Medial Patellofemoral Ligament Reconstruction Research Articles

Incidence of Early Adverse Events Following Medial Patellofemoral Ligament Reconstruction.

The current literature lacks data regarding perioperative complications after medial patellofemoral ligament reconstruction (MPFLr). The objective of this study was to identify the incidence and predictors of adverse events in the first 90 days after MPFLr. Patients undergoing primary MPFLr between January 1, 2010, and December 31, 2019, were included. Predictors of readmission for any reason were identified using a multivariable logistic regression analysis. A total of 140 MPFLrs were included in the final analysis. Of these, 17 patients (12.1%) were admitted in the first 90 days after MPFLr. The most common reason for readmission was pain (7/140, 5%), followed by cellulitis (5/140, 3.5%). The only major complication was pulmonary embolism experienced by one patient (1/140, 0.7%). Univariate logistic regression analysis demonstrated that patients who ever smoked were 4.5 times (p = 0.005) more likely to be readmitted in the first 90 days. Although additional soft-tissue procedures increased the readmission rated by 21% (p = 0.810) and additional chondral procedure increased by 35% (p = 0.568), the multivariable analysis did not reveal a significant difference. Surgeons can use this information to counsel patients on what to expect following MPFLr.

Outcomes of Trochleoplasty versus Tibial Tubercle Osteotomy for Treatment of Patellar Instability Associated with Trochlear Dysplasia: A Systematic Review and Meta-analysis.

This study compared the outcomes of tibial tubercle osteotomy (TTO) and trochleoplasty for the treatment of patellar instability associated with trochlear dysplasia. This was a systematic review of the literature including published articles that describe either trochleoplasty or TTO in addition to medial patellofemoral ligament reconstruction for the surgical treatment of patellar instability associated with trochleoplasty. Main outcomes assessed were Kujala and International Knee Documentation Committee (IKDC) scores, in addition to recurrent instability and complications. Outcome measures reported were provided in a table format and a subjective analysis was performed. Ten studies were included with a total of 362 knees including 132 in the trochleoplasty group and 230 in the TTO group. Mean follow-up ranged from 27.6 to 61.3 months. At the final follow-up, both Kujala and IKDC scores improved significantly in all studies that reported both preoperative and postoperative scores in both groups. There was a total of three instability events in the trochleoplasty group as opposed to 21 in the TTO group. Both procedures, trochleoplasty and TTO, may provide satisfactory functional improvement in patients with patellar instability associated with trochlear dysplasia. However, trochleoplasty may be a better option to minimize the risk of recurrent instability. Level of evidence: level IV, systematic review of level III and level IV studies.

Medial Patellofemoral Ligament Reconstruction With Concomitant Tibial Tubercle Osteotomy

Background: Patellar instability, often associated with medial patellofemoral ligament rupture, is prevalent in adolescents. Risk factors include trochlear dysplasia, patella alta, abnormal patellar tilt, and increased tibial tubercle to trochlear groove (TT-TG) distance. Indication: A variety of surgical options are available for addressing patellar instability, and the selection of each technique should be tailored to the unique pathoanatomy of each patient. Medial patellofemoral ligament reconstruction (MPFLR) is indicated for patients with patellar instability, and tibial tubercle osteotomy (TTO) is indicated for patients with a TT-TG >20 mm. Technique Description: An anterior midline incision is performed to expose the patella, patellar tendon, and tibial tubercle. Diagnostic arthroscopy is performed to assess patellar engagement and cartilage integrity, followed by the TTO. Three guidewires are placed with 15° of obliquity, to guide a 6-cm osteotomy, from medial to lateral and from proximal to distal. A distal cortical hinge must be left intact. A 15-mm medial resection of the tibial tubercle is performed to avoid protrusion against the skin, which is followed by medialization of the tubercle and fixation with K-wires until dynamic testing ensures proper alignment and definitive fixation is achieved with cannulated headless screws. A lateral retinacular lengthening is performed to balance patellar forces. MPFLR is executed using a semitendinosus allograft. The graft is anchored to the patella and drawn through a surgically created plane to the medial femoral condyle. The femoral tunnel is created under fluoroscopy guidance, and the graft is then passed and secured. Graft tension and patellar mobility are adjusted according to dynamic testing. Once patellar stability is achieved and maintained through range of motion, the graft is then fixed. Results: Patients can expect improved clinical outcomes with a high return-to-sports rate following both isolated MPFLR and concomitant TTO. The combination of MPFLR + TTO significantly reduces revision rate, compared to isolated MPFLR in patients with increased TT-TG distance, and enhances postoperative patellofemoral tracking. Discussion/Conclusions: MPFLR + TTO improves patellofemoral tracking and corrects patellar instability, substantially improving postoperative outcomes compared to MPFLR alone. Patients with patellar instability and an increased TT-TG may be effectively treated with MPFLR + TTO. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

The Effect of C-Arm Position on Femoral Tunnel Placement in Medial Patellofemoral Ligament Reconstruction

