Patellofemoral Alignment Research Articles

Are Patellofemoral Joint Alignment and Shape Associated With Structural Magnetic Resonance Imaging Abnormalities and Symptoms Among People With Patellofemoral Pain?

Background: Patellofemoral malalignment has been observed among people with patellofemoral pain (PFP) and may be associated with the presence of imaging features of osteoarthritis, symptoms, and function. Purpose: To determine whether patellofemoral joint alignment and bony shape are associated with (1) cartilage, bone, and soft tissue morphological abnormalities defined on magnetic resonance imaging (MRI) and (2) reported symptoms and function among people with PFP. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Participants (mean ± SD age, 30.2 ± 9.5 years; range, 14-50 years; 78 females, 58.6%) completed questionnaires regarding demographics, pain, symptoms, and function and underwent a 3-T MRI scan of their more symptomatic eligible knee. Structural MRI abnormalities were scored with the MOAKS (Magnetic Resonance Imaging Osteoarthritis Knee Score), and MRI alignment and shape were measured with standardized methods. Associations among MOAKS features, PFP symptoms, and alignment and shape measures were evaluated with regression analyses (α = .05). Results: Minor cartilage defects were present in 22 (16.5%) participants, patellar osteophytes in 83 (62.4%), anterior femur osteophytes in 29 (21.8%), Hoffa synovitis in 81 (60.9%), and prefemoral fat pad synovitis in 49 (36.8%). A larger Insall-Salvati ratio was significantly associated with the presence of patellar osteophytes (odds ratio [OR], 51.82; 95% CI, 4.20-640.01), Hoffa synovitis (OR, 60.37; 95% CI, 4.66-782.61), and prefemoral fat pad synovitis (OR, 43.31; 95% CI, 4.28-438.72) in the patellofemoral joint. A larger patellar tilt angle was significantly associated with the presence of minor cartilage defects (OR, 1.10; 95% CI, 1.00-1.20), the presence of patellar osteophytes (OR 1.12; 95%CI 1.02-1.22), and prefemoral fat pad synovitis (OR, 1.11; 95% CI, 1.03-1.20) in the patellofemoral joint. Finally, a larger bisect offset was significantly associated with the presence of minor cartilage defects (OR, 1.05; 95% CI, 1.00-1.11) and patellar osteophytes (OR, 1.07; 95% CI, 1.01-1.14) in the patellofemoral joint. The majority of patellofemoral alignment measures were not associated with symptoms or function. Conclusion: For people with PFP, the presence of morphological abnormalities defined on MRI appears to be related to particular patellofemoral alignment measures, including higher Insall-Salvati ratio (indicating patella alta), larger patellar tilt angle (indicating greater lateral tilt), and larger bisect offset (indicating greater lateral displacement). Hardly any associations were found with symptoms or function. So there might be a distinct subgroup of PFP that is more prone to developing patellofemoral osteoarthritis later in life, as particular alignment measures seem to be associated with the presence of patellar osteophytes. Prospective studies are required to investigate the longitudinal relationship between alignment or bony shape and morphological abnormalities defined on MRI in this patient population.

Lateral retinacular release via a prolonged incision versus arthroscopic lateral retinacular release in osteofascial medial patellofemoral ligament reconstruction for recurrent patellofemoral dislocation

Objective To compare the short-term outcomes between lateral retinacular release (LRR) via a prolonged incision versus arthroscopic LRR in osteofascial medial patellofemoral ligament reconstruction (MPFL-R) for recurrent patellofemoral dislocation. Methods From May 2012 to March 2015, 51 patients with recurrent patellofemoral dislocation were treated at the Department of Joint Surgery, The Third Affiliated Hospital to Hebei Medical University. They were 16 males and 35 females, aged from 20 to 36 years (mean 27.2 years). Of them, 28 underwent LRR via a prolonged incision in MPFL-R (incision group) and 23 did arthroscopic LRR in MPFL-R (microscopic group). Imaging changes were assessed by comparing preoperative and postoperative values of patella extensibility, patellar tilt angle, trochlear groove angle and tibial tuberosity-trochlear groove spacing (TT-TG); the knee joints were scored with Kujala and Lysholm functional rating systems at the last follow-ups. Results The 2 groups were compatible due to insignificant differences in the general data between them preoperatively (P>0.05). The 51 patients were followed up for 10 to 32 months (average, 20 months). The rate of dislocation in the incision and microscopic groups were 0 and 8.7% (2/23), respectively. There were no such complications in either group as patellar fracture, deep venous thrombosis of the lower extremity or limited joint extension or flexion. The last follow-ups revealed that no patients in either group were inflicted with patellofemoral re-dislocation. In the incision group, the patella extensibility, patellar tilt angle, Kujala score and Lysholm score were, respectively, 19.65%±0.75%, 12.39°±0.76°, 56.37±2.94 points and 51.64±6.22 points preoperatively, and 10.34%±0.60%, 8.83°±0.89°, 92.68±2.75, and 90.71±1.91 points postoperatively; in the microscopic group, the patella extensibility, patellar tilt angle, Kujala score and Lysholm score were, respectively, 19.56%±0.62%, 12.35°±0.66°, 57.46±3.08 points and 52.20±6.94 points preoperatively, and 10.24%±0.66%, 8.78°±0.92°, 92.53±3.32 points and 90.41±2.90 points postoperatively. There were significant differences between the preoperative and postoperative values in both 2 groups (P 0.05). There were no significant differences between the 2 groups in all the above preoperative and postoperative values (P>0.05). Conclusion In MPFL-R for recurrent patellofemoral dislocation, both LRR via a prolonged incision and arthroscopic LRR can improve the patellofemoral joint alignment and stability of the tibia, leading to good short-term outcomes. Key words: Arthroscopy; Patellar ligament; Patellar dislocation; Lysis

