Can Dynamic Spinal Stabilization Be an Alternative to Fusion Surgery in Adult Spinal Deformity Cases?

BACKGROUND: Rigid stabilization and fusion surgery are widely used for the correction of spinal sagittal and coronal imbalance (SCI). However, instrument failure, pseudoarthrosis, and adjacent segment disease are frequent complications of rigid stabilization and fusion surgery in elderly patients. In this study, we present the results of dynamic stabilization and 2-stage dynamic stabilization surgery for the treatment of spinal SCI. The advantages and disadvantages are discussed, especially as an alternative to fusion surgery. METHODS: In our study, spinal, sagittal, and coronal deformities were corrected with dynamic stabilization performed in a single session in patients with good bone quality (without osteopenia and osteoporosis), while 2-stage surgery was performed in patients with poor bone quality (first stage: percutaneous placement of screws; second stage: placement of dynamic rods and correction of spinal SCI 4-6 months after the first stage). One-stage dynamic spinal instrumentation was applied to 20 of 25 patients with spinal SCI, and 2-stage dynamic spinal instrumentation was applied to the remaining 5 patients. RESULTS: Spinal SCI was corrected with these stabilization systems. At 2-year follow-up, no significant loss was observed in the instrumentation system, while no significant loss of correction was observed in sagittal and coronal deformities. CONCLUSION: In adult patients with spinal SCI, single or 2-stage dynamic stabilization is a viable alternative to fusion surgery due to the very low rate of instrument failure. CLINICAL RELEVANCE: This study questions the use of dynamic stabilization systems for the treatment of adult degenerative deformities.

Use of Dynamic Spinal Instruments (Dynesys) in Adult Spinal Deformities According to Silva-Lenke and Berjano-Lamartina Classifications.

BACKGROUND: Adult spinal deformities (ASD) present complex challenges in spine surgery. The diverse nature of these deformities requires a comprehensive understanding of their classification and treatment options. Traditional approaches, such as fusion and rigid stabilization are associated with complications, including screw loosening, breakage, proximal junctional kyphosis (PJK), and pseudoarthrosis. Dynamic stabilization techniques have emerged as promising alternatives, to reduce these complications and preserve spinal motion. OBJECTIVE: This study investigated the effectiveness of dynamic stabilization using the Dynesys system in the surgical treatment of adult degenerative spinal deformities, with a particular emphasis on their classification. METHODS: ASDs were classified according to the Berjano-Lamartina (BL) and Silva-Lenke (SL) classifications. We analyzed the efficacy of the Dynesys system in enhancing sagittal balance, radiological parameters, and clinical outcomes in this context. RESULTS: Dynamic stabilization of patients with ASDs using the Dynesys system significantly improved the visual analog scale and Oswestry Disability Index scores and decreased the complication rates. Patients with BL types 2, 3, and 4 experienced a significant improvement in sagittal balance followed by sagittal vertical axis measurements (p = 0.045, p = 0.015, and p < 0.0001, respectively). CONCLUSION: The SL and BL classifications, which were originally developed for rigid spinal stabilization, can be applied in dynamic stabilization. Furthermore, dynamic stabilization using the Dynesys system can be used as an alternative to rigid stabilization in SL levels 2 and 3, and BL types 1, 2, and 3, and in some patients with type 4 ASDs.

Is The Modular Dynamic System as Effective as Classical Dynamic Systems in Long Segment Dynamic Thoracolumbar Stabilization?

AIM: To evaluate the outcomes of dynamic stabilization in the multilevel degenerative spondylotic spine, and to compare the two dynamic systems (Dynesys® and Orthrus®) to reveal the increasing role of dynamic systems in the management of the degenerative spine. MATERIAL AND METHODS: A total of 74 patients who received dynamic stabilization for degenerative pathologies were retrospectively analyzed. Demographic details: preoperative data including neurological status, pain scores, and radiology; and intraoperative data including blood loss, duration of surgery, complications, and postoperative data including the neurologic status, duration of hospital stay, and pain scores were examined. RESULTS: Patients in both groups showed statistically significant improvements in their Visual Analog Scale and Oswestry Disability Index scores. Significant corrections of thoracic kyphosis (T2-T12), the sagittal vertical axis, and T10-L2 thoracolumbar kyphosis were obtained in our cohort (p < 0.05). A total of 4 patients received revision surgery due to screw loosening. Patients were discharged after 3-4 days and mobilized on the first postoperative day. CONCLUSION: We did not experience any serious issues in terms of stabilization in the cases in which we employed both systems. Our patients' clinical results were satisfactory in both systems. Existing systems can be used safely even in long-segment stabilization surgeries.

