Mohammadreza Chehrassan

Pedicle screw insertion techniques: an update and review of the literature.

Pedicle screw construct have become one of the most practiced procedure in spinal surgery. Despite commonly used, questions remain about their safety especially for the thoracic spine and in deformity where difficulty in positioning can lead to pedicle breach and adjacent structures injury. Misplacement rates have been reported to be from 5 to 41% in the lumbar spine and from 3 to 55% in the thoracic spine. Hence, various procedures have been described in order to improve pedicle screw insertion accuracy. Aim of this study is to evaluate current concepts on pedicle screws placement techniques to better understand recent attitude and clarify some doubts when selecting the most proper method.

Single level cervical fusion by an anterior approach using autologous bone graft influences the adjacent levels degenerative changes: clinical and radiographic results at 10-year minimum follow-up

IntroductionCervical degenerative pathology can produce pain and disability and, in case of failure of conservative treatment surgery is indicated.Materials and methods107 patients affected by single level cervical degenerative pathology were surgically treated by Cloward procedure. On radiographs, the sagittal segmental alignment (SSA) of the affected level and sagittal alignment of the cervical spine were measured.Results Preoperatively, mean SSA was 0.6° and at the last follow-up 1.8°. In particular, adjacent-level degeneration occurred more frequently in Group A than in Group B.Conclusion Lordotic SSA angle can be considered a protective factor against adjacent-level degeneration.

Surgical tricks for open lumbar discectomy.

Herniated disc syndrome in the lumbar spine is the consequence of the conflict between a spinal root or cauda equina and a fragment of nucleus pulposus migrated through the annulus fibrosus. Patients usually complain of pain or paraesthesia travelling down to the lower extremity in the corresponding dermatome. In the majority of cases symptoms and radiographic signs regress with conservative measures [1]. However, many patients experience persistent symptoms or severe rapid pain progression with sensitive and motor deficits due to the rapid compression of one or more spinal roots. Lumbar discectomy is usually indicated after 6–12 weeks of conservative treatment if pain remains intractable or in case of severe sensitive or motor deficits [2, 3].

Outcomes of total hip replacement in limbs affected by poliomyelitis

Introduction The outcomes of total hip replacement in patients suffering from residual poliomyelitis are poorly covered in the literature. In this retrospective study we posed the question of whether total hip replacement performed for degenerative hip diseases in limbs with residual poliomyelitis could determine satisfactory mid-term clinical and radiographic results, with a reasonable complication rate. Methods A retrospective study was carried out to assess the results of 14 total hip replacements performed on 14 patients with residual poliomyelitis on the involved limb from June 1999 to September 2011. Average age at the time of surgery was 51 years (range 26-66 years). Mean duration of follow-up was 92 months (range 52-156 months). Surgery was performed through a direct lateral approach on all hips. All but one were cementless implants. Results 2 implants failed, 1 due to traumatic acetabular fracture 6 days after surgery, and 1 due to aseptic cup loosening 13 years after surgery. Surgery was uneventful in all patients except 1 (7%), who experienced a transient sensory sciatic nerve palsy. At the latest follow up Harris Hip Score was 83.3 (range 72-91) with a marked improvement when compared to preoperative score (average 52, range 32-78). No dislocations had occurred. Conclusions Total hip replacement can be considered a feasible option for hip osteoarthritis in patients with limbs affected by residual poliomyelitis. Longer follow-up studies are needed to assess the effectiveness of unconstrained total hip replacement in polio patients.

Transforaminal lumbar interbody fusion.

L2–L3–L4 posterolateral arthrodesis associated with asymmetric right transforaminal interbody fusion at L3–L4 intervertebral space was planned. The patient was placed on a suitable spine frame in prone position with the hips in neutral extension, in order to maintain lumbar lordosis. A proper positioning allows the abdomen to hang free to reduce abdominal pressure, which leads to diminished venous engorgement and intraoperative bleeding. A standard midline approach was performed from L1 to L5. The supraspinous and interspinous ligaments were carefully left intact. Once the posterior processes were carefully exposed, the articular processes of L2, L3 and L4 joints were detected. Joint capsule of L2–L3 preserved intact in order to avoid proximal junction kyphosis. In order to find the entry point for pedicle screw we usually place a forceps over the transverse process to identify the proximal and distal margins of the pedicle. The cortex on the entry point is opened with an awl where the articular joint reaches the transverse process. Pedicles were gently drilled with a 2.7 mm drill bit. This technique provides a very fine hole during the pedicle penetration, which can be corrected simply in case of incorrect trajectory creation. The integrity of the walls of the pedicles was checked. 2 mm K-wires were inserted in each pedicle. Fluoroscopy

Single level anterior cervical discectomy and interbody fusion

Degenerative disorder of cervical intervertebral disc is a common cause of neck and upper limb pain. There are several reported surgical techniques available for decompression and stabilization of the interested segment in order to treat the degenerative disorder of cervical disc [1]. Anterior cervical discectomy and interbody fusion (ACDIF) for a single level can be performed in different ways to provide good stability and restoring sagittal segmental alignment [2]; however, the rationale for the choice between different techniques remains unclear [1, 3]. The aim of this video case presentation is to show the surgical technique of ACDIF using stand-alone polyetheretherketone (PEEK) cage.