SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
An investigation of sixty-seven embalmed cadaver hands was performed to determine if the topography of articular surfaces was related to thumb basal joint arthritis. The trapezial articular surface tended to be flatter in women and joints with early degenerative changes. The trapezial surface was transformed from a saddle type to a semi-cylindrical type with advancing arthritis.
Explore the source record for details and available documents.
The amount of mechanical energy transferred by two-joint muscles between leg joints during squat vertical jumps, during landings after jumping down from a height of 0.5 m, and during jogging were evaluated experimentally. The experiments were conducted on five healthy subjects (body height, 1.68-1.86 m; and mass, 64-82 kg). The coordinates of the markers on the body and the ground reactions were recorded by optical methods and a force platform, respectively. By solving the inverse problem of dynamics for the two-dimensional, four-link model of a leg with eight muscles, the power developed by the joint (net muscular) moments and the power developed by each muscle were determined. The energy transferred by two-joint muscles from and to each joint was determined as a result of the time integration of the difference between the power developed at the joint by the joint moment, and the total power of the muscles serving a given joint. It was shown that during a squat vertical jump and in the push-off phase during running, the two-joint muscles (rectus femoris and gastrocnemius) transfer mechanical energy from the proximal joints of the leg to the distal ones. At landing and in the shock-absorbing phase during running, the two-joint muscles transfer energy from the distal to proximal joints. The maximum amount of energy transferred from the proximal joints to distal ones was equal to 178.6 +/- 45.7 J (97.1 +/- 27.2% of the work done by the joint moment at the hip joint) at the squat vertical jump. The maximum amount of energy transferred from the distal to proximal joints was equal to 18.6 +/- 4.2 J (38.5 +/- 36.4% of work done by the joint moment at the ankle joint) at landing. The conclusion was made that the one-joint muscles of the proximal links compensate for the deficiency in work production of the distal one-joint muscles by the distribution of mechanical energy between joints through the two-joint muscles. During the push-off phase, the muscles of the proximal links help to extend the distal joints by transferring to them a part of the generated mechanical energy. During the shock-absorbing phase, the muscles of the proximal links help the distal muscles to dissipate the mechanical energy of the body.
OBJECTIVE: To evaluate radiographically the humeroulnar (HU) and humeroradial (HR) joint spaces in patients with long-term rheumatoid arthritis (RA). METHODS: An inception cohort of 74 patients with RA were followed for 15 yr. At the end-point, 148 elbows were radiographed by a standard method. The HU and HR joint spaces were examined from the anteroposterior radiographs by measuring the shortest tangential distance in the middle of the joints. Destruction of the elbow joints, assessed with the Larsen method on a scale of 0-5, was studied in relation to the joint-space measurements. RESULTS: Mean (s.d.) HU joint space (n=148) in RA patients was 2.5 (1.1) mm, range 0-4 mm [2.9 (0.8) mm in men and 2.4 (1.1) mm in women]. Mean (s.d.) HR joint space (n=140) was 2.3 (0.9) mm, range 0-4 mm [2.5 (0.8) mm in men and 2.3 (1.0) mm in women]. HU and HR spaces of the affected joints (Larsen grades 2-5) [1.9 (s.d. 1.1) and 1.8 (0.9) mm respectively] were notably narrower than those of the unaffected (Larsen grades 0-1) joints [3.1 (0.7) and 2.9 (0.6) mm]. All the joints graded as Larsen 4 or 5 (n=13) had a value of 0 mm for both joint spaces. Both the HU and the HR joint-space narrowing was associated with increasing destruction (Larsen grading) of the joint. [r= -0.69 (95% CI -0.77 to -0.60) and r= -0.70 (-0.78 to -0.60)]. The monotonic narrowing was significantly increasing from unaffected (Larsen 0, 1), slightly (2), moderately (3) to severely (4, 5) affected joints (P<0.001). A step in this process occurred between Larsen grades 3 and 4, when the mean joint space diminished from 1.4 and 1.5 respectively to 0 mm. CONCLUSIONS: Joint-space narrowing is a frequent consequence of rheumatoid affection of the elbow joint. HR joint space decreases together with HU joint space; however, the HR joint space is already slightly narrower at the start. The narrowing is a rather late phenomenon, occurring only after erosive destruction. This should be borne in mind when using the Larsen method to evaluate changes in the elbow joint.
