The volar anatomy of the distal radius--an MRI study of the FCR approach

Antibody-Dependent Enhancement: ″Evil″ Antibodies Favorable for Viral Infections

The pandemics caused by emerging viruses such as severe acute respiratory syndrome coronavirus 2 result in severe disruptions to public health. Vaccines and antibody drugs play essential roles in the control and prevention of emerging infectious diseases. However, in contrast with the neutralizing antibodies (NAbs), sub- or non-NAbs may facilitate the virus to enter the cells and enhance viral infection, which is termed antibody-dependent enhancement (ADE). The ADE of most virus infections is mediated by the Fc receptors (FcRs) expressed on the myeloid cells, while others are developed by other mechanisms, such as complement receptor-mediated ADE. In this review, we comprehensively analyzed the characteristics of the viruses inducing FcRs-mediated ADE and the new molecular mechanisms of ADE involved in the virus entry, immune response, and transcription modulation, which will provide insights into viral pathogenicity and the development of safer vaccines and effective antibody drugs against the emerging viruses inducing ADE.

The prevalence and distribution of the flexor carpi radialis brevis muscle in the Turkish population

The flexor carpi radialis brevis (FCRB) is a very rare anomalous muscle that is usually asymptomatic but may cause various pathologies, such as radial-sided wrist pain. The aim of this study was to determine the prevalence of FCRB in the Turkish population, its location, and sex differences. Forearm, wrist, and hand magnetic resonance images of 849 individuals aged 18-65 years were retrospectively evaluated in this study. The survey found an FCRB prevalence of 4%, with a prevalence of 3.6% among women and of 4.7% among men. However, the difference between the sexes was not statistically significant (p = 0.629). The origin of all 34 FCRBs identified was the distal third of the anterior aspect of the radius; the insertion site of 28 was the second metacarpal bone, whereas that of the remaining 6 was the os trapezium. In conclusion, the data of this study report the prevalence of FCRB for the first time in the Turkish population, which will contribute to radiological and surgical evaluations in the region and help in early and accurate diagnosis of various pathological conditions that may be caused by FCRB.

Absence of Flexor Carpi Radialis Identified During Volar Approach for Fixation of Distal Radius Fracture: A Case Report

Introduction

Volar locking plate fixation of distal radius fractures is commonly performed because of its good clinical outcomes. The flexor carpi radialis (FCR) approach is one of the most popular approaches to dissecting the volar side of the distal radius because of its simplicity and safety. We describe an extremely rare case of an absent FCR identified during a volar approach for fixation of a distal radius fracture.

Case Report

A 40-year-old male with comminuted distal radius fracture underwent surgery using the usual FCR approach and volar locking plate. We could not identify the absence of the FCR tendon preoperatively because of severe swelling of the distal forearm. At first, we wrongly identified the palmaris longus (PL) tendon as the FCR because it was the tendinous structure at the most radial location of the volar distal forearm. When we found the median nerve just radial to the PL tendon, we were then able to identify the anatomical abnormality in this case. To avoid iatrogenic neurovascular injuries, we changed the approach to the classic Henry's approach.

Conclusion

Although the FCR approach is commonly used for fixation of distal radius fractures because of its simplicity and safety, this is the first report of complete absence of the FCR during the commonly performed volar approach for fixation of a distal radius fracture, to our knowledge. Because the FCR is designated as a favorable landmark because of its superficially palpable location, strong and thick structure, and rare anatomical variations, there is the possibility of iatrogenic complications in cases of the absence of the FCR. We suggest that surgeons should have a detailed knowledge of the range of possible anomalies to complete the fixation of a distal radius fracture safely.

