Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0231749 (knee pain)
 2,815 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The alterations in thigh muscle properties of chondromalacia patellae patients during isometric and dynamic endurance tests were studied using a variokinetic knee testing system linked to surface EMG. A total of 41 patients (chondromalacia group) with arthroscopically certified chondromalacia of the patella were studied. The control group consisted of 31 healthy adult volunteers with no history of knee pain or trauma. Peak torque values were 21% (p < 0.01) and force output values 25% (p < 0.05) lower on the symptomatic side of the chondromalacia group than in the control group. The decrease in the ratio between integrated EMG (IEMG) and measured force were found in all parts of the quadriceps femoris muscle in patients with chondromalacia of the patella in isometric extension. No change in the normalized IEMG levels of the thigh muscles were found between chondromalacia patients and controls in dynamic endurance test. The severity of the chondromalacia of the patella did not affect the level of electromyographic activation in thigh muscles. The ratio of normalized EMG levels of vastus medialis and vastus lateralis did not differ between the groups. The present study showed that chondromalacia patellae patients have reduced force and electromyographic activation levels of quadriceps femoris muscle. Especially, the explosive strength of the quadriceps femoris muscle is reduced.
 ...
PMID:Decreased torque and electromyographic activity in the extensor thigh muscles in chondromalacia patellae. 771 30

We studied a group of 602 patients who had anterior cruciate ligament reconstructions between 1987 and 1992. An autogenous patellar tendon graft was used, regardless of preexisting patellofemoral pain or chondromalacia. The surgeon and rehabilitation protocol were the same for all patients, with emphasis on obtaining full knee hyperextension postoperatively. All patients were evaluated by a questionnaire designed to determine the incidence and severity of anterior knee pain as it relates to sporting or daily living activities, prolonged sitting, stair climbing, and kneeling. Range of motion for the study group was recorded during physical examination. We compared the findings with those from a control group of 122 patients who had no previous knee injury. The study group reported a mean score of 89.5 +/- 12.5, compared with 90.2 +/- 12.3 in the control group. Both the operative and control groups reported little or no symptoms during sporting activities (94% and 92%, respectively). No differences were noted with respect to the other activities surveyed. These results demonstrate that anterior knee pain after anterior cruciate ligament reconstruction is not an inherent complication associated with patellar tendon harvesting. We suggest that the increased incidence of anterior knee pain with an autogenous patellar tendon graft can be prevented by obtaining full knee hyperextension postoperatively. This goal can be achieved through preoperative rehabilitation and a postoperative protocol emphasizing early restoration of full knee hyperextension.
 ...
PMID:Preventing anterior knee pain after anterior cruciate ligament reconstruction. 900 90

The aim of this study was to evaluate the effect of bicycle pedal design on the mechanics of the patellofemoral joint. Previous research determined that for certain riders the non-driving varus and internal knee moments could be reduced by switching from fixed to free floating pedals (Ruby and Hull, 1993). It was postulated that the presence of varus and internal knee moments during fixed pedal cycling may adversely affect patellofemoral joint contact mechanics which could lead to the development of anterior knee pain. To investigate the effect of pedal design the hypothesis that varus and internal intersegmental knee moments significantly increase patellofemoral contact pressure, contact area and contact force was tested. To test this hypothesis cycling loads were simulated in vitro using a six-degree-of-freedom load application system (LAS). Using the LAS, varus moments ranging from 0-20 Nm and internal knee moments ranging from 0-10 Nm were applied simultaneously with quadriceps force at knee flexion angles of 60 and 90 degrees. Patellofemoral contact patterns were measured using pressure sensitive film. An applied 10 Nm internal moment significantly increased both contact area by 16% and contact force by 22% at 90 of flexion. The application of a 20 Nm varus moment modestly yet significantly increased contact area by 6% and contact force by 5%. When applied in combination, varus and internal knee moments increased contact area and force by as much as 29% and 28% respectively. The mean contact pressure was not significantly increased by either of the two moments. The results suggest that non-driving intersegmental knee moments subject the patellofemoral joint to loads and contact patterns which may accelerate the development of chondromalacia.
 ...
PMID:The effect of intersegmental knee moments on patellofemoral contact mechanics in cycling. 979 67

