Shape Of Scaphoid Research Articles

Nonunion scaphoid bone shape prediction using iterative kernel principal polynomial shape analysis.

The scaphoid is an important mechanical stabilizer for both the proximal and distal carpal columns. The precise estimation of the complete scaphoid bone based on partial bone geometric information is a crucial factor in the effective management of scaphoid nonunion. Statistical shape model (SSM) could be utilized to predict the complete scaphoid shape based on the defective scaphoid. However, traditional principal component analysis (PCA) based SSM is limited by its linearity and the inability to adjust the number of modes used for prediction. This study proposes an iterative kernel principal polynomial shape analysis (iKPPSA)-based SSM to predict the pre-morbid shape of the scaphoid, aiming at enhancing the accuracy as well as the robustness of the model. Sixty-five sets of scaphoid images were used to train SSM and nine sets of scaphoid images were used for validation. For each validation image set, three defect types (tubercle, proximal pole, and avascular necrosis) were virtually created. The predicted shapes of the scaphoid by PCA, PPSA, KPCA, and iKPPSA-based SSM were evaluated against the original shape in terms of mean error, Hausdorff distance error, and Dice coefficient. The proposed iKPPSA-based scaphoid SSM demonstrates significant robustness, with a generality of 0.264mm and a specificity of 0.260mm. It accounts for 99% of variability with the first seven principal modes of variation. Compared to the traditional PCA-based model, the iKPPSA-based scaphoid model prediction demonstrated superior performance for the proximal pole type fracture, with significant reductions of 25.2%, 24.7%, and 24.6% in mean error, Hausdorff distance, and root mean square error (RMSE), respectively, and a 0.35% improvement in Dice coefficient. This study showed that the iKPPSA-based SSM exploits the nonlinearity of data features and delivers high reconstruction accuracy. It can be effectively integrated into preoperative planning for scaphoid fracture management or morphology-based biomechanical modeling of the scaphoid.

Scaphoid fractures : Current diagnostic and treatment concepts

Scaphoid fractures are by far the most frequent fractures of the carpal bones of the hand and often lead to problematic healing processes if the diagnostics and treatment are inadequate. The main complication of ascaphoid fracture is pseudarthrosis, which leads to carpal collapse and degenerative arthritis of the wrist if left untreated. Early diagnosis and individualized differentiated treatment aim to achieve bony healing with restoration of the scaphoid shape and preservation of the function of the wrist. The anatomical and biomechanical characteristics of the scaphoid can impede bony healing after afracture and, in contrast to the diagnostics and treatment, cannot be influenced. Ahistory of trauma and typical clinical signs of ascaphoid fracture should lead to systematic imaging diagnostics with obligatory computed tomography. Only by determining the exact fracture morphology can an appropriate treatment concept be established. Conservative treatment should be restricted to stable fractures without relevant displacement. Fractures of the proximal scaphoid pole are considered unstable even if they are not displaced. Operative treatment is indicated for all unstable fractures. The favored surgical procedure is osteosynthesis with acannulated double-threaded screw, which can be used in aretrograde or antegrade manner and in aminimally invasive or open technique, depending on the fracture type. Surgical treatment results in earlier bony healing and quicker restoration of function but can be associated with ahigher complication rate. Posttraumatic osteoarthritis after healing in malalignment is usually asymptomatic.

Scaphoid Arterial supply: A Review

Scaphoid, the boat-shaped carpal bone, is largely covered by articular cartilage. It has a much more complex arterial supply than previously reported, moreover, this arterial pattern has been hypothesized to lead to avascular necrosis after fracturesScaphoid blood supply has long been documented as scarce; it arises from the radial artery giving palmar and dorsal branches. There is high-grade evidence reporting two main arteries entering from the distal half of the scaphoid and middle to lower-grade evidence reporting several arteries scattered over the entire scaphoid and anastomosis of the radial artery with intercarpal arteries. Dorsal arteries are slightly larger in diameter and many more than volar ones. The scaphoid shape is associated with variations in arterial supply patterns. Scaphoid surgery preserving vascular supply is the gold standard. Scaphoid blood supply is not as poor as previously documented, as current evidence supports even proximal pole vascularization. We recommend surgery to preserve the blood supply and foster research in this area.

