The sagittal suture runs down the middle of the skull from the forehead back to the crown area. The deformity of the sagittal suture that is most widely recognized is that of sagittal craniosynotosis. But by far the more common deformity of the sagittal suture, and one that is far more minor than synostosis, is ridging. This is where a portion of the sagittal suture, usually the posterior area, develops a raised ridge. Such a raised sagittal ridge is often not noticed until adulthood in men who become aware of its presence with loss of hair coverage. It gives the head shape a peaked appearance from the front view.
The posterior sagittal ridge extends anteriorly from the original posterior fontanelle area, usually about 10 to 12 cms where it becomes flatter. This is a thickened area of bone where the suture line remains visible. Access for its reduction requires a small incision placed perpendicular to the orientation of the suture line. Whether it is placed at its most posterior end or in the middle depends on how long it is and whether its full length can be accessed from its posterior end.
With a long curved retractor a high speed handpiece and burr is used to methodically reduce its height from back to front. The usual bone height reduction is 4 to 5mms to make it confluent with the surrounding skull. Throughout its reduction the serpiginous suture line remains visible. When the bone shavings are removed and piled together they recreate the shape of the sagittal ridge.
The small incision is closed over a drain as the bone will tend to ooze blood for several hurts after surgery. This blood may eventually be resorbed but it recreates the prominence of the ridge for some time and may be a stimulus for some bone reformation. Thus it is better to have it evacuated until the morning after surgery.
The posterior sagittal ridge skull deformity can be effectively reduced through a very small scalp incision which goes on to heal conspicuously. The key steps are a limited scalp incision, high speed bone shaving and the use of a postoperative drain.
Dr. Barry Eppley