Features of intra-hamate vascularity and its possible relationship with avascular risk of hamate fracture.

BACKGROUND: The angiography with micro-computed tomography (micro-CT) has been proved its great advantages on investigating the intra-osseous vascularity of carpal bones. But few researches have focused on the intra-hamate vascularity. This study aimed to illustrate the intra-osseous arteries of the hamate and the relationship between the intra-hamate vascularity and the avascular risk of different types of hamate fractures. METHODS: Six normal cadaveric hamates were investigated with red lead (Pb3O4) micro-CT angiography. The intra-osseous arteries of specimens were clearly enhanced and the three-dimensional model was reconstructed. In order to study the features of the arterial entrances and intra-hamate vascularity, the diameters, quantities, locations of enhanced arteries, and the locations of transversal/proximal pole fracture lines on the body of the hamate were statistically compared. Besides, in order to analyze the relationship between intra-hamate vascularities and different hamate fractures, 127 cases of hamate fractures who presented in our hospital from March 2003 to June 2017 were retrospectively studied. RESULTS: A total of 94 cases were followed up (range: 4-37 months; mean: 12.4 months) effectively. The overall union rate of hamate fractures was as high as 92.6% (87 of 94 cases), while non-union of fracture on hamate hook was more common (P = 0.031). The arterial entrances were located around the dorsal, volar, radial, ulnar non-articular surfaces of the hamate body and the hook of the hamate. Generally, there were one to two trunk arteries on the volar non-articular surface and one to three trunk arteries on the dorsal non-articular surface. They formed one or two arterial arches, from which some branches were emitted and supplied the proximal parts. The intra-osseous vascularities of the hamate body were generally located in the radial part. The blood supply of the hook was mainly from the volar non-articular surface in most specimens. Hamate fractures could be classified into four types: fractures of the transversal/proximal pole, medial tuberosity, dorsal coronal of the hamate body, and fractures of the hamate hook. CONCLUSIONS: This study showed new features of intra-hamate vascularity and the results will guide surgeons to reduce the vascular damage during the hamate fracture operations. The fracture lines of different types of hamate fractures may disrupt the intra-hamate arteries. The intra-hamate vascularities will have different influences on the avascular risks of different hamate fractures.

Computer-assisted Surgery for Scaphoid Fracture.

The computer-assisted surgery (CAS) has significantly improved the accuracy, reliability and outcomes of traumatic, spinal, nerve surgery and many other operations with a less invasive way. The application of CAS for scaphoid fractures remains experimental. The related studies are scanty and most of them are cadaver researches. Some intrinsic defects from the registration procedure, scan and immobilization of limbs may inevitably result in deviations. Some deviations become more obvious with operations of small bones (such as scaphoid) although they are acceptable for spine and other orthopedic surgeries. We reviewed the current literatures on the applications of CAS for scaphoid operation and summarized technical principles, scan and registration methods, immobilization of limbs and their outcomes. On the basis of the data, we analyzed the limitations of this technique and envisioned its future development.

[Diagnosis and treatment of crush syndrome of chest and arm].

Objective: To investigate pathogenesis, diagnosis, and treatment of crush syndrome of chest and arm. Methods: Between January 2010 and January 2015, 5 cases of crush syndrome of chest and arm caused by pressing oneself in a coma after CO poisoning or alcoholic intoxication were treated. There were 4 males and 1 female with an average age of 36.7 years (range, 28-46 years). Two patients involved left upper limb and chest, while the other three patients involved right upper limb and chest. The crushed time ranged from 4 to 12 hours (mean, 7 hours). All 5 cases received emergency decompression and vacuum sealing drainage (VSD). After surgery, the patients were transferred to Intensive Care Unit to receive continuous renal replacement therapy (CRRT). The wounds were repaired with skin grafts after the patients' condition were stable. Results: The hospitalization time was 26-48 days (mean, 33 days). Necrosis of the skin graft occurred in 1 case, which cured after debridement and skin graft again. The skin graft survived in the other cases and the wounds healed by first intension. Five patients were followed up 12-18 months (mean, 15 months). At last follow-up, the results were excellent in all 5 cases according to the assessment criteria proposed by GU Yudong. The patients got full recovery of their upper limb activities and sensation. All the patients returned to the normal life and work. Conclusion: CO poisoning, drunkenness, and pressing oneself together will lead the crush syndrome to severe and rapid progress. The key of the treatment is a comprehensive therapy including a thorough and rapid tension reduction to save the limb function, CRRT, and correction of anemia and electrolyte imbalance.

New findings about the intrascaphoid arterial system.

We investigated the intraosseous arteries of six normal cadaveric scaphoids using red lead injection and three-dimensional reconstruction with micro-computed tomography. The arterial entrances were generally located around the dorsal ridge, the insertion of the scaphocapitate ligament and the radial part of the radioscaphocapitate ligament. Two to three trunk arteries entered the scaphoid on dorsal ridge at the level of the waist. The distal part of the scaphoid was mainly supplied by arteries from the waist. The blood supply of about 40% of proximal part of the scaphoid was poor. The blood supply from the scaphoid dorsal ridge plays an important role, not only for the proximal part of the scaphoid, but also for the waist and even the distal pole. The intrascaphoid arterial pattern may be contributory to nonunion, especially in proximal pole fractures.

