Influence of Human Bone Marrow Mesenchymal Stem Cells Secretome from Acute Myeloid Leukemia Patients on the Proliferation and Death of K562 and K562-Lucena Leukemia Cell Lineages.

Leukemias are among the most prevalent types of cancer worldwide. Bone marrow mesenchymal stem cells (MSCs) participate in the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases such as leukemias, to a yet unknown extent. Here we described the effect of secretome of bone marrow MSCs obtained from healthy donors and from patients with acute myeloid leukemia (AML) on leukemic cell lineages, sensitive (K562) or resistant (K562-Lucena) to chemotherapy drugs. Cell proliferation, viability and death were evaluated, together with cell cycle, cytokine production and gene expression of ABC transporters and cyclins. The secretome of healthy MSCs decreased proliferation and viability of both K562 and K562-Lucena cells; moreover, an increase in apoptosis and necrosis rates was observed, together with the activation of caspase 3/7, cell cycle arrest in G0/G1 phase and changes in expression of several ABC proteins and cyclins D1 and D2. These effects were not observed using the secretome of MSCs derived from AML patients. In conclusion, the secretome of healthy MSCs have the capacity to inhibit the development of leukemia cells, at least in the studied conditions. However, MSCs from AML patients seem to have lost this capacity, and could therefore contribute to the development of leukemia.

Thromboprophylaxis with unilateral pneumatic device led to less edema and blood loss compared to enoxaparin after knee arthroplasty: randomized trial.

BACKGROUND: Pharmacological and mechanical thromboprophylaxis are frequently used together after total knee arthroplasty (TKA). Most studies in this context compare anticoagulants versus a combination of these drugs with an intermittent pneumatic compression device (IPCD). However, there is uncertainty about the need for the combination of both and whether a unilateral IPCD would alone affect other important clinical outcomes: edema and blood loss. We compared the effects of enoxaparin versus unilateral portable IPCD after TKA on edema and blood loss. We hypothesised that unilateral IPCD would cause the same level of edema and the same blood loss as enoxaparin. METHODS: In this open, randomized trial (1:1), adults with no history of coagulation disorders, anticoagulant use, venous thromboembolism, liver or malignant diseases underwent TKA. For 10 days, participants received the IPCD, used 24 h/day on the operated leg from the end of surgery, or 40 mg of enoxaparin, starting 12 h after surgery. All underwent the same rehabilitation and were encouraged to walk on the same day of surgery. We measured edema (thigh, leg and ankle circumference) before and on the third postoperative day. Blood loss (volume accumulated in the suction drain and drop of hemoglobin and hematocrit in 48 h) was a secondary outcome. RESULTS: We randomized 150 patients and lost 3 to follow-up with enoxaparin and 2 with IPCD. There was no case of symptomatic venous thromboembolism. Four patients needed transfusions (three receiving enoxaparin), one had infection and one hemarthrosis (both in the enoxaparin group). Leg circumference increased by approximately 2 cm for enoxaparin group and 1.5 cm in IPCD (p <  0.001). The increase in ankle circumference was about 1.5 cm in the enoxaparin group (p <  0.001), and almost zero in IPCD (p = 0.447). Enoxaparin group lost 566.1 ml (standard deviation, SD, 174.5) of blood in the first 48 h, versus 420.8 ml (SD 142.5) in the IPCD. CONCLUSIONS: Exclusively mechanical prophylaxis after TKA with portable IPCD only on the operated leg reduces leg and ankle swelling and post-operative blood loss compared to exclusively pharmacological prophylaxis with enoxaparin. Portable devices that can prevent deep vein thrombosis and pulmonary embolism without increasing blood loss or other risks should be further investigated. TRIAL REGISTRATION: REBEC RBR-8k2vpx. Registration date: 06/04/2019.

The use of negative-pressure wound therapy after total knee arthroplasty is effective for reducing complications and the need for reintervention.