Background: Medial patellofemoral ligament (MPFL) reconstruction is a common treatment for patellar instability. Yet nearly 40% of revisions result from femoral tunnel misplacement. One reason may be the positioning of the C-arm relative to the knee. Purpose: To assess how the C-arm’s position affects femoral MPFL placement when the image receptor is positioned either contralateral or ipsilateral to the operated knee. Study Design: Controlled laboratory study. Methods: Ten human cadaveric knee specimens were dissected, and the femoral MPFL insertion site was identified and marked using a 10-mm eyelet. According to the possible clinical scenarios, true lateral radiographs in 2 different C-arm positions were taken. In the first scenario, the image receptor was on the ipsilateral side, being 5 cm away from the knee with the x-ray beam directed from medial to lateral (ML5). In the second scenario, the image receptor was on the contralateral side, being 25 cm away from the knee with the x-ray beam directed from lateral to medial (LM25). In each radiograph, the eyelet position was recorded and the distance (proximal-distal and anterior-posterior) from the optimal radiographic insertion point according to the literature was determined. Differences between the groups were calculated using the Wilcoxon signed-rank test, and a P value of <.05 was considered significant. Results: The anatomic femoral MPFL insertion in the ML5-position was located a mean of 2.7 ± 2.4 mm proximal and 4.5 ± 5.5 mm anterior to the Schöttle point. This resulted in an absolute distance of 7.2 ± 3.0 mm. In the LM25-position, it was located a mean of –0.7 ± 1.8 mm distal and 3.0 ± 5.3 mm anterior, which resulted in an absolute distance of 5.4 ± 3.2 mm. The ML5 was located more anterior (1.5 ± 2.1 mm) and proximal (3.4 ± 2.4 mm) compared with the LM25 position. Measurements following methods described in the literature significantly differed in both axes in the LM25 view when compared with the ML5 view measurements ( P = .005). Conclusion: Compared with the ipsilateral C-arm position (ML5), the contralateral C-arm position (LM25) showed a smaller range with a lower standard deviation in identifying the femoral MPFL approach across all measurement methods. Clinical Relevance: When applying the method according to Schöttle et al to locate the femoral MPFL insertion point, it should be noted that in the proximal-distal orientation, the femoral MPFL insertion point is situated proximal to the Blumensaat line in the contralateral view (LM25). In contrast, when using the ipsilateral view (ML5), the femoral MPFL footprint is positioned just distal to the proximal edge of the medial condyle.

Surgical management of first-time patellar dislocations in paediatric patients may lower rates of redislocation compared to conservative management: A systematic review and meta-analysis.

The purpose of this study is to assess whether early surgical intervention for first-time patellar dislocations in paediatric patients is superior to conservative management. We hypothesized that surgical intervention would lead to lower redislocation rates compared to conservative treatment. Three online databases (PubMed, MEDLINE and EMBASE) were searched from inception to 14 March 2024 to identify studies investigating the management options for acute first-time patellar dislocations in paediatric patients. Data pertaining to patient demographics, patient management, redislocation rates and Kujala scores, evaluating function, were abstracted. Weighted means and meta-analyses were conducted to compare rates of redislocation, as well as Kujala scores. The quality of included studies was assessed using the methodological index for non-randomized studies criteria for non-randomized studies and the ROB2 tool for randomized controlled trials (RCTs). A total of 11 studies and 761 patients were included in this review. The weighted mean post-operative combined rates of redislocation in the surgical group was 25.1%, compared to 46.4% in the conservative group at a mean follow-up of 53.2 months (12-168). The relative risk (RR) of redislocation was 0.82 (95% confidence interval [CI]: 0.65-1.04, I2 = 0%, p = 0.11), favouring surgery compared to conservative management. A subgroup meta-analysis of two recent RCTs with 110 patients demonstrated an RR of redislocation of 0.53 (95% CI: 0.31-0.91, I2 = 0%, p = 0.02), favouring surgery. Kujala scores among three comparative studies showed a mean difference of -2.7 (95% CI: -6.1 to 0.68, I2 = 0%, p = 0.12), favouring conservative treatment. The weighted mean redislocation rate in 131 patients undergoing medial patellofemoral ligament reconstruction (MPFLR) was 3.1%, compared to 39.4% in 203 patients undergoing other surgical procedures, such as lateral release and medial imbrication, Roux-Goldwaith and MPFL repair. Furthermore, the conservative groups experienced a complication rate of 0.9% compared to 2.9% across the surgical groups. Surgical management for first-time patellar dislocations in a paediatric population, particularly MPFLR, may be more beneficial in lowering redislocation rates than conservative management. No significant differences in Kujala scores were found. Level IV.

The Benefits of a Rehabilitation Program Following Medial Patellofemoral Ligament Reconstruction

The medial patellofemoral ligament (MPFL) is critical for patellar stability. This study investigates the efficacy of a one-year physical therapy rehabilitation program following MPFL reconstruction using Synthetic Graft (SG) and Quadriceps Tendon Autograft (QTA). Thirty-five patients aged 18–38 underwent MPFL reconstruction (20 SG, 15 QTA). They participated in a structured rehabilitation program to improve their range of motion (ROM), muscle strength, pain management, and overall quality of life (QoL). The program included physiotherapy and MLS laser, Game Ready Therapy, EMS, TENS, TECAR, and lymphatic drainage. Before and after the program, assessments included knee flexion and extension using goniometry, muscle strength via the Medical Research Council (MRC) scale, knee circumference, pain intensity on the Visual Analogue Scale (VAS), and QoL with the EQ-5D instrument. Significant improvements were observed in knee flexion (37.57° vs. 114.71°, p < 0.001), muscle strength (MRC scale 1–4 points vs. 4–5 points, p < 0.001), and pain reduction (VAS 6.66 vs. 0.46, p < 0.001). The functional coefficient of mobility and QoL scores also markedly increased. Patients with QTA improved some parameters better than those with SG. These findings support the effectiveness of a comprehensive rehabilitation program in enhancing knee functionality, reducing pain, and improving QoL post-MPFL reconstruction. Personalized rehabilitation protocols are recommended to optimize recovery outcomes.

