Differential expressions of lysyl oxidase family in ACL and MCL fibroblasts after mechanical injury

Lysyl oxidase (LOX) family has the capacity to catalyse the cross-linking of collagen and elastin, implicating its important fundamental roles in tissue development and injury healing. However, the variations in expression of the LOX family in the normal and injured anterior cruciate ligament (ACL) are not fully known. To better understand the role of LOX family in the self-healing inability mechanism of injured ACL, this study is to measure the LOX family's differential expressions in ACL and medial collateral ligament (MCL) fibroblasts after mechanical injury induced by using an equi-biaxial stretching chamber. The cells received various degrees of mechanical stretch 0% (resting state), 6% (physiological state) and 12% (injurious state), respectively. The gene profile and protein expressions were analysed by semi-quantitative PCR, quantitative real-time PCR and Western blotting. At physiological state, gene expression showed LOX in ACL was 2.6–5.2 folds higher than that in MCL in all culture time periods, LOXL-4 1.2–3.6 folds, but LOXL-3 in MCL showed 1.1–4.8 folds higher than that in ACL. In injurious state, MCL gene expressions were 2.8–29.6 folds higher than ACL in LOX, LOXL-2, LOXL-3 and LOXL-4 at 2, 6 and 12 h periods. These differential expression profiles of the LOX family in the two ligament tissues were further used to explain the intrinsic differences between ACL and MCL, and why injured ACL could not be amenable to repair itself, whereas MCL could.     

Differential MMP-2 activity of ligament cells under mechanical stretch injury: an in vitro study on human ACL and MCL fibroblasts.

Recent studies have revealed that following injuries, ligament tissues such as anterior cruciate ligaments (ACL), release large amounts of matrix metalloproteinases (MMPs). These enzymes have a devastating effect on the healing process of the injured ligaments. Although these enzymes are produced following ligament injuries, because of different healing capacities seen between the medial collateral ligament (MCL) and ACL, we were curious to find if the MMP activity was expressed and modulated differently in these tissues. For this purpose ACL and MCL fibroblasts were seeded on equi-biaxial stretch chambers and were stretched in different levels. The stretched cells were assayed using Zymography, Western Blot and global MMP activity assays. The results showed that within 72 h after injurious stretch, production of 72 kD pro-MMP-2 increased in both ACL and MCL. However, the ACL fibroblasts generated significantly more pro-MMP-2 than the MCL fibroblasts. Furthermore we found in ACL pro-MMP-2 was converted more into active form. With 4-aminophenyl mercuric acetate (APMA) treatment, large amounts of pro-MMP-2 were converted into active form in both. This indicates that there is no significant difference between ACL and MCL fibroblasts in post-translational modification of MMP-2. The fluorescent MMP activity assays revealed that the MMP family activities were higher in the injured ACL fibroblasts than the MCL. Since the MMPs are critically involved in extracellular matrix (ECM) turnover, these findings may explain one of the reasons why the injured ACL hardly repairs. The higher levels of active MMP-2 seen in the ACL injuries may disrupt the delicate balance of ECM remodeling process. These results suggest that the generation and modulation of MMP-2 may be directly involved in the different responses seen in ACL and MCL injuries.     

Differential expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in anterior cruciate ligament and medial collateral ligament fibroblasts after a mechanical injury: Involvement of the p65 subunit of NF-κB

The anterior cruciate ligament (ACL) is known to have a poor healing ability, especially in comparison with the medial collateral ligament, which can heal relatively well. In this study, we detected significant increases in the mRNA levels of multiple matrix metalloproteinases (MMPs) (MMP-1, -2, -7, -9, -11, -14, -17, -21, -23A, -24, -25, -27, and -28) and tissue inhibitors of metalloproteinases (TIMPs) (TIMP-1, -2, -3, and -4) in ACL fibroblasts after an in vitro injury with an equi-biaxial stretch chamber. However, only some MMPs (MMP-7, -9, -14, -21, and -24) showed increases in injured medial collateral ligament fibroblasts, and to a much lesser degree than that observed in the injured ACL fibroblasts. Zymography revealed a 6.3-fold increase of MMP-2 activity in injured ACL but not medial collateral ligament fibroblasts, which agrees with the global MMP activities assay. Bay-11 and curcumin can significantly decrease MMP-2 activities to 13% and 29% in injured ACL fibroblasts, respectively, which implies the involvement of p65 subunits of nuclear factor κB and AP-1 pathways. Furthermore, Bay-11 can decrease the global MMP activity released from injured ACL fibroblasts in a dose-dependent manner. In summary, the differential expression and activities of MMPs might help to explain the poor healing ability of ACL, and the p65 subunit of nuclear factor κB might be a potential target to facilitate the ACL repair.     

