BROKEN THIGHBONE

(FEMUR FRACTURE)


our website is for educational purposes only.  the information provided is not a substitution for seeing a medical doctor.  for the treatment of a medical condition, see your doctor.  we update the site frequently but medicine also changes frequently.  thus the information on this site may not be current or accurate. 

 

What is a Femur Fracture (broken thigh bone)?

The femur is our thigh bone and its the biggest bone in our body, and its also a very strong bone.  Therefore, you can imagine that it takes a lot of force to break this bone. 

A broken femur usually seen in people after a major trauma (like high speed car accident), and people who break their femur often have other bodily injuries.  If someone sustained a force big enough to break this big bone, theres a good chance that smaller bones broke also.  A hip fracture (see talk) will occur at the same time in about 5% of cases (however its overlooked in 1/3 of cases because everyone is so focused on the femur shaft fracture...its more dramatic with the leg bent out of place). 

 

broken thigh bone femur fracture
broken thigh bone femur fracture anatomy

How is a Femur Fracture (broken thigh bone) diagnosed?

Patients with this injury come into the emergency room after a high-energy accident, and are complaining of significant thigh pain (its not uncommon for the patient to be unconscious from other injuries, and therefore unable to direct doctors to the problem.  Its therefore important for the doctors to inspect both arms and legs to find any signs of a broken bone). 

X-rays alone will diagnose the fracture. X-rays of the hip and knee (the joint above and below the femur) should also be taken to look for other injuries. 

How is a Femur Fracture (broken thigh bone) treated?

Surgery is almost always required for these fractures to heal correctly. 

Until surgery is performed, the femur is placed into traction (this pulls the leg straight to this helps to realign the bone and prevent any of the nerves or blood vessels in the thigh from being kinked by a bent leg).

During surgery, the bone fragments are realigned and then a stainless steel rod (called an “intramedullary nail”) is placed down down the center of the bone to hold the bone in place while it heals.  Even though the size of the fracture can be very large, the size of the surgical incision is often pretty small because the nail is threaded down the center of the femur from the top (near the hip) or from the bottom (near the knee) using live x-rays (fluoroscopy) to guide the nail into position (technical notes). 

Realignment of the bone fragments is not done through a surgical incision, but rather, indirect by moving the whole leg once the patient is sedated. 

The best part about fixing this broken bone with a nail is that people are able to start walking on the injured leg almost immediately after surgery.  Getting people out of bed and walking again (it takes a few months to get back to normal) lowers the risk of blood clots, pneumonia, bed sores and generalized muscle deconditioning.  It helps people young and old get back to their normal lives much faster. 

In some cases, when the bone is broken near the ends of the bone (the crack extends close to the hip or knee), its very hard to get the bone fragment stabilized with a nail.  In such cases, a surgical incision is made over the fracture site and the bone is put back together directly using screws and a metal plate.  

What is the long term outcome?  

The bone will heal in 98% of cases treated with an intramedullary nail.  

However, in rare cases the bone wont heal if too much was smashed during the injury.  If this occurs then a repeat surgery is needed to place new bone (called bone graft) and stimulate healing.  

The femur bone must be straight (cannot be bent more than 5 degrees) and also rotationally in line before inserting the nail, otherwise the foot can stick out to the side from malrotation of the leg.  It may sound easy: "just make the leg straight:, but in cases where the bone is in broken into many pieces it easier said than done.  If the rotation is off after surgery, people will complain of an abnormal walking pattern, and will often need a revision surgery to straighten things out.  

Another issue is that patients frequently complain of some hip pain and generalized leg weakness after the injury, most likely because of damage to the quad muscles during the injury.  Physical therapy can help but sometimes the strength of the injured leg will never equal the other side. 

The risk of infection is low, less than 1%, and this is partly because the incision is very small, and also because the femur has a good blood supply that allows our immune system to quickly respond to any bacteria.

Reference

1) Wolinsky PR et al. Reamed intramedullary nailing of the femur: 551 cases. JOT 19999; 46: 392-99. full article. 78% mvc, 70% male, avg age 27. 15% open fx.

2) Winquist RA, Hanson ST. Comminuted fractures of the femoral shaft treated with intramedullary nailing. Ortho Clin NA 1980; 11: 633-647. full article. classification by comminuted, I: small fragment (>75% cortical contact); II: 50% cortical contact; 3: minimal cortical contact; 4: no contact.

Surgical techniques

1) Bick EM. The intramedullary nailing of fractures by G. Küntscher: Translation of article in Archiv für Klinische Chirurgie, 200:443, 1940. CORR 196860:5-12. full article.  classic paper reporting first use of nails. 

2) Winquist RA, et al. Closed intramedullary nailing of femoral fractures. A report of 520 caes. JBJS 1984; 66: 529-39. full article. full weight bearing regardless of comminution, outcomes IMN: 99% union, <1% infxn. More recent papers using static interlocks have similar outcomes (Sojbjerg et al). 

3) Ricci WM et al. Trochanteric versus piriformis entry portal for the treatment of femoral shaft fractures. JOT 2006; 20: 663-7. full article. either entry has equal successful with the correctly selected nail. troch entry req. less fluoro time, less surgical time. piriformis is colinear with canal, less risk varus malalign.

4) Ricci WM et al. Retrograde versus antegrade nailing of femoral shaft fractures. JOT 2001; 15: 161-169. full article. more hip pain antegrade, more knee pain retrograde. no outcome differences.

5) Brumback RJ et al. Immediate weight-bearing after treatment of a comminuted fracture of the femoral shaft with a statically locked intramedullary nail. JBJS 1999; 81: 1538-44. full article. no loss of reduction, no shortening. no advantage to the dynamization.

6) Egol KA et al. Mismatch of current intramedullary nails with the anterior bow of the femur. JOT 2004; 18(7): 410-5. see article. inc risk perf anterior cortex b/c straighter nails.

7) Bone et al. Treatment of femoral fractures in the multiply injured patient with thoracic injury. CORR 1998; 347: 57-61. full article. higher union rate, larger nails with reaming, no effect on pulmonary outcome, no risk fat embolism.

Complications

5) Tornetta P IIIKain MSCreevy WRDiagnosis of femoral neck fractures in patients with a femoral shaft fracture: Improvement with a standard protocol. J Bone Joint Surg Am 200789:39-43. full article. 9% incidence of ipsilateral femoral neck fx, missed 20% of time. get ct scan hip w. 2-mm cuts

6) Lindsey JD, Krieg JC. Femoral malrotation following intramedullary nail fixation JAAOS 2011; 19: 17-26. full article. ct scan helps with diagnosis of malrotation.

7) Braten M et al. Torsional deformity after intramedullary nailing of femoral shaft fractures. Measurement of anteversion angles in 110 patients. JBJS Br 1993; 75: 799-803. full article. sets 15 degrees rotation as risk for sx. external rotation more problematic.

8) Ricci WM et al. Angular malalignment after intramedullary nailing of femoral shaft fractures. JOT 2001; 15: 90-95. full article. 10% incidences, highest risk proximal comminuted fx. over 5 degrees any plane causes sx.

8) Perez EA et al. Is there a gluteus medius tendon injury during reaming through a modified medial trochanteric portal. A cadaver study. JOT 2007; 21: 617-20. full article. 10-40% postop hip pain but no visible damage to this tendon, pain may be from injury to piriformis/obturator internus.  

 

Questions? Email us: contact@bonetalks.com