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

Patella dislocations and patellofemoral instability: a current concepts review

ABSTRACT Lateral patellar dislocation affects young, active patients with an incidence rate of 5.8 per 100 000. The management of first episode dislocations is non-surgical in the majority of cases, unless associated pathology dictates surgical intervention. Approximately 40% of cases that are treated non-surgically will develop recurrent patellofemoral instability. Evidence supports surgical intervention in these cases; however, the best approach is debatable. Most research and consensus statements agree that medial patellofemoral ligament reconstruction (MPFLR) should be performed in most cases. Additional procedures can be used 'a la carte' according to certain conditions or pathology. A tibial tubercle osteotomy (TTO) is usually indicated in patients with maltracking and/or patella alta, but the direction and degree of correction must be carefully considered. Trochleoplasty is technically demanding and should be reserved for a select few patients with severe trochlear dysplasia. It should be performed by an experienced knee surgeon due to the high risk of inadvertent complications. Level of evidence: Level 5 Keywords: patellofemoral instability, patellar dislocation

Normalisation of Patella Alta with MPFL Reconstruction Reduces the Prevalence of Risk Factors Associated With Recurrent Patella Dislocations - A Prospective Cross Sectional Study

Background: Patella alta is a well-established risk factor for recurrent lateral patella dislocations. Medial patellofemoral ligament (MPFL) reconstruction has been shown to consistently reduce patella height. Our hypothesis is that MPFL reconstruction reduces the number of risk factors for recurrent dislocations through the correction of patella alta, resulting in a decreased risk of recurrence.Methods: A prospective cross-sectional case series of 33 knees which underwent MPFL reconstruction for lateral patella dislocations. Information on patellar height utilising the Insall-Salvati (IS) and Caton-Deschamps (CD) ratios, Tibial Tuberosity–Trochlear Groove (TT-TG) distance, trochlear dysplasia, and outcome scores were recorded pre-operatively and post-operatively. The mean change in patella height and the number of knees which achieved normalisation of patella alta were determined. Student’s paired samples T-tests were used to compare the differences in the means scores of the groups pre-operatively and post-operatively. The McNemar test for paired categorical data was used to compare the number of the patella alta corrected after MPFL reconstruction. A pre-determined significance of alpha level of 0.05 was used.Results: The mean age of 33 patients included in the study was 21.5 years (range, 16 – 34 years). There was statistically significant reduction in patella height between pre-operative and post-operative measurements using the various patella height indices for all patients (p<0.001), and normalisation of patella alta (CD ≥1.3) for 90% of patients post-operatively (p<0.004). One third of patients 33.3% had at least 3 risk factors pre-operatively. This was reduced to 18.2% after MPFL reconstruction, representing a 45.5% decrease. A statistically significant improvement in the outcome scores was found – Kujala score 57.1 ± 14.1 pre-operatively to 94.8 ± 5.1 post-operatively (p<0.0001). The recurrent dislocation rate was 3.0%.Conclusion: MPFL reconstruction for lateral patella dislocation results in a statistically significant improvement in clinical outcomes and decrease in patellar height ratios. Normalisation of abnormal patella height culminated in the reduction of anatomical risk factors associated with recurrent dislocations.

Intra-articular horizontal dislocation of the patella: a rare injury and review of the literature

Acute traumatic intra-articular dislocation of the patella is not a common presentation in orthopaedic practice; less frequently observed than extra-articular dislocation of the patella. In some of these cases, closed reduction is not possible and an open reduction in the operating theatre must be performed. In this case report, we present an elderly patient with an intra-articular horizontal dislocation of the patella without any other bony or ligamentous lesions seen in a postreduction MRI. We conducted a literature review looking at intra-articular patella dislocations, identifying 64 published studies (articles, case reports and papers). The following sources of data were searched until December 2017: PubMed, OVID, Google Scholar, Scopus, using the search strategy of (intra-articular dislocation of patella, horizontal patellar dislocation) with no limitation on the year or language of publication. The patient presented in this case report was managed with a closed reduction under general anaesthesia, without the need of any surgical intervention. As proposed in the literature, the hypothesis of an intra-articular entrapment of the patella due to the trapped osteophytes of the superior pole of the patella into the intercondylar notch was thought to be the cause of intra-articular dislocation in this elderly patient.

