Integrin α4 mediates ATDC5 cell adhesion to negatively charged synthetic polymer hydrogel leading to chondrogenic differentiation.

Negatively charged synthetic hydrogels have been known to facilitate various cellular responses including cell adhesion, proliferation, and differentiation; however, the molecular mechanism of hydrogel-dependent control of cell behavior remains unclear. Recently, we reported that negatively charged poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel induces chondrogenic differentiation of ATDC5 cells via novel protein reservoir function. In this study, we identified the cell adhesion molecules binding to PAMPS gels that act as mechanoreceptors. First, we performed a pull-down assay by particle gels using cell membrane proteins of ATDC5, and found that multiple membrane proteins bound to the PAMPS gel, whereas the uncharged poly(N,N'-dimethylacrylamide) gel as control did not bind to any membrane proteins. Western blot analysis indicated differential binding of integrin (ITG) isoforms to the PAMPS gel, in which the α4 isoform, but not α5 and αv, efficiently bound to the PAMPS gel. ITG α4 knockdown decreased cell spreading of ATDC5 on PAMPS gels, whereas the enhanced expression increased the behavior. Furthermore, ITG α4 depletion suppressed PAMPS gel-induced expression of bone morphogenic protein (BMP) 4 contributing to chondrogenic differentiation, in concordance with the reduction of ERK activation. These results demonstrated that membrane protein binding to PAMPS gels occurred in a charge-dependent manner, and that ITG α4 plays a crucial role in cell spreading on PAMPS gels and acts as a mechanoreceptor triggering cellular signaling leads to chondrogenic differentiation.

Post-operative pain control following arthroscopic rotator cuff repair: peri-articular injection versus interscalene brachial plexus block.

PURPOSE: To compare post-operative pain relief with peri-articular injection (PI) versus interscalene brachial plexus block (IBPB) after arthroscopic rotator cuff repair (ARCR) surgery. METHODS: We retrospectively reviewed 121 consecutive patients undergoing ARCR surgery divided into two groups: the PI group and the IBPB group. We compared complications and self-reported pain score measured using a Numerical Rating Scale (NRS) during the initial 24 hours after surgery. RESULTS: The NRS scores recorded in the recovery room (0), 0.5, and four hours post-operatively were higher in the PI group (n = 38) than the IBPB group (n = 52) (2.1 vs. 0.8, p = 0.014; 1.4 vs. 0.5, p = 0.0069; and 1.3 vs. 0.5, p = 0.012, respectively). However, the NRS scores recorded at 16, 20, and 24 hours post-operatively were lower in the PI group than in the IBPB group (1.4 vs. 3.1, p < 0.0001; 1.4 vs. 3.2, p < 0.0001; and 1.7 vs. 3.2, p = 0.00046, respectively). The incidences of post-operative nausea and temporary numbness in the upper arm were significantly lower in the PI group than in the IBPB group (7.9% vs. 33%, p = 0.0052; and 13% vs. 85%, p < 0.0001, respectively). CONCLUSIONS: Although IBPB provided superior pain control during the initial few hours after ARCR surgery, PI was superior from 16 to 24 hours post-operatively. The rates of side effects, such as nausea and temporary arm numbness, were also lower in the PI group than in the IBPB group.

Comparison Between Isotropic 3-Dimensional Fat-Suppressed T2-Weighted Fast Spin Echo (FSE) and Conventional 2-Dimensional Fat-Suppressed Proton-Weighted FSE Shoulder Magnetic Resonance Imaging at 3-T in Patients With Shoulder Pain.

OBJECTIVE: The aims of this study were to compare isotropic 3-dimensional fat-suppressed T2-weighted fast spin echo (FSE) imaging (T2FS) with 2-dimensional fat-suppressed proton-density-weighted FSE imaging (2D-PDFS) and evaluate feasibility of isotropic 3-dimensional FSE shoulder imaging at 3-T magnetic resonance imaging (MRI). METHODS: Seventy-eight patients who underwent shoulder MRI were evaluated. Three-dimensional T2FS and 2D-PDFS were qualitatively graded for delineation of anatomic structures. In quantitative analysis, mean relative signal intensity and relative signal contrast between each structure of the shoulder were compared. RESULTS: Three-dimensional T2FS showed significantly higher scores for rotator cuff (P = 0.020), lower scores for bone (P < 0.001), and higher relative contrast of rotator cuff to fluid (P < 0.001) and labrum to fluid (P < 0.001) in comparison with 2D-PDFS. No significant difference in relative signal intensity of the rotator cuff, labrum, joint fluid, cartilage, and bone marrow was demonstrated. CONCLUSIONS: Isotropic 3-dimensional FSE MRI has similar image quality and diagnostic performance to conventional 2-dimensional sequence in evaluation of the rotator cuff.

