The effect of hallux valgus on the anatomy of the nerves around the first metatarsal bone

OBJECTIVE

To identify the variations in the location of the nerves that may be at risk in hallux valgus (HV) surgery, and to reveal whether these nerves are affected by the anatomical changes associated with HV.

METHOD

In the formalin fixed, 46 lower extremities (19 female, 27 male) (9 normal, 14 mild HV, 21 moderate/severe HV), extensor hallucis longus tendon (EHL), deep plantar artery, medial dorsal cutaneous (MDCN), deep fibular (DFN), common plantar digital (CPDN) and proper plantar digital (PPDN) nerves were examined. The branches of MDCN extending to the medial side of foot were recorded in three segments. The positional topography of nerves according to EHL were analyzed on 360° circle and clock models.

RESULTS

Sex-related differences observed in some parameters in direct measurements were not found in the clock model comparisons. In advanced HV angles (> 20°), DFN was closer to EHL in the distal part of the metatarsal bone, while there was no difference in the proximal. The intersection of the medial branch of the MDCN with the EHL was more proximal in HV cases than in normal feet. The location of the nerves in the clock pattern did not change in HV. Of the nerve branches reaching the medial side of the foot, 65.2% were in Part I, 71.7% in Part II, and 4.3% in Part III.

CONCLUSION

Sex differences in the distance of the nerves to the EHL disappeared when the size effect of the cross-section of the first metatarsal bone region was eliminated with the clock model. Only in advanced HVA (>20°) (not in mild HV), the DFN being closer to the EHL distally and the intersection of the medial branch of the MDCN with the EHL in HV being more proximal than in normal can be interpreted as specific reflections of HV progress. The variations we revealed in the number of branches reaching the inside of the foot may explain the diversity of neuromas or nerve injuries associated with HV surgery.

Connection between medial dorsal cutaneous nerve and saphenous nerve: case report

PURPOSE

There are no data on the connection of the saphenous nerve (SN), located on the medial side of the foot, with the terminal branches of the superficial fibular nerve. The aim of this study is to reveal the variation that surgeons should pay attention to for anesthesia applied in foot surgeries.

METHODS

In this study, the left foot of a 70-year-old female cadaver fixed with formalin was dissected. The distance to the medial malleolus and the incision line was recorded using digital caliper to determine the reference points in the resulting variation.

RESULTS

It was observed that a branch from the SN, which arose from the SN and proceeded anteriorly to the upper part of the medial malleolus and continued towards the dorsum of the foot, hooked with a branch from the medial dorsal cutaneous nerve (MDCN). The branches arising from this hook were distributed on the medial edge of the foot up to the proximal metatarsophalangeal joint I. The distance of this nerve connection to the medial malleolus is 91.14 mm, and the distance to the incision line is 15.76 mm.

CONCLUSIONS

It is suggested that the case presented as an unusual SN variation, which may affect the success of local anesthesia in invasive procedures to the medial part of the foot and could be considered in the evaluation of sensory loss after anteromedial surgical approach to the ankle, should be included in the classification of the cutaneous innervation pattern of the foot.

Testing the suitability of neuroanatomical tracing method in human fetuses with long years of postmortem delay

PURPOSE

Human tissues in gross anatomical archives with long years of postmortem delays are considered suboptimal relative to recently fixed materials for neuroanatomical tracing studies, yet efficacy of neuroanatomical tracing on archival fetal tissues largely unexplored. We aimed to explore the suitability of human archival tissue in neuroanatomical tracing with lipophilic carbocyanine dyes.

METHODS

We used crystal and paste forms 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) and analogues for neuroanatomical tracing on different peripheral nerves in 15-18-year archival old formalin-fixed human fetuses. We employed bright-field, fluorescent and confocal microscopy to visualize the peripheric nerve traces, spinal cord and vibratome cut sections. Fluorescent signal of the dyes on epineurium and on axonal membranes were visualized under fluorescence and confocal microscopes and performance of the dye diffusion was assessed by semi-quantitative image analysis.

RESULTS

We followed up seven lipophilic dye embeddings in 16-28 gestational week-old human fetuses (n = 4) with 16.75 ± 1.29-year postmortem delay. The mean distance of distally moved carbocyanine dye diffusion measured on epineurium was detected as 25.11 ± 9.1 mm.

CONCLUSION

Based on the results of 13 distinct studies performed neuroanatomical tracing with human tissues in the immediate postmortem hours or days, average traced distance was 16.32 ± 15.95 mm, and a 95% confidence interval lower limit of 4.9 mm and upper limit of 27.73 mm. The tracing distances we observed in our current study fall entirely within this confidence interval. To our awareness, this is the first report to demonstrate that specific neuroanatomical tracing presented in axonal membrane level on peripheral nerves is possible on gross anatomical repositories.

