MiR-22-3p facilitates bone marrow mesenchymal stem cell osteogenesis and fracture healing through the SOSTDC1-PI3K/AKT pathway.

Bone fractures are the most common form of musculoskeletal trauma worldwide. Numerous microRNAs (miRNAs) have been suggested to be participants in regulating bone-related diseases. Recent studies revealed the regulatory role of miR-22-3p in osteogenic differentiation, but its role in fracture healing has not been investigated previously. Here, a rat femoral fracture model was established, Bone marrow mesenchymal stem cells (BMSCs) were isolated to detect the specific function and underlying mechanisms of miR-22-3p. MiR-22-3p and sclerostin domain-containing 1 (SOSTDC1) expression was determined by RT-qPCR and immunohistochemistry staining. The levels of proteins associated with osteogenic differentiation were assessed by western blotting. Flow cytometry was conducted to identify the isolated rat BMSCs. Alizarin red staining, alkaline phosphatase staining and Oil Red O staining were used to evaluate the osteogenic and adipogenic differentiation of rat BMSCs. The interaction between miR-22-3p and SOSTDC1 was verified using a luciferase reporter assay. Haematoxylin and Eosin (H&E) staining of the bone tissues was performed to analyse the effect of miR-22-3p on histopathological changes in vivo. MiR-22-3p was downregulated in the callus tissues of rat femoral fracture, while the expression of SOSTDC1 was upregulated. The isolated rat BMSCs had the capacity for both osteogenic and adipogenic differentiation. The differentiation capacity of BMSCs into osteoblasts was increased by miR-22-3p overexpression. MiR-22-3p activated the PI3K/AKT pathway by targeting SOSTDC1. SOSTDC1 overexpression and PI3K/AKT signalling inhibitor LY294002 abolished the enhancing effect of miR-22-3p overexpression on the osteogenesis of BMSCs. Thus MiR-22-3p facilitated the femoral fracture healing in rats. MiR-22-3p overexpression promoted fracture healing via the activation of PI3K/AKT pathway by targeting SOSTDC1.

Revisiting the flexion-valgus type unicondylar posterolateral tibial plateau depression fracture pattern: classification and treatment.

OBJECTIVE: This study aimed to reclassify posterolateral tibial plateau fractures caused by a flexion-valgus force and describe this fracture pattern to provide a relatively programmed surgical treatment based on morphological characteristics that may improve reduction and stabilization. METHODS: We retrospectively reviewed the fracture pattern and injury mechanism of patients with posterolateral tibial plateau fractures who underwent surgery at the First Affiliated Hospital of Nanjing Medical University between January 2014 and April 2020. The cohort was divided into three types. Type I was a depression fracture of the posterolateral platform with an intact posterolateral cortex. Type II was a depression fracture of the posterolateral platform with a disrupted posterolateral cortex. Type III was a depression fracture of the posterolateral platform in combination with anterior cruciate ligament (ACL) rupture or tibial insertion avulsion fracture of the ACL. The lateral window of the modified Frosch approach with an L-type locking plate was used for patients with type I and type III fractures. For patients with type II fractures, both lateral and posterolateral windows of the modified Frosch approach were used for surgery, and a T-plate on the posterior side with an L-plate on the lateral side were used for fixation. The Rasmussen radiology scoring was used to evaluate the quality of surgical reduction and the Rasmussen functional scoring evaluation standard was used to evaluate knee joint function. RESULTS: A total of 69 tibial plateau fractures (36 male, 33 female) involving the posterolateral platform were discovered and included in this study. All patients suffered flexion-valgus force at the moment of the accident. There were 32 cases of Type I fracture, 28 cases of Type II fracture, and 9 cases of Type III fracture. The patients were followed up for 12-30 (mean 20.8 ± 9.4) months. The postoperative Rasmussen radiological scores for the three types of fractures were 15-17 (mean 16.31 ± 0.78), 14-17 (mean 15.93 ± 0.94), and 14-17 (mean 16.22 ± 0.97), respectively. The postoperative Rasmussen functional scores for the three types of fractions were 27-30 (mean 27.97 ± 0.90), 27-29 (mean 27.36 ± 0.56), and 27-29 (mean 27.56 ± 0.73), respectively. CONCLUSION: Flexion-valgus posterolateral tibial plateau fractures were divided into three types based on the integrity of the posterolateral wall and ACL injuries. We hope the classification can play a certain reference role in recognizing and treating flexion-valgus-type posterolateral tibial plateau fractures.