OBJECTIVE: To evaluate radiographically the glenohumeral (GH) joint space in patients with long-term rheumatoid arthritis (RA). METHODS: A cohort of 74 patients with RA were followed prospectively for 15 yr. At the end point, 148 shoulders were radiographed using a standard method. The GH joint space was examined from the radiographs using a method developed previously for population studies; the joint space was measured at three different sites and the average of the three measurements, the integral space, was calculated. Destruction of the GH joints was assessed with the Larsen method on a scale of 0-5 and compared with the joint space measurements. RESULTS: The mean GH joint space in RA patients was 3. 1 (S.D. 3.3), range -17.3 to 5.7 mm; 2.7 mm (S.D. 4.5) in men and 3. 2 mm (S.D. 2.8) in women. The mean of the affected joints (Larsen grades 2-5), 1.7 mm (S.D. 4.5), was notably narrower than the mean 4. 4 mm (S.D. 0.6) of the non-affected (Larsen grades 0-1) joints. Pathological GH joint space, less than 2 mm, was found in five (15%) of 36 joints in men and in 14 (13%) of 112 joints in women. All the joints graded as Larsen 4 and 5 (n = 17) fulfilled this pathological criterion. Joint space narrowing was associated [r = - 0.66, 95% confidence interval (CI): -0.56 to -0.75] with increasing destruction (Larsen grading) of the joint. The narrowing was significant between non- (Larsen 0, 1), moderately (Larsen 2, 3) and severely (Larsen 4, 5) affected joints (P < 0.001). However, a remarkable step in this process occurred between Larsen grades 3 and 4 when the mean joint space diminished from 3.1 to 0.3 mm. CONCLUSIONS: Joint space narrowing is a frequent consequence of GH joint rheumatoid affection. However, joint space narrowing is a late phenomenon occurring not until after marked erosive destruction, which should be noted when using the Larsen method for GH joints.
OBJECTIVE: To determine the anatomic communications among compartments within the carpus, metacarpophalangeal and metatarsophalangeal joints, stifle joint, and tarsus in llamas. SAMPLE POPULATION: 88 limbs from 22 llamas necropsied because of reasons unrelated to disease of the carpus; tarsus; or metacarpophalangeal, metatarsophalangeal, or stifle joints. PROCEDURE: 1 compartment (randomly assigned) of each joint was injected with blue latex solution. Communication between joint compartments was determined by observation of latex in adjacent compartments following frozen sectioning. RESULTS: Of the 44 carpi, 30 (68%) had anatomic separation between the radiocarpal and middle carpal joints, whereas the remaining 14 (32%) had communication between the radiocarpal and middle carpal joints. In the metacarpophalangeal or metatarsophalangeal joints, medial and lateral joint compartments remained separate in 83 of 88 (94%) joints injected. The tibiotarsal and proximal intertarsal joints communicated in all tarsi examined, whereas 14 of 38 (37%) communicated between the proximal intertarsal and distal intertarsal joints. Communication between the distal intertarsal and tarsometatarsal joints was detected in 17 of 25 (68%) specimens; all 4 tarsal joints communicated in 11 of 42 (26%) specimens examined. Examination of 33 stifle joints that were successfully injected revealed communication between the femoropatellar, medial femorotibial, and lateral femorotibial joints. CONCLUSIONS AND CLINICAL RELEVANCE: These data suggest that it is important to determine the joint communications specific to each llama prior to treatment of septic arthritis. The metacarpophalangeal or metatarsophalangeal joint compartments may be considered separate, although the lateral and medial compartments infrequently communicate along the proximal palmar or plantar aspect.
