Isolated Medial Patellofemoral Ligament Reconstruction Can Be an Effective Procedure in Patellofemoral Instability with Risk Factors

2019 ◽  
Vol 33 (10) ◽  
pp. 992-997 ◽  
Author(s):  
Fabian Blanke ◽  
Kathrin Watermann ◽  
Maximilian Haenle ◽  
Andreas Feitenhansl ◽  
Carlo Camathias ◽  
...  
Keyword(s):  
Risk Factors ◽  
Clinical Outcome ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Patellofemoral Instability ◽  
Effective Procedure ◽  
Mpfl Reconstruction ◽  
Trochlear Groove ◽  
Severe Problem ◽  
Outcome Scores

AbstractPatellofemoral instability is a severe problem in young and active patients. This pathology is influenced by ligamentous, bony, and neuromuscular parameters. The reconstruction of the medial patellofemoral ligament (MPFL) evolved to a primary procedure, but combined procedures were more frequently performed in the past years. However, additional operative procedures are associated with increased morbidity and no absolute indication can be identified in the literature. This study is intended to clarify whether addressing only ligamentous influence factors (MPFL) in chronic patellofemoral instability is sufficient to produce good clinical outcomes, or whether other risk factors influence the results negatively and should also be treated at some point. In 52 patients with chronic patellofemoral instability patellar height according to Caton-Deschamps, trochlear dysplasia according to Dejour, the leg axis, the femoral antetorsion, tibial tubercle (TT)–trochlear groove, and TT–posterior cruciate ligament distance were evaluated. All patients were treated with isolated MPFL reconstruction. After a minimum follow-up period of 24 months (24–36 months), the clinical outcome results were calculated using the scoring system according to Lysholm and Tegner. Correlation between clinical outcome scores and anatomic risk factors were calculated. The analysis was performed using a standard statistical software package (JMP version 12, SAS Institute, Cary, NC). The average postoperative Lysholm score increased significantly from 57.23 ± 19.9 to 85.9 ± 17.2 points (p < 0.0001) after isolated MPFL reconstruction. Moreover, the Tegner and Lysholm scores significantly improved both in patients without and with different risk factors postoperative. There were no significant differences in the outcome sores between the groups. Even the degree of trochlear dysplasia (types I–III) did not influence the results. Finally, there was no significant correlation found between all collected risk factors and the postoperative outcome scores. Isolated MPFL reconstruction can be an effective procedure in patients with patellofemoral instability and mild to moderate risk factors.

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.

Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability Regardless of Tibial Tubercle–Trochlear Groove Distance and Patellar Height: Outcomes at 1 and 2 Years

2019 ◽  
Vol 47 (6) ◽  
pp. 1331-1337 ◽  
Author(s):  
Brandon J. Erickson ◽  
Joseph Nguyen ◽  
Katelyn Gasik ◽  
Simone Gruber ◽  
Jacqueline Brady ◽  
...  
Keyword(s):  
Patellar Instability ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Patellar Height ◽  
Mpfl Reconstruction ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
Outcome Scores ◽  
Recurrent Patellar Instability

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.

Effect of Isolated Medial Patellofemoral Ligament Reconstruction in Patellofemoral Instability Regardless of Predisposing Factors

2020 ◽  
Author(s):  
Jae Ik Lee ◽  
Mohd Shahrul Azuan Jaffar ◽  
Han Gyeol Choi ◽  
Tae Woo Kim ◽  
Yong Seuk Lee
Keyword(s):  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Case Series ◽  
Patellofemoral Instability ◽  
International Knee Documentation Committee ◽  
Predisposing Factors ◽  
Mpfl Reconstruction ◽  
Patellar Tilt ◽  
Case Series Study

