Intra-Articular Distal Radius Fracture with Lunate Fossa Rotated and Associated Lesions: Radiologic Analysis

Introduction: Intra-articular distal radial fractures in young patients occur in high energy trauma which can lead to a combination of bone and ligaments lesions. An articular step superior to 2 mm is pejorative, for that an adequate radiologic analysis is necessary accessing to the best surgical treatment. The purpose of our study was to investigate this type of fracture and expose radiologic analysis (radiograph and CT-scan) of bone and ligamentous associated lesions of this specific twisted lunate facet fracture for recognizing it and accessing to the best surgical treatment. Patients and Methods: Seven patients with severely displaced type 4 articular fractures of the distal radius whose wrists had been exposed to violent compression are reported in our series, they are required open treatment for the reduction and fixation of disrupted articular surfaces by using an antero-medial approach which allows direct access to the fragment of the lunate facet and easier visualization of the distal radio-ulnar joint. Results: All the patients were clinically examined with antero-posterior and lateral X ray, completed by a CT scan, all the fractures were type IV according to Melone classification. In all of our seven cases there was a lesion of the distal radioulnar joint (DRUJ) identified in the CT scan. The CT scan allowed us to individualize well the void of the lunate fossa and calculate his exact degree of rotation, which is very important for planning therapeutic management. Discussion: In all of our cases the CT scan was to expose all of the osseous and ligamentous injuries;in the sagittal reconstruction we were able to objectify and calculate the exact degree of the rotation of the lunate fossa fragment;in the frontal reconstruction the void of the lunate fossa is visible and in the axial reconstruction we can determine the incongruence of the distal radio-ulnar joint (DRUJ). Intra-articular involvement has long been recognized as a poor prognostic factor in fractures of the distal radius. However, despite early studies reporting poor results with non operative treatment for these injuries, most authors opposed operative intervention, due to lack of a good radiological analysis and the CT scan;knowledge that a number of studies have shown that inadequate reduction of intra-articular distal radius fractures leads to the development of arthritis.

Application of 3 dimension-printed injection-molded polyether ether ketone lunate prosthesis in the treatment of stage Ⅲ Kienböck’s disease: A case report

BACKGROUND Polyether ether ketone(PEEK)is a high-performance medical polymer,and there are some clinical cases of PEEK prosthesis implantation.However,application of 3D-printed injection-molded PEEK lunate prosthesis for treatment of stage Ⅲ Kienböck’s disease has not been reported.This study’s purpose was to analyze the clinical efficacy of 3D-printed injection-molded PEEK lunate prosthesis in the treatment of stage Ⅲ Kienböck’s disease and thus provide a good therapeutic choice for Kienböck’s disease.CASE SUMMARY We report a patient with stage Ⅲ Kienböck’s disease.With the healthy lunate bone as reference,3D lunate reconstruction was performed using a mirroring technique.A PEEK lunate prosthesis was prepared by 3D printing and injection molding,and then it was inserted into the original anatomical position after removing the necrotic lunate bone.Wrist pain and function,anatomical suitability of the lunate prosthesis,and complications were evaluated and analyzed postoperatively.At the last visit(one year after surgery),the range of motion,grasp force,visual analog scale score and Cooney score of the affected wrist were significantly improved,and postoperative X-ray examination indicated that the lunate prosthesis had good anatomical suitability for adjacent bony structures.CONCLUSION The 3D-printed injection-molded PEEK lunate prosthesis demonstrated definite efficacy in treating stage Ⅲ Kienböck’s disease.

Influence of volar margin of the lunate fossa fragment fixation on distal radius fracture outcomes:A retrospective series

BACKGROUND Distal radius fractures accompanied by the volar margin of the lunate fossa(VMLF)lesions are often overlooked or inadequately reduced in clinical practice.AIM To investigate the impact of VMLF fragment in distal radius fractures on the stability and function of the wrist joint.METHODS This was a retrospective study of patients with distal radius fractures who underwent surgical treatment between January 2013 and December 2017.The patients were divided into two groups according to whether the VMLF fragments were fixed or not.X-rays and computed tomography were performed before surgery,immediately postoperatively,and at 1,3,and 6 mo to measure the scapholunate angle,radiolunate angle,capitolunate angle,and effective radiolunate flexion(ERLF).The Mayo wrist score and disabilities of the arm,shoulder,and hand(DASH)score were determined at 1 year.RESULTS Thirty-five patients were included.There were 15 males and 20 females.Their mean age was 52.5±14.3(range:19-70)years.There were 38 wrists(17 on the left side,15 on the right,and three bilateral;16 in the fixed group,and 22 in the unfixed group).The interval between trauma and surgery was from 1 h to 1 mo.The incidence of postoperative wrist instability in the unfixed group(86.4%)was higher than in the fixed group(25.0%)(P≤0.001).Ten patients had ERLF>25°in the unfixed group and none in the fixed group(P=0.019).The Mayo wrist score was 94±5.7 in the fixed group and 68±15.1 in the unfixed group(P<0.001).The DASH score was 4.6±2.5 in the fixed group and 28.5±19.5 in the unfixed group(P<0.001).CONCLUSION Injuries of VMLF,even small fractures,might damage the radial-lunar ligament,leading to postoperative wrist instability,sagittal force line imbalance,and poor recovery of wrist joint function.

