Severe inwardly pointing knee after medial patellofemoral ligament reconstruction: a case report.

We report the case of a 26-year-old woman who presented with a profound gait disturbance and total disability following a medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. It is common knowledge that patellar instability is associated with multiple risk factors, including but not limited to loss of the MPFL, trochlear dysplasia, patella alta, an abnormally placed tibial tuberosity on the tibia, quadriceps contracture, genu valgum, excess of femoral anteversion, excess of external tibial torsion, and foot pronation. Since the relative importance of each is unknown, it is imperative that pre-operative evaluation considers these. Two additional surgeries failed to improve her severe disability. Subsequent evaluation, 8 years after her initial MPFL reconstruction, revealed the presence of an excess of external tibial torsion and genu valgum. Complete resolution of disability resulted following tibial osteotomy, suggesting the importance of torsional deformity contributing to patellofemoral instability. Gait disturbance is an unrecognised complication after MPFL reconstruction.

Increased femoral anteversion in females with anterior knee pain relates to both the neck and the shaft of the femur.

INTRODUCTION: Increased femoral anteversion (FAV) can have many clinical manifestations, including anterior knee pain (AKP). To our knowledge, no studies have measured the location of FAV in a cohort of female AKP patients. The objective of this research is to determine whether the increased FAV in AKP females originates above the lesser trochanter, below the lesser trochanter or at both levels. MATERIALS AND METHODS: Thrity-seven consecutive AKP female patients (n = 66 femurs) were recruited prospectively. There were 17 patients (n = 26 femurs; mean age of 28 years) in whom the suspicion for the increased FAV of the femur was based on the clinical examination (pathological group-PG). The control group (CG) consisted of 20 patients (n = 40 femurs; mean age of 29 years) in whom there was no increased FAV from the clinical standpoint. All of them underwent a torsional computed tomography of the lower limbs. FAV was measured according to Murphy´s method. A segmental analysis of FAV was performed using the lesser trochanter as a landmark. RESULTS: Significant differences in the total FAV (18.7 ± 5.52 vs. 42.46 ± 6.33; p < 0.001), the neck version (54.88 ± 9.64 vs. 64.27 ± 11.25; p = 0.0006) and the diaphysis version (- 36.17 ± 8.93 vs. - 21.81 ± 11.73; p < 0.001) were observed between the CG and the PG. The difference in the diaphyseal angle between CG and PG accounts for 60% of the total difference between healthy and pathological groups, while the difference between both groups in the angle of the neck accounts for 40%. CONCLUSION: In chronic AKP female patients with increased FAV, the two segments of the femur contribute to the total FAV, with a different pattern among patients and controls, being the compensation mechanism of the diaphysis much lower in the pathological femurs than in the controls.

Brain network functional connectivity changes in patients with anterior knee pain: a resting-state fMRI exploratory study.

BACKGROUND: This study investigates the functional brain connectivity in patients with anterior knee pain (AKP). While biomechanical models are frequently employed to investigate AKP, it is important to recognize that pain can manifest even in the absence of structural abnormalities. Leveraging the capabilities of functional magnetic resonance imaging (fMRI), this research aims to investigate the brain mechanisms present in AKP patients. METHODS: Forty-five female subjects (24 AKP patients, 21 controls) underwent resting-state fMRI and T1-weighted structural MRI. Functional brain connectivity patterns were analyzed, focusing on pain network areas, and the influence of catastrophizing thoughts was evaluated. RESULTS: Comparing patients and controls, several findings emerged. First, patients with AKP exhibited increased correlation between the right supplementary motor area and cerebellum I, as well as decreased correlation between the right insula and the left rostral prefrontal cortex and superior frontal gyrus. Second, in AKP patients with catastrophizing thoughts, there was increased correlation of the left lateral parietal cortex with two regions of the right cerebellum (II and VII) and the right pallidum, and decreased correlation between the left medial frontal gyrus and the right thalamus. Furthermore, the correlation between these regions showed promising results for discriminating AKP patients from controls, achieving a cross-validation accuracy of 80.5%. CONCLUSIONS: Resting-state fMRI revealed correlation differences in AKP patients compared to controls and based on catastrophizing thoughts levels. These findings shed light on neural correlates of chronic pain in AKP, suggesting that functional brain connectivity alterations may be linked to pain experience in this population. RELEVANCE STATEMENT: Etiopathogenesis of pain in anterior knee pain patients might not be limited to the knee, but also to underlying alterations in the central nervous system: cortical changes might lead a perpetuation of pain. KEY POINTS: • Anterior knee pain patients exhibit distinct functional brain connectivity compared to controls, and among catastrophizing subgroups. • Resting-state fMRI reveals potential for discriminating anterior knee pain patients with 80.5% accuracy. • Functional brain connectivity differences improve understanding of pain pathogenesis and objective anterior knee pain identification.

