Patellofemoral Malalignment Research Articles

Long-Term Evaluation of the Roux-Elmslie-Trillat Procedure for Patellar Instability

Background Few published articles exist reporting the long-term evaluation of the Roux-Elmslie-Trillat procedure. Purpose To assess the long-term effect of the Roux-Elmslie-Trillat procedure in preventing recurrent subluxation and dislocation of the patella. Study Design Case series; Level of evidence, 4. Methods Eighteen patients who underwent the Roux-Elmslie-Trillat procedure for dislocation or subluxation of the patella were identified from a group previously evaluated at a mean follow-up of 3 years. The prevalence of recurrent subluxation or dislocation at a mean follow-up of 26 years was compared with the prevalence reported at the mean follow-up of 3 years. Although not the focus of this study, Cox functional scores were obtained from the smaller group and compared with the results at the 3-year follow-up. Results Seven percent (95% confidence interval, 0.00-0.32) of the patients had recurrent subluxation at 26 years compared with 7% (95% confidence interval, 0.03-0.13) of the study population reported at 3 years (P = 1.00). Fifty-four percent (95% confidence interval, 0.27-0.79) rated their affected knee as good or excellent at 26 years compared with 73% (95% confidence interval, 0.64-0.81) of the larger study population reported at 3 years (P = .14). Conclusion The prevalence of recurrent subluxation and dislocation in patients with patellofemoral malalignment who underwent the Roux-Elmslie-Trillat procedure for dislocation or subluxation of the patella is similar at 3 and 26 years after the procedure. The long-term functional status of the affected knee in patients who underwent the Roux-Elmslie-Trillat procedure declined.

Histologic Retinacular Changes Associated With Ischemia in Painful Patellofemoral Malalignment

Ischemic changes in 31 samples of lateral retinacula excised at surgical realignment in patients with isolated symptomatic patellofemoral malalignment resistant to conservative treatment were evaluated with conventional histology, electron microscopy, immunohistochemistry, and molecular biology. Morphologic and ultrastructural changes associated with ischemia including hypervascularization and increased vascular endothelial growth factor release were identified in painful patellofemoral malalignment. It is hypothesized that periodic short episodes of ischemia could be implicated in the pathogenesis of anterior knee pain in most cases of isolated symptomatic patellofemoral malalignment in active young patients by triggering neural proliferation.

Limb Positioning Is Critical for Defining Patellofemoral Alignment and Femoral Shape

The source of patellofemoral pain is a common orthopaedic complaint that often is difficult to determine because of the lack of correlation between symptoms and specific clinical measurements. Excessive joint contact stresses resulting from patellofemoral malalignment and pathologic femoral shape often are associated with this pain. These measures are likely sensitive to the limb position (orientation and position relative to the imaging system with which they are quantified). Because of this sensitivity, the measures have large variations and do not show correlations with subjective symptoms. The purpose of this study was to determine if varying limb position resulted in significant changes in standard clinical measures of patellofemoral alignment and femoral shape. This dependence was investigated by simulating alterations in limb position through resectioning of three-dimensional magnetic resonance image sets (20 healthy knees) to create axial images with altered orientation (eight images) or location (four images) relative to a fixed reference. By quantifying the variability of the clinical measures across all images, it was determined that simulated alterations in limb position produced greater variability in femoral shape and patellofemoral alignment measures than the variability seen across control subjects. This indicated that a standardized method for establishing limb position relative to the imager is warranted.

Fracture of the proximal tibia following Elmslie–Trillat osteotomy: a report of two cases

Medialization of the tibial tuberosity has generally been accepted as the surgical procedure for treatment of recurrent dislocation of the patella, patellofemoral malalignment, and patellofemoral pain. Proximal tibial fracture is one of the more common complications after osteotomy. There have been some previous reports of fractures occurring after Fulkerson osteotomy, but only when patients started to do weight bearing exercise soon after the operation. Recently, however, Godde et al. 5 reported two cases in which fracture of the proximal tibia was sustained even 6 months after Fulkerson osteotomy. As far as we know, however, prior to this paper there has been no report of fracture following Elmslie—Trillat osteotomy. In this paper, we present two cases of proximal tibial fracture; one of which was sustained by stamping the foot while dancing and the other while jogging. Both fractures occurred at the proximal tibia more than 5 month after the osteotomy.

