Bilateral triceps tendon approach is flexible and efficient in the treatment of type C distal humerus fractures.

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.

A novel cerclage wiring technique in intertrochanteric femoral fractures treated by intramedullary nails in young adults.

BACKGROUND: Intertrochanteric femoral fractures (IFFs) in young adults, generally due to severe trauma, are increasingly presented. Different from IFFs in the geriatric population, these fractures in young adults are always comminuted and substantially displaced. Natural traction induced by musculature following IFFs determines closed reduction on a fracture table is extremely difficult. METHODS: To achieve anatomical reduction before intramedullary nail (IMN) fixation, we made an extended or a mini petrotrochantetic incision to facilitate temporary reduction using a pointed clamp. Subsequently, a curved and cannulated wire-passer was employed to pass through a multistrand cable to surround displaced fragments and strengthen intertrochanteric fixation. Afterward, a standard procedure was conducted to nail the fracture. RESULTS: We used the surgical technique in 9 young patients with an age range of 28~ 48 years old. The fractures were categorized as AO/OTA 31-A2.2 (3 cases) and 31-A2.3 (6 cases). The injury-to-surgery interval was 2.5 days on average. Mean operation time was 55 min. All fractures achieved anatomical reduction and healed within 14 weeks postoperatively without cable breakage, implant irritation or deep infection. CONCLUSIONS: In conclusion, the surrounding technique with cerclage wire in IFFs in young adults is an effective surgical technique with easily achieved anatomical reduction to facilitate operative maneuvers and fracture healing.

[A primary study on simulation of fracture strength based on BP neural networks].

OBJECTIVE: To model the relationship between stimulating stress and fracture strength using BP neural networks, and to provide a theoretical basis for accurate prediction of the rate of fracture healing. METHODS: The bilateral tibiae in New Zealand rabbits were osteotomized and fixed by stress-relaxation plate(SRP) and rigid plate(RP), respectively. The stress shielding rate and bending strength of the healing fractures were measured at 2 to 48 weeks postoperatively. A BP neural network was constructed and trained using the experimental data of the stress-relaxation group. Then the trained network was used for simulation to predict fracture strength of the two groups from the stress at the fracture site. RESULTS: With the input of the data that has been used to train the network, fracture strength similar to those measured in experiment was calculated from the BP neural network. However, poor results were obtained with the input of new data. CONCLUSION: BP neural network can be used to investigate the influence of various factors on fracture healing quantitatively, and to predict the rate of healing. However, the model still needs to be perfected. More experimental or clinical data are needed to train the network

A first order system model of fracture healing.

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.