**6.3. Nonpharmacological techniques**

Intrathecal morphine is less hydrophobic than other opioids, has a longer duration in the cerebrospinal fluid, and provides very good postoperative analgesia [75]. On the other hand, another study reported that morphine should not be used even in small doses due to these side effects [76]. Opioids are known to produce more effective and long-lasting anesthesia when used with local anesthetics. Opioids are known to produce more effective and long-lasting anesthesia when used with local anesthetics [77, 78]. In a study of TKA cases, we compared the use of intrathecal morphine and fentanyl for postoperative analgesia and found that fentanyl provided more effective postoperative analgesia [79]. Long-acting opioids (LAO) are often used for malignant, nonmalignant, and different pain treatments. A lot of work about LAO (oxycodone, morphine) has been done in this regard. In a study on LAO, there was a decrease in pain while there was an increase in vomiting and sedation [80]. After the use of LAO (oxycodone), the rehabilitation of patients was found to be better in TKA cases [81]. In the studies performed, intravenous PCA and oxycodone were compared and there was no difference in pain [82], and no difference in pain after LAO (oxycodone) used after total joint arthroplasty [83].

Gabapentin has been shown to be effective in the treatment of herpetic neuralgia, neuropathic pain [84], and diabetic neuropathy [85]. These anticonvulsant drugs, which have been used for a long time in the management of chronic pain, have started to be used in acute postoperative analgesia in recent years. They may cause side effects such as sedation and dizziness. It has been shown that administration of pregabalin (300 mg preoperatively and 150–50 mg twice daily for the first 14 days postoperatively) reduces the incidence of opioid consumption and neuropathic pain development after TKA [86]. We also have studies showing that postoperative analgesia is reduced after the application of preoperative gabapentin and pregabalin in lower extremity surgeons [87, 88]. Another study has shown that gabapentin effectively reduces postoperative narcotics consumption and pruritus incidence [89]. In another metaanalysis trial, the use of pregabalin shows that it could improve pain control at 24 and 48 h with rest, reduce morphine consumption, and improve knee flexion level, as well as reduce nausea, vomiting, and pruritic event rate. However, pregabalin increased the incident rate of dizziness after total knee arthroplasty (TKA) and total hip arthroplasty (THA) but could not

Ketamine is used by anesthetists for sedation and general anesthesia. With the detection of the N-methyl-d-aspartate receptor's role in nociceptive pain transmission and central sensitization, ketamine has begun to be used as a potential antihyperalgesic agent. Subanesthetic low doses of ketamine provide significant analgesic efficacy without psychomimetic side effects [45]. Low-dose ketamine has no adverse effects on respiratory and cardiovascular system and does not cause nausea-vomiting, urinary retention and constipation or postoperative ileus. In patients receiving TKA, low-dose ketamine infusion has been shown to reduce morphine consumption postoperatively (3 μg/kg per minute intraoperatively and 1.5 μg/kg

*6.2.5. Gabapentinoids (gabapentin and pregabalin)*

100 Primary Total Knee Arthroplasty

improve the pain control at 72 h with rest [90].

*6.2.6. Ketamine*

per minute for 48 h) [91].

There have been many studies on surgical techniques and equipment, but most have had no or limited effect on postoperative analgesia. These studies focused on drains, surgical approaches, tourniquet use, prosthetic types, and reshaping of the patellar surface. A comparison of cooling and compression techniques with the control group showed that postoperative pain and morphine consumption were reduced [92]. The efficacy of TENS administration in postoperative analgesia after TDP was not demonstrated [93]. The results of cryotherapy are contradictory. The potential benefits of cryotherapy in a meta-analysis are not clinically significant [94]. Routine use is therefore not recommended.
