Mark S. Eskander

Bone morphogenetic protein in spine surgery: current and future uses.

The clinical use of bone morphogenetic protein (BMP) in spinal fusion surgery has recently become controversial. After its approval by the US FDA in July 2002, BMP was adopted by many spine surgeons as a replacement for the more traditional iliac crest bone graft to avoid the complications associated with bone graft harvest. However, as broad clinical use escalated, reports increased of potentially serious complications associated with BMP. Controversy continues, particularly regarding the safety of BMP and whether it should routinely replace iliac crest bone graft for spinal fusion surgery.

Use of the trauma pelvic orthotic device (T-POD) for provisional stabilisation of anterior-posterior compression type pelvic fractures: a cadaveric study.

OBJECTIVE To demonstrate that a commercially available pelvic binder the trauma pelvic orthotic device (T-POD) is an effective way to provisionally stabilise anterior-posterior compression type pelvic injuries. METHODS Rotationally unstable pelvic injuries were created in 12 non-embalmed human cadaveric specimens. Each pelvis was then stabilised first with a standard bed sheet wrapped circumferentially around the pelvis and held in place with a clamp. After recreating the symphyseal diastasis, the pelvis was stabilised with the T-POD. Reduction of the symphyseal diastasis was assessed by comparing measurements obtained via pre- and post-stabilisation AP radiographs. RESULTS The mean symphyseal diastasis was reduced from 39.3mm (95% CI 30.95-47.55) to 17.4mm (95% CI -0.14 to 34.98) with the bed sheet, and to 7.1mm (95% CI -2.19 to 16.35) with the T-POD. CONCLUSIONS Although both a circumferential sheet and the T-POD were able to decrease symphyseal diastasis consistently, only the T-POD showed a statistically significant improvement in diastasis when compared to injury measurements. In 75% of the cadaveric specimens (9 of 12), the T-POD was able to reduce the symphysis to normal (<10mm diastasis). Both a circumferential sheet and the T-POD are effective in provisionally stabilising Burgess and Young anterior-posterior compression II type pelvic injuries, but the T-POD is more effective in reducing symphyseal diastasis.

Does Medial Tenderness Predict Deep Deltoid Ligament Incompetence in Supination-External Rotation Type Ankle Fractures?

Objective: To identify whether medial tenderness is a predictor of deep deltoid ligament incompetence in supination-external rotation ankle fractures. Design: All Weber B lateral malleolar fractures with normal medial clear space over a 9 month period were prospectively included in the study. Fracture patterns not consistent with a supination-external rotation mechanism were excluded. Setting: High-volume tertiary care referral center and Level I trauma center. Patients/Participants: Fifty-five skeletally mature patients with a Weber B lateral malleolar fracture and normal medial clear space presenting to our institution were included. Intervention: All study patients had ankle anteroposterior, lateral, and mortise radiographs. Each patient was seen and evaluated by an orthopedic specialist and the mechanism of injury was recorded. Each patient was assessed for tenderness to palpation in the region of the deltoid ligament and then had an external rotation stress mortise radiograph. Main Outcome Measure: Correlating medial tenderness with deep deltoid competence as measured by stress radiographs. Results: Thirteen patients (23.6%) were tender medially and had a positive external rotation stress radiograph. Thirteen patients (23.6%) were tender medially and had a negative external rotation stress radiograph. Nineteen patients (34.5%) were nontender medially and had a negative external rotation stress radiograph. Ten patients (18.2%) were nontender medially and had a positive external rotation stress radiograph. We calculated a χ2 statistic of 2.37 as well as the associated P value of 0.12. Medial tenderness as a measure of deep deltoid ligament incompetence had a sensitivity of 57%, a specificity of 59%, a positive predictive value of 50%, a negative predictive value of 66%, and an accuracy of 42%. Conclusion: There was no statistical significance between the presence of medial tenderness and deep deltoid ligament incompetence. There is a 25% chance of the fracture in question with medial tenderness having a positive external rotation stress and a 25% chance the fracture with no medial tenderness having a positive stress test. Medial tenderness in a Weber B lateral ankle fracture with a normal clear space on standard plain radiographs does not ensure the presence of a positive external rotation stress test.

