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The meniscus is a semilunar fibrocartilage structure that plays important roles in maintaining normal knee biomechanics and function. The roles of the meniscus, including load distribution, force transmission, shock absorption, joint stability, lubrication, and proprioception, have been well established. Injury to the meniscus can disrupt overall joint stability and cause various symptoms including pain, swelling, giving-way, and locking. Unless treated properly, it can lead to early degeneration of the knee joint. Because meniscal injuries remain a significant challenge due to its low intrinsic healing potential, most notably in avascular and aneural inner two-thirds of the area, more efficient repair methods are needed. Mesenchymal stem cells (MSCs) have been investigated for their therapeutic potential in vitro and in vivo. Thus far, the application of MSCs, including bone marrow-derived, synovium-derived, and adipose-derived MSCs, has shown promising results in preclinical studies in different animal models. These preclinical studies could be categorized into intra-articular injection and tissue-engineered construct application according to delivery method. Despite promising results in preclinical studies, there is still a lack of clinical evidence. This review describes the basic knowledge, current treatment, and recent studies regarding the application of MSCs in treating meniscal injuries. Future directions for MSC-based approaches to enhance meniscal healing are suggested.

Few clinical studies have compared uniplane high tibial osteotomy (HTO) with biplane HTO. The study aim was to compare the radiological and clinical results of uniplane HTO and biplane HTO, especially in terms of the increase in the posterior tibial slope (PTS). Medial opening-wedge HTO patients' medical records and radiological results from a single institution were retrospectively reviewed. Pre- and postoperative serial radiographs, including the Rosenberg, lateral view, and standing anteroposterior view of the whole lower extremity, magnetic resonance imaging at postoperative day 2, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score at postoperative 2 years were reviewed to evaluate radiological and clinical results, including the change in PTS. A total of 61 knees, including 34 for uniplane and 27 for biplane HTOs, were enrolled. There were no significant differences in the pre- and postoperative mechanical angles or incidences of the lateral hinge fractures, and all patients showed complete union at postoperative 2 years. The PTS was increased more in the biplane group than in the uniplane group (3.1 ± 2.6 in biplane vs. 0.8 ± 1.7 in uniplane, p

This report describes a novel endoscopic fusion technique performed with unilateral biportal endoscopy (UBE) that is known as extreme transforaminal lumbar interbody fusion (eXTLIF) and is performed with a large spacer. We also present the short-term results of this procedure. Previous studies reported that minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) could achieve acceptable rates of fusion; therefore, it is often used for treating various degenerative lumbar diseases. Moreover, MIS-TLIF can be performed with a unilateral approach; hence, it is commonly performed with the UBE technique. The biportal endoscopic TLIF procedure is usually performed with a single spacer in the interbody space. It is important to insert the maximum amount of graft material into the preparation site via an autologous bone marrow transplant or any other suitable substance with spacer insertion. Because MIS-TLIF with UBE is performed in water, it might provide an inadequate environment for excellent fusion. Therefore, a modified method was used to increase the surface contact area and insert the maximum amount of bone material with a larger spacer. However, the use of a large spacer necessitates a larger spacer orifice. For this purpose, eXTLIF was performed, which inserts the spacer more laterally compared with the current TLIF position. We report the surgical method and short-term results, which have been satisfactory thus far. [ Orthopedics . 2022;45(3):163–168.]

The water channel aquaporin 4 (AQP4) regulates the flux of water across the cell membrane, maintaining cellular homeostasis. Since AQP4 is enriched in the sarcolemma of skeletal muscle, a functional defect in AQP4 may cause skeletal muscle dysfunction. To investigate a novel mechanism underlying skeletal muscle atrophy, we examined AQP4 expression and its regulation in muscle using the rotator cuff tear (RCT) model. Human and mouse AQP4 expression was significantly decreased in atrophied muscle resulting from RCT. The size and the number of myotubes were reduced following AQP4 knockdown. Atrogin 1-mediated ubiquitination of AQP4 was verified with an ubiquitination assay after immunoprecipitation of AQP4 with an anti-AQP4 antibody. In this study, we identified high mobility group box 1 (HMGB1) as a potent upstream regulator of atrogin 1 expression. Atrogin 1 expression was increased by recombinant mouse HMGB1 protein, and the HMGB1-induced atrogin 1 expression was mediated via NF-κB signaling. Our study suggests that loss of AQP4 appears to be involved in myocyte shrinkage after RCT, and its degradation is mediated by atrogin 1-dependent ubiquitination. HMGB1, in its function as a signaling molecule upstream of the ubiquitin ligase atrogin 1, was found to be a novel regulator of muscle atrophy.

