Radial Styloid Research Articles

THE PATH OF SCREW INSERTION FOR STABILIZATION OF THE SCAPHOLUNATE JOINT: A CADAVERIC STUDY

The aim of this study was to determine the path of screw placement to avoid breaching the articular surface of both lunate and scaphoid bones at the radiocarpal and midcarpal joints. An Acutrak screw was inserted into the right scapholunate joint of ten cadavers starting immediately distal to the tip of the radial styloid and aiming for the tip of the ulnar styloid. The articular surfaces of the scaphoid and lunate bones in all ten cadavers were exposed and examined. A computed tomography (CT) scan of four wrists was performed. Eight of the ten cadavers had no perforation or destruction of the articular surfaces. Screw stabilization of the scapholunate joint can be performed without perforation or destruction of the lunate or scaphoid surfaces. We recommend that if this form of fixation is being used then the screw should be inserted commencing at the radial styloid tip and aiming for ulnar styloid tip, under radiological guidance.

Radiographic assessment of ligamentous injuries in distal radius fractures after open reduction and internal fixation

Concomitant ligamentous injury in distal radius fractures (DRF) may explain continued pain following surgery. The purpose of this study was to compare radiographic measurements assessing scaphoid translation in DRF after reduction, to measurements performed on normal radiographs. This may allow noninvasive evaluation of radiocarpal ligamentous integrity. Fifty postoperative radiographs were evaluated. The distance between the ulnar border of the radial styloid and the radial border of the scaphoid was measured midway between the styloid tip and scaphoid base, and then divided by scaphoid width at the same level. The measured ratios were compared to previously established normal data, established radiographic measurements of fracture reduction, fracture characteristics and fixation methods. Radiographic scaphoid position measurements differed significantly from normals (p = 0.0001). Fracture characteristics, surgical difficulty, and technique were not associated with scaphoid position. Despite accurate surgical reduction, abnormal positioning of the scaphoid may persist. This may reflect ligamentous injury, which generates suboptimal clinical results. Identifying and addressing ligamentous injury during surgery may prevent the development of instability and improve outcome after DRF.

Distal Radius Attachments of the Radiocarpal Ligaments: An Anatomical Study

Background Understanding the anatomy of the ligaments of the distal radius aids in the surgical repair of ligamentous injuries and the prediction of intraarticular fracture patterns. Purposes (1) to measure the horizontal and vertical distances of the origins of the radiocarpal ligaments from the most ulnar corner of the sigmoid notch and the joint line, respectively; and (2) to express them as a percentile of the total width of the bony distal radius. Methods We dissected 8 cadaveric specimens and identified the dorsal radiocarpal, radioscaphocapitate, and the long and short radiolunate ligaments. Results The dorsal radiocarpal ligament attached from the 16th to the 52nd percentile of the radial width. The radioscaphocapitate ligament attached around the radial styloid from the 86th percentile volarly to the 87th percentile dorsally. The long radiolunate ligament attached from the 59th to the 85th percentile, and the short radiolunate ligament attached from the 14th to the 41st percentile. Discussion There was a positive correlation between the radial width and the horizontal distance of the ligaments from the sigmoid notch. These findings may aid individualized surgical repair or reconstruction adjusted to patient size and enable further standardized research on distal radial fractures and their relationship with radiocarpal ligaments.

Three-Dimensional Correction of Distal Radius Intra-Articular Malunions Using Patient-Specific Drill Guides