MMP-1 overexpression induced by IL-1β: possible mechanism for inflammation in degenerative lumbar facet joint

Background

More and more attention has been focused on the inflammation or degeneration caused by biochemical factors in radiculopathy during lumbar facet joint degeneration. This study was designed to examine the expression and relationship of MMP-1/TIMP-1 and interleukin-1β (IL-1β), and to analyze the possible mechanism in degenerative lumbar facet joint disease.

Methods

Lumbar facet joint cartilage and synovial tissues in 36 cases of posterior lumbar surgery were harvested to investigate IL-1β and MMP-1/TIMP-1 by immunohistochemistry and Western blot analysis. Double labeling immunofluorescence and real-time PCR, respectively, were used to assess the relationship between IL-1β and MMP-1.

Results

IL-1β and MMP-1 were low in the lumbar disc herniation (LDH) group, and increased markedly in the lumbar spinal canal stenosis (LSCS) group (P < 0.05). However, there is no significant difference of TIMP-1 between LDH group and LSCS group (P > 0.05). Double staining results indicated that IL-1β overlapped with MMP-1 in the LSCS group. Moreover, real-time PCR results showed that MMP-1 mRNA in chondrocytes in vitro was affected in a dose- and time-dependent manner in response to IL-1β stimulation.

Conclusions

Overexpression of MMP-1, induced by IL-1β, plays an important role in the inflammatory process of lumbar facet joint degeneration.     

Differential regulation of MMP-2 in the gastrohepatic ligament of the gastroesophageal junction

Introduction

Ligamentous attachments maintain the normal anatomic position of the gastroesophageal (GE) junction. Failure of these elastic ligaments through an alteration in collagen synthesis, deposition, and metabolism may be a primary etiology of hiatal hernia formation. Differential expression of zinc-dependent matrix metalloproteinases (MMPs) is largely responsible for collagen remodeling. The purpose of this study was to survey baseline levels of MMPs in supporting ligaments of the GE junction from patients without hiatal hernia.

Methods

Following an institutional review board-approved protocol, plasma and tissue biopsies of the gastrohepatic ligament (GHL), gastrophrenic ligament (GPL), and phrenoesophageal ligament (PEL) were obtained in six patients without a hiatal hernia during laparoscopic anterior esophageal myotomy for achalasia. Total protein extracts from tissue biopsies were analyzed for elastases MMP-2, -9, and -12 and collagenases MMP-1, -3, -7, -8, and -13 using a multiplex profiling kit (R&D Systems, Minneapolis, MN). Data are reported as mean ± standard deviation. Statistical significance (p < 0.05) was determined using Tukey’s test and analysis of variance.

Results

In control patients without hiatal hernias, increased levels of MMP-2 (p < 0.02) were detected in the GHL compared with the GPL and PEL, respectively. Tissue levels of MMP-1, -12, and -13 were not detectable.

Conclusions

Gelatinase-A (MMP-2) is present in the GHL and plasma of control patients. The GHL may provide the primary GE junction supporting ligament to compare tissue from patients with type I (sliding) and type III (paraesophageal) hiatal hernias to examine the role of altered collagen metabolism in hiatal hernia formation.     

Surgical management of multiple knee ligament injuries

Objectives

To summarize our experience and mid-term results of reconstruction with Iliotibial tract grafts for multiple ligament injuries.

Methods

Between July 1997 and December 2003, multiple ligament injuries of 15 patients were reconstructed with Iliotibial tract grafts in arthroscopy. There were 5 women and 10 men. The mean age at the time of the surgery was 30.5 years (range 25–43 years). There were 7 cases who were injured with combined ACL rupture and the PCL, and 8 cases were with disruption of both the ACL and the PCL, combined with damage of the medial collateral ligament.

