Accuracy of 837 pedicle screw positions in degenerative lumbar spine with conventional open surgery evaluated by computed tomography.

BACKGROUND: The spatial and directional accuracy of the positioning of pedicle screws in the lumbosacral spine with conventional open surgery assessed by computed tomography (CT) has been published in several studies, systematic reviews and meta-analyses with a short-term follow-up. Inaccurate pedicle screw insertion may cause neurologic symptoms and weakens the construct. METHODS: The data of 147 patients operated on with transpedicular screw fixation based on anatomical landmarks, supported by fluoroscopy, by a senior neurosurgeon in our clinic between 2000 and 2010 were analyzed retrospectively. The accuracy of the pedicle screw position was assessed by using postoperative CT images and graded in 2-mm increments up to 6 mm by two independent surgeons and partly by an independent radiologist. RESULTS: A total of 837 lumbosacral pedicle screws were inserted in 147 randomly selected patients by a senior neurosurgeon. A mean accuracy of 85.7% of the screws being inside the pedicles was identified by the surgeon observers, with 3.3% being perforated 4 mm or more outside the pedicles. Postoperative neurologic symptoms were observed on the side corresponding to the breach in an average of 25.9% of patients with pedicle perforations, and 89.2% of the misplaced screws were either medially or inferiorly inserted. CONCLUSIONS: Screw application reached a mean accuracy of 85.7% based on anatomical landmarks supported by fluoroscopy, warranting computer-assisted navigation for increased accuracy. Our results of 24 patients (16.3%) with the breached screws indicate that the direction of the breach may be more important than the absolute deviation in causing new neurologic symptoms.

[An unusual etiology for pain in the back, hip and leg in a young woman]. / Nuoren naisen mystinen alaselkä-lonkka-alaraajakipu.

We present a 28-year old woman, suffering from low back and right leg pain for 5 years, with motor and sensory deficits of the leg. Disc herniation, hip related pain, depression, and even an osteoid osteoma were suspected during the years, and several imaging studies had been undertaken. Based on an ENMG-study a lesion affecting the right L5-nerve root distal to the ganglion was suspected. On a pelvic MRI a nonenhancing tumor of the right L5-root was seen. The tumor was resected operatively. On histologic examination an uncommon granulocellular tumor was diagnosed. The patient recovered almost completely.

Role of albumin coating of tympanostomy tubes: long-term clinical evaluation.

OBJECTIVE: Our previous work has shown that albumin coating of tympanostomy tubes prevented adhesion of proteins or bacteria on the tube surface in vitro and in a 9-month prospective follow-up study. This study was continued until all tubes were extruded. STUDY DESIGN: A prospective, clinical trial. METHODS: The randomized, double-blind clinical trial had 149 patients. The randomization was revealed after the follow-up period of 9 months. The number of tube sequelae in ears with human serum albumin (HSA)-coated titanium tympanostomy tubes was compared with the contralateral ears with uncoated, otherwise identical titanium tubes. The follow-up continued until all tubes were extruded, followed by evaluation of each tympanostomized patient. RESULTS: No significant difference between the two tube types emerged after the 9-month follow-up. Among the patients younger than 2 years, one of the three typical bacteria causing acute otitis media (AOM), Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, was found in 45% of all bacterial cultures taken during AOM. However, among patients older than 2, one of these bacteria appeared in 17% of all the bacterial cultures and in 8% of cultures taken during the summer. CONCLUSIONS: After the first 9 follow-up months, no difference was found in the sequelae related to uncoated and HSA-coated tubes. The typical bacteria causing AOM were found less frequently among patients older than 2 years. A profile of tympanostomy patients in Finland will be given.

Albumin-coated tympanostomy tubes: prospective, double-blind clinical study.

OBJECTIVES: Coating an implant with albumin prevents adhesion of proteins, bacteria, and platelets and thus may lead to its improved and prolonged function. Previously, we have demonstrated the inhibition of binding of fibronectin, one of the most adhesive glycoproteins, on human serum albumin (HSA)-coated tympanostomy tubes and the durability of this binding inhibition in a 8-month trial. We have also demonstrated that the HSA coating inhibits the binding of Staphylococcus aureus and Pseudomonas aeruginosa to titanium plates. This prospective study evaluated the effect of albumin coating on tympanostomy tube sequelae and on the outcome of tympanostomized patients. STUDY DESIGN: Double-blind, prospective, randomized clinical trial. METHODS: Two otolaryngological centers in southern Finland enrolled 179 pediatric patients. Number of tube occlusions and otorrhea and tube ventilation time in the ears with HSA-coated titanium tympanostomy tubes were compared with the contralateral ear with its uncoated, otherwise identical titanium tube during a 9-month follow-up period. RESULTS: In HSA-coated tubes, average ventilation time was slightly longer and the number of early tube occlusions significantly less (P < .05). Moreover, in patients with perioperative bleeding, the coating prolonged average ventilation time of tympanostomy tubes significantly (P < .05). CONCLUSIONS: HSA coating reduces early tube occlusions by preventing adherence of blood and secretion.

Is there a connection between the clinical response after an external fixation test or a subsequent lumbar fusion and the pre-test intervertebral kinematics?

STUDY DESIGN: Evaluation of a possible correlation of clinical symptoms of chronic low back pain (LBP) patients before and after application of external spinal fixation (ESF) with three-dimensional motion patterns. OBJECTIVE: To determine whether the intervertebral kinematics in chronic LBP patients correlate with pain relief after stabilization of the suspected painful segments. SUMMARY OF BACKGROUND DATA: Chronic LBP is a complex clinical entity with mechanical, biochemical, and psychosocial components. Although clinically controversial, ESF has been shown to reduce intervertebral motion, and thus, it provides a mechanism to investigate the mechanical aspect of LBP. METHODS: Thirty-four chronic LBP patients were tested with ESF of the suspected painful segments. The subjective pain relief experienced by the patients during the test and 2 years after spinal fusion surgery was determined, along with the Oswestry Disability Index. Before removal of ESF, the three-dimensional intervertebral kinematics of the painful segments (specifically range of motion, coupling patterns, and motion asymmetries) were analyzed with a precision optoelectronic camera system during active trunk motions. A series of linear correlations were performed between the clinical measures and the motion parameters. RESULTS: The subjective pain relief during the ESF test was nominally, but not significantly, associated with lateral bending asymmetry ( = 0.22) and "abnormal" axial rotation-lateral bending coupling ( = 0.13). The improvement in the Oswestry Disability Index both post-test and at 2 years after lumbar fusion surgery was significantly correlated with the extension range of motion ( = 0.049 and = 0.036, respectively) and the extension-to-flexion range of motion ratio ( = 0.035 and = 0.044, respectively). CONCLUSIONS: The "abnormal" motion patterns of chronic LBP patients did not correlate with subjective pain relief after ESF of the suspected symptomatic levels or with the midterm outcome of subsequent lumbar fusion surgery. The results suggest that preserved motion of the symptomatic segments before surgery is positively correlated with the clinical result of the subsequent spinal fusion in case of a positive ESF test result.