Application of 3D printing and computer-assisted surgical simulation in preoperative planning for acetabular fracture / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the feasibility and effectiveness of using 3D printing and computer-assisted surgical simulation in preoperative planning for acetabular fractures.</p><p><b>METHODS</b>A retrospective analysis was performed in 53 patients with pelvic fracture, who underwent surgical treatment between September, 2013 and December, 2015 with complete follow-up data. Among them, 19 patients were treated with CT three-dimensional reconstruction, computer-assisted virtual reset internal fixation, 3D model printing, and personalized surgery simulation before surgery (3D group), and 34 patients underwent routine preoperative examination (conventional group). The intraoperative blood loss, transfusion volume, times of intraoperative X-ray, operation time, Matta score and Merle D' Aubigne & Postel score were recorded in the 2 groups. Preoperative planning and postoperative outcomes in the two groups were compared.</p><p><b>RESULTS</b>All the operations were completed successfully. In 3D group, significantly less intraoperative blood loss, transfusion volume, fewer times of X-ray, and shortened operation time were recorded compared with those in the conventional group (P<0.05). According to the Matta scores, excellent or good fracture reduction was achieved in 94.7% (18/19) of the patients in 3D group and in 82.4% (28/34) of the patients in conventional group; the rates of excellent and good hip function at the final follow-up were 89.5% (17/19) in the 3D group and 85.3% (29/34) in the conventional group (P>0.05). In the 3D group, the actual internal fixation well matched the preoperative design.</p><p><b>CONCLUSIONS</b>3D printing and computer-assisted surgical simulation for preoperative planning is feasible and accurate for management of acetabular fracture and can effectively improve the operation efficiency.</p>

Expression of lipoprotein related genes in subchondral bone of early experimental osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To study the expression of lipoprotein related genes in subchondral bone of early experimental os-teoarthritis, which may play an important role in the pathogenesis of osteoarthritis.</p><p><b>METHODS</b>Animals are equally divided into two groups: experimental group and control group, both of which contain fifteen rats of similar weight. The right knee joints of experimental group underwent surgery,which involved in both medial collateral ligament(MCL) transaction and medial meniscectomy, while the control group was only carried out with a sham operation. Rats were killed at 1, 2 and 4 weeks postsurgery to obtain the right knee joints. Total RNA of the subchondral bone was extracted,and then hybridized to Agilent Whole Rat Genome Microarray. Differentially expressed genes analysis was used to study the chemokine signaling pathway.</p><p><b>RESULTS</b>Apoa5 expression was down-regulated at 1, 2 weeks post-surgery, Apoc2 expression was up-regulated at 1 week after surgery, Apol3 expression was up-regulated at 1 and down-regulated at 4 weeks post-surgery, Lrp1 expression was down-regulated at 1, 2 weeks after surgery. Lrp5 was down-regulated at 2 weeks after surgery. Gpihbp1, Lpl, Tfpi and Vldlr were up-regulated at 1 weeks after surgery. Lrpap1 and RGD1309808 were down-regulated at 4 weeks after surgery.</p><p><b>CONCLUSION</b>Dysregulation of lipoprotein related genes plays an important role in pathogenesis of early experimental osteoarthritis.</p>

Simultaneous bilateral patellar tendon rupture without predisposing systemic disease or steroid use: a case report / 中华创伤杂志(英文版)

There is a dearth of case reports describing simultaneous bilateral patellar tendon ruptures in the medical literature. These ruptures are often associated with systemic disorders such as lupus erythematosus or chronic steroid use. The author describes a case of a 24-year-old man who sustained traumatic bilateral patellar tendon ruptures without any history of systemic disease or steroidal medication. We repaired and reattached the ruptured tendons to the patella and augmented our procedure with allogeneic tendon followed by wire loop reinforcement. One year after operation, the patient regained a satisfactory range of motion of both knees with good quadriceps strength and no extensor lag. The recurrent microtrauma from a history of intense sports activity and a high body mass index may have played an important role in this trauma event.

