Comparison of quantitative evaluation between cutaneous and transosseous inertial sensors in anterior cruciate ligament deficient knee: A cadaveric study.

BACKGROUND: Recently several authors have reported on the quantitative evaluation of the pivot-shift test using cutaneous fixation of inertial sensors. Before utilizing this sensor for clinical studies, it is necessary to evaluate the accuracy of cutaneous sensor in assessing rotational knee instability. To evaluate the accuracy of inertial sensors, we compared cutaneous and transosseous sensors in the quantitative assessment of rotational knee instability in a cadaveric setting, in order to demonstrate their clinical applicability. METHODS: Eight freshly frozen human cadaveric knees were used in this study. Inertial sensors were fixed on the tibial tuberosity and directly fixed to the distal tibia bone. A single examiner performed the pivot shift test from flexion to extension on the intact knees and ACL deficient knees. The peak overall magnitude of acceleration and the maximum rotational angular velocity in the tibial superoinferior axis was repeatedly measured with the inertial sensor during the pivot shift test. Correlations between cutaneous and transosseous inertial sensors were evaluated, as well as statistical analysis for differences between ACL intact and ACL deficient knees. RESULTS: Acceleration and angular velocity measured with the cutaneous sensor demonstrated a strong positive correlation with the transosseous sensor (r = 0.86 and r = 0.83). Comparison between cutaneous and transosseous sensor indicated significant difference for the peak overall magnitude of acceleration (cutaneous: 10.3 ± 5.2 m/s2, transosseous: 14.3 ± 7.6 m/s2, P < 0.01) and for the maximum internal rotation angular velocity (cutaneous: 189.5 ± 99.6 deg/s, transosseous: 225.1 ± 103.3 deg/s, P < 0.05), but no significant difference for the maximum external rotation angular velocity (cutaneous: 176.1 ± 87.3 deg/s, transosseous: 195.9 ± 106.2 deg/s, N.S). CONCLUSIONS: There is a positive correlation between cutaneous and transosseous inertial sensors. Therefore, this study indicated that the cutaneous inertial sensors could be used clinically for quantifying rotational knee instability, irrespective of the location of utilization.

Is the canal flare index a reliable means of estimation of canal shape? Measurement of proximal femoral geometry by use of 3D models of the femur.

BACKGROUND: The canal flare index (CFI; the ratio of the diameter of the femoral canal at the isthmus in the anteroposterior (A-P) view to the diameter of the medullary canal 20 mm above the lesser trochanter) is often used as a canal characteristic. Clinically, however, CFI measurements are sometimes untrustworthy because of femoral rotation and, especially, greater anteversion among Japanese patients. Our objectives were to analyze femoral geometry, by use of 3D CAD models, to evaluate the effects of rotational error, and to seek an index less affected by rotation. METHODS: Computed axial tomography (CAT) scan data from 60 femurs were used. By use of CAD software, 3D femoral models were created. The outside of the femur and the inside canal width 20 mm (P20) and 10 mm proximal (P10), and 10 mm (D10), 20 mm (D20), 30 mm (D30), and 40 mm (D40) distal from the center of the lesser trochanter, and at the isthmus were measured for different angles of femoral rotation. CFI, FFI (femoral flare index; the ratio of the extra-cortical diameters at the same levels as for the CFI), and other canal ratios (P20/D10, P20/D20, P20/D30, and P20/D40) were then calculated and the effect of rotational errors was investigated. RESULTS: Mean CFI, FFI, P20/D10, P20/D20, P20/D30, and P20/D40 were 4.29, 2.08, 2.05, 2.49, 2.85, and 3.09 in the position without rotational error. CFI was not related to anteversion but had a negative correlation with isthmus canal width (only). In contrast FFI was almost constant at approximately 2.1 for different anteversion and age. With regard to the effect of rotational error, CFI changed by 1.31, FFI by 0.40, P20/D10 by 0.41, P20/D20 by 0.40, P20/D30 by 0.59, and P20/D40 by 0.80 for a variety of rotational angles. CONCLUSIONS: Outside femoral shape was little different for any person; as a result, FFI was almost constant. In contrast, CFI was revealed to be affected by canal width at the isthmus only. With regard to the effect of rotation, P20/D20 was much less affected by rotation than CFI; it could, therefore, be an appropriate index for expressing proximal canal shape.

