Predictors of Satisfactory Outcomes With Fixed-Bearing Lateral Unicompartmental Knee Arthroplasty: Up to 7-year Follow-Up.

BACKGROUND: There is little literature available examining factors that may predict functional recovery after lateral unicompartmental knee arthroplasty (UKA). The purpose of this study was to report short to mid-term effectiveness and evaluate predictors of better outcome following lateral UKA. METHODS: We retrospectively reviewed 248 patients (260 knees) who underwent lateral UKA from January 2013, with a mean 5-year follow-up. The primary outcome measures comprised the Hospital for Special Surgery (HSS) score and patient satisfaction. Multivariate regression analyses were implemented to investigate associations between these factors with a satisfactory outcome. Implant survival was estimated by Kaplan-Meier analysis. RESULTS: Complete follow-up was available for 186 patients (198 knees). At last follow-up, the HSS scores were changed from 52.1 (range, 38-80) preoperatively to 85.6 (range, 61-98) (P < .001), The OKS improved from 22.8 (range, 16-32) preoperatively to 42.7 (range, 30-47) postoperatively (P < .01). The 5-year survival was 99.5%. The multivariate analysis showed that the following factors tended to obtain a satisfactory outcome: higher proportion of ASA class I (P < .001), diagnosis of primary OA (P = .007), postoperative limb alignment (P = .007), and higher preoperative HSS score (P = .019). Patients with valgus 9°-12° reported the highest HSS scores among different subgroups (P < .001). CONCLUSION: Following lateral UKA, postoperative outcomes were satisfactory in patients with lower ASA scores, diagnosis with primary OA, higher preoperative HSS scores and those with postoperative valgus alignment. It is important to understand these correlations to help appropriate patient selection to obtain optimal function after lateral UKA.

Assessment of radiolucent lines in patients with lateral unicompartmental knee arthroplasty and the relationship between these lines and the outcome.

PURPOSE: To assess the radiolucent lines (RLLs) around both tibial and femoral components in patients following lateral unicompartmental knee arthroplasty (UKA). METHODS: We performed a retrospective review of the records of a consecutive series of patients who had undergone lateral UKA. The RLLs were assessed with standard anteroposterior and lateral radiographs post-operatively. The patient-reported outcome measures included the Hospital for Special Surgery (HSS) score and Oxford knee score (OKS). The femoral component position (FCP) and femoral-tibial angle (FTA) were also recorded. RESULTS: A total of 198 UKAs that had appropriate radiographs and outcome scores were reviewed with a median follow-up of 33 (range, 12-71) months. The results suggested that 69 cases (34.8%) had RLLs on the standard radiographs. The incidence rates of femoral and tibial physiological RLLs were 11.6% (23/198) and 26% (52/198), respectively, of which 3% (6/198) concerned both components. All RLLs were considered "physiologic lines" that developed within one year after surgery. There were no significant differences among the types of RLLs in any of the outcome measures. No differences in FCP (P = .359) or FTA (P = .111) at the last follow-up were seen. CONCLUSIONS: It was found that one-third of UKAs had RLLs on radiographs following lateral UKA. All RLLs developed within one year after surgery. As a clinical consequence, the development of RLLs does not affect the short-term outcomes after lateral UKA.

MicroRNA-377-3p alleviates IL-1ß-caused chondrocyte apoptosis and cartilage degradation in osteoarthritis in part by downregulating ITGA6.

Increasing evidence indicates that altered expression of microRNAs (miRNAs) is associated with osteoarthritis (OA) progression. In our study, we demonstrated that miR-377-3p is underexpressed in OA-affected cartilage and IL-1ß-treated chondrocytes. Overexpression of miR-377-3p enhanced chondrocyte proliferation and restrained apoptosis and signs of cartilage matrix degradation and of an inflammatory response. Furthermore, ITGA6 was identified as a target gene of miR-377-3p. The latter was found to directly bind to the 3' untranslated region (3'UTR) of ITGA6 mRNA and downregulate ITGA6. In addition, ITGA6 expression was high in OA-affected tissues and negatively correlated with miR-77-3p expression. Overexpression of ITGA6 reversed the effects of miR-377-3p on IL-1ß-caused chondrocyte apoptosis, cartilage matrix degradation, and the inflammatory response. Moreover, bioinformatic analysis and a luciferase assay indicated that miR-377-3p expression is regulated by long noncoding RNA NEAT1, which binds to miR-377-3p and inactivates it. We showed that NEAT1 was highly expressed in OA-affected cartilage, negatively correlated with miR-377-3p levels, and positively correlated with ITGA6 levels. These findings provide information for the development of future treatments of OA, suggesting that miR-377-3p may be a therapeutic target in OA.

