Open reduction and internal fixation of crescent fracture-dislocation: anterior or posterior approach?

INTRODUCTION: To date, the approach that prevails in the open reduction and internal fixation of crescent fracture-dislocations (CFD) remains unknown. This study aimed to compare the outcomes of CFD treated via the anterior or posterior approach. MATERIALS AND METHODS: Data from 64 cases of CFDs openly reduced through an anterior (group A, n = 31) or a posterior (group B, n = 33) approach were retrospectively analyzed. Functional results, reduction quality, residual displacements in the axial and coronal planes, pelvic asymmetry deformity, and correlations between Day's classification were compared. Complications and fracture union were also recorded. All patients were followed up for at least 12 months. RESULTS: The functional scores were similar between the two groups, and all fractures achieved good or excellent reduction postoperatively. In the coronal plane, the excellent/good ratio in group B was higher than in group A. The mean residual displacement in the coronal plane was significantly higher in group A than in group B, with group A showing greater displacement in both planes for Day I fractures and in the coronal plane for Day II fractures. The residual displacement in both planes for Day III fractures was comparable between the groups. The pelvic asymmetry deformity was equal between the two groups and among the different Day's fracture types. CONCLUSIONS: Open reduction and internal fixation of CFDs obtained satisfactory outcomes through an anterior or posterior approach. The posterior approach achieved a better sacroiliac joint reduction. The optimal indication for the posterior approach was a Day I fracture, followed by a Day II fracture. No correlation was found between the surgical approach and reduction quality in Day III fractures.

Prognosis-related molecular subtyping in head and neck squamous cell carcinoma patients based on glycolytic/cholesterogenic gene data.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) remains an unmet medical challenge. Metabolic reprogramming is a hallmark of diverse cancers, including HNSCC. METHODS: We investigated the metabolic profile in HNSCC by using The Cancer Genome Atlas (TCGA) (n = 481) and Gene Expression Omnibus (GEO) (n = 97) databases. The metabolic stratification of HNSCC samples was identified by using unsupervised k-means clustering. We analyzed the correlations of the metabolic subtypes in HNSCC with featured genomic alterations and known HNSCC subtypes. We further validated the metabolism-related subtypes based on features of ENO1, PFKFB3, NSDHL and SQLE expression in HNSCC by Immunohistochemistry. In addition, genomic characteristics of tumor metabolism that varied among different cancer types were confirmed. RESULTS: Based on the median expression of coexpressed cholesterogenic and glycolytic genes, HNSCC subtypes were identified, including glycolytic, cholesterogenic, quiescent and mixed subtypes. The quiescent subtype was associated with the longest survival and was distributed in stage I and G1 HNSCC. Mutation analysis of HNSCC genes indicated that TP53 has the highest mutation frequency. The CDKN2A mutation frequency has the most significant differences amongst these four subtypes. There is good overlap between our metabolic subtypes and the HNSCC subtype. CONCLUSION: The four metabolic subtypes were successfully determined in HNSCC. Compared to the quiescent subtype, glycolytic, cholesterogenic and mixed subtypes had significantly worse outcome, which might offer guidelines for developing a novel treatment strategy for HNSCC.

Morphological analysis of the posterior elements of associated both-column acetabular fractures.

BACKGROUND: It is still in dispute as to whether a posterior approach is applied to reduce the posterior fractures of associated both-column acetabular fractures (ABC-AFs). PURPOSE: To analyze the morphological changes in the posterior elements including the posterior column (PC) and/or associated posterior wall (PW) fragments to provide a reference for surgical planning. MATERIAL AND METHODS: The 3D computed tomography (CT) data of 100 cases of ABC-AFs were retrospectively analyzed using Mimics and 3-Matic software. The line distribution of the retroacetabular surface (RAS), the acetabular fossa, and the size of the PW fragments were analyzed. RESULTS: Fracture lines (n = 89) on RAS appeared in three patterns: transverse lines (n = 41) on the cephalic (65.8%) and caudal (29.3%) thirds; oblique lines (n = 34) on the mid-caudal thirds; and multifragmentary lines (n = 14). The lines of the displaced PW fragment (n = 61) were widely distributed in intra- and extra-articular regions. The mean radian of the PW fragments was >90° in 67.2% of cases and involved anteriorly to the vertex in 90.2% of cases. The average fracture span on the RAS was 0.60-1.00 in 63.9% of cases. The mean length of the spike of PW fragments was >20 mm in 80.3% of cases. DISCUSSION: For PC fractures, transverse lines on the cephalic third of RAS indicated a possibility of the anterior approach, while transverse lines on the distal third or oblique and multifragmentary lines suggest the posterior approach. A displaced PW fragment was involved more extensively both intra-and extra-articularly and may be optimally treated via a posterior approach.

