In 141 patients with ossification of posterior longitudinal ligament, open-door expansive laminoplasty was done from 1980 to 1998. A follow-up study was made. 10 patients with cervical cord injury and cerebral diseases before or after operation were excluded. 121 of 131 patients were followd directly one to fifteen years(mean: 5 years and 3 months). Subjects included 93 male and 28 female. At the time of operation, their ages ranged from 40 to 80 years(mean:59.5). Operative results were evaluated using the Japanese Orthopaedic Association’s Score(JOA Score) and Hirabayashi’s improvement rate. X-ray was taken to measure the range of cervical spine motion, curvature of the cervical spine and progression of ossified masses.

Preoperative JOA scores ranged from 2 to 14 points(mean:9.1), postoperative JOA scores ranged 7 to 17 points(mean:14.1). The mean improvement rate was 62%. The range of cervical spine motion decreased from 26.6 degrees prior to operation to 10.8 degrees after operation. Lordotic curvature also fell from 11.8 degrees before operation to 6.6 degrees after operation. In 20 patients, the postoperative kyphotic curvature increased to 5 degrees of more, although no difference was seen in their improvement rates compared with patients whose lordosis remained unchanged. 80 of 121 patients experienced progression of ossified masses. Three patients underwent additional laminectomy due to progression of ossification or insufficient expansion.

Operation took an average 80 minutes and mean amount of blood loss was 215 ml. No patients had postoperative motor paralysis caused by C5 or C6 nerve damage and no serious complications were seen.

In 14 rabbits we determined the origin of the cells effecting healing of the tendon of supraspinatus inserted into a bony trough. After two weeks both the cellularity of the underlying bone and the thickness of the subacromial bursa were significantly increased in the operated compared with the control shoulders. The cellularity of the stump of the tendon, however, was significantly decreased in the operated shoulders. In this model, both the underlying bone and the subacromial bursa but not the stump of the tendon contributed to the process of repair.

We conclude that the medial stump should be debrided judiciously but that cutting back to bleeding tissue is not necessary during repair of the rotator cuff. Moreover, great care should be taken to preserve the subacromial bursa since it seems to play an important role in the healing process.

We examined macroscopically and microscopically 55 cadaver rotator-cuff tendons attached to their humeral heads to determine the distance between the edge of the articular cartilage and the tendon insertion of the supraspinatus (the width of the sulcus) and the score of regressive changes at the sulcus. In 33 specimens we measured the tensile strength. The width of the sulcus was correlated with the score of regressive changes and with the ultimate tensile strength of the supraspinatus tendon.

The width of the sulcus correlated positively with the score of regressive changes (r = 0.66, p < 0.0001), but there was a negative correlation between the latter and the ultimate tensile strength (r = −0.81, p = 0.001) and between the width of the sulcus and the ultimate tensile strength (r = −0.74, p = 0.004).

We believe that the width of the sulcus is a simple and useful clinical indicator of the integrity and the tensile strength of the supraspinatus tendon.