Knee Capsule Research Articles

Postoperative analgesic effectiveness of ultrasound guided combined femoral - sciatic nerve block versus combined adductor canal block – I PACK block in patients undergoing total knee arthroplasty: A double- blind randomized study

ABSTRACT Background For successful rehabilitation and optimal functional outcomes after total knee arthroplasty surgery, patients must have effective pain control. Peripheral nerve blocks offer an excellent solution for perioperative multimodal analgesia and are advocated to reduce postoperative opioid consumption. Objectives The objective of this study is to compare the efficacy of combined Femoral-Sciatic nerve block and Adductor- interspace between the popliteal artery and the capsule of the posterior knee (IPACK) block in terms of total rescue analgesia dosage and ambulation on the first postoperative day. Method This is a prospective, randomized, double-blinded trial was conducted at Ain Shams University Hospital. Sixty patients scheduled for total knee arthroplasty (TKA) were randomly divided into two equal groups: one group received a Femoral-Sciatic nerve block, and the other received an Adductor-IPACK block. Both ultrasound-guided blocks were performed by injecting 20 mL of 0.25% bupivacaine immediately after anaesthesia induction. The postoperative opioid requirement in the first 24 hours was assessed using the visual analogue scale (VAS). Motor power, intraoperative fentanyl consumption, intraoperative hemodynamic changes, procedure time, surgery duration, tourniquet time, and technique complications were also recorded. Results Femoral-Sciatic group had lower opioid consumption. The Adductor-IPACK group showed a statistically significant higher Modified Bromage score. However, there was no statistically significant difference between the groups in the postoperative pain score assessed using the VAS. Conclusion Based on our study, we conclude that Femoral-Sciatic blocks required a lower dose of rescue analgesia compared to the Adductor-IPACK group. The Adductor-IPACK group also experienced lesser postoperative muscle power impairment.

A randomized clinical trial of addition of IPACK block or selective tibial nerve block to adductor canal block for postoperative pain management after total knee arthroplasty

Background & Objective: Postoperative pain after total knee arthroplasty (TKA) is a significant factor influencing the surgical outcome. Adductor canal block (ACB) has no analgesic effect on the posterior knee capsule, which is innervated by the terminal branches of the tibial nerve and the posterior branch of the obturator nerve. We compared ACB plus IPACK block (infiltration of the interspace between the popliteal artery and the posterior capsule of the knee) versus ACB with selective tibial nerve block (TNB) for pain management after TKA.
 Methodology: We enrolled 70 patients, aged 40-80 y, body mass index of 18.5-35 kg/m2, scheduled for TKA in the study. Patients were randomly allocated to one of the two equal groups; Group 1 to receive ACB with IPACK block and Group 2 to receive ACB with TNB. Duration of sensory block, motor block, time to first rescue analgesic request, time to ambulation, and hospital length were noted in both groups. The 0-10 numeric rating scale (NRS) was used to measure the pain intensity in the patients. 
 Results: Duration of sensory block, motor block, time to first rescue analgesic request, time to ambulation, and hospital length were significantly increased in Group 2 than in Group 1 (P < 0.001). The numeric rating scale was significantly lower in Group 2 at 8 h only but was comparable in other measurements. Range of motion and the strength of quadriceps were comparable between both groups at 24, 48, and 72 h postoperatively.
 Conclusions: Adductor canal block with IPACK preserved motor function better and reduced the time to ambulation and hospital stay compared to tibial nerve block with adductor canal block. However, adductor canal block with selective tibial nerve block prolongs sensory block, the time to first analgesia request, and reduces postoperative opioid consumption at first 24 h. Both methods had a comparable effect on quadriceps strength.
 Abbreviations: ACB - Adductor Canal Block; IPACK - Infiltration of local anesthetic between the Popliteal Artery and Capsule of the Knee; TNB - Tibial Nerve Block; TKA - Total Knee Arthroplasty
 Key words: Total Knee Arthroplasty; Adductor Canal Block; IPACK; Selective Tibial Nerve Block.
 Citation: Abogabal MA, Zahra SW, Abdel-ElsalamWM, Wafaa Madhy Abdelwahed WM. A randomized clinical trial of addition of IPACK block or selective tibial nerve block to adductor canal block for postoperative pain management after total knee arthroplasty. Anaesth. pain intensive care 2023;27(5): 567−574. DOI: 10.35975/apic.v27i5.2313
 Received: July 25, 2023; Reviewed: August 18, 2023; Accepted: August 26, 2023