The Effect of Concomitant Arthroscopic Lateral Retinacular Release on Postoperative Patellar Position and Orientation in Open Wedge High Tibial Osteotomy.

PurposeThe purpose of this study was to evaluate the effect of concomitant arthroscopic lateral release (LR) in open wedge high tibial osteotomy (OWHTO) by comparing the pre- and postoperative radiological parameters of patellar position and orientation.Materials and MethodsThe study was comprised of 19 knees undergoing OWHTO and concomitant LR and 18 knees undergoing OWHTO alone. Radiological parameters for patellar position and orientation included the Caton-Deschamps index (CDI), Blackburne-Peel index (BPI), patellar tilting angle (PTA), patellar lateral shift (PLS), and patellofemoral distance (PFD), which were evaluated in the preoperative period and at one year after surgery.ResultsPatellar height was significantly reduced after surgery as indicated by the decrease in BPI (p=0.03) in the OWHTO/LR group, and decrease in CDI (p=0.03) and BPI (p=0.04) in the OWHTO alone group. PTA and PLS were significantly reduced after the combined OWHTO/LR procedure (p=0.04 and p=0.04, respectively). By contrast, no significant changes were detected when isolated OWHTO was performed.ConclusionsOWHTO induced a postoperative decrease in patellar height in both groups. Regarding the change in patellofemoral alignment, concomitant LR in OWHTO significantly decreased lateral patellar tilt and shift, while no significant difference in those parameters were noted in the OWHTO alone knees.

Association between patellofemoral congruence and patellofemoral chondropathy in patients with anterior knee pain: A T2 mapping knee MRI study.

In this study, the T2 mapping magnetic resonance imaging technique was used to evaluate early cartilage changes associated with patellofemoral alignment and morphology. Fifty four patients (Study group: 38 females, 16 males) with anterior knee pain and a randomly selected and age-matched 50 controls (Control group; 37 females, 13 males) were compared by two blinded authors in terms of T2 values of the patella medial, lateral facet, and trochlea, Insall-Salvatti index, lateral trochlear inclination angle, patellar tilt angle, sulcus angle, and patella medial and lateral facet lengths. The inter- and intra-observer reliability tests were assessed. The T2 medial patellar facet value, T2 lateral patellar facet value, T2 trochlea value, Visual Analog Scale, tibial tubercle - greater trochanter distance, and patellar tilt angle measure were statistically significantly higher in the study group. Based on our study findings, the T2 mapping magnetic resonance imaging (MRI) technique was found to be reliable test that can be used to diagnose early cartilage damage in patients with anterior knee pain. In patients with anterior knee pain, especially with decreased Insall Salvatti index, low lateral trochlear inclination angle, and higher patellar tilt angle, adding a T2 mapping sequence to the standard knee MRI protocol is recommended to help detect early cartilage damage.