OBJECTIVE: This article compares characteristics of physicians who have invested in health care business (joint ventures) to characteristics of physicians who have not, based on a survey of Florida physicians. DATA SOURCES/STUDY SETTING: In early 1990, a survey was mailed to a stratified random sample of 1,000 Florida physicians. Half were randomly selected from lists of joint-ventured physicians who had been identified as owners in a previous study by the Florida Health Care Cost Containment Board. The remaining half were assumed to be non-joint-ventured (although incomplete results from the previous study meant that some of these physicians would be joint ventured as well). We tagged survey variables with additional variables from the same year representing exogenous influences. STUDY DESIGN: The survey was mailed to a stratified random sample of physicians across specialty and geographic area, with half to identified joint-ventured physicians and half to a control group, some of whom were expected to be joint-ventured. Thus, results regarding differences would be understated. Key variables include referring versus nonreferring physician, to shed light on motivation for joint-venturing; clientele served, to see if systematic differences had implications related to access for poor or underserved persons; geographic area, to see if joint-ventures were undertaken to increase access in rural areas; and other practice variables such as size and type of practice. DATA COLLECTION/EXTRACTION METHODS: Data from all received surveys were encoded and analyzed using SPSS. Incomplete surveys were also encoded so that all information would be available for possible use. PRINCIPAL FINDINGS: Results indicate that joint-ventured physicians are more likely than non-joint-ventured physicians to be referring physicians. Also, joint-ventured physicians report serving lower proportions of Medicaid and self-pay (uninsured) patients and higher proportions of Medicare patients. Joint-ventured physicians are also more likely to practice in urban areas, to practice full time, to be members of larger practices, and to practice in group practices. Further, joint-ventured physicians are more likely to practice in areas with high proportions of Medicare patients. CONCLUSIONS: Policymakers should continue to regard physician joint ventures as problematic, since results of this study indicate that physicians who engage in a joint venture almost always have the ability to refer patients to that joint venture due to the nature of their practices. Results also show that joint ventures are associated with decreased access: that is, they provide care to lower proportions of poor and underserved patients and rural patients than their non-joint ventured counterparts.
OBJECTIVE: Serial synovial biopsy samples are increasingly being used for the evaluation of novel therapies for rheumatoid arthritis (RA). Most studies have used tissues from knee biopsies, but technical improvements have made serial small joint arthroscopy feasible as well. Theoretically, there could be differences in the features of synovial inflammation between various joints as a result of mechanical factors, differences in innervation, and other factors. We therefore undertook this study to compare the cell infiltrate in paired synovial biopsy samples from inflamed knee joints and paired inflamed small joints of patients with RA. METHODS: Nine RA patients with both an inflamed knee joint and an inflamed small joint (wrist or metacarpophalangeal joint) underwent an arthroscopic synovial biopsy of both joints on the same day. Multiple biopsy specimens were collected and stained for macrophages, T cells, plasma cells, fibroblast-like synoviocytes, and interleukin-6 (IL-6) by immunohistochemistry. Sections were evaluated by digital image analysis. RESULTS: There were no significant differences in mean cell numbers for all markers investigated in samples from the knee joint compared with samples from the small joints. We detected statistically significant correlations for the numbers of sublining macrophages, T cells, and plasma cells, as well as for IL-6 expression, between the knee joint and the small joints. However, there was no significant correlation between different joints for the numbers of intimal macrophages or fibroblast-like synoviocytes. CONCLUSION: The results of this study show that the inflammation in one inflamed joint is generally representative of that in other inflamed joints. Therefore, it is possible to use serial samples from the same joint, selecting either large or small joints, for the evaluation of antirheumatic therapies.