Effects of osteochondral defect size on cartilage regeneration using a double-network hydrogel.

BACKGROUND: There has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages. We have studied the chondrogenic induction ability of a PAMPS/PDMAAm double-network (DN) gel and found it to induce chondrogenesis in animal osteochondral defect models. The purpose of this study was to investigate whether the healing process and the degree of cartilage regeneration induced by the cell-free method using DN gel are influenced by the size of osteochondral defects. METHODS: A total of 63 mature female Japanese white rabbits were used in this study, randomly divided into 3 groups of 21 rabbits each. A 2.5-mm diameter osteochondral defect was created in the femoral trochlea of the patellofemoral joint of bilateral knees in Group I, a 4.3-mm osteochondral defect in Group II, and a 5.8-mm osteochondral defect in Group III. In the right knee of each animal, a DN gel plug was implanted so that a vacant space of 2-mm depth was left above the plug. In the left knee, we did not conduct any treatment to obtain control data. Animals were sacrificed at 2, 4, and 12 weeks after surgery, and gross and histological evaluations were made. RESULTS: The present study demonstrated that all sizes of the DN gel implanted defects as well as the 2.5mm untreated defects showed cartilage regeneration at 4 and 12 weeks. The 4.3-mm and 5.8-mm untreated defects did not show cartilage regeneration during the 12-week period. The quantitative score reported by O'Driscoll et al. was significantly higher in the 4.3-mm and 5.8-mm DN gel-implanted defects than the untreated defects at 4 and 12 weeks (p < 0.05). The 2.5-mm and 4.3-mm DN gel implanted defects maintained relatively high macroscopic and histological scores for the 12-week implantation period, while the histological score of the 5.8-mm DN gel implanted defect had decreased somewhat but statistically significantly at 12 weeks (p = 0.0057). CONCLUSIONS: The DN gel induced cartilage regeneration in defects between 2.5 and 5.8 mm, offering a promising device to establish a cell-free cartilage regeneration therapy and applicable to various sizes of osteochondral defects.

Effects of initial graft tension on clinical outcome after anatomic double-bundle anterior cruciate ligament reconstruction: comparison of two graft tension protocols.

BACKGROUND: In anatomic double-bundle anterior cruciate ligament (ACL) reconstruction, there are great controversies concerning the ideal graft tension protocols. The purpose of this study was to clarify differences in the effect of two graft tension protocols on the clinical outcome after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction by comparing the minimum 2-year clinical results. METHODS: Ninety-seven patients with unilateral anatomic double-bundle ACL reconstruction were divided into two groups. In the first 44 patients (Group I), a 40-N tension was applied to each of the two hamstring autografts at 30° of knee flexion, and simultaneously fixed onto the tibia. In the remaining 53 patients (Group II), a 30-N tension was applied to each graft at 10° of knee flexion, and simultaneously fixed onto the tibia. Each patient was examined 2 years after surgery. RESULTS: There wasn't a significant difference in the background of the two groups. There was no significant difference in the postoperative anterior laxity between the two groups. The average was 1.1 mm and 0.9 mm in Groups I and II, respectively. There wasn't any differences between the two groups in Lysholm knee score, International Knee Documentation Committee (IKDC) evaluation and muscle strength. Four patients had loss of knee extension in a range of 5° and 10° in Group I and none of the patients in Group II exhibited any loss in knee extension; which was statistically significant (p = 0.025). CONCLUSION: The two initial graft tension protocols did not result in any significant differences in the Lysholm knee score and IKDC grade. However, it was noted that the 40-N tension applied to each graft at 30° of knee flexion more significantly induced loss of knee extension in comparison to the 30-N tension applied to each graft at 10°. From a clinical viewpoint, the loss of knee extension is one of the pathological conditions that should be absolutely avoided after ACL reconstruction. Therefore, the 30-N tension applied to each graft at 10° is preferable to the other graft tension protocol.

Hyaluronic acid enhances the effect of the PAMPS/PDMAAm double-network hydrogel on chondrogenic differentiation of ATDC5 cells.

