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OBJECTIVE: To assess the feasibility of using standard components from the small AO external fixator set to support fractures of the distal radius with a construct incorporating distal fixation in the periarticular radius fragment that would allow for primary mobilization of the wrist joint during fracture healing. METHODS: In a prospective pilot study of a nonbridging external fixator in early 2001, 6 consecutive cases of fracture in the distal radius presenting at a tertiary care centre, the Hamilton General Division of Hamilton Health Sciences, were compared with 6 historical controls treated with a standard bridging construct immobilizing the wrist. Both groups were or had been treated with closed reduction and external fixation of the distal radius under fluoroscopic control. Fracture alignment was measured on radiographs after healing and removal of the fixation devices; additional (secondary) outcome measures were pin-tract sepsis and implant loosening (treatment failure). RESULTS: Compared radiographically with controls, alignments after fracture healing were improved (and virtually anatomic) with use of the nonbridging external fixator. The incidence of pin-tract sepsis was similar in the 2 groups, neither of which included any treatment failures. CONCLUSIONS: Nonbridging external fixation of comminuted distal radius fractures can be accomplished safely and effectively. The results of this pilot study suggest that improved radiographic alignment may be achieved with this technique. [ABSTRACT FROM AUTHOR]

Objective: To review the reported efficacy of various imaging techniques in assessing stability of the neck in blunt trauma patients, and to present the protocol and preliminary results of a modified traction test protocol. Design: This is a prospective cohort study. Setting: A regional trauma unit in Southern Ontario. Patients: People with blunt-trauma injuries who came to the author's consultant practice with "C-spine not cleared" status, from January 2001 through December 2003. Interventions: A fluoroscopically controlled test of axial traction followed by flexion/extension stressing. Outcome Measures: Radiographic confirmation of the absence of pathological motion under load. Results: In 51 cases studied to date, no instabilities have been found. Four cases of minor ligamentous hypermobility have been detected, with stability confirmed and no surgery required. There have been no failures to depict the neck completely, no missed instabilities and no complications of the procedure. Conclusions: Cervical stability can be reliably confirmed with this test without any requirement for advanced imaging technology. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess the efficacy of soft, semirigid and hard cervical collars to immobilize the neck in a destabilized cadaver model. DESIGN: This is a laboratory experiment. SETTING: The anatomy research lab of McMaster University. PATIENTS: None. Fresh cadavers from elderly patients suffering terminal medical illness and free of cervical structural disease were studied. INTERVENTIONS: Destabilizing discoligamentous lesions of the neck were created in the cadavers. Radiographs were taken in maximum displacement in the prone, decubitus and side-bending positions, first unsupported and then with soft, semirigid and hard collars applied. Displacements in angulation and translation were measured from the radiographs. OUTCOME MEASURES: Radiographic displacement under gravity load. RESULTS: In all cases there was no effective limitation of pathological displacement, and in many cases displacement was increased after collar application. CONCLUSIONS: Cervical collars do not effectively support the unstable neck, and may be ineffective in preventing pathological displacements. [ABSTRACT FROM AUTHOR]

Background: Whether lumbar arthrodesis can relieve isolated low-back pain in the absence of focal neurological findings or instability is unclear. The results of published studies are also inconsistent with regard to whether temporary back-pain relief with external spinal skeletal fixation can predict lasting back-pain relief after arthrodesis. This report presents the results, with regard to clinical benefit and complications, of more than 100 external spinal skeletal fixation procedures undertaken as a prelude to lumbar arthrodesis.Methods: The records of all patients who underwent external spinal skeletal fixation between 1989 and 1999 were reviewed with attention to perioperative complications, pain relief from the test procedure, the clinical benefit from a subsequent arthrodesis, and the functional status after the arthrodesis. Analyzed data included the frequency of neurological complications and infections and the benefit (Prolo score) after staged spinal arthrodesis in patients who underwent arthrodesis after temporarily experiencing pain relief with the test procedure.Results: A total of 103 external spinal skeletal fixation procedures were undertaken. Neurological complications occurred in two procedures (2%); one resulted in permanent sciatica. Infections occurred in five patients (5%). Sixty patients experienced pain relief during the external fixation test, but only twenty-seven of forty-nine patients who went on to have an arthrodesis and had sufficient follow-up reported that they were doing well at a minimum of one year later. In no case did the external spinal skeletal fixation procedure cause a permanent increase in low-back pain.Conclusions: On the basis of this analysis, external spinal skeletal fixation should not be used as a predictor of pain relief after lumbar arthrodesis. [ABSTRACT FROM AUTHOR]

Competing Interests: The author reports no conflicts of interest.