OBJECTIVE: To evaluate radiographically the acromioclavicular joint space in patients with long-term rheumatoid arthritis (RA). METHODS: A cohort of 74 patients with RA was followed prospectively for 15 yr. At the end point, 148 shoulders were radiographed with a standard method. The acromioclavicular (AC) joint space was examined from the radiographs with a method developed previously for population studies; the joint space was measured at its superior and inferior border, and the average of the two measurements, the integral space, calculated. RESULTS: Mean AC joint space in RA patients was 4.9 (S.D. 3.7), range 0-20.5 mm; 6.2 mm (S.D. 5.1) in men and 4.5 mm (S.D. 3. 0) in women. An AC joint space wider than 7 mm in men was found in 11 (31%) out of 36 joints and wider than 6 mm in women in 17 (15%) out of 112 joints. Joint space widening was associated (r=0.87, 95% CI 0.82-0.90) with increasing destruction (Larsen grading) of the joint and it seems to be an inevitable consequence of AC joint affection in RA. Joint space widening is more progressive on the caudal side because of the nature of the erosive destruction. Degeneration with joint space narrowing was observed in 8 (11%) patients (11 joints, 7%; three bilateral). CONCLUSIONS: The largest value of the joint space may be used when evaluating rheumatoid AC joint space. In RA patients, a joint space of >7 mm in men and >5 mm in women is a sign of destructive AC joint affection.
Radiologic, pathologic, and ancillary methods were used to determine the occurrence of degenerative joint disease involving multiple joints of immature and adult dogs. Animals were selected for the development of hip joint dysplasia and chronic degenerative joint disease. Of disease-prone dogs, 82% (45 of 55 dogs) had radiologic changes, indicative of hip dysplasia, by 1 year of age. At necropsy, more abnormal joints were identified than by radiographic examination. Among 92 dogs between 3 to 11 months of age that had joint abnormalities, 71% had hip joint involvement; 38%, shoulder joint involvement; 22%, stifle joint involvement; and 40% had multiple joint involvement. Polyarthritis was asymptomatic and unexpected. Radiographic examination of older dogs also revealed evidence of degenerative joint disease in many joints. Multiple joint involvement was substantiated at necropsy of young and mature dogs. A similar pattern of polyarticular osteoarthritis was revealed in a survey (computer search) of necropsy reports from medical case records of 100 adult and elderly dogs. Usually, the joint disease was an incidental observation, unrelated to the clinical disease or to the cause of death. The frequent occurrence of degenerative changes in several joints of dogs aged 6 months to 17 years indicated that osteoarthritis may be progressive in these joints and raises the possibility that systemic factors are involved in the disease process.
BACKGROUND: Conventional wisdom holds that hyperextension of the metacarpophalangeal joint of the thumb is secondary to degenerative subluxation of the trapeziometacarpal joint as occurs in osteoarthritis. We propose that a hypermobile metacarpophalangeal joint may have a causative role in the development of primary osteoarthritis at the base of the thumb by concentrating forces on the palmar aspect of the trapeziometacarpal joint. METHODS: Twenty fresh-frozen cadaveric forearm specimens were obtained post mortem from donors with no history of connective-tissue disease. Each specimen was categorized by its passive range of metacarpophalangeal joint motion. Testing was conducted with Fuji ultra-low-pressure-sensitive film while the hand was in the lateral-pinch mode with the metacarpophalangeal joint in each of the following positions: unrestrained, pinned in neutral, pinned in 30 degrees of flexion, and pinned in maximal hyperextension. Quantitative analysis of the trapezial contact surface at each of the metacarpophalangeal joint positions was performed, and the center of pressure was determined. Each specimen was then classified according to the extent of arthritic disease (nonarthritic, moderately arthritic, or affected by end-stage arthritis). RESULTS: In specimens affected by end-stage osteoarthritis, the center of