Locating the Origin of Femoral Maltorsion Using 3D Volumetric Technology-The Hockey Stick Theory.

BACKGROUND: The origin of femoral maltorsion is often unknown. However, defining the origin of the rotation of the femoral maltorsion can be useful for establishing the most suitable point to do an external derotational osteotomy. Previous studies have not considered the femoral diaphysis in their investigations of the origin of the deformity. The study of the whole morphology of the femur with 3D volumetric tools, including the femoral diaphysis can contribute to a better understanding of the behavior of femoral maltorsion. METHODS: An atypical case of unilateral femoral anteversion was selected. Both femurs were used to obtain 3D bio-models. The mirror image of the asymptomatic side was obtained and overlapped with the symptomatic femur. The Hausdorff-Besicovitch method was used to evaluate the morphologic discrepancies (in mm) between the two femurs in three zones: (1) the femoral neck, (2) the proximal diaphysis, and (3) the distal diaphysis. The differences between the two femurs were analyzed and its correlation was statistically defined using a lineal regression model. RESULTS: The deformity in the distal diaphysis increased from the supracondylar area until the apex of the antecurvatum angle (R2 = 0.91) and then decreased until the base of the femoral neck (R2 = (-0.83)), to finally increase significantly in the femoral neck area (R2 = 0.87). All of the correlations were statistically significant (p-value ˂ 0.001). CONCLUSION: The femoral maltorsion originates in the supracondylar area and its rotational axis is the longitudinal axis of the femoral diaphysis. Even though the deformity affects the femoral diaphysis, its clinical relevance is much higher in the femoral neck since the rotational axis passes through its base. Thus, the osteotomy can be conducted along all of the femoral diaphysis as long as it is done perpendicular to it.

A 3D-CT Analysis of Femoral Symmetry-Surgical Implications.

BACKGROUND: Mirroring the image of the affected side is a widely used technique for surgical planning in orthopedic surgery, especially for fractures and custom-made prostheses. Our objective is to evaluate the three-dimensional symmetry of the femurs using finite element analysis and manual alignment. METHODS: Using the computed tomography of 15 patients without lower limb pathology, 30 3D biomodels of their femurs were obtained. The error obtained through image manipulation was calculated and broken down into a rendering error and a manual overlay error. The Hausdorff-Besicovitch method was applied to obtain the total asymmetry. The manipulation error was theb subtracted from it to obtain the intrapersonal asymmetry. RESULTS: The mean intrapersonal asymmetry was 0.93 mm. It was obtained by subtracting the error derived from rendering and alignment of 0.59 mm (SD 0.17 mm) from the overall mean error of 1.52 mm (SD 1.45). CONCLUSIONS: Intrapersonal femoral asymmetry is low enough to use the mirror image of the healthy side as a reference for three-dimensional surgical planning. This type of planning is especially useful in deformity surgery when the objective of the surgery is not to restore only one specific parameter but to obtain a general functional morphology when a healthy contralateral femur is available.

Parametric finite element model of medial patellofemoral ligament reconstruction model development and clinical validation.

BACKGROUND: Currently, there is uncertainty regarding the long-term outcome of medial patellofemoral ligament reconstructions (MPFLr). Our objectives were: (1) to develop a parametric model of the patellofemoral joint (PFJ) enabling us to simulate different surgical techniques for MPFLr; (2) to determine the negative effects on the PFJ associated with each technique, which could be related to long-term deterioration of the PFJ. METHODS: A finite element model of the PFJ was created based on CT data from 24 knees with chronic lateral patellar instability. Patella contact pressure and maximum MPFL-graft stress at five angles of knee flexion (0, 30, 60, 90 and 120°) were analysed in three types of MPFLr: anatomic, non-anatomic with physiometric behaviour, and non-anatomic with non-physiometric behaviour. RESULTS: An increase in patella contact pressure was observed at 0 and 30° of knee flexion after both anatomic and non-anatomic MPFLr with physiometric behaviour. In both reconstructions, the ligament was tense between 0 and 30° of knee flexion, but at 60, 90 and 120°, it had no tension. In the third reconstruction, the behaviour was completely the opposite. CONCLUSION: A parametric model of the PFJ enables us to evaluate different types of MPFLr throughout the full range of motion of the knee, regarding the effect on the patellofemoral contact pressure, as well as the kinematic behaviour of the MPFL-graft and the maximum MPFL-graft stress.

