Traumatic Patellar Research Articles

Operative Repair of Medial Patellofemoral Ligament Injury Versus Knee Bracing in Acute First-Time Traumatic Patellar Dislocation: A Systematic Review and Meta-Analysis

Operative Repair of Medial Patellofemoral Ligament Injury Versus Knee Bracing in Acute First-Time Traumatic Patellar Dislocation: A Systematic Review and Meta-Analysis

Turkish Version of the Norwich Patellar Instability Score: Minimal Detectable Change among Patients with Traumatic Patellar Dislocation

Objective: This study aimed to calculate the minimal detectable change (MDC) in the Norwich Patellar Instability score (NPI) and validate the score for Turkish-speaking individuals with patellar instability. Method: Sixty-four patients (mean age 21.87 ± 9.44 years) who had experienced at least one patellar dislocation during athletic activities participated in the study. The Turkish version of the NPI (NPI-T) was evaluated for reliability and internal consistency. The Minimal Detectable Change was calculated as an overall value for the participants. MDC was calculated based on the standard error of measurement (SEM) and the selected confidence level (ICC) for the study population. Pearson's correlations were examined to assess construct validity between the Kujala Patellofemoral Disorder score and the Lysholm Knee Score. Result: The MDC for the NPI-T was 17.29, with a SEM of 6.24. The score demonstrated high internal consistency, with a Cronbach’s alpha value of 0.85, indicating substantial reliability. The consistency of measurements was excellent, with an ICC2,1 of 0.95. Additionally, the NPI-T score exhibited a strong negative correlation with both the Kujala (r = -0.85, p < 0.001) and Lysholm (r = -0.89, p < 0.001) scores. A floor effect was observed, but no ceiling effect was present. Conclusion: The study confirms that the NPI-T demonstrates strong psychometric properties, with high internal consistency and excellent reliability, as evidenced by its low MDC and SEM. The use of the NPI-T as a reliable and valid tool for assessing patellar instability in patients with patellar dislocation will provide valuable information to clinicians.

Clinical Presentation, Surgical Treatment, and Outcome of Traumatic Patellar Luxation in 11 Dogs and 5 Cats: A Single-Centre Retrospective Study between 2011 and 2022.

Patellar luxation (PL) is commonly diagnosed in dogs and cats; however, a traumatic cause is poorly reported in the literature. The aim of this study was to report the clinical presentation, surgical treatment, and outcome in dogs and cats surgically treated for traumatic PL. This is a retrospective study. Medical records of dogs and cats operated for traumatic PL were reviewed. Short- and long-term follow-ups were assessed with medical records and telephone interviews with owners and referring veterinarians. Data on signalment, lameness, PL characteristics, surgery, complications, and outcome were recorded. Eleven dogs and 5 cats were included. Both species had a median lameness grade of 4/5 and a median PL grade of 3/4. PL was medial in most cases (13/16). Joint capsule lesions were identified in 15 cases, 4 cases had trochlear ridge cartilage damage. All cases had a capsular imbrication, 12 cases had a fabello-patellar suture (FPS). Mean long-term follow-up time was 70.8 ± 42.5 months in 9 dogs and 4 cats. Ten cases out of 13 had no lameness at the 2-month follow-up, and 11/13 cases had no long-term lameness. Eleven cases out of 13 had no PL at the 2-month follow-up. No long-term PL was reported by owners. Complications were mild in 5 cases, moderate in 1, severe in 3. Functional outcome was full in 10 cases and acceptable in 3. Soft tissue techniques and FPS were effective in the surgical treatment of traumatic PL in dogs and cats, resulting in acceptable to full long-term function in all cases, with limited severe complications.

