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PubMed2006

Prospective analysis of uncomplicated bone bruises in the pediatric knee.

To determine the incidence of uncomplicated knee bone contusions in pediatric patients. MRI studies were obtained using either high-field (1.5 T) or mid-field strength magnets (0.2-0.3 T), identifying 48 pediatric patients suitable for study. Contusion location, size, and any ligamentous or meniscal injuries were recorded. Exclusionary criteria did not include plain film findings, the interval between injury to imaging, or history of patellar dislocation [Fulkerson (2002) 30:447-456]. Uncomplicated bone bruises were those occurring in the absence of other internal derangements of the knee, such as meniscal and ligament tears. Consensus imaging findings by two reviewing radiologists revealed a 25% incidence of uncomplicated bruises (12/48 patients). These bone bruises involved the lateral and medial knee compartments 56 and 44% of the time, respectively. Bruises of the lateral compartment were larger (2.4 cm) than those found in the medial compartment (1.8 cm). Given the high incidence of symptomatic but uncomplicated contusions identified in this study of a pediatric population, we suggest appropriate joint rest and follow-up without other intervention as a primary course of treatment.

Adolescent↗
PubMed1990

Patellofemoral malalignment: a report of 68 cases treated by proximal and distal patellofemoral reconstruction.

A series of 68 knees were reviewed retrospectively at an average of 56 months following surgical treatment for patellar dislocation and subluxation. Fifty-three knees in 48 patients were assessed both subjectively by questionnaire and objectively by examination, and 15 knees were evaluated by questionnaire only. All cases were treated by a proximal and distal reconstruction as described by Trillat (1964). The surgery was performed by one surgeon (MC) and reviewed independently (DW). The results were excellent in 48 knees (71 per cent), good in 12 (17 per cent) and poor in 8 (12 per cent). In no patient had there been any further episodes of dislocation. We consider this a straightforward procedure producing consistent correction of patellofemoral instability with a low morbidity.

Adolescent↗
PubMed1990

Acute hemarthrosis of the knee: indications for diagnostic arthroscopy.

The objective of this study was to define the role of early diagnostic knee arthroscopy for patients with an acute knee injury and hemarthrosis. Forty-five patients with an acute knee injury followed by a posttraumatic hemarthrosis during a 1-year period were prospectively reviewed. All patients were evaluated preoperatively followed by examination under anesthesia and arthroscopy of the knee. The majority of patients, 32 (71%), had an anterior cruciate ligament tear. Meniscal tears occurred in 21 patients (47%). Meniscal tears requiring surgery occurred in only 10 of 25 meniscal tears (40%). Seven patients (16%) had medial collateral ligament and/or posteromedial capsular sprain. Eight patients (18%) had an osteochondral fracture or patellar dislocation associated with an osteochondral fracture. The majority of knees with a torn meniscus or osteochondral fracture had an anterior cruciate ligament tear. Clinically, 18 of 21 knees (86%) with an acute complete anterior cruciate ligament tear were diagnosed preoperatively with the Lachman test. The Lachman test conducted with patients under anesthesia was positive for 19 of 21 knees (90%) with an acute complete anterior cruciate ligament tear. The preoperative examination correctly identified six of seven knees (86%) with a medial collateral ligament sprain. The preoperative Lachman test was positive in only two of five knees (40%) with a partial anterior cruciate ligament tear. The Lachman test with patients under anesthesia was positive for four of five knees (80%) with an acute partial anterior cruciate ligament tear. Preoperative examination yielded the correct diagnosis in only 9 of 21 knees (43%) with a meniscal tear and 1 of 6 knees (17%) with an osteochondral fracture.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed2006

In vitro investigation of the effect of medial patellofemoral ligament reconstruction and medial tibial tuberosity transfer on lateral patellar stability.