We suggest that a clinical diagnosis of posterior cord syndrome indicates primary posterior decompression in cervical spondylotic myelopathy cases. We present two unique cases of failed anterior decompression in neutrally aligned necks with compressive myelopathy and a literature review. Two recent cases of cervical spondylotic myelopathy that failed to respond after anterior surgical decompression and fusion surgery were observed at our institution. Both patients had motor strength preservation but were unable to stand and walk independently and had other clinical findings consistent with posterior cord syndrome rather than the more common anterior or central cord syndromes, and both responded well to staged posterior decompression. Posterior cervical decompression successfully relieved posterior cord syndrome symptoms after a failed anterior decompression in both of our cases. Posterior cord syndrome is a rare syndrome best diagnosed clinically and should be considered in cases of cervical spondylotic myelopathy in which motor strength testing is preserved., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Orthopaedic Surgeons.)

Study Design: This is a retrospective cohort experience reported with concurrent survey PROM outcomes., Objective: To describe the results of open PLIF reconstruction for a select group of mechanical back pain patients who have mono- or bi-segmental discopathy on MRI imaging, a clinical history of repeated severe and disabling acute mechanical back pain symptoms, and the irregular lumbar motion pattern in returning erect from the flexed position known as the "instability catch"., Summary of Background Data: The literature of fusion surgery for back pain relief in "mechanical" back pain reveals inconsistent results and in the majority presents only a vague description of these syndromes. Internal Lumbar Disc Degeneration with Instability catch "ILDDIC" may be one subset of these patients who are uniquely benefitted from spine stabilization., Methods: The senior author (DAB) in midsummer 2015 began to offer smaller fusion procedures to selected patients on an overnight-stay basis using a standard perioperative care protocol. For practice audit, in December 2020 a mailed survey questionnaire requesting VAS pain scores and SF-36 physical function scores was sent out to all 111 patients who had been treated this way, which group included 30 cases of ILDDIC. We report here on the success of open PLIF reconstruction in achieving back pain relief for these patients., Results: Some 24 of 30 patients returned the mailed survey questionnaire, and the remaining six could not be reached. All 24 responders reported significant relief of back pain and improved physical function, at a mean of 30 months from surgery. Review of the available clinical records (LFU < 1 year) from the six nonresponders also recorded positive early benefit., Conclusion: The diagnosis of ILDDIC requires both imaging and clinical correlates and may define a subgroup of the mechanical back pain population uniquely suited to achieve pain relief through lumbar fusion., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Study Design: This is an anatomic study using cadaveric material., Objective: To provide anatomic descriptions of the normal lumbar sublaminar ridge in the lateral recess and its potential to impact on the exiting nerve root there, with implications to surgical technique in lumbar spinal stenosis., Summary of Background Data: The lateral extent of the sublaminar ridge-the bony, superior insertion site of the ligamenta flava-and its topological relationship to the nerve root are not described in the literature. In the setting of degenerative lumbar stenosis this structure can hypertrophy and impinge the nerve root within the lateral recess even after excision of the corresponding ligamentum flavum. Failure to address this may contribute to failed lateral recess decompression., Methods: Fifteen lumbar vertebrae, not obviously degenerated, were resected en bloc from three fixed adult human cadavers and then transected through the pedicles, leaving the posterior column and neural elements intact and articulated. The shape of the sublaminar ridge in the lateral recess and its relationship to the exiting nerve root were carefully examined., Results: The exiting nerve root consistently crosses the sublami- nar ridge immediately inferior to the mid-pedicle, lateral to the subarticular gutter, and on the medial aspect of the true intervertebral foramen. A hypertrophic ridge can compress the exiting root by elevating the nerve root superiorly against the bony underside of the pedicle or displacing it anteriorly against the disc or vertebral body., Conclusion: The sublaminar ridge in the lateral recess may contribute to degenerative lumbar stenosis. Comprehensive appreciation of this anatomy may facilitate thorough lateral recess decompression.Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Case: We report a unique case of compressive myelopathy caused by late kyphosis angulation of a previously operated dens base fracture nonunion challenged by age-related ankyloses of the lateral articulations C1 to C2 and a solid posterior fusion mass., Conclusions: Posterior column shortening such as commonly practiced for progressive kyphosis or myelopathy may be precluded at the atlantoaxial level for potential vascular risk to the vertebral artery. A standard anterior cervical approach and the application of basic surgical spine care principles lead to a simple solution in the unique and highly complex anatomy of our case.