Three-dimensional morphological analysis of quadrilateral plate fragments in associated both-column acetabular fractures.

OBJECTIVE: To investigate whether the fracture morphology of quadrilateral plate (QP) fragments is associated with the anterior and posterior columns in associated both-column (ABC) fractures. MATERIALS AND METHODS: Three-dimensional computed tomography data of 100 ABC fractures treated at our hospital from August 2016 to August 2019 were retrospectively analyzed using Mimics and 3-matic software. The distribution of fracture lines was described using the fracture mapping technique. RESULTS: One fragment presented on the QP was confirmed in 88% of the patients. The QP fragments' fracture lines were divided into the anterior oblique (AO), superior posterior oblique (SPO), and mid-posterior oblique (MPO) lines, occurring in 100, 86, and 8 cases, respectively. AO lines were distributed along the arcuate line. SPO lines were continuations of the AO lines, which were distributed to the posterior column from the greater sciatic notch to the lesser sciatic notch. MPO lines were involved in the QP's central area. A simple fracture was found at the proximal AO and SPO lines in 80% and 86% of all displaced fractures, respectively. AO lines distal to the superior rim of the acetabula were confirmed to be comminuted fractures in 32% of all cases. CONCLUSIONS: In ABC fractures, there was only one QP fragment in nearly 90% of all cases. The QP fractures were mainly present in the QP's peripheral area. More than 80% of the fracture patterns on the cephalic side of the QP were simple. The reduction and internal fixation of QP fractures in ABC fractures should be in the cephalic region.

[Discrimination of quality markers of Shujin Huoxue Capsules based on five principles coupled with cobweb model].

The quality markers(Q-markers) of Shujin Huoxue Capsules were comprehensively discriminated based on the five principles of transfer and traceability, specificity, compatibility, effectiveness and measurability. The compounds that could be transferred from the original medicinal materials to the preparation were selected with the principle of transfer and traceability. The specific components in the prescription were screened by reviewing literature with the principle of specificity. According to the principle of compatibility, the attributes of compounds were evaluated by the sovereign, minister, assistant and guide combination rules of the original medicinal materials in the prescription. According to the principle of measurability, the measurable components were summarized by reference to the pharmacopoeia and literature combined with the content. The mechanism of Shujin Huoxue Capsules in the treatment of osteoporosis was studied through network pharmacology based on the principle of effectiveness, which was the evaluation index of effectiveness. The chemical components screened out above were regarded as candidate Q-markers, and the cobweb model was plotted to obtain the comprehensive score of Q-markers. Hydroxysafflor yellow A, trachelosid, eleutheroside B, α-cyperone, protocatechuic acid, protocatechualdehyde and 4-methoxy salicylaldehyde were discriminated as the Q-markers of Shujin Huoxue Capsules based on the five principles combined with cobweb model.

Knockdown of TREM-1 suppresses IL-1ß-induced chondrocyte injury via inhibiting the NF-κB pathway.

Triggering receptor expressed on myeloid cells 1 (TREM-1) is a recently discovered molecule that modulates inflammatory responses. This study aimed to investigate the specific function of TREM-1 in chondrocytes and its association with the pathophysiology of osteoarthritis (OA). We observed upregulation of TREM-1 in OA cartilage compared to normal tissues. Knockdown of TREM-1 suppressed interleukin 1 beta (IL-1ß)-induced extracellular matrix (ECM) metabolic imbalance, pro-inflammatory cytokine production, decrease in cell viability and apoptosis. Mechanistic analyses further revealed that IL-1ß-induced activation of the NF-κB pathway is suppressed upon TREM-1 knockdown, similar to the effect of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB. TREM-1 expression was consistently increased in a mouse OA model in vivo, and its silencing led to inhibition of matrix metallopeptidase-13 (MMP-13) production, increased collagen type II synthesis and decreased NF-κB signaling. Our data collectively suggest that TREM-1 plays a critical in OA development through regulation of NF-κB signaling. Pharmacological inhibition of TREM-1 may therefore present an effective novel therapeutic approach for OA.

