Free-gliding screw fixation in slipped capital femoral epiphysis: potentially growing im-plants for symptomatic and prophylactic pinning.

INTRODUCTION: In situ fixation is the gold standard for mild and moderate slipped capital femoral epiphysis (SCFE) cases. The condition is associated with a low percentage of avascular necrosis and chondrolysis.[1] The present study examines the postoperative femoral neck remodelling and implant elongation in cases of therapeutic and prophylactic in situ fixation using the free-gliding screw system. AIM: The aim of our study was to assess the postoperative femoral neck growth and evaluate the biomechanical evolution and complication's rate for 19 therapeutic and 11 prophylactic in situ fixations with a free-gliding screw. MATERIALS AND METHODS: We measured the preoperative and postoperative articulo-trochanteric distance (ATD), alpha angle (α angle) and screw elongation in symptomatic hips and in contralateral hips with prophylactic fixation. We compared the radiographic param-eters of 30 hips. RESULTS: ATD remains approximately the same for symptomatic cases, whereas it increases for prophylactic fixated hip. Screw elongates in both group with statistically higher value for the prophylactic group. The alpha angle remains pathological in these cases with a mean value of 67.12±4.62°, but decreases for group II. Screw elongates by a mean value of 3.14±2.74 mm for group I and 6.78±8.81 mm for group II. CONCLUSIONS: Prophylactic in situ fixation with free-gliding screws does not affect the proximal femoral growth (ATD), and does not decrease the alpha angle significantly. Screw elongates statistically in both groups, but more significantly for group II. For symptomatic hips, the in situ fixation allows the femoral neck to grow with ATD preserved, but significantly less than in group II. The alpha angle decreases but remains pathological.

Insufficient proximal medullary filling of cephalomedullary nails in intertrochanteric femur fractures predicts excessive postoperative sliding: a case-control study.

OBJECTIVE: Excessive postoperative sliding is a common complication of intramedullary nails in the treatment of intertrochanteric femur fractures. The aim of this study was to identify risk factors for excessive postoperative sliding in the intertrochanteric fractures treated with an intramedullary nail. METHODS: A retrospective analysis of 369 patients with femoral intertrochanteric fractures treated with short intramedullary nails between February 2017 and September 2020 was performed. Patients were classified into an excessive sliding group (ES group) and a control group according to the sliding distance after 6 months of follow-up. The proximal medullary filling degree (MFD), fracture reduction patterns in the anteroposterior (AP) view and lateral view, and tip-apex distance (TAD) were evaluated and compared in each group. RESULTS: Thirty-three cases were included in the ES group, and 336 cases were included in the control group. No significant differences in age, sex, fracture side, AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification, Dorr classification, Singh Osteoporosis Index (SOI), American Society of Anesthesiologists classification (ASA), TAD or fracture reduction patterns in the AP view were noted between the two groups. The negative reduction pattern can strongly predict excessive postoperative sliding (OR 4.286, 95% CI 1.637-11.216, P = 0.003). The incidence of excessive postoperative sliding increased by 8.713-fold when the MFD decreased by 10% (OR 8.713, 95% CI 1.925-39.437, P = 0.005). CONCLUSIONS: A low medullary filling degree and negative fracture reduction pattern in the lateral view were both independent risk factors for excessive postoperative sliding.

Reconstruction of a Pediatric Lateral Femoral Condyle After Septic Necrosis with a Free Vascularized Fibular Epiphysis: A Case Report.

CASE: A 5-year-old girl presented with severe valgus deformity of the right knee after septic necrosis of the lateral femoral condyle. Reconstruction was performed using the contralateral proximal fibular epiphysis on the anterior tibial vessels. Union was evident after 6 weeks, and full weight bearing was permitted after 12 weeks. Two years of follow-up showed no deformity or length discrepancy and 90° range of motion. CONCLUSION: The pattern of 1 femoral condyle resorption due to osteomyelitis is a rare presentation. The presented method of reconstruction could be implemented as a novel technique to reconstruct the growing knee joint in such a condition.

