IPACK Block Efficacy for Acute Pain Management after Total Knee Replacement: A Review.

PURPOSE OF REVIEW: Patients often experience a significant degree of knee pain following total knee replacement (TKR). To alleviate this pain, nerve blocks may be performed such as the adductor canal block (ACB). However, ACBs are unable to relieve pain originating from the posterior region of the knee. A new type of nerve block known as the IPACK block may be used in conjunction with ACBs as it is designed to inhibit nerve branches innervating this area. In this article, we examine the rationale behind the IPACK procedure, how it is performed, and clinical trials examining its efficacy. RECENT FINDINGS: 5 of the 7 clinical trials examined in this article showed the IPACK + ACB block to show superior efficacy in treating pain following TKR compared to other blocks. These blocks included PMDI+ACB, SPANK+ACB, PAI+ACB, ACB alone, and SCAB. 2 of the 7 clinical trials showed the IPACK + ACB to be less effective in managing patients pain following TKR compared to other blocks which included the CACB and 4 in 1 block. In most instances, the IPACK + ACB showed superior efficacy in managing patients' pain following TKR when compared to other types of nerve blocks. This was determined by measuring usage of opioids, reported postoperative pain, and length of hospital stays following TKR. Thus, we suppose the IPACK block may be used in conjunction with the ACB to effectively reduce patient's pain following TKR.

Effect of adductor canal block combined with infiltration between the popliteal artery and posterior capsular of the knee on chronic pain after total knee arthroplasty: a prospective, randomized, double-blind, placebo-controlled trial.

INTRODUCTION: Total knee arthroplasty (TKA) is accompanied by severe postoperative pain, which is reported to be an important cause of chronic pain. Ultrasound-guided adductor canal block (ACB) combined with infiltration between the popliteal artery and posterior capsular of the knee (IPACK) has been proven to have a better effect on relieving acute pain after TKA. However, whether it has a significant effect on the incidence of chronic pain after TKA has not been reported. This trial was designed to investigate the effect of ultrasound-guided ACB combined with IPACK on the incidence and intensity of chronic pain after TKA. METHODS: In this prospective, randomized, double-blind, placebo-controlled study, 100 subjects scheduled for TKA were randomly (1:1) divided into two groups: the ropivacaine group and the placebo group. Patients in each group received ultrasound-guided ACB + IPACK procedures with 0.25% ropivacaine or equal volume normal saline. All patients received multimodal analgesia. Pain intensity was assessed using the Numerical Rating Scale (NRS). The primary outcome was the incidence of chronic pain at 3 months after TKA by telephone follow-up. In addition, pain intensity in early resting and mobilized states, chronic pain intensity, the time to first rescue analgesia; opioid consumption; CRP and IL-6 after the operation; length of postoperative hospital stay; and cost of hospitalization and postoperative complications; as well as the function of the knee in the early stage after the operation, were recorded. RESULTS: Ninety-one participants were included in the final analysis. At 3 months, the incidence of chronic pain was 30.4% in the ropivacaine group, significantly lower than 51.1% in the placebo group. Compared with the placebo group, the ACB + IPACK with ropivacaine group had significantly lower pain scores at 4 hours, 8 hours, 16 hours, and 24 hours after the operation; increased the knee range of motion at 8 hours and 24 hours after the operation; and a significantly decreased incidence of chronic pain at 3 months after the operation. During the follow-up period, there were no nerve block-related complications in either group. CONCLUSION: In the context of multimodal analgesia protocols, ACB combined with IPACK before surgery decreases the incidence and intensity of chronic pain 3 months after TKA compared with placebo injection. In addition, it reduces the NRS scores, whether at rest or during mobilization, and improves knee function within 24 hours after TKA. TRIAL REGISTRATION: This trial was registered in the China Clinical Trial Center (registration number ChiCTR2200065300) on November 1, 2022.

Investigation of Optimal Needle Position for Radiofrequency Ablation-Based Blockade of Interspace between the Popliteal Artery and the Posterior Capsule of the Knee: A Cadaveric Study.