Femoral malrotation from diaphyseal fractures results in changes in patellofemoral alignment and higher patellofemoral stress from a finite element model study

BackgroundMalrotation of the femur is a frequent complication in the management of a diaphyseal fracture. It is often responsible for pain and adverse functional results. Among these complications, contact stress effects on the patellofemoral joint are recognized as predictive factors of impaired results. The purpose of this study was to analyze the effect of malrotation on stress distribution on the patellofemoral joint, using radiological measurement and three-dimensional finite element models. MethodsFunctional analysis of the patellofemoral joint was evaluated in eight knee pairs from patients with unilateral femoral fractures and subsequent femoral malrotation. A computed tomography-based protocol allowed patellofemoral joint analysis. A finite element model of the healthy (contralateral) knee was then created from 3D reconstruction at 30° flexion. In a finite element model, incremental rotational malalignment was simulated to observe changes in stress distribution on the patellar surface. ResultsFemoral malrotation was associated with anomalies of patellofemoral joint rotational alignment. Internal rotation resulted in increased stress on the lateral side of the patella, and external rotation increased inferior medial side stress. ConclusionsRotational disorders of the distal femur resulted in increased stress on the patellofemoral joint and alignment changes. Malrotation in internal and external rotation might cause patellofemoral pain syndrome from rotations <10°. Care should be taken especially for internal malrotation in the management of femoral shaft fracture.

Does the patellofemoral joint need articular cartilage?—clinical relevance

The patellofemoral joint (PFJ) is enigmatic and we know the pathomorphology for anterior knee pain (AKP) is multifaceted. This paper review alignment and biomechanical factors associated with AKP both in the younger generation with or without cartilage changes and discusses the importance or obscurity of cartilage in the PFJ pathoanatomic changes such as trochlear dysplasia (TD), patella alta, increased femoral anteversion, lateralized tibial tubercle, external tibial torsion and valgus deformity affects the patellofemoral articulation. In order to achieve effective and durable results, it is of importance that any significant deviation in patellofemoral alignment should be corrected by realignment surgery, before considering cartilage procedures in the PFJ Patellofemoral alignment factors in both the frontal plane, the transverse plane and as well as the sagittal plan needs to evaluated thoroughly by not only clinical examination and X-ray, but also by MRI scans or CT scans.

MRI findings associated with medial patellofemoral capsuloligamentous plication.

To review the MRI appearance of medial patellofemoral capsuloligamentous plication (also known as reefing or imbrication) for proximal patellar realignment in patients with patellofemoral instability. Retrospective analysis of our surgical and PACS databases identified cases of medial plication performed between June 2011 and July 2016. Pre- and postoperative MRI characteristics were reviewed. Correlation was made with operative reports and clinical records to define postoperative appearances on MRI. Forty-one patients underwent medial plication during the study period; 29 were excluded owing to a lack of postoperative imaging. Ultimately, 12 knees were included in 11 patients who had postoperative MRI studies available (8 women and 3 men, mean age 27.3 ± 10.2years). Ten (83%) of the surgeries were performed open and 2 (17%) arthroscopically. There were differences in the post-surgical MRI appearance of medial plications carried out after surgery using the open and arthroscopic techniques. The open technique produces a "heaped up" distal vastus medialis obliquus (VMO) with centralized patellar insertion (100%), which was absent in the case of arthroscopic plication, where subtle medial retinaculum thickening was demonstrated without alteration of its patellar insertion. The mean postoperative lateral patellar and patellofemoral congruence angles measured 2.5° ± 5.6° and 12.4° ± 19.9° respectively. A significant association was found regarding change in patellofemoral alignment (p = 0.018 and p = 0.004 respectively). The MRI appearance of medial plication is not well described in the radiology literature; radiologists should be familiar with anticipated post-plication findings to avoid potential confusion for pathology and allow more accurate interpretation of postoperative imaging findings from this common surgery.

Imaging of Juvenile Hip Conditions Predisposing to Premature Osteoarthritis-Erratum.