Polymorphisms in the MDM2 gene and risk of malignant bone tumors: a meta-analysis.

There are several studies published to assess the associations of murine double minute 2 (MDM2) genetic polymorphisms with risk of malignant bone tumors, but they reported contradictory results and failed to confirm a strong and consistent association. To assess the evidence regarding the associations of MDM2 genetic polymorphisms with the risk of malignant bone tumors, we conducted a meta-analysis of epidemiological studies. The pooled odds ratio (OR) with its 95% confidence intervals (95% CI) was used to assess these possible associations. Four studies with a total of 3,958 individuals were finally included the meta-analysis. Meta-analysis of two studies on MDM2 SNP309 polymorphism showed that MDM2 SNP309 polymorphism was associated with an increased risk of malignant bone tumors (G versus T: OR = 1.72, 95% CI 1.35-2.20, P < 0.001; GG versus TT: OR = 2.64, 95% CI 1.59-4.39, P < 0.001; GG/GT versus TT: OR = 1.87, 95% CI 1.33-2.62, P < 0.001; GG versus TT/GT: OR = 2.20, 95% CI 1.38-3.51, P = 0.001). Meta-analysis of those two studies on MDM2 rs1690916 polymorphism showed that MDM2 rs1690916 minor allele A was associated with decreased risk of malignant bone tumors (OR = 0.60, 95% CI 0.46-0.77, P < 0.001). Meta-analyses of available data show that there are significant associations of MDM2 SNP309 polymorphism and MDM2 rs1690916 polymorphism with malignant bone tumors.

High-throughput absolute quantification sequencing reveals the adaptive succession and assembly pattern of plastisphere communities in municipal sewer systems: Influence of environmental factors and microplastic polymer types.

Municipal sewer systems have received increasing attention due to the magnitude of the microplastic stock and its potential ecological impacts. However, as a critical aspect of the adverse impacts, little is known about the plastisphere that forms in these engineered environments. Using high-throughput absolute quantification sequencing, we conducted a systemic study combining field survey and laboratory batch test to explain the general plastisphere pattern and the role of environmental and polymeric factors in driving plastisphere succession and assembly there. We demonstrated the capacity of microplastics to support high levels of microbial colonization, increasing by 8.7-56.0 and 1.26-5.62 times at field and laboratory scales, respectively, despite the less diverse communities hosted in the resulting plastisphere. Sediment communities exhibited higher diversity but greater loss of specific operational taxonomic units in their plastisphere than in the wastewater. The former plastisphere had primarily an enhanced methanogenesis-oriented metabolic network linked to hydrolysis fermentation, hydrogen-producing acetogenesis, and denitrification, while the latter had a pronounced niche partitioning and competitive interaction network. Exogenous substrate flux and composition were key in stimulating plastisphere community growth and succession. Furthermore, the high nitrogen baseline facilitated alternative niche formation for plastisphere nitrifiers and denitrifiers, and the plastisphere pathogens associated with denitrification and plastic biodegradation functions increased significantly. The aerobic state also promoted a 1.71 times higher colonizer load and a denser interaction pattern than the anaerobic state. Selective filtering by polymers was evident: polyethylene supported higher plastisphere diversity than polypropylene. This study provides new insights into the mechanisms driving colonizer loads and the adaptive succession and assembly of the plastisphere in such a typically hydrodynamic and highly contaminated environment. The results help to fill the knowledge gap in understanding the potential role of microplastics in shaping the microecology of sewers and increasing health risks and substrate loss during sewer transfer.

Land use, stratified wastewater and sediment, and microplastic attribute factors jointly influence the microplastic prevalence and bacterial colonization patterns in sewer habitats.