Comparison of Staple, Anchor, and Tenodesis Screw for Posterior Tibialis Tendon Fixation: A Biomechanical Analysis.

Various posterior tibialis tendon fixation techniques are described in literature. Suture anchor, staple and tenodesis screws are widely used for posterior tibialis tendon transfer, but their stiffness and the maximal ultimate failure load were not tested before. We aimed to compare the initial ultimate failure load and stiffnesses of suture anchor, staple and tenodesis screws on bovine tendon fixation to bovine metaphyseal bone. Thirty-five fresh bovine ankle joints and hooves were obtained from a local abattoir. Metatarsals bones with long extensor tendons were harvested. Staple group had 15, suture anchor group had 10, and tenodesis screw group had 10 samples. All fixations were tested with Instron® ElectroPuls® E10000 Test Instrument. Ultimate failure load and failure location were noted. Staple group's median ultimate failure load was 210.03 N (IQR: 133.43), suture anchor group's was 124.33 N (IQR: 63.67), and tenodesis screw group's was 394.46 N (IQR:115.09). Median stiffness of the staple group was 19.87 N/m (IQR: 15.29); the tenodesis screw group's was 20.28 N/m (IQR: 6.18), the anchor group's was 8.54 N/m (IQR: 4.35). Staples' failure occurred on tendon-staple interface, while suture anchors' occurred on anchor-suture interface and tenodesis screws' occurred on tendon-suture interface. Tenodesis screws' ultimate failure load was the highest (tenodesis vs anchor and staple p < .001 and p = .032, respectively). Staple fixation is less expensive than the other methods and can provide sufficient fixation strength but was weaker than the tenodesis screw fixation. Staples are still a good choice for tendon to bone fixation, whereas the suture anchors provide lower fixation strength at a higher cost.

Can neurological recovery occur after late decompression of an intradural cement leakage?

Percutaneous vertebroplasty (PV) can be applied widely from osteoporotic to metastatic fractures. Pain, radiculopathy, spinal cord compression, pulmonary embolism, and infection are common complications of this procedure. However, rare complications such as intradural cement leakage have also been reported. There is little or no data on the results obtained after the late intervention. In addition, the midline total laminectomy method, which is the classical method, was predominantly used in intradural cement leaks after PV. We would like to report a 69-year-old female patient who underwent vertebroplasty for her L1 osteoporotic fracture about 3 months ago in an external center and subsequently developed paresis. The patient's surgery was successfully performed without the need for stabilization by hemilaminectomy. The improvement in the clinical findings of our case despite the late decompression shows that surgery is the most satisfactory option in such patients. As a surgical method, total excision can be achieved with the posterior hemilaminectomy approach.

Radiological and Clinical Follow-up of Alpha-D Cervical Disk Prosthesis.

Background: Fusion surgery is applied to prevent segmental instability after surgery for cervical disk herniation. Motion-sparing surgeries have been developed to prevent adjacent segment disease after fusion surgery. Total disk replacement, one of these methods, has been applied in the cervical region for more than 20 years. We aimed to investigate the medium-term radiological and clinical outcomes of patients who had received Alpha-D disk prosthesis after cervical disk surgery, in terms of incidence of heterotopic ossification (HO) and other complications. Methods: We included 33 patients (17 women and 16 men) diagnosed with single-level cervical disk herniation and who had received prosthesis after anterior discectomy. The average follow-up period was 36 (18-78) months. The patients were followed up postoperatively at month 4, year 1, and annually thereafter. Patients, who had Alpha-D cervical disk prosthesis (CDP) (Medikon, Turkey), were monitored via radiological (standard and dynamic X-ray) and clinical (visual analog scale [VAS] and neck disability index [NDI]) modalities. Dynamic X-ray images were evaluated by an independent radiologist for HO and prosthesis movement. Results: Mean patient age was 40 ± 6.88 years. HO was observed in 7 (21.21%) patients, 6 of which were men. Significant intersex differences were noted for HO and movement rates (p = 0.039). Clinically, the mean preoperative and post-operative NDI levels were 35.4 ± 3.9 and 4 ± 2, respectively, whereas the mean pre- and post-operative VAS levels were 7 ± 1 and 1 ± 1, respectively. There was a clinically significant postoperative improvement in all the patients. However, there was no significant difference between the patients with and without HO in terms of age, operation level, and mean pre- and postoperative VAS, and postoperative NDI levels (p > 0.05). Despite the fact that there was a significant difference (p = 0.038) in favor of patients without HO in terms of mean preoperative NDI levels, this was not considered clinically significant. Conclusion: In the present study, all the patients demonstrated clinically significant improvement following CDP surgery. HO rate after CDP surgery was 21.21% in the medium term, and movement was preserved in 5 of the 7 patients with partial HO. The fact that the CDP design was based on the one-to-one reproduction of the movement segment in the cervical spine, might account for the underlying cause of success. However, these good results in the medium term may change in cases with long-term clinical follow-up.

