Avraam Ploumis

Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques.

IntroductionWith the advances and improvement of computer-assisted surgery devices, computer-guided pedicle screws insertion has been applied to the lumbar, thoracic and cervical spine. The purpose of the present study was to perform a systematic review of all available prospective evidence regarding pedicle screw insertion techniques in the thoracic and lumbar human spine. Materials and methodsWe considered all prospective in vivo clinical studies in the English literature that assessed the results of different pedicle screw placement techniques (free-hand technique, fluoroscopy guided, computed tomography (CT)-based navigation, fluoro-based navigation). MEDLINE, OVID, and Springer databases were used for the literature search covering the period from January 1950 until May 2010.Results26 prospective clinical studies were eventually included in the analysis. These studies included in total 1,105 patients in which 6,617 screws were inserted. In the studies using free-hand technique, the percentage of the screws fully contained in the pedicle ranged from 69 to 94%, with the aid of fluoroscopy from 28 to 85%, using CT navigation from 89 to 100% and using fluoroscopy-based navigation from 81 to 92%. The screws positioned with free-hand technique tended to perforate the cortex medially, whereas the screws placed with CT navigation guidance seemed to perforate more often laterally.ConclusionsIn conclusion, navigation does indeed exhibit higher accuracy and increased safety in pedicle screw placement than free-hand technique and use of fluoroscopy.

Meniscal Tear Characteristics in Young Athletes with a Stable Knee: Arthroscopic Evaluation

Background There has been great interest in the literature regarding meniscal tears in unstable knees, but there is not as much information available on stable knees. Purpose To report the characteristics of isolated meniscal tears (type and location) in athletes with intact cruciate ligaments. Study Design Case series; Level of evidence, 4. Methods Arthroscopic surgery was performed on 314 (83.1%) knees in the acute phase (<6 weeks) of injury and on 64 (16.9%) knees more than 6 weeks after injury for a total of 364 athletes (378 knees). Coopers classification was used to classify the meniscal tears according to the type and location. Results Overall, 262 of 378 tears (69.3%) were located in the medial meniscus and 116 (30.7%) in the lateral meniscus. Vertical tears (77.5%) were significantly more frequent than were horizontal tears (22.5%; ϰ2 test, P < .001). A total of 23.2% of tears involved the peripheral zones (zone 0 or 1), and tears that extended into the posterior horn accounted for 75.7%. Regarding the tear shape between male and female athletes, on both sides there were no statistically significant differences in the percentage of horizontal, bucket-handle, longitudinal, or radial tears. Conclusion The characteristics of isolated meniscal tears differ with regard to the sport, sex, and tear location and type from those seen in unstable knees. This knowledge is useful in knee injury management.

Biomechanical comparison of anterior lumbar interbody fusion and transforaminal lumbar interbody fusion.

Study Design An in vitro biomechanical comparison of 2 fusion techniques, anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF), on cadaveric human spines. Objective To compare the immediate construct stability, in terms of range of motion (ROM) and neutral zone, of ALIF, including 2 separate approaches, and TLIF procedures with posterior titanium rod fixation. Summary of Background Data Both ALIF and TLIF have been used to treat chronic low back pain and instability. In many cases, the choice between these 2 techniques is based only on personal preference. No biomechanical performance comparison between these 2 fusion techniques is available to assist surgical decision. Methods Twelve cadaveric lumbar motion segments were loaded sinusoidally at 0.05 Hz and 5 Nm in unconstrained axial rotation, lateral bending and flexion extension. Specimens were randomly divided into 2 groups with 6 in each group. One group was assigned for TLIF whereas the other group for ALIF. In the ALIF group, there were 3 steps. First, the lateral ALIF procedure with the anterior longitudinal ligament (ALL) intact was performed. Afterwards, the ALL was cut without removing the ALIF cage. Finally, another appropriately sized ALIF cage was inserted anteriorly. Biomechanical tests were conducted after each step. Results In the ALIF group, the lateral ALIF and subsequent anterior ALIF reduced segmental motion significantly (P=0.03) under all loading conditions. Removing the ALL increased ROM by 59% and 142% in axial rotation and flexion extension, respectively (P=0.03). The anterior ALIF approach was able to achieve similar biomechanical stability of the lateral approach in lateral bending and flexion extension (P>0.05) under all loading conditions. The TLIF procedure significantly reduced the range of motion compared with the intact state (P=0.03). However, no statistical difference was detected between the TLIF group and the ALIF group (P>0.05). Conclusions Both ALIF and TLIF procedures combined with posterior instrumentation significantly improved construct stability of intact spinal motion segments. However, there was no statistical difference between these 2 fusion techniques. The 2 ALIF approaches (lateral and anterior) also had similar construct stability even though anterior longitudinal ligament severing significantly reduced stability.