BACKGROUND: A double-network (DN) gel, which was composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid) and poly-(N,N'-dimethyl acrylamide) (PAMPS/PDMAAm), has the potential to induce chondrogenesis both in vitro and in vivo. The present study investigated whether DN gel induced chondrogenic differentiation of ATDC5 cells in a maintenance medium without insulin, and whether supplementation of hyaluronic acid enhanced the chondrogenic differentiation effect of DN gel. METHODS: ATDC5 cells were cultured on the DN gel and the polystyrene (PS) dish in maintenance media without insulin for 21 days. Hyaluronic acid having a molecular weight of approximately 800 kDa was supplemented into the medium so that the concentration became 0.01, 0.1, or 1.0 mg/mL. The cultured cells were evaluated using immunocytochemistry for type-2 collagen and real time PCR for gene expression of type-2 collagen, aggrecan, and Sox9 at 7 and 21 days of culture. RESULTS: The cells cultured on the DN gel formed nodules and were stained with an anti-type-2 collagen antibody, and expression of type-2 collagen and aggrecan mRNA was significantly greater on the DN gel than on the PS dish surface (p < 0.05) in the hyaluronic acid-free maintenance medium. Hyaluronic acid supplementation of a high concentration (1.0 mg/mL) significantly enhanced expression of type-2 collagen and aggrecan mRNA in comparison with culture without hyaluronic acid at 21 days (p < 0.05). CONCLUSIONS: The DN gel induced chondrogenic differentiation of ATDC5 cells without insulin. This effect was significantly affected by hyaluronic acid, depending on the level of concentration. There is a high possibility that hyaluronic acid plays an important role in the in vivo hyaline cartilage regeneration phenomenon induced by the DN gel.

Effects of culture on PAMPS/PDMAAm double-network gel on chondrogenic differentiation of mouse C3H10T1/2 cells: in vitro experimental study.

BACKGROUND: Recently, several animal studies have found that spontaneous hyaline cartilage regeneration can be induced in vivo within a large osteochondral defect by implanting a synthetic double-network (DN) hydrogel, which is composed of poly-(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and poly-(N,N'-dimethyl acrylamide) (PDMAAm), at the bottom of the defect. However, the effect of hydrogel on hyaline cartilage regeneration remains unexplained. The purpose of this study was to investigate the chondrogenic differentiation of C3H10T1/2 cells on PAMPS/PDMAAm DN gel. METHODS: C3H10T1/2 cells of 1.0 × 105 were cultured on PAMPS/PDMAAm DN gel in polystyrene tissue culture dishes or directly on polystyrene tissue culture dishes. We compared cultured cells on PAMPS/PDMAAm DN gel with those on polystyrene dishes by morphology using phase-contrast microscopy, mRNA expression of aggrecan, type I collagen, type II collagen, Sox 9 and osteocalcin using real-time RT-PCR, and local expression of type II collagen using immunocytochemistry. RESULTS: C3H10T1/2 cells cultured on the PAMPS/PDMAAm DN gels formed focal adhesions, aggregated rapidly and developed into large nodules within 7 days, while the cells cultured on the polystyrene surface did not. The mRNA levels of aggrecan, type I collagen, type II collagen, Sox 9 and osteocalcin were significantly greater in cells cultured on the PAMPS/PDMAAm DN gel than in those cultured on polystyrene dishes. In addition, C3H10T1/2 cells cultured on PAMPS/PDMAAm DN gel expressed more type II collagen at the protein level when compared with cells cultured on polystyrene dishes. CONCLUSIONS: The present study showed that PAMPS/PDMAAm DN gel enhanced chondrogenesis of C3H10T1/2 cells, which are functionally similar to mesenchymal stem cells. This suggests that mesenchymal stem cells from the bone marrow contribute to spontaneous hyaline cartilage regeneration in vivo in large osteochondral defects after implantation of PAMPS/PDMAAm DN gels.

Intra-articular administration of hyaluronic acid increases the volume of the hyaline cartilage regenerated in a large osteochondral defect by implantation of a double-network gel.