Whole meniscus regeneration using polymer scaffolds loaded with fibrochondrocytes / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the feasibility of regenerating a whole menisci using poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds loaded with meniscal cells in rabbits undergoing total meniscectomy, and to explore its protective effect on cartilage degeneration.</p><p><b>METHODS</b>A solvent casting and particulate leaching technique was employed to fabricate biodegradable PHBV scaffolds into a meniscal shape. The proliferated meniscal cells were seeded onto the polymer scaffolds, transplanted into rabbit knee joints whose lateral menisci had been removed. Eight to 18 weeks after transplantation, the rege- nerated neomenisci were evaluated by gross and histological observations. Cartilage degeneration was assessed by Mankin score.</p><p><b>RESULTS</b>Eighteen weeks after transplantation, the implants formed neomenisci. Hematoxylin and eosin (HE) staining of the neomenisci sections revealed regeneration of fibrocartilage. Type I collagen in the neomenisci was also proved similar to normal meniscal tissue by immunohistochemical analysis and Sirius scarlet trinitrophenol staining. Articular cartilage degeneration was observed 8 weeks after implantation. It was less severe as compared with that in total meniscectomy controls and no further degeneration was observed at 18 weeks. At that time, the regenerated neomenisci strongly resembled normal meniscal fibrocartilage in gross and histological appearance, and its mechanical property was also close to that of normal meniscus.</p><p><b>CONCLUSIONS</b>The present study demonstrates the feasibility of tissue-engineering a whole meniscal structure in total meniscectomy rabbit models using biodegradable PHBV scaffolds together with cultured allogeneic meniscal cells. Cartilage degeneration is decreased. But long-term in vivo investigations on the histological structure and cartilage degeneration of the neomenisci regenerated by this method are still necessary to determine the clinical potential of this tissue engineering avenue.</p>

Treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and steel-wire internal fixation / 中国骨伤

<p><b>OBJECTIVE</b>To study the curative effects of the treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and steel-wire internal fixation.</p><p><b>METHODS</b>From January 2003 to June 2009, 28 patients of tibial avulsion fracture of the posterior cruciate ligament were treated with open reduction and steel-wire internal fixation through posteromedial inverted "L" approach. There were 19 males and 9 females with an average age of 35.3 years old ranging from 16 to 55 years. The X-ray examination showed that there were II degree displaced in 10 cases and III degree in 18 patients. The affected lower extremity was put in a controlled hinge knee brace after operation. The patients were asked to do passive extension and flexion of the knee joint with the assistance of a CPM 2 weeks after operation,and allowed to be partial weight-bearing as tolerated with the hinged brace locked in extension if concomitant injuries allowed 4 weeks postoperatively. The brace were removed 6 weeks later.</p><p><b>RESULTS</b>Among them, 25 patients were followed up for 6 to 24 months with an average of 15 months. The X-ray examination showed satisfactory reduction, and bony union was obtained in all the patients. The Lachman test was negative in all patients. No complications such as malunion or joint stiffness were found. The extension of affected knee was normal and its flexion were (136 +/- 12) degrees. According to Lysholm knee score system,it was preoperatively (41.80 +/- 6.16) and (94.10 +/- 8.26) six months after surgery respectively. Twenty-two cases were excellent, 2 cases good and 1 fair.</p><p><b>CONCLUSION</b>Treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and internal fixation with wires through posteromedial inverted "L" approach is a safe, effective method, due to its stable fixation and relatively low expense. It is believed as an ideal choice for tibial avulsion fracture of the posterior cruciate ligament.</p>

