Effect of Local Infiltration Analgesia, Peripheral Nerve Blocks, General and Spinal Anesthesia on Early Functional Recovery and Pain Control in Total Knee Arthroplasty
The LIA technique found to be a safe and effective treatment option for early functional recovery and pain control in TKA. The method showed significant advantages in terms of mobilization and muscle strength in the early postoperative period, whereas pain relief was almost similar in all study groups.
Nowadays, postoperative pain is still one of the most critical issues for clinicians. Treatment of postoperative pain after total knee arthroplasty (TKA) is even more challenging. To achieve better results, physicians should pay attention to the early mobilization, good functional outcome, optimal and enhanced recovery. Therefore, the primary goals are to reduce pain and immobilization and to minimize opioid dependency and their adverse events.
Improving these factors can significantly influence on patient morbidity, satisfaction, the degree of required postoperative care, and economic perspectives.
Currently, there is the number of techniques available such as peripheral nerve blocks, epidural analgesia as well as local infiltration analgesia (LIA) and (systemic) opioids. To reduce the postoperative pain after TKA, the method known as regional anaesthesia are broadly used. In common, femoral nerve blocks (FNB) are the most preferred method. This technique works by blocking the femoral nerve, the lateral femoral cutaneous nerve and branches of the obturator nerve; but, despite these techniques, the problem of pain is not entirely resolved.
In 2008, an alternative method was introduced by Kerr and Koha for postoperative pain control after TKA, which includes the direct blockage of nerve conduction by intraoperative administration of analgesic. The number of previous studies showed significant results with the use of LIA as compared to placebo or (peripheral) analgesic catheters. Due to its side effects and early mobilization, fewer data are available which favours the LIA over continuous epidural analgesia.
Therefore, the authors conducted this study to analyze the effect of different techniques of anaesthesia on early functional recovery and pain relief in TKA.
Rationale behind research
- In literature, no study analyzes the effect of various anaesthetic techniques such as LIA, catheter-based techniques individually as well as in combination with general or spinal anaesthesia on postoperative pain control.
- Therefore, the present study was conducted, it evaluated the femoral nerve block and general anaesthesia, epidural catheter and spinal anaesthesia, LIA combined with general anaesthesia and spinal anaesthesia respectively, on early functional recovery and pain control in primary TKA.
To study the effect of local infiltration analgesia (LIA), peripheral nerve blocks, general and spinal anaesthesia on functional recovery and pain control in primary total knee arthroplasty.
- Study outcomes:
- Pain score: Self-reported pain scores for numeric rating scores (NRS) at rest and with activity (0 = no pain; 10 = worst pain) from the day of surgery until postoperative day 4 were collected and analyzed.
- Mobilization: Grade of mobilization ranging from 1 to 6 as per our institutional grading system of mobilization was analyzed with the grades: 1 = bedridden, 2 = sitting, 3 = standing, 4 = walking in the room, 5 = walking on the floor, 6 = walking stairs.
- Muscle strength: Muscle strength was recorded according to the parameters of the British Medical Research Council (M0/5-M5/5) and passive range of motion (degrees of extension and flexion) were examined.
- Range of motion: Range of motion was documented daily from pre-operative day until postoperative day 7.
- Time period: Day of surgery(OP), Day 1, Day 2, Day 3, Day 4, Day 5, Day 6 and Day 7
- Pain: The NRS scores slightly increased at postoperative day 1 as compared to the rest (p = 0.182), after that, it did not show any significant differences at any time (p > 0.05).
- Mobilization: A gradual decrease in the grade of mobilization (0 to 6) after surgery was observed and all groups reached their base level of mobilization on day 6.
- Muscle strength: In all the groups from day 3 onwards, the muscle strength was increased after surgery. Compared to the LIA groups, GA&FNB revealed statistically significant reduction in muscle strength at day 1 (3.4 ± 0.9 and 3.3 ± 0.8 vs. 2.7 ± 0.8 each; p < 0.001 and p = 0.001, respectively) and day 2 (3.8 ± 0.8 and 3.7 ± 0.8 vs. 3.3 ± 0.9 each; p = 0.011 and p = 0.039, respectively); at day 3 only GA&LIA showed higher muscle strength as compared to GA&FNB (4.0 ± 0.6 vs 3.7 ± 0.7; p = 0.019). Additionally, the values of SP&EPI were reported to be significantly lower as compared to GA&LIA from day 1 to 3 (2.9 ± 0.9 vs.3.4 ± 0.9, p = 0.042; 3.3 ± 1.0 vs 3.8 ± 0.8, p = 0.026 and 3.6 ± 0.8 vs 4.0 ± 0.6, p = 0.024, respectively).
- Range of motion: The mean of the reported range of motion was comparable and not different among the groups (p > 0.05) except SP&LIA which demonstrated a higher flexion at day 1 (56.1° ± 13.9°) as compared to GA&FNB (48.5° ± 13.7°; p = 0.001). From postoperative day 1, flexion gradually increased while extension decreased. All groups reached 80° of flexion on day 6.
The LIA method aims to relieve the pain by blocking pain conduction at its origin. To get the maximum effect, the injection was injected according to a standardized protocol. The results of the study supported the LIA techniques by visualization of the majority of nerves supplying the knee. Peripheral nerve block mainly blocked by the posterior part of the knee, which is the most affected area of the knee. In the current study, posterior knee pain was managed by performing an FNB combined with a single shot SNB.
Previous studies reported a significant decrease in pain and opioid use in less than 48 hours with LIA. Similarly, a meta-analysis conducted by Keijsers et al. showed a 12.3% decrease in pain scores at rest and a 14.8% decrease in opioid consumption at 24 h after surgery. No significant differences were observed between FNB (comparable with GA&FNB) and epidural catheters (SP&EPI) for TKA regarding pain (at rest and with activity) in the early postoperative period. However, the side effects such as hypotension or urinary retention were higher with epidural catheters. Data comparing LIA with continuous epidural analgesia are limited and favour LIA over continuous epidural analgesia, mainly due to the side-effects and early mobilisation.
LIA have better results as compared to (peripheral) analgesic catheters. The outcomes of a recent systematic review and meta-analysis were in concordance with the results of GA&FNB and GA&LIA showing no significant differences in NRS scores. On the day of surgery, the catheter-based groups showed a significantly lower dose of hydromorphone compared to the LIA groups (p < 0.001). Moreover, the spinal anaesthesia group with an epidural catheter (SP&EPI) revealed an up to 58% lower dose of hydromorphone compared to all other groups from the day of surgery until day 3.
As compared to LIA groups, the patients of GA&FNB on the day of surgery weren't able to stand in front of the bed or even start to ambulate at postoperative day 1; an effect attributed to possible residual muscular weakness from the two peripheral nerve blocks. The prevailing concern attributed to the LIA technique is the potentially toxic side effects, which might be evoked by a joint and tissue infiltration of local anaesthetics like ropivacaine.
Concluding, the outcomes of this study suggest that the LIA technique has an advantage in terms of mobilization and muscle strength in early postoperative periods. The clinicians could use the LIA technique for postoperative pain management after assessing the risk-to-benefit ratio for each case individually.