PURPOSE: Two different operative techniques for stabilizing the patella against lateral displacement movement were investigated. TYPE OF STUDY: In vitro experimental study. METHODS: Five human cadaver knee specimens with a normal Q-angle were mounted in a kinematic knee simulator and investigated under simulated isokinetic extension motions. Patellar movement was measured while a 100-N laterally directed subluxation load was applied to the patella. Ligament loading of the medial patellofemoral ligament was measured using a strain gauge based buckle transducer inserted in the fibers of the ligament. The knee was evaluated in an intact physiologic state, as well as after medial transfer of the tibial tuberosity, and after the medial patellofemoral ligament was transected and reconstructed using a hamstring autograft. RESULTS: A significant reduction in lateral displacement and ligament load was observed with the use of the hamstring autograft reconstruction compared with the medial transfer of the tibial tuberosity. CONCLUSIONS: Medial transfer of the tibial tuberosity showed no significant relief of ligament loading and stabilizing effect on patellar movement, whereas reconstruction of the medial patellofemoral ligament showed a significant stabilizing effect on patellar movement. CLINICAL RELEVANCE: In cadaver specimens, we evaluated the effect of tibial tubercle transfer and the patellofemoral ligament and found that reconstruction of the patellofemoral ligament alone was sufficient to restore stability in a cadaveric model. Additionally, we found that the flexion angle had little effect on the loading of the medial patellofemoral ligament autograft, which would support early mobilization of patients after surgery. We found that the graft was not unduly loaded.

Aged↗
PubMed2002

Dynamic magnetic resonance imaging.

Among the devices helping with an accurate diagnosis, neither MRI nor arthroscopy is perfect; both delineate pathology in the knee joint with reasonable sensitivity and specificity. MRI, as a noninvasive and nonionizing modality, has made a significant contribution to the understanding of musculoskeletal disturbances. Static images through the patellofemoral joint in different degrees of flexion reveal only the degree of patellar tilt or subluxation, parameters that can be measured also on the axial view of conventional radiography. The accuracy of patellar position on static axial MRI is limited by the absence of muscle contraction, movement, and loading. Dynamic axial images of patellofemoral articulation can demonstrate the degree of flexion where patellar malalignment is maximal and assess whether or not it reduces. Arthroscopy, aside from its diagnostic values, provides the opportunity for treatment of intra-articular changes contributing to knee joint disturbances, but it is an invasive technique with potential risks of complications. The performed cost-effectiveness analysis of MRI is based mainly on estimation of intra-articular pathology of the acutely-injured knee [49,52,56]. There are scarce data on the cost-effectiveness of MRI of patellofemoral alignment in patellofemoral pain knees. Total examination time for active movement dynamic MRI procedure is approximately 8 to 10 minutes, thus it can be performed during routine MRI examination of the knee. In cases of suspected patellofemoral malalignment with symptoms that mimic other types of internal derangement of the knee joint, dynamic MRI can be a procedure of choice for detection of transient patellar dislocation, whereas a single clinical examination cannot differentiate from other internal knee pathologies. Dynamic MRI, although in an experimental phase, gives us a new perspective for dynamic study of the patellofemoral joint.

Arthroscopy↗
PubMed2001

Q-angle influences tibiofemoral and patellofemoral kinematics.

Numerous surgical procedures have been developed to correct patellar tracking and improve patellofemoral symptoms by altering the Q-angle (the angle between the quadriceps load vector and the patellar tendon load vector). The influence of the Q-angle on knee kinematics has yet to be specifically quantified, however. In vitro knee simulation was performed to relate the Q-angle to tibiofemoral and patellofemoral kinematics. Six cadaver knees were tested by applying simulated hamstrings, quadriceps and hip loads to induce knee flexion. The knees were tested with a normal alignment, after increasing the Q-angle and after decreasing the Q-angle. Increasing the Q-angle significantly shifted the patella laterally from 20 degrees to 60 degrees of knee flexion, tilted the patella medially from 20 degrees to 80 degrees of flexion, and rotated the patella medially from 20 degrees to 50 degrees of flexion. Decreasing the Q-angle significantly tilted the patella laterally at 20 degrees and from 50 degrees to 80 degrees of flexion, rotated the tibia externally from 30 degrees to 60 degrees of flexion, and increased the tibiofemoral varus orientation from 40 degrees to 90 degrees of flexion. The results show that an increase in the Q-angle could lead to lateral patellar dislocation or increased lateral patellofemoral contact pressures. A Q-angle decrease may not shift the patella medially, but could increase the medial tibiofemoral contact pressure by increasing the varus orientation.

Aged↗
PubMed1994

Refixation of large chondral fragments on the weight-bearing area of the knee joint: a report of two cases.

