Modified Langenskiöld Procedure for Congenital Patella Dislocations in Pediatric Patients

Background: Great difficulty and more failures were the descriptions of the treatment of congenital patella dislocation in pediatric patients. This study aims to evaluate the outcomes of patients with congenital patellar dislocations treated with the modified Langenskiöld procedure. Methods: The medical records of 16 knees in 11 patients with a diagnosis of congenital patella dislocation were collected from September 2016 to March 2019. They were treated with the modified Langenskiöld procedure. The mean follow-up period was 37.8 months. The outcome measures were the Lysholm score, Kujala score, patellar stability, and knee range of motion. Results: Eleven patients, namely, eight girls and three boys, with 16 knees were enrolled. The mean age at the time of operation was 3.1 years. The post-operative mean Lysholm score was 94.8 (SD 5.1; 87–100), whereas the Kujala score was 95 (SD 5.9; 86–100). There were no recurrent dislocations, and all patients had full extension postoperatively. Conclusion: The modified Langenskiöld procedure is a promising solution for the treatment of congenital patella dislocations. Level of evidence: Level IV; Case Series; Treatment Study

The novel dynamic MPFL-reconstruction technique: cheaper and better?

Purpose Reconstruction of the medial patellofemoral ligament (MPFL) is an established procedure to restore patellar stability. Aim of this study is to evaluate the results of a dynamic MPFL reconstruction technique in a large university hospital setting. Methods Two hundred and thirteen consecutive patients with 221 knees were surgically treated for recurrent lateral patellar dislocation. All patients obtained dynamic reconstruction of the MPFL with detachment of the gracilis tendon at the pes anserinus while maintaining the proximal origin at the gracilis muscle. Patellar fixation was performed by oblique transpatellar tunnel transfer. Follow-up data including Kujala and BANFF score, pain level as well as recurrent patella instability were collected at a minimum follow-up of 2 years. Results Follow-up could be obtained from 158 patients (71%). The mean follow-up time was 5.4 years. Mean pain level was 1.9 ± 2.0 on the VAS. Mean Kujala score was 78.4 ± 15.5. Mean BANFF score was 62.4 ± 22.3. MPFL-reconstructions that were performed by surgeons with a routine of more than ten procedures had a significantly shorter surgical time 52.3 ± 17.6 min. Male patients yielded higher satisfaction rates and better clinical scores compared to females. Complications occurred in 27.2% of procedures, 20.9% requiring revision surgery of which were 9.5% related to recurrent patellar instability. 78% of all patients indicated they would undergo the procedure again. Conclusion Dynamic MPFL reconstruction presents a reproducible procedure with increased complication rates, inferior to the results of static reconstruction described in the literature. Despite, it appears to be an efficient procedure to restore patellar stability in a large university hospital setting, without the necessity for intraoperative fluoroscopy. Trial registration The study was registered in ClinicalTrials.gov with the registration number NCT04438109 on June 18th 2020.

Ability of Medial Patellofemoral Ligament Reconstruction to Overcome Lateral Patellar Motion in the Presence of Trochlear Flattening: A Cadaveric Biomechanical Study

Background: Medial patellofemoral ligament (MPFL) reconstruction is an established operative procedure to restore medial restraining force in patients with patellar instability. In the setting of a shallow sulcus, it is unclear whether an isolated MPFL reconstruction is sufficient to restore patellofemoral stability. Hypothesis: Progressively increasing the sulcus angle would have an adverse effect on the ability of an MPFL reconstruction to restrain lateral patellar motion. Study Design: Controlled laboratory study. Methods: Seven fresh-frozen human cadaveric knees were harvested and prepared for experimentation. Each specimen was run through the following test conditions: native, lateral retinacular release, lateral retinacular repair, MPFL release, MPFL reconstruction, and MPFL reconstruction with trochlear flattening. Four 3-dimensional printed wedges (10°, 20°, 30°, and 40°) were created to insert beneath the native trochlea to raise the sulcus angle incrementally and simulate progressive trochlear flattening. For each test condition, the knee was positioned at 0°, 15°, 30°, and 45° of flexion, and the force required to displace the patella 1 cm laterally at 10 mm/s was measured. Group comparisons were made with repeated measures analysis of variance. Results: In the setting of an MPFL reconstruction, as the trochlear groove was incrementally flattened, the force required to laterally displace the patella progressively decreased. A 10° increase in the sulcus angle significantly reduced the force at 15° ( P = .01) and 30° ( P = .03) of knee flexion. The force required to laterally displace the patella was also significantly lower at all knee flexion angles after the addition of the 20°, 30°, and 40° wedges ( P≤ .05). Specifically, a 20° increase in the sulcus angle reduced the force by 29% to 36%; a 30° increase, by 35% to 43%; and a 40° increase, by 40% to 47%. Conclusion: Despite an MPFL reconstruction, the force required to laterally displace the patella decreased as the sulcus angle was increased in our cadaveric model. Clinical Relevance: An isolated MPFL reconstruction may not be sufficient to restore patellar stability in the setting of a shallow or flat trochlea. Patients with an abnormal sulcus angle may have recurrent instability postoperatively if treated with an isolated MPFL reconstruction.