Implantation of PAMPS/PDMAAm double-network (DN) gel can induce hyaline cartilage regeneration in the osteochondral defect. However, it is a problem that the volume of the regenerated cartilage tissue is gradually reduced at 12 weeks. This study investigated whether intra-articular administration of hyaluronic acid (HA) increases the volume of the cartilage regenerated with the DN gel at 12 weeks. A total of 48 rabbits were used in this study. A cylindrical osteochondral defect created in the bilateral femoral trochlea was treated with DN gel (Group DN) or left without any implantation (Group C). In both Groups, we injected 1.0 mL of HA in the left knee, and 1.0 mL of saline solution in the right knee. Quantitative histological evaluations were performed at 2, 4, and 12 weeks, and PCR analysis was performed at 2 and 4 weeks after surgery. In Group DN, the proteoglycan-rich area was significantly greater in the HA-injected knees than in the saline-injected knees at 12 weeks (P = 0.0247), and expression of type 2 collagen, aggrecan, and Sox9 mRNAs was significantly greater in the HA-injected knees than in the saline-injected knees at 2 weeks (P = 0.0475, P = 0.0257, P = 0.0222, respectively). The intra-articular administration of HA significantly enhanced these gene expression at 2 weeks and significantly increased the volume of the hyaline cartilage regenerated by implantation of a DN gel at 12 weeks. This information is important to develop an additional method to increase the volume of the hyaline cartilage tissue in a potential cartilage regeneration strategy using the DN gel.

Biomechanical comparison of the strength of adhesion of polymethylmethacrylate cement to zirconia ceramic and cobalt-chromium alloy components in a total knee arthroplasty.

PURPOSE: The purpose of this study was to clarify the biomechanical characteristics of cement-material interfaces for the zirconia ceramic and cobalt-chromium (Co-Cr) alloy femoral components used for total knee arthroplasty. METHODS: In the first sub-study, we compared the strength of adhesion of the cement to flat plates, by tensile testing under dry and moistened conditions. In the second sub-study, we compared the maximum load of the cement-component complex by tensile testing. In the third sub-study, we compared the fatigue characteristics of the cement-component complex by use of a dynamic tensile testing machine. RESULTS: Under dry conditions, the maximum strength of adhesion to the zirconia ceramic plate was the same as that to the Co-Cr alloy plate. Under moistened conditions, however, the strength of adhesion to the zirconia ceramic plate was significantly lower (p = 0.0017) whereas the strength of adhesion to the Co-Cr alloy plate was not reduced. Maximum load for the cement-component complexes for zirconia ceramic and Co-Cr alloy was no different under both dry and moistened conditions. Fatigue testing showed that cement-zirconia adhesion was stronger than cement-Co-Cr alloy adhesion (p = 0.0161). CONCLUSIONS: The strength of adhesion of cement to zirconia ceramic is substantially weaker under wet conditions than under dry conditions. The mechanical properties of cement-zirconia ceramic component complexes and cement-Co-Cr alloy component complexes are equivalent.

Evaluation of glenoid morphology and bony Bankart lesion in shoulders with traumatic anterior instability using zero echo time magnetic resonance imaging.

Background: Preoperative computed tomography (CT) evaluation of bone morphometry aids in determining treatment strategies for shoulder instability. The use of zero echo time (ZTE) sequence in magnetic resonance imaging (MRI), a new bone cortex imaging technique, may help reduce radiation exposure and medical costs. Therefore, this study aimed to evaluate the glenoid morphology and detect the presence of bony Bankart lesion using ZTE MRI in shoulders with anterior instability and compare its diagnostic accuracy with that of CT. Methods: Thirty-six patients (36 shoulders) with anterior instability who underwent preoperative CT and MRI examinations between April 2019 and October 2021 were retrospectively analyzed. The percentages of glenoid bone defects on 3-dimensional (3D) CT and ZTE images were determined, and the correlation between these percentages was evaluated. The number of cases with bony Bankart lesion on CT and 2 types of ZTE (3D and CT-like) images was determined, and the diagnostic accuracy of ZTE for detecting bony Bankart lesion was assessed, with CT as the gold standard. Patients with bony Bankart lesion on CT images were divided into 2 groups based on whether the lesion was detectable on 3D ZTE or CT-like images. The longer diameters of bony Bankart lesion were compared between the groups. Results: The median percentage of glenoid bone loss was 12.1% (range, 1.3%-45.9%) and 12.3% (range, 0%-46.6%) on 3D CT and 3D ZTE images, respectively. The Spearman's rank correlation coefficient was 0.89. Bony Bankart lesion was detected in 18, 13, and 8 shoulders of the 36 patients on CT, 3D ZTE, and CT-like images, respectively. The overall diagnostic accuracy of the CT-like and 3D ZTE images for detecting bony Bankart lesion was 86.1% and 72.2%, respectively. A significant difference was observed between the groups with and without bony Bankart lesion on CT-like images in terms of the long diameter of the bone fragments on CT (P < .01). Conclusion: ZTE MRI demonstrated high reproducibility for the evaluation of glenoid bone defect in shoulders with anterior instability. Although no significant difference in the measurement was observed compared with that on CT, the ability of ZTE MRI to delineate bone Bankart lesion remains limited.