Postoperative evaluation of drill holes for arthroscopic Bankart repair with suture anchors by the use of computed tomography.

BACKGROUND: Here we investigated the angle and placement of bone holes for suture anchors using postoperative computed-tomography scapula scans. METHODS: The study group comprised 20 shoulders from 20 consecutive patients (13 males and seven females; mean age 23.4 years) who underwent arthroscopic Bankart repair. All anchors were inserted through the anterior portal after establishing a bone hole at the edge of the glenoid articular surface using a drill. Computed tomography images of the scapula were taken 1 month postoperatively and used to create three-dimensional scapula models with Mimics and Magics software. Bone holes in the anterior-inferior (3:00-6:00) position were assigned either to the non-perforated group if they were positioned entirely inside the glenoid bone or to the perforated group if the far cortex of the glenoid was penetrated by the drill. The angle between the glenoid articular surface and the bone hole was measured in the oblique coronal and transverse plane views. The length of the bone hole was also assessed. RESULTS: Of the 85 bone holes investigated, 42 were in the 3:00-6:00 position. Perforation was detected in 16 of these 42 holes (38.2%). The angle in the oblique coronal plane view and the length of the bone hole were significantly larger in the non-perforated group than in the perforated group; however, the angle in the transverse plane view did not significantly differ between the two groups. CONCLUSIONS: Before inserting an implant in the anterior-inferior area, the angle between the drill guide and the glenoid surface in the oblique coronal plane view should be carefully checked to ensure that the length of the hole inside the glenoid bone is adequate.

Quantitative analysis of attachment of the labrum to the glenoid fossa: a cadaveric study.

PURPOSE: This study investigated the direct and continuous attachment of the labrum to the glenoid fossa, including the fibrocartilaginous tissue, using image-analysis software and histology. METHODS: Twenty-six cadaveric shoulders (11 male, 15 female; mean age 80.1 years; age range 36-103 years) were used. The glenoid of each specimen was divided into six pie-slice-shaped pieces from the center perpendicular to the articular surface by radial incisions at the 2, 4, 6, 8, 10, and 12 o'clock positions. The general distribution of the labrum, including the fibrocartilage, was assessed in hematoxylin and eosin-, Safranin O- and Azan-Mallory-stained sections. The continuous length of attachment of the labrum to the glenoid was measured using image-analysis software. The width of attachment to the articular surface of the glenoid was assessed in each position. RESULTS: The labrum attached to both the articular surface and the neck of the glenoid in all shoulders (100 %) in the 4 and 6 o'clock positions. The mean length of the entire attachment to the glenoid was 4.6 mm (range 3.2-6.1 mm). The width of attachment from the bony edge of the glenoid to the edge of the labrum on the articular surface ranged from 0 to 4.3 mm. The length of the entire attachment of the labrum was shortest in the 2 o'clock position (p = 0.229). Additionally, the length of the entire attachment of the labrum was longest in the 4 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01). CONCLUSION: In the 4 and 6 o'clock positions, the labrum attached to both the articular surface and neck of the glenoid in all of the shoulders (100 %). The length of the entire attachment to the labrum, including the fibrocartilage, was shortest in the 2 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01).

Evaluation of lower extremity gait analysis using Kinect V2® tracking system.

