I am sort of excited about this post, but there is... a lot to unpack. For the sake of brevity I will try to give you a "path" for your character to follow. This is by no means exhaustive look at crush injuries, but rather a plausible scenario. I will mark timing with 
and "expect your character to" with 
for easy reference. Keeping in mind you are squeamish, I kept all photo links very mild and hopefully shouldn't cause you any discomfort. So without further ado: Crush Injury
Treatment of crush injuries will depend upon resources available at a hospital. When we are looking at crush injuries caused by earthquakes, hundreds of people may be effected, putting strain on the local hospitals resources. I will side step this issue for the most part and tell you the "ideal" treatment, but when writing your story consider how the hospital, nurses, and doctors may be affected by a mass casualty event. What is the atmosphere like in the hospital? Tense, crowded, rushed?
Where resources are severely limited, limb amputation may be performed more frequently as amputating a limb takes WAY LESS resources and time than what I am about to describe. I am going to assume you want to save the leg, so here we go:
Surgery for crush injuries includes six parts, four of which are performed during the first surgery ideally within six hours of extraction of limb from rubble. 1) Infection Control: antibiotics are given through an intravenous catheter (IV). Expect your character to be on IV antibiotics in the hospital for at least two weeks. The wound is then debrided of dirt, rubble, and necrotic (dead) tissue and irrigated with sterile water. 2) Prophylactic Fasciotomy: This is a procedure in which the skin, connective tissue, and muscle is sliced open with two incisions on the inner and outer lower leg. This is done in order to prevent the development of compartment syndrome which is when swelling within the limb puts pressure on the blood vessels and causes necrosis (death) of tissues. After surgery, expect your patient to have these open wounds which would be covered with a suction device called a wound vac. I don't know how squeamish you are exactly, but I personally don't think this image is too disturbing and gives you a good idea of what this device looks like. 3) Fracture management: broken bones will be stabilized with rods and pins. External fixation devices are the most common for crushing injuries: meaning the leg is immobilized with metal pins sticking through the skin as seen here. These devices can be removed without surgery after 6 weeks. 4) Revascularization: a specialized vascular surgeon (not the ER surgeon or orthopedic surgeon) will take a segment of the great saphenous vein from the uninjured leg to make an arterial graft for the affected leg in order to restore blood flow to the area. Expect a 5 cm incision closed with staples on the character's inner shin of the unaffected limb which would have been used to extract the vein. Stables can be removed after 2 weeks. 5) Fasciotomy closure: Two weeks after injury, after swelling has gone down, the fasciotomy can be closed. A skin graft is taken from the thigh of the uninjured leg and used to close the wound. A wound vac is used to "suction" the wound closed and is removed after another two weeks. 6) Nerve repair: During the initial surgery, damage to the nerves will be noted and marked for later repair. A specialized neurosurgeon will perform nerve repair three to four weeks after injury. Expect an incision closed with thin sutures along the back of the knee extending to the outer knee.
Wound care: Nonsurgical wounds will be covered with moist dressings which are "packed" into the crevices and valleys of the wound. Gauze is used to wrap the entire leg and keep dressings in place. Wounds are healed by secondary intention meaning from the bottom and outside to upwards and inwards. First granulation tissue (red, grainy tissue) fills in the open wound and builds up. It can take up to ten weeks for new skin (dermis) to begin to form. Dressings should be changed every twelve hours or more frequently if the wound is actively oozing/draining.
Ok, that concludes everything you should know about surgery and the wound itself. Now let's talk about the FUN STUFF! Everything else. 
I will now break down four common complications of crush injuries which are collectively aptly called crush syndrome and would most definitely affect your character.
Hyperkalemia: When muscle is damaged, cells rupture and release their contents into the blood stream. The first and most concerning molecule released into the blood stream is the electrolyte potassium. High potassium in the blood stream is called hyperkalemia. Large, rapid influxes of potassium can actually stop the heart (we use it during open heart surgery to stop the heart from beating with literally a spray bottle filled with the stuff). When a limb is trapped and all the blood vessels in that limb are compressed, all that potassium sits inside of the trapped limbs. But when you release that pressure, suddenly all that potassium rushes back straight into the heart. Hyperkalemia after crushing injuries can cause death within ten minutes due to cardiac arrest and is the primary reason we might choose to amputate the limb inside the field rather than free the limb (keeping all the potassium trapped inside the crushed portion), particularly in mass causality events such as an earthquake where resources are limited. However, we can also give massive amounts of fluids (2+ liters) through an IV to prevent cardiac arrest. Over the course of the next 48 hours hyperkalemia will be managed in the hospital to prevent irregular heart beats. Nurses administer insulin with dextrose (sugar) and calcium in order to push potassium into the cells and out of the blood stream. Expect these medications to be administered to your character for at least two days along with their antibiotics through an IV pump. If hyperkalemia is severe enough, the patient will be placed on hemodialysis to clear the potassium from the blood, which I will explain in the next section.
