Functional Hand-Based Splint in the Treatment of Metacarpal Fractures

Background: Post-treatment stiffness remains a significant hurdle following treatment for displaced or minimally displaced metacarpal fractures. Treatment goals should focus on a stable and acceptable reduction, minimal patient morbidity, and optimal mobility. Methods: A retrospective review of all non-operative metacarpal fractures over a five-month period at a tertiary center hand clinic treated with a hand-based splint were reviewed for radiologic and clinical stability. The splint allowed metacarpophalngeal joint, interphalangeal joint, and radiocarpal joint motion. Data collected included age, handedness, type and location of fracture, occupation, and ability to continue working. Radiologic images were reviewed by a radiologist not otherwise involved in patient care. Results: Thirty-three patients were reviewed with a total of 39 fractures of the second, third, fourth, and fifth metacarpals. Nine patients had nondominant hand fractures while 24 were dominant hand injuries. Twenty out of 24 patients employed pre-injury were able to continue working without missing any days. Three patients were lost to the final follow-up. The average splint duration was 24 days. Twenty-seven of 30 patients showed no change in alignment from start of splinting to end, while three showed some change but remained within non-operative criteria. Conclusion: A hand-based functional splint for metacarpal fractures allows for excellent maintenance of fracture reduction, early or immediate return to pre-injury activities, low patient morbidity, and maintains functional motion throughout treatment. It can be applied to any non-operative fracture of the second through the fifth metacarpal.

CT Scan versus Saline Load Test for Detection of Traumatic Wrist Arthrotomy

Background Traumatic arthrotomy of the wrist is most commonly detected using the saline load test (SLT); however, little data exists on the effectiveness of the SLT to this specific joint. The use of computed tomography (CT) scan has been validated as an alternative method to detect traumatic arthrotomy of the knee, as the presence of intra-articular air can be seen when there is violation of the joint capsule. Question/Purpose The purpose of this study was to determine the ability of CT scan to identify arthrotomy of the wrist capsule and compare the diagnostic performance of CT versus traditional SLT. Materials and Methods Ten fresh frozen cadavers which had undergone transhumeral amputation were initially used in this study. A baseline CT scan was performed to ensure no intra-articular air existed prior to intervention. After baseline CT, an arthrotomy was created at the 6R radiocarpal portal site. The wrists then underwent a postarthrotomy CT to identify the presence or absence of intra-articular air. Following CT, the wrists were subjected to the SLT to detect the presence of extravasation from the arthrotomy. Results Nine cadavers were included following baseline CT scan. Following arthrotomy, intra-articular air was visualized in eight of the nine cadavers in the postarthrotomy CT scan. Air was seen in the radiocarpal joint in eight of the nine wrists; midcarpal joint in seven of the nine wrists; and distal radioulnar joint in six of the nine wrists. All wrists (nine of the nine) demonstrated extravasation during the SLT. The mean volume of extravasation occurred at 3.7 mL (standard deviation = 2.6 mL), with a range of 1 to 7 mL. Conclusion CT scan correctly identified eight of the nine simulated traumatic arthrotomies. Injection of 7 mL during the SLT was necessary to identify 100% of the arthrotomies. Clinical Relevance CT scan is a sensitive modality for detection of traumatic arthrotomy of the wrist in a cadaveric model.

Activation of sensorimotor integration processes with a brain-computer interface

A BCI-controlled hand exoskeleton activates neuroplasticity mechanisms, promoting motor learning. The contribution of perception to this phenomenon is understudied. The aim of this study was to assess the impact of sensorimotor integration on the effectiveness of neurorehabilitation based on the learning of a hand opening movement by stroke patients using BCI and to investigate the effect of ideomotor training on spasticity in the paretic hand. The study was conducted in 58 patients (median age: 63 (22; 83) years) with traumatic brain injury, ischemic (76%) or hemorrhagic (24%) stroke in the preceding 2 (1.0; 12.0) months. The patients received 15 (12; 21) ideomotor training sessions with a BMI-controlled hand exoskeleton. Hand function was assessed before and after rehabilitation on the Fugl–Meyer, ARAT, Frenchay, FIM, Rivermead, and Ashworth scales. An increase in muscle strength was observed in 40% of patients during flexion and extension of the radiocarpal joint and in 29% of patients during the abduction and adduction of the joint. Muscle strength simultaneously increased during the abduction and adduction of the radiocarpal joint (p < 0.004). Ideomotor training is ineffective for reducing spasticity because no statistically significant reduction in muscle tone was detected. Improved motor performance of the paretic hand was positively correlated with improvements in daily activities. Motor training of the paretic hand with a robotic orthosis activates kinesthetic receptors, restores sensation and improves fine motor skills through better sensorimotor integration.

Distal Radius Fracture with Bone Fragment Protruded into the Radiocarpal Joint: Two Case Reports

Distal radius fractures often involve comminuted fragments of the dorsal cortex of the radius, but bone fragments rarely protrude into the radiocarpal joint. We report two cases of distal radius fracture with bone fragment protrusion into the radiocarpal joint. To the best of our knowledge, there are no English reports of distal radius fracture with bone fragment protrusion into the radiocarpal joint. Despite the rarity of these cases, clinicians should still be mindful of such injuries and not overlook the possibility of presence of bone fragments within the joint. Missed intra-articular fragments may cause pain, limited range of motion, and subsequent osteoarthritis.