Background and Objectives: The interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block has been widely used in perioperative settings to control posterior knee pain and can additionally be used for chronic knee pain. In this cadaveric study, we aimed to investigate the needle tip position and its proximity to the articular branch of the tibial nerve (ABTN) during an iPACK-targeted radiofrequency procedure. Materials and Methods: An ultrasound-guided iPACK block was performed on 20 knees of 10 cadavers. We injected 0.1 mL each of blue and green gelatinous dye near the tibial artery (point A) and posterior knee capsule (point B), respectively, and evaluated the spread of both around the ABTN. For a hypothetical conventional radiofrequency ablation (RFA) lesion (diameter, 2.95 mm) and cooled RFA lesion (diameter, 4.9 mm), we counted the number of specimens in which the ABTNs would be captured. Results: The percentage of specimens in which the ABTN would be captured by a cooled RFA lesion was 64.71% at point A and 43.75% at point B (p = 0.334). Meanwhile, the percentage of specimens in which the ABTN would be captured by a conventional RFA lesion was 58.82% from point A and 25% from point B (p = 0.065). Conclusions: When performing an RFA-based iPACK block, the needle tip may be positioned either lateral to the tibial artery or in the space between the posterior knee capsule and the tibial artery. However, more studies with larger samples are needed to verify these results before the clinical use of this procedure can be recommended.

Addition of Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee (IPACK) to Local Infiltration Analgesia for Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: Local infiltration analgesia (LIA) is a popular analgesic technique commonly administered during total knee arthroplasty (TKA). Recent studies have demonstrated that the infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) can be complementary to analgesic modalities. However, the combined and relative efficacy of LIA and IPACK is unclear. We aimed to evaluate the analgesic and functional outcomes among LIA, IPACK, and LIA + IPACK. METHODS: A total of 120 patients undergoing primary TKA were randomly allocated to 1 of 3 groups: LIA (50 mL of 0.25% ropivacaine and 2.0 µg/mL epinephrine); IPACK (20 mL of 0.25% ropivacaine and 2.0 µg/mL epinephrine); and LIA + IPACK. The primary outcome was the visual analog scale (VAS) pain score. Secondary outcomes were opioid use, knee range of motion (ROM), quadriceps muscle strength, mobilization distance, timed up and go (TUG) test, and postoperative complications. RESULTS: The mean VAS pain scores were significantly higher after using IPACK alone than after using LIA + IPACK and LIA within 24 hours (all P＜.05). LIA + IPACK had lower mean VAS pain scores than LIA when the knees were at rest (within 12 hours, P < .05) and flexion (within 8 hours, P＜.05). Patients receiving LIA + IPACK and LIA had significantly lower morphine equivalents (ME) than those receiving IPACK alone within 24 hours (26.3, 28.9 versus 47.8, both P＜.05) and during hospitalization (98, 101.6, versus 128.4 both P＜.05). Both LIA + IPACK and LIA had higher ROM (within 2 days), higher level of muscle strength (within 12 hours), longer mobilization distances (within 1 day), and shorter TUG time (till discharge) compared with IPACK alone (all P＜.05), while LIA + IPACK only had a higher knee ROM than LIA on the first postoperative day (P＜.05). There was no significant difference in any other outcomes. CONCLUSION: This randomized controlled trial demonstrated that there were significantly lower pain scores, less opioid consumption, and better functional results with LIA + IPACK and LIA when compared with IPACK alone, suggesting that IPACK alone was inferior for pain control.

Clinical effects of interspace between the popliteal artery and capsule of the posterior knee block with multimodal analgesia for total knee arthroplasty: a systematic review and meta-analysis.