AbstractThe purpose of this study was to evaluate the outcomes of isolated medial patellofemoral ligament (MPFL) reconstruction, regardless of the presence of predisposing factors. A total of 21 knees that underwent isolated MPFL reconstruction from March 2014 to August 2017 were included in this retrospective series. Radiographs of the series of the knee at flexion angles of 20, 40, and 60 degrees were acquired. The patellar position was evaluated using the patellar tilt angle, sulcus angle, congruence angle (CA), and Caton-Deschamps and Blackburne-Peel ratios. To evaluate the clinical outcome, the preoperative and postoperative International Knee Documentation Committee (IKDC) and Lysholm knee scoring scales were analyzed. To evaluate the postoperative outcomes based on the predisposing factors, the results were separately analyzed for each group. Regarding radiologic outcomes, 20-degree CA was significantly reduced from 10.37 ± 5.96° preoperatively to −0.94 ± 4.11° postoperatively (p = 0.001). In addition, regardless of the predisposing factors, delta values of pre- and postoperation of 20-degree CA were not significantly different in both groups. The IKDC score improved from 53.71 (range: 18–74) preoperatively to 94.71 (range: 86–100) at the last follow-up (p = 0.004), and the Lysholm score improved from 54.28 (range: 10–81) preoperatively to 94.14 (range: 86–100) at the last follow-up (p = 0.010). Isolated MPFL reconstruction provides a safe and effective treatment for patellofemoral instability, even in the presence of mild predisposing factors, such as trochlear dysplasia, increased patella height, increased TT–TG distance, or valgus alignment. This is a Level 4, case series study.

scholarly journals Isolated medial patellofemoral ligament reconstruction for recurrent patellofemoral instability: analysis of outcomes and risk factors

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Filippo Migliorini ◽  
Francesco Oliva ◽  
Gayle D. Maffulli ◽  
Jörg Eschweiler ◽  
Matthias Knobe ◽  
...  
Keyword(s):  
Risk Factors ◽  
Surgical Outcomes ◽  
Ligament Reconstruction ◽  
Medial Patellofemoral Ligament ◽  
Patellofemoral Instability ◽  
Mpfl Reconstruction ◽  
Medial Patellofemoral Ligament Reconstruction ◽  
The Mean ◽  
Tegner Score

Abstract Background The medial patellofemoral ligament (MPFL) is always damaged after patellar dislocation. In selected patients, MPFL reconstruction is necessary to restore a correct patellar tracking. Despite the large number of different techniques reported to reconstruct the MPFL, there is no consensus concerning the optimal procedure, and debates is still ongoing. The present study analysed the results after isolated MPFL reconstruction in patients with patellofemoral instability. Furthermore, a subgroup analysis of patients presenting pathoanatomical risk factors was made. Methods In November 2020, the main electronic databases were accessed. All articles reporting the results of primary isolated MPFL reconstruction for recurrent patellofemoral instability were considered for inclusion. Only articles reporting a minimum 12-month follow-up were eligible. Results Data from a total of 1777 knees were collected. The mean age of the patients involved was 22.8 ± 3.4 years. The mean follow-up was 40.7 ± 25.8 months. Overall, the range of motion (+ 27.74; P < 0.0001) and all the other scores of interests improved at last follow-up: Kujala (+ 12.76; P = 0.0003), Lysholm (+ 15.69; P < 0.0001), Tegner score (+ 2.86; P = 0.006). Seventy-three of 1780 patients (4.1%) showed a positive apprehension test. Thirty of 1765 patients (1.7%) experienced re-dislocations, while 56 of 1778 patients (3.2%) showed persisting joint instability. Twenty-five of 1786 patients (1.4%) underwent revision surgeries. Conclusion Isolated MPFL reconstruction for recurrent patellofemoral instability provides reliable surgical outcomes. Patients with pathoanatomical predisposing factors reported worse surgical outcomes.

scholarly journals Failure Analysis in Patients With Patellar Redislocation After Primary Isolated Medial Patellofemoral Ligament Reconstruction

2020 ◽  
Vol 8 (6) ◽  
pp. 232596712092617 ◽  
Author(s):  
Matthias J. Feucht ◽  
Julian Mehl ◽  
Philipp Forkel ◽  
Andrea Achtnich ◽  
Andreas Schmitt ◽  
...  
Keyword(s):  
Revision Surgery ◽  
Medial Patellofemoral Ligament ◽  
Femoral Tunnel ◽  
Trochlear Dysplasia ◽  
Patellofemoral Instability ◽  
Tibial Tuberosity ◽  
Mpfl Reconstruction ◽  
Tunnel Position ◽  
Femoral Tunnel Position ◽  
Valgus Malalignment