Local torsion of distal femur is a risk factor for patellar dislocation.

PURPOSE: It has been widely reported that femoral anteversion is a risk factor for patellar dislocation. This study aims to evaluate whether internal torsion of the distal femur is noticeable in patients without increased femoral anteversion and to assess whether it is a risk factor for patellar dislocation. METHODS: A retrospective analysis was conducted on 35 patients (24 females, 11 males) with recurrent patellar dislocation but without increased femoral anteversion treated in our hospital from January 2019 to August 2020. All patients underwent knee X-rays, digital radiography of lower-limbs, and CT scans of hip, knee, and ankle joints to measure femoral anteversion angle, distal femoral torsion angle, TT-TG and Caton-Deschamps index. Thirty-five control cases were matched on age and sex to compare the difference of anatomic parameters between the two groups, and the logistic analysis was used to analyze risk factors for patellar dislocation. Perman correlation coefficient was used to evaluate the correlation among femoral anteversion, distal femoral torsion and TT-TG. RESULTS: Greater distal femoral torsion was still observed in patients with patellar dislocation but without increased femoral anteversion. The torsion angle of distal femur, TT-TG distance and incidence of Patella Alta in patients with patellar dislocation were greater than those in control group, and the inter-group differences were statistically significant (P < 0.05). The torsion angle of distal femur (OR = 2.848, P < 0.001), TT-TG distance (OR = 1.163, P = 0.021) and Patella Alta (OR = 3.545, P = 0.034) were risk factors for patellar dislocation. However, no significant correlation was found among femoral anteversion, distal femoral torsion and TT-TG in patients with patellar dislocation. CONCLUSION: On the condition that femoral anteversion did not increase, increased distal femoral torsion was commonly observed in patients with patellar dislocation, which represents an independent risk factor for patellar dislocation.

Calibration procedure and biomechanical validation of an universal six degree-of-freedom robotic system for hip joint testing.

PURPOSE: Among various test methods for different human joints, the use of robot systems has attracted major interest and inherits the potential to become a gold standard in biomechanical testing in the future. A key issue associated with those robot-based platforms is the accurate definition of parameters, e.g., tool center point (TCP), length of tool or anatomical trajectories of movements. These must be precisely correlated to the physiological parameters of the examined joint and its corresponding bones. Exemplified for the human hip joint, we are creating an accurate calibration procedure for a universal testing platform by using a six degree-of-freedom (6 DOF) robot and optical tracking system for recognition of anatomical movements of the bone samples. METHODS: A six degree-of-freedom robot (TX 200, Stäubli) has been installed and configured. The physiological range of motion of the hip joint composed of a femur and a hemipelvis was recorded with an optical 3D movement and deformation analysis system (ARAMIS, GOM GmbH). The recorded measurements were processed by automatic transformation procedure (created in Delphi software) and evaluated in 3D CAD system. RESULTS: The physiological ranges of motion were reproduced for all degrees of freedom with the six degree-of-freedom robot in adequate accuracy. With the establishment of a special calibration procedure by using a combination of different coordinate systems, we were able to achieve a standard deviation of the TCP depending of the axis between 0.3 and 0.9 mm and for the length of tool between + 0.67 and - 0.40 mm (3D CAD processing) resp. + 0.72 mm to - 0.13 mm (Delphi transformation). The accuracy between the manual and robotic movement of the hip shows an average deviation between - 0.36 and + 3.44 mm for the points on the movement trajectories. CONCLUSION: A six degree-of-freedom robot is appropriate to reproduce the physiological range of motion of the hip joint. The described calibration procedure is universal and can be used for hip joint biomechanical tests allowing to apply clinically relevant forces and investigate testing stability of reconstructive osteosynthesis implant/endoprosthetic fixations, regardless of the length of the femur, size of the femoral head and acetabulum or whether the entire pelvis or only the hemipelvis will be used.

[Review of closed reduction techniques for femoral neck fracture].

