Potential of patellar height measurement methods in predicting recurrent patellar dislocation incidence: a case-control study.

BACKGROUND: Recurrent patellar dislocation (RPD) is a multifactorial disease that affects young and active people. Patellar height measurements are used clinically to screen and diagnose knee conditions. However, there are no known studies that have assessed and compared the performance of patellar height indices for predicting the incidence of RPD, which could be used to recommend surgical treatment after primary patellar dislocation. This case-control study aimed to determine if the patellar height index could be used to predict the incidence of RPD, and to identify the optimal method in terms of its diagnostic ability for RPD. METHOD: Altogether, 133 patients (52 patients with RPD [Group R] and 81 sex- and age-matched controls [Group C]) were enrolled in this study. The Insall-Salvati (IS), Blackburne-Peel (BP), Caton-Deschamps (CD), and modified IS (mIS) methods were used to measure the patellar height index. The intra-observer and inter-observer reliabilities of these four methods were determined using intraclass correlation coefficients. A receiver operating characteristic curve analysis was performed to evaluate the predictive ability of each index and identify the cut-off values that indicated significantly increased risk of RPD. RESULTS: Patient demographics were similar between the two groups. The inter-observer and intra-observer reliabilities were good for all four methods. In patients with RPD, the mean index values for the four methods were significantly higher than those in the matched controls. The area under the curve (AUC) values for IS, BP, CD, and mIS were 0.91 (standard error [SE], 0.03; 95% confidence interval [CI], 0.84-0.96), 0.72 (SE, 0.05; 95% CI, 0.63-0.81), 0.86 (SE, 0.03; 95% CI, 0.79-0.92), and 0.96 (SE, 0.01; 95% CI, 0.94-0.99), respectively. CONCLUSION: Patellar height indices had high predictive performance for the incidence of RPD. The mIS method had the highest AUC.

Comparison of functional outcome and complications of locking plate versus coracoclavicular fixation in the treatment of unstable distal clavicle fractures: the multicenter, propensity-matched TRON study.

PURPOSE: This multicenter, retrospective study aimed to compare clinical outcomes and complications between locking plate fixation and new coracoclavicular (CC) fixation for patients with unstable distal clavicle fracture. METHODS: We included 142 patients in this TRON study. The mean follow-up was 15.5 (6-31) months. The patients were divided into two groups: the locking plate group (Group L) and CC fixation group (Group C). To adjust for baseline differences between the groups, a propensity score algorithm was used to match two groups in a 1:1 ratio. After matching, we compared operation time and the University of California Los Angeles (UCLA) shoulder score at 3 and 6 months postoperatively and at last follow-up as clinical outcomes and the rate of complications. RESULTS: After matching, 20 cases from each group remained. Operation time was shorter in Group C (75 [22, 111] vs. 100 [38, 120] min; P = 0.023). At 3 months postoperatively, UCLA score in Group C was better, but no significant differences between the groups were found at 6 months and last follow-up after surgery. The rate of complications was not significantly different between the groups. CONCLUSION: CC fixation might be equivalent to locking plate fixation in clinical outcome, and the operation time is shorter than that required for locking plate fixation.

The Association of Bohler's Angle With Postoperative Pain and Gender for Displaced Intra-Articular Calcaneal Fracture, Multicenter Retrospective Study-TRON Study.