Purpose To evaluate the surgical methods according to the status of tunnels at the time of revision anterior cruciate ligament reconstruction (ACLR) and to evaluate clinical outcomes of revision ACLR in patients who underwent primary ACLR with the anatomic 4-tunnel double-bundle (DB) technique. Methods A total of 487 patients who underwent primary anatomic DB ACLR from April 2010 to July 2016 were retrospectively reviewed, and among those knees, the patients who underwent revision ACLR were included in the study. The patients with concomitant posterior cruciate ligament injuries were excluded. Forty patients (40 knees) were identified and enrolled. The surgical methods were reviewed. The range of motion, objective laxity using KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score after revision ACLR were compared with those after primary ACLR in the same patient using paired t-test with Bonferroni correction. Results The timing of reinjury after primary ACLR and mean interval between primary and revision ACLR were 18 months (range 1.5-80 months) and 24 months (range 4-82 months), respectively. Among 40 patients, 38 patients (95%) underwent 1-stage revision with the DB technique using pre-existing tunnels without compromised positioning of the grafts, and the other 2 patients (5%) underwent 2-stage revision. The postrevision range of motion, KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score were 137 ± 7°, 2.4 ± 1.2 mm, 91.4 ± 5.8, 98.9 ± 2.2, 78.6 ± 11.5, and 5.5 ± 1.2, respectively, and did not show any differences from those after primary ACLR. Conclusions In the revision setting after primary anatomic DB ACLR, most of the cases could be managed with 1-stage revision with DB technique using pre-existing tunnels, and the objective laxity and clinical scores after revision DB ACLR were comparable with those after primary DB ACLR. Level of Evidence Case series, Level IV.

Background Only limited data are available regarding postural stability between anterior cruciate ligament (ACL)-injured patients with medial meniscus (MM) tear and those with lateral meniscus (LM) tear. The purpose of this study was to compare preoperative postural stability for both involved and uninvolved knees in ACL rupture combined with MM and LM tears. It was hypothesized that there would be a significant difference in postural stability between these two groups. Methods Ninety-three ACL-injured patients (53 combined with MM tears vs. 40 combined with LM tears) were included. Static and dynamic postural stability were evaluated with the overall stability index (OSI), anterior–posterior stability index (APSI), and medial–lateral stability index (MLSI) using stabilometry. Knee muscle strength was evaluated using an isokinetic testing device. Results In the static postural stability test, none of the stability indices showed significant differences between the two groups for both knees (p > 0.05). In the dynamic postural stability test for involved side knees, the OSI and APSI were significantly higher in the LM tear group compared to the MM tear group (OSI: 2.0 ± 0.8 vs. 1.6 ± 0.5, p = 0.001; APSI: 1.5 ± 0.6 vs. 1.3 ± 0.5, p = 0.023), but not the MLSI (p > 0.05). In the static and dynamic postural stability tests in each group, there were no significant differences between the involved and uninvolved side knees (p > 0.05). There was no significant difference in the knee muscle strength between the two groups (p > 0.05). All postural stability showed no significant correlation with knee muscle strength (p > 0.05). Conclusion Dynamic postural stability was poorer in patients with ACL rupture combined with LM tear than in those with MM tear. Therefore, close monitoring for postural stability would be necessary during preoperative and postoperative rehabilitation, especially for patients with ACL rupture combined with LM tear. Level of evidence: Level III

BACKGROUND Spinal and pelvic injuries during an unexpected perturbation are closely related to spinal stability, which is known to be controlled by abdominal stabilization maneuvers. This study aimed to evaluate the effects of unexpected perturbations on trunk stability and abdominal stabilization strategies in 42 sedentary adults while sitting. MATERIAL AND METHODS Abdominal stabilization strategies consisted of bracing and hollowing maneuvers. Abdominal bracing maneuvers (ABM) were focused on the abdominal wall muscles [inferior oblique (IO), exterior oblique (EO)], and abdominal hollowing maneuvers (AHM) were focused on deep muscle (TrA) activation. The subjects were instructed in abdominal stabilization maneuvers. Afterward, subjects were seated in a chair that could be moved forward or backward suddenly with the support surface. RESULTS Angular displacements of the upper thorax, lower thorax, and lumbopelvic during unexpected perturbation, with different abdominal stabilization maneuvers, were measured. During forward perturbation (d=0.71, F=10.324, P=0.001) and backward perturbation in high speed (d=0.62, F=9.265, P=0.011), there were significant differences in angular displacements of the upper thorax between hollowing and bracing maneuvers. Additionally, significant differences were found in the lumbopelvic angular displacement between the hollowing and bracing maneuvers (d=0.62, F=4.071, P=0.044). CONCLUSIONS Our findings indicate that the ABM is a better stabilizing technique for the upper thorax, and the AHM is a better stabilizing technique for the lumbopelvic region during unexpected perturbations at high speed in the seated position.

Knee cartilage is in an aqueous environment filled with synovial fluid consisting of water, various nutrients, and ions to maintain chondrocyte homeostasis. Aquaporins (AQPs) are water channel proteins that play an important role in water exchange in cells, and AQP1, -3, and -4 are known to be expressed predominantly in cartilage. We evaluated the changes in AQP expression in chondrocytes from human knee articular cartilage in patients of different ages and identified the key factor(s) that mediate age-induced alteration in AQP expression. The mRNA and protein expression of AQP1, -3 and -4 were significantly decreased in fibrocartilage compared to hyaline cartilage and in articular cartilage from older osteoarthritis patients compared to that from young patients. Gene and protein expression of AQP1, -3 and -4 were altered during the chondrogenic differentiation of C3H10T1/2 cells. The causative factors for age-associated decrease in AQP included H2O2, TNFα, and HMGB1 for AQP1, -3, and -4, respectively. In particular, the protective effect of AQP4 reduction following HMGB1 neutralization was noteworthy. The identification of other potent molecules that regulate AQP expression represents a promising therapeutic approach to suppress cartilage degeneration during aging.