Interpretations of the Term "Watershed Line" Used as Reference for Volar Plating

Objective  The objective of this systematic review is to provide an overview of all interpretations of the definition of the watershed line used in literature. Methods  The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed for this review. A comprehensive search was performed for definitions of the watershed line given in literature. A total of 32 studies giving an explicit interpretation of the definition of the watershed line or anatomical reference for plate positioning in writing and/or imaging were included. Results  In 32 studies, we found eight different landmarks used to refer to the watershed line or correct plate positioning. Five studies used two different soft tissue landmarks. Six different bony landmarks were described in 24 studies. These could further be subdivided into three anatomical interpretations, described in seven studies, in which the term "watershed line" is explained as a distinguishable anatomical line, and two surgical interpretations, described in 15 studies, which are purely reflecting the optimal location of the volar plate. One interpretation of the watershed line described in two studies combined both anatomical and surgical landmarks. Conclusion  The (mis)interpretation of the definition of the term "watershed line" as described by Orbay is subject to the type of landmarks and purpose used: soft tissue or bony landmarks and an anatomical or a surgical purpose. A clear distinction can be made between interpretations using bony landmarks, as the true watershed line is defined and definitions using soft tissue landmarks, which might represent the reference points surgeons use in clinical practice.

The Watershed Line of the Distal Radius: Cadaveric and Imaging Study of Anatomical Landmarks

Background  Placement of volar plates remains a challenge as the watershed line may not be an easy-identifiable distinct line intraoperatively. Objectives  The main objective of this article is to define how anatomical landmarks identifiable upon the volar surgical approach to the distal radius relate to the watershed line. Methods  We identified anatomical landmarks macroscopically upon standard volar approach to the distal radius in 10 cadaveric forearms and marked these with radiostereometric analysis (RSA) beads in cadaveric wrists. The RSA beads were then referenced against the volar osseous structures using quantification of three-dimensional computed tomography and advanced imaging software. Results  The mean measurements were the radial and ulnar prominences 11.1 mm and 2.1 mm proximal to the joint line of the distal radius, respectively. The interfossa sulcus was 0.3 mm proximal and 3 mm dorsal to the ulnar prominence. The watershed line was between 3.5 (minimal) and 7.6 (maximal) mm distal to the distal line of insertion of the pronator quadratus. Conclusion  The watershed line is situated distal to the pronator quadratus, but with a wide variability making it an impractical landmark for plate position. The osseous ulnar prominence is a good anatomical reference for safe plate positioning, as it is located on the watershed line and easily palpated at surgery. One should keep in mind the sulcus-the point on the watershed line where the flexor pollicis longus runs-can be situated just proximal to the ulnar prominence. Clinical Relevance  To provide anatomical landmarks that are easy to identify upon surgical approach without the direct need for intraoperative imaging.

MRI Study on the Distance between the Distal Radius and the Flexor and Extensor Tendons: Is There Any Room for Error/Hardware?

Purpose  This study aims to quantify the distances between the cortex of the distal radius and flexor and extensor tendons. Methods  We analyzed 50 magnetic resonance images (MRI) of intact wrist without pathology. The distances between the volar cortex and the flexor pollicis longs (FPL), index flexor digitorum profunduns (FDPi), flexor digitorum profundus (FDP), and flexor digitorum superficialis (FDS) were measured at the level of the watershed line and 3- and 6-mm proximal to this level. The distances between the dorsal cortex and the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor pollicis longus (EPL), extensor indicis proprius (EIP), and the extensor digitorum communis (EDC) were measured at the level of Lister's tubercle and 5-mm distal to this level. Analysis was descriptive. Results  At the watershed line, the FPL, FDPi, FDP, and FDS were located at an average of 3.1, 2.4, 3.6, and 5.1 mm, respectively, volar to the volar cortex. The distances of the FDP and FDS increased at 3-mm proximal to the watershed line and increased for all four tendons at 6-mm proximal to the watershed line. Dorsally, at Listers' tubercle the ECRL, ECRB, EPL, EIP, and EDC were identified at an average of 0.7, 0.5, 0.5, 2.6, and 3.2 mm, respectively, dorsal to the dorsal cortex of the distal radius. At 5-mm more distal, these tendons were located on average 1.2, 1.0, 0.7, 1.9, and 1.8 mm, respectively, dorsal to the dorsal cortex. Conclusion  On the volar side, on average there is enough room for a volar plate when staying proximal to the watershed line. On the dorsal side, there is virtually no room for protruding screws as physical anatomical space is limited to a maximum of 0.7 mm from cortex to the closest tendon (the FDP), with screw increments being 2 mm. Level of Evidence  This is a Level II Study.