A relationship between Böhler angle (BA) before or after surgery and clinical outcomes remains unclear. This retrospective multicenter cohort study aimed to compare pain and functional outcomes between a group in which the reduction angle was preserved and a group in which the reduction angle was lost during follow-up, and to clarify the risk factors leading to loss of last follow-up BA. From 2014 to 2018, 271 cases of calcaneal fractures were surgically treated at ten facilities. We divided patients into Group L (lost reduction of fracture) and Group P (preserved reduction of fracture). We matched subjects between the 2 groups according to age, sex and BA before surgery and compared American Orthopedic Foot and Ankle Society (AOFAS) score between the groups. We investigated the correlation between the amount of BA loss and postoperative pain. The factors leading to loss of last follow-up BA were examined by logistic regression analysis. Ultimately, 112 patients were eligible. After matching, each group included 38 patients. There was no difference between the 2 groups in total AOFAS score. However, the pain component of AOFAS score at 6 months and 12 months were worse in group L than in group P (p = .011, p = .031, respectively). We also showed a weak correlation between the amount of BA loss and postoperative pain. Logistic regression analysis revealed that female and BA before surgery independently predicted loss of reduction (odds ratios: 4.66, 95% CI: 1.15-18.9 and odds ratios: 0.90, 95% CI: 0.82-0.99, respectively). We clarified that reduction and preservation of BA within its normal range should lead to decrease postoperative pain. Female and lower pre-BA were risk factors leading to loss of reduction of BA in operative treatment of calcaneal fractures.

Delayed anterior cruciate ligament reconstruction increases the incidence of medial meniscal bucket handle tears and medial compartment chondral injuries in patients aged 40 years and older.

INTRODUCTION: No widely accepted evidence-based indications exist for the initial surgical management of patients with anterior cruciate ligament (ACL) injuries ≥ 40 years old, and treatment for these patients remains controversial. This study aimed to evaluate the association between elapsed time from ACL injury to surgery and the incidence of meniscal tears and chondral injury in patients aged ≥ 40 years. MATERIALS AND METHODS: The patients who underwent primary ACL reconstruction were divided into two groups based on elapsed time from injury to surgery: early group, < 12 months; and delayed group, ≥ 12 months. Patient records were reviewed for incidence and types of meniscal tears and chondral injuries in each group. Chondral injury grades were evaluated with International Cartilage Regeneration and Joint Preservation Society (ICRS) Criteria. RESULTS: This study evaluated 67 knees in the early group and 33 knees in the delayed group. Mean ages in each group were 46.9 ± 6.5 and 46.9 ± 6.0. The delayed group showed significantly higher rates of medial meniscal tear [31 of 33, 93.9% vs 29 of 67, 43.3%; P < 0.0001; odds ratio (OR), 20.31; 95% confidence interval (CI), 4.49-91.9], medial femoral condyle chondral injuries ≥ ICRS grade II (15 of 33, 45.5% vs 8 of 67, 11.9%; P < 0.001; OR, 6.15; 95% CI 2.24-16.83), and medial tibial chondral injuries ≥ ICRS grade II (7 of 33, 21.2% vs 3 of 67, 4.5%; P < 0.05; OR, 5.74; 95% CI 1.38-23.9) compared with the early group. With respect to types of medial meniscal tear, the delayed group showed a significantly higher frequency of bucket handle tears (11 of 33, 33.3%) compared with the early group (2 of 67, 3.0%; P < 0.0001; OR, 16.25; 95% CI 3.34-79.1). CONCLUSIONS: Delayed ACL reconstruction was associated with increased incidence of chondral injuries and medial meniscal tears, particularly bucket handle tears in this cohort. LEVEL OF EVIDENCE: Level III.

Relationship between patellar mobility and patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction.

Patellofemoral cartilage degeneration is a potential complication of anterior cruciate ligament reconstruction (ACLR) surgery. Hypomobility of the patella in the coronal plane is often observed after ACLR. Few studies, however, have examined the relationship between cartilage degeneration in the patellofemoral joint and mobility after ACLR. The present study investigated 1) the coronal mobility of the patella after ACLR, 2) the relationship between patellar mobility and cartilage degeneration of the patellofemoral joint, and 3) the relationship between patellar mobility and knee joint function after ACLR. Forty patients who underwent medial hamstring-based ACLR participated in the study. Lateral and medial patellar displacements were assessed with a modified patellofemoral arthrometer, and the absolute values of the displacements were normalized to patient height. The International Cartilage Repair Society (ICRS) cartilage injury classification of the patellar and femoral (trochlear) surfaces, and the Lysholm Knee Scoring Scale were used to evaluate knee function. Lateral and medial patellar displacements were reduced compared with the non-operated knee at the second-look arthroscopy and bone staple extraction operation (second operation; 24.4 ± 7.9 months after ACLR, P<0.01). The ICRS grades of the patellofemoral joint (patella and trochlea) were significantly worse than those pre-ACLR. Neither lateral nor medial patellar mobility, however, were significantly correlated with the ICRS grade or the Lysholm score. Although patellar mobility at approximately 2 years after ACLR was decreased compared to the non-operated knee, small displacement of the patella was not related to cartilage degeneration or knee joint function at the time of the second operation.