Objective: To present the results of a new alternative in the technique lumbar pedicle screw reconstruction in osteopenic bone. Pedicle screw fixation is compromised in osteopenic bone and adjunct fixation commonly requires incremental technology that can increase cost and risk, and which may not commonly be available. Readily available low cost techniques are desirable., Patients and Methods: This is a retrospective review of a prospectively accumulated case series of all patients presenting to the senior author's (DAB) practice for elective lumbar reconstruction at a tertiary spine referral center. All consecutive patients treated by the senior author 2002-2012 who were unexpectedly found to be severely osteopenic at surgery are reported., Results: In seventy-four cases with imaging and clinical information available at an average of five years after surgery there was no screw lucency or accelerated disc degeneration observed despite these screws purposefully projecting into the suprajacent disc space within the limits of the construct. No patient had presented for instrumentation-related revision surgery of any sort., Conclusion: Transosseous intradiscal screw fixation is a potentially viable alternative in surgical stabilization of the unexpectedly osteopenic lumbar spine., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Study Design: This is a prospective cohort study., Objective: The aim of this study was to define the probability of successful morning-after discharge after adult spine surgery achieved with a standard care protocol as applied to patients with a large variety of common degenerative spine disorders., Summary of Background Data: Qualifying criteria for ambulatory or overnight-stay adult spine surgery are not well defined in either the spine or anesthesia literature. Most reports simply go to American Society of Anesthesiology risk classification or surgical technique alternatives and do not present a clearly defined patient care and case management protocol., Methods: A standardized protocol of patient preparation, preoperative comorbidities optimization, and perioperative care was applied in a prospective cohort of 126 patients including 83 lumbar and 41 cervical procedures. Office and hospital chart records were reviewed for relevant outcomes., Results: Fully 122 of 124 appropriately selected cases were able to successfully achieve uneventful same-day discharge without any need for readmission, unscheduled early emergency room or clinic visits, or other major complications. Both failures were for urinary retention in senior males and resolved after a single-day admission to the main hospital., Conclusion: A wide variety of common degenerative spinal pathology in adults can be routinely and safely managed on an overnight-stay basis without requirement for formal hospital inpatient admission in patients appropriately selected and pre-educated to the experience and whose major comorbidities are preoperatively optimized., Level of Evidence: N/A.

Study Design A systematic review of the literature. Objectives To review the published results to date of motion-preserving direct reconstruction of C1 ring fractures with combined coronal plane displacement of at least 7 mm (rule of Spence) and so at risk for Dickman type I or II disruption of the transverse atlantal ligament (TAL). Methods A structured literature review prompted by successful management of a typical case. Results To date only 65 such cases are reported and follow-up is almost uniformly short. Although reported clinical success is uniform, the case mix is heterogenous and confirmation/classification of ligamentous injury at baseline is often lacking. Conclusions Direct C1 stabilization shows promise as a "more selective" option in managing displaced atlas fractures with probable TAL disruption but cannot yet be recommended as a practice standard. Prospective clinical studies are indicated and should be structured so as to differentiate between Dickman type I and type II injuries of the TAL.

Study Design Case report and review of the literature. Objective To present a unique case of L5 radiculopathy caused by a sacral stress fracture without neurologic compression. Methods We present our case and its clinical evolution and review the available literature on similar pathologies. Results Relief of the unusual mechanical loading causing sacral stress fracture led to rapid resolution of radiculopathy. Conclusion L5 radiculopathy can be caused by a sacral stress fracture and can be relieved by simple mechanical treatment of the fracture.