HomeRadioGraphicsVol. 38, No. 2 PreviousNext ErrataFree AccessImaging of Juvenile Hip Conditions Predisposing to Premature Osteoarthritis—ErratumCarl Kraus, Rama S. Ayyala, Jonathan K. Kazam, Tony T. WongCarl Kraus, Rama S. Ayyala, Jonathan K. Kazam, Tony T. WongCarl KrausRama S. AyyalaJonathan K. KazamTony T. WongPublished Online:Mar 12 2018https://doi.org/10.1148/rg.2018174019MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Originally published in:RadioGraphics 2017;37(7):2204–2205 • https://doi.org/10.1148/rg.2017170067Imaging of Juvenile Hip Conditions Predisposing to Premature OsteoarthritisCarl Krsaus, Rama S. Ayyala, Jonathan K. Kazam, Tony T. WongErratum in:RadioGraphics 2018;38(2):662 • https://doi.org/10.1148/rg.2018174019Supplemental presentation, slide 8: The line beginning with “Acetabular line” should read as follows: “Acetabular line: Drawn connecting the superolateral acetabular roof to the ipsilateral triradiate cartilage (angle formed with horizontal line should be less than [not greater than] 30°).”Article HistoryPublished online: Mar 12 2018Published in print: Mar 2018 FiguresReferencesRelatedDetailsCited ByMedium-term outcomes of total hip arthroplasty in juvenile patientsFrancescoLuceri, IlariaMorelli, Carlo MariaSinicato, AlbertoDella Grazia, FabioVerdoni, NicolaMaffulli, Giuseppe M.Peretti, DomenicoCurci2020 | Journal of Orthopaedic Surgery and Research, Vol. 15, No. 1Accompanying This ArticleImaging of Juvenile Hip Conditions Predisposing to Premature Osteoarthritis: Pediatric ImagingNov 13 2017RadioGraphicsRecommended Articles Hip Imaging in Athletes: Sports Imaging SeriesRadiology2016Volume: 280Issue: 2pp. 351-369Developmental Hip Dysplasia Diagnosis at Three-dimensional US: A Multicenter StudyRadiology2018Volume: 287Issue: 3pp. 1003-1015Radiography, CT, and MRI of Hip and Lower Limb Disorders in Children and AdolescentsRadioGraphics2019Volume: 39Issue: 3pp. 779-794Relationship of Trochlear Morphology and Patellofemoral Joint Alignment to Superolateral Hoffa Fat Pad Edema on MR Images in Individuals with or at Risk for Osteoarthritis of the Knee: The MOST StudyRadiology2017Volume: 284Issue: 3pp. 806-814Imaging of Sports-related Injuries of the Lower Extremity in Pediatric PatientsRadioGraphics2016Volume: 36Issue: 6pp. 1807-1827See More RSNA Education Exhibits Developmental Dysplasia of the Hip: Clinical and Imaging Findings for Early Diagnosis and TreatmentDigital Posters2018To Correctly Understand the Graf Classification—Recognize the Relationship of the Black Ball to the White WallDigital Posters2020Adult Hip Dysplasia - An Updated Imaging ApproachDigital Posters2020 RSNA Case Collection Developmental hip dysplasia RSNA Case Collection2021Osteoarthritis of L hipRSNA Case Collection2020Patella FractureRSNA Case Collection2020 Vol. 38, No. 2 Metrics Altmetric Score PDF download

Investigation of the Relationship between Anterior Knee Pain and Chondromalacia Patellae and Patellofemoral Malalignment.

The study aimed to investigate whether there is any association of anterior knee pain and knee function with chondromalacia stage and patellofemoral alignment in patients with anterior knee pain for over a month and with chondromalacia patellae (CMP) detected by magnetic resonance imaging (MRI). We reviewed the medical records of 38 patients who underwent a knee MRI examination and were diagnosed with chondromalacia based on the MRI. Knee MRI images were evaluated by a radiologist for chondromalacia staging. Patients were divided into two groups as early stage (stage 1-2) and advanced stage (stage 3-4) chondromalacia. Patients' demographical data (age, sex, and occupation), clinical features, physical examination findings and patellofemoral pain severity scale, kujala patellofemoral scoring system, and functional index questionnaire scores were obtained from their medical records. Trochlear sulcus angle, sulcus depth, lateral patellofemoral angle, patellar translation, and Insall-Salvati index were measured using the MRI images. The mean patient age was higher in the advanced stage CMP group compared to the early stage CMP group (p=0.038). There was no statistically significant difference regarding other demographical data (p>0.05). MRI measurement parameters did not show difference between the groups (p>0.05). Patients in the advanced stage CMP group had higher patellofemoral pain severity score, lower kujala patellofemoral score, and lower functional index questionnaire score compared to the early stage CMP group. The differences were statistically significant (p=0.008, p=0.012, and p=0.026, respectively). As chondromalacia stage advances, the symptom severity worsens and knee functions decline; however, MRI measurements do not show difference between early and advanced stage CMP patients.

Magnetic resonance imaging-based morphological and alignment assessment of the patellofemoral joint and its relationship to proximal patellar tendinopathy.

To assess the differences in morphology and alignment of the knee between patients with proximal patellar tendinopathy (PPT) and a control group, using MRI and focusing on the patellofemoral joint. We retrospectively included 35 patients with clinically diagnosed and unequivocal findings of PPT on knee MRI, the case group. For the control group, we included 70 patients who underwent knee MRI for other reasons, with no clinical or MRI evidence of PPT. Patients and controls were matched for age and gender, with all subjects reporting frequent physical activity. MRIs were evaluated by two musculoskeletal radiologists, who assessed parameters of patellar morphology, trochlear morphology, patellofemoral alignment, and tibiofemoral alignment. The differences in parameters between cases and controls were assessed using Student's ttest. Logistic regression was applied to assess the associations between the MRI parameters and the presence of PPT. The patellar height Insall-Salvati ratio was different between cases and controls (1.37 ± 0.21 vs. 1.24 ± 0.19; p = 0.003). The subchondral Wiberg angle was higher in cases than controls (136.8 ± 7.4 vs. 131.7 ± 8.8; p = 0.004). After applying logistic regression, significant associations with PPT were found [odds ratios (95%CI)] for patellar morphology [1.1 (1.0, 1.2)] and patellar height [1.3 (1.0, 1.7)]. Patellar height and the subchondral patellar Wiberg angle were greater in patients with PPT and significantly associated with PPT.