The impact of musculoskeletal diseases on mortality-comparison with internal diseases: A 15-year longitudinal study.

BACKGROUND: Aging is associated with an increased incidence of diabetes (DM), hypertension (HT), hyperlipidemia (HL), as well as musculoskeletal disorders, such as osteoarthritis (OA) and osteoporosis (OP). However, the impact of musculoskeletal disorders on mortality remains unclear. This study investigated the risk of mortality if having knee OA or OP. METHODS: 601 participants (mean age 67.8 ± 5.3 years) who underwent musculoskeletal check-ups in Yakumo town were enrolled in this study, 248 were males and 353 were females. The following parameters were assessed: age, sex, body mass index, smoking habit, alcohol drinking habit, physical exercise habit, knee OA, OP, HT, DM and HL. Kaplan-Meier survival curves for smoking, drinking and physical exercise habits, knee OA, OP, HT, DM and HL were prepared, and the log-rank test was performed. Furthermore, the Cox hazard model was used for multivariate analysis of all variables. RESULTS: Knee OA, OP, HT, and DM were associated with a significantly higher mortality rate. Cox regression analysis results showed a hazard ratio of 1.972 for OA (95%CI: 1.356-2.867), 1.965 for DM (1.146-3.368), 1.706 for smoking habits (1.141-2.552), and 1.614 for OP (1.126-2.313). Cardiovascular diseases were the most common causes of death. CONCLUSIONS: Smoking, knee OA, OP and DM were all associated with increased risk of mortality. Knee OA had a high hazard ratio, comparable to that of DM. These findings suggest that interventions against smoking, knee OA, OP and DM may reduce the risk of mortality.

Osteoarthritis-derived chondrocytes are a potential source of multipotent progenitor cells for cartilage tissue engineering.

The natural healing capacity of damaged articular cartilage is poor, rendering joint surface injuries a prime target for regenerative medicine. While autologous chondrocyte or mesenchymal stem cell (MSC) implantation can be applied to repair cartilage defects in young patients, no appropriate long-lasting treatment alternative is available for elderly patients with osteoarthritis (OA). Multipotent progenitor cells are reported to present in adult human articular cartilage, with a preponderance in OA cartilage. These facts led us to hypothesize the possible use of osteoarthritis-derived chondrocytes as a cell source for cartilage tissue engineering. We therefore analyzed chondrocyte- and stem cell-related markers, cell growth rate, and multipotency in OA chondrocytes (OACs) and bone marrow-derived MSCs, along with normal articular chondrocytes (ACs) as a control. OACs demonstrated similar phenotype and proliferation rate to MSCs. Furthermore, OACs exhibited multilineage differentiation ability with a greater chondrogenic differentiation ability than MSCs, which was equivalent to ACs. We conclude that chondrogenic capacity is not significantly affected by OA, and OACs could be a potential source of multipotent progenitor cells for cartilage tissue engineering.

Hypoxia-inducible factor-2α induces expression of type X collagen and matrix metalloproteinases 13 in osteoarthritic meniscal cells.