Vertical patellar dislocation: A pediatric case report and review of the literature

Vertical patellar dislocations (VPDs) are a rare event, and even more so among pediatric female patients. There have been less than 30 vertical patellar dislocations reported in the literature since the first in 1844. In this type of dislocation, the patella rotates about its vertical axis with the articular surface facing either medially or laterally. The mechanism of injury for a VPD can be broadly divided into two themes: a twisting injury or direct impact to the medial or lateral edge of the patella. We present a 10-year-old girl with a VPD after experiencing a twisting injury when descending a playground slide. The purpose of this study is to present a case report and review of the literature on vertical patella dislocations, including mechanisms of injury and suggested methods of treatment. We aim to provide a comprehensive understanding of the various categories of patella dislocations to alleviate confusion when classifying patellar dislocations. Furthermore, we provide clear suggestions for reduction methods and techniques with regards to vertical patellar dislocations, including a suggested protocol for an irreducible patella.

Bipolar Osteochondral Allograft Transplantation of the Patella and Trochlea

Objective To evaluate clinical, functional, and radiographic outcomes of patients who underwent bipolar osteochondral allograft transplantation (OCAT) of the patellofemoral joint (PFJ). Design Prospectively collected data on 18 knees who underwent fresh osteochondral allograft transplantation of the patella and trochlea by a single surgeon were reviewed. Inclusion criteria were: high-grade chondral lesions of PFJ (5 knees), or recurrent patella dislocations with trochlear dysplasia and chondral injury to the patella and/or trochlea (13 knees). Functional scores were obtained preoperatively and at follow-up appointments included Knee injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), Oxford, Cincinnati, Tenger-Lysholm, visual analogue scale (VAS)–pain, and Single Assessment Numeric Evaluation (SANE). Grafts were also evaluated using Osteochondral Allograft MRI Scoring System (OCAMRISS). Results Three patients were lost to follow-up, leaving 4 knees in group 1, and 11 knees in group 2. Average age was 28.9 years (range 16-52 years). The average follow-up was 33.2 months (range 12-64 months). There was significant improvement of KOOS (from 38.7 to 83.1), IKDC (from 28.2 to 76.6), Tegner-Lysholm (from 38.3 to 88.3), Oxford (from 22.7 to 42.9), Cincinnati (from 35.1 to 83.6), VAS (from 71 to 17.9.), and SANE (from 43.3 to 83) ( P < 0.0001). The OCAMRISS score for patella was 2.23 and for trochlea 4.69. There were no revisions or conversions to arthroplasty Conclusion Bipolar OCAT of the patella and trochlea provide significant improvement in functional outcomes, relief from pain, activity level, and prevent recurrent instability.

Novel Device to Accurately Locate Femoral Insertion Landmark in Medial Patellofemoral Ligament (MPFL) Reconstruction

Medial Patello Femoral Ligament (MPFL) is the main stabilizer of the patellar bone in the knee complex. This fan shaped ligament prevents lateral dislocations of patella, especially during the initial 30° of knee flexion as there is minimal bony support from femur on the lateral aspect of the patella [1–2]. Patella dislocations are one of the common knee joint pathologies and it has been reported that each dislocation of the patella induces micro-tears in the MPFL [3]. It has been also observed in previous studies that there exists a very high chance of patellar re-dislocations for those individuals who have experienced the dislocation once. Complete MPFL rupture occurs in 94% of the patients suffering from repeated patellar dislocations [3–4]. Out of the 130 various methods of MPFL reconstruction, the Double Bundle Procedure is the most commonly used as it provides a larger degree of pain-free range of motion [5–8]. Locating the exact drilling location on the medial aspect of the patella and the medial femur is a challenge for the surgeon and literature suggests that the current procedure leads to non-anatomical placement of the ligament [9]. A novel device has been developed (Pat-Rig) to address the issue of locating the exact drill locations of the ligament graft tunnels into the patella [10–12]. This paper addresses the second problem of locating the femoral landmark accurately.