PATELLOFEMORAL INSTABILITY MANAGEMENT IN A PROSPECTIVE PAEDIATRIC COHORT IN EDINBURGH

Patellofemoral instability (PFI) is a common cause of knee pain and disability in the paediatric population. Patella alta, lateralised tibial tubercle, medial patellofemoral ligament (MPFL) deficiency, genu valgum and trochlear dysplasia are well known risk factors.A prospective database was created including patients referred through our physiotherapy pathway following first-time patella dislocation. Patella alta and lateralisation of the tibial tuberosity was treated with a Fulkerson-type tibial tubercle osteotomy(TTO). Medial patellofemoral ligament was reconstructed using quads tendon autograft pull-down technique. A modified Sheffield protocol was used postoperatively allowing weightbearing in a hinged knee brace.Forty patients were identified with 8 patients having bilateral presentations. Male to female ratio was 12:28 with an age range of 4–17 years. Eight patients had congenital PFI, five patients acquired PFI through traumatic patella dislocation and twenty-seven patients developed PFI from recurrent dislocations. Structural abnormalities were found in 38(95%) of patients. Patella alta (Caton-Deschamps index >1.2) was identified in 19(47%) patients, genu valgum in 12(30%) patients, increased tibial tubercle-trochlear groove distance(TT-TG>20mm) was present in 9(22.5%) patients and persistent femoral anteversion(> 20 deg) in 7(17%) patients.Eight patients were treated with TTO and MPFL reconstruction, three patients with MPFL reconstruction alone and five patients had guided growth for genu valgum correction. Ten patients are awaiting surgery. No postoperative patients had recurrence of PFI at their latest follow up.PFI is a common problem in the adolescent paediatric population with identifiable structural abnormalities. Correcting structural pathology with surgery leads to predictable and safe outcomes.

Combined quadriceps medial patellofemoral ligament reconstruction and osteochondral fixation offers good patient-reported outcomes and low rates of recurrent instability for osteochondral defects secondary to acute patella dislocation.

Chondral injuries secondary to traumatic patella dislocation are common, and a subgroup of these are significant defects with fragments amenable to fixation. There is a paucity of published evidence assessing patients managed with combined acute patellofemoral stabilisation and osteochondral fixation. The purpose of this study is to report the outcomes of patients with osteochondral injuries secondary to acute traumatic patella dislocation treated with combined early fragment fixation and MPFL reconstruction using a quadriceps tendon turndown technique which has distinct advantages for this cohort, including preventing chondral overloading and non-violation of the patella bone. Patients who underwent combined quadriceps tendon MPFL reconstruction and osteochondral fixation were included. Patient demographics, defect characteristics, complications and reoperations were evaluated. Patients were assessed with Lysholm, Kujala, KOOS-PF scores and satisfaction scale at follow up. Pre-operative MRI was assessed for presence of radiological risk factors for patella dislocation and post-operative MRI was used to assess cartilage quality with MOCART 2.0 score. A total of 19 patients (63.2% female) were included. The mean age was 17.4 ± 4.8years and patients were followed up at a mean 15.8 ± 5.1months post-surgery. The mean defect size was 2.4 cm2 ± 1.3 cm2, with the most common defect location being the patella (13/19; 68.4%) followed by the lateral femoral condyle (5/19; 26.3%). At final follow up, the overall mean Lysholm, Kujala, and KOOS-PF scores were 84.9 ± 11.1, 89.7 ± 5.8 and 80.6 ± 13.6, respectively. Seventeen patients (89.5%) were satisfied with their outcome. The mean MOCART 2.0 score at final follow-up was 72.5. One patient required medial capsular plication with removal of a loose chondral body and microfracture and 3 knees required minor reoperations. Combined acute osteochondral fragment fixation and MPFL reconstruction using a quadriceps tendon graft offers good radiological and patient-reported outcomes with high satisfaction and low rates of recurrent patella dislocation. To our knowledge, this is currently the largest series of its kind in the literature and the results of this study provide a rationale for a combined approach using a quadriceps tendon graft for this cohort. Level IV.

Bilateral isolated traumatic patella fracture: A case report

Bilateral isolated traumatic patella fracture: A case report

Patterns of Associated Knee Ligament and Chondral Injuries in First-Time Traumatic Patellar Dislocation: A Retrospective Magnetic Resonance Imaging (MRI) -Based Study.