With surgical modifications reflecting plate design differences of the specific rigid locking plate adding a metal wedge, uniplane high tibial osteotomy (HTO) has fewer lateral-hinge fractures and fewer plate irritations than biplane HTO. Uniplane HTO with a rigid locking plate adding a metal wedge was compared with biplane HTO with a rigid locking plate including a proximal D-hole. For comparison, the HTO patients’ medical records and radiological results in a single institution were retrospectively reviewed. The Oxford knee score 2 years post-operation, CT scan at post-operative day 2 and serial standing long-bone scanography were reviewed to evaluate clinical outcome and radiological results, including the incidence of lateral-hinge fracture, plate irritation and correction loss to varus alignment. A total of 103 knees, including 59 uniplane HTO and 44 biplane HTO, were enrolled. The Oxford scores were 38.1 ± 7.8 in the uniplane group and 35.9 ± 8.3 in the biplane group (ns). On CT scans, more lateral-hinge fractures developed in the biplane group, and seven knees (12%) of the uniplane group and 12 knees (27%) of the biplane group had Takeuchi type I stable hinge fracture (p

Purpose We compared the clinical and radiologic results of human umbilical cord-blood derived mesenchymal stem cells (hUCB-MSCs)cartilage regeneration procedures combined with HTO to those of microfracture with HTO. Methods From August 2017 to December 2018, HTO patients with International Cartilage Regeneration and Joint Preservation Society (ICRS) grade IV cartilage defects over 200 mm2 on medial femoral condyle (MFC) were enrolled. For comparison, all participants were divided into two groups: those who had undergone an hUCB-MSC induced cartilage regeneration procedure (group MSC) and those with microfractures only (group C, controls). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), and Lysholm scores were evaluated post-operatively at 18 months. Radiologically, mechanical axis (MA) and joint space width (JSW) were evaluated. Results A total of 100 knees were enrolled (43 in group MSC, 57 in group C). The IKDC score in group MSC (69) was better than that in group C (62; P P

BACKGROUND There is limited study about the human umbilical cord-blood derived mesenchymal stem cell (hUCB-MSC) cartilage regeneration procedures combined with high tibial osteotomy (HTO). We compared the clinical and radiological results of hUCB-MSC cartilage regeneration procedures combined with HTO to those of microfracture with HTO. METHODS From August 2017 to December 2018, HTO patients with International Cartilage Regeneration and Joint Preservation Society (ICRS) grade IV cartilage defects over 200 mm2 on medial femoral condyle (MFC) were enrolled. For comparison, all participants were divided into two groups: those who had undergone an hUCB-MSC induced cartilage regeneration procedure (group MSC) and those with microfractures only (group C, controls). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), and Lysholm scores were evaluated post-operatively at 18 months. Radiologically, mechanical axis (MA) and joint space width (JSW) were evaluated. RESULTS A total of 100 knees were enrolled (43 in group MSC, 57 in group C). The IKDC score in group MSC (69) was better than that in group C (62; P

Background Stable water dynamics during endoscopic spine surgery improves the surgeon's comfort and patient's outcomes. We aimed to measure the water dynamics during spinal surgery and identify the factors that facilitate stable water dynamics. Methods This open-label, prospective, proficiency-matched, in vivo study included patients with single-level degenerative spinal disease. After assessing their heights and balancing the matched instrument, we measured the irrigation fluid pressure in various situations. We performed multiple regression analysis based on odds ratio (OR), confidence interval (CI), and relationships (proficiency-matched) with possible instrumental and physical characteristics. The instrumental factors were the presence and length of a rigid cannulation, and the physical characteristics were body mass index (body mass index [BMI]), skin-to-dura depth, height (interaction with BMI), and body weight (interaction with BMI). Results Of the 36 patients, 29 were included. The mean pressure of the operation cavity was 16.66 ± 9.12 cm H2O (12.25 ± 6.71 mm Hg). Water pressure with the rigid cannulation (9.41 ± 2.94 cm H2O [6.92 ± 2.16 mm Hg]) was significantly lower than that without cannulation (23.43 ± 7.57 cm H2O [17.26 ± 5.57 mm Hg], P Conclusions During biportal endoscopy, we suggest maintaining water pressure between 4.41 cm H2O (2.41 mm Hg) and 31.00 cm H2O (22.83 mm Hg). Compared to physical characteristics, placement of the cannula and appropriate cannula length are important factors that affect water dynamics.