Poster 329: Adductor Canal Block versus Adductor Canal Block Plus IPACK Block for Post-Operative Analgesia Following ACL Reconstruction with Bone-Patellar Tendon-Bone Autograft: A Single-Blind, Randomized Controlled Study

Objectives: In an effort to reduce reliance on opioid analgesics, an increased emphasis has been placed on peripheral nerve blocks for pain control following ACL reconstruction. The commonly used adductor canal block may provide inadequate post-operative analgesia, as it spares sensory function to the posterior aspect of the knee. This region can be specifically targeted using an IPACK (Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee) block potentially leading to improved pain control. The purpose of the current study was to compare clinical outcomes of an isolated standard adductor canal block versus combined ACB and IPACK blocks with respect to level of post-operative pain, opioid consumption, and satisfaction in patients undergoing ACL reconstruction using a bone-patellar tendon-bone (BPTB) autograft. Methods: We prospectively recruited patients undergoing ACL reconstruction with BPTB autograft at a single institution. Subjects were randomized pre-operatively to either control or experimental groups using a pre-established block randomization and were blinded to their treatment group. Patients in the control group received the standard-of-care ACB consisting of 15-ml of Bupivacaine (0.25%). Patients in the experimental group received 20-ml of Bupivacaine (0.25%) injected into the interspace between the popliteal artery and capsule of the knee in addition to the 15-ml Bupivicaine ACB. Post-operative pain level, pain control, and pain satisfaction were collected at 24hrs, 48hrs, 72hrs and one week postoperatively. Satisfaction with pain control was assessed using a 0-10 numeric scale with 0 equal to not satisfied and 10 equal to completely satisfied. Pain level was measured using a Visual Analog Scale (VAS) from no pain to extreme pain. The type and quantity of pain medications including 325-5 mg Percocet, Tylenol, and other pain medications were recorded at each time point. Variables were assessed using Shapiro-Wilks test for normality and T-test or non-parametric tests for continuous variables and Chi-squared tests for categorical variables. Results: A total of 20 patients were preliminarily analyzed with all patients having at least 1 week of post-operative follow-up. The mean age of the cohort was 28.75 ± 9.15 years, mean body mass index (BMI) was 24.0 ± 4.82 kg/m2 and 55% (n=11) were Male. The two arms consisted of 12 patients randomized to the control arm and 8 to the experimental arm. There were no statistically significant differences between the groups with respect to age, BMI, or sex (p > 0.05). Patients who received the IPACK block had significantly higher satisfaction with pain control at 24hrs post-operatively compared to those who did not (7.62 vs. 5.25, p=0.01). Patients who received the IPACK block used less total number of prescribed opioids tablets than those in the control arm (8.5 vs. 11.15, p=0.52), and had less pain at 24 hours (51.12 vs. 65.17, p=0.24) and 48 hours (51.00 vs. 57.92, p=0.55). (Table 1) Conclusions: Patients who received combined IPACK and ACB blocks exhibited better pain control and higher satisfaction with their care compared to those who received the standard-of-care ACB alone following ACL reconstruction using autograft tissue. [Table: see text]

Poster 120: Understanding the Biological Basis of Contracture Using a Mouse Model of Single Hindlimb Immobilization-Induced Fibrosis

Poster 120: Understanding the Biological Basis of Contracture Using a Mouse Model of Single Hindlimb Immobilization-Induced Fibrosis

Poster 128: The Effect of Meniscotibial Ligament Disruption and Repair on Posterior Medial Meniscal Root Forces