Flurbiprofen concentration in soft tissues is higher after topical application than after oral administration.

AIM: To compare tissue concentrations of flurbiprofen resulting from topical application and oral administration according to the regulatory approved dosing guidelines. METHOD: Sixteen patients were included in this study. Each patient was randomly assigned to the topical application or oral administration group. In each group, a pair of tapes or a tablet, containing a total of 40 mg flurbiprofen, was administered twice at 16 and 2 h before the surgery. RESULTS: The flurbiprofen concentration in the fat, tendon, muscle and periosteum tissues was significantly higher (P < 0.0330) after topical application (992 ng g⁻¹ [95% CI 482, 1503], 944 [95% CI 481, 1407], 492 [95% CI 248, 735], and 455 [95% CI 153, 756], respectively) than after oral administration (150 ng g⁻¹ [95% CI 84, 217], 186 [95% CI 118, 254], 82 [95% CI 49, 116],and 221 [95% CI, 135, 307], respectively). CONCLUSION: Topical application is an effective method to deliver flurbiprofen to the human body, particularly to soft tissues near the body surface.

Hyaluronic acid affects the in vitro induction effects of synthetic PAMPS and PDMAAm hydrogels on chondrogenic differentiation of ATDC5 cells, depending on the level of concentration.

BACKGROUND: It has been a common belief that articular cartilage tissue cannot regenerate in vivo. Recently, however, we have found that spontaneous hyaline cartilage regeneration can be induced in vivo by implanting a synthetic double-network (DN) hydrogel, which is composed of poly-(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and poly-(N,N'-dimethyl acrylamide) (PDMAAm). However, the mechanism of this phenomenon has not been clarified. Recently, we have found that single-network PAMPS and PDMAAm gels can induce chondrogenic differentiation of ATDC5 cells in vitro even in a maintenance medium. In the in vivo condition, there is a strong possibility that the induction effect of the gel itself is enhanced by some molecules which exist in the joint. We have noticed that the joint fluid naturally contains hyaluronic acid (HA). The purpose of this study is to clarify in vitro effects of supplementation of HA on the differentiation effect of the PAMPS and PDMAAm gels. METHODS: We cultured the ATDC5 cells on the PAMPS gel, the PDMAAm gel, and the polystyrene (PS) dish surface with the maintenance medium without insulin for 7 days. HA having a molecular weight of approximately 800 kDa was supplemented into the medium so that the concentration became 0.00, 0.01, 0.10, or 1.00 mg/mL. We evaluated the cultured cells with phase-contrast microscopy and PCR analyses. RESULTS: On the PAMPS gel, supplementation with HA of 0.01 and 0.10 mg/mL significantly increased expression of type-2 collagen mRNA (p = 0.0008 and p = 0.0413) and aggrecan mRNA (p = 0.0073 and p = 0.0196) than that without HA. On the PDMAAm gel, supplementation with HA of 1.00 mg/mL significantly reduced expression of these genes in comparison with the culture without HA (p = 0.0426 and p = 0.0218). CONCLUSIONS: The in vitro induction effects of the PAMPS and PDMAAm gels on chondrogenic differentiation of ATDC5 cells are significantly affected by HA, depending on the level of concentration. These results suggested that there is a high possibility that HA plays an important role in the in vivo spontaneous hyaline cartilage regeneration phenomenon induced by the PAMPS/PDMAAm DN gel.

Influence of the gel thickness on in vivo hyaline cartilage regeneration induced by double-network gel implanted at the bottom of a large osteochondral defect: short-term results.