PURPOSE: Combination of regional anaesthesia technique that is most effective in analgesia and postoperative functional outcome with the fewest complications needs investigation. Interspace between the popliteal artery and the capsule of the posterior knee block (IPACK) has been introduced clinically. We evaluated the efficacy of IPACK in combination with other nerve blocks after total knee arthroplasty. METHODS: Data were obtained from PubMed, Cochrane Library, Web of Science, and Sciencedirect. Studies that compared outcomes using IPACK combined with other regional nerve blocks after total knee arthroplasty with other analgesic modalities and those which used pain scores or opioid consumption as primary or secondary outcomes were included. RESULTS: Seventeen articles (20 trials, 1652 patients) were included. IPACK supplementation significantly reduced rest pain scores after total knee arthroplasty at postoperative hours 8-12(95%CI - 0.85 [- 1.36, - 0.34], I2 = 94%, p = 0.001), postoperative day 1 (95% CI - 0.49 [- 0.85, - 0.14], I2 = 87%, p = 0.006), and postoperative day 2 (95% CI - 0.28 [- 0.51, -0.05], I2 = 72%, p = 0.02); there was no significant difference at postoperative day 3 or discharge (95% CI - 0.14 [- 0.33, 0.05], I2 = 0%, p = 0.14). Combination treatment resulted in reduced dynamic pain scores at postoperative hours 8-12 (95%CI - 0.52 [- 0.92, - 0.12], I2 = 86%, p = 0.01) and postoperative day 1(95% CI - 0.49 [- 0.87, - 0.11], I2 = 88%, p = 0.01). There was no difference between postoperative day 2(95% CI - 0.29 [- 0.63, 0.05], I2 = 80%, p = 0.09), postoperative day 3 or discharge (95% CI - 0.45 [- 0.92, 0.02], I2 = 83%, p = 0.06). In addition, it strongly reduced postoperative opioid consumption within 24 H (95% CI - 0.76 [- 1.13, - 0.39], I2 = 85%, p < 0.00001), 24-48 H (95% CI - 0.43 [- 0.85, - 0.01], I2 = 83%, p = 0.04), and total opioid use (95% CI - 0.64 [- 1.07, - 0.22], I2 = 86%, p = 0.003). Although IPACK supplementation improved timed up and go test and walking distance at postoperative day 2, there was no statistically significant difference at other time periods or obvious improvement in knee range of motion and quadriceps strength. IPACK block supplementation could shorten the length of stay (LOS) (95% CI - 0.40 [- 0.64, - 0.15], I2 = 70%, p = 0.001) and improve patient satisfaction (95% CI 0.43 [0.01, 0.84], I2 = 87%, p = 0.04). CONCLUSION: Based on these results, IPACK supplementation, in addition to standard postoperative analgesia, can be used effectively and safely to relieve early postoperative pain after total knee arthroplasty.

Adductor Canal Block Combined With IPACK Block for Postoperative Analgesia and Function Recovery Following Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study.

BACKGROUND: This study aimed to explore the analgesic effect among adductor canal block (ACB) combined with infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) block, ACB, and IPACK block following total knee arthroplasty (TKA). METHODS: One hundred twenty patients were randomly allocated into 3 groups including group A (ACB + IPACK block), group B (ACB), and group C (IPACK block). The primary outcome was postoperative pain score. The secondary outcome was opioid consumption. Other outcomes included functional evaluation and postoperative complications. RESULTS: Group A showed the lowest pain scores within 8 hours at rest and with knee maximum flexion (P < .001). From 12 to 24 hours, group C showed the highest pain scores, while no significant difference was found between group A and group B. No significant difference was found among the 3 groups 24 hours postoperatively. Group C showed the most opioid consumption within the first 24 hours and during the hospitalization, while no significant difference was found between group A and group B. No significant difference was found among the 3 groups including function evaluation and postoperative complications. CONCLUSION: ACB + IPACK block can improve early analgesia when compared with ACB. However, the small statistical benefit to the addition of IPACK block to ACB may be unlikely to be clinically significant. Further studies may focus on patient selection and how to prolong the effect of IPACK block.

Comparison of iPACK and periarticular block with adductor block alone after total knee arthroplasty: a randomized clinical trial.

PURPOSE: The infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) has been described to provide analgesia without loss of muscle strength and is effective in functional recovery. This study compared iPACK + ACB (adductor canal block) with PAI (periarticular infiltration) + ACB and ACB alone in terms of postoperative analgesia and functional improvement. METHODS: This double-blinded randomized controlled trial included 105 patients undergoing unilateral total knee arthroplasty. Patients received ACB, iPACK + ACB, and PAI + ACB along with spinal anesthesia. The primary outcome was the area under the curve (AUC) numeric rating scale (NRS) at 48 h. Secondary outcomes were cumulative postoperative analgesic consumption within 48 h, timed up-and-go test, range of motion, length of hospital stay, patient satisfaction, and adverse events. RESULTS: The 48-h AUC movement NRS score in the iPACK + ACB group was significantly lower than in the PAI + ACB and ACB groups (p < 0.05). At the postoperative 48th h, the opioid consumption of the iPACK + ACB group was lower than those of the ACB and PAI + ACB groups (p < 0.001). The patients in the iPACK + ACB group had significantly shorter discharge and mobilization days than the ACB and PAI + ACB groups (p < 0.001). CONCLUSIONS: The adding of an iPACK block to the ACB improves postoperative analgesia and reduces opioid consumption. In addition, this approach improves functional performance and reduces hospital stay.

