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).

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.

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.

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.

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.

Deep flexion helps to avoid popliteal artery injury during all-inside lateral meniscal repair: A cadaveric study.

BACKGROUND: Arthroscopic meniscus repair rarely leads to major complications such as popliteal artery injury. The distance between the suturing device and the popliteal artery, and the risk of popliteal artery injury at different knee flexion angles during all-inside lateral meniscal repair remain unclear. METHODS: All-inside devices were inserted into 10 human cadaveric knees at the posterior horn of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120° knee flexion; posterior segment of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120°; and anteromedial portal at 90°. Distance and positional relationship between the device and popliteal artery were measured radiographically. RESULTS: In posterior horn repair through the anterolateral portal, the median distance increased from 5.7 mm at 60° to 9.1 mm at 90° (P = 0.63) and 18.0 mm at 120° (P = 0.02). The device pushed the wire at 60° in three cases, 90° in one case, and 120° in 0 cases. In posterior segment repair through the anterolateral portal, the median distance was 12.6 mm at 60°, 10.4 mm at 90°, and 18.3 mm at 120° (P = 0.08). The median distance at 90° was 18.1 mm through the anteromedial portal, the same as that at 120° through the anterolateral portal (P = 0.43), but greater than that at 90° through the anterolateral portal (P = 0.04). The wire was not pushed in any case. CONCLUSION: Although all-inside repair of the posterior part of the lateral meniscus through the anterolateral portal is risky, deeper knee flexion reduces the risk of popliteal artery injury.

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.

A Novel Heterozygous Mutation in the T-box Protein 4 Gene in an Adult Case of Small Patella Syndrome.

INTRODUCTION: Small patella syndrome (SPS) is a rare skeletal dysplasia relating to the T-box protein 4 (TBX4) gene, which regulates the development of lower extremities. Patients typically present with recurrent patellar dislocation (RPD) in childhood or adolescence, leading to a diagnosis of SPS and subsequent treatment to improve activity levels. However, those with mild symptoms may not be diagnosed when young and present later after skeletal maturation, which might compromise treatment options. Further understanding of genetic mutations of SPS could possibly help early diagnosis and following adequate surgical treatment. In this case report, we present a surgically treated adult female case of RPD associated with SPS, carrying a novel heterozygous mutation in the TBX4 gene. CASE REPORT: A 19-year-old female presented with persistent right knee pain after an atraumatic episode ofpatellar dislocation during walking. The patient had a history of recurrent patella instability of the right knee with an onset at the age of 8 years due to a minor trauma. Patellar apprehension sign was positive bilaterally. There was radiological evidence of bilateral small patellae, hypoplastic femoral trochlea, and tibial tuberosity. A direct sequencing of the coding regions in the TBX4 gene had confirmed the diagnosis of SPS. A novel heterozygous mutation (p.L39PfsX35) was found in the patient and her father. Surgical treatment was indicated and the patient underwent an isolated medial patellofemoral ligament (MPFL) reconstruction while no distal realignment osteotomy was performed due to hypoplastic tibial tuberosity. Excellent subjective and objective outcomes were obtained at 1 year postoperatively. DISCUSSION: To the best of our knowledge, this is the first reported SPS case with a novel mutation in the TBX4 gene in an Asian population. While a satisfying short-term outcome was obtained by an isolated MPFL reconstruction, early genetic diagnosis in childhood with adequate surgical treatment (e.g., Roux-Goldthwait procedure) would be ideal considering the limited treatment options in skeletally matured patients. The reported case has added one mutation variant of the TBX4 gene, which may help prevent delays in diagnosis of SPS.

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.

Fluoxetine ameliorates cartilage degradation in osteoarthritis by inhibiting Wnt/ß-catenin signaling.