BACKGROUND: A double-network (DN) gel, which is composed of poly(2-acrylamido-2-methylpropanesulfonic acid) and poly(N,N'-dimethyl acrylamide), can induce hyaline cartilage regeneration in vivo in a large osteochondral defect. The purpose of this study was to clarify the influence of the thickness of the implanted DN gel on the induction ability of hyaline cartilage regeneration. METHODS: Thirty-eight mature rabbits were used in this study. We created an osteochondral defect having a diameter of 4.3-mm in the patellofemoral joint. The knees were randomly divided into 4 groups (Group I: 0.5-mm thick gel, Group II: 1.0-mm thick gel, Group III: 5.0-mm thick gel, and Group IV: untreated control). Animals in each group were further divided into 3 sub-groups depending on the gel implant position (2.0-, 3.0-, or 4.0-mm depth from the articular surface) in the defect. The regenerated tissues were evaluated with the Wayne's gross and histological grading scales and real time PCR analysis of the cartilage marker genes at 4 weeks. RESULTS: According to the total Wayne's score, when the depth of the final vacant space was set at 2.0 mm, the scores in Groups I, II, and III were significantly greater than that Group IV (p<0.05), although there were no significant differences between Groups I and IV at a 3.0-mm deep vacant space. The expression levels of type-2 collagen in Groups II and III were significantly higher (p<0.05) than that in Group IV. CONCLUSIONS: The 1.0-mm thick DN gel sheet had the same ability to induce hyaline cartilage regeneration as the 5.0-mm thick DN gel plug. However, the induction ability of the 0.5-mm thick sheet was significantly lower when compared with the 1.0-mm thick gel sheet. The 1.0-mm DN gel sheet is a promising device to establish a cell-free cartilage regeneration strategy that minimizes bone loss from the gel implantation.

Development of a salmon-derived crosslinked atelocollagen sponge disc containing osteogenic protein-1 for articular cartilage regeneration: in vivo evaluations with rabbits.

BACKGROUND: We have developed crosslinked salmon-derived atelocollagen sponge, which has a denaturation temperature of 47 degrees Celsius. The purpose of this study is to evaluate the fundamental in vivo efficacy of the osteogenic protein (OP) -1 containing salmon-derived collagen sponge disc (SCS) on cartilage regeneration, using a rabbit model. METHODS: A total of 24 rabbits were used in this study. In each animal, a full-thickness osteochondral defect was created in each femoral trochlea. Then, each 12 rabbits were randomly divided into the two groups. In Group I, an OP1-SCS disc was implanted into the defect in the right knee. In Group II, a SCS disc without OP-1 was implanted into the defect in the right knee. A control group of 12 rabbits was assembled from randomly-selected left knees from among the first two groups. In Group-III, we applied no treatment for a defect in the left knee to obtain the untreated control. All rabbits were sacrificed at 12 weeks after surgery. In each group, 10 animals were used for histological and immunohistological evaluations, and the remaining 2 were used for real-time polymerase chain reaction (PCR) analyses. RESULTS: In Group I, a regenerated cartilage tissue rich in proteoglycan and type-2 collagen was found at 12 weeks, although the width was thicker than that of Group II. In Group II, the defect was filled with thick inhomogeneous tissues, including cartilage, fibrous, and bone tissues at 12 weeks. Concerning the gross observation and histological scores at 12 weeks, the ANOVA showed significant differences (p < 0.0001, and p < 0.0001, respectively). The post-hoc test indicated that the gross observation and histological scores of Group I was significantly greater than those of Groups II (p = 0.035, and p = 0.0104, respectively) and III (p < 0.0001, and p < 0.0001, respectively), while Group II was significantly greater than Group III (p = 0.0069, and p = 0.005, respectively). The real time PCR analysis showed that gene expression of type-2 collagen and aggrecan of Group I was greater than that of Group II. CONCLUSIONS: The present study clearly demonstrated that the implantation of the OP1-SCS disc without any cultured cells may induce spontaneous hyaline-like cartilage regeneration to greater degrees than implantation of only the salmon-derived collagen sponge disc.

A quantitative technique to create a femoral tunnel at the averaged center of the anteromedial bundle attachment in anatomic double-bundle anterior cruciate ligament reconstruction.

