Failure of transodontoid screw fixation

1998 ◽  
Vol 88 (1) ◽  
pp. 158-160 ◽  
Author(s):  
Shahin Etebar ◽  
David W. Cahill
Keyword(s):  
Screw Dislocation ◽  
Screw Fixation ◽  
Rare Complication ◽  
Type Ii ◽  
Content Type ◽  
Odontoid Fractures ◽  
Surgical Fusion ◽  
Anterior Body ◽  
Postoperative Fracture ◽  
Fine Print

✓ Anterior odontoid screw fixation is being performed with increasing frequency and may currently be the treatment of choice for Type II and selected Type III odontoid fractures, because it is the only surgical fusion that preserves C1–2 motion. Typically patients are immobilized postoperatively in a simple cervical collar. The authors present a case of postoperative fracture of the anterior body of the axis secondary to screw dislocation 5 weeks after single anterior odontoid screw osteosynthesis. Possible reasons for this rare complication and its implications for the technique are discussed.

Biomechanical evaluation of a bioresorbable odontoid screw

2005 ◽  
Vol 2 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Christopher P. Ames ◽  
Neil R. Crawford ◽  
Robert H. Chamberlain ◽  
Vivek Deshmukh ◽  
Belma Sadikovic ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Odontoid Process ◽  
Type Ii ◽  
Content Type ◽  
Odontoid Fractures ◽  
Titanium Screws ◽  
Piston Displacement ◽  
Initial Fracture ◽  
Strength And Stiffness ◽  
Fine Print

Object. The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws. Methods. Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury. Conclusions. The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.

A clinical comparison of one- and two-screw odontoid fixation

1998 ◽  
Vol 89 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Jeffrey D. Jenkins ◽  
Domagoj Coric ◽  
Charles L. Branch
Keyword(s):  
Screw Fixation ◽  
Union Rate ◽  
Clinical Safety ◽  
Content Type ◽  
Odontoid Fractures ◽  
Efficacious Treatment ◽  
Significant Difference ◽  
Fixation Techniques ◽  
The One ◽  
Fine Print

Object. The optimal treatment of Type II odontoid fractures is controversial. Various therapies have been used, including nonrigid immobilization, halo orthosis, posterior atlantoaxial arthrodesis, and odontoid screw fixation. Of these, odontoid screw fixation is the only treatment modality that provides immediate stabilization and preserves normal motion at C1–2. It has been suggested in cadaveric biomechanical studies that there is no advantage to using more than one screw for anterior odontoid fixation. The authors compared the clinical safety and efficacy of one- and two-screw anterior odontoid fixation. Methods. The authors retrospectively reviewed the medical records and radiographs of 42 consecutive patients who had undergone fixation for treatment of odontoid fractures at a single institution between 1989 and 1995. The group treated with a single screw consisted of 20 patients (11 males and nine females) with an average age of 54 years. The union rate in this group, as determined by postoperative dynamic radiographs, was 81%. The group treated with two screws consisted of 22 patients (13 men and nine women) with an average age of 64 years, whose union rate was 85%. Conclusions. Anterior odontoid screw fixation is a safe and efficacious treatment for odontoid fractures. In the authors' experience there was no significant difference in the successful union rates achieved with either the one- or two-screw fixation techniques (81% and 85%, respectively; χ2 = 0.09, p = 0.76).

Choice of treatment of odontoid fractures

1982 ◽  
Vol 57 (4) ◽  
pp. 496-499 ◽  
Author(s):  
Robert J. Schiess ◽  
Richard L. DeSaussure ◽  
James T. Robertson
Keyword(s):  
Initial Treatment ◽  
Conservative Therapy ◽  
Diagnosis And Treatment ◽  
Content Type ◽  
Odontoid Fractures ◽  
Surgical Fusion ◽  
Choice Of Treatment ◽  
Duration Of Hospitalization ◽  
Fine Print

✓ This paper presents a discussion of the diagnosis and treatment of odontoid fractures, based upon the authors' experience with this entity over the last 10 years. Conservative therapy and surgical fusion are compared with respect to efficacy and duration of hospitalization. Arthrodesis is recommended for consideration in the initial treatment of all unstable odontoid fractures.