Lateral Unicompartmental knee arthroplasty for a secondary osteonecrosis of the lateral femoral condyle. A case report.

BACKGROUND: Secondary osteonecrosis of the knee is a rare event. There are few reports regarding management of this condition. The aim of the present study is to report treatment outcomes for secondary osteonecrosis of the lateral condyle treated with unicompartmental knee arthroplasty (UKA). CASE PRESENTATION: A 54-year-old woman with idiopathic thrombocytopenic purpura, who received low-dosage corticosteroids, complained of knee pain for 5 years and difficulty walking in the last 5 months. Fixed-bearing lateral UKA was performed under general anesthesia combined with midthigh saphenous nerve block. The patient could walk without ambulation aid shortly after the operation and achieved satisfactory knee joint function at the 6-week follow-up. The knee society score (KSS) increased from 68 to 91. The follow-up period was up to 1 year. There was no pain, loosening, or fracture of the prosthesis at the latest follow-up. CONCLUSIONS: This case study demonstrates successful management of secondary osteonecrosis of the lateral femoral condyle is possible with a fixed bearing lateral UKA. Early diagnosis, rigorous indication, and appropriate surgical techniques were critical to maximizing prosthesis stability in lateral UKA.

Does Unicompartmental Knee Replacement Offer Improved Clinical Advantages Over Total Knee Replacement in the Treatment of Isolated Lateral Osteoarthritis? A Matched Cohort Analysis From an Independent Center.

BACKGROUND: The purpose of this study is to compare the functional and radiographic results, perioperative complications, satisfaction rate, and mid-term survivorship after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) for the treatment of lateral compartmental knee osteoarthritis (LCKO). METHODS: Between March 2007 and September 2017, we identified 35 patients with primary TKAs and 121 patients with lateral UKAs (LUKAs) for LCKO with a minimum follow-up of 2 years (mean 5.3 years, range 2-12.4). The matched variables were age, gender, operation side, body mass index, American Society of Anesthesiologist grade, initial diagnosis, osteoarthritis grade in lateral compartment, and follow-up time. All patients were assessed using the Oxford Knee Score, Hospital for Special Surgery score, range of motion, length of hospital stay, satisfaction, and complications. Survivorship of UKA and TKA implants was also compared. RESULTS: At last follow-up, LUKA had a significantly better postoperative Oxford Knee Score, Hospital for Special Surgery score, range of motion, shorter length of hospital time, and higher satisfaction rate than matched TKA group. There were significant differences regarding patellar tendon injury (P = .043), superficial wound infection (P = .028), patellar snapping or impingement (P = .047), and stiffness (P < .001). Five-year survivorships free from revision were similar in both groups (99.2% vs 97.1%, P = .347). CONCLUSION: LUKA for LCKO demonstrated more favorable 5-year results in comparison with TKA. Furthermore, LUKA achieved comparable mid-term survivorship and was less likely to suffer from wound infection and knee stiffness, although not overall surgical complications.

Superior femoral component alignment can be achieved with Oxford microplasty instrumentation after minimally invasive unicompartmental knee arthroplasty.

