Gerdy's tubercle as a novel anatomical landmark for the proximal tibial cut in total knee arthroplasty.

OBJECTIVES: This study aimed to explore the use of Gerdy's tubercle (GT) as an innovative and dependable anatomical landmark for the proximal tibial cut in total knee arthroplasty (TKA) in cases with extensive knee degeneration. MATERIALS AND METHODS: One hundred dry tibia bones and 10 formalin-fixed cadaveric knee specimens of both sexes were examined. A Zimmer NexGen tibial cutting guide and a Mitutoyo digital caliper were utilized to align the guide with the tibia's mechanical axis. The procedure was replicated on cadaver knees using a standardized medial parapatellar arthrotomy approach. Measurements included the distance from GT superior border to the resection line and the length of the tibia. A radiological study involving magnetic resonance imaging examinations of 48 patients, which were evaluated focusing on the upper border of GT and the least degenerated segment of the posterolateral part of the lateral tibial condyle, was conducted. RESULTS: Anatomical measurements of GT and proximal tibial areas in 110 specimens showed slight but consistent variations with cadaver measurements. Magnetic resonance imaging analysis of 48 patients revealed notable sex differences in the distance between the superior border of GT and the tibia's posterolateral surface. There was also a significant negative correlation between the distance from GT to the posterolateral corner and cartilage thickness. CONCLUSION: Proper alignment in TKA is crucial for success, but identifying an extra-articular landmark for horizontal tibial resection remains challenging, particularly in severely arthritic knees. This study introduces GT as a novel anatomical landmark for TKA, offering a more reliable reference for achieving desired joint levels in knees with significant degenerative changes.

Tibial nerve branching pattern and compatibility of branches for the deep fibular nerve.

PURPOSE: In individuals who develop drop foot due to nerve loss, several methods such as foot-leg orthosis, tendon transfer, and nerve grafting are used. Nerve transfer, on the other hand, has been explored in recent years. The purpose of this study was to look at the tibial nerve's branching pattern and the features of its branches in order to determine the suitability of the tibial nerve motor branches, particularly the plantaris muscle motor nerve, for deep fibular nerve transfer. METHODS: There were 36 fixed cadavers used. Tibial nerve motor branches were observed and measured, as were the lengths, distributions, and thicknesses of the common fibular nerve and its branches at the bifurcation region. RESULT: The motor branches of the tibial nerve that supply the soleus muscle, lateral head, and medial head of the gastrocnemius were studied, and three distinct forms of distribution were discovered. The motor branch of the gastrocnemius medial head was commonly observed as the first branch to divide, and it appeared as a single root. The nerve of the plantaris muscle was shown to be split from many origins. When the thickness and length of the motor branches measured were compared, the nerve of the soleus muscle was determined to be the most physically suited for neurotization. CONCLUSION: In today drop foot is very common. Traditional methods of treatment are insufficient. Nerve transfer is viewed as an application that can both improve patient outcomes and hasten the patient's return to society. The nerve of the soleus muscle was shown to be the best candidate for transfer in our investigation.

Investigating the Effects of Trigeminal Impression and Internal Acoustic Opening Morphology Differences for Possible Surgical Applications.

PURPOSE: The exhaustive information regarding the types of trigeminal pore (TP) or trigeminal impression (TI), internal acoustic opening (IAO), and related surgical approaches is lacking in the literature. Therefore, this study is performed to further elucidate the types of TP or TI, IAO, and the relationships with critical surgical landmarks in the skull base. METHODS: Trigeminal impression (TI) and internal acoustic opening (IAO) found in 11 dry skulls, 24 right temporal bones, and 25 left temporal bones were examined on both sides to define their relationship to each other and nearby structures. The age and sex of these bones were not identified. Besides these, 77 skulls were examined by radiologic imaging methods. These skulls were identified by gender. RESULTS: According to test results, there was a significant difference between the left and right internal acoustic opening in the case of horizontal dimension (HD). The left HD-IAO is bigger than the right one. In addition, right HD-IAO, vertical dimension (VD) of right internal acoustic opening, left HD-IAO, and left VD-IAO values differed significantly in male and female patients. CONCLUSIONS: Investigating the relationship of TI and IAO with relevant structures suggests that surgical approaches involving the TP and IAO indicated that surgical approaches considering the TI and IAO variations may be used in the development of surgical processes and primary surgical interventions.