Complex atlantoaxial fractures

1999 ◽  
Vol 91 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Bernard Guiot ◽  
Richard G. Fessler
Keyword(s):  
Motor Vehicle ◽  
Screw Fixation ◽  
Specific Treatment ◽  
Type Ii ◽  
Transarticular Screw ◽  
Content Type ◽  
Ring Type ◽  
Type Iii ◽  
Posterior Ring ◽  
Fine Print

Object. The authors conducted a retrospective study to evaluate the treatment of complex C1–2 fractures. Methods. There were 10 cases of complex C1–2 fractures. Six patients were men (median age 58 years) and four patients were women (median age 55.5 years). Injuries resulted from seven falls, two motor vehicle accidents, and one diving incident. Three patients suffered from upper-extremity weakness. Neurological function in seven patients was intact preoperatively. Fracture combinations included six Jefferson/Type II odontoid, two anterior ring/Type II odontoid, one posterior ring/Type II odontoid, and one posterior ring/Type III odontoid/Type III hangman's fracture. All patients underwent surgery, five after halo immobilization for an average of 4 months failed to provide stability. Treatment included placement of six odontoid screws, one posterior C1–2 transarticular screw, one odontoid screw with anterior C1–2 transarticular screw fixation, one C1–2 transarticular screw with C1–2 Songer cable fusion, and one odontoid screw with bilateral C-2 pedicle screw fixation. Specific treatment was determined by the combination of fractures. Postoperatively, all patients were immobilized in a hard collar for 3 months. There were no intraoperative surgery-related complications. The mean follow-up period was 28.5 months. Neurological recovery was observed in one of three patients who presented with neurological deficits. Fusion occurred in all cases. Conclusions. The goals in treating these complex fractures are to achieve early maximum stability and minimum reduction in range of motion. These are often competing phenomena. Frequently in cases of atlas—axis fracture, odontoid screw fixation combined with hard collar immobilization is the best therapy, provided the transverse atlantal ligament is competent. If not, C1–2 stabilization with placement of transarticular screws is required for best results.

Direct anterior screw fixation for recent and remote odontoid fractures

2000 ◽  
Vol 93 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Ronald I. Apfelbaum ◽  
Russell R. Lonser ◽  
Robert Veres ◽  
Adrian Casey
Keyword(s):  
Screw Fixation ◽  
Fusion Rate ◽  
Content Type ◽  
Odontoid Fractures ◽  
Hardware Failure ◽  
University Of Utah ◽  
Bone Fusion ◽  
Anterior Screw Fixation ◽  
Operative Findings ◽  
Fine Print

Object. The management of odontoid fractures remains controversial. Only direct anterior screw fixation provides immediate stabilization of the spine and may preserve normal C1–2 motion. To determine the indications, optimum timing, and results for direct anterior screw fixation of odontoid fractures, the authors reviewed the surgery-related outcome of patients who underwent this procedure at two institutions. Methods. One hundred forty-seven consecutive patients (98 males and 49 females) who underwent direct anterior screw fixation for recent (≤ 6 months postinjury [129 patients]) or remote (≥ 18 months postinjury [18 patients]) Type II (138 cases) or III (nine cases) odontoid fractures at the University of Utah (94 patients) and National Institute of Traumatology in Budapest, Hungary (53 patients) between 1986 and 1998 are included in this study (mean follow up 18.2 months). Data obtained from clinical examination, review of hospital charts, operative findings, and imaging studies were used to analyze the surgery-related results in these patients. In patients with recent fractures there was an overall bone fusion rate of 88%. The rate of anatomical bone fusion of recent fractures was significantly (p ≤ 0.05) higher in fractures oriented in the horizontal and posterior oblique direction (compared with anterior oblique), but this finding was independent (p ≥ 0.05) of age, sex, number of screws placed (one or two), and the degree or the direction of odontoid displacement. In patients with remote fractures there was a significantly lower rate of bone fusion (25%). Overall, complications related to hardware failure occurred in 14 patients (10%) and those unrelated to hardware in three patients (2%). There was one death (1%) related to surgery. Conclusions. Direct anterior screw fixation is an effective and safe method for treating recent odontoid fractures (< 6 months postinjury). It confers immediate stability, preserves C1–2 rotatory motion, and achieves a fusion rate that compares favorably with alternative treatment methods. In contradistinction, in patients with remote fractures (≥ 18 months postinjury) a significantly lower rate of fusion is found when using this technique, and these patients are believed to be poor candidates for this procedure.