Adductor Canal Block Combined With iPACK (Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee) Block vs Periarticular Injection for Analgesia After Total Knee Arthroplasty: A Randomized Noninferiority Trial.

BACKGROUND: The combination of adductor canal block (ACB) and infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block may provide sufficient motor-sparing anterior and posterior knee analgesia after total knee arthroplasty. This study aimed to determine if ACB with iPACK block was noninferior to ACB with periarticular injection (PAI) when combined with postoperative multimodal analgesia regimen. METHODS: Seventy-six patients were randomized to receive either ACB + iPACK block and continuous ACB (CACB) (ACB + iPACK group) or PAI and CACB (ACB + PAI group). Noninferiority was concluded for the primary outcome if the adjusted mean between-group difference in pain on movement at 12 postoperative hours was within 1.3 points on a visual analog pain scale. Pain scores, morphine consumption, functional performance, and adverse events were the secondary outcome measures assessed for superiority. RESULTS: Adjusted mean differences, (ACB + iPACK) - (ACB + PAI), in anterior and posterior knee pain scores on movement at 12 postoperative hours were -0.66 (-1.86, 0.54) and -0.19 (-1.36, 0.99), respectively. The upper limit of 95% confident interval was lower than the prespecified noninferiority limit. The mean visual analog scale pain scores were low and no clinically significant differences between groups. However, morphine requirement at 48 postoperative hours was significantly higher (P < .05) and showed greater reduced quadriceps strength at 0 and 45 degrees on postoperative day 0 (P = .006 and .04, respectively) in the ACB + iPACK group. CONCLUSIONS: ACB with iPACK block provides a noninferior analgesia compared with PAI when combined with CACB. However, patients who received ACB + iPACK block may require higher amounts of opioids and have worse immediate functional performance. LEVEL OF EVIDENCE: Therapeutic level I.

The Effect of the IPACK Block on Pain After Primary TKA: A Double-Blinded, Prospective, Randomized Trial.

BACKGROUND: The purpose of this study was to determine if infiltration of local anesthetic between the interspace between the popliteal artery and capsule of the knee (IPACK) provides benefit in total knee arthroplasty. METHODS: Patients were randomized into continuous adductor canal block with IPACK block or continuous adductor canal block with sham subcutaneous saline injection. Only the anesthesiologist performing the block was aware of randomization status. After surgery, a blinded assessor recorded opioid consumption, pain scores, and gait distance. RESULTS: There were 35 patients in the IPACK group and 34 in the NO IPACK group. There was no difference demographically between the groups. In the postanesthesia care unit (PACU), the average (P = .0122) and worst (P = .0168) pain scores at rest were statistically lower in the IPACK group. There was no difference in the pain scores during physical therapy (P = .2080). There was no difference in opioid consumption in the PACU (P = .7928), or at 24 hours (P = .7456). There was no difference in pain scores on POD 1 in the AM (P = .4597) or PM (P = .6273), or in the walking distance (P = .5197). There was also no difference in length of stay in the PACU (P = .9426) or hospital (P = .2141). CONCLUSION: The IPACK group had lower pain scores at rest in the PACU, but this is likely not clinically significant. The routine use of the IPACK is not supported by the results of this study. There may be indications for the use of the IPACK block as a rescue block or in patients who have contraindications to our standard multimodal treatment regimen or in patients with chronic pain or opioid dependence.

Efficacy of Adductor Canal Block Combined With Additional Analgesic Methods for Postoperative Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study.

BACKGROUND: The aim of this study is to evaluate the efficacy of adductor canal block (ACB) combined with additional analgesic methods in total knee arthroplasty (TKA) and investigate whether blocking the sensory nerves that are distributed in the posterior and lateral aspect of knee could improve postoperative pain control. METHODS: Two hundred scheduled patients for TKA were randomly allocated into 4 groups: Group A received ACB combined with iPACK (interspace between the popliteal artery and capsule of the knee) block and lateral femoral cutaneous nerve block (LFCNB); Group B received ACB combined with iPACK block; Group C received ACB combined with LFCNB; and Group D received ACB only. Postoperative pain score was the main primary outcome. Secondary outcomes included the morphine consumption and analgesic duration. Other outcomes included knee range of motion, quadriceps strength, ambulation, Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index physical function, timed up and go (TUG) test, and complications. RESULTS: Groups A, B, and C had lower postoperative pain scores within 12 hours at rest and 8 hours with activity than Group D (P < .05). In addition, Group A had lower morphine consumption than both Group C (P < .05) and Group D (P < .01). Group A had the longest analgesic duration (19.21 ± 3.22 hours) among all groups. There were no significant differences among the groups in terms of mobility and complication after surgery. CONCLUSION: Combining ACB with both iPACK and LFCNB is an effective method for decreasing early postoperative pain in TKA without increasing the complications or affecting the early rehabilitation.

