Novel classification for multi-ligament knee injury including both tibiofemoral joint factor and patellofemoral joint factor (193)

Objectives: Multi-ligament knee injury (MLKI) shows very varied symptoms which was depended on the combination of injured ligaments. Schenck`s knee dislocation classification which was one of useful classifications for surgeon in decision making. However, Schenck`s classification is only referred to the factors of cruciate ligament and collateral ligament. It is well known that knee joint consists of two important structure; tibiofemoral joint and patellofemoral joint. Knee extensor structure is one of important factors of knee function. Dislocation of patella, quadriceps or patella tendon rupture are sometimes occurred in the knee trauma and provided severe instability or disability of knee function. Of course, these injuries were also target for consideration of treatment. Moreover, knee extensor structure disruption was sometimes combined with other knee ligaments such as cruciate or collateral ligament. Unfortunately, the case of combined cruciate or collateral ligament with knee extensor structure disruption could not classified in the previous classifications. Therefore, we proposed new classification for MLKI which contains both femorotibial factor and patellofemoral factor. We established and defined several categories in accordance with number of injured ligaments, combination of injured ligaments, and additional combined injury such as fracture, nerve injury, vascular injury. It was hypothesized that all cases at least two ligaments involved situation not only combination of tibiofemoral factor, but also including patellofemoral factor, could classify and divide into the new established classification. Methods: The present study was conducted in 2019, involving patient who was diagnosed MLKI at our institute. The study followed both retrospective and prospective observational design including data collected from Apr 2007 to Aug 2020. The experimental design was reviewed and approved (Accession No. 0-0602) by the Ethics Committee of our institute. The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000. Inclusion criteria were the cases of two or more injured ligaments diagnosed clinically and by MRI testing and dynamic X-ray testing. Detail of ligament around knee joint were defined as follows; ‘cruciate ligaments` which contains ACL and PCL; ‘collateral ligaments` which contains MCL and posterolateral corner (PLC) certainly include lateral collateral ligament, and; ‘patellofemoral joint factor` which contains medial patellofemoral ligament (MPFL), quadriceps tendon and patellar tendon. Exclusion criteria was any prior knee surgery cases. Total 65 MLKI cases were met the inclusion criteria and were enrolled in this study. We focused on the number of injured ligaments, combination of the injured ligaments, and complication such as fracture, neurovascular injury. Based on the number of injured ligaments, 2 injured ligaments case was categorized as Type A, 3 injured ligaments case was as Type B, 4 ligaments case was as Type C, and 5 ligaments case was as Type D, respectively. We defined that injured ligament counting was follows; cruciate ligament group; ACL and/or PCL, collateral ligament group; MCL and/or PLC, and PF joint group; one of the MPFL or patellar tendon or quadriceps tendon. Depended on the combination of injured ligaments, each case was subdivided into 1 to 5 in Type A and B, into 1 to 3 in Type C. Additional injuries with MLKI were also subdivided as follows; MLKI with fracture case was defined as X, with neurovascular injury case was as Y, and both fracture and neurovascular injury case was as Z. (Table 1, 2, 3, and 4). For each case, final decision of injured ligament was recorded under clinical examination and image evaluation. MLKI cases were divided into both Schenk’s KD classification and the present new established classification. Results: Fifty-seven of 65 cases were divided into Schenck’s KD classification as follows; 19 cases of ACL+MCL and 13 cases of ACL+PLC and 9 cases of PCL+PLC and 2 cases of PCL+MCL as KD-?, 4cases of ACL+PCL as KD-? and one case of ACL+PCL with fracture as KD-?2, 6 cases of ACL+MCL, 2 cases of ACL+PCL+PLC as KD-?, and 1 case of ACL+PCL+MCL+MCL with fracture as KD-?5, respectively. Eight cases (12.3%) could not be divided into Schenk’s KD classification. Combination of these 8 cases were follows; 2 cases of PLC+MPFL, and single case of ACL+MCL+PLC, ACL+PCL+MCL+PLC+MPFL, ACL+MPFL, PCL+PLC+MPFL+ fracture, ACL+MCL+MPFL, and PCL+ patella tendon, respectively. Seven of 8cases contained PF joint factor injury. At the established new classification for MLKI, all 65 cases were divided into each category, successfully. PLC+MPFL was divided into Type-A5, ACL+MCL+PLC was Type-B2, ACL+PCL+MCL+PLC+MPFL was Type-D, ACL+MPFL was Type-A4, PCL+PLC+MPFL was Type-B3-X, ACL+MCL+MPFL was Type-B3, and PCL+ patella tendon was Type-A4. Conclusions: Several classification systems have been reported for diagnosis of MLKI cases. Kennedy `s classification and the French Society of Orthopedic Surgery and Traumatology 2008 classification were focused on the mechanism and direction of dislocation. These classifications were available for understanding comprehension mechanism of injured knee. However, previous classifications including Schenck’s classification were lack of PF joint factor. It is very important for knee surgeon that understanding injured mechanism as well as number of injured ligaments and combination of injured ligaments for decision making for surgery. The present classification was useful for MLKI case which contains both tibiofemoral factor and patellofemoral factor.

