Biomechanical testing of different posterior fusion devices on lumbar spinal range of motion.

BACKGROUND: Recent minimal-invasive posterior fusion devices are supposed to provide stability and obtain fusion in combination with interbody cages in the instrumented segment. The aim of the present study is to evaluate the primary stability of two minimal-invasive posterior prototypes compared to an established spinous process plate and standard pedicle screw instrumentation. METHODS: Seven fresh frozen human cadaver lumbar spines (L2-L5) were tested in a spinal testing device with a moment of 7.5 Nm. Spinal stability was determined as mean range of motion (RoM) in the segment L3/L4 during extension-flexion, lateral bending and axial rotation. The RoM was measured during five conditions: 1. intact; 2. working prototype composed of an interspinous device and process plates; 3. an established spinous process fixation device 4. working prototype of facet fixation and 5. pedicle screw fixation. FINDINGS: All devices caused a significant reduction of RoM during extension-flexion. The RoM during lateral bending was significantly reduced to 37% (of intact) by pedicle screws and 68% by facet fixation prototype. During axial rotation the RoM was significantly reduced to 52% by pedicle screws and to 86% by facet fixation prototype. The other devices had no significant influence on RoM during lateral bending and axial rotation. INTERPRETATION: The facet fixation prototype provided less primary stability compared to pedicle screws, but had significant advantages over spinous process fixation techniques. The results encourage further testing of this implant as a minimal-invasive approach for posterior fixation.

Misdiagnosis of Thoracolumbar Posterior Ligamentous Complex Injuries and Use of Radiographic Parameter Correlations to Improve Detection Accuracy.

STUDY DESIGN: Retrospective study. PURPOSE: To evaluate radiological parameters as indicators for posterior ligamentous complex (PLC) injuries in the case of limited availability of magnetic resonance imaging. OVERVIEW OF LITERATURE: Traumatic thoracolumbar spinal fractures with PLC injuries can be misdiagnosed on X-rays or computed tomography scans. This study aimed to retrospectively assess unrecognized PLC injuries and evaluate radiographic parameters as indicators of PLC injuries requiring surgery. METHODS: In total, 314 patients with type A and type B2 fractures who underwent surgical treatment between 2001 and 2010 were included. The frequency of misdiagnosis was reassessed, and radiographic parameters were evaluated and correlated. RESULTS: The average age of the patients was 51.8 years. There were 225 type A3/A4 and 89 type B2 fractures; 39 of the type B2 fractures (43.8%) had been misdiagnosed as type A fractures. Type B fractures presented with a significantly higher kyphotic wedge angle and Cobb angle and a lower sagittal index (SI) than type A fractures. In addition, the normalized interspinous distance was higher in type B2 fractures. The significant mathematical indicators for PLC injuries were as follows: Cobb angle+kyphotic wedge angle >29°; Cobb angle2 >170°; and vertebral angle/SI >25. CONCLUSIONS: The results demonstrated that PLC injuries are frequently misdiagnosed. Correlations between certain radiological parameters associated with PLC injuries can be useful indicators of the presence of such injuries requiring surgery.

Arthroscopic treatment of bilateral snapping scapula syndrome: a case report and review of the literature.

Snapping scapula syndrome represents a rare entity in shoulder surgery. Clinically, it presents as shoulder pain and loud crepitus during shoulder movement. Moreover, glenohumeral bursitis can cause additional pain. Snapping scapula syndrome is caused by an increased angulation of the superomedial part of the scapula combined with bursitis. Other common causes such as subscapular osteochondroma or rib fracture non-unions were excluded. We report a 24-year-old female patient with persisting shoulder pain and disturbing crepitus during movement of the left shoulder. Radiographic examination revealed increased angulation of the superomedial scapula on both sides and MRI, bursitis of the left shoulder. The patient was successfully treated with minimally invasive arthroscopic trimming of the prominent osseous formation at the left scapula combined with bursectomy. Additionally, specific pain-adapted physiotherapeutic exercises of both shoulders were performed. The patient had a pain-free shoulder movement without crepitus on both sides at the 6th month follow-up.

CERAMENT treatment of fracture defects (CERTiFy): protocol for a prospective, multicenter, randomized study investigating the use of CERAMENT™ BONE VOID FILLER in tibial plateau fractures.

BACKGROUND: Bone graft substitutes are widely used for reconstruction of posttraumatic bone defects. However, their clinical significance in comparison to autologous bone grafting, the gold-standard in reconstruction of larger bone defects, still remains under debate. This prospective, randomized, controlled clinical study investigates the differences in pain, quality of life, and cost of care in the treatment of tibia plateau fractures-associated bone defects using either autologous bone grafting or bioresorbable hydroxyapatite/calcium sulphate cement (CERAMENT™|BONE VOID FILLER (CBVF)). METHODS/DESIGN: CERTiFy (CERament™ Treatment of Fracture defects) is a prospective, multicenter, controlled, randomized trial. We plan to enroll 136 patients with fresh traumatic depression fractures of the proximal tibia (types AO 41-B2 and AO 41-B3) in 13 participating centers in Germany. Patients will be randomized to receive either autologous iliac crest bone graft or CBVF after reduction and osteosynthesis of the fracture to reconstruct the subchondral bone defect and prevent the subsidence of the articular surface. The primary outcome is the SF-12 Physical Component Summary at week 26. The co-primary endpoint is the pain level 26 weeks after surgery measured by a visual analog scale. The SF-12 Mental Component Summary after 26 weeks and costs of care will serve as key secondary endpoints. The study is designed to show non-inferiority of the CBVF treatment to the autologous iliac crest bone graft with respect to the physical component of quality of life. The pain level at 26 weeks after surgery is expected to be lower in the CERAMENT bone void filler treatment group. DISCUSSION: CERTiFy is the first randomized multicenter clinical trial designed to compare quality of life, pain, and cost of care in the use of the CBVF and the autologous iliac crest bone graft in the treatment of tibia plateau fractures. The results are expected to influence future treatment recommendations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT01828905.