Background: Reconstruction of the medial patellofemoral ligament (MPFL) has become a popular surgical procedure to address patellofemoral instability. As a consequence of the growing number of MPFL reconstructions performed, a higher rate of failures and revision procedures has been seen. Purpose: To perform a failure analysis in patients with patellar redislocation after primary isolated MPFL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Patients undergoing revision surgery for reinstability after primary isolated MPFL reconstruction were included. Clinical notes were reviewed to collect demographic data, information on the primary surgery, and the mechanism of patellar redislocation (traumatic vs nontraumatic). Preoperative imaging was analyzed regarding femoral tunnel position and the prevalence of anatomic risk factors (ARFs) associated with patellofemoral instability: trochlear dysplasia (types B through D), patella alta (Caton-Deschamps index >1.2, patellotrochlear index <0.28), lateralization of the tibial tuberosity (tibial tuberosity–trochlear groove distance >20 mm, tibial tuberosity–posterior cruciate ligament [TT-PCL] distance >24 mm), valgus malalignment (mechanical valgus axis >5°), and torsional deformity (internal femoral torsion >25°, external tibial torsion >35°). The prevalence of ARF was compared between patients with traumatic and nontraumatic redislocations and between patients with anatomic and nonanatomic femoral tunnel position. Results: A total of 26 patients (69% female) with a mean age of 25 ± 7 years were included. The cause of redislocation was traumatic in 31% and nontraumatic in 69%. Position of the femoral tunnel was considered nonanatomic in 50% of patients. Trochlear dysplasia was the most common ARF with a prevalence of 50%, followed by elevated TT-PCL distance (36%) and valgus malalignment (35%). The median number of ARFs per patient was 3 (range, 0-6), and 65% of patients had 2 or more ARFs. Patients with nontraumatic redislocations showed significantly more ARFs per patient, and the presence of 2 or more ARFs was significantly more common in this group. No significant difference was observed between patients with anatomic versus nonanatomic femoral tunnel position. Conclusion: Multiple anatomic risk factors and femoral tunnel malposition are commonly observed in patients with reinstability after primary MPFL reconstruction. Before revision surgery, a focused clinical examination and adequate imaging including radiographs, magnetic resonance imaging (MRI), standing full-leg radiographs, and torsional measurement with computed tomography or MRI are recommended to assess all relevant anatomic parameters to understand an individual patient’s risk profile. During revision surgery, care must be taken to ensure anatomic placement of the femoral tunnel through use of anatomic and/or radiographic landmarks.

Age at Time of Surgery but Not Sex Is Related to Outcomes After Medial Patellofemoral Ligament Reconstruction

2019 ◽  
Vol 47 (7) ◽  
pp. 1638-1644 ◽  
Author(s):  
Laurie A. Hiemstra ◽  
Sarah Kerslake
Keyword(s):  
Quality Of Life ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Patellofemoral Instability ◽  
Mpfl Reconstruction ◽  
Linear Regression Models ◽  
Level Of Evidence ◽  
Time Of Surgery ◽  
Patient Reported

Background: Medial patellofemoral ligament (MPFL) reconstruction has become a well-accepted procedure for recurrent patellofemoral instability. Despite a growing volume of research assessing surgical results, the relationship of age and sex to outcomes after MPFL reconstruction surgery is unclear. Purpose: To investigate whether age at the time of surgery or sex influenced patient-reported quality of life and clinical outcome after MPFL reconstruction for recurrent lateral patellofemoral instability. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2010 and May 2016, 328 patients underwent primary patellofemoral stabilization. Demographic and clinical data were collected preoperatively. Patients completed the Banff Patellofemoral Instability Instrument (BPII) at the pre- and postoperative visits and were assessed clinically at 12 and 24 months. To assess the effects of age at surgery and sex on BPII, multiple linear regression models were fit predicting BPII at 12 and 24 months. An unadjusted regression was applied with the predictors being age at the time of surgery and sex. A second regression model was applied adjusting for age at first dislocation, grade of trochlear dysplasia, knee hyperextension, and the WARPS/STAID score—a measure of the risky patellofemoral instability characteristics of the patient. Results: Of 328 patients, 298 (91%) had complete data and minimum 12-month BPII scores available for analysis. There were 11 redislocations in the cohort (3.4%), all in female patients. When stratified by sex, baseline characteristics were not statistically different except for higher age at first dislocation ( P = .022) as well as higher WARPS/STAID scores ( P = .006) for males. Age at the time of surgery was statistically significant for each postoperative follow-up, with lower BPII scores apparent for each 10-year increase in age at the time of surgery. In the adjusted model, the WARPS/STAID score was significantly associated with the preoperative BPII score. For the 24-month postoperative BPII scores, age at time of surgery and preoperative WARPS/STAID score were both significant. Lower BPII scores were apparent for each 10-year increase in age at the time of surgery, as well as for lower scores on the WARPS/STAID classification. Conclusion: This study demonstrated that when adjusted for risky pathoanatomy, neither age at first dislocation nor sex influences patient-reported quality of life outcomes after MPFL reconstruction. Age at the time of surgery was correlated with outcome, with lower BPII scores apparent for each 10-year increase in age at the time of MPFL reconstruction.

