Objective:To explore whether tryptophan metabolism is related to bone growth by comparing the differences in tryptophan metabolism after rotator cuff tear (RCT) repair between rats with normal bone remodeling capability and those with defective bone remodeling capability.Methods:Of the 50 adult female Sprague Dawley (SD) rats used for this study, 18 were randomly selected to undergo bilateral ovariectomy (OVX) (OVX group), and the remaining 32 underwent bilateral OVX sham surgery (sham surgery group). All rats were maintained in standard conditions. Three months after surgery, 4 rats were randomly selected from OVX group and the sham surgery group, respectively, for Micro CT identification of bone loss at the rat humeral head. The remaining rats in OVX group underwent RCT modeling and surgical repair of acute supraspinatus muscle transection (OVX+RCT group) ( n=14); the remaining rats in the sham surgery group were subjected to either surgical repair of acute supraspinatus muscle transection (RCT group, n=14) or RCT sham surgery (SO group, n=14). The grip power of the rats was tested 2 weeks after surgery. The supraspinatus tendon-bone complex was harvested for evaluation of new bone formation and growth through real-time fluorescence quantitative polymerase chain reaction (qPCR), hematoxylin eosin (HE) staining, and immunohistochemistry (IHC) staining. The tryptophan metabolism was analyzed using ultra high performance liquid chromatography (UPLC). Results:The grip power test showed that SO group had the greatest grip power, followed by RCT group and OVX+RCT group, with statistically significant differences between the 3 groups ( P<0.05). The qPCR showed that the relative expression of osteosclerosis in the tendon-bone complex in SO group was significantly higher than that in OVX+RCT group and RCT group; IHC staining showed that the relative expression of osteocalcin in RCT group was significantly higher than that in SO group and OVX+RCT group ( P<0.05). The UPLC showed that the content of tryptophan in the rotator cuff tendon-bone complex was similar among SO, RCT, and OVX+RCT groups, showing no significant difference ( P>0.05). The qPCR showed that the expression of indoleamine 2, 3-dioxygenase 2 in the Kynurenic acid metabolism pathway showed an increasing trend from SO group to RCT group to OVX+RCT group, with OVX+RCT group significantly higher than SO group ( P<0.05). The expression of 3-hydroxybenzoate 3, 4-dioxygenase in OVX+RCT group was significantly higher than that in RCT group and in SO group ( P<0.001). The subtypes A and B of monoamine oxidase in the 5-hydroxytryptamine metabolism pathway increased from SO group to RCT group to OVX+RCT group. The subtypes A and B of monoamine oxidase in the 5-hydroxytryptamine metabolism pathway increased among SO, RCT, and OVX+RCT groups( P<0.001). The expression of dopamine decarboxylase in the indole metabolism pathway in OVX+RCT group was significantly higher than that in SO group ( P<0.01). The expression of cytochrome P450 oxidoreductase increased from SO group to RCT group to OVX+RCT group ( P<0.001). Conclusions:The tryptophan metabolism in the supraspinatus tendon-bone complex after RCT in rats is mainly dominated by kynurenic acid metabolism, followed by 5-hydroxytryptamine metabolism. In RCT bone remodeling, the 5-hydroxytryptamine metabolic pathway changes the most, followed by the indole pathway. The contents of niacin and xanthurenic acid in the kynurenic acid metabolism pathway are related to bone growth; the 5-hydroxytryptamine, hydroxyindoleacetic acid, and melatonin in the 5-hydroxytryptophan metabolic pathway are related to bone growth; the tryptophan and indole lactate in the indole metabolism pathway are related to bone growth. Therefore, tryptophan metabolism is related to bone growth, providing potential therapeutic targets for RCT repair.