pressure on the trapeziometacarpal joint moved dorsally by 56.8% of the length of the trapezial surface with metacarpophalangeal joint flexions of 30 degrees (p < 0.01), whereas the corresponding values were 28.2% and 40.9% in the hyperextended and neutral metacarpophalangeal joint positions, respectively. In specimens with moderate osteoarthritis, 30 degrees of metacarpophalangeal joint flexion also produced the most dorsal trapeziometacarpal center of pressure (44.8%); however, this center of pressure was not significantly different from the centers of pressure at the other metacarpophalangeal joint positions. In nonarthritic specimens, the center of pressure was again significantly more dorsal with metacarpophalangeal joint flexion of 30 degrees than it was at the other positions (p < 0.01). CONCLUSION: Metacarpophalangeal joint flexion effectively unloaded the most palmar surfaces of the trapeziometacarpal joint regardless of the presence or severity of arthritic disease in this joint.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
High compressive loads are transmitted through the shoulder across the acromioclavicular (AC) joint to the axial skeleton during activities of daily living and can lead to early joint degeneration or instability. The objective of this study was to quantify the effect of joint compression on the biomechanics of the intact and capsule-transected AC joint during application of three loading conditions. A robotic/universal force-moment sensor testing system was utilized to apply an anterior, posterior or superior load of 70 N in combination with 10 or 70 N of joint compression to fresh-frozen cadaveric shoulders (n=12). The application of joint compression to the intact AC joint decreased the posterior translation in response to a posterior load (-6.6+/-2.5 vs -3.7+/-1.0 mm, p<0.05). Joint compression also decreased the in situ force in the superior AC capsule by 10 N while increasing the joint contact force by 20 N for all loading conditions (p<0.05). The application of joint compression to the capsule-transected AC joint significantly decreased the amount of posterior and superior translation during posterior (-12.7+/-6.1 vs -5.5+/-3.2 mm, p<0.05) and superior (5.3+/-2.9 vs 4.2+/-2.3 mm, p<0.05) loading, respectively, while significantly increasing the coupled translations (anterior-posterior, superior-inferior or proximal-distal) in all loading conditions (p<0.05). The joint contact force also significantly increased by 20 N for all loading conditions (p<0.05). This quantitative data suggests: (1) common surgical techniques such as distal clavicle resection, which initially reduce painful joint contact, may cause unusually high loads to be supported by the soft tissue structures at the AC joint; and (2) compressive loads transmitted across a capsule-transected AC joint could be concentrated over a smaller area due to the increased coupled motion and joint contact force.
REASONS FOR PERFORMING STUDY: The centrodistal (CD) and tarsometatarsal (TMT) joints are often injected individually with a corticosteroid to resolve lameness caused by osteoarthritis (OA). There are no data available regarding diffusion of methylprednisolone (MP) from the TMT joint to the CD joint. HYPOTHESIS: A therapeutic concentration of MP diffuses into the CD joint after methylprednisolone acetate (MPA) is administered into the TMT joint. OBJECTIVE: To measure the concentration of MP in the CD joint after MPA was administered into the TMT joint. METHODS: MPA was administered into a TMT joint of 16 horses. At different times, the ipsilateral CD joint of these horses was injected with a small amount of saline and recovered saline was measured for concentration of MP using high performance liquid chromatography. RESULTS: Six hours after administration of MPA into the TMT joint, a therapeutic concentration of MP was found in all 10 CD joints sampled at this time. CONCLUSIONS: Horses with pain arising from the distal 2 joints of the hock can be treated by administering MPA into the TMT joint alone. POTENTIAL RELEVANCE: Administering MPA into the TMT joint only, to treat OA of the distal 2 hock joints, reduces the difficulties and risks associated with centesis of the CD joint.
