The Oswestry-Bristol Classification.

AIMS: Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management. We have developed an MRI-specific classification system to assess the severity of trochlear dysplasia, the Oswestry-Bristol Classification (OBC). This is a four-part classification system comprising normal, mild, moderate, and severe to represent a normal, shallow, flat, and convex trochlear, respectively. The purpose of this study was to assess the inter- and intraobserver reliability of the OBC and compare it with that of the Dejour classification. METHODS: Four observers (two senior and two junior orthopaedic surgeons) independently assessed 32 CT and axial MRI scans for trochlear dysplasia and classified each according to the OBC and the Dejour classification systems. Assessments were repeated following a four-week interval. The inter- and intraobserver agreement was determined by using Fleiss' generalization of Cohen's kappa statistic and S-statistic nominal and linear weights. RESULTS: The OBC showed fair-to-good interobserver agreement and good-to-excellent intraobserver agreement (mean kappa 0.68). The Dejour classification showed poor interobserver agreement and fair-to-good intraobserver agreement (mean kappa 0.52). CONCLUSION: The OBC can be used to assess the severity of trochlear dysplasia. It can be applied in clinical practice to simplify and standardize surgical decision-making in patients with recurrent patella instability. Cite this article: Bone Joint J 2020;102-B(1):102-107.

Scoring system for optimal management of acute traumatic patellar dislocation: A multicenter study.

BACKGROUND: In first-time acute traumatic patellar dislocations, numerous anatomic and clinical factors are complicatedly associated and should be comprehensively considered for the optimal management of conservative or surgical intervention. The purpose of this study was to establish a scoring system, using a concept that is not complicated and easily used in clinic. METHODS: Of 131 first-time acute traumatic patellar dislocations, 81 patients (51 females, 30 males) with an average age of 19.6 (95%CI, 17.5-21.6) years and an average follow-up duration of 17.1 (95% CI, 12.3-21.9) months, who underwent conservative treatment after first-time dislocations, were reviewed. Based on the odds ratios applying logistic regression analysis, the scoring system was established. RESULTS: The scoring system (total: 10 points) had simple composition of age <20 (2 points), sports injury (1 points), hemarthrosis (1 points), and image findings of a bony fragment (3 points), lateral shift of the patella (1 points), and trochlear dysplasia (2 points). A threshold score of 6.5 was determined using the area under receiver operating characteristic curve of 0.893 (p < 0.0001). In logistic regression analysis, a score of ≥7 was shown to be a dominant factor for recurrence (OR = 27.1, p < 0.0001). Furthermore, the association between the score and recurrence risk was as follows: a score of ≤4 = low risk (1/21 cases, 5%); a score of 5-7 = medium risk (13/27 cases, 48%); a score of ≥8 = high risk (30/33 cases, 91%). CONCLUSIONS: Based on the simple scoring system, patients who scored ≥8 were considered suitable for surgical treatment because of the high rate of recurrence, whereas those who scored ≤4 were considered suitable for conservative treatment because of the low rate of recurrence.

A new classification of injury patterns of the medial patellofemoral ligament after acute lateral patella dislocation detected using magnetic resonance imaging studies.

INTRODUCTION: Acute lateral patellar dislocation is a very common condition in orthopedics, especially among adolescents and physically active patients. To evaluate distinct medial patellofemoral ligament (MPFL) injury patterns and the associated knee pathology after acute lateral patellar dislocation (ALPD) using magnetic resonance imaging (MRI) studies, which is essential for the development of treatment protocols. MATERIALS AND METHODS: MRI images of 74 ALPD patients were taken between January 2015 to December 2016. Images were evaluated using standardized protocols. RESULTS: The prevalence of MPFL injury following ALPD was 97.3% (72/74 patients). Among the 72 patients with MPFL, the prevalence of Type Ⅰ injury was 26.4% (19/72). Since only bone marrow edema and a partial tear were showed on MRI of these patients, conservative treatment was given. Tear of the MPFL occurred at the patellar attachment (Type Ⅱa) in 16 patients (16/72, 22.2%), at the middle area of the ligament (Type Ⅱb) in 5 patients (5/72, 6.9%), and at the femoral attachment (Type Ⅱc) in 27 patients (27/72, 37.5%). For Type Ⅱ injuries, all patients had the surgery to reconstruct the MPFL. The prevalence of Type Ⅲ MPFL injury was 6.9% (5/72) after the surgery. CONCLUSION: MPFL injury of is a common sequel following ALPD. We assessed the distinct injury pattern and associated pathology of MPFL using MRI studies. A good understanding of the injury pattern and associated knee pathology of MPFL is essential in managing patients with ALPD, especially if surgical intervention is considered.

