Spontaneous pre-axial polydactyly in Swiss mice

ABSTRACT: Spontaneous polydactyly has been described in several species, but only one report about it in Swiss mice. The aim of the current study was to report the spontaneous occurrence of pre-axial polydactyly in Swiss mice. Clinical examination showed one extra toe laterally to the first digit, in the plantar region, alopecia in the back, altered face growth anatomy and changed perineal region anatomy. Pre-axial polydactyly in the tibial side, fused metatarsals and Y-shaped free phalanges were evidenced in the radiographic images. Pre-axial polydactyly observed in the plantar region differed from that in reports on albino Swiss mice with post-axial polydactyly (Po/Po+) phenotype featured by one extra toe in the ulnar side of one, or both, front limbs, which is the dominant feature. The observed findings highlight the importance of both clinical examinations and close attention by professionals involved in rodents’ breeding on physical changes resulting from different causes, including the genetic ones, since they reveal mutations and, sometimes, new biomodels.

Is it really safe to evaluate symptomatic extensor carpi ulnaris tendon instability by magnetic resonance imaging (MRI)?

The extensor carpi ulnaris (ECU) tendon is in the sixth extensor compartment of the wrist and is isolated from other tendons by a different sheath. Extensor carpi ulnaris pathologies are characterized by pain locally localized to the wrist ulnar side. Outpatient records and wrist MRI (magnetic resonance imaging) tests were retrospectively scanned between January 2018 and July 2019. By examining the anamnesis and examination notes of the patients in the outpatient clinic records, patients with wrist ulnar side pain, pain or sensitivity on the ulnar styloid and provocation test (synergy) were assigned to the first study group (Group 1).The second study group was composed of patients who underwent wrist MR for the diagnosis or differential diagnosis of a synovial cyst around the wrist, without ulnar side pain (Group 2).While evaluating MR images in the axial plane, the depth and width of the ulnar groove, thickness of the ECU tendon were measured. The position of the ECU tendon relative to the ulnar groove and the forearm rotation during the shooting were recorded.105 cases evaluated, there were 41 cases in the symptomatic subgroup and 64 cases in the asymptomatic subgroup. Among all patients, the mean patient age was 38.05.In the evaluation according to whether cases were symptomatic or not, there was no significant relationship between being symptomatic and the degree of instability and MR withdrawal position. Our study suggests that ECU instability in MR is not a specific condition, and detection of MR in instability may not be associated with a patient’s symptoms.

Widespread Mechanic's Hands in Antisynthetase Syndrome With Anti-OJ Antibody

Mechanic's hand is a representative manifestation of antisynthetase syndrome (AS) but is observed in other forms of dermatomyositis1. This is a nonpruritic, hyperkeratotic, and scaly eruption on the ulnar side of the thumb and radial side of other fingers; occasionally the palms, fingertips, and feet are involved. However, a widespread type affecting the whole palm and fingers is extremely rare in anti-OJ antibody.

Leading Wrist Injuries in a Golfing Population. Golf Swing Biomechanics a Significant Cause of Pathology

