OBJECTIVES: To assess the biomechanical performance of a novel bridging plate for treating Rockwood III acromioclavicular joint dislocation. METHODS: A novel bridging plate structure was designed based on CT data from a patient with Rockwood type III acromioclavicular joint dislocation, and a finite element model of the bridging plate-acromioclavicular joint interaction was constructed. The stress and deformation characteristics and biomechanical compatibility of the plate under post-reduction, normal loading, and impact loading conditions were analyzed to evaluate its fixation mechanism and clinical advantages. RESULTS: The stiffness of the bridging system was 27.78 N/mm, close to that of acromioclavicular joint ligaments (26.05 N/mm) and meeting the requirements for flexible deformation. Under normal loading, the maximum stress in the bridging system was 88.29 MPa to sustain physiological activities; under impact loading, the maximum stress reached 480 MPa, and the cable underwent plastic deformation to dissipate energy and effectively buffer local stress concentrations, thereby reducing the risk of rigid bone fractures. The high-stress regions in the bone primarily occurred at the edges of the C1-C4 screw holes. The maximum bone stress was 0.762 MPa under normal loading and 5.963 MPa under impact loading, accounting for 2.86% and 1.66% of the corresponding bolt stresses, respectively. CONCLUSIONS The novel bridging plate is better adapted to biomechanical characteristics of the acromioclavicular joint compared to traditional internal fixation. This fixation system provides sufficient stability while allowing physiological micromotion to facilitate postoperative rehabilitation. Significant flexible deformation can occur at the connection between the fixation ring and the cable, and brittle materials should not be used in this region. The issue of stress concentration at the C1-C4 screw holes requires special attention in its clinical application.
Acromioclavicular Joint/surgery* ; Humans ; Bone Plates ; Biomechanical Phenomena ; Finite Element Analysis ; Joint Dislocations/surgery* ; Fracture Fixation, Internal/methods*

Temporomandibular joint (TMJ) disc displacement is one of the most significant subtypes of temporomandibular joint disorders, but its etiology and mechanism are poorly understood. In this study, we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc. By constructing a rat model of TMJ arthritis, we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund's complete adjuvant. By mimicking inflammatory conditions with interleukin-1 beta in vitro, we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment. In contrast, three-dimensional (3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils, inappropriate arrangement, and decreased Young's modulus. Mechanistically, inflammation-related activation of the nuclear factor kappa-B (NF-κB) pathway occurs during the progression of TMJ arthritis. NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro, and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo. Therefore, the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs, offering a potential therapeutic target for disc displacement.
Animals ; NF-kappa B/metabolism* ; Temporomandibular Joint Disorders/pathology* ; Temporomandibular Joint Disc/metabolism* ; Rats ; Rats, Sprague-Dawley ; Disease Models, Animal ; Male ; Collagen/metabolism* ; Cells, Cultured ; Joint Dislocations/pathology* ; Interleukin-1beta ; Arthritis, Experimental

OBJECTIVES: Magnetic resonance imaging (MRI) was used to study the efficacy of modified anterior splint (MAS) combined with anterior repositioning splint (ARS) in maintaining the normal disk-condyle relationship. METHODS: We obtained clinical and imaging data of 10 patients with acute anterior disk displacement without reduction (ADDwoR) of the temporomandibular joint undergoing successful mandibular manipulation in the Affiliated Stomatological Hospital, Nanchang University from January to June 2024. The MAS and ARS were used for subsequent treatment. Maximum active mouth opening (MMO) and visual analogue score (VAS) were recorded before treatment and 2 weeks, 1 month, and 3 months after treatment. The changes in the disk-condyle relationship, disk-condyle angle, joint effusion, and double contour sign before and after treatment were analyzed through MRI. RESULTS: Three months after treatment, the MMO increased from 28.90 mm to 46.85 mm, VAS decreased from 4.68 to 0.61, and the disk-condyle angle decreased from 58.84° to 25.99°. MRI analysis found that 6 patients showed normal disk-condyle relationship, 2 patients exhibited displacement with reduction, and 2 patients exhibited ADDwoR. The disk-condyle angle was 58.84° before treatment and 25.99° after treatment. CONCLUSIONS The MAS combined with ARS could further stabilize the coordinated disk-condyle relationship and reduce the recurrence rate.
Humans ; Male ; Magnetic Resonance Imaging ; Female ; Adult ; Temporomandibular Joint Disorders/diagnostic imaging* ; Splints ; Middle Aged ; Mandible ; Temporomandibular Joint Disc ; Occlusal Splints ; Temporomandibular Joint ; Young Adult ; Joint Dislocations/therapy*