Foraminoplasty with Partial Pediculectomy in Degenerative Spondylolisthesis Cases with Nerve Compression.

BACKGROUND: Degenerative spondylolisthesis refers to a forward displacement of a vertebra relative to the underlying vertebra. Patients with radicular pain and/or neurogenic claudication are considered suitable candidates for surgical intervention. The aim of this study was to present clinical results of dynamic stabilization applied after pediculectomy and neural foramen enlargement in patients with degenerative spondylolisthesis and normal spinal sagittal balance. MATERIALS AND METHODS: All patients who underwent pediculectomy and dynamic stabilization for lumbar degenerative spondylolisthesis were retrospectively identified. Diagnosis was made with detailed neurological and radiological imaging examinations for the anatomical location of the pain. Demographic data, visual analog scale scores, and quality-of-life scores were obtained. RESULTS: Patients included 3 (33.3%) men and 6 (66.7%) women with a mean age of 61.3 ± 13.0 years (range, 46-80 years) at initial symptom onset. Grade 1 degenerative spondylolisthesis was present in 5 (55.6%) patients, and grade 2 was present in 4 (44.4%) patients. Pathology was detected in L4-5 in 4 patients (44.4%) and L5-S1 in 5 patients (55.6%). In all patients, at the 3-month follow-up, statistically significant decrease in visual analog scale and Oswestry Disability Index scores was observed. At the last follow-up, no implant-related complications requiring revision were observed. CONCLUSIONS: In patients without any pathology in the sagittal balance, the optimal physiological treatment modality can be created by applying posterior dynamic stabilization together with pediculectomy to support the posterior tension band.

Clinical and radiological analysis of the effects of three different lumbar transpedicular dynamic stabilization system on disc degeneration and regeneration.

Objective: This study aims to assess the clinical outcomes of three transpedicular dynamic systems in treating degenerative disc disease and evaluate their impact on both clinical and radiological aspects of the operated and adjacent segments. Materials and methods: A total of 111 patients who underwent posterior transpedicular short-segment dynamic system procedures for treatment of degenerative disc disease were included. The patients were categorized into three groups, namely, Group 1 (Dynesys system, n = 38), Group 2 (Safinaz screw + PEEK rod, n = 37), and Group 3 (Safinaz screw + titanium rod, n = 36). Disc regeneration in the operated segment and disc degeneration in the operated, upper, and lower adjacent segments were assessed using the Pfirrmann Classification. Results: Postoperatively, a statistically significant difference was observed in visual analog scale and Oswestry Disability Index scores (p < 0.001). However, no statistically significant difference was seen in disc degeneration/regeneration and degeneration scores of the upper and lower adjacent segments between the preoperative and postoperative groups (p = 0.763, p = 0.518, p = 0.201). Notably, a positive effect on disc regeneration at the operated level (32.4%) was observed. No significant differences were found between the groups in terms of operation rates, screw loosening, and screw breakage after adjacent segment disease (p > 0.05). Conclusion: In patients without advanced degeneration, all three dynamic systems demonstrated the ability to prevent degeneration in the adjacent and operated segments while promoting regeneration in the operated segment. Beyond inhibiting abnormal movement in painful segments, maintaining physiological motion and providing axial distraction in the operated segment emerged as key mechanisms supporting regeneration.