Split spinal cord malformations in children

1998 ◽  
Vol 88 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Yusuf Ersşahin ◽  
Saffet Mutluer ◽  
Sevgül Kocaman ◽  
Eren Demirtasş
Keyword(s):  
Spinal Cord ◽  
Neurological Deficits ◽  
Single Type ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
Spinal Lesion ◽  
The Mean ◽  
Fine Print

Object. The authors reviewed and analyzed information on 74 patients with split spinal cord malformations (SSCMs) treated between January 1, 1980 and December 31, 1996 at their institution with the aim of defining and classifying the malformations according to the method of Pang, et al. Methods. Computerized tomography myelography was superior to other radiological tools in defining the type of SSCM. There were 46 girls (62%) and 28 boys (38%) ranging in age from less than 1 day to 12 years (mean 33.08 months). The mean age (43.2 months) of the patients who exhibited neurological deficits and orthopedic deformities was significantly older than those (8.2 months) without deficits (p = 0.003). Fifty-two patients had a single Type I and 18 patients a single Type II SSCM; four patients had composite SSCMs. Sixty-two patients had at least one associated spinal lesion that could lead to spinal cord tethering. After surgery, the majority of the patients remained stable and clinical improvement was observed in 18 patients. Conclusions. The classification of SSCMs proposed by Pang, et al., will eliminate the current chaos in terminology. In all SSCMs, either a rigid or a fibrous septum was found to transfix the spinal cord. There was at least one unrelated lesion that caused tethering of the spinal cord in 85% of the patients. The risk of neurological deficits resulting from SSCMs increases with the age of the patient; therefore, all patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations.

Bilateral open-door cervical expansive laminoplasty with hydroxyapatite spacers and titanium screws

2002 ◽  
Vol 96 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Masakazu Takayasu ◽  
Teruhide Takagi ◽  
Toshihisa Nishizawa ◽  
Koji Osuka ◽  
Takehiko Nakajima ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Cervical Spinal Cord ◽  
Intraoperative Complications ◽  
Fixation Strength ◽  
Open Door ◽  
Quick Method ◽  
Simple Method ◽  
Content Type ◽  
Titanium Screws ◽  
Fine Print

Object. The authors report a simple method for bilateral open-door cervical expansive laminoplasty in which hydroxyapatite (HA) spacers are secured by titanium screws. A biomechanical study was also conducted to confirm the strength of the screw fixation. Methods. A unilateral posterior approach was used to allow preservation of the posterior supporting elements (the posterior tension band) until the laminae were cut at the base. A bilateral open-door expansive laminotomy was then performed in standard fashion. Appropriate-sized HA spacers were selected, held with a specially designed holder, and placed between the split laminae. The screw holes were made in the laminae along the direction of the screw holes in the spacer, and two screws were inserted ventrolaterally to the laminae, resulting in instantaneous fixation. This procedure was performed in 15 patients; clinical results were successful, and there were no significant intraoperative complications. Follow-up radiological studies revealed no evidence of displacement of the spacers or screw backout. The screw artifacts observed on magnetic resonance imaging were minimal, allowing evaluation of the cervical spinal cord. The sagittal alignment of the cervical spine was well preserved. In the biomechanical studies the authors found that the screw fixation was of satisfactory strength, compared with other methods of fixation. Conclusions. Bilateral open-door cervical expansive laminoplasty in which HA spacers are secured by titanium screws is a simple and quick method that yields sufficient fixation strength.

Vertical atlantoaxial distraction injuries: radiological criteria and clinical implications

2004 ◽  
Vol 1 (3) ◽  
pp. 273-280 ◽  
Author(s):  
L. Fernando Gonzalez ◽  
David Fiorella ◽  
Neil R. Crawford ◽  
Robert C. Wallace ◽  
Iman Feiz-Erfan ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Control Group ◽  
Lateral Mass ◽  
Healthy Individuals ◽  
Mr Images ◽  
Content Type ◽  
Radiological Criteria ◽  
Surgical Fusion ◽  
Imaging Results ◽  
Fine Print

