scholarly journals Coronal and Transverse Malalignment in Pediatric Patellofemoral Instability

2021 ◽  
Vol 10 (14) ◽  
pp. 3035
Author(s):  
Robert C. Palmer ◽  
David A. Podeszwa ◽  
Philip L. Wilson ◽  
Henry B. Ellis

Patellofemoral instability (PFI) encompasses symptomatic patellar instability, patella subluxations, and frank dislocations. Previous studies have estimated the incidence of acute patellar dislocation at 43 per 100,000 children younger than age 16 years. The medial patellofemoral ligament (MPFL) complex is a static soft tissue constraint that stabilizes the patellofemoral joint serving as a checkrein to prevent lateral displacement. The causes of PFI are multifactorial and not attributed solely to anatomic features within the knee joint proper. Specific anatomic features to consider include patella alta, increased tibial tubercle–trochlear groove distance, genu valgum, external tibial torsion, femoral anteversion, and ligamentous laxity. The purpose of this paper is to provide a review of the evaluation of PFI in the pediatric and adolescent patient with a specific focus on the contributions of coronal and transverse plane deformities. Moreover, a framework will be provided for the incorporation of bony procedures to address these issues.

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0013
Author(s):  
Alexandra H. Aitchison ◽  
Kenneth M. Lin ◽  
Daniel W. Green

Background: Tibial tubercle to trochlear groove distance (TT-TG) and external tibiofemoral rotation (TFR) through the knee joint have been identified potential contributing factors to patellar instability. In patients with a fixed or obligatory lateral patella dislocation (FOD), the normal force vector of the extensor mechanism is altered, so instead of a direct axial pull to cause extension, it exerts a lateralizing and external rotatory force on the tibia via the tibial tubercle. Hypothesis/Purpose: The purpose of this study is to investigate postoperative changes in TT-TG and TFR after medial patellofemoral ligament reconstruction (MPFLR) in two clinical cohorts: standard traumatic patellar instability (SPI) patients and FOD patients. We hypothesized that by surgically relocating the patella in the trochlea, and re-establishing medial sided soft tissue tension, the increased medializing force vector on the patella may exert enough force to alter resting rotation of the tibia in relation to the femur in the FOD group. Methods: A retrospective study was performed from April 2009 to February 2019. FOD and SPI patients under 18 years with available magnetic resonance imaging (MRI) of the knee before and after MPFLR were eligible. All FOD patients in the time frame were analyzed and SPI patients were randomly selected. Exclusion criteria were outside institution MRI, concomitant alignment procedures done at the time of MPFLR, and prior MPFLR or tibial tubercle osteotomy. TT-TG and TFR (using the posterior femoral and tibial condylar lines) were measured blindly on initial axial MRI. Statistical analysis using a paired sample t-test was performed with significance set at p<0.05. Results: A total of 30 patients were included, 14 in the FOD group and 16 in the SPI group. The mean age at time of surgery was 13.9 years (range 10-17 years), 53% of the cohort was female, and the mean time from surgery to follow-up MRI was 2.0 years. Demographics by group are shown in Table 1. TT-TG and TFR were not significantly different preoperatively versus postoperatively in the SPI group (Table 2). In the FOD group, both TT-TG (17.7 vs 13.7, P=.019) and TFR (8.6 vs 3.1, P=.025) decreased significantly on postoperative MRI. Conclusion: The postoperative decrease in TT-TG and TFR in the FOD group suggests that MPFLR in fixed or obligatory dislocators can improve the external rotation deformity through the level of the joint, and thus may help normalize the forces acting through the extensor mechanism. Tables/ Figures [Table: see text][Table: see text]


2020 ◽  
Vol 8 (3_suppl2) ◽  
pp. 2325967120S0012
Author(s):  
Dax T. Varkey ◽  
Jacob Gorbaty ◽  
Susan Odum ◽  
Dana P. Piasecki ◽  
James E. Fleischli