For patients with femoral neck fractures who plan to undergo internal fixation, satisfied alignment of fracture ends is an important prerequisite for internal fixation stability and fracture healing. There are many reports on the reduction methods of displaced femoral neck fractures, which can be summarized into three categories:First, the solely longitudinal traction of lower limbs, supplemented by other manipulations such as rotation and compression; Second, the resultant force formed by the longitudinal traction of lower limbs and the lateral traction;the third is accomplished by vertical traction in the axis of femur with hip joint flexed. Each reduction method has its own advantages, but no single method can be applied to all fracture displacement. In this paper, some classical reduction techniques in the literatures are briefly reviewed. It is hoped that clinicians will not be limited to a certain reduction method, they should analyze the injury mechanism and fracture displacement process according to the morphology features and flexibly select targeted reduction methods to improve the success rate of closed reduction of femoral neck fracture.

[Imaging measurement and analysis of related indexes of variation of femoral head rotation center].

OBJECTIVE: To provide guidance for hip replacement by analyzing the variation of femoral head rotation center in different hip diseases. METHODS: A total of 5 459 patients were collected from March 2016 to June 2021, who took positive and proportional plain films of both hips for various reasons. The relative position between the rotation center of the femoral head and the apex of the greater trochanter was measured. The positive variation is more than 2 mm above the top of the great trochanter, and the negative variation is more than 2 mm below the top of the great trochanter. A total of 831 patients with variation of femoral head rotation center were collected and were divided into 4 groups according to different diseases, and the variation was counted respectively. There were 15 cases in the normal group involving 10 cases of positive variation and 5 cases of negative variation. There were 145 cases of avascular necrosis of femoral head involving 25 cases of positive variation and 120 cases of negative variation. There were 346 cases of congenital hip dysplasia involving 225 cases of positive variation(including 25 cases of typeⅠ, 70 cases of type Ⅱ, 115 cases of type Ⅲ and 15 cases of type Ⅳ), and 121 cases of negative variation(including 50 cases of crowe typeⅠ, 60 cases of typeⅡ, 10 cases of type Ⅲ and 1 case of type Ⅳ). There were 325 cases of hip osteoarthritis group involving 45 cases of positive variation and 280 cases of negative variation. RESULTS: There was significant difference in variation of femoral head rotation center among the four groups(P<0.05). There was significant difference in variation of femoral head rotation center among different types of congenital hip dysplasia(P<0.05). There were significant differences in cervical trunk angle and eccentricity among different variations of femoral head rotation center(P<0.05). CONCLUSION: The variation of femoral head rotation center is related to cervical trunk angle and eccentricity. The variation of femoral head rotation center is an important factor in hip diseases. The variation of femoral head rotation center is different in different hip diseases. Avascular necrosis of the femoral head and osteoarthritis of the hip were mostly negative variations. With the aggravation of congenital hip dysplasia, the variation of femoral head rotation center gradually changed from negative variation to positive variation.The variation of femoral head rotation center should be paid attention to in the preoperative planning of hip arthroplasty. It is of great significance to select the appropriate prosthesis and place the prosthesis accurately.

Three-Dimensional Preoperative Virtual Planning in Derotational Proximal Femoral Osteotomy.

Anterior knee pain (AKP) is a common pathology among adolescents and adults. Increased femoral anteversion (FAV) has many clinical manifestations, including AKP. There is growing evidence that increased FAV plays a major role in the genesis of AKP. Furthermore, this same evidence suggests that derotational femoral osteotomy is beneficial for these patients, as good clinical results have been reported. However, this type of surgery is not widely used among orthopedic surgeons. The first step in attracting orthopedic surgeons to the field of rotational osteotomy is to give them a methodology that simplifies preoperative surgical planning and allows for the previsualization of the results of surgical interventions on computers. To that end, our working group uses 3D technology. The imaging dataset used for surgical planning is based on a CT scan of the patient. This 3D method is open access (OA), meaning it is accessible to any orthopedic surgeon at no economic cost. Furthermore, it not only allows for the quantification of femoral torsion but also for carrying out virtual surgical planning. Interestingly, this 3D technology shows that the magnitude of the intertrochanteric rotational femoral osteotomy does not present a 1:1 relationship with the correction of the deformity. Additionally, this technology allows for the adjustment of the osteotomy so that the relationship between the magnitude of the osteotomy and the correction of the deformity is 1:1. This paper outlines this 3D protocol.