Introduction First-time acute traumatic patellar dislocation, when managed without a knee magnetic resonance imaging (MRI) scan, may lead to missed diagnoses of important associated knee injuries. The aim of this study was to ascertain the incidence of associated ligamentous and cartilaginous injuries in first-time traumatic patella dislocation. Methods This was a five-year retrospective study on patients aged 16-45 who had knee MRI scans showing the characteristic bone bruise patterns seen in traumatic lateral patellar dislocation. Anonymized data from the hospital picture archiving and communication system (PACS) was obtained with each scan reviewed by a consultant radiologist, a fellowship-trained orthopaedic knee specialist, and an orthopaedic registrar or resident. Results A total of 200 knee MRI scans were screened. 61 eligible knee MRI scans were included in the study. The patients' ages ranged from 16 to 42 years old, with a mean of 25 years. 73.8% were male. A medial patellofemoral ligament (MPFL) tear or rupture occurred in 58 of 61 knees (95%) with MPFL attenuation in three (5%) injured knees. Meniscal injuries were identified in 5 of 61 knees (8.2%), medial collateral ligament (MCL) injuries in 11 of 61 knees (18%), osteochondral injuries and loose bodies in 17 of 61 knees (27.9%), and anterior cruciate ligament (ACL) injury in one knee (1.6%). Conclusions This single-centre MRI-based study has provided information on the incidence of associated chondral and ligamentous injuries in patients with first-time acute traumatic patellar dislocation. This information will be useful for clinicians when counselling patients and will add to the available literature on this injury. An MRI scan should be obtained in cases of suspected first-time traumatic patellar dislocations, especially in active young patients, due to the incidence of other associated traumatic knee lesions that might need surgical treatment and lead to persisting knee symptoms if neglected.

A Randomized Controlled Trial Comparing a Patella-Stabilizing, Motion-Restricting Knee Brace Versus a Neoprene Nonhinged Knee Brace After a First-Time Traumatic Patellar Dislocation

Background: A traumatic lateral patellar dislocation is a common injury in adolescents and young adults. The majority of first–time dislocations can be treated nonoperatively. Various types of knee braces are used for nonoperative treatment, but evidence on the most preferable bracing method is lacking. Purpose: To evaluate the efficacy of a patella–stabilizing, motion-restricting knee brace versus a neoprene nonhinged knee brace for the treatment of a first–time traumatic patellar dislocation at 3 years of follow–up. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 101 skeletally mature patients with a first–time traumatic patellar dislocation were enrolled in the study. After exclusion criteria were applied, 79 patients with a first–time traumatic patellar dislocation were randomized and allocated into 2 study groups: group A, with a patella–stabilizing, motion-restricting knee brace (hinged to allow knee range of motion [ROM] of 0°-30°) and group B, with a neoprene nonhinged knee brace (not restricting any knee motion). Both groups received similar physical therapy instructions and were advised to use the brace continuously for 4 weeks. Overall, 64 patients completed the trial. Results: The redislocation rate in group A was 34.4% (11/32) and in group B it was 37.5% (12/32) (risk difference, –3.1% [95% CI, –26.6% to 20.3%]; P = .794). Patients in group A had less knee ROM than those in group B at 4 weeks (90° vs 115°, respectively; P < .001) and 3 months (125° vs 133°, respectively; P = .028). Patients in group A had more quadriceps muscle atrophy than patients in group B at 4 weeks (24/32 vs 16/32, respectively; P = .048) and 3 months. At 6 months, patients in group B reported better functional outcomes than patients in group A (Kujala score mean difference, 4.6; P = .012), although no clinically relevant difference was found at 3 years. Conclusion: The use of a patella–stabilizing, motion-restricting knee brace for 4 weeks after a first–time traumatic patellar dislocation did not result in a statistically significant reduction in redislocations versus a neoprene nonhinged knee brace, although this trial was underpowered to detect more modest differences. Knee immobilization was associated with quadriceps muscle atrophy, less knee ROM, and worse functional outcomes in the first 6 months after the injury. Registration: NCT01344915 (ClinicalTrials.gov identifier).