Background: Post-laminectomy syndrome is a common cause of dissatisfaction after endoscopic interlaminar approach. Our aim was to evaluate the efficacy and safety of our two newly designed instruments for laminotomy, a dural protector attached to the scope and a knot pusher for water-tight suturing of the incidental dural tears. Material and Methods: This was a multicenter evaluation. Efficacy was quantified as the pre-to-postoperative improvement in pain (visual analog scale), disability (Oswestry Disability Index), patient satisfaction (modified MacNab score), and length of hospital stay. Safety was quantified by the incidence and location of dural tears, rate of revision, and radiological outcomes. Outcomes were evaluated between the control (before instrument development) and experimental (after instrument development) groups. Results: There was a significant improvement in leg pain in the experimental group (p = 0.03), with greater patient satisfaction in the control group (p < 0.01). There was no incidence of dural tears in the area of the traversing and exiting nerve roots in the experimental group. Water-tightness of sutures was confirmed radiologically. Conclusion: The novel dural protector and the knot pusher for water-tight sutures improved the efficacy and safety of decompression and discectomy; however, a prolonged operative time was a drawback.

PURPOSE: To compare the radiological and clinical outcomes using simple medial meniscus posterior horn (MMPH) root repair using an all-inside meniscal repair device combined with high tibial osteotomy (HTO) and HTO alone. METHODS: Between November 2013 and December 2016, patients treated for MMPH root tear along with HTO were enrolled. Based on the tear gap, the participants were divided into repairable ( 2 mm) categories. The participants in each group were divided into those amenable to simple MMPH root repair using an all-inside meniscal repair device and those that required no procedure for meniscus. Radiological parameters including mechanical femorotibial alignment (MA), posterior tibial slope (PTS) and medial joint-space width (JSW) were evaluated preoperatively and postoperatively at 2 years. For clinical evaluation, the WOMAC score was determined at the 2-year visit postoperatively. RESULTS: A total of 81 knees including 48 repairable (group R) and 33 unrepairable (group I) knees were enrolled. A total of 43 knees underwent simple MMPH root repair using an all-inside meniscal repair device (subgroup r), whereas the other 38 knees did not (subgroup n). The MA, PTS, and their postoperative changes as well as the WOMAC scores showed no differences. However, the JSW in group Rr increased from 3.1 to 3.6 mm, but decreased from 3.7 to 3.4 in group Rn, which was a statistically significant difference. CONCLUSION: Simple MMPH root repair using an all-inside meniscal repair device combined with HTO was more effective for the maintenance of JSW compared with HTO without a meniscal procedure in patients with repairable MMPH root tear and varus alignment. However, other options are needed for unrepairable MMPH root tear.

Arthroscopic partial resection is indicated for patients who have symptomatic discoid meniscus with overall satisfactory clinical outcomes. Reports regarding regeneration of discoid meniscus after arthroscopic surgery are limited. There are only two reports for children in the literature. To the authors’ knowledge, the present study is the first report in the literature to report regeneration of discoid lateral meniscus after arthroscopic partial meniscectomy in an adult patient. The diagnosis was confirmed by both magnetic resonance imaging and arthroscopy. Surgeons should be aware that regeneration of discoid meniscus can occur in adult as well as pediatric patients. Level of evidence V.

The purpose of this study was to assess post-operative patient subjective satisfaction and to analyze associated peri-operative factors following biplanar medial open wedge high tibial osteotomy (OWHTO). The study cohort consisted of 88 patients with a minimum of two years of follow-up. Patient satisfaction was evaluated with a questionnaire that assessed (1) overall satisfaction, (2) pain relief, (3) daily living functions, and (4) cosmesis. Patients were categorized into two groups (satisfied or unsatisfied) based on overall satisfaction questionnaire. Pre- and post-operative objective clinical statuses were assessed with a knee scoring system based on the American Knee Society (AKS), the Western Ontario McMaster University Osteoarthritis Index (WOMAC), and range of motion. Of the 88 patients, 85.2% were graded as satisfied according to the overall satisfaction estimation. The percentage of patients satisfied with pain relief, daily living functions, and cosmesis were 85.2%, 86.4%, and 86.4%, respectively. Multivariable logistic regression analysis demonstrated that pre-operative Hip-Knee-Ankle angle (HKAA) (odds ratio (OR) = 1.812), post-operative AKS knee score (OR = 1.156), and post-operative HKAA (OR = 0.717) were significantly associated with overall satisfaction. Pre-operative HKAA (OR = 1.436), post-operative WOMAC activity score (OR = 0.865), and post-operative HKAA (OR = 0.505) were significant predictors for satisfaction with pain reduction, daily living functions, and cosmesis, respectively. Biplanar medial OWHTO is an effective treatment for osteoarthritis with varus deformity in terms of subjective satisfactory outcome. Several factors, including pre- and post-operative HKAA, post-operative AKS and WOMAC score, were significant predictors for subjective satisfaction. Level of evidence: Level III