Interspace between Popliteal Artery and posterior Capsule of the Knee (IPACK) Injectate Spread: A Cadaver Study.

OBJECTIVES: Local anesthetic injection into the interspace between the popliteal artery and the posterior capsule of the knee (IPACK) has the potential to provide motor-sparing analgesia to the posterior knee after total knee arthroplasty. The primary objective of this cadaveric study was to evaluate injectate spread to relevant anatomic structures with IPACK injection. METHODS: After receipt of Institutional Review Board Biospecimen Subcommittee approval, IPACK injection was performed on fresh-frozen cadavers. The popliteal fossa in each specimen was dissected and examined for injectate spread. RESULTS: Ten fresh-frozen cadaver knees were included in the study. Injectate was observed to spread in the popliteal fossa at a mean ± SD of 6.1 ± 0.7 cm in the medial-lateral dimension and 10.1 ± 3.2 cm in the proximal-distal dimension. No injectate was noted to be in contact with the proximal segment of the sciatic nerve, but 3 specimens showed injectate spread to the tibial nerve. In 3 specimens, the injectate showed possible contact with the common peroneal nerve. The middle genicular artery was consistently surrounded by injectate. CONCLUSIONS: This cadaver study of IPACK injection demonstrated spread throughout the popliteal fossa without proximal sciatic involvement. However, the potential for injectate to spread to the tibial or common peroneal nerve was demonstrated. Consistent surrounding of the middle genicular artery with injectate suggests a potential mechanism of analgesia for the IPACK block, due to the predictable relationship between articular sensory nerves and this artery. Further study is needed to determine the ideal site of IPACK injection.

[Lower limb postoperative analgesia evolution : Time for sensitive blocks]. / Evolution de l'analgésie après chirurgie du membre inférieur. La place des blocs sensitifs.

For about twenty years, peripheral nervous blocks have become the gold standard in postoperative analgesia for knee and foot surgery. The development of echography adapted to anesthesia gave anesthesiologists the opportunity to perform distal, mostly sensitive nerve blocks. Proximal nervous blocks associated analgesia used to be better than general (intravenous or oral) analgesia. Most of all it was associated with fewer side effects (nauseas, vomiting, drowsiness…). They reached an analgesia level comparable to central nerve blocks (epidural) with also fewer side effects (hypotension, bradycardia, lateralization...). A main problem with those blocks was that they involved motor blockade, impeding fast revalidation and walking restart. Distal nerve blocks, without motor blockade, offer as efficient analgesia as produced by proximal nerve blocks, without impeding motricity. Using those new techniques, it is now possible, with optimal analgesia, to allow almost immediate walking after a total knee replacement, and to perform most surgical foot operations in a one-day procedure.

Depuis une vingtaine d'années, les blocs nerveux périphériques sont devenus les techniques de choix pour l'analgésie de la chirurgie osseuse du genou et du pied. L'avènement de l'échographie adaptée à l'anesthésie permet désormais la réalisation de blocs nerveux distaux essentiellement sensitifs. Les blocs périphériques proximaux offraient une antalgie supérieure par rapport à l'antalgie intraveineuse ou per os traditionnelle, avec moins d'effets secondaires généraux (nausées, vomissements, somnolence…). Ils procuraient une antalgie semblable aux blocs centraux (épidurale en particulier), avec beaucoup moins d'effets secondaires (hypotension, bradycardie, latéralisation). Le défaut principal de ces blocs est qu'ils s'accompagnaient de blocs moteurs, constituant un obstacle à la rééducation rapide et à la reprise de la marche. La réalisation de blocs distaux, dépourvus d'effet moteur permet d'obtenir une antalgie aussi efficace que les celle des blocs proximaux, mais sans entraver la motricité. Grâce au développement de ces techniques, il est désormais possible, avec une antalgie optimale, de permettre la reprise quasi immédiate de la marche après mise en place d'une prothèse de genou, et de pratiquer la majorité de la chirurgie du pied en hôpital de jour.