To analyze the feasibility of combining computer-assisted 3-dimensional planning with patient-specific drill guides and to evaluate this technology's surgical outcomes for distal radius intra-articular malunions. Six symptomatic patients with intra-articular malunions of the distal radius with a stepoff of more than 2 mm were treated with an outside-in corrective osteotomy. The described cases consist of 2 malunited volar Barton fractures, 2 radial styloid fractures, 1 AO-type C1 fracture, and 1 die-punch fracture. The osteotomies were guided by 3-dimensionally generated aiming guides that allowed precise cutting and the reduction of up to 2 fragments. All 6 patients were examined clinically and radiologically after 1 year. The surgical outcomes were quantitatively analyzed by comparing the preoperative and postoperative computed tomographic data. In all 6 cases, the osteotomies were consolidated 8 weeks postoperatively. After 1 year, 4 patients were pain-free, 1 had mild pain, and 1 experienced moderate pain during heavy work. Wrist motion and grip strength were improved in all patients. The postoperative radiographs showed no articular stepoff or degenerative changes. Patient-specific aiming guides provided a reliable method to correct intra-articular malunions of the distal radius. This technique allows the surgeon to safely perform difficult intra-articular osteotomies and may help limit the need for salvage procedures such as partial or complete wrist arthrodesis. Therapeutic IV.

Ligament Origins Are Preserved in Distal Radial Intraarticular Two-Part Fractures: A Computed Tomography-Based Study

Background Operative fixation of intraarticular distal radius fractures is increasingly common. A greater understanding of fracture patterns will aid surgical fixation strategy. Previous studies have suggested that ligamentous insertions may less commonly be involved, but these have included heterogeneous groups of fractures and have not addressed Lister's tubercle. Purpose We hypothesize that fracture lines of distal radial intraarticular 2-part fractures have reproducible patterns. They propagate through the cortical bone between ligament origins and do not involve Lister's tubercle. Methods Axial CT scans of two-part intraarticular distal radius fractures were assessed independently by two examiners. The fractures were mapped onto a grid and the cortical breaches expressed as a percentile of the total radial width or length. The cortical breaches were compared with the ligamentous insertions on the distal and Lister's tubercle. Associated injuries were also documented. Results The cortical breaches occurred between the ligamentous insertions in 85%. Lister's tubercle was not involved in 95% of the fractures. Three major fracture patterns emerged: radial styloid, dorsal, and volar. Each major pattern had two subtypes. Associated injuries were common. Scapholunate dissociation was associated with all types, not just the radial styloid fracture pattern. Conclusions The fracture patterns of two-part intraarticular fractures mostly involved the interligamentous zones. Three major groups were identified: dorsal, volar, and radial styloid. Lister's tubercle was preserved with fractures tending to propagate radial or ulnar to this structure. We suggest conceptualizing fracture fragments as osseo-ligamentous units to aid prediction of fracture patterns and associated injury. Study Design Diagnostic III Level of Evidence 3.

English

INTRODUCTION: Muscular composition of first dorsal compartment of the wrist has important role in the movement of thumb. Multiplicity of tendons of Abductor Pollicis Longus and extensor pollicis Brevis has a significant role in DE QUERVIANS STENOSING TENOSYNOVITIS. It is a disease in which pain and swelling occurs on movement of thumb or compression of first dorsal compartment of wrist in the radial styloid process due to stenosing Tenosynovitis of the Abductor pollicis Longus and Extensor pollicis Brevis. Abductor pollicis Longus and extensor pollicis Brevis are two of outcropping muscles located in the dorsal carpel region. The Abductor pollicis Longus arises from posterior surface of the middle one third of the radius, ulna and adjoining interosseous membrane, in distal forearm it usually splits into two slips and attached to radial side of first metacarpal and Trapezium. The EPB is attached to the posterior surface of radius and adjacent interosseous membrane. Thus knowledge of such variations is important for surgeons while performing plastic reconstructive surgeries.

Ultrasound-Guided Corticosteroid Injection for the Treatment of de Quervain’s Tenosynovitis

Ultrasound-Guided Corticosteroid Injection for the Treatment of de Quervain’s Tenosynovitis

Volar Ligament Repair for Radiocarpal Fracture-dislocation

Radiocarpal fracture-dislocations are uncommon injuries, comprising a spectrum of trauma to the capsuloligamentous complex and osseous structures of the radiocarpal joint along with the adjacent structures. Management guidelines are derived from limited case series and expert opinions. An understanding of the relevant anatomy suggests that restoration of an anatomically reduced joint in conjunction with repair or reconstruction of the osseous and soft tissue structures optimizes outcome. Special consideration should be given to repair of the radial styloid, intercarpal ligaments, and radiocarpal capsuloligamentous complex. The authors report 2 patients with radiocarpal fracture-dislocations in which reduction and stabilization of the carpus was achieved using suture anchor fixation of the volar extrinsic radiocarpal ligaments.