Medial Patellofemoral Ligament Reconstruction and Osteosynthesis for Traumatic Patellar Dislocation with Patellar Osteochondral Fracture with Open Physes: a Case Report

Medial Patellofemoral Ligament Reconstruction and Osteosynthesis for Traumatic Patellar Dislocation with Patellar Osteochondral Fracture with Open Physes: a Case Report

Clinical outcome of Patella stability after fixation of Osteochondral fracture in Acute Primary Traumatic Patella Dislocation without MPFL Repair or Reconstruction

Introduction: Conservative management is advisable for acute primary traumatic patella dislocation (PTPD). Surgical treatment is reserved for osteochondral fractures (OCF), medial patello femoral ligament (MPFL) avulsion/tear, compound injuries, and any underlying bony abnormalities requiring correction. MPFL repair (at avulsed site) or reconstruction along with underlying bony correction in PTPD is controversial. The purpose of this study is to evaluate patella stability after fixation of OCF in PTPD without performing MPFL repair or reconstruction, even in the presence of any underlying bony abnormalities. Material and Methods: This is a retrospective study of eight patients who had PTPD with OCF along with MPFL injury who presented between 2016 and 2019. Pre-operative X-rays and MRI were done to assess the status of MPFL, identify the presence of OCF and to calculate Insall-Salvati index, Tibial Tuberosity-Trochlear groove distance and Trochlear dysplasia. All patients underwent surgery by open approach and OCF fixation by bioabsorbable pins or suture material. MPFL was neither repaired at avulsed site nor reconstructed and even no bony corrections were done. Results: Average size of OCF fragments is 15*7 mm and all involving medial facet of patella. Lysholm score improved significantly from 32.8 to 94.8 and Kujala score from 49.1 to 96 at the end of 6 months. None of the patient had patella instability till latest follow-up, average follow-up period is 4.5 years (3–6 years). Clinically, apprehension test was negative in all cases with full ROM. Post-operative imaging including X-ray and MRI showed complete healing of the OCF along with complete healing/regeneration of MPFL with same pre-existing bony abnormalities if present preoperatively. Conclusion: This study shows excellent patella stability and full knee function along with complete union of OCF and complete healing/regeneration of MPFL in PTPD even in the presence of underlying bony abnormality. Hence, in PTPD with OCF, there is no need to repair/reconstruct MPFL or to correct underlying bony pathology, only OCF fixation is required.

Diagnostic Imaging of Patellofemoral Instability.

Throughout the literature, patellofemoral instability (PI) is defined as an increased risk of re-/luxation of the patella within the patellofemoral joint (PFJ). In most patients it is caused by traumatic patella luxation or the existence of a range of predisposing anatomic risk factors leading to an unphysiological movement sequence within the PFJ also known as patellofemoral maltracking. In order to provide an individualized therapy approach, clinical and radiological evaluation of those risk factors of variable magnitude becomes essential. Diagnostic imaging such as magnetic resonance imaging (MRI), plain radiography, and computed tomography (CT) are straightforward diagnostic tools in terms of evaluation and treatment of PI. In this review we performed a precise analysis of today's literature concerning the radiological evaluation of anatomic risk factors leading to PI. The purpose of the review is to present a logical compilation of the different anatomical risk factors causing PI and provide a straight overview of valuable radiological imaging techniques. PI is frequently based on a multifactorial disposition. The most relevant predisposing risk factors are trochlea dysplasia, rupture of the medial patellofemoral ligament (MPFL), patella alta, abnormal tibial tubercle to trochlea groove distance (TT-TG), femoral torsion deformities, and genu valgum. Although plain X-rays may provide basic diagnostic value, cross-sectional imaging (MRI, CT) is the standard radiological tool in terms of evaluation and detection of severity of predisposing anatomic variants leading to PI. · Based on today's literature, PI is characterized as an increased risk of patella re-/luxation within the PFJ.. · Underlying anatomic risk factors of variable magnitude mark the pathological cause of PI.. · Modern diagnostic imaging (MRI and CT) permits straightforward diagnosis of the typical features in terms of PI.. · To provide an individualized therapy approach, precise radiological evaluation and determination of the severity of predisposing anatomic anomalies are essential.. · Maas KJ, Warncke ML, Leiderer M et al. Diagnostic Imaging of Patellofemoral Instability. Fortschr Röntgenstr 2021; 193: 1019 - 1033.