INTRODUCTION: Microsoft Kinect V2® (Kinect) is a peripheral device of Xbox® and acquires information such as depth, posture, and skeleton definition. In this study, we investigated whether Kinect can be used for human gait analysis. METHODS: Ten healthy volunteers walked 20 trials, and each walk was recorded by a Kinect and infrared- and marker-based-motion capture system. Pearson's correlation and overall agreement with a method of meta-analysis of Pearson's correlation coefficient were used to assess the reliability of each parameter, including gait velocity, gait cycle time, step length, hip and knee joint angle, ground contact time of foot, and max ankle velocity. Hip and knee angles in one gait cycle were calculated in Kinect and motion capture groups. RESULTS: The coefficients of correlation for gait velocity (r = 0.92), step length (r = 0.81) were regarded as strong reliability. Gait cycle time (r = 0.65), minimum flexion angle of hip joint (r = 0.68) were regarded as moderate reliability. The maximum flexion angle of the hip joint (r = 0.43) and maximum flexion angle of the knee joint (r = 0.54) were regarded as fair reliability. Minimum flexion angle of knee joint (r = 0.23), ground contact time of foot (r = 0.23), and maximum ankle velocity (r = 0.22) were regarded as poor reliability. The method of meta-analysis revealed that participants with small hip and knee flexion angles tended to have poor correlations in maximum flexion angle of hip and knee joints. Similar trajectories of hip and knee angles were observed in Kinect and motion capture groups. CONCLUSIONS: Our results strongly suggest that Kinect could be a reliable device for evaluating gait parameters, including gait velocity, gait cycle time, step length, minimum flexion angle of the hip joint, and maximum flexion angle of the knee joint.

Ultrasonographic Assessment of Femoral Torsion Angle Based on Tilting Angles of Femoral Neck and Condylar Axis.

Femoral anteversion has been assessed with ultrasound using femoral neck tilting angle (FN-TA); however, femoral torsion angle (FTA), which is defined using FN-TA and condylar axis tilting angle, has not been assessed with ultrasound. This study aimed to establish the ultrasonographic assessment of FTA (US-FTA) by comparing data obtained through US-FTA and computed tomography (CT). Twenty-one patients (age range, 38-82 y) with 21 intact hips were included. In the US-FTA, the femoral head and anterior tubercle of the greater trochanter were used as bony landmarks. The intra-rater and inter-rater reliabilities and standard error of measurement (SEM) of US-FTA were 0.994 (SEM 0.93) and 0.994 (SEM 0.94), respectively. A strong agreement was found between FTA variables obtained with ultrasound and CT (R = 0.939, p < 0.001). Ultrasound is useful and can be a valid alternative to CT for the evaluation of the femoral torsion angle without radiation exposure.

Application of full-scale three-dimensional models in patients with rheumatoid cervical spine.

Full-scale three-dimensional (3D) models offer a useful tool in preoperative planning, allowing full-scale stereoscopic recognition from any direction and distance with tactile feedback. Although skills and implants have progressed with various innovations, rheumatoid cervical spine surgery remains challenging. No previous studies have documented the usefulness of full-scale 3D models in this complicated situation. The present study assessed the utility of full-scale 3D models in rheumatoid cervical spine surgery. Polyurethane or plaster 3D models of 15 full-sized occipitocervical or upper cervical spines were fabricated using rapid prototyping (stereolithography) techniques from 1-mm slices of individual CT data. A comfortable alignment for patients was reproduced from CT data obtained with the patient in a comfortable occipitocervical position. Usefulness of these models was analyzed. Using models as a template, appropriate shape of the plate-rod construct could be created in advance. No troublesome Halo-vests were needed for preoperative adjustment of occipitocervical angle. No patients complained of dysphasia following surgery. Screw entry points and trajectories were simultaneously determined with full-scale dimensions and perspective, proving particularly valuable in cases involving high-riding vertebral artery. Full-scale stereoscopic recognition has never been achieved with any existing imaging modalities. Full-scale 3D models thus appear useful and applicable to all complicated spinal surgeries. The combination of computer-assisted navigation systems and full-scale 3D models appears likely to provide much better surgical results.

