WEBVTT - How Do Broken Bones Heal? 0:00:01.920 --> 0:00:04.720 Welcome to brain Stuff, a production of I Heart Radio. 0:00:06.240 --> 0:00:10.400 Hey brain Stuff, Lauren Bogle bomb here. If you experience 0:00:10.480 --> 0:00:13.160 engine trouble, you take your car to or mechanic. If 0:00:13.240 --> 0:00:16.079 your pipes leak, you call a plumber. And if you 0:00:16.120 --> 0:00:19.000 fracture a leg, the usual course of action is to 0:00:19.160 --> 0:00:23.400 visit a doctor. But unlike other things that may break 0:00:23.440 --> 0:00:26.760 in life, bones begin healing on their own before you 0:00:26.920 --> 0:00:31.160 even set foot in a waiting room. Doctors often play 0:00:31.200 --> 0:00:35.160 a vital, sometimes life saving roll in a bones healing process, 0:00:35.800 --> 0:00:40.720 but these experts basically help the body heal itself. Doctors 0:00:40.720 --> 0:00:44.280 provide optimal conditions for bone repair and healing to take place. 0:00:44.760 --> 0:00:48.120 The rest is up to your cells. Sometimes broken bones 0:00:48.159 --> 0:00:50.760 can heal so thoroughly within a few months that even 0:00:50.760 --> 0:00:55.639 an X ray can't determine the original fracture line. So 0:00:55.840 --> 0:00:59.280 how does this amazing biological process work? How can a 0:00:59.360 --> 0:01:03.000 fractured live m grow back to its former strength. Let's 0:01:03.040 --> 0:01:05.319 first take a closer look at just what bones are 0:01:05.319 --> 0:01:10.080 made of and how alive they really are. It's easy 0:01:10.120 --> 0:01:13.319 to think of your bones as solid, lifeless matter upon 0:01:13.360 --> 0:01:16.920 which all of our living tissue just sits. But your 0:01:16.959 --> 0:01:19.160 skeleton is as much a living part of your being 0:01:19.280 --> 0:01:22.920 as your softer tissues and organs. The body stores minerals 0:01:22.920 --> 0:01:26.400 in the hard compact bone itself, and inside the center 0:01:26.400 --> 0:01:28.600 of the bone, the body produces red blood cells and 0:01:28.640 --> 0:01:31.480 the red marrow, and stores fat and the yellow marrow. 0:01:32.959 --> 0:01:36.360 It's important to remember that your bones are constantly changing. 0:01:36.880 --> 0:01:40.960 Cells called osteoclasts break down old bone so that osteo 0:01:41.040 --> 0:01:44.560 blasts can replace it with new bone tissue, a process 0:01:44.600 --> 0:01:49.080 called bone remodeling. Another type of cell called the chondrablast 0:01:49.200 --> 0:01:53.080 forms new cartilage. These are three of the primary cells 0:01:53.120 --> 0:01:56.600 responsible for bone growth, and not just the bone growth 0:01:56.640 --> 0:02:01.560 you experience early in life. This constant bone remodeling gradually 0:02:01.600 --> 0:02:04.440 replaces old bone tissue with new tissue over the course 0:02:04.440 --> 0:02:09.040 of months. But what happens when a bone breaks? Almost 0:02:09.040 --> 0:02:11.880 immediately after the break, the body begins to try and 0:02:11.919 --> 0:02:15.400 put itself back together again, and doctors often divide the 0:02:15.440 --> 0:02:21.359 overall process into four phases. First, there's a fracture hematoma. 0:02:21.639 --> 0:02:24.560 When a bone breaks, the fissure also severs the blood 0:02:24.600 --> 0:02:27.640 vessels running down the length of the bone, and blood 0:02:27.760 --> 0:02:30.400 leaks out of these veins and quickly forms a clot. 0:02:30.800 --> 0:02:35.200 That's the fracture hematoma. This helps to stabilize the bone 0:02:35.240 --> 0:02:38.960 and keep both pieces lined up for mending. The clot 0:02:39.040 --> 0:02:41.440 also cuts off the flow of blood to the jagged 0:02:41.520 --> 0:02:45.960 bone edges. Without fresh blood, these bone cells quickly die. 0:02:46.400 --> 0:02:49.560 Swelling and inflammation follow due to the work of cells 0:02:49.600 --> 0:02:53.919 removing dead and damaged tissue. Tiny blood vessels grow into 0:02:53.919 --> 0:02:59.320 the fracture hematoma to fuel the healing process. After several days, 0:02:59.320 --> 0:03:02.919 the fracture he toma develops tougher tissue, transforming it into 0:03:02.960 --> 0:03:07.440 a soft callous. The cells, called fiber blasts begin producing 0:03:07.520 --> 0:03:10.800 fibers of collagen, which is the tough protein that mostly 0:03:10.840 --> 0:03:15.040 makes up bone and connective tissue. The condrablasts then begin 0:03:15.120 --> 0:03:18.600 to produce a type of cartilage called fibro cartilage. This 0:03:18.760 --> 0:03:21.800 forms up through the callous, transforming it again into a 0:03:21.840 --> 0:03:26.000 tougher