Golf participation has increased significantly over the past 50 years. Injury rates have mirrored this increase with amateur and elite golfers suffering a similar injury incidence to rugby players. The upper limb is the second most common anatomical site of injury in this population. Wrist injury and specifically the ulnar side of the leading wrist is the most prevalent. Leading wrist injuries affect the tendons, fibrocartilage, bones and neural structures that are located on the ulnar side of the wrist and hand as well as the soft tissue aponeurosis and bony and ligamentous canals that traverse the wrist joint. The most commonly injured lateral wrist structure is the Extensor Carpi Ulnaris tendon. This is particularly liable to injury due to the forces placed on it during the golf swing. Other structures on the medial side of the leading wrist associated with golf related injury and pathology include Triangular Fibro-cartilage, the hamate bone, the bony canals through which the nerves travel, as well as the flexor aponeurosis and Flexor Carpi Ulnaris tendon. Risk injury to the medial aspect of the leading wrist is increased by the newer golfing theories and techniques which endeavour to create increase golf club head speeds by storing greater energy by a phenomenon called “lag”. Lag results in greater speed as the club head releases at impact but results in injury to the medial wrist anatomical structures. Swing biomechanics, and their alteration and augmentation are a major factor in medial wrist injury. Diagnosis of these pathologies requires careful history and examination, as well as the use of radiology and electrodiagnostic medicine to confirm the pathology and degree. Treatment is targeted to the specific disability. Classical treatments are mostly employed and usually involve rest and anti-inflammatory treatments. Newer therapies such as Platelet Rich Plasma injection and Deep Oscillation therapy have proven beneficial. Splinting is often employed on return to play. Early diagnosis and cessation of the offending activity often allays the need for surgery. The rhyme that “minutes to diagnosis means weeks to recovery” is particularly apt for medial wrist golf injuries. Surgery will be required in long standing or chronic cases. Return to play, unlike many sports injuries, will require careful golf biomechanical assessment and alteration in swing dynamics. The objective of this chapter is to identify how the new biomechanical manipulation of the wrist and specifically the leading wrist has resulted in increased injuries to this anatomical structure. The type of injury, diagnosis and treatment is discussed in detail. Club head speed is generated through a combination of improved golf club equipment, golf payer fitness and manipulation of the golf club by the left wrist resulting in increased golf club lag and torque which all contribute to wrist injuries.

Finite element analysis of different locking plate fixation methods for the treatment of ulnar head fracture

Background Ulnar head fractures are increasingly higher with the growing proportion of the elderly people. Failure to achieve a stable anatomic reduction of ulna head fracture may lead to a distal radioulnar joint (DRUJ) dysfunction and nonunion of the distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. Hence, the purpose of this study is to use finite element analysis to explain the advantages and disadvantages of ulnar-side locking plate fixation compared with dorsal-side locking plate fixation and its screw arrangement in the treatment of ulnar head fractures. Methods FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. 20 N axial compression, 50 N axial compression, 1 N∙m torsion moment, 1 N∙m lateral bending moments, and 1 N∙m extension bending moments. Under these conditions, values of the von Mises stress (VMS) distribution of the implant, peak VMS, the relative displacement of the head and shaft fragments between the fracture ends and the displacement and its direction of the models were investigated. Results The stress values of ulnar-side plates were lower than those of dorsal-side plates. And the ulnar-plate fixation system also has smaller maximum displacement and relative displacement. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions In conclusion, our study indicated that ulnar-side locking plates resulted in a lower stress distribution in the plate and better stability than dorsal-side locking plates for ulnar head fracture fixation. Adding an additional screw to the ulnar head could increase the stability of the fixation system and provide an anti-torsion function. This study requires clinical confirmation of its practicality in the treatment of ulnar head fractures. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.

Four Unusual Cases of Congenital Forelimb Malformations in Dogs

Four dogs were presented with thoracic limb deformity. After clinical and radiographic examinations, a diagnosis of congenital malformations was performed for each of them. In one case, a deformity involving both the radial and ulnar side of the distal limb was observed. Based on clinical and radiological evaluations, a diagnosis of postaxial terminal longitudinal ulnar hemimelia was performed. The term ectrodactyly was used to refer different malformations characterized by skin and soft tissue separation of the distal forelimb observed in two dogs. Simple complete uncomplicated syndactyly of the right forelimb, and complex incomplete uncomplicated syndactyly of the left forelimb were diagnosed in the fourth case. To the authors’ knowledge, ectrodactyly and simple complete uncomplicated syndactyly are very uncommon anomalies in companion animals and have been rarely documented. Moreover, postaxial terminal longitudinal ulnar hemimelia has still not been reported in dogs.