Abnormal activation of the Wnt/ß-catenin signaling is implicated in the osteoarthritis (OA) pathology. We searched for a pre-approved drug that suppresses abnormally activated Wnt/ß-catenin signaling and has a potency to reduce joint pathology in OA. We introduced the TOPFlash reporter plasmid into HCS-2/8 human chondrosarcoma cells to estimate the Wnt/ß-catenin activity in the presence of 10 µM each compound in a panel of pre-approved drugs. We found that fluoxetine, an antidepressant in the class of selective serotonin reuptake inhibitors (SSRI), down-regulated Wnt/ß-catenin signaling in human chondrosarcoma cells. Fluoxetine inhibited both Wnt3A- and LiCl-induced loss of proteoglycans in chondrogenically differentiated ATDC5 cells. Fluoxetine increased expression of Sox9 (the chondrogenic master regulator), and decreased expressions of Axin2 (a marker for Wnt/ß-catenin signaling) and Mmp13 (matrix metalloproteinase 13). Fluoxetine suppressed a LiCl-induced increase of total ß-catenin and a LiCl-induced decrease of phosphorylated ß-catenin in a dose-dependent manner. An in vitro protein-binding assay showed that fluoxetine enhanced binding of ß-catenin with Axin1, which is a scaffold protein forming the degradation complex for ß-catenin. Fluoxetine suppressed LiCl-induced ß-catenin accumulation in human OA chondrocytes. Intraarticular injection of fluoxetine in a rat OA model ameliorated OA progression and suppressed ß-catenin accumulation.

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.

Wnt/ß-catenin signaling suppresses expressions of Scx, Mkx, and Tnmd in tendon-derived cells.

After tendon injuries, biomechanical properties of the injured tendon are not fully recovered in most cases. Modulation of signaling pathways, which are involved in tendon development and tendon repair, is one of attractive modalities to facilitate proper regeneration of the injured tendon. The roles of TGF-ß signaling in tendon homeostasis and tendon development have been elucidated. In contrast, the roles of Wnt/ß-catenin signaling in tendon remain mostly elusive. We found that the number of ß-catenin-positive cells was increased at the injured site, suggesting involvement of Wnt/ß-catenin signaling in tendon healing. Activation of Wnt/ß-catenin signaling suppressed expressions of tenogenic genes of Scx, Mkx, and Tnmd in rat tendon-derived cells (TDCs) isolated from the Achilles tendons of 6-week old rats. Additionally, activation of Wnt/ß-catenin reduced the amounts of Smad2 and Smad3, which are intracellular mediators for TGF-ß signaling, and antagonized upregulation of Scx induced by TGF-ß signaling in TDCs. We found that Wnt/ß-catenin decreased Mkx and Tnmd expressions without suppressing Scx expression in Scx-programmed tendon progenitors. Our studies suggest that Wnt/ß-catenin signaling is a repressor for tenogenic gene expressions.

Associations among pain catastrophizing, muscle strength, and physical performance after total knee and hip arthroplasty.

AIM: To investigate whether reductions in pain catastrophizing associated with physical performance in the early period after total knee arthroplasty (TKA) or total hip arthroplasty (THA). METHODS: The study group of 46 participants underwent TKA or THA. The participants were evaluated within 7 d before the operation and at 14 d afterwards. Physical performance was measured by the Timed Up and Go (TUG) test, and 10-m gait time was measured at comfortable and maximum speeds. They rated their knee or hip pain using a visual analog scale (VAS) for daily life activities. Psychological characteristics were measured by the Pain Catastrophizing Scale (PCS). Physical characteristics were measured by isometric muscle strength of knee extensors and hip abductors on the operated side. The variables of percent changes between pre- and post-operation were calculated by dividing post-operation score by pre-operation score. RESULTS: Postoperative VAS and PCS were better than preoperative for both TKA and THA. Postoperative physical performance and muscle strength were poorer than preoperative for both TKA and THA. The percent change in physical performance showed no correlation with preoperative variables. In TKA patients, the percent change of PCS showed correlation with percent change of TUG (P = 0.016), 10-m gait time at comfortable speeds (P = 0.003), and 10-m gait time at maximum speeds (P = 0.042). The percent change of muscle strength showed partial correlation with physical performances. The percent change of VAS showed no correlation with physical performances. On the other hand, in THA patients, the percent change of hip abductor strength showed correlation with percent change of TUG (P = 0.047), 10-m gait time at comfortable speeds (P = 0.001), and 10-m gait time at maximum speeds (P = 0.021). The percent change of knee extensor strength showed partial correlation with physical performances. The percent change of VAS and PCS showed no correlation with physical performances. CONCLUSION: Changes in pain catastrophizing significantly associated with changes in physical performance in the early period after TKA. It contributes to future postoperative rehabilitation of arthroplasty.

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.

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.

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.