Correction to: Femoral insertion site of the graft used to replace the medial patellofemoral ligament influences the ligament dynamic changes during knee flexion and the clinical outcome.

Unfortunately, the author missed out to indicate the affiliation which is basic requirement as a part of his thesis. The affiliation is now updated here.

Radiographic Location Does Not Ensure a Precise Anatomic Location of the Femoral Fixation Site in Medial Patellofemoral Ligament Reconstruction.

BACKGROUND: A frequently used method to determine the anatomic femoral fixation point in the operating room during medial patellofemoral ligament (MPFL) reconstruction is the radiographic method. However, the ability of this radiological method to establish an anatomic femoral attachment point might not be as accurate as expected. PURPOSE: (1) To evaluate the accuracy of the radiological method to locate the anatomic femoral fixation point in MPFL reconstruction surgery and (2) to determine the factors influencing the predictability of this method to obtain this objective. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 100 consecutive 3-dimensional computed tomography (3D CT) knee examinations were performed at 0° of extension in 87 patients treated for chronic lateral patellar instability. For each knee, 2 virtual 7 mm-diameter femoral tunnels were created: 1 using the adductor tubercle as a landmark (anatomic tunnel) and the other according to the radiological method described by Schöttle et al (radiographic tunnel). We measured the percentage of overlap between both tunnels. Moreover, of the 100 included knees, 10 were randomly selected for a variability study. RESULTS: Considering an overlap area greater than 50% as reasonable, the radiographic method achieved this in only 38 of the 100 knees. Intrarater and interrater reliability were excellent. There was a trend for female patients with severe trochlear dysplasia to have less overlap. This model accounted for 64.2% of the initial variability in the data. CONCLUSION: An exact anatomic femoral tunnel placement could not be achieved with the radiographic method. Radiography provided only an approximation and should not be the sole basis for the femoral attachment location. Moreover, in female patients with severe trochlear dysplasia, the radiographic method was less accurate in determining the anatomic femoral fixation point, although differences were not statistically significant.

Failed medial patellofemoral ligament reconstruction: Causes and surgical strategies.

Patellar instability is a common clinical problem encountered by orthopedic surgeons specializing in the knee. For patients with chronic lateral patellar instability, the standard surgical approach is to stabilize the patella through a medial patellofemoral ligament (MPFL) reconstruction. Foreseeably, an increasing number of revision surgeries of the reconstructed MPFL will be seen in upcoming years. In this paper, the causes of failed MPFL reconstruction are analyzed: (1) incorrect surgical indication or inappropriate surgical technique/patient selection; (2) a technical error; and (3) an incorrect assessment of the concomitant risk factors for instability. An understanding of the anatomy and biomechanics of the MPFL and cautiousness with the imaging techniques while favoring clinical over radiological findings and the use of common sense to determine the adequate surgical technique for each particular case, are critical to minimizing MPFL surgery failure. Additionally, our approach to dealing with failure after primary MPFL reconstruction is also presented.

Femoral insertion site of the graft used to replace the medial patellofemoral ligament influences the ligament dynamic changes during knee flexion and the clinical outcome.

PURPOSE: This study's purpose was to investigate how an ideal anatomic femoral attachment affects the dynamic length change pattern of a virtual medial patellofemoral ligament (MPFL) from an extended to a highly flexed knee position; to determine the relative length and length change pattern of a surgically reconstructed MPFL; and to correlate femoral attachment positioning, length change pattern, and relative graft length with the clinical outcome. METHODS: Twenty-four knees with isolated nonanatomic MPFL reconstruction were analysed by three-dimensional computed tomography at 0°, 30°, 60°, 90°, and 120° of knee flexion. The lengths of the MPFL graft and a virtual anatomic MPFL were measured. The pattern of length change was considered isometric if the length distance changed <5 mm through the entire dynamic range of motion. RESULTS: Knee flexion significantly affected the path lengths between the femoral and patellar attachments. The length of the anatomic virtual MPFL decreased significantly from 60° to 120°. Its maximal length was 56.4 ± 6.8 mm at 30°. It was isometric between 0° and 60°. The length of the nonanatomic MPFL with a satisfactory clinical result decreased during flexion from 0° to 120°. Its maximal length was 51.6 ± 4.6 mm at 0° of knee flexion. The lengths measured at 0° and 30° were isometric and statistically greater than the lengths measured at higher flexion degrees. The failed nonanatomic MPFL reconstructions were isometric throughout the dynamic range, being significantly shorter (27.1 ± 13.3 %) than anatomic ligaments. CONCLUSION: The femoral attachment point significantly influences the relative length and the dynamic length change of the grafts during knee flexion-extension and graft isometry. Moreover, it influences the long-term outcome of the MPFL reconstructive surgery. A nonanatomic femoral fixation point should not be considered the cause of persistent pain and instability after MPFL reconstruction in all cases. LEVEL OF EVIDENCE: III.