Corpus callosum area and sectioning: a radioanatomical study correlated with MRI and cadaver morphometry.

PURPOSE: The corpus callosum (CC) is the primary interhemispheric connection between the two cerebral hemispheres. Besides their similar morphological characters, there are differences in their measurements. This study aimed to divide the CC into groups using planes based on the anterior commissure (AC) and posterior commissure (PC) and to detect differences in CC magnetic resonance imaging (MRI) and cadaver samples between these groups. METHODS: The study included 80 patients (40 male and 40 female patients) who underwent normal MRI in the midsagittal plane, and 38 cerebral hemispheres from 40 adult cadaver brains, with each hemisected in the midsagittal plane. The medial surface of the CC was divided vertically into three parts (the anterior, middle, and posterior zones) according to the AC and PC. Areas and parameters were measured in both the cadaveric hemispheres and patient MRI images. RESULTS: The total CC area and CC areas between, anterior, and posterior to the AC-PC vertical lines were the same in both the MRI and cadaver samples. In addition, morphometric measurements like the CC length, AC-PC length, and CC height at the AC and PC vertical lines, and their correlations were also found to be similar between the MRI and cadaver samples. CONCLUSION: This study proposes three areas according to AC and PC classification (anterior, middle, and posterior). This new proposed classification is suitable for stereotactic interventions and is useful for obtaining data from MRI images. However, it should be kept in mind that there may be changes and variations.

The adductor magnus tendon is a viable option for medial patellofemoral ligament reconstruction, but with a busy surrounding neurovascular topography.

PURPOSE: To describe the proximity of the neurovascular structures surrounding the adductor magnus (ADM), to delineate a safe boundary focusing on the techniques used during graft harvest and to evaluate whether the length of the ADM tendon is sufficient for safe medial patellofemoral ligament (MPFL) reconstruction. METHODS: Sixteen formalin-fixed cadavers were dissected. The area surrounding the ADM, the adductor tubercle (AT) and the adductor hiatus was exposed. The following measurements were performed: the (1) total length of MPFL, (2) distance between the AT and the saphenous nerve, (3) the point where the saphenous nerve pierces the vasto-adductor membrane, (4) the point where the saphenous nerve crosses the ADM tendon, (5) the musculotendinous junction of the ADM tendon, and (6) the point where the vascular structures exit the adductor hiatus. Additionally, (7) the distance between the ADM musculotendinous junction and the nearest vessel (popliteal artery), (8) the distance between the ADM (at the level where the saphenous nerve crosses) and the nearest vessel, (9) the length between the AT and the superior medial genicular artery, and finally (10) the depth between the AT and the superior medial genicular artery were analyzed. RESULTS: The in situ length of the native MPFL was 47.6 ± 42.2 mm. The saphenous nerve pierces the vasto-adductor membrane at a mean distance of 100 mm, although it crosses the ADM itself at an average of 67.6 mm. The vascular structures, on the other hand, become vulnerable at a distance of 89.1 ± 114.0 mm from the AT. After harvesting the ADM tendon, the mean length was found to be 46.9 mm, which was insufficient for fixation. Partial release from the AT resulted in a more adequate length for fixation (65.4 ± 88.7 mm). CONCLUSION: The adductor magnus tendon is a viable option for the dynamic reconstruction of the MPFL. Knowledge of the surrounding busy neurovascular topography is paramount for a procedure typically performed in a minimally invasive way. The study results are clinically relevant, as they suggest that tendons should be shorter than the minimum distance from the nerve. If in some cases the length of the MPFL is longer than the distance of the ADM from the nerve, the results suggest that a partial dissection of the anatomical structures might be needed. Direct visualization of the harvesting region might be considered in such cases.

Pronator quadratus musculo-osseous free flap for wide hard palatal defect reconstruction: An anatomical study.

