Hossein Elgafy

Computed tomography of normal distal tibiofibular syndesmosis

ObjectiveThe purpose of this study was to determine the shape and measurements of the normal distal tibiofibular syndesmosis on computed tomographic scans and to identify features that could aid in the diagnosis of syndesmotic diastasis using computed tomography (CT).Materials and methodsCT scans of 100 patients with normal distal tibiofibular syndesmoses were reviewed retrospectively. In 67% the incisura fibularis was deep, giving the syndesmosis a crescent shape. In 33% the incisura fibularis was shallow, giving the syndesmosis a rectangular shape. The measurements of both types were taken using the same reference points.ResultsThe mean age of the patients was 40xa0years, and there were 53 men and 47 women. The mean width of the distal tibiofibular syndesmosis anteriorly between the tip of the anterior tibial tubercle and the nearest point of the fibula was 2xa0mm. The mean width of the distal tibiofibular syndesmosis posteriorly between the medial border of the fibula and the nearest point of the lateral border of the posterior tibial tubercle was 4xa0mm. In men the mean width of the distal tibiofibular syndesmosis, anterior and posterior, was 2xa0mm and 5xa0mm, respectively, and in women it was 2xa0mm and 4xa0mm, respectively.ConclusionThis study provides measurements of the normal tibiofibular syndesmosis to aid in the diagnosis of occult diastasis.

Subtalar arthroscopy for persistent subfibular pain after calcaneal fractures.

This is a report of 10 consecutive patients who had subtalar arthroscopy for persistent pain in the subfibular area after open reduction and internal fixation for intraarticular calcaneal fractures. The average period between the injury and the subtalar arthroscopy was 14.3 months (range, 6–36 months). The average follow-up period after subtalar arthroscopy for the patients who did not require further treatment was 16.7 months (average, 11–35 months). All the patients except two had chondromalacia. Three had grade II, three had grade III, and two had grade IV. Five patients had intra-articular adhesion. Two patients had a loose body. The power shaver has been used for debridement of the damaged cartilage and excision of the adhesion. Eight patients (80%) had considerable pain relief and did not require further local injection or surgical management. The two patients who required subtalar fusion had grade IV chondromalacic lesions. Only four patients had improvement in the range of motion of the subtalar joint. The preoperative American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score for the whole group was 69.9 points (range, 68–74 points), which was improved postoperatively to 77.2 points (range, 48–90 points). Subtalar arthroscopy for persistent pain after calcaneal fractures should be considered, especially if the radiological examination shows mild degenerative changes in the subtalar joint.

Ipsilateral arcuate foramen and high-riding vertebral artery: implication on C1–C2 instrumentation

BACKGROUND CONTEXTnSeveral methods for C1-C2 stabilization have been described in the literature. These include C1-C2 transarticular and C1 lateral mass screws. In patients with aberrant anatomy such as a high-riding vertebral artery (VA) or the presence of an arcuate foramen at C1, there exists a higher risk of VA injury. This may lead to excessive bleeding, stroke, and possibly death. There have been several studies determining the incidence of arcuate foramen and high-riding VA occurring individually in the general population, but none have determined their occurrence simultaneously.nnnPURPOSEnTo determine the prevalence of ponticulus posticus and high-riding VA occurring simultaneously in the general population.nnnSTUDY DESIGNnRadiological study.nnnMETHODSnOne hundred consecutive computed tomography (CT) scans of the cervical spine were reviewed. Scans that contained an arcuate foramen were identified, and it was indicated whether the foramen was right sided, left sided, or bilateral. In the same group, the thickness of the isthmus and the internal height of the lateral mass of C2 were measured. The VA was considered high riding if the isthmus thickness was less than 5 mm or the isthmus internal height was less than 2 mm.nnnRESULTSnFourteen out of one hundred (14%) patients had a fully formed arcuate foramen. Of these, six were left sided, three were right sided, and five were bilateral. In addition, there were 24 (24%) patients with partially formed ponticulus posticus. Thirty-two (32%) patients were identified to have a high-riding VA. Of these, 13 were left sided, 9 were right sided, and 10 were bilateral. Five (5%) had an ipsilateral arcuate foramen and high-riding VA.nnnCONCLUSIONSnThe arcuate foramen and high-riding VA are common anomalies that are often not recognized. Although ipsilateral high-riding VA and arcuate foramen rarely occur in the general population, proper identification of these anomalies on preoperative CT scan facilitates planning the safest technique for C1-C2 instrumentation.