Results

Fifteen patients were followed up for a mean of 7.5 years (range 6–12 years). The overall mean postoperative Lysholm score was 84.3 ± 5.7. At final IKDC qualification, 60.0 % of the knees were normal or nearly normal. The overall average Tegner activity score decreased significantly at the re-examination compared to the activity score before accident (3.6 ± 0.5 vs. 5.1 ± 0.6).

Conclusions

Reconstruction with Iliotibial tract grafts in arthroscopy was a reliable treatment for multiple ligament injuries.     

Biomechanical evaluation of augmented and nonaugmented primary repair of the anterior cruciate ligament: an in vivo animal study

Purpose

The purpose of this study was to evaluate in a sheep model the biomechanical performance of augmented and nonaugmented primary repair of the anterior cruciate ligament (ACL) following transection at the femoral end during a 12-month postoperative observation.

Methods

Forty sheep were randomly assigned to nonaugmented or augmented primary ACL repair using a polyethylene terephthalate (PET) band. At two, six, 16, 26 and 52 weeks postoperatively four sheep in each group were sacrificed and biomechanical testing performed.

Results

Compared with nonaugmented primary ACL repair, the PET-augmented repair demonstrated superior biomechanical results from 16 weeks postoperatively onwards in terms of anterioposterior (AP) laxity, tensile strength and ligament stiffness. The augmentation device works as a stress shield during the ligament healing process. The nonaugmented ACL repair also resulted in ligament healing, but the biomechanical properties were at a significantly lower level.

Conclusion

These results support the previously reported histological findings following augmented primary ACL repair. This animal study on the healing capacity of the ACL may provide some important contributions to how primary healing in certain types of ruptures can be achieved.

Clinical relevance

I     

α-Smooth muscle actin and TGF-β receptor I expression in the healing rabbit medial collateral and anterior cruciate ligaments

The aim of our study was to advance the knowledge about the biological differences in the healing of the anterior cruciate ligament (ACL) versus the medial collateral ligament (MCL). We quantified α-smooth muscle actin (α-SMA) expression and TGF-β receptor I (TGF-βRI) expression in experimentally injured rabbit ligaments (from day 3 to 12 weeks post-injury). Myofibroblasts (α-SMA positive cells) were identified as early as the third day post-injury in MCL and their density increased steadily up to day 21. Myofibroblasts were also detected in injured ACL but their density remained very low at all time points. The percentage of positive TGF-βRI area significantly increased in both injured ligaments compared to controls, with a peak expression at day 21; however, it remained constantly lower in ACL compared to MCL. A significant correlation was found between the percentage of TGF-βRI positive cells and the percentage of α-SMA expression only in injured MCL. These results provide evidence that myofibroblasts are important players in MCL remodelling after injury. The combined presence of myofibroblasts and TGF-βRI in the first 3 weeks post-MCL injury may partially explain the difference in the MCL and ACL healing process.     

Knee Abduction Affects Greater Magnitude of Change in ACL and MCL Strains Than Matched Internal Tibial Rotation In Vitro

Background

Anterior cruciate ligament (ACL) injures incur over USD 2 billion in annual medical costs and prevention has become a topic of interest in biomechanics. However, literature conflicts persist over how knee rotations contribute to ACL strain and ligament injury. To maximize the efficacy of ACL injury prevention, the effects of underlying mechanics need to be better understood.

Questions/purposes

We applied robotically controlled, in vivo-derived kinematic stimuli to the knee to assess ligament biomechanics in a cadaver model. We asked: (1) Does the application of abduction rotation increase ACL and medial collateral ligament (MCL) strain relative to the normal condition? (2) Does the application of internal tibial rotation impact ACL strain relative to the neutral condition? (3) Does combined abduction and internal tibial rotation increase ligament strain more than either individual contribution?

Methods

A six-degree-of-freedom robotic manipulator was used to position 17 cadaveric specimens free from knee pathology outside of low-grade osteoarthritis (age, 47 ± 8 years; 13 males, four females) into orientations that mimic initial contact recorded from in vivo male and female drop vertical jump and sidestep cutting activities. Four-degree rotational perturbations were applied in both directions from the neutral alignment position (creating an 8° range) for each frontal, transverse, and combined planes while ACL and MCL strains were continuously recorded with DVRT strain gauges implanted directly on each ligament. Analysis of variance models with least significant difference post hoc analysis were used to assess differences in ligament strain and joint loading between sex, ligament condition, or motion task and rotation type.

