| Spinal Nerve. | Motor Paralysis. | Anesthesia. | Reflexes. | |||
|---|---|---|---|---|---|---|
| Cervical. | - | 1. | Death from pressure of odontoid. | |||
| 2-3. | Death from paralysis of diaphragm. | |||||
| 4. | Deltoid muscles of upper arm. | Upper shoulder, outer arm. | Pupil. | |||
| 5. | Supinators of hand. | Outside of arm and forearm. | Pupil, scapular, supinator, triceps. | |||
| 6. | Biceps, triceps, extensors of wrist. | Outer half of hand. | Pupil, scapular, triceps, post. wrist. | |||
| 7. | Pronators of wrist, latissimus dorsi. | Inner side of arm and forearm. | Pupil, scapular, post. wrist, ant. wrist, palmar. | |||
| 8. | Flexors of wrist, hand, muscles. | Inner side of hand. | Scapular, post, wrist, ant. wrist, palmar. | |||
| Dorsal. | - | 1. | Thumb. | Ulnar supply to hand. | Scapular, palmar. | |
| 2-12. | Muscles to back and abdomen. | Skin over the back and abdomen in areas corresponding to distribution of spinal nerves. | Epigastric, 4-7; abdominal, 7-11. | |||
| Lumbar. | - | 1. | Psoas and sartorius. | Groin. | Cremasteric. | |
| 2. | Quadriceps extensor femoris. | Outside of thigh. | Cremasteric, patellar. | |||
| 3. | Abductors and inner rotators of thigh. | Front and inside of thigh. | Cremasteric. | |||
| 4. | Adductors of thigh, tibialis anticus. | Inside of leg, ankle, and foot. | Gluteal. | |||
| 5. | Outward rotators of thigh, flexors of knee and ankle. | Back of thigh and leg; outside of foot. | Gluteal. | |||
| Sacral. | - | 1-2. | Muscles of foot, peronei. | Outside of leg. | Plantar. | |
| 3-5. | Perineal muscles. | Perineum, anus, sacrum, genitals. | Ankle clonus. | |||
Injuries low in the lumbar segments cause incontinence of urine and feces because of the location of the centres for the rectum and bladder at this level. Injuries higher up cause retention by paralyzing the expulsive muscles of the abdomen. The reflexes which most interest the surgeon and which are of importance to him in diagnosticating these and other traumatic conditions are the following, with their method of detection (Bradford):
| Pupillary: | Dilatation produced by pinching side of neck. |
| Scapular: | Scratching skin over scapula causes muscles to contract. |
| Supinator: | Tapping tendon at wrist causes flexion of arm. |
| Triceps: | Tapping tendon at elbow causes extension of arm. |
| Posterior wrist: | Tapping tendons causes extension of hand. |
| Anterior wrist: | Tapping tendons causes flexion of wrist. |
| Palmar: | Scratching palm causes flexion of fingers. |
| Epigastric: | Stroking mammæ causes retraction of epigastrium. |
| Abdominal: | Stroking abdomen causes retraction. |
| Cremasteric: | Stroking inner side of thigh causes retraction of scrotum. |
| Patellar: | Striking patellar tendon causes extension of leg. |
| Gluteal: | Stroking buttock causes dimpling in gluteal fold. |
| Plantar: | Stroking sole of foot causes flexion and retraction of leg. |
| Ankle clonus: | Forcible extension causes rhythmical flexion. |
Much will depend upon the minute character of the injury, its location, and the amount of displacement of fragments. Fracture of a spinous process causes irregularity of the tips of the spines, with frequently the displacement of a fragment which may be moved beneath the skin, with or without crepitus. Fracture of one or both laminæ will permit mobility of the spinous process, with perhaps displacement. It is difficult to elicit crepitus. The neural arch may thus be broken without serious involvement of the body of a vertebra. On the other hand, the body itself may be fragmented, compressed out of shape, or so loosened as to permit of easy displacement.
DISLOCATION OF THE SPINE.
A limited proportion of serious and paralyzing injuries to the spine consists of dislocation of some of its component parts without fractures. These may be considered as pure types of dislocation, but they constitute less than one-fourth of such cases. In a large proportion of these spinal injuries the actual lesion consists of the combination of fracture with the displacement which it permits. Such conditions are referred to as fracture dislocations. Unilateral dislocation in the cervical region produces a distortion of the neck simulating wryneck, the face being turned to the opposite side. Except in very fat individuals irregularity will be perceived in the line of the cervical spines. When high up dyspnea is a constant feature. Traumatic dislocations are sharply differentiated, so far as the treatment is concerned, from those of slow production as the result of cervical spondylitis. In the acute cases the muscles are spasmodically contracted on the dislocated side. Irregularity of contour may be detected with the finger in the pharynx.
Fig. 415
Fracture dislocation with great displacement—patient almost completely recovered. (Buffalo Museum.)
In the lower portions of the spine, which are both larger and more protracted, are more frequent combinations of both injuries and fewer instances of the single type of either. Except in the cervical region it is exceedingly difficult to distinguish between these lesions, for the question of operation or no operation is decided by other and more conspicuous features ([Figs. 416] and [417]).