Osseointegrated proximal interphalangeal joint prostheses with a replaceable joint spacer were used in 25 joints in 19 patients (five men and 14 women) aged 45 (16-67) years. Indications for surgery were post-traumatic arthrosis (nine joints in eight patients), primary osteoarthrosis (10 joints in eight patients), and rheumatoid arthritis (six joints in three patients). A silicone joint spacer was attached to titanium fixtures by short titanium stems that extended from the spacer and fitted into a central canal in the screws. The arthroplasty was done in one stage, which included resection of the joint followed by grafting of marrow and cancellous bone from the iliac crest into adjacent medullary cavities before insertion of the titanium fixture. Follow up at 8.5 (5-11) years showed that 47 out of 50 fixtures (94%) had successfully osseointegrated while 17 of 25 joint spacers (68%) had fractured. However, because of the design of the prostheses fractured joint spacers could easily be replaced and a new spacer could be connected to already osseointegrated screws. The joint spacer was replaced in 11 fingers once or several times. Range of movement (ROM) in the whole series (four fusions excluded) was 41 (0-85) degrees with an extension defect of 15 (0-55) degrees. In eight joints with permanently intact joint spacers the ROM was 39 (0-60) degrees with extension defects of 16 (0-40) degrees. In six joints in which the spacer was replaced once the ROM was 43 (0-85) degrees with an extension defect of 16 (0-55) degrees. Our data confirm good long-term osseointegration of titanium fixtures and that a joint spacer, if needed, can be replaced by a new spacer that can be attached to already osseointegrated screws without jeopardizing the ROM.
OBJECTIVE: To investigate the effect of change in the orientation of the distal radioulnar joint on the force in the joint and the strain in the interosseous membrane. DESIGN: Biomechanical study in fresh frozen cadavers. BACKGROUND: The articular surfaces of the distal radioulnar joint may be orientated in parallel with the long axis of the forearm (a Type I joint) or at an oblique angle opening distally to the ulnar side (a Type II joint). METHODS: Three cadaveric upper limbs were held on a custom built frame allowing measured rotation and axial loading across the wrist. Measurements of force in the distal radioulnar joint and strain in the interosseous membrane were taken and repeated after replacement of the distal radioulnar joint with prosthetic Type I and Type II joints. FINDINGS: The force in the joint and the strain in the interosseous membrane increased with increasing load across the wrist (P < 0.0001). The force in the Type I joint was reduced compared to the normal or Type II joint. This difference was greater with increasing load and was significant at 8 kg (P < 0.001). The strain in the interosseous membrane was maximal at neutral forearm rotation and decreased with increasing pronation and supination. INTERPRETATION: The force in the joint is greater with the Type II distal radioulnar joint. We believe this compressive force increases joint stability and this orientation of the articular surfaces should be considered in the design of a total distal radioulnar joint arthroplasty.
UNLABELLED: Joint mobilization is a common treatment used by healthcare professions for management of a variety of painful conditions, including inflammatory joint and muscle pain. We hypothesized that joint mobilization would reduce the bilateral hyperalgesia induced by muscle and joint inflammation. Mechanical hyperalgesia was measured by examining the mechanical withdrawal threshold of the rat's paw before and after induction of inflammation with 3% carrageenan (gastrocnemius muscle) or 3% kaolin/carrageenan (knee joint), and for 1 hour after knee joint mobilization. The mobilization consisted of rhythmically flexing and extending the knee joint to the end of range of extension while the tibia was simultaneously moved in an anterior to posterior direction. A bilateral decrease in mechanical withdrawal thresholds occurred 1, 2, and 4 weeks after inflammation of the knee joint or muscle. In animals with muscle inflammation, mobilization of the knee joint increased the mechanical withdrawal threshold bilaterally when given 1, 2, or 4 weeks after inflammation. However, in animals with knee joint inflammation, mobilization of the knee joint at 4 weeks increased the mechanical withdrawal threshold but had no effect when administered 1 or 2 weeks after inflammation. Therefore, joint mobilization reduces hyperalgesia induced by chronic inflammation of muscle and joint. PERSPECTIVE: This article shows that unilateral joint mobilization reduces bilateral hyperalgesia induced by chronic muscle or joint inflammation. Understanding the pain conditions in which mobilization produces an analgesic effect should assist the clinician in selecting appropriate treatment techniques. The bilateral effect suggests that central mechanisms could mediate the analgesia.