Position of interbody spacer in transforaminal lumbar interbody fusion: effect on 3-dimensional stability and sagittal lumbar contour

Study Design Biomechanical study. Objective To test 2 different intervertebral positions of a semilunar cage and their effects on 3-dimensional stability and segmental lordosis in a model of transforaminal lumbar interbody fusion (TLIF). Summary of Background Data In his original TLIF description, Harms recommended decortication of endplates, followed by placement of mesh cages in the middle-posterior intervertebral third. Subsequent studies presented conflicting recommendations: anterior placement of the spacer-cage for better load-sharing versus placement on the stronger posterolateral endplate regions. Methods Six human lumbar spinal functional units were first tested intact. TLIF was performed using a semilunar poly-ether-ether-ketone cage randomly inserted in the anterior (TLIF-A) or posterior (TLIF-P) disc space. Pedicle screws and rods were added. Unconstrained pure moments in axial-torsion, lateral-bending (LB), and flexion-extension (FE) were applied under 0.05 Hz and ±5 Nm sinusoidal waveform. Segmental motions were recorded. Range of motion (ROM) and neutral zone (NZ) were calculated. Pairwise comparisons were made using nonparametric Wilcoxon-matched pairs signed rank sum test with statistical significance set at P<0.05. Results TLIF-A and TLIF-P significantly decreased ROM (P<0.05) of the intact spinal functional unit, in FE and LB. In axial-torsion, decrease of ROM after TLIF procedures was not significant (P>0.05). Δ-ROM between TLIF-A and TLIF-P was not significant (P>0.05). TLIF-A and TLIF-P significantly decreased NZ in LB (P<0.05). In FE, TLIF-P significantly decreased NZ (P<0.05); TLIF-A showed a trend toward significance (P=0.09). Δ-NZ between TLIF-A and TLIF-P was not significant (P>0.05). Segmental lordosis of TLIF-A and TLIF-P on C-arm views showed angle differences within the range of measurement error of Cobb angles. Conclusions Difference in ROM and NZ between anterior (TLIF-A) or posterior (TLIF-P) positions was not statistically significant. Similarly, both positions did not influence segmental lordosis.

The appearance of kissing contusion in the acutely injured knee in the athletes

Background: Bone contusions are often identified at magnetic resonance imaging (MRI) in the acutely injured knee. Contusions of both surfaces of the joint are known as kissing contusions. Objective: To determine the frequency, type, and distribution of kissing contusions occurring in association with injuries of the knee joint. Methods: 255 MRI examinations in athletes with acutely injured knees (197 men; 58 women; mean age 24.2 years) were reviewed by two independent examiners; 219 MRIs were done within the first month after the injury and 36 within two to four months. None of the knees had been injured before. No fractures were present on x ray. Results: Bone contusions were diagnosed in 71 cases (27.8%); 55 (22.5%) were identified as single contusions and 16 (6.3%) as kissing contusions. Eight of the kissing contusions were associated with anterior cruciate ligament tears, three with menisceal tears, four were isolated lesions, and one was delayed, following a menisceal tear. The 32 bone contusions (16 kissing contusions) were located as follows: lateral femoral condyle (n = 14; 8 type I, 6 type II); lateral tibial condyle (n = 9; 3 type I, 1 type II, 5 type III); medial tibial condyle (n = 7; 2 type I, 5 type III); medial femoral condyle (n = 2; both type I). The associated injuries were confirmed by arthroscopy in 12/16 patients. Conclusions: Kissing contusion is a significant injury often associated with ligamentous or menisceal injuries. Type I lesions are most common on the lateral femoral condyle and type III on the lateral tibial condyle.

Effectiveness of botulinum toxin injection with and without needle electromyographic guidance for the treatment of spasticity in hemiplegic patients: a randomized controlled trial

Abstract Purpose: To compare the effects of botulinum toxin injection with and without needle electromyographic guidance for the treatment of spasticity. Method: A randomized controlled study was conducted in a tertiary university hospital. Twenty-seven adult hemiplegic patients with spasticity due to brain or spinal cord damage were included. Spastic muscles were injected with botulinum toxin with or without EMG guidance. The modified Ashworth scale and modified Barthel index in each patient pre- and post-injection were documented. Results: In group A, which consisted of 15 patients (55.55%), the injection was administered with needle electromyographic guidance, while in 12 patients (44.44%) of group B without electromyographic guidance with the use of anatomic landmarks only. The follow-up period was 3 months. At 3 weeks post-injection, spasticity was decreased (p < 0.05) in all patients and the mean (SD) reduction of spasticity was higher (p < 0.05) in group A (1.67 (0.5)) than group B (1.25 (0.46)). Similarly, the mean (SD) functional modified Barthel index improved statistically significantly (p < 0.001) post-injection (45.37 (8.43)) than pre-injection (54.07 (9.610), especially in group A (p < 0.05). Conclusion: The effectiveness of intramuscular botulinum toxin injection for the treatment of spasticity in hemiplegic patients is superior when performed with needle electromyographic guidance than without electromyography. Implications for Rehabilitation It is recommended that botulinum toxin muscle injections of hemiplegic limbs be performed with EMG guidance More spasticity reduction and functional improvement at 3 months post-injection was observed in patients injected with botulinum toxin by the use of combined EMG guidance and anatomic landmarks EMG guidance might also save amount of botulinum toxin due to less spasticity observed during injection than when injection is performed with anatomic landmarks only

Rotaglide total knee arthroplasty: a long-term follow-up study.

