Morphometric feature description of the proximal ulna based on quantitative measurement: a key consideration for implant design

PURPOSE

To perform quantitative measurements of the anatomic morphology of the proximal ulna and establish the morphologic references based on Chinese for the surgical protocol and implant design.

METHODS

The computed tomography data of 156 upper extremities were involved in this study. The ulna model was reconstructed in Mimics. Ten distance and 6 angle parameters were measured by 4 independent investigators with a new quantitative measurement method. The intraclass correlation coefficient was used to evaluate the measuring reliability. Gender and side differences of measured parameters were evaluated.

RESULTS

Measurements showed a mean coronoid height of 15 mm, which was 42% of ulnar height with gender-specific differences (mean 16 mm in men and 14 mm in women, P < 0.001). A mean unsupported anteromedial facet width of 8 mm was 61% of the coronoid anteromedial facet. A larger opening angle correlates to a larger olecranon-diaphysis angle (P < 0.001) and larger coronoid height (P = 0.001). A mean proximal ulna dorsal angulation of 4.7° is present in 80% of models at an average of 52 mm distal to olecranon tip. The average proximal ulna varus angulation was 16° at a mean of 74 mm distal to the olecranon tip. Morphological features between the left and right sides were highly consistent. The ICC was between 0.789 and 0.978 for inter-observer and between 0.696 and 0.997 for intra-observer reliability.

CONCLUSIONS

The proximal ulna features variable morphology but minor side differences among individuals. Over half of the anteromedial facet was not supported by the proximal ulnar diaphysis, making the coronoid vulnerable to elbow trauma. Preconditioning or customized design of the ulnar plate in the clinical setting with the help of contralateral morphology may be a good choice.

Modified C7 pedicle subtraction osteotomy for the correction of cervicothoracic kyphosis

BACKGROUND

Osteotomies in the cervical spine are technically challenging. The purpose of this study was to evaluate the feasibility of the modified pedicle subtraction osteotomy (PSO) technique at C7 to be used for the treatment of cervicothoracic kyphosis secondary to ankylosing spondylitis.

METHODS

A total of 120 cervical spine computed tomography (CT) scans (of 82 male and 38 female patients) were evaluated. The scans were taken parallel to the middle sagittal plane and the sagittal plane intersecting the pedicles. Simulated osteotomy was performed by setting the apex of the wedge osteotomy at different points, and morphologic measurements were obtained. Seven patients with cervicothoracic kyphosis who underwent a modified PSO at C7 between May 2009 and June 2015 were retrospectively evaluated. The mean follow up was 32.9 months (range 21-54 months). Preoperative and postoperative chin-brow vertical angle (CBVA), sagittal vertical axis (SVA) and sagittal Cobb angle of the cervical region were reviewed. The outcomes were analyzed through various measures, which included the 36-Item Short Form Health Survey (SF-36) and a visual analog scale for neck pain.

RESULTS

In this morphometric study, a modified PSO was performed on 87 patients (59 male and 28 female) with a reasonable ratio of 72.5%. In the case series, radiographic parameters and health-related quality-of-life measures were found to show significant postoperative improvement in all patients. No major complications occurred, and no implant failures were noted until the latest follow up.

CONCLUSIONS

The modified PSO is a safe and valid alternative to the classic PSO, allowing for excellent correction of cervical kyphosis and improvement in health-related quality-of-life measures.

Morphometric analysis of occipital condyles using alternative imaging technique

PURPOSE

The occipital condyles (OCs) are crucial anatomical structures in the cranial base. To our knowledge, there is no cone beam computed tomography (CBCT)-based study on the morphometric analysis of OCs. The aim of this study was to evaluate the morphometric analysis of OCs using CBCT.

METHODS

CBCT images of 200 OCs from 100 patients of which 39 males and 61 females in the age group of 18-67 years were included in the study population. Linear and angular measurements of OCs were performed.

RESULTS

The average OC width, length, height, sagittal angle, and effective height were 10.3 ± 1.3 mm, 19.6 ± 2.0 mm, 9.1 ± 1.4 mm, 7.4 ± 1.7 mm, and 35.3 ± 5.2 mm. Condylar width and sagittal angle measurements were found significantly different between the right and left sides; and were not found significant difference between the right and left sides in the measurements of condylar height, length, and effective height. Also the average intercondylar anterior distance (ICAD), intercondylar posterior distance (ICPD), distance between the basion and the anterior apex of the occipital condyle (B-AAOC), distance between the basion and posterior apex of the occipital condyle (B-PAOC), distance between the opisthion and anterior apex of occipital condyle (O-AAOC), and distance between the opisthion and posterior apex of occipital condyle (O-PAOC) were 20.9 ± 1.5 mm, 44.0 ± 2.0 mm, 12.3 ± 1.9 mm, 34.5 ± 4.2 mm, 29.8 ± 1.7 mm, and 27.0 ± 2.1 mm. There was not significant difference in the morphometric measurements among age groups. All morphometric measurements showed a significant difference depending on gender.