Bifocal Patellar Tendon Avulsion Fractures in Children and Adolescents: Diagnosis and Treatment Considerations for a Unique Injury Pattern

PurposeTo highlight important diagnostic and treatment considerations in patients who present with bifocal patellar tendon avulsion fractures from the tibial tubercle and inferior patellar pole.MethodsRadiographic presentation, surgical technique, and complications of 5 children who sustained bifocal patellar tendon avulsion fractures with ≥6 months postoperative follow-up were retrospectively reviewed. Hospital for Special Surgery (HSS) Brief Functional Activity Scale (HSS Pedi-FABS), Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference, PROMIS mobility, and Pediatric International Knee Documentation Committee Scale (Pedi-IKDC) were assessed at most recent follow-up.ResultsFive children (4 boys, 1 girl) presented with bifocal patellar tendon avulsion fractures with a median follow-up of 12.8 months (range 7.7 to 26.4). In 1 case, advanced imaging was not pursued, and the bifocal nature of injury was subsequently discovered intraoperatively. In all other cases, magnetic resonance imaging (MRI) correctly characterized the bifocal injuries and revealed the full extent of fractures and soft tissue injury. Surgical management involved suture anchor repair with heavy nonabsorbable sutures. Postoperative functional and patient-reported outcomes were within the range of population healthy/normative values (for those that were available for comparison, e.g., Pedi-IKDC), and clinically relevant improvement was noted when comparing preoperative and postoperative patient-reported outcome measures of both pain and mobility.ConclusionsAdvanced imaging (e.g., MRI) is required to understand the full extent of injury and should be obtained in the setting of traumatic patella alta to evaluate for the presence of a bifocal lesion and plan surgical intervention accordingly. These patients demonstrate satisfactory functional and patient-reported outcomes after operative repair.Level of EvidenceIV, therapeutic case series.

A Closer Look is necessary: Traumatic luxation of the patella as a co-injury of an acl-rupture

Aims and Objectives:The rupture of the acl is considered to be one of the most common knee injuries in sports traumatology. Many patients report that they felt the sensation of a luxated patella during their knee distorsion. In many cases patients patients with the suspicion of a traumatic patella luxation showed in the mri a complete rupture of the acl.Materials and Methods:We report about 10 patients consulting our department within the last year after a significant knee trauma. In the mri as well as during the arthroscopic evaluation they showed a complete rupture of the acl as well as the findings of a fresh, traumatic patella luxation. We evaluated and analysed the preoperative and intraoperative pictures (mri and arthrosopy).Results:All patients showed in the posttraumatic mri a complete rupture of the acl as well as an at least partial rupture of the mpfl and a rupture of the medial retinaculum. 4 patients showed a persistent subluxation of the patella, 8 patients showed also a rupture of the medial collateral ligament. During the operation we verified a significant instability of the patella in 8 patients so that a stabilization of the patella was performed (open medial stabilization or mpfl reconstruction) in the same operation the acl was reconstructed (semi-t).Eventhough the patients were treated with only one operation and the regaining of motion was prolonged compared with isolated acl-reconstruction, after 12 months postoperatively all patients had a satisfactory range of motion.Conclusion:The typical trauma mechanism for an acl rupture is a valgus position of the knee in combination with an external rotation of the tibia, which leads to an enlargement of the q-angle which is considered a predisposition for a patella luxation. If an acl rupture occurs, the patella can luxate within the same trauma. In the posttraumatic mri the rupture of the mpfl is often misinterpreted as a rupture of the medial collateral ligament, particularly if the patella is, as in most cases, in full reposition. Within an acl-rupture a luxation of the patella can occur simultaneously, leading to a significant instability which needs to be treated (medial stabilization or mpfl-reconstruction). Our data shows that a single stage treatment with acl-reconstruction and medial stabilization is technical practicable and mid-term investigation shows good clinical results without a higher risk of an arthrofibrosis.