Objective:To compare the short-term efficacy between proximal femoral bionic nails (PFBN) and 3G Gamma nails in the fixation intertrochanteric femoral fractures in the elderly.Methods:A retrospective study was conducted to analyze the data of 78 elderly patients with intertrochanteric femoral fracture who had been admitted to Department of Trauma Surgery, The Hospital Affiliated to Qingdao University from October 2021 to December 2022. There were 35 males and 43 females with an age of (76.0±7.9) years. By Evans classification: 6 cases of type Ⅰ, 21 cases of type Ⅱ, 24 cases of type Ⅲ, 23 cases of type Ⅳ, and 4 cases of type Ⅴ. The patients were divided into 2 groups according to their internal fixation methods: a PFBN group of 35 patients fixed by PFBN and a Gamma group of 43 cases fixed with 3D Gamma nails. The time from injury to operation, hospital stay, operation time, intraoperative blood loss, weight-bearing time, fracture healing time, and Harris hip score, visual analogue scale (VAS) and incidence of complications at 6 months after operation were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). All patients were followed up for (14.0±4.0) months. There were no significant differences between the PFBN and Gamma groups in operation time [(58.9±8.2) min versus (58.1±6.8) min], intraoperative blood loss [(138.0±24.9) mL versus(126.8±25.7) mL], hospital stay [(10.9±2.9) d versus (10.3±4.0) d],fracture healing time [(5.0±1.3) months versus (5.1±1.3) months], or good and excellent rate by the Harris hip score [82.9% (29/35) versus 76.7% (33/43)], VAS score [0(0, 1) points versus 1(0, 1) points], or incidence of complications at 6 months after operation [2.9% (1/35) versus 4.7% (2/43)] (all P>0.05). However, the complete weight-bearing time for the PFBN group was (5.3±1.2) weeks, significantly earlier than that for the Gamma group [(6.9±1.4) weeks] ( P<0.05). Conclusion:In the fixation of intertrochanteric femoral fractures in the elderly patients, both PFBN and 3D Gamma nails can achieve satisfactory short-term efficacy, but PFBN is more beneficial to the functional recovery of the hip joint because it leads to earlier complete weight-bearing time than 3D Gamma nails.

Objective:To compare the therapeutic effects of intramedullary nail fixation, simple tibial plate fixation, and tibial plate + posterior-to-anterior screw fixation in the surgical treatment of lower 1/3 spiral fracture of the tibia combined with posterior malleolar fracture.Methods:A retrospective study was conducted to analyze the clinical data of 78 patients with lower 1/3 spiral fracture of the tibia combined with posterior malleolar fracture who had been treated at Department of Orthopedics, The Hospital Affiliated to Qingdao University from June 2015 to June 2022. There were 46 males and 32 females with an age of (48.9±14.6) years. The patients were divided into 3 groups according to their fixation methods. Group A (18 patients) underwent simple intramedullary nail fixation, group B (40 patients) simple tibial plate fixation, and group C (20 patients) tibial plate fixation for tibial fractures and posterior-to-anterior screw fixation for posterior malleolar fractures. The operation time, intraoperative blood loss, fracture union time, postoperative complications, as well as ankle-hindfoot scores of American Orthopaedic Foot and Ankle Society (AOFAS) and Baird-Jackson scores at pre- and post-operation were compared among the 3 groups.Results:The differences in the preoperative baseline data were not statistically significant among the 3 groups, indicating comparability ( P>0.05). All patients were followed up for (24.9±10.1) months. The fracture union time in Group A was 14.0(13.0, 14.0) weeks, significantly longer than that in groups B and C [13 (13, 14) weeks] ( P<0.05). The AOFAS ankle-hindfoot score and Baird-Jackson score at the last postoperative follow-up in all patients were better than those before surgery ( P<0.05). The AOFAS ankle-hindfoot scores at the last follow-up in groups B and C [95.5 (86.0, 96.0) points and 96.0 (89.5, 98.5) points] were significantly higher than that in group A [86.5 (78.0, 93.0) points] ( P<0.05), and the Baird-Jackson scores at the last follow-up in groups B and C [93.0 (88.8, 95.0) points and 95.0 (91.0, 98.0) points] were also significantly higher than that in group A [86.0 (78.0, 89.5) points] ( P<0.05). All the 7 cases of complications (3 ones of poor fracture union and 4 ones of anterior knee pain) were observed in group A. Conclusion:In the surgical treatment of lower 1/3 spiral fracture of the tibia combined with posterior malleolar fracture, tibial plate fixation and tibial plate + posterior-to-anterior screw fixation can achieved better therapeutic effects than intramedullary nail fixation.