Objectives: Patellofemoral instability (PFI) is a painful condition affecting approximately 7 patients per 100,000 in the US. Unfortunately, as many as 50% of young patients with patellar dislocations can go on to recurrent instability and have debilitating symptoms. With a wide range of operative techniques, and subsequent reoperation and complication rate cited in the literature, it becomes challenging to create an appropriate algorithm with which to treat patients. The goal of our study was to determine the reoperation rate, risk factors for reoperation, and patient reported outcomes after Tibial Tubercle Transfer (TTT), Medial Patellofemoral Ligament Reconstruction (MPFLR), or a combination of the two, for patellofemoral instability surgery. Methods: We retrospectively identified patients who underwent MPFLR and TTT by querying the surgical database at our single institution from 2002-2018 for CPT codes associated with the procedures (CPT-27418, CPT-27427). Patients were included if they had an MPFLR and/or TTT performed for PFI whether recurrent or single dislocation. Patients were excluded if either additional ligamentous reconstruction was performed simultaneously, indications for the procedure was for a condition other than PFI or if records were incomplete. 497 patients were eligible to be included. Radiographic measurements, demographic parameters, and subsequent revision procedures and their indications were identified. A modified anterior knee pain survey was conducted by mail and with follow-up phone survey. Chi-Square Tests or Fishers Exact Test were used to compare differences for categorical data and Wilcoxon rank sum tests were used to compare the non-parametric pain scores. A multivariable logistic regression was used to determine the association between patient demographics, radiographic parameters and procedure type. Results: The overall rate of reoperation amongst all patients was 25.6%. The rate of reoperation for MPFL alone (19.9%) was lower than that of TTT alone (34.8%) or both procedures simultaneously (26.4%) (P = .007). There was a trend towards increased major reoperation rates and revision stabilization procedures in patients with isolated TTT (P = .16). There was no association with tibial tubercle to trochlear groove (TTTG) distance and the rate of reoperation (P = .99). A preoperative Dejour classification D was associated with a higher reoperation rate (28%) than those with Dejour A-C (P=.43). A Caton-Deschamp ratio >1.3 increased the odds of having a revision stabilization surgery (odds ratio 2.303). Patients who had a revision surgery for any reason were more likely to report pain while walking compared to those who did not (P = <.0001). Conclusion: The overall reoperation after PFI surgery is higher than previously reported. Patients who underwent further procedures were more likely to report continued knee pain when walking. Our results would suggest that patients with trochlear dysplasia and patella alta are more likely to undergo future procedures for instability, and may benefit from more aggressive initial treatment, such as MPFLR and TTT in combination.


2017 ◽  
Vol 5 (1_suppl) ◽  
pp. 2325967117S0001
Author(s):  
Federico Alfano ◽  
Walter Spreafico

Objectives: The aim of this study is to show the different surgical procedures for treating the objective patellar instability, including the different tibial tubercle osteotomies and the sulcus deepening trochleoplasty. Methods: This study analyzed the Caton-Deschamps index used for assessment of patellar height, the distance from the tibial tubercle to the troclear groove (TT-TG) on CT Scan in the axial view, and the different trochlear and patellar morphotypes. This study included 19 knees (19 patients) treated in an objective and documented patellofemoral instability. Results: We have had good results with both the transfer of the tibial tuberosity as the trochleoplasty. A reconstruction of the medial patellofemoral ligament was performed in both procedures. Recurrence of instability is very rare after these procedures and this is more likely to result from missed associated abnormalities. Conslusion: Accurate preoperative planning of the patellar height and determining the location of the tibial tubercle and the trochlear and patellar morphotypes for satisfactory results are required. However, as with any surgical procedure, both tibial tubercle osteotomy and the sulcus deepening trochleoplasty are susceptible of complications.


2018 ◽  
Vol 6 (2) ◽  
pp. 29-36 ◽  
Author(s):  
Alexander A. Sautenko ◽  
Egor V. Ogarev ◽  
Alexander G. Eltsin ◽  
Vladimir N. Merkulov ◽  
Dmitry S. Mininkov