Clinical parameters of laminoplasty and laminectomy with fusion in the treatment of cervical spondylosis and analysis of postoperative sagittal balance.

Background/aim: Cervical spondylosis is a progressive disease that causes degenerative changes affecting the spine, intervertebral discs, facets, and ligaments. With anterior and posterior surgical interventions, effective treatments can be applied in cervical spondylotic myelopathy (CSM). The relationship between regional and global spinal alignment and functional and pain outcomes was examined and it was revealed that these parameters play a significant role in obtaining good results. The aim of this study was to compare the perioperative and follow-up results of patients with CSM who underwent laminoplasty or laminectomy with fusion. Materials and method: CSM patients who were operated on between 2015 and 2020 and had at least 2 years of clinical and radiological follow-up were analyzed retrospectively. The patients were divided into 2 groups as the laminoplasty group and the laminectomy with fusion group, according to a simple random method. Demographic, clinical, radiological, and perioperative parameters were examined. Measurements were made by an independent observer using Surgimap and 2 years was considered to be sufficient time for the spine to take its final shape. Result: A total of 112 patients, including 68 males and 44 females, were included. Of these patients, 69 were in the laminectomy with fusion group, and 43 were in the laminoplasty group. Patient ages ranged from 39 to 85 years. The mean follow-up period was 36.28 months. In both groups, at the 3-month follow-up, a statistically significant improvement in the clinical parameters (neck disability index, visual analogue scale, modified Japanese Orthopaedic Association scores) was observed. When the preoperative cervical radiological parameters were evaluated, no statistically significant difference was found between the groups. The C2-C7 lordotic angles and the cervical SVA values were increased in the postoperative period, for both groups (p < 0.001). Although it is noteworthy that the increases were higher in the laminectomy with fusion group, no statistically significant difference was found between the groups. Conclusion: Deformity in a spinal segment may indirectly affect another segment. Being aware of the compensatory mechanisms and radiological parameters will help in determining the effective treatment plan.

Turkish version of the patient-based Constant-Murley Score: Its cross-cultural adaptation, validity, reliability and comparison with the clinician-based version.

Objectives: The aim of this study was to translate, cross-culturally adapt the patient-based Constant-Murley Score (p-CMS), assess its validity, reliability, and compare it with the clinician-based CMS (c-CMS). Patients and methods: This cross-sectional study included a total of 51 shoulders of 46 patients (22 males, 24 females; mean age: 49±10 years; range, 29 to 70 years) with shoulder pain between December 2015 and July 2016. After translation of p-CMS, each participant was asked to complete the final Turkish version of the p-CMS. The c-CMS was assessed by a physiatrist who was blinded to the p-CMS. Retest of the p-CMS was performed in patients (n=15) who did not receive any treatment between two visits (Days 3 to 5). Results: A total of 51 shoulders (n=5 bilateral shoulder pain) were tested. Strength, subjective, objective, and total scores were significantly different between the p-CMS and c-CMS (p<0.001). Pain scores of the c-CMS and p-CMS revealed similar results with 95% limits of agreement of -3.81 and 4.81. Weighted kappa statistics demonstrated that the levels of agreement ranged between 0.343 and 0.698 in subjective and between 0.379 and 0.515 in objective components. For test-retest reliability of the p-CMS, intraclass correlation coefficient values ranged between 0.838 and 0.995. Conclusion: The Turkish version of the p-CMS has internal consistency and test-retest reliability to evaluate shoulder function in Turkish patients with shoulder pathologies. Considering the differences in test protocols and scoring methods of c-CMS and p-CMS, their interchangeable use is not supported.

Preoperative Magnetic Resonance Imaging Abnormalities Predictive of Lumbar Herniation Recurrence After Surgical Repair.