Current Concepts in the Management of Patellar Instability

Patellar instability is a common presenting clinical entity in the field of orthopedics. This not only can occur from baseline morphologic variability within the patellofemoral articulation and alignment, but also from traumatic injury. While conservative management is many times employed early in the treatment course, symptomatic patellar instability can persist. This article reviews the available indexed published literature regarding patellar instability. Given the debilitating nature of this condition and the long term sequelae that can evolve from its lack of adequate recognition and treatment, this article details the most current methods in the evaluation of this entity as well as reviews the most up-to-date surgical treatment regimens that are available to address this condition.

Measurement of Tibial Tuberosity-Trochlear Groove Offset Distance by Weightbearing Cone-Beam Computed Tomography Scan.

Background:Computed tomography (CT) scans are useful for objectively measuring bone alignment because they show bone detail particularly well, and these scans have been used extensively to assess patellar orientation. The tibial tubercle–trochlear groove (TT-TG) offset distance has been shown to be influenced by knee flexion and weightbearing, yet conventional CT scans are obtained with the subject relaxed, supine, and with the knee in full extension. A new cone-beam CT scanner has been designed to allow for weightbearing images, potentially providing a more physiologically relevant assessment of patellofemoral alignment.Purpose/Hypothesis:The purpose of this study was to measure the TT-TG offset in healthy individuals without any history of knee complaints when CT scans were obtained while fully weightbearing on a flexed knee. Our hypothesis was that the TT-TG offset measurement in these healthy knees would be reproducible and less than the historically reported normal range.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Twenty healthy volunteers without any history of knee complaint were recruited to undergo a weightbearing cone-beam CT scan of the knee flexed at 30°. The scans were reviewed by a radiologist and an orthopaedic surgeon, and TT-TG offset was measured using the digital tools of a picture archiving and communication system. Paired t tests were used to compare TT-TG offset on 2 separate occasions for both raters. Inter- and intrarater reliability were assessed using a 2-way mixed-effects model intraclass correlation coefficient with corresponding 95% confidence intervals for TT-TG offset.Results:The mean TT-TG offset was 2.7 mm. There were no statistically significant differences in TT-TG offset between raters (P rater1 = .70; P rater2 = .49) and time of read (P time1 = .83; P time2 = .19). Good to moderate interrater reliability was found at the time of both reads, and good intrarater reliability was found for both raters.Conclusion:When measured by CT scan and obtained from a subject while weightbearing on a flexed knee, the TT-TG offset is reproducible and the distance is less than that obtained via a conventional CT scan.

Differences in patellofemoral alignment as a result of patellar shape in cruciate-retaining total knee arthroplasty without patellar resurfacing at a minimum three-year follow-up

BackgroundAlthough the patellofemoral (PF) joint shape of the femoral implant in a particular prosthetic design is identical, the articular surface shape of the patella varies between individuals. The present study investigated the effects of patellar shape on the postoperative PF joint in a cruciate-retaining total knee arthroplasty (CR-TKA) without patellar resurfacing and with at least three years of follow-up. MethodsThis study investigated 76 knees of 62 patients who underwent CR-TKA without patellar resurfacing for varus osteoarthritis. Shape of the patella was classified in terms of the patellar facet angle (angle formed by the medial and lateral articular surfaces) as measured on axial plain X-ray. Subjects were divided into Group A with patellar facet angle ≤126° (34 knees) and Group B with patellar facet angle >126° (42 knees). ResultsAnterior knee pain (AKP) was evident in four knees in Group A and one knee in Group B. Postoperative lateral patellar tilt angle was significantly larger in Group A than in Group B. Progression of osteosclerosis in the patella was present in 12 knees in Group A and three knees in Group B. ConclusionThis study found that for a patella with a small patellar facet angle, lateral tilt of the patella was significantly increased after TKA, and a high rate of osteosclerosis was evident at >3years after operation. Performing TKA without patellar resurfacing on a patella with a small patellar facet angle may entail a higher risk of postoperative AKP; pre-operative evaluation of the shape of the patella is therefore important.

