Laxometer and Strip Removal for Increasing Safety

This lecture was presented by Dr. Parsa Mohebi at 15th annual meeting of international society of hair restoration surgery.
Accurate measurement of scalp laxity is crucial in minimizing the chance of donor complications in patients with a tight scalp or patients that require a larger number of grafts in one session. The Laxometer is a device which is utilized to measure the scalp laxity or mobility in a precise fashion.

Previously, we have shown that the Laxometer can help in the evaluation of scalp laxity before surgery and it can produce a metric while patients undergo a scalp exercise program prior to surgery to increase scalp laxity. Scalp laxity assessment has traditionally been a manual process and it requires individual judgments based upon the surgeon’s experience. Prior to the introduction of this tool, there were no tools for measurement of scalp laxity to confirm the surgeon’s individual judgment. Removing too wide of a strip increases the risk of closure problems and wound complications such as: wide scars, telogen effluvium around the donor wound and possible skin necrosis. The area above the mastoids seem to be more at risk of donor wound complications (Pictures I, 2 and 3).

In this study, we have closed half of the donor area in 37 patients and evaluated the impact of donor excision on the laxity of the donor area. Laxity measurements were done before and after the incisions were made at three locations: (I) the right, (2) midline and (3) left side of the donor area above the mastoid bone approximately 10- 15cm from the midline on both sides of the donor area. The excision was made using a double bladed knife to insure the uniformity of the incision. The measurement of laxity on secondary section was done after excising half of the strip. We removed one side of the donor strip based upon the maximum width that was considered safe. Laxity measurements were made before and after closure of half of the wound (see figures 4, 5 and 6). Laxity measurements before and after donor strip excision were compared at the not-yet -excised side. If scalp laxity on the secondary portion (left side) was reduced after closure of the primary portion (right side), the width of the secondary portion should be adjusted downward.

Only 6 patients needed adjustment in removing the secondary portion of the strip.

Only 6 patients needed adjustment in removing the secondary portion of the strip.

We performed this study on 37 patients who underwent a strip method hair transplant. In only six patients we had to limit the width of the secondary section of strip due to reduction in Laxometer reading because of decreasing laxity after closure of the primary section. Laxity of scalp was measured on the left side after removal of the strip on the right side in all cases.
Final strip width (mm)

The impact of closing half of the wound showed that the tension on the wound (1) increased on the secondary side in six patients (16%) and stayed the same in 31 (84%) patients. With this knowledge, 6 patients had the strip removed in two separate steps adjusting the width of the donor strip in the secondary portion to reflect the laxity measurements that were obtained. In most patients (84%), we succeeded to safely remove the entire length of strip without any need to decrease the width of strip. When the measurements showed a reduction of laxity, the strip width could be altered before completing the surgery.

The Laxometer is an ideal device in strip hair transplant surgery to measure the scalp laxity of the donor area and reduce the possible complications with a donor strip that may be too wide. A metric can be obtained in (1) the preoperative state. (2) During the surgery and (3) after half of the projected strip was removed. With the strip removed in two sections, adjustment for strip width for the second half of the strip could be performed according to the metric obtained on the secondary side. The Laxometer also gives the surgeon a metric when patients undergo scalp exercises to improve scalp laxity in the tight scalps.