Preoperative simulated surgery on 3D model assists osteotomy feasibility verification and surgical guidance for patients with cubitus valgus/varus deformity: a retrospective observational study.

BACKGROUND: As the common delayed complication of supracondylar fractures in children, cubitus valgus/varus deformity might lead to pain and loss of motion of the elbow. The current corrective treatment might not be accurate enough and even contribute to postoperative deformity. This study retrospectively analyzed the clinical value of preoperative simulated surgery on 3D model-assisted osteotomy feasibility verification and surgical guidance for cubitus valgus/varus deformity. METHODS: Seventeen patients were selected from October 2016 to November 2019. Deformities were analyzed from imaging data and 3D models and corrected after the simulated operations. The radiographic evaluation comprised osseous union, carrying angle, and anteversion angle of the distal humerus. The clinical evaluation was performed according to the Hospital for Special Surgery (HSS) scoring system. RESULTS: All patients underwent the operation successfully and had no postoperative deformity. The carrying angle was significantly improved postoperatively (P < 0.001). The anteversion angle of the distal humerus did not change significantly (P > 0.05). The HSS score rose after surgery (P < 0.001). The function of the elbow joint was excellent in seven cases and good in ten cases. CONCLUSION: Simulated surgery on 3D model plays an important role in osteotomy plan and surgical guidance, contributing to good surgical efficacy.

[Finite element analysis of different reconstruction methods of coracoclavicular ligament for acromioclavicular joint dislocation].

OBJECTIVE: This study aims to examine the biomechanical effects of different reconstruction methods, including single-bundle, double-bundle anatomical reconstruction, and double-bundle truly anatomical reconstruction of the coracoclavicular ligament on the acromioclavicular joint using finite element analysis, to provide a theoretical basis for the clinical application of truly anatomical coracoclavicular ligament reconstruction. METHODS: One volunteer, aged 27 years old, with a height of 178 cm and a weight of 75 kg, was selected for CT scanning of the shoulder joint. Three-dimensional finite element models of single-bundle reconstruction, double-bundle anatomical reconstruction, and double-bundle truly anatomical reconstruction of coracoclavicular ligament were established by using Mimics17.0, Geomagic studio 2012, UG NX 10.0, HyperMesh 14.0 and ABAQUS 6.14 software. The maximum displacement of the middle point of the distal clavicle in the main loading direction and the maximum equivalent stress of the reconstruction device under different loading conditions were recorded and compared. RESULTS: The maximum forward displacement and the maximum backward displacement of the middle point of the distal clavicle in the double-bundle truly anatomic reconstruction were the lowest, which were 7.76 mm and 7.27 mm respectively. When an upward load was applied, the maximum displacement of the distal clavicle midpoint in the double-beam anatomic reconstruction was the lowest, which was 5.12 mm. Applying three different loads forward, backward, and upward, the maximum equivalent stress of the reconstruction devices in the double-beam reconstruction was lower than that in the single-beam reconstruction. The maximum equivalent stress of the trapezoid ligament reconstruction device in the double-bundle truly anatomical reconstruction was lower than that in the double-bundle anatomical reconstruction, which was 73.29 MPa, but the maximum equivalent stress of the conoid ligament reconstruction device was higher than that of the double-bundle anatomical reconstruction. CONCLUSION: The truly anatomical reconstruction of coracoclavicular ligament can improve the horizontal stability of acromioclavicular joint and reduce the stress of the trapezoid ligament reconstruction device. It can be a good method for the treatment of acromioclavicular joint dislocation.