Lateral Release for Anterior Knee Pain Without Instability. Outcome Evaluation at Long Term Follow Up

Treatment of patellofemoral pain syndrome with lateral retinaculum release. In a subset of patients with anterior knee pain (AKP) no predisposing factors can be identified, apart from a vague imbalance of the extensor mechanism arising from weakness of vastus medialis obliquus or overcostraint from lateral retinaculum. In those rare cases, after failure of nonsurgical therapy, current treatment consists of surgical transection of the lateral retinaculum release (LR) with an open or arthroscopic technique. Historically LR was performed alone to treat pathologies like patellar instability that needed a different approach like a transposition. Moreover, literature suggests that results obtained by the LR in the short term decrease after few years of follow-up, advising its use as a corollary act during other procedures. Aim of the present paper was to analyze at a long-term follow-up a cohort of patients suffering from AKP and treated with LR, in terms of subjective scores, pain reduction, return to activities, and patello-femoral alignment, trying to describe indications for this procedure. A retrospective review of patient with AKP that performed a Lyonnese CT scan and underwent LR was performed. Exclusion criteria were: missing information, history of patellar dislocation, diagnosed pathologies different from a patellofemoral disorder, associated pathologies, traumatic injuries, and disorders affecting the collagenous tissue. 54 agreed to undergo a follow-up examination, and signed the informed consent for the participation in this study. Demographic, clinical, radiological data were analyzed, along with NRS, Tegner, and Kujala scores. Mean follow up was 74 month; patients were divided in two groups according to the presence of subjective instability. Instability group was made of 21 patients, while stability group was made of 33 patients. At follow up the benefit of LR was statistically significant for all the scores with a p<0,0001 in both groups. The parameters used for radiological evaluation of the joint alignment were not affected by the surgery, showing a non statistically significant difference for both groups. Comparing the two groups revealed no statistical difference in terms of NRS score and Tegner level, respectively with a p<0,151 and p<0,543. An interesting correlation was found, instead, when comparing the Kujala scores between the groups, with a p<0,00145 in favor of the stability group. The main finding of this paper is that LR appears to be effective in treating patello-femoral pain, in those patients without malalignment and without subjective sensation of instability. This paper also depicts worst results with LR as the only treatment for a patellofemoral pain with instability. In conclusion, the paper demonstrates an actual efficacy of LR able to obtain a good outcome and patient satisfaction even on the long term. It should not be indicated for the treatment of instability because the results are worse and tend to decrease over time, and for this pathology should only be a secondary concomitant procedure. More well-designed studies with clearly de?ned inclusion criteria, standardized methods of assessment, and adequate follow-up are certainly needed, in order to understand the missing aspects, and to uniform the scientific community in regards of the effectiveness of LR.

DOES MCCONNELL TAPING OR THE STABILITY THROUGH EXTERNAL ROTATION OF THE FEMUR (SERF) STRAP AFFECT REARFOOT PLANTAR LOADING PATTERNS DURING WALKING IN HEALTHY ADULTS?

Background: Changes in patellofemoral joint biomechanics have the potential to influence function of the lower extremity. McConnell taping has been proposed to reduce pain in individuals with patellofemoral pain syndrome (PFPS). It is also believed to improve vastus medialis oblique (VMO) muscle, patellofemoral alignment, and stride length. The stability through external rotation of the femur (SERF) strap has been developed to pull the femur externally to stabilise the patellofemoral joint, in order to reduce patellofemoral pain and improve lower limb kinematics. A lack of literature has examined effects of these two treatment methods on plantar pressures. Therefore, the aim of this study was to investigate the effects of McConnell taping and the SERF strap on rearfoot plantar loading patterns during walking in healthy adults. Materials and Methods: Twenty-three participants (12 males and 11 females, age: 26.52±6.4 years) were randomly tested under 3 conditions: 1) no tape, 2) McConnell taping, and 3) SERF strap. Each participant was instructed to walk on a 2 m pressure plate at their own natural pace. Three valid stance phases of the right foot were recorded for each condition. Maximum pressures of medial heel and lateral heel, contact area of medial heel and lateral heel, initial heel contact, foot axis angle, and centre of pressure were collected. Results: There were significant differences of maximum pressures of lateral heel (p = 0.011) with McConnell taping condition and the SERF strap condition demonstrating higher pressures than the no-tape condition (p = 0.042, p = 0.010 respectively). However, significant differences of other variables were not found. Conclusion: The differences of maximum pressures of lateral heel between the conditions could be a clinical role for McConnell taping or SERF strap use in reducing rearfoot pronation in individuals with lower extremity problems especially PFPS.