Introduction Chronic neck pain in office workers is a prevalent occupational disorder. Recently, smartphone applications (apps) have increased rapidly, and provide the benefits in terms of accessibility to health information. The objective of this study was to examine the effectiveness of an app-based exercise in office workers on pain intensity, functional disability, exercise adherence, muscle strength, quality of life and fear-avoidance. Methods 20 office workers participated in the study excluding one drop-out. The app-based exercise group (n = 11) conducted neck exercise through the mobile app in the workplace environment for at least 10–15 min/day, 2 days/week for 8 weeks while the control group (n = 9) received a brochure showing how to correct their posture themselves during the same period. Evaluations using the following were performed at baseline and after 8 weeks: the Visual Analog Scale (VAS), for pain intensity; Neck Disability Index (NDI), for functional disability; level of exercise adherence; maximal voluntary flexion/extension strength (MVFS/MVES); 36-Item Short-Form Healthy Survey (SF-36), for quality of life; and Fear-Avoidance Belief Questionnaire (FABQ). Results Within the app-based exercise group, the VAS (P = 0.003) and NDI (P = 0.005) improved significantly after the app-based neck exercise. MVES (P = 0.013), physical component summary (P = 0.02) of the SF-36, and the work-related subscale (P = 0.011) in the FABQ improved significantly. The level of exercise adherence was high. In VAS and NDI, there were statistically significant differences in the amounts of improvement between the groups. Conclusion An app-based neck exercise positively effects pain intensity, functional disability and partially improves muscle strength, SF-36 score, and FABQ score.

Background: Tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction can be a serious complication, and there is controversy over how to prevent it. This study aimed to suggest surgical approaches to prevent TW using an allo-Achilles tendon graft, and then to evaluate TW after these surgical tips were applied. Materials and Methods: Sixty two patients underwent ACL reconstruction with an allo-Achilles tendon graft. Four surgical approaches were used: Making a tibial tunnel by bone impaction, intraarticular reamer application, bone portion application for the femoral tunnel, and an additional bone plug application for the tibial tunnel. After more than 1-year, followup radiographs including anteroposterior and lateral views were taken in 29 patients encompassing thirty knees. The diameter of the tunnels at postoperation day 1 (POD1) and at followup was measured and compared. Results: In 18 knees (60%), there were no visible femoral tunnel margins on the radiographs at POD1 or followup. In the other 12 cases, which had visible femoral tunnel margins on followup radiographs, the mean femoral tunnel diameter was 8.6 mm. In the tibial tunnel, the mean diameters did not increase on all three levels (proximal, middle, and distal), and there was no statistically significant difference between the diameters at POD1 and followup. Conclusion: The suggested tips for surgery involving an allo-Achilles tendon graft can effectively prevent TW after ACL reconstruction according to this case series. These surgical tips can prevent TW.

To explore the feasibility of a newly developed smartphone-based exercise program with an embedded self-classification algorithm for office workers with neck pain, by examining its effect on the pain intensity, functional disability, quality of life, fear avoidance, and cervical range of motion (ROM).Single-group, repeated-measures design.The laboratory and participants' home and work environments.Offices workers with neck pain (N=23; mean age ± SD, 28.13±2.97y; 13 men).Participants were classified as having 1 of 4 types of neck pain through a self-classification algorithm implemented as a smartphone application, and conducted corresponding exercise programs for 10 to 12min/d, 3d/wk, for 8 weeks.The visual analog scale (VAS), Neck Disability Index (NDI), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), Fear-Avoidance Beliefs Questionnaire (FABQ), and cervical ROM were measured at baseline and postintervention.The VAS (P.001) and NDI score (P.001) indicated significant improvements in pain intensity and functional disability. Quality of life showed significant improvements in the physical functioning (P=.007), bodily pain (P=.018), general health (P=.022), vitality (P=.046), and physical component scores (P=.002) of the SF-36. The FABQ, cervical ROM, and mental component score of the SF-36 showed no significant improvements.The smartphone-based exercise program with an embedded self-classification algorithm improves the pain intensity and perceived physical health of office workers with neck pain, although not enough to affect their mental and emotional states.

Several surgical techniques have been suggested to anatomically reconstruct the posterolateral corner of the knee joint. However, most of them are open techniques that require dissection of the skin and soft tissues without utilizing the advantages of arthroscopic-assisted techniques. Therefore, this study aimed to describe a novel arthroscopic technique that anatomically reconstructs the posterolateral corner of the knee joint. This novel arthroscopic technique can properly identify important landmarks for reconstruction and anatomically reconstruct the three key components (lateral collateral ligament, popliteus tendon, and popliteofibular ligament) of the posterolateral corner of the knee joint.