Wide hard palate defects include congenital and acquired defects that are six square centimeters or larger in size. Obturator prostheses and autologous soft tissue transfers have been used to reconstruct palatal defects. This study aims to repair wide, hard palatal defects by using a pronator quadratus musculo-osseous free flap to achieve subtotal reconstruction. Seventeen formalin-fixed cadavers were dissected. Free musculo-osseous pronator quadratus flaps were prepared after a 12 cm curvilinear volar skin incision. Standard 30 × 23 mm (690 ± 52.12 mm2) hard palate defects were made by chisels and saws. A subcutaneous tunnel was created between the mandibular edge cross point of the facial vessels and the retromolar trigone through the subcutaneous to the superficial musculoaponeurotic system by dissection. Area measurements of the pedicle and palate defects were performed by the ImageJ program (National Institutes of Health, Bethesda, MD, USA) on drawings over an acetate layer of materials. Mandibular distances of gonion-facial vessel cross point (a), gonion-gnathion (m), and facial vessels' cross point-retromolar entrance point (h) were measured. Ratios of h/m and a/m were calculated. The mean pronator quadratus area was 2349.39 ± 444.05 mm2, and the arterial pedicle pronator quadratus diameter was 2.32 ± 0.34 mm. The mean pedicle length of the pronator quadratus was 117.13 ± 8.10 mm. Study results showed that musculo-osseous pronator quadratus flaps' bone and muscle parts perfectly fit on the defects in all cadavers. Pronator quadratus musculo-osseous flap is a feasible surgical option for wide, hard palatal defect reconstruction strategies.

Alternative Path for Optic Nerve Decompression in Pseudotumor Cerebri With Full Endoscopic Lateral Transorbital Approach.

Endonasal endoscopic approaches are the most preferred surgical methods in patients with pseudotumor cerebri because of easy access to the optic nerve, but the choice of this technique may not apply to all endoscopic endonasal cases. Moreover, there may be difficulties in practice in some cases, including the coronavirus disease 2019 pandemic. This study aimed to suggest an alternative endoscopic approach by lateral orbitotomy for optic nerve decompression in patients with pseudotumor cerebri. The study was performed using 5 fresh-frozen cadaver heads (bilaterally, total of 10 sides) injected intravenously with colored silicone preserved in the cold chain. An average of 2.5 cm skin incision was made to fit the lateral orbitotomy. The lengths of the recurrent meningeal artery (mm), the meningo-orbital band (mm), and the optic nerve (mm) to the orbital margin were measured. After these morphometric measurements, optic nerve decompression was performed endoscopically, and the length of the decompression was measured (mm). The average length (mm) between the orbital rim and meningeal recurrent artery (or meningolacrimal branch) was 16.2 mm, between the orbital rim and the meningo-orbital band was 18.5 mm, and between the orbital rim and optic nerve was 44.1 mm. The average optic nerve decompression length was 4.4 mm. The endoscopic lateral orbitotomy approach provides easy access to the optic nerve by anatomically following the recurrent meningeal artery and the meningo-orbital band. It can be a safe second-line approach after endonasal approaches for optic nerve decompression in pseudotumor cerebri.

Microsurgical anatomy of the anterior cerebral artery and the arterial supply of the cingulate gyrus.

PURPOSE: The cingulate gyrus is a potential surgical area to treat tumours, psychiatric diseases, intractable pain and vascular malformations. The aim of the study was to define the topographic anatomy and arterial supply of the cingulate gyrus located on the medial surface of the cerebral hemisphere. METHODS: We studied thirty-six hemispheres, each hemisected in the midsagittal plane. The vertical thickness of the cingulate gyrus was measured at the anterior commissure (AC), posterior commissure (PC), and genu levels of the corpus callosum. The branches of the anterior and posterior cerebral arteries supplying each zone were noted separately. The arterial pathways were transformed to digital data in AutoCAD to identify the condensation and reduction areas. RESULTS: The mean AC-PC distance was 27.17 ± 1.63 mm. The thinnest region was the genu level of the corpus callosum (10.29 mm). The superior internal parietal artery (SIPA), inferior internal parietal artery (IIPA) and pericallosal artery (PrCA) supplied all zones of the cingulate gyrus. The anterior zone received the greatest supply. The arterial condensation and reduction areas on both sides of cingulate gyrus and its x, y, and z coordinates specified. CONCLUSIONS: The target cingulotomy (TC) area was determined for anterior cingulotomy. The properties of the TC area are that the thinnest region of the cingulate gyrus is supplied relatively less than other areas and is close to the anterior cingulotomy areas in the literature. The arterial reduction area (ARA) was found to be suitable for corpus callosotomy in terms of avoiding haemorrhage.

