Rapid spread of mannan to the immune system, skin and joints within 6 hours after local exposure.

Psoriasis (Ps), psoriatic arthritis (PsA) and rheumatoid arthritis (RA) are common diseases dependent on environmental factors that activate the immune system in unknown ways. Mannan is a group of polysaccharides common in the environment; they are potentially pathogenic, because at least some of them induce Ps-, PsA- and RA-like inflammation in mice. Here, we used positron emission tomography/computed tomography to examine in-vivo transport and spread of mannan labelled with fluorine-18 [18 F]. The results showed that mannan was transported to joints (knee) and bone marrow (tibia) of mice within 6 h after intraperitoneal injection. The time it took to transport mannan, and its presence in blood, indicated cellular transport of mannan within the circulatory system. In addition, mannan was filtered mainly through the spleen and liver. [18 F]fluoromannan was excreted via kidneys, small intestine and, to some extent, the mouth. In conclusion, mannan reaches joints rapidly after injection, which may explain why mannan-induced inflammatory disease is targeted to these tissues.

Diagnostic distribution of non-traumatic upper limb disorders: vibrotactile sense in the evaluation of structured examination for optimal diagnostic criteria.

BACKGROUND: Upper limb disorders (ULDs) are common, and so are the difficulties in specific diagnoses of these disorders. Prior studies have shed light on the nerves in the diagnostic approach beside disorders related to muscles, tendons and joints (MCDs). OBJECTIVE: The study aimed to compare the distribution of upper limb disorders, and the vibration perception threshold (VPT) in different diagnostic groups according to 1) A-criteria: the SALTSA consensus criteria, including MCDs and four peripheral neuropathies, and 2) B-criteria: including MCDs and 10 different neuropathy diagnoses--re-defined in an attempt to refine diagnostic criteria of peripheral neuropathy in respect of different MCDs; and further to discuss the impact of the presented criteria. METHODS: 161 patients--recruited from 21 general practitioners--were examined by the same examiner according to the two sets of diagnostic criteria. VPT measurements were conducted in all patients. RESULTS: Three patients did not fulfill the criteria of any ULD diagnosis. A/B criteria were fulfilled for 181/183 upper limbs, respectively, out of which 29.3%/163.3% were neuropathy diagnoses alone, 23.8%/10.9% MCD alone, and 46.9%/25.7% were categorized as neuropathy in combination with MCD diagnoses. The overall agreement on presence of neuropathy was high (75%), but on focal level there was a large discrepancy. According to the A-criteria, patients with symptoms located at wrist and shoulder were primarily defined with wrist diagnoses, and only few had concomitant shoulder diagnoses. In contrast, the B-criteria primarily defined neuropathy located at the shoulder, often concomitantly with neuropathy of the radial and the median nerve at the elbow, but seldom at the wrist level. In MCDs defined by both sets of criteria--Rotator cuff syndrome and medial/lateral epicondylitis--the A-criteria defined more MCDs than the B-criteria, the B diagnoses typically constituted only a part of the A diagnoses and additionally defined neuropathy. The B-criteria showed more significant VPT findings than the A-criteria concerning the discrimination between limbs with and contralateral limbs without diagnoses as well as between diagnostic groups with and without neuropathy. CONCLUSIONS: The VPT findings suggest the B-criteria to be superior to A-criteria for differentiating between patients with and without neuropathy. This study shows that neuropathy is extensive in ULDs when specific diagnostic criteria are used. Additionally it suggests the importance of a critical revision of the current diagnostic criteria of upper limb neuropathy, and the differential diagnoses concerning the MCDs. Management and prevention is highly dependent on correct diagnoses.

Pronator syndrome: a retrospective study of median nerve entrapment at the elbow in female machine milkers.

Pronator syndrome (median nerve entrapment at the elbow) is a rare condition, but it is more common among women than men. A long-term retrospective follow-up study evaluating the outcome of surgical release of the median nerve for female machine milkers has never been carried out before, nor has a long-term study of non-treated female milkers with pronator syndrome. In the present study, two groups of machine milkers (surgical and non-surgical) were compared. The clinical examination focused on two parameters: focal tenderness and individual muscle strength. The results showed that the surgical group had no focal tenderness on palpation over the median nerve at the elbow and no selective weakness in the muscles examined, as compared to what was found before surgery. In the non-surgical group, focal tenderness was found in 12 out of 14, and 10 out of 14 showed the same weakness as in an earlier examination. While this study has limitations in sample size, surgical release of the median nerve at the elbow level, in cases of pronator syndrome, appears to provide an immediate as well as long-term return to normal strength of FPL and FDP II, along with a significant improvement in subjective status. In the non-surgical group, spontaneous improvement of the strength of FPL and FDP II was found in only four out of the 14 cases.