Results

For the female drop vertical jump simulation in the intact knee, isolated abduction and combined abduction/internal rotational stimuli produced the greatest change in strain from the neutral position as compared with all other stimuli within the ACL (1.5% ± 1.0%, p ≤ 0.035; 1.8% ± 1.3%, p ≤ 0.005) and MCL (1.8% ± 1.0%, p < 0.001; 1.6% ± 1.3%, p < 0.001) compared with all other applied stimuli. There were no differences in mean peak ACL strain between any rotational stimuli (largest mean difference = 2.0%; 95% confidence interval [CI], ?0.9% to 5.0%; p = 0.070). These trends were consistent for all four simulated tasks. Peak ACL strain in the intact knee was larger than peak MCL strain for all applied rotational stimuli in the drop vertical jump simulations (smallest mean difference = 2.1%; 95% CI, ?0.4% to 4.5%; p = 0.047).

Conclusions

Kinematically constrained cadaveric knee models using peak strain as an outcome variable require greater than 4° rotational perturbations to elicit changes in intraarticular ligaments.

Clinical Relevance

Because combined rotations and isolated abduction produced greater change in strain relative to the neutral position for the ACL and MCL than any other rotational stimuli in this cadaver study, hypotheses for in vivo investigations aimed toward injury prevention that focuses on the reduction of frontal plane knee motion should be considered. Furthermore, reduced strain in the MCL versus the ACL may help explain why only 30% of ACL ruptures exhibit concomitant MCL injuries.

     

The kinematic analysis of female subjects after double-bundle anterior cruciate ligament reconstruction during single-leg squatting

Background

The kinematic characteristics of female anterior cruciate ligament (ACL)-injured subjects were recognized in our previous study using an electromagnetic device comparing both female control groups and male ACL-injured subjects during single-leg squatting.

Objective

To assess the kinematic characteristics of female subjects after double-bundle ACL reconstruction during single-leg squatting.

Methods

Three-dimensional motion analysis was performed for single-leg squatting in female subjects after ACL reconstruction. We evaluated the relative angles between the pelvis, thigh, and lower leg using an electromagnetic device during single-leg squatting in 28 female subjects with ACL reconstruction. All patients included in this study restored their sports performance level to 90 % or higher.

Results

Comparing the involved leg to the uninjured leg of female subjects after ACL reconstruction, the involved leg demonstrated significantly more hip adduction and less knee varus than the uninjured leg. Comparing the anterior cruciate ligament-reconstructed female subjects to the healthy female controls, the involved leg after ACL reconstruction demonstrated significantly less hip flexion, more hip external rotation, more hip adduction, and more knee flexion than the dominant leg of the control group.

Conclusion

This kinematic study exhibited kinematic characteristics of ACL-reconstructed knees of female subjects. Double-bundle anterior cruciate ligament reconstruction could not quite restore the normal kinematics of female-involved legs compared with both uninjured legs of female subjects and healthy female controls. In future studies, restoring the correct alignment of ACL reconstructed knee during single-leg squatting would be expected to reduce ACL re-injury and to assist a safe return to sport activities.     

Anterior cruciate ligament reconstruction with the ligament augmentation and reconstruction system: a systematic review

Purpose

The Ligament Augmentation and Reconstruction System (LARS) is a third generation of synthetic ligament, designed to overcome the issues of graft failure and synovitis which led previous generations of synthetic ligaments to fall out of favour. The theoretical benefits of LARS are appealing but this has not led to widespread uptake of the system in preference to autograft. The aim of this systematic review is to assess whether the evidence exists to support the use of LARS with respect to outcomes and complications.

Methods

A systematic search process was undertaken from January 1990 to June 2012 to identify primary evidence relating to the use of LARS in anterior cruciate ligament (ACL) single ligament reconstruction.

Results

Nine studies were found meeting the search criteria including a single randomised controlled trial, two comparative series and six further observational case series. Overall the methodological quality of the studies was poor with follow-up to a maximum of five years. Reported outcome scores were good for LARS and comparable to autograft techniques. Complication rates were low and comparable to those published for autograft techniques within the wider literature. Two reported incidences of synovitis were identified in case reports.

