Incidence, mechanism of injury, and treatment of fractures of the patella in children

Management and subsequent outcomes of patellar sleeve injuries: A retrospective case series of 90 pediatric and adolescent patients

Purpose

This study aims to report the epidemiology of patellar sleeve injuries, describe diagnostic findings and treatment, and assess functional outcomes following different treatments.

Methods

A medical database was queried from 1990 to 2016 to identify patients ≤18 years presenting to a single pediatric institution with a patellar sleeve injury. Patients with significant comorbidities or previously operatively treated for ipsilateral knee injuries were excluded. Standard demographic data, mechanism of injury, skeletal maturity, injury-related radiographic parameters, along with treatment paradigms, post-treatment clinical and radiographic findings, and patient-reported outcomes were collected.

Results

A total of 90 patients, mean age of 10.7 years (range: 7-17) was included, of which 69 (77%) were male. Seventy-three percent of all injuries occurred while playing sports (particularly football/basketball/soccer), with "direct blow" or "landing" being the most prevalent mechanisms of injury. Twenty-six (29%) underwent operative treatment, with transosseous suture fixation being the most popular surgical technique (73%). Of the 64 (71%) non-operatively treated patients, 18 (39%) were placed in a hinged knee brace locked in extension with the remainder split between casting and standard knee immobilizer. Compared to the non-operative cohort, a higher percentage of the operative group had a pre-treatment extensor lag (p < 0.001) and greater fragment displacement (p < 0.001) with patella alta (p < 0.001) on imaging. There was no difference in outcome scores (Pedi-IKDC/Lysholm) or patella alta on radiographs between groups. Post-treatment surveys indicated no difference in residual pain or ability to return to sport.

Conclusion

This large case series provides valuable epidemiologic, clinical, and radiographic data describing patellar sleeve fractures, along with outcomes following non-operative and operative treatments.

Level of evidence

IV.

Bilateral Sleeve Fracture of the Patella in a Healthy 11-Year-Old Male: A Case Report

Bilateral sleeve fracture of the patella (SFP) in skeletally immature children is a rare injury. We report the case of a healthy 11-year-old male who suffered bilateral SFP while playing tag. The avulsed fragments of his left patella were highly comminuted. Open reduction and internal fixation (ORIF) were performed using suture anchors, and the knees were immobilized using a cylinder cast for three weeks. At the one-year follow-up assessment, both knees were found to have regained full strength with no extension lag. However, we observed malunion due to lateral shift of the avulsed fragment, cystic lesions, and clicking in the patella, and the patient experienced residual pain in the left knee. Based on this, we conclude that the sleeve fracture of the patella with comminuted cartilaginous fragments was difficult to treat and might have led to poor clinical results if anatomical reduction and fixation had not been performed.

Quadriceps tendon autograft for pediatric anterior cruciate ligament reconstruction results in promising postoperative function and rates of return to sports: A systematic review

PURPOSE

To assess the performance of the quadriceps tendon (QT) autograft in pediatric anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic search of MEDLINE, PubMed, and EMBASE was conducted on March 1, 2021. Studies of all levels of evidence reporting outcomes and/or complications after QT autograft ACLR in pediatric patients (≤ 18 years old) were eligible for inclusion. Study demographics, patient demographics, reported outcomes, and complications were abstracted. Screening and data abstraction were designed in accordance with PRISMA and R-AMSTAR guidelines. Descriptive statistics were presented when applicable, with data for heterogeneous outcomes presented in narrative summary fashion.

RESULTS

A total of 14 studies examining 596 patients (46.3% female), mean age 15.4 years, were included in this systematic review. Mean postoperative Lysholm scores ranged from 94.0 to 99.5. Mean postoperative IKDC subjective scores ranged from 75.9 to 94.0. Limb symmetry index ranged from 96.8 ± 10.4 to 100.4 ± 7.6% across multiple hop tests. Return to sports (RTS) rates ranged from 88.9 to 91.7%. Eleven studies reported postoperative complications, whereby 16 patients (4.8%) experienced contralateral complications and injuries. Forty-six patients (9.4%) experienced ipsilateral complications, including ten graft failures (2.5%) and two growth disturbances (0.6%).

CONCLUSIONS

QT autograft ACLR in the pediatric population retains the potential of regaining a preinjury level of knee stability, and yields promising postoperative function and rates of RTS, yielding comparable outcomes relative to HT autograft and the reference-standard BPTB ACLR that have previously been described in the literature. Moreover, use of the QT autograft is associated with low rates of postoperative complications, including graft failure and growth disturbances in this active and high-risk patient population in observational studies to date. Therefore, clinical equipoise exists to further appraise the influence of QT autograft on postoperative outcomes compared to aforementioned autograft options in a randomized control trial fashion.

LEVEL OF EVIDENCE

IV.

Common and Consequential Fractures That Should Not Be Missed in Children

Missed or delayed diagnosis of fractures in children is not uncommon owing to their immature skeletons, unique fracture patterns, and distinctive radiologic findings. The term occult is used to describe radiographically subtle fractures. Some of these fractures can be associated with excellent outcomes despite the pitfalls of delayed diagnosis. However, a subset of these injuries have more guarded prognoses when missed, despite their harmless radiographic appearance. A high index of suspicion should be maintained when treating pediatric extremity injuries with clinical findings disproportionate to a benign-appearing radiograph. Moreover, overreliance on radiology reports can perpetuate diagnostic error. In cases of discrepancy, timely follow-up for repeat examination or immediate advanced imaging can help avoid missed diagnoses. Most critically, the one diagnosis not to miss is nonaccidental trauma, as continued exposure to abuse puts the child at risk of further injury and death. [Pediatr Ann. 2022;51(9):e357-e363.].

Clinical and Radiographic Differentiation of Pediatric Patellar Sleeve Fractures and Other Inferior Pole Pathologies

BACKGROUND

Inferior pole patellar sleeve fractures (PSFs) are rare injuries that occur in skeletally immature patients that may be missed or falsely diagnosed as an inferior pole fracture (IPF) or Sinding-Larsen-Johansson syndrome (SLJS).

PURPOSE

The objective of this study was to evaluate and compare clinical and radiographic features of patients with PSF, IPF, and SLJS.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Retrospective review of skeletally immature patients diagnosed with PSF, IPF, and SLJS between