New findings about the intrascaphoid arterial system

Surgical Treatment of Scaphoid Fractures: Recommendations for Management

Background: Several operative treatments exist for scaphoid fractures, varying by approach (e.g., ercutaneous, volar, or dorsal), implant type (e.g., screw or Kirschner wire), and bone raft choice (e.g., none, nonvascularized, or vascularized). Many previous systematic eviews and meta-analyses have investigated outcomes following different surgicalÚpproaches, the use of vascularized versus nonvascularized bone graft for scaphoidßracture nonunions, and treatment for specific fracture patterns. However, given the advancements n scaphoid fracture treatment in recent years, there is a need for updated treatment recommendations hat would be beneficial to hand surgeons. Purpose: We present a comprehensive review of the operative treatment of scaphoid fractures based on recent literature and propose a unified treatment algorithm for managing these fractures. Methods: The English-language literature was searched from 2002 to 2023 for high evidence level (e.g., randomized trials), review, and meta-analysis articles with the following search terms: "scaphoid, "u8220"scaphoid" AND "nonunion, " and "scaphoid" AND "malunion. " Each article was creened by the authors to determine the scaphoid fracture scenario addressed and ubsequent treatment recommendations. The findings from article reviews were then rganized by scaphoid fracture types in this manuscript. Results: A total of 95 pertinent articles were ultimately selected and used as the basis for reviewing different scaphoid fracture scenarios. A treatment algorithm was then proposed based on literature review. Conclusion: This summary of the recent literature can guide hand surgeons in addressing scaphoidßractures. Future research in scaphoid fracture treatment, particularly for nonunions, would be most beneficial n the form of systematic review, meta-analysis, or multicenter prospective randomized clinical trials. Level of Evidence: IV.

Arthroscopic Bone Grafting and Robot-assisted Fixation for Scaphoid Nonunion

OBJECTIVES

Scaphoid nonunion remains a challenging problem to manage with no general consensus on its treatment recommendations. We propose a novel minimally invasive (MIS) technique of arthroscopic bone grafting (ABG) with robot-assisted fixation for the treatment of scaphoid nonunions.

METHODS

Patients with radiographically proven scaphoid nonunion treated by this novel surgical technique were included. Following arthroscopic debridement and iliac crest bone grafting, the scaphoid was fixed percutaneously using either multiple Kirschner (K)-wires or a headless compression screw using a robotic navigation system.

RESULTS

Six male patients with an average age of 29.2 years were enrolled. Four patients had scaphoid waist fractures, and the other two were proximal pole fractures. During wrist arthroscopy, punctate bleeding of the proximal scaphoid fragment was observed in four out of the six patients. Half of the patients were fixed using a headless compression screw and the other half using multiple K-wires. All the guidewires were placed with a single-attempt using the robotic navigation system. Postoperatively, all the scaphoid fractures had complete radiographic union by 16 weeks. At a mean follow-up of 18.3 months, there were significant improvements in wrist range of motion, grip strength, and patient-rated outcomes. No intraoperative or early postoperative complications were encountered in any of our patients.

CONCLUSION

Arthroscopic bone grafting with robot-assisted fixation is a feasible and promising therapeutic option for scaphoid nonunions, regardless of the vascularity of the proximal pole fragment. This novel technique allows for anatomic restoration of the scaphoid alignment and accurate, targeted placement of implants into the scaphoid nonunion site within a single-attempt using a robotic navigation system.