OBJECTIVES: To evaluate whether Hypoxia-inducible factor-2α (HIF-2α) regulates expression of endochondral ossification-related molecules in human OA meniscus. METHODS: Expressions of HIF-2α, type X collagen (COL10), matrix metalloproteinase (MMP)-13, and vascular endothelial growth factor (VEGF) in non-OA and OA menisci were analyzed by real-time RT-PCR and immunohistochemistry (IHC). Meniscal cells from OA patients were treated with interleukin-1ß (IL-1ß) and gene expression was analyzed. After knockdown of HIF-2α in OA meniscal cells, COL10 and MMP-13 expression were analyzed by RT-PCR, western blotting, immunofluorescence and ELISA. RESULT: Histological analysis demonstrated weak staining of the superficial layer and large round cells in OA meniscus. RT-PCR analysis showed that HIF-2α, COL10, MMP-13, and VEGF mRNA expressions were higher in OA than non-OA meniscal cells. IHC showed a coordinated staining pattern of HIF-2α, COL10, and MMP-13 in OA meniscus. IL-1ß treatment increased HIF-2α, COL10, and MMP-13 expressions in OA meniscal cells, and knockdown of HIF-2α suppressed IL-1ß-mediated increase in COL10 and MMP-13 expression. CONCLUSIONS: These results suggested that HIF-2α may cause meniscal matrix degradation by transactivation of MMP-13. HIF-2α may be a therapeutic target for modulating matrix degradation in both articular cartilage and meniscus during knee OA progression.

Gait Speeds Associated with Anxiety Responses to Pain in Osteoarthritis Patients.

OBJECTIVE: Patients with lower limbs osteoarthritis (OA) had slower walking speeds than healthy. Gait speed, which is associated with leg muscle strength, is a consistent predictor of health and functional status. The effects of pain and pain-related psychological constructs for gait speeds have been uncertain. Therefore, we investigated whether gait speed in patients with OA of lower limbs is associated with pain-related psychological constructs using a performance-based measure. METHODS: The study group comprised 59 patients with advanced knee or hip OA. Gait speeds were measured at comfortable and maximum levels during 10-m walks. Covariates included 1) pain intensity measured with a visual analogue scale (VAS), 2) psychological constructs measured with a short-version pain anxiety symptoms scale (PASS-20) and the hospital anxiety and depression scale (HADS), and 3) bilateral knee extensor and hip abductor muscle strength. Each variable was subjected to multivariate analysis with gait speed. RESULTS: Single regression analysis showed that gait speeds were significantly correlated with VAS and PASS-20 scores, and muscle strength, not with HADS. Multiple regression analysis showed that PASS-20 score was significant correlating factor for gait speeds. CONCLUSIONS: Anxiety-related responses to pain were significant correlating factor for gait speeds, in patients with OA of lower limbs.

Does the Q - H index show a stronger relationship than the H:Q ratio in regard to knee pain during daily activities in patients with knee osteoarthritis?

[Purpose] The purpose of this study was to elucidate the relationship between knee muscle strength and knee pain in activities of daily living, based on consideration of the difference between extension and flexion strength (Q - H) and the hamstring:quadriceps (H:Q) ratio in patients with knee osteoarthritis. [Subjects and Methods] The participants were 78 females with knee osteoarthritis, and a total of 133 knees that had not been treated surgically were the targets of this research. The legs were divided according to dominance. Isometric knee extension and flexion muscle strength and knee pain during activities of daily living were measured. The H:Q ratio (flexion/extension muscle strength) and the difference between extension and flexion strength, (extension muscle strength/weight) minus (flexion muscle strength/weight), that is, Q - H, were calculated. The correlation between these indices and the knee pain score during activities of daily living was investigated. [Results] Greater knee pain during activities of daily living was related to lower knee extension muscle strength and Q - H in both the dominant and nondominant legs. Knee flexion muscle strength and the H:Q ratio were not significantly correlated with knee pain during any activities of daily living. [Conclusion] Knee extension muscle strength and Q - H were found to be significantly correlated with knee pain during activities of daily living, whereas the H:Q ratio was not.