Combined reconstruction of medial collateral ligament and posterior cruciate ligament using one femoral tunnel: a technical note and case report applicable to limited-resource settings.

Knee dislocations are severe injuries difficult to treat. Specially in low-resources scenarios, reconstruction of multiple ligaments can be challenging. We describe a technical note that can be reconstruct multi ligaments using ipsilateral hamstrings autograft. A posteromedial knee incision is made to visualise the medial corner of the knee and to reconstruct medial collateral ligament (MCL) and posterior cruciate ligament (PCL) with semitendinosus and gracilis tendon graft, using one femoral tunnel from the anatomic femoral insertion of the MCL to the anatomic femoral insertion of the PCL. After 1-year follow-up, the patient returned to his previous function with a Lysholm score of 86. This technique can reconstruct more than one ligament anatomically with limited graft resource.

A New Procedure for Reconstructing the Knee Extension Mechanism After Resection of the Knee Joint and Patella: A Case Report.

CASE: We reconstructed the knee extension mechanism using a novel procedure for a 16-year-old adolescent girl with osteosarcoma that invaded her femur, patella, and patellar tendon. The knee joint was replaced with a megaprosthesis, and the extension mechanism was reconstructed using artificial ligaments sandwiched with bone cement forming a patella. At the one-year follow-up, she could walk using a knee orthosis without crutches. CONCLUSIONS: Reconstruction of the knee extension mechanism after patellectomy remains challenging. Our new method achieved an acceptable knee function and is, therefore, useful for patients undergoing excision of the knee joint and extension mechanism.

Simple Arthroscopic Technique to Perform Retrograde Drilling for Osteonecrosis of the Femoral Condyles with the Use of Anterior Cruciate Ligament Guide.

This technical note describes a simple arthroscopic technique that was introduced without the need for further staff during an operation to address osteonecrosis of the medial femoral condyle. A 2.4 mm pin was positioned through the sleeve of an anterior cruciate ligament (ACL) tibial guide and marked with a steri-strip at its body, aiming at 5-10 mm distance between the tips of guide and the pin. The steri-strip serves as a marker and as a stop for inadvertent violation of the cartilage. The tip of the ACL was positioned just over the bone lesion, while the marked 2.4 mm pin was inserted through the ACL tibial guide from anterior surface of the femur. A stab incision was made and without advancing the sleeve to the bone, the pin was drilled to the marked position while cartilage integrity was confirmed arthroscopically. This arthroscopic technique is simple, fast and effective and is performed without the need for special equipment.

The effectiveness of fixation of hydroxyapatite-coated helical blade in preventing of the cut-out observed in treatment with proximal femoral nail of fractures of the femur intertrochanteric in elderly.