Surgical management of sternoclavicular septic arthritis.

INTRODUCTION: Septic arthritis of the sternoclavicular joint (SCJ) is a rare condition and has many diagnostic and therapeutic standards. The purpose of this study was to evaluate our experience with surgical and diagnostic management to provide a surgical pathway to help surgeons treat this disease. METHOD: We retrospectively reviewed five patients who were managed surgically between 1999 and 2007. All patients underwent structured diagnostic and treatment protocols. The functional outcome was evaluated using the Constant Score. PATIENTS: The patients had the following underlying medical conditions: laryngeal cancer, port-explantation linked to a rectum carcinoma, spondylodiscitis, and brain stem infarct with reduced general condition; one patient had no underlying medical problems. Three patients underwent a simple incision, debridement and drainage, and two patients underwent an extended intervention with partial resection of the sternoclavicular joint. The mean duration of follow-up was 29 months (range 24-36 months). All patients had well-healed wounds without signs of reinfection. The Constant Score for the functional outcome at the time of the last follow-up was 76 points (range 67-93 points). All patients recovered completely from SCJ disease. CONCLUSION: Our recommendations for the management of septic arthritis of the sternoclavicular joint include standard treatment steps and assessments. The early stages of infection can be managed by simple incision, debridement and drainage. In advanced stages of infection, a more radical intervention is preferable.

Septic arthritis of the shoulder joint: an analysis of management and outcome.

We retrospectively reviewed the records of 21 patients (23 shoulders) who underwent surgical treatment for septic arthritis of the shoulder joint, between 2000 and 2007. Patients were on average 63.7 (41-85) years old; they were treated either by arthroscopic debridement (12 shoulders) or by combined arthroscopic and open procedures (11 shoulders). The mean duration of symptoms prior to surgery was 16 (5-76) days. The mean Constant score recorded at the last follow-up - on average 353 months (25-43) after surgery - was 73 (46-82) points. Patients with symptoms for two weeks or less prior to surgery had better results and a lower re-operation rate than those with symptoms longer than two weeks. Early infection can be managed arthroscopically, and satisfactory results can be expected. In advanced infection, a more radical approach is more appropriate.

Fatigue stress fractures of the pelvis: a rare cause of low back pain in female athletes.

Stress fracture of the pelvis represents one rare differential diagnosis among the manifold causes of low back pain in female athletes. We report a case of fatigue stress fracture of the pelvis in a 24-year-old female athlete as an unusual differential diagnosis of low back pain that should be taken into consideration. According to the literature the incidence of low back pain in athletes ranges from 1% to 30% and is influenced by sport type, gender, training intensity, training frequency and technique. In some cases, no specific pain generator is found, which makes diagnosis and treatment difficult. The frequency of the injury and the treatment options are discussed, based on published studies.

The influence of elementary silver versus titanium on osteoblasts behaviour in vitro using human osteosarcoma cell lines.

Purpose. The antimicrobial effect of a silver-coated tumor endoprosthesis has been proven in clinical and experimental trials. However, in the literature there are no reports concerning the effect of elementary silver on osteoblast behaviour. Therefore, the prosthetic stem was not silver-coated because of concerns regarding a possible inhibition of the osseointegration. The aim of the present study was to investigate the effect of 5-25 mg of elementary silver in comparison to Ti-6Al-4V on human osteosarcoma cell lines (HOS-58, SAOS). Methods. Cell viability was determined by measuring the MTT proliferation rate. Cell function was studied by measuring alkaline phosphatase (AP) activity and osteocalcine production. Results. In the HOS-58 cells, the AP activity was statistically significant (P < 0.05) higher at a supplement of 5-10 mg of silver than of Ti-6 Al-4V at the same doses. For both cell lines, a supplement above 10 mg of silver resulted in a reduced AP activity in comparision to the Ti-6 Al-4V group, but a statistically significant difference (P < 0.05) was observed at a dose of 25 mg for the SAOS cells only. At doses of 20-25 mg in the HOS-58 cells and 10-25 mg in the SAOS cells, the reduction of the proliferation rate by silver was statistically significant (P < 0.05) compared to the Ti-6 Al-4V supplement. Discussion. In conclusion, elementary silver exhibits no cytotoxicity at low concentrations. In contrast, it seems to be superior to Ti-6 Al-4V concerning the stimulation of osteogenic maturation at these concentrations, whereas at higher doses it causes the known cytotoxic properties.