Adolescent and Caregiver-derived Utilities for Traumatic Patella Dislocation Health States.

The treatment of a first-time traumatic patella dislocation in children and adolescents remains controversial. Preference-based health utility assessments can provide health-related quality of life information for orthopaedic conditions and their subsequent treatment. The purpose of this study was to determine utilities for pediatric acute traumatic patella dislocation and subsequent treatment health states from both children with patellar dislocation, and their parents. Adolescents with acute first-time patella dislocations and their parents were identified. Six patella dislocation health states were defined: (1) Immediate post injury (Injury), (2) Postdislocation and nonoperative treatment with physical therapy (Rehabilitation), (3) Immediately poststabilization surgery (Postsurgical), (4) Recurrent dislocation after treatment (Recurrent dislocator), (5) Stable knee after initial treatment but unable to participate in sport at previous level (Stable return to lower function), and (6) Stable knee after initial treatment and fully able to participate in sport at previous level (Stable return to same function). Classic feeling thermometer utilities acquisition was performed, with self-report (patient) and proxy-report (parent) interviews performed separately. Patients' physical activity levels were collected using the UCLA Activity Score and the HSS Pedi-FABS. Comparisons between groups were made using Mann-Whitney U test and Wilcoxon signed-rank test. Ninety-five adolescents and 95 parents were included. Median (interquartile range) patient utilities for Injury, Rehabilitation, Postsurgical, Recurrent dislocator, Stable return to lower function, and Stable return to same function health states were: 25 (10 to 45), 50 (35 to 62.5), 30 (15 to 48.5), 20 (10 to 40), 70 (50 to 80), and 100 (100 to 100), respectively. Caregiver-derived utilities for children going through these health states were: 25 (10 to 49.5), 50 (25 to 60), 40 (15 to 60), 20 (5 to 40), 60 (50 to 77.5), and 100 (100 to 100). Stable return to a lower function was assigned a significantly higher utility by adolescents than their caregivers (P=0.03); highly active adolescents assigned a significantly higher utility to achieving a stable return to same function (P=0.02) while assigning significantly lower utility to health states in which they were not fully participating in sport. Adolescents and their parents felt that successful treatment of an acute patella dislocation was equivalent to perfect health (utility=1); however, adolescents assigned a significantly higher utility to a stable but lower functioning health state compared with their parents. Baseline functional status is an important modifier of health state preference-highly active adolescents assign a significantly greater disutility to health states in which they are not participating in sports at their regular level of play. These findings provide insight into the health-related quality of life impact for acute patella dislocations and their management, and potentially support minimizing time out of play and more aggressive treatment of first time acute patellar dislocations in athletic adolescents. Level III.

Magnetic Resonance Imaging Findings in Acute Traumatic Patellar Dislocation

Magnetic Resonance Imaging Findings in Acute Traumatic Patellar Dislocation

Operative Repair of Medial Patellofemoral Ligament Injury Versus Knee Brace in Children With an Acute First-Time Traumatic Patellar Dislocation: A Randomized Controlled Trial