Sensate Neurovascular Island Flap for Thumb Reconstruction

Thumb pulp defects require adequate reconstruction for satisfactory sensate function and aesthetic appearance. We report a reconstructive case using a sensate neurovascular island flap raised from the ulnar side of the middle finger for a tactile thumb pad defect. The flap was elevated as a modified version of the conventional heterodigital neurovascular island flap in order to restore thumb sensation without the “double-sensibility” phenomenon. The ulnar digital nerve of the flap was sectioned at the middle phalanx level of the donor digit and coaptated to the ulnar and radial digital nerves of the thumb through end-to-side and end-to-end neurorrhaphy. The remaining radial digital nerve of the donor finger was preserved, and the proximal end of the sectioned nerve was coaptated end-to-side to the radial digital nerve to prevent neuroma formation. No postoperative complications including venous congestion were observed. This technique is a relatively simple and reliable option for reconstructing thump pulp defects.

Utilization of the autologous vein on the ulnar side of the dorsal hand for arteriovenous fistula creation

We previously described the success and usefulness of two operative techniques for creating a radial artery-first or second dorsal metacarpal vein arteriovenous fistula (AVF) in the first interdigital space of the dorsal hand using the most distal site and autologous veins in the upper limb. These techniques utilize the dorsal metacarpal veins on the radial side of the dorsal hand. Developing these ideas, we devised a novel operative technique for creating a transposed radial artery-third metacarpal vein AVF in the first interdigital space of the dorsal hand using the most distal vein on the ulnar side of the upper limb and most distal site in the upper limb. The distinctive advantage of this technique is that it can be applied to patients whose cephalic vein in the forearm and the dorsal metacarpal veins on the radial side of the dorsal hand are of a poor quality. We herein report the steps of this technique and describe its successful performance in a patient who has been on hemodialysis for 14 months without any additional vascular access interventions or postoperative complications. We consider this technique to be a valuable option in select patients who meet the applicable conditions. The creation of the first AVF as distally as possible is ideal, and it offers a further viable option of distal native vascular access that may be overlooked.

Finite element analysis of different locking-plate fixation methods for the treatment of ulnar head fracture

Background: Ulnar head fractures are increasingly higher with the growing proportion of the elderly people. Failure to achieve a stable anatomic reduction of ulna head fracture may lead to a distal radioulnar joint (DRUJ) dysfunction and nonunion of the distal radius. Due to the lack of the postoperative reporting outcomes and the biomechanical studies, it has not been well established about the optimal management of the comminuted distal ulna head fracture. Hence, the purpose of this study is to use finite element analysis to explain the advantages and disadvantages of ulnar-side locking plate fixation compared with dorsal-side locking plate fixation and its screw arrangement in the treatment of ulnar head fractures.Methods: FE models of the ulnar head fracture and the models of ulnar-side locking plate and dorsal-side plate with two or three distal screws was constructed. In order to simulate forces acting on the ulnar and the osteosynthesis material during daily-life activity in subjects who underwent reconstructive surgery, we applied three loading conditions to each model, viz. 20 N axial compression, 50 N axial compression, 1 N∙m torsion moment, 1 N∙m lateral bending moments, and 1 N∙m extension bending moments. Under these conditions, values of the von Mises stress (VMS) distribution of the implant, peak VMS, the relative displacement of the head and shaft fragments between the fracture ends and the displacement and its direction of the models were investigated. Results: The stress values of ulnar-side plates were lower than those of dorsal-side plates. And the ulnar-plate fixation system also has smaller maximum displacement and relative displacement. When adding a screw in the middle hole of the ulnar head, the values of model displacement and the peak stress in fixation system are lower, but it may evidently concentrate the stress on the middle screw. Conclusions: In conclusion, our study indicated that ulnar-side locking plates resulted in a lower stress distribution in the plate and better stability than dorsal-side locking plates for ulnar head fracture fixation. Adding an additional screw to the ulnar head could increase the stability of the fixation system and provide an anti-torsion function. This study requires clinical confirmation of its practicality in the treatment of ulnar head fractures. This study requires clinical confirmation as to its practicality in the treatment of ulnar head fracture.