Medial Patellofemoral Ligament Reconstruction

Background: Patellar instability is a relatively common condition in the young, active population and causes disruption of the medial patellofemoral ligament (MPFL). MPFL reconstruction is often performed to restore this medial stabilizer and reduce the risk of recurrent instability. Indications: Isolated MPFL reconstruction has been shown to reduce the risk of recurrent patellar dislocation. It is indicated in our patients who have had more than 1 dislocation in the absence of other significant bony malalignment or cartilage defects that require concurrent surgery. Technique Description: Diagnostic arthroscopy is first performed to evaluate the patellar and trochlear cartilage surfaces. A medial approach to the patella is then performed and the 2 free limbs of the allograft are secured to the patella at the 9 to 11 (or 1 to 3) o’clock position. A small approach to the femoral insertion site of the MPFL is performed and confirmed with fluoroscopy, and the graft is secured to the femur with a biotenodesis screw. Postoperative examination confirms improved stability of the patella, and the patient performs a gradual return to play protocol. Results: Recent studies have demonstrated overall good clinical outcomes after MPFL reconstruction, with improved patellar stability and high patient satisfaction. One systematic review found an 85% rate of return to sport with a low risk (7%) of recurrent subluxation or dislocation. Discussion/Conclusion: MPFL reconstruction is a reliable option for improving patellar stability in patients with recurrent dislocations. We believe our technique, which optimizes the fixation and footprint of the graft on the patella and allows for easy visualization of femoral anatomy on fluoroscopy, can improve the reproducibility of the procedure and provide optimal clinical outcomes.

Anatomic medial patellofemoral ligament (MPFL) reconstruction with and without tibial tuberosity osteotomy for objective patellar instability

Purpose The aim of this study was to evaluate the clinical outcomes of patients treated with anatomic medial patellofemoral ligament (MPFL) reconstruction with and without tibial tuberosity osteotomy (TTO). Correlations between patient's age, gender, pre-injury physical activity and the achieved results were investigated as secondary endpoints. Methods An observational retrospective study with prospective collected data was performed. Inclusion criteria were: treatment with anatomic MPFL reconstruction with gracilis tendon according to Schӧttle’s technique performed between 2011 and 2017; associated TTO as unique accessory procedure; skeletal joint maturity; a minimum follow-up of 12 months after surgery. Clinical outcomes were assessed with the Kujala, Lysholm and Tegner scores. Results Forty patients (42 knees) were included, 64% of them underwent TTO. The Kujala score significantly improved from 47.4 ± 17.6 preoperatively to 89.4 ± 13.6 postoperatively (p < 0.01). The average Lysholm score was 45.6 ± 20.5 preoperatively: it showed a significant increase to 89.8 ± 12.8 postoperatively (p < 0.01). Pre-injury mean Tegner was 5.9 ± 1.8, while it dropped to 3.0 ± 1.6 after injury. After surgery, Tegner resulted 4.9 ± 1.6. Forty-three percent of patients regained the pre-injury sport activity level. Redislocation rate was 2.4%. Conclusion Anatomic MPFL reconstruction allows excellent patellar stability recovery, knee functionality improvement, return to Activities of Daily Living and a low redislocation rate. Better results were achieved in younger (under 30 years old) and higher sports activity-level subjects. The TTO association provided clinical results comparable to isolated MPFL reconstructions, suggesting that the two procedures can be safely accomplished together without affecting the positive outcomes. Level of evidence Level IV.

