Gregg R. Klein

Long-term evaluation of vertebral artery injuries following cervical spine trauma using magnetic resonance angiography.

Study Design. A prospective study to determine the long‐term outcome of traumatically induced vertebral artery injuries. Magnetic resonance angiography was performed at the time of cervical injury and at a follow‐up office visit. Objective. To determine the long‐term outcome in terms of arterial flow competency of traumatically induced vertebral artery injuries. Summary of Background Data. Vertebral artery injury associated with cervical spine trauma has been well documented; however its healing or nonhealing potential has not been elucidated. Methods. During the 7‐month period from July 1993 to January 1994, all patients admitted to the authors institution with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of the cervical spine to determine the patency of their vertebral arteries. Magnetic resonance angiography was performed at the time of injury and at a follow‐up office visit. Twelve of 61 patients were found to have a lack of signal flow within one of their vertebral vessels during this study period. Results. Eighty‐three percent of the patients (five of six) who were available for follow‐up observation in this study did not manifest flow reconstitution of their vertebral arteries after an average 25.8‐month follow‐up period. Conclusions. According to these data, most patients with vertebral artery injuries after nonpenetrating cervical spine trauma do not reconstitute flow in the injured vertebral arteries. This lack of flow must be considered if future surgery in this region of the cervical spine is contemplated.

Use of cervicothoracic junction pedicle screws for reconstruction of complex cervical spine pathology

Study Design. A retrospective review of 21 patients in which cervical pedicle screw fixation was used at C7 with or without upper thoracic pedicle screw fixation. Objective. To evaluate the use of pedicle screw placement in the lower cervical spine. Summary of Background Data. The use of posterior cervical spine fixation, including lateral mass fixation, has become increasingly popular in recent years. However, lateral mass fixation at C7 is often hindered by lack of substantial high quality bone. The end level of long cervical spine constructs is frequently C7 or T1. Dissatisfaction with lateral mass fixation at C7 and T1 led the authors to use lower cervical pedicle screw fixation for several cervical spine disorders. Methods. Twenty‐one patients who had undergone cervical pedicle screw fixation at C7 were reviewed retrospectively. There were 12 males and 9 females, with an average age of 52 years. All pedicle screws were placed, after direct palpation of the pedicle, with a right angle nerve hook after laminoforaminotomy at C7. Results. There were no neurologic complications related to pedicle screw placement, and no patient was symptomatically worse after the operation. Six patients with root pathology improved. Of 14 patients with cervical myelopathy, 12 improved at least one Nurick grade, and 2 had no improvement. There were no failures of fixation or complications related to pedicle fixation at a minimum of 1 year follow‐up. Conclusion. Pedicle screws in C7 placed with laminoforaminotomy and palpation technique appears to be safe and efficacious. Excellent fixation can be achieved.

Return to play criteria for the athlete with cervical spine injuries resulting in stinger and transient quadriplegia/paresis.

BACKGROUND CONTEXTnFortunately, catastrophic cervical spinal cord injuries are relatively uncommon during athletic participation. Stinger and transient quadriplegia/paresis are more frequent injuries that have a wide spectrum of clinical severity and disabilities. Although the diagnosis of these injuries may not be clinically difficult, the treatment and decision about when or if the athlete may return to play after such an injury is often unclear.nnnPURPOSEnThis article reviews the current literature to help determine reasonable guidelines for return-to-play criteria after cervical spine injuries in the athlete.nnnMETHODSnThe contemporary English literature and experience-based guidelines for return to play after cervical spine injuries in the athlete were reviewed.nnnRESULTSnDespite the frequency of cervical-related injuries among athletes participating in contact and collision sports, no consensus exists within the medical field as to a standard guideline approach for return to preinjury activity level.nnnCONCLUSIONnThe issue of return to play for an athlete after a cervical spine injury is controversial. Tremendous extrinsic pressures may be exerted on the physician from noninvolved and involved parties. The decision to return an athlete to a particular sport should be based on the mechanism of injury, objective anatomical injury (as demonstrated by clinical examination and radiographic evaluation) and an athletes recovery response.

Efficacy of magnetic resonance imaging in the evaluation of posterior cervical spine fractures.

