Franco Postacchini

Results of disc prosthesis after a minimum follow-up period of 2 years.

Study Design This study analyzed retrospectively 46 patients undergoing artificial disc replacement. Objective To assess the clinical and radiographic outcomes of patients who had Charitè SB III disc prosthesis. Summary of Background Data Results of disc prosthesis have been reported only at very short‐term follow‐up periods; preoperative diagnosis and criteria used to evaluate the clinical outcomes were not reported. Methods Forty‐six patients who had had a disc prosthesis were evaluated clinically and radiographically at least 2 years after surgery. Preoperative diagnosis included disc degeneration in 22 patients and failed disc excision in 24 patients. Disc prosthesis was implanted at a single vertebral level in 36 patients and at two levels in 10 patients. Follow‐up evaluation was performed after an average of 3.2 years (range, 2–5 years). Results Sixty‐three percent of patients reported satisfactory results. The success rate was 69% in patients who underwent isolated disc replacement and 77% in those with no previous back surgeries. Seven patients who had unsatisfactory results underwent posterolateral fusion without removing the artificial disc. Two patients underwent removal of the prosthesis. No failure of the implants or loosenings or wear of the polyethylene core were found. Vertebral motion averaged 9° at the operated levels and 16° at the adjacent levels. Conclusion A wrong surgical indication, rather than failure of the prosthesis, appears to be the main cause of unsatisfactory results of disc replacement at medium‐term evaluations. Prospective and longer term studies are needed to establish whether disc prosthesis may offer advantages compared with spinal fusion.

Pedicle instrumentation in the thoracic spine: A morphometric and cadaveric study for placement of screws

STUDY DESIGN In part 1 of the study, the morphometry of thoracic pedicles and bony landmarks for pedicle screw placement were evaluated. In part 2, pedicle screws were inserted in fresh cadavers, using a different entry point in the left and right pedicles. OBJECTIVES To identify the safest entry point and screw orientation for pedicle screws in the thoracic spine. SUMMARY OF BACKGROUND DATA A few morphometric investigations have been performed on thoracic vertebrae, but the safest technique for screw insertion in thoracic pedicles has not been analyzed. METHODS Mean, range, and standard deviations of pedicle transverse diameter and pedicle orientation were measured in 99 dried thoracic vertebrae. We evaluated the position of the bottom of the superior facet and that of the superior border of the transverse process in relation to the center of the pedicle. The relation between the pedicle axis and the superior facet in the frontal plane was also assessed. In part 2 of the study, pedicle screws were inserted in fresh cadavers at the intersection between the superior border of the transverse process and the middle of the superior facet (entry point A) and between the former and the lateral two thirds of the facet (entry point B). RESULTS The smallest transverse diameter was found at 16 (mean 4.3 mm) where pedicles measured less than 5 mm in 68% of the specimens. In the frontal plane, the pedicle axis intersected the middle of the superior facet in 15% of specimens, the lateral two-thirds in 62%, and the lateral border of the facet in 23%. Of the 126 screws inserted in fresh human cadavers, 15 (24%) of the screws inserted using entry point A and 10 (16%) of those inserted using entry point B violated the pedicle cortex (P > 0.05). Six (10%) of the screws inserted using entry point A compared with no screw inserted using entry point B penetrated the anterior vertebral cortex (P = 0.03). CONCLUSIONS Pedicles between T4 and T8 may not be wide enough for screw fixation. An entry point for pedicle screws located at the intersection between the superior border of the transverse process and the lateral two thirds of the superior facet seems more likely to be in line with the pedicle axis than do other entry points. In the lower thoracic vertebrae this entry point, in combination with insertion of the screws more medially oriented than the pedicle axis, significantly reduces the risk of violating the anterior vertebral cortex.

