Measuring Occipital Scalp Laxity Before Donor Strip Harvesting in Hair Transplantation

October 2014 | Volume 13 | Issue 10 | Original Article | 1248 | Copyright © October 2014

Yau-Li Huang MD,a,b Shyue-Luen Chang MD,a,b Mei-Ching Lee MD,a,b
Chih-Hsiang Chang,a,b Sindy Hu MD MS,a,b and Michael H Gold MDc

aDepartment of Dermatology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan
bDepartment of Cosmetic Science, Chang Gung University of Science and Technology, Linkou, Taiwan
cDepartment of Medicine, Division of Dermatology, Vanderbilt University School of Medicine, Nashville, TN

BACKGROUND: Occipital scars from donor strip harvesting during hair transplantation are an important cosmetic concern. Scalp laxity has an important role, due to the more frequent use of dense packing and megasession transplantation, which requires more grafts and creates a wider, longer donor scar.
OBJECTIVE: To determine if the use of a simple, objective measurement of occipital scalp laxity could reduce scar length by allowing for adjustment of donor strip harvesting during hair transplantation.
METHODS AND MATERIALS: This retrospective study included data from 39 patients who underwent hair transplantation with >2000 follicular units: 25 patients underwent measurement of occipital scalp laxity (measurement group); the other 14 did not (control group). We measured and calculated preoperative scalp parameters for hair transplantation, including follicular unit density at occipital scalp, length and width of the donor strip, and estimated total number of grafts. All patients underwent standard follicular-unit hair transplantation, at which time the actual total number of grafts was determined.
RESULTS: Mean occipital follicular unit density in the measurement group was 74.16 follicles per cm2, which did not significantly differ from the controls (73.29; t=0.410, d.f.=37, P>0.05). The mean length of the occipital surgical wound was significantly shorter in the measurement group than in the controls (19.16 vs 27.50 cm, respectively; t=10.412, d.f.=37, P<0.05). The difference between the estimated and actual total number of grafts was significant in the measurement group (2139.44 vs 2397.64, respectively; paired t=3.095, d.f.=48, P<0.05) but not in the control group (2277.71 vs 2296.71, respectively; paired t=0.175, d.f.=26, P>0.05). Accuracy in estimating the total number of grafts was poor for the measurement group, as the number of actual grafts significantly exceeded estimates.
CONCLUSION: Use of data from a simple, objective method to measure occipital scalp laxity simplified adjustment of strip harvesting, allowed for use of wider strips, and resulted in smaller donor wounds and scars from hair transplantation; however, accuracy in estimating the total number of grafts was reduced.

J Drugs Dermatol. 2014;13(10):1248-1252.


Follicular-unit hair transplantation (FUT) is the gold standard in hair restoration surgery.1,2,4,5,7 On occipital donor scalp, Langer’s lines, ie, lines of minimum tension, are on the horizontal axis, parallel to crease lines. Incisions made along or parallel to these lines heal with minimal scaring.3,9 A long scar on occipital scalp is an important cosmetic concern for patients undergoing FUT with donor strip harvesting (Figures 1-2). To increase the number of grafts, a longer, wider strip must be collected from the occipital scalp. When numerous grafts are required for dense packing or megasession transplantation, the width of the strip can be increased if a shorter horizontal scar is desired.3,4,6,8,9,11 However, donor wounds should be closed with minimum tension to prevent unsightly scarring. Thus, scalp laxity has an important role and can be used to calculate strip width when attempting to reduce strip length in procedures that require numerous grafts.10,11,14 We attempted to determine if the use of a simple, objective measurement of occipital scalp laxity could reduce scar length by allowing for adjustment of donor strip harvesting during hair transplantation (HT).


This retrospective study included data from 39 patients (mean age, 40.5 years) who underwent HT requiring >2000 follicular units (FU). All patients had sought treatment at the dermatology department of Chang Gung Memorial Hospital in Taiwan during the period from June 2008 to August 2010. All HT surgeries were performed by one or more members of a group of three dermatologic surgeons. To most effectively compare differences between patients who did and did not undergo measurement of scalp laxity, we only analyzed data from patients who required a large number of grafts (>2000 FU), eg, those undergoing megasession HT.
The measurement group comprised 25 patients with data on occipital scalp laxity (March 2009 to August 2010); the other 14 patients (control group) had not undergone measurement of scalp laxity (June 2008 to March 2009) because they had been treated before measurement of scalp laxity was introduced at our center. At that time, the dimensions of donor strips were estimated and designed solely on the basis of the dermatologic surgeons’ subjective experience.