Numerical investigation of mechanical effects caused by various fixation positions on a new radius intramedullary nail

Fracture of the radius diaphysis is an unusual injury in adults. Open reduction and plate osteosynthesis has been recommended by most of the authors. However, this trend has started to change with the recent introduction of newly designed interlocking intramedullary (IM) nails. New generation of IM nails are developed in order to utilise the advantages of IM nails against plates. Because of its anatomical structure, the radius bone has a complex geometry. Therefore, the callus structure, which forms during the healing period, should not be affected from external effects, such as excessive loads or motion. In this study, effects of radial styloid process (RSP), dorsal side and ulnar notch edge fixations of a new design radius IM nail on the healing period were numerically investigated. A three-dimensional solid model of radius was obtained from computed tomography images of a volunteer and callus structure model, was placed accordingly and different fixations of implants were performed. The models were analysed under axial loads transferring from the wrist to the radius bone using finite element method. As a result of the analysis, fixation of IM nail from RSP was found to be beneficial on healing period in terms of both callus motion and emerging stresses.

The bicipital tuberosity and distal radius are unreliable landmarks for radial head implant alignment

As more anatomic asymmetric radial head implants emerge, it is necessary to determine the optimal landmarks to ensure correct rotational orientation. The bicipital tuberosity and distal radius are possible bony landmarks that can be used for rotational alignment of asymmetric prostheses; however, they have not been validated. The purpose of this study was to evaluate the reliability of the bicipital tuberosity and distal radius as rotational landmarks for orientation of asymmetric radial head prostheses. Measurements were made from computer tomography scans of 50 elbows in order to determine the rotational relationships between the radial head, bicipital tuberosity, biceps tendon footprint, and distal radius. The maximum radial head diameter was oriented 65° ± 28° from the bicipital tuberosity, 119°±38° from the biceps tendon footprint, 82° ± 29° from the radial styloid, and 76° ± 28° from the volar surface of the distal radius. All of these landmarks had a significantly greater variance than a proposed acceptable clinical tolerance of 10° (P < .001). The results demonstrate that the measured landmarks show no consistent rotational relationship with the maximum diameter of the radial head. In order to maximize the utility of more anatomic asymmetric radial head implant systems, further studies are necessary to identify more reliable rotational landmarks to ensure optimal implant positioning.

Dart-throwing motion in patients with scapholunate instability: a dynamic four-dimensional computed tomography study

When the normal wrist rotates along the 'dart-throwing' plane, the proximal row remains still, with most motion occurring at the midcarpal joint. Whether this behaviour is maintained when the scapholunate ligaments are torn is not known. If this is the case, patients having a scapholunate ligament repair could benefit from early dart-throwing exercises without the risk of pulling the sutures apart. Using dynamic computer tomography, we analysed the carpal behaviour of six normal wrists and six wrists with scapholunate instability during dart-throwing motion. In the normal wrists, the scaphoid and lunate did not flex or extend, but translated along the frontal plane an average 5.9 and 5.6 mm, respectively. When the scapholunate ligaments were torn, the scaphoid shifted towards the radial styloid considerably more than the lunate (12.8 mm versus 4.8 mm; p = 0.005), inducing a scapholunate gap. Based on these findings, we cannot recommend dart-throwing exercises after scapholunate ligament repair, unless the joint is stabilized with wires or screws.