Purpose: A 48-hour trial of dexamethasone coanalgesia became our standard practice in May 2008. This is our research Ethics Board-approved review of this experience to date with attention to perioperative narcotics use and pain scores for the first 48 hours after surgery as well as length of stay (LOS), wound healing complications, and infections in the first 6 months, compared with the historical precedent control cohort., Methods: Surgical case logs identified cases of 1- and 2-level elective lumbar decompression and fusion surgery performed since protocol initiation (cases) and for a like period beforehand (controls). Minimum of 6 months follow-up (sufficient to identify acute and subacute wound healing problems and perioperative infections) information was required. Hospital, Pain Service, and office records were reviewed for the extraction of outcomes data., Results: We identified 132 cases and 146 controls. In 41 additional cases records were deficient. Baseline characteristics were equivalent. Cases included 70 males (53%) and 62 females (47%) of mean age 54 years (range, 18-84 y). Seventy-five (57%) cases were narcotics dependant (mean of 79.5 mg-morphine-equivalent daily). Controls included 78 males (53%) and 68 females (47%) of mean age 55 years (range, 27-85 y). Eighty-nine (61%) controls were narcotics dependant (mean 101.2 mg-morphine-equivalents daily). Mean morphine-equivalents narcotic consumption for 48 hours after surgery was 262.9 mg in cases and 280.7 mg in controls. VAS pain scores at 48 hours after surgery averaged 4.4 and 6.9 during rest and activity in the cases, and 3.7 and 6.3 during rest and activity in the controls. LOS averaged 3.9 days in cases and 5.2 days in controls. Delayed wound healing and surgical site infections were not observed in either group., Conclusions: Systemic dexamethasone after 1- and 2-level lumbar fusion surgery demonstrated minimal impact on 48 hours perioperative narcotics use with no detriment to pain control, wound healing, or infections. LOS was shortened by 25%.

Study Design: This is a unique case report., Objectives: To describe a successful case of Teriparatide treatment of odontoid nonunion., Summary of Background Data: Animal models suggest that this drug may enhance fracture healing, and there are 3 similar cases previously published elsewhere., Methods: We describe the evolution of our case over time with serial computed tomography scan imaging confirming the treatment success., Results: Drug treatment of the odontoid nonunion was successful., Conclusion: Drug treatment of the odontoid nonunion may be an option and merits formal study.

Study Design Prospective observational cohort. Objective To document the accuracy of uncovertebral anatomic targeting in positioning cervical disc arthroplasty. Summary of Background Data Disc arthroplasty implants depend on midline placement for optimum mechanical function. Fluoroscopy is used to delineate the midline. Anatomic targeting from the uncovertebral joints in the neck may be adequate. We have investigated the efficacy of uncovertebral anatomic targeting for cervical disc arthroplasty. Methods Anatomic uncovertebral midline targeting for disc arthroplasty insertion was performed in 18 male (mean age 51 years, range 27 to 67) and 22 female (mean age 50, range 35 to 70) patients receiving a total of 59 implants over a 5-year period. Device insertion was under only lateral imaging control. Postinsertion operative fluoroscopy with optimized centering was used to record implant position in the anteroposterior plane, and centerline analysis was performed using cursor measurement technology from the GE PACS™ imaging system (GE Medical Systems, Mt. Prospect, IL). Results Analysis found a mean deviation from the ideal midline placement of only 0.7 mm (range, 0 to 2.9 mm). Only three devices were more than 2 mm off the anatomic midline. Conclusion This anatomic technique is effective, safely minimizing imaging resource needs and X-ray exposure to the patient and operating team.

Spinal epidural hematoma is a rare condition that usually presents with acute, severe pain at the location of the hemorrhage, with radiation to the extremities. It can rapidly develop to include progressive and severe neurologic deficit. The pathophysiology often remains unclear. However, epidural hematoma in the lumbar spine is best described as the result of internal rupture of the Batson vertebral venous plexus. Clinical evaluation of pain control and neurologic deficit is the most important tool in early diagnosis. Currently, MRI is the diagnostic method of choice. Regardless of the setting, symptomatic spinal epidural hematoma is typically managed with urgent surgical decompression of the spinal canal.

