Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Patellar Dislocation”

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.

At least 721 records · Page 40Linked to original sources

Easily missed injuries around the knee.

Most fractures around the knee are easily detected on high-quality radiographs. However, some fractures and musculotendinous and ligamentous injuries have subtle findings and may be difficult to detect even with optimal images; these injuries include tibial plateau fractures, Segond fractures, stress fractures, fibular head fractures and dislocations, injuries to the patella and extensor mechanism, and Salter type fractures. Clinically suspected tibial plateau fractures unseen on standard views may be seen on tangential or tunnel projections. Segond fractures usually have a characteristic appearance on anteroposterior radiographs but occasionally are seen only on tunnel views. Stress fractures of the proximal tibia may be accompanied by a vague band of increased sclerosis or endosteal callus on either side of the epiphyseal scar. Correct diagnosis of fibular head dislocations requires clinical suspicion, since these injuries often are not recognized on initial radiographs. Careful evaluation of the congruity of the tibiofibular joint on the lateral projection is the key to diagnosis. Vertical patellar fractures are often nondisplaced and are best evaluated with sunrise or Merchant views; avulsion fractures from the proximal or distal poles, with lateral views; and osteochondral fractures, with sunrise or internal oblique views. Salter I injuries can be visualized on oblique and anteroposterior views obtained with stress applied to the knee. Some occult Salter I fractures are diagnosed on follow-up radiographs, which show periosteal reaction. Imaging modalities other than radiography are rarely needed to diagnose fractures but are useful for evaluating the extent of displacement or confirming soft-tissue injuries.

Fractures, Bone↗

Patella alta and gonarthrosis.

The frequency of patella alta as defined by the method of Insall & Salvati in knees with femoro-patellar osteoarthrosis was determined. Patella alta was six times as frequent in knees with osteoarthrosis than in those with a normal femoro-patellar joint. Patella alta is more common in women and is often bilateral.

Female↗

Anterior approach to the knee with osteotomy of the tibial tubercle for bicondylar tibial fractures.

Eight patients--six who had a bicondylar fracture of the tibia and two who had a complex fracture-dislocation--were treated by open reduction and internal fixation that was achieved through an anterior approach to the knee. The approach included elevation of the tibial tubercle, proximal retraction of the extensor mechanism (patellar tendon, retropatellar fat pad, and patella), and transection and detachment of the anterior horn of one or both menisci. The extent of the approach depended on the specific need for exposure. The quality of reduction was better and the rate of complications was lower, compared with conventional approaches. The main advantage of this approach is that the tibial plateau and the intercondylar notch are exposed clearly and completely; this is a prerequisite for the rapid reconstruction of the joint surface and, in some patients, for the reattachment or primary suture of the cruciate ligaments. I recommend the anterior approach with osteotomy of the tibial tubercle in the treatment of patients who have a severe displaced bicondylar fracture of the proximal end of the tibia.

Adolescent↗

Effect of experimental patellar luxation on the knee joint in the rat.

In 16 male Wistar albino rats the patella was fixed to the lateral aspect of the lateral condylus of the femur. Animals with luxated knee joint and controls were sacrificed 7-9 months after surgery. Operated knee joints were processed for histology and subjected to morphometric analysis in comparison to the controls.- It was found that (1) the artificial disturbance of the femoro-patellar junction resulted in a severe destruction of articular cartilages of the tibio-femoral and femoro-patellar junction; (2) the destructions progressed with time; (3) there was no substantial difference between the changes of the medial and lateral articular surfaces of the femur and tibia; (4) changes comprised focal cartilage necrosis, widening of cartilaginous area under the tide-mark, proliferation of subchondral bone and formation of osteophytes; (5) the fact that a change of the statics of femoro-patellar junction leads to panarthrosis, moreover that articular capsule, menisci, epi-, meta-, and diaphyseal bone areas are also involved, indicate the complexity of the question. The findings indicated that changes of the femoro-patellar junction play a role in the degenerative processes of the knee joint. It is concluded that early recognition and treatment of femoro-patellar alterations may help in the prevention of knee panarthrosis.

Animals↗

Ballet injuries: the Australian experience.

There is a distinct difference between ballet injuries and sports injuries in general, and the sports medicine physician needs to study the technique of dance and the specific injuries that it may produce in order to treat dancers effectively. In Australia, which is typical of other countries where ballet is performed, ballet injuries include strained lumbar muscles, sprained ankle, Achilles tendinitis, clicking hip, jumper's knee, chondromalacia, stress fractures, patellar subluxation, and other knee and tendon problems.