In most cases of cartilage avulsion, the chondral fragments are severely damaged, and refixation is therefore impossible. We present two cases with large intact cartilage fragments from the weight-bearing area of the femoral condyle after patellar dislocation. We tried refixation using fibrin sealant (Tisseel-Kit, Immuno AG, Vienna, Austria) and polydioxanone-pins (Bio-fix-Pins, Miracon AB, Helsingborg, Sweden). At second look arthroscopy, we found only one third to one half of the defects healed. Due to these results, the refixation of chondral fragments without attached bone seems to be questionable.

Adolescent↗
PubMed1993

Arthroscopically assisted proximal extensor mechanism realignment of the knee.

An arthroscopically assisted proximal extensor mechanism realignment procedure has been designed and performed on 27 knees in 24 patients. The study group has been followed a minimum of 18 months. The procedure consists of a lateral retinacular release and an arthroscopically controlled plication of the medial patellar retinaculum and oblique fibers of the vastus medialis. The indications for this procedure include recurrent patellar instability and acute initial patellar dislocation with a concomitant fracture of either the patella or lateral margin of the intertrochlear sulcus. Using a simple subjective rating system for the patellofemoral joint, 25 of the 27 knees (92.5%) were subjectively rated good or excellent by the patient. Objective criteria also indicated a high success rate. There were two recurrent subluxations. There were two relatively minor complications. The average time for return to full presurgical activities, including previous sports, was 4 months.

Adolescent↗
PubMed1997

The outcome of operatively treated anterior cruciate ligament disruptions in the skeletally immature child.

The purpose of this study was to evaluate the outcome of transphyseal ligament reconstruction in skeletally immature children with midsubstance anterior cruciate ligament (ACL) disruption. Five consecutive patients (mean age, 12.9 years; range, 8 to 14 years) with radiographically documented "wide" open growth plates and a minimum of 5 cm of expected remaining growth, underwent intra-articular reconstruction of the ACL. Operative treatment included three ACL reconstructions using hamstring tendons and two with quadriceps patellar tendon. All involved a centrally placed 6-mm or smaller tibial drill hole through an open physis and graft placement in an over-the-top position on the femur. At an average follow-up of 7.4 years (range, 4.5 to 9.9 years), no patient had a positive anterior drawer, Lachman, or pivot shift test. On KT-1000 arthrometer testing, all patients had 3 mm or less of increased anterior-posterior displacement (mean +/- SD = 1.0 +/- 1.6 mm). Magnetic resonance imaging showed that four tibial physes had fused in a symmetric fashion and one was still open. Orthoroentgenograms showed that no patient had a significant leg length discrepancy (-0.8 mm +/- 3.4 mm). The mean increase in height postoperatively was 17.7 cm (range, 7.6 to 31.0 cm). Overall, using the International Knee Documentation Committee (IKDC) evaluation form, there were four patients with grade A and one with grade C. The one patient with a poor IKDC grade had sustained a subsequent patellar dislocation with osteochondral fracture. In conclusion, ACL reconstruction using small drill holes placed through open tibial physes does not seem to adversely affect outcome or future growth.

Adolescent↗
PubMed1999

The Insall-Burstein total knee replacement in osteoarthritis: a 10-year minimum follow-up.

A total of 99 Insall-Burstein posterior stabilized (IBPS) knee replacements were implanted in 86 osteoarthritic patients. We reviewed 60 knees with a 10- to 15-year follow-up. Using the Knee Society score, 35 knees (58%) were excellent, 15 (25%) good, 4 (7%) fair, and 6 (10%) poor. Flexion at follow-up was 106 degrees on average. Moderate patellofemoral crepitation was present in 5 knees (9%), and 11 knee required excision of a synovial nodule proximal to the patella. Radiographic analysis showed 5 osteolytic lesions (8%) around well-fixed tibial and femoral components and minimal (1 mm) narrowing of the medial polyethylene thickness in 7 knees (12%). There were 6 (10%) failures requiring reoperation because of aseptic loosening (4 knees), deep infection (1 knee), and recurrent patellar dislocation (1 knee). Survivorship analysis using revision as the endpoint showed a cumulative success rate of 92% at 10 years. In this study, the IBPS knee has shown good long-term results with low rates of aseptic loosening and no failures attributable to polyethylene wear.

Aged↗
PubMed2000

Orthopaedic outcome of total knee replacement in haemophilia A.