Background. Patellar instability is a common problem in pediatric patients. Up to 2%–3% of all knee injuries are associated with acute patellar dislocation. According to the data in the literature, patients aged 10–17 years are at the highest risk of patellar dislocation and subsequent instability. These patients must be evaluated according to the proposed algorithm to select the optimal treatment method. Aim. To diagnose patellar instability in children and subsequently select the optimal treatment method based on acquired data. Materials and methods. The study is based on data acquired through the examination and treatment of 147 patients at the 9th Department of Pediatric Traumatology and Orthopedics. Great emphasis was put on computed tomography (CT) data, its essential parameters, which require the most thorough analysis, and assessment methods. These parameters include patellar tilt, dysplasia of the distal metaepiphysis of the femur, the tibial tubercle–trochlear groove index, and the rotational relation of the femur and tibia. Results. A novel algorithm for patient examination using CT is proposed. Data obtained by multislice CT (MSCT) had a significant influence on the selection of the surgical method for treating patients with patellar instability. Conclusion. The examination of patients with patellar instability using MSCT in adherence to the proposed diagnostic algorithm allows the selection of the optimal treatment method, which will increase the likelihood of rapid recovery of patients and their return to the level of activity similar to that before injury.


2018 ◽  
Vol 46 (4) ◽  
pp. 883-889 ◽  
Author(s):  
Joseph N. Liu ◽  
Jacqueline M. Brady ◽  
Irene L. Kalbian ◽  
Sabrina M. Strickland ◽  
Claire Berdelle Ryan ◽  
...  

Background: Medial patellofemoral ligament (MPFL) reconstruction has become one of the most common and widely used procedures to regain stability among patients with recurrent lateral patellar dislocation. While recent studies demonstrated low recurrence rates, improved patient-reported outcome measures, and a high rate of return to sports, limited literature explored its effectiveness as an isolated intervention in the context of trochlear dysplasia. Purpose: To determine the efficacy of isolated MPFL reconstruction in treating patellar instability in the setting of trochlear dysplasia. Study Design: Case series; Level of evidence, 4. Methods: This was a retrospective review of consecutive patients who underwent uni- or bilateral medial patellofemoral ligament reconstruction for patellofemoral instability with a minimum 2-year follow-up. No osteotomies were included. Pre- and postoperative assessment included ligamentous laxity, patellar crepitus, tilt, translation, apprehension, and radiographic features, including tibial tubercle-trochlear groove (TT-TG) distance, Dejour classification, and Caton-Deschamps index. Results: A total of 121 MPFL reconstructions were included. Mean age at surgery was 23.8 years, and 4.4 dislocation events occurred before surgery. Mean follow-up was 44 months; 76% of patients were female. Mean preoperative TT-TG ratio was 13.5, and mean Caton-Deschamps ratio was 1.2; 92% of patients had Dejour B, C, or D trochlear dysplasia. Kujala score improved from 55.0 preoperatively to 90.0 ( P < .001). Almost all patients (94.5%) were able to return to sports at 1 year, with 74% returning to the same or higher level of play. Only 3 patients reported a postoperative dislocation or subluxation event. Discussion: For patients without significantly elevated TT-TG distances or significant patella alta, isolated MPFL reconstruction provides a safe and effective treatment for patellofemoral instability, despite the presence of trochlear dysplasia. Most patients are able to return to sports by 1 year postoperatively at the same or higher level of play.


2017 ◽  
Vol 5 (5_suppl5) ◽  
pp. 2325967117S0018
Author(s):  
Ritwik Kejriwal ◽  
Peter Annear

Objectives: Surgical management of patellar instability includes proximal realignment procedure such as MPFL reconstruction. The decision to add a distal realignment procedure of tibial tubercle transfer is based on severity of patellar instability judged on either TTTG distance or arthroscopic patellofemoral tracking. We set out to validate our use of arthroscopic patellofemoral tracking for patellar instability management algorithm by analyzing its reproducibility and whether it correlates with patellar instability. Methods: A prospective observational study was carried out at Perth Orthopaedic and Sports Medicine Centre. Patient clinical presentations were divided into three groups - patellofemoral instability, patellofemoral pain, and no patellofemoral symptoms. Standard technique included low flow arthroscopy with single anterolateral viewing portal. Height of the fluid bag and presence of a knee holder was recorded. Knee flexion angle where patella first centrally engages in the trochlear groove was defined as Patellofemoral Congruent Angle (PCA). PCA was estimated by the primary surgeon and the angle was confirmed using a sterile goniometer. A second surgeon, blinded to the initial assessment, then repeated the measurements. Surgeon estimation error, interobserver reliability, and correlation with clinical presentation was analysed. Results: 57 knees were assessed for interobserver reliability. Intra-class correlation was 0.994 between surgeon’s estimate and goniometer reading. Intra-class correlation was 0.992 between the two surgeon’s readings suggesting a very high correlation. 157 patients had their PCA recorded and compared with their diagnosis. Mean PCA was 40 degrees in normal patients, and 118 degrees in patellar instability (p-value <0.001). Conclusion: Arthroscopic assessment of patellofemoral tracking is reproducible and correlates with patellar instability. A cut-off value of 40 degrees is recommended to differentiate normal tracking from abnormal.