Targeting Soluble Epoxide Hydrolase and Cyclooxygenases Enhance Joint Pain Control, Stimulate Collagen Synthesis, and Protect Chondrocytes From Cytokine-Induced Apoptosis

Objective: To determine the symptomatic and disease-modifying capabilities of sEH and COX inhibitors during joint inflammation.Methods: Using a blinded, randomized, crossover experimental design, 6 adult healthy horses were injected with lipopolysaccharide (LPS; 3 μg) from E. coli in a radiocarpal joint and concurrently received the non-selective cyclooxygenase (COX) inhibitor phenylbutazone (2 mg/kg), the sEH inhibitor t-TUCB (1 mg/kg) or both (2 mg/kg phenylbutazone and 0.1, 0.3, and 1 mg/kg t-TUCB) intravenously. There were at least 30 days washout between treatments. Joint pain (assessed via inertial sensors and peak vertical forces), synovial fluid concentrations of prostanoids (PGE2, TxB2), cytokines (IL-1β, IL-6, TNF-α) and biomarkers of collagen synthesis (CPII) and degradation (C2C) were measured at pre-determined intervals over a 48-h period. The anti-apoptotic effect of COX and sEH inhibitors was determined via ELISA technique in primary equine chondrocytes incubated with TNF-α (10 ng/ml) for 24 h. Apoptosis was also determined in chondrocytes incubated with sEH-generated metabolites.Results: Combined COX and sEH inhibition produced significantly better control of joint pain, prostanoid responses, and collagen synthesis-degradation balance compared to each compound separately. When administered separately, pain control was superior with COX vs. sEH inhibition. Cytokine responses were not different during COX and/or sEH inhibition. In cultured chondrocytes, sEH inhibition alone or combined with COX inhibition, but not COX inhibition alone had significant anti-apoptotic effects. However, sEH-generated metabolites caused concentration-dependent apoptosis.Conclusions: Combined COX and sEH inhibition optimize pain control, attenuate loss of articular cartilage matrix during joint inflammation and cytokine-induced chondrocyte apoptosis.

Radiocarpal Contact Pressures Are Not Altered after Scapholunate Ligament Tears

Background The scapholunate interosseous ligament (SLIL) couples the scaphoid and lunate, preventing motion and instability. Prior studies suggest that damage to the SLIL may significantly alter contact pressures of the radiocarpal joint. Questions/Purposes The purpose of this study was to investigate the contact pressure and contact area in the scaphoid and lunate fossae of the radius prior to and after sectioning the SLIL. Methods Ten cadaveric forearms were dissected distal to 1-cm proximal to the radiocarpal joint and a Tekscan sensor was placed in the radiocarpal joint. The potted specimen was mounted and an axial load of 200 N was applied over 60 seconds. Results Sectioning of the SLIL did neither significantly alter mean contact pressure at the lunate fossa (p = 0.842) nor scaphoid fossa (p = 0.760). Peak pressures were similar between both states at the lunate and scaphoid fossae (p = 0.301–0.959). Contact areas were similar at the lunate fossa (p = 0.508) but trended toward an increase in the SLIL sectioned state in the scaphoid fossa (p = 0.055). No significant differences in the distribution of contact pressure (p = 0.799), peak pressure (p = 0.445), and contact area (p = 0.203) between the scaphoid and lunate fossae after sectioning were observed. Conclusion Complete sectioning of the SLIL in isolation may not be sufficient to alter the contact pressures of the wrist. Clinical Relevance Injury to the secondary stabilizers of the SL joint, in addition to complete sectioning of the SLIL, may be needed to induce altered biomechanics and ultimately degenerative changes of the radiocarpal joint.

Internal Mechanics of a Subject-Specific Wrist in the Sagittal Versus Dart-Throwing Motion Plane in Adult and Elder Models: Finite Element Analyses

Introduction: Most of the wrist motions occur in a diagonal plane of motion, termed the dart-throwing motion (DTM) plane; it is thought to be more stable compared with movement in the sagittal plane. However, the effect of the altered carpus motion during DTM on the stress distribution at the radiocarpal joint has yet to be explored. Aim: To calculate and compare the stresses between the radius and two carpal bones (the scaphoid and the lunate) in two wrist positions, extension and radial extension (position in DTM), and between an adult and an elder model. Methods: A healthy wrist of a 40-year-old female was scanned using Magnetic Resonance Imaging in two wrist positions (extension, radial extension). The scans were transformed into three-dimensional models and meshed. Finite element (FE) analyses in each position of the wrist were conducted for both adult and elder models, which were differentiated by the mechanical properties of the ligaments. The distal surfaces of the carpal bones articulating with the metacarpals were loaded by physically accurate tendon forces for each wrist position. Results: The von Mises, shear stresses and contact stresses were higher in the extension model compared with the radial-extension model and were higher for the radius-scaphoid interface in the adult model compared with the elder model. In the radius-scaphoid interface, the stress differences between the two wrist positions were smaller in the elder model (11.5% to 22.5%) compared with the adult model (33.6–41.5%). During radial extension, the contact area at the radius-lunate interface was increased, more so in the adult model (222.2%) compared with the elder model (127.9%), while the contact area at the radius-scaphoid was not affected by the position of the wrist in the adult model (100.9%) but decreased in the elder model (50.2%) during radial extension. Conclusion: The reduced stresses during radial extension might provide an explanation to our frequent use of this movement pattern, as the reduced stresses decrease the risk of overuse injury. Our results suggest that this conclusion is relevant to both adults and elder individuals.