OBJECTIVE: There are currently no standard criteria for evaluating the risk of recurrent disk herniation after surgical repair. This study investigated the predictive values of 5 presurgical imaging parameters: paraspinal muscle quality, annular tear size, Modic changes, modified Phirrmann disk degeneration grade, and presence of sacralization or fusion. METHODS: Between 2015 and 2018, 188 patients (89 female, 99 male, median age 50) receiving first corrective surgery for lumbar disk herniation were enrolled. Microdiskectomy was performed in 161 of these patients, and endoscopic translaminar diskectomy approach was performed in 27 patients. Clinical status was evaluated before surgery and 4, 12, and 24 months post surgery using a visual analog scale, Oswestry Disability Index, and Short Form 36. RESULTS: Recurrent disk herniation was observed in 21 of 188 patients. Seventeen of the recurrent disk herniations were seen in those who underwent microdiskectomy and 4 in those who underwent endoscopic translaminar diskectomy. There were significant differences in visual analog scale, Oswestry Disability Index, and Short Form 36 scores at 4, 12, and 24 months between patients with recurrence and the 167 no-recurrence patients. The median annular tear length was significantly greater in patients with recurrence than without recurrence. In addition, there were significant differences in recurrence rate according to Modic change type distribution, sacralization or fusion presence, Pfirmann disk; degeneration grade distribution, dichotomized annular tear size, dichotomized Modic change; and type and simplified 3-tier muscle degeneration classification distribution. CONCLUSIONS: Patients with poor clinical scores and recurrence exhibited additional radiologic abnormalities before surgery, such as poor paraspinal muscle quality, longer annular tears, higher Modic change type, higher modified Phirrmann disk degeneration grade, and sacralization or fusion. This risk evaluation protocol may prove valuable for patient selection, surgical planning, and choice of postoperative recovery regimen.

Lumbar Dynamic Stabilization With 2-Stage Surgery: Early Results.

BACKGROUND: Screw loosening, which is a major problem in dynamic systems, can be easily overcome with 2-stage surgery. In this article, the clinical and radiological results of patients undergoing dynamic stabilization with a Dynesys device in 2 stages are discussed. METHODS: A total of 10 male and 13 female adult patients were included in this single-center retrospective study conducted between 2018 and 2021. The mean age of the patients was 65.6 years. All of the patients had pain complaints that affected their daily lives. Bone density T scores were determined with the dual-energy x-ray absorptiometry method before patients were admitted for surgery. In the first surgery, Dynesys system pedicle screws were inserted. After 6 months of osteointegration, Dynesys system spacers and elastic bandages were placed. Preoperative, early postoperative, and late postoperative visual analog pain scale (VAS) scores and Oswestry Disability Index (ODI) scores were determined and statistically compared. RESULTS: Patients were followed for an average of 30 months. Complications and recurrence were not observed. Neurological deficits were not observed after patients recovered from anesthesia. Significant improvement was observed in the ODI and VAS parameters in the preoperative (ODI: 66.2%, VAS: 7.8), early postoperative (ODI: 20.3%, VAS: 2.4), and late postoperative (ODI: 6.8% and VAS: 1.1) periods. Symptomatic improvement was seen in all patients. No screw breakage or loosening was detected by radiological evaluation in any of the patients during the 2-year follow-up period. CONCLUSIONS: In our experience, the insufficiency of the proximal and distal end screws is eliminated when 2 stages of dynamic system stabilizations are completed after osteointegration of the screws.

Spinal fusion in facioscapulohumeral dystrophy for hyperlordosis: A case report.

RATIONALE: Facioscapulohumeral muscular dystrophy (FSHD) is the third most common muscular dystrophy, which is associated with facial, shoulder girdle, and paraspinal muscle atrophy. Most of the patients develop hypokyphosis and hyperlordosis in the course of the disease, to preserve standing posture. Corrective fusion is contraindicated in these patients as the surgery results with loss of compensatory hyperlordosis and leads to loss of trunk balance while standing. Although spinal fusion in neuromuscular scoliosis is a known treatment option, there are no studies in the literature on the spinal fusion of this specific patient group. PATIENT CONCERNS: In this case report we have presented a 66-year-old woman, who was admitted with back and abdominal pain, inability to sit straight, abdominal discomfort, and numbness in the lower extremities after prolonged sitting. DIAGNOSES: The patient developed severe hyperlordosis causing intra-abdominal disorders, radicular symptoms, and sitting discomfort due to FSHD. INTERVENTIONS: The patient underwent T2-S1 fusion and successful fusion was achieved. OUTCOMES: Individualized Neuromuscular Quality of Life Questionnaire (INQoL) was used to assess preoperative and 3 years postoperative functional outcomes. All domains and total score improved at the end of the follow-up period and successful fusion was verified radiologically. LESSONS: This case suggests that spinal fusion may provide functional improvement in carefully selected patient groups. Patient stratification considering spinal disability is required for further studies in this specific indication.