BACKGROUND: Wound healing complications are causal factors of prosthesis infection and poor postoperative evolution of patients after total knee arthroplasty (TKA). Negative-pressure wound therapy (NPWT) can be an option to minimize these complications. The aim of this study is to compare the complications of patients undergoing TKA who used a portable NPWT device in the immediate postoperative period with those of a control group. METHODS: A total of 296 patients were evaluated. Patients were divided into two groups: those who used NPWT for seven days in the postoperative period (Group 1 - prospective evaluated) and those who used conventional dressings (Group 2 - historical control group). Epidemiological data, comorbidities, local parameters related to the surgical wound and complications were evaluated. RESULTS: The groups did not differ in regard to sex, age and clinical comorbidities. Overall, 153 (51.7%) patients had at least one risk factor for wound complications. Patients who used NPWT had a lower rate of complications (28.5% vs. 45.7%, p = 0.001) and a lower rate of reintervention in the operating room (2% vs. 8.5%, p = 0.001). Patients in group 1 had a lower incidence of hyperaemia (14.7% vs. 40.2%, p = 0.01), skin necrosis (2.1% vs. 8.5%, p = 0.04) and wound dehiscence (3.1% vs 10.1%, p = 0.03). The use of NPWT was a protective factor for the presence of complications, with an odds ratio of 0.36 (95% CI 0.206-0.629). CONCLUSION: The number of complications related to the wound after TKA is high; however, most of them are minor and have no impact on the treatment and clinical evolution of patients. The use of NPWT decreased the number of surgical wound complications, especially hyperaemia, dehiscence and necrosis, and reduced the need for reintervention.

Combined Reconstruction of the Anterolateral Ligament in Patients With Anterior Cruciate Ligament Injury and Ligamentous Hyperlaxity Leads to Better Clinical Stability and a Lower Failure Rate Than Isolated Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare functional outcomes, residual instability, and rupture rates in patients with ligamentous hyperlaxity undergoing isolated anterior cruciate ligament (ACL) reconstruction or combined ACL and anterolateral ligament (ALL) reconstruction. METHODS: Two groups of patients were evaluated and compared retrospectively. Both groups consisted of patients with ACL injuries and associated ligamentous hyperlaxity, defined based on the modified Beighton scale with a minimum score of 5. Group 1 patients underwent anatomical ACL reconstruction, and group 2 patients underwent anatomical ACL reconstruction combined with ALL reconstruction. Group 1 consisted of historical controls. The presence of associated meniscal injury, subjective International Knee Documentation Committee and Lysholm functional scores, KT-1000 measurements, the presence of a residual pivot-shift, and the graft rupture rate were evaluated. The study was performed at University of São Paulo in Brazil. RESULTS: Ninety patients undergoing ACL reconstruction with ligamentous hyperlaxity were evaluated. The mean follow up was 29.6 ± 6.2 months for group 1 and 28.1 ± 4.2 months for group 2 (P = .51). No significant differences were found between the groups regarding Beighton scale, gender, the duration of injury before reconstruction, follow-up time, preoperative instability, or associated meniscal injuries. The mean age was 29.9 ± 8.1 years in group 1 and 27.0 ± 9.1 years in group 2 (P = .017). In the final evaluation, group 2 patients showed better anteroposterior clinical stability as evaluated by KT-1000 arthrometry (P = .02), better rotational stability as evaluated by the pivot-shift test (P = .03) and a lower reconstruction failure rate (21.7% [group 1] vs 3.3% [group 2]; P = .03). Clinical evaluations of postoperative functional scales showed no differences between the 2 groups (P = .27 for International Knee Documentation Committee; P = .41 for Lysholm). CONCLUSIONS: Combined ACL and ALL reconstruction in patients with ligamentous hyperlaxity resulted in a lower failure rate and improved knee stability parameters compared to isolated ACL reconstruction. No differences were found in the functional scales. LEVEL OF EVIDENCE: Level III, case control study.