CONCLUSIONS

The morphometric evaluation of OCs may be effectively examined using CBCT. Linear and angular measurements data of OCs in the present study may be used as a reference database for future morphometric and surgical investigations.

Endonasal Operative Corridor Expansion by Sphenoidal Pneumosinus Dilatans in Tuberculum Sellae Meningiomas

BACKGROUND

A retrospective cohort study of patients with tuberculum sellae meningioma (TSM)-associated sphenoidal pneumosinus dilatans (PSD) over a recent epoch was evaluated using a propensity-matched morphometric analysis.

METHODS

A total of 38 patients with TSM and sphenoidal PSD were identified and matched by age and sex to 32 patients without tumors (controls).

RESULTS

Overall, no significant difference between test and control groups was noted in sphenoid sinus size or other parameters; however, significantly greater mean distances from the posterior margin of the planum sphenoidale to the diaphragma sella (0.76 ± 0.23 vs. 1.03 ± 0.27, respectively; P = 0.0001) and angle between the planum sphenoidale to anterior face of sella turcica (113.41 ± 10.58 vs. 123.21 ± 12.55, respectively; P = 0.001) were seen in patients with TSM and PSD, suggestive of a selective expansion of the tuberculum sellae region. TSM/sphenoid sinus morphologies were divided into 3 types (A, B, and C) based on the extent of tumor and sinus morphology. There was progressive increase in tumor volume and anteroposterior sinus diameter from sphenoidal PSD types A-C, which influenced selection of surgical approach.

CONCLUSIONS

This study suggests that TSM-associated sphenoidal PSD leads to more selective splaying of the tuberculum sellae region rather than cumulative increase in sinus volume. This may lead to operative corridor expansion for endonasal access to TSM associated with sphenoidal PSD. A radiologic classification scheme for sphenoidal PSD associated with TSM is suggested that may aid surgical decision-making.

A Morphometric Study of the Obturator Nerve around the Obturator Foramen

OBJECTIVE

Obturator neuropathy is a rare condition. Many neurosurgeons are unfamiliar with the obturator nerve anatomy. The purpose of this study was to define obturator nerve landmarks around the obturator foramen.

METHODS

Fourteen cadavers were studied bilaterally to measure the distances from the nerve root to relevant anatomical landmarks near the obturator nerve, including the anterior superior iliac spine (ASIS), the pubic tubercle, the inguinal ligament, the femoral artery, and the adductor longus.

RESULTS

The obturator nerve exits the obturator foramen and travels infero-medially between the adductors longus and brevis. The median distances from the obturator nerve exit zone (ONEZ) to the ASIS and pubic tubercle were 114 mm and 30 mm, respectively. The median horizontal and vertical distances between the pubic tubercle and the ONEZ were 17 mm and 27 mm, respectively. The shortest median distance from the ONEZ to the inguinal ligament was 19 mm. The median inguinal ligament lengths from the ASIS and the median pubic tubercle to the shortest point were 103 mm and 24 mm, respectively. The median obturator nerve lengths between the ONEZ and the adductor longus and femoral artery were 41 mm and 28 mm, respectively.

CONCLUSION

The obturator nerve exits the foramen 17 mm and 27 mm on the horizontal and sagittal planes, respectively, from the pubic tubercle below the pectineus muscle. The shallowest area is approximately one-fifth medially from the inguinal ligament. This study will help improve the accuracy of obturator nerve surgeries to better establish therapeutic plans and decrease complications.

Morphometric Study on Male Specimens of Hyalomma anatolicum (Acari: Ixodidae) in West of Iran

BACKGROUND

Hyalomma anatolicum is the well-known hard tick, which is one of the most important livestock and human pathogens vector, wide range in host and distributed in all over the Hyalomma geographic fauna as well as in Iran. Taxonomy of the Hyalomma ssp. is debatable whereas their identification is a problematic work. The reasons for this claim is time consuming Delpy's researches in Iran also Schulze School, Feldman-Muhsam and the Russian tick workers. We would like to understand morphometric variation in the field collected H. anatolicum in Iran also validating some morphologic quantitative and qualitative characters.

METHODS

A total 247 field-collected tick specimens from different geographical regions in west of Iran includes Khuzestan and Lorestan Provinces were studied. The morphologic characters of the ticks were measured by the calibrated stereomicroscope armed scaled lens. The measurements were analyzed using SPSS for windows, version 16 on an IBM PC, so varied shapes of species in different geographic regions were drawn by the aid of a drawing tube connected to a light stereomicroscope.

RESULTS

One way ANOVA test revealed significant differences among the quantitative parameters in five zones (P < 0.001) also each zone to other zone by Post Hoc Tests e.g. LSD. No significant differences in the lateral grooves length/conscutum length ratio parameter were found.

CONCLUSION

Morphometric variation in Hyalomma spp is poorly studied. The variation in range and quantity of the morphometric parameters of H.anatolicum underlies that the correct recognition and key construction for Hyalomma species dependes on a complement morphometric study on the other species.