Objectives: Meniscal injuries occur in as many as 1% of active people, and while outcomes for tears at the posterior medial meniscal root (PMMR) are well cited, the risk factors for injury have room for greater understanding. Incidence of disruption to the meniscotibial ligament (MTL) is correlated to occurrence of PMMR tears, suggesting that disruption to the MTL may increase forces at the PMMR and put the PMMR at greater risk of injury. The effect of an MTL disruption and repair on three-dimensional forces at the PMMR is unknown. The purpose of this study was to determine if MTL insufficiency alters forces at the PMMR., if a tenodesis procedure can restore PMMR forces to that of an MTL intact state, and to determine how knee flexion angle impacts PMMR root forces in the MTL intact and cut states. We hypothesize that all shear forces will increase following MTL disruption. Methods: Ten fresh-frozen cadaveric knees (Average age: 53.2 years) were tested in three conditions (Intact, MTL Cut, MTL Tenodesis). Specimens were dissected down to the knee capsule with ligaments intact. A 3D load cell construct (Figure 1) was installed inside the tibia such that 3D forces of the PMMR could be measured when the joint was loaded. Each specimen was mounted to a materials testing machine (Instron) via a custom fixture that allowed the specimen flexion angle to be changed in 30 degree increments. The specimen was first loaded to 500 N of compression with 0 N-m of torque, then to 5 N-m of internal torque with 50 N of compression, and finally to 5 N-m of external torque with 50 N of compression. 3D forces at the PMMR were recorded for all loading sequences, and the process was repeated for each flexion angle (0°, 30°, 60°, and 90°). PMMR forces along each axis (compression- tension, anterior-posterior shear, and medial-lateral shear) were compared across MTL testing states across flexion angles using linear mixed modelling. Results: When the joint was loaded in compression, MTL Cut state significantly increased compression of the PMMR (p = 0.0368), and the Tenodesis state did not significantly restore tension-compression forces of the PMMR (Intact→Tenodesis: p = 0.008)(Figure 1). When the joint was loaded in external rotation, the MTL Cut State significantly increased compression (p < 0.0001), significantly decreased anterior shear (p = 0.0003), and, in high flexion angles, significantly decreased ML shear forces of the PMMR (Figure 1). The Tenodesis state did not significantly restore tension-compression (Intact→Tenodesis: p < 0.0001) or AP forces (Intact→Tenodesis: p = 0.0002) of the PMMR (Figure 1). Conclusions: The key finding of this study is that MTL disruption increases compression forces and decreases AP shear forces seen at the root when the joint is loaded in compression and external rotation. These findings indicate that the intact MTL protects the PMMR from compression and shear loads during movements where the joint is loaded in compression and external rotation, movements that are clinically reported to put the knee joint at risk of PMMR injury. The authors believe these relationships are observed because the MTL may play a role in maintaining meniscal hoop stresses, which converts joint compression loads into tension and shear forces along the meniscal attachment points. When the MTL is disrupted, the other meniscal attachment points, the PMMR included, see elevated compression loads as a result. This is the first study to measure 3D forces at the PMMR, a necessary capability to assess PMMR injury risk. It is notable that the tenodesis procedure performed in this study did not restore PMMR forces. Future studies should develop improved centralization or tenodesis procedures to better restore PMMR forces and decrease likelihood for PMMR injury after MTL disruption.

Analgesic Effectiveness of Motor-sparing Nerve Blocks for Total Knee Arthroplasty: A Network Meta-analysis.

The analgesic effectiveness of contemporary motor-sparing nerve blocks used in combination for analgesia in total knee arthroplasty is unclear. This network meta-analysis was conducted to evaluate the analgesic effectiveness of adding single-injection or continuous adductor canal block (ACB) with or without infiltration of the interspace between the popliteal artery and the capsule of the posterior knee (iPACK) to intraoperative local infiltration analgesia (LIA), compared to LIA alone, after total knee arthroplasty. Randomized trials examining the addition of single-injection or continuous ACB with or without single-injection block at the iPACK to LIA for total knee arthroplasty were considered. The two primary outcomes were area-under-the-curve pain scores over 24 to 48 h and postoperative function at greater than 24 h. Secondary outcomes included rest pain scores at 0, 6, 12, and 24 h; opioid consumption (from 0 to 24 h and from 25 to 48 h); and incidence of nausea/vomiting. Network meta-analysis was conducted using a frequentist approach. A total of 27 studies (2,317 patients) investigating the addition of (1) single-injection ACB, (2) continuous ACB, (3) single-injection ACB and single-injection block at the iPACK, and (4) continuous ACB and single-injection block at the iPACK to LIA, as compared to LIA alone, were included. For area-under-the-curve 24- to 48-h pain, the addition of continuous ACB with single-injection block at the iPACK displayed the highest P-score probability (89%) of being most effective for pain control. The addition of continuous ACB without single-injection block at the iPACK displayed the highest P-score probability (87%) of being most effective for postoperative function. The results suggest that continuous ACB, but not single-injection ACB and/or single-injection block at the iPACK, provides statistically superior analgesia when added to LIA for total knee arthroplasty compared to LIA alone. However, the magnitude of these additional analgesic benefits is clinically questionable.