BACKGROUND: This study aimed to retrospectively evaluate the effectiveness of hydroxyapatite-coated (HA-coated) implants and other caput-collum implants in preventing cut-out observed in treatment with proximal femoral nail (PFN) of intertrochanteric femur fractures in elderly patients. METHODS: A total of 98 consecutive patients (56 males and 42 females; mean age: 79.42 (61-115) years) treated with three differ-ent PFNs for intertrochanteric femoral fractures were retrospectively examined. The mean of the follow-up period was 7.87 (4-48) months. It was used a threaded lag screw in 40 patients, an HA-coated helical blade in 28 patients and a non-coated helical blade in 30 patients for PFN. The reduction quality, fracture type, and radiological outcomes among all groups were evaluated. RESULTS: Unstable type was seen in 50 (52.1%) patients according to AO Foundation/Orthopedic Trauma Association fracture classi-fication. An acceptable-good reduction quality was seen in 87 (88.8%) of all patients. The average of tip-apex distance (TAD) value was 27.61 mm, calcar-referenced TAD (CalTAD) value was 28.72 mm, caput-collum diaphyseal angle was 128,° Parker's anteroposterior ratio was 46.36%, and Parker's lateral ratio was 46.82%. The best suitable implant position was observed in 49 (50%) patients. Cut-out was observed in 7 (7.14%) patients, and secondary varus displacement of more than 10° was observed in 12 (12.24%) patients. Correlation analysis and multivariate logistic regression analysis showed a significant difference between HA-coated and other implants in cut-out. Furthermore, implant type was the strongest predictive factor for cut-out complications in the multivariate logistic regression analysis. CONCLUSION: HA-coated implants may reduce the long-term cut-out risk due to increased osteointegration and bone ingrowth in elderly patients with intertrochanteric femoral fractures with poor bone quality. However, this alone is not enough; a suitable screw position, optimal TAD values, and excellent reduction quality are other important factors.

Predicting soft tissue thicknesses overlying the iliac crests and greater trochanters of younger and older adults.

Soft tissues overlying the hip play a critical role in protecting against fractures during fall-related hip impacts. Consequently, the development of an efficient and cost-effective method for estimating hip soft tissue thicknesses in living people may prove to be valuable for assessing an individual's injury risk and need to adopt preventative measures. The present study used multiple linear stepwise regression to generate prediction equations from participant characteristics (i.e., height, sex) and anthropometric measurements of the pelvis, trunk, and thigh to estimate soft tissue thickness at the iliac crests (IC) and greater trochanters (GT) in younger (16-35 years of age: 37 males, 37 females) and older (36-65 years of age: 38 males, 38 females) adults. Equations were validated against soft tissue thicknesses measured from full body Dual-energy X-ray Absorptiometry scans of independent samples (younger: 13 males, 13 females; older: 13 males, 12 females). Younger adult prediction equations exhibited adjusted R2 values ranging from 0.704 to 0.791, with more explained variance for soft tissue thicknesses at the GT than the IC; corresponding values for the older adult equations were higher overall and ranged from 0.819 to 0.852. Predicted and actual soft tissue thicknesses were significantly correlated for both the younger (R2 = 0.466 to 0.738) and older (R2 = 0.842 to 0.848) adults, averaging ≤ 0.75cm of error. This research demonstrates that soft tissue thicknesses overlying the GT and IC can be accurately predicted from equations using anthropometric measurements. These equations can be used by clinicians to identify individuals at higher risk of hip fractures who may benefit from the use of preventative measures.

Continuous improvement in optimizing the timing of axial, hip, and femoral fracture fixation.

Benefits of early stabilization of femoral shaft fractures, in mitigation of pulmonary and other complications, have been recognized over the past decades. Investigation into the appropriate level of resuscitation, and other measures of readiness for definitive fixation, versus a damage control strategy have been ongoing. These principles are now being applied to fractures of the thoracolumbar spine, pelvis, and acetabulum. Systems of trauma care are evolving to encompass attention to expeditious and safe management of not only multiply injured patients with these major fractures, but also definitive care for hip and periprosthetic fractures, which pose a similar burden of patient recumbency until stabilized. Future directions regarding refinement of patient resuscitation, assessment, and treatment are anticipated, as is the potential for data sharing and registries in enhancing trauma system functionality.

The treatment of a femoral shaft fracture in patients with a previous post-traumatic femoral deformity using a Clamshell osteotomy.