Purpose To evaluate dynamic three-dimensional (3D) kinematic properties of the anterior cruciate ligament (ACL)-insufficient knees and healthy contralateral knees in awake patients during the Lachman test using biplane fluoroscopy. Materials and Methods Ten patients with unilateral ACL-insufficient knees and healthy contralateral knees were enrolled in this study. Each patient underwent the Lachman test three times in the awake state. The knee joint motions were captured using biplane fluoroscopy. After manual registration of 3D surface data from 3D-computed tomography to biplane images, dynamic 3D kinematic data were analyzed. Results The average anteroposterior (AP) translation of the medial femoral epicondyle of the ACL-insufficient knees (11.5±4.2 mm) was significantly greater than that of the contralateral knees (7.7±3.5 mm) (p

Purpose We aimed to compare posterior cruciate ligament (PCL) tibial tunnel location after tibial guide insertion medial (between the PCL remnant and the medial femoral condyle) and lateral (between the PCL remnant and the anterior cruciate ligament) to the PCL stump as determined by in vivo 3-dimensional computed tomography (3D-CT). Methods Tibial tunnel aperture location was analyzed by immediate postoperative in vivo CT in 66 patients who underwent single-bundle PCL reconstruction, 31 by over-the-PCL and 35 by under-the-PCL tibial guide insertion techniques. Tibial tunnel positions were measured in the medial to lateral and proximal to distal directions of the posterior proximal tibia. Results The center of the tibial tunnel aperture was located more laterally (by 2.7 mm) in the over-the-PCL group than in the under-the-PCL group ( P = .040) and by a relative percentage (absolute value/tibial width) of 3.2% ( P = .031). Tibial tunnel positions in the proximal to distal direction, determined by absolute value and relative percentage, were similar in the 2 groups. Conclusions Tibial tunnel apertures were located more laterally after lateral-to-the-PCL tibial guide insertion than after medial-to-the-PCL tibial guide insertion. There was, however, no significant difference between these techniques in distance from the joint line to the tibial tunnel aperture. Insertion lateral to the PCL stump may result in better placement of the PCL in its anatomic footprint. Level of Evidence Level III, retrospective comparative study.

The aim of this study was to investigate the patterns of contralateral motor overflow (i.e. mirror movement) between the homologous body parts on the right and left side, in stroke patients during single-finger and multi-finger maximum force production tasks. Forty subjects, including stroke (n=20) and normal subjects (n=20), participated in this study. The stroke subjects maximally pressed force sensors with their fingers in a flexed position using a single (index, middle, ring, or little) or all fingers (all 4 fingers) using the impaired (IH) or unimpaired (UIH) hand, while the non-patient subjects used their right hands for the same tasks. The maximal voluntary forces in the ipsilateral and unintended pressing forces of each contralateral finger were recorded during the tasks. The magnitude of motor overflow to the contralateral side was calculated using the index of contralateral independence (CI). During the single finger tasks, the finger CI was significantly decreased in the UIH (91%) compared with that in the IH (99%) or normal hands (99%). Likewise, the multiple finger tasks showed that the CI was significantly lower in the UIH (84%) compared with that in the IH (96%) or normal hands (99%). However, the maximal forces were significantly lower in the IH relative to those in the UIH and normal hands. These data demonstrate that stroke patients have greater motor overflow from the UIH to the IH.

Sensitivity of the myofascial trigger point (MTrP) can be inhibited by electrical stimulation of remote site. However, it remains unclear whether remote pain control of the MTrP occurs in the same spinal segment or in the supraspinal system.The aims of this study were to identify whether the remote pain control occurs in the spinal segment corresponding to the MTrP or in the supraspinal system.Test subjects (n = 10) received transcutaneous electrical nerve stimulation for 5 minutes, whereas control subjects (n = 10) received no intervention. The threshold for tactile sensory modulation at the lateral elbow was assessed using Von Frey filaments. The pressure sensitivities of MTrPs in both the infraspinatus and upper trapezius muscles were quantified by algometry. Measurements were performed at baseline and 1 and 15 minutes after the intervention.Increases of the tactile threshold at the remote site decreased the sensitivity of the MTrP innervated by same spinal segment. However, no changes were observed at MTrP sites innervated by contralateral fibers or those from different spinal segment.MTrP sensitivity is more strongly affected by interventions at remote ipsilateral sites in the same spinal segment than by stimulation of extra-segmental sites.

Extensive bone bleeding and an uncomfortable hematoma can develop due to the opening gap and space during a medial open high tibial osteotomy (HTO). Tranexamic acid (TXA) has been used in various orthopaedic surgeries to reduce bleeding and wound complications. However, no study has investigated the effect of TXA during HTO. Therefore, the purpose of this study is to evaluate the efficacy of TXA in reducing postoperative blood loss in patients undergoing HTO. The hypothesis is that topical TXA administration will reduce postoperative bleeding in patients undergoing medial opening HTO. Topical TXA (2 g in 20 mL saline) was administered at the osteotomy site in patients (n = 15) who underwent medial open HTO from November 2015 to March 2016. Patients (n = 15) who underwent medial open wedge HTO by the same surgeon from October 2014 to October 2015 were enrolled as a control group for comparison. Drainage volumes on postoperative days (PODs) 1, 2, and 3 as well as hemoglobin (Hb) level on PODs 1, 6, and 13 were measured and compared. Mean total postoperative drainage volume was 246 mL in the TXA group and 377 mL in the control group. Mean drainage volume on POD 1 was 138 mL in the TXA group and 277 mL in the control group (p 0.05). An extensive hematoma requiring additional surgery developed in one case in the control group. No wound complications were detected in the TXA group. Topical TXA was effective for reducing postoperative bleeding after medial open HTO. The level of evidence of the study is Level 3.