The capacity of microplastics to harbor and propagate bacteria has been the focus of attention over the last decade. Such microplastic-supported bacterial colonization behavior in the municipal sewer system could be a critical ecological link influencing the biogeochemical activities and risks in receiving waters in urban areas, given the alarming microplastic loads discharged there. This study conducted a large-scale survey covering a wide range of residential and industrial catchments in Shanghai, China. We aimed to assess the microplastic prevalence and bacterial colonization patterns in different sewer habitats and to explore the role of land use, stratified wastewater and sediment, and microplastic attributes in shaping the patterns. We found that the sewer system formed a temporal but pronounced microplastic pool, with land use playing a significant role in the variability of microplastic prevalence. Industrial sewers contained a high abundance of microplastics with large particle sizes, diverse polymer compositions, and shapes. However, while there was a spatial discrepancy between urban and suburban areas in the abundance of microplastics in residential sewers, their predominant polymer and shape types were simple, i.e., polyethylene terephthalate (PET) and fibers. Sewer habitat characteristics, particularly the stratified wastewater and sediment determined microbial colonization patterns. The latter acted as a long-term sink for microplastics and supported the high growth of colonizers. In contrast, the wastewater plastisphere presented novel niches, hosting communities with a marked proportion of unique bacterial genera after colonization. Besides, statistics showed a highly positive and dense co-occurrence network of the plastisphere communities, especially those from the industrial sewer sediment, with enhanced metabolic activity, cellular processes and systems, and increased human pathogenic potential. Findings indicated a coarse and uncertain effect of the selective pressure of microplastic attributes on plastisphere community structure differentiation.

[Analyzing the Pollution Sources and Mechanisms of Urban Rivers Based on Identifying the Molecular Signature of Dissolved Organic Matter].

Dissolved organic matter (DOM) is an essential component of river pollutants. Under the new situation of black water treatment in urban areas of China, in view of the widespread problem of unclear sources of multiple pollutants, further analysis of DOM components in urban rivers from the molecular level is a key link to deeply explore the sources, causes, and mechanism of river pollution so as to achieve efficient management. In this study, the urban rivers in the central city were selected as the research object, and a total of five rivers were selected that were seriously affected by the discharge sewage of four combined and separated sewer systems, respectively. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), this study identified the molecular formulae and analyzed the elemental composition and compound groups of DOM in water and sediment samples at each site in dry and wet weather. The results showed that:①although CHO molecules and lignins were the main compounds in the urban river DOM, the high proportion of lipids, proteins, and heteroatomic compounds (especially CHOS molecules) revealed the anthropogenic pollution in rivers, which also led to the increase in DOC, TN, and NH+4-N. ②Surfactants such as C17H28O3S and C18H30O3S were ubiquitous in all urban rivers, which could be used as markers of domestic wastewater pollution. ③In wet weather, the rainfall inputs, storm runoffs, and hydraulic disturbance jointly led to the increase in the proportion of CHO molecules and lignin compounds; the decrease in proteins and lipids; the rise of DOC, TN, and NH+4-N concentrations in river water; and the decrease in DOC, TN, and NH+4-N concentrations and proteins and lipids in river sediments. ④The abundance of multi-heteroatomic compounds and condensed aromatics in the combined sewer system was higher than that in the separated sewer system, which may have been more severely polluted by domestic wastewater and storm runoff, especially kitchen wastewater. This study provides new insight for clarifying the critical causes of pollution in the new stage and provides an essential basis for further precision prevention and control of water pollution.

Long-Noncoding RNA MANCR is Associated With Head and Neck Squamous Cell Carcinoma Malignant Development and Immune Infiltration.

Recent studies have demonstrated an important role for mitotically associated long non-coding RNA (MANCR) in carcinogenesis and cancer progression, but its function has not been elucidated in head and neck squamous cell carcinoma (HNSCC). In this study, we identified differentially expressed MANCR from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases across 24 cancer types and included 546 HNSCC patients. Furthermore, high expression of MANCR was verified in HNSCC cell lines and tissue by using real-time quantitative PCR (RT-qPCR) analysis. The Kaplan-Meier analysis showed a worse prognosis with higher levels of MANCR for HNSCC. The univariate Cox regression and multivariate Cox regression analyses revealed that MANCR was a high-risk factor in patients with HNSCC. Thereafter, we carried out the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. It was indicated that MANCR participates in axonogenesis and ECM-receptor interaction. Further enrichment analysis demonstrated that the expression of MANCR was positively correlated with the T gamma delta (tgd) cells, neutrophils, and Th1 cells, and negatively correlated with the infiltration of B cells, CD8 T cells, and T cells in HNSCC. In addition, in vitro experiments showed that knockdown of MANCR in HNSCC cells markedly inhibited cell proliferation, migration, and invasion. We find that MANCR was elevated in HNSCC and promoted the malignant progression of HNSCC. MANCR may serve as a potential biomarker in prognostic implications for HNSCC patients. The positive correlation between MANCR and immune infiltration cells may provide novel therapeutic targets and personalized immune-based cancer therapy for HNSCC.