PURPOSE: Oxford microplasty (MP) instrumentation has been developed to facilitate the reproducible and consistent performance of minimally invasive unicompartmental knee arthroplasty (MI-UKA) operation. The aim of this study was to compare the clinical and radiographic results of two groups of patients implanted using either a conventional instrumentation technique or an MP technique. METHODS: A prospective cohort study of 108 knees in 108 patients who underwent an MI-UKA procedure using either conventionally instrumented UKA (CI-UKA) (52 knees of 52 patients) or MP-assisted UKA (MP-UKA) (56 knees of 56 patients). The clinical assessment included the Oxford Knee Score (OKS), the Knee Society Score (KSS), a visual analogue scale (VAS) for pain, and range of motion (ROM). Complications were also recorded. RESULTS: No significant differences were observed between the two groups regarding OKS, KSS, VAS, and ROM. There were also no significant differences in terms of mechanical limb alignment and tibia implant alignment. However, the MP-UKA group showed significantly more accurate positioning of the femoral component than the CI-UKA group. Additionally, the MP-UKA group had more femoral prostheses implanted in the "satisfactory" range and fewer "outliers" than the CI-UKA group. No significant difference in complications was noted between the two groups. CONCLUSION: This study suggested that compared with CI-UKA, MP-UKA provides significant improvements in increasing the accuracy of sagittal and coronal implantation of the femoral component and in reducing the numbers of outliers for femoral prosthetic alignment. It is advocated that the MP system should be considered when MI-UKA is performed. LEVEL OF EVIDENCE: Therapeutic study, Level IV.

Up to twelve year follow-up of the Oxford phase three unicompartmental knee replacement in China: seven hundred and eight knees from an independent centre.

PURPOSE: There have been few large sample studies reporting the midterm outcome of Oxford phase 3 unicompartmental knee arthroplasty (UKA) in Asian patients. METHODS: The study included 708 consecutive medial Oxford UKAs between February 2005 and May 2014 in Chinese patients. All cases were performed for the recommended indications with a minimally-invasive surgical technique. The functional and radiological outcomes were subsequently examined. In particular, we divided patients into the spontaneous osteonecrosis of the knee (SONK) group and the osteoarthritis (OA) group. RESULTS: All patients were reviewed with a mean follow-up of 6.2 years (range 2.7-12 years). At the latest follow up, the mean Oxford knee score (OKS) increased from 22.5 to 38.5 points, while the mean knee society score (KSS) increased from 43.6 to 86.1 points. The mean visual analogue scale pain score decreased from 7.9 to 1.5 points and the mean range of motion (ROM) increased from 112.5° to 125.2°. A total of 13 UKAs (1.88%) required revisions. The most common reason was bearing dislocation and osteoarthritis of the lateral compartment. Using revision for any cause as an endpoint, the five-year cumulative survival rate was 98.8% and the ten-year survival rate was 94.3%. There was no statistically significant difference between the SONK group and the OA group for the five-year cumulative survival rate (98.7% vs. 98.8%, P > 0.05). CONCLUSION: This study demonstrates that Oxford UKA is a good option for the treatment of anteromedial OA and SONK of the knee in Asian patients.

Lactoferrin Inhibits IL-1ß-Induced Chondrocyte Apoptosis Through AKT1-Induced CREB1 Activation.

BACKGROUND/AIMS: Chondrocyte apoptosis is largely responsible for cartilage degeneration in osteoarthritis (OA). Interleukin-1 beta (IL-1ß) is widely used as a chondrocyte apoptosis-inducing agent, while lactoferrin (LF) is an anabolic reagent which has the potential to inhibit chondrocyte apoptosis. We assessed the effects of LF on cartilage degeneration in IL-1ß-induced chondrocytes and in a rat model of OA, and explored the potential molecular mechanisms involved. METHODS: Human articular chondrocytes (HACs) were treated with IL-1ß alone or in combination with LF. MTT and flow cytometric assays were used to detect changes after treatment with LF. Western blotting was used to examine the relevant molecules regulating apoptosis. RESULTS: We found that IL-1ß reduced the viability of HACs, whereas 200 µg/mL of LF significantly counteracted the inhibitory effect of IL-1ß. LF significantly inhibited IL-1ß-induced HAC apoptosis. The protein expression of the apoptotic markers Caspase-3 and PARP was also significantly reduced in the LF treatment group when analyzed by western blotting. Furthermore, we found that LF triggered CREB1 phosphorylation in IL-1ß-induced HAC apoptosis through AKT1 signaling. In addition, LF promoted the repair of articular cartilage damage in a rat OA model with elevated p-CREB levels. CONCLUSIONS: These studies suggest that LF has an anti-apoptotic effect on IL-1ß-induced chondrocytes, and thus may be a promising novel therapeutic agent for OA.