Three-dimensional Intralunate Arteries Visualization with Red Lead (Pb3O4) Angiography.

BACKGROUND: The etiology of Kienböck's disease is controversial, and the blood supply is a possible pathogenic factor. The red lead (Pb3O4) angiography with micro-computed tomography (micro-CT) of lunate to investigate intralunate arteries has rarely been reported. This study aimed to investigate a new, reasonable, and simplified technique to study the intraosseous arterial pattern of normal lunates. METHODS: This study investigated the intraosseous arterial pattern of six normal cadaveric lunates through Pb3O4injection and three-dimensional reconstruction with micro-CT. The intraosseous arteries of all specimens were clearly enhanced. The data of enhanced arteries and nutrient foramina were shown as median (Q1, Q3) and analyzed with Wilcoxon signed-rank test. RESULTS: The mean number of total nutrient foramina was 2.00 (1.75, 2.00) on the palmar side and 3.50 (2.50, 4.25) on the dorsal side. The number with enhanced arteries on the palmar side was 1.00 (0.75, 2.00) and on the dorsal side was 3.50 (1.75, 4.00). There were no significant differences between the number of nutrient foramina on the palmar and dorsal sides of the lunates, no matter the total number or enhanced arteries. The intraosseous arterial pattern in normal lunates can be classified into three types: the dominate stems from the palmar side, from the dorsal side, and from both sides with anastomosis. CONCLUSIONS: The Pb3O4angiography with micro-CT is a simplified, quicker, and reliable method to study intraosseous arteries.

Microstructure study of normal lunates with micro-computed tomography.

In order to study the microstructure characteristics of normal lunate bones, eight fresh cadaver normal lunates were scanned with micro-computed tomography. High-resolution images of the micro-structure of normal lunates were obtained and we analyzed the nutrient foramina. Then nine regions of interest (ROI) were chosen in the central sagittal plane so that we could obtain the parameters of trabecular bones of ROIs. The distal lamellar-like compact structure had statistically significant differences when it was compared with the ROIs in the volar and dorsal ends of the distal cortex. The difference of diameter between the volar and dorsal foramina was significant (P<0.05). However, there was no significant difference regarding the number. The trabecular bones of the volar and dorsal distal ends had lower intensity than those of the distal central subchondral bone plate. The diameters of the nutrient foramina on the volar cortex were larger than those on the dorsal. This research provided more detailed information about microstructure of normal lunate and the nutrient foramina on cortex, and a reference for further study about diseased lunate.

Microstructure Study of Normal Lunates with Micro-computed Tomography / 华中科技大学学报（医学）（英德文版）

In order to study the microstructure characteristics of normal lunate bones,eight fresh cadaver normal lunates were scanned with micro-computed tomography.High-resolution images of the micro-structure of normal lunates were obtained and we analyzed the nutrient foramina.Then nine regions of interest (ROI) were chosen in the central sagittal plane so that we could obtain the parameters of trabecular bones of ROIs.The distal lamellar-like compact structure had statistically significant differences when it was compared with the ROIs in the volar and dorsal ends of the distal cortex.The difference of diameter between the volar and dorsal foramina was significant (P＜0.05).However,there was no significant difference regarding the number.The trabecular bones of the volar and dorsal distal ends had lower intensity than those of the distal central subchondral bone plate.The diameters of the nutrient foramina on the volar cortex were larger than those on the dorsal.This research provided more detailed information about microstructure of normal lunate and the nutrient foramina on cortex,and a reference for further study about diseased lunate.

Surgical Fixation of Fourth and Fifth Metacarpal Shaft Fractures with Flexible Intramedullary Absorbable Rods: Early Clinical Outcomes and Implications.

BACKGROUND: To avoid the irritation of tendons and soft tissues as well as hardware-related problems, we designed an intramedullary fixation with bioabsorbable rods for the treatment of the metacarpal shaft fractures. METHODS: Five patients with nine shaft fractures of the fourth and fifth metacarpi were treated with intramedullary absorbable implants and followed up with an average of 4.2 months postoperatively. RESULTS: At final follow-up, all patients achieved fracture union with no signs of inflammatory or subcutaneous effusion. There was no shortening, angulatory, or rotatory deformity. There was almost full active extension range of motion (ROM) of the metacarpophalangeal joints while the active flexion ROM of these joints was 80.7 ± 9.6°. Compared with the contralateral hand, the grip strength of the injured hand was 94.0 ± 9.6%. X-rays showed that the arch of the second to fifth metacarpal heads was smooth. There were no intramedullary lytic changes and soft tissue swellings. CONCLUSION: The intramedullary absorbable implants are a safe, simple, and practical treatment for fourth and fifth metacarpal fractures with good early clinical outcomes and no significant complications.