Upper extremity nerve involvement in Swedish female machine milkers.

Entrapment of the median nerve in the proximal forearm, the so-called pronator syndrome, is considered a rather rare condition but it is four times more common in women than in men. In this study, 23 of 30 female machine milkers with symptoms in the forearm and hand were clinically diagnosed as having the pronator syndrome. The diagnosis of median nerve involvement was based on the clinical history and on physical examination by a hand surgeon. All 23 milkers complained of aching in the volar part of the forearm and had a sensation of numbness, tingling, and decreased muscle strength in their hands, mostly in the hands which usually were statically loaded with heavy equipment. Objectively, all had an experience of tenderness over the pronator teres muscle. Furthermore, they showed reduced muscle strength, especially in the following muscles: pronator teres (PT), flexor carpi radialis (FCR), flexor pollicis longus (FPL), and flexor digitorum profundus II (FDP II). To validate the manual muscle testing, Mannerfeldt's intrinsicmeter was used to quantify the clinically observed weakness. Eight of the 23 milkers with pronator syndrome were surgically released from neuropathy and were almost symptom-free at follow-up after six months. One patient had a slight sensation of numbness and had to be given surgical carpal tunnel release later on. The external exposure of the arm during the application of the milking cluster probably causes muscle and fascial tensions that induce compression of the nerve. Further studies are needed to establish the level of the internal exposure.

Experimental osteonecrosis of the lunate. Revascularization may cause collapse.

Is lunate collapse in Kienböck's disease a consequence of spontaneous revascularization, leading to focal osteolysis? A literature review of osteonecrosis in other locations such as the femoral head and bone allografts showed clearly that the loss of mechanical integrity is due to cellular processes which follow the spontaneous restoration of blood supply. We found no evidence in the literature that the lunate has been shown to be avascular at the time of collapse. On the contrary, increased osteoclastic activity has been reported. We excised and reimplanted the lunate in two monkeys, and found spontaneous revascularization, leading to increased osteoblastic activity. Other parts of the bone were destroyed by osteoclasts, leading to collapse. This histological example suggests that it may be possible to make an analogy with osteonecrosis in other locations. Thus, changes on plain radiography may indicate that the bone is revascularized spontaneously. Before performing operative revascularization of the lunate, one should consider that revascularization is a probable cause for collapse.

Distal radius fracture and the distal radioulnar joint--anatomical considerations.

The ulna represents the non-rotating, stable and weightbearing part of the forearm around which the radius rotates in pronation and supination. The distal radioulnar joint is the distal half of an articulation, the proximal half of which is the proximal radioulnar joint. In spite of the distance between the two, the distal and proximal radioulnar joints together form a bi-condylar joint, the "forearm joint", with the axis of rotation running from the centre of the radial head out distally into the interosseous space towards the centre of the ulnar head. The end of the radius together with the hand and what is held in the hand will rest against the stable, immobile ulnar head, which acts as the keystone of the wrist. Mobility and stability of the distal radioulnar joint is accomplished by the combined action between fully congruent articulating surfaces and intact radioulnar ligaments. Following a distal radius fracture, the semilunar notch of the radius will no longer be congruent to the ulnar head due to the displacement of the distal fracture fragment of the radius into either dorsal angulation, radial angulation, or both. The stabilizing ligaments will tear. Any posttraumatic disabling dysfunction of the distal radioulnar joint should accordingly be treated by a corrective osteotomy of the radius at the fracture site in order to achieve full congruity between the semilunar notch and the ulnar head. Resection of the ulnar head deprives the wrist its keystone and should therefore be avoided.

The distal radioulnar joint in relation to the whole forearm.

The functional anatomy of the distal radioulnar joint was studied in relation to the whole forearm, using three fresh-frozen, above-elbow amputation specimens. The specimens demonstrate how the proximal and distal radioulnar joints together form a bicondylar joint of special character. The proximal "condyle," the radial head, rotates axially, whereas the distal "condyle," the ulnar head, is fixed with respect to rotation. The ordinary articulation of a bicondylar joint (pure axial rotation) is thereby changed into pronation-supination. Axial rotation is preserved proximally, while distally the radius swings around the ulnar head. The mobile radius is distally attached to the stable ulnar head by the dorsal and volar radioulnar ligaments, the dorsal ligament being tight for stabilization in supination and the volar ligament being tight in pronation. The ulnar head also serves as a keystone, carrying the load of the radius. Removal of the ulnar head allows the radius to "fall in" towards the ulna, with narrowing of the interosseous space.

Hyperpressure in the trapezius muscle associated with fibrosis.