The aim of this study was to assess the safety and clinical outcome of patients with a femoral shaft fracture and a previous complex post-traumatic femoral malunion who were treated with a clamshell osteotomy and fixation with an intramedullary nail (IMN). The study involved a retrospective analysis of 23 patients. All had a previous, operatively managed, femoral shaft fracture with malunion due to hardware failure. They were treated with a clamshell osteotomy between May 2015 and March 2020. The mean age was 42.6 years (26 to 62) and 15 (65.2%) were male. The mean follow-up was 2.3 years (1 to 5). Details from their medical records were analyzed. Clinical outcomes were assessed using the quality of correction of the deformity, functional recovery, the healing time of the fracture, and complications. The mean length of time between the initial injury and surgery was 4.5 years (3 to 10). The mean operating time was 2.8 hours (2.05 to 4.4)), and the mean blood loss was 850 ml (650 to 1,020). Complications occurred in five patients (21.7%): two with wound necrosis, and three with deep vein thrombosis. The mean coronal deformity was significantly corrected from 17.78° (SD 4.62°) preoperatively to 1.35° (SD 1.72°) postoperatively (p < 0.001), and the mean sagittal deformity was significantly corrected from 20.65° (SD 5.88°) preoperatively to 1.61° (SD 1.95°; p < 0.001) postoperatively. The mean leg length discrepancy was significantly corrected from 3.57 cm (SD 1.27) preoperatively to 1.13 cm (SD 0.76) postoperatively (p < 0.001). All fractures healed at a mean of seven months (4 to 12) postoperatively. The mean Lower Extremity Functional Scale score improved significantly from 45.4 (SD 9.1) preoperatively to 66.2 (SD 5.5) postoperatively (p < 0.001). Partial cortical nonunion in the deformed segment occurred in eight patients (34.8%) and healed at a mean of 2.4 years (2 to 3) postoperatively. A clamshell osteotomy combined with IMN fixation in the treatment of patients with a femoral shaft fracture and a previous post-traumatic femoral malunion achieved excellent outcomes. Partial cortical nonunions in the deformed segment also healed satisfactorily.

Operative Traction Technique for an Intertrochanteric Femur Fracture in a Patient with Transfemoral Amputation: A Case Report.

CASE: A 53-year-old woman with a history of transfemoral amputation presented to the emergency department with an ipsilateral intertrochanteric femur fracture. Standard fracture tables that use a boot to pull traction are not helpful in these cases, which makes achieving adequate traction for reduction difficult. CONCLUSION: We describe a unique technique to manipulate an amputated extremity using 2 Schanz pins attached to a weight through a traction rope. This practical technique provided adequate skeletal traction for reduction and internal fixation in our case and can be performed on a standard radiolucent table without the need for special table attachments.

Effect of demographic features on morphometric variables of the knee joint: Sample of a 20 to 40-year-old Turkish population.

This study aimed to investigate the relationship between body mass index (BMI), age, and sex and morphological risk factors that may cause internal knee injuries. The magnetic resonance images of 728 participants who met the inclusion criteria and had a mean age of 34.4 ±â€…6.8 years were analyzed retrospectively. Demographic differences were analyzed by measuring 17 morphological parameters known to be associated with internal knee injuries. Men had a higher anterior cruciate ligament length (ACLL), anterior cruciate ligament width, (ACLW) lateral femoral condylar width (LFCW), medial femoral condylar width (MFCW), lateral femoral condylar depth (LFCD), distal femoral width (DFW), and intercondylar femoral width (IFW) than women (P < .05). By contrast, the medial meniscus bone angle (MMBA) was lower in men than in women (P < .05). Women aged 31 to 40 years had a lower Insall-Salvati index (ISI) and lateral tibial posterior slope (LTPS) than those aged 21 to 30 years (P < .05), whereas men aged 31 to 40 years had a lower ISI than those aged 21 to 30 years (P < .05). Women with BMI ≥ 30 had a higher LFCW and MFCW but a lower ISI than those with BMI < 30 (P < .05). Men with BMI ≥ 30 had a higher LFCW, MFCW, DFW, and MMBA than those with BMI < 30 (P < .05). The use of value ranges structured according to demographic characteristics, rather than a single value range for all patient groups, may contribute to the evaluation and treatment of the morphological features that are thought to be effective in the development of internal knee injuries. These values may also shed light on future radiological risk scoring systems and artificial intelligence applications in medicine.

Single intraoperative infrared laser optimized bone repair in rat femoral osteotomies with experimentally induced osteoporosis.

