ABSTRACT
PURPOSE@#The purpose of this study was to assess and compare elbow range of motion, triceps extension strength and functional results of type C (AO/OTA) distal humerus fractures treated with bilateral triceps tendon (BTT) approach and olecranon osteotomy (OO). At the same time, we are also trying to know whether BTT approach can provide sufficient vision for comminuted intra-articular fractures of the distal humerus, and whether it is convenient to convert to the treatment to total elbow arthroplasty (TEA) or OO.@*METHODS@#Patients treated with OO and BTT approaches for type C distal humerus fractures between July 2014 and December 2017 were retrospectively reviewed. Inclusion criteria include: (1) patients' age were more than 18 years old, (2) follow-up was no less than 6 months, and (3) patients were diagnosed with type C fractures (based on the AO/OTA classification). Exclusion criteria include: (1) open fractures (Gustillo type 2 or type 3), (2) treated by other approaches, and (3) presented with combined injuries of ipsilateral upper extremities, such as ulnar nerve. Elbow range of motion and triceps extension strength testing were completely valuated, when the fractures had healed. Assessment of functional results using the Mayo elbow performance score and complications were conducted in final follow-up. The data were compared using the two tailed Student's t-test. All data were presented as mean ± standard deviation.@*RESULTS@#Eighty-six patients of type C distal humerus fractures, treated by OO and BTT approach were retrospectively reviewed between July 2014 and December 2017. Fifty-five distal humerus fractures (23 males and 32 females, mean age 52.7 years) treated by BTT approach or OO were included in this study. There were 10 fractures of type C1, 16 type C2 and 29 type C3 according to the AO/OTA classification. Patients were divided into two surgical approach groups chosen by the operators: BTT group (28 patients) and OO group (27 patients). And the mean follow-up time of all patients was 15.6 months (range, 6-36 months). Three cases in BTT group were converted to TEA, and one converted to OO. Only one case in BTT group presented poor articular reduction with a step more than 2 mm. There were not significantly different in functional outcomes according to the Mayo elbow performance score, operation time and extension flexion motion are values between BTT group and OO group (p > 0.05). Complications and reoperation rate were also similar in the two groups. Triceps manual muscle testing were no significant difference in the two groups, even subdivided in elder patients (aged >60 years old).@*CONCLUSION@#BTT is a safe approach to achieve similar functional result comparing with OO. BTT were not suitable for every case with severe comminuted pattern, but it avoids the potential complications related to OO, and has no complications concerning with triceps tendon. It is convenient for open reduction internal fixation and flexible to be converted to OO, as well as available to be converted to TEA in elder patients.
Subject(s)
Adolescent , Aged , Female , Humans , Infant , Male , Middle Aged , Elbow Joint/injuries , Fracture Fixation, Internal/methods , Fractures, Comminuted , Humeral Fractures/surgery , Humerus , Range of Motion, Articular , Retrospective Studies , Tendons , Treatment OutcomeABSTRACT
Objective To investigate the effects of external fixator with dynamic device under low frequency and controlled micromovement on the callus calcification and mechanical property of healing bone.MethodsForty-five sheep were performed transverse osteotomy with a gap of 2 mm on the mid-shafts of both tibias,and the hind limbs were fixed with unilateral external fixators connected to a controlled micromovement device.Ten days after osteotomy,one hind limb of each sheep was randomly selected for micromovement(30 min/d).According to different micromovement frequencies,the sheep were randomly divided into 3 groups: 0.5 Hz group,1 Hz group and 5 Hz group(n=15).The amplitude of micromovement was 0.25 mm and the micromovement stopped by the end of the fourth week postoperation.The other hind limb of each sheep was served as control group without micromovement.Morphometry of callus was done at the end of 4,6 and 9 weeks after osteotomy.Bone formation velocity,bone mineral density and biomechanical properties were compared at the end of 9 weeks.Results The areas of mineralized bone and osteoid in different miromovement groups were larger than that of control group at the end of 4,6 weeks postoperation(P
ABSTRACT
A first order system model is proposed for simulating the influence of stress stimulation on fracture strength during fracture healing. To validate the model, the diaphyses of bilateral tibiae in 70 New Zealand rabbits were osteotomized and fixed with rigid plates and stress-relaxation plates, respectively. Stress shielding rate and ultimate bending strength of the healing bone were measured at 2 to 48 weeks postoperatively. Ratios of stress stimulation and fracture strength of the healing bone to those of intact bone were taken as the system input and output. The assumed first order system model can approximate the experimental data on fracture strength from the input of stress stimulation over time, both for the rigid plate group and the stress-relaxation plate group, with different system parameters of time constant and gain. The fitting curve indicates that the effect of mechanical stimulus occurs mainly in late stages of healing. First order system can model the stress adaptation process of fracture healing. This approach presents a simple bio-mathematical model of the relationship between stress stimulation and fracture strength, and has the potential to optimize planning of functional exercises and conduct parametric studies.
Subject(s)
Animals , Rabbits , Biomechanical Phenomena , Fracture Healing , Physiology , Mathematics , Models, Animal , Models, BiologicalABSTRACT
Objective To report the therapeutic results of Hybrid external fixator in treatment of open metaphyseal fractures of the tibia.Methods From March 2000 to July 2004,19 cases of proximal tibial meta- physeal fractures and six cases of Pilon fractures were treated with Hybrid external fixators.By Gustilo classification, eight cases were of typeⅡ,10 typeⅢA,five typeⅢB and two typeⅢC.The wounds were closed directly after thorough debridement in 21 cases,and closed by pedicled flap transposition or free flap transplantation in four. Fasciotomy was performed in three.Closed indirect reduction of the fractures was done in 11 cases,while open reduction was carried out through an extended wound or a limited incision in 14.Anatomical reduction was done for the articular fractures,if any,and Hybrid external fixators were employed to stabilize fractures in all the cases in this series.Results All the patients had a mean follow-up of 15.7 months (ranging from 9 to 26 months) which re- vealed bone union of the fracture in all cases with a mean healing time of 8.8 months.Two patients had their external fixators replaced with plates and iliac bone graft to get fracture union.The fixators were removed 2.9 to 21 months (mean,9.4 months) after operation.Except for two cases of secondary healing,all the wounds healed primarily without serious complication,such as infection.The final follow-up revealed a knee motion range of more than 90?in 15 cases,less than 70?in four,whose knee motion range was improved to more than 90?after knee release performed one year later.In all the six cases of Pilon fractures,the ankle joint recovered normal range of motion.Traumatic arthritis occurred in two cases of Piion fracture 11 months after operation.Evaluation by Rasmussen's functional and radiological scoring system demonstrated excellent knee function in 13 cases,good in three,fair in two and poor in one,with a good to excellent rate of 84.2%.The ankle function was excellent in three cases,good in two and poor in one,with a good to excellent rate of 83.3%.Conclusions In treatment of open tibial metaphyseal fractures, the Hybrid external fixator can well maintain the stability of the fragments with a low incidence of soft tissue com- plications and insignificant interference with the knee motion.However the bone healing time can be prolonged with a definite rate of nonunion.