OBJECTIVE: To review the biomechanical research progress of internal fixation of tibial plateau fracture in recent years and provide a reference for the selection of internal fixation in clinic. METHODS: The literature related to the biomechanical research of internal fixation of tibial plateau fracture at home and abroad was extensively reviewed, and the biomechanical characteristics of the internal fixation mode and position as well as the biomechanical characteristics of different internal fixators, such as screws, plates, and intramedullary nails were summarized and analyzed. RESULTS: Tibial plateau fracture is one of the common types of knee fractures. The conventional surgical treatment for tibial plateau fracture is open or closed reduction and internal fixation, which requires anatomical reduction and strong fixation. Anatomical reduction can restore the normal shape of the knee joint; strong fixation provides good biomechanical stability, so that the patient can have early functional exercise, restore knee mobility as early as possible, and avoid knee stiffness. Different internal fixators have their own biomechanical strengths and characteristics. The screw fixation has the advantage of being minimally invasive, but the fixation strength is limited, and it is mostly applied to Schatzker typeⅠfracture. For Schatzker Ⅰ-Ⅳ fracture, unilateral plate fixation can be used; for Schatzker Ⅴand Ⅵ fracture, bilateral plates fixation can be used to provide stronger fixation strength and avoid the stress concentration. The intramedullary nails fixation has the advantages of less trauma and less influence on the blood flow of the fracture end, but the fixation strength of the medial and lateral plateau is limited; so it is more suitable for tibial plateau fracture that involves only the metaphysis. Choosing the most appropriate internal fixation according to the patient's condition is still a major difficulty in the surgical treatment of tibial plateau fractures. CONCLUSION Each internal fixator has good fixation effect on tibial plateau fracture within the applicable range, and it is an important research direction to improve and innovate the existing internal fixator from various aspects, such as manufacturing process, material, and morphology.
Humans ; Biomechanical Phenomena ; Bone Plates ; Fracture Fixation, Internal ; Fracture Fixation, Intramedullary ; Tibial Fractures/surgery* ; Tibial Plateau Fractures

Bone Transplantation/adverse effects* ; Transplantation, Autologous/adverse effects*

From inception to development, from development to leaps, from theoretical innovation to technological progress, and from the diagnosis and treatment of orthopedic diseases to the pursuit of root causes for prevention and treatment, every step forward of orthopedics in China owes much to breakthroughs in related basic researches. Based on representative achievements in basic researches that have promoted and propelled clinical application innovations in the history of orthopedic development in China, the author summarized and elucidated the crucial role of basic research in the development of orthopedics in China. The analysis of the current issues in basic orthopedic researches in China aimed to explore the future development of orthopedics. May orthopedic colleagues continue to strive, be focused on the scientific frontier, delve deeper into basic research, and tirelessly irrigate the everlasting source of vitality for the evergreen tree of China ′s orthopedic cause!