Rotator cuff tear characteristics: how comparable are the pre-operative MRI findings with intra-operative measurements following debridement during arthroscopic repair?

PURPOSE: Magnetic resonance (MRI) is a valuable imaging method which can detect pre-operative rotator cuff tear characteristics accurately. However, tendon degeneration almost always necessitates a certain amount of debridement during arthroscopic repair, which alters tear size and shape. The aim of this study is to question the accuracy of the pre-operative tear size and classification in MRI and its relation to the tear size and type of the debrided tendon during arthroscopic repair. METHODS: A retrospective survey was performed to identify shoulders that underwent arthroscopic rotator cuff repair. Rotator cuff tears with an adequate history, a standard pre-operative MRI, and available surgical video records with appropriate measurements were included. Traumatic tears, calcifying tendonitis, isolated subscapularis tears, and revisions were excluded. In total, 60 shoulders' (30 males, 27 females; age 55.2 [35-73]) preoperative MRIs and intra-operative measurements were analyzed by orthopaedic surgeons and radiologists. Tear width and type were recorded. Interdisciplinary and intradisciplinary consistency of measurements and classifications were analyzed. Tear width measured on pre-operative MRI and after debridement were compared. RESULTS: Average measured tear width was 9 ± 5.3 mm on MRI. Surgeons (9.98 ± 4.6 mm) measured tears significantly wider than radiologists (7.71 ± 6.6 mm). Radiologists (ICC, 0.930; CI, 0.883-0.959) showed superior consistency on MRI than surgeons (CI, 0.502; CI, 0.105-0.726). Average tear width measured after debridement (29.3 ± 9.6 mm) was significantly higher than tear width measured on pre-operative MRI (p < 0.0001). None of the researchers assessing tear type on pre-operative MRI showed agreement with surgeons assessing intra-operative data. CONCLUSIONS: There were significant differences between the pre-operative tear characteristics on MRI and the debrided tendon characteristics during surgery, which were extensive enough to classify the tear in a different category.

A multidisciplinary clinical approach to facioscapulohumeral muscular dystrophy.

BACKGROUND AND PURPOSE: Impaired shoulder function is the most disabling problem for daily life of Fascioscapulohumeral muscular dystrophy (FSHD) patients. Scapulothoracic arthrodesis can give a high impact to the functionality of patients. Here we report our experience with scapulothoracic arthrodesis and spinal stenosis surgery in FSHD patients. METHODS: 32 FSHD patients were collected between 2015-2016. Demographical and clinical features were documented. All the patients were neurologically examined. The Medical Research Council (MRC) and the FSHD evaluation scale was used to assess muscle involvement1. Scapulothoracic arthrodesis and spinal stenosis surgeries were performed in eligible patients. RESULTS: There were 16 male and 16 female (mean age 34.4 years; range 12-73) patients. 6 shoulders of 4 patients aged between 2132 years underwent scapulothoracic arthrodesis (two bilateral, one left and one right sided). Only one 63 years old female patient with severe hyperlordosis had spinal fusion surgery. All of the patients undergoing these corrective surgeries have better functionality in daily life, as well as superior shoulder elevation. CONCLUSION: Until the emergence and clinical use of novel therapeutics, surgical interventions are indicated in carefully selected patients with FSHD to improve arm movements, the posture and the quality of life of patients in general. Scapulothorosic arthrodesis is a management with good clinical results and patient satisfaction. In selected cases other corrective orthopedic surgeries like spinal fusion may also be considered.

Does a core stabilization exercise program have a role on shoulder rehabilitation? A comparative study in young females.