Purpose The purpose of this study was to perform a serial assessment of the radiologic parameters of the mechanical axis (MA) and the weight-bearing line (WBL) using a weight-bearing anteroposterior (AP) long-standing view of the lower extremity to determine whether the postoperative MA and WBL change with time. Methods A total of 90 consecutive lower limbs were examined retrospectively from a weight-bearing AP long-standing view of the lower extremity obtained from 120 patients who underwent open-wedge high tibial osteotomy (OWHTO). A total of 30 patients were excluded because of (1) complications (7 patients) such as bone graft collapse or broken screws, malunion, or nonunion arising after surgery and (2) no acquisition of a regular series of weight-bearing AP long-standing views of the lower extremity (23 patients). The AP long-standing view of the lower extremity was taken, and weight-bearing AP long-standing views of the lower extremity at 1 month, 6 months, 1 year, and 2 years postoperatively were used for assessment of serial change. The Picture Archiving Communication System (Marotech, Inc, St-Augustin-de-Desmaures, Quebec, Canada) was used for radiologic measurements of the WBL ratio and MA. Serial changes were compared between 1 month, 6 months, 1 year, and 2 years postoperatively. Results The WBL ratio progressively shifted medially, with significant changes at all time points until 1 year postoperatively (1 month to 6 months, P = .04; 6 months to 1 year, P = .04; 1 year to 2 years, P = .22). Even though the MA angle showed a similar decreasing trend, it showed no statistical difference ( P > .05). Conclusions This study showed that after OWHTO, the WBL shifts progressively medially until 1 year postoperatively. Level of Evidence Level IV, diagnostic study.

BACKGROUND Mixed use of T1- or T2-weighted magnetic resonance imaging (MRI) in histographic analysis has impeded cross-reference of studies on fatty degeneration of muscles in patients with back pain. OBJECTIVE The current study aimed to establish the measurement reliability of histographic analysis for normal and painful paraspinal muscles between T1- and T2-weighted MRI. METHODS T1- and T2-weighted MRI at the L4-5 level were performed in 31 patients with unilateral back pain. Two raters conducted the histographic analysis on 2 separate occasions. Multifidus, erector spinae, and psoas major muscles were assessed on both normal and painful sides. RESULTS Intra- and interrater reliability of the parameters were generally excellent for both T1- (intrarater: 0.83 ± 0.13 and interrater: 0.93 ± 0.08) and T2-weighted images (intrarater: 0.93 ± 0.12 and interrater: 0.92 ± 0.12). Histogram width was fair to good for both kinds of image. Intraclass correlation coefficients were similar between painful and normal sides. CONCLUSIONS The evidence that most histographic analysis parameters had excellent reliability for both T1- and T2-weighted images allows for cross-reference of the results between the two kinds of image. Moreover, the results of this study support the availability of histographic analysis for assessment of fatty degeneration in patients with back pain.

This mediolateral excursion of the bearing during knee motion is supposed to be caused by external rotation of the tibia during knee extension. However, to our knowledge, there is no published clinical evidence supporting these hypotheses. The current study aimed to evaluate the mediolateral excursion of the bearing during flexion-extension motion of the knee after medial unicompartmental knee arthroplasty (UKA). In 52 knees, varus/valgus (F-VarVal) or rotational position (F-Rot) of the femoral component and relative location of the bearing were measured with the standing anteroposterior and modified axial view, respectively. We adopted the modified axial radiographs that are simple to assess the bearing position in the flexed knee. The modified axial view showed excellent inter- and intraobserver agreements. F-Rot in the modified axial view and CT showed a high agreement in terms of validity (r = 0.98; p

Medial opening wedge high tibial osteotomy (HTO) has become increasingly popular as an alternative to lateral closing wedge osteotomy for the treatment of medial compartment knee osteoarthritis with varus deformity. The present systematic review was conducted to provide an objective analysis of total knee arthroplasty (TKA) outcomes following previous knee osteotomy (medial opening wedge vs. lateral closing wedge). A literature search of online databases (MEDLINE, EMBASE, Cochrane Library database) was made, in addition to manual search of major orthopaedic journals. The methodological quality of each of the studies was assessed on the Newcastle–Ottawa Scale and Effective Practice and Organization of Care. A total of ten studies were included in the review. There were eight studies with Level IV and two studies with Level III evidence. Eight studies reported clinical and radiologic scores. Comparative studies between TKA following medial opening and lateral closing wedge HTO did not demonstrate statistically significant clinical and radiologic differences. The revision rates were similar. However, more technical issues during TKA surgery after lateral closing wedge HTO were mentioned than the medial open wedge group. The quadriceps snip, tibial tubercle osteotomy, and lateral soft tissue release were more frequently needed in the lateral closing wedge HTO group. In addition, because of loss of proximal tibia bone geometry in the lateral closing wedge HTO group, concerns such as tibia stem impingement in the lateral tibial cortex was noted. The present systematic review suggests that TKA after medial opening and lateral closing wedge HTO showed similar performance. Clinical and radiologic outcome including revision rates did not statistically differ from included studies. However, there are more surgical technical concerns in TKA conversion from lateral closing wedge HTO than from the medial opening wedge HTO group. IV.