Expression of tenocyte lineage-related factors in regenerated tissue at sites of tendon defect.

BACKGROUND: The healing mechanism of ruptured or injured tendons is poorly understood. To date, some lineage-specific factors, such as scleraxis and tenomodulin, have been reported as markers of tenocyte differentiation. Because few studies have focused on tenocyte lineage-related factors with respect to the repaired tissue of healing tendons, the aim of this study was to investigate their expression during the tendon healing process. METHODS: Defects were created in the patellar tendons of rats, and the patellae and patellar tendons were harvested at 3 days and at 1, 2, 3, 6, 12, and 20 weeks after surgery. They were studied using micro-computed tomography, and paraffin-embedded sections were then prepared for histological evaluation. Reverse transcription-polymerase chain reactions were performed to analyze the expression of genes related to the tenocyte lineage, chondrogenesis, and ossification. RESULTS: Repaired tissue became increasingly fibrous over time and contained a greater number of vessels than normal tendons, even in the later period. Safranin O staining revealed the existence of proteoglycan at 1 week and its persistence through 20 weeks. Ossification was detected in all tendons at 12 weeks. The expression of tenocyte lineage-related genes was high at 1 and 2 weeks. Chondrogenic genes were up-regulated until 6 weeks. Runt-related transcription factor 2, an osteogenic gene, was up-regulated at 20 weeks. CONCLUSIONS: In our tendon defect model, cells participating in the tendon healing process appeared to differentiate toward tenocyte lineage only in the early phase, and chondrogenesis seemed to occur from the early phase onward. To improve tendon repair, it will be necessary to promote and maintain tenogenesis and to inhibit chondrogenesis, especially in the early phase, in order to avoid erroneous differentiation of stem cells.

Low and high body mass index and lower numbers of screws in the articular segment are risk factors for non-union of distal humeral fractures in the elderly: A multi-center retrospective study (TRON study).

Background: Distal humerus fracture in the elderly is a challenging fracture for orthopedic surgeons. Non-union is one of the serious complications of distal humerus fracture after surgery. This retrospective multicenter study aimed to estimate the incidence of distal humeral non-union after open reduction and internal fixation, determine factors related to non-union, and compare the postoperative results of cases with non-union to cases with the union. Methods: Among 423 patients diagnosed with distal humeral fracture and who were treated by surgical therapy in 2010-2020 from our database called TRON. Only 190 subjects met the inclusion criteria. We performed a logistic regression analysis with the presence of non-union as the response variable to examine risk factors. We compare the Mayo Elbow Performance Scores of cases with non-union to cases with the union. Results: Non-union occurred after surgery in 15 patients (7.9%). The logistic regression analysis showed that body mass index<20 kg/m2 and ≥25 kg/m2, and ≤3 screws in the articular segment were significant explanatory factors for non-union (odds ratio 10.4 and 47.8, respectively). The Mayo Elbow Performance Scores were significantly worse in patients with non-union. Discussion: Low and high body mass index and three or fewer screws in the articular segment might be risk factors for non-union of distal humerus fracture in the elderly. Non-union is associated with poor clinical outcomes.

Double-bundle anterior cruciate ligament reconstruction in patients aged 60 years and older.