Comparison of adductor canal block and IPACK block (interspace between the popliteal artery and the capsule of the posterior knee) with adductor canal block alone after total knee arthroplasty: a prospective control trial on pain and knee function in immediate postoperative period.

BACKGROUND: Adductor canal block (ACB) is a peripheral nerve blockade technique that provides good pain control in patients undergoing total knee arthroplasty which however does not relieve posterior knee pain. The recent technique of an ultrasound-guided local anesthetic infiltration of the interspace between popliteal artery and the capsule of posterior knee (IPACK) has shown promising results in providing significant posterior knee analgesia without affecting the motor nerves. MATERIALS AND METHODS: A prospective study was conducted from September 2016 to March 2017 in a total of 120 patients undergoing unilateral total knee arthroplasty. The initial 60 consecutive patients received ACB + IPACK (Group 1, n = 60), and the subsequent 60 patients received ACB alone (Group 2, n = 60). All patients were evaluated with VAS score for pain recorded at 8 h, postoperative day (POD) 1 and POD 2 after the surgery. The secondary outcome measures assessed were the range of movement (ROM) and ambulation distance. RESULTS: VAS score showed significantly (p < 0.005) better values in ACB + IPACK group compared to the ACB group. The mean ROM of knee and ambulation distance also showed significantly better values in ACB + IPACK group compared to the ACB group. CONCLUSION: ACB + IPACK is a promising technique that offers improved pain management in the immediate postoperative period without affecting the motor function around the knee joint resulting in better ROM and ambulation compared to ACB alone.

Anesthetic and Analgesic Management for Outpatient Knee Arthroplasty.

PURPOSE OF REVIEW: Total knee arthroplasty traditionally has been associated with significant postoperative pain that can limit recovery and prolong hospital length of stay. Recently, however, due to financial pressures and an emphasis on improving patient satisfaction, many institutions are implementing outpatient and short-stay programs for patients undergoing this procedure. An effective perioperative anesthetic plan is an essential quality of a successful outpatient joint replacement program. RECENT FINDINGS: Improved technology and innovation has led to more effective and efficient strategies that contribute to a smoother and quicker postoperative course. The use of peripheral nerve blocks in conjunction with a variety of systemic analgesics has reduced post-operative pain compared to older modalities. Specifically, the adductor canal and IPACK blocks have become increasingly popular due to their analgesic efficacy and muscle sparing characteristics. Outpatient knee arthroplasty is becoming a reality with advancements in surgical pathways that incorporate these newer modalities with an emphasis on multidisciplinary coordination.

Pulsed radiofrequency of iPACK (interspace between the popliteal artery and the posterior knee capsule) for pain control following meniscus repair - A case report.

Adequate postoperative pain control is an essential factor for the success of rehabilitation programs after meniscus repair (MR). The pulsed radiofrequency of the interspace between the popliteal artery and the posterior knee capsule (PRF-iPACK) is a recently developed method. This study aimed to evaluate the use of PRF-iPACK in patients who underwent MR. We performed PRF-iPACK guided by ultrasonography for patients who underwent MR with aggravated pain. PRF-iPACK was performed following MR four weeks after surgery. The pain was evaluated using the visual analogue scale (VAS), Lysholm score, and the Euroqol-5 Dimension (EQ-5D). In this study, two patients participated. For the results, a week and three months after treatment, the mean VAS score, Lysholm score, and EQ5D improved from 7 to 1 and 0 respectively, and 42 to 86 and 90 respectively, and 0.48 to 0.82 and 0.92 respectively. We concluded that PRF-iPACK is an adequate and safe procedure for managing postoperative pain after MR. It may enhance the postoperative rehabilitation program.

Comparison of the popliteal artery and the capsule of the posterior knee (IPACK) block and the genicular nerve block in primary total knee arthroplasty: A prospective randomized trial.