Patellofemoral and tibiofemoral alignment in a fully weight-bearing upright MR: Implementation and repeatability.

To develop methods for evaluating 3D patellofemoral and tibiofemoral alignment in vertical open-bore magnetic resonance (MR) scanners, with participants upright and fully weight-bearing; and to evaluate the repeatability of these methods in individuals with patellofemoral osteoarthritis (OA) and in asymptomatic knees. Our methods extend previously validated, reliable methods for evaluating alignment into an upright MR environment. In 10 participants with early patellofemoral OA and 10 with asymptomatic knees, we acquired sagittal T1 -weighted turbo spin echo images in a 3T scanner to create accurate participant-specific 3D anatomical surface models. In a vertical open-bore 0.5T MR scanner, we obtained lower-resolution sagittal gradient echo images to capture bony position and orientation data. Participants were scanned in a position of squatting with the knees flexed 30°, three separate times to evaluate repeatability. Bone segmentation was performed manually, surface models were registered to data from the 0.5T scanner, and 3D patellofemoral and tibiofemoral alignment was calculated in all six degrees of freedom (three rotations and three translations). Intraclass correlation coefficients (ICCs) were ≥0.94, with the exception of patellar spin (0.79). Standard errors of measure (SEM) were <2° rotation and <0.9 mm translation. Repeatability remained adequate when stratified by group, with the exception of patellar spin (ICC 0.57 for asymptomatic knees vs. 0.91 for OA knees). We demonstrate methods for evaluating 3D alignment in upright fully weight-bearing participant positions in a vertical open-bore MR scanner. With the exception of patellar spin, repeatability was good to excellent. 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:841-847.

Patellofemoral morphology and alignment: reference values and dose–response patterns for the relation to MRI features of patellofemoral osteoarthritis

We aimed to (1) determine reference values for trochlear morphology and patellofemoral (PF) alignment in adults without magnetic resonance imaging (MRI)-defined PF full thickness cartilage damage or knee pain; and (2) evaluate dose-response patterns for these measures with prevalent MRI-defined PF structural damage and/or knee pain. The Framingham Community Cohort is a population-based sample of ambulatory adults aged ≥50 years. We evaluated six morphology and alignment measures using MRI (n=985), and reported reference values (mean±2SD) in a subsample without MRI-defined PF full thickness cartilage damage or knee pain (n=563). With restricted cubic spline Poisson regression, we evaluated dose-response patterns of each of the six measures with prevalent MRI-defined PF structural damage or joint pain. Our primary outcome was full thickness cartilage damage. For dose-response curves, prevalence ratios (PR) increased monotonically for all measures except patellar tilt, which rose with both lateral and medial tilt. Associations were generally strongest in the lateral PF compartment. PR for the strongest predictors of full thickness cartilage damage reached clinical relevance (PR>1.5) at sulcus angle (SA) ≥135.0°; patellar tilt angle at ≤1.0° and ≥15.0°; and bisect offset ≥57.0%. Lateral trochlear inclination (LTI) achieved PR>1.5at ≤23.0° for full thickness cartilage damage with pain. SA, patellar tilt, and bisect offset were most strongly associated with full thickness cartilage damage. LTI, patellar tilt and bisect offset had stronger associations with the addition of pain. These findings contribute to better identifying a subset of patients who may benefit from mechanically based interventions.

Patellofemoral Osteoarthritis Progression and Alignment Changes after Open-Wedge High Tibial Osteotomy Do Not Affect Clinical Outcomes at Mid-term Follow-up

To evaluate the clinical and radiological outcomes of open-wedge high tibial osteotomy (OWHTO) with respect to the patellofemoral joint and to assess whether patellofemoral osteoarthritis (OA) progression and alignment changes after OWHTO affect clinical outcomes. Inclusion criteria were consecutive patients who underwent OWHTO from March 2005 to September 2013. Exclusion criteria were loss to follow-up within 2years and absence of second-look arthroscopy findings at the time of plate removal. The clinical parameters, including anterior knee pain while climbing stairs, Japanese Orthopedic Association score, and Oxford Knee Score, were evaluated. Radiological outcomes, including weight-bearing line ratio, modified Blackburne-Peel ratio, posterior tibial slope, tilting angle, lateral shift ratio, and patellofemoral OA (Kellgren-Lawrence grade), were evaluated preoperatively and at the final follow-up. Cartilage status (International Cartilage Repair Society grade) was evaluated at the initial HTO and at plate removal. Fifty-three patients (60 knees) were included in this study. The mean follow-up was 58.2 ± 22.4months. Two knees (3%) presented with mild anterior knee pain after OWHTO. The mean Japanese Orthopedic Association score (66.9 ± 11.2 to 91.2 ± 9.7) significantly improved (P < .001), and the mean Oxford Knee Score at the final follow-up was 42.0 ± 5.3. The mean modified Blackburne-Peel ratio (0.9 ± 0.1 to 0.7 ± 0.1, P < .001) and tilting angle (6.8 ± 3.7 to 5.6 ± 3.4, P= .033) significantly decreased after OWHTO, whereas no significant changes in posterior tibial slope (P= .511) and lateral shift ratio (P= .522) were observed. Radiologically, patellofemoral OA had progressed in 15 knees (27%), and arthroscopically patellofemoral cartilage degeneration had progressed in 27 knees (45%). However, there was no significant correlation between changes in patellofemoral alignment and clinical outcomes. Changes in patellofemoral alignment and patellofemoral OA progression did not affect the clinical outcomes of OWHTO at mid-term follow-up. Level IV, therapeutic case series.