The surgical treatment of central lumbar stenosis. Multiple laminotomy compared with total laminectomy

We assigned 67 patients with central lumbar stenosis alternately to either multiple laminotomy or total laminectomy. The protocol, however, allowed multiple laminotomy to be changed to total laminectomy if it was thought that the former procedure might not give adequate neural decompression. There were therefore three treatment groups: group I consisting of 26 patients submitted to multiple laminotomy; group II, 9 patients scheduled for laminotomy but submitted to laminectomy; and group III, 32 patients scheduled for, and submitted to, laminectomy. The mean follow-up was 3.7 years. Bilateral laminotomy at two or three levels required a longer mean operating time than total laminectomy at an equal number of levels. The mean blood loss at surgery and the clinical results did not differ in the three groups. The mean subjective improvement score for low back pain was higher in group I but there was also a higher incidence of neural complications in this group. No patient in group I had postoperative vertebral instability, whereas this occurred in three patients in groups II and III, who had lumbar scoliosis or degenerative spondylolisthesis preoperatively. Multiple laminotomy is recommended for all patients with developmental stenosis and for those with mild to moderate degenerative stenosis or degenerative spondylolisthesis. Total laminectomy is to be preferred for patients with severe degenerative stenosis or marked degenerative spondylolisthesis.

Surgical management of lumbar spinal stenosis

Eighty consecutive patients with lumbar spinal stenosis surgically treated during a 5-year period by the author were reviewed. Patients were placed in the following categories: lateral spinal stenosis (10), central-mixed stenosis (29), spinal stenosis after laminectomy and/or fusion (32), and spinal stenosis with degenerative scoliosis (9). Contrast-enhanced computed tomograpic (CT) scans were helpful in determining the levels requiring decompression. However, in the multiply operated patient, contrast-enhanced CT scans were misleading in six patients. Patients with lateral spinal stenosis were treated with unilateral laminectomy and partial facetectomy. The 29 patients with central-mixed stenosis underwent decompressive laminectomy and bilateral facetectomies. Six fusions were done. In the nine patients with spinal stenosis and scoliosis, concave-side partial facetectomies and laminectomies were done as well as spinal fusions. The 32 patients with spinal stenosis after previous laminectomy and spinal fusions were the most difficult group to analyze, and their treatment was the least standardized. There were 19 good, eight fair, and five poor results in those who had undergone previous surgery. Fifty-seven of the 80 patients (71%) experienced a good result from their surgical treatment.

ANTERIOR DISLOCATION OF THE SHOULDER IN ELDERLY PATIENTS

Of 545 consecutive patients with anterior shoulder dislocations, 108 (20%) were aged 60 years or more at the time of injury. We reviewed and radiographed 95 of these elderly patients after a mean follow-up of 7.1 years. Axillary nerve injuries were seen in 9.3% of the 108 patients, but all recovered completely in 3 to 12 months. There were single or multiple recurrences of dislocation in 21 patients (22.1%), but within this group age had no influence on the tendency to redislocate. Tears of the rotator-cuff were diagnosed by imaging studies or clinically in 58 patients (61%), including all who had redislocations. Sixteen patients required surgery. Eight with a single dislocation and a cuff tear had only repair of the torn cuff. Of the eight patients with multiple dislocations requiring operation, five also had a torn cuff and needed either a stabilising procedure and a cuff repair or repair of the cuff only. All patients who were operated on had a satisfactory result, with the exception of those with multiple redislocations and a cuff tear who had repair of the cuff only. Anterior shoulder dislocation in elderly subjects is more common than is generally believed; 20% suffer redislocation and 60% have a cuff tear. Operation may be needed to repair a torn cuff or to stabilise the shoulder. Patients with multiple redislocations will probably require both procedures.

Scapular Dyskinesis and SICK Scapula Syndrome in Patients With Chronic Type III Acromioclavicular Dislocation

PURPOSE This study was aimed at evaluating whether scapular dyskinesis and, eventually, SICK (Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, and dysKinesis of scapular movement) scapula syndrome develop in patients with chronic type III acromioclavicular (AC) dislocation. METHODS Scapulothoracic motion was studied in 34 patients with chronic AC dislocation by use of the protocol described by Kibler et al. and Burkhart et al. An anteroposterior radiograph of the scapulae with the arms abducted was also obtained. The SICK Scapula Rating Scale was applied to patients with SICK scapula syndrome. Shoulder function was assessed with the Constant score and Simple Shoulder Test (SST). RESULTS Of the 34 patients, 24 (70.6%) had scapular dyskinesis with the arms at rest, and 14 of these (58.3%) had SICK scapula syndrome. The mean SICK Scapula Rating Scale score was 6.9 points (out of a possible 20 points). Clinical and radiographic evaluations with the arms abducted at 90 degrees confirmed scapular dyskinesis in 61.7% and 64.7% of patients, respectively (P > .05). The Constant score was 83 points for the pathologic side and 91 points for the contralateral side. The Constant score value was 75 and 88, respectively, in patients with dyskinesis and those without dyskinesis (P < .05); the mean value for the SST was 8 of 12 and 10 of 12, respectively. CONCLUSIONS Chronic type III AC dislocation causes scapular dyskinesis in 70.6% of patients. Of the latter, 58.3% have SICK scapula syndrome develop. Dyskinesis might be due to loss of the stable fulcrum of the shoulder girdle represented by the AC joint and due to the superior shoulder pain caused by the dislocation. The values for the Constant score and SST were lower in patients with dyskinesis. LEVEL OF EVIDENCE Level IV, prognostic case series.