The patellofemoral joint is a complex articulation based on its dependence on both dynamic and static restraints for stability. Classification of patellofemoral disorders has been frought with confusion. However, progress has been made in the classification and understanding of these disorders by improved understanding of the biomechanics of the joint and by clarification of the terminology to describe patellofemoral pathology. The term chondromalacia patella, although once used as an all-inclusive term for anterior knee pain, is now widely accepted as a term used to describe pathologic lesions of the patellar articular cartilage found at arthroscopy or arthrotomy. An adequate classification system should aid in proper diagnosis and treatment of specific problems. If properly devised, it should also aid in the comparison of results between different treatment centers. In addition, it should be a system that is simple and useful in the clinical setting with minimal use of complicated imaging techniques. From a clinical perspective, patellofemoral problems in the skeletally mature patient fall into three broad categories: 1) patellofemoral instability, i.e., subluxation or dislocation; 2) patellofemoral pain with malalignment but no episodes of instability; and 3) patellofemoral pain without malalignment. The myriad of patellofemoral disorders then fall into subclassifications of these categories. Treatment algorithms can be broadly developed based on the general category, with specific treatments based on the subclassification. In this paper, the authors will present a review of the pertinent literature documenting patellofemoral classification systems and develop concepts of clinical classification of patellofemoral disorders based on the three categories described above.
 ...
PMID:Clinical classification of patellofemoral pain and dysfunction. 980 78

Anterior knee pain is a frequent musculoskeletal complaint affecting adolescent population with incidence of 36% in 14 years old schoolchildren. Until late sixties anterior knee pain used to be associated with chondromalacia. This review discusses etiology and treatment of anterior knee pain. Various etiologic theories exist ranging from trauma and patellar maltracking to retinacular nerves injury. None of these theories has been generally accepted and etiology of patellofemoral pain remains unclear.
 ...
PMID:[Anterior knee pain syndrome: a historical review]. 985 57

Fifty-seven consecutive patients (33 men and 24 women), with a mean age of 32 years (range 16-53 years), who suffered from an isolated full-thickness cartilage defect of the patella and disabling knee pain of long duration, were treated by autologous periosteal transplantation to the cartilage defect. The first 38 consecutive patients (group A) were postoperatively treated with continuous passive motion (CPM), and the next 19 consecutive patients (group B) were treated with active motion for the first 5 days postoperatively. In both groups, the initial regimens were followed by active motion, slowly progressive strength training, and slowly progressive weight bearing. In group A, after a mean follow-up of 51 months (range 33-92 months), 29 patients (76%) were graded as excellent or good, 7 patients (19%) were graded as fair, and 2 patients (5%) were graded as poor. In group B, after a mean follow-up of 21 months (range 14-28 months), 10 patients (53%) were graded as excellent or good, 6 patients (32%) were graded as fair, and 3 patients (15%) were graded as poor. Altogether, nine of the fair or poor cases (50%) were diagnosed with chondromalacia of the patella. Our results, after performing autologous periosteal transplantation in patients with full-thickness cartilage defects of the patella and disabling knee pain, are good if CPM is used postoperatively. The clinical results using active motion postoperatively are not acceptable, especially not in patients with chondromalacia of the patella.
 ...
PMID:Superior results with continuous passive motion compared to active motion after periosteal transplantation. A retrospective study of human patella cartilage defect treatment. 1046 13

Anterior knee pain is not a disease, but a syndrome with numerous causes. This paper describes its appearance in the patellofemoral joint in sportsmen and in untrained people. Chondromalacia patellae is a condition of the cartilage, not a disease, that is, it is never diagnosed alone. Relative muscular insufficiency, especially of the knee extensors, may occur in children and adolescents, as they grow rapidly. The consequence is a unbalance of active stabilizers and the disturbance of the slippery trail of patella, particularly in the presence of dysplasia of patellofemoral joint. The impingement syndrome pain occurs in sportsmen and people overloading the patellofemoral joint. Other causes of anterior knee pain should be excluded in clinical examination and slippery trail of patella, its position, and signs of instability should be determined. This paper gives an overview of patellar chondromalacia, lateral pressure syndrome, patellar subluxation, patellar acute and recurrent luxation, and idiopathic anterior knee pain. The treatment is basically conservative. Stretching exercises and the strengthening of certain groups of femoral muscles serves to regain the balance, thus normalising the slippery trail and taking off the burden from the patellofemoral joint. If conservative treatment fails, surgery is the alternative.
 ...
PMID:[Anterior knee pain associated with sports and work]. 1183 Nov 27