The Danger Zone for Iatrogenic Neurovascular Injury in All-Inside Lateral Meniscal Repair in Relation to the Popliteal Tendon: An MRI Study

Background: Lateral meniscal repair can endanger the nearby neurovascular structure (peroneal nerve or popliteal artery). To our knowledge, there have been no studies to evaluate the danger zone of all-inside meniscal repair through the anteromedial (AM) and anterolateral (AL) portals in relation to the medial and lateral edges of the popliteal tendon (PT). Purpose: To establish the risk of neurovascular injury and the danger zone in repairing the lateral meniscus in relation to the medial and lateral edges of the PT. Study Design: Descriptive laboratory study. Methods: Using axial magnetic resonance imaging (MRI) studies at the level of the lateral meniscus, lines were drawn to simulate a straight, all-inside meniscal repair device, drawn from the AM and AL portals to both the medial and lateral edges of the PT. In cases in which the line passed through the neurovascular structure, a risk of iatrogenic neurovascular injury was deemed, and measurements were made to determine the danger zones of neurovascular injury in relation to the medial or lateral edges of the PT. Results: Axial MRI images of 240 adult patients were reviewed retrospectively. Repairing the body of the lateral meniscus through the AM portal had a greater risk of neurovascular injury than repairs made through the AL portal in relation to the medial edge of the PT ( P = .006). The danger zone in repairing the lateral meniscus through the AM portal extended 1.82 ± 1.68 mm laterally from the lateral edge of the PT and 3.13 ± 2.45 mm medially from the medial edge of the PT. Through the AL portal, the danger zone extended 2.81 ± 1.94 mm laterally from the lateral edge of the PT and 1.39 ± 1.53 mm medially from the medial edge of the PT. Conclusion: Repairing the lateral meniscus through either the AM or the AL portals in relation to the PT can endanger the peroneal nerve or popliteal artery. Clinical Relevance: The surgeon can minimize the risk of iatrogenic neurovascular injury in lateral meniscal repair by avoiding using the all-inside meniscal device in the danger zone area as described in this study.

Neural Stem Cells for Early Intervention of Ischemic Stroke: Neural Stem Cell Therapy for Early Phase Ischemic Stroke

Clinical treatments for ischemic stroke are limited. Neural stem cell (NSC) transplantation can be a promising therapy. Clinically, ischemia and subsequent reperfusion lead to extensive neurovascular injury that involves inflammation, disruption of the blood-brain barrier, and brain cell death. NSCs exhibit multiple potentially therapeutic actions against neurovascular injury. Currently, tissue plasminogen activator (tPA) is the only FDA-approved clot-dissolving agent. While tPA’s thrombolytic role within the vasculature is beneficial, tPA’s non-thrombolytic deleterious effects aggravates neurovascular injury, restricting the treatment time window (time-sensitive) and tPA eligibility. Thus, new strategies are needed to mitigate tPA’s detrimental effects and quickly mediate vascular repair after stroke. Up to date, clinical trials focus on the impact of stem cell therapy on neuro-restoration by delivering cells during the chronic stroke stage. Also, NSCs secrete factors that stimulate endogenous repair mechanisms for early-stage ischemic stroke. This review will present an integrated view of the preclinical perspectives of NSC transplantation as a promising treatment for neurovascular injury, with an emphasis on early-stage ischemic stroke. Further, this will highlight the impact of early sub-acute NSC delivery on improving short-term and long-term stroke outcomes.