Combined reconstruction of the anterolateral ligament in chronic ACL injuries leads to better clinical outcomes than isolated ACL reconstruction.

PURPOSE: To evaluate the results of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction in patients with chronic ACL injury. It was hypothesized that patients who underwent combined ACL and ALL reconstruction would exhibit less residual laxity and better clinical outcomes. METHODS: Two groups of patients were evaluated and compared retrospectively. Both groups consisted only of patients with chronic (more than 12 months) ACL injuries. Patients in group 1 underwent anatomical intra-articular reconstruction of the ACL and patients in group 2 underwent anatomic intra-articular ACL reconstruction combined with ALL reconstruction. The presence of associated meniscal injury, the subjective International Knee Documentation Committee (IKDC) and Lysholm functional outcome scores in the postoperative period, KT-1000 evaluation, the presence of residual pivot shift and graft rupture rate were evaluated. RESULTS: One hundred and one patients who underwent reconstruction of chronic ACL injuries were evaluated. The median follow-up was 26 (24-29) months for group 1 and 25 (24-28) months for group 2. There were no significant differences between groups regarding gender, age, duration of injury until reconstruction, follow-up time or presence of associated meniscal injuries in the preoperative period. Regarding functional outcome scores, patients in group 2 presented better results on both the IKDC (p = 0.0013) and the Lysholm (p < 0.0001) evaluations. In addition, patients in group 2 had better KT-1000 evaluation (p = 0.048) and a lower pivot shift rate at physical examination, presenting only 9.1% positivity versus 35.3% in the isolated ACL reconstruction (p = 0.011). Regarding re-ruptures, group 1 presented 5 (7.3%) cases, and group 2 presented no cases. CONCLUSION: The combined ACL and ALL reconstruction in patients with chronic ACL injury is an effective and safety solution and leads to good functional outcomes with no increase in complication rate. The clinical relevance of this finding is the possibility to indicate this type of procedure when patients present with more than 12 months after injury for surgery. LEVEL OF EVIDENCE: Level III.

Histopathological analysis of the posterior cruciate ligament in primary osteoarthritis.

BACKGROUND: According to some authors, the indication of an arthroplasty maintaining the posterior cruciate ligament (PCL) demands adequate structural preservation and proprioceptive function of this ligament. The nervous fibers contained in the synovial neurovascular bundle (NVB) around the PCL are involved in proprioception. A study evaluating the grade of PCL and NVB degeneration by using clinical, radiological, and perioperative parameters in knee arthritis patients, in theory, could help surgeons in the decision of preserving or not preserving the PCL in a particular patient. QUESTIONS: (1) Can the degree of the PCL collagen fibers degeneration be predicted by clinical, radiographic, and perioperative parameters in knee arthritis patients? (2) Is the NVB histological degeneration status predictable using clinical, radiographic, and perioperative parameters in the same subset of patients? (3) Is there a correlation between the degree of the PCL collagen fibers degeneration and NVB status in knee arthritis patients? METHODS: Eighty-nine PCLs (85 patients) obtained from total knee replacement surgery were studied. The histologic degeneration of PCL collagen fibers and the NVB status (preserved, degenerated, not detected) were evaluated. These histological degeneration patterns were correlated with clinical and radiographic parameters and with anterior cruciate ligament (ACL) status. RESULTS: A small prevalence of preserved NVB was related to Grades IV and V of Ahlbäck's classification, ACL absence, and severe PCL degeneration. The clinical and radiological parameters studied were not able to predict the grade of histological degeneration of the PCL. CONCLUSIONS: Ahlbäck's classification and ACL status provided useful information about NVB integrity. LEVEL OF EVIDENCE: Basic Science Level IV.

Assessment of the Anterolateral Ligament of the Knee by Magnetic Resonance Imaging in Acute Injuries of the Anterior Cruciate Ligament.