Background: A lateral patellar dislocation (LPD) is the most common traumatic knee injury with hemarthrosis in children. The redislocation rate is high. Varying operative and nonoperative treatments have been advocated with no consensus on the best treatment. Purpose: (1) To evaluate if arthroscopic-assisted repair of the medial patellofemoral ligament (MPFL) in patients with an acute first-time traumatic LPD would reduce the recurrence rate and offer better objective/subjective knee function compared with a knee brace without repair. (2) To study the presence of anatomic patellar instability risk factors (APIFs) and their association with a redislocation. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This was a prospective series of 74 skeletally immature patients aged 9 to 14 years (38 girls and 36 boys; mean age, 13.1 years) with a first-time traumatic LPD, with clinical examinations, radiographs, magnetic resonance imaging, and diagnostic arthroscopic surgery performed within 2 weeks of the index injury. The child was randomized to either (1) a knee brace (KB group) for 4 weeks and physical therapy or (2) arthroscopic-assisted repair (R group) of the MPFL with anchors, 4 weeks with a soft cast splint, and physical therapy. The follow-up time was 2 years. Results: The redislocation rate was significantly lower in the R group than in the KB group at final follow-up: 8 patients (22%) versus 16 patients (43%), respectively (P = .047). The Knee injury and Osteoarthritis Outcome Score for children sport/play and quality of life subscales had lower scores in the R group compared with the KB group; the significant differences were among those with redislocations. The mean Kujala score was excellent in the KB group (95.9) and good in the R group (90.9). An impaired Limb Symmetry Index (median, 83%) for concentric quadriceps torque at 90 deg/s was found only in the R group. Eighty-one percent of the study patients had ≥2 APIFs. Trochlear dysplasia (trochlear depth <3 mm) had the highest odds ratio for redislocations (2.35 [95% CI, 0.69-8.03]), with no significant association between APIFs and a redislocation. Conclusion: Operative repair of an MPFL injury in the acute phase in skeletally immature children with a primary traumatic LPD significantly reduced the redislocation rate but did not improve subjective or objective knee function compared with a knee brace without repair. The majority of the patients in both groups were satisfied with their knee function. There was a high representation of APIFs, which needs to be considered when evaluating the risk of redislocations. Registration: ISRCTN 39959729 (Current Controlled Trials).

Distal Femoral Valgus and Recurrent Traumatic Patellar Instability: Is an Isolated Varus Producing Distal Femoral Osteotomy a Treatment Option?

Genu valgum, a risk factor for recurrent patellofemoral instability, can be addressed with a varus producing distal femoral osteotomy (DFO). The purpose of this study is to report 3-year clinical and radiographic outcomes on a series of skeletally mature adolescents with traumatic patellofemoral instability and genu valgum who underwent a varus producing DFO. Consecutive patients (n=11) who underwent an isolated DFO for recurrent traumatic patellar instability over a 4-year study period (2009 to 2012) were reviewed. All patients were below 19 years of age, skeletally mature, had ≥2 patellar dislocations, genu valgum (≥ zone II mechanical axis) and failed nonoperative treatment. Exclusion criteria included less than three-year follow-up, congenital or habitual patellar instability, osteotomy indicated for pathology other than patellar instability, or biplanar osteotomies. Demographic, clinical, and radiographic data were retrospectively analyzed. Recurrence of instability and outcome measures (Kujala and Tegner Activity Scale) were collected at final followed-up prospectively. Ten of 11 patients (average age, 16 y; range, 14 to 18 y; 4 male individuals: 7 female individuals) with an average follow-up of 4.25 years (range, 3.2 to 6.0 y) met inclusion criteria. The average body mass index (BMI) of all patients was 31.3 (range, 19.7 to 46.8) with 91% considered overweight (BMI>25) and 55% obese (BMI>30). The average preoperative lateral distal femoral angle was 75.4 degrees with an average correction of 10.4 degrees (range, 7 to 12 degrees) (P<0.001). Mean patellar height ratios were reduced; with Caton-Deschamps Index significantly reduced to 1.08 (range, 0.86 to 1.30) (P<0.005). The average postoperative Kujala score was 83.6 (range, 49 to 99) with 7 subjects (70%) reporting good to excellent function (Kujala > 80) and 8 (80%) having no further episodes of instability. The mean postoperative Tegner activity score was 5.5 (range, 3 to 7). A distal femoral varus producing osteotomy may change radiographic parameters associated with patellar instability and improve clinical outcomes by reducing symptomatic patellofemoral instability in this patient population. Level IV.

Diagnosis and Management of Traumatic Patellar Instability in the Pediatric Patient.