Additional screws fixation on fractured vertebrae versus only short-segment posterior instrumentation for thoracolumbar A3 fracture without neurologic deficit / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the clinical results of additional screws fixation on fractured vertebrae versus only short-segment posterior transpedicular instrumentation for A3 thoracolumbar fracture without neurologic deficit.</p><p><b>METHODS</b>Clinical data of 52 cases of thoracolumbar burst fracture without neurologic deficit were retrospectively analyzed. All patients were divided into 2 groups due to different instrumentation and all fractures were classified as type A3 according to AO Classification.From January 2005 to December 2006, 23 cases in group A were treated by short-segment posterior instrumentation combined with additional screws fixation on fractured vertebrae. There were 18 male and 5 female with a mean age of (35.3+/-8.3) years. The fracture segment included 1 in T11, 9 in T12, 11 in L1 and 2 in L2. From January 1999 to December 2004, 29 cases in group B were treated only by conventional short-segment posterior transpedicular instrumentation. There were 20 male and 9 female with a mean age of (37.3+/-6.8) years. The fracture segment included 1 in T11, 7 in T12, 20 in L1 and 1 in L2. The clinical effect and radiographic measurements were respectively compared preoperatively, immediate and 2 years postoperatively.</p><p><b>RESULTS</b>All patients were followed up and the mean follow-up time was (37.4+/-10.9) months (from 24 to 48 months). There was no statistic difference of mean JOA and VAS score between 2 groups preoperatively, immediate and 2 years postoperatively (P>0.05). The average immediate postoperative correction of Cobb's angle was 13.7 degrees+/-7.7 degrees in group A, which was statistically significantly higher than that of 8.8 degrees+/-5.0 degrees in group B (P<0.01). The mean kyphosis correction loss of 2.9 degrees+/-1.5 degrees in group A was statistically significantly lower than that of 5.0 degrees+/-2.9 degrees in group B 2 years postoperatively (P<0.01). The average restoration of anterior height of fractured vertebral body immediate postoperatively was (29.4+/-6.0)% and (21.7+/-6.9)% respectively. The mean correction loss of anterior height 2 years postoperatively was (3.1+/-0.8)% and (6.6+/-3.0)% respectively. The average restoration of posterior height of fractured vertebral body immediate postoperatively was (8.5+/-3.2)% and (6.1+/-1.8)% respectively. The mean correction loss of posterior height 2 years postoperatively was (2.0+/-0.8)% and (3.4+/-1.0)% respectively. There were significant differences in average restoration of anterior/posterior height immediate postoperatively and correction loss of anterior/posterior height 2 years postoperatively between the 2 groups (P<0.01). According to fracture fragments protruded into the spinal canal on immediate postoperative CT image, there were complete reduction in 11 cases (47.8%) and partial reduction in 12 cases (52.2%) in group A, which was statistically significantly better than those in group B (P<0.01). There was no severe neurologic complications and no other complications related to additional screws fixation postoperatively. Pedicle screw breakage occurred in 2 cases in group B and none in group A.</p><p><b>CONCLUSIONS</b>Better initial kyphosis correction and less loss of correction 2 years after operation can be obtained by using additional screws fixation on fractured vertebra for thoracolumbar A3 fracture without neurologic deficit.</p>

Arthroscopic diagnosis and treatment of posttraumatic chronic ankle pain / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the arthroscopic diagnosis and treatment of the chronic ankle pain after injury.</p><p><b>METHODS</b>From April 1999 to June 2008, 39 patients with posttraumatic chronic ankle pain were treated. The mean duration between the initial injury and treatment was 18 months (2 months to 11 years). There were 15 males and 24 females with a mean age of 32 years (15 to 58 years). All the patients were treated with arthroscopic debridement. The preoperative and postoperative ankle functions were evaluated by the AOFAS (the American Orthopaedic Foot and Ankle Society) Clinical Rating System for the ankle-hindfoot.</p><p><b>RESULTS</b>Twenty-six patients had osteochondral lesions. Impingement syndrome in ankle was observed in 21 patients. The impingement tissue included synovial hypertrophy in 3 patients, ligament injury in 10 patients (7 patients had anterior talofibular ligament injury and 3 patients had anteroinferior tibiofibular ligament injury), meniscoid tissue in 6 patients, pathological labrum in 3 patients. All the patients were followed up with an average of (14.2+/-8.4) months (ranged from 5 to 36 months). The AOFAS scores increased significantly from pre-operative (59.7+/-16.9) to post-operative (68.8+/-21.2), and it was obvious in relieving pain, which was pre-operative (22.8+/-10.0) and post-operative (29.5+/-12.1).</p><p><b>CONCLUSION</b>Arthroscopy can be used to diagnose the cause of chronic ankle pain after injury. Furthermore, arthroscopic debridement was useful to relieve the pain and improve the joint function, and it is appropriate for patients who had no fractures and dislocations.</p>