Porcine FcεRI Mediates Porcine Reproductive and Respiratory Syndrome Virus Multiplication and Regulates the Inflammatory Reaction

Porcine reproductive and respiratory syndrome virus (PRRSV) shows characteristic antibody-dependent enhancement (ADE) of infection and causes porcine systemic inflammation, which is similar to a type I allergic reaction; however, the role of porcine FcεRI in ADE is still unclear. In this study, the expression of different Fc receptors (FcRs) on macrophages was investigated in a PRRSV 3D4/21 cell infection model in the presence or absence of PRRSV antibody. The transcription level of FcγII and FcεRI was significantly up-regulated under PRRSV-antibody complex infection. Internalization and proliferation of PRRSV were promoted by the ADE mechanism when FcεRI was expressed in permissive 3D4/21 cells and the non-permissive cell line HEK 293T. Transcriptome sequencing data showed that the expression levels of AKT, ERK and other signal molecules in the anti-inflammatory pathway were significantly increased, especially in the cells infected with the PRRSV-antibody immune complex. Inflammatory regulatory molecules such as PLA2G6, LOX, TRPM8 and TRPM4 were significantly up-regulated following PRRSV infection but significantly down-regulated in the cells infected with the PRRSV-antibody immune complex. Our results demonstrated that FcεRI could be involved in PRRSV ADE, the antigen presenting process and regulation of the inflammatory response during PRRSV infection, which provides new insights into PRRSV infection mediated by FcεRI and the PRRSV-antibody immune complex.

Absence of flexor carpi radialis identified during volar approach for fixation of distal radius fracture: a case report

Background

Volar locking plate fixation of distal radius fractures is commonly performed because of its good clinical outcomes. The flexor carpi radialis (FCR) approach is one of the most popular approaches to dissecting the volar side of the distal radius because of its simplicity and safety. We describe an extremely rare case of an absent FCR identified during a volar approach for fixation of a distal radius fracture.

Case presentation

A 59-year-old woman with distal radius fracture underwent surgery using the usual FCR approach and volar locking plate. We could not identify the absence of the FCR tendon preoperatively because of severe swelling of the distal forearm. At first, we wrongly identified the palmaris longus tendon as the FCR because it was the tendinous structure at the most radial location of the volar distal forearm. When we found the median nerve just radial to the palmaris longus tendon, we were then able to identify the anatomical abnormality in this case. To avoid iatrogenic neurovascular injuries, we changed the approach to the classic Henry’s approach.

Conclusions

Although the FCR approach is commonly used for fixation of distal radius fractures because of its simplicity and safety, this is the first report of complete absence of the FCR during the commonly performed volar approach for fixation of a distal radius fracture, to our knowledge. Because the FCR is designated as a favorable landmark because of its superficially palpable location, strong and thick structure, and rare anatomical variations, there is the possibility of iatrogenic complications in cases of the absence of the FCR. We suggest that surgeons should have a detailed knowledge of the range of possible anomalies to complete the fixation of a distal radius fracture safely.

[Effectiveness comparison between minimally invasive surgery and traditional open reduction internal fixation in treatment of unstable distal radial fractures]

Objective

To compare the effectiveness of minimally invasive percutaneous internal fixation and traditional open reduction via Henry approach and internal fixation in the treatment of unstable distal radial fractures.

Methods

Fifty-six patients with unstable distal radial fractures that met the selection criteria between October 2013 and December 2014 were randomly divided into minimally invasive group (26 cases) and traditional group (30 cases). They were treated with oblique T-shaped locking plate internal fixation via minimally invasive percutaneous approach or traditional Henry approach. There was no significant difference in gender, age, side, causes of injury, fracture classification, and time from injury to operation between 2 groups ( P>0.05). The length of incision, operation time, intraoperative blood loss, hospitalization time, and fracture healing time were recorded in 2 groups. The difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation were compared between 2 groups. The visual analogue scale (VAS) score, the percentage of the lateral wrist flexion and extension range, forearm rotation, and the hand grip strength (recorded as FS%, FR%, and HG% , respectively) were compared between 2 groups at 4 weeks and 3 months postoperatively. The wrist function was evaluated through the disability of arm-shoulder-hand (DASH) scores at 3 months postoperatively.