Effectiveness and safety of transforaminal lumbar interbody fusion in patients with previous laminectomy

PurposeTo determine the efficacy and safety of transforaminal lumbar interbody fusion (TLIF) for revision lumbar spine surgery in patients with previous laminectomy. The secondary objective was to evaluate the clinical and radiological outcome after such a procedure.MethodsRetrospective case series study. Eighty-two patients were included. There were 48 women (58.5xa0%) and 34 men (41.5xa0%) with a mean age of 51xa0years (range 26–84) at the time of index procedure. The outpatient and inpatient charts were reviewed to identify patients’ demographic data, preoperative, perioperative, and postoperative data. The outcome measures were assessed by Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. An independent spine surgeon and musculoskeletal radiologist reviewed the imaging studies.ResultsThe average operative time was 160xa0min (range 131–250). The average estimated blood loss was 652xa0cc (100–1,400xa0cc). Nineteen patients (23.1xa0%) required blood transfusion. Five patients (6xa0%) had dural tear. One patient (1.2xa0%) had a surgical site infection. Two patients (2.4xa0%) had thromboembolic events. The average hospital stay was 3.8xa0days (2–5xa0days). At a mean follow-up of 28xa0months, there were statically significant improvement in the ODI and VAS for back and leg pain. None of the patients’ radiographs showed hardware failure or pedicle screw loosening and no patient returned to the operating room for pseudarthrosis.ConclusionsThe current study confirmed that TLIF approach in patients with previous laminectomy is effective and safe with good outcomes.

The Radiographic Failure of Single Segment Posterior Cervical Instrumentation in Traumatic Cervical Flexion Distraction Injuries

Background/Objectives: Unilateral and bilateral cervical facet subluxations, dislocations, and/or fractures may be managed with anterior, posterior, or combined surgical approaches. The primary objective of this study was to identify radiographic features that predispose to poor radiographic outcomes (kyphosis) when these injuries are treated with single segment posterior cervical instrumentation and fusion. Method: A retrospective radiographic review was performed on 65 patients whose unilateral or bilateral facet subluxation/dislocations or fracture dislocation was managed with single segment posterior cervical instrumentation and fusion. The pre- and postoperative plain radiographs, CT, and MRI were assessed to identify the fracture type, degree of kyphosis, translation, and radiographic failure. Results: 2 patients (3.5%) demonstrated gross radiographic failure of the posterior instrumentation. Both had bilateral facet subluxation without fracture and ultimately required anterior revision. Kyphosis at...

Rationale of Revision Lumbar Spine Surgery

Revision lumbar spine surgeries are technically challenging with inconstant outcome results. This article discusses the preoperative, intraoperative, as well as postoperative management in these difficult patients. Successful intervention requires a detailed history and physical examination and carefully chosen diagnostic tests. Preoperative planning is paramount in these cases. The decision-making process should address the timing of the surgery, surgical approach, level of interbody fusion required, correction of sagittal imbalance, type of osteotomy, location of the osteotomy, and the end of the construct. Surgeons should be prepared to manage associated complications such as dural tear and massive blood loss. The use of autograft and/or biologic graft is necessary to help in achieving a successful fusion. Postoperative management includes prophylactic antibiotic, anticoagulation, nutritional support, and brace.

Clinical outcome and subsequent sequelae of cement extravasation after percutaneous kyphoplasty and vertebroplasty: a comparative review:

Background Injection of cement during vertebroplasty and kyphoplasty can leak into surrounding structures and could be symptomatic. Purpose To identify the sites and incidence of cement extravasation after kyphoplasty and vertebroplasty, and to evaluate their impacts on clinical outcomes. Material and Methods A retrospective review of 316 patients treated with kyphoplasty and vertebroplasty; 411 cases were included (223 kyphoplasty and 188 vertebroplasty). Cement extravasation was evaluated postoperatively by computed tomography (CT) scan of the spine. Clinical outcomes were assessed by visual analog scale (VAS) and Oswestry Disability Index (ODI). Results There was a statistically significant difference in the incidence rate of cement extravasation between vertebroplasty and kyphoplasty groups (Pu2009<u20090.04). The most common site of cement extravasation was in paravertebral soft tissues for vertebroplasty (nu2009=u200933, 40.7%) and for kyphoplasty (nu2009=u200930, 30%). In the subgroup where cement leaked into the intradiscal space, adjacent vertebral body fractures occurred in 3/26 vertebrae (11.5%) in the vertebroplasty group and in 2/18 vertebrae (11.1%) in the kyphoplasty group. Both groups showed a statistically significant decrease in both VAS (Pu2009<u20090.001) and ODI scores (Pu2009<u20090.001). There was no significantly difference in patient satisfaction between those who had cement extravasation and those who did not, in both groups. Conclusion Kyphoplasty has an advantage in terms of less risk of cement extravasation. However, this factor did not reflect on subsequent sequelae or final clinical outcomes. This study did not find a distinct correlation between intradiscal cement extravasation and increased risk of adjacent vertebral fractures.