Australia↗

Surgical treatment of congenital dislocation of the patella.

Eleven patients with 17 involved knees were surgically treated for congenital dislocation of the patella between 1978 and 1993. Ten patients with 13 involved knees followed up for a minimum of 2 years postoperatively composed the study group. Six patients had both involved knees operatively treated. In four patients, congenital dislocation of the patella was associated with a recognizable syndrome. All patients had fixed, painful lateral dislocation of the patella that could not be reduced. The average age at presentation was 7 years and 9 months (range, 2 months to 15 years). All patients underwent an extensive procedure including lateral release and advancement of the vastus medialis obliquus. Skeletally immature children underwent medial transfer of the entire patellar tendon. Skeletally mature patients underwent medial transfer of the tibial tubercle. Ten patients with 13 involved knees were followed up for > or = 2 years. Mean follow-up was 5.1 years (range, 1-17.5). At last follow-up, all patients reported a marked increase in activity tolerance and relief of pain. Average extension lag improved from 15 degrees before to 2 degrees after surgery. One superficial wound infection occurred; no patient developed a deep infection. One peroneal neurapraxia occurred but resolved with observation. Redislocation of the patella occurred in the immediate postoperative period in one patient. Operative treatment of congenital dislocation of the patella can predictably improve knee function when all aspects of the complex pathologic anatomy are addressed.

Adolescent↗

The effect of electrostimulation and high load exercises in patients with patellofemoral joint dysfunction. A preliminary report.

Traditional conservative treatment for patellar disorders is successful in about 80 percents of cases. We introduced two new conservative treatment protocols for patellar pathology in order to further improve the success rate. The first protocol consisted of high load/low repetition quadriceps femoris training (10 patients) while the second enclosed selective electrostimulation of vastus medialis muscle (7 patients). Results were evaluated clinically and neurophysiologically. High load/low repetition training resulted in significant increase of maximal voluntary contraction of quadriceps muscle (P < 0.001). Significant gain of Activity (P = 0.017) and Kujala scores (P = 0.07) was observed in group with high load/low repetition quadriceps training compared to patients with electrostimulation. There was no significant change in neurophysiological or clinical status between the beginning and the end of treatment with electrostimulation. Our results indicate that high load/low repetition quadriceps femoris training poses an important alternative to traditional conservative treatment protocol for patellar disorders.

Electric Stimulation↗

Chondromalacia induced by patellar subluxation: morphological and morphometrical aspects in rabbits.

The purpose of this study was to describe morphologically and quantify the changes of the articular cartilage in chondromalacia, concerning both the chondrocytes and extracellular matrix. Eight rabbits were submitted daily to patellar subluxation, causing chondromalacia after two weeks. The knee fragments obtained were processed by the standard methods. These experimental conditions caused degenerative alterations of the articular cartilage, varying from a slight decrease of proteoglycans, to fibrillations, clefts, and horizontal splitting. The results showed a significantly increase number of chondrocytes (p < 0,000139), although smaller in size (p < 0,000109). The immobilization for 2 weeks and the intermittent passive daily motion afterwards for a period of 2 weeks, was effective to cause patellar chrondomalacia in rabbits.

Animals↗

Reconstruction of the medial patellofemoral ligament with autologous quadriceps tendon.

In knees with insufficient or previously disrupted medial retinacular and patellofemoral ligaments caused by subluxation or dislocation, anatomic reconstruction of the medial patellofemoral ligament may be performed. This procedure involves harvesting of an 8 x 70-mm medial quadriceps tendon graft, which leaves the quadriceps tendon retinacular attachment intact and avoids patellar and femoral drill holes. This graft is passed beneath the retinaculum adjacent to the femoral epicondyle and is sutured to the medial intermuscular septum-a procedure that reproduces the medial patellofemoral ligament and is supported by imbrication of the remaining medial retinaculum. The tension of the graft and of the medial retinaculum is set at closure with the knee in 30 degrees to 45 degrees of flexion; this allows the patella to be moved a distance equal to 25% of its width. Avoidance of drill holes allows the procedure to be used regardless of skeletal maturity and reduces fracture complications, inadequate graft placement, and failure of fixation. Postoperative rehabilitation includes immediate knee motion from 0 degrees to 90 degrees and partial weight bearing.

Arthroscopy↗

Evaluation of patellar retinacular tension during total knee arthroplasty. Special emphasis on lateral retinacular release.