PURPOSE: To evaluate the epidemiology of injuries and abnormalities of the anterolateral ligament (ALL) by magnetic resonance imaging (MRI) in cases of acute anterior cruciate ligament (ACL) injury. METHODS: MRIs of patients with acute ACL injury were evaluated. Acute injuries of the ACL were considered in cases in which the patient reported knee trauma occurring less than 3 weeks prior and when bone bruise in the femoral condyles and tibial plateau was identified. ALL abnormality was considered when it showed proximal or distal bone detachment, discontinuity of fibers, or irregular contour associated with periligamentous edema. The ALL was divided into femoral, tibial, and meniscal portions, and the lesions and/or abnormalities of each portion were characterized. The correlation of ALL injury with injuries of the lateral meniscus was evaluated. RESULTS: A total of 101 MRIs were initially evaluated. The ALL was not characterized in 13 (12.8%) examinations, resulting in 88 (87.1%) cases of injury evaluation. Of these, 55 (54.4%) patients had a normal ALL, and 33 (32.6%) showed signs of injury. Among the cases with injury, 24 (72%) patients showed proximal lesions, 7 (21%) showed distal lesions, and 2 (6.0%) patients presented both proximal and distal lesions. The meniscal portion of the ALL appeared abnormal in 16 (48%) patients. No relationship was found between ALL injury and lateral meniscus injury. CONCLUSIONS: Based on MRI analysis of acute ACL injuries with bone bruising of the lateral femoral condyle and lateral tibial plateau, approximately a third demonstrated ALL injuries of which the majority was proximal. LEVEL OF EVIDENCE: Level IV, case series.

Anterolateral ligament abnormalities are associated with peripheral ligament and osseous injuries in acute ruptures of the anterior cruciate ligament.

PURPOSE: Few studies have used MRI to identify the ALL. As it was shown that it is not possible to precisely characterize this ligament in all examination, it is important to identify concomitant lesions that can help in diagnosing ALL abnormalities. It is important to characterise this injury due to its association with anterolateral knee instability. Thus, the present study was performed to determine the frequency of ALL injuries in patients with acute ACL rupture and to analyse its associated knee lesions. METHODS: Patients with acute ACL injuries were evaluated by MRI. Among this population, the ALL was classified as non-visualised, injured or normal. The possible abnormalities of the meniscus, collateral ligaments, popliteus tendon, posterior cruciate ligament, Iliotibial band (ITB), anterolateral capsule and osseus injuries were evaluated. The association of an ALL injury with these other knee structures as well as sex and age was calculated. RESULTS: Among the 228 knees evaluated, the ALL could not be entirely identified in 61 (26.7%). Of the remaining 167, 66 (39.5%) presented an ALL abnormality and only four (6.1%) were Segond fractures. ALL abnormalities were associated with lesions of the lateral collateral ligament, medial collateral ligament, popliteus tendon, ITB, anterolateral capsule and osseous contusions of the femoral condyle and tibial plateau. No correlation was found with medial meniscus, lateral meniscus and posterior cruciate ligament injuries. There was no association between ALL injuries and gender, and older patients were more likely to present an ALL injury. CONCLUSION: ALL injuries are present in approximately 40% of ACL injuries, and a minority of these are Segond fractures. These injuries are associated with peripheral ligament injuries, anterolateral structures lesions and bone contusions, but there is no association with meniscal injuries. Surgeons must be aware of these associations to consider an ALL lesion even if it is not completely clear in imaging evaluation, especially if a high degree of anterolateral instability is present on physical examination. LEVEL OF EVIDENCE: III.

Combined reconstruction of the posterior cruciate ligament and medial collateral ligament using a single femoral tunnel.