Effects of millimeter-wave for preventing joint stiffness in the immobilized knee rat model

AimTo explore the effects and mechanism of millimeter-wave treatment on the development of joint stiffness in the immobilized knee rat model. MethodsTwenty-four Sprague–Dawley (SD) rats were randomly divided into the control group (O, n = 8), the surgical control group (OC, n = 8), and the millimeter-wave treatment group (MO, n = 8). After immobilized knee modeling, the knee mobility and quadriceps diameter was measured at the 6th week. Hematoxylin and eosin and Masson staining were performed to detect the pathology and fibrous lesions of the knee joint. Furthermore, the expression of TGF-β1 and Collagen I was quantified by immunohistochemical assay in the knee capsule, and Western blotting was performed to quantify the protein expression of NF-κB and MuRF1 in skeletal muscle. ResultsCompared with the O group, knee mobility, and quadriceps diameter was decreased (P < 0.01), and articular capsule fibrosis and quadriceps atrophy occurred in all rats with fixed knee joints. Compared with the OC group, millimeter-wave treatment significantly increased articular mobility and the quadriceps diameter; and improved the fibrotic lesions of the joint capsule and quadriceps atrophy. Moreover, levels of TGF-β1, Collagen I, and MuRF1 were upregulated (P < 0.01) by knee immobilization, and collagen fiber content in the articular capsule was also increased (P < 0.01). However, millimeter-wave treatment reversed it. The most noteworthy result was that NF-κB expression was not significantly different in all groups. ConclusionMillimeter-wave treatment reversed joint contracture and quadriceps atrophy caused by joint fixation, inhibited TGF-β1 and Collagen I protein expression of the joint capsule and reduced MuRF1 expression of the quadriceps muscle, thereby inhibiting the development of joint stiffness.

Comparison of Analgesic Efficacies of the iPACK (Interspace Between the Popliteal Artery and Capsule of the Posterior Knee) and Genicular Nerve Blocks Used in Combination With the Continuous Adductor Canal Block After Total Knee Arthroplasty: A Randomized Clinical Trial

BackgroundThe interspace between the popliteal artery and capsule of the posterior knee (iPACK) block and the genicular nerve block (GNB) are motor-sparing nerve blocks used for knee pain relief. We compared the analgesic efficacies of ultrasound-guided iPACK block and GNB when combined with continuous adductor canal block after total knee arthroplasty. MethodsIn this randomized control study, 132 total knee arthroplasty patients were assigned to the iPACK, GNB, and iPACK + GNB groups. All patients received combined spinal anesthesia and continuous adductor canal block. The primary outcome was the 8-hour postoperative pain score during movement. Secondary outcomes were pain scores, posterior knee pain, intravenous morphine consumption, and tibial and common peroneal nerve sensorimotor function. All included patients completed the study. ResultsThe 4-hour and 8-hour postoperative pain scores during movement were significantly lower in the iPACK + GNB group than that in the iPACK group (−2.5 [3.6, 1.3]; P < .001 and −2 [-3, −1]; P < .001, respectively). The differences in rating pain scores and posterior knee pain were not clinically relevant. The iPACK group demonstrated a significantly higher intravenous morphine consumption than did the GNB and iPACK + GNB groups during the first 48 hours postoperatively (P < .001) but were not clinically relevant. There was no incidence of complete sensorimotor blockade in any of the groups. ConclusionThe iPACK–GNB combination relieved pain during movement better than the iPACK block alone during the 8 hours postoperatively after total knee arthroplasty in setting of multimodal analgesia such as adductor canal block.

Inhibition of knee joint sensory afferents alters covariation across strides between quadriceps muscles during locomotion.