Full arthroscopic lateral retinacular release with hook knife and quadriceps pressure-pull test: long-term follow-up.

The most important causes of anterior knee pain include patellofemoral malalignment which causes patella-condyle contact anomalies at the patellofemoral joint, excessive patellar lateral pressure increase, trauma and overuse. In this article, besides presentation of late clinical results of 169 lateral retinacular release cases which were surgically treated between January 1995 and December 2002 with the help of a hook knife from the anterolateral portal due to lateral compression syndrome and patellar maltracking, we also described quadriceps tendon pressure-pull test which strongly indicates patellofemoral pain during physical examination of a patient with anterior knee pain. In addition to radiological patellofemoral imaging methods, we describe dynamic arthroscopic patellofemoral joint examination which is applied perarthroscopically to all of our surgically treated patients. We divided the patients into two groups: group 1 was the younger group with age 16-40 years; group 2 was the older group with age >41 years. Preoperative mean Lysholm scores for group I was 67.6 and 98.6, postoperatively, whereas it was 62.3 preoperatively and 91.4 postoperatively in group 2. This improvement of Lysholm scores postoperatively was statistically significant for each of the two groups (p=0.001). For group 1 preoperative IKDC scores were A in 8 patients, B in 61 patients and C in 11 patients, whereas it was A in 78 patients and B in 2 patients postoperatively. For group 2 preoperative IKDC scores were A in 2 patients, B in 43 patients, C in 36 patients and D in 8 patients, whereas it was A in 78 patients and B in 11 patients. This improvement of IKDC scores postoperatively was also statistically significant for each of the two groups (p=0.001). Preoperative and postoperative congruent angles of all patients were also measured. Preoperative mean congruent angle was +16.4 in group 1 while mean congruent angle was -7.1 postoperatively. For group 2 preoperative mean congruent angle was +18.7 preoperatively and -6.9 postoperatively. This improvement was statistically significant for each of the two groups (p=0.001). The overall number of patellar lateral compression syndrome cases were 51 (24 in group 1, 27 in group 2), patellar lateralization cases were 64 (28 in group 1, 36 in group 2) and patellar subluxation cases were 54 (28 in group 1, 26 in group 2). At the evaluation of arthroscopic lateral patellar facet and lateral femoral condylar chondral pathologies, we statistically showed that patellar chondral pathologies were more severe than the femoral chondral pathologies (p=0.001). In our opinion, the severity of patellar lateral facet chondral lesions, although it has a thicker layer of cartilage, is due to distribution of load to a larger contact area of lateral femoral condyle. Statistically increasing severity of femoral (Kendall's tau-b: 0.248, p=0.001) and patellar chondral lesions (Kendall's tau-b: 0.444, p=0.0001) with age is compatible with our arthroscopic and clinical observations. The most important complication seen in our cases was fibrosis at the site of lateral release, seen in three patients. They were healed without any sequela with local corticosteroid injection into the fibrosis tissue. We did not see any hemarthrosis or haematoma as a complication.

The effect of foot orthoses on patellofemoral pain syndrome.

In a retrospective review of 102 patients treated for chondromalacia pa-tellae and patellofemoral pain syndrome/retropatellar dysplasia (PFPS/RPD), the effectiveness of semiflexible foot orthoses was investigated. The combined disorders were diagnosed in 89.3% of the patients. Subjects were 46 women and 54 men, aged 12 to 87 years (mean, 37.9 years; SD, 15.9), who exhibited excessive forefoot varus or rearfoot varus. The initial screening and clinical diagnosis were based on an examination by an orthopedist. Particular attention was directed to patellar crepitation, patellofemoral malalignment, Q-angle measurements, limitation of range of motion, and knee effusion. Patients were evaluated for the onset and duration of patellofemoral pain and degree of knee joint disease. Semiflexible orthoses for each subject were fabricated, based on a clinical lower extremity biomechanical examination. At their follow-up visit, 76.5% were improved and 2% were asymptomatic, showing a significant decrease in the level of pain with orthoses intervention (chi-square P <.001). Although multiple treatment modalities are used for these patients, the results suggest that the use of semiflexible orthoses is significant in reducing symptoms of PFPS/RPD.

The effect of a single treatment of the Protonics system on biceps femoris and gluteus medius activation during gait and the lateral step up exercise.