Disseminated coccidioidomycosis of the spine

A 27-year-old man presented with neck pain. Computed tomography (CT) scan of the cervical spine showed nearcomplete destruction of the C5 vertebral body with focal kyphosis (Fig. 1). Magnetic resonance imaging showed a large retropharyngeal abscess with no evidence of epidural abscess or spinal cord compression (Fig. 2). Results of the CT-guided needle biopsy were positive for Coccidioides immitis. The patient underwent drainage of retropharyngeal abscess, C5 corpectomy, C4–6 arthrodesis with fibular allograft, and instrumentation. Two years after his initial surgery, he presented to the emergency room with a large, swollen wound on his left

Proposed alternative revision strategy for broken S1 pedicle screw: radiological study, review of the literature, and case reports

BACKGROUND CONTEXTnThere have been many reports outlining differing methods for managing a broken S1 screw. To the authors best knowledge, the technique used in the present study has not been described previously. It involves insertion of a second pedicle screw without removing the broken screw shaft.nnnSTUDY DESIGNnRadiological study, literature review, and two case reports of the surgical technique.nnnPURPOSEnTo report a proposed new surgical technique for management of broken S1 pedicle screws.nnnMETHODSnComputed tomography (CT) scans of 50 patients with a total of 100 S1 pedicles were analyzed. There were 25 male and 25 female patients with an average age of 51 years ranging from 36 to 68 years. The cephalad-caudal length, medial-lateral width, and cross-sectional area of the S1 pedicle were measured and compared with the diameter of a pedicle screw to illustrate the possibility of inserting a second screw in S1 pedicle without removal of the broken screw shaft. Two case reports of the proposed technique are presented.nnnRESULTSnThe left and right S1 pedicle cross-sectional area in female measured 456.00 ± 4.00 and 457.00 ± 3.00 mm(2), respectively. The left and right S1 pedicle cross-section area in male measured 638.00 ± 2.00 and 639.00 ± 1.00 mm(2), respectively. There were statistically significant differences when comparing male and female S1 pedicle length, width, and cross-sectional area (p<.05). At 2-year follow-up, the two case reports of the proposed technique showed resolution of low back pain and radicular pain. Plain radiograph and CT scan showed posterolateral fusion mass and hardware in good position with no evidence of screw loosening.nnnCONCLUSIONSnThe S1 pedicle dimensions measured on CT scan reviewed in the present study showed that it may be anatomically feasible to place a second screw through the S1 pedicle without the removal of the broken screw shaft. This treatment method will reduce the complications associated with other described revision strategies for broken S1 screws.

Biomechanical analysis on of anterior transpedicular screw-fixation after two-level cervical corpectomy using finite element method

Background: Anterior cervical trans‐pedicle screw fixation was introduced to overcome some of the disadvantages associated with anterior cervical corpectomy and fusion. In vitro biomechanical studies on the trans‐pedicle screw fixation have shown excellent pull‐out strength and favorable stability. Comprehensive biomechanical performance studies on the trans‐pedicle screw fixation, however, are lacking. Methods: The control computed tomography images (C2‐T2) were obtained from a 22‐year‐old male volunteer. A three dimensional computational model of lower cervical spine (C3‐T1) was developed using computed tomography scans from a 22 year old human subject. The models of intact C3‐T1 (intact group), anterior cervical trans‐pedicle screw fixation (trans‐pedicle group), and anterior cervical corpectomy and fusion (traditional group) were analyzed with using a finite element software. A moment of 1 N·m and a compressive load of 73.6 N were loaded on the upper surface and upper facet joint surfaces of C3. Under six conditions, four parameters such as the range of motion, titanium mesh plant stress, end‐plate stress, and bone‐screw stress were measured and compared on two treatment groups. Findings: Compared with the intact model, the range of motions for treatment groups were decreased. Compared with cervical corpectomy and fusion, the titanium plant, C4 upper end‐plate and C7 lower end‐plate stresses in trans‐pedicle group were reduced. No significant difference was discovered on bone‐screw stress between the two groups for lateral flexion and rotation, but bone‐screw stress is smaller in trans‐pedicle group when compared with traditional group. With exception of individual difference, trans‐pedicle group had better biomechanical results than traditional group in range of motions, titanium mesh plant stress, end‐plate stress and bone‐screw stress. Interpretation: The trans‐pedicle method has better biomechanical properties than the anterior cervical corpectomy and fusion making it a viable alternative for cervical fixations. HighlightsAnterior trans‐pedicle screw fixation reconstruction FE model was built.Biomechanical properties on this model were comprehensively analyzed.By comparing the two reconstruction models, better biomechanical properties in this model were discovered.Bone‐screw interface stresses were greater in the caudal level than in cranial level.