[Biomechanical research of transforaminal lumbar interbody fusion model].

Based on the surgical model using transforaminal lumbar interbody fusion (TLIF) to treat lumbar spondylolisthesis, this paper presents the investigations of the biomechanical characteristics of cage and pedicle screw in lumbar spinal fusion implant fixed system under different combinations with finite element method. Firstly, combining the CT images with finite element pretreatment software, we established three dimensional nonlinear finite element model of human lumbar L4-L5 segmental slight slippage and implant under different fixed combinations. We then made a comparison analysis between the biomechanical characteristics of lumbar motion range, stress distribution of cage and pedicle screw under six status of each model which were flexion, extension, left lateral bending, right lateral bending, left axial rotation and right axial rotation. The results showed that the motion ranges of this model under different operations were reduced above 84% compared with those of the intact model, and the stability of the former was improved significantly. The stress values of cage and pedicle screw were relatively larger when they were fixed by single fusion device additional unilateral pedicle screw, but there was no statistically significant difference. The above research results would provide reference and confirmation for further biomechanics research of TLIF extracorporal specimens, and finally provide biomechanical basis for the feasibility of unilateral internal fixed diagonal intervertebral fusion TLIF surgery.

[Construction and analysis of a finite element model of human L4-5 lumbar segment].

In the present study, a finite element model of L4-5 lumbar motion segment was established based on the CT images and a combination with image processing software, and the analysis of lumbar biomechanical characteristics was conducted on the proposed model according to different cases of flexion, extension, lateral bending and axial rotation. Firstly, the CT images of lumbar segment L4 to L5 from a healthy volunteer were selected for a three dimensional model establishment which was consisted of cortical bone, cancellous bone, posterior structure, annulus, nucleus pulposus, cartilage endplate, ligament and facet joint. The biomechanical analysis was then conducted according to different cases of flexion, extension, lateral bending and axial rotation. The results showed that the established finite element model of L4-5 lumbar segment was realistic and effective. The axial displacement of the proposed model was 0.23, 0.47, 0.76 and 1.02 mm, respectively under the pressure of 500, 1 000, 1 500 and 2 000 N, which was similar to the previous studies in vitro experiments and finite element analysis of other people under the same condition. The stress distribution of the lumbar spine and intervertebral disc accorded with the biomechanical properties of the lumbar spine under various conditions. The established finite element model has been proved to be effective in simulating the biomechanical properties of lumbar spine, and therefore laid a good foundation for the research of the implants of biomechanical properties of lumbar spine.

The impact of thyroid function on total spine bone mineral density in postmenopausal women.

PURPOSE: Osteoporosis has been a widespread concern for older women, especially postmenopausal women. Thyroid function is crucial for bone metabolism. However, the relationship between thyroid function variation within thyroxine reference range and bone mineral density (BMD) remains ambiguous. The objective of this study was to evaluate the effect of subclinical hypothyroidism or hyperthyroidism on total spinal BMD in postmenopausal women. METHODS: Based on data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010, multivariable weighted logistic regression was used to evaluate the relationships between total spine BMD and TSH among postmenopausal women aged ≥50. RESULTS: After accounting for a number of variables, this study discovered that the middle TSH tertile was associated with a decreased probability of osteoporosis. Additionally, the subgroup analysis revealed that postmenopausal women over the age of 65 or people with an overweight BMI had a clearer relationship between total spine BMD and TSH. CONCLUSION: The total spinal BMD had a positive relationship with thyroid stimulating hormone in postmenopausal women, and that appropriate TSH level (1.38-2.32 mIU/L) was accompanied by higher total spinal BMD.

Coffee and the risk of osteoarthritis: a two-sample, two-step multivariable Mendelian randomization study.