scholarly journals Recent advances and future trends in patellofemoral instability

2020 ◽  
Vol 1 ◽  
pp. 110-117
Author(s):  
Bobby Singh Anand ◽  
Sebastian Ho ◽  
Srinivas Kambhampati
Keyword(s):  
Risk Factors ◽  
Patellofemoral Joint ◽  
Joint Instability ◽  
Medial Patellofemoral Ligament ◽  
Young Patients ◽  
Patellofemoral Instability ◽  
Mpfl Reconstruction ◽  
Future Trends ◽  
Management Options ◽  
Selection Of

Patellofemoral joint instability (PFJI) is a challenging condition affecting primarily young patients. It can be both physically and mentally disabling. There are numerous factors which contribute to stability of the patellofemoral joint and thorough clinical assessment and appropriate radiological investigations are essential in determining which risk factors need to be corrected to prevent further episodes of dislocation. One of the key operations utilized in the management of PFJI is medial patellofemoral ligament (MPFL) reconstruction, to restore the patellar restraint against lateral translation. The complications that can result from MPFL reconstruction can be largely divided into complications resulting from technical error or selection of operation for a patient’s specific risk factors. Some risk factors of PFJI can precipitate the need for additional operations being performed alongside MPFL reconstruction, including trochleoplasty, lateral retinacular lengthening, and tibial tuberosity osteotomy. Failure to identify the need for concurrent operations will result in persistent PFJI. This update article will outline the approach to assess a patient presenting with PFJI and the risk factors which should be identified and corrected. It will also cover the various management options with respect to these factors, with some important considerations for each.

scholarly journals Isolated Medial Patellofemoral Ligament Reconstruction for Patellar Instability Regardless of the Tibial Tubercle Trochlear Groove Distance: Outcomes at 1 and 2 Years

2018 ◽  
Vol 6 (7_suppl4) ◽  
pp. 2325967118S0007
Author(s):  
Brandon J. Erickson ◽  
Joseph Nguyen ◽  
Katelyn Gasik ◽  
Jacqueline Brady ◽  
Beth E. Shubin Stein
Keyword(s):  
Patellar Instability ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Patellar Height ◽  
Mpfl Reconstruction ◽  
Tibial Tubercle ◽  
Trochlear Groove ◽  
One Year ◽  
Recurrent Patellar Instability

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.

Deepening trochleoplasty and medial patellofemoral ligament reconstruction normalize patellotrochlear congruence in severe trochlear dysplasia

2019 ◽  
Vol 101-B (3) ◽  
pp. 325-330 ◽  
Author(s):  
P. Balcarek ◽  
F. Zimmermann
Keyword(s):  
Contact Area ◽  
Medial Patellofemoral Ligament ◽  
Trochlear Dysplasia ◽  
Mpfl Reconstruction ◽  
Control Group ◽  
Study Group ◽  
Trochlear Groove ◽  
Contact Ratio ◽  
Patellar Tilt ◽  
Patellofemoral Alignment