BACKGROUND: In the anatomic double-bundle ACL reconstruction, 2 femoral tunnel positions are particularly critical to obtain better clinical results. Recently, a few studies have reported quantitative identification methods for posterolateral (PL) bundle reconstruction. Concerning anteromedial (AM) bundle reconstruction, however, no quantitative clinically available methods to insert a guide wire at the center of the direct attachment of the AM mid-substance fibers have been reported to date. METHODS: First, we determined the center of the femoral attachment of the AM mid-substance fibers using 38 fresh frozen cadaveric knees. Based on this anatomical sub-study, we developed a quantitative clinical technique to insert a guide wire at the averaged center for anatomic double-bundle ACL reconstruction. In the second clinical sub-study with 63 patients who underwent anatomic ACL reconstruction with this quantitative technique, we determined the center of an actually created AM tunnel. Then, we compared the results of the second sub-study with those of the first sub-study to validate the accuracy of the quantitative technique. In both the sub-studies, we determined the center of the anatomical attachment and the tunnel outlet using the "3-dimensional clock" system. The tunnel outlet was evaluated using the "transparent" 3-dimensional computed tomography. RESULTS: The averaged center of the direct attachment of the AM bundle midsubstance fibers was located on the cylindrical surface of the femoral intercondylar notch at "10:37" (or "1:23") o'clock orientation in the distal view and at 5.0-mm from the proximal outlet of the intercondylar notch (POIN) in the lateral view. The AM tunnel actually created in ACL reconstruction was located at "10:41" (or "1:19") o'clock orientation in the average and at 5.0-mm from the POIN. There was no significant difference between the 2 center locations. CONCLUSIONS: The quantitative technique enabled us to easily create the femoral AM tunnel at the averaged center of the direct attachment of the AM bundle midsubstance fibers with high accuracy. This study reported information on the geometric location of the femoral attachment of the AM bundle and a clinically useful technique for its anatomical reconstruction.

Prospective clinical comparisons of semitendinosus versus semitendinosus and gracilis tendon autografts for anatomic double-bundle anterior cruciate ligament reconstruction.

BACKGROUND: The data available from the previously reported clinical studies remains insufficient concerning the hamstring graft preparation in double-bundle anterior cruciate ligament (ACL) reconstruction. OBJECTIVE: To test the hypothesis that there are no significant differences between the semitendinosus tendon alone and the semitendinosus and gracilis tendon graft fashioning techniques concerning knee stability and clinical outcome after anatomic double-bundle ACL reconstruction. METHODS: A prospective study was performed on 120 patients who underwent anatomic double-bundle ACL reconstruction according to the graft fashioning technique. The authors developed the protocol to use hamstring tendon autografts. When the harvested doubled semitendinosus tendon is thicker than 6 mm, each half of the semitendinosus tendon is doubled and used for the anteromedial (AM) and posterolateral (PL) bundle grafts (Group I). On the other hand, when the harvested semitendinosus tendon is under 6 mm in thickness, the gracilis tendon is harvested additionally. The distal half of the semitendinosus and gracilis tendons are doubled and used for the AM bundle graft, and the remaining proximal half of the semitendinosus tendon is doubled and used for the PL bundle grafts (Group II). Sixty-one patients were included in Group I, and 59 patients in Group II. The two groups were compared concerning knee stability and clinical outcome 2 years after surgery. RESULTS: The postoperative side-to-side anterior laxity averaged 1.3 mm in both groups, showing no statistical difference. There were also no significant differences between the two groups concerning the peak isokinetic torque of the quadriceps and the hamstrings, the Lysholm knee score, and the International Knee Documentation Committee evaluation. CONCLUSION: There were no significant differences between the two graft fashioning techniques after anatomic double-bundle ACL reconstruction concerning knee stability and postoperative outcome. The present study provided orthopedic surgeons with important information on double-bundle ACL reconstruction with hamstring tendons. LEVEL OF EVIDENCE: Level II; prospective comparative study.

The impact of early mobility on functional recovery after hip fracture surgery.

PURPOSE: To examine the effect of early mobility (EM) on functional recovery after hip fracture surgery, and to investigate the potential factors that delay mobility. METHODS: In this retrospective observational study, 110 hip fracture patients were divided into two groups according to the days between surgery and mobility referred to as the EM and the delayed mobility groups. Demographic data, perioperative data, functional outcomes, and discharge destination were compared statistically between the groups using univariate analysis and logistic regression analysis. As a sensitivity analysis, the factors associated with the timing of physiotherapy were also assessed. RESULTS: The EM group had significantly better walking ability and Barthel index (p < 0.05), and home discharge rate (p = 0.004). The factors associated with delayed mobility (odds ratio; 95% confidence interval) were delayed postoperative physiotherapy initiation (3.59; 1.76-7.33), days from admission to surgery (1.23; 1.04-1.46), and postoperative CRP (1.14; 1.01-1.29) and hemoglobin level (0.72; 0.54-0.96). Furthermore, patients who received surgery on the day before any holiday were significantly delayed in physiotherapy intervention (p = 0.006). CONCLUSIONS: This study demonstrated that EM after hip fracture surgery was associated with improving functional recovery and home discharge rate, and early physiotherapy intervention was associated with EM.