Purpose: To investigate the potential causal relationship between coffee consumption and osteoarthritis (OA), and to disentangle whether body mass index (BMI) and Bone mineral density (BMD) mediate this relationship. Methods: We performed two-sample and two-step Mendelian randomization (MR) analyses utilizing publicly available genome-wide association studies (GWAS) summary statistics to estimate the association between coffee intake and OA risk (including knee OA, hip OA, knee or hip OA, and total OA), as well as the possible mediating effects of BMI and BMD. In addition, data of different coffee types (decaffeinated coffee, instant coffee, ground coffee-including espresso, filter, etc., and other coffee types) were used to explore the effect of coffee type on the risk of OA. Results: In two-sample MR, coffee intake increased the risk of OA in various sites, with the most significant impact observed in knee osteoarthritis (KOA) (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.57-2.61, p < 0.001). The effect on self-reported OA was minimal (OR 1.03, 95% CI 1.01-1.05, p = 0.006). Further analysis of different types of coffee revealed that only decaffeinated coffee was causally associated with both KOA (OR 4.40, 95% CI 1.71-11.33, p = 0.002) and self-reported OA (OR 1.13, 95% CI 1.02-1.26, p = 0.022). In two-step MR, BMI explained over half of the coffee intake-all OA risk association, while BMD accounted for less than 5% of the mediation effect. Conclusion: Our study suggests that coffee intake increase the risk of OA, with BMI playing a significant mediating role. Decaffeinated coffee appears to have the greatest impact on OA risk compared to other types of coffee. Therefore, managing BMI and selecting appropriate types of coffee should be included in the health management of individuals who frequently consume coffee.

Lactoferrin inhibits dexamethasone-induced chondrocyte impairment from osteoarthritic cartilage through up-regulation of extracellular signal-regulated kinase 1/2 and suppression of FASL, FAS, and Caspase 3.

Dexamethasone (Dex) is commonly used for osteoarthritis (OA) with excellent anti-inflammatory and analgesic effect. However, Dex also has many side effects following repeated use over prolonged periods mainly through increasing apoptosis and inhibiting proliferation. Lactoferrin (LF) exerts significantly anabolic effect on many cells and little is known about its effect on OA chondrocytes. Therefore, the aim of this study is to investigate whether LF can inhibit Dex-induced OA chondrocytes apoptosis and explore its possible molecular mechanism involved in. MTT assay was used to determine the optimal concentration of Dex and recombinant human LF (rhLF) on chondrocytes at different time and dose points. Chondrocytes were then stimulated with Dex in the absence or presence of optimal concentration of rhLF. Cell proliferation and viability were evaluated using MTT and LIVE/DEAD assay, respectively. Cell apoptosis was evaluated by multi-parameter apoptosis assay kit using both confocal microscopy and flow cytometry, respectively. The expression of extracellular signal-regulated kinase (ERK), FAS, FASL, and Caspase-3 (CASP3) at the mRNA and protein levels were examined by real-time polymerase chain reaction (PCR) and immunocytochemistry, respectively. The optimal concentration of Dex (25 µg/ml) and rhLF (200 µg/ml) were chosen for the following experiments. rhLF significantly reversed the detrimental effect of Dex on chondrocytes proliferation, viability, and apoptosis. In addition, rhLF significantly prevented Dex-induced down-regulation of ERK and up-regulation of FAS, FASL, and CASP3. These findings demonstrated that rhLF acts as an anabolic effect on chondrocytes through significantly reversing Dex-induced chondrocytes apoptosis. This study may contribute to further investigating the clinical application of LF on OA.

[Pre-operative assessment of the patellofemoral joint in unicompartmental knee replacement using Oxford Phase III and its influence on outcome].