Association between Weitbrecht's Retinaculum Injury and Femoral Head Necrosis in Femoral Neck Fractures.

OBJECTIVE: To investigate associations between femoral head necrosis (FHN) and injury to the retinaculum of Weitbrecht in patients with femoral neck fractures who had undergone initial trials of either closed reduction or direct open reduction. METHODS: This prospective observational study included 110 patients with displaced femoral neck fractures admitted to the Sixth People's Hospital Affiliated to Shanghai Jiaotong University and Shanghai Tongji Hospital between January 2008 and May 2017. Among these, 25 patients underwent initial closed reductions, and 85 patients underwent an open reduction directly. Watson-Jones anterolateral approach was used during the surgery for injury to the retinaculum of Weitbrecht, and FHN was assessed as a surgical outcome. The severity of injury to the retinaculum of Weitbrecht was evaluated using a scoring system developed by our surgical team. Follow-up was at least 24 months. RESULTS: The initial closed reduction treatment group had significantly higher total scores of injury to the retinaculum of Weitbrecht (6.24 ± 2.20 vs 4.62 ± 2.12, p = 0.009) compared to the open reduction group. High total scores were significantly associated with initial trials of closed reduction treatment, especially for the broken and released injury to the superior and anterior retinacula (both p = 0.01). Twenty-six patients experienced FHN postoperatively, with mean onset time of 19.42 ± 3.87 months. FHN was significantly associated with the severity of injury to the retinaculum of Weitbrecht (p < 0.001) at the superior, anterior, and inferior retinacula. FHN was significantly associated with injury to the retinaculum of Weitbrecht in females. CONCLUSIONS: Femoral neck displacement in patients treated initially with closed reduction is associated with subsequent injury to the retinaculum of Weibrecht, which may lead to FHN. Severity of injury to the retinaculum of Weibrecht may be used as a biomarker to evaluate bone necrosis in patients with femoral neck fractures.

Long Non-Coding RNA (lncRNA) in Oral Squamous Cell Carcinoma: Biological Function and Clinical Application.

Oral squamous cell carcinoma (OSCC) is a type of malignancy with high mortality, leading to poor prognosis worldwide. However, the molecular mechanisms underlying OSCC carcinogenesis have not been fully understood. Recently, the discovery and characterization of long non-coding RNAs (lncRNAs) have revealed their regulatory importance in OSCC. Abnormal expression of lncRNAs has been broadly implicated in the initiation and progress of tumors. In this review, we summarize the functions and molecular mechanisms regarding these lncRNAs in OSCC. In addition, we highlight the crosstalk between lncRNA and tumor microenvironment (TME), and discuss the potential applications of lncRNAs as diagnostic and prognostic tools and therapeutic targets in OSCC. Notably, we also discuss lncRNA-targeted therapeutic techniques including CRISPR-Cas9 as well as immune checkpoint therapies to target lncRNA and the PD-1/PD-L1 axis. Therefore, this review presents the future perspectives of lncRNAs in OSCC therapy, but more research is needed to allow the applications of these findings to the clinic.

miR-383 negatively regulates osteoblastic differentiation of bone marrow mesenchymal stem cells in rats by targeting Satb2.

Emerging evidence indicates that microRNAs (miRNAs, miRs) play diverse roles in the regulation of biological processes, including osteoblastic differentiation. In this study, we found that miR-383 is a critical regulator of osteoblastic differentiation. We showed that miR-383 was downregulated during osteoblastic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). Overexpression of miR-383 suppressed osteoblastic differentiation of BMSCs by downregulating alkaline phosphatase (ALP), matrix mineralization, and mRNA and protein levels of RUNX2 and OCN, whereas a knockdown of miR-383 promoted osteoblastic differentiation in vitro. The results of in vivo analysis indicated that inhibition of miR-383 expression enhanced the efficacy of new bone formation in a rat calvarial defect model. Mechanistic experiments revealed that special AT-rich-sequence-binding protein 2 (Satb2) was a direct and functional target of miR-383. Knockdown of Satb2 had inhibitory effects resembling those of miR-383 on the osteoblast differentiation of rat BMSCs. In addition, the positive effect of miR-383 suppression on osteoblastic differentiation was apparently abrogated by Satb2 silencing. Collectively, these results indicate that miR-383 plays an inhibitory role in osteogenic differentiation of rat BMSCs and may act by targeting Satb2.