Trends in Lateral Retinacular Release from 2010 to 2017

Historically, lateral retinacular release (LRR) procedures have been utilized in the treatment of a variety of patellofemoral disorders, including lateral patellar instability. However, in the past decade, there has been an increasing awareness of the importance of the lateral stabilizers in patellar stability, as well as the complications of LRR, such as recurrent medial patellar instability. The purpose of this study was to investigate current trends in LRR procedures from 2010 through 2017 using a large national database. The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for arthroscopic LRR procedures (the Current Procedural Terminology [CPT] code, 29873) from 2010 to 2017. The number and incidence of lateral release procedures, both isolated and nonisolated, were analyzed and separated into cohorts for analysis. Age and gender of the LRR cohort was investigated and compared with all other orthopaedic procedures during the same time period in the NSQIP database. In addition, concomitant procedures and associated International Classification of Disease-9th Revision (ICD-9) and ICD-10th Revision (ICD-10) codes were analyzed over time and between LRR groups. From 2010 to 2017, 3,117 arthroscopic LRRs were performed. The incidence for LRR was 481.9 per 100,000 orthopaedic surgeries in 2010 and significantly decreased to 186.9 per 100,000 orthopaedic surgeries in 2017 (p < 0.01). LRR was more commonly performed in females (66%) and 58% of patients were under 44 years of age. In addition, LRR was most commonly performed with a concomitant meniscectomy (36%), synovectomy (19%), or microfracture (13%), and for a diagnosis of pain (22%). The overall incidence of LRR procedures significantly decreased from 2010 to 2017. LRRs were more commonly performed in younger, female patients for a diagnosis of pain with the most common concomitant procedure being meniscectomy, synovectomy, or microfracture.

Patellar instability MRI measurements are associated with knee joint degeneration after reconstruction of the medial patellofemoral ligament

Objective To qualitatively and quantitatively evaluate the 2-year magnetic resonance imaging (MRI) outcome after MPFL reconstruction at the knee and to assess MRI-based risk factors that predispose for inferior clinical and imaging outcomes. Materials and methods A total of 31 patients with MPFL reconstruction were included (22 ± 6 years, 10 female). MRI was performed preoperatively in 21/31 patients. Two-year follow-up MRI included quantitative cartilage T2 and T1rho relaxation time measurements at the ipsilateral and contralateral knee. T2relative was calculated as T2patellofemoral/T2femorotibial. Morphological evaluation was conducted via WORMS scores. Patellar instability parameters and clinical scores were obtained. Statistical analyses included descriptive statistics, t-tests, multivariate regression models, and correlation analyses. Results Two years after MPFL reconstruction, all patellae were clinically stable. Mean total WORMS scores improved significantly from baseline to follow-up (mean difference ± SEM, − 4.0 ± 1.3; P = 0.005). As compared to patients with no worsening of WORMS subscores over time (n = 5), patients with worsening of any WORMS subscore (n = 16) had lower trochlear depth, lower facetal ratio, higher tibial-tuberosity to trochlear groove (TTTG) distance, and higher postoperative lateral patellar tilt (P < 0.05). T2relative was higher at the ipsilateral knee (P = 0.010). T2relative was associated with preoperatively higher patellar tilt (P = 0.021) and higher TTTG distance (P = 0.034). TTTG distance, global T2 values, and WORMS progression correlated with clinical outcomes (P < 0.05). Conclusion MPFL reconstruction is an optimal treatment strategy to restore patellar stability. Still, progressive knee joint degeneration and patellofemoral cartilage matrix degeneration may be observed, with patellar instability MRI parameters representing particular risk factors.

Primary Medial Patellofemoral Ligament Reconstruction in Military Servicemembers: Can We Reliably Restore Preinjury Function and Stability?