2018 ◽  
Vol 6 (7_suppl4) ◽  
pp. 2325967118S0007
Author(s):  
Brandon J. Erickson ◽  
Joseph Nguyen ◽  
Katelyn Gasik ◽  
Jacqueline Brady ◽  
Beth E. Shubin Stein

Background: Several surgical options exist for treatment of recurrent patellar instability. The treatments can be divided into ligamentous and bony procedures. It is currently unclear which patients require a bony procedure in addition to a soft tissue reconstruction. Purpose: To report the one and two-year outcomes of patients following medial patellofemoral ligament (MPFL) reconstruction performed in isolation regardless of the patellar height, tibial tubercle trochlear groove distance (TT-TG) or trochlear dysplasia. Hypothesis:: Patients will have <5% re-dislocation rate and significant improvements in patient reported outcome measures (PROMs) following isolated MPFL reconstruction. Methods: All patients with recurrent patellar instability and without significant unloadable chondral defects, failed previous surgery or pain greater than or equal to 50% as their chief complaint, were prospectively enrolled beginning March of 2014. All patients underwent a primary, unilateral, isolated MPFL reconstruction regardless of concomitant bony pathology for treatment of recurrent patellar instability. Patients were followed at standard intervals. PROMs were collected at one year and two year follow up visits. Information on recurrent subjective instability, dislocations, and ability to return to sport (RTS) was recorded. TT-TG and patellar height (using the Caton-Deschamps index) were measured on magnetic resonance images. Results: Overall, 90 patients (77% female; average age 19.4 +/- 5.6 years) underwent a MPFL reconstruction from March 2014 to August 2017; 63 (70%) of whom reached one year follow up, and 35 of these patients (39%) reached 2-year follow-up. No patient experienced a redislocation; 96% of patients at one year and 100% of patients at two years had no subjective patellofemoral instability. RTS rates at one and two years were 59% and 75% respectively. No patient experienced a complication at one year. All patients had a clinically and statistically significant improvement from baseline to 1-year follow-up in the following PROMs: Knee injury and Osteoarthritis Outcome Score Quality of Life (KOOS QOL) (32.7 to 72.0; p<0.001), International Knee Documentation Committee (IKDC) (51.4 to 82.6; p<0.001) Kujala (62.2 to 89.5; p<0.001), and all general health PROM. No clinically and statistically significant change was seen between 1- and 2-year follow-ups in all outcome scores (all p>0.05). A non-statistically significant increase was seen in sporting activity of the Pediatric Functional Activity Brief Scale (Pedi-FABS) (13.9 to 16.7 p=0.292) at 2 years. Average patient satisfaction was 9.3 of 10 (10 being most satisfied) at 1- and 2-year follow-up. Average TT-TG was 15.1 +/- 4.0. Average patellar height was 1.25 +/- 0.17. Conclusion: Isolated MPFL reconstruction is an effective treatment for patellar instability and provides significant improvements in PROMs with a low redislocation/instability rate at early 1 and 2 year follow up, regardless of bony pathologies including TT-TG, Caton-Deschamps Index and trochlear dysplasia. The goal of this ongoing prospective study is to follow these patients out for 5 to 10 years to assess what radiologic and physical examination factors predict failure of isolated MPFL reconstruction.


2019 ◽  
Vol 47 (6) ◽  
pp. 1331-1337 ◽  
Author(s):  
Brandon J. Erickson ◽  
Joseph Nguyen ◽  
Katelyn Gasik ◽  
Simone Gruber ◽  
Jacqueline Brady ◽  
...  