Rhabdomyolysis: This occurs when protein from damaged muscles is released into the blood stream. (Fun fact, you can actually get rhabdomyolysis from drinking too many protein shakes so be careful!) Large protein molecules cannot be removed from the blood by the kidneys and can actually get trapped inside the small blood vessels of the kidneys, causing acute kidney injury. When this occurs we put patients on hemodialysis, which is basically an external system which pulls blood from the body, filters it, and then returns it to the body. The machine looks like this and you can expect your character to be on this for at least three days while the kidney heals. Hemodialysis requires a specially trained ICU nurse to manage and we are in the room at least once an hour changing fluid bags and measuring input and output of fluids from the patient’s body. Blood is drawn from an IV at least every four hours to monitor electrolytes, kidney function, and other fun stuff I won't get into.
Sepsis is an infection of the blood and is commonly caused by large, open wounds. We give antibiotics to try to prevent this from occurring and to treat it, but it is still very common. The most dangerous symptom of sepsis is hypotension (low blood pressure). Expect your character to be on at least two medications (levophed and vasopressin) to increase their blood pressure for at least 3-7 days. These medications are given through a special, very large IV inserted into the neck as seen here. Sepsis also causes water from the blood to leak into the surrounding tissues. This is a big problem when the water leaks into the lungs in a condition known as flash pulmonary edema which leads to:
Acute respiratory distress syndrome: FINALLY I am ready to talk about "waking up" after surgery! Sort of. 
During surgery your character will be intubated which is when a breathing tube is inserted through the mouth into the trachea and a machine called a ventilator breathes for them. With minor surgeries, the tube is immediately removed. This will not be the case with your character, because they will have respiratory complications (fluid in the lungs) related to crush syndrome. Expect your character to be intubated after they are out of surgery as seen here for at least three days, but actually more like a week or more. Expect your character to be in a medically induced coma for most of that time with at least 1-2 sedative medications on board (my favorite is propofol; it's the one that is white colored and Michael Jackson overdosed on). During this time your character will have a urinary catheter draining their urine and a feeding tube giving them liquid food.
Waking up and Extubation: Coming out of sedation and off the ventilator is a process! We slowly wean the patient off the ventilator by decreasing the amount of oxygen or "support" the patient is receiving (basically how much work the ventilator is doing compared to the patient's own breathing effort). At the same time we wean them off sedation. People who are intubated and confused may try to rip the tube out of their mouth as they are coming off sedatives, so we restrain them with soft wrist restraints. This can be distressing and disorientating when your character first wakes up. Expect gagging on the tube, biting, and a bit of trashing. Expect the nurse to frequently remind your character that they are in the hospital, that they are being treated for an injury to their foot, and that they have a tube in their mouth that is breathing for them. The nurse will also encourage friends and family members to talk with the patient to reassure them and calm them down. During this time, your character may attempt to communicate by mouthing words, using their phone, or writing on a sheet of paper (although their hand is usually shaky and the hand writing can be atrocious). Most nurses can identify simple words around the breathing tube such as, "bathroom", "water", "pain", "cold", or "insert-family-member-name-here". (Note, if they ask for water, we can moisten their mouth with a wet sponge). It is normal to increase sedation if the patient is anxious to put them back to sleep and then try to decrease it again the next day. Expect the nurse to turn off sedation completely for about 2-3 hours everyday for three days while the respiratory therapist turns off all support from the ventilator to see if the patient "flies". Once the patient is able to breath on their own with sedation completely off, the respiratory therapist will remove the tube (extubate the patient) and put the patient on supplemental oxygen, usually with a nasal cannula. Expect your character to not have a voice for about 2-3 hours and then a horse for another day. Most young, healthy patients are completely "there" mentally by the time the tube is removed and they are very happy when it is finally taken out. At this time the feeding tube and urinary catheter can be removed. Expect your character to complain about being thirsty and for the nurses to give them ice chips first and then slow sips of water. Food is reintroduced slowly with liquids (juices and jello) first and then soft foods the next day and finally regular food on the third day.
Long Term Recovery: As soon as a patient is off the ventilator ( day three to seven), physical therapy begins working with the patient in the hospital. They will focus on upper body strength and movement of the unaffected limb. Remember the affected leg must be immobilized with no weight on it for six weeks. Expect your character to be discharged from the hospital (assuming their is literally ZERO complications) about a month after initial injury (about one week after nerve repair surgery). All wound vacs will be removed at this time and your character will be instructed on how to clean and dress their own wounds (with water only, wet to dry dressing as described above). They will continue to go to physical therapy 2-3 times per week at a outpatient treatment center. About two weeks after injury your character can have his external fixator device removed and the physical therapist will begin working on rebuilding leg strength. Ten weeks after the injury, expect new skin growth and scar formation. The patient can now clean all wounds (surgical and traumatic) with mild soap and should continue watching for signs of infection. Three to four months after injury (after 6-12 weeks of physical therapy) expect your character to have close to full use of his leg with lingering pain, numbness, scars, and possible weakness.
Thanks for bearing with me through ALL THAT!!! I'm sure it was WAY MORE than you thought or wanted. Yeah, crush injuries are complicated and take a long time to recover from! Happy writing! 