This study aimed to evaluate the effect of infrared laser (IRL) on bone repair in ovariectomized rats subjected to femoral osteotomies. Of 32 rats, half underwent bilateral ovariectomy (OVX) and the other half underwent sham ovariectomy (SHAM). A period of 3 months was defined to observe the presence of osteoporosis. The rats were subjected to osteotomies in the femurs and then fixed with a miniplate and 1.5-mm system screws. Thereafter, half of the rats from both SHAM and OVX groups were not irradiated, and the other half were irradiated by IRL using the following parameters: wavelength, 808 nm; power, 100 mW; 60 s for each point; 6 J/point; and a total of 5 points of bone gap. All animals were euthanized 60 days after surgery. The femur gap was scanned using micro-computed tomography (micro-CT). The samples were then examined under a confocal laser microscope to determine the amounts of calcein and alizarin red. The slides were stained with alizarin red and Stevenel's blue for histometric analysis. In the micro-CT analysis, the OVX groups had the lowest bone volume (P < 0.05). When the laser was applied to the OVX groups, bone turnover increased (P < 0.05). New bone formation (NBF) was comparable between SHAM and OVX/IR (P > 0.05) groups; however, it was less in the OVX groups (P < 0.05). In conclusion, the results encourage the use of IRL intraoperatively as it optimizes bone repair, mainly in animals with low bone mineral density.

Single-Stage Total Knee Arthroplasty and Open-Wedge Distal Femoral Osteotomy for Osteoarthritis with Femoral Shortening and Extra-Articular Varus Deformity: A Case Report.

CASE: A 76-year-old female patient with a history of pyogenic arthritis of the right knee in childhood presented with severe osteoarthritis of the right knee with 24-mm femoral shortening and severe extra-articular femoral varus deformity. She received single-stage total knee arthroplasty (TKA) combined with a medial open-wedge distal femoral osteotomy and achieved good postoperative clinical and radiological results. CONCLUSION: This case illustrated that extra-articular open-wedge distal femoral osteotomy and TKA performed simultaneously may be efficacious for severe extra-articular deformities with femoral shortening.

Daytime administration of melatonin has better protective effects on bone loss in ovariectomized rats.

OBJECTIVE: To explore the difference in the protective effects of intraperitoneal injection of exogenous melatonin of daytime or nighttime on bone loss in ovariectomized (OVX) rats. METHODS: After bilateral ovariectomy and sham surgery, 40 rats were randomly divided into four groups: sham operation group (Sham), ovariectomy (OVX), and daytime melatonin injection group (OVX + DMLT, 9:00, 30 mg/kg/d) and nighttime injection of melatonin (OVX + NMLT, 22:00, 30 mg/kg/d). After 12 weeks of treatment, the rats were sacrificed. The distal femur, blood and femoral marrow cavity contents were saved. The rest of the samples were tested by Micro-CT, histology, biomechanics and molecular biology. Blood was used for bone metabolism marker measurements. CCK-8, ROS, and Cell apoptosis are performed using MC3E3-T1 cells. RESULTS: Compared with treatment at night, the bone mass of the OVX rats was significantly increased after the daytime administration. All microscopic parameters of trabecular bone increased, only Tb.Sp decreased. Histologically, the bone microarchitecture of the OVX + DMLT was also more dense than the bone microarchitecture of the OVX + LMLT. In the biomechanical experiment, the femur samples of the day treatment group were able to withstand greater loads and deformation. In molecular biology experiments, bone formation-related molecules increased, while bone resorption-related molecules decreased. After treatment with melatonin administration at night, the expression of MT-1ß was significantly decreased. In cell experiments, the MC3E3-T1 cells treated with low-dose MLT had higher cell viability and greater efficiency in inhibiting ROS production than the MC3E3-T1 cells treated with high-dose MLT, which in turn more effectively inhibited apoptosis. CONCLUSION: Daytime administration of melatonin acquires better protective effects on bone loss than night in OVX rats.