Patellofemoral pain, a frequent complaint among women, is attributed in part to excessive femoral internal rotation, leading to patellofemoral malalignment. The Protonics resistive dynamic knee orthosis was designed to facilitate hamstring activation, leading to a less anteriorly tilted pelvis and less femoral internal rotation. This decrease in femoral internal rotation is thought to improve patellofemoral joint alignment, thereby reducing knee pain. In this position, the gluteus medius (GM) would be more effective against the force of gravity. Therefore, this study's purpose was to determine the effects of a single application of the Protonics orthosis on knee pain and biceps femoris (BF) and GM activation. 21 females (23.4+/-3.1 years, 1.66+/-0.05 m, 65.3+/-20.4 kg) with a history of chronic PFP participated in the study. Data were collected during level walking and a lateral-step up exercise in three conditions: pre-treatment (PRE), a placebo condition collected after the orthosis was set at zero resistance (PLAC), and post-treatment (POST). PLAC and POST were performed after the orthosis had been removed from the subject's leg. Percent of gait cycle activated, integrated EMG (IEMG), and level of pain (VAS scale) were measured in each condition. An ANOVA was used to determine significance between conditions (alpha=0.05). Use of the Protonics orthosis did not result in any change in the level of knee pain, IEMG or duration of activation for the BF or GM. Our results do not support an increase in hamstring activation or decrease in GM activation following a single treatment with the Protonics orthosis.

Treatment of patellar tracking and pain in patellofemoral malalignment: Conservative versus surgery

Abstract The purpose of this study was to compare the effectiveness of non-operative and post-operative physiotherapy-rehabilitation programmes in patellofemoral pain syndrome that originated from patellofemoral malalignment. Forty-two subjects (21 non-operative, 21 post-operative) were included in the study. Pain, patellar tilt, congruence, sulcus and Q angles, Cincinnati scale, functional tests, hamstring tightness, iliotibial band tightness, and thigh circumference measurement were compared. When the pre-treatment data were compared within groups, there were statistically significant differences in favour of post-operative group as regards pain, hamstring tightness and Q angle (p < 0.05). When the post-treatment data were compared within both groups, there were significant differences in favour of postoperative group as regards pain, patellar tilt congruence angles, vertical jump tests, standing broad jump, and squat tests (p < 0.05).

Patellofemoral Pain Syndrome: A Critical Analysis of Current Concepts

Patellofemoral pain syndrome (PFPS) is one of the most common diagnoses treated by physical therapists in the orthopedic setting. The etiological mechanism of PFPS is poorly understood, however it is purported that biomechanical dysfunction of the patellofemoral joint leads to anterior knee pain and decreased function. Current rehabilitation of PFPS focuses on restoring normal patellofemoral mechanics by resolving patellofemoral malalignment, promoting tissue extensibility, promoting optimal timing and strength of the vastus medialis obliquus muscle, and normalizing mechanics of the subtalar joint. However, most of the aforementioned management strategies have not been subjected to scientific scrutiny and therefore lack an evidence-base. The expansive range of therapies currently being utilized is an indication that there is little consensus on the most efficient and effective management strategies for PFPS. The purpose of this paper is to discuss the normal anatomy and biomechanics of the patellofemoral joint in detail and provide a critical analysis of the current literature as it relates to conservative management of PFPS.

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.

Theoretical use of 3D CT to predict method of patella realignment

Procedures for the treatment of patello-femoral malalignment are grouped into two categories, proximal realignment and distal realignment. However, no clear indications in respect of these realignments have been reported. We have tried to evaluate patello-femoral alignment three-dimensionally using CT. The results lead us to group patients with recurrent patella dislocation into three types. Type 1 comprises patients with normal patello-femoral alignment. Type 2 comprises patients whose patella only deviates laterally and who need proximal realignment. Type 3 comprises patients whose patella and tibial tuberosity both deviate laterally and who need both proximal and distal realignment.