Triple Endobutton technique for the treatment of Neer type II lateral clavicle fractures: 2-year findings.

BACKGROUND: Although various kinds of operative procedures have been reported in the literature, there is still no undisputed gold standard technique for the treatment of Neer type II lateral clavicle fractures. This trauma is classified as a bone fracture, but it is primarily a ligamentous problem due to the instability it generates. This study analyzed the clinical and radiological results of treatment for Neer type II lateral clavicle fractures using the triple Endobutton (Smith & Nephew) technique in 20 patients with at least 2 years of follow-up. METHODS: This study enrolled 20 patients with Neer type II distal clavicle fractures who underwent the triple Endobutton technique using 3 Endobuttons (1 with a closed loop and 2 without) and 3 No. 5 Ethibond sutures (Ethicon Inc.) from October 2017 to May 2020. Patients were assessed with clinical and radiological follow-up at 3, 6, 12, and 24 months postoperatively. Clinical assessments consisted of the visual analog scale and the Constant score. Radiological evaluation was achieved by measuring the coracoclavicular distance. RESULTS: The mean follow-up was 35 ± 9 months (range, 24-55 months). The visual analog scale and Constant scores revealed significant improvements from 6 ± 1 (range, 4-8) and 42 ± 4 (range, 35-48) scores preoperatively to 1 ± 1 (range, 0-1) and 94 ± 2 (range, 90-98) scores at the final evaluation, respectively (P < .001). The coracoclavicular distance of the injured side was an average of 9 ± 1 mm (range, 7-12 mm) at the final follow-up radiograph which was not significantly different from that of the contralateral side (P = .75). CONCLUSIONS: In this study, the triple Endobutton technique was a safe, reliable, and novel surgical technique that yielded good to excellent short-term clinical and radiological outcomes for the treatment of Neer type II distal clavicle fractures.

Clinical Features and Surgical Strategies of Distal Radius Posttraumatic Deformity.

Objective: To investigate the clinical features and surgical strategies of distal radius posttraumatic deformity. Methods: A retrospective analysis was performed on the data of 30 patients with distal radius posttraumatic deformity treated by osteotomy and orthopedic surgery in the department of orthopedics, the First Affiliated Hospital of Nanjing Medical University, from February 2016 to November 2018. All the patients underwent preoperative anterior and lateral X-ray plain scanning of bilateral wrist joints, showing different degrees of radius shortening, inferior ulnar and radial mismatch, palmar angle, and ulnar deviation angle, among which 11 patients had an uneven joint surface. After a full evaluation, osteotomy and orthopedic surgery were performed to restore the original anatomical structure, plaster fixation was performed for two weeks after surgery, and regular outpatient follow-up was conducted. The function of the wrist was evaluated by the MMWS (wrist joint improvement) scoring scale before and after surgery, and the changes in the wrist joint-related treatment parameters were evaluated according to X-ray. Results: All 30 patients had no neurological symptoms after surgery, and all wounds healed within the first stage. All patients were followed up for 6-12 months, with an average healing time of 3.5 months. There was no reduction loss, internal fixation loosening, or fracture in the regular postoperative review. Postoperative MMWS (wrist joint improvement) score scale data were significantly higher than those before surgery, and there were differences between groups (P < 0.05). Postoperative treatment parameters of wrist joints such as palmar inclination angle, ulnar deviation angle, radius height, and lower ulnar and radial matching were significantly improved, and there were differences between groups (P < 0.05). Conclusions: The patients with distal radius posttraumatic deformity have the clinical characteristics of shortening of radius, mismatch of lower ulnar and radius, an abnormal inclination of palm, and ulnar declination. For patients with distal radius posttraumatic deformity, osteotomy and orthopedic surgery can effectively improve wrist function and improve patients' quality of life, which is worthy of clinical reference.

