QUESTION: I fractured two pelvic bones in a bike crash a few weeks ago and I have been told that the bones are stable and should heal without surgery. I am currently partial weight bearing and starting to do some physical therapy. I am wondering if the scar tissue from this fracture will strengthen the affected bones, or will I be more susceptible to future fractures? – DAVE
Dr. DENNIS DEVITO RESPONDS: Most pelvic fractures are the result of high energy trauma (as in motor vehicle accidents) so I feel your pain, Dave, as this must have been a serious bike crash. The pelvis is actually composed of three bones — the ilium (the wings), the ischium (the sit bone), and the pubis — and the two pelvic halves are connected to form the pelvic ring.
The sacrum is the lowest portion of the spinal column and forms the posterior connection of the pelvic ring, held in place by the strong sacro-iliac ligaments. The front of the ring is made up of the pubic bones. The three portions of the pelvis (ilium, ischium, pubis) also come together to form the acetabulum or “hip cup” which supports body weight when standing, and pelvic fractures that involve this region are more serious since they involve the hip joint, often requiring surgery if the bone is out of position.
The ischium is the posterior portion of the pelvis, and the portion below the hip thickens to form the ischial tuberosity which is very strong and rarely broken. The tuberosity supports weight while sitting and you can feel the ischium when you sit on your fingers. The other significant aspect to the ischial tuberosity is that this is the attachment of the hamstring tendons; so tightness of this muscle group affects the way the pelvis tilts (posteriorly) resulting in more flexion of the lumbar spine (a less efficient bike posture).
Pubic fractures are very common, usually occurring on both sides, and if displaced can damage portions of the bladder. Sometimes an injury will widely separate the two pubis halves where they are connected in the midline, and the pelvic ring needs to be ‘closed’ back together with surgery. Minimally displaced fractures are often treated with partial weight bearing until comfortable. Fractures of the iliac wing are generally the most benign and can occur from falls onto the side of the hip, causing lateral compression. The gluteal muscles cushion this bone and also provide for a good blood supply for rapid healing.
Because the pelvis is considered a closed ring, fractures usually occur in two regions (rare to see single breaks). Breaks are generally classified as being stable (not likely to move further out of position) or unstable (usually requiring surgery). For orthopedic surgeons, an x-ray of the pelvis tells most of the story and would explain what kind of recovery to expect.
However, it sounds like yours is stable, implying that as your pain level decreases, you can bear more weight. As a masters rider, the inactivity and walking restrictions make the recovery more prolonged as you must re-build muscle strength and endurance. Bone healing takes 6-8 weeks, but muscle conditioning may resume once pain is minimal, along with a flexibility routine. Andy Schleck missed the Tour de France this year because he had a pelvic fracture (which was really a fracture of the sacrum), and exertional pain prevented him from the maximal efforts required for peak performance.
One of the amazing things about bone is that it is the only tissue in the body that heals without forming scar. Once a fracture knits back together, it slowly remodels by dissolving away the injured bone and replacing it with new, healthy bone. Eventually, the fracture is gone; of course, the older you are, the longer this process can take.
Sometimes there is a permanent ‘bump’ or misshapen area on the bone (this could be a problem if it was directly on the sit bone); however, the bone is just as strong as it was pre-injury and generally not likely to break again. Occasionally, the soft tissues around the bone may form scar (which doesn’t make the bone stronger), but this usually loosens up with stretching and muscle strengthening.
Good luck on your recovery and after your doctor has cleared you to resume full weight bearing, focus on core strengthening, hip range of motion (especially hamstring stretching), and building endurance in your cycling muscles.
Dennis P. Devito, M.D., is an orthopedic surgeon at Children’s Orthopedics of Atlanta and is an avid road cyclist. His practice is focused on children and young athletes, especially those with spinal conditions. An avid cyclist from a running background, he spent 15 years intensely competing as an amateur triathlete and was a multi-time member of the USA World Long Course Triathlon Team.