A consecutive series of 16 patients with classical Haemophilia underwent 21 total knee replacements between 1989 and 1997 for haemophilic arthropathy. The patients received Factor VIII replacement therapy via continuous infusion, and fibrin glue was used to facilitate haemostasis. Three different types of prostheses were used. A follow-up evaluation was undertaken between 2 and 10 years after the operation (mean 5.6 years) and two patients with infection were excluded. Knee scores averaged 77.5 (pre-operative 24. 1) and functional scores averaged 84.4 (preoperative 23.2). There were no cases with aseptic loosening of the prosthesis. Complications included one early deep infection controlled by conversion of the TKR into an arthrodesis, one case of late septic loosening that had to be re-operated upon, one case of patellar dislocation, two cases of stiff knee (fibro-arthrosis) that required manipulation under anaesthesia, one postoperative hepatitis, one superficial infection treated by incision and drainage and four febrile patients with no clear source of infection, who responded to antibiotics alone. In conclusion, TKR offers haemophilic patients a long-lasting improvement of their quality of life and we therefore advocate its use with the appropriate indications.

Adult↗
PubMed1990

Previous injuries and persisting symptoms in female soccer players.

One hundred and fifty players in a female senior soccer division, starting up a new season, were examined for past injuries and persisting symptoms. An incidence of 0.18 injury/player/year was found, which is not significantly different from previously reported injury rates for male soccer. Sprains to the lower extremity and shin-splints were the most common previous injuries. Forty-three percent of the players had some kind of persistent symptom as a result of a past injury. Symptoms from previous ankle and knee sprains and from overuse injuries were the most common. Players who had sustained an ankle joint injury were more prone to have persistent symptoms (p less than 0.05) if they had persistent mechanical instability. Compared to previous retrospective studies on men's soccer, the women showed a higher rate of previous patellar dislocations. These injuries often caused persistent symptoms. The women showed fewer serious knee injuries. This might depend on a real difference in incidence or is just a reflection of female players ceasing to play soccer after a severe knee injury.

Adolescent↗
PubMed1996

The diagnostic validity of magnetic resonance imaging in acute knee injuries with hemarthrosis. A single-blinded evaluation in 69 patients using high-field MRI before arthroscopy.

Sixty-nine patients with traumatic knee hemarthrosis were evaluated an average of 3 days after trauma by high field (1.5T) magnetic resonance imaging (MRI) using sagittal T1, T2-weighted and coronal 3D-gradient echo images. All knees were arthroscopically examined shortly afterwards. The diagnostic validity of MRI for intraarticular pathology was determined using arthroscopy as golden standard. All patients had pathological findings on arthroscopy. The injuries were sports-related in 77% of the cases. MRI was highly sensitive (86%) and specific (92%) for diagnosis of anterior cruciate ligament tears. Diagnosis of medial meniscal tears showed a 74% sensitivity and 66% specificity. MRI detected lateral meniscal tears in 50% with an 84% specificity. As such, MRI missed 10 significant meniscus ruptures requiring surgical treatment. The sensitivity for partial or total medial collateral ligament tears was 56%, the specificity 93%. Rupture of the medial retinaculum in cases with patellar dislocation or significant damage of articular cartilage were only detected by MRI in a few cases (27% and 20% sensitivity, respectively). MRIs low diagnostic validity for intraarticular pathology with hemarthrosis may be attributed to the shifting paramagnetic properties of the blood remains and catabolic processes in meniscal and chondral tissues during the hemoglobin degradation process. Accordingly, MRI, with the technique used, could neither replace arthroscopy in the diagnosis and screening of acute knee injuries, nor select patients with need for immediate arthroscopic meniscal surgery.

Acute Disease↗
PubMed1992

Significance of arthroscopy in children with knee joint injuries.

Clinical and arthroscopic findings after knee joint injury were evaluated in 35 children aged 4-15 years. Arthroscopy revealed a rupture of the anterior cruciate ligament in 9 patients; two lesions were only partial. Eight children suffered from patellar dislocation. Eleven patients showed minimal synovial and cartilaginous lesions as the only cause of hemarthrosis, hydrarthrosis and clinical symptoms. Three had chondral lesions due to a dysplastic patella. The clinical diagnosis was confirmed in only 12 of 35 cases. Arthroscopic therapy was performed in 15 and open surgical intervention in 16 patients. Our results show that hemarthrosis and persisting symptoms after a knee trauma in children indicate a severe knee injury. The diagnostic procedure and treatment should be as ambitious as in adults.

Adolescent↗
PubMed1991

Patellofemoral joint abnormalities in athletes: evaluation by kinematic magnetic resonance imaging.