Patellofemoral Pain in Female Athletes

Patellofemoral pain syndrome (PFPS) is the most common complaint in female athletes. There are clear structural, biomechanical, sociological, and hormonal differences between women and men that contribute to an increased incidence of PFPS in women. Unfortunately, the etiology of PFPS is still not well understood. It may represent the end result of multiple intrinsic and extrinsic factors. Three major factors can be attributed to its etiology: quadriceps muscle imbalance and/or weakness, lower extremity and patellofemoral malalignment, and physical overload of patellofemoral joint. Exclusion of intraarticular pathology is essential to diagnose PFPS. Imaging can be helpful to diagnose any associated patellar instability. Conservative management, a mainstay in management, includes rehabilitation focusing on proprioception, strength, flexibility, endurance, and a gradual progression of the musculoskeletal load. Various training programs are in use, including isometric open kinetic chain exercises and eccentric closed kinetic chain exercises. Surgery may be required if conservative measures fail. Various procedures have been described, including lateral retinaculum release and proximal and distal realignment procedures.

Articular cartilage contact pressure after tibial tuberosity transfer. A cadaveric study.

Medial transfer of the tibial tuberosity has been commonly used for treatment of recurrent dislocation of the patella and patellofemoral malalignment. In this study, six fresh human cadaveric knees were used. Static intrajoint loads were recorded using Fuji Prescale pressure-sensitive film for contact pressure and contact area determination in a closed kinetic chain knee testing protocol. Peak pressures, average contact pressures, and contact areas of the patellofemoral and tibiofemoral joints were calculated on native intact knee specimens and after tibial tuberosity transfer. All native intact knee specimens had a normal Q angle. Medialization of the tibial tuberosity significantly increased the patellofemoral contact pressure. Medial displacement of the tibial tuberosity also significantly increased the average contact pressure of the medial tibiofemoral compartment and changed the balance of tibiofemoral joint loading. The results of our study suggest that caution should be used when transferring a patellar tendon in the face of a preexisting normal Q angle as this will result in abnormally high peak pressure within the tibiofemoral joint. Overmedialization of the tibial tuberosity should be avoided in the varus knee, the knee after medial meniscectomy, and the knee with preexisting degenerative arthritis of the medial compartment.

Computed tomography and magnetic resonance imaging evaluation of patellofemoral instability

Malalignment and tracking abnormalities of the patellofemoral joint are common causes of anterior knee pain,which are often difficult to evaluate clinically. Conventional radiography, as well as the cross-sectional imaging modalities of computed tomography (CT) and magnetic resonance imaging (MRI) are useful tools for both detecting and quantifying these abnormalities. Acute transient dislocation of the patella, on the other hand, is a relatively uncommon injury accounting for only 2% to 3% of all acute injuries of the knee, and can also be a difficult diagnosis to establish on the basis of history and physical findings alone. MRI is a sensitive, noninvasive method for detecting prior acute transient dislocation of the patella. This article begins by describing the role of CT and MRI as it pertains to the detection of abnormal patellofemoral tracking. Both static and dynamic techniques are described along with the standard criteria used to establish and quantify patellofemoral malalignment abnormalities. Next, the constellation of MRI findings most commonly encountered after acute transient dislocation of the patella are described. These findings include a typical bone bruise pattern involving the anterolateral aspect of the lateral femoral condyle and inferomedial patella, hemarthrosis, and injury to the medial soft-tissue restraints (especially the medial patellofemoral ligament). After transient dislocation of the patella, patients with significant osteochondral injury or disruption of the medial soft-tissue restraints may benefit from surgical repair. The role of MRI in preoperative planning is discussed as it relates to the detection of osteochondral injuries as well as injury to the medial soft-tissue restraints.

Neural growth factor expression in the lateral retinaculum in painful patellofemoral malalignment.

We studied 7 samples of lateral retinaculae excised at the time of surgical realignments. They were obtained from patients with isolated symptomatic patellofemoral malalignment resistant to conservative treatment and were evaluated with immunohistochemistry and immunoblotting. We found that neural growth factor is higher in patients with pain than in those with instability as the main symptom. Neural growth factor is related to neural proliferation in vessels and perivascular tissue and to the release of neuroceptive transmitters, such as substance P. We postulate that both mechanisms are involved in the pathogenesis of pain in isolated symptomatic patellofemoral malalignment.

Fulkerson's modified Elmslie-Trillat procedure for objective patellar instability and patellofemoral pain syndrome.