Lateral displacement, sulcus angle and trochlear angle are associated with early patellofemoral osteoarthritis following anterior cruciate ligament reconstruction.

Patellofemoral osteoarthritis (PFOA) occurs in approximately half of anterior cruciate ligament (ACL)-injured knees within 10-15years of trauma. Risk factors for post-traumatic PFOA are poorly understood. Patellofemoral alignment and trochlear morphology may be associated with PFOA following ACL reconstruction (ACLR), and understanding these relationships, particularly early in the post-surgical time period, may guide effective early intervention strategies. In this study, patellofemoral alignment and trochlear morphology were investigated in relation to radiographic features of early PFOA 1-year post-ACLR. Participants (aged 18-50years) had undergone ACLR approximately 1year prior to being assessed. Early PFOA was defined as presence of a definite patellofemoral osteophyte on lateral or skyline radiograph. Sagittal and axial plane alignment and trochlear morphology were estimated using MRI. Using logistic regression, the relationship between alignment or morphology and presence of osteophytes was evaluated. Of 111 participants [age 30±8.5; 41 (37%) women], 19 (17%) had definite osteophytes, only two of whom had had patellofemoral chondral lesions noted intra-operatively. One measure of patellar alignment (bisect offset OR 1.1 [95% confidence interval 1.0, 1.2]) and two measures of trochlear morphology (sulcus angle OR 1.1 [1.0, 1.2], trochlear angle OR 1.2 [1.0, 1.5]) were associated with patellofemoral osteophytes. Patellofemoral malalignment and/or altered trochlear morphology were associated with PFOA 1year following ACLR compared to individuals post-ACLR without these features. Clarifying the role of alignment and morphology in post-traumatic PFOA may contribute to improving early intervention strategies aimed at secondary prevention. IV.

Is the effectiveness of patellofemoral bracing modified by patellofemoral alignment and trochlear morphology?

BackgroundThis study was performed to determine if the effectiveness of patellofemoral bracing as a treatment for patellofemoral osteoarthritis is influenced by patellofemoral joint alignment and trochlear morphology. We hypothesized that those with more extreme patellar malalignment would benefit more from bracing.MethodsThirty-eight patients who had received bracing as part of a comprehensive treatment plan for patellofemoral osteoarthritis were selected for this study. Ten measures of patellar alignment were taken from X-rays. These alignment measures were divided into percentile groups (tertiles) for contingency table analysis. Treatment outcome was measured by Western Ontario and Macmasters Universities Osteoarthritis Index (WOMAC) scores and these were dichotomised into two groups according to “Improved” or “Not Improved” according to the minimum clinically important difference (MCID). Spearman’s rho test was performed for continuous variables and Fisher’s exact test was performed for correlation between tertile groups and MCID categories.ResultsThirty-eight patients (9 male and 29 female) between the ages of 51 to 89 were included in this study. WOMAC scores ranged from −25 to 41.67, with a mean change of −3.97, 31.6, 44.7 and 31.6% of patients falling into the “Improved” group for Global, Pain and Function scores respectively. We found a non-significant trend shown (p = 0.058, correlation coefficient 0.31) between bisect offset and change in WOMAC global, indicating a trend for higher change in WOMAC scores with increasing bisect offset. Statistically significant correlations were found between mean MCID categories for the WOMAC global and function groups when analysed against percentile groups for bisect offset (p < 0.01) and patellar subluxation distance (p < 0.05), indicating those in higher percentile groups were more likely not to improve after six months.ConclusionHigher bisect offset and patellar subluxation distance measures were associated with poorer outcomes. However, due to the limited sample size, more studies are required to fully examine this relationship.