To compare the effects of advanced bone flap and no bone flap on the healing of osteotomy gap in open-wedge high tibial osteotomy (OW-HTO) for the treatment of medial compartment osteoarthritis and knee inversion.Methods:A retrospective study was conducted to analyze the 85 patients who had undergone OW-HTO from March 2021 to December 2021 at Trauma Emergency Centre, The Third Hospital of Hebei Medical University for medial compartment osteoarthritis and knee inversion. The patients were divided into 2 groups according to whether bone flap was grafted. In group A of 42 patients who received advanced bone flap intraoperatively, there were 32 females and 10 males with an age of (63.7±6.6) years; in group B of 43 patients who received no advanced bone flap intraoperatively, there were 31 females and 12 males with an age of (63.2±9.4) years. The measures recorded and compared between the 2 groups included: osteotomy gap healing rates at 3, 6, 12, and 18 months postoperatively; Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS) for pain, and Knee injury and Osteoarthritis Outcome Score (KOOS) at 6 and 18 months postoperatively; medial proximal tibial angle (MPTA) and femorotibial angle at immediate postoperation and 18 months postoperation; postoperative complications.Results:The differences in preoperative general information between the 2 groups were not statistically significant, showing comparability ( P>0.05). The osteotomy gap healing rates at 3, 6, 12, and 18 months postoperatively in group A were significantly higher than those in group B ( P<0.05). The WOMAC (26.1±5.9), VAS (4.1±1.4), and KOOS (47.0±9.7) scores at 6 months postoperatively in group A were significantly lower than those in group B (31.3±8.3, 4.8±1.6, and 56.1±11.9) ( P<0.05), but the differences in the above indicators between the 2 groups at 18 months postoperatively were not statistically significant ( P>0.05). There was no statistically significant difference in MPTA or femorotibial angle at immediate postoperation between the 2 groups ( P>0.05). At 18 months postoperatively, the MPTA in group A (88.7°±1.1°) was significantly better than that in group B (87.7°±1.5°) ( P<0.05). The total complication rate in group B [27.9% (12/43)] was signifcantly higher than that in group A [2.4% (1/42)]( P<0.05). Conclusions:In the OW-HTO treatment of the patients with medial compartment osteoarthritis and knee inversion, application of an advanced bone flap to fill the osteotomy gap can accelerate the gap healing and reduces occurrence of delayed healing or non-healing of the osteotomy gap.

Objective:To characterize the biomechanics of distal dynamic locking and distal static locking of proximal femur bionic nails (PFBN) in fixation of intertrochanteric fractures by a finite element analysis.Methods:The CT image data from the hip to the upper tibia from an adult male volunteer were used to establish a three-dimensional model of the femur by Mimics 20.0 and Geomagic 2013 which was processed further into a model of Evans type I intertrochanteric fracture by software NX 12.0. With reference to the internal fixation parameters commonly used, 4 models of PFBN fixation were established: distal single transverse nail dynamic locking (model A), single oblique nail dynamic locking (model B), single nail static locking (model C) and double nail dynamic locking (model D). Abaqus 6.14 software was used to load and analyze the internal fixation stresses and displacements of fracture ends.Results:Under a 2100N loading, the peak stress was located upon the main nail in the 4 models. The smallest peak stress upon the main nail was in Model D (161.9 MPa), decreased by 15.9% compared with model A (192.5 MPa), by 15.6% compared with model B (191.9 MPa), and by 0.9% compared with model C (163.3 MPa). The peak stress upon the fixation screw was the largest in model A (95.3 MPa), the smallest in model B (91.5 MPa), and 91.5 MPa and 92.2 MPa in models C and D, respectively. The overall displacements of the implants, in a descending order, were 10.14 mm in model A, 10.10 mm in model B, 10.09 mm in model C, and 10.05 mm in model D. Similarly, the displacements of fracture ends were 0.125 mm in model A, 0.121 mm in model B, 0.110 mm in model C, and 0.098 mm in model D.Conclusion:Compared with dynamic locking, distal static locking of PFBN provides a better mechanical stability and reduces stress concentration upon internal fixation.