Results

The length of incision, operation time, intraoperative blood loss, and hospitalization time in minimally invasive group were significantly less than those in traditional group ( P<0.05). The incisions of 2 groups were all achieved primary healing. All patients were followed up 10-16 months (mean, 12.6 months). There was no radial artery injury, screw too long, or screw entering the joint space. In minimally invasive group, 1 patient had the symptoms of median nerve irritation after operation, and recovered completely at 1 month; in traditional group, there were 2 cases of tendon irritation after operation. There was no significant difference in the fracture healing time, the difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation between 2 groups ( P>0.05). At 4 weeks after operation, the VAS score in minimally invasive group was significantly less than that in traditional group, and the FS%, FR%, and HG% were significantly higher than those in traditional group ( P<0.05). There was no significant difference in above indicators between 2 groups at 3 months after operation ( P>0.05). The DASH score in minimally invasive group was significantly less than that in traditional group at 3 months after operation ( t=-5.308, P=0.000). The patient's aesthetic evaluation of postoperative wound in minimally invasive group was better than in traditional group.

Conclusion

For treatment of unstable distal radial fractures, the metacarpal minimally invasive internal fixation has the advantages of smaller wound, incisional concealment, and quicker recovery of wrist joint.

The EFCR Approach and the Radial Septum-Understanding the Anatomy and Improving Volar Exposure for Distal Radius Fractures: Imagine What You Could Do With an Extra Inch

Locked volar plating is the most common surgical procedure to address distal radius fractures. The extended flexor carpi radialis approach continues to be an excellent method for visualizing distal radius fractures and applying a volar plate. A new understanding of the anatomy allows for better visualization and reduction of the many different distal radius fracture patterns surgeons commonly see. Within the extended flexor carpi radialis approach, we describe the radial septum in further detail including the anatomy which comprises the radial septum triangle. Knowledge of this area allows for better visualization, more anatomic reductions, and fewer complications.

Anatomic considerations when performing the modified Henry approach for exposure of distal radius fractures

BACKGROUND

Identify the proximity of anatomic structures during the modified Henry approach (MHA).

METHODS

Distances between median nerve (MN), palmar cutaneous branch (PCB), radial artery (RA) and the flexor carpi radialis (FCR) were measured at the wrist crease (WC), 5 and 10 cm proximal in 16 fresh frozen cadavers. The FPL origin and innervation was measured.

RESULTS

Most at risk was the MN proximally and the PCB distally while the RA was safe. Innervation occurred at the proximal third of the FPL's origin along the ulnar aspect.

CONCLUSION

The MHA is safe when understanding the proximity of structures.

MRI Evaluation of Achilles Tendon Rotation and Sural Nerve Anatomy: Implications for Percutaneous and Limited-Open Achilles Tendon Repair

BACKGROUND

Limited-open and percutaneous Achilles tendon (AT) repair techniques have limited visibility, which may result in sural nerve violation and poor tendon targeting. The goal of this study was to assess the in vivo rotation of the AT and its distance to the sural nerve in ruptured and nonruptured ATs to develop guidelines to aid in limited-open and percutaneous repair techniques.

METHODS

A retrospective review was conducted to identify magnetic resonance imaging (MRI) studies of patients with ruptured and healthy (nonruptured) ATs. AT rotation and distance to the sural nerve in the anterior-posterior (A-P) and medial-lateral (M-L) planes were measured at the level of and proximal to the ankle.

RESULTS

The AT was externally rotated in both ruptured and nonruptured cohorts. Ruptured ATs showed greater external rotation than nonruptured ATs at the ankle (15.8 ± 16.2 degrees vs 5.9 ± 9.0 degrees, P = .008) but not at 10 cm proximal to the tendon's insertion (10.9 ± 10.9 degrees vs 6.1 ± 8.4 degrees, P = .139). Proximal AT rotation was negatively correlated with rupture height (r = -0.477, P = .029). At 4 cm proximal to the AT insertion, the sural nerve was closer anteriorly to and farther laterally from the AT in ruptures than in nonruptures (P < .001). At 10 cm proximal to the AT insertion, the sural nerve was farther posteriorly and laterally from the AT in ruptures than in nonruptures (P = .027 and P < .001, respectively).