Background: This study aimed to examine the clinical outcomes of double-bundle (DB) anterior cruciate ligament (ACL) reconstruction in patients aged ≥60 years. Methods: Anatomical DB-ACL reconstruction using hamstring tendon autografts was performed in 13 patients aged ≥60 years at our institution between June 2012 and May 2018. The patients included seven men and six women, and the mean age at surgery was 65.0 years (range, 60-73 years). The mean time from injury to surgery was 80.5 months (range, 1-480 months), and the mean follow-up time was 26.2 months (range, 24-42 months). All patients were assessed based on physical examination findings, clinical scores, Kellgren-Lawrence grades preoperatively and at the final postoperative follow-up, intraoperative meniscal or chondral lesions, and perioperative complications. Status of returning to sports for all patients was assessed at the final follow-up. Results: The mean side-to-side differences by arthrometer improved from 4.3 mm (range, 2-8 mm) to 0.9 mm (range, 0-2 mm), and the positive pivot-shift test decreased from 100% to 8%. The mean extensor muscle strength was 93.3% (range, 74-116%) postoperatively. The mean Lysholm score improved from 71.1 (range, 27-85) to 95.2 (range, 89-100). Ten of the 13 patients (77%) returned to their pre-injury level of sports performance, and one patient (8%) returned to sports with less intensity. Intraoperatively, meniscal tears were observed in 10 patients (77%), and chondral lesions >grade 2 were observed in 11 (85%). One patient developed perioperative complications. At the final follow-up, the Kellgren-Lawrence grade worsened in only one patient. No re-injury or infection was observed, and revision surgery was not required for any patients. Conclusions: Anatomical DB-ACL reconstruction could provide satisfactory clinical outcomes and knee function restoration in patients aged ≥60 years. Level of evidence: A retrospective study, case series (IV).

Chondrogenic capacity and alterations in hyaluronan synthesis of cultured human osteoarthritic chondrocytes.

During osteoarthritis there is a disruption and loss of the extracellular matrix of joint cartilage, composed primarily of type II collagen, aggrecan and hyaluronan. In young patients, autologous chondrocyte implantation can be used to repair cartilage defects. However, for more elderly patients with osteoarthritis, such a repair approach is contraindicated because the procedure requires a large expansion of autologous chondrocytes in vitro leading a rapid, perhaps irreversible, loss of the chondrocyte phenotype. This study investigates whether osteoarthritic chondrocytes obtained from older patients can be expanded in vitro and moreover, induced to re-activate their chondrocyte phenotype. A decrease in chondrocyte phenotype markers, collagen II, aggrecan and SOX9 mRNA was observed with successive expansion of cells in monolayer culture. However, chondrogenic induction in three-dimensional pellet culture successfully rescued the expression of all three marker genes to native levels, even with 4th passage cells-cells representing an approximate 625-fold expansion in cell number. This data supports the use of osteoarthritic cells for autologous implantation repair. In addition, another set of gene products were explored as useful markers of the chondrocyte phenotype. Differentiated primary chondrocytes exhibited a common pattern of hyaluronan synthase isoforms that changed upon cell expansion in vitro and, reverted back to the original pattern following pellet culture. Moreover, the change in isoform pattern correlated with changes in the molecular size of synthesized hyaluronan.

Surface markers and gene expression to characterize the differentiation of monolayer expanded human articular chondrocytes.

Autologous chondrocyte implantation (ACI) is a method of cartilage repair. To improve the quality of regenerated tissue by ACI, it is essential to identify surface marker expression correlated with the differentiation status of monolayer expanded human articular chondrocytes and to define the index for discriminating dedifferentiated cells from monolayer expanded human articular chondrocytes. Normal human articular chondrocytes were cultured in monolayer until passage 4. At each passage, mRNA expression of collagen type I, II, and X and aggrecan was analyzed by real-time quantitative PCR, and the surface marker expression of CD14, CD26, CD44, CD49a, CD49c, CD54, and CD151 was analyzed by fluorescence-activated cell sorting (FACS). The ratios of mRNA levels of collagen type II to I (Col II/Col I) represented the differentiation status of chondrocytes more appropriately during monolayer culture. The surface marker expression of CD44, CD49c, and CD151 was upregulated according to the dedifferentiation status, whereas that of CD14, CD49a, and CD54 was downregulated. The most appropriate combination of the ratio of Col II/Col I was CD54 and CD44. Cell sorting was performed using a magnetic cell sorting system (MACS) according to CD54 and CD44, and real-time quantitative PCR was performed for the cell subpopulations before and after cell sorting. The expression of collagen type II and aggrecan of the chondrocytes after MACS was higher than that before sorting, but not significantly. The mean fluorescence intensity (MFI) ratio of CD54 to CD44 could be an adequate candidate as the index of the differentiation status.