Aims The aim of this study was to evaluate cartilaginous patellotrochlear congruence and patellofemoral alignment parameters after deepening trochleoplasty in severe trochlear dysplasia. Patients and Methods The study group comprised 20 patients (two male, 18 female; mean age 24 years (16 to 39)) who underwent deepening trochleoplasty and medial patellofemoral ligament (MPFL) reconstruction for the treatment of recurrent lateral patellar dislocation due to severe trochlear dysplasia (Dejour type B to D). Pre- and postoperative MRI investigations of the study group were compared with MRI data of 20 age- and gender-matched control patients (two male, 18 female; mean age 27 years (18 to 44)) regarding the patellotrochlear contact ratio, patellotrochlear contact area, posterior patellar edge-trochlear groove ratio, and patellar tilt. Results Preoperatively, all parameters in the study group indicated significant patellar malalignment, including a reduced patellotrochlear contact ratio (mean 0.38 (0.13 to 0.59) vs mean 0.67 (0.48 to 0.88); p < 0.001), reduced contact area (mean 128 mm2 (87 to 190) vs mean 183 mm2 (155 to 227); p < 0.001), increased patellar lateralization (mean 0.82 (0.55 to 1.0) vs mean 0.99 (0.93 to 1.1); p < 0.001) and increased patellar tilt (mean 25.8° (8.1° to 43.0°) vs mean 9.1° (0.5° to 16.8°); p < 0.001). Postoperatively, all parameters in the study group improved significantly and reached normal values compared with the control group. The patellotrochlear contact ratio increased to a mean of 0.63 (0.38 to 0.85) (p < 0.001), the contact area increased to a mean of 187 mm2 (101 to 255) (p < 0.001), the posterior patellar edge-trochlear groove ratio improved to a mean of 0.96 (0.83 to 0.91) (p < 0.001), and the patellar tilt decreased to a mean of 13.9° (8.1° to 22.1°) (p < 0.001) postoperatively. Conclusion Deepening trochleoplasty and MPFL reconstruction normalized the patellotrochlear congruence and patellofemoral alignment parameters. Modifying the dysplastic trochlea involves approximating the trochlear morphology to the shape of the patella rather than inducing a patella and trochlea mismatch. Cite this article: Bone Joint J 2019;101-B:325–330.

scholarly journals Why do MPFL reconstructions fail today?

2020 ◽  
Vol 8 (5_suppl4) ◽  
pp. 2325967120S0029
Author(s):  
Felix Zimmermann ◽  
Peter Balcarek
Keyword(s):  
Risk Factors ◽  
Revision Surgery ◽  
Patellar Instability ◽  
Trochlear Dysplasia ◽  
Valgus Deformity ◽  
Patellar Height ◽  
Tibial Tuberosity ◽  
Mpfl Reconstruction ◽  
Trochlear Groove ◽  
Type B

Aims and Objectives: The medial patellofemoral ligament (MPFL) is the most important passive stabilizer of the patella. In recurrent lateral patellar dislocations reconstruction of the MPFL with an autologous tendon transplant is a frequently performed surgical procedure that shows a low redislocation rate between 1%-7%. However, a complication rate of up to 26% and a reoperation rate of 4% has also been observed. The question, therefore, arises which parameter determines MPFL reconstruction failure. Thus, the purpose of this study was to identify reasons for MPFL reconstruction failure with regard to patients’ complaints leading to reoperation. Materials and Methods: Between July 2015 and May 2019 28 patients (M/F 9/19; mean age 27 ± 8 years) with postoperative complaints after MPFL reconstructive surgery had to undergo revision surgery. Preoperative failure analysis included clinical examination (ROM, ReDPAT, J-sign, and Patella-Glide Test) and radiological imaging with regard to anatomical risk factors of patellar instability and MPFL tunnel positioning. Anatomical predisposition was assessed according to Dejour’s classification of trochlear dysplasia, tibial tuberosity-trochlear groove distance, tibial tuberosity-posterior cruciate ligament distance, patellar height, varus/valgus malalignment and torsional profile. Results: Three major reasons for revision surgery were identified: (1) patellar redislocation, (2) limited range of motion (ROM), and (3) anterior knee pain (AKP). Sixteen of the 28 patients (57%) suffered from recurrent patellar dislocation. Severe trochlear dysplasia (type B/D according to Dejour) (44%), valgus deformity (19%), increased patellar height (19%), and misplaced femoral drill channels (31%) could be identified as risk factors for redislocation. An increased TT-TG (>20mm) or TT-PCL (>24mm) distance could not be observed in any patient in this group. Limited ROM with an average maximum flexion ability of about 92 ± 26° was observed in 10 of the 28 patients (36%), of which 9 patients additionally complained of AKP. Misplaced femoral drill channels (80%), severe trochlear dysplasia (type B/D according to Dejour) (20%) and postoperative decreased patellar height (20%) could be identified as risk factors for postoperative limited ROM. Other reasons for postoperative AKP were increased femoral antetorsion (n=1) and retropatellar cartilage damage (n=2) without any loss of ROM. Conclusion: Recurrent dislocation of the patella, limited ROM and AKP were identified as most common complications after MPFL reconstruction leading to revision surgery. Failures are mainly due to neglected bony risk factors of patellar instability (trochlear dysplasia, patella alta and valgus deformity) and to misplaced femoral drill channels. Appropriate patient selection and an accurate surgical technique appear mandatory for a good clinical outcome when patellar instability is treated solely with an MPFL reconstruction.

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