Spinal surgeons' learning curve for lumbar microendoscopic discectomy: a prospective study of our first 50 and latest 10 cases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Microendoscopic discectomy (MED) is a minimally invasive operation that allows rapid recovery from surgery for lumbar disc herniation, but has replaced traditional open surgery in few hospitals because most surgeons avoid its long learning curve. We evaluated the effectiveness and safety of lumbar MED at stages of spinal surgeons' learning curve.</p><p><b>METHODS</b>Fifty patients receiving MED from June 2002 to February 2003 were divided into chronological groups of ten each: A - E. The control group F was ten MED patients treated later by the same medical team (September - October 2006). All operations were performed by the same team of spinal surgeons with no MED experience before June 2002. We compared groups by operation time, blood loss, complications and need for open surgery after MED failure.</p><p><b>RESULTS</b>Operation times by group were: A, (107 +/- 14) minutes; B, (85 +/- 13) minutes; C, (55 +/- 19) minutes; D, (52 +/- 12) minutes; E, (51 +/- 13) minutes; and F, (49+/- 15) minutes. Blood loss were: A, (131 +/- 73) ml; B, (75 +/- 20) ml; C, (48 +/- 16) ml; D, (44 +/- 17) ml; E, (45 +/- 18) ml; and F, (45 +/- 16) ml. Both operation time and blood loss in groups C, D, E and F were smaller and more stable compared with groups A and B. Japanese Orthopedic Association assessment (JOA) score of each group in improvement rate immediately and one year after operation were as follows (in percentage): A, (79.8 +/- 8.8)/(89.8 +/- 7.7); B, (78.6 +/- 8.5)/(88.5 +/- 7.8); C, (80.8 +/- 11.3)/(90.8 +/- 6.7); D, (77.7 +/- 11.4)/(88.9 +/- 9.3); E, (84.0 +/- 8.7)/(89.6 +/- 9.0); and F, (77.8 +/- 11.6)/(86.9 +/- 8.4). Groups showed no statistical difference in improvement rates. Complications developed in three patients in group A, two in group B, and none in the other groups.</p><p><b>CONCLUSIONS</b>Spinal surgeons performing MED become proficient after 10 - 20 operations, when their skill becomes fairly sophisticated. Patients' improvement rate is the same regardless of surgeons' phase of learning curve.</p>

Concurrent arthroscopic bicruciate ligament reconstruction using Achilles tendon-bone allografts: experience with 15 cases / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the clinical outcome of arthroscopically assisted combined anterior and posterior cruciate ligament (ACL/PCL) reconstructions using Achilles tendon-bone allografts.</p><p><b>METHODS</b>Associated meniscus injuries were treated according to established methods prior to ligament reconstructions during arthroscopic surgery. Thirty Achilles tendon-bone allografts were used to reconstruct torn ACL and PCL in 15 knees. At postoperative follow-up, all knees were graded using the modified IKDC and the Lysholm scoring systems just as done preoperatively.</p><p><b>RESULTS</b>were analyzed compared with the contralateral healthy knees. Results: Eleven men and 4 women with a minimum of 3-year follow-up (mean 38 months) were included in the study. Preoperatively, the group ratings by the modified IKDC standards were all severely abnormal. Twelve bicruciate reconstructions were performed in subacute or chronic stage (larger than 3-8 weeks), 3 for acute ligamentous deficiencies (less than or equal to 3 weeks). The noticeable early complication was transitory local fever combined with joint effusion in one case. At postoperative follow-up, 9 knees were normal, 5 nearly normal and 1 abnormal. On Lysholm score the difference was statistically significant (t- test, P less than 0.001) before and after operation.</p><p><b>CONCLUSIONS</b>Achilles tendon-bone allograft offers an alternative for simultaneous arthroscopic ACL/PCL reconstructions. However, further investigation is needed to eradicate its potential immunogenicity for better use.</p>

Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-beta1 delivery for cartilage tissue engineering / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-beta1 (TGF-beta1) to cartilage defects can enhance chondrogenesis. In this study, we assessed the feasibility of using biodegradable chitosan microspheres as carriers for controlled TGF-beta1 delivery and the effect of released TGF-beta1 on the chondrogenic potential of chondrocytes.</p><p><b>METHODS</b>Chitosan scaffolds and chitosan microspheres loaded with TGF-beta1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. In vitro drug release kinetics, as measured by enzyme-linked immunosorbent assay, was monitored for 7 days. Lysozyme degradation was performed for 4 weeks to detect in vitro degradability of the scaffolds and the microspheres. Rabbit chondrocytes were seeded on the scaffolds containing TGF-beta1 microspheres and incubated in vitro for 3 weeks. Histological examination and type II collagen immunohistochemical staining was performed to evaluate the effects of released TGF-beta1 on cell adhesivity, proliferation and synthesis of the extracellular matrix.</p><p><b>RESULTS</b>TGF-beta1 was encapsulated into chitosan microspheres and the encapsulation efficiency of TGF-beta1 was high (90.1%). During 4 weeks of incubation in lysozyme solution for in vitro degradation, the mass of both the scaffolds and the microspheres decreased continuously and significant morphological changes was noticed. From the release experiments, it was found that TGF-beta1 could be released from the microspheres in a multiphasic fashion including an initial burst phase, a slow linear release phase and a plateau phase. The release amount of TGF-beta1 was 37.4%, 50.7%, 61.3%, and 63.5% for 1, 3, 5, and 7 days respectively. At 21 days after cultivation, type II collagen immunohistochemical staining was performed. The mean percentage of positive cells for collagen type II in control group (32.7% +/- 10.4%) was significantly lower than that in the controlled TGF-beta1 release group (92.4% +/- 4.8%, P < 0.05). Both the proliferation rate and production of collagen type II in the transforming growth factor-beta1 microsphere incorporated scaffolds were significantly higher than those in the scaffolds without microspheres, indicating that the activity of TGF-beta1 was retained during microsphere fabrication and after growth factor release.</p><p><b>CONCLUSION</b>Chitosan microspheres can serve as delivery vehicles for controlled release of TGF-beta1, and the released growth factor can augment chondrocytes proliferation and synthesis of extracellular matrix. Chitosan scaffolds incorporated with chitosan microspheres loaded with TGF-beta1 possess a promising potential to be applied for controlled cytokine delivery and cartilage tissue engineering.</p>

Development and potential of a biomimetic chitosan/type II collagen scaffold for cartilage tissue engineering / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Damaged articular cartilage has very limited capacity for spontaneous healing. Tissue engineering provides a new hope for functional cartilage repair. Creation of an appropriate cell carrier is one of the critical steps for successful tissue engineering. With the supposition that a biomimetic construct might promise to generate better effects, we developed a novel composite scaffold and investigated its potential for cartilage tissue engineering.</p><p><b>METHODS</b>Chitosan of 88% deacetylation was prepared via a modified base reaction procedure. A freeze-drying process was employed to fabricate a three-dimensional composite scaffold consisting of chitosan and type II collagen. The scaffold was treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Ultrastructure and tensile strength of the matrix were carried out to assess its physico-chemical properties. After subcutaneous implantation in rabbits, its in vivo biocompatibility and degradability of the scaffold were determined. Its capacity to sustain chondrocyte growth and biosynthesis was evaluated through cell-scaffold co-culture in vitro.</p><p><b>RESULTS</b>The fabricated composite matrix was porous and sponge-like with interconnected pores measuring from 100-250 microm in diameter. After cross-linking, the scaffold displayed enhanced tensile strength. Subcutaneous implantation results indicated the composite matrix was biocompatible and biodegradable. In intro cell-scaffold culture showed the scaffold sustained chondrocyte proliferation and differentiation, and maintained the spheric chondrocytic phenotype. As indicated by immunohistochemical staining, the chondrocytes synthesized type II collagen.</p><p><b>CONCLUSIONS</b>Chitosan and type II collagen can be well blended and developed into a porous 3-D biomimetic matrix. Results of physico-chemical and biological tests suggest the composite matrix satisfies the constraints specified for a tissue-engineered construct and may be used as a chondrocyte carrier for cartilage tissue engineering.</p>