Truly anatomic coracoclavicular ligament reconstruction with 2 EndoButton devices for acute Rockwood type V acromioclavicular joint dislocations: 5-year findings.

BACKGROUND: To date, mid-term clinical and radiologic outcomes of treatment for acute Rockwood type V acromioclavicular (AC) joint dislocations using 2 EndoButton devices (Smith & Nephew, Andover, MA, USA) have not been reported in the literature. METHODS: We reviewed 25 patients (15 men and 10 women) with acute AC joint separations who were treated with truly anatomic coracoclavicular ligament reconstruction using 2 EndoButton devices between May 2013 and October 2015. Clinical assessments consisted of the visual analog scale score and the Constant score. Radiologic evaluation was achieved by measuring the coracoclavicular distance and AC distance. Previously, this same patient cohort was reviewed after 2 years of follow-up using similar methods. RESULTS: All 25 patients were available for mid-term follow-up 5 years after the operation. The mean duration of follow-up was 76 ± 7 months (range, 66-90 months). Of the patients, 23 (92%) continued to be satisfied or very satisfied with the treatment results. The visual analog scale score and Constant score improved significantly when compared with the baseline scores (0 ± 0 and 96 ± 3, respectively, at 5-year follow-up vs. 5 ± 1 and 45 ± 6, respectively, postoperatively) and remained essentially unchanged when compared with the 2-year follow-up data (0 ± 0 and 96 ± 3, respectively, at 5-year follow-up vs. 0 ± 1 and 95 ± 3, respectively, at 2-year follow-up). On the 5-year radiographs, 3 patients (12%) demonstrated loss of reduction and 5 patients (20%) had calcifications noted. There was, however, no significant difference in clinical outcomes or patient satisfaction when comparing patients with radiographically abnormal findings vs. patients with anatomic reduction. CONCLUSION: Truly anatomic coracoclavicular ligament reconstruction using 2 EndoButton devices results in satisfactory functional outcomes at 5 years postoperatively. In contrast to baseline, all cases improved significantly.

Forearm Interosseous Membrane Maintains the Stability of Proximal Radioulnar Joint.

OBJECTIVE: To evaluate the effect of the proximal and central bundles of the interosseous membrane on the stability of proximal radioulnar joint. METHODS: Twenty fresh samples of human forearm provided by the anatomy room of the Department of Human Anatomy of Nanjing Medical University were included in this study. They were used to explore the effect of proximal interosseous membrane bundle on the stability of proximal radioulnar joint. The proximal bundle was reconstructed along the original attachment point. The reconstructions of central bundle were divided into the reconstruction of original attachment point on radius-midpoint of the ulnar original attachment point (reconstruction A) and original attachment point reconstruction (reconstruction B). The loads of the proximal radioulnar joint in different positions were measured. The load of the proximal radioulnar joint was analyzed in neutral, pronation, and supination positions. RESULTS: After resection of proximal and central fascicles, the loads of proximal radioulnar joint in neutral, pronation, and supination positions were significantly lower than those before resection (P < 0.05). After reconstruction, the loads of proximal radioulnar joint in neutral and supination positions were higher than those after resection (P < 0.05). After reconstruction, the loads of proximal radioulnar joint in neutral and supination positions were higher than those after resection (P < 0.05), and that after reconstruction B in pronation position was higher than that after resection (P < 0.05), while there was no significant difference between reconstruction A and after resection (P > 0.05). In supination position, the load of reconstruction B was higher than that of reconstruction A (P < 0.05). After reconstruction of the proximal and central bundles, the proximal radioulnar joint could not reached the same load as it could before resection (P < 0.05). CONCLUSION: The stability of proximal radioulnar joint is affected by central bundle and proximal bundle. Reconstruction can increase the stability of proximal radioulnar joint.

Effectiveness of Diagnosis and Treatment of Spiral Fracture of the Distal Third of the Tibia Combined with Posterior Malleolus Fracture A Series of Ten Cases.