Purpose This study was designed to compare the preoperative strengths and endurances of the quadriceps and hamstring muscles in patients with anterior cruciate ligament (ACL) versus posterior cruciate ligament (PCL) tears. Methods Quadriceps and hamstring muscle strength and endurance were compared between 20 prospectively enrolled patients with isolated PCL tears and a retrospective, matched control group of 20 patients with isolated ACL tears. The maximal torque (60°/s) and total work (180°/s) of the quadriceps and hamstring were evaluated with an isokinetic testing device. Results Total work (1,094.4 ± 505.8 J v 797.5 ± 332.7 J, P = .035) and peak torque (129.9 ± 56.2 N ∙ m v 98.2 ± 37.4 N ∙ m, P = .046) of the quadriceps muscle on the involved side were higher in the PCL tear group than in the ACL tear group. However, there were no significant differences between the PCL tear group and ACL tear group in hamstring muscle strength (45.8 ± 42.3 N ∙ m and 46.0 ± 24.4 N ∙ m, respectively; P = .940) and endurance (429.3 ± 238.9 J and 382.4 ± 256.1 J, respectively; P = .574) on the involved side. Conclusions The strength and endurance of the quadriceps muscle of the injured limb were greater after PCL tears than after ACL tears. However, there were no significant between-group differences in hamstring muscle strength and endurance on the involved side. Level of Evidence Level III, retrospective comparative study.

Purpose The purpose of this study was to evaluate and compare femoral and tibial tunnel volume enlargement (TVE) after arthroscopic posterior cruciate ligament (PCL) reconstruction by remnant bundle preservation using Achilles allograft or mixed graft. Methods Seventy-eight patients undergoing primary arthroscopic single-bundle PCL reconstruction were initially included. Fifty-six of these patients underwent follow-up for a minimum of 1 year postoperatively and were divided into 2 groups: group A received Achilles allograft (n = 27), and group B received mixed graft (n = 29). The clinical evaluation included the International Knee Documentation Committee rating, Lysholm score, Tegner activity score, and Telos stress test (Telos, Weiterstadt, Germany). All of the patients were evaluated for TVE by computed tomography scanning at the 1-year follow-up; the results were compared with the data from 1 week postoperatively. A volume increment of more than 44%, which indicates 2 mm of widening of the tunnel diameter, was defined as TVE. Results The overall incidence of TVE after single-bundle PCL reconstruction was 3.6% (2 of 56 patients) for the femoral tunnel and 5.4% (3 of 56 patients) for the tibial tunnel. The overall mean tunnel difference between 1 week postoperatively and the final follow-up was 12.0% for the femoral tunnel and 10.6% for the tibial tunnel. The mean femoral TVE was 10.1% in group A and 13.8% in group B; the mean tibial TVE was 9.9% in group A and 11.2% in group B. These differences were not statistically significant. The functional outcome was improved in both groups, showing no statistical difference at the 1-year follow-up. Conclusions The femoral and tibial TVE caused by single-bundle PCL reconstruction using the remnant bundle–preservation technique showed no significant differences between the Achilles allograft and the mixed graft over a short-term follow-up. Furthermore, the overall incidence of TVE in PCL reconstruction in this study was low. Level of Evidence Level II, prospective comparative study.

The aim of this study was to investigate the mechanism underlying the development of gap differences in total knee arthroplasty using the navigation-assisted gap technique and to assess whether these gap differences have statistical significance. Ninety-two patients (105 knees) implanted with cruciate-retaining prostheses using the navigation-assisted gap balancing technique were prospectively analysed. Medial extension and flexion gaps and lateral extension and flexion gaps were measured at full extension and at 90° of flexion. Repeated measures analysis of variance was used to compare the mean values of these four gaps. The correlation coefficient between each pair of gaps was assessed using Pearson’s correlation analysis. Mean intra-operative medial and lateral extension gaps were 20.6 ± 2.1 and 21.7 ± 2.2 mm, respectively, and mean intra-operative medial and lateral flexion gaps were 21.6 ± 2.7 and 22.1 ± 2.5 mm, respectively. The pairs of gaps differed significantly (P

In this report, we describe a case of brain abscess due to odontogenic infection. A 53-year-old female who had been suffering from headache and trismus for two weeks visited the Department of Oral and Maxillofacial Surgery at the Sun Dental Hospital (Daejeon, Korea). Even after several routine tests, we still could not make a diagnosis. However, after the combined multidisciplinary efforts of oral surgeons and neurosurgeons, the patient was treated for odontogenic infection and made an uneventful recovery. Therefore, patients with infections in the head and neck region showing symptoms such as headache, changes in mental state, nausea, vomiting, seizures, hemiplegia, speech disturbance, and visual disturbance, a brain abscess should be included in the list of differential diagnoses.