Middle Facet Coalition



By:  Robert H. Sheinberg, D.P.M., D.A.B.P.S., F.A.C.F.A.S. 

Tarsal coalitions are an abnormal union of two bones in the foot.  This condition may involve one or both feet.  Symptoms usually occur between the ages of eight and fourteen, depending on the location of the coalition.  It will adversely affect a child’s ability to run or participate in sports.  Coalitions are congenital in nature and not caused by an injury.  Symptoms may first appear after an acute injury or after overuse to the foot or ankle.  In 50% or more of the cases, it occurs on both feet.


  • Calcaneal navicular coalition ages 8-12.
  • Middle facet subtalar joint coalitions ages 10-16.


  • Generally unknown.
  • Usually due to failure of bones to separate with a resultant lack of joint formation.
  • Hereditary.


  • Pain in the foot and/or ankle, worse with activity and better with rest.
  • Muscle cramps and/or spasms in the outer leg muscles.
  • Stiffness and limited movement in the foot and ankle.
  • Fatigue or tiredness in the legs, especially with increase in weightbearing activities.
  • Muscle weakness in the legs.
  • Pain in the knees, hips and/or back.


  • Flatfoot with weightbearing.
  • Decreased motion in the midfoot and rearfoot joints.
  • Pain with palpation over the midfoot.
  • Pain with attempted range of motion of midfoot and rearfoot joints.
  • Often mild local swelling.
  • Tenderness in the legs due to muscle spasm and/or compensation.
  • Difficulty walking and running.
  • If one foot affected, one foot may appear to turn outward compared to the other foot.
  • Spasms may be produced upon physical examination.


  • X-rays are taken to determine type of tarsal coalition present.  Due to the abnormal bridging, secondary changes including bone spurs and arthritis may also be seen.  CT scans are always necessary to get better clarity of the problem.


  • Acute symptoms of pain and swelling are treated with cast immobilization and rest. 
  • Physical therapy may be implemented to decrease muscle spasms and increase muscle strength. 
  • Orthotic devices are often utilized to prevent abnormal joint movement causing the pain.
  • When a child has continued pain and difficulty walking surgical intervention may be required. 


  • Certain coalitions (calcaneal navicular bars) can be removed with excellent long-term outcome.  Other coalitions (middle facet subtalar joint) do not have as good of a prognosis.  If treated early good long-term outcome may be achieved.  If treated late the coalition may be too advanced to surgically remove and fusing the joint may be necessary to eliminate pain, spasm and deformity.  Excellent long-term outcomes are common following nonsurgical or surgical treatment of these conditions.  If a fusion of the joint is necessary the pain will be completely eliminated and the return to most activities is common.


3D reconstructions and CT scan of Middle Facet Subtalar Tarsal Coalition (Arrows Pointing to Coalition)


The following images are that of a 3D reconstruction of a CT scan that demonstrates the coalition of the middle facet of the subtalar joint.


This image is a coronal plane view of a CT scan also showing a middle facet coalition.



Pictures of a middle facet coalition.  The Left foot is affected and the Right is not.  In the first picture, the left foot is flatter and rotated out compared to the right.  The next two pictures are intra-operative pictures of  removal of the bony coalition. We then place a subtalar joint implant to correct the foot posture as well as keep space at the surgical excision site.  The last photograph is of the flouroscopic image of the implant placement in the operating room


The following is an example of a 12 year old female with a combination coalition of the middle and posterior facets that has stopped her from doing athletic activites because of pain. The top images are the lateral view (left) and oblique view (right) of the middle and posterior facet. The bottom left is the axial view of the middle facet.

The next set of images are CT scans in the transverse or axial view that demonstrate the irregularity of the facet and arthritic changes occuring at the area which cause the individual pain with activity. The bottom set of images are a sequence of the CT scan to show the irregularities from the coalition and its extent.

Pre and Postop pictures status post middle facet coalition resection and subtalar implant (below)



CT scan of middle facet coalition


The images below demonstrate x-rays of an 8 year old female who is have pain with activities of the left foot and limited motion of the foot. Mother notices that when she walks her left foot turns out more than the right foot. X-rays demonstrates the close approximation of the middle facet of the subtalar joint of the left foot (yellow arrow) compared to the right foot (red arrow) where there is an open gap. 



CT Scans of middle facet coalition