Sport-related injuries to articular structures often alter the sensory information conveyed by joint structures to the nervous system. However, the role of joint sensory afferents in motor control is still unclear. Here, we evaluate the role of knee joint sensory afferents in the control of quadriceps muscles, hypothesizing that such sensory information modulates control strategies that limit patellofemoreal joint loading. We compared locomotor kinematics and muscle activity before and after inhibition of knee sensory afferents by injection of lidocaine into the knee capsule of rats. We evaluated whether this inhibition reduced the strength of correlation between the activity of vastus medialis (VM) and vastus lateralis (VL) both across strides and within each stride, coordination patterns that limit net mediolateral patellofemoral forces. We also evaluated whether this inhibition altered correlations among the other quadriceps muscle activity, the time-profiles of individual EMG envelopes, or movement kinematics. Neither the EMG envelopes nor limb kinematics was affected by the inhibition of knee sensory afferents. This perturbation also did not affect the correlations between VM and VL, suggesting that the regulation of patellofemoral joint loading is mediated by different mechanisms. However, inhibition of knee sensory afferents caused a significant reduction in the correlation between vastus intermedius (VI) and both VM and VL across, but not within, strides. Knee joint sensory afferents may therefore modulate the coordination between the vasti muscles but only at coarse time scales. Injuries compromising joint afferents might result in altered muscle coordination, potentially leading to persistent internal joint stresses and strains.NEW & NOTEWORTHY Sensory afferents originating from knee joint receptors provide the nervous system with information about the internal state of the joint. In this study, we show that these sensory signals are used to modulate the covariations among the activity of a subset of vasti muscles across strides of locomotion. Sport-related injuries that damage joint receptors may therefore compromise these mechanisms of muscle coordination, potentially leading to persistent internal joint stresses and strains.

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

BackgroundLocal 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. MethodsA 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. ResultsThe 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. ConclusionThis 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.

Outcomes of double-incision posterior knee release for severe knee flexion contracture.

Many surgical solutions for knee flexiondeformity in the pediatric population alter the anatomical bony alignment in the distal femur. Posterior knee capsule release has been presented as an alternative surgical procedurethat maintains the anatomical shape of relevant bones while solving the issue of knee flexion contracture. The aim of this study is to assess the results of a double-incision posteriorknee capsulotomy release performed on pediatric patients with neuromuscular or congenital severe knee flexion deformity. Thirty cases (24 patients, mean age 7.4 years) of severe knee flexion contractures were retrospectively analyzed in a cohort of varying underlying conditions (including spina bifida, muscular dystrophy, cerebral palsy, sclerodermia, and congenital patellar dislocations). Posterior knee release was performed through medial and lateral short incisions with subsequent serial casting. Range and pace of correction as well as the complication rate were recorded. Follow-up information (>1 year) included functionality (FMS scale) and pain (Kujala/Knee Injury Osteoarthritis Score [KOOS]) scales. Significant correction in the knee position was achieved in all analyzed knees (from mean 40.2° to 0.7°; P < 0.01). Twenty-nine out of 30 cases achieved correction by 7 days postoperatively (average number of casts: 1.93 ± 1.05). Overall complication rate in the analyzed cohort reached 6.7% (2/30 cases; double metaphyseal fracture and arthrofibrosis). At follow-up (22.3 months on average), functional ambulation and pain parameters improved drastically, with no further complications observed. Double-incision posterior knee release is an effective method of knee contracture release, which does not affect the axial alignment of the distal femoral bone. Thus, posterior knee release should be considered as potential alternatives to osteotomies and eight-plate corrections, which are currently the basic methods of knee contracture treatment.