BACKGROUND: Spiral fractures of the tibia are often the result of torsion trauma. In clinical practice, this type of fracture is frequently complicated by posterior malleolus fractures. This study aimed to observe the effectiveness of diagnosis and treatment of these fractures in a single hospital in China. Posterior malleolus fractures are sometimes occult, occurring alongside spiral fractures of the distal third of the tibia; posttraumatic arthritis can result if they are missed. METHODS: This study includes 128 consecutive patients with tibia fractures between May 1, 2008, and April 30, 2012. Patients in the early study period underwent radiography only, and subsequent patients underwent both radiography and computed tomography (CT). The causes of the fractures were evaluated. Intramedullar nailing was performed for the tibia fractures. Percutaneous cannulated screw fixation was used for the posterior malleolus fractures. Patients were followed up for a minimum of 3 months. RESULTS: Twenty-eight patients had spiral fractures of the mid-distal third of the tibia. Ten of the 28 patients were complicated by posterior malleolus fractures. Diagnosis was initially missed in one early patient who underwent radiography only. Three cases of posterior malleolus fractures were identified by radiography. A CT was performed in all ten patients and showed that approximately 25% to 50% of the ankle joint surface of posterior malleolus fractures was involved. One early diagnosis was missed that had a displaced posterior malleolus fracture after intramedullary nailing. Using CT as the gold standard, radiography had sensitivity of 33.3%, specificity of 100.0%, positive predictive value of 100%, and negative predictive value of 73.9%. All correctly diagnosed patients healed well, without ankle pain. CONCLUSIONS: Computed tomography helped identify most posterior malleolus fractures, and radiography alone might miss it. Intramedullary nailing and posterior malleolus screw fixation were straightforward and effective treatments.

Flexion-valgus unicondylar tibial plateau depression fracture pattern: Classification and treatment.

PURPOSE: The authors have identified a subset of unicondylar tibial plateau depression fracture patterns caused by a flexion-valgus force. The purpose of this study was to describe this fracture pattern and suggest a modified lateral approach that may allow for improved reduction and stabilization. METHODS: The preoperative radiographs and CT scans of 102 patients who sustained unicondylar tibial plateau fractures (OTA 41B) were reviewed. Twenty-six fracture patients had posterolateral (PL) tibial plateau depression fractures. By medical record review and telephone follow-up, the injury mechanism of the 22 unicondylar tibial plateau fractures was confirmed as a flexion-valgus force. The radiographic features of those cases were analyzed and measured. To address this specific fracture pattern, a modified approach combined with a novel intra-articular osteotomy was applied. RESULTS: According to the morphological characteristics, this tibial plateau fracture pattern could be divided into two subtypes: type A was a confined, basin-like articular surface depression fracture located in the PL quadrant, and type B was a cancellous fracture involving the PL tibial plateau resulting in a decrease in the posterior slope. One radiographic hallmark of this fracture pattern is an anatomically or a mechanically intact posterior column wall. The novel approach was applied to both types. The postoperative radiographic measurements revealed excellent reduction quality. On axial scans, the distance between the most posterior rafting screw and the tangent line of the tibial plateau rim was 3.0 ±â€¯2.07 mm (from -1.9 to 4.3), and the angulation between them was 8.9 ±â€¯3.02° (from -7.3 to 15.6). These results indicated excellent PL quadrant coverage from the rafting screws. CONCLUSION: Flexion-valgus force-induced unicondylar tibial plateau depression fracture is a unique injury pattern. We suggest a novel surgical approach to address this injury's key features, which may facilitate exposure and enhance fixation strength.

Truly anatomic coracoclavicular ligament reconstruction with 2 Endobutton devices for acute Rockwood type V acromioclavicular joint dislocations.