Object. The authors sought to establish radiological criteria for the diagnosis of C1–2 vertical distraction injuries. Methods. Conventional radiography, computerized tomography (CT), and magnetic resonance (MR) imaging findings in five patients with a C1–2 vertical distraction injury were correlated with their clinical history, operative findings, and autopsy findings. The basion—dens interval (BDI) and the C-1 and C-2 lateral mass interval (LMI) were measured in 93 control patients who underwent CT angiography; these measurements were used to define the normal BDI and LMI. The MR imaging results obtained in 30 healthy individuals were used to characterize the normal signal intensity of the C1–2 joint. The MR imaging results were compared with MR images obtained in five patients with distraction injuries. In the 93 patients, the BDI averaged 4.7 mm (standard deviation [SD] 1.7 mm, range 0.6–9 mm) and the LMI averaged 1.7 mm (SD 0.48 mm, range 0.7–3.3 mm). Based on CT scanning in the five patients with distraction injuries, the BDIs (mean 11.9 mm, SD 3.2 mm; p < 0.001) and LMIs (mean 5.5 mm, SD 2 mm; p < 0.0001) were significantly greater than in the control group. Fast—spin echo inversion-recovery MR images obtained in these five patients revealed markedly increased signal distributed throughout the C1–2 lateral mass articulations bilaterally. Conclusions. In 95% of healthy individuals, the LMI ranged between 0.7 and 2.6 mm. An LMI greater than 2.6 mm indicates the possibility of a distraction injury, which can be confirmed using MR imaging. Patients with a suspected C1–2 distraction injury may be candidates for surgical fusion of C1–2.

Posterior petrous meningiomas: 82 cases

2005 ◽  
Vol 102 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Zhe Bao Wu ◽  
Chun Jiang Yu ◽  
Shu Sen Guan
Keyword(s):  
Facial Nerve ◽  
Clinical Manifestations ◽  
Petrous Bone ◽  
Type I ◽  
Type Ii ◽  
Posterior Surface ◽  
Total Resection ◽  
Content Type ◽  
Functional Preservation ◽  
Fine Print

Object. The aim of this study was to discuss posterior petrous meningiomas—their classification, clinical manifestations, surgical treatments, and patient outcomes. Methods. A retrospective analysis was performed in 82 patients with posterior petrous meningiomas for microsurgery. According to the anatomical relationship with the posterior surface of the petrous bone and with special reference to the internal auditory canal (IAC), posterior petrous meningiomas were classified into three types: Type I, located laterally to the IAC (28 cases); Type II, located medially to the IAC, which might extend to the cavernous sinus and clivus (32 cases); and Type III, extensively attached to the posterior surface of the petrous bone, which might envelop the seventh and eighth cranial nerves (22 cases). Sixty-eight (83%) of 82 cases involved total resection. The rate of anatomical preservation of facial nerve was 97.5%, whereas the functional preservation rate was 81%. The rate of hearing preservation was 67%. All Type I tumors were completely resected, and the rate of anatomical preservation of facial nerve was 100% and functional preservation was 93%. Regarding Type II lesions, 75% of 32 cases involved total resection; the rate of anatomical preservation of facial nerve was 97% and functional preservation was 75%. For Type III lesions, 73% of 22 cases were totally resected. The rate of anatomical preservation of facial nerve in patients with this tumor type was 95%, whereas functional preservation was 73%. Conclusions. Clinical manifestations and surgical prognoses are different among the various types of posterior petrous meningiomas. It is more difficult for Types II and III tumors to be resected radically than Type I lesions, and postoperative functional outcomes are significantly worse accordingly. The primary principles in dealing with this disease entity include preservation of vital vascular and central nervous system structures and total resection of the tumor as much as possible.

A rare complication of hardware failure in neurostimulation

2000 ◽  
Vol 93 (2) ◽  
pp. 330-331
Author(s):  
Amr Mohamed Sarwat ◽  
Kota Sadashiv Karanth ◽  
John Christopher Sutcliffe
Keyword(s):  
Skin Rash ◽  
Rare Complication ◽  
Electrical Insulation ◽  
Content Type ◽  
Hardware Failure ◽  
Fine Print

✓ The authors report on a rare complication of neurostimulation. Two patients presented with a skin rash after undergoing neurostimulator implantation, and the implants were found to have faulty electrical insulation. The rash was centered over the source of current leak and disappeared when the problem was corrected.

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