Special Considerations for Pediatric Patellar Instability.

Patellar instability in children and adolescents is a challenging subset to treat. Varied forms of instability, ranging from episodic dislocation to fixed dislocation, have been recognized. It is of utmost importance for the treating physician to recognize these different patterns of instability and their associated risk factors, as more complex patterns of instability would require more extensive surgical procedures. Medial patellofemoral ligament (MPFL) reconstruction, by itself, may not suffice or may not be appropriate for the more complex instability patterns. Appropriate and early treatment of such instability in children would allow for functional progression and possible remodeling of the trochlea. However, early treatment has the associated risk of growth disturbances when surgical procedures are performed around open physis or if adult-type bony procedures are performed in children. Recent knowledge about the relationship between trochlea, MPFL femoral attachment, and distal femoral physis could help to advance safe surgical care for these patients. This article reviews the pathophysiology, risk factors, and the existing classification systems for patellar instability in children and adolescents. It focuses on varied surgical techniques, which are unique to the pediatric population, and summarizes the outcomes of these surgical techniques.

Patellar luxation and articular lesions in dogs: a retrospective: study research article / Luxação de patela e lesões articulares em cães: estudo retrospectivo

This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal's age, body weight, and degree of luxation. The rate of redislocation was also evaluated. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface, and enthesophytes. Extra-patellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, cranial cruciate ligament rupture, and meniscal prolapse. Such lesions were frequently found in animals with Grade II or III luxation who were aged 24 months or more, and they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favor articular degeneration and should be treated surgically. Conservative treatment relieves pain, but does not address tissue alterations.(AU)

O estudo descreve as lesões articulares em cães com luxação de patela. Elas foram associadas com a idade do animal, massa corporal e grau de luxação. Foi avaliada também a porcentagem de casos com recidiva. As lesões patelares observadas foram erosão da cartilagem articular, exposição óssea subcondral, superfície patelar achatada ou côncava e entesófitos. As lesões extra patelares incluíram sinovite, osteófitos, ausência do sulco troclear, erosão das bordas condilares, espessamento da cápsula, lesão do tendão do músculo extensor digital, ruptura do ligamento cruzado cranial e prolapso de menisco. As lesões foram encontradas com maior frequência em animais com luxação de Grau II ou III e idade de 24 meses ou mais, sendo mais graves em cães com massa corporal superior a 15 kg. A luxação patelar ocasiona alterações que favorecem a degeneração articular e devem ser tratadas cirurgicamente. O tratamento conservativo alivia a dor, mas não corrige as alterações teciduais.(AU)

A new classification system of patellar instability and patellar maltracking.