Does radiographic location ensure precise anatomic location of the femoral fixation site in medial patellofemoral ligament surgery?

PURPOSE: To correlate the location of the medial patellofemoral ligament femoral fixation site in knees suffering a chronic lateral patellar instability, by using radiographic references and by using the most important anatomic reference point (i.e. the adductor tubercle) identified by means of 3-dimensional (3D) surface reconstructions by computed tomography (CT) imaging. METHODS: Thirty consecutive knee 3D-CT examinations at 0º of knee extension were obtained from patients (20 females, 10 males; median age of 23.5 years; range, 14-48 years) treated for chronic lateral patellar instability with at least two documented patellar dislocations. For each knee, three virtual 7-mm-diameter femoral tunnels were created. One of the tunnels used an anatomic fixation landmark (anatomic fixation), while the other two used established radiologic methods. We calculated the percentage of the anatomic tunnel covered by the tunnel created according to the method described by Schoettle, and the percentage of the anatomic tunnel covered by the tunnel created according to the method described by Stephen. These percentages were compared using paired Student's t test. RESULTS: The percentage of anatomic tunnel area covered by the femoral tunnel created using Schoettle's method was 36.7 ± 25.2 %. When using Stephen's method, the percentage of overlap with the anatomic femoral tunnel was 25.5 ± 21.5 %. There were no significant differences between the two radiographic methods (n.s.). CONCLUSION: None of the standard radiographic methods allowed a precise anatomic femoral placement. Conventional radiographic identification of the femoral graft placement site is only an approximation and should not be the sole basis for femoral attachment location. LEVEL OF EVIDENCE: IV.

State-of-the-art of bone marrow imaging in multiple myeloma.

PURPOSE OF REVIEW: Multiple myeloma is a common hematological malignancy arising in the bone marrow. Bone lesions were initially depicted with conventional radiography, although recently F-FDG PET/CT and MRI are recognized as having a clear role in the initial workup and in the evaluation of therapy response. RECENT FINDINGS: Tumor development produces osteolysis and expansive lesions. Although tumor burden and extent are key prognostic factors, different cancer hallmarks can also be evaluated in vivo through noninvasive imaging. SUMMARY: This imaging-based virtual biopsy approach might be useful to define several relevant prognostic markers, such as angiogenesis, cellularity, metabolic trapping and bone morphology and elasticity, both before and during treatment, to predict tumor behavior and the early effect of therapy.

Tissue harmonic sonography in the diagnosis of common bile duct stones: a comparison with endoscopic retrograde cholangiography.

PURPOSE: To revisit the diagnostic accuracy of sonography in the detection of choledocholithiasis using modern equipment with tissue harmonic imaging (THI) and endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy as the gold standard. METHODS: A total of 107 patients with clinically suspected choledocholithiasis were examined with THI before undergoing ERCP. The sonographic findings that were prospectively evaluated included the presence of choledocholithiasis, size of common bile duct, sonographic view and patient position that best visualized the stone(s), visualization of the distal common duct, and duration of examination. The accuracy of sonography compared with ERCP and sphincterotomy was calculated. RESULTS: Sonography correctly detected stones in 65 of 76 patients (sensitivity of 86%). The specificity and the overall accuracy were 87% and 86%, respectively. The sensitivity of sonography was higher with dilated extrahepatic duct (44% in patients with common bile duct measuring less than 6 mm in diameter, 82% between 6 and 10 mm, and 100% with common bile duct larger than 10 mm). The lateral approach with the patient in left lateral decubitus position of the patient was the most effective in 47% of the cases. CONCLUSION: Sonography with THI is an accurate technique for the detection of choledocholithiasis that may be used as the first-choice technique to avoid unnecessary procedures in a high percentage of patients, especially those with dilated biliary tree.