Effects of adductor canal block combined with infiltration between the popliteal artery and capsule of the knee on pain management and early rehabilitation compared with epidural analgesia for patients undergoing total knee arthroplasty: a prospective randomised controlled trial

Total knee arthroplasty (TKA) is often regarded as one of the most painful orthopedic operations. Variety of regional anesthetic procedures are used to reduce this pain. Infiltration between the popliteal artery and capsule of the posterior knee (IPACK) is increasingly being utilized in conjunction with adductor canal block (ACB) to provide adequate analgesia for TKA. The aim of study is to assess the analgesic effectiveness of ACB + IPACK block and epidural analgesia (EA) after TKA during the early stages of physical therapy. This prospective study included 58 patients who underwent unilateral TKA surgery. Patients were randomized into two groups as EA group (n = 30) and ACB + IPACK group (n = 28). The visual analogue scale (VAS) scores of the patients at the postoperative 8th (PO8th) hour, 1st postoperative day (POD1), and postoperative 2nd day (POD2) during the active and passive physical therapy movements, VAS scores during the ambulation, and active and passive range of movement values in POD1 were recorded. In addition, ambulation rates of the patients at the PO8th hour, 25 meters ambulation times in POD1, and completion times of 10 assisted squats in POD1 were recorded. The ACB + IPACK group had a substantially higher PO8th hour VAS score (p = 0.038). However, there was no significant difference in POD1, POD2 VAS scores. The analgesics consumption and VAS scores during ambulation were comparable among groups. Ambulation rate (22 (78.5%) vs. 16 (53.3%), p = 0.043) and speed (139.65 ± 57.12 sec. vs. 188.66 ± 77.95 sec., p = 0.023) were significantly better in the ACB + IPACK group. The strength of quadriceps contractions was similar in both groups. The use of a combination of ACB + IPACK block for postoperative analgesia in TKA patients is not only successful in reducing postoperative pain, but also a promising treatment with favourable effects on early ambulation and rehabilitation.

Comparison between Ultrasound Guided The Genicular Nerve Block And Infiltration Between The Popliteal Artery And The Capsule Of The Posterior Knee (IPACK) Block for Post-Operative Pain Relief in Total Knee Replacement Surgery

Comparison between Ultrasound Guided The Genicular Nerve Block And Infiltration Between The Popliteal Artery And The Capsule Of The Posterior Knee (IPACK) Block for Post-Operative Pain Relief in Total Knee Replacement Surgery

Comparison of adductor canal block, peri–articular injection or infiltration between popliteal artery and posterior knee capsule with adductor canal block in total knee arthroplasty

Background: Moderate to severe postoperative pain is experienced by patients after total knee arthroplasty (TKA), which has an impact on postoperative rehabilitation, patient satisfaction, and overall results. Aim: Patients receiving total knee arthroplasty under general anesthesia were evaluated to see how well the combined adductor canal block and infiltration of the interspace between popliteal artery and the capsule of posterior knee block (IPACK) reduced post-operative discomfort. These treatments were compared to adductor canal block (ACB) and peri-articular injections alone (PAIs). Patients and methods: 60 patients were randomly allocated into three groups (20 in each). All that Group I patients got was an adductor block. Patients in Group II only received the periarticular injection. The IPACK (interspace between popliteal artery and posterior knee capsule) block and adductor block procedures were performed on patients in Group III. The Numeric Rating Scale (NRS) was used to measure post-operative pain as the primary endpoint both during physical therapy and when the patient was at rest. Mobilization was assisted by the Timed Up-and-Go (TUG) and MRC tests, and the second objective was postoperative analgesia, which was assessed by the total number of analgesics used and the time it took until the first rescue analgesic was delivered. Results: The total amount of morphine consumed in IQR amongst the three study groups was statistically different (p-value 0.005). Total postoperative morphine consumption in groups II and III was statistically significantly lower than in groups I (p-value 0.005), and there was also a significant difference between groups II and III (p-value 0.005), indicating that group II had significantly less total morphine consumption than the other two groups. Conclusion: In contrast to combination IPACK-ACB and ACB alone, we came to the conclusion that adding PAIs to the pain management regimen for patients having TKA enhances analgesia quality and reduces opioid intake. Even though the combined IPACK-ACB block was less successful than PAIs, it nevertheless showed superior pain scores at rest and during physiotherapy and required less opioid consumption than ACB alone, making it a viable option to PAIs in situations where this technique is not practical.

No risk of iatrogenic peroneal nerve injury in all-inside lateral meniscal repair with either 14- or 18-mm needles through the popliteus tendon in the standard arthroscopic knee conditions.

