Separation of a bipartite patella combined with quadriceps tendon rupture: a case report

Accessory fragment migration in a professional baseball player with bipartite patella: A case report

INTRODUCTION

Bipartite patella (BP) is usually recognized as an incidental radiographic finding. Therefore, no reports have observed the process of accessory fragment migration. We present the case of a professional baseball pitcher with significant migration of the fragment during follow-up.

PRESENTATION OF CASE

A 26-year-old man was diagnosed with symptomatic BP and underwent conservative therapy. Eleven months later, he was unable to play baseball because of gradually worsening knee pain without obvious trauma. On radiographs, the accessory fragment which had located at the superolateral pole 11 months earlier migrated posterolaterally. The diagnosis of Saupe's type III BP was established, and open excision of the accessory fragment was performed. Postoperatively, full-weight-bearing walking and range-of-motion exercises were started the day after surgery. Three months after surgery, he could pitch with all his power without pain.

DISCUSSION

Since our patient was a professional baseball right-handed pitcher who needed to step strongly on his left knee during pitching, strong traction force from the vastus lateralis was likely to have been repeatedly applied to the accessory fragment. It might lead to migration of the accessory fragment. The open excision of the accessory fragment was performed because the accessory fragment had migrated away from the patella body.

CONCLUSION

We report a case of professional baseball player with symptomatic BP, in which case the chronological migration of the accessory fragment was observed without obvious trauma. When the accessory fragment is identified without obvious trauma, one of the differential diseases could be a BP.

Bilateral multipartite patellae avulsions associated with a unilateral quadriceps tendon rupture

Multipartite (or bipartite) patella is a developmental anomaly that occurs in 2%-6% of individuals. In 50%, the variant is bilateral. Multipartite patella is usually an asymptomatic condition. Quadriceps tendon rupture is also a rare entity occurring mostly in men aged >40 years and usually results from an acute eccentric quadriceps contracture. The authors present a case of a patient with bilateral multipartite patellae that sustained bilateral multipartite avulsions as well as an associated unilateral quadriceps tendon rupture. This constellation of injuries has never been reported in the literature. The patient was treated with excision of the multipartite patella fragments and quadriceps tendon repair on the side with the extensor mechanism disruption. He was treated non-operatively for the contralateral lower extremity multipartite patella avulsion. This report, along with a thorough review of the literature, serves to demonstrate the clinical and radiographic characteristics of this unusual injury.

New variant of bipartite patella with traumatic separation and complete disruption of the extensor mechanism of the knee

Very few case reports have been reported on traumatic separation of the bipartite patella along with quadriceps tendon rupture. These reports relate to separation of superolateral bipartite patella (Saupe type 3). We describe a new variant which to our knowledge has not been described or classified so far, which is purely a superior bipartite patella with traumatic separation and complete functional disruption of the extensor mechanism of the knee in a young patient working in the army which was managed with open reduction and internal fixation along with repair of the extensor mechanism of the knee achieving complete functional recovery.

Bipartite patella separation and partial quadriceps tendon rupture in the setting of trauma

Normal development of the patella typically involves fusion of secondary ossification centers into a single bone during adolescence, with failure of fusion resulting in bipartite and tripartite patellae. In such variants, injury to incomplete ossification center fusion, though uncommon, has been reported to occur in the setting of traumatic quadriceps tendon rupture. The authors present a rare and complex case of traumatic bipartite fragment separation, patellar avulsion, and a complex partial quadriceps tendon tear confirmed surgically in a 36-year-old male. In this case, a tear in the lateral aspect of the quadriceps tendon attached to the nonfused patellar ossification center resulted in retraction of the band containing the bipartite fragment and separation of the patellar fragments, with superior displacement of the smaller bony avulsion likely due to complex attachments from the medial aspect of the quadriceps tendon. Knowledge of the classical locations of a bipartite and tripartite patella can aid in the differentiation of the anatomic variant versus patellar avulsion. Additionally, knowledge of the variable and complex nature of the quadriceps tendon aids in understanding the process of patellar avulsions and various tears, leading to the appropriate orthopedic management.

Traumatic Rupture of an Intermediate Tendon in a Patient with Patellar Duplication

Patellar duplication is a rare asymptomatic condition. The diagnosis is often made following a traumatic event associated with an injury to the knee extensor mechanism. The treatment is often surgical and consists in removal of the smaller part of the patella with tendon reinsertion. The presence and rupture of an intermediate tendon between the two parts of the patella have not been reported in the modern literature. We present a traumatic rupture of an intermediate tendon in a patient with horizontal patellar duplication. The surgical management consisted of tenorrhaphy protected with a figure-of-eight tension band wire approximating the two parts of the patella. The patient recovered full knee range of motion and quadriceps strength at the last 8-month follow-up.