MPFL Reconstruction in Skeletally Immature Patients: Comparison Between Anatomic and Non-Anatomic Femoral Fixation—Systematic Review

Background: MPFL reconstruction in children with open physis may be challenging, as a major concern during the surgery is to preserve the distal femoral physis. The purpose of this study was to compare the complication rate and the patient-reported outcomes in skeletally immature patients who underwent MPFL reconstruction using an anatomic (A) or non- anatomic (NA) surgical technique. Methods: For this systematic review, the authors adhered to the PRISMA guidelines. The literature search was conducted from inception to 31 May 2024. Three databases were used: Pubmed, Scopus and Cochrane library. We included skeletally immature patients who underwent MPFL reconstruction for chronic or recurrent patellar instability. The included studies should describe the surgical technique, report clinical outcomes and complications. Patients with closed physis, prior ipsilateral knee surgery, concomitant surgical procedures except for lateral retinacular release, multiligament knee injury, congenital or acute patellofemoral instability, hyperlaxity or less than 12 months follow up were excluded. Risk of bias was assessed using ROBINS-I, MINORS and MCMS scores. Results: Data from 304 procedures were collected, of which 208 were performed using an anatomic technique and 96 using a non-anatomic technique. Patient age at the time of surgery ranged from 8 to 17 years. The follow-up time ranged between 12 and 116.4 months. Postoperative Kujala (−0.73, p = 0.55) and Tegner (−0.70, p = 0.80) scores were better in the anatomic group compared to the non-anatomic one. Higher rates of recurrent instability (OR 0.91; 95%CI 0.44–1.86, p = 0.85), redislocation (OR 1.21; 95%CI 0.42–3.51, p = 0.8), subluxation (OR 0.73; 95%CI 0.29–1.83, p = 0.62), a positive apprehension test (OR 0.92; 95%CI 0.27–3.13, p = 0.89), stiffness (decreased ROM) (OR 1.63; 95%CI 0.33–1.72, p = 0.54) and reoperation (OR 1.16; 95%CI 0.35–3.80, p = 0.8) were reported in papers using the anatomic technique. Conclusions: The findings of this systematic review reveal that there is no significant difference between anatomic and non-anatomic MPFL reconstruction techniques in terms of patient-reported outcomes and complications. Thus, the choice of surgical technique might be left up to surgeon’s preference. Further high-quality, pediatric-oriented studies with long-term follow–up are needed to better guide clinical decision-making.

Patellofemoral Instability in the Pediatric and Adolescent Population: From Causes to Treatments.

Patella instability is one of the most common knee injuries in the adolescent patient. There are several pathoanatomic risk factors which should be assessed via several modalities, including X-rays, magnetic resonance imaging (MRI), or even CT scan. We intend to review these risk factors along with the nonsurgical and surgical techniques used to prevent recurrent dislocations. We completed an extensive review of the recent literature concerning pediatric and adolescent patellar dislocation and subsequent treatment modalities. We review in detail the risk factors such as patella alta, trochlear dysplasia, lateralization of the tibial tubercle or medialization of the trochlear groove (increased tibial tubercle to trochlear groove (TT-TG) distance), lower limb malalignment, excessive femoral anteversion and/or tibial torsion, and hyperlaxity. There are classification systems for dislocators, and a natural progression of instability that patients often proceed through. Only after a patient has continued to dislocate after bracing and physical therapy is surgical treatment considered. Surgical techniques vary, with the workhorse being the medial patellofemoral ligament (MPFL) reconstruction. However, there are a variety of other techniques which add onto this procedure to address other anatomic risk factors. These include the tibial tubercle osteotomy to address a large TT-TG distance or trochleoplasty to address the lack of a trochlear groove. Nonsurgical and surgical treatments for patella dislocators are tailored to the pathoanatomic risk factors in each patient.

