First and foremost, I hope that your son is doing better.
Time frame-I hope that you meant to say 2017 and not 2010, as that's a long time to try and make a claim about an incident happening in terms of manufacturing, since manufacturing processes are changing all of the time
Run down the saftety rules for the product and make sure that your son did not violate them. The toy should not be used near water, should be used on flat surfaces instead of uneven ones, should not be used on hills or inclines, should not be used near stairs, should not be used indoors, and your child should wear shoes at all times while riding the vehicle
As for the age of your child, this particular vehicle is recommended for ages 3-7, so your son was in the appropriate age group to use this toy. You should also confirm that the weight limit for the vehicle was not exceeded (130 pounds) and that no more than 2 riders were riding the vehicle at the same time at the time of the incident
Next, you should confirm that the toy has not been recalled by visiting the Mattel recall page available online at: http://service.mattel.com/us/recall.aspx
Your next step can be any number of things, but I recommend you do all of these things in this order:
Contact the company - start by composing an e-mail to Fisher Price stating the incident occurred, the time and date when the incident occurred, the way the incident occurred, and the result of the incident including your sons injuries and the cost that you endured as a result of the injuries. I always recommend that your first contact be via e-mail so it's not a case of he said/she said and there is documented evidence of what the company was aware of. State that you would like to discuss the issue at length with a representative for the company and that you are looking to seek compensation for the medical bills that you incurred.
You can find a form to e-mail the company at the Mattel website at: http://service.mattel.com/us/ContactUs.aspx
which is the branch of customer service that the Power Wheels fall under. Make sure to include the amount of money that you are out as a result of the incident, your full name and address, an e-mail address where you can be reached, and a telephone number where you can be reached in the e-mail. Be prepared to provide medical bills and reports if they are asked for by the manufacturer.
Once the e-mail has been sent, comes the hard part, waiting for them to answer. If you have not heard back from anyone at the company in 10 days, then you should call the customer service line for Power Wheels at 1-800-348-0751
While you are waiting to hear back from the company, there are a couple of other things that you can do in the meantime.
Contact W.A.T.C.H. (World Against Toys Causing Harm) about the incident that occurred and the injuries that your son obtained as a result of riding the vehicle. They can be contacted on their website at: https://toysafety.org/contact-us/
or via phone at: 1-877-55-WATCH
Report the incident to the Consumer Product Safety Commission, the government agency that handles product complaints. You can file an incident report with them by visiting their website: https://www.saferproducts.gov/CPSRMSPublic/Incidents/ReportIncident.aspx
Report the incident to Consumer Reports. When you contact them make sure that you include your name, e-mail address, mailing address, telephone number, the age of your child, the name and model number of the toy involved in the incident, how old the toy was at the time of the incident, where the toy was purchased, and what caused the incident. You can contact them by visiting their website at: https://ec.consumerreports.org/ec/customerservice/customer-service.htm
After you've contacted the agencies mentioned above, there are some things that you can do to make sure that other parents are aware of the incident. If you visit parenting blogs where Power Wheels are mentioned, you can comment about your incident in the comments. If you are a blogger, an article about the incident can go a long way to get the company's attention.
You can contact the company through social media using Twitter and/or Facebook. State that you have a serious safety concern about one of their products and you would like a representative to get in touch with you.
If you still haven't heard back from the manufacturer, you can try sending a certified letter directly to their headquarters to make sure that they receive your complaint.
Visit the Fisher Price website and write a product review about the vehicle, stating the injuries that occurred. You can also write a review at the store where you purchased the item and on Amazon which allows you to review products that you have not purchased on their site.
Good luck to you!