OBJECTIVES: This study aims to evaluate the effect of core stabilization exercises and to explore the immediate effect of core muscles-activated posture on shoulder maximal voluntary isometric contraction (MVIC) strength. PATIENTS AND METHODS: Between November 2016 and January 2015, a total of 75 healthy female volunteers (mean age 25.36 years; range, 18 to 30 years) were included. Of these, 42 consecutive volunteers were assigned as the study group, while the remaining 33 volunteers were assigned as the control group. The study group completed a six-week core stabilization home-based exercise program. Two measurements were performed with six-week interval. A set of three repetitions for each shoulder side was performed by an electronic dynamometer under two conditions: core muscles relaxed and activated. Measurements were monitored real-time with a connected computer and recorded in Newton. RESULTS: The activation of core muscles during the measurement significantly decreased the MVIC values in both groups (p<0.05). The MVIC values significantly increased after home-based exercise program in both conditions (p<0.05). CONCLUSION: Our study showed that six-week core stabilization exercise program had a significant positive effect on the shoulder MVIC strength. This result may support the use of core stabilization exercises in the early periods of shoulder rehabilitation when the shoulder muscle strengthening exercises are painful.

Postoperative changes in sacropelvic junction in short-segment angular kyphosis versus Scheuermann kyphosis.

PURPOSE: To comparatively evaluate the biomechanical alterations those occur in the sagittal plane of sacropelvic junction in angular kyphosis (AK) and Scheuermann kyphosis (SK) patients after surgery. METHODS: The spine radiographs of 52 patients operated for short-segment AK (n = 20) or SK (n = 32) were studied. Main outcome measures were sacral slope, pelvic incidence, pelvic tilt, lumbar lordosis, and thoracic kyphosis angles. RESULTS: In AK group, local and thoracic kyphosis angles, as well as lumbar lordosis angle, showed statistically significant reduction with surgery. Thoracic kyphosis and lumbar lordosis angles were reduced significantly in SK group. Postoperatively, there were significant differences between groups in lumbar lordosis, pelvic tilt angle, and sacral slope (p = 0.021, p = 0.001, and p = 0.027, respectively). Thoracic kyphosis angle and sacral slope were increased, and there was a remarkable correlation between thoracic kyphosis and lumbar lordosis values in the AK group. CONCLUSIONS: The results of this study suggest that a significant sacropelvic improvement can be achieved by balanced sagittal vertical axis and T1 spinopelvic leading to a good sagittal alignment of spine in patients with AK and SK. Changes seen in morphological parameters after surgery may be closely related with baseline biomechanics and structure of the spine and pelvis. Therefore, further clinical and scientific trials are necessary both to elucidate the biomechanics, their clinical implications, and to develop new techniques and models for spine and pelvis surgery.

Osteoblastoma of the trapezoid bone and triquetral bone: report of two cases.

Osteoblastoma is a benign local aggressive tumor mostly localized in the vertebra or long bones. Carpal location and recurrence are extremely rare. Treatment options include either curettage or wide en bloc resection which causes functional disability in the hand and wrist and should be reserved only for recurrence. We present a case of recurrent trapezoid osteoblastoma previously treated with curettage of the trapezoid bone and a case of primary triquetral osteoblastoma.

Melatonin administration acutely decreases the diffusing capacity of carbon monoxide in human lungs.

BACKGROUND: Most physiological measurements of the pulmonary diffusing capacity use carbon monoxide (CO) as a tracer gas. Similar to CO, melatonin binds the hemoglobin in the blood. OBJECTIVE: The present study was designed to assess the effect of exogenous melatonin administration on pulmonary functions including diffusing capacity for carbon monoxide (DL(CO)) in healthy subjects. METHODS: The study was performed in a randomized, double-blind, placebo-controlled manner. DL(CO) was measured in 22 healthy male volunteers (age 18-25 years) who were randomized to melatonin (n = 11) and placebo administration (n = 11). At baseline, DL(CO), alveolar volume (V(A)) and other spirometric parameters such as forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), peak expiratory flow (PEF) and maximal voluntary ventilation (MVV) were measured. DL(CO) was then corrected for the hemoglobin concentration. Measurements were repeated in a double-blind fashion 60 min after the administration of melatonin (1 mg) or placebo. RESULTS: DL(CO) was significantly decreased (39.31 +/- 4.75 vs. 34.82 +/- 6.18 ml/min/mm Hg) 60 min after the melatonin administration (p = 0.01), while FEV(1), FVC, FEV(1)/FVC, PEF and MVV values did not demonstrate significant differences. Placebo administration did not result in significant alteration in any of these parameters. CONCLUSIONS: In healthy subjects, oral administration of melatonin acutely influences the DL(CO) without affecting other pulmonary function test results. We conclude that melatonin may have a reducing effect on the DL(CO) in the lungs.