Osteophyte growth in early thumb carpometacarpal osteoarthritis.

OBJECTIVE: Osteophyte formation is a critical part of the degeneration of a joint with osteoarthritis (OA). While often qualitatively described, few studies have succeeded in quantifying osteophyte growth over time. Using computed tomography (CT) image data from a longitudinal, observational study of thumb carpometacarpal (CMC) OA, our aim was to quantify osteophyte growth volume and location over a three-year period in men and women. METHOD: Ninety patients with early thumb OA were recruited and assessed at baseline, 1.5 years, and 3 years with CT imaging. Osteophyte volume and location on the trapezium and first metacarpal were determined using a library of 46 healthy subjects as a nonarthritic reference database. RESULTS: There was a significant increase in osteophyte volume for women and men over the three-year follow-up in the trapezium (86.8 mm3-120.5 mm3 and 165.1 mm3-235.3 mm3, means respectively) and in the proximal metacarpal (63 mm3-80.4 mm3, and 115.8 mm3-161.7 mm3, respectively). The location of osteophyte initiation and growth was consistent across subjects and was located in non-opposing regions on the trapezium and first metacarpal. Osteophyte growth occurred about the radial and ulnar margins of the trapezial facet, while on the proximal metacarpal, growth occurred principally about the volar and dorsal margins of the facet. CONCLUSION: Osteophyte growth occurred in early thumb osteoarthritis over three years. Growth was localized in specific, non-opposing regions on the trapezium and metacarpal, raising intriguing questions about the triggers for their formation, whether the mechanisms are mechanical, biological or a combination of both.

Early morphologic changes in trapeziometacarpal joint bones with osteoarthritis.

OBJECTIVE: Characterising the morphological differences between healthy and early osteoarthritic (EOA) trapeziometacarpal (TMC) joints is important for understanding osteoarthritis onset, and early detection is important for treatment and disease management. This study has two aims: first, to characterise morphological differences between healthy and EOA TMC bones. The second aim was to determine the efficacy of using a statistical shape model (SSM) to detect early signs of osteoarthritis (OA). METHODS: CT image data of TMC bones from 22 asymptomatic volunteers and 47 patients with EOA were obtained from an ongoing study and used to generate a SSM. A linear discriminant analysis (LDA) classifier was trained on the principal component (PC) weights to characterise features of each group. Multivariable statistical analysis was performed on the PC to investigate morphologic differences. Leave-one-out classification was performed to evaluate the classifiers performance. RESULTS: We found that TMC bones of EOA subjects exhibited a lower aspect ratio (P = 0.042) compared with healthy subjects. The LDA classifier predicted that protrusions (up to 1.5 mm) at the volar beak of the first metacarpal were characteristic of EOA subjects. This was accompanied with widening of the articular surface, deepening of the articular surface, and protruding bone growths along the concave margin. These characteristics resulted in a leave-one-out classification accuracy of 73.9% (95% CI [61.9%, 83.8%]), sensitivity of 89.4%, specificity of 40.9%, and precision of 75.9%. CONCLUSION: Our findings indicate that morphological degeneration is well underway in the EOA TMC joint, and shows promise for a clinical tool that can detect these features automatically.

The effects of partial carpal fusions on wrist range of motion.

UNLABELLED: The objective of this investigation was to evaluate the effects of different partial wrist fusions on wrist motion. A total of 20 cadaveric wrists were tested in the intact state and after undergoing either a four-corner fusion or 2- and 3-bone fusion. The moment-rotation behaviour was measured in 24 directions of wrist motion about the forearm axis. The 2- and 3-bone fusion groups demonstrated increased radial deviation and pure flexion. Pure flexion was decreased in the four-corner fusion group. Radial extension and pure extension were decreased in all treatments compared with normal range of motion. Increasing the number of carpal bones within the fusion construct did not alter the functional axis of the wrist. Essentially equivalent motion is possible with 2-bone, 3-bone and four-corner fusions, with the exceptions of pure flexion and radial deviation. This data may influence surgeons when choosing between treatment methods. LEVEL OF EVIDENCE: N/A.

Men and women have similarly shaped carpometacarpal joint bones.

