Stefano Gumina

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.

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.

Contralateral recurrent lumbar disc herniation. Results of discectomy compared with those in primary herniation.

STUDY DESIGN The surgical outcomes of patients who underwent discectomy for contralateral recurrent herniation and primary herniation were evaluated. OBJECTIVE To assess whether the clinical results in patients undergoing surgery for contralateral recurrent disc herniation may be as good as those reported after primary discectomy. SUMMARY OF BACKGROUND DATA No retrospective or prospective investigation has been conducted on the surgical treatment of contralateral recurrent lumbar disc herniation. METHODS Sixteen patients who underwent surgery for recurrent disc herniation at the same level as primary disc excision, but on the opposite side, were analyzed prospectively from the recurrence of contralateral radicular pain (Group 1). All patients had reported a satisfactory results after primary discectomy. Fifty consecutive patients who underwent disc excision during the study period, who did not report recurrent radicular pain, were analyzed for comparison (Group 2). Overall patient satisfaction, pain severity, functional outcome, and work status were evaluated. RESULTS At the 2-year follow-up, the clinical outcome was rated as satisfactory in 14 of 16 patients in Group 1 and in 45 of 50 in Group 2 (P > 0.05). Twelve patients in Group 1 and 42 in Group 2 had resumed their work or daily activities at the same level as before the operation (P > 0.05). Radicular pain was significantly improved in both groups at the 6-month and 2-year follow-ups. At the 6-month follow-up, low back pain was significantly improved only in the patients in Group 2; however, at the 2-year follow-up, low back pain was significantly improved in both groups. CONCLUSIONS Clinical results in patients reoperated on for contralateral recurrent lumbar disc herniation compare favorably with those reported after primary discectomy. The improvement of pain in the low back and lower limbs reported by the majority of patients 2 years after reoperation suggests that fusion is not needed in this patient population.

Subacromial space in adult patients with thoracic hyperkyphosis and in healthy volunteers

The assumption that subacromial space decreases in patients with thoracic hyperkyphosis arises from sporadic and personal observations. The purpose of this study was to compare width of subacromial space calculated on radiographs and CT scans of a high number of patients with thoracic hyperkyphosis that registered on exams of healthy volunteers. We measured the subacromial space, using Petersson’s method, on radiographs of 47 patients with idiopathic or acquired thoracic hyperkyphosis and of 175 healthy shoulder volunteers. Both groups were further distinguished considering gender and age. Females with hyperkyphosis were also divided in two subgroups: those with a kyphotic curve of less (24 patients) or more (19 patients) than 50°, respectively. Subacromial space of all patients and of 21 volunteers was also evaluated using CT. Acromio-humeral space was less wide in patients with hyperkyphosis with respect to coeval volunteers of the same gender; in females and in subjects older than 60. Subacromial width of females with hyperkyphosis whose curve was more than 50° was significantly narrower (p<0.05) than that measured on radiograms or CT scans of females with a less severe spinal deformity. Decrease of subacromial space may be attributed to less posterior tilting of the scapula and to dyskinesis of the scapular movement. Scapular malposition causes an anomalous orientation of the acromion that may contribute to subacromial impingement. Patients with thoracic hyperkyphosis greater than 50° had a subacromial space narrower than that measured in patients with a less severe kyphosis. This suggests that subacromial width is directly related to severity of thoracic kyphosis. Because hyperkyphosis of patients with osteoporotic vertebral fractures may worsen over the time, subacromial decompression could give only temporary shoulder pain relief.

The morphometry of the coracoid process – its aetiologic role in subcoracoid impingement syndrome

Abstract Anatomical morphometric studies of the coracoid process and coraco-glenoid space were carried out on 204 dry scapulae. No statistically significant correlations were found between length, or thickness of the coracoid process, prominence of the coracoid tip, coracoid slope, coraco-glenoid distance, or position of the coracoid tip with respect to the uppermost point of the glenoid. These anatomical characteristics were independent of the dimensions of the scapulae. Three configurations of the coraco-glenoid space were identified. Type I configuration was found in 45% of scapulae and Type II and Type III, in 34% and 21% of specimens, respectively. The lowest value of the coraco-glenoid distance were seen in Type I scapulae. Morphometric characteristics which might predispose to subcoracoid impingement were found in 4% of Type I scapulae. A total of 27 scapulae, nine with each type of configuration were submitted to CT scanning. Scapulae with a Type I configuration were found to have low values for the coraco-glenoid angle and coracoid overlap, which are known to be associated with a short coraco-humeral distance. Subjects with a Type I configuration, and severe narrowing of the coraco-glenoid space, appear to be predisposed to coraco-humeral impingement. These morphometric characteristics may be easily evaluated on CT scans.Résumé Des études d’anatomie morphométrique du processus coraco ont été menées sur 204 omoplates sèches. Aucune corrélation statistiquement significative n’a été trouvée entre la longueur, ou l’épaisseur, du processus coraco, la proéminence du point coraco, la pente coraco, la distance coracogléno et la position du point coraco par rapport au sommet de la gléno. Ces caractéristiques sont indépendantes des dimensions de l’omoplate. Trois configurations de l’espace coracogléno ont été identifiées: Type I, Type II et Type III. Les caractéristiques morphometriques qui peuvent prédisposer à une friction subcoraco ont été trouvées sur 4% des omoplates avec une configuration de Type I. Un total de 27 omoplates, 9 de chaque type de configuration, a été soumis à une tomographie osseuse. Les omoplates du premier type de configuration présentent un angle coracogleno de faible valeur, ce qui est connu pour être associé avec une distance coracohumerale faible. Les sujets présentant une configuration de premier type et un sévère rétrécissement de l’espace coracogleno, apparaissent être prédisposés à une friction coracohumérale. Ces caractéristiques morphométriques peuvent aisément être évaluées par tomographie osseuse.

The association between arterial hypertension and rotator cuff tear: the influence on rotator cuff tear sizes

BACKGROUND This study was conducted to establish whether hypertension increases the risk of occurrence of rotator cuff tear and influences its size. MATERIALS AND METHODS A case-control design was used. We studied 408 consecutive patients (228 men, 180 women) who underwent arthroscopic rotator cuff repair. Tear size was determined during surgery. The control group included 201 individuals. For the study purpose, participants were divided into 2 groups by presence or absence of hypertension. We applied a logistic regression model to investigate if hypertension affects the risk of cuff tear. A multinomial logistic regression model was applied to explore the association between hypertension and tear size. We used the analysis of covariance method to determine if the duration of hypertension influences the severity of the tear; finally, we compared mean duration of antihypertensive therapy in patients with small, large, and massive tears. All analyses were adjusted for age and sex. RESULTS Hypertension was associated with a 2-fold higher risk of tear occurrence (odds ratio [OR], 2.05; 95% confidence interval [CI], 41-2.98). No association was detected between hypertension and the probability of a small tear (OR, 0.63, 95% CI, 0.33-1.19). Hypertensive individuals were 2 times more likely to experience large tear (OR, 02.09; 95% CI, 1.39-3.16) and 4 times more likely to experience massive tear (OR, 04.30; 95% CI, 2.44-7.58) than normotensive individuals. Mean duration of antihypertensive therapy significantly increased from small tear (1.08 years) to large tear (3.20 years) to massive tear (6.34 years) patients (analysis of covariance: F((2,403)) = 16.357, P = 1.48 × 10(-7)). CONCLUSIONS Our data provide evidence that hypertension is a significant risk factor for the occurrence and severity of rotator cuff tears.