To date there is no classification of patellar dislocations considering clinical and radiological pathologies. As a result many studies mingle the dislocation's underlying pathologies, so that there are no consistent therapy recommendations. It is this article's objective to introduce a patellar dislocation classification based on the current literature to allow for the application of a structured diagnosis and treatment algorithm. The classification is based on instability criteria as well as on clinical and radiological analyses of maltracking and on loss of patellar tracking. There are five types of patellar instability and maltracking. The rare type 1 is a simple (traumatic) patellar dislocation without maltracking and instability with a low risk of redislocation. Type 2 has a high risk of redislocation after primary dislocation; there is no maltracking. Here, a stabilising operation (in most cases MPFL reconstruction) is indicated and sufficient. Type 3 shows both instability and maltracking. Maltracking is mainly caused by: (a) soft tissue contracture, (b) patella alta, (c) pathological tibial tuberosity-trochlea groove distance, (d) valgus deviations and (e) torsional deformities. Stabilisation by means of isolated MPFL reconstruction is not sufficient in these types and additional osseous corrective surgeries are required to achieve physiological patellar tracking and to prevent redislocation. Type 4 features a highly unstable "floating patella" with complete loss of tracking caused by severe trochlear dysplasia. Therapy of choice is trochleoplasty, and if necessary combined with bony and soft-tissue procedures. Type 5 shows a patellar maltracking without instability. Maltracking can only be fixed by means of corrective osteotomy. The classification is referenced to current literature and each type is introduced by a case example. The resulting treatment consequence is also presented.

Non-surgical treatment for acute patellar dislocation with special emphasis on the MPFL injury patterns.

PURPOSE: The objective of present study was to propose a new classification for acute MPFL injury, which can help choose optimal treatment method for certain injury type. METHODS: Eighty-five patients with acute patellar dislocation treated non-surgically were retrospectively reviewed. They were assigned into two groups according to the newly introduced classification scheme, which classified MPFL injury into three types: injury in overlap region, injury in non-overlap region and combined injury of both regions. For study purpose, patients with combined injury were not included. Of 85 patients, 33 were in the overlap-region group (Group 1) and 52 in the non-overlap-region group (Group 2). Clinical patellar instability rate and patellofemoral score were measured and recorded at 2-year follow-up. RESULTS: The patellar instability rate was 15.2 % in Group 1 and 38.5 % in Group 2, with statistically significant difference between the two groups (P = 0.022). The mean visual analogue scale for Group 1 and Group 2 was 15.6 points and 28.3 points, respectively (P = 0.026). The mean Kujala score was 91.1 points and 82.6 points (P = 0.009), with a good or excellent subjective result recorded for 27 of 33 patients (81.8 %) in Group 1 compared with 30 of 52 patients (57.7 %) in Group 2 (P = 0.021). CONCLUSIONS: Non-surgical treatment achieves better clinical outcomes with respect to a lower patellar instability rate and better subjective function for the overlap-region injury of MPFL than for the non-overlap-region injury, and can be considered as treatment of choice for overlap-region injury of MPFL. The optimal choice for the non-overlap-region injury still requires further researches. LEVEL OF EVIDENCE: Therapeutic, Level IV.

[Classification and treatment of patella fractures]. / Einteilung und Therapie der Patellafraktur.

Patella fractures are rare and account for approximately 1% of all fractures. They are classified regarding their localization (proximal, distal) and appearance. The aim of any treatment is reconstruction of the extensor mechanism and joint surface. If dislocation and cartilage steps are less than 2 mm, conservative treatment may be indicated. Operative treatment is only necessary if a dislocation is more than 2 mm or when the extensor mechanism is unstable. Depending on the shape of the fracture, tension band wiring, interfragmentary screw fixation and combinations are the main techniques. Because patellectomy has functionally the worst result it should be avoided. Sleeve fractures (children) need exact reconstruction of the joint surface. In elderly patients conservative treatment or surgical patella-enclosing wiring techniques for stabilization are the best options due to low bone quality.

Process for applying the international classification of functioning, disability and health model to a patient with patellar dislocation.