Vertebral Artery Anatomy : A Review of Two Hundred Fifty Magnetic Resonance Imaging Scans

Study Design. The aim of this study is to characterize the anatomy of vertebral arteries using magnetic resonance imaging scans of 250 consecutive patients. Objectives. To document the prevalence of midline vertebral artery (VA) migration in a subgroup of patients presenting with neck pain, radiculopathy, or myelopathy and to identify the course of the VA through the TFs. Summary of Background Data. Knowledge of VA anomalies and their respective prevalence may help surgeons decrease the incidence of iatrogenic injury to this artery. Methods. In this retrospective review of 281 consecutive patients, who had an magnetic resonance imaging for axial neck pain, radiculopathy, or myelopathy, anatomic measurements were obtained from C2 to C7. Results. The observed VA anomalies can be classified into following 3 main groups: (1) intraforaminal anomalies-midline migration, (2) extraforaminal anomalies, and (3) arterial anomalies. Midline migration of the VA was identified in 7.6% (19/250) of patients. The etiology can be degenerative or traumatic. It is important to note that the pattern of medial migration was clockwise rotation from caudal to cephalad and was present in all of our patients with anomalous arteries. Additionally, at C6, only 92% (460/500) of VAs were located within their respective transverse foramens and hypoplastic VAs were identified in 10% (25/250) of patients. Conclusion. Anomalies that must be considered before surgery include interforamenal anomalies, extraforamenal anomalies, and arterial anomalies. The intraforaminal anomalies involve midline migration, which places the VA at direct risk during corpectomy. Extraforaminal anomalies are related to VAs entering the transverse foramen at a level other than C6, which can increase the risk of injury during the anterior approach to the cervical spine. Arterial anomalies can be fenestrated, hypoplastic, or absent. These raise concern with the ability to maintain cerebral perfusion in the setting of damage to one of the VAs with the presence of contralateral arterial abnormality.

The effect of an orthopedic trauma room on after-hours surgery at a level one trauma center

Purpose: The purpose of this study is to examine the effect of establishing a dedicated operating room for unscheduled orthopedic cases and to evaluate a group of patients with isolated femur fractures. The frequency of after-hours surgery and the impact of patients who present with acute orthopedic injuries are reviewed. Methods: A retrospective review of all orthopedic cases from the operating room scheduling system at a level-one trauma center was undertaken from October 2003 to September 2005. Before October 2004, unscheduled cases were placed on a shared add-on list, and no special priority was given to orthopedic cases. Additionally, a subset of adult patients with isolated femoral shaft fractures was identified to evaluate time from admission to surgery, operative time, frequency of transfer of care between surgeons, and total length of hospital stay. Results: The number of orthopedic cases was 1799 in fiscal year 2004 (FY04) and 2046 in FY05, an increase of 14%. Overall, the hospital experienced an increase in level-one trauma activations from 1450 in FY04 to 1580 in FY05 (8.2%), and an increase in the number operative trauma cases from 447 to 494 (9.5%). Cases after 7:00 pm declined from 197 in FY04 to 165 in FY05, a decrease of 16%. Cases between midnight and 7:00 am declined from 63 in FY04 to 35 in FY05, a decrease of 44%. For the subset of femur fracture patients, transfer of care to another operating surgeon occurred 4.5 times more frequently. The median delay between admission and surgery increased from 5.7 hours to 10.9 hours. Median case duration increased from 106 to 127 minutes. Conclusions: It is possible to dramatically decrease the occurrence of after-hours orthopedic surgery in a level-one trauma center through the use of a dedicated room for unscheduled orthopedic trauma cases. Benefits include less frequent activation of after-hours operating room resources, fewer disruptions to the OR schedule and office hours, and more frequent fracture care by orthopedic traumatologists. The impact of a longer delay between admission and surgical treatment and more frequent transfer of care between surgeons deserves further evaluation.