Tension of a suture placed to the patella to close the medial capsule during 35 primary total knee arthroplasties was measured. The increase in tension with flexion after arthrotomy was significantly smaller in 10 knees with a subvastus incision (subvastus group) than in 25 knees with a standard medial parapatellar incision (standard group). With the prosthesis in place, the patella showed maltracking with the no-thumb technique in 1 knee (10%) of the subvastus group and in 9 knees (36%) of the standard group. A lateral retinacular release was performed in 5 of these 10 knees but not in the remaining 5 knees because the increase in tension was a minimum. There was no case of patellar maltracking at an average follow-up period of 2.1 years after surgery, suggesting that a lateral release is not always needed if retinacular tension shows no significant increase, even cases where the patella dislocates with the no-thumb technique.

Aged↗

[2-dimensional CT arthrotomography in the postoperative follow-up of a new anterior cruciate ligament plasty].

Fifty-eight patients underwent intraarticular reconstruction of the anterior cruciate ligament. This was performed by using an autogenous transplant from the mid portion of the patellar ligament with a proximal and distal bone block, as described by Hertel. For comparison with the conventional X-ray examination, HRCT was performed to study the early postoperative results. In four patients (7%) dislocation of the bone block in the femoral condyle was seen. Two-dimensional reconstruction proved to be a satisfactory method for demonstration of the exact position of the autogenous transplant in both coronary and sagittal planes.

Adolescent↗

Comparison of surgical treatments for knee dislocation.

This retrospective study compared three surgical procedures for acute knee dislocation. Eleven patients (group 1) underwent direct repair of the cruciate ligaments, 6 patients (group 2) underwent anterior cruciate ligament (ACL) reconstruction with hamstring tendons and posterior cruciate ligament (PCL) reattachment, and 6 patients (group 3) underwent PCL reconstruction with ipsilateral bone-patellar tendon-bone and ACL reconstruction with doubled semitendinosus and gracilis tendons. Average follow-up was 6.9 years (range: 24 months to 19 years). Surgical results were evaluated using the IKDC evaluation form, KT-2000 arthrometer, and Lysholm and Tegner scores. Statistical analysis was performed using Fisher's exact test and the Cochran-Mantel-Haenszel test to compare different surgical procedures. In terms of stability and range of motion, results were less favorable after direct repair and cruciate ligament reattachment. Better results were reported after combined ACL and PCL reconstruction. Average side-to-side total anteroposterior translation as measured by the KT-2000 arthrometer at 20 degrees +/- 5 degrees of knee flexion was 6.67 mm, 3.6 mm, and 3.2 mm in groups 1, 2, and 3, respectively. At final International Knee Documentation Committee (IKDC) evaluation, only 2 group 3 patients achieved a group qualification A, while a group qualification B was achieved by 5 patients (2 patients in group 1, 2 patients in group 2, and 1 patient in group 3). Nine patients in group 1, 4 patients in group 2, and 3 patients in group 3 achieved group qualifications C and D (fair or poor results). Based on these results, we do not recommend reattachment of the cruciate ligaments after knee dislocation for obtaining a stable knee with full range of motion.

Adolescent↗

Fully arthroscopic stabilization of the patella.

The authors present a new fully arthroscopic technique for the treatment of patellofemoral instability consisting of plication of the medial patellar retinaculum and release of the lateral patellar retinaculum. The indication for this procedure is not only acute patellar luxation, but also recurrent patellar luxation and subluxation. The procedure has been performed on 17 patients, 6 male and 11 female, between the ages of 14 and 27 years. The indication for surgical arthroscopic treatment was patellar instability in 3 patients, acute patellar luxation in 4, and recurrent patellar luxation in 10 patients. Postoperative results after follow-up of 12 to 26 months have been good with no recurrence of subluxation or luxation. This procedure is a valuable technique for treating patellar maltracking and instability and acute and recurrent patellar luxation, particularly in adolescents and young adults.

Acute Disease↗

The unstable patella in children.

The authors reviewed 102 unstable patellas which had been observed and treated from 1964 to 1990. They were divided according to whether they suffered from traumatic dislocations, recurrent dislocations or malformative instability. The clinical findings were the major stage of the check up. In the field of imaging, standard X-rays had to be performed in all cases. MRI was of interest in the congenital dislocations, in order to thoroughly investigate the soft tissue anomalies. Two types were described: Type 1 was observed in children with joint laxity, but without major X-ray anomalies; Type 2, a major femoropatellar dysplasia could be formed with some bone deformity. The latter was observed in the malformative instability. Four different surgical procedures have been used, from the release of the retinacula of patella to the medial displacement of the patellar tendon or the tibial tuberosity. This study emphasises the concept of a true development dysplasia of patella (DDP) which can gather the different varieties of the instability of patella.

Adolescent↗