BACKGROUND: Truly anatomic coracoclavicular ligament reconstruction (TACCR) according to the original insertions is a creative new method for the treatment of severe acromioclavicular separation. This research analyzed the clinical and radiologic results of TACCR in 25 patients with at least 2-year follow-up. METHODS: The study enrolled 25 patients with Rockwood type V acromioclavicular joint dislocations who underwent TACCR using 2 Endobutton (Smith & Nephew Inc., Andover, MA, USA) devices from May 2013 to October 2015. Patients were assessed with clinical and radiologic follow-up at 3, 6, 12, 18, and 24 months postoperatively. The clinical assessments consisted of the visual analog scale and the Constant score. The radiographic evaluations were performed by measurements of the coracoclavicular distance. RESULTS: The mean follow-up was 34 ± 6.8 months (range, 24-48 months). The visual analog scale and Constant scores revealed significant advancements from 5 ± 0.9 (range, 4-7) and 45 ± 5.6 (range, 30-54) scores preoperatively to 0 ± 0.5 (range, 0-2) and 95 ± 2.9 (range, 91-98) scores at 24 months postoperatively, respectively. The coracoclavicular distance significantly decreased from 23 ± 5.4 mm (range, 16-34 mm) preoperatively to 8 ± 0.9 mm (range, 7-10 mm) at the final follow-up. CONCLUSIONS: TACCR represents a safe, reliable and creative surgical technique that yields good to excellent clinical and radiologic outcomes in the treatment of severe acromioclavicular separation.

Changes of cervical sagittal alignments during motions in patients with cervical kyphosis.

Changes of cervical sagittal alignment during motion in cervical kyphosis patients have never been published before. This study was to investigate the changes and provide a better reference for orthopedic treatment.Randomized double-blind repeat trial was carried out on 60 patients with cervical kyphosis. On standard position, hyper flexion, and hyper extension sagittal radiographs, the following measurements were made: the C2-7 vertebral body spatial alignment angle (∠A), C2-7 vertebral lower terminal lamina tilt angle (∠B), C2/3 to C6/7 segmental intervertebral space angle (∠C), the distance from the posterior edge of odontoid to C7 vertebral body (D value), and the difference of angle A, B, and C between cervical flexion and extension movement. Another 60 healthy volunteers were enrolled, of whom the cervical curve apex was determined using Borden's method to compare change and distribution characteristics to patients with cervical kyphosis and C value.In standard lateral position, ∠A was positive and increased from C2 to C7. In hyper extension position, ∠A decreased with reducing amplitude from C2 to C7 compared with the standard position, whereas in hyper flexion position, the average value of ∠A increased with decreasing amplitude from C2 to C7. ∠B followed similar change regularities as ∠A with a larger mean value. In cervical flexion and extension movement, ∠A change of upper vertebral body (∠D) was almost equal to ∠A change of lower vertebral body and ∠C change between the adjacent 2 vertebral bodies (∠E). The curve apex distribution was almost between C4 and C5 in cervical kyphosis patients. A significant difference was observed between cervical kyphosis patients and normal people in C value and D value.The correction of the cervical kyphosis can be carried out from the apex of the cervical spine that provides a solid theoretical foundation for the correction of the cervical kyphosis.

Coracoclavicular ligaments anatomical reconstruction: a feasibility study.

BACKGROUND: This study assessed the feasibility of anatomical coracoclavicular (CC) ligaments reconstruction, using three-dimensional (3D) measurement and virtual drilling. METHODS: One-hundred-and-five 3D shoulder models were constructed using SuperImage software, based on computed tomography (CT) scan data. For each model the attachment sites and footprint dimensions of the CC ligaments were defined and adjusted according to constant anatomical ratios and individual measurement results. Different drilling techniques and 3D measurements were carried out separately on each model. RESULTS: The collinear drilling technique with one bundle was used to breach the clavicle and/or coracoid process bone cortex in 38 of 105 models (36.2%); the percentage with two bundles was 90.5% (95/105). No cortical breach was observed using the non-collinear drilling technique. CONCLUSIONS: The non-collinear drilling technique provides the capability to prepare bony tunnels without any risk of cortical breach.