Study Design: This is a retrospective study of sequential cohorts., Objective: To assess the efficacy of tranexamic acid in decreasing operative blood loss and the need for intraoperative transfusion in metastatic spine surgery., Summary of Background Data: Significant published data have established the efficacy of antifibrinolytic drugs in limiting surgical bleeding during heart surgery and total joint replacement. One study in scoliosis suggested benefit in spine surgery as well., Methods: During a 6-month trial period, 14 patients with spine cancer undergoing palliative intralesional tumor excision and concomitant instrumentation to stabilize the spine in the hands of a single surgeon were administered tranexamic acid intraoperatively in the attempt to minimize operative blood loss. They were then compared to the immediately preceding 14 patients., Results: Estimated operative blood loss was 1385 mL in the study group treated with tranexamic acid and 1815 mL in controls not receiving the drug, and was not found to be significantly decreased in this study., Conclusions: Control of operative bleeding in metastatic spine surgery can be problematical. Optimum protocol might include routine preoperative angiographic tumor embolization to decrease lesion vascularity in all cases, but angiography is not without risk. Noninvasive prophylaxis of tumor bleeding would have obvious desirable advantages but was, unfortunately, not achieved in this study.

The objective of this cohort study--conducted at a regional trauma unit in southern Ontario, Canada--was to review the imaging history of open-section, iliac-wing bone graft donor sites in lumbar fusion patients. Intervention entailed review of available X-ray and CT scan images for all patients undergoing lumbar fusion with iliac autograft in the senior author's practice over a 4-year period. Outcome was radiographic confirmation of the absence of bony reconstitution at the iliac harvest site. Of 239 primary fusions performed, 209 complete imaging records were available for review. The images of a further 20 patients who had surgery with the senior author prior to the study period and who presented at the office in the first half of 2000 were also assessed. All cases showed persistence of the iliac donor harvest site defect. Only minimal marginal sclerosis to suggest attempted remodeling was observed. We conclude that iliac-wing bone graft donor sites do not remodel. Given that iliac harvesting is known to increase strain in the pelvis, and that lumbosacral stabilization increases stress in the pelvis, permanent deficiency of iliac bone stock at donor harvest site may be a factor in both primary donor site pain and the observed high frequency of this problem in lumbosacral fusion patients.

Study Design: This repeated-measures biomechanical study evaluated the tensile force required to cause bipedicular (hangman's) fractures in isolated porcine C2 specimens, and the subsequent force to failure after direct fracture repair with bipedicular lag screws., Objectives: To assess the pullout strength of direct lag screw fixation of hangman's fracture, relative to the strength of the intact specimens., Summary of Background Data: Clinical studies have reported successful treatment of hangman's fractures by direct screw repair followed by a collar after surgery. However, to the authors' best knowledge, there has not yet been a biomechanical analysis of the force required for screw pullout after direct repair., Methods: Of 60 mounted porcine C2 specimens subjected to tensile anteroposterior force, hangman's fracture occurred in 15 cases, 12 of which were fixed with bipedicular 4.0-mm lag screws. These fixed specimens were retested to failure in the same manner., Results: Most specimens had laminar fractures after the application of tensile force, with 15 of 60 (25%) showing bipedicular fractures. The force to bipedicular failure was 3259.1 +/- 148.5 N (mean +/- standard error of the mean). After screw fixation, the force to failure of the same specimens was 882.0 +/- 108.5 N (mean +/- standard error of the mean), or 27.3% of the intact bone., Conclusions: The pullout strength was substantial (882 N), although the relative strength of fixation was only 27.3% of the fracture strength shown by the intact specimens. The findings are discussed in relation to previous studies. To the authors' best knowledge, this is the first study to examine screw pullout forces after direct repair of hangman's fracture.

The removal of potentially painful lumbar pedicle screw implants is a recognized procedure not yet extensively reported in the literature. The extensive dissection required to accomplish it is such that this operation is generally done on an inpatient basis. A defined protocol of pre-, intra-, and postoperative care was instituted in the senior author's practice in 1995, with the goal of accomplishing these operations on a day-surgical basis. We report the results of 70 such procedures performed in the calendar years 1995-1999 with attention to the efficacy of the protocol in facilitating ambulatory care. The protocol is safe and effective.

This case report describes the successful treatment of a case of Clostridium perfringens postoperative discitis and suggests a management protocol for this condition. The medical literature to date reports only one similar case, treated without success. The patient has been well but the affected space later collapsed with mechanical pain and has required fusion. C. perfringens discitis can be treated successfully.