Use of platelet-leukocyte membrane in arthroscopic repair of large rotator cuff tears: a prospective randomized study.

BACKGROUND Arthroscopic rotator cuff repair generally provides satisfactory results including decreased shoulder pain and improved shoulder motion. Unfortunately, imaging studies demonstrate that the retear rate associated with the available arthroscopic techniques may be high. The purpose of this study was to evaluate the clinical and magnetic resonance imaging (MRI) results of arthroscopic rotator cuff repair with and without the use of platelet-leukocyte membrane in patients with a large posterosuperior rotator cuff tear. METHODS Eighty consecutive patients with a large full-thickness posterosuperior rotator cuff tear were enrolled. All tears were repaired using an arthroscopic single-row technique. Patients were randomized to treatment either with or without a platelet-leukocyte membrane inserted between the rotator cuff tendon and its footprint. In patients treated with this membrane, one membrane was utilized for each suture anchor. The primary outcomes were the difference between the preoperative and postoperative Constant scores and the repair integrity assessed by MRI according to the Sugaya classification. The secondary outcome was the difference between the preoperative and postoperative Simple Shoulder Test (SST) scores. RESULTS The only significant differences between the two groups involved the patient age and the preoperative and postoperative Constant scores; the differences in the Constant score were due to differences in the shoulder pain subscore. At a mean of thirteen months of follow-up, rotator cuff retears were observed only in the group of patients in whom the membrane had not been used, and a thin but intact tendon was observed more frequently in this group as well. The use of the membrane was associated with significantly better repair integrity (p = 0.04). CONCLUSIONS The use of the platelet-leukocyte membrane in the treatment of rotator cuff tears improved repair integrity compared with repair without membrane. However, the improvement in repair integrity was not associated with greater improvement in the functional outcome. In fact, the Constant scores of the two groups would have been similar if the shoulder pain component (which had differed preoperatively) had been excluded.

Ligamenta flava in lumbar disc herniation and spinal stenosis. Light and electron microscopic morphology.

Methods. Ligamenta flava obtained from nine patients with lumbar disc hernlation and ten patients with lumbar stenosis were studied at histologic, histochemical, and ultrastructural levels. Lumbar ligaments flava removed from six patients who underwent surgeries for thoracolumber fractures were used as controls. Results. Ligements flave from control subjects consisted of large elastic fibers, thin bundles of collagen fibers, and few spindle-shaped fibroblasts In proximity to the laminal insertion the ligaments had fibrocarilagireous features. In the control subjects who were age 50 or older, the cells decreased in number and areas that had fewer and thinner elastic fibers and a more abundant collagen component were visible occasionally. In patients with disc herniation, the ligaments had similar morphologic features to those of the controls of similar ages. The ligamenta flava from patients with lumbar stenosis showed areas of fibrosis in which the cells were often represented by actively synthesizing fibroblests and areas of chondroid metaplasia. Degenerating elastic fibres were seen occasionally while calcified areas were observed often. Conclusions. Ligamenta flava undergo slight fibrotic and chondrometaplastic changes with aging. No peculiar changes occur in patients with disc herniation. In spinal stenosis, fibrotic changes, chondroid metaplasia, and calcification reduce the dencity of the ligaments, which may thus bulge into the spinal canal in the standing position even if they are normal in thickness.

Stenosis of lumbar intervertebral foramen: anatomic study on predisposing factors.