The intramuscular pressure at rest and during load in 25 symptomatic trapezius muscles was found to be higher than in 32 asymptomatic muscles. Operative findings in 4 patients revealed dense fibrosis around the muscle, including the accessory nerve, which might explain the increased intramuscular pressure. Fibrotic tissue release resulted in the relief of symptoms and normalized pressure both at rest and during load. We believe trapezius fibrosis may be a new entity to include in the neck-shoulder syndrome.

The correlation between work environment and the occurrence of cervicobrachial symptoms.

The correlation between symptoms from the neck and upper extremities and some individual and work-related factors was analyzed in 2814 industrial workers. Physical stress by type of job was the factor most strongly correlated with ongoing cervicobrachial symptoms. Symptoms from the neck and upper extremities were twice as common in workers who used vibrating hand tools. Mental stress at the onset of the symptoms was associated with an increased prevalence of trapezius myalgia and with lateral humeral epicondylitis and "radial tunnel syndrome" in the dominant arm. Women had about double the rate of cervicobrachial symptoms as did men. Short stature increased the rate of symptoms from the neck, shoulders, and hands as did overweight. Playing of racquet sports decreased the risk of symptoms from the neck and hands.

Sickness absenteeism in an engineering industry--an analysis with special reference to absence for neck and upper extremity symptoms.

Neck and upper extremity symptoms (NES) are reported to increase among industrial workers. In order to quantify sickness absenteeism and relate it to some factors a questionnaire study was performed among 2,814 workers occupied at a Swedish engineering industry. Questions pertaining to age, sex, worker category, work with vibrating handtools, type of job and smoking habits were analyzed and correlated to sickness absenteeism for the previous year (1983). We found that the average days lost for personal illness was 17.2 days; 16.2 for men and 23.5 days for women. Ninety-four persons, 77 men and 17 women comprising 3.0% of all employees were sicklisted for NES corresponding to 3.3% of total sickness time lost. Blue-collar workers were sicklisted for NES five times more often than white collar workers and women in type 3 jobs (high NE stress), twice that of men occupied in the same type of job. Smokers had significantly higher absenteeism than non-smokers for any reason studied including NES. The study indicated a high prevalence of present NES problems (23%) but also that NES as a cause of leave of absence was relatively rare (3%).

Evaluation of impairment in the upper extremity.

A system for evaluation of physical impairment in the hand and upper extremity was developed and has been tested and used by many hand surgeons around the world. It was approved for international application by the International Federation of Societies for Surgery of the Hand. A method for evaluating amputation and sensory and motion impairments has been devised for the hand and upper extremity. Amputation impairment percentage values were determined for each digit or position thereof for the hand, wrist, elbow, and shoulder. By a principle of progressive multiplication of percentage values, impairment of a part can be related to the hand, upper extremity, and eventually the whole person. Sensory impairment is given 50% that of an amputation. Impairment of finger motion can result from lack of flexion (F), extension (E), or ankylosis (A). The method for evaluating flexion impairment is based on a combined angular measurement principle that was correlated with the linear measurement of Boyes. Values for flexion and ankylosis impairment were obtained from the American Medical Association guide. Values for extension impairment were derived from the formula A = E + F. Values for hyperextension were given consideration in the impairment tables. The sum of impairments as related to the whole hand equals the total impairment. The method to combine various impairments is based on the principle that each impairment acts not on the whole part (e.g., the finger) but on the remaining portion (e.g., proximal interphalangeal joint and proximally) after the preceding impairment has acted (e.g., on the distal interphalangeal joint). When there is more than one impairment to a given part, these must be combined before conversion to a larger part. The combined values determination is based on the formula "A% + B% (100% - A%) = the combined values of A% + B%." Based on this principle, the physical loss of each anatomic segment is related to the part, to the entire hand, and then to the body. The common impairment values have been placed in a table form for easier use.

The distal radioulnar joint.

Reconstructive surgery of the distal radioulnar joint should be considered for those in the age range of 20 to 50 years, particularly in those patients having sustained a high-energy injury and in cases where there is a great demand on the wrist joint for heavy work and sports activities. Meticulous preoperative planning in terms of correct clinical and radiologic evaluation and strict adherence to restoration of the joint congruency and restoration of ligament function are most important in obtaining reliable, long-term results in the vast majority of patients.

Radiologic examination and measurement of the wrist and distal radio-ulnar joint. New aspects.