Research progress on femoral attachment positioning during medial patellofemoral ligament reconstruction

To review research progress on femoral attachment positioning during medial patellofemoral ligament (MPFL) reconstruction, so as to provide a reference for accurate positioning in clinic. The literature at home and abroad on femoral attachment positioning during MPFL reconstruction was extensively reviewed and summarized. MPFL is the main ligament that restricts patellar outward migration, so MPFL reconstruction is the main treatment for patellar dislocation, but the accuracy of intraoperative femoral attachment positioning will significantly affect the effectiveness. At present, there are three main methods for femoral attachment positioning in MPFL reconstruction, including imaging positioning, bony landmark positioning, and new technology. Among them, the main imaging positioning method is the "Schöttle point" method, but it has high requirements for fluoroscopic positioning, and can only be accurately positioned under standard lateral fluoroscopy of the femur. The bony landmark positioning method mainly locates the femoral attachment by touching or dissecting the bony landmarks such as adductor tubercles and medial epicondyle of femur, but its disadvantages are that the positioning is not accurate enough, the intraoperative visual field exposure requirements are high, and a large incision is required. In order to avoid the problem that the simple bony landmark positioning method, in recent years, the combination of bony landmarks combined with arthroscopy, three-dimensional (3D) printing technology, and robot-assisted positioning methods have begun to be used in clinical practice. New technology localization methods have shown good results by preparing guides before operation, planning positioning paths in advance, or directly using robots to assist positioning during operation. The accurate positioning of the femoral attachment in MPFL reconstruction is crucial, and the method of accurate and rapid intraoperative determination needs to be further improved and optimized. In the future, it is expected that the combination of computer image recognition correction technology and intraoperative position assistance will solve this problem.

Clinical and Radiological Outcomes After Isolated Double-Bundle Medial Patellofemoral Ligament Reconstruction: A 5-Year Analysis.

There are few studies that have examined clinical and radiological outcomes at 5 years after isolated medial patellofemoral ligament (MPFL) reconstruction. To date, midterm outcomes after isolated double-bundle (DB) MPFL reconstruction are not well known. Isolated DB MPFL reconstruction using a patellar suture anchor technique would lead to improved functional scores and radiological findings, and these improvements would remain stable over the 5-year postoperative period. Case series; Level of evidence, 4. Isolated MPFL reconstruction was performed in patients with recurrent patellar instability between March 2013 and February 2017. Clinical and functional evaluations were performed via an interview using the Kujala, Lysholm, and Tegner scores preoperatively and at 6, 12, 24, and 60 months postoperatively. Radiographs were taken preoperatively, immediately postoperatively, and at 24 and 60 months after surgery. Radiographic assessments included measuring the modified Insall-Salvati ratio, congruence angle, and lateral patellofemoral angle. A total of 31 patients (31 knees) underwent isolated MPFL reconstruction; 4 patients did not complete 5-year follow-up, and thus, 27 patients (27 knees) were enrolled in the study. The mean age at the time of surgery was 22.0 ± 6.4 years (range, 14-32 years). All clinical and functional scores significantly improved in the first 2 years (P < .001), with the mean Kujala, Lysholm, and Tegner scores improving from 52.7 to 90.7, 49.6 to 92.7, and 2.9 to 5.1, respectively. There was no significant difference in scores between 2- and 5-year follow-up. All radiographic parameters significantly improved between preoperatively and immediately postoperatively (P < .001), with mean values for the modified Insall-Salvati ratio, congruence angle, and lateral patellofemoral angle improving from 1.7° to 1.6°, 5.7° to -6.6°, and 3.0° to 5.9°, respectively. No significant differences were observed in radiographic measurements between the postoperative time points. No patients experienced a patellar redislocation or fracture. The prospective analysis of isolated DB MPFL reconstruction at 5-year follow-up showed that clinical and radiological outcomes significantly improved postoperatively and were maintained to 5 years. These midterm results suggest that isolated DB MPFL reconstruction is an effective treatment option for patients with patellar instability.

Anatomic physeal-sparing MPFL reconstruction in skeletally immature patients shows favourable outcomes at a minimum of 24-month follow-up.

Recurrent patellar dislocation is a prevalent orthopaedic issue among active paediatric and adolescent populations. Bony surgical procedures are not recommended in growing patients; therefore, the focus of surgery is on restoring the medial patellar ligaments, with different reconstructive techniques available. This retrospective case series focuses on the 2-year outcomes of medial patellofemoral ligament (MPFL) reconstruction in skeletally immature patients with open physis. Twenty-four consecutive patients with patellofemoral instability and open growth plates underwent anatomic MPFL reconstruction with a physeal-sparing technique. All subjects have had more than three episodes of true patellar dislocations. Preoperative radiographic examination included anteroposterior and lateral views to assess patella alta and limb alignment. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle-trochlear groove (TT-TG) distance. The patients were questioned regarding complications and clinical outcomes using the visual analogue scale (VAS), Kujala and Paediatric International Knee Documentation Committee (Pedi-IKDC) score. Variables were evaluated using paired t test with significance at p < 0.05. The mean age at the time of operation was 13.04 years (9-16 years). The cohort was followed for a mean duration of 38.66 months (24-86 months). The mean time from injury to surgery was 50.45 days (16-80 days). No growth arrest, limb-length discrepancies or angular deformities were observed post-operatively during the whole follow-up period. No patellar re-dislocations were recorded throughout the study period. The VAS score improved significantly from 5.67 (4-8) to 1.88 (0-4) (p < 0.01). The Kujala score improved significantly from 64.67 (44-81) preoperatively to 87.58 (77-100) post-operatively (p < 0.01). The Pedi-IKDC also increased significantly from 58.81 (34.80-77.70) preoperatively to 90.64 (70.70-100) post-operatively (p < 0.01). The vast majority of patients (87.5%) returned to their pre-injury activity level. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant. Physeal-sparing MPFL reconstruction in children and adolescents yields excellent midterm results and allows patients to return to sports without redislocation of the patella. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant. IV: case series with no comparative group.