Study Design. In Study 1 the authors measured the vertical and sagittal dimensions of the intervertebral foramen in dried lumbar vertebrae. In Study 2 the dimensions of the intervertebral foramen were measured in fresh cadaveric spines in which the soft tissues forming the foraminal walls were preserved. Objectives. To investigate whether disc narrowing, or other factors related to the morphometry of lumbar vertebrae, may predispose to foraminal stenosis. Summary of Background Data. Predisposing factors to foraminal stenosis have been little investigated. Previous studies suggested that narrowing of the disc space might cause a reduction in the foraminal dimensions; however, it is not clear whether such a reduction is to such an extent as to compress the nerve root within the foramen. Methods. In Study 1 the vertical and sagittal dimensions of 160 intervertebral foramens were measured on dried white spines. Measurements were performed in the presence of a normal height of the disc space, obtained using a silicone rubber disc, and repeated in the same specimen after disc removal. Foraminal dimensions were then related to the sagittal diameter of the spinal canal and the pedicle length. In Study 2, the authors evaluated the dimensions of 50 intervertebral foramens of fresh cadaveric spines, in which the soft tissues forming the foraminal walls and the nerve root were preserved. In specimens showing normal or slightly decreased disc height, the foraminal dimensions were measured before and after disc excision. Results. In Study 1 the reduction in the foraminal height after disc removal was, on average, 6.5 mm (P < 0.0001). In both Studies 1 and 2 the sagittal dimensions of the foramen were not significantly reduced after disc removal. No significant difference was found in Study 1 in the sagittal dimensions of the foramen between specimens showing normal or degenerated facet joints. In Study 2 a compression of the nerve root within the foramen was found in one specimen, showing a concomitant central stenosis at multiple levels. A significant correlation was found between the sagittal diameters of the foramen and the sagittal diameter of the spinal canal and the pedicle length. Conclusions. Narrowing of the disc space significantly reduces the vertical diameter of the foramen but has no significant effects on its sagittal dimensions. In contrast, the sagittal dimensions of the foramen are strictly related to the sagittal diameter of the spinal canal and the pedicle length. These results suggest that in patients with developmental or combined stenosis of the central spinal canal, a concomitant foraminal stenosis is likely to be present, or at least should be suspected.

Predisposing factors in degenerative spondylolisthesis: A radiographic and CT study

Summary. We report a prospective study analysing whether possible factors predisposing to degenerative spondylolisthesis (DS) must be present concomitantly in order to cause vertebral slipping. Standard and flexion-extension radiographs were obtained from 27 patients with DS and 27 without spondylolisthesis. The level of the intercrestal line, the lumbosacral angle, the presence of sacralization of L5 and vertebral motion at the L4 – L5 level were assessed. Facet joint orientations were measured on CT scans. Only facet joint orientation and vertebral motion at the spondylolisthetic level were significantly different in patients with DS compared with controls. Facet joints were oriented more sagittally both at the spondylolisthetic level and at the levels above and below. An inverse linear correlation was found between the sagittal orientation of facet joints and the mobility of the slipped vertebra. Abnormal sagittal orientation of facet joints and hypermobility of the spondylolisthetic vertebra appear to play major roles among possible factors predisposing to DS. Both factors should be considered in the planning of surgical treatment.Résumé. Nous rapportons une étude prospective analysant si des possibles facteurs prédisposant à un spondylolisthesis dégénératif (DS) doivent être présents en même temps, afin de provoquer un glissement vertebral. Les clichés standards et la flexion-extension ont été obtenus sur 27 patients avec DS et 27 sans olisthésis. Le niveau de la ligne intercrestal, l’angle lombo-sacré, la présence de sacralization de L5 et la mobilité vertébral au niveau L4 – L5 ont été déterminés. L’orientation des facettes articulaires ont été mesurées sur des tomodensitométries. Seules l’orientation des facettes articulaires et la mobilité vertébrale au niveau olisthétique étaient différentes de fa*on significative chez les patients avec DS en comparaison avec le groupe de côntrole. Les facettes articulaires sont orientées plus sagittalement aux deux niveaux olisthétique et aux niveaux au-dessus et en-dessous. Une corrélation linéaire inverse fût trouvée entre l’orientation sagittale des facettes articulaires et de la mobilité de la vertébre déplacée. L’orientation anormale des facettes articulaires et l’hypermobilité de la vertébre olisthétique semble jouer un role important, prédisposant au DS. Les deux facteurs doivent être pris en consideration pour la planification d’un traitement chirurgical.