Degenerative lumbar spondylolisthesis with spinal stenosis is commonly treated with laminectomy. Recent reports have consistently supported the incremental clinical benefit of associated in situ arthrodesis with or without instrumentation. Resection of the lamina may result in intraoperative dural tear or epidural scar formation. Fifty-six consecutive patients with back pain, neuroclaudication, or both, in addition to degenerative spondylolisthesis with spinal stenosis, underwent a surgical procedure that incorporated fusion after reduction of the spondylolisthesis deformity with preservation of the lamina and the balance of the posterior elements. Clinical records were reviewed and patients interviewed at a mean of 33 months after surgery. Oswestry Disability Index scores were obtained independently at baseline and at a late review. Late imaging was available a mean of 28 months after operation. Clinical and imaging analyses and Oswestry scoring confirmed results comparable to the published outcomes of in situ fusion after formal laminectomy. Resection of the lamina may not be necessary in the treatment of degenerative lumbar spinal stenosis with spondylolisthesis.

This is a prospective study of sequential cohorts of patients undergoing elective lumbar discectomy scheduled on a day-surgical basis between April 1995 and October 1998, representing all such cases from the author's practice during the review period. Preliminary review of the first 38 cases was undertaken 18 months after this surgical program was initiated and revealed an 18% rate of failure in achieving same-day discharge. Subsequent review of the balance of 92 additional cases revealed this failure rate was decreased to only 2% through a combination of appropriate perioperative patient education and the institution of a low-dose perioperative narcotic routine.

This paper describes the design, evaluation, and application of a new system for quantifying two-dimensional collagen fiber orientation in soft tissue. Series of transmitted polarized light images were collected using a custom-designed macroscope. Combined analysis of pixel brightness, and hue from images collected with a compensator plate, permitted the assignment of each pixel into the appropriate orientation band. Experiments were performed to quantify the linearity and noise of the system. Validation was performed on a specimen composed of strain-birefringent plastic strips at various orientations. Preliminary collagen fiber orientation data is presented from a tendon specimen. This study demonstrates the utility of this approach for studying collagen fiber orientation across large areas.

We compared the donor site morbidity in fifty-seven consecutive patients in whom a bone graft had been procured from the iliac crest through an incision parallel to the superior cluneal nerves and perpendicular to the posterior iliac crest (the study group) with that in fifty-three consecutive patients in whom the graft had been procured through an oblique incision parallel to the posterior iliac crest (the control group). Numbness, tenderness, and pain at the donor site one and six months postoperatively were assessed by means of an interview with the patient and a review of the records. The prevalence of symptoms in the control group was greater than that in the study group. At one month, thirty-nine patients (74 per cent) in the control group had numbness, compared with twenty-five (44 per cent) in the study group (p = 0.001). At six months, thirty-one patients (58 per cent) in the control group had numbness, compared with fourteen (25 per cent) in the study group (p = 0.0002). Thirty-six patients (68 per cent) in the control group and twenty-four (42 per cent) in the study group had tenderness over the incision at one month (p = 0.005), and twenty-seven (51 per cent) and eleven (19 per cent), respectively, had tenderness at six months (p = 0.0003). Forty patients (75 per cent) in the control group and forty-six patients (81 per cent) in the study group had deep pain in the region of the iliac crest at one month, compared with thirty-two (60 per cent) and thirty-one (54 per cent), respectively, at six months. The mean analog score for pain at the donor site was 7 of 10 points in the control group and 6 points in the study group (p = 0.001) at one month and 3 and 2 points, respectively, at six months (p = 0.001).

Study Design: Repeated in vitro mechanical tests were performed on porcine and human interspinous ligament specimens with progressive disruption of the collagen fiber network to evaluate the existence of mechanical interactions between collagen fibers., Objective: To evaluate the existence of a load pathway in the interspinous ligament whereby loads are transmitted between collagen fibers., Summary of Background Data: Mechanical tests demonstrate that the interspinous ligament resists spinal flexion, but the collagen fibers are not oriented to oppose separation of the spinous processes. This seeming contradiction could be explained by the existence of mechanical interactions between collagen fibers of the interspinous ligament., Methods: In vitro mechanical tests were performed on porcine and human bone-interspinous ligament-bone specimens. The collagen network of the ligament substance was disrupted by passing a scalpel blade though the ligament substance. Repeated tests were performed with progressive disruption of the collagen fiber network., Results: The stiffness of the interspinous ligament specimens was reduced as the collagen fiber network was disrupted, but approximately half of the initial stiffness was maintained when the collagen fiber network was severely disrupted. In this case, no intact collagen fibers remained., Conclusions: Mechanical interactions exist between collagen fibers in the interspinous ligament. The mechanism of the interactions is unknown.