PURPOSE: Lesions of the medial collateral ligament (MCL) are the most common knee ligament injuries, and lesions associated with the anterior cruciate ligament or the posterior cruciate ligament (PCL) in knee dislocations should be reconstructed to prevent failure of the central pivot reconstruction. The purpose of this study was to evaluate the outcomes of combined PCL/MCL reconstruction using a single femoral tunnel with a minimum 2-year follow-up. METHOD: A retrospective study of thirteen patients with combined PCL/MCL injuries was conducted. The patients underwent PCL and MCL reconstruction using an Achilles tendon allograft with a single tunnel in the medial femoral condyle, thereby avoiding tunnel conversion. RESULTS: All patients achieved a range of motion of at least 100°. The mean loss of extension and flexion values compared to the contralateral side was 1° ± 2° and 9° ± 10°, respectively. Our results included 26 reconstructions with three (11.5 %) failures, two in the PCL (15.3 %) and one in the MCL (7.6 %), in three different patients. In the final evaluation, the mean IKDC subjective score was 71.63 ± 16.23, the mean Lysholm score was 80.08 ± 13.87, and the median Tegner score was 6 (range = 2-7). CONCLUSION: The PCL/MCL reconstruction technique using a single femoral tunnel and an Achilles tendon allograft is safe, avoids the convergence of tunnels in the medial femoral condyle, has excellent results, and is reproducible. LEVEL OF EVIDENCE: IV.

Biomechanical study of strength and stiffness of the knee anterolateral ligament.

BACKGROUND: Recent studies clearly characterize the anatomical parameters of the knee anterolateral ligament (ALL). The potential clinical importance of this ligament is exemplified by some patients with possible combined Anterior Cruciate Ligament (ACL) and ALL rupture who do not progress satisfactorily following isolated ACL reconstruction. Previous biomechanical studies have assessed the resistance parameters of the ALL in order to address potential reconstruction strategies; however, these have reported conflicting results. Thus, this study aimed to evaluate the linear resistance of the ALL by means of a biomechanical study in cadaveric knees. METHODS: Fourteen cadaveric knees were used. The ALL was dissected, and all structures that connect the femur and the tibia, except for the ALL, were sectioned. The ALL was subjected to a tensile test with the knee around 30 to 40 degrees, in a way that the ALL was aligned with the machine. The strength at the maximum resistance limit, deformation and stiffness of the ALL were evaluated. RESULTS: The mean maximum strength of the ALL was 204.8 +/- 114.9 N. The stiffness was 41.9 +/- 25.7 N/mm and the deformation 10.3 +/- 3.5 mm. CONCLUSION: The ALL has a mean ultimate tensile strength of 204.8 N. This suggests that simple bands of all autologous or homologous grafts commonly used in clinical practice for ligament reconstruction around the knee possess the required biomechanical resistance characteristics for ALL reconstruction.

"Fatigue meniscal tears": a description of the lesion and the results of arthroscopic partial meniscectomy.

PURPOSE: The purpose of this study was to describe the clinical outcomes of partial meniscectomy in patients with "fatigue meniscal tear", which presents as a non-traumatic tear with abrupt onset of symptoms of a radial tear in the transition between the middle and posterior thirds of the meniscus. METHODS: We prospectively followed 71 patients with "fatigue meniscal tear" (41 women and 30 men, mean age of 63 years, SD 6.9 years) recruited among 497 patients with isolated medial meniscal lesions treated between January 2006 and June 2011. Inclusion criteria were spontaneous abrupt onset knee pain, minor or no trauma, no radiographic or MRI osteoarthritis, no bone oedema, pre-operative magnetic resonance image of medial meniscus tear, and arthroscopic evaluation demonstrating radial or vertical flap tear in the body to posterior horn junction of the medial meniscus. We followed all patients for a minimum of two years and reviewed their clinical symptoms, physical exam, functional outcome, and patient satisfaction at last follow-up. RESULTS: The average follow-up was 4.2 years, with a minimum follow-up of two years. Among the 71 patients, there were 59 (83.1 %) good or excellent results and 12 (16.9 %) poor results. These 12 patients demanded further treatment because of persistent pain, with three of the patients developing subchondral bone fracture. All patient complaints and poor outcomes could be identified in the initial six months after surgery. There was no gender difference in the subgroup analysis. CONCLUSION: Our findings indicate that patients with "fatigue meniscal tear" benefit from arthroscopic partial meniscectomy, with only 16.9 % reporting unfavourable results. LEVEL OF EVIDENCE: IV, Cohort study or case series.