CONCLUSION

We found that the AT was more externally rotated in ruptured than in nonruptured tendons at the ankle and that its distance to the sural nerve differed between the 2 cohorts in the A-P and M-L planes, likely due to increased AT rotation and swelling with ruptures. To minimize sural nerve injury and improve tendon targeting, we suggest an external rotation of 11 degrees at the proximal end of the rupture and 16 degrees at the distal end when using percutaneous and limited-open AT repair devices to try to minimize sural nerve violation and increase tendon capture, which can decrease rates of complication and rerupture.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Minimally invasive percutaneous plate osteosynthesis for distal radius fractures with long-segment metadiaphyseal comminution

INTRODUCTION

Distal radius fractures with both metaphyseal and diaphyseal comminution are commonly encountered injuries due to high-energy trauma. However, effectively treating patients with this disease remains challenging for the surgeon.

HYPOTHESIS

The goal of this study was to evaluate the outcomes of minimally invasive percutaneous plate osteosynthesis (MIPPO) technique for distal radius fractures with long-segment metadiaphyseal comminution.

MATERIAL AND METHODS

Nine patients with distal radius fractures involving long-segment metadiaphyseal comminution were treated with MIPPO from June 2011 to May 2012. Radiograph index, the range of motion of the wrist and forearm, grip strength, the Disabilities of the Arm, Shoulder, and Hand (DASH) score were assessed at final follow-up. Additionally, time to bone healing, time to return to work or activity, and postoperative complications were also recorded.

RESULTS

All nine fractures healed by 13±1.3 weeks postoperatively. At an average follow-up of 15.9±3.6 months, the radiographs revealed a mean radial inclination of 18.2±2.7°, a mean volar tilt of 10.7±3.2°, and a radial shortening of 2.3±1.0mm. Nine patients had excellent wrist function according to the DASH score, range of motion, and grip strength. Except one patient experienced delayed healing of the distal incision, no complications occurred. All patients resumed work or activity within 16.2±1.9 weeks.

DISCUSSION

Volar MIPPO is a safe and effective surgical treatment method for distal radius fractures with long-segment metadiaphyseal comminution, with few potential complications.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Treatment strategy for distal radius fractures with ipsilateral arteriovenous shunts

PURPOSE

To describe our management of 3 patients with chronic renal failure who sustained distal radius fractures in limbs containing dialysis shunts.

METHODS

The 3 patients were 48-61 years old, and 2 of them were men. Because the injured limbs contained arteriovenous shunts, tourniquets were not used. Volar locking plate fixation was applied via the Henry approach. The patients' grip strength; visual analog scale scores; Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores; modified Mayo scores; and their range of wrist joint motion were assessed during the final follow-up examination. In addition, complications and the presence/absence of dysfunction of the forearm shunt were also investigated.

RESULTS

The mean duration of the postoperative follow-up period was 9 months (range, 7-10 mo), and the subjects' mean wrist motion values were 75°, 79°, 78°, and 87° during flexion, extension, pronation, and supination, respectively. Grip strength on the affected side as a percentage of that seen on the healthy side ranged from 71% to 90%. The patients' visual analog scale; QuickDASH; and modified Mayo scores were all excellent, and bone union was achieved in all 3 cases. No shunt dysfunction or skin soft tissue complications were noted.

CONCLUSIONS

Volar locking plate fixation via the Henry approach might be useful for treating distal radius fractures in cases in which an arteriovenous shunt is present in the same limb. Shunt dysfunction and hemorrhaging are of concern during open surgery, but these were not issues in our patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Flexor carpi radialis tendon ultrasound pictorial essay

