corrected immediately, as the patient has been receiving only 17% of the recommended therapeutic dose 1

Implement Multimodal Analgesia Protocol

First-Line: Non-Opioid Foundation

• Acetaminophen 1000 mg IV or PO every 6 hours as baseline treatment for all pain intensities, as it decreases supplementary analgesic requirements and is strongly recommended in elderly trauma patients 2
• Add NSAIDs or COX-2 selective inhibitors for moderate-to-severe pain if renal function is adequate and no contraindications exist 2
• NSAIDs should be used with extreme caution in elderly patients and are contraindicated in those with renal dysfunction 2
• Consider the patient's creatinine clearance, history of GI bleeding, cardiovascular disease, and concurrent anticoagulation before initiating NSAIDs 2, 3

Second-Line: Weak Opioids for Inadequate Response

• Tramadol can be added to the acetaminophen/NSAID regimen if pain control remains inadequate, though it should be used cautiously in patients with renal dysfunction (dose and frequency should be reduced) 2
• Avoid codeine as it is constipating, emetic, and associated with perioperative cognitive dysfunction in elderly patients 2

Third-Line: Strong Opioids for Breakthrough Pain Only

• Reserve morphine or oxycodone for severe breakthrough pain unresponsive to the above measures, using the lowest effective dose for the shortest duration 2
• In elderly patients with renal dysfunction, avoid oral opioids and reduce both dose and frequency of IV opioids (e.g., halve the standard dose) 2

Consider Regional Anesthesia Techniques

Peripheral Nerve Blocks

• Femoral nerve block or posterior lumbar plexus block should be strongly considered for refractory hip pain, as these provide superior analgesia with fewer side effects compared to systemic opioids in elderly patients 2
• Continuous infusion via catheter is superior to single-shot approaches for extended analgesia 2
• Posterior lumbar plexus blocks have greater efficacy than femoral nerve blocks for hip procedures but carry higher complication risk, requiring careful risk-benefit assessment 2
• Carefully evaluate anticoagulation status before performing any neuraxial or plexus blocks to avoid bleeding complications 2

Chemical Denervation

• For truly refractory cases in elderly patients with multiple comorbidities, chemical hip denervation targeting articular branches of femoral and obturator nerves has demonstrated significant pain reduction and improved functional outcomes 4
• This technique showed 50% of patients able to sit within 5 days post-procedure with no adverse events in a case series 4

Adjunctive Non-Pharmacological Measures

• TENS (Transcutaneous Electrical Nerve Stimulation) for 30 minutes daily has demonstrated significant pain reduction during ambulation and improved functional recovery in elderly hip patients 5
• Immobilization, ice packs, and proper positioning should be implemented alongside pharmacological therapy 2

Critical Monitoring Considerations

• Assess renal function before and during NSAID/opioid therapy, as elderly patients are particularly susceptible to volume-dependent renal failure 2
• Monitor for cognitive dysfunction, as opioids and certain adjuncts increase delirium risk in elderly patients 2
• Ensure adequate thromboprophylaxis with LMWH or UFH, as immobility from pain increases DVT risk 2
• Implement pressure care protocols and active warming strategies, as elderly patients are highly susceptible to pressure sores and hypothermia 2

Common Pitfalls to Avoid

• Do not continue subtherapeutic dosing of methocarbamol—this is the most immediate correctable issue 1
• Do not use NSAIDs in patients with renal dysfunction or combine with anticoagulants (3-6 fold increased bleeding risk) 2, 3
• Do not rely on codeine for pain control in elderly patients due to adverse cognitive and GI effects 2
• Do not administer opioids as first-line therapy—always establish non-opioid foundation first 2
• Do not perform neuraxial blocks in anticoagulated patients without appropriate timing and risk assessment 2