Morphometric Assessment of the Carotid Foramen for Lateral Surgical Approach

OBJECTIVES

This study aimed to compare the right and left sides of the carotid foramen (CF) to determine its precise location according to certain anatomical landmarks.

MATERIALS AND METHODS

Twenty human dry skulls were included in the study. A digital caliper and a digital image analysis software were used to obtain direct anatomical numerical values. Then, the same parameters on dry skulls were assessed with computed tomography (CT).

RESULTS

CF was found to be round shaped (62.5%), oval shaped (32.5%), and tear-drop shaped (5%). In all cases, the position of CF was seen as just postero-laterally of the foramen lacerum. According to the jugular foramen, CF was seen to be anterior in 85% and antero-medial in 15% of the cases. Regarding the morphometric values of the surface area, the length and width of CF were observed to be 37.86±11.24 mm2, 8.02±1.09 mm, and 6.86±0.90 mm at direct anatomical measurements and 39.69±10.07 mm2, 7.89±1.14 mm, and 6.41±0.90 mm at CT, respectively. The angles between the supramastoid crest-CF-zygoma root and the supramastoid crest-CF-mastoid process were determined as 37.11±6.87º and 42.22±6.40º at direct anatomical measurements and 36.59±4.94º and 43.71±4.55º at CT, respectively.

CONCLUSION

A significant difference in sides was not observed in relation with the numerical data of CF obtained from CT or from direct anatomical measurements of dry skulls. Moreover, a significant difference was not found between radiological and direct anatomical measurements. Therefore, precise radiological assessment of this region by an experienced neuroradiologist may be assumed as a fundamental need for successful surgeries of the skull base, in addition to thorough anatomical knowledge of neurootologists and neurosurgeons.

Evaluation of the stapedial tendon growth dynamic in human fetuses

PURPOSE

The main objective of the study was to investigate the morphometric properties of the stapedial tendon (ST) for pediatric otosurgeons and anatomists.

METHODS

The present study was placed on 15 fetuses (8 females, 7 males) aged from 20 to 30 weeks of gestation (at mean, 24.27 ± 3.24 weeks) using the collection of the Anatomy Department of Medicine Faculty, Mersin University. All measurements were obtained with a digital image analysis software.

RESULTS

In terms of male/female or right/left comparisons, no statistically significant difference was found in relation with the numerical data of ST. The surface area, length, and width of ST were detected as follows: 0.61 ± 0.15 mm², 1.27 ± 0.30 mm, and 0.45 ± 0.08 mm, respectively. The absence of ST was observed in two fetuses with and without severe malformations. In another fetus with cleft lip and polydactyly, multiple abnormalities were bilaterally identified in the middle ear: (1) the absence of the incudostapedial joint and (2) the presence of an abnormal tissue attaching to the stapes. The abnormal tissue was determined to be irregular dense connective tissue using light microscope and electron microscope.

CONCLUSION

Our findings showed that ST did not proportionally grow according to increasing gestational weeks. In the light of the numerical data, we thought that similar to stapes, ST attains the adult size in the fetal period. As ST anomalies may accompany severe malformations (e.g., cleft lip, polydactyly or syndactyly) that can be easily detected on observation by clinicians, we suggest that the detailed examination of middle ear in newborns should be taken into account for early diagnosis of conductive hearing loss to prevent any management delays.

Morphometric properties of the facial nerve in fetal temporal bones

OBJECTIVES

The main aim of the study was to examine the development and course of the facial nerve within fetal temporal bones from an anatomical and neuro-otological perspective.

METHODS

The study was conducted on 32 temporal bones from obtained fetuses (7 females, 9 male), on a mean gestational age of 26.75 ± 4.36 (range, 20-34) weeks from the collection of the Anatomy Department of Medicine Faculty. All the measurements were collected with a digital image analysis software.

RESULTS

Neither male/female nor right/left significant differences were observed in relation with the algebraic data of the segment lengths and angles of the facial nerve (p > 0.05). Linear functions for meatal, labyrinthine, tympanic, and mastoid segment lengths of the facial nerve were calculated as: y = -1.206 + 0.200 × Age (weeks), y = -1.868 + 0.153 × Age (weeks), y = -2.327 + 0.325 × Age (weeks), and y = -1.507 + 0.246 × Age (weeks), respectively. In addition, linear functions for first and second genu angles were calculated as: y = 105.475-0.117 × Age (weeks) and y = 140.446-0.042 × Age (weeks), respectively.