Imaging in pelvic osteomyelitis: support for early magnetic resonance imaging

Background: Children with pelvic osteomyelitis may present with symptoms that are nonspecific. Conventional imaging modalities including plain radiographs, ultrasound, technetium bone scan, and computed tomography rarely demonstrate pathology that is diagnostic of this condition. As a result, accurate diagnosis is often delayed, and children may undergo surgical diagnostic or therapeutic procedures that may be avoided. We report the radiographic and magnetic resonance imaging (MRI) findings in 23 children admitted with a suspected diagnosis of pelvic osteomyelitis. We are presenting imaging findings in children with suspected pelvic osteomyelitis with emphasis on MRI abnormalities and to propose an anatomical classification based on the patterns of pelvic involvement. Methods: The medical records and imaging reports of all patients admitted to our institution with a history and physical examination suggestive of pelvic osteomyelitis between July 31, 1992, and March 10, 2003 were reviewed. Criteria were defined for the diagnosis of pelvic osteomyelitis based on criteria used by Farley et al in 1985. Specific attention was paid to the imaging strategies used and the influence of each radiographic method on the ultimate diagnosis. Results: Abnormalities on the MRI included soft tissue inflammation and bone edema. These findings were bright on T2 and short inversion time Short T1 inversion recovery (STIR) images and enhanced after gadolinium administration. Five distinct patterns of pelvic involvement were observed, each corresponding to a cartilaginous epiphysis or apophysis. These were the sacroiliac joint, triradiate cartilage, pubic symphysis, ischium, and iliac apophysis. One patient had a noninfectious cause of presentation with a deep vein thrombosis, whereas another was diagnosed with Hodgkin lymphoma in addition to osteomyelitis of the ischium. Conclusions: Magnetic resonance imaging is a sensitive technique for evaluation of pyogenic infections involving the pelvis. In patients presenting with clinical findings and laboratory studies suggesting an infectious process, MRI with gadolinium enhancement should be performed as an early study. Magnetic resonance imaging is also effective in identifying other conditions that may resemble pelvic osteomyelitis. Level of Evidence: This is a level II diagnostic study.

The association between preoperative spinal cord rotation and postoperative C5 nerve palsy

BACKGROUND C5 nerve palsy is a known complication of cervical spine surgery. The development and etiology of this complication are not completely understood. The purpose of the present study was to determine whether rotation of the cervical spinal cord predicts the development of a C5 palsy. METHODS We performed a retrospective review of prospectively collected spine registry data as well as magnetic resonance images. We reviewed the records for 176 patients with degenerative disorders of the cervical spine who underwent anterior cervical decompression or corpectomy within the C4 to C6 levels. Our measurements included area for the spinal cord, space available for the cord, and rotation of the cord with respect to the vertebral body. RESULTS There was a 6.8% prevalence of postoperative C5 nerve palsy as defined by deltoid motor strength of ≤ 3 of 5. The average rotation of the spinal cord (and standard deviation) was 2.8° ± 3.0°. A significant association was detected between the degree of rotation (0° to 5° versus 6° to 10° versus ≥ 11°) and palsy (point-biserial correlation = 0.94; p < 0.001). A diagnostic criterion of 6° of rotation could identify patients who had a C5 palsy (sensitivity = 1.00 [95% confidence interval, 0.70 to 1.00], specificity = 0.97 [95% confidence interval, 0.93 to 0.99], positive predictive value = 0.71 [95% confidence interval, 0.44 to 0.89], negative predictive value = 1.00 [95% confidence interval, 0.97 to 1.00]). CONCLUSIONS Our evidence suggests that spinal cord rotation is a strong and significant predictor of C5 palsy postoperatively. Patients can be classified into three types, with Type 1 representing mild rotation (0° to 5°), Type 2 representing moderate rotation (6° to 10°), and Type 3 representing severe rotation (≥ 11°). The rate of C5 palsy was zero of 159 in the Type-1 group, eight of thirteen in the Type-2 group, and four of four in the Type-3 group. This information may be valuable for surgeons and patients considering anterior surgery in the C4 to C6 levels.