Functional Consequence of Distal Brachioradialis Tendon Release: A Biomechanical Study

Open reduction and internal fixation of distal radius fractures often necessitates release of the brachioradialis from the radial styloid. However, this common procedure has the potential to decrease elbow flexion strength. To determine the potential morbidity associated with brachioradialis release, we measured the change in elbow torque as a function of incremental release of the brachioradialis insertion footprint. In 5 upper extremity cadaveric specimens, we systematically released the brachioradialis tendon from the radius and measured the resultant effect on brachioradialis elbow flexion torque. We defined release distance as the distance between the release point and the tip of the radial styloid. Brachioradialis elbow flexion torque dropped to 95%, 90%, and 86% of its original value at release distances of 27, 46, and 52 mm, respectively. Importantly, brachioradialis torque remained above 80% of its original value at release distances up to 7 cm. Our data demonstrate that release of the brachioradialis tendon from its insertion has minor effects on its ability to transmit force to the distal radius. These data imply that release of the distal brachioradialis tendon during distal radius open reduction internal fixation can be performed without meaningful functional consequences to elbow flexion torque. Even at large release distances, overall elbow flexion torque loss after brachioradialis release would be expected to be less than 5% because of the much larger contributions of the biceps and brachialis. Use of the brachioradialis as a tendon transfer donor should not be limited by concerns of elbow flexion loss, and the tendon could be considered as an autograft donor.

Extensile Surgical Exposures of the Radius: A Comparative Anatomic Study

To evaluate and compare exposures of the radius using 3 surgical approaches. Our hypotheses were that the anterior flexor carpi radialis approach allows greater exposure of the distal radius than does the volar-ulnar approach, and the extensile flexor carpi radialis approach allows comparable proximal and midshaft exposure of the radius compared with the dorsal Thompson approach. We performed anterior and dorsal exposures of the radius on 10 matched pairs of cadavers (20 forearms) randomly assigned to 1 anterior and 1 dorsal approach. We measured and compared the anatomic features and limits of the anterior flexor carpi radialis approach, volar-ulnar approach to the distal radius, and the dorsal Thompson approach. The anterior flexor carpi radialis approach exposed 3.3 cm of distal radius width, was convertible to an extensile approach proximally, required sacrifice of 3 arterial branches, and was limited by the junction of the radial and ulnar arteries. This approach provided 79% of radius exposure and ended 4.7 cm distal to the radiocapitellar joint. The volar-ulnar approach to the distal radius exposed 3.1 cm of distal radius width. The dorsal Thompson approach sacrificed no arterial branches, provided 69% of radius exposure, was limited by the first compartment distally and the posterior interosseous nerve proximally, and ended within 2.6 cm of the radiocapitellar joint. The posterior interosseous nerve coursed 19, 14, and 6 mm dorsolateral to the distal, middle, and proximal margins, respectively, of the supinator insertion on the radius. The volar-ulnar approach provided less access to the radial styloid and was not as extensile as the flexor carpi radialis approach. The Thompson approach provided more proximal exposure than the flexor carpi radialis approach. Improved knowledge of the anatomy, limits of exposure, and comparison of features between approaches to the radius may facilitate surgical planning and exposure.

A control study of the radial extracorporeal shock wave therapy for treatment of stenosing tenosynovitis at the radial styloid

Objective To investigate the effectiveness and safety of radial extracorporeal shock waves therapy (RSWT) in treating stenosing tenosynovitis at the radial styloid.Methods Forty-seven patients with stenosing tenosynovitis at the radial styloid were randomly divided into the treatment group(32 cases) and control group (15 cases).Patients in the treatment group received three sessions of RSWT,while those in the control group received conservative therapy with Votalin emulsion and local massage.Visual analog scale (VAS) was used to evaluate the extent of pain before the therapy and 1 or 4 weeks after the last therapy session.Results In the treatment group pain was alleviated and wrist function was improved.The VAS improved from (7.12 ±1.74) prior therapy to (2.16 ± 1.05) and (0.50 ± 0.71) 1 week and 4 weeks after the therapy,respectively.The difference before and after the treatment was significant (P ＜ 0.05).The VAS improved from (6.60 ±1.72) prior therapy to (4.06± 1.83) and (3.46±2.23) 1 week and 4 weeks after the therapy respectively in the control group.The difference before and after the treatment was significant (P ＜ 0.05),while the VAS scores at 1 week and 4 weeks after the therapy were not different(P ＞ 0.05).Conclusion RSWT is a new treatment option for stenosing tenosynovitis at the radial styloid that has such advantages as being effective,simple,atraumatic and safe. Key words: Tenosynovitis; Pain; Radial extracorporeal shock waves