Arthroscopic Hip Capsular Repair Improves Patient-Reported Outcome Measures and Is Associated With a Decreased Risk of Revision Surgery and Conversion to Total Hip Arthroplasty.

Purpose: To perform a systematic review to assess the effect of capsular repair compared with nonrepair on patient-reported outcome measures (PROMs) and conversion to total hip arthroplasty (THA) after hip arthroscopy in patients with femoroacetabular impingement syndrome. Methods: We initially searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and PubMed databases, as well as ongoing clinical trials (https://clinicaltrials.gov), on December 15, 2022. The eligibility criteria were randomized controlled trials (Level Ⅰ) and prospective comparative studies (Level II) of patients who underwent capsular repair and nonrepair via hip arthroscopy with a minimum follow-up period of 2 years. We registered this protocol a priori on PROSPERO (identification No. CRD42021239306). We assessed the risk of bias using the Methodological Index for Non-randomized Studies (MINORS) appraisal tool. Results: This review included 5 studies with a total of 639 patients (270 with capsular repair [average age, 35.4 years; 41% female patients] and 369 with nonrepair [average age, 37.3 years; 38% female patients]). In the included studies, surgical procedures consisting of labral repair and pincer or cam osteoplasty were performed via hip arthroscopy. The modified Harris Hip Score was measured in all the included studies, and the standardized mean difference in PROMs for capsular repair versus nonrepair in the included studies was 0.42 (95% confidence interval [CI], 0.20 to 0.63). A sensitivity analysis of randomized controlled trials achieved consistent results (standardized mean difference in PROMs, 0.31; 95% CI, 0.02 to 0.60). Capsular repair was not associated with a reduction in revision surgery (risk difference, -0.02; 95% CI, -0.06 to 0.03; 26 of 270 patients with capsular repair vs 42 of 369 with nonrepair) but was associated with a reduction in conversion to THA (risk difference, -0.05; 95% CI -0.09 to -0.01; 12 of 270 patients with capsular repair vs 38 of 369 with nonrepair). The average Methodological Index for Non-randomized Studies (MINORS) score in the included studies was 20. Conclusions: Patients who undergo capsular repair in conjunction with other arthroscopic hip preservation techniques have better PROMs and a lower incidence of THA conversion. Level of Evidence: Level II, systematic review of Level I and II investigations.

Role of S100A12 in the pathogenesis of osteoarthritis.

S100A12 is a member of the S100 protein family, which are intracellular calcium-binding proteins. Although there are many reports on the involvement of S100A12 in inflammatory diseases, its presence in osteoarthritic cartilage has not been reported. The purpose of this study was to investigate the expression of S100A12 in human articular cartilage in osteoarthritis (OA) and to evaluate the role of S100A12 in human OA chondrocytes. We analyzed S100A12 expression by immunohistochemical staining of cartilage samples obtained from OA and non-OA patients. In addition, chondrocytes were isolated from knee cartilage of OA patients and treated with recombinant human S100A12. Real-time RT-PCR was performed to analyze mRNA expression. Protein production of matrix metalloproteinase 13 (MMP-13) and vascular endothelial growth factor (VEGF) in the culture medium were measured by ELISA. Immunohistochemical analyses revealed that S100A12 expression was markedly increased in OA cartilages. Protein production and mRNA expression of MMP-13 and VEGF in cultured OA chondrocytes were significantly increased by treatment with exogenous S100A12. These increases in mRNA expression and protein production were suppressed by administration of soluble receptor for advanced glycation end products (RAGE). Both p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) inhibitors also suppressed the increases in mRNA expression and protein production of MMP-13 and VEGF. We demonstrated marked up-regulation of S100A12 expression in human OA cartilages. Exogenous S100A12 increased the production of MMP-13 and VEGF in human OA chondrocytes. Our data indicate the possible involvement of S100A12 in the development of OA by up-regulating MMP-13 and VEGF via p38 MAPK and NF-κB pathways.