Conclusions

The current literature supports the use of LARS in the short to medium term. However, high-quality studies with long-term follow-up are required to determine whether the use of LARS is preferable to autograft for ACL reconstruction over the longer term. Synovitis appears to be a rare complication closely related to imperfect graft positioning.     

Differential sensitivity to NO-induced apoptosis between anterior cruciate and medial collateral ligament cells

It is well known that the anterior cruciate ligament (ACL) of the knee joint has poorer healing responses than the medial collateral ligament (MCL). Nitric oxide (NO) induces free radicals and plays a key role in the induction of apoptosis in various wound-healing models. We hypothesized that the poor healing response of the ACL may be ascribed to high susceptibility to apoptosis, and we investigated the difference in susceptibility to apoptosis between ACL and MCL cells after treatment with sodium nitroprusside, a NO donor. Apoptosis was evaluated by phase contrast microscopy, electron microscopy, DNA gel electrophoresis, and flow cytometric analysis. Although morphological changes and DNA ladders were observed in both ACL and MCL cells after 2mM sodium nitroprusside treatment, ACL cells were more prone to apoptosis at 1mM. Based on flow cytometric analysis, DNA fragmentation at 1mM sodium nitroprusside was significantly greater in ACL cells than in MCL cells (58.6% ± 1.6% vs. 11.9% ± 2.2%). Caspase-3 inhibitor (Ac-Asp-Glu-Val-Asp-CHO) and caspase-9 inhibitor (Ac-Leu-Glu-His-Asp-CHO) completely inhibited this DNA fragmentation. In conclusion, the ACL and MCL cells exhibit essential differences, and the differential sensitivity to NO-induced apoptosis between the ACL and MCL cells may be a reflection of these differences.     

The biomechanics of biodegradable versus titanium interference screw fixation for anterior cruciate ligament augmentation and reconstruction

Purpose

The ligament augmentation and reconstruction system (LARS) is one of the options available for anterior cruciate ligament (ACL) reconstruction. To date, however, there are no published data regarding the biomechanical properties of LARS fixation for ACL reconstruction. The aim of this study was to investigate the biomechanical properties of various LARS interference-screw fixations.

Methods

A total of 100 LARS ligaments were fixed in porcine femurs with five different interference screws (four biodegradable screws and one titanium interference screw) introduced from inside-out or extra-articularly outside-in. Each group consisted of ten specimens. The constructs were cyclically stretched and subsequently loaded until failure. We evaluated the maximum load before failure, elongation during cyclic loading, stiffness, and failure mode.

Results

Elongation during cyclical loading for all devices tested was significantly larger between the first and 20th cycles than between the 20th and 500th cycles (p?p?>?0.05). All specimens failed because of ligament pull-out from the bony tunnel.

Conclusions

Our findings suggest that biomechanical secure fixation of the LARS for ACL reconstruction can be achieved using either biodegradable or titanium interference screws. The stability of fixation is independent of the approach, type of investigation, and type of fixation (extra-articular outside-in or intra-articular inside-out).     

Cordycepin prevented IL-β-induced expression of inflammatory mediators in human osteoarthritis chondrocytes

Purpose

Cordycepin, a nucleoside derivative isolated from Cordyceps, has been reported to exert anti-inflammatory, antitumor, antidiabetic and renoprotective effects. Osteoarthritis (OA) is a degenerative joint disease with an inflammatory component that drives the degradation of cartilage extracellular matrix. This study aimed to assess the effects of cordycepin on human OA chondrocytes.

Methods

In this study, human OA chondrocytes were pretreated with cordycepin at 10, 50 or 100 μM and subsequently stimulated with interleukin-1β (IL-1β) (5 ng/ml) for 24 h. Production of prostaglandin E₂ (PGE2) and nitric oxide (NO) were evaluated by the Griess reaction and an enzyme-linked immunosorbent assay (ELISA). Gene expression of matrix metalloproteinase (MMP)-13, IL-6, inducible nitric oxide synthase (iNOS) and cyclo-oxygenase (COX-2) was measured by real-time polymerase chain reaction (PCR). MMP-13 and IL-6 proteins in culture medium were determined using cytokine-specific ELISA. Western immunoblotting was used to analyse the iNOS and COX-2 protein production in culture medium. Nuclear factor kappa-B (NF-κB) activity regulation was explored using Western immunoblotting.