Local Ectopic Implantation for Salvaging an Amputated Thumb

Relatively few cases of the ectopic implantation of an amputated thumb have been reported. The majority of ectopic sites are far from the original anatomic site, and anastomosis of the artery cannot be avoided in the secondary replantation surgery, which increases the failure rate. We conducted an anatomic study to investigate the possibility of performing local ectopic implantation of an amputated thumb at the wrist level such that an arterial pedicled thumb could be harvested in the secondary surgery. Thirty radial arteries were dissected from the point 3 cm proximal to the radial styloid to the point at which they passed over the radial styloid. Each branch with a diameter >0.8mm was selected. The mean number of branches was 3.2 > ± 1.37, and the mean diameter was 1.09 ± 0.83 mm. The mean diameter of the ulnar digital artery in the thumb was 1.08 ± 0.15 mm at the metacarpophalangeal joint level. Following anatomic research, an amputated thumb was ectopically implanted locally and replanted during a secondary operation without anastomosis of the artery. The amputated thumb survived, and its function was partially restored. In conclusion, the branches of the radial artery that have a similar diameter to the ulnar digital artery of the thumb can always be located at the wrist level. Local ectopic implantation is feasible and can help prevent the need for anastomosis of the artery during the secondary replantation surgery.

An anatomical study of the ECRL and ECRB: Feasibility of developing a preoperative test for evaluating the strength of the individual wrist extensors

Tendon transfers are essential for reconstruction of hand function in tetraplegic patients. To transfer the extensor carpi radialis longus (ECRL), the extensor carpi radialis brevis (ECRB) has to be sufficiently strong. However, there is currently no reliable clinical test to individually analyse both muscles. In order to develop a reliable preoperative clinical test, the anatomy of the muscle (innervation) areas of ECRB, ECRL and brachio-radialis (BR) was examined. In 20 arms, the ECRB, ECRL and BR were dissected and localised. Subsequently, muscle-innervation points were mapped and categorised. A novel method, computer-assisted surgical anatomy mapping (CASAM), was used to visualise muscle areas and innervation points in a computed arm with average dimensions. For both ECRL and ECRB a 100% area could be identified, a specific area in the computed average arm in which the muscle was present for all 20 arms. For the ECRL, this area was situated at 16% of the distance between the lateral epicondyle and the deltoid muscle insertion. The ECRB 100% area was 5 times bigger than that of the ECRL and was located at 40% of the distance between the lateral epicondyle and the radial styloid process. The ECRL and BR showed one to three innervation points, the ECRB one to four. In 47% of the cases, there was a combined nerve branch innervating both the ECRL and the ECRB. It is feasible to develop a preoperative test; the 100% areas can be used for needle electromyography (EMG) or local anaesthetic muscle injections.

Effects of Elastic Wrist Taping on Maximum Grip Strength

In this study, we examined the effects of elastic wrist taping with different pressure levels on the maximum grip strength. The subjects were 20 healthy male university students. The tape was wrapped three times around the wrist at the radial and ulnar styloid process. Taping pressure was measured using a pressure measuring system for stockings and bandages. A pressure sensor was placed over the palmaris longus muscle tendon, 1.5 cm proximal to the palmar crease of the subject’s wrist on the dominant upper limb. The following experimental conditions were assessed: control condition (CC), without attachments; sensor condition (SC), with an attached sensor and a cover tape with minimum pressure application (1–5 hPa); and four pressure conditions (PCs), with pressure applications of 30, 60, 90, and 120 hPa using elastic tapes. Grip strength was significantly greater for CC than for PCs. However, the overall decrease in grip strength was still relatively small. No differences were observed in the grip strengths among the four PC groups. Our results showed that grip strength exertion decreased on the application of higher pressures of elastic tape wrapping and that the degree of decrease was similar for all PCs above 30 hPa.

