Francesco Lolli

Complications of thoracic pedicle screws in scoliosis treatment.

Study Design. A retrospective study. Objective. To analyze complications with thoracic pedicle screws in scoliosis treatment at our Department over a 3-year period (1999–2001). Summary of Background Data. The use of pedicle screws remains controversial for thoracic scoliosis for fear of complications. Methods. A total of 115 consecutive patients who underwent posterior fusion using 1035 transpedicular thoracic screws were reviewed. All patients presented a main thoracic scoliosis with a mean Cobb angle of 75.4° (range, 60°–105°). For thoracic screw placement, a mini-laminotomy technique was used, inserting a spatula inside the vertebral canal to palpate the borders of the pedicle. Postoperative CT scan was used in 25 patients (21.7%) to study a total of 311 screws, when the screw position was questionable. Results. An independent spine surgeon retrospectively reviewed medical records and radiographs of the patients, at a mean follow-up of 4 years. There were 18 screws misplaced (1.7%) in a total of 13 patients (11.3%). Screw malposition was symptomatic only in 1 patient (pleural effusion and fever) and asymptomatic in the other 12 cases (10.4%). Other complications included intraoperative pedicle fractures in 15 patients (13%), dural tears (without neurologic complications) in 14 cases (12.1%), and superficial wound infections in 2 (1.7%). Another operation for screw removal was performed in 5 patients (4.3%), due to pleural effusion (in 1 case), asymptomatic late lateral loosening of a malpositioned screw (in 1), and the possible future risks related the intrathoracic screw position despite the lack of any symptoms (in 3). Two cases (1.7%) were retreated due to wound infection, without removing instrumentation. There was no loss of correction at follow-up. Conclusions. The thoracic pedicle screw placement in scoliosis patients requires utmost caution. The mini-laminotomy technique was beneficial in increasing safety of the procedure with an acceptable incidence of complications.

Transforaminal Lumbar Interbody Fusion in Degenerative Disk Disease and Spondylolisthesis Grade I: Minimally Invasive Versus Open Surgery.

Background: Interbody fusion represents an efficient surgical treatment in degenerative lumbar disease, achieving satisfying outcome in >90% of cases. Various studies have affirmed the advantages of percutaneous and minimally invasive techniques with regard to minimized damage on soft tissues during surgical procedure, but their efficacy in comparison with the classic open surgical procedures has not yet been demonstrated. Materials and Methods: This is a retrospective study. We compared 30 consecutive patients affected by disk degenerative disease or grade I degenerative spondylolisthesis that were treated with minimally invasive transforaminal lumbar interbody fusion (mini-TLIF) to a group of 34 consecutive patients presenting similar pathologic findings and demographic characteristics that underwent interbody fusion by traditional open approach (open-TLIF). All patients were treated between 2006 and 2010. Patients’ mean age was 46 years (min 28–max 56) and 51 years (min 32–max 58), respectively. Mean follow-up was 23 months (min 12–max 38) and 25 months (min 12–max 40), respectively. Clinical evaluation was performed by using Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) questionnaires. Radiographic evaluation was performed on standing and dynamic x-rays before operation and at final follow-up. Results: There was a statistically significant improvement in clinical scores (VAS and ODI) in both groups. Early postoperative VAS score was significantly lower in the mini-TLIF group. Mean hospital stay and mean blood loss were significantly higher in the open-TLIF group than in the mini-TLIF group (7.4 vs. 4.1 d and 620 vs. 230 mL, respectively). Surgical time length of the procedure was higher in the mini-TLIF group. There were no major neurological complications in any of the patients. At final follow-up, radiographic evaluation showed good implant stability in both groups. Conclusions: Mini-TLIF is a safe and efficient procedure and, when correctly and carefully performed, can reach good results, similar to those obtained with traditional open surgical techniques, even though it may require a longer surgical time at least during the first stages of the learning curve. Reduced surgical invasiveness, short hospital stay, and limited blood loss represent the major advantages of minimally invasive technique.

Hydroxyapatite-based biomaterials versus autologous bone graft in spinal fusion: An in vivo animal study

Study Design. An in vivo study was designed to compare the efficacy of biomimetic magnesium-hydroxyapatite (MgHA) and of human demineralized bone matrix (HDBM), both dispersed in a mixture of biomimetic MgHA nanoparticles, with that of an autologous bone graft. Objective. The objective of this study was to evaluate 2 new bone substitutes as alternatives to a bone autograft for spinal fusion, determining their osteoinductive and osteoconductive properties, and their capacity of remodeling, using a large animal model. Summary of Background Data. Spinal fusion is a common surgical procedure and it is performed for different conditions. A successful fusion requires potentially osteogenic, osteoinductive, and osteoconductive biomaterials. Methods. A posterolateral spinal fusion model involved 18 sheep, bilaterally implanting test materials between the vertebral transverse processes. The animals were divided into 2 groups: 1 fusion level was treated with MgHA (group 1) or with HDBM-MgHA (group 2). The other fusion level received bone autografts in both groups. Results. Radiographical, histological, and microtomographic results indicated good osteointegration between the spinous process and the vertebral foramen for both materials. Histomorphometry revealed no significant differences between MgHA and autologous bone for all the parameters examined, whereas significantly lower values of bone volume were observed between HDBM-MgHA and autologous bone. Moreover, the normalization of the histomorphometric data with autologous bone revealed that MgHA showed a significantly higher value of bone volume and a lower value of trabecular number, more similar to autologous bone than HDBM-MgHA. Conclusion. The study showed that the use of MgHA in an ovine model of spinal fusion led to the deposition of new bone tissue without qualitative and quantitative differences with respect to new bone formed with autologous bone, whereas the HDBM-MgHA led to a reduced deposition of newly formed bone tissue. Level of Evidence: N/A