Topographical Anatomy of the Superficial Temporal Artery.

AIM: To describe in detail the gross anatomy of the superficial temporal artery (STA), its course and branches, its relationships with the branches of the facial nerve, and certain anatomical and surgical landmarks to preserve these structures in daily neurosurgical practice, and to use the STA during revascularization surgery. MATERIAL AND METHODS: This cadaveric study was conducted on 16 cadaver heads bilaterally, in which 32 silicon/latex-injected STAs were dissected using a microdissection technique in a neuroanatomy laboratory. The distances between the facial nerve, tragus, STA, superficial temporal vein (STV), and imaginary lines created between important anatomical landmarks were measured. The curvilinear lengths of STA and STV were also measured. RESULTS: The average distances of the most posteriorly located branch of the facial nerve to the frontal region and the tragus at the midpoint of zygoma in the horizontal plane, at the superior border of the zygoma and at the level of the superior border of the parotid gland, were measured as 25.39, 29.84, and 15.56 mm, respectively. The average distance directly measured between the tragus and STA was 39.29 mm, and that between the tragus and STV was 20.26 mm. The average curvilinear lengths of the frontal and parietal branches of STA were 97.63 and 96.45 mm, respectively. CONCLUSION: Understanding the clinical anatomy of the STA and its branches and its relationships with other structures is of critical importance for a successful and noncomplicated surgery. Our findings will be useful not only for surgical approaches such as pterional craniotomy and orbitozygomatic approaches but also for cerebral revascularization.

Protection of the innervation of the tensor fasciae latae in hip direct anterior and anterolateral approaches: a cadaver study.

PURPOSE: This study aims to reveal the exact course of the superior gluteal nerve (SGN) branch innervating the tensor fascia lata (TFL) and show how it can be protected in the direct anterior approach (DAA) and anterolateral approach (ALA). METHODS: The anterolateral regions of 22 thighs from formalin-fixed cadavers were dissected. 3 anatomical points were determined. Point A, B, C indicates where the SGN enters the gluteus minimus (GMin) fibres, the SGN leaves the gluteal muscles, the SGN enters the TFL, respectively. Measurements were made on 3 separate lines. RESULTS: On the anterior superior iliac spine (ASIS) and the head of the fibula line (Line 1), the horizontal-vertical distances from point B and C to the ASIS were 7.99 ± 3.65 mm-40.40 ± 11.50 mm and 11.74 ± 6.61 mm-70.35 ± 14.11 mm respectively. The horizontal-vertical distances from point A, B, C to the greater trochanter (GT) were 32.41 ± 9.97 mm-55.28 ± 12.25 mm; 67.70 ± 8.54 mm-17.76 ± 13.57 mm; 63.92 ± 9.96 mm-13.00 ± 7.92 mm on the GT and the head of the fibula line (Line 2), respectively. The horizontal-vertical distances from point A, B, C to the GT were 24.58 ± 9.83 mm-42.54 ± 12.86 mm; 9.45 ± 7.92 mm-36.25 ± 9.06 mm; 26.18 ± 11.12 mm-64.05 ± 11.67 mm on the ASIS and the GT line (Line 3). CONCLUSIONS: In the DAA, the increased risk of damaging the branch of the SGN that innervates the TFL must be kept in mind. The protection of this branch can be ensured with easy and applicable rules.

The microanatomy of the Sylvian fissure.