AVOIDING POPLITEAL NEURO-VASCULAR INJURY DURING ILIOTIBIAL BAND ACL RECONSTRUCTION

Background: For patients with significant growth remaining, the Iliotibial Band ACL reconstruction technique has proven to be reliable procedure with minimal risk for growth disturbance. Recent dissection studies confirm the neuro-vascular bundle is within 1 cm of the ACL graft over the top position, confirming the importance of careful graft passage technique to avoid neurovascular injury. Purpose: The purpose of this study was to evaluate the over the top graft passage technique using pediatric 3-D knee models. Instrument placement for graft passage was assessed for its proximity to the posterior aspect of the femur, maintaining a safe distance from the neurovascular bundle. Materials and Methods: 3D knee models (ages 7, 9, 11 years) were printed from high resolution knee CT scans, including a hinge/pivot mechanism to allow for simulation of knee position during flexion and extension. Various curved tip instruments were used to evaluate the path of the graft passage, with several goals: 1. Allow the instrument to create a graft path through the posterior capsule in the most anatomic femoral position. 2. Keep the tip of the instrument close to posterior and lateral cortex of the femur, to avoid neurovascular injury. The instruments varied in design, arc of curvature, overall length, diameters. Results: Clamp passage was performed using a retrograde approach, i.e. through the notch, passing outside the periosteum of the postero-lateral femur (Figure 1). For some clamps, the arc of the curvature allowed for passage of the instrument with minimal risk of neurovascular injury. For some clamp configurations, the clamps deviated significant from the posterior aspect of the femur during graft passage, which may increase the risk of neurovascular bundle injury. In each case, an instrument was identified that met the criteria for safe passage, but different instruments were required based upon the size of the knee joint. Conclusions: The ITB ACL reconstruction is one of the best options for ACL reconstruction in the skeletally immature. The neurovascular structures are very close to the path for over the top graft placement. Due to the wide range of knee dimensions in this group, different clamp designs may be necessary for optimal over the top graft passage. 3D knee models may guide surgeons for procedure technique and optimal instrument selection for safe graft passage. [Figure: see text]

A Diagnostic Algorithm to Guide Operative Intervention of Zone 5 Flexor Injuries

Background: Given the importance of the neurovascular structures in the volar forearm, accurate diagnosis of zone 5 flexor injuries is critical. Purpose: We sought to test the hypothesis that tendinous injury would be more likely in the distal 50% of the forearm and muscle belly injury would be more likely in the proximal 50% of the forearm. Methods: From December 2015 to December 2016, we conducted a prospective clinical study of patients 18 years and older with zone 5 flexor lacerations. We excluded those with concomitant ipsilateral injuries in flexor zones 1 to 4, multiple lacerations in flexor zone 5, prior neurovascular injuries, crush injuries, patients who underwent operative exploration prior to transfer to our facility, and patients who were unable or unwilling to provide consent. Neurovascular and musculotendinous injuries on physical examination were recorded. All patients underwent operative exploration. Physical examination accuracy and the incidence of musculotendinous and neurovascular injury in the distal 50% of the forearm were compared with the proximal 50% of the forearm. Results: The distal 50% of the forearm (group 1, n = 14) had higher probability of tendon injury (64%), whereas lacerations of the proximal 50% of the forearm (group 2, n = 5) did not result in any tendinous injuries. Rather, all patients in group 2 had muscle belly injuries. There was no difference in the rate of neurovascular injury between groups. Physical examination alone was highly accurate in diagnosing nerve injuries (93%–100%) but less accurate in diagnosing arterial injuries (79%–80%) regardless of the location of injury. Conclusions: Due to the lack of tendinous injuries in proximal zone 5 lacerations, along with the accuracy of physical examination in determining the presence of neurovascular injuries, patients with lacerations in the proximal half of the forearm, without evidence of nerve or arterial injury, can likely be observed in lieu of immediate operative exploration.