Adult's Degenerative Scoliosis: Midterm Results of Dynamic Stabilization without Fusion in Elderly Patients—Is It Effective?

Study Design. A retrospective study. Purpose. Posterolateral fusion with pedicle screw instrumentation used for degenerative lumbar scoliosis can lead to several complications. In elderly patients without sagittal imbalance, dynamic stabilization could represent an option to avoid these adverse events. Methods. 57 patients treated by dynamic stabilization without fusion were included. All patients had degenerative lumbar de novo scoliosis (average Cobb angle 17.2°), without sagittal imbalance, associated in 52 cases (91%) with vertebral canal stenosis and in 24 (42%) with degenerative spondylolisthesis. Nineteen patients (33%) had previously undergone lumbar spinal surgery. Results. At an average followup of 77 months, clinical results improved with statistical significance. Scoliosis Cobb angle was 17.2° (range, 12° to 38°) before surgery and 11.3° (range, 4° to 26°) at last follow-up. In the patients with associated spondylolisthesis, anterior vertebral translation was 19.5% (range, 12% to 27%) before surgery, 16.7% (range, 0% to 25%) after surgery, and 17.5% (range, 0% to 27%) at followup. Complications incidence was low (14%), and few patients required revision surgery (4%). Conclusions. In elderly patients with mild degenerative lumbar scoliosis without sagittal imbalance, pedicle screw-based dynamic stabilization is an effective option, with low complications incidence, granting curve stabilization during time and satisfying clinical results.

Treatment of scoliosis in patients affected with Prader-Willi syndrome using various techniques

BackgroundThe incidence of spinal deformity in children with Prader-Willi syndrome (PWS) is high, with 86% of these patients found to have a significant structural scoliosis; however, there are very few case reports describing surgical treatment for this deformity.MethodsThe authors reviewed a case series consisting of 6 patients who underwent spine surgery for scoliosis. Childrens mean age at index surgery was 12 years and 10 months (range, 10 to 15 yrs). Clinical evaluation revealed the typical phenotypic features of the PWS in all of the patients; 4 subjects had a karyotype confirmation of PWS. Major structural curves showed preoperative mean Cobb angles of 80.8° (range, 65° to 96°). Hybrid instrumentation with sublaminar wires, hooks and screws was used in the first 2 patients, while the remaining 4 were treated with titanium pedicle screw constructs.ResultsThe mean clinical and radiological follow-up was 3 years and 10 months (range, 2 years to 9 years). Major complication rate was 50%. One patient who developed a major intraoperative complication (paraparesis) prevented spinal fusion to be obtained: the neurologic deficit resolved completely after instrumentation removal. Solid arthrodesis and deformity correction in both coronal and sagittal plane was, however, achieved in the other 5 cases and no significant curve progression was observed at follow-up. Another major short-term complication was encountered 3 months after surgery in a patient who experienced the detachment of a distally located rod and required correction through revision surgery and caudal extension by one level. Cervico-thoracic kyphosis was seen in 1 patient who did not require revision surgery.ConclusionsSpine reconstructive surgery in patients with PWS is rare and highly demanding.The best method of reconstruction is posterior multilevel pedicle screw fixation. Moreover, even with modern techniques, the risk of complications is still high. These new techniques, however, have shown to improve the postoperative course by allowing for immediate mobilization without any brace or cast. The use of the growing rod techniques, requiring repeated surgeries, should be carefully evaluated in each single case.

Long-term systemic metal distribution in patients with stainless steel spinal instrumentation: a case-control study.