Comparison of Clinical and Radiological Outcomes With Body Mass Index After Medial Patellofemoral Ligament Reconstruction.

Medial patellofemoral ligament (MPFL) reconstruction is a commonly employed surgical approach for recurrent patellar dislocation. However, the impact of elevated body mass index (BMI) on postoperative complication rates remains controversial. To compare the clinical, radiographic, and functional outcomes of patients with normal BMI (18.5-24.9 kg/m2) and those with elevated BMI (≥25 kg/m2) who underwent MPFL reconstruction for recurrent acquired lateral traumatic patellar dislocation. Cohort Study; Level of evidence, 3. A total of 70 patients who underwent MPFL reconstruction for recurrent patellar dislocation were included in this study. Patients with recurrent patellar dislocation were categorized into 2 groups based on their BMI: the normal BMI group and the elevated BMI group. Functional scores (Lysholm, International Knee Documentation Committee [IKDC], Tegner, and Kujala scores) and radiological measurements (patellar tilt angle, patellofemoral trochlear congruence, lateral patellofemoral angle, and lateral patellar displacement) were evaluated both preoperatively and at the last follow-up. The occurrence of postoperative complications at the last follow-up was also recorded. Differences in functional scores and radiological parameters before and after surgery were analyzed with paired-samples t tests or Wilcoxon signed-rank tests. Comparisons between groups were conducted using independent-samples t tests or the Kolmogorov-Smirnov test. In the normal BMI group, there were 13 male patients and 27 female patients, with a mean follow-up duration of 26.15 ± 13.16 months. The mean age in this group was 21.93 ± 7.94 years. The elevated BMI group consisted of 12 male patients and 18 female patients, with a mean follow-up duration of 27.50 ± 15.79 months and a mean age of 23.30 ± 8.43 years. At the final follow-up, the incidence of surgical failure (patellar redislocation or subluxation and necessitating secondary surgery) was significantly higher in the elevated BMI group (6 out of 30 patients; 20.0%) compared with the normal BMI group (1 out of 40 patients; 2.5%) (P < .05). Both groups demonstrated significant improvement in postoperative Lysholm, IKDC, Tegner, and Kujala scores compared with the preoperative period (P < .05). Notably, the normal BMI group had significantly higher preoperative Lysholm and Tegner scores compared with the elevated BMI group (P < .05). Furthermore, the elevated BMI group exhibited less improvement in Tegner and Kujala scores compared with the normal BMI group (P < .05). Postoperative radiological parameters in both groups returned to the normal range (P < .05). There were no statistically significant differences between the 2 groups in terms of radiological parameters and their corresponding differences. Our study demonstrated statistically significant increases in postoperative clinical scores for both groups, although the intergroup differences varied. Specifically, patients with elevated BMI demonstrated poorer preoperative Lysholm and Tegner scores. The postoperative improvement in radiological parameters was equally good between the 2 groups.

Postoperative Access and Compliance Following Medial Patellofemoral Ligament Reconstruction in Hispanic Adolescents Mirrors the Non-Hispanic Adolescent Population.

Disparity in surgical care of patellar instability patients has not been fully investigated in the adolescent Hispanic population. This demographic has been shown to have differences in their care, including a lower rate of surgical treatment for patellar instability. Socioeconomic factors have been cited as a factor that influences patient outcomes and its relationship with ethnicity in context of patellar instability has not been evaluated. Review performed of patients <19 years of age who underwent MPFL reconstruction between September 2008 and December 2015. Demographics, patient median household income data, and clinical variables were collected. Generalized linear mixed model (GLMM) with subject as random effects factor was utilized to evaluate differences between ethnicity groups due to nonindependence of data. It was then expanded to incorporate interactions between ethnicity and income. Ninety-five patellar dislocation events met criteria in 85 adolescents (mean age: 15.5y). Thirty-four (40%) adolescents identified as Hispanic. In univariate analysis no differences were found between Hispanic and non-Hispanic patients. The multivariate GLMM demonstrated a significant interaction between ethnicity and income. The Hispanic group in the >100% State median income category had the highest rate of postoperative clinic appointments attended ( P =0.019). The Hispanic group in the <100% State median income category had the lowest rate of physical therapy appointments attended ( P =0.044). No differences were observed for duration of follow-up ( P =0.57) or final Kujala score ( P =0.75). Hispanic ethnicity alone is not associated with inferior postoperative management after MPFL reconstruction in adolescents. However, when socioeconomic status is considered, Hispanic patients of lower-income backgrounds are found to have lower compliance with postoperative rehab recommendations. Level III.

Medial Patellofemoral Ligament Reconstruction Improves Patella Alta.

