Average Two-point Discrimination Research Articles

A versatile method for reconstruction of finger defects: reverse digital artery flap

Four types of the reverse digital artery flap—standard, extended, and innervated standard and extended—were developed for 52 finger defects. The arising pattern of the dorsal branch which was included in the innervated flap was studied and classified in cadaver dissections. Topographically, the described “Lai's line” is a useful guide to locate the underlying digital artery. Refinements in flap design and surgical technique resulted in favourable functional and cosmetic results. The average two-point discrimination of the reconstructed fingertip was 6.8 mm and 3.9 mm in the noninnervated and innervated flaps, respectively. This versatile flap is an ideal and reliable option for one-stage reconstruction of various finger defects.

Results of primary repair of digital nerves

Recovery of sensitivity following repair of 54 digital nerves was evaluated after one to seven years. Normal two-point discrimination has been regained in only seven cases (13%), two-point discrimination between 6 and 10 mm in 20 (37%), between 11 and 15 mm in 13 (24%) and protective sensation in 14 (26%). A close correlation between age and recovery of sensation after repair has been confirmed by statistical analysis. Microsurgical repair of digital nerves gives satisfactory results, since a normal or good two-point discrimination can be obtained in one-half of cases while sensation improves in the others. However a high rate of complete recovery of sensation is to be expected only in children.

Tactile Sensitivity in Systemic Sclerosis

The two-point and circle discriminations of the third digit of the hand were studied in 25 patients with systemic sclerosis as compared to 25 healthy controls matched for sex and age. 1 patient (4%) had diminished two-point discrimination = 10 mm and other signs of neuropathy. Mean two-point discrimination in the controls was 3.44 mm, SD 1.00 mm, and mean + 2 SD 5.44 mm. The normal two-point discrimination of the pulp of the digit could be defined as less than or equal to 5 mm. The circle discrimination was not diminished in any case. 8 patients (32%) complained of numbness of the digits, but examinations revealed neuropathy in only 1 case. Determination of two-point discrimination of the digit is recommended to screen neuropathy in systemic sclerosis.

Primary peripheral nerve repair in the hand and upper extremity.

A small consecutive series of primary nerve repairs in civilian injuries demonstrates that normal two-point discrimination and stereognosis can be anticipated not only in digital-nerve injuries but in mixed sensory and motor nerve injuries. Motor return follows and approaches normal in most patients. During the study period, 15 delayed repairs of mixed nerve lacerations were done. Two-point discrimination and stereognosis did not return to normal in any of the patients with mixed-nerve injuries or in one quarter of those with sensory-nerve injuries. Motor return never graded better than 3 on a scale of 0-4. Therefore, this author feels primary repair is superior to secondary repair and that almost all civilian injuries can be made surgically clean by debridement.