External spinal skeletal fixation, pioneered by the Association for the Study of Internal Fixation as an alternative in thoracolumbar fracture management, has been effective in temporarily relieving mechanical low back pain. This investigational technique was been proposed as an alternative in the selection of patients with back pain as candidates for pain relief through fusion. This is the report of a prospective and randomized clinical trial that has defined prognostic benefit (good outcome in 61% of control patients versus 90% of the study group) in selecting patients with mechanical back pain (verified through facet blocks or discograms) as candidates for pain relief through fusion surgery.

Study Design: Human tissue specimens were examined for the presence of neural end-organs under light and electron microscopy., Objectives: To define the innervation of the thoracolumbar fascia in problem back pain patients who have articular abnormality defined through pain-provocation discography or facet blocks., Summary of Background Data: Previous investigators have defined the presence of innervation in control (no back pain) tissue specimens., Methods: Tissue specimens were harvested during surgery from 24 back pain patients who had not undergone previous lumbar surgery. Specimens were fixed immediately in the operating room and later processed and studied under light and electron microscopy., Results: Structural and ultrastructural studies failed to identify specific neural end-organs in any of the specimens. Serendipidously, microscopic changes suggestive of ischemia or inflammation in this tissue were found., Conclusions: These findings suggest that the thoracolumbar fascia may be deficiently innervated in problem back pain patients.

After institutional review defined an unacceptable mortality rate in nonoperative treatment of elderly patients with odontoid process fracture without neurological deficit, we undertook a prospective study to determine the influence of early surgical stabilization on perioperative mortality in geriatric odontoid process fracture patients without neurologic injury. Analysis suggests that acute perifracture mortality in this high-risk group can be significantly decreased and potentially eliminated by this approach.

Objective: To define the functional outcome and residual disability in adults treated for isolated femoral shaft fractures., Design: A retrospective case study of HMRI records. The mean follow-up was 34.5 months from the time of injury., Setting: A tertiary-care teaching hospital., Patients: One hundred and thirty adults with femoral shaft fractures. Of these, 47 were isolated and qualified for study., Interventions: Primary reamed intramedullary nailing performed between April 1987 and September 1990., Main Outcome Measures: Reoperation and return to work., Results: Of the 47 patients, primary healing occurred in 41 (87%) patients; 6 (13%) patients had delayed union or nonunion. Twenty (43%) patients had delayed implant-related pain after fracture healing; 85% of these had relief of pain after implant removal. Of 41 patients available for analysis of function based on return to work, 33 (80%) had returned to work full time in their original occupation at the time of follow-up, and 4 (10%) were working in other full-time employment; 3 (7%) were working part time. Only one (2%) patient was disabled and unable to work., Conclusions: Primary reamed intramedullary nailing is an effective method of achieving consistent primary union in adults with femoral shaft fractures. However, the majority of patients will require secondary surgery. Most patients will be able to return to work after these injuries.

Objective: To compare postoperative morbidity and length of hospital stay after combined anterior and posterior spinal fusion for patients treated by a one-stage procedure and those treated in two stages, 1 to 2 weeks apart., Design: Retrospective review of all cases handled by the first author between July 1989 and November 1991. The patients had been referred for treatment of severe spinal deformity, scoliosis or kyphosis by combined anterior and posterior spinal fusion., Setting: The operations were performed at McMaster University Medical Centre, Hamilton, Ont., by the first author, who was assisted by another specialist in spinal surgery and a fellow or resident., Patients: Eleven operations of each type were performed. The mean age of the 22 patients was 16.6 and 14.6 years for those who underwent the one-stage and the two-stage procedures respectively. The diagnoses included neuromuscular disease, neurofibromatosis, spina bifida, congenital kyphoscoliosis and severe idiopathic spinal curvature. The one-stage procedure was used after the surgical team became able to provide the care associated with this type of major surgery; selection of patients also involved preoperative risk assessment and the feasibility of combining two surgical procedures that would take a maximum of 9 hours. The preoperative plan was to spend a maximum of 9 hours in performing the one-stage procedure., Interventions: Similar surgical procedures were performed in both groups. The average number of intervertebral levels fused during the anterior component of the operation was 4.6 in the one-stage procedure and 6.0 in the two-stage procedure. Thoracolaparotomy was performed in four patients who underwent the two-stage procedure. During the posterior component of the operation, instrumentation was inserted through an average of 11.6 and 12.6 intervertebral levels in the groups undergoing the one-stage and the two-stage procedures respectively. Total operating time averaged 7 hours and 15 minutes for the one-stage procedure and 11 hours for the two-stage procedure. Mean blood loss was 1830 mL for the one-stage procedure and 2270 mL for the two-stage procedure., Main Outcome Measures: The number of days spent in the intensive care unit (ICU) and the total number of days spent in hospital, as well as morbidity after the operation, were determined., Results: Postoperative morbidity included five minor complications in patients who underwent a one-stage procedure; all of these complications resolved well. Among those who underwent the two-stage procedure there were 11 complications; in two patients further surgery was required. The patients' stay in the ICU averaged 2.6 and 7.7 days respectively for one-stage and two-stage procedures, and the total stay in hospital averaged 14 and 33 days respectively., Conclusions: When possible, the one-stage procedure for anterior and posterior spinal fusion is preferred over the two-stage procedure because of a significant reduction in the length of stay in the ICU and in hospital, as well as reduced morbidity. However, this analysis should be interpreted cautiously because of the small number of cases and the variables encountered in treating this type of spinal deformity.

