Circular RNAs (circRNAs) represent a distinct group of RNA molecules produced through back-splicing of precursor mRNAs. Their covalently closed structure, which lacks both a 5′ cap and a poly(A) tail, renders them highly resistant to exonucleolytic degradation and contributes to their remarkable intracellular stability. Although circRNAs were historically viewed as noncoding transcripts, accumulating evidence indicates that certain circRNAs can undergo translation under appropriate molecular contexts. Two major modes of noncanonical translation have been described so far: initiation mediated by internal ribosome entry sites (IRESs) and translation triggered by N6-methyladenosine (m6A) modification. Recent studies have revealed that, beyond their canonical classification as non-coding RNAs, circRNAs can give rise to functional peptides through cap-independent translational mechanisms. Accumulating evidence indicates that circRNA-encoded peptides participate in key biological processes during tumor initiation and progression by modulating tumor-associated signaling pathways and protein-protein interaction networks. Functionally, these peptides may promote tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition, while others exert tumor-suppressive effects by inhibiting oncogenic signaling pathways or interfering with critical protein interactions. Their dual and context-dependent functions highlight the complexity of circRNA-mediated regulation and suggest that these translation products participate in multiple layers of tumor initiation and progression. In this review, we synthesize current knowledge regarding the molecular mechanisms that enable circRNAs to be translated, with particular attention to IRES-driven initiation, m6A-dependent regulation, ribosome accessibility, and the structural determinants required for translation competence. We further summarize well-characterized circRNA-encoded peptides and discuss how they influence tumor-associated signaling networks. In addition, we examine the potential translational applications of these peptides, including their value as diagnostic indicators, prognostic markers, or therapeutic entry points. Their inherent sequence stability, relative expression specificity, and detectability in clinical specimens make circRNA-derived peptides promising candidates for future biomarker and therapeutic development. Overall, circRNA translation research is reshaping our understanding of RNA function and offers new perspectives for studying tumor biology. We propose that expanding investigations into circRNA-encoded peptides will not only improve the mechanistic resolution of cancer research but may also pave the way for innovative strategies in precision oncology, including RNA-based therapeutics and peptide-targeting interventions.

Circular RNAs (circRNAs) represent a distinct group of RNA molecules produced through back-splicing of precursor mRNAs. Their covalently closed structure, which lacks both a 5′ cap and a poly(A) tail, renders them highly resistant to exonucleolytic degradation and contributes to their remarkable intracellular stability. Although circRNAs were historically viewed as noncoding transcripts, accumulating evidence indicates that certain circRNAs can undergo translation under appropriate molecular contexts. Two major modes of noncanonical translation have been described so far: initiation mediated by internal ribosome entry sites (IRESs) and translation triggered by N6-methyladenosine (m6A) modification. Recent studies have revealed that, beyond their canonical classification as non-coding RNAs, circRNAs can give rise to functional peptides through cap-independent translational mechanisms. Accumulating evidence indicates that circRNA-encoded peptides participate in key biological processes during tumor initiation and progression by modulating tumor-associated signaling pathways and protein-protein interaction networks. Functionally, these peptides may promote tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition, while others exert tumor-suppressive effects by inhibiting oncogenic signaling pathways or interfering with critical protein interactions. Their dual and context-dependent functions highlight the complexity of circRNA-mediated regulation and suggest that these translation products participate in multiple layers of tumor initiation and progression. In this review, we synthesize current knowledge regarding the molecular mechanisms that enable circRNAs to be translated, with particular attention to IRES-driven initiation, m6A-dependent regulation, ribosome accessibility, and the structural determinants required for translation competence. We further summarize well-characterized circRNA-encoded peptides and discuss how they influence tumor-associated signaling networks. In addition, we examine the potential translational applications of these peptides, including their value as diagnostic indicators, prognostic markers, or therapeutic entry points. Their inherent sequence stability, relative expression specificity, and detectability in clinical specimens make circRNA-derived peptides promising candidates for future biomarker and therapeutic development. Overall, circRNA translation research is reshaping our understanding of RNA function and offers new perspectives for studying tumor biology. We propose that expanding investigations into circRNA-encoded peptides will not only improve the mechanistic resolution of cancer research but may also pave the way for innovative strategies in precision oncology, including RNA-based therapeutics and peptide-targeting interventions.

ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m⁶A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m⁶A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m⁶A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.

ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m⁶A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m⁶A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m⁶A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.

ObjectiveHepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. The main risk factors associated with HCC include viral hepatitis (B and/or C), alcohol abuse, and metabolic dysfunction-associated steatotic liver disease (MASLD), which progressively advance to liver fibrosis, cirrhosis, and ultimately evolve into HCC. Surgical resection represents the most effective treatment for HCC, while recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive cell therapies, have provided improved treatment prospects for patients with unresectable HCC. However, the complex metabolic heterogeneity of HCC limits the therapeutic efficacy. Metabolic intermediates acyl-CoA not only provide energy and substrates for numerous biochemical reactions but also serve as donors for protein lysine acylation, a major class of post-translational modification (PTM). Therefore, a deeper understanding of the molecular mechanisms underlying protein lysine acylation and hepatocarcinogenesis is urgently needed. MethodsThe levels of protein lysine acylation and silence information regulator 5 (SIRT5) expression levels in clinical HCC samples were analyzed by Western blot. Quantitative malonylome and succinylome of HCC samples were analyzed by antibody-based affinity enrichment coupled with tandem mass spectrometry. The proliferation of HCC cells was analyzed with Cell Counting Kit-8 (CCK-8) assays, the apoptosis was quantified by Annexin V-FITC/propidium iodide (PI) staining coupled with flow cytometry, and the ability of cells to migrate was assayed by Transwell assays. The enzymatic activity of glutathione S-transferase Mu 1 (GSTM1) was quantified. Transgenic mice with hepatic overexpression of SIRT5 were constructed using CRISPR-Cas9, and primary hepatocarcinogenesis was induced by administration of diethylnitrosamine. ResultsWestern blot analysis indicated that the expression level of SIRT5 was elevated in clinical samples from HCC patients, and the levels of lysine malonylation, glutarylation, and succinylation were significantly reduced in HCC tissues. Knockout of SIRT5 in MHCC-97H and MHCC-97L hepatoma cells suppressed cell proliferation, and increased the percentage of apoptotic cells significantly. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the differentially malonylome and succinylome of HCC samples revealed significant enrichment in two major classes of biological processes: core energy metabolism (e.g., glycolysis/gluconeogenesis, tricarboxylic acid metabolic process, fatty acid beta oxidation) and detoxification and oxidative stress response (e.g., response to toxic substance, chemical carcinogenesis, reactive oxygen species (ROS)). SIRT5 removes malonylation from lysine residues in GSTM1 and restores its detoxification activity, which is crucial for the survival of hepatocytes under stressed conditions. More importantly, in vivo experiment indicated that hepatic-specific overexpression of SIRT5 in mice accelerated diethylnitrosamine-induced liver fibrosis and hepatocarcinogenesis, indicating the critical role of SIRT5 in HCC progression. ConclusionThis study highlights the previously unrecognized SIRT5-GSTM1 axis as a key regulator in hepatocarcinogenesis, and suggests a potential target for the treatment of patients with HCC.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