OBJECTIVE: To determine whether anterior knee pain and/or radiological evidences of degeneration of the patellofemoral joint influence the outcome of unicompartmental knee arthroplasty (UKA). METHODS: Between January 2006 and December 2010, 95 consecutive patients (100 knees) with unicompartmental knee osteoarthritis were treated with Oxford UKA, including 34 males and 61 females. The mean age was 68.2 years (range, 55-82 years). The average Body Mass Index was 26.3 kg/m(2)(range, 24-28 kg/m(2)). Pre-operative there were 43 knees (43.0%) with anterior knee pain and 57 knees (57.0%) without it. Pre-operative radiological status of the patellefemoral joint were defined using Ahlback and Altman systems. The pre- and post-operative results of Oxford Knee Score (OKS), American Knee Society Score (AKS) and Western Ontario and Macmaster (WOMAC) were compared using paired t-test, the results between different groups were compared using grouped t-test. RESULTS: All cases were followed up for average 50 months (24-84 months). At the last follow-up, none had complications of infection, fat embolism, deep vein thrombosis, malposition of prosthesis, dislocation or loosing. The mean femoral component alignment was -0.7° ± 5.2° (valgus/varus), -0.8° ± 4.5°(flexion/extension); the mean tibial component alignment was -0.1° ± 2.2°(valgus/varus), -0.4° ± 2.4° (flexion/extension). The clinical outcomes were significantly improved compared with pre-operation regardless of presence (OKS: t = 19.04, P < 0.01; AKS knee:t = 38.56, P < 0.01;AKS function:t = 39.29, P < 0.01;WOMAC:t = 43.22, P < 0.01) or absence (OKS: t = 31.57, P < 0.01; AKS knee:t = 40.34, P < 0.01; AKS function:t = 43.62, P < 0.01; WOMAC: t = 47.06, P < 0.01) of anterior knee pain. The results were significantly improved compared with pre-operation (P < 0.01) regardless of whether degeneration of the patellofemoral joint. There was no statistically significant difference in outcome between patients with evidence of degeneration in the medial patellofemoral joint and those without (P > 0.05) . Patients with lateral patellofemoral degeneration had a worse score than those without, OKS (t = 2.56, P = 0.01) and WOMAC (t = 2.20, P = 0.03) by the Altman score, OKS (t = 2.29, P = 0.02) by the Ahlback score. For AKS measures there was no statistically significant difference in outcome (P > 0.05) . CONCLUSIONS: Neither anterior knee pain nor radiological evidence of medial patellofemoral joint degeneration would influnence the outcome of UKA, lateral patellofemoral joint degeneration have an increased risk of a poor result.

A standardized technique for lateral unicompartmental knee arthroplasty.

OBJECTIVES: We developed a new standardized procedure for lateral unicompartmental knee arthroplasty (UKA) to maximize the benefits and minimize the risks of surgery in patients with osteoarthritis (OA). METHODS: This retrospective study recruited patients who underwent lateral UKA at our hospital between January 2014 and January 2016. Demographic characteristics and preoperative and postoperative American Knee Society (AKS) clinical scores (including pain, clinical, and knee mobility scores) were collected. RESULTS: A total of 158 patients (35 male and 123 female) who underwent 160 lateral UKAs were analyzed. Their AKS clinical scores (0-100 points) improved from 53.1 ± 4.1 (range 45-62) preoperatively to 97.0 ± 1.7 (range 92-99) (p < 0.001) postoperatively with additional improvements of 9.1 ± 1.8 (range 3-14) to 47.3 ± 1.5 (range 45-49) (p < 0.001) for pain, 49.7 ± 9.7 (range 35-70) to 97.1 ± 4.1 (range 90-100) (p < 0.001) for function, and 105.0 ± 4.4° (equivalent to ∼100-115°) to 125.5 ± 5.3° (∼110-135°) (p < 0.001) for a range of motion (ROM). No patients required reoperations or revisions. Two patients were readmitted within 60 days due to severe knee swelling. CONCLUSION: The lateral UKA protocol was reproducible and the patients had a good postoperative outcomes. Yet, large-scale, multi-center, prospective studies are needed to further confirm our findings.

Association between physical activity and bone mineral density in postmenopausal women: a cross-sectional study from the NHANES 2007-2018.

