Sleep after hip or knee replacement: what helps and when to call

Sleep disturbance after total joint replacement is common. Pain is an obvious reason, but it is not the only one. Anesthesia can temporarily alter the sleep-wake cycle. Swelling can build through the day. Opioids and other medications can cause drowsiness at one time and fragmented sleep at another. Less daytime activity, longer naps, worry, and having to sleep in a new position can also make a normal night feel out of reach.

The relationship works in both directions: pain interrupts sleep, and poor sleep can increase pain sensitivity. A 2024 review in Arthroplasty Today concluded that temporary postoperative sleep disruption is expected and that pre-existing sleep disorders, medical conditions, age, anesthesia, and pain management can all influence the pattern. Review the evidence on sleep and total joint arthroplasty.

Many patients notice a frustrating pattern around the second or third week: daytime function improves, activity increases, stronger pain medicine is used less often, and nighttime discomfort becomes more noticeable. The American Association of Hip and Knee Surgeons describes this as a familiar part of early recovery for both hip and knee patients.

What matters is the direction of travel. Interrupted sleep that gradually becomes less frequent usually fits normal recovery. Pain that is suddenly much worse, is accompanied by a new warning sign, or keeps intensifying instead of settling deserves a call to the surgical team.

A good night starts several hours before bed. Spread walking and therapy through the day instead of saving a hard session for late evening. If the joint becomes more swollen after activity, use the icing and elevation schedule provided by your care team. Keep daytime naps brief enough that you are still sleepy at bedtime, and return to a consistent wake time even after a rough night.

Take prescribed pain medicines exactly as directed and plan the timing with your surgical team so the intended effect covers bedtime. Do not wait until pain is severe and then take extra medication. The medication after surgery guide explains how a multimodal plan uses different tools without relying on one drug to do everything.

For many people, sleeping on the back is simplest at first. If you elevate the leg, support the calf and ankle so the knee can rest close to straight. Avoid spending hours with a large pillow only behind the bent knee unless your own surgeon or therapist has given different instructions, because prolonged flexion can work against regaining extension.

Side sleeping may become comfortable as swelling and tenderness improve. A pillow between the legs can reduce pressure and keep the operated leg from twisting. The safe timing depends on comfort, balance, wound protection, and any instructions specific to your operation, so use your postoperative plan rather than forcing a position because a calendar says you should be ready.

Hip precautions are not identical for every surgical approach or every patient. Some people may sleep on their back or on the non-operated side with pillows for support, while others receive temporary restrictions based on the approach, soft tissues, stability, or a more complex reconstruction.

Do not assume that advice from another patient applies to your hip. Follow the position and pillow instructions given for your procedure. When turning, keep the trunk and legs moving together instead of sharply twisting the operated hip. If a position creates a sense of instability, a sharp groin pain, or a new mechanical clunk, stop and contact the surgical team.

Do not add an over-the-counter sleep product, a leftover prescription sedative, cannabis, or alcohol without checking how it interacts with the medicines in your recovery plan. Diphenhydramine and other sedating products may cause confusion, urinary retention, or falls in some adults. Prescription sedatives can compound drowsiness and breathing risk.

The U.S. Food and Drug Administration warns that combining an opioid with benzodiazepines, alcohol, or other central nervous system depressants can cause extreme sleepiness and slowed or difficult breathing. Read the FDA opioid safety communication. Never double an opioid dose to make yourself sleep.

Melatonin sounds simple, but the joint replacement evidence is mixed. A 2024 randomized trial after knee replacement found no meaningful difference in the main sleep-disturbance score at two weeks, although there was a small, short-lived trend toward more sleep during the first few nights. A 2025 systematic review of seven randomized trials likewise found no consistent melatonin benefit across total joint replacement studies.

That does not mean melatonin is never appropriate. It means patients should not treat it as a proven substitute for pain control, a safe sleep environment, and attention to medication interactions. Ask the surgeon, primary care clinician, or pharmacist before adding it, especially if you take blood thinners, sedatives, or several medications.

If you use CPAP or another device for sleep apnea, tell the surgical and anesthesia teams before surgery and follow the plan for using it after surgery. Bring the device when instructed. Opioids can suppress breathing, and sleep-disordered breathing increases the concern for respiratory complications.

A caregiver should call 911 for slow, shallow, or difficult breathing, blue or gray lips, severe confusion, or inability to wake the patient. These are emergencies, not routine sleep problems. If naloxone was prescribed, the household should know where it is and how to use it while emergency help is on the way.

Contact the surgical team promptly for pain that is suddenly or progressively worse, a new wound opening or drainage, spreading redness, fever, a new painful or markedly swollen calf, new numbness or weakness, a fall, or a new feeling that the joint is unstable. Call 911 for chest pain, sudden shortness of breath, fainting, or signs of opioid overdose.

Persistent insomnia also deserves attention even without an emergency. Call if sleep remains severely limited despite following the plan, if side effects prevent you from taking prescribed medicine safely, or if anxiety, low mood, restless legs, urinary symptoms, or a pre-existing sleep disorder may be contributing. The answer may be a medication adjustment, an activity change, treatment of another medical problem, or a closer look at the joint.

Use the instructions provided for your operation as the final authority. A practical evening checklist is:

Patients in Honolulu, Oahu, Hilo, and across Hawaii should leave the preoperative visit knowing the expected sleeping position, the evening medication schedule, who to call after hours (Physicians Exchange, (808) 524-2575, reaches the on-call team when the office is closed), and how sleep apnea equipment fits into the plan. Neighbor-island patients should keep those instructions and emergency contacts easy to reach where they will recover.

Sleep is one part of a larger preparation and rehabilitation pathway. The joint replacement recovery guide covers home setup, walking, swelling control, nutrition, therapy, and warning signs.

• American Association of Hip and Knee Surgeons: sleep after hip replacement
• American Association of Hip and Knee Surgeons: sleep after knee replacement
• Pettit RJ, et al. Total Joint Arthroplasty and Sleep: The State of the Evidence. 2024.
• Nithagon P, et al. How Do We Improve Sleep Quality After Total Joint Arthroplasty? 2025.
• Haider MA, et al. Melatonin after primary total knee arthroplasty: randomized controlled trial. 2024.