Investigation for Shoulder Kinematics Using Depth Sensor-Based Motion Analysis System / 대한정형외과학회잡지

Purpose@#The purpose of this study was to analyze the motion of the shoulder joint dynamically through a depth sensor-based motion analysis system for the normal group and patients group with shoulder disease and to report the results along with a review of the relevant literature. @*Materials and Methods@#Seventy subjects participated in the study and were categorized as follows: 30 subjects in the normal group and 40 subjects in the group of patients with shoulder disease. The patients with shoulder disease were subdivided into the following four disease groups: adhesive capsulitis, impingement syndrome, rotator cuff tear, and cuff tear arthropathy. Repeating abduction and adduction three times, the angle over time was measured using a depth sensor-based motion analysis system. The maximum abduction angle (θmax ), the maximum abduction angular velocity (ωmax ), the maximum adduction angular velocity (ωmin ) , and the abduction/adduction time ratio (tabd / tadd ) were calculated. The above parameters in the 30 subjects in the normal group and 40 subjects in the patients group were compared. In addition, the 30 subjects in the normal group and each subgroup (10 patients each) according to the four disease groups, giving a total of five groups, were compared. @*Results@#Compared to the normal group, the maximum abduction angle (θmax ), the maximum abduction angular velocity (ωmax ), and the maximum adduction angular velocity (ωmin ) were lower, and abduction/adduction time ratio (tabd /tadd ) was higher in the patients with shoulder disease. A comparison of the subdivided disease groups revealed a lower maximum abduction angle (θmax ) and the maximum abduction angular velocity (ωmax ) in the adhesive capsulitis and cuff tear arthropathy groups than the normal group. In addition, the abduction/adduction time ratio (tabd /tadd ) was higher in the adhesive capsulitis group, rotator cuff tear group, and cuff tear arthropathy group than in the normal group. @*Conclusion@#Through an evaluation of the shoulder joint using the depth sensor-based motion analysis system, it was possible to measure the range of motion, and the dynamic motion parameter, such as angular velocity. These results show that accurate evaluations of the function of the shoulder joint and an in-depth understanding of shoulder diseases are possible.

In vivo 3-dimensional Kinematics of Cubitus Valgus after Non-united Lateral Humeral Condyle Fracture

BACKGROUND: Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan. METHODS: Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, 90° flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion. RESULTS: Ulno-humeral joint moved to the varus on the coronal plane during flexion, 25.45° in the non-united cubitus valgus group and −2.03° in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane −26.75° in the non-united cubitus valgus group and −3.09° in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern. CONCLUSIONS: The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

Risk Factors for Wound Infection in Spinal Surgery: A Focus on Diabetes Mellitus / 대한척추외과학회지

STUDY DESIGN: Retrospective study. OBJECTIVES: To identify risk factors for infection after spinal surgery. SUMMARY OF LITERATURE REVIEW: Infection after spinal surgery is relatively uncommon. However, such infections cause serious consequences and increased costs and sequelae. Risk factors for infection after spinal surgery include a posterior approach, instrumentation, the use of an allogenic bone graft, transfusion, and a long operating time. Patient-related factors include diabetes and obesity. MATERIALS AND METHODS: From January 2009 to December 2013, 350 patients who underwent surgery at our hospital due to spinal disease, including 10 patients with a postoperative spinal infection, were evaluated. We investigated patients' age, gender, morbidity due to diabetes mellitus, body mass index, level of surgery, approach, location, instrumentation, and operation type. RESULTS: Ten of the 350 patients developed a spinal infection after surgery. The proportion of diabetic patients among the infected patients was higher than among the non-infected patients, although the difference was not statistically significant. Additionally, the proportion of diabetic patients with hemoglobin A1c levels greater than 7.0% was higher among the infected patients. Operating time, the surgical approach, drain tube insertion, transfusion, and the use of an allogenic bone graft were not significantly different between the infected and non-infected patient groups. CONCLUSIONS: Uncontrolled diabetes is the most important risk factor for the development of spinal infection after surgery. Therefore, in order to prevent infection after surgery, blood glucose should be controlled before surgery.