Background: It is unclear which patients with recurrent patellar instability require a bony procedure in addition to medial patellofemoral ligament (MPFL) reconstruction. Purpose: To report 1- and 2-year outcomes of patients after isolated MPFL reconstruction performed for patellar instability regardless of patellar height, tibial tubercle–trochlear groove (TT-TG) distance, or trochlear dysplasia. Study Design: Case series; Level of evidence, 4. Methods: All patients with recurrent patellar instability and without significant unloadable chondral defects (Outerbridge grade IV), cartilage defects (especially inferior/lateral patella), previous failed surgery, or pain >50% as their chief complaint were prospectively enrolled beginning March 2014. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of concomitant bony pathology for treatment of recurrent patellar instability. Information on recurrent subjective instability, dislocations, ability to return to sport (RTS), and outcome scores was recorded at 1 and 2 years. TT-TG distance, patellar height (with the Caton-Deschamps index), and trochlear depth were measured. Results: Ninety patients (77% female; mean ± SD age, 19.4 ± 5.6 years) underwent MPFL reconstruction between March 2014 and August 2017: 72 (80%) reached 1-year follow-up, and 47 (52.2%) reached 2-year follow-up (mean follow-up, 2.2 years). Mean TT-TG distance was 14.7 ± 5.4 mm (range, –2.2 to 26.8 mm); mean patellar height, 1.2 ± 0.11 mm (range, 0.89-1.45 mm); and mean trochlear depth, 1.8 ± 1.4 mm (range, 0.05-6.85 mm). Ninety-six percent of patients at 1 year and 100% at 2 years had no self-reported patellofemoral instability; 1 patient experienced a redislocation at 3.5 years. RTS rates at 1 and 2 years were 90% and 88%, respectively. Mean time to RTS was 8.8 months. All patients had clinically and statistically significant improvement in mean Knee injury and Osteoarthritis Outcome Score–Quality of Life (32.7 to 72.0, P < .001), mean International Knee Documentation Committee subjective form (51.4 to 82.6, P < .001), and mean Kujala score (62.2 to 89.5, P < .001). No difference existed between 1- and 2-year outcome scores (all P > .05). Conclusion: At early follow-up of 1 and 2 years, isolated MPFL reconstruction is an effective treatment for patellar instability and provides significant improvements in outcome scores with a low redislocation/instability rate regardless of bony pathologies, including TT-TG distance, Caton-Deschamps index, and trochlear dysplasia. Future data from this cohort will be used to assess long-term outcomes.


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Gary Ulrich, BS ◽  
Hemant Pandit, FRCS (Orth), DPhil (Oxon)

Background and Hypothesis:  Patellofemoral instability represents a disabling condition, which presents primarily in active, young patients with an increased incidence in the female sex. A patellar dislocation can occur from a high-energy trauma or from an atypical anatomy, such as trochlear dysplasia, patellar dysplasia, patella alta, increased tibial tuberosity-trochlear groove (TT-TG) distance, increased Q-angle, and ligamentous laxity. When a patient presents with patellofemoral instability, the orthopedic surgeon faces many decisions regarding the treatment. Since the risk of a second dislocation after an acute dislocation resides at approximately 17%, many orthopedic surgeons treat the first patellar dislocation non-operatively barring the patient lacks any atypical anatomy. However, after a second dislocation, the likelihood of recurrent dislocations increases to approximately 50%, which directs most orthopedic surgeons to surgical treatment. The current work reviews the anatomical predispositions, clinical presentation, and treatment of patellofemoral instability.   Experimental Design or Project Methods:  The review was constructed via an extensive literature search utilizing the databases of MEDLINE/PubMed, SportDiscus, CINAHL, and Cochrane Central Register of Controlled Trials.   Results:  Multiple treatments exist for patellofemoral instability, which include non-operative treatment, MPFL reconstruction, tibial tubercle osteotomy, and trochleoplasty, along with many other procedures. Each case requires a tailored approach to successfully treat the patellofemoral instability.   Conclusion and Potential Impact:  Patellofemoral instability represents a potentially debilitating condition of anterior knee pain and limited activity. Understanding the anatomical predispositions, clinical presentation, and treatment of patellofemoral instability marks the first step to caring for patients with this condition.


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