OBJECTIVE: To investigate the effectiveness of modified single patellar tunnel medial patella femoral ligament (MPFL) reconstruction in the treatment of recurrent patellar dislocation. METHODS: Between January 2023 and June 2023, a total of 61 patients with recurrent patellar dislocation who underwent MPFL reconstruction with autologous semitendinosus were enrolled and divided into 2 groups using random number table method. In the patellar anchor group, 31 patients were treated with MPFL reconstruction with double medial patellar anchors, and 30 patients in the patellar tunnel group were treated with MPFL reconstruction with single patellar tunnel. The femoral ends of both groups were fixed with absorbable compression screws. There was no significant difference in baseline data such as gender, age, side, tibial tubercle-trochlear groove (TT-TG), Q angle, Caton-Deschamps index, number of dislocation, and preoperative Kujala score, preoperative patellar inclination angle ( P>0.05). Patellar tunnel, patellar anchor position, patellar reduction, and the patellar inclination angle were measured by CT scan after operation. Kujala score was used to evaluate the function of knee joint before operation, at 2 weeks and 1, 3, 6, 12 months after operation. Incision aesthetic satisfaction score was performed at 3 months after operation. The signal-to-noise quotient (SNQ) of the transplanted tendon was measured by knee MRI at 12 months after operation to compare the maturity of the graft between the two groups. RESULTS: There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). Knee CT reexamination showed that the patellar tunnel and the patellar anchor position were consistent with the intraoperative fluoroscopy. There was no significant difference in the difference of the patellar inclination angle between the two groups before and after operation ( P>0.05). All patients were followed up 12-14 months (mean, 12.8 months). There was 1 case of patellar anchor suture rejection in patellar anchor group, and the wound healed after debridement and dressing change. During the follow-up, there was no complication such as recurrence of patellar dislocation, infection and postoperative stiffness. The Kujala scores of the two groups significantly improved at each time point after 1 month of operation when compared with those before operation ( P<0.05), and the Kujala scores of the two groups returned to normal levels at 3 months after operation. The Kujala score in the patellar tunnel group was significantly higher than that in the patellar anchor group in the very early stage (2 weeks) ( P<0.05), and there was no significant difference between the two groups at other time points ( P>0.05). Patients in the patellar tunnel group were significantly better than those in the patellar anchor group in the score of incision aesthetic satisfaction at 3 months after operation and the SNQ at 12 months after operation ( P<0.05). CONCLUSION Modified single patellar tunnel MPFL reconstruction was used to treat patients with recurrent patellar dislocation without pathological TT-TG. The slide-fixation structure formed by single patellar tunnel positioning provides a variable degree of freedom for the reconstructed MPFL, which shows good effectiveness in the very early stage of the rehabilitation process.
Humans ; Patellar Dislocation/surgery* ; Male ; Female ; Plastic Surgery Procedures/methods* ; Adult ; Patellar Ligament/surgery* ; Recurrence ; Treatment Outcome ; Young Adult ; Adolescent ; Patella/surgery* ; Suture Anchors ; Hamstring Tendons/transplantation* ; Knee Joint/surgery* ; Transplantation, Autologous