[Cartilage implantation for the bone and cartilage destruction in rheumatoid arthritis].

Current pharmacological treatment of rheumatoid arthritis developed to increase the chance for reaching complete remission. However, it is unclear that it could help regeneration or repair of the destroyed cartilage. One of the most prominent candidates for the treatment of destroyed cartilage in rheumatoid arthritis after complete remission is the mesenchymal stem cells.

Do heel-unloading orthoses improve clinical outcomes in patients after surgical treatment of calcaneal fracture? A propensity-matched, multicenter analysis of the TRON database.

BACKGROUND: Postoperative protocols after surgical treatment of calcaneal fracture have not been standardized to date. There are only a few reports on the efficacy of heel-unloading orthoses (HUOs; Mars shoe, Graffin orthosis), and thier efficacy is uncertain. OBJECTIVES: The purpose of this study was to compare postoperative radiologic and clinical outcomes in patients with calcaneal fractures who used Graffin orthosis. STUDY DESIGN: Multicenter retrospective study. METHODS: We finally extracted 182 patients from a database of the Trauma Research Group of Nagoya and divided them into two groups: group C (underwent casting or splinting only) and group O (Graffin orthosis was used). A propensity score algorithm was used to match group C to group O in a 1:1 ratio. We evaluated American Orthopaedic Foot and Ankle Society (AOFAS) score at three and six months after surgery and at final follow-up. Differences in reduction of the Böhler angle between the two groups were evaluated radiographically. All data were analyzed with a t-test or Fisher's exact test. P < .05 was considered statistically significant. RESULTS: The AOFAS score 3 months after surgery in group O was significantly higher than that in group C (69.57 vs. 77.22; P = .004). However, there were no statistically significant differences between group C vs. group O in AOFAS scores at 6 months after surgery and at final follow-up (81.92 vs. 85.67 and 89.18 vs. 88.13; P = .087 and 0.597, respectively). There was no significant statistical difference in the reduction of the Böhler angle (5.07 vs. 5.89; P = .529). CONCLUSIONS: At 3 months postoperatively, the orthosis group showed predominantly better functional results. We believe that heel-unloading orthoses are useful for patients who require an early return to work and to daily life.

Inflammatory effect of advanced glycation end products on human meniscal cells from osteoarthritic knees.

OBJECTIVE: To investigate the inflammatory effects of advanced glycation end-products (AGEs) through the receptor for AGE in meniscal cells from osteoarthritic knees, and examine effects of hyaluronan (HA) on AGE-induced inflammation. METHODS: Meniscal cells from human osteoarthritic knees were cultured with or without glycolaldehyde-AGE-bovine serum albumin and 800 kDa HA. The amount of prostaglandin E(2) (PGE(2)) protein was determined using an enzyme immunoassay system. Expression of cyclooxygenase (COX)-1, COX-2, membrane associated prostaglandin E synthase (mPGES)-1 and cytosolic PGES (cPGES) was analyzed by real-time reverse transcription polymerase chain reaction and western blotting. RESULTS: PGE(2) synthesis was significantly increased by AGEs, and AGE-induced PGE(2) production was attenuated by addition of HA. While COX-2 and mPGES-1 expression was significantly upregulated by AGEs, COX-1 and cPGES expression was not affected by AGE. AGE-stimulated COX-2 and mPGES-1 expression was attenuated by HA through CD44 (HA receptor). However, the changes in COX-1 and cPGES expression were almost negligible. CONCLUSION: In meniscal cells from osteoarthritic knees, AGEs increased the production of inflammatory mediators, including PGE(2), COX-2 and mPGES-1. Furthermore, HA could decrease AGE-induced production of PGE(2), COX-2 and mPGES-1 through CD44.