Imaging of patellar fractures

Patellar fractures account for approximately 1% of all skeletal fractures and may result from direct, indirect, or combined trauma. Because of the importance of patellar integrity for knee extension and the risk of associated injury to the extensor mechanism, accurate reporting and description of fracture type is paramount for appropriate management. This pictorial essay aims to review the normal anatomy of the patella, the mechanisms of injury and different types of patellar fractures, with a brief introduction to therapeutic management.

Teaching Points

• Patellar fractures are classified according to their morphology and degree of displacement.

• Direct trauma results in stellate fractures.

• Indirect trauma results in transverse fractures.

• Displacement should raise suspicion for retinacular injury.

Developmental anomaly of ossification type patella partita

PURPOSE

Bipartite patella has been recognized as an incidental radiographic finding. However, symptomatic bipartite patella is occasionally diagnosed in adolescents and young athletes. The incidence of bipartite patella has been reported at 0.2-1.7, and 1-2 % of these cases are symptomatic. The purpose of this review article was to discuss current concepts relevant to developmental anomaly of ossification type patella partita.

METHODS

A PubMed database search using the key words "bipartite patella" was performed. Clinical papers reporting the bipartite patella were included. Four German-language studies were also included, three for incidence of bipartite patella and one for classification.

RESULTS

A new classification of developmental anomaly of ossification type patella partita based on location and number of fragment was recently proposed. It is simple and useful and applicable to all types of bipartite or tripartite patella. Several imaging studies have reportedly been used to evaluate symptomatic bipartite patella. MRI is currently the most appropriate method used to assess patients with bipartite patella. Although surgical procedures have been developed that reduce excessive traction force by the vastus lateralis muscle on the bipartite fragment, there is not sufficient evidence to support their use for routine treatment of painful bipartite patella.

CONCLUSION

In most symptomatic cases, movement at the interface between the bipartite fragment and the body of the patella presumably causes the pain. Therefore, the existence of apparent motion at the interface should be confirmed by specific imaging studies before surgery. Magnetic resonance imaging findings may provide such evidence by demonstrating a fluid bright signal across the segmentation, typical of pseudoarthrosis.

LEVEL OF EVIDENCE

V.

Efficacy of surgical interventions for a bipartite patella

Bipartite patella is a relatively rare phenomenon. This anomaly is typically asymptomatic but can become painful with overuse, strenuous activities, or trauma, which is why it is typically seen in a young, athletic population. Although nonsurgical management is the initial treatment, if symptoms persist, surgical intervention may be necessary. Multiple surgical options exist, such as excision or fixation of the fragment or release of lateral soft tissue structures. The authors report the efficacy of various surgical interventions on a symptomatic bipartite patella, with outcomes related to symptom relief and ability to return to preoperative levels of activity. A systematic review was performed using multiple databases. Studies reporting outcomes of symptom relief or ability to return to activity following surgical intervention for a bipartite patella were included. Surgical technique, type of bipartite, and complications were recorded. Twenty-four articles with a total of 122 patients and 127 knees were included and reviewed. Relief of pain was achieved in 84.1% of patients, with 98.3% able to return to their preoperative activity levels after surgery. For patients with a symptomatic bipartite patella, return to preoperative activity levels with zero to minimal pain can be achieved with excellent results using any of the reported surgical methods.

Clinical features and classification of bipartite or tripartite patella

The purposes of this study were to report clinical features of the developmental anomaly of ossification type bipartite or tripartite patella using a large series and to propose a new classification for the developmental anomaly of ossification type bipartite or tripartite patella. The first author prospectively examined 111 patients with symptomatic or asymptomatic bipartite (131 knees) or tripartite (8 knees) patellae. Eighty-six (77%) were male and 25 (23%) were female. Forty-three patients (39%) showed right knee involvement and 40 (36%) showed left, while 28 (25%) showed involvement in both knees. Forty-six bipartite and 4 tripartite patellae (36%) were symptomatic and 85 bipartite and 4 tripartite patellae (64%) were asymptomatic at initial examination. The median age at onset of pain of symptomatic patients (50 knees) was 15.6 ± 8.1 years (range, 10-51 years). The most common symptom was pain at the separated fragments during or after strenuous activity in all 50 knees. Physical examination revealed localized tenderness over the separated fragments in all 50 knees. Bipartite or tripartite patellae were classified by evaluating location and number of fragments. One hundred fifteen knees (83%) were classified as supero-lateral bipartite type, 16 (12%) were lateral bipartite type, 6 (4%) were supero-lateral and lateral tripartite type, and 2 (1%) were supero-lateral tripartite type. For the developmental anomaly of ossification type bipartite or tripartite patella, a classification based on both location and number of fragments is simple and easy to understand and applicable to all types of bipartite or tripartite patella.

Focal lesions of the patella

Focal lesions of the patella may be identified during the investigation of anterior knee pain or as an incidental finding on radiological images. This pictorial review describes the radiographic appearances of a wide range of conditions that have been seen in this sesamoid bone. Where appropriate, computed tomography and magnetic resonance features have been included.