OBJECTIVE: To investigate the effectiveness of Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy in treating Tönnis type Ⅲ and Ⅳ developmental dysplasia of the hip (DDH) in children and explore the urgical timing. METHODS: A retrospective collection was performed for 74 children with Tönnis type Ⅲ and Ⅳ DDH who were admitted between January 2018 and January 2020 and met the selection criteria, all of whom were treated with Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy. Among them, there were 38 cases in the toddler group (age, 18-36 months) and 36 cases in the preschool group (age, 36-72 months). There was a significant difference in age between the two groups ( P<0.05), and there was no significant difference in gender, side, Tönnis typing, and preoperative acetabular index (AI) ( P>0.05). During follow-up, hip function was assessed according to the Mckay grade criteria; X-ray films were taken to observe the healing of osteotomy, measure the AI, evaluate the hip imaging morphology according to Severin classification, and assess the occurrence of osteonecrosis of the femoral head (ONFH) according to Kalamchi-MacEwen (K&M) classification criteria. RESULTS: All operations of both groups were successfully completed, and the incisions healed by first intention. All children were followed up 14-53 months, with an average of 27.9 months. There was no significant difference in the follow-up time between the two groups ( P>0.05). At last follow-up, the excellent and good rates according to the Mckay grading were 94.73% (36/38) in the toddler group and 83.33% (30/36) in the preschool group, and the difference between the two groups was significant ( P<0.05). The imaging reexamination showed that all osteotomies healed with no significant difference in the healing time between the two groups ( P>0.05). There was no significant difference in AI between the two groups at each time point after operation ( P>0.05), and the AI in the two groups showed a significant decreasing trend with time extension ( P<0.05). The result of Severin classification in the toddler group was better than that in the preschool group at last follow-up ( P<0.05). There was no significant difference in the incidence of ONFH between the two groups ( P>0.05). In the toddler group, 2 cases were K&M type Ⅰ; in the preschool group, 3 were type Ⅰ, and 1 type Ⅱ. There was no dislocation after operation. CONCLUSION Salter osteotomy combined with subtrochanteric shortening and derotational osteotomy is an effective way to treat Tönnis type Ⅲ and Ⅳ DDH in children, and surgical interventions for children aged 18-36 months can achieve better results.
Humans ; Osteotomy/methods* ; Developmental Dysplasia of the Hip/diagnostic imaging* ; Retrospective Studies ; Male ; Child, Preschool ; Female ; Infant ; Femur/surgery* ; Child ; Treatment Outcome ; Hip Dislocation, Congenital/surgery*

OBJECTIVE: To review the research progress of pathological changes of glenohumeral capsule in patients with recurrent shoulder anterior dislocation (RSAD). METHODS: The literature on shoulder capsules, both domestic and international, was reviewed. The anatomy, histology, and molecular biology characteristics of the glenohumeral capsule in RSAD patients were summarized. RESULTS: Anatomically, the glenohumeral capsule is composed of four distinct parts: the upper, lower, anterior, and posterior sections. The thickness of these sections is uneven, and the stability of the capsule is further enhanced by the presence of the glenohumeral and coracohumeral ligaments. Histologically, the capsule tissue undergoes adaptive changes following RSAD, which improve its ability to withstand stretching and deformation. In the realm of molecular biology, genes associated with the regulation of structure formation, function, and extracellular matrix homeostasis of the shoulder capsule's collagen fibers exhibit varying degrees of expression changes. Specifically, the up-regulation of transforming growth factor β ₁ (TGF-β ₁), TGF-β receptor 1, lysyl oxidase, and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 facilitates the repair of the joint capsule, thereby contributing to the maintenance of shoulder joint stability. Conversely, the up-regulation of collagen type Ⅰ alpha 1 (COL1A1), COL3A1, and COL5A1 is linked to the recurrence of shoulder anterior dislocation, as these changes reflect the joint capsule's response to dislocation. Additionally, the expressions of tenascin C and fibronectin 1 may play a role in the pathological processes occurring during the early stages of RSAD. CONCLUSION Glenohumeral capsular laxity is both a consequence of RSAD and a significant factor contributing to its recurrence. While numerous studies have documented alterations in the shoulder capsule following RSAD, further research is necessary to confirm the specific pathological anatomy, histological, and molecular biological changes involved.
Humans ; Joint Capsule/metabolism* ; Shoulder Dislocation/metabolism* ; Recurrence ; Shoulder Joint/metabolism* ; Tenascin/metabolism* ; Transforming Growth Factor beta1/genetics* ; Collagen Type I/genetics* ; Extracellular Matrix/metabolism*

OBJECTIVE: To explore the effectiveness of partial translocation of flexor carpi radialis tendon in the treatment of traumatic dislocation of the first carpometacarpal joint. METHODS: The clinical data of 6 patients with traumatic dislocation of the first carpometacarpal joint who met the selection criteria between March 2020 and June 2024 were retrospectively analyzed. There were 3 males and 3 females with an average age of 33.5 years (range, 16-42 years). All the 6 cases were treated with plaster immobilization for 4-6 weeks, and the time from injury to operation was 6-12 weeks, with an average of 8.8 weeks. All patients underwent reconstruction of the metacarpophalangeal anterior oblique ligament and dorsal posterior oblique ligament of the first carpometacarpal joint with partial translocation of flexor carpi radialis tendon. The pain relief was evaluated by visual analogue scale (VAS) score before and after operation, and the pinch force, palmar abduction and radial abduction angles of the affected side and the healthy side were recorded before and after operation, and the ratio of the above indexes between the affected side and the healthy side was calculated to evaluate the effectiveness. RESULTS: All the incisions healed by first intention after operation, and there was no complication related to operation such as neurovascular injury. All patients were followed up 6-19 months (mean, 12.7 months). The range of motion of the thumb on the affected side was the same as that on the healthy side, the first carpometacarpal joint was stable without recurrent dislocation and pain. At last follow-up, the VAS score, the pinch force of the affected side, the abduction angle of the palmar side of the affected thumb, the abduction angle of the radial side of the affected thumb, and the pinch force ratio, the palmar abduction angle ratio of the thumb, and the radial abduction angle ratio of the thumb of the affected side to the healthy side significantly improved when compared with those before operation ( P<0.05). CONCLUSION Partial translocation of the flexor carpi radialis tendon to reconstruct the metacarpophalangeal and dorsal radial ligaments for the treatment of traumatic dislocation of the first carpometacarpal joint is a reliable surgical method.
Humans ; Carpometacarpal Joints/surgery* ; Male ; Female ; Adult ; Adolescent ; Retrospective Studies ; Joint Dislocations/surgery* ; Young Adult ; Tendons/surgery* ; Tendon Transfer/methods* ; Plastic Surgery Procedures/methods* ; Treatment Outcome ; Range of Motion, Articular ; Ligaments, Articular/injuries*