Analysis of pedicle and translaminar facet fixation in a multisegment interbody fusion model

Study Design. This is a biomechanical study. We compared pedicle screws and translaminar screws in the setting of multisegment interbody fusions. Objectives. We investigated the significance of the middle segment pedicle screws in a 2-level interbody fusion model and examined translaminar screw fixation as an alternative to pedicle screw fixation in this 2-level model. Summary of Background Data. Surgical treatment of disc disease focuses on restoration of normal disc height and restriction of abnormal motion. Interbody fusion significantly reduces motion and restores disc space height. Combined anterior and posterior fusion improves fusion rates. Methods. Human cadavers were tested for range of motion (ROM) and stiffness. Each specimen underwent a 2-level interbody fusion and posterior fixation. There were 3 types of posterior fixation: pedicle screws at 3 levels, pedicle screws at 2 levels, and translaminar facet screws. Biomechanical testing was repeated for each group. Results. The overall ROM decreased after the interbody fusion (P < 0.05). There were no significant differences in construct stiffness for torsion, but there were significant differences when comparing intact to the 3 groups for both flexion and extension (P < 0.05). ROM at L2 and L4 was significantly less for all groups in comparison to the intact condition (P < 0.05). Conclusions. This study supports the omission of the middle segment screws in a 2-level interbody fusion. In addition, translaminar screws are similar to pedicle fixation in a 2-level interbody lumbar fusion.

Treatment of Distal Biceps Tendon Ruptures Using a Single-Incision Technique and a Bio-Tenodesis Screw

No consensus exists in the literature on the optimal operative treatment method for distal biceps tendon ruptures. It is our hypothesis that a single-incision technique with a poly-L-lactide Bio-Tenodesis screw (Arthrex, Inc, Naples, Florida) is a safe and effective method for operative management of distal biceps tendon ruptures, with success and complication rates comparable to previous reports in the literature. This article describes a prospective case series of 29 consecutive patients (30 operations) managed by the same surgeon over 34 months. Average follow-up was 19.6 months. Two patients were lost to follow-up. Elbow range of motion (ROM) and strength; Disabilities of the Arm, Shoulder, and Hand (DASH) score; and SF-12 score were measured at various time points up to 2 years. All patients had full extension and supination. Supination and flexion strength was at least 4/5 in all patients. Mean DASH, SF-12 Physical Component (PCS), and SF-12 Mental Component (MCS) scores were 5.86 (range, 0-16.67), 50.35 (range, 30.4-60.1), and 57.15 (range, 41.7-64.4), respectively. These scores are comparable to normative values reported by the American Academy of Orthopaedic Surgeons. Complication rates were similar to those previously reported in the literature. This type of fixation allowed for early mobilization of the operative arm. Our study demonstrates that use of a tenodesis screw for distal biceps repair results in DASH and SF-12 scores comparable to the norm for the general population with complications similar to those seen in past studies. In addition, biomechanical studies suggest that the repair is strong enough to allow early ROM, and the fixation technique may allow for more anatomic positioning of the distal biceps along the ulnar border of the bicipital tuberosity.

Two-year radiostereometric analysis evaluation of femoral head penetration in a challenging population of young total hip arthroplasty patients.

This prospective, randomized protocol evaluated femoral head penetration after total hip arthroplasty in a young population. Forty-five patients randomly received either a cross-linked or conventional ultrahigh-molecular-weight polyethylene (UHMWPE) liner in a noncemented hemispheric cup (Trilogy, Zimmer, Warsaw, Ind) with a 28-mm femoral head. Radiostereometric analysis film pairs, Harris hip, UCLA, SF-12, and Western Ontario and McMaster Universities scores were obtained through 2 years. Median femoral head penetration was less among cross-linked compared to conventional liners as follows: 0.06 mm (0.04-0.08 mm) vs 0.08 mm (0.02-0.19 mm) at 6 months, 0.07 mm (-0.14 to 0.16 mm) vs 0.11 mm (0.01-0.27 mm) at 1 year, and 0.065 mm (-0.04 to 0.193 mm) vs 0.169 mm (0.09-0.22 mm) at 2 years. Clinical outcomes were similar between the groups. Highly cross-linked UHMWPE demonstrated 55% less femoral head penetration compared to conventional polyethylene at 2 years. Despite improvements in the manufacturing process and sterilization of conventional UHMWPE, the femoral head penetration rate is unchanged from historical standards.