BACKGROUND Mobile-bearing knee designs represent an alternative to conventional fixed-bearing implants in total knee arthroplasty. The purpose of this study was to determine the clinical results of a mobile-bearing knee implant. METHODS From 1990 to 1998, 326 primary consecutive mobile-bearing total knee prostheses were implanted in 260 patients who had a mean age and standard deviation of 66.7 ± 6.9 years. Femoral and tibial components were cemented in all knees, and the patella was resurfaced in 199 knees (61%). Patients were evaluated with the use of the Knee Society clinical rating system and radiographic examinations. Complications were noted, and survivorship of the prostheses was determined. RESULTS The mean follow-up period was 156 ± 27.3 months, with maximum follow-up at eighteen years. The mean Knee Society knee score improved from 32.4 ± 21.2 preoperatively to 92.6 ± 10.0 at the time of the last follow-up (p = 0.00), and the mean Knee Society functional score improved from 39.3 ± 18.7 preoperatively to 66.7 ± 18.6 at the time of the last follow-up (p = 0.00). Mean knee flexion improved from 92.3° ± 14.5° preoperatively to 112.1° ± 13.4° at the time of the last follow-up (p = 0.00). There were twenty-four (7.4%) knees that required revision. In eighteen (5.5%) knees, worn out or broken polyethylene was found and a polyethylene-only exchange was done. Six knees (1.8%) were fully revised. The survival rate was 0.96 (95% confidence interval, 0.93 to 0.98) at ten years and 0.87 (95% confidence interval, 0.79 to 0.93) at eighteen years. CONCLUSIONS A fully congruent, mobile-bearing total knee prosthesis had excellent survivorship during the ten to eighteen-year follow-up interval.

Surgical treatment of lumbar spinal stenosis with microdecompression and interspinous distraction device insertion. A case series

BackgroundInterspinous distraction devices (IPDD) are indicated as stand-alone devices for the treatment of spinal stenosis. The purpose of this study is to evaluate the results of patients undergoing surgery for spinal stenosis with a combination of unilateral microdecompression and interspinous distraction device insertion.MethodsThis is a prospective clinical and radiological study of minimum 2 years follow-up. Twenty-two patients (average age 64.5 years) with low-back pain and unilateral sciatica underwent decompressive surgery for lumbar spinal stenosis. Visual Analogue Scale, Oswestry Disability Index and walking capacity plus radiologic measurements of posterior disc height of the involved level and lumbar lordosis Cobb angle were documented both preoperatively and postoperatively. One-sided posterior subarticular and foraminal decompression was conducted followed by dynamic stabilization of the diseased level with an IPDD (X-STOP).ResultsThe average follow-up time was 27.4 months. Visual Analogue Scale and Oswestry Disability Index improved statistically significantly (p < 0.001) in the last follow-up exam. Also, the walking distance increased in all patients but two. Posterior intervertebral disc height of the diseased level widened average 1.8 mm in the postoperative radiograph compared to the preoperative. No major complication, including implant failure or spinous process breakage, has been observed.ConclusionsThe described surgical technique using unilateral microdecompression and IPDD insertion is a clinically effective and radiologically viable treatment method for symptoms of spinal stenosis resistant to non-operative treatment.

Dysphagia Associated with Cervical Spine and Postural Disorders

Difficulties with swallowing may be both persistent and life threatening for the majority of those who experience it irrespective of age, gender, and race. The purpose of this review is to define oropharyngeal dysphagia and describe its relationship to cervical spine disorders and postural disturbances due to either congenital or acquired disorders. The etiology and diagnosis of dysphagia are analyzed, focusing on cervical spine pathology associated with dysphagia as severe cervical spine disorders and postural disturbances largely have been held accountable for deglutition disorders. Scoliosis, kyphosis–lordosis, and osteophytes are the primary focus of this review in an attempt to elucidate the link between cervical spine disorders and dysphagia. It is important for physicians to be knowledgeable about what triggers oropharyngeal dysphagia in cases of cervical spine and postural disorders. Moreover, the optimum treatment for dysphagia, including the use of therapeutic maneuvers during deglutition, neck exercises, and surgical treatment, is discussed.

Spleen rupture after surgery in Marfan syndrome scoliosis

Spleen rupture occurred in a 14-year-old girl with Marfan syndrome after posterior spinal instrumented fusion and thoracoplasty for scoliosis. Splenectomy successfully treated this unusual complication of spinal surgery. The etiology, diagnosis, and management of spleen rupture following pediatric spinal surgery are discussed.