OBJECTIVE: To evaluate the early effectiveness of transosseous suture fixation in treating recurrent acute patellar dislocation with patellar osteochondral fractures (OCFs). METHODS: A retrospective analysis was conducted on 19 patients with recurrent acute patellar dislocation and patellar OCFs, who underwent transosseous suture fixation between January 2018 and December 2022 and were followed up 2 years. The cohort included 8 males and 11 females, aged 13-21 years (mean, 16.2 years). Patients experienced 2-5 times of patellar dislocation (mean, 3.2 times). The interval from the last dislocation to operation ranged from 3 to 15 days (mean, 9.6 days). Preoperative imaging revealed the intra-articular osteochondral fragments and medial patellofemoral ligament (MPFL) injury. Clinical outcomes were evaluated using the visual analogue scale (VAS) score for pain, the International Knee Documentation Committee (IKDC) score, the Hospital for Special Surgery (HSS) knee score, the Lysholm score, and the Tegner score. Postoperative complications were recorded. During follow-up, the knee X-ray films, CT, and MRI were taken to evaluate fragment healing, displacement, and the morphology and tension of the MPFL reconstruction graft. RESULTS: All incisions healed primarily, and no complication occurred such as infection, joint stiffness, patellofemoral arthritis, or redislocation. Patients were followed up 24-60 months (mean, 43.5 months). At 12 months postoperatively and the last follow-up, significant improvements ( P<0.05) were observed in VAS, Lysholm, IKDC, HSS, and Tegner scores compared to preoperative values. Further improvements were observed at last follow-up compared with the 12 months postoperatively, and the differences were significant ( P<0.05). Imaging studies demonstrated satisfactory osteochondral fragment positioning with stable fixation. At last follow-up, all fragments had healed, and MPFL reconstruction grafts exhibited optimal morphology and tension. No joint adhesion or fragment displacement occurred. CONCLUSION For recurrent acute patellar dislocation with patellar OCFs, transosseous suture fixation proves to be both safe and effective, achieving satisfactory early effectiveness.
Humans ; Male ; Female ; Patellar Dislocation/surgery* ; Adolescent ; Young Adult ; Retrospective Studies ; Patella/surgery* ; Suture Techniques ; Treatment Outcome ; Recurrence ; Fracture Fixation, Internal/methods* ; Fractures, Bone/surgery* ; Follow-Up Studies