PURPOSE: Microsurgical anatomy of the Sylvian fissure is still a popular research topic for neurosurgeons. It is important for surgeons who perform skull base and Sylvian fissure surgical procedures to master the anatomy of the region. In our study, we aimed to review the current literature on the subject. METHODS: We reviewed the literature concerning the Sylvian fissure. In addition, we made a microdissection of four human cadaveric brains in order to take images of relevant anatomic structures. RESULTS: The Sylvian fissure includes both superficial and deep compartments. From the beginning of the surface structures and variable thickened subarachnoid membrane to the vascular structures located at the operculo-insular compartment, the surgical technique requires meticulous dissection in all stages of the surgery. CONCLUSIONS: From the view of neurosurgery, novel anatomical knowledge should enhance the success of the surgery. From the view of neuroscience, the Sylvian fissure and the Sylvian cistern have unique anatomical, vascular, and genotypical properties to the other areas of the cerebrum, making them complex and special.

Posteromedial Compartment Arthroscopy of the Knee and Resection of Osteophytes: An Anatomic Perspective on Posteromedial Knee Impingement.

Posteromedial knee pain is a common clinical problem. It is often accompanied by degenerative changes or tears in the posterior horn of the medial meniscus and/or pain during deep flexion of the knee. In more advanced cases, it is accompanied by the osteophytic formation of a cam lesion that develops gradually in the posterior of the medial condyle of the femur and, with it (or less frequently without it), an osteophytic lesion at the posterior of the tibia (i.e. pincer lesion) occurs. It is believed that resection of the cam lesion may delay the progression of knee osteoarthritis, similarly to repairing the posterior horn of the medial meniscus. In this technical note, we describe a 2-portal technique for resection of cam lesions by posteromedial knee arthroscopy using anatomic landmarks. Using both portals provides better visualization and a better approach.

Morphology of the trigeminal ganglion: anatomical structures related to trigeminal radiofrequency rhizotomy.

BACKGROUND: Trigeminal neuralgia is the most common example of craniofacial neuralgia. Its etiology is unknown and is characterized by severe episodes of paroxysmal pain. The trigeminal ganglion and its adjacent anatomical structures have a complex anatomy. The foramen ovale is of great importance during surgical procedures such as percutaneous trigeminal rhizotomy for trigeminal neuralgia. OBJECTIVE: We aimed to identify the anatomical structures associated with the trigeminal ganglion and radiofrequency rhizotomy on cadavers and investigate their relationship with the electrodes used during rhizotomy to determine the contribution of the electrode diameter and length to the effectiveness of the lesion formation on the ganglion. METHODS: Five fresh-frozen cadaver heads injected with red silicone/latex were used. A percutaneous puncture was made by inserting of a cannula through the foramen ovale to create a pathway for electrodes. The relationships between the electrodes, Meckel's cave, trigeminal ganglion, and neurovascular structures were observed and morphometric measurements were obtained using a digital caliper. RESULTS: Trigeminal ganglion, therefore the electrode in its final position, shows proximity with important anatomical structures. The electrode was inserted posteriorly into the foramen ovale in all of the specimens and was located on the retrogasserian fibers. This study revealed that the electrodes targeting the ganglion and passing through the foramen ovale may cause a radiofrequency lesion due to the contact effect of the dura itself pressing on the electrode. Pushing the cannula beyond the petroclival angle may result in puncturing of the dura propria and moving further away from the target area. CONCLUSION: The success of radiofrequency rhizotomy is directly related to the area affected by the lesion. Understanding the mechanism of action underlying this procedure will ensure the effectiveness, success, and sustainability of the treatment.

Neurovascular anatomy of pronator quadratus for reanimation of blepharoptosis.