Reconstruction of long-bone fractures with compression plates may give rise to stress shielding under the metal plate, which may be associated with late clinical problems due to insufficiency fractures around the implants. Therefore, it is common practice to remove forearm plates after fracture healing is completed. Increasing concern has been expressed recently about the complications and morbidity associated with forearm-implant removal. A retrospective review of the management of 111 forearm diaphyseal fractures at a major Canadian centre confirmed a substantial complication rate in elective forearm-plate removal. Because the true incidence of late insufficiency fracture is not well defined, elective forearm-plate removal may be contraindicated in the asymptomatic patient.

A lumbar decompression and fusion with instrumentation was successfully completed on a patient with a history of acute brachial neuritis (ABN) and recurring Guillain Barré syndrome (GBS). Three weeks post-surgery there was a mild exacerbation of the GBS, which resolved with plasmapheresis. This case report shows that surgery may be conducted safely on a patient whose history includes GBS and ABN, without devastating neurological consequences.

Impressive clinical reports have come from several major spinal research centers regarding the results of using the AO spinal internal fixator, a recently released pedicle screw rod system. A retrospective review of the first 2 years of clinical results from a diverse group of orthopedic surgeons using this device at a Canadian University center may provide some insight into potential clinical outcomes in general use. These results contrast with the outcome data provided to date, which have been presented by expert academic spinal surgeons. The results suggest that there may be room for considering limited release of this device, perhaps with the requirement for special certification in its application.

Surgical treatment of odontoid fractures has usually been carried out by C1-2 arthrodesis rather than by fracture fixation. An alternative treatment of compression screw fixation was used to treat selected acute odontoid fractures and nonunions. Ten patients were operated on. A variety of lag-screw types were used to compress and secure the fracture. Screw placement was considered excellent in five cases; in four, the screw tip protruded through the posterosuperior cortex of the dens by 1-3 mm. One patient died as a result of multiple injuries 2 days after surgery. In all other cases, including four cases of odontoid pseudarthroses, the fractures achieved solid union. It was concluded that screw fixation can be used for the successful treatment of selected odontoid fractures and nonunions.

Post-traumatic compartment syndrome in the foot is an unusual but well-recognized entity. If there is an awareness of the condition at the time of presentation it can be diagnosed and treated effectively. A case of compartment syndrome in the foot of a 17-year-old boy after massive lower-extremity trauma is described. The simple and readily available diagnostic techniques are emphasized and an alternative approach to plantar decompression, which avoids exposure of and potential damage to the posterior tibial neurovascular bundle, is presented.

The clinical problem of primary and secondary vertebral tumours is encountered with increasing frequency throughout North America as oncologic management protocols evolve and the population continues to age. These lesions can present problems of pain, instability and paralysis. Optimal surgical palliation is often of benefit when more conservative methods have been unsuccessful. Vertebral tumours can be approached either anteriorly or posteriorly. These alternatives have led to the evolution in the clinical community of two "camps" championing their respective approaches. The authors have reviewed the accumulated literature up to December 1988 and have found that anterior approaches offer improved clinical outcome without substantially increased morbidity.