Is it safe to reconstruct the knee Anterolateral Ligament with a femoral tunnel? Frequency of Lateral Collateral Ligament and Popliteus Tendon injury.

PURPOSE: This study sought to determine the safety limits for performing a femoral bone tunnel to reconstruct the knee anterolateral ligament (ALL) by establishing its distance from the lateral collateral ligament (LCL) and the popliteus muscle tendon (PT) on the lateral femoral condyle. METHODS: Anatomic study on 48 knee cadaveric specimens. The femoral attachments of the studied structures were isolated, and the distance between them was measured. For each cadaver, the percentage of cases in which at least 50 % of the LCL and PT would be injured when using 4- to 12-mm-diameter drills in an ALL reconstruction procedure was evaluated. RESULTS: The LCL and PT were 3.8 mm and 10.2 mm distant from the ALL, respectively. A 4-mm tunnel would cause LCL injury in 8.3 % of cases, with increasing incidence of injury up to 87.5 % with a 12-mm drill. Injury to the PT would start with the 10-mm drill, causing injury in 2.0 % of cases. CONCLUSIONS: Performing a tunnel in the center of the ALL may cause an iatrogenic injury to the LCL origin. No cases of PT injury are expected to occur with drills smaller than 10 mm.

The meniscal insertion of the knee anterolateral ligament.

PURPOSE: The aim of this study is to characterize in detail the meniscal insertion of the anterolateral ligament (ALL) of the knee, establishing parameters regarding the circumference of the lateral meniscus and the popliteal muscle tendon (PMT) groove in addition to its histological analysis. METHODS: A total of 33 knees of cadavers were dissected. The ALL and the lateral meniscus were removed en bloc. After removal of the anatomical specimen, the meniscus circumference, the ALL insertion points on the external surface of the lateral meniscus, and the PMT groove were measured. Eight menisci were subjected to histological analysis. RESULTS: The ALL was found in all dissections performed. The ALL insertion occurred macroscopically in the transition between the anterior horn and the lateral meniscus body, specifically beginning at 36.0% and ending at 41.9% of the meniscal circumference, occupying a mean area of 5.6 mm. The distance between the end of the ALL meniscal insertion and the beginning of the PMT groove averaged 12.9 mm. In the histological evaluation, in longitudinal sections, we observed dense collagen fibers of the ligament inserting on the external surface of the meniscus. It is possible to observe a spreading of collagen fibers at the moment of meniscal insertion. CONCLUSIONS: The ALL meniscal insertion was found in all dissected specimens, beginning with approximately 36% of the meniscal outer diameter, 12.9 mm anterior to the beginning of the PMT groove. The histological analysis confirmed the presence of true ligamentous tissue in the dissected specimens.

Are the osseous and tendinous-cartilaginous tibial tuberosity-trochlear groove distances the same on CT and MRI?

OBJECTIVE: To verify whether the tibial tuberosity-trochlear groove distance (TT-TG) and the tendinous-cartilaginous TT-TG (the distance between the patellar tendon and trochlear groove: PT-TG) are identical using computed tomography (CT) and magnetic resonance imaging (MRI) techniques. SUBJECTS AND METHODS: The TT-TG and PT-TG distances were measured on the same knee samples by three observers (two measurements per observer) using CT and MRI scans collected retrospectively. The reproducibility of the measurements was assessed using the interclass correlation coefficient (ICC). The means and standard deviations of four measurements were calculated for each patient. A paired t-test was used to assess differences between measurements. RESULTS: Fifty knee samples (32 with patellar instability and 18 with other conditions) were evaluated. The inter- and intraobserver reliability was excellent for all four measurements (>0.8). On average, the TT-TG distance on MRI was 3.1-3.6 mm smaller than that on CT, and the PT-TG distance on MRI was 1.0-3.4 mm larger than the TT-TG distance on MRI. CONCLUSION: The osseous TT-TG and tendinous-cartilaginous PT-TG distances determined by CT and MRI were not identical.