Avascular Necrosis of the Scaphoid-Preiser Disease: Outcomes of 39 Surgical Cases

There is no established treatment standard for patients with idiopathic avascular necrosis of the scaphoid, also known as Preiser Disease. We evaluated outcomes of operative interventions performed for patients diagnosed with Preiser Disease and assessed scaphoid morphology in the contralateral wrists. We performed a retrospective review of all patients undergoing surgery for Preiser disease between 1987 and 2019 at our institution. A total of 39 wrists in 38 patients were identified. The mean age was 37 years at the time of surgery, and the median follow-up time was 5.3 years. The patients were classified according to the Herbert and Kalainov classifications. Pre- and postoperative pain and functional outcomes were evaluated, and Mayo Wrist Scores were calculated. Reoperations for complications were recorded. Scaphoid shapes were assessed for wide/type 1 and slender/type 2 scaphoids in the contralateral unaffected wrist in patients with unilateral disease. Overall, pain and Mayo Wrist Scores improved, while flexion/extension decreased slightly and grip strength remained stable. In a comparison of the 2 main surgery groups, 17 wrists with a pedicled vascular bone graft and 12 wrists with salvage surgery (4-corner fusion/proximal row carpectomy) showed similar functional outcomes. Similar outcome scores were found regardless of preoperative Herbert or Kalainov classifications. Radiographic morphologic evaluation of the contralateral side determined that 4 of 8 patients had a slender scaphoid shape, which has been shown to have a more limited vascular network when compared to full scaphoids. A treatment algorithm of Preiser disease is lacking and the optimal surgical treatment remains controversial. Pedicled vascular bone grafts had similar functional outcomes as salvage procedures, but preserving the scaphoid was possible in 70% of the pedicled vascular bone graft cases. A slender scaphoid is potentially more common in patients with Preiser disease who undergo surgery. Therapeutic IV.

3D analysis and computer assisted reconstruction for scaphoid non-union

The odd shape of the scaphoid is a challenge to our spatial sense. Computer assistance is of an unmatched value when reconstructing a non-united scaphoid: From CT data a true 3-D-model can be generated, fully interactive; thus it can be moved, manipulated and of course also printed for hands-on experience. Comparing the virtual 3-D-models of the nonunion with the healthy contralateral scaphoid, the exact amount of the deformity is calculated which allows for the planning of an anatomically precise reconstruction of the scaphoid shape. Finally, computer generated patient specific instruments will facilitate the implementation of this planning intraoperatively. This proceeding enables us to reconstruct the non-united scaphoid markedly more accurately and with this reliably normalize wrist kinematics. Meanwhile we have applied this technique successfully in more than 50 cases of scaphoid-nonunions presenting with significant deformity.

The Vascular Anatomy of the Scaphoid: New Discoveries Using Micro–Computed Tomography Imaging

The purpose of this study was to investigate the intraosseous vascular anatomy of the scaphoid using recent advances in micro-computed tomography (micro-CT) imaging and 3-dimensional reconstruction. We also studied the effect of scaphoid shape and screw position on the intraosseous vascular structure. Thirteen upper extremities were injected with a contrast agent. The scaphoid bones were extracted and scanned using a micro-CT scanner. The vascular impact of screw insertion at various axes through the scaphoid was calculated and compared using the generated 3-dimensional models. The specimens were 3-dimensionally-printed and the morphology was assessed according to bone dimensions. A relationship between the internal vascular patterns and these morphological features was determined. All specimens received vascular inflow from the dorsal ridge forming a vascular network that supplied an average of 83% of the bone's volume. This network was supplemented in 4 specimens with volar vessels entering at the waist. Another network was identified, created by vessels entering volarly at the tubercle, which supplied the remainder of the scaphoid. One specimen did not receive any vessels at the tubercle. With regards to screw placement, screws placed in the central axis were the least disruptive to the internal vascularity, followed by the antegrade (dorsal) insertion axis. Two morphological bone types were identified: type I or full scaphoids and type II or slender scaphoids. Type I possessed a more robust internal vascular network than type II scaphoids. This study identifies 2 distinct types of scaphoid morphology with 1 of them having a less robust blood supply, which may prove to be related to development of nonunion, avascular necrosis, or Preiser disease. Central axis and antegrade (dorsal) screw fixation may be least disruptive to the internal blood supply. Safer fixation of the scaphoid bone may be achieved by knowledge of intraosseous vascular patterns.