Patellofemoral instability (PFI) is a common problem with various anatomic risk factors identified, including patella alta as one of the most powerful predictors. Given that the medial patellofemoral ligament (MPFL) is the primary soft tissue stabilizer of the patella, a common procedure to treat recurrent patellar instability is MPFL reconstruction. The aim of this study is to examine the relationship between MPFL reconstruction and patellar height. We hypothesize that after reconstruction, patellar instability patients would have demonstrable reduction in patella height and patella alta correction. Patient records were queried for patients who underwent MPFL reconstruction for recurrent patellar instability. Patient and operative demographics were collected. We measured Insall-Salvati ratio (ISR), Caton Deschamps index (CDI), and Blackburne-Peel ratio (BPR) in all patients at various time points. The height indices were compared across the preoperative, immediately postoperative, and 6-month time points in a pairwise fashion using paired-sample t-tests. Further subgroup analysis of patients (n=27) with elevated preoperative Caton Deschamps Index (defined as >1.3) was completed. The final cohort was 103 patients. There was a significant difference between pre- and postoperative ISR (P<0.001) and at 6-month follow up (P<0.001), between preoperative CDI and the 6-month follow-up (P<0.0010), and between the postoperative and preoperative CDI (P<0.001). There was also a difference between preoperative and postoperative BPR (P<0.001), as well as between the preoperative and 6-month follow-up BPR (P=0.002). Twenty-seven patients had an initial CDI greater than 1.3. Differences were observed between pre- and postoperative mean CDI (P=0.001) and at 6-month follow-up (P=0.006), between both postoperative and 6-month ISR (both P<0.001), and preoperative mean BPR and the postoperative (P=0.004) and 6-month mean BPR (P=0.027). Patients with pre-existing patella alta and recurrent patella dislocations who undergo isolated MPFL reconstruction have decreased patella alta at their 6-month follow-up as measured by ISR, CDI, and BPR. Patients without patella alta do not demonstrate statistically significant differences after their MPFL reconstruction. III (retrospective comparative study).

Combined Medial Patellofemoral Ligament Reconstruction and Tibial Tubercle Osteotomy Has a Lower Risk of Recurrent Instability Requiring Revision Stabilization at 2 Years Than Either Procedure Alone

PurposeThe goal of this study was to utilize a large nationwide administrative database to directly compare usage, complications, and need for revision stabilization surgery after medial patellofemoral ligament reconstruction (MPLFR), tibial tubercle osteotomy (TTO), and combined MPFLR and TTO (MPFLRTTO). MethodsThe PearlDiver Mariner database was queried for all reported cases of MPLFR, TTO, and combined MPFLR and TTO performed between 2010 and 2020 using Current Procedural Terminology codes. Subsets from those cohorts with laterality-specific International Classification of Diseases, Tenth Revision codes for patellar instability were used to evaluate 2-year incidence of infection, stiffness, fracture, and revision stabilization with MPFLR and/or TTO. Multiple Linear regression and chi-squared analysis were used to analyze incidence trends and to compare complication rates. ResultsA total of 70,070 patients were identified. MPFLR was found to be the most common procedure (73.1%) followed by TTO (19.2%) and then MPFLRTTO (7.6%). MPLFR was observed to have the lowest overall complication rate (5.4%), while both TTO (7.5%) and MPFLRTTO (7.1%) had higher complication rates (P<.001). MPFLR had the highest rate of revision stabilization surgery at 3.7% compared with TTO at 2.7% and MPFLRTTO which carried the lowest risk for revision at 2.4% (P<.001). ConclusionIsolated MPFLR is the most common modality used for patellar instability, with increasing prevalence and the lowest 2-year complication rate. Isolated tibial tubercle osteotomy was unchanged in its utilization and had the highest overall complication rate. Combined MPFLR and TTO increased the overall complication rate but had a lower 2-year rate of recurrent instability requiring revision than MPFLR alone.

Comparable Outcomes Between Autologous Chondrocyte Implantation and Osteochondral Allograft Transplantation in the Setting of Patellar Realignment

PurposeThe purpose of this study was to determine clinical and functional outcomes in patients treated with autologous chondrocyte implantation (ACI) or osteochondral allograft (OCA) transplantation for chondral defects secondary to patellar instability with concomitant medial patellofemoral ligament (MPFL) reconstruction and tibial tubercle osteotomy (TTO) for patellar realignment. MethodsA retrospective review identified patients who underwent ACI or OCA transplantation with concomitant MPFL reconstruction and TTO . Patients were excluded if they did not have concomitant MPFL reconstruction and TTO, had the presence of other intra-articular pathologies, or failed to complete postoperative subjective outcome evaluations at a minimum of 2 years following surgery. Subjective outcome measures included the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), International Knee Documentation Committee (IKDC) evaluation, and Short Form Health Survey (SF-12) physical scores, collected a minimum of 2 years after surgery. Defect location, size, complications, and rate of subsequent surgery were determined. ResultsEighteen total patients were included in this study. The ACI cohort included 11 patients with 13 total defects that were treated with ACI. The OCA cohort included 7 patients with 10 total defects that were treated with OCA. This was due to a number of patients in either group having multiple cartilage defects. Twenty-three total chondral defects were compared to analyze clinical and functional outcomes following surgical correction (ACI: n=13, OCA: n=10). Five defects were noted on the femoral condyle and 18 on the patellar facets/central ridge. Defects were comparable between groups including, size measured during index-arthroscopy (ACI = 3.34 cm2, 95% CI [2.3 cm2 - 4.4 cm2] vs OCA = 4.03 cm2, 95% CI [3.1 cm2 - 5.0 cm2]; P=.351), Outerbridge classification (ACI = 54.8% grade 4 vs OCA = 60.0% grade 4; P=1.000), and AMADEUS score (ACI = 47.1 vs OCA = 58.6; P=.298). Postoperative outcomes were comparable including revision rate (ACI = 15.4% vs OCA = 10.0%; P=1.000) and 2-year IKDC scores (ACI = 74.2, 95% CI [65.2 - 83.2] vs OCA = 51.2, 95% CI [30.3 - 72.1]; P=.077). ACI did have significantly higher 2-year KOOS JR (85.1, 95% CI [76.9 - 93.3] vs 63.7, 95% CI [49.1 - 78.3]; P=.031) and SF-12 scores (54.1, 95% CI [52.0 - 56.2] vs 42.6, 95% CI [35.8 - 49.4]; P=.007) compared to OCA. ConclusionACI or OCA transplantation for chondral defects with concomitant MPFL reconstruction and TTO can be safely performed in an outpatient setting with functional and clinical outcomes being comparable. Level of EvidenceRetrospective Case Series Study (Level 3)