Instability of the patella is a common cause of knee pain and dysfunction in pediatric and adolescent patients and can be due to several factors. Although some patients will recall a specific traumatic event others may not, requiring the diagnosis to be made on the basis of physical examination and imaging. Congenital dislocation and connective tissue disorders should also be considered, even in the setting of trauma. There are radiographic parameters that may identify causes of instability such as trochlear and patellar abnormalities, and magnetic resonance imaging can identify signs of trauma such as bony edema, loose osteochondral fragments, and increased tibial tubercle-trochlear groove distance. The first line of treatment for instability is most commonly nonoperative in nature; however, there are many options for operative management in the event of severe chondral injury or recurrent dislocation. Surgical management to best restore stability of the patellofemoral joint varies depending on the skeletal maturity of the patient and the source of instability (ligamentous, osteocartilaginous, or both). A combination of soft tissue, bony, and anatomic ligamentous repair or reconstruction is used to best augment patellar tracking and optimize patient outcome. [Orthopedics. 2017; 40(5):e749-e757.].

Economic Decision Model for First-Time Traumatic Patellar Dislocations in Adolescents

Background: The surgical management of traumatic patellar dislocations in adolescents is associated with a lower rate of recurrent dislocations compared with nonoperative care. However, the attendant cost of surgery and the quality-of-life benefit of a surgical treatment strategy are unclear. Purpose: To compare the cost-utility of 3 management strategies for acute first-time patellar dislocations in adolescents: (1) nonoperative treatment only, (2) initial nonoperative treatment with surgery only for recurrent dislocations, and (3) immediate surgery. Study Design: Economic and decision analysis; Level of evidence, 2. Methods: A 10-year state-transition Markov model was constructed to compare the cost-utility of the 3 index treatment protocols. Utilities used to define health states were derived from a telephone interview of 60 adolescents with a history of acute patellar dislocations. The probability of transition between each health state was informed by the available literature. Direct costs were estimated using a statewide ambulatory surgery database, and indirect costs were estimated based on parental lost productivity. Effectiveness was expressed in quality-adjusted life years (QALYs). The principal outcome measure was the incremental cost-effectiveness ratio (ICER). Results: In the base case for our model, nonoperative treatment only was the least costly ($7300) but also the least effective (5.30 QALYs); initial nonoperative treatment with delayed surgery cost $10,500 for a 5.93 QALY benefit, while immediate surgical treatment cost $17,100 and provided 6.32 QALY benefits. Compared with nonoperative treatment only, initial nonoperative treatment with delayed surgery was associated with an ICER of $5100 per QALY. When immediate surgery was compared with a strategy of delayed surgery, immediate surgery provided incremental benefits at an ICER of $17,000 per QALY. The model was sensitive to the probability of surgical versus nonoperative treatment to achieve a full return to preinjury activity versus an intermediate lower state. When the probability of achieving a full return to preinjury activity with initial nonoperative treatment exceeds 47.5% (compared with 34.2% in the base case), then initial nonoperative treatment with delayed surgery is preferred to immediate surgery. Similarly, when the probability of achieving a full return to full preinjury activity with surgery falls below 51% (compared with 64% in the base case), then delayed surgery after initial nonoperative treatment is preferred. Conclusion: Immediate surgery and delayed surgical treatment are both cost-effective treatment options; however, immediate surgical treatment provides the highest QALY gains within a 10-year time horizon. Our model sensitivity analysis highlights the role of optimizing functional and quality-of-life benefits in the treatment of acute traumatic patellar dislocations. These findings have implications for clinical guidelines and policy decisions relating to adolescent patellar dislocations.

Isolated Bilateral Traumatic Patellar Fracture: A Case Report

Background: Patellar fracture accounts for approximately 1% of all skeletal fractures. Bilateral fracture of the patella is even rarer, comprising less than 3% of all patellar injuries. Case Description: A 28 year old man presented with bilateral patellar fracture after car accident and direct dashboard injury while driving, with superficial abrasion on both fracture sites. Mentioned fracture had transverse fracture pattern which was fixed with two Kirschner wire following tension band principle. Our patient was able to squat, sit in crossed leg position and perform his household activities by the end of 2nd month. He regained his full strength and ability to perform normal daily activities by the end of 6th months, without any post-operative complaints. Discussion: A case of bilateral patellar fracture as a consequence of dashboard injury is presented and pathomechanical and operative management and follow up of such injuries is discussed.