Results

Pretreatment with cordycepin significantly inhibited the production of PGE2 and NO induced by IL-1β. Cordycepin also significantly decreased the IL-1β-stimulated gene expression and production of MMP-13, IL-6, iNOS and COX-2 in OA chondrocytes. Pretreatment with cordycepin attenuated IL-1β-induced activation of NF-κB by suppressing degradation of its inhibitory protein nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκB-α) in the cytoplasm.

Conclusions

We show for the first time the anti-inflammatory activity of cordycepin in human OA chondrocytes. Thus, with this unique profile of actions, cordycepin may prove to be a potentially attractive and new therapeutic/preventive agent for OA.     

Lectin-like oxidized low-density lipoprotein receptor 1 and matrix metalloproteinase expression in ruptured and unruptured multiple dissections of distal middle cerebral artery: case report

Purpose

Oxidized low-density lipoprotein receptor 1 (LOX1) is a critical factor for atherosclerosis in a variety of vascular diseases; however, its major role in cerebral arterial dissecting aneurysm is unclear.

Clinical presentation

We present a case of remarkable contrast of LOX1 expression in ruptured and unruptured multiple middle cerebral artery dissections and discuss the correlation of LOX1 with matrix metalloproteinases (MMPs). A 59-year-old woman presented with subarachnoid hemorrhage associated with left temporal subcortical hematoma. Emergent cerebral angiography demonstrated aneurysmal dilatation at the origin of the left anterior temporal artery (ATA) and occlusion on the distal side of ATA. Infectious aneurysm was excluded. Intraoperative findings showed ruptured dissection of the left ATA and unruptured aneurysmal dilatation of another temporal branch of the left M1 portion. Both lesions were trapped by clips and resected. Histopathological examination confirmed that both ruptured and unruptured aneurysmal dilatations were diagnosed as arterial dissections. Immunohistochemical examination demonstrated remarkable expressions of LOX1, MMP-2, and MMP-9 in hypertrophic media outside the intima in ruptured dissection, on the other hand, those expressions in the intima and inside hypertrophic media in the unruptured dissection.

Conclusions

This is the first report to reveal immunohistochemical findings of LOX1 and MMPs in multiple dissections of MCA. The contrast localization of LOX1 and MMPs might contribute to the fragility of the arterial wall layer of ruptured/unruptured arterial dissections.     

Autologous transplantation of culture-born myofibroblasts into intact and injured rabbit ligaments

Purpose

The myofibroblast, a contractile fibroblastic cell expressing α-smooth muscle actin (α-SMA), has been reported to play a role in ligament healing. The aim of this study was to evaluate the feasibility of transplanting culture-derived myofibroblasts in injured rabbit medial collateral ligaments (MCL) and in intact anterior cruciate ligaments (ACL).

Methods

Fibroblasts isolated from the iliotibial band were cultured in the presence of transforming growth factor beta-1 (TGF-β1) for five days and analysed for α-SMA expression. In a concentration of TGF-β1 ≥ 10 ng/ml, the differentiation rate into myofibroblast was 90%. After labelling with PKH26, α-SMA -positive cells were transplanted in intact ACL and in injured MCL of ten rabbits.

Results

Survival of PKH-26+ cells was seen in all intact and damaged ligaments one day after injection. The density of PKH-26+ cells had decreased at seven days postinjection in both ligaments. Double-positive PKH-26+/α-SMA+ cells were only observed in injured MCL at seven days postinjection. Moreover, we found that genetically modified fibroblasts differentiate into myofibroblasts and can be transplanted into ligaments.

Conclusions

Our data demonstrate that culture-born myofibroblasts survive and maintain α-SMA expression up to one week after transplantation. This study provides the first insight into the feasibility of transplanted mechanically active cells for ligament reconstruction.     

Matrix metalloproteinase, tissue inhibitor of metalloproteinase and transforming growth factor-beta 1 in frozen shoulder, and their changes as response to intensive stretching and supervised neglect exercise

Background

Frozen shoulder is characterized with thickening and contracture of joint capsular. The mechanism of this disorder is not yet clear, however, some proteins have been related to frozen shoulder. This study was to compare the serum levels of proteins related to frozen shoulder, such as matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP) and transforming growth factor-beta (TGF-β) between frozen shoulder and normal subjects; and before and after physical exercise active stretching and gentle thawing in frozen shoulder patients.