fibro cartilagenus callous, which bridges the gap between the 0:03:26.040 --> 0:03:29.720 two pieces of bone. This callous generally lasts for about 0:03:29.760 --> 0:03:35.120 three weeks. Next, osteoblasts move in and produce bone cells, 0:03:35.160 --> 0:03:39.280 transforming the callous into a bone callous. This hard shell 0:03:39.440 --> 0:03:42.480 lasts three to four months, and it provides the necessary 0:03:42.480 --> 0:03:45.520 protection and stability for the bone to enter the final 0:03:45.560 --> 0:03:49.880 stage of healing. At this point, the body establishes the 0:03:49.880 --> 0:03:53.040 position of the bone within the flesh, begins reabsorbing bits 0:03:53.040 --> 0:03:56.320 of dead bone, and has that hard callous to bridge 0:03:56.320 --> 0:04:00.080 the gap between the two pieces of bone. However, this 0:04:00.320 --> 0:04:02.760 bulge of tissue needs a lot of work before the 0:04:02.800 --> 0:04:08.160 bone can take any strain. Osteoclasts and osteoblasts spend months 0:04:08.280 --> 0:04:12.720 remodeling bone by replacing the bone callous with harder, compact bone. 0:04:13.520 --> 0:04:17.719 These cells also decrease the callous buld, gradually returning the 0:04:17.720 --> 0:04:21.200 bone to its original shape. The blood circulation within the 0:04:21.200 --> 0:04:25.159 bone improves, and the resulting influx of bone strengthening nutrients 0:04:25.240 --> 0:04:30.120 such as calcium and phosphorus strengthen the bone. However, even 0:04:30.200 --> 0:04:33.640 in the best of cases, fractures often require medical attention 0:04:33.720 --> 0:04:38.279 to heal as smoothly as possible. Of first, there's the diagnosis. 0:04:38.720 --> 0:04:41.880 Before any further treatment can happen, the doctor must determine 0:04:41.920 --> 0:04:44.960 whether a fracture occurred at all, and, if so, the 0:04:45.000 --> 0:04:49.040 severity of the injury. Doctors generally accomplished this by examining 0:04:49.040 --> 0:04:51.800 the patient and inspecting X rays or other images of 0:04:51.839 --> 0:04:55.720 the damaged area. Then, once they figure out what needs 0:04:55.720 --> 0:04:59.240 to be done. There's immobilization. This is how the doctor 0:04:59.279 --> 0:05:01.919 helps your body line up the broken bone and limit 0:05:01.960 --> 0:05:05.760 mobility so that the growing calluses aren't damaged. They can 0:05:05.800 --> 0:05:09.200 help immobilize the affected area with a splint, cast brace, 0:05:09.320 --> 0:05:13.160 or sling. A realigning broken bones can be painful, so 0:05:13.279 --> 0:05:15.799 during this step a patient might need anything from local 0:05:15.839 --> 0:05:20.960 anesthetic to spinal anesthesia to temporarily lessen the pain. In 0:05:21.040 --> 0:05:25.160 the case of more complex fractures that require very specific immobilization, 0:05:25.440 --> 0:05:29.119 the doctor may apply traction, which is a system of weights, ropes, 0:05:29.120 --> 0:05:33.360 and pulleys that constantly pull on fractured limbs to maintain alignment. 0:05:35.200 --> 0:05:39.000 Most fractures can be treated without surgery, but sometimes doctors 0:05:39.040 --> 0:05:42.960 perform surgery to remove foreign materials or bone fragments, or 0:05:43.240 --> 0:05:46.039 sometimes the best way to stabilize certain fractures is to 0:05:46.240 --> 0:05:49.719 go in and align the bones with metal rods, implanted screws, 0:05:49.760 --> 0:05:52.920 and pins. Some fractures, such as those to the hip 0:05:52.920 --> 0:05:59.680 and joints, require artificial replacements. Finally, there's rehabilitation. The same 0:06:00.040 --> 0:06:03.479 bullization that keeps stress off the healing bone also leaves 0:06:03.520 --> 0:06:06.880 the surrounding muscles with little to do. This leads to 0:06:06.880 --> 0:06:10.560 the loss of muscle mass, strength, and flexibility. The special 0:06:10.600 --> 0:06:15.159 exercise regimes allow individuals to gradually rehabilitate their newly healed 0:06:15.200 --> 0:06:23.560 limbs without risking re injury. Today's episode is based on 0:06:23.600 --> 0:06:26.119 the article how do broken bones Heal? On how stuff 0:06:26.120 --> 0:06:29.120 works dot com, written by Robert Lamb. Brain Stuff is 0:06:29.160 --> 0:06:31.280 production of by Heart Radio in partnership with how stuff 0:06:31.320 --> 0:06:34.000 works dot Com, and it's produced by Tyler Clang. The 0:06:34.080 --> 0:06:36.320 four more podcasts from my heart Radio, visit the i 0:06:36.400 --> 0:06:39.160 heart Radio app, Apple Podcasts, or wherever you listen to 0:06:39.240 --> 0:06:40.080 your favorite shows.