BACKGROUND AND PURPOSE: The International Classification of Functioning, Disability and Health (ICF) has been proposed as a possible framework for organizing physical therapist practice. The purpose of this case report is to describe an evaluative and diagnostic process that is based on the ICF framework for a patient with a patellar dislocation. CASE DESCRIPTION: The patient was a 23-year-old woman who sustained a right knee and patellofemoral joint injury, resulting in a sprain of the medial collateral ligament and a suspected sprain of the medial patellofemoral ligament. Evaluation at 4 weeks demonstrated a primary impairment of patellar instability associated with the primary activity limitation of limited walking distances. A plan of care to address impairments, activity limitations, and participation restrictions was developed, with modifications made on the basis of the patient's health condition and personal and environmental factors. OUTCOMES: The patient attained all of her goals for therapy and was able to return to her normal activities and recreational pursuits without a recurrence of a patellar dislocation. Lower-Extremity Function Scale scores increased from 30 out of 80 to 76 out of 80 during the course of treatment. DISCUSSION: The ICF model has been proposed as a framework for developing diagnostic classifications for rehabilitation professionals. The ICF model also should be assessed with regard to whether it provides a useful process for clinical decision making. The ICF model directs practitioners to address patients' problems at the level of the whole person, with modifications made on the basis of health conditions and personal and environmental factors.

Surgical options for patellar stabilization in the skeletally immature patient.

Patellar dislocations in children and youth are estimated to occur in 29 of 100,000 individuals. Recurrent patellar dislocations in the skeletally immature patient are often associated with distinct pathoanatomies, which include patella alta, trochlear dysplasia, and contractures of the central and/or lateral structures of the extensor mechanism. This paper discusses the features of patellar instabilities classified as traumatic versus atraumatic, congenital versus acquired, and fixed dislocations versus habitual dislocations. Suggestions for the surgical management of these various classifications of patellar instabilities, on the basis of the principle of identification and correction of the pathoanatomies unique to the individual, are provided.

Patellar tendonitis and patellar dislocations.

Common sports injuries, such as patellar tendonitis and patellar dislocation, can be treated either surgically or with rehabilitation and physical therapy. Most patients with patellar tendonitis will respond well to conservative measures; however, some recalcitrant cases will require surgical intervention. To date, the literature is not able objectively to identify the patients best suited to surgery. Likewise, in the case of patellar dislocations, it is still unclear which patients respond best to conservative therapy and which respond best to surgical treatment, although evidence continues to accumulate. A practical approach to this problem can be deduced from the available evidence, but more well-designed clinical trials are needed for the establishment of definitive treatment protocols.

Acute and recurrent patellar instability in the young athlete.

Many reports of patellofemoral instability treatment suffer the same flaws of inappropriate patient selection, poor injury definition, insufficient activity assessment, and, especially in skeletally immature patients, limited followup found in other orthopedic literature. A significant number of dogmatic statements concerning risk factors and treatment interventions continue to be recycled through the literature without adequate clinical or laboratory substantiation, even in the face of contradictory data. Traditionally, patellar instability has been treated with variable periods of immobilization, sporadic rehabilitation, and an expected full return to sports activity. The reality is that many young athletes have long-term retropatella pain and sport-limiting extensor mechanism impairment following patellar dislocations. Most athletes benefit from an initial nonoperative program that is aggressive, multidimensional, and responsive to early treatment outcomes. Concurrent osteochondral injuries are common and a major contributor to adverse outcomes. Diagnostically, MRI is improving in its ability to detail osteochondral injury and it plays an important role in determining the location and extent of MPFL injury. The primary stabilizing role of the MPFL in the normal knee and its injury as an essential lesion of patella instability has been appreciated only recently. There is growing interest in exchanging the myriad of nonanatomic extensor mechanism reconstructions for more anatomic procedures based on restitution of the MPFL.

[Anterior transfer of the gracilis in repairing of recurrent dislocation and subluxation of the patella].

OBJECTIVE: To introduce anterior transfer of the gracilis in the treatment of recurrent subluxation and dislocation of the patella, and evaluate its effects. METHODS: Six patients with recurrent subluxation of the patella and 2 patients with postoperative recurrence of dislocation of the patella were treated with anterior transfer of the gracilis based on the lateral retinacular release and medial tightening. The efficacy was reviewed. RESULTS: The mean follow-up time was 22.4 months. No recurrence of subluxation of the kneecap occurred, and 7 cases had excellent results. CONCLUSION: Anterior transfer of the graciclis in repairing recurrent subluxation of the patella is easy to perform, and can effectively avoid the recurrence of subluxation of the patella.