Following fractures of the distal radius, a relatively high incidence of complications is caused by malalignment in the distal radio-ulnar (DRU) joint; recent anatomic and clinical investigations have shown congruity of that joint to be of significant importance for restoring the function of the wrist. The radius forms a moderately arched bone, which moves around the ulna in pronation and supination. Biomechanically, the ulna may be regarded as the pillar around which the radius moves. In an anatomic investigation of 5 arm specimens, we have shown that the maximum cartilage contact in the DRU joint between the ulnar head and the distal radius occurs in the neutral rotation position. A proposed routine examination method of the wrist and forearm includes a true antero-posterior and a lateral projection of the radius and the ulna, performed with the forearm and wrist in a neutral rotation, a neutral wrist deviation and with the elbow angled 90 degrees. Such an examination implies a standardized and reproducible method. In a radioanatomic investigation, a series of 50 healthy wrists and forearms were examined. A simple measuring technique is presented, applicable to the DRU joint and wrist favouring the ulna as the bone through which a reproducible long axis of the forearm/wrist may be drawn. It is suggested that the length of the radius should be judged relative to the ulna. Ulnar head inclination and radio-ulnar angle are new concepts, being major characteristics of the DRU joint. These angles of the right and left wrist were equal and no difference was found between the sexes. Minor alterations of the distal radius may be revealed when estimating these angles.

Metacarpophalangeal joint replacement with osseointegrated endoprostheses.

A new type of endoprosthesis for reconstruction of the metacarpophalangeal (MCP) joint has been tested. The novel arthroplasty consists of a joint mechanism with two screw-shaped fixtures for bone anchorage. These fixtures, of commercially pure titanium, are gently screwed into the anchoring bone on each side of the diseased joint, the aim being to achieve osseointegration, i.e. a direct contact between implant and bone without interposed soft tissue layers. The hand was immobilized in a dorsal splint for 8-10 days post-operatively after which a carefully controlled mobilization program was initiated. In principle, the titanium fixtures, the surgical technique and the primary immobilization represent an approach similar to that previously used in various reconstruction procedures of the jaw. This paper describes 5 case histories of reconstructions required because of osteoarthrosis in a single MCP joint. Prior to the operation, all patients suffered from severe problems resulting from their arthrotic joints and they had not been able to work for several months. After surgery they were evaluated by a clinical assessment program and X-rays were taken at various times of follow-up. As well as visual inspection all radiograms were subjected to densitometry by means of a computer-based image-analysis system in order to provide information on the development of bone density in the bone-to implant interface region. From a functional point of view the treatment with osseointegrated prostheses must be regarded as being successful. All patients were able to go back to their original work and their hands had a satisfactory range of movement and grip strength with no signs of impaired function on longer follow-up time. Clinical problems were one re-operation, one case of implant fracture and one case requiring exchange of the joint mechanism. The computer-assisted evaluation of the radiograms revealed the presence of calcified tissue in many sections where the naked eye was not capable of differentiating any bone. In conclusion, it seems possible to establish osseointegration of MCP-endoprostheses in the arthrotic human joint in complicated cases which were regarded as contraindicated for any other joint arthroplasty.

Anatomical studies on the geometry and stability of the distal radio ulnar joint.

In fresh-frozen amputated- and cadaver arm specimens the anatomy and stability of the distal radio ulnar joint were investigated. The articulating surface of the sigmoid notch of the radius and the corresponding surface of the ulnar head facing the sigmoid notch were studied in transverse cryo sections. In each specimen the radius of the curvature of the sigmoid notch was 4-7 mm larger than that of the ulnar head and consequently pronation and supination are combined rotation-sliding movement in the distal radio ulnar joint. The radio ulnar ligament consists of a dorsal and a volar fibrous part, broadly attached to the distal rim of the sigmoid notch and converging towards the fovea of the ulnar head. The cartilaginous disc is centrally located between these fibrous strands. In neutral position the articulating surface of the sigmoid notch is optimally covering the articulating surface of the ulnar head. This contact area is gradually diminished during pronation-supination until only a marginal contact remains at the end of each movement. The distal radius is kept stable in pronation by the volar part and in supination by the dorsal part of the radio ulnar ligament.

The distal radio ulnar joint. The influence of geometry and ligament on simulated Colles' fracture. An experimental study.

In five fresh frozen arm specimens Colles' fracture was simulated by a dorsal wedge osteotomy of the distal radius. A spring load was applied to the cortex of the distal radius fragment exerting a constant traction force in proximal direction. The distal radius fragment showed minimal dorsal angulation as the forearm was positioned in neutral or pronation, assuming the distal radio ulnar joint including its radio ulnar ligament was kept intact. As the forearm was moved into supination the distal fragment angulated dorsally to close the dorsal open gap in spite of the ligament being intact. When the radio ulnar ligament was detached the stability was however lost in any forearm position. The result supports the concept of immobilizing a satisfactorily reduced Colles' fracture in neutral position, possibly in slight pronation but never in supination.