The influence of accessory rods and connectors on the dynamic response of spine fixation

Purpose This study presents a nondestructive technique to assess the influence of accessory rods and connectors on the dynamic response of spine fixation.Methods Eighteen spine specimens were divided into three construct groups such as group I (2 rods [2R]), II (2 primary rods + 2 accessory rods with 2 transverse connectors [4R+2TC]) and III (2 primary rods + 2 accessory rods with 4 transverse connectors [4R+4TC]). Anterior corpectomy was performed for all specimens. A custom test setup was built to assess the dynamic responses of constructs in flexion-extension (FE) and left-right lateral bending (LRLB) motions. This setup can slide in lateral direction, and it is excited with an electrodynamic shaker vibrated at band limited random frequencies. Accelerometer and reusable dynamic strain sensors were installed on constructs to monitor the dynamic responses. Quasi-static eccentric loading tests were performed to determine the range of motion (RoM).Results The results demonstrated that accessory rods significantly increase the resonance frequency (RF) and decrease the strain over standard 2R construction. Although 4R+4TC provided greatest reduction in rod strain over 4R+2TC and 2R, additional 2 connectors have no significant influence on dynamic response in FE motion.Conclusions An increase in the number of rods has a significant role on the improvement of the fixation's integrity in FE and LRLB motions. However, the additional transverse connectors have significant involvements only in LRLB motion. RF obtained from dynamic tests correlated with the RoM which indicates that the technique could be used as an addendum to the quasi-static test.

Evaluation of Trans-laminar Facet Screw for Lumbar Spine Fixation and Fusion: A Systematic Review

Background Translaminar facet screws are an excellent solution for stabilization of the vertebral motion. It is simple, does not require any specialized equipment, and has the advantages of being a procedure of lesser magnitude, lesser operative time and few complication rate. Recently there is growing interest in this technique to augment the anterior lumbar fusions to achieve global fusion less invasively. Aim of the Work to evaluate the role of translaminar facet screw in lumber fixation and fusion inclusion different techniques of translaminar facet screw fixation, its advantages and disadvantages. Methodology: This systematic review included a discussion of all available studies meeting the eligible criteria including: well conducted descriptive studies, cohort, articles, accepted manuscripts, clinical trials, analytic studies and the literature of reviews, technical notes. Results The small volume of the metal in comparison with pedicle screw constructs provides faster patient recovery and reduce the rate of infection and also provide an adequate area for placement of bone grafts. The low cost of the implants is an added advantage in view of the rising costs of health care. Conclusion Translaminar facet screw fixation is feasible, cheaper and effective in lumbar fixation. The technique is not demanding as transpedicular screw with easier learning curve.

Scapular spine base fracture with long outside-in superior or posterior screws with reverse shoulder arthroplasty

Background: The purpose of the present study was to determine how long superior screws alone or in combination with posterior placement of metaglene screws protruding and penetrating into the scapular spine in reverse total shoulder arthroplasty affect the strength of the scapular spine in a fresh cadaveric scapular model.Methods: Seven fresh cadaver scapulas were allocated to the control group (short posterior and superior screws) and seven scapulas to the study group (spine base fixation with a 4-inch-long superior screw, three with both long superior and long posterior screws).Results: The failure load was lower in the spine fixation group (long screw [869 N] vs. short screw [1,123 N]); however, this difference did not reach statistical significance (p>0.05). All outside-in long superior or superior plus posterior screws failed due to scapular spine base fracture; failures in the short screw group were due to acromion fracture. An additional posterior outside-in screw failed to significantly decrease the failure load of the acromion spine.Conclusions: The present study highlights the significance of preventing a cortical breach or an outside-in configuration when a superior or posterior screw is inserted into the scapular spine base.

A Case of Unanticipated difficult Intubation in a patient posted for C5-C6 Posterior Fixation

Management of a “difficult airway” poses one of the most relevant and challenging tasks for anesthesiologists. Unanticipation with difficult airway and endotracheal intubation during the conduction of general anesthesia may result in complications and fatality. We report the case of a 14 yr old boy for planned C5-C6 spine fixation under general anaesthesia. Unanticipated difficult oral intubation after three failed attempts, managed by a stylleted cuffed endotracheal tube, head up tilt of the operation table, shoulder support, cricoid pressure and rotation of the endotracheal tube anticlockwise at the glottic opening.

Cervical Spine Myelopathy from Metalloma Association with Chronic Retention of a Bullet

A Civilian gunshot wound associated with metallosis in the cervical spine region was an extremely rare case; hence, the clinician had difficulty with diagnosis and surgical treatment. A 57–year-old gentleman had a history of a gunshot wound injury going back 30 years. He presented with neck pain, progress of paresthesia of upper extremities and progressively difficult ambulation for 3 months. Radiographic and pathological diagnosis from tissue of the 7th paravertebral of the cervical spine showed foreign bodies consistent with metallosis. The patient showed improvement of symptoms after posterior cervical spine fixation and decompression. He had full recovery at 1 year follow up. Metallosis can occur in cases of chronic exposure to lead and metals. The results of this chronic process of metallosis will develop to metalloma, which then compresses the spinal cord and develops into myelopathy. The patient had a bullet, or piece of metal at the cervical spine, so surgical removal was performed to prevent further compression of the spinal cord from metalloma.

C2 quad-screws facilitate 4-rod fixation across the cervico-thoracic junction

Background: Cervical spine deformity is a potentially devitalizing problem. Contemporary techniques for repair and reconstruction include fusion using rods of tapered diameter alone, or quadruple-rod constructs in which primary rods are joined to floating accessory rods by connectors. Here, we present how we utilized a quadruple-rod construct to perform five C2 to thoracic spine fusions. Methods: Our hospital electronic medical record revealed five patients who underwent the four rod C2-thoracic spine fixation. Patients ranged in age from 14-years-old to 78-years-old. The mean operative time was 715.8 min (range 549–987 min), and average estimated blood loss was 878 cc (range 40–1800 cc). Results: None of the five patients sustained any intraoperative complications, and none demonstrated progressive kyphotic deformity over the average follow-up interval of 8 months. Conclusion: We successfully treated five patients with degenerative or oncologic cervical pathology requiring fixation across the cervicothoracic junction utilizing a 4-rod C2-cervicothoracic fusion technique.