STUDY DESIGNnA retrospective study using two independent, blinded musculoskeletal radiologists to evaluate the sensitivity, specificity, and predictive value of cervical spine magnetic resonance imaging in detecting posterior element fractures of the cervical spine.nnnOBJECTIVEnTo evaluate the sensitivity, specificity, and predictive value of magnetic resonance imaging, using computed tomographic scanning as the gold standard, in the diagnosis of posterior element cervical spine fractures.nnnSUMMARY OF BACKGROUND DATAnFew investigators have evaluated the accuracy of magnetic resonance imaging in the determination of cervical spine fractures.nnnMETHODSnFrom January 1994 through June 1996, 75 cervical spine fractures in 32 patients were confirmed by computed tomography. Two musculoskeletal radiologists who were blinded to the clinical history and presence or absence of cervical injury among the study population, independently evaluated each cervical magnetic resonance image recording the presence or absence of soft tissue or bony injury.nnnRESULTSnThe overall sensitivity and specificity rates for the diagnosis of a posterior element fracture by magnetic resonance imaging was 11.5% and 97.0%, respectively. The positive predictive value for this group was 83%, and the negative predictive value was 46%. In reference to anterior fractures, the sensitivity was 36.7% and the specificity 98%. Positive and negative predictive values were 91.2% and 64%, respectively.nnnCONCLUSIONSnMagnetic resonance imaging was not effective in recognizing bony injury to the cervical spine and in particular was not as sensitive or as specific as computed tomography in identifying cervical spinal fractures. Computed tomography remains the study of choice for the detection and precise classification of bony injuries to the cervical region, especially when plain radiographs are difficult to evaluate. Magnetic resonance imaging, although not as effective as computed tomography in defining specific bony disorders, remains the gold standard in the evaluation of spinal cord injury, occult vascular injury, and intervertebral disc disruption (hyperextension injury), including herniation and other soft tissue disorders (hematoma, ligament tear).

Image-guided anterior cervical corpectomy : A feasibility study

STUDY DESIGNnA feasibility study was performed to determine the efficacy of using image-guided frameless stereotaxy to perform anterior corpectomy of the cervical spine.nnnOBJECTIVEnTo assess the feasibility of using image-guided stereotaxy in performing anterior cervical corpectomy.nnnSUMMARY OF BACKGROUND DATAnAnterior cervical decompression including discectomy and corpectomy is a commonly performed procedure. Particular concern about invasion of the vertebral artery arises while performing this procedure to gain maximal lateral decompression. At present, surgeons have only landmarks and experience to guide them in performance of this potentially dangerous procedure.nnnMETHODSnFour cadavers (average age, 40.3 years) were used. A lateral corpectomy trough was created in Group 1 by a standard technique using visual landmarks. In the second group of corpectomy troughs, an image-guided frameless stereotactic system was used. After completion of the experiment, each cadaver had a corpectomy trough at every level on one side performed in a standard manner and on the other with image guidance. Using the image guidance system, an independent observer measured the distance from the corpectomy trough (lateral border) to the medial border of the foramen transversarium.nnnRESULTSnThe average distance from the lateral border of the trough to the medial border of the foramen transversarium in the standard trough group was 5.10 mm (range, 1.72-7.71 mm), and the average distance from the medial border of the foramen transversarium to the image-guided trough was 4.34 mm (range, 3.34-5.48 mm). The trend of the comparison between the two troughs was toward significance at P = 0.08.nnnCONCLUSIONSnImage-guidance provided improved accuracy when compared with that of a standard technique, implying clinical potential for image-guided corpectomy. Less variability is seen using an image-guided approach.

Health outcome assessment before and after anterior cervical discectomy and fusion for radiculopathy : A prospective analysis

STUDY DESIGNnA prospective assessment, performed using the Health Status Questionnaire, of the outcomes for 28 patients with cervical radiculopathy treated with one- or two-level anterior cervical discectomy and fusion.nnnOBJECTIVEnTo assess patient outcome using the Health Status Questionnaire after one- or two-level anterior cervical discectomy and fusion.nnnSUMMARY OF BACKGROUND DATAnAlthough outcomes for many types of surgical procedures already have been evaluated, few have focused on the results of cervical surgery.nnnMETHODSnBefore and after anterior cervical discectomy and fusion for cervical radiculopathy, 28 patients filled out the Health Status Questionnaire. The average follow-up interval was 21.8 months. There were 10 men and 18 women, with an average age of 44 years. All outcome instruments were graded for individual scores of general health, physical function, role limitation because of physical health problems, role limitation because of emotional problems, social function, mental health, bodily pain, and energy. Data were analyzed using the age (< 55 vs. > 55), workers compensation status, and education status of the patient. Preoperative and postoperative scores were compared for each subscale.nnnRESULTSnStatistically significant improvements were found in postoperative scores for bodily pain (P < 0.001), vitality (P = 0.003), physical function (P = 0.01), role function/physical (P = 0.0003), and social function (P = 0.0004). No significant differences were found before and after surgery for three health scales: general health, mental health, and role function associated with emotional limitations. Age, educational status, and history of compensation litigation did not appear to affect outcome measures.nnnCONCLUSIONSnAlthough this is a preliminary report involving 28 patients, it would appear, based on the results of the Health Status Questionnaire, that anterior cervical discectomy and fusion performed on appropriately selected patients is a highly reliable surgical procedure for the management of cervical radiculopathy. Additional disease-specific questions may provide more sensitivity in evaluating radiculopathy after surgical and nonsurgical intervention.

The efficacy of using an image-guided Kerrison punch in performing an anterior cervical foraminotomy. An anatomic analysis.