Early mobility on the first day after hip fracture surgery was associated with improving walking ability and independence of daily activities on postoperative days 7 and 14, as well as on the time to discharge to own home.Early mobility was specifically associated with the timing of physiotherapy intervention, the days from admission to surgery and the medical condition including perioperative anemia. In particular, patients who received surgery on the day before any holiday were significantly delayed in physiotherapy intervention.

Clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years: a multicenter, retrospective study.

BACKGROUND: This study aimed to clarify the clinical outcomes of surgical treatment for end-stage ankle osteoarthritis in patients aged ≥ 75 years and compare these outcomes with those of patients aged < 75 years. METHODS: A total of 148 patients, including 65 who underwent total ankle arthroplasty and 83 who underwent ankle arthrodesis, were retrospectively surveyed. Clinical outcomes were assessed preoperatively and at the last follow-up using the Japanese Society for Surgery of the Foot Hindfoot Scale and a self-administered foot evaluation questionnaire (SAFE-Q). Patient characteristics, including age, sex, body mass index, radiographic severity, and follow-up period, were also assessed. The patients were divided into older (≥ 75 years) and younger (< 75 years) age groups. Improvements in outcomes were then compared between age groups using univariate analysis and analysis of covariance adjusted for patient characteristics. Total ankle arthroplasty and ankle arthrodesis were analyzed separately. RESULTS: All clinical outcome scores improved postoperatively in the older age groups for both procedures. Scores for the pain and pain-related subscale of the SAFE-Q improved by 37 points (p < 0.001) in post-total ankle arthroplasty patients and by 35 points in post-ankle arthrodesis patients (p < 0.001). Furthermore, multivariate analysis showed that the improvements observed in all scores were not different between the older and younger age groups for both post-total ankle arthroplasty and post-ankle arthrodesis patients, except for the SAFE-Q physical functioning subscale score for post-ankle arthrodesis patients. The clinical outcomes improved significantly in post-total ankle arthroplasty and post-ankle arthrodesis patients aged ≥ 75 years. Moreover, these improvements were similar to those observed in patients aged < 75 years. CONCLUSIONS: Surgical treatment of end-stage ankle osteoarthritis can be a viable treatment option, even in elderly patients, and can be expected to improve similarly to younger patients.

Quantitative Assessment of Calf Muscle Volume, Strength, and Quality After Achilles Tendon Rupture Repair: A 1-Year Prospective Follow-up Study.

BACKGROUND: A number of studies have reported that calf muscle atrophy is a common long-term problem after Achilles tendon repair; however, there is still a lack of data concerning early postoperative morphological changes in the calf muscle after surgery. PURPOSE: To investigate changes over time in calf muscle volume and fatty degeneration during 1 year after Achilles tendon repair. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A prospective 1-year serial magnetic resonance imaging study was carried out with 20 patients who underwent tendon repair for unilateral acute Achilles tendon rupture. The magnetic resonance imaging assessment in addition to clinical and functional evaluations was performed at 1, 3, 6, and 12 months after surgery. The muscle volume of the medial and lateral gastrocnemius, soleus, and flexor hallucis longus (FHL) and fatty degeneration of the medial and lateral gastrocnemius and soleus were measured for the calf muscles, and the relative volume and fatty degeneration changes in the affected leg compared with the healthy contralateral leg were calculated as a percentage ([injured/healthy control] × 100) to assess structural changes over time. RESULTS: Muscle volumes of the medial gastrocnemius, lateral gastrocnemius, soleus, and FHL were 92.3%, 92.8%, 84.6%, and 95.9% at 12 months after surgery, respectively. Medial and lateral gastrocnemius and FHL muscle volumes improved over time and recovered to almost equal to that of the healthy side at 12 months after surgery. The soleus muscle volume did not recover significantly over time and was statistically significantly smaller than that of the healthy side at 12 months (P = .029). Fatty degeneration rates of the medial gastrocnemius, lateral gastrocnemius, and soleus were 118.2%, 113.9% and 121.1% at 12 months after surgery, respectively. Fatty degeneration of the medial and lateral gastrocnemius did not change significantly, but there was a statistically significant increase in fatty degeneration of the soleus over time (P < .001). CONCLUSION: Within the triceps surae muscle, the soleus was the most negatively affected by injury and repair for both muscle volume and fatty degeneration. Postoperative management to recover the soleus muscle function before a return to sporting activities should be considered in the future.