Risk Factors for Wound Infection in Spinal Surgery: A Focus on Diabetes Mellitus

OBJECTIVES@#To identify risk factors for infection after spinal surgery.SUMMARY OF LITERATURE REVIEW: Infection after spinal surgery is relatively uncommon. However, such infections cause serious consequences and increased costs and sequelae. Risk factors for infection after spinal surgery include a posterior approach, instrumentation, the use of an allogenic bone graft, transfusion, and a long operating time. Patient-related factors include diabetes and obesity.@*MATERIALS AND METHODS@#From January 2009 to December 2013, 350 patients who underwent surgery at our hospital due to spinal disease, including 10 patients with a postoperative spinal infection, were evaluated. We investigated patients' age, gender, morbidity due to diabetes mellitus, body mass index, level of surgery, approach, location, instrumentation, and operation type.@*RESULTS@#Ten of the 350 patients developed a spinal infection after surgery. The proportion of diabetic patients among the infected patients was higher than among the non-infected patients, although the difference was not statistically significant. Additionally, the proportion of diabetic patients with hemoglobin A1c levels greater than 7.0% was higher among the infected patients. Operating time, the surgical approach, drain tube insertion, transfusion, and the use of an allogenic bone graft were not significantly different between the infected and non-infected patient groups.@*CONCLUSIONS@#Uncontrolled diabetes is the most important risk factor for the development of spinal infection after surgery. Therefore, in order to prevent infection after surgery, blood glucose should be controlled before surgery.

Minimally Invasive Transforaminal Lumbar Interbody Fusion / 대한척추외과학회지

STUDY DESIGN: A retrospective study OBJECTIVES: To introduce the technique of minimally invasive transforaminal lumbar interbody fusion and examine its clinical and radiologic results. SUMMARY OF LITERATURE REVIEW: Transforaminal lumbar interbody fusion with a mini-incision using a tubular retractor was recently developed. The aim of this procedure is to reduce the approach-related morbidity and achieve better results in an effective and safe manner. MATERIALS AND METHODS: Thirty eight patients were followed up for more than 1 year. Their mean age was 57 years and the mean follow-up was 19 months. The diagnosis was spinal stenosis, spondylolisthesis and recurred herniated nucleus pulposus in 22, 14 and 2 patients, respectively. The Oswestry disability index, intervertebral disc space height, fusion rate and complications were evaluated. RESULTS: The Oswestry disability index improved from 30 points (range, 50~16 points) to 10 points (range, 2-24 points) at the last follow-up. Thirty-four patients (90%) showed excellent or good results. The intervertebral disc space height increased from 8.7 mm to 10.8 mm. Two cases showed nonunion but the clinical results were good. Complications included one case of infectious spondylitis requiring antibiotics, one case of cage dislodgement requiring additional surgery and one case of a pedicle screw malposition showing no clinical symptoms. CONCLUSIONS: Minimally invasive transforaminal lumbar interbody fusion reduced the soft tissue injury and blood loss and shortened the recovery period compared to the traditional open techniques.

Effects of Mechanical Stimulation and Scaffolds for Nucleus Pulposus Replacement of Intervertebral Disc / 대한정형외과연구학회지

PURPOSE: In this study, we investigated the potential of injectable hydrogel scaffolds for the regeneration of nucleus pulposus. MATERIALS AND METHODS: We prepared injectable hydrogels [Chitosan-Pluronic (CP), CP/Osteogenic Protein-1 (CP/OP-1), CP/Gly-Arg-Gly-Asp-Ser (CP/GRGDS), CP/GRGDS/OP-1] for this study. One of the four potential materials was selected through the cell viability tests. For each material, primary cultured nucleus pulposus (NP) cells from New Zealand rabbits were seeded onto each material. For the investigation of the effects of mechanical stimulation, the commercially available bioreactor was used. 0.2 MPa of intermittent hydrostatic pressure was imposed for 3 days after 7th day of seeding with the pattern of 2 min and 15 min for stimulating and resting, respectively. The specimens were harvested at 1, 10, 14 day after seeding for analyses. RESULTS: The MTT assay for 5 days revealed that CP/OP-1 group showed significant increase. The other two groups (CP/GRGDS and CP/GRGDS/OP-1) showed that the proliferation rate increased until 3 days after culture, while it decreased on day 5. The mechanical stimuli induced higher amounts of DNA measured in CP/OP- 1 on day 5 after culture. However, no significant difference was observed between two groups. CONCLUSION: We came to the conclusions that the biochemical environment as well as mechanical stimulation may play an important role in regenerating nucleus pulposus matrix, especially in CP/OP-1 in this study. However, further study are recommended in relation to mechanical effects as well as biochemical conditions.