The morphologic and morphometric features of the triquetrum

Fractures of the triquetrum are the second most common form of isolated carpal bone fracture after the scaphoid. However, data on triquetrum morphology and morphometry are sparse. The aim of this study was to describe the morphology of triquetrum using anatomical landmarks, evaluate its morphometric features, and determine its vascular entry points. The morphological and morphometrical features of 87 adult dry triquetral bones (39 left, 48 right) were determined by measuring length, width and thickness. The number and locations of nutrient foramina wider than 0.5 mm were recorded. Mean length, width and thickness were 17.37 mm (range, 14.26-22.13), 12.65 mm (range, 10.37-15.85) and 11.41 mm (range, 8.98-18.23), respectively. The facet articulating with the pisiform was oval in 40 bones, round in 8 and amorphous (neither round nor oval) in 39. The mean length of the interarticular ridge was 7.09 ± 0.9 mm. The mean number of nutrient foramina was significantly greater on the dorsal than on the other aspects. The dorsal predominance of nutrient foramina makes the bone weaker in the dorsal region, which could explain why fractures are more common in this region. Also, the dorsal aspect is rich in blood supply, which could explain why avascular necrosis is less common in triquetral fractures. As most of the vascularization is on the dorsal side, there is need for caution when performing triquetrum surgery. LEVEL OF EVIDENCE: Level 2.

Clinical and Epidemiological Features of Scaphoid Fracture Nonunion: A Hospital-Based Study in Beijing, China

Objective

Studies exploring the epidemiological characteristics of scaphoid fracture nonunion are important to understand the causes and lead to effective prevention strategy. However, such knowledge is limited especially in China. This study aims to reveal the clinical and epidemiological features of scaphoid fracture nonunion in Chinese patients.

Methods

This was a retrospective study, which was based on patients with scaphoid fracture nonunion treated in a Chinese national orthopedic referral center from 1 August 2009 to 1 August 2020. The basic demographic and clinical characteristics, including gender, age at diagnosis of scaphoid fracture nonunion, dominant hand, the location of fracture, the side, the causes of the injury, age of the injury, age of the treatment for scaphoid fracture nonunion, and the delay period, were retrieved from the medical records. The patients were divided into a non‐delay group and a delay group based on whether they had visited the doctor within 1 month after the injury. Scaphoid fracture was classified into the proximal, waist, and distal fractures according to the location. The t‐test or Mann–Whitney U test was used to compare the difference between groups when the dependent variable is continuous, while a chi‐square test was used when the dependent variable is categorical.

Results

A total of 363 patients were included in this study. The mean age at the diagnosis of scaphoid fracture nonunion was 32 (ranging from 14 to 78). Waist fracture nonunion (76.5%) was most common. Among the 169 patients who sought medical care within 1 month after the injury (non‐delay group), more than half (90 cases) were misdiagnosed. 23 cases could not recall the injury, so the time of delay could not be determined. Among the 171 patients who did not seek medical care for acute injury (delay group), the average time was 52 months between the initial injury and the treatment. The proportion of waist nonunions was higher among patients in the delay group than that in the non‐delay group.

Conclusions

Nonunion of scaphoid fracture is caused mainly by delayed treatment and misdiagnosis in China, suggesting that timely treatment and improved diagnosis could lower the prevalence. The fracture location may be a factor contributing to the delaying of seeking medical care.

Volar rerouting of the 1,2 intercompartmental supraretinacular artery vascularized bone graft for middle and distal scaphoid nonunions

BACKGROUND

The bone graft vascularized by the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) placed on the scaphoid by a dorsal approach is a technique used to treat scaphoid nonunions with avascular necrosis of the proximal pole and without significant bone loss or carpus collapse. We present the results of patients treated with a volar rerouting of the 1,2 ICSRA graft under the tendons of the first extensor compartment to treat more distal scaphoid nonunions than the proximal pole. The aim of this study was to assess the clinical and radiological outcomes of patients operated with this technique with the hypothesis that it would allow to treat more distal nonunions than those of the proximal pole.

PATIENTS AND METHODS

This retrospective study involved patients treated by a volar rerouting of the 1,2 ICSRA graft for nonunions of the middle and distal thirds of the scaphoid. Assessments included clinical outcomes and radiological bone consolidation. QuickDASH and Mayo Wrist scores were computed. Range of motion and grip strength were evaluated for both the operated and the contralateral sides.

RESULTS

Nineteen patients were followed-up for 33 months (range: 6-75). Mean postoperative QuickDASH score was 10 (range: 0-45), and mean Mayo wrist score was 85 (range: 50-100). Flexion and extension, ulnar and radial deviations were statistically different between the affected and healthy sides (p<0,05). Consolidation was achieved in 17 patients (89%).

