The aim of this study was to determine whether chilled irrigation
saline decreases the incidence of clinical upper limb palsy (ULP;
a reduction of one grade or more on manual muscle testing; MMT),
based on the idea that ULP results from thermal damage to the nerve
roots by heat generated by friction during bone drilling. Irrigation saline for drilling was used at room temperature (RT,
25.6°C) in open-door laminoplasty in 400 patients (RT group) and
chilled to a mean temperature of 12.1°C during operations for 400
patients (low-temperature (LT) group). We assessed deltoid, biceps,
and triceps brachii muscle strength by MMT. ULP occurring within
two days post-operatively was categorised as early-onset palsy.Aims
Methods
We have reviewed 1858 patients who had undergone a cervical laminoplasty and identified 43 (2.3%) who had developed a C5 palsy with a MMT (MRC) grade of 0 to 2 in the deltoid, with or without involvement of the biceps, but with no loss of muscular strength in any other muscles. The clinical features and radiological findings of patients with (group P; 43 patients) and without (group C; 100 patients) C5 palsy were compared. CT scanning of group P revealed a significant narrowing of the intervertebral foramen of C5 (p <
0.005) and a larger superior articular process (p <
0.05). On MRI, the posterior shift of the spinal cord at C4–5 was significantly greater in group P, than in group C (p <
0.01). This study is the first to correlate impairment of the C5 nerve root with a C5 palsy. It may be that early foraminotomy in susceptible individuals and the avoidance of tethering of the cord by excessive laminoplasty may prevent a post-operative palsy of the C5 nerve root.
