scholarly journals SPONTANEOUS CORRECTION OF EXTERNAL TIBIOFEMORAL ROTATION AND TIBIAL TUBEROSITY-TROCHLEAR GROOVE DISTANCE OCCURS AFTER MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION IN FIXED OR OBLIGATORY DISLOCATORS

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0013
Author(s):  
Alexandra H. Aitchison ◽  
Kenneth M. Lin ◽  
Daniel W. Green
Keyword(s):  
Patellar Instability ◽  
Ligament Reconstruction ◽  
Medial Patellofemoral Ligament ◽  
Extensor Mechanism ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Medial Patellofemoral Ligament Reconstruction ◽  
Force Vector ◽  
Tibiofemoral Rotation ◽  
The Mean

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]

scholarly journals Outcomes And Reoperation Rates After Tibial Tubercle Transfer And Medial Patellofemoral Ligament Reconstruction

2020 ◽  
Vol 8 (3_suppl2) ◽  
pp. 2325967120S0012
Author(s):  
Dax T. Varkey ◽  
Jacob Gorbaty ◽  
Susan Odum ◽  
Dana P. Piasecki ◽  
James E. Fleischli
Keyword(s):  
Knee Pain ◽  
Ligament Reconstruction ◽  
Medial Patellofemoral Ligament ◽  
Patellofemoral Instability ◽  
Reoperation Rate ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Medial Patellofemoral Ligament Reconstruction ◽  
Tibial Tubercle Transfer ◽  
Reoperation Rates

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.

Clinical Outcomes After Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability Among Patients With Trochlear Dysplasia

2018 ◽  
Vol 46 (4) ◽  
pp. 883-889 ◽  
Author(s):  
Joseph N. Liu ◽  
Jacqueline M. Brady ◽  
Irene L. Kalbian ◽  
Sabrina M. Strickland ◽  
Claire Berdelle Ryan ◽  
...  
Keyword(s):  
Patellar Instability ◽  
Ligament Reconstruction ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Patellofemoral Instability ◽  
Mpfl Reconstruction ◽  
Trochlear Groove ◽  
Return To Sports ◽  
Medial Patellofemoral Ligament Reconstruction

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.

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