DISCUSSION

This technical modification allowed good functional outcomes and scaphoid consolidation. It expands the classic indications of the vascularized 1,2 ICSRA bone graft to more distal nonunions than the proximal pole.

LEVEL OF EVIDENCE

IV.

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.

Distal Versus Conventional Transradial Artery Access for Coronary Angiography and Intervention: A Meta-Analysis

BACKGROUND

Distal transradial artery access (dTRA) through the anatomical snuffbox is a novel approach for performing coronary angiography and interventions. However, the safety and efficacy of dTRA as compared to conventional TRA (cTRA) remains unknown. We aim to evaluate the outcomes of dTRA versus cTRA for coronary angiography and intervention.

METHODS

Electronic search of the National Library of Medicine PubMed and Cochrane Library databases was performed until April 2019 for studies comparing the clinical outcomes of dTRA approach versus conventional TRA (cTRA) approach in coronary angiography and interventions. Random-effects DerSimonian-Laird risk ratios (RR) were calculated. The main outcome was failure of access site utilization. Other outcomes included access site hematoma, radial artery spasm, dissection, and occlusion.

RESULTS

Five studies (4 observational and 1 randomized controlled) with a total of 6746 patients (dTRA n = 3209 and cTRA n = 3537) were available for analysis. The failure rate was similar in dTRA and cTRA groups (5.26% versus 3.75%; RR = 1.36; 95%CI 0.41-4.48; p = 0.62). Similarly, no difference was observed between dTRA and cTRA in regards to access site hematoma (1.20% versus 1.24%, RR = 1.01; 95%CI 0.49-2.07; p = 0.99), radial artery spasm (1.42 versus 3.84%, RR = 0.91; 95%CI 0.32-2.62; p = 0.86), or radial artery dissection (0.11 versus 0.20%, RR = 0.63; 95%CI 0.18-2.16; p = 0.46). The rate of radial artery occlusion was lower with dTRA (2.30 versus 4.86%, RR = 0.51; 95%CI 0.32-0.81; p = 0.004) as compared to cTRA.

CONCLUSION

Distal TRA appears to be a safe and effective alternative to conventional TRA. The outcomes of this novel technique warrant further randomized studies.

Qualitative and quantitative analysis of patellar vascular anatomy by novel three-dimensional micro-computed-tomography: Implications for total knee arthroplasty

BACKGROUND

The blood supply of the patella is highly related to patellofemoral complications in total knee arthroplasty. The purpose of this study was to determine (1) the dominant blood supply for the patella and (2) the anatomic characteristics of the extraosseous and intraosseous vascularity of the patella.

METHODS

In 13 fresh cadaveric knees, the femoral arteries were cannulated and perfused with a lead-based contrast agent. Patellae were harvested and scanned with a micro-computed-tomography scanner. The three-dimensional microarchitecture of the vascularity was reconstructed and evaluated. For the volumetric analysis, the vessel densities of the anterior, central and subchondral sides were compared.

RESULTS

A well-anastomosed prepatellar vascular network was found to cover the anterior surface of the patella, with main arteries from multiple directions, yielding 18.8 ± 3.1 (standard deviation) intraosseous branches into the patella. Along the intraosseous branches of the prepatellar vascular network, vessel density decreased (P < 0.001) by 0.54 ± 0.29% on the anterior side, 0.40 ± 0.24% on the central side and 0.23 ± 0.19% on the subchondral side. Arteries in the infrapatellar fat pad produced 5.1 ± 1.8 intraosseous branches, mainly located in the distal apex. Almost no arteries penetrated into the patella from the quadriceps tendon, patellar ligament or medial/lateral retinaculum.

CONCLUSION

The prepatellar vascular network is the dominant blood supply. Close exposure and extensive dissection around the patella should be avoided to preserve the prepatellar vascular network. The infrapatellar fat pad was recommended to be preserved when a lateral reticulum release was performed.

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.