BACKGROUND: Physical activity (PA) is generally encouraged for the treatment of osteoporosis. However, epidemiological statistics on the level of physical activity required for bone health are scarce. The purpose of this research was to analyze the association between PA and total spine bone mineral density (BMD) in postmenopausal women. METHODS: The research study included postmenopausal women aged ≥ 50 from the National Health and Nutrition Examination Survey. The metabolic equivalent (MET), weekly frequency, and duration of each activity were used to calculate PA. Furthermore, the correlations between BMD and PA were investigated by multivariable weighted logistic regression. RESULTS: Eventually, 1681 postmenopausal women were included, with a weighted mean age of 62.27 ± 8.18 years. This study found that performing ≥ 38MET-h/wk was linked to a lower risk of osteoporosis after controlling for several covariates. Furthermore, the subgroup analysis revealed that the connection between total spine BMD and moderate-to-vigorous PA was more obvious among postmenopausal women aged < 65 years or individuals with normal BMI (< 25 kg/m2). CONCLUSION: Physical activity ranging from moderate to vigorous was linked to higher total spine BMD in postmenopausal women.

[Short- and mid-term effectiveness of unicompartmental knee arthroplasty for post-traumatic arthritis of knee].

Objective: To investigate the short- and mid-term effectiveness of unicompartmental knee arthroplasty (UKA) for post-traumatic arthritis (PTA) of knee. Methods: The clinical data of 30 patients with PTA of unilateral knee between March 2014 and September 2021 was retrospectively analyzed. There were 14 males and 16 females with an average of 64.5 years (range, 33-81 years). The average body mass index was 26.7 kg/m 2 (range, 19.8-35.6 kg/m 2). The types of injuries that caused PTA included intra-articular fracture in 16 cases, extra-articular fracture in 8 cases, and soft tissue injury in 6 cases. The initial injuries were treated by conservative therapy in 12 cases and by surgical therapy in 18 cases. Ten cases were medial compartment osteoarthritis and 20 cases were lateral compartment osteoarthritis. According to Kellgren-Lawrence staging, there were 19 cases of grade Ⅲ and 11 cases of grade Ⅳ. The operative time, the length of hospital stay, complications, and subjective satisfaction were recorded. The Oxford Knee Function Score (OKS), Hospital for Special Surgery (HSS) score, and knee range of motion (ROM) were used to evaluate knee function. Weight-bearing X-ray films were taken to measure the femoro-tibial angle (FTA) and to assess alignment correction of the lower limb. Results: The operative time ranged from 50 to 95 minutes (mean, 63.7 minutes), the length of hospital stay ranged from 3 to 8 days (mean, 6.9 days). Superficial infection occurred in 2 patients, while the remaining incisions healed by first intention. There was no deep vein thrombosis or neurovascular injury. All patients were followed up 17-109 months (median, 70 months). At last follow-up, OKS score, HSS score, and ROM in 30 cases significantly improved when compared with those before operation (P<0.05). Lower limb alignment was significantly corrected and there was significant difference in FTA of the varus and valgus knees between pre- and post-operation ( P<0.05). The patient satisfaction rate was 86.7% (26/30). Two cases developed contralateral osteoarthritis progression during follow-up. No bearing dislocation, prosthesis loosening or sinking occurred and none required further revision. Conclusion: For patients with PTA of knee, UKA can obtain definite short- and mid-term effectiveness with high patient satisfaction.

Desferrioxamine alleviates UHMWPE particle-induced osteoclastic osteolysis by inhibiting caspase-1-dependent pyroptosis in osteocytes.