La luxation radiocarpienne (à propos de neuf cas)

Radiocarpal dislocation is an uncommon entity in traumatolgy. The purpose of this study was to detail the pathogenesis of radiocarpal dislocation and describe its complications and treatment. Nine radiocarpal dislocations were reviewed retrospectively. Dorsal displacement was observed for seven dislocations, anterior displacement for two dislocations. All were associated with fractures of the radial styloid. Treatment was always surgical. At last follow-up (mean 3 years), the overall functional outcome was satisfactory. The Green and O’Brien (modified by Cooney) score was excellent for three patients, fair for four, and mediocre for two. Two cases of radiocarpal degeneration were observed at last follow-up. Intracarpal and/or distal radio-ulnar lesions must be stabilized in order to limit the risk of future degeneration.

SCAPHOID TRANSLATION MEASUREMENTS IN NORMAL WRISTS

The purpose of this study was to establish a normal measure of scaphoid position in the radioulnar plane in standard neutral, radial and ulnar deviation posteroanterior radiographs. This measurement may allow indirect evaluation of the radiocarpal ligaments and comparison between normal and pathologic states (following radius fractures, perilunate dislocations). Measurements were trialed on 74 normal wrist radiographs and 25 cadaver wrists. We evaluated the distance between the radial styloid and the scaphoid and corresponding scaphoid width. The ratio of distance/width at the mid styloid level (0.35, imprecision SD = 0.1) had the lowest random error and is therefore the most precise measurement of true scaphoid translation. This measurement is independent of scapholunate ligament integrity and may provide a better assessment of the radiocarpal component of ulnar translational instability. Abnormal movement of the scaphoid in the radioscaphoid joint likely reflects ligamentous injury. Identifying and addressing these injuries may prevent the development of arthritis.

Upper extremities musculoskeletal disorders: Prevalence and associated ergonomic factors in an electronic assembly factory

To determine the magnitude, distribution and associated ergonomic factors of upper extremities musculoskeletal disorders (UEMSD) among workers of electronic assembly in Thailand. This was a cross-sectional study. 591 of 853 workers in an electronic and electrical appliance assembly factory in Bangkok, Thailand, participated in this study. A self-administered questionnaire consisting of demographic data and ergonomic factors was collected from October 2010 to January 2011. Clinical examination of each worker was performed by an occupational physician. The criteria for diagnosis of UEMSD came as a result of a consensus reached by a group of orthopedists. The associated factors were analyzed using a multiple logistic regression. The point prevalence of clinically diagnosed UEMSD was as follows: radial styloid tenosynovitis - 13.03% (95% CI: 10.31-15.75), trigger finger - 9.48% (95% CI: 7.11-11.84), carpal tunnel syndrome - 8.12% (95% CI: 5.91-10.33), lateral epicondylitis - 3.38% (95% CI: 1.92-4.85), and medial epicondylitis - 1.69% (95% CI: 0.65-2.73), respectively. The adjusted odds ratio with statistical significance associated with UEMSD was as follows: high force of wrist - 1.78 (95% CI: 1.06-2.99), awkward posture of wrist - 2.37 (95% CI: 1.28-4.37) and contact stress at wrists - 1.75 (95% CI: 1.02-3.00) to develop radial styloid tenosynovitis. For trigger finger, the ratios were awkward posture of fingers - 2.09 (95% CI: 1.12-3.90) and contact stress on finger - 1.86 (95% CI: 1.04-3.34). For medial epicondylitis, it was an awkward posture of using elbows - 3.14 (95% CI: 1.10-8.95). However, this study did not find any associations between repetitive motion and any UEMSD. UEMSD are most commonly found in electronic assembly workers. The relevant parties should provide comprehensive ergonomic resolution for these workers.