Implications for Femoral Tunnel Placement in Medial Patellofemoral Ligament Reconstruction Considering the Sagittal Trochlear Groove Curvature in Severe Trochlear Dysplasia Before and After Deepening Trochleoplasty

Background: Medial patellofemoral ligament reconstruction (MPFL-R) aims to restore proper ligament function with minimal changes in length during range of motion, yet the ideal area for femoral fixation of the graft remains controversial. Purpose: To determine the region where the isometric circular path of a simulated MPFL graft (best-fit circle) follows the sagittal radius curvature of the trochlea in normal (nontrochlear dysplastic) knees and to evaluate the best-fit circle coverage of different femoral fixation points in knees with severe trochlear dysplasia (TD) and after deepening trochleoplasty. Study Design: Controlled laboratory study. Methods: Twelve patients (4 male, 8 female; mean age, 24 ± 8 years) who underwent surgical treatment for recurrent lateral patellar instability due to severe TD were prospectively enrolled in this study. Four previously defined reference points for the femoral MPFL-R (Schöttle, Fujino, Stephen, and Oka) were identified, and the best-fit circle was drawn along the sagittal trochlear groove curvature. The divergence between each best-fit circle and the trochlear groove was calculated, with negative values indicating relative slackening and positive values indicating relative tightening of the simulated MPFL graft. Measurements were made on true-lateral fluoroscopic images before and after deepening trochleoplasty and compared with those of a sex-matched control group. Results: The best-fit circle of the Schöttle point followed the sagittal curvature of the trochlea most closely in both the control and trochlear dysplastic knees, followed by the Fujino, Stephen, and Oka points. As the radius of the trochlear groove curvature increased, the divergence of all best-fit circles to the trochlear groove became negative (all P < .05). This effect was most pronounced at the Stephen and Oka points, followed by the Fujino and Schöttle points (all P < .05). After deepening trochleoplasty, the divergence of the Schöttle point changed toward positive values (11.6% at 40°; P < .001). Concurrently, the best-fit circle divergence of all other reference points improved toward baseline (all P < .05). Conclusion: The isometric circle of the Schöttle point provides the best congruence with the sagittal trochlear groove curvature in both the normal trochlea and the dysplastic trochlea. After trochleoplasty, the best-fit circles of more distal femoral fixation points resulted in better congruence with the deepened trochlear groove, whereas the best-fit circle of Schöttle indicated graft tension during flexion. Clinical Relevance: According to the present study, different femoral fixation points should be considered depending on whether the TD is corrected.

Medial Patellofemoral Ligament Reconstruction in Adolescents: What Parents Care About.

Numerous techniques exist for pediatric medial patellofemoral ligament (MPFL) reconstruction (MPFL-R). Pediatric orthopaedic surgeons and patient families must navigate choices between allograft and autograft, incision type, and surgery cost. While previous research has found similar surgical outcomes among different MPFL-R techniques, minimal data exists on what patients and their families prefer. To engage in shared decision-making (SDM), pediatric orthopaedic surgeons must understand family preferences, including between incision type and cost. We conducted a study utilizing choice-based conjoint (CBC) analysis to explore these preferences. A survey was developed using Sawtooth Software (Lighthouse Studio version 9.2.0) to gather demographic information and preferences on surgical scenarios via CBC analysis. Anonymous participants, recruited via the Prolific crowdsourcing platform, qualified if they were US residents over 18 years of age with children aged 13 to 17. Data analysis involved the Hierarchical Bayes (HB) method to generate utility scores to determine the desirability of attributes. The study included 496 participants who prioritized surgical success (average importance 48.8%) followed by co-pay amount (21.5%), incision size (17.4%), and return to sport (12.3%). Participants earning over $200,000 annually prioritized incision size over cost (25.8% vs. 12.1%, P<0.0053). Those with incomes below $50,000 valued recovery time at a lesser extent than other income groups (10.4% than 12.3% overall importance P<0.0003). The sex of the child significantly influenced preferences: incision size was more important to parents of girls (21.1%) than boys (14.0%, P<.0001). The importance of surgery success and recovery time also differed by sex, being higher for boys (50.4%, 13.1%) than girls (47.0%, 11.7%; P=0.025, 0.026, respectively). This CBC analysis suggests parents of adolescent patients undergoing MPFL-R most value surgical success (avoiding revision surgery), followed by copay, incision size, and time to return to sport. Of note, parent income level and sex of the child significantly influenced parental preferences. We hope this information will assist orthopaedic surgeons in SDM in MPFL-R surgery. Level III.