Treatment of the scaphoid humpback deformity – is correction of the dorsal intercalated segment instability deformity critical?

Treatment of scaphoid fractures has been focused mainly on achieving union, with less attention to restoring normal scaphoid shape and orientation. Malalignment of one carpal bone will disrupt the kinetics of the entire wrist. The dorsal intercalated segment instability deformity associated with scaphoid waist nonunion is a nondissociative form of carpal instability. It has to be reduced in the treatment of scaphoid waist nonunions to avoid kinetic problems that will lead to arthritic changes. Computerized tomography scanning has become indispensable to visualize the humpback deformity clearly. Different techniques may be used to restore the normal anatomy of scaphoid, from non-vascularized graft to arthroscopic bone grafting, and also the option of vascularized bone grafting.

Guest Editorial

Guest Editorial

Histopathological Changed of the Hypophysis in Malnutrition in Elderly Subjects

Major objectives in forensic gerontology are physical and mental disorders during aging, which can be caused by various factors involving nutrition and stress, often accompanied by dysfunction in the neuroendocrine systems including the hypophysis. The objective of the present study was to investigate the histopathological changes in the adenohypophysis in elderly subjects using autopsy materials. Hypophyses with a scaphoid shape (group S: 16 males and 4 females; mean age, 78.6 years) and a normal one (group C: 30 males and 20 females; mean age, 65.2 years) were compared. Incidence of the scaphoid-shaped hypophysis mildly increased with age, being 17% in the elderly over 65 years of age. The weight of the pituitary gland in group S (0.42 +/- 0.1 g) was lower than that of group C (0.65 +/- 0.2 g). The degree of fibrosis was higher in group S (31.6% +/- 5.4%) than in group C (18.3% +/- 6.3%). Immunohistochemical staining showed no significant differences in the proportion of the ACTH cells and the TSH cells between the two groups (p > 0.05). However, there was an increase in the proportion of gonadotrophs, prolactin cells, and S-100-containing cells in group S and a decrease in that of GH cells (p < 0.05). These findings may be associated with reduced anabolic, gonadal and hepatic functions due to malnutrition.

Die Skaphoidpseudarthrose: Kritische Analyse der derzeitigen Wiederherstellungsverfahren

INTRODUCTION: Currently performed surgical procedures for scaphoid nonunion were evaluated on the basis of a retrospective study of two different treatment groups. METHOD: 55 patients with scaphoid nonunion were evaluated clinically and radiologically on average 10.7 years after the Matti-Russe procedure. The Matti-Russe group was compared to a group of 43 patients with scaphoid nonunion who received bone grafting and Herbert screw fixation with an average follow up of 11.0 years RESULTS: 69% of all patients of the Matti-Russe group developed mostly advanced osteoarthritis of the carpus. In 38% a malunion of the scaphoid was and in 18% a DISI-deformity was found. The majority of patients after Matti-Russe procedure experienced limitations concerning the range of motion. At time of follow up, only 21% of the patients treated with the Herbert screw suffered from an osteoarthritis of the carpus, mainly in an initial stadium. A scaphoid malunion was found in 7% and a DISI-deformity in 5% of the patients. A minority of the Herbert screw group presented a decreased range of motion at follow up. DISCUSSION: Internal fixation and bone grafting is currently the gold standard in the surgical treatment of scaphoid nonunions. The correct reconstruction of the scaphoid shape is crucial for the outcomes.