Functional assessment of combined reconstruction of the anterior cruciate ligament and posterolateral corner with a single femoral tunnel: a two-year minimum follow-up.

PURPOSE: A technique for combined reconstruction of the anterior cruciate ligament (ACL) and posterolateral corner (PLC) with a single femoral tunnel was recently described. This technique aims to avoid tunnel confluence in the lateral femoral condyle. Because there have been no studies on the functional outcomes and possible complications of this technique, our goal is to demonstrate a two-year minimum follow-up of patients who underwent this type of reconstruction. METHODS: Nine patients were prospectively evaluated. The ACL was reconstructed with an anatomic single bundle, and the PLC structures reconstructed were the lateral collateral ligament, the popliteus tendon, and the popliteofibular ligament. Patients were evaluated using the objective and subjective International Knee Documentation Committee (IKDC) and the Lysholm and Tegner scales before and after the surgical procedure. RESULTS: The mean follow-up period of the studied patients was 27.3 months. The mean subjective IKDC score rose from 43.6 to 84.0, and the Lysholm score rose from 62.1 to 90.8. In the final assessment, six patients were classified as IKDC A and three as IKDC B. According to the Tegner scale, five patients were able to return to their level of activity prior to the injury. There were no reconstruction failures. One patient experienced postoperative infection and pain in the lateral scar. CONCLUSIONS: The results of the reconstruction of ACL injuries associated with PLC with a single femoral tunnel produced a good functional outcome and a low incidence of complications.

MRI evaluation of the anterolateral ligament of the knee: assessment in routine 1.5-T scans.

OBJECTIVE: This study evaluated the ability of routine 1.5-T MRI scans to visualize the anterolateral ligament (ALL) and describe its path and anatomic relations with lateral knee structures. MATERIALS AND METHODS: Thirty-nine 1.5-T MRI scans of the knee were evaluated. The scans included an MRI knee protocol with T1-weighted sequences, T2-weighted sequences with fat saturation, and proton density (PD)-weighted fast spin-echo sequences. Two radiologists separately reviewed all MRI scans to evaluate interobserver reliability. The ALL was divided into three portions for analyses: femoral, meniscal, and tibial. The path of the ALL was evaluated with regard to known structural parameters previously studied in this region. RESULTS: At least a portion of the ALL was visualized in 38 (97.8%) cases. The meniscal portion was most visualized (94.8%), followed by the femoral (89.7%) and the tibial (79.4%) portions. The three portions of the ALL were visualized in 28 (71.7%) patients. The ALL was characterized with greater clarity on the coronal plane and was visualized as a thin, linear structure. The T1-weighted sequences showed a statistically inferior ligament visibility frequency. With regard to the T2 and PD evaluations, although the visualization frequency in PD was higher for the three portions of the ligament, only the femoral portion showed significant values. CONCLUSION: The ALL can be visualized in routine 1.5-T MRI scans. Although some of the ligament could be depicted in nearly all of the scans (97.4%), it could only be observed in its entirety in about 71.7% of the tests.

Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits.

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

Extensor mechanism injury, infection, and an extended time between trauma and surgical approach are related to the need for total knee arthroplasty removal after traumatic dehiscence.