Trochleoplasty and à-la-carte procedures for patellar instability in young and active patients: Clinical outcomes at minimum 2 Years follow-up

IntroductionPatellar instability is a common condition affecting approximately 6 individuals per 100,000, but among adolescents, this incidence is notably higher. Trochlear dysplasia has been recognized as the pathoanatomic risk factor exerting the most significant biomechanical influence. Over time, various surgical techniques have been developed to address trochlear dysplasia. The purpose of this study is to evaluate the clinical outcomes, return to sport, as well as complications and re-operation rate of sulcus deepening trochleoplasty performed in a cohort of young and active patients using the Bereiter technique. Materials and methodsBetween January 2019 and February 2022, 11 cases of recurrent patellar dislocations underwent trochleoplasty. Preoperative radiological assessment included X-rays, CT scans following the Lyons and MRI. Inclusion criteria for the study and trochleoplasty indications included patients aged 10–25 with recurrent patellar dislocations unresponsive to nonoperative treatment and minimum type B trochlear dysplasia. Clinical follow-up occurred at 1-3-6 months and annually, with control X-rays at these intervals. Patient-reported outcome scores included the Knee Society Score, Kujala score, and Karnofsky performance status scale. ResultsBetween January 2019 and February 2022, 11 patients underwent trochleoplasty and were included in this study. Preoperative radiological measurements indicated mean values: sulcus angle (152.5°), trochlear depth (3.4 mm), Caton-Deschamps index (1.2), tibial tuberosity to trochlear groove (TT-TG) distance (17.5 mm), external patellar tilt angle (6.8°), femoral anteversion (11.5°), and tibial torsion (32°). All patients were followed up for at least 2 years, with an average of 43 months. Concurrent surgeries included tibial tuberosity transposition (100 %), MPFL reconstruction in 9 cases (81.8 %) and 2 patients also underwent division of the external alar ligament (18,2 %). PROMs at final follow-up showed mean values: Knee Society Score (KSS) (80.5), Kujala score (88.3), and Karnofsky performance status scale (88.8). Return to sport was reported by all active patients. Three cases required secondary surgical intervention for removal of the screws. ConclusionTrochleoplasty, especially with the Bereiter "thin flap" approach, improves patellofemoral congruency. Combining trochleoplasty with tibial tuberosity transposition addresses mal-tracking related to severe dysplasia and other à-la-carte procedures like medial patellofemoral ligament (MPFL) reconstruction enhance stability. In young and active patients, it resolves instability issues and reduces the likelihood of further dislocations with high return to sport rates.

Good 5-year results and a low redislocation rate using an á la carte treatment algorithm for patellofemoral instability in patients with severe trochlea dysplasia.

Trochlear dysplasia is a major risk factor for recurrent patellar instability, reduced quality of lifeand osteoarthritis of the patellofemoral joint. Patellar instability in patients with trochlear dysplasia can be treated by trochleoplasty, usually in combination with medial patellofemoral ligament reconstruction (MPFL-R). An á la carte treatment algorithm, which also addresses patella alta, lateralisation of the tibial tuberosityand valgus or torsional malalignment when present has been standard in one clinic for treatment of patellar instability patients since 2009, based on the hypothesis that it results in optimal subjective and clinical outcome, normalisation of the lateral trochlea inclination (LTI) angle and a low rate of patellar redislocation. This prospective study reports the 5-year results for consecutive patients with high-grade trochlea dysplasia operated according to the algorithm 2010-2017, evaluated preoperatively and 1, 2and 5 years postoperatively. Clinical information on previous surgery and postoperative patellar stability, range-of-motion (ROM)and subsequent surgery were registered. Subjective outcome was evaluated by four patient-reported outcome measures (PROMs): Kujala, Lysholm, International Knee Documentation Committee and Knee injury and Osteoarthritis Outcome Score. The LTI angle was measured pre- and postoperatively on magnetic resonance imaging scans. There were 131 patients (87 females) with a median age of 22 years (range: 14-38). All had a trochleoplasty and an MPFL-R. Additional procedures (tibial tuberosity medialisation/distalisation and/or femoral/tibial osteotomy) were performed in 52%. All PROM scores improved from preoperatively to 1-year follow-up with further improvement at 2 and 5 years after surgery (p < 0.05). Three patients (2%) had a traumatic patellar dislocation 9, 12and 24 months postoperativelyand 38% underwent subsequent surgery (hardware removal, arthroscopically assisted brisement force, knee arthroscopy). A normalisation of the LTI angle (≥11°) was achieved in 76%. Treatment according to the à la carte algorithm for patients with patellar instability and high-grade trochlear dysplasia resulted in significant clinical and subjective improvement in all PROM scores and a very low redislocation rate (2%) 5years after surgery. Level II.