The objectives of this prospective study were to evaluate the risk of peroneal nerve (PN) injury in simulated all-inside lateral meniscal repair with sutures placed through the popliteus tendon (PT) and to determine the optimal needle length. Twenty-nine axial magnetic resonance images (MRI) of postoperative knees with infused intra-articular fluid and in a figure-of-four position were used. The cross-sectional length of the PT was divided into four equal parts with measurements performed at the 25%, 50% and 75% points according to their anteroposterior arrangement. Simulated repairs were performed with 14-mm and 18-mm straight needles via the anteromedial (AM) and anterolateral (AL) portals. Distances from the needle tip following full insertion through the PT to the PN and from the anterior PT border to the posterior knee capsule were measured to determine PN injury risk and ideal needle insertion depths at the different landmarks. Simulated repairs onthe 29 knee MRI images resulted in no incidences of PN injury. The average distances from the needle tip to the PN of the 14-mm needle were significantly greater than the 18-mm needle in all the simulated repairs (P < 0.02), except at the 25% point in the AM approach. When using the 14-mm needle, capsule underpenetration was found in three knees (10.3%) at the 25% point during the AM approach, in one knee (3.4%) at the 50% and 75% points in the AM approach, and in all repairs from the AL portal. The average distances from the anterior PT border to the capsule at the 25%, 50%, and 75% division points on the PT in the AM approach were 7.7 ± 2.7mm, 7.9 ± 2.5mm and 7.6 ± 2.8mm, respectively, whilst in the AL approach were 8.4 ± 2.9mm, 8.1 ± 2.8mm and 7.6 ± 2.7mm. Simulated all-inside lateral meniscal repair with suture placement through the PT with 14-mm and 18-mm needles was safe. The measurements in this study can be used to determine potential PN injury risk in relation to the PT and the appropriate needle length for safe lateral meniscal repairs.

What's New in Adult Reconstructive Knee Surgery.

What's New in Adult Reconstructive Knee Surgery.

The Efficacy and Safety of Regional Nerve Blocks in Total Knee Arthroplasty: Systematic Review and Direct Meta-Analysis

BackgroundRegional nerve blocks are widely used in primary total knee arthroplasty (TKA) to reduce postoperative pain and opioid consumption. The purpose of our study was to evaluate the efficacy and safety of regional nerve blocks after TKA in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management. MethodsWe searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published before March 24, 2020 on femoral nerve block, adductor canal block, and infiltration between Popliteal Artery and Capsule of Knee in primary TKA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of the regional nerve blocks compared to a control, local peri-articular anesthetic infiltration (PAI), or between regional nerve blocks. ResultsCritical appraisal of 1,673 publications yielded 56 publications representing the best available evidence for analysis. Femoral nerve and adductor canal blocks are effective at reducing postoperative pain and opioid consumption, but femoral nerve blocks are associated with quadriceps weakness. Use of a continuous compared to single shot adductor canal block can improve postoperative analgesia. No difference was noted between an adductor canal block or PAI regarding postoperative pain and opioid consumption, but the combination of both may be more effective. ConclusionSingle shot adductor canal block or PAI should be used to reduce postoperative pain and opioid consumption following TKA. Use of a continuous adductor canal block or a combination of single shot adductor canal block and PAI may improve postoperative analgesia in patients with concern of poor postoperative pain control.

IPACK (Interspace between the Popliteal Artery and the Capsule of the Posterior Knee) Block Combined with SACB (Single Adductor Canal Block) VersusSACB for Analgesia after Total Knee Arthroplasty