BACKGROUND: Surgical wound-related traumatic complications are rarely reported in the literature. Traumatic dehiscence is unpredictable because of the trauma magnitude and the potential of associated injuries. This study aims to report the clinical outcomes and complications of a case series due to traumatic dehiscence after total knee arthroplasty (TKA) and establish possible criteria for prognosis for maintaining the implant. METHODS: Patients admitted to an emergency room due to traumatic dehiscence after TKA were retrospectively evaluated. Patient data was analyzed and patients who maintained or not the arthroplasty were compared to establish prognosis factors. RESULTS: Thirty-two patients with traumatic dehiscence after TKA were evaluated. The trauma occurred on a mean of 14.3 +/- 25.0 days after the surgical procedure, and debridement in the operating room was performed on a mean of 6.2 +/- 4.9 hours after the trauma. Twenty patients maintained the arthroplasty until the end of follow-up and did not require revision. Factors related to arthroplasty removal were associated extensor mechanism injury (p = 0.026), time from trauma to surgical debridement (p = 0.035), and infection (p = 0.0001) CONCLUSION: Traumatic dehiscence after total knee arthroplasty is an event with a high rate of complications. Extensor mechanism Injury, infection, and extended time between trauma and surgical intervention were poor prognostic factors for arthroplasty maintenance.

Muscle function, Lysholm score and hop performance in individuals with clinical indications for the combined reconstruction of the anterior cruciate and the anterolateral ligaments of the knee: A cross-sectional study.

OBJECTIVE: To evaluate hip and knee muscular function, knee patient-reported outcome measures and hop performance in patients with a clinical indication for combined ACL+ALL reconstruction surgery compared to patients with an isolated ACL reconstruction surgery indication (preoperative phase) and to a control group. DESIGN: Cross-sectional study. METHODS: The sample was composed of male individuals, aged between 18 and 59 years, divided into three groups (ACL, ACL+ALL and Control). Isokinetic dynamometry was performed for the flexor and extensor knee muscles and for the hip abductors and adductors. SLHT, COHT and the Lysholm score were performed. Pain, swelling, and thigh trophism were also measured. RESULTS: The study participants were 89 male individuals: 63 in the injury group and 26 in the control group. After applying the criteria for an ALL reconstruction indication, 33 patients were assigned to the ACL Group and 30 patients to the ACL+ALL Group. Regarding knee and hip muscle function, both groups presented worse results when compared to the control group, however, did not show significant differences compared to each other. Regarding the functional variables, the ACL+ALL group showed a significantly shorter distance achieved in the Crossover Hop Test than the other groups, as well as more pain during the tests. CONCLUSION: Knee and hip muscular functions are impaired after an ACL injury and do not seem to be influenced or worsened in individuals with greater rotational instability with clinical indications for combined reconstruction of the anterior cruciate and the anterolateral ligaments of the knee.

Preferences and Practices of Brazilian Orthopedists for Thromboprophylaxis Techniques in Total Knee Arthroplasty: Survey Among Members of the Brazilian Society of Knee Surgery (SBCJ).

Objective The present study describes the preferences and current practices of a sample of knee surgeons in Brazil regarding thromboprophylaxis in total knee arthroplasty (TKA). Method In the present internet survey, surgeons from the Brazilian Knee Surgery Society (SBCJ, in the Portuguese acronym) voluntarily answered an anonymous questionnaire including time of personal surgical experience, perceptions about the best thromboprophylaxis options, and actual practices in their work environment. Results From December 2020 to January 2021, 243 participants answered the questionnaire. All, except for 3 (1.2%), reported using thromboprophylaxis, and most (76%) combined pharmacological and mechanical techniques. The most prescribed drug was enoxaparin (87%), which changed to rivaroxaban (65%) after discharge. The time of thromboprophylaxis initiation varied according to the length of training of the knee surgeon ( p ≤ 0.03), and their preferences and practices differed according to the Brazilian region ( p < 0.05) and the health system in which the surgeons work (public or private sector; p = 0.024). The option for mechanical thromboprophylaxis also depended on the training time of the surgeon. Conclusion Thromboprophylaxis preferences and practices in TKA are diverse across Brazilian regions and health systems (public or private sectors). Given the lack of a national clinical guideline, most orthopedists follow either their hospital guidelines or none. The mechanical prophylaxis method and the little use of aspirin are the points that most diverge from international guidelines and practices.