OBJECTIVES: To compare the efficacy of genicular block and interspace between the popliteal artery and the posterior capsule (IPACK) block in the reduction of postoperative pain, the need for rescue analgesics, and the effects on a range of motion (ROM) in patients with TKA. METHODS: This prospective randomized controlled study was carried out between February and May 2023. Based on the block method, 60 participants were divided into three equal groups. These groups included the IPACK block group (n=20), the genicular block group (n=20), and control group (n=20). Western Ontario and McMaster Universities Arthritis Index (WOMAC), Knee Society score (KSS) and Oxford Knee score (OKS) were used for clinical evaluation in the postoperative period. RESULTS: The KSS and OKS scores of the IPACK and GNB were significantly lower than the control group (p<0.001, p<0.001). The timed up and go (TUG) values of the IPACK and GNB groups at 12th and 24th hour were significantly lower than the control group (p<0.001, p<0.001). The Tramadol rescue values of the IPACK block and control groups were significantly higher than the GNB group (p=0.028, p=0.001, respectively). The ROM values of the IPACK and GNB groups were significantly higher than the control group (p<0.001, p<0.001). CONCLUSION: Both GNB and IPACK blocks had a significant positive impact on postoperative pain scores within the initial 24 hours following total knee arthroplasty (TKA). In comparison with IPACK, GNB had lower opioid consumption in the early postoperative period while also promoting better mobilization.

Combined Single-Shot Infiltration Between the Popliteal Artery and Capsule of the Knee and Adductor Canal Block With Bupivacaine, Dexmedetomidine, and Dexamethasone for Total Knee Arthroplasty: A Propensity-Matched Analysis.

Background: To investigate if combined single-shot adductor canal blockade (ACB) and infiltration between the popliteal artery and capsule of the knee (IPACK) provide better postoperative pain management compared to ACB alone for patients undergoing unilateral total knee arthroplasty (TKA). Methods: This retrospective cohort study included adult patients who underwent primary, unilateral TKA. Patients were separated into 2 cohorts: single-shot ACB alone (performed with bupivacaine 0.25%) and combined single-shot ACB + IPACK (performed with bupivacaine 0.25%, dexmedetomidine 1 mg/kg, and dexamethasone 4 mg). Patients were propensity-matched 1:1. The primary study outcome was total opioid consumption converted to morphine milligram equivalents (MME) per eight-hour interval and postoperative day. Secondary outcomes included pain scores, length of stay, ambulation distance, return to emergency department, hospital readmission, and 30-day adverse events. Results: One hundred eighty patients were identified, of which propensity matching used 71% to yield 64 patients receiving ACB alone and 64 receiving combined ACB + IPACK. Combined ACB + IPACK had significantly lower total summative MME throughout the entire postoperative stay (P = .002) and cumulatively after the first 24 hours (P < .001). Combined ACB + IPACK also had lower mean pain scores for 0-8 hours (P = .005) and 8-16 hours (P = .009) postoperatively. There were no significant differences in secondary outcomes. Conclusions: Combined single-shot ACB + IPACK block was associated with lower total narcotic intake and mean pain scores during most of the immediate postoperative period following primary, unilateral TKA compared to ACB alone. Implementing longer-acting, single-shot ACB + IPACK for TKA can balance effective and more selective pain management with early rehabilitation.

Comparative Efficacy of iPACK vs Popliteal Sciatic Nerve Block for Pain Management Following Total Knee Arthroplasty: A Retrospective Analysis.

Introduction Total knee arthroplasty (TKA) is associated with severe acute postoperative pain. The use of tourniquets and drains (T/D) is common in TKA but may have an influence on postoperative pain and muscular strength. The infiltration of local anesthetic between the popliteal artery and capsule of the knee (iPACK block) is a motor-sparing block that provides analgesia to the posterior aspect of the knee. However, evidence regarding its efficacy is scarce. This study aims to assess the effectiveness of iPACK block and the impact of T/D use on pain and muscular strength after TKA. Material and methods A retrospective study was carried out including patients who underwent TKA from January 2020 to April 2023. Patients were allocated into groups according to the peripheral nerve block performed and T/D use. Results We included 415 patients in this study. No differences were found in pain at rest or the need for rescue analgesia between patients who received an iPACK block or sciatic nerve block (SNB) with T/D applied. Patients who received a SNB reported lower pain scores on movement (p = 0.019), but with a higher prevalence of motor block (p < 0.001). Patients who underwent surgery without using T/D reported lower pain scores on movement (p = 0.021) and reduced need for rescue analgesia (p = 0.041). Conclusion These findings indicate that iPACK block can facilitate early mobilization after TKA without significant impact on postoperative muscle strength. Furthermore, the use of a T/D may be a source of postoperative pain that could compromise early rehabilitation.