Characterizing the morphology of the carpometacarpal (CMC) joint bones and how they vary across the population is important for understanding the functional anatomy and pathology of the thumb. The purpose of this paper was to develop a statistical shape model of the trapezium and first metacarpal bones to characterize the size and shape of the whole bones across a cohort of 50. We used this shape model to investigate the effects of sex and age on the size and shape of the CMC joint bones and the articulating surface area of the CMC joint. We hypothesized that women have similar shape trapezium and first metacarpal bones compared to men, following scaling for overall size. We also hypothesized that age would be a significant predictor variable for CMC joint bone changes. CT image data and segmented point clouds of 50 CMC bones from healthy adult men and women were obtained from an ongoing study and used to generate two statistical shape models. Statistical analysis of the principal component weights of both models was performed to investigate morphological sex and age differences. We observed sex differences, but were unable to detect any age differences. Between men and women the only difference in morphology of the trapezia and first metacarpal bones was size. These findings confirm our first hypothesis, and suggest that the women have similarly shaped trapezium and first metacarpal bones compared to men. Furthermore, our results reject our second hypothesis, indicating that age is a poor predictor of CMC joint morphology.

Neurolysis of the distal superficial radial nerve for dysaesthesia due to nerve tethering.

The subcutaneous course of the superficial radial nerve over the radial border of the wrist and hand renders it very susceptible to injury. Both traumatic and iatrogenic injury can produce tethering of this nerve, presenting as dysaesthesia. This study was designed to evaluate the efficacy of neurolysis of the distal superficial radial nerve for this condition. Twenty-five cases of tethered superficial radial nerves underwent neurolysis. At final follow-up (mean 3.5 years), fourteen cases reported symptomatic resolution while eleven continued to experience dysaesthesia. Intra-operatively, evidence of external abnormality, scarring, or compression was identified in only six cases, and its presence did not correlate with symptomatic outcome. Although the majority of patients were improved postoperatively, the success rate was lower than anticipated. Therefore, while neurolysis of the superficial radial nerve offers the opportunity for pain relief, it does not reliably produce success.

[NeuFlex Silastic implant in metacarpophalangeal joint arthroplasty]. / Metakarpophalangeale Arthroplastik mit der NeuFlex-Silastikprothese.

The NeuFlex joint implant is, like the Swanson prosthesis, a silicone-spacer-implant for metacarpophalangeal arthroplasty in rheumatoid arthritis or osteoarthritis. The implant design differs essentially through a preformed, 30 degrees anatomically neutral angle and palmar lying movement center, which reduces strain across the hinge by 35%. The Swanson prosthesis is straight with a dorsal lying movement center. The advantage of this new design is an improved overall function arc and range of movement in the MCP-joint with a better grip-function. Results of simulator and laboratory tests are presented and interpreted. In 50 patients (168 MCP-joints), early results show an average functional arc of movement of 61 degrees and an average extensor lag of 12 degrees. The 30 degrees pre-bend angle, corresponding to the normal resting angle of the hand, and the improved flexor tendon excursion and moment arm appear to be the main reasons for the substantially improved flexion following use of the NeuFlex device.

Neuroimaging of declarative memory in schizophrenia.

The past three decades have seen tremendous growth in our understanding of the cerebral underpinnings of schizophrenia. including the neural correlates of the cognitive impairment seen in this syndrome. In this article we review the role that structural and functional neuroimaging has played in elucidating the cerebral basis for the declarative memory deficits associated with schizophrenia. Memory impairment in schizophrenia appears to involve abnormal connectivity between the prefrontal cortex and three regions important in normal learning and memory: the hippocampus, thalamus, and cerebellum.

Bone-retinaculum-bone reconstruction of scapholunate ligament injuries.

This article describes the indications for the use of a bone-retinaculum-bone autograft in soft tissue reconstruction of the torn scapholunate ligament. Specific surgical technique and postoperative management are highlighted. Initial results of a primary cohort of patients undergoing this technique are described. The technique is mainly indicated for patients with scapholunate ligament tears that are moderately easy to reduce by open methods.

Late-onset obsessive-compulsive disorder: a case series.

Obsessive-compulsive disorder (OCD) is a common and potentially disabling illness with onset usually in the second or third decade of life. Onset after age 50 is relatively rare and may be more likely to have an organic etiology. Out of an OCD patient population of over 1,000, the authors found 5 cases in which symptoms of OCD first developed late in life. Four of the 5 patients had intracerebral lesions in the frontal lobes and caudate nuclei, findings consistent with current theories about the pathogenesis of "idiopathic" OCD.

Thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is an often misdiagnosed cause of neck, shoulder, and arm disability. Neurovascular compression may be seen in the interscalene triangle, costoclavicular space, or posterior to the pectoralis minor, although any cause of abnormalities of shoulder girdle alignment may cause a localized area of brachial plexus compression. Nerve compression in this way may lead to upper extremity weakness, pain, paresthesias, and numbness. A careful and detailed medical history and physical examination are essential to proper identification of thoracic outlet syndrome, which remains primarily a clinical diagnosis. Diagnostic testing may differentiate other causes of pain or neurologic symptoms of the upper extremity from TOS. Clinical management is often challenging.