Sustained static stress-induced chondrocyte apoptosis in the rat cervical vertebral growth plate and its signal transduction mechanisms.

Apoptosis of the vertebral growth plate chondrocytes plays an important role in the pathogenesis of intervertebral disk degeneration. In this paper, we have successfully established an experimental model induced by static stress and provided a useful method to study the mechanisms of chondrocyte apoptosis. A sustained static load of ≥0.2 MPa over at least 12 h was observed to induce chondrocyte apoptosis, up-regulation of bax and caspase-3 expression, and down-regulation of bcl-2 expression.

Sustained static stress-induced chondrocyte apoptosis in the rat cervical vertebral growth plate and its signal transduction mechanisms.

Apoptosis of the vertebral growth plate chondrocytes plays an important role in the pathogenesis of intervertebral disk degeneration. In this paper, we have successfully established an experimental model induced by static stress and provided a useful method to study the mechanisms of chondrocyte apoptosis.A sustained static load of C0.2 MPa over at least 12 h was observed to induce chondrocyte apoptosis, up-regulation of bax and caspase-3 expression, and down-regulation of bcl-2 expression.

Static mechanical stress induces apoptosis in rat endplate chondrocytes through MAPK and mitochondria-dependent caspase activation signaling pathways.

Mechanical stress has detrimental effects on cartilaginous endplate chondrocytes due to apoptosis in vivo and in vitro. In this study, we investigated the possible apoptosis signaling pathways induced by mechanical stress in cultured rat cervical endplate chondrocytes. Static mechanical load significantly reduced cell viability in a time- and load-dependent manner, as demonstrated by the Cell Counting Kit-8 (CCK-8) assay. Chondrocyte apoptosis induced by mechanical stress was confirmed by annexin V/propidium iodide (PI) staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Western blot analysis revealed that static load-induced chondrocyte apoptosis was accompanied by increased phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 mitogen-activated protein kinase (MAPK). The loss of mitochondrial membrane potential (ΔΨm), increased Cytochrome c release, and activated Caspase-9 and Caspase-3, indicating that the mitochondrial pathway is involved in mechanical stress-induced chondrocyte apoptosis. Treatment with inhibitors of JNK (SP600125), p38 MAPK (SB203580), and ERK (PD98059) prior to mechanical stimulation reversed both the static load-induced chondrocyte apoptosis and the activation of JNK, p38 MAPK, and ERK. Taken together, the data presented in this study demonstrate that mechanical stress induces apoptosis in rat cervical endplate chondrocytes through the MAPK-mediated mitochondrial apoptotic pathway.

Clavicle and coracoid process drilling technique for truly anatomic coracoclavicular ligament reconstruction.

BACKGROUND: High-grade acromioclavicular (AC) joint separations require surgical treatment, as conservative treatment may result in functional decline or persistent pain. Although many surgical techniques have been described in the literature, there is still no non-controversial gold standard procedure for AC joint dislocation. The different orientation of the two components of the coracoclavicular (CC) ligaments has been proven to account for different functions. However, the majority of the techniques reconstruct the CC ligaments with a single structure. The purposes of this study were to assess the feasibility of truly anatomic coracoclavicular ligament reconstruction (TACCR) and to determine the corresponding drilling parameter. METHODS: We constructed virtual three-dimensional (3D) models of 105 shoulders from computed tomography (CT) scan data by using SuperImage software. For each model, the attachment sites and footprint dimensions of the conoid and trapezoid ligaments were defined and adjusted according to previously defined anatomic parameters and individual measurement results. Virtual drilling and 3D measurement were carried out in each model separately. Guided by the drilling parameter, we performed TACCR on 24 shoulders from 12 whole cadavers after transecting the AC and CC ligaments. RESULTS: The collinear drilling technique was noted to breach the bone cortex of the clavicle and/or the coracoid process in 95 of 105 virtual models (90.5%). No cortical breach was observed using a non-collinear drilling technique. The anteversion angulation of the conoid-coracoid tunnel ranged from 10° to 15° (mean value 12.4°). The extraversion angulation of the conoid-coracoid tunnel varied from 5° to 10° (mean value 6.8°). The anteversion angulation of the trapezoid-coracoid tunnel ranged from 20° to 30° (mean value 25.2°). There were no failures when performing the non-collinear drilling technique on cadaver models. CONCLUSIONS: The collinear drilling technique is not technically feasible for TACCR. For this reason, we recommend the non-collinear drilling technique, which provides the ability to prepare bony tunnels without any risk of cortical breach. CLINICAL RELEVANCE: Based on this computer and cadaver model study, we have devised a novel drilling technique to restore the CC ligaments anatomically.