Methods

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 was measured from frozen shoulder and normal subjects by using ELISA. Functional assessment of shoulder joint in frozen shoulder patients was based on abbreviated Constant score. Frozen shoulder patients were randomly divided into intensive stretching and supervised neglect groups. Abbreviated Constant score and serum samples of frozen shoulder patients were evaluated at baseline, week-6, and week-12 after exercise, while only baseline serum samples of control were measured. MMP/TIMP ratio was calculated from the total sum of MMP-1 and MMP-2 levels divided by the total sum of TIMP-1 and TIMP-2 levels.

Results

Baseline MMP-1 and MMP-2 levels were significantly lower, while TIMP-1, TIMP-2, and TGF-β1 levels were significantly higher in frozen shoulder group than in control. Increased MMPs and decreased TIMPs were significantly greater after intensive stretching than after supervised neglect exercise. Abbreviated Constant score improvement was significantly higher in intensive stretching group than in supervised neglect group.

Conclusions

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 may be associated to frozen shoulder. Active stretching can improve frozen shoulder better than supervised neglect, as demonstrated by the improvement of Constant score.     

Sagittal view of the tibial attachment of the anterior cruciate ligament on magnetic resonance imaging and the relationship between anterior cruciate ligament size and the physical characteristics of patients

Background

It is necessary to create bone tunnels within the native footprint during anatomic anterior cruciate ligament (ACL) reconstruction. Predicting the size of the ACL preoperatively may be useful in order to determine the diameter of the bone tunnels preoperatively or during surgery. The tibial insertion site of the ACL includes a depressed area, the ACL fovea, which is generally observed in the sagittal view on magnetic resonance imaging (MRI). The purposes of this study were to measure the anteroposterior diameter of the ACL fovea in the sagittal view on MRI and to investigate its associations with the physical characteristics of patients.

Methods

One hundred patients (100 knees; 50 males and 50 females; mean age, 33 years) were included in this study. The anteroposterior diameter of the ACL fovea was measured in the sagittal view on MRI. The relationships between the diameter of the ACL fovea and physical characteristics including height, weight, and body mass index (BMI) were analyzed.

Results

The mean diameter of the ACL fovea was 16.1 mm in male patients and 14.3 mm in female patients, which were comparable to the previously reported values. There were significant positive correlations between the diameter of the ACL fovea and height and weight, but not BMI. The number of knees in which the diameter of the ACL fovea was <13 mm was 14 (14 %), and females were more likely to have ACL fovea diameter <13 mm.

Conclusions

The study indicated that it is possible to predict the size of the ACL before surgery by measuring the diameter of the ACL fovea on MRI. Physical characteristics of patients correlated with the diameter of the ACL fovea. Especially in female patients, it is important to consider the size of the ACL preoperatively.     

Allograft ligament transplantation in anterior cruciate ligament reconstruction patients with meniscal tears

Background

It currently remains unclear whether the meniscal repair clinical results were affected by the graft used in anterior cruciate ligament (ACL) reconstruction. This retrospective study designed to evaluate the difference in clinical outcomes of meniscal repair using autograft and allograft for the ACL reconstruction.

Methods

The injury of the ACL and meniscus was evaluated with MRI and treated simultaneously. One hundred and eighty-nine cases were initially fulfilled the study criteria, and had the surgery in the period June 2007 and July 2010. Thirty-four patients were lost to follow-up. Seventy-five patients underwent meniscus repair with autograft reconstruction of the ACL (autograft group) and 80 patients underwent meniscus repair with allograft reconstruction of the ACL (allograft group).

Results

The meniscus healing rate based on the clinical examination of Barrett’s criteria was 81.3 % (61/75) in the autograft group and 80.0 % (64/80) in the allograft (P > 0.05). There was no significant difference in the Lysholm scores in the allograft group compared to the allograft group (89.1 ± 10.6 versus 88.7 ± 11.2, P > 0.05). The values of immunoglobulin’s and complements (IgG, IgA, IgM, C3 and C4) were not significantly different between the two groups (P > 0.05).

Conclusion

The data support our assumption that patients undergoing meniscal repair associated with ACL reconstruction with allograft had good clinical outcomes. Although allograft implantation induces an immunological response on a subclinical level, there were no signs of allograft affecting the nature of meniscus healing.