Disorders of the flexor carpi radialis tendon (FCRt) are often missed even though they are a relatively frequent cause of volar radial wrist pain. They can manifest as tenosynovitis, tendinopathy, synovial sheath cysts with or without scaphoid-trapezoid-trapezium (STT) joint pathology, and partial or complete rupture. Because FCRt disorders often present with non-specific symptoms and a non-diagnostic clinical examination, imaging is often necessary for accurate evaluation and therapeutic planning. Conventional radiography provides good visualization of the neighboring bones and joints, as well as rare intratendinous calcifications. MRI enables evaluation of the FCRt and adjacent anatomical structures with excellent tissue resolution. In comparison, ultrasound (US) evaluation of the FCRt is less commonly described in the radiology literature, despite its affordability, exquisite soft tissue resolution, and the advantages of quick, dynamic diagnostic imaging. This pictorial essay describes and demonstrates the normal anatomy of the FCRt, its US examination technique and normal US appearance, and US findings of clinically relevant FCRt disorders.

Distal volar radial plates: how anatomical are they?

BACKGROUND

Fractures of the distal radius are common, with volar locking plates being increasingly used in their treatment. They aim to provide stable internal fixation and are designed to mirror the natural anatomy. Current volar plate designs incorporate a volar cortical angle (VCA) of 25 degrees.

HYPOTHESIS

The aim of this study is to determine whether the VCA in uninjured distal radii corresponds accurately with modern volar plate designs.

MATERIALS AND METHODS

A retrospective radiological analysis utilizing Computed Tomography scans to assess the VCA of 100 distal radii. Each distal radius was subjected to 3 measurements of the VCA in the sagittal plane.

RESULTS

One hundred patients were identified (67 male, 33 female; mean age 37.4 years). The mean VCA was 32.9 degrees (S.D.±5.14 degrees). The VCA in male patients was significantly greater than in females (33.6 vs 31.5 degrees; P=0.04). There was a statistically significant difference between the lateral VCA and medial VCA (32.2 vs 34.3 degrees, P=0.02).

DISCUSSION

Our study clearly demonstrates that the VCA measured in the distal radius is significantly greater than the volar angulation incorporated within modern plate design. Given that the aim of ORIF is to anatomically reconstruct the distal radius, our study highlights that this may not be possible with current plates.

LEVELS OF EVIDENCE

Level IV Retrospective case series.

Minimally invasive plate osteosynthesis for distal radius fractures

BACKGROUND

Fractures of distal radius are common injury in all age groups. Cast treatment with or without close reduction is a viable option. However, the results are often unsatisfactory with restricted function. The open reduction and internal fixation often results in extensive soft tissue dissection and associated high rates of infect and delayed/nonunion. The distractor/external fixator have reported good functional and anatomical results but the incidence of pin traction infection nerve injury and cosmedic deformity are high. We introduced a modified operative technique for minimally invasive plate osteosynthesis (MIPO) for distal radial fracture and evaluated the functional outcomes and complications.

MATERIALS AND METHODS

22 distal radial fractures (10 left, 12 right) were treated using the MIPO technique and two small incisions with a palmar locking plate from August 2009 to August 2010. The wrist function was assessed according to Dienst wrist rating system, and postoperative complications were recorded.

RESULTS

According to Dienst wrist rating system, 13 patients showed excellent results, 6 cases showed good results and 3 patients had moderate results. No patient had poor results. Thus, the excellent and good rate was 86.4%. One patient had anesthesia in the thenar eminence and this symptom disappeared after 3 months. One patient had delayed healing in the proximal wrist crease. Two patients had mild pain on the ulnar side of the wrist and two patients had limited wrist joint function.

CONCLUSION

The MIPO technique by using two small palmar incisions is safe and effective for treatment of distal radial fractures.

Safety profile of sural nerve in posterolateral approach to the ankle joint: MRI study

The posterolateral approach to ankle joint is well suited for ORIF of posterior malleolar fractures. There are no major neurovascular structures endangering this approach other than the sural nerve. The sural nerve is often used as an autologous peripheral nerve graft and provides sensation to the lateral aspect of the foot. The aim of this paper is to measure the precise distance of the sural nerve from surrounding soft tissue structures so as to enable safe placement of skin incision in posterolateral approach. This is a retrospective image review study involving 64 MRI scans. All measurements were made from Axial T1 slices. The key findings of the paper is the safety window for the sural nerve from the lateral border of tendoachilles (TA) is 7 mm, 1.3 cm and 2 cm at 3 cm above ankle joint, at the ankle joint and at the distal tip of fibula respectively. Our study demonstrates the close relationship of the nerve in relation to TA and fibula in terms of exact measurements. The safety margins established in this study should enable the surgeon in preventing endangerment of the sural nerve encountered in this approach.