To evaluate the combination of the infiltration between the popliteal artery and the posterior capsule of the knee (iPACK) block and single adductor canal block (SACB) versus SACB for motor-sparing knee analgesia effects after total knee arthroplasty (TKA). PubMed, Ovid, Cochrane Library, and other databases were searched from the inception to January 2021. Randomized controlled trials (RCTs) comparing patients receiving iPACK plus SACB with patients receiving SACB after TKA were included. The included studies were assessed by two reviewers according to the Cochrane risk of bias criteria. Meta-analysis was performed with STATA 13.0 software, the risk ratios (RR) and mean differences (MD) were used to compare dichotomous and continuous variables. The primary outcome was ambulation pain and secondary outcomes were rest pain, opioid consumption, function ability, clinical outcomes, and complications. Seven RCTs (304 knees in iPACK + SACB group; 305 knees in SACB group) were included. The follow-up periods ranged from 2 days to 3 months. Pooled data indicated lower pain scores at ambulation (p < 0.0001) for iPACK + SACB. When comparing the pain scores of subgroups analyzed at specific periods, lower scores in subgroups within 12h (at rest and ambulation) and after 48h (at ambulation) were observed in the iPACK + SACB group. Analysis demonstrated greater reduction in morphine consumption (p=0.007) in the iPACK + SACB group. The iPACK + SACB group is also superior to the SACB group regarding function ability, which included range of motion (ROM) (p=0.001), time up to go (TUG) test (p=0.030), and ambulation distance (p < 0.0001). No difference was found in clinical outcomes or complications. With the iPACK added to SACB, pain scores, morphine consumption, functional ability were improved. Additional high-quality studies are required to further address this topic.

Synergistic effects of robotic surgery and IPACK nerve block on reduction of opioid consumption in total knee arthroplasty

BackgroundThere are numerous strategies to combat postoperative analgesia and expedite recovery after total knee arthroplasty (TKA). The purpose of this study was to determine opioid consumption, length of stay, and functional outcomes after robotic versus standard TKA in the setting of various regional pain modalities. MethodsA consecutive series of patients treated with unilateral primary robotic or standard TKA from January 2018–February 2021 were retrospectively identified. Regional pain modalities included peri-articular injection (PAI), adductor canal block (ACB), and infiltration between popliteal artery and capsule of knee (IPACK). Patient demographics, operative/perioperative variables, and postoperative function were recorded. Daily opiate consumption was calculated as morphine milligram equivalents (MME). Multivariate regression was performed to control for age, sex, and race. ResultsAfter review, 283 patients (177 Females; 106 Males) were included. Robotic TKA patients received IPACK + ACB (36), while standard TKA patients received either ACB (45), IPACK + ACB (167), or PAI (35). Daily inpatient opioid consumption in the standard IPACK + ACB (p = 0.02) and robotic IPACK + ACB groups (p = 0.0001) was significantly lower compared to standard ACB. When combined with IPACK block, robotic procedures synergistically lowered opiate consumption (p = 0.004) compared to standard procedures and led to earlier discharge (p = 0.003). The robotic IPACK + ACB cohort also demonstrated improved early ambulation compared to standard ACB, (p = 0.05), whereas the same benefit was not seen for patients who received IPACK during standard TKA. ConclusionsThe utilization of IPACK block decreases inpatient postoperative opioid requirements following TKA. Robotic TKA and IPACK block appeared to have a synergistic effect on opioid consumption and postoperative recovery.

Successful Chemical Synovectomy in a Patient with Acquired von Willebrand Syndrome with Chronic Synovitis Due to Recurrent Knee Hemarthrosis: A Case Report.

Acquired von Willebrand syndrome (AVWS) is a rare, non-hereditary bleeding disorder related to heterogeneous medical conditions such as hematological malignancies and cardiovascular and autoimmune diseases. We describe the clinical course of a 62-year-old man with polycythemia vera who experienced post-traumatic knee and leg swelling due to hemarthrosis. He was treated at another center with low molecular weight heparin due to misdiagnosed deep vein thrombosis further exacerbating the ongoing bleeding. At our center, he was diagnosed with AVWS with reduced von Willebrand factor (VWF):GPIbR plasma activity and loss of high molecular weight multimers (HMWM). He was treated with compressive bandages with resolution. Five months later, on clinical recurrence of knee and leg swelling, knee ultrasound scan showed the presence of chronic synovitis and a hemorrhagic Baker’s cyst with signs of rupture. The treatment consisted of chemical synovectomy with rifampicin and steroids preceded by systemic replacement therapy using plasma-derived factor VIII-VWF concentrate. At the end of the treatment cycle, our patient reported complete resolution of knee pain and restoration of joint range of motion and function. Ultrasound evaluation confirmed complete resolution of knee capsule distension and Baker’s cyst. Hemarthrosis is an anecdotal presentation of AVWS and chemical synovectomy was successful in treating this complication. A multidisciplinary approach allowed an effective management of this rare complication.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40744-022-00477-2.