Background: Medial patellofemoral ligament (MPFL) reconstruction for patellar instability is a commonly performed procedure with a reported high rate of return to preinjury activity. However, no previous study has assessed the functional outcomes of military servicemembers undergoing MPFL reconstruction. Hypothesis: Primary MPFL reconstruction confers patellar stability, but with limited return to preinjury function and ability to maintain unrestricted military active duty status. Study Design: Case series; Level of evidence, 4. Methods: Using the Management Analysis and Reporting Tool database, we conducted a retrospective review of active duty servicemembers throughout the US Department of Defense Health System who underwent primary MPFL reconstruction between 2012 and 2015. Demographic variables were recorded as well as ability to return to impact activities—defined as running, jumping, rucking with a load >40 pounds (18 kg), and returning to airborne operations—and to remain on active duty status. The rates of recurrent instability and the need for subsequent surgeries were identified and assessed for statistical significance using uni- and multivariate analyses. Patients were evaluated for a minimum of 2 years postoperatively. Results: Of the 213 patients who underwent primary MPFL reconstruction, including 34 with concomitant tibial tubercle osteotomy, 19 (8.9%) patients developed recurrent instability. The presence of bilateral patellar instability was associated with higher recurrence rate. Patients with bilateral instability comprised 47.3% of those with recurrence but only 24.9% of patients without recurrence ( P = .019). Impact activity restrictions were present in 57.6% of patients (n = 121), with 86 patients (52.1%) undergoing medical separation from the military. Patients who were prescribed activity restriction before surgery were significantly more likely to have postoperative activity restrictions (64.5%; P = .019), and junior enlisted servicemembers were more likely to be medically separated from service postoperatively than higher ranking senior enlisted members or officers. Conclusion: Only 42.4% of US military servicemembers undergoing primary MPFL reconstruction were able to return to unrestricted impact activity after surgery. Bilateral instability negatively affected return to impact activities. Military servicemembers, particularly junior enlisted members, should be counseled on this poor prognosis for a full return to unrestricted activity postoperatively.

Age at surgery is correlated with pain scores following trochlear osteotomy in lateral patellar instability: a cross-sectional study of 113 cases

Background A trochlear osteotomy aims to restore patellar stability in patients with recurrent patellar instability and trochlear dysplasia. The age of patients at time of surgery could be a relevant factor which influences outcome. We hypothesized that lower age at time of surgery is associated with better patient-reported outcomes. Methods A retrospective study was conducted on patients with patellar instability and trochlear dysplasia. Patients were contacted by phone for informed consent and were then asked to complete online patient-reported outcome measurements (PROMs). The PROMs consisted of the Kujala Knee Score (KKS) (Kujala et al., Arthroscopy 9(2):159-63, 1993; Kievit et al. Knee Surg Sports Traumatol Arthrosc. 21(11):2647-53, 2013), the Short Form 36-item health survey (SF-36v1) (Ware, Med Care 73-83, 1992; Aaronson et al., J Clin Epidemiol. 51(11):1055-68, 1998), and visual analog scale (VAS) scoring pain, instability, disability, and satisfaction on a 0–100 scale. Multivariable linear regression models were used to study the effect of age on the PROM scores. Results For this study, 125 surgical procedures in 113 patients were included. Mean VAS pain at rest was 19 and at activity 38; mean Kujala score was 73. Multivariable regression analysis revealed that age at the time of surgery was correlated with VAS pain at rest, with a 0.95 increase of VAS score (scale 0–100) for every year of age. Recurrence of instability was observed in 13 (10%) knees. Conclusion In this cross-sectional study, pain scores of 113 patients who have undergone a lateral facet elevating trochlear osteotomy for patellar instability were reported. Age at time of surgery was correlated with an increased pain score at rest with an average of 9.5 points (scale 0–100) for every 10 years of age. Age at time of surgery was not correlated with overall satisfaction.

Posterior-stabilized Arthroplasty Versus Cruciate-retaining Arthroplasty in Treatment of Osteoarthritis: a 5-year Follow-up Study

Backgroud: A prospective cohort study was performed to compare clinical outcomes between cruciate-retaining (CR) and posterior-stabilized (PS) arthroplasty.Methods: In total, 210 patients (210 knees) underwent CR arthroplasty (n=102) and PS arthroplasty (n=108) from January 2014 to January 2015. The Knee Society Score (KSS), range of motion, patellar stability, and complications were compared between the CR and PS groups 5 years postoperatively. Results: The CR group comprised 99 knees and the PS group comprised 105 knees at the 5-year follow-up. In the CR and PS groups, the mean postoperative KSS improved to 90±5 and 91±4, and the function score improved to 87±4 and 84±6, respectively (p>0.05). The mean postoperative range of motion was −2°±3° extension to 114°±8° flexion in the CR group and −2°±4° extension to 126°±7° flexion in the PS group, with no significant difference (p>0.05). In terms of patellofemoral complications, eight patients had patellar clunk syndrome, one had patellar subluxation, and one had patellar lateral facet fracture in the PS group. Three patients had patellar clunk syndrome, and one had symptomatic subluxation in the CR group. These patellofemoral complications were significantly different between the groups (p<0.05).Conclusions: CR and PS TKA can achieve good clinical outcomes with respect to the KSS. Better knee flexion but more patella complications in the PS arthroplasty than CR group 5 years postoperatively.Trail registration: This study was approved by our hospital institutional ethics committee.