The patellofemoral joint is one of the most common sources of painful symptoms encountered by athletes and is one of the most frequently injured joints. Patellar incongruency is the primary pathologic condition that affects the patellofemoral joint and has been reported to be associated with patellar subluxation, patellar dislocation, chondromalacia, and arthrosis. The diagnosis of patellofemoral incongruency by physical examination alone is extremely difficult because the clinical signs may stimulate other types of internal derangements of the knee, and there is a high incidence of combined abnormalities. In consideration of these issues, a kinematic MRI technique was developed to identify and characterize abnormal anatomic and functional aspects of the patellofemoral joint. Because the patellofemoral joint is often injured in athletes and patellofemoral incongruency is a common site of their pain, this article will discuss the use of kinematic MRI to assess the anatomy and function of the patellofemoral joint, with an emphasis toward special problems that may be found in relation to sports-related activities.

Athletic Injuries↗
PubMed2000

Ten- to 12-year followup of the Insall-Burstein I total knee prosthesis.

The Insall-Burstein Posterior Stabilized knee prosthesis (Insall-Burstein I), developed at The Hospital for Special Surgery in 1978, has a metal-backed nonmodular tibial component. The polyethylene articular surface was directly molded. The purpose of the current study was to evaluate long-term wear with this design. The first 100 total knee arthroplasties (86 patients) performed by the senior author were followed prospectively. The average age of the patients at the time of surgery was 69.7 years (range, 45-89 years). The primary diagnoses were osteoarthritis in 77 knees (66 patients), inflammatory arthritis in 17 knees (14 patients), and posttraumatic arthritis in the remaining six knees (six patients). Thirty-eight knees (35 patients) had varus angulation, 14 knees (13 patients) had valgus angulation, and 48 knees (40 patients) had a 0 degrees to 10 degrees tibiofemoral angle preoperatively. All patients were evaluated at 10 to 12 years followup. Knee Society scores and radiographs were obtained. Thirty-six knees were in 30 patients who had died and two knees were in two patients who were infirm. Telephone evaluation only was available for eight knees (seven patients), leaving 54 knees (47 patients) for direct clinical and radiographic evaluation. No patients were lost to followup. The average Knee Society clinical score at latest followup was 91.6 points. The average function score was 69 points. One knee arthroplasty failed because of tibial loosening, one failed because of patella wear and fracture, two failed because of sepsis, and two failed because of nonspecific pain. There were seven patella fractures (7%) in the 100 knees. One of the fractures resulted in a total knee revision (noted above), two resulted in patellar component revision, and another resulted in patellar component removal. The remaining three patella fractures were discovered incidentally and were asymptomatic. There were no patellar dislocations. At long-term radiographic analysis, valgus alignment averaged 6 degrees (range, 0 degrees-11 degrees). Polyethylene wear averaged 0.40 mm. There was no catastrophic wear of tibial polyethylene. Thirty-two knees in 32 patients (65%) had radiolucencies in at least one zone; no lucency filled a zone, and none was wider than 2 mm. The absence of clinically significant tibial polyethylene wear at long-term followup is of particular interest. The performance of the molded, nonmodular polyethylene articulation is encouraging and needs to be analyzed critically against the more widely used machined, modular components used today.

Aged↗
PubMed2003

Patellar tracking during simulated quadriceps contraction.

The current study compared patella tracking during simulated concentric and eccentric quadriceps contractions in 12 knees from cadavers using a three-dimensional electromagnetic tracking system. The patella shifted (translated) and tilted medially during approximately the initial 22 degrees tibiofemoral flexion. The patella then shifted and tilted laterally for the remaining arc of tibiofemoral flexion (90 degrees). At 90 degrees tibiofemoral flexion, the patella had an orientation of lateral patella shift and lateral patella tilt. Patella shift was significantly more lateral between 40 degrees and 70 degrees tibiofemoral flexion during concentric quadriceps action than during eccentric contraction. Patella tilt was significantly more lateral between 45 degrees and 55 degrees tibiofemoral flexion during concentric quadriceps contraction than during eccentric action. No other significant differences were seen between the quadriceps contraction conditions. The current study supports the hypothesis that patellar instability is most likely a result of various anatomic and physiologic factors causing a failure of the extensor mechanism to deliver the patella into the femoral sulcus and that a patellar dislocation rarely would occur in a normal knee.

Biomechanical Phenomena↗