STUDY DESIGNnThis study comprised two parts: first, a feasibility study to determine the efficacy of using an image-guided Kerrison punch while performing a foraminotomy during an anterior cervical decompression and, second, an anatomic analysis using vector measurement to determine the distance from the entrance of the neuroforamen to the medial margin of the vertebral artery in the subaxial cervical spine.nnnOBJECTIVEnTo assess the feasibility of using an image-guided Kerrison punch when performing an anterior foraminotomy and to obtain data regarding the distance from the vertebral artery to the entrance of the neuroforamen.nnnSUMMARY OF BACKGROUND DATAnThe documented incidence of catastrophic iatrogenic vertebral artery injury in anterior cervical decompression is low. The use of a real-time image-guidance surgical system should reduce the risk of this complication.nnnMETHODSnTwelve cadaveric cervical spines were harvested. Standard anterior cervical discectomies with bilateral foraminotomies were performed in the subaxial cervical spine using an image-guided Kerrison. Surgically significant morphometric data were measured using a computer-assisted image-guided surgical system.nnnRESULTSnSuccessful navigation into all neuroforamina in the subaxial cervical spine was attained using the image-guided Kerrison punch. The vector measurement from the neuroforamen to the vertebral artery averaged 5.8 +/- 1.2 mm at C3-C4, 6.5 +/- 1.6 mm at C4-C5, 7.9 +/- 1.4 mm at C5-C6, and 9.1 +/- 1.8 mm at C6-C7. Statistically significant differences (P < 0.05) were found between all cervical levels except C3-C4 and C4-C5.nnnCONCLUSIONnAn image-guided Kerrison punch may be used successfully when performing cervical foraminotomies during an anterior cervical discectomy, thus eliminating the risk of potential vertebral artery injury. These data confirm previous findings by other authors. Knowledge of these data may aid the spine surgeon in performing a foraminotomy during anterior cervical decompression.

Uncemented total hip arthroplasty in patients with a history of pelvic irradiation for prostate cancer

BACKGROUNDnPelvic irradiation for a malignant tumor may cause osteonecrosis of the acetabulum. The purpose of this study was to evaluate the outcome of uncemented total hip arthroplasty in patients with a history of pelvic irradiation for the treatment of prostate cancer.nnnMETHODSnWe performed a retrospective review of the clinical records and radiographs of fifty-eight patients (sixty-six hips) who had had radiation therapy for prostate cancer and had subsequently undergone an elective primary uncemented total hip arthroplasty at our institution. The mean age of the patients at the time of the index operation was seventy-four years. The mean duration of follow-up was 4.8 years (range, two to 7.5 years).nnnRESULTSnAt the time of the final follow-up, fifty-one patients (fifty-eight hips) who were still living and had been followed for a minimum of two years had a well-ingrown and functioning replacement. The mean Harris hip score had significantly improved from 47 points preoperatively to 90 points at the time of the final follow-up (p < 0.05). The mean scores on the physical and mental health measures of the Short Form-36 had also improved significantly from 45.1 and 65.3 points, respectively, before the operation to 73.4 and 83.7 points postoperatively (p < 0.05 for both). There was no aseptic loosening of either component in any of the hips. Two hips had revision of the femoral component; one was revised because of a periprosthetic fracture of the femur and the other because of subsidence of the femoral component.nnnCONCLUSIONSnUncemented total hip arthroplasty can be a successful option for the treatment of coxarthrosis in patients with a history of pelvic irradiation for prostate cancer. Osseointegration of uncemented components does not seem to be compromised in these patients in the short term.nnnLEVEL OF EVIDENCEnTherapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Distraction extension injuries of the cervical spine.

Twenty-four consecutive patients with cervical distraction extension injuries were retrospectively reviewed to study the safety and efficacy of various treatment protocols in this type of cervical spine injury. Sixteen of 24 patients with cervical distraction extension injuries underwent surgical stabilization. All patients undergoing surgical stabilization were noted to have a stable fusion at their latest follow-up. There were three instances of surgically related neurologic deterioration as a result of over-distraction of the anterior column interspace at the time of graft placement. The overall mortality rate was 42% in this aged patient population. Anterior reconstruction of the cervical spine with an anterior cervical graft and plate acting as a tension band is the ideal treatment method for stabilization of acute distraction extension injuries involving primarily the soft tissue structures (anterior longitudinal ligament and intervertebral disc). Type 2 injuries, depending on the degree of displacement and the adequacy of closed reduction, may need to be approached initially posteriorly to obtain adequate alignment, followed by an anterior reconstructive procedure. Great care should be taken during anterior graft placement to avoid over-distraction of the spine. If nonsurgical intervention is selected, close regular radiographic follow-up is necessary to detect early vertebral malalignment, which may predispose to spinal cord dysfunction. Older patients sustaining this injury have a high mortality rate.