Diagnostic imaging and arthroscopy for wrist pain.

Chronic wrist pain may be evaluated by physical examination, imaging, and arthroscopy. Arthroscopy provides an attractive diagnostic and therapeutic modality in selected patients. Currently the correlation between arthroscopic findings and symptomatic pathology is not clear, because arthroscopy often identifies asymptomatic pathology. Nevertheless, the ability to diagnose and treat intra-articular pathology simultaneously provides a substantial advantage over radiographic analysis.

The effect of wrist guards on bone strain in the distal forearm.

There are increasing epidemiologic and biomechanical data suggesting that wrist guards are effective in preventing wrist injuries in snowboarders and in-line skaters. However, there have been few studies designed to determine how they function. In this study we explored the load-sharing function of wrist guards at subfailure loading levels. To do so, we measured bone strain in the distal radius, distal ulna, and midshaft of the radius in cadaveric forearms with and without two types of commercially available wrist guards. We also measured construct stiffness and energy absorption during testing. Our most significant findings were that dorsal and volar distal radius bone strain were reduced with both wrist guards, and wrist guards increased energy absorption. We also found a reduction in dorsal distal ulnar bone strain, but only with the one guard in which the volar plate was elevated off the heel of the hand. In our loading configuration, wrist guards did not increase bone strain at the radial midshaft. These findings provide insight into how wrist guards protect the wrist: during low-energy falls they function partly by load-sharing, as well as by absorbing impact energy.

Portable mini-fluoroscopy improves operative efficiency in hand surgery.

A paired case cohort study was performed using retrospective review of operative times for defined hand surgical procedures in an attempt to quantify efficiency with and without the use of portable fluoroscopy. Patients included in the study underwent 1 of 4 defined surgical procedures controlled to ensure similar operative technique (total wrist fusion, in situ 4-corner fusion, closed reduction/internal fixation using K-wires of phalangeal shaft fractures, and metacarpophalangeal or interphalangeal joint fusions using K-wires). One group used intraoperative standard film radiographs and the other used portable mini-fluoroscopy to examine hardware placement. Both groups were paired by operative procedure to eliminate procedure bias on overall operating time. Analysis demonstrated a 38% reduction in total operative time in the group using portable mini-fluoroscopy compared with standard intraoperative radiographs.

Traumatic nerve injuries about the elbow.

Although not common, nerve injuries about the elbow occur because of the proximity of the three upper extremity nerves or because of the relationship of the median, ulnar, and radial nerves to the bony and soft-tissue structures about the elbow joint. Nerve injuries at and about the elbow joint occur more frequently with fractures than with any other kind of trauma. Nerve injuries may be found with periarticular fractures, dislocations, gunshot wounds, lacerations, and other iatrogenic causes.

Mania associated with St. John's wort.

BACKGROUND: St. John's wort, the popular herbal remedy touted as an antidepressant, is generally thought to be benign, with few reported side effects. Given its possible efficacy as an antidepressant, evaluation of its propensity to cause affective switching should be evaluated. METHODS: This report presents two cases of mania temporally associated with the use of St. John's wort (hypericum). RESULTS: As with other antidepressant agents, St. John's wort may precipitate hypomania, mania, or an increased cycling of mood states, particularly in patients with occult bipolar disorder. CONCLUSIONS: Because the majority of people who take this popular over-the-counter preparation do so without formal psychiatric evaluations, risk of hypericum-induced mania may be significant. Physicians should screen patients for a history of hypomania or mania before recommending use of St. John's wort for depression.

Neuroimaging of hallucinations: a review of the literature.

While hallucinations have been described for over two millennia, their cause remains unclear. Brain-based models suggest that abnormal cerebral excitation and a lack of normal cerebral inhibition may play primary roles, but evaluation of these hypotheses has been hampered by difficulty in studying the hallucinatory state. Recent advances in neuroimaging have provided researchers with tools to study a variety of mental states, including hallucinations. We review the literature regarding the structural and functional neural correlates of hallucinations. Despite small sample sizes and methodological differences, several studies describe similar results: hallucinations are associated with sensory modality-specific activation in cerebral areas involved in normal sensory processing. Furthermore, neural activation may be specifically related to distinct phenomenological features of the hallucinatory experience. Further work is needed to better understand the neural basis of hallucinations.