Study Design: Case-control study. Objective: To verify whether metal ions in the serum of patients bearing spinal stainless steel instrumentation were elevated over the long-term period after implantation of stainless steel prostheses and to determine whether these levels could predict potential unfavorable outcomes. Summary of Background Data: Instrumented spinal arthrodesis, the standard procedure to correct scoliosis, routinely remains in situ for the lifetime of the patient. Elevated metal ion levels have been reported at short-term follow-up, but the long-term status, possibly related to systemic toxic effects, is unknown. Methods: Twenty-two patients treated for scoliosis with posterior spinal arthrodesis using stainless steel instrumentation were included. Minimum follow-up was 10 years. Oswestry Disability Index and visual analog scale were recorded. Chromium (Cr) and nickel (Ni) levels were measured (ng/mL) and compared with levels in a control group including 30 healthy subjects. A receiver-operating characteristic curve was calculated on the basis of the clinical assessment (pain and disability) and the x-ray picture; the cutoff values for the parameters were settled, and the ion-testing potential was considered as a surrogate marker for failure. Results: The level of Cr was significantly increased in patients, compared with controls (P=0.018). A remarkable Cr release without any clinical-radiologic sign was recorded in some female patients. A high specificity (93%), positive likelihood ratio (7.00), and overall accuracy (77%) were calculated for Cr; these indicate a high risk of failure when the levels exceeded the cutoff value, which was 0.6 ng/mL. No significant difference between the groups was found for Ni (P=0.7). Conclusions: Cr testing is suggested as a reliable marker for the malfunctioning assessment and as a support for standard procedures, especially with doubtful diagnosis. Furthermore, high levels of Cr ions were observed in female patients. This finding deserves attention especially when counseling young fertile women.

The Cervical Trauma in Children: Difficulties in Diagnosis and Treatment Choice

Cervical traumas in children are often misunderstood and treated incorrectly. Injuries of the cervical spine are relatively rare in children but are a distinct clinical entity compared with those found in adults. The unique biomechanics of the pediatric cervical spine leads to a different distribution of injuries and distinct radiographic features. The treatment of cervical spine injuries in children must be founded on an understanding of spine development. Differences in injury patterns, interpretation of radiographic studies, and management of injuries are a direct result of the unique anthropometrics and biomechanics of a child. The literature specifically addressing cervical spine injuries in children is scarce most studies have been focused on adults. In more recent years, as distinct aspects of the pediatric spine have been better appreciated, more attention has been given exclusively to injuries of the cervical spine in younger patients. We describe two cases of cervical trauma of different entity for which the incorrect evaluation of the trauma led to a difficult diagnostic-therapeutic path.

Magnetically controlled growing rod in early onset scoliosis

Background Magnetically controlled growing rods (MCGR) are increasingly used for the treatment of early onset scoliosis. Aim of the study is to retrospectively review our patients treated with MCGR focusing on complications. Materials and methods We retrospectively reviewed 7 patients, affected by early onset scoliosis and surgically treated with magnetically controlled growing rods (minimum follow up 6 months). There were 7 children, 3 females and 4 males, with an age ranging from 4 to 11 years. The aetiology was 6 idiopathic (infantile or juvenile), 1 congenital. In one case a VEPTR was first implanted before using MCGR. In all cases a dual growing rod was implanted, using as distal anchors pedicle screws, as proximal anchors hooks. Results At a minimum follow up of 6 months, after performing 5.7 lengthening procedures per patient (lengthening performed every 60-90 days), main thoracic scoliosis was corrected from 62.7° to 32.0° (mean correction 49%), lumbar curve form 58.5° to 32.0° (45%). The correction was maintained at final follow up. No neurological or infective complications occurred. In one patient a revision surgery was performed due to persistent sciatica secondary to lumbar misplaced screw. In another one, a revision was performed due to proximal hooks mobilization. At final follow up, no patient presents pain or functional limitation. Conclusions Those results showed that MCGR can be safely and effectively used in patients affected by early onset idiopathic scoliosis, with an acceptable complications incidence (33%) if compared with literature regarding

Growing spinal systems and early onset deformities: is hyperkhyphosis a contraindication?

Materials and methods We retrospectively reviewed 16 paediatric patients affected by kyphotic spinal deformity (T3-T12 kyphosys > 60°) surgically treated with Growing Rod or VEPTR-like systems from 2006 to 2011. There were 8 males and 8 females, with a mean age of 7 years (range, 4 to 11). The aetiology was: idiopathic scoliosis (5 cases), kyphosis in Morquio disease (1) and in Pott disease (1), congenital scoliosis (3), trisomy 8 (1), Escobar syndrome (1), Prader Willi (1), spondylocostal dysplasia (1), arthrogryposis (2). Dual growing rod was implanted in 9 cases, VEPTR in 9 (always rib to spine construct). Pre-operative main thoracic scoliosis averaged 64° (range, 10° to 100°), lumbar scoliosis 55° and thoracic kyphosis 71° (60° to 90°), 67° in patients treated with growing rod and 77° for those treated with VEPTR.

Is there a correlation between pelvic incidence and proximal junctional kyphosis (PJK) after surgery for adult scoliosis

Materials and methods 78 consecutive patients (63 women 15 men) were included in the study, mean age of 66 years (range 60-77), surgically treated at our Division between 2000 and 2005. In all cases the diagnosis was idiopathic scoliosis, with positive sagittal imbalance. In 29 cases (37.2 %) a previous arthrodesis was performed. All patients were treated with posterior arthrodesis with pedicle instrumentation and a pedicle subtraction osteotomy (PSO) in 17 cases and Smith Petersen osteotomy ( SPO ) at multiple levels in 25 cases. The clinical and radiographic questionnaires (Oswestry, VAS) filled in before and after surgery and at final follow-up were evaluated.