Magnetic resonance scanning vs axillary radiography in the assessment of glenoid version for osteoarthritis

BACKGROUND

Osteoarthritic shoulders are mainly associated with glenoid retroversion. Total shoulder arthroplasty with the glenoid component implanted in retroversion predisposes to loosening of the glenoid prosthesis. Correction of glenoid retroversion through anterior eccentric reaming, before glenoid component implantation, is performed to restore normal joint biomechanics. Accurate preoperative assessment is required to ascertain the degree of retroversion and calculate the degree of reaming.

MATERIALS AND METHODS

We assessed the utility of magnetic resonance imaging (MRI) for the assessment of glenoid version in glenohumeral osteoarthritis compared with standard plain axillary radiography (AXR). Two independent observers reviewed both types of imaging in 48 primary osteoarthritic shoulders on 2 separate occasions.

RESULTS

The mean glenoid version measured was -14.3° on MRI and -21.6° on AXR (mean difference, -7.36°; P < .001). Intraobserver and interobserver reliability coefficients were 0.96 and 0.9, respectively, for MRI and 0.8 and 0.71, respectively, for AXR. Glenoid retroversion was greater in 73% of AXR.

CONCLUSION

We demonstrated that MRI is more reproducible in the assessment of glenoid version in osteoarthritis and provides excellent intraobserver and interobserver reliability. MRI is useful for preoperative osseous imaging for total shoulder arthroplasty because it offers a more precise method of determining glenoid version compared with x-ray imaging in addition to the standard assessment of rotator cuff integrity.

Anterolateral surgical approach to the malunited distal radius fracture for corrective osteotomy and bone-graft harvest

The most common complication after distal radius fractures is union with deformity. When symptomatic, distal radial malunions may require operative intervention. Numerous approaches to the distal radius have been described. Most volar approaches involve sectioning the brachioradialis and opening the first extensor compartment to permit adequate exposure. When bone graft is required, this may necessitate a separate incision and further add to the morbidity. We present an alternative anterolateral surgical approach to the distal radius, which allows for excellent exposure, and minimal trauma to the tendons while permitting harvest of local bone graft through the same incision.

The cadaveric anatomy of the distal radius: implications for the use of volar plates

INTRODUCTION

Fractures of the distal radius are common upper limb injuries, representing a substantial proportion of the trauma workload in orthopaedic units. With ever increasing advancements in implant technology, operative intervention is becoming more frequent. As growing numbers of surgeons are performing operative fixation of distal radial fractures, an accurate understanding of the relevant surgical anatomy is paramount. The flexor carpi radialis (FCR) tendon forms the cornerstone of the Henry approach to the volar cortex of the distal radius. A number of key neurovascular structures around the wrist are potentially at risk during this approach, especially when the FCR is mobilised and placed under retractors.

METHODS

In order to clarify the safe margins of the FCR approach, ten fresh frozen human cadaver limbs were dissected. The location of the radial artery, the median nerve, the palmar cutaneous branch of the median nerve and the superficial branch nerve were measured with respect to the FCR tendon. Measurements were taken on a centre-to-centre basis in the coronal plane at the watershed level. In addition, the distances between the tendons of brachioradialis, abductor pollicis longus and flexor pollicis longus, and the radial artery and median nerve were measured to create a complete picture of the anatomy of the FCR approach to the distal radius.

RESULTS

The structure most at risk was the palmar cutaneous branch of the median nerve. It was located on average 3.4mm from the FCR tendon. The radial artery and the main trunk of the median nerve were located 7.8mm and 8.9mm from the tendon. The superficial branch of the radial nerve was 24.4mm from the FCR tendon and 11.1mm from the brachioradialis tendon.

CONCLUSIONS

Operative intervention is not without complication. We believe a more accurate understanding of the surgical anatomy is key to the prevention of neurovascular damage arising from the surgical management of distal radial fractures.