Comparison of Large-Gauge Needle, Corneal Knife, and No. 11 Blade for Percutaneous Achillotomy

Background In the Ponseti technique, the residual equinus deformity is corrected with percutaneous tenotomy. This experimental study aimed to compare the safety and effectiveness of a large-gauge needle, a corneal knife, and a No. 11 blade in percutaneous achillotomy performed in rats. Methods Ninety Achilles tendons of 45 Sprague-Dawley rats were analyzed, following division into three study groups. In the study, group I (needle), group II (corneal knife), and group III (No. 11 blade) were compared on the basis of bleeding, incision length, requirement for primary suture, range of motion, and resulting neurovascular injury at day 0. Moreover, the groups were compared in terms of range of motion, macroscopic and microscopic adhesions, and tenocyte morphology at days 21 and 42 postoperatively. Results On day 0, one suture was required in group III, whereas in groups I and II, no sutures were required. Postoperative bleeding was greater in group III and similar in groups I and II. Neurovascular injury was not observed in any of the groups. Three incomplete tenotomies were observed in group III and one incomplete tenotomy was observed in group II. Importantly, all tenotomies were complete in group I. In all groups, the range of motion was similar. The macroscopic adhesion score revealed high adhesion in group III (P = .009). According to Tang's criteria, microscopic adhesion was significantly higher on day 21 in group III compared with the other groups (P <0.001). No significant differences were observed in tenocyte morphology based on the Bonar criteria (P = .850). Conclusions In the results obtained from this animal study, we observed less bleeding, less adhesion, and less incomplete tenotomy in the large-gauge needle and corneal knife groups compared with the No. 11 blade group during the percutaneous Achilles tenotomy performed in rats.

Abstract P732: Genetic Ablation of Endothelial C3a-Receptor Confers Cerebrovascular Protection Independent of the Dynamics of Reperfusion in Stroke

Background: Stroke enhances endothelial C3a Receptor (C3aR End ) expression and humoral levels of C3a which is further exacerbated by intravenous thrombolysis (IVT). Therefore, it is critical to investigate the role of C3aR End in post-stroke neurovascular injury. Hypothesis: Genetic depletion of C3aR is vasculoprotective in stroke. Methods: Using a loxP - Cre approach (C3aR Flox/Flox xCdh5 Cre ), we generated mice conditionally deficient or sufficient in C3aR End (C3aR End-/- or C3aR End+/+ ), and subjected males (6±0.5-mo old) to thrombotic stroke (TS). Cerebral blood flow (CBF), behavioral outcomes, infarct volume, blood brain barrier (BBB) leakage, brain hemoglobin (Hb) content, brain tissue oxygen (PbtO 2 ) , neutrophil polarization ( Proinflammatory N1: Li6G + CD206 - vs. Antiinflammatory N2: Li6G + CD206 + ) and their brain infiltration were analyzed. P<0.05 was considered statistically significant. Results: TS resulted in similar degree of cerebral ischemia in both groups (N=10/gp); however, CBF, behavior, and infarct volume were significantly improved in C3aR End-/- vs. C3aR End+/+ mice at 72h post-TS. BBB-leakage and brain-Hb at 72h were less in C3aR End-/- vs. C3aR End+/+ mice but this did not meet significance (N=5/gp). Interestingly, C3a infusion 3h post-TS significantly enhanced BBB-leakage and brain-Hb in C3aR End+/+ but not in C3aR End-/- mice at 72h (N=5/gp), demonstrating that C3a in conjunction with C3aR End exacerbates neurovascular injury in TS. Moreover, late-IVT at 4h post-TS (2 mg/kgbwt; N=8/gp) significantly enhanced PbtO 2 in C3aR End-/- vs. C3aR End+/+ mice when assessed at 6h. Finally, C3aR deficiency significantly enhanced the N2/N1 ratio relative to the C3aR sufficient group at 24h post-TS (N=3/gp); thus inducing an anti-inflammatory effect and reduced neutrophil brain infiltration. Conclusion: C3aR End plays a critical role in stroke injury. Future studies targeting brain specific C3aR End are warranted.