OBJECTIVE: To explore early curative effect of upper joint capsule reconstruction combined with biceps tendon transposition in treating irreparable rotator cuff tears. METHODS: From October 2019 to March 2021, 16 patients with irreparable rotator cuff tear were underwent arthroscopic autogenous semitendinosus tendon transplantation for upper articular capsule reconstruction combined with biceps tendon transposition, included 12 males and 4 females, aged from 53 to 72 years old with an average of (62.13±5.35) years old; 3 patients on the left side and 13 patients on the right side. All patients had preoperatively limited joint mobility, resting pain, and mobility pain, and had a history of failure to respond to conservative treatment for more than 8 months. The duration of preoperative symptoms ranged from 45 to 144 months with an average of (85.25±32.08) months. Visual analogue scale (VAS) of shoulder pain, University of California Los Angeles (UCLA) score, Constant-Murley score, active and passive motion of shoulder joint were compared before operation and 2 years after operation, complications were recorded. RESULTS: All 16 patients were followed up for 21 to 32 months with an average of (24.25±3.57) months. There were no complications such as incision infection, vascular and nerve injury, retear occurred. VAS, UCLA and Constant-Murley scores were improved from (5.75±1.18), (11.88±3.38) and (33.38±9.34) before operation to (1.13±0.89), (32.56±2.71), (89.06±6.25) at 2 years after operation (P<0.05). Anterior flexion, abduction, lateral external rotation and lateral internal rotation of shoulder joint were improved from (79.75±21.36) °, (62.06±10.49) °, (19.19±5.41) °, (3.04±0.21) °, respectively to (156.94±13.18) °, (116.19±12.59) °, (42.63±6.07) °, (8.16±0.64) ° at 2 years after operation. Anterior flexion, abduction, lateral lateral rotation and lateral internal rotation of shoulder joint were improved from (116.28±21.47) °, (107.12±9.67) °, (27.62±4.70) °, (4.21±0.41) °, respectively to (165.28±7.15) °, (153.34±4.69) °, (52.46±4.46) °, (9.68±0.68) ° at 2 years after operation, and the difference was statistically significant (P<0.05). CONCLUSION Arthroscopic autograft of semitendinosus tendon combined with transposition of biceps tendon could achieve satisfactory early clinical results in treating patients with irreparable rotator cuff tear, which is a reliable and effective surgical method.
Humans ; Male ; Female ; Middle Aged ; Aged ; Arthroscopy/methods* ; Rotator Cuff Injuries/physiopathology* ; Plastic Surgery Procedures/methods* ; Range of Motion, Articular ; Shoulder Joint/surgery* ; Tendon Transfer

OBJECTIVE: To explore clinical effect of autologous osteochondral transplantation (AOT) in the treatment of recurrent anterior dislocation of the shoulder joint with glenoid cartilage defect in rabbits by establishing a model of recurrent anterior dislocation of the shoulder joint with < 20% glenoid cartilage defect in rabbits. METHODS: Twenty-four male New Zealand white rabbits, aged 6-month-old, weighed (2.69±0.17) kg were selected. The labrum of shoulder joint of rabbits was artificially destroyed to establish a model of recurrent anterior dislocation of shoulder joint with cartilage defect. They were divided into AOT surgery group and simple suture group, with 12 rabbits in each group. AOT group were underwent AOT surgery, while simple suture group was treated with simple Bankart suture for recurrent shoulder joint dislocation. At 6 and 12 weeks after operation, 6 rabbits between two groups were sacrificed for sampling. The dietary conditions, activity conditions, mental states of rabbits and healing conditions of grafts in the specimens were observed and compared between two groups. HE staining was used to observe cell creep, cell morphology, inflammatory cell infiltration, fibrochondrocytes and their arrangement. Masson staining was used to observe the formation and arrangement of collagen fibers; Safrane-green staining was used to observe the regeneration of articular cartilage, subchondral bone and bone tissue. Bone mineral density (BMD), bone volume (BV) and trabecular thickness (Tb.Th) between two groups were measured by Micro-CT to evaluate the remodeling of shoulder glenoid bone defects by autologous osteochondral cartilage. RESULTS: After different surgical interventions were carried out in both groups of rabbits, at 6 weeks after the operation, the abduction, extension, internal rotation and external rotation of the shoulder joint on the operated side showed limited range of motion compared with the contralateral side, while adduction and forward flexion showed no obvious abnormalities compared with the contralateral side. At 12 weeks after operation, the range motion of tshoulder joints in both groups of rabbits had returned to the state before modeling. The effects of HE staining, Masson staining and safrane-green staining at 12 weeks after operation in both groups were stronger than the staining results at 6 weeks after operation. Moreover, the results of HE staining, Masson staining and safranin fixation green staining in AOT group at 6 and 12 weeks after operation were all higher than those in simple suture group. Micro-CT scan results at 6 and 12 weeks after operation showed that BMD (0.427±0.014), (0.466±0.032) g·cm-3, BV(116.171±3.527), (159.327±3.500) mm3, and Tb.Th (0.230±0.006), (0.285±0.009) mm in AOT group, which were higher than those of simple suture group in BMD(0.358±0.011), (0.384±0.096) g·cm-3, BV(72.657±3.903), (118.713±3.860) mm3, and Tb.Th(0.204±0.009), (0.243±0.007) mm;and the differences were statistically significant (P<0.05). CONCLUSION AOT procedure could effectively promote osteogenesis and fibrocartilage regeneration in the cartilage defect area of the shoulder glenoid <20%, which is conducive to reshaping the structure of the shoulder glenoid.
Animals ; Rabbits ; Male ; Transplantation, Autologous ; Cartilage, Articular/injuries* ; Shoulder Dislocation/physiopathology* ; Bone Transplantation ; Shoulder Joint/surgery*