Twenty two knees were either operated for objective patellar instability (Group A: 14 patients) or patellofemoral pain syndrome (Group B: 8 patients) using Fulkerson's modified Elmslie-Trillat procedure. The objective of this retrospective study was to evaluate the results of this method and to detect whether or not there were differences in the outcome comparing the two groups. Twenty knee joints (Group A: 13; group B: 7) were available for clinical and radiographic examination after an overall mean follow-up of 63 months. Duration of pre- and postoperative physical therapy was significantly longer for group B, the activity level increased significantly for these patients and the Q-angle could be corrected significantly in this group comparing pre- and postoperative values. The overall outcome (Turba score) detected no statistically significant difference between the groups, only good and excellent results were obtained. No signs of osteoarthritis were found radiologically. A pathological patellar congruence angle could be corrected significantly by this method. We conclude that Fulkerson's modified Elmslie-Trillat operation is an excellent treatment method with a very low morbidity for patients with patellofemoral malalignment after failed conservative treatment.

Immunohistochemical analysis for neural markers of the lateral retinaculum in patients with isolated symptomatic patellofemoral malalignment. A neuroanatomic basis for anterior knee pain in the active young patient.

We evaluated 13 lateral retinacula excised at the time of Insall proximal realignments or isolated lateral retinacular releases performed in patients with isolated symptomatic patellofemoral malalignment recalcitrant to nonoperative treatment. Evaluation was performed by means of conventional histologic and immunohistochemical analysis for neural markers (S-100 protein, neurofilament protein, substance P, and neural growth factor). The observations reported here provide a neuroanatomic basis for anterior knee pain syndrome in active young patients with isolated symptomatic patellofemoral malalignment and support the clinical observation that the lateral retinaculum may have a key role in the origin of this pain as a result of increased neural growth factor production, which induces proliferation of nociceptive axons, mainly in a perivascular location.

Reproducibility of patellofemoral CT scan measurements.

At least seven parameters have been described for the measurement of patellofemoral malalignment on CT scanning; three of which measure lateral patellar tilt, two lateral patellar shift and two femoral trochlear dysplasia. We studied 22 knees in 18 patients complaining of patellofemoral pain in order to investigate the reproducibility of these methods. CT scans of the patellofemoral joint were performed in each knee at 0 degrees and 20 degrees of flexion. The seven parameters were recorded from each scan by three independent observers in a blind study. The reproducibility was studied by means of the intraclass correlation coefficient (ICC). Parameters measuring lateral patellar tilt showed excellent reliability (ICC>75%). The measurements of lateral patellar shift and femoral trochlear dysplasia showed a fair or poor correlation (ICC<75%). We suggest that parameters for measuring lateral patellar tilt only should be used from CT scanning when planning treatment for patello-femoral malalignment.

Effect of foot position on electromyographic activity of the vastus medialis oblique and vastus lateralis during lower-extremity weight-bearing activities.

Repeated measures analysis of the effects of foot wedges on quadriceps muscle function. To investigate the relationship between foot position and 2 quadriceps muscle activation conditions: maximum voluntary isometric quadriceps muscle contractions with the knee extended and 1-leg short squats with a knee flexion range of motion of 0 degree to 50 degrees. Abnormal foot position has been suggested as an important factor which may lead to patellofemoral malalignment. No previous studies have examined the effects of foot position on activation of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles using weight-bearing exercises. Sixteen healthy volunteers performed the 2 exercises under 3 foot conditions: level surface, a 10 degrees medial wedge, and a 10 degrees lateral wedge. Subjects' electromyographic data for the VMO and VL were analyzed using ANOVA. The normalized VMO/VL ratio was significantly greater during the short squat than during the maximum voluntary isometric muscle contractions, but no significant differences were identified across the 3 foot positions. Clinicians should understand that the benefit of using a foot orthotic to correct a pronated or supinated foot might not result from a change in quadriceps muscle activation intensity but from other mechanical factors.

Lateral release and proximal realignment for patellofemoral malalignment. A prospective study of 40 knees in 36 adolescents followed for 1-8 years.

We performed lateral release and proximal realignment for painful patellofemoral malalignment in 36 adolescents (40 knees), with a mean age of 14 (9-16) years. The mean follow-up was 4 (1-8) years. The subjective outcome was excellent in 20 knees, good in 13, fair in 5, and poor in 2. The mean radiographic correction of the lateral patellar shift was 75%, and of the tilting angle of the patellar 27%. There was a positive association between the realignment effect and the subjective outcome.