OBJECTIVE: To summarize the methods of ankle hinge position design in the correction of clubfoot deformity by Ilizarov method, and to explore its application value in the prevention of ankle dislocation. METHODS: A retrospective study was conducted including 28 patients with rigid clubfoot deformity (34 feet) who met the selection criteria and admitted between September 2021 and December 2024. There were 19 males and 9 females with an average age of 31.8 years (range, 19-47 years). According to Dimeglio classification, there were 21 feet of degree Ⅲ and 13 feet of degree Ⅳ. The causes were traumatic sequelae in 9 cases, congenital foot deformity in 15 cases, spina bifida sequelae in 1 case, peripheral neuropathy in 1 case, and cerebral palsy sequelae in 2 cases. The malformation lasted from 6 to 46 years, with an average of 29.3 years. All patients were treated with Ilizarov circular external fixator, and the hinge position of ankle joint was planned according to the standard lateral X-ray film of foot and ankle and the principle of Ilizarov limb deformity correction center of rotation angulation (CORA) before operation. The 2008 International Clubfoot Study Group (ICFSG) scoring system was used to evaluate the efficacy. RESULTS: The deformity of rigid clubfoot was completely corrected in all patients, and the patients could walk with plantar weight-bearing, and the ankle weight-bearing walking significantly improved when compared with that before operation. There was no complication such as ankle dislocation, talus impact or extrusion, local skin necrosis, needle tract infection, or numbness of extremities during the correction process. All patients were followed up 5-39 months, with an average of 18.1 months. At last follow-up, according to the ICFSG scoring system, 23 feet were excellent, 10 feet were good, and 1 foot was fair, and the excellent and good rate was 97%. CONCLUSION Designing the position of the ankle hinge according to the principle of CORA can effectively avoid ankle dislocation, talus impingement, tibiotalar joint extrusion, and other ankle adverse events in the process of correcting clubfoot deformity, which has good application value in clinical practice.
Humans ; Male ; Female ; Clubfoot/diagnostic imaging* ; Ilizarov Technique/instrumentation* ; Adult ; Retrospective Studies ; External Fixators ; Ankle Joint/diagnostic imaging* ; Middle Aged ; Joint Dislocations/prevention & control* ; Treatment Outcome ; Young Adult

OBJECTIVE: To compare the effectiveness of clavicular hook plate fixation in the treatment of acromioclavicular joint dislocation and distal clavicle fractures. METHODS: A clinical data of 90 patients, who underwent clavicular hook plate fixation between January 2014 and June 2023, was retrospectively analyzed. There were 40 patients with distal clavicle fractures (fracture group) and 50 with acromioclavicular joint dislocations (dislocation group). There was no significant difference in the baseline data of gender, age, cause of injury, side of injury, time from injury to operation, and constituent ratio of osteoporosis patients between the two groups ( P>0.05). The time to remove the internal fixators and the occurrence of complications were recorded. Before removing the internal fixator and at 3 months after removing, the visual analogue scale (VAS) score was used to evaluate the degree of pain, and the mobility of the shoulder joint in forward flexion, elevation, and abduction was measured. Before removing the internal fixators, the Constant-Murley score and the University of California, Los Angeles (UCLA) score were used to evaluate the function of the shoulder joint. X-ray films of the shoulder joint were taken during follow-up to observe the occurrence of subacromial osteolysis, acromioclavicular joint osteoarthritis, and distal clavicle bone atrophy. Subgroup comparison was conducted between patients with and without subacromial osteolysis in the two groups. RESULTS: All incisions healed by first intention in both groups. All patients were followed up 1-9 years, with a median of 5 years; the difference in follow-up time between the two groups was not significant ( P>0.05). During follow-up, subacromial osteolysis occurred in 74 cases, including 41 cases of typeⅠand 33 cases of type Ⅱ, distal clavicle bone atrophy in 15 cases, and acromioclavicular joint osteoarthritis in 8 cases. There were significant differences in the removal time of internal fixators, the incidence of bone atrophy, and the incidence of osteoarthritis between the two groups ( P<0.05). There was no significant difference in the incidence of subacromial osteolysis ( P>0.05). Before removing the internal fixators, there was no significant difference in VAS score, UCLA score, and Constant-Murley score between the two groups ( P>0.05), while there were significant differences in shoulder joint range of motion in all directions ( P<0.05). After removing the internal fixators, only the difference in elevation was significant ( P<0.05). Within the group comparison, the VAS score and mobility of shoulder joint in abduction and elevation after removing the internal fixators were significantly superior to those before removing ( P<0.05). In the fracture and dislocation groups, there was only a significant difference in plate length between the subgroup with and without subacromial osteolysis ( P<0.05), while there was no significant difference in the above other indicators ( P>0.05). CONCLUSION Clavicular hook plate is a good choice for treating acromioclavicular dislocation or distal clavicle fractures, but the incidence of subacromial osteolysis is higher, and the degree of bone resorption is more severe in fracture patients. After removal of the internal fixator, the shoulder functions significantly improve. It is recommended to remove the internal fixator as soon as possible within the allowable range of the condition.
Humans ; Clavicle/surgery* ; Acromioclavicular Joint/surgery* ; Bone Plates ; Fracture Fixation, Internal/instrumentation* ; Fractures, Bone/surgery* ; Male ; Retrospective Studies ; Female ; Adult ; Middle Aged ; Treatment Outcome ; Joint Dislocations/surgery* ; Aged ; Range of Motion, Articular ; Young Adult ; Postoperative Complications