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.

Lunate dislocation with avulsed triquetral fracture: A case report

BACKGROUND Lunate dislocation is an uncommon traumatic wrist injury that require prompt surgical management.Misdiagnosis or delayed treatment often leads to a poor outcome.Open reduction and surgical repair of disrupted ligaments are done in most cases to prevent long-term joint dysfunction.However,this method has certain limitations that include partial functional improvement,which poses a high risk for degenerative arthritis and wrist instability.CASE SUMMARY A 37-year-old man presented to the Emergency Department of our hospital following a motorcycle accident.Physical examination revealed swelling and tenderness of the right hand and wrist.The patient was initially misdiagnosed with a wrist contusion by an emergency physician,but was eventually diagnosed with lunate dislocation associated with a triquetral avulsed fracture,indicated for open reduction and ligament repair.We performed closed reduction and two Kirschner wire fixations following Tavernier’s method.The injured hand was protected with a standard short-arm orthosis for one month.The patient returned to normal daily work without discomfort at five months postoperatively.Encouragingly,there was no lunate necrosis or arthritis in the latest radiologic examinations.CONCLUSION This case provides evidence that the closed reduction technique for addressing such cases can reduce soft tissue destruction.

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

Background： The etiology of Kienb-ck＇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 Pb3O4 injection 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 Pb3O4 angiography with micro-CT is a simplified, quicker, and reliable method to study intraosseous arteries.

Slippery Surface of Nepenthes alata Pitcher： The Role of Lunate Cell and Wax Crystal in Restricting Attachment Ability of Ant Camponotus japonicus Mayr

This study attempts to investigate how the slippery surface of Nepenthes alata pitchers restricts the attachment ability of ant Camponotus japonicus Mayr, via climbing behavior observation and friction force measurement. Ants exhibited ineffective climbing behaviors and rather small friction forces when attached to upward-oriented slippery surfaces, but opposite phenomena were shown when on inverted surfaces. Friction forces of intact, claw tip-removed and pad-destroyed ants were measured on intact and de-waxed slippery surfaces, exploring the roles of wax crystals and lunate cells in restricting ant＇s attachment. On downward-directed slippery surfaces, greater forces were exhibited by intact and pad-destroyed ants; on the two slippery sur- faces, pad-destroyed ants presented slightly smaller forces and clawless ants generated considerably smaller forces. Somewhat different force was provided by clawless ants on upward and downward oriented slippery surfaces, and slightly higher force was shown when ants climbed on wax-removed surface. Results indicate that the lunate cells contribute greatly to decrease the friction force, whereas the wax crystals perform a supplementary role. Mechanical analysis suggests that the directionally growing lunate cells possess a sloped structure that effectively prevents the claw＇s mechanical interlock, reducing the ant＇s attachment ability considerably. Our conclusion supports a further interpretation of slippery surface＇s anti-attachment mecha- nism, also provides theoretical reference to develop biomimetic slippery plate to trap agricultural insect.

Capitate transposition to replace necrotic lunate bone with a pedicle for Kienbock's disease:review of 30 cases

Objective To investigate the clinical application of capitate transposition with a pedicle in 30 cases of Kienbock’s disease.Methods The external diameter and curvature of the capitate head and proximal facet of the lunate were observed and measured in 100 specimens. The vascularity of the capitate was also investigated. Capitate transposition with a vascular pedicle was designed to treat 30 patients with advanced Kienbock’s disease who were followed up for 2 to 16 years and then analyzed according to Evans's scoring system.Results Aseptic necrosis did not occur in the transposed capitate because the pedicle fascia including the dorsal branch of the anterior interosseous artery ensured the vascularity of proximal two thirds of the capitate. The transposed capitate reestablished a relatively pain-free radiocarpal joint. Follow-up results showed that grip strength and motion arc were up to 70% of contralateral side.Conclusions Capitate transposition with a pedicle is a reliable treatment method for advanced Kienbock’s disease,with favorable prognosis for at least five years postoperatively.