Morphometric analysis of the peroneal tubercle using a three-dimensional computed tomography model.

BACKGROUND: The peroneal tubercle is a small bony ridge located on the lateral wall on the calcaneus immediately inferior to the lateral malleolus and separates the peroneus brevis and peroneus longus tendons. The size and configuration of the peroneal tubercle has been implicated in the pathogenesis of peroneal tendon tears and tenosynovitis and is the increasing object of clinical interest. However, the morphology of the tubercle is difficult to assess with precision. METHODS: We utilized a new method to evaluate the three-dimensional (3D) geometry of 46 calcanei from 34 consecutive patients; average patient age was 48.0 years who underwent lower extremity computed tomography (CT) for clinical treatment of non-peroneal tubercle-related conditions. The 3D geometries of calcanei were reconstructed by using the computer software to calculate the surface 3D models. To measure the size of the peroneal tubercle, we virtually excised it from the 3D calcaneus model and made a precise measurement of the height. RESULTS: Peroneal tubercles with measured heights of 1mm or more were detected in 65% of the feet, with an average tubercle height of 2.59mm. Peroneal tubercles were larger and more frequent in middle-aged or older than younger patients.

Hip Arthroscopic Synovectomy and Labral Repair in a Patient With Rheumatoid Arthritis With a 2-Year Follow-up.

The arthroscopic surgical procedures reported previously for a rheumatic hip joint have been primarily performed as diagnostic procedures. Only a few studies have reported the success of arthroscopic surgery in hip joint preservation. We encountered a special case in which joint remodeling was seen in a patient with rheumatoid arthritis treated with biological drugs after hip arthroscopic synovectomy and labral repair. We report the case of a 39-year-old woman with rheumatism, which was controlled with tocilizumab, prednisolone, and tacrolimus. The hip joint showed Larsen grade 3 destruction, and the Harris Hip Score was 55 points. Because of the patient's strong desire to undergo a hip preservation operation, we performed hip arthroscopic synovectomy and repair of a longitudinal labral tear. After 2.5 years, the joint space had undergone rebuilding with improvement to Larsen grade 2, and the Harris Hip Score had improved to 78 points; the patient was able to return to work with the use of 1 crutch. It is possible to perform hip arthroscopic surgery for rheumatoid arthritis with a hip preservation operation with biological drugs.

Arthroscopic synovectomy of the metacarpophalangeal and proximal interphalangeal joints.

Few reports about clinical experience in arthroscopy of finger joints exist. Furthermore, little attention has been given to arthroscopic synovectomy of rheumatoid fingers. Herein, we describe our experience with arthroscopic synovectomy of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in patients with rheumatoid arthritis.Arthroscopic synovectomy was performed in 45 finger joints (18 MCP joints, 26 PIP joints, and 1 interphalangeal thumb joint) of 23 patients with rheumatoid arthritis. All procedures were performed on an outpatient basis under regional anesthesia. The diameter of the arthroscope for small joints was 1.5 mm, and a mini shaver system with a 2.5-mm cutter was used for synovectomy. We developed new portals for PIP joints that were established on the dorsolateral aspect at a position more lateral than previously reported portals.Intraarticular structures of finger joints were well visualized, and magnified observation of the articular cartilage and synovial membrane was possible. Because insertion of the instruments into the palmar cavity was not possible without causing damage to the articular surfaces, synovectomy of the palmar capsule could not be performed. However, arthroscopic synovectomy of the dorsal capsule under visual control could be safely performed using the 2-portal technique. None of the patients experienced postprocedural complications. Swelling of each joint disappeared after the procedure and did not return in many cases for a long period. Furthermore, no joints required reoperation.We conclude that arthroscopy of MCP and PIP joints is useful not only for the assessment of articular cartilage and synovium but also for synovectomy in rheumatoid arthritis.