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.

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.

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.

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.

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.

[The clinical features and surgical treatment strategies of cervical kyphosis].

OBJECTIVE: To analyze the clinical characteristics and the surgical treatment strategy of cervical kyphosis. METHODS: From March 2006 to October 2009, 31 cases of cervical kyphosis were treated. According to the clinical features and imaging findings, different treatment methods were used. There were 9 patients in operation group, including 4 male and 5 female patients, aged from 17 to 72 years (average age of 35 years). Among them, 5 cases were idiopathic kyphosis and 4 cases were caused by laminectomy or other reasons. There were 22 patients in conservative treatment group, including 11 male and 11 female patients, aged from 14 to 40 years (average age of 29 years), who were all idiopathic cervical kyphosis. Before and 1 week after operation, clinical assessment were taken for the patients in operation group using Spinal Cord Injuries Classification Standard of American Spinal Injury Association (AISA). During the periodic review, the anteroposterior, normal sagittal films of cervical spine were taken. At 1 week and every 6 months after operation, MRI films were also taken. These films were studied to evaluate the effects of the operations. In the conservative group, assessment of treatment results by studying anteroposterior and normal lateral views of cervical spine were were taken every month. The clinical characteristics and the surgical treatment strategies of these patients were analyzed. RESULTS: In operation group, 9 cases were followed up for 6 to 18 months, all patients did not failed in internal fixation and fusion. AISA neurological score and neurological function significantly improved. Three days after operation the average Cobb angle was -1.29 ° (preoperative 54.24 °). In conservative group, the average Cobb angle was -5.41 ° (before treatment 11.20 °) 4 months after the treatment. The symptoms of neck shoulder and back pain disappeared, and all patients were followed up for 3 to 24 months, with no recurrence of symptoms. CONCLUSIONS: In the early period of cervical kyphosis, adopt postural therapy, plaster braces to correct an imbalance in cervical spine biomechanics can prevent deformity development. According to patients' clinical characteristics, choosing individual treatment programs can correct the severe cervical kyphosis and achieve good outcome.

[The surgical treatment of severe adolescent idiopathic cervical kyphosis].

OBJECTIVE: To summarize the clinical characteristics of severe adolescent idiopathic cervical kyphosis and the operation method. METHODS: A retrospective study was performed in 12 adolescent patients with severe cervical kyphosis treated from July 2003 to January 2007. Preoperative the Cobb angle of kyphosis range from 55 degrees to 73 degrees (average 61 degrees ). According to the angles between the posterior vertebral body tangents at every involved level on lateral cervical radiograph in extension, the osteotomy angles and range of lamina and facet were decided. The anterior release and posterior osteotomy were performed firstly. Then skull traction was maintained in order to correct the deformity as long as possible, fusion and internal fixation was completed after 7-10 days. The cervical coronal and sagittal planes X-rays and the MR were hold after operation 3 days, 3 months, 6 months, 1 year and 2 years. At the same time the treatment result, bone fusion and the instrumentation were followed up, and the symptoms were compared between pre-operation and post-operation. RESULTS: The defect appearance of the patients was improved significantly, with the total disappearance of neck pain and improvement of nerve function. Post-operational cervical spine MR showed that the physiological curve of cervical spine was restored, cerebral spinal fluid line was clear in the kyphosis area and no spinal cord compression was found. X-ray imaging of post-operation 3 d showed that Cobb angle ranged from -12.3 degrees to 11.2 degrees with an average of -2.0 degrees . Beside one patient's AISA score was D, other patient's AISA score was E. CONCLUSIONS: The severe adolescent idiopathic cervical kyphosis has its own clinical manifestation. It is an ideal treatment to completely assess the deformity, have staging operation and skull traction between two operations.

[Clinical research of delayed hyperextension injury concomitance spinal cord injury of cervical spine].

OBJECTIVE: To discuss Clinic feature and turnover of delayed hyperextension injury concomitance spinal cord injury of cervical spine. METHODS: The clinic data of 30 patients delayed hyperextension injury of cervical spine were reviewed and analyzed. Course of disease was from 3 months to 8 years. Thirty patients were divided into three groups according to course of disease. The first group, 3 - 6 months, 17 cases; the second group, 6 - 12 months, 8 cases; the third group, 12 months-8 years, 5 cases. Neurological function improvement rates were evaluated according to the JOA scores at preoperative, 3 months and 1 year post operation, and complications were observed in three groups. Twenty-six cases were treated with anterior decompression, bone graft and plate fixation. Four cases were treated with posterior decompression, bone graft and plate fixation. RESULTS: The patient number of the three group exist with statistical significance. Thirty patients were followed up for 18 - 39 months, 23 months on average. Neurological function recovery rates were 23.8% in the first group, 53.9% in the second group and 54.3% in the third group at 1 year post operation. JOA scores of the first group and the second group with statistical significance at 3 months and 1 year post operation. JOA scores of the first group and the third group with statistical significance at 3 months and 1 year post operation. JOA scores of the second group and the third group without statistical significance at 3 months and 1 year post operation. CONCLUSIONS: Incidence of hyperextension injury associated with spinal cord injury of cervical spine would degrade along with course of disease prolong. If delayed spinal cord injury occurred earlier, the patient's condition was severer and badly improvement rate.

[Sagittal diameters measurements on MR of the cervical spinal cord in normal subjects].

OBJECTIVE: To offer normal reference of diameter of the cervical spinal cord and available diameter of cervical spinal canal and to screen scientific radiographic criteria to define and quantify cervical spinal cord disease. METHODS: The magnetic resonance images of 120 normal people had been measured. The data of diameters of cervical spinal cord, CSF, M, the ratio of diameters of cord and CSF, and the ratio of diameters of cord and M had been collected and statistical analysis was made. And the relationships between the data above and each of gender, the length of C-spine and age were evaluated. In addition, the ratio of diameters of cord and CSF, and the ratio of diameters of cord and M was evaluated. RESULTS: The study showed that in healthy people, the diameters of cervical spinal cord, CSF and M was larger in the males than in the females, decreased with age, and increased with the length of C-spine but the diameter of CSF. And the ratio of diameters of cord and CSF increased with age and not affected by the length of C-spine. However, the ratio of diameters of cord and M was not affected by age and the length of C-spine. CONCLUSION: The ratio of diameters of cord and M is not affected by individual variation and can be used to evaluate cervical spinal cord atrophy, compression and impaired in patients with cervical myelopathy and can be important information in looking for clinically critical points.