OBJECTIVE: To evaluate the effects of posterior cruciate ligament(PCL) resection on soft tissue elasticity and knee stability in total knee arthroplasty(TKA). METHODS: Six adult cadaveric knee specimens (involving 10 knees) were included in the study. With the assistance of the robotic system(TiRobot Recon, TINAVI, Beijing), total knee arthroplasty (TKA) was performed sequentially using cruciate retaining (CR) prostheses and posterior stabilizing (PS) prostheses. Between the two surgical procedures, the femoral and tibial osteotomy surfaces were not altered;only the posterior cruciate ligament (PCL) was resected and the intercondylar fossa was treated. After installing the femoral trial component, a soft tissue balance solver was used to apply tension ranging from 30 N to 90 N in 5 N increments at 0°, 10°, and 90° of knee flexion. Meanwhile, the medial and lateral joint gaps were measured synchronously. Based on the tension-gap coupling data, the equivalent elastic coefficients of the medial and lateral soft tissue sleeves at different knee flexion angles, as well as the range of the joint line convergence angle (JLCA) under fixed varus-valgus stress, were calculated. Additionally, the gap balance status under 80 N of tension was analyzed. Self-control comparisons of each indicator were conducted before and after PCL resection to analyze the change patterns. RESULTS: After PCL resection, in the fully extended position (knee flexion 0°). The medial equivalent elastic coefficient was 32.2 (25.7, 63.3) N·mm^-1 for the CR prosthesis and 27.7 (22.0, 51.9) N·mm^-1 for the PS prosthesis, and the statistically significant difference (P=0.013). The range of JLCA was 0.41°(0.26, 0.55)° for the CR prosthesis, which was smaller than 0.75° (0.40, 0.98)° for the PS prosthesis, and the difference was statistically significant(P=0.041). At 90° of knee flexion, the medial joint gap was 10.7(10.1, 11.7) mm for the CR prosthesis, which was smaller than 12.1(10.9, 15.1) mm for the PS prosthesis, with a statistically significant difference(P=0.011). No statistically significant differences were observed in other joint gaps. CONCLUSION PCL resection reduces the rigidity of the medial soft tissues in the fully extended knee and increases the medial joint gap in the flexed position, thereby affecting knee stability and balance. This finding suggests that PS and CR prostheses may require different morphological designs, and there should be differences in indications and osteotomy strategies between CR-TKA and PS-TKA. CR-TKA is more suitable for patients with preoperative medial soft tissue laxity.
Humans ; Posterior Cruciate Ligament/physiopathology* ; Knee Joint/physiopathology* ; Arthroplasty, Replacement, Knee ; Elasticity ; Male ; Female ; Middle Aged ; Aged ; Biomechanical Phenomena ; Adult