Painful disorders of the patellofemoral joint are one of the most frequent complaints in orthopaedic and sports medicine. The purpose of this study was to assess the value of single photon emission computed tomography (SPECT) bone imaging compared with arthroscopy in the differential diagnosis of anterior knee pain. Twenty-seven patients with chronic anterior knee pain and 27 age matched control patients were examined prospectively. All patients underwent a detailed clinical history and a thorough physical examination of the knee. Planar and SPECT knee scintigraphy was performed using 99mTc methylene diphosphonate (99mTc-MDP). Subsequently, arthroscopic examination of all three compartments of the affected knee was performed. The association between the scintigraphic findings and arthroscopy was examined statistically. Planar and SPECT scintigrams were classified as follows: focal or diffuse uptake in the patella only (eight patients), uptake in the patella and a corresponding focus in the distal femur (12 patients), and uptake in the patella associated with linear increased activity along the distal femur (six patients). One patient had no patellofemoral SPECT abnormalities. Six of eight patients with isolated increased patellar activity were diagnosed with chondromalacia of the patella, while 2/8 patients had arthroscopic findings unrelated to patellofemoral abnormalities. Seven of 12 patients with corresponding uptake in the patella and distal femur were diagnosed with patellofemoral arthritis. Eleven other patients with corresponding patellar and femoral activity were diagnosed with increased lateral patellar compression syndrome. In these patients the patellar foci were always lateral, and they separated during flexion of the knee. Seven patients had further scintigraphic findings in addition to patellofemoral abnormalities, unsuspected clinically. Nine of 27 patients in the control group (33%) had either focal or diffuse increased patellar uptake. Compared to arthroscopy SPECT imaging had a sensitivity of 100% for patellofemoral abnormalities and a specificity of 64% (negative predictive value, 100%; and positive predictive value, 72%). The overall observed agreement between SPECT and arthroscopy was 81% (kappa=0.63). It is concluded that SPECT imaging of the knee is highly sensitive for the diagnosis of patellofemoral abnormalities. SPECT significantly improves the detection of maltracking of the patella and the ensuing increased lateral patellar compression syndrome. This information could be used to treat patellofemoral problems more effectively.
 ...
PMID:Incremental diagnostic value of 99mTc methylene diphosphonate bone SPECT in patients with patellofemoral pain disorders. 1267 69

A 49-year-old woman with right knee pain and a chondral defect on the medial femoral condyle underwent an osteochondral transfer. The patient initially had pain relief, but then sustained a twisting injury and had progressive chondromalacia and pain on the affected side. She subsequently underwent a total knee replacement, and the tissue from the osteochondral transfer (OATS) site was harvested for analysis. In vitro MR microimaging of the excised joint segment revealed undamaged, full-thickness cartilage on the OATS plug, intact cartilage on the posterior condyle, and severely thinned and damaged cartilage on the anterior condyle. Alcian blue-stained sections revealed that proteoglycans were present throughout the OATS core but were nearly absent in the native cartilage. Quantitative T(1) data acquired after equilibration with Gd-DTPA indicated a distribution of matrix fixed charge in the OATS plug and anterior tissue that agreed well with histology and literature observations, while the posterior native cartilage appeared to have fixed charge similar to that of the OATS tissue. Histology revealed poor graft integration between OATS and native cartilage, with a distinct layer of fibrous tissue at the posterior interface. MRI images, by comparison, showed a hypointense feature at the posterior interface but uniform intensity across the anterior interface. Quantitative T(2), magnetization transfer and T(1) data acquired with and without gadolinium contrast showed dependences on depth, location, and pathology that were consistent with measurements reported in the literature for articular cartilage.
 ...
PMID:Ex vivo magnetic resonance microscopy of an osteochondral transfer. 1272 Feb 71

We present a case of chondromalacia of the fabella, describe a provocative diagnostic test and review the literature on this unusual cause of knee pain.
 ...
PMID:The fabella: a forgotten source of knee pain? 1519 3


<< Previous 1 2 3 4 Next >>