Coracoclavicular ligament attachment regions of the Chinese population: a quantitative anatomic study.

It is reported that the coracoclavicular (CC) ligaments arise at a constant region, which is proportional to the size of the clavicle and the coracoid process. However, all cadavers in those studies were from whites or African-Americans. The aim of this study was to evaluate dimension and orientation of CC footprints in Chinese cadavers and to determine whether race-dependent differences in these measurements exist. A total of 172 shoulders from 87 Chinese cadavers were used in this study, and the CC ligaments including the coracoid and the lateral clavicle were exposed. After measurement of the length of the CC ligaments, the ligaments were dissected and the insertion sites as well as the footprint centers were identified and marked. Each CC insertion dimension and its distance to the bony landmarks were recorded. Ratios representing the distance from the clavicular landmarks to each footprint center divided by clavicular length and clavicular width were calculated. These ratios were calculated for the coracoid process as well. The mean length of the clavicle and the coracoid process was 139.9 ± 9.4 and 40.5 ± 4.0 mm. The distance from the lateral edge of the clavicle to the conoidal center and to the trapezoidal center was 35.7 ± 3.4 and 21.8 ± 2.7 mm, respectively. The distance from the tip of the coracoid to the conoidal center and to the trapezoidal center was 35.1 ± 3.2 and 29.7 ± 2.9 mm, respectively. The ratios of the distance to the conoidal center and to the trapezoidal center divided by clavicular length and coracoidal length were 25.5, 15.6, 86.8 and 73.4 %, respectively. While absolute differences in the origin of the CC ligaments exist between different races, the ratio of these origins to the size of the clavicle and the coracoid process is constant.

Apoptosis of endplate chondrocytes in post-laminectomy cervical kyphotic deformity. An in vivo animal model in sheep.

PURPOSE: The present study was performed to establish an animal model of cervical kyphosis after laminectomy (C2-C5), and to determine the role of endplate chondrocytes apoptosis in cervical kyphosis after laminectomy. METHODS: Twenty-four 3-month-old sheep were randomly divided into two groups: the laminectomy group (n = 12), and the control group (n = 12). The cervical spine alignment was evaluated on a lateral cervical spine X-ray using Harrison's posterior tangent method before surgery and at follow-up. Cartilaginous endplate chondrocyte apoptosis was confirmed using transmission electron microscopy and terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick-end labelling. RESULTS: The mean preoperative cervical curvature (C2-5) in the surgery group was -15.8°. The cervical curvature was 19.1° at 3 months post-operation and decreased to 20.2° at the final follow-up postoperatively. The cervical curvature was significantly decreased in the laminectomy group compared with the control group at the last follow-up (P < 0.001), which was a direct indication of kyphotic change. The incidence of apoptotic cells in the surgery group was significantly higher at the 3- and 6-month follow-up than the incidence in the control group. CONCLUSIONS: The frequency of endplate chondrocyte apoptosis in the laminectomy group was significantly higher than in the control group, indicating that chondrocyte apoptosis may play a pivotal role in the progress of post-laminectomy cervical kyphosis.