PURPOSE: Pronator quadratus (PQ) is a quadrilateral muscle on a volar distal side of the forearm. The purpose of this study was to establish a novel surgical technique for reanimation of the upper eyelid for severe ptosis using PQ functional free muscle flap. METHODS: The current study is a cadaveric study, designed to assess a PQ free flap transfer that lies between the frontalis muscle and the upper eyelid. Fourteen PQ from fourteen embalmed cadavers were dissected, and their neurovascular pedicles were isolated. Then they were transferred to the area on the contralateral side between the frontalis muscle and upper eyelid tarsal cartilage. Measurements of the PQ flap, antebrachial region, orbitofrontal region, recipient vessels, and motor nerve were performed using a caliper. The extendibility of neurovascular pedicles was evaluated by measurements of lengths. In addition, the diameter of PQ flap vascular pedicle vessels was compared with recipient vessels. RESULTS: The mean width of the proximal border of PQ was 41.92 ± 2.05 mm and the distal border of the PQ was 42.84 ± 4.04 mm. The mean PQ artery (type II, Mathes-Nahai flap classification) length was found to be 117.72 ± 7.77 mm. The mean diameter of the anterior interosseous nerve was 1.89 ± 0.08 mm. The mean diameter of the uppermost branch of the frontal branch of the facial nerve was 1.18 ± 0.25 mm. The length and diameter of neurovascular pedicles of muscle flaps were adequate for microvascular anastomoses and neurorrhaphy. CONCLUSIONS: The results of this anatomical study demonstrate that the PQ free flap transfer has anatomical features that are suitable and compatible with the surgical treatment of blepharoptosis.

Computer-based multimodal training module facilitates standardization of complete mesocolic excision technique for right-sided colon cancer: Long-term oncological outcomes.

AIM: The aim of this study is to demonstrate our video training tool developed to teach and standardize complete mesocolic excision (CME) for right-sided colon cancer and also to present our long-term oncological outcomes. METHOD: Educational narrative videos were produced to demonstrate the technical steps of CME. First, a three-dimensional animation video was prepared. Then cadaveric dissections were recorded in a step-by-step fashion, following the sequences of open and minimally invasive surgery. These were followed by videos of real-life demonstrations of surgical procedures, enhanced by superimposed animations of key anatomical structures. In order to demonstrate the impact of this training module on outcomes of patients undergoing CME, we retrospectively queried data from before (2005-2010) and after (2011-2019) implementation of standardized CME in our practice. RESULTS: A total of 180 consecutive patients underwent right hemicolectomy between 2005 and 2019. Fifty-four patients underwent surgery before and 126 patients after CME principles were elaborated and standardized. Of those patients who had surgery after the training module, 58 (46%) underwent open surgery and 68 (54%) underwent laparoscopic colectomy. Demographics, perioperative parameters and morbidity were comparable between the groups. The 5-year overall and disease-free survival rates were significantly improved after implementation of CME training (p = 0.059 and p = 0.041, respectively). Also, 5-year overall and disease-free survival rates for all patients were considerably better than our reported national outcomes. CONCLUSION: Our comprehensive step-by-step training video module for the CME technique demonstrates surgical anatomical planes and important vascular structures and variations. The video also helps standardization of the CME technique and should contribute to improved histopathological and oncological outcomes.

Temporal Artery and Temporal Region Supplied by the Middle Cerebral Artery: An Anatomical Study.

ABSTRACT: This study was conducted to describe in detail the branching patterns of cortical branches from the middle cerebral artery supplying the feeding of the temporal region, to define the arterial structure of temporal artery (TA) and to determine the effect of this arterial supply to the temporal region. The arteries of brains (n = 22; 44 hemispheres) were prepared for dissection after filling them with colored latex. TA was defined, and its classification was described, specifying its relationship with other cortical branches. A new classification was defined related to TA terminology. TA was found in 95% of cadavers, and it originated as an early branch in 75% and from the inferior trunk in 24% of cadavers. TA was classified as Type 0: No TA, Type I: single branch providing two cortical branches, Type II: single branch providing three or more cortical branches and Type III: double TA. Type I-TA (45%) was the most common, and Type II-TA arterial diameter was significantly larger than that of other types. All cadavers showed the cortical branches of temporal region from middle cerebral artery, anterior TA , middle TA, posterior TA and temporooccipital artery, except temporopolar artery (81%). Temporopolar artery, anterior TA, and middle TA primarily originated from TA, an early branch, but posterior TA and temporooccipital artery primarily originated from the inferior trunk. Detailed knowledge about cortical branches together with TA and also this region's blood supply would enable increased prediction of complications, especially in cases with these region-related pathologies, and would make interventions safer.