Editorial Commentary: Medial Patellofemoral Ligament Reconstruction for Knee Patellar Instability: When Are Soft Tissue Procedures Not Enough?

2018 ◽  
Vol 34 (2) ◽  
pp. 511-512 ◽  
Author(s):  
Miho J. Tanaka
Cartilage ◽  
2019 ◽  
pp. 194760351989472 ◽  
Author(s):  
Charles L. Holliday ◽  
Laurie A. Hiemstra ◽  
Sarah Kerslake ◽  
John A. Grant

Objective The purpose of this study was (1) to determine which risk factors for patellar instability were associated with the presence of patellofemoral cartilage lesions and (2) to determine how cartilage lesion presence, size, and grade affect postoperative disease-specific quality of life. Design Preoperative, intraoperative, and postoperative demographic, anthropometric (body mass index, Beighton score, hip rotation), radiographic (crossover sign, trochlear bump), cartilage lesion morphology (presence, size, location, grade), and outcomes data (Banff Patella Instability Instrument 2.0 [BPII 2.0]) were prospectively collected from patients undergoing isolated medial patellofemoral ligament reconstruction. For all knees ( n = 264), single and multivariable logistic regression was used to determine if any patellar instability risk factors affected the odds of having a cartilage lesion. In patients with unilateral symptoms ( n = 121), single variable linear regression was used to determine if the presence, size, or ICRS (International Cartilage Regeneration & Joint Preservation Society) grade of cartilage lesions could predict the 12 or 24+ month postoperative BPII 2.0 score. Results A total of 84.5% of knees had patellofemoral cartilage lesions (88.3% involved the distal-medial patella). Trochlear dysplasia (high grade: odds ratio = 15.7, P < 0.001; low grade: odds ratio = 2.9, P = 0.015) was associated with the presence of a cartilage lesion. The presence, size, and grade of cartilage lesions were not associated with 12 or 24+ month postoperative BPII 2.0 scores. Conclusions Trochlear dysplasia was a risk factor for the development of patellofemoral cartilage lesions in this patient population. Cartilage lesions most commonly involve the distal-medial patella. There was no significant relationship between patellofemoral cartilage lesion presence, size, or grade and postoperative BPII 2.0 scores in short-term follow-up.


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]


2018 ◽  
Vol 6 (5) ◽  
pp. 232596711877427 ◽  
Author(s):  
Nikhil Kumar ◽  
Tracey P. Bastrom ◽  
M. Morgan Dennis ◽  
Andrew T. Pennock ◽  
Eric W. Edmonds

Background: Recurrent patellar instability is commonly treated with medial patellofemoral ligament reconstruction (MPFLR), and the use of allograft in anterior cruciate ligament reconstructions has demonstrated inferior outcomes. Purpose: To compare the outcomes of allografts versus autografts in adolescent MPFLR for patellar instability. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective chart review was completed on patients younger than 18 years who underwent MPFLR for recurrent instability after failed nonoperative management over an 8-year period with a minimum 2-year follow-up. Patients were divided into autograft or allograft hamstring cohorts for comparison. Primary outcome measures were return to normal activity, incidence of redislocation/subluxation, pain, stiffness, other complications, and Kujala scores. Statistical analysis using unpaired t tests was performed, with an alpha value set at P < .05. Results: After criteria were applied, 59 adolescents (36 allograft, 23 autograft; 38 girls, 21 boys) with a mean ± SD age of 15.2 ± 1.7 years and a mean follow-up of 4.1 ± 1.9 years (allograft, 3.3 ± 1.1 years; autograft, 5.7 ± 2.1 years; P ≤ .001) were included. Seven patients had concurrent osteotomies (3 allograft, 4 autograft), 11 patients had concurrent loose body removals (5 allograft, 6 autograft), and 9 patients had concurrent lateral release (7 allograft, 2 autograft). Between groups, no significant difference was found in change between preoperative and most recent follow-up (mean, 1.2 ± 2.1) or rate of return to sports (mean, 73.3%). In total, 9 surgeries failed (3 allograft, 6 autograft). For the surviving grafts, a statistical difference in mean Kujala scores at final follow-up was noted (allograft, 92.7; autograft, 97.4; P = .02). Conclusion: We identified no significant differences in return to activity, pain score changes, and incidences of failure between patients undergoing MPFLR with allograft versus autograft. Although teenagers with surviving autograft MPFLR reported statistically higher Kujala scores, the mean score difference of 5 points was not clinically significant. It appears that using allograft tendon instead of autograft tissue for MPFLR in this teenage population does not adversely affect long-term outcomes.


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