Comparison of operative and non-operative treatment of acute undisplaced or minimally-displaced scaphoid fractures: a meta-analysis of randomized controlled trials.

BACKGROUND: Traditionally, acute undisplaced or minimally-displaced scaphoid fractures are treated by casting in short- or long-arm casts. Although reports have shown that operative treatment is safe, effective and produces satisfactory results, outcomes from current studies comparing these two methods are questionable. The aim of this meta-analysis was to evaluate the effects of operative versus non-operative treatment for acute undisplaced or minimally-displaced scaphoid fractures in adults. METHODS: Computerized searches were performed without language restrictions and all randomized controlled studies providing information on the effects of operative versus non-operative treatment on the outcomes of acute undisplaced or minimally-displaced scaphoid fractures were included. The weighted and standard mean difference (WMD and SMD) or the relative risk (RR) were calculated for continuous or dichotomous data respectively. RESULTS: A total of six studies reported in seven publications were included, representing data on 340 fractures. Meta-analysis indicated that operative treatment resulted in significantly better functional outcomes in the short term when compared with non-operative treatment. Consistently, patients who accepted surgery had a more rapid return to work. Further, surgery was advantageous in preventing delayed union of the fractures, a finding supported by the results of analysis of the time to fracture union. A number-needed-to-treat analysis revealed that more than 20 patients would have to undergo operative treatment to prevent one delayed union. CONCLUSION: Acute undisplaced or minimally-displaced scaphoid fractures demonstrate faster recovery with operative treatment; however, the current meta-analysis does not provide evidence supporting the routine use of operative treatment for all acute undisplaced or minimally-displaced scaphoid fractures.

Percutaneous vertebroplasty compared with conservative treatment in patients with chronic painful osteoporotic spinal fractures.

The efficacy of percutaneous vertebroplasty (PVP) for patients with chronic painful osteoporotic compression fractures remains unknown. The purpose of this study was to compare the efficacy of PVP and conservative treatment (CT) for pain relief and functional outcome in patients with chronic compression fractures and persistent pain. Ninety-six patients with chronic compression fractures confirmed by MRI and persistent severe pain for 3 months or longer were prospectively randomly assigned to undergo PVP (n=46, Group A) or CT (n=50, Group B). The primary outcome was pain relief and functional outcome at 1 week, 1 month, 3 months, 6 months and 1 year. A total of 89 patients (46 in Group A and 43 in Group B) completed the 1 year follow-up assessment. Pain relief and functional outcomes were significantly better in Group A than in Group B, as determined by visual analogue scale scores, Oswestry Disability Index scores, and Roland Morris Disability scores at 1 week, 1 month, 3 months, 6 months and 1 year (all p<0.001). The final clinical follow-up assessment indicated complete pain relief in 39 Group A patients and 15 Group B patients (p<0.001). PVP for patients with chronic compression fractures and persistent severe pain was associated with better pain relief and improved functional outcomes at 1 year compared to CT.

Histological changes of the skeletal muscle due to muscle tension: a study in rats.

OBJECTIVE: To analyze the influence of muscle tension in the histological changes of the skeletal muscle. METHODS: Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with only the neurovascular pedicles intact; the tibial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon were lengthened by 0.5 cm in lengthened group, shortened by 0.5 cm in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th weeks after operation, the specimens were taken from gastrocnemius muscle for histological study by light and electron microscope. RESULTS: In comparison between the groups, the gastrocnemius muscles in the shortened group showed less severe muscle atrophy and connective tissue proliferation, bigger diameter and cross section area of the muscle fibre than those in the normal and lengthened groups in all the postoperative periods. CONCLUSION: A proper high tension of the muscle may decrease the muscle dystrophy and stops the histological changes of skeletal muscle by having much longer fibre length and bigger cross sectional area. Also increases the muscle function as the muscle active force-generating range is determined by muscle fibre length, while maximum muscle force is determined by physiologic cross-sectional area.