Objective:To determine the relationship between tibial plateau stresses and malunion by exploring the changes in mechanical conduction in the knee joint after malunion of Hoffa fracture of the tibial plateau.Methods:This study selected 28 knee joint specimens treated with formalin for preservation, half of which were from male and half from female individuals with an age of (51.4±9.5) years. Their structures were intact, and flexion-extension activities normal. X-ray examinations excluded osteoporosis, tuberculosis, and diseases that could have potentially affected bone quality. The knee specimens were divided into a control group (intact tibia) ( n=4) and 6 groups of tibial plateau Hoffa fracture malunion model: 3 vertical malunion groups (groups V1, V2, and V3, with a vertical displacement of 1, 2, and 3 mm, respectively, n=4) and 3 separation malunion groups (groups S3, S5, and S7, with a separation displacement of 3, 5, and 7 mm, respectively), with half males and half females in each group. After a 600N vertical load was applied at passive knee flexions at 0°, 30°, 60°, 90°, and 120°, the stress levels in the medial and lateral compartments of the knee joint were measured using pressure-sensitive films. Results:Under a vertical load of 600 N, when the knee joint was in a neutral position (flexion of 0°), the differences in the medial and lateral tibial plateau stress values were not statistically significant between the malunion models groups and the control group ( P>0.05). When the knee flexion increased to 30°, the medial tibial plateau stress in the V3 and S7 groups was significantly greater than that in the control group ( P<0.05). At a knee flexion of 60°, the medial plateau stress was significantly greater in the V3, S5 and S7 groups than that in the control group, and the differences were significantly greater than the comparisons at a knee flexion of 30° (all P<0.05). When the knee flexion was 90°, the medial plateau stress in the V2, V3, S5 and S7 groups was significantly greater than that in the control group ( P<0.05), but the lateral tibial plateau stress in the V3 group was significantly smaller than that in the control group ( P<0.05). When the knee flexion was further increased to 120°, the differences in the medial and lateral plateau stress values were statistically significant between all the malunion groups and the control group ( P<0.05), and the differences significantly greater than the comparisons at a knee flexion of 90° (all P<0.05). Under a vertical load of 600 N, the differences in the stresses on the medial and lateral plateaus were not statistically significant between the control group and all the malunion groups at a knee flexion of 0° ( P>0.05). When the knee flexion increased to 30°, the difference between the medial and lateral stresses was not statistically significant in the control group ( P>0.05), but was statistically significant in the V3 and S7 groups ( P<0.05). When the knee flexion reached 60°, 90°, and 120°, the differences between the medial and lateral tibial plateau stresses in all the groups were statistically significant ( P<0.05). Conclusions:The peak knee stresses after malunion of Hoffa fracture of the tibial plateau correlate with the severity of malunion and knee flexion angles. The mechanical properties are not significantly different between a mild malunion knee and a normal knee, but a significant displacement (vertical displacement >2 mm and separation displacement ≥5 mm) may increase the peak knee stresses to increase the risk of knee osteoarthritis. When the severity of malunion is certain, an increase in knee flexion angle increases the difference in the peak stress between the medial and lateral tibial plateaus, thus increasing the risk of knee osteoarthritis.

Surgical treatment has been established as the standard method for the treatment of intertrochanteric fractures in the elderly. The design of internal fixation devices has become the key to improve surgical outcomes and reduce postoperative complications. Centered on optimizing biomechanical performance and minimally invasive implantation, coupled with continuous material improvements, the design philosophy of internal fixation devices has also been constantly evolving. There have been several milestone advancements, such as the transition from eccentric fixation to central fixation, the adoption of sliding compression fixation, the replacement of traditional screws with spiral blades, and the shift from single to double (combination) nails. However, the incidence of internal fixation-related complications has remained at a relatively high level of 5% to 10%, without significant breakthroughs. Increasing evidence suggests that in-depth analysis of the anatomy, physiological mechanisms, and mechanical transmission characteristics of the proximal femur can help elucidate the root causes of internal fixation failures. Based on this, the proximal femoral bionic nail (PFBN) has emerged as a new design concept. By fully mimicking the anatomical, mechanical, and biological characteristics of the proximal femur, the PFBN can regulate the local mechanical environment, providing a revolutionary solution and a new approach for the treatment of proximal femoral fractures. This innovative design also has the potential to drive the paradigm shift in the treatment strategies of other fractures.