CONCLUSION

The regression equations and the scatter plot with increment curve, representing the growth dynamics of the facial nerve can be used for estimating its lengths and for understanding its development. The data suggest that there is a dramatic change transition from fetal life to the gathered data of adulthood in the length of meatal and mastoid segments as well as in the second genu angle; in addition, there is a partial change in the length of labyrinthine and tympanic segments as well as in the first genu angle.

Quantitative assessment of the growth dynamics of the teres major in human fetuses

PURPOSE

The main objective of the study was to examine the use of teres major (TM) as a flap in the pediatric surgeries from an anatomical perspective by: (1) revealing the growth dynamics of the developing TM; (2) assessing the possible interconnecting structures between TM and latissimus dorsi (LD); (3) exposing the innervation patterns of TM in human fetuses.

METHODS

Study was conducted on 50 fetuses (26 females and 24 males), on a mean gestational age of 22.86 ± 3.21 (range 18-30) weeks. All the measurements were collected with a digital caliper and a digital image analysis software. Additionally, structural relations between TM and LD were examined in detail and further classified.

RESULTS

No significant difference of side and sex was detected on TM measurements (p > 0.05). Linear functions for the surface area, width, length of the superior and inferior margins of TM were detected as follows: y = - 257.142 + 18.334 × age (weeks), y = - 5.497 + 0.545 × age (weeks), y = - 1.621 + 1.068 × age (weeks), and y = - 2.147 + 1.284 × age (weeks), respectively. As classified in five types, a number of 33 muscular or tendinous connections between TM and LD were detected. Musculo-tendinous slips from TM to triceps brachii (TB) were evident in four sides. Innervation of TM was observed to be providing by the lower subscapular nerve in all the cases.

CONCLUSION

First, linear functions, representing the developing fetal morphometry obtained by our study can be adapted for estimating the morphometric of this muscle in early childhood. Besides, acknowledging the diverse appointments of TM with the surrounding muscles such as LD and TB may facilitate the prevention of neurovascular structures and the application of surgical procedures during tendon transfers. In brief, our findings are highly potent to bring the attention of pediatric surgeons.

Evaluation of the origin and branching patterns of the iliolumbar artery and its implications on pelvic and vertebral surgery

Objectives:

To evaluate the origin, distribution pattern, branches, and neighboring structures of the iliolumbar artery (ILA) concerning the anterolateral surgical approaches to the spine.

Methods:

This study was performed in the Anatomy Department of Medical School, Mersin University, Mersin, Turkey between 2014 and 2015. Pelvises of 11 male formalin-fixed human cadavers were dissected by anterior and posterior approaches under surgical microscope. The origins, distribution patterns, calibers, and distances to certain structures were measured.

Results:

The ILA was found as a single trunk on 17 sides arising either from the IIA (12 sides, 70.6%) or the PT (5 sides, 29.4%). The average caliber of those originated from the posterior trunk was significantly larger (p=0.010). The ILA started as a single trunk in 17 sides, while its lumbar and iliac branches separately originating from different arteries in 4 sides. The close relation of the posterior rami of both the lumbar and iliac branches with transverse process and spinal nerve were noted.

Conclusion:

Findings suggest that the ILA and its branches may have different and significant patterns, which may be crucial to consider during certain surgical procedures, such as far lateral disc herniation and posterior pelvic fixations.

Bilateral persistent sciatic vein: report of a case with developmental, histological and clinical aspects

OBJECTIVE

Bilateral large variant veins were encountered in the lower extremity. It was aimed to identify the structural characteristics of this rare case and then, regarding the structural features, to overview its formation process and denomination.

MATERIAL AND METHOD

During the routine dissection of a 93-year-old male cadaver, bilateral large variant veins were found at the thigh. Valves of the veins were examined and evaluated together with the vascular wall histology.

RESULTS

The variant vein was loosely attached to the sciatic nerve by fibrous tissue and had anastomoses with the popliteal vein in the popliteal fossa on each side. The popliteal veins were hypoplastic on both sides. The right variant vein was passing through the fibers of the adductor magnus muscle 56.2 mm above the adductor hiatus, which corresponds to the third perforating branch of deep femoral vein. The left one was turning to the front over the adductor magnus muscle, at the lower border of quadratus femoris muscle. The left variant vein was corresponding to the descending branch of the medial circumflex femoral vein. Both variant veins had one incomplete and three well-developed valves.

CONCLUSION

In accordance with the findings, the variant vein was concluded to be an embryonic remnant, rather than an acquired one subsequent to any obstruction of the femoral vein. Regarding their connection with the popliteal vein but not with the internal iliac vein, both variant veins were denominated as "lower type persistent sciatic vein". Such a variation would be important with respect to the risk of complication during popliteal sciatic nerve blockade.