BACKGROUND: Cell death and inflammation are the two important triggers of wear particle-induced osteolysis. Particles, including cobalt-chromium-molybdenum and tricalcium phosphate, have been reported to induce pyroptosis in macrophages and osteocytes. Although macrophage pyroptosis facilitates osteoclastic bone resorption and osteolysis, whether osteocyte pyroptosis is involved in osteoclastic osteolysis still needs further investigation. Desferrioxamine (DFO), an FDA-approved medication and a powerful iron chelator, has been proven to reduce ultrahigh-molecular-weight polyethylene (UHMWPE) particle-induced osteolysis. However, whether DFO can ameliorate UHMWPE particle-induced osteolysis by decreasing pyroptosis in osteocytes is unknown. RESULTS: A mouse calvarial osteolysis model and the mouse osteocyte cell line MLO-Y4 was used, and we found that pyroptosis in osteocytes was significantly induced by UHMWPE particles. Furthermore, our findings uncovered a role of caspase-1-dependent pyroptosis in osteocytes in facilitating osteoclastic osteolysis induced by UHMWPE particles. In addition, we found that DFO could alleviate UHMWPE particle-induced pyroptosis in osteocytes in vivo and in vitro. CONCLUSIONS: We uncovered a role of caspase-1-dependent pyroptosis in osteocytes in facilitating osteoclastic osteolysis induced by UHMWPE particles. Furthermore, we found that DFO alleviated UHMWPE particle-induced osteoclastic osteolysis partly by inhibiting pyroptosis in osteocytes. Schematic of DFO reducing UHMWPE particle-induced osteolysis by inhibiting osteocytic pyroptosis. Wear particles, such as polymers, generated from prosthetic implant materials activate canonical inflammasomes and promote the cleavage and activation of caspase-1. This is followed by caspase-1-dependent IL-ß maturation and GSDMD cleavage. The N-terminal fragment of GSDMD binds to phospholipids on the cell membrane and forms holes in the membrane, resulting in the release of mature IL-ß and inflammatory intracellular contents. This further facilitates osteoclastic differentiation of BMMs, resulting in excessive bone resorption and ultimately leading to prosthetic osteolysis. DFO reduces UHMWPE particle-induced osteolysis by inhibiting osteocytic pyroptosis.

Locking compression plate and cerclage band for type B1 periprosthetic femoral fractures preliminary results at average 30-month follow-up.

We present results of 12 type B1 periprosthetic femoral fractures treated with locking compression plate and cerclage band from January 2003 to June 2007. The average follow-up was 30.1 months. Twelve fractures united in an average period of 4.8 months. The mean Harris hip score was 84.4. One patient presented with loosening of proximal screws at 5 months. This patient was treated nonoperatively as she had radiographic evidence of fracture union. One patient with delayed union required 9 months to heal. Unfortunately, 1 month later, she sustained a type C fracture during a slipping injury and treated with cast immobilization. The fracture united after 4 months. None had complications of loss of reduction, plate break, and wound infection.

Prosthesis size distribution in Oxford phase III unicompartmental knee arthroplasty - Based on more than 1900 Chinese patients.

INTRODUCTION: It is difficult to determine the optimal size of unicompartmental knee arthroplasty (UKA) prosthesis both pre-operatively and intra-operatively. Inappropriate femoral and tibial components are still the leading cause of failure. Several guidelines based on the Western population may not apply to the Chinese patients. We consequently try to investigate distributions of Oxford-UKA prosthesis in Chinese patients in order to provide a good reference for surgeons preoperatively. METHODS: From January 2010 to December 2019, 1909 patients (2307 knees) with primary anteromedial osteoarthritis accepted Oxford phase III UKA. Statistical analyses were performed on the distributions of the femoral, tibial, and matching of the femoral-tibial prosthesis. The possible factors affecting the sizes of femoral components, including gender, height based on gender were investigated. RESULTS: 1. The distributions of femoral size components include extra-large (XL) 0, large (L) 1.08%, medium (M) 26.09%, small (S) 59.64%, extra-small (XS) 13.18%; the tibial sizes components were F 0, E 0.69%, D 7.80%, C 19.59%, B 24.79%, A 34.16%, AA 12.96%. 2. The matching of femur-tibia components were L-E 0.52%,L-D 0.52%,M-E 0.17%, M-D 7.28%,M - C 16.60%,M - B 1.95%,M-A 0.13%, M-AA 0.04%, S-C 2.99%, S-B 22.67%, S-A 31.12%, S-AA 2.82%, XS-B 0.17%, XS-A 2.90% and XS-AA 10.10%. The optimal matches between femoral and tibial components were: XL with F; L with E; M with C and D; S with A and B. 3. The patient's gender and height based on gender are necessary considerations for selection of femoral components (P＜0.01). CONCLUSION: In Chinese patients, the size of femoral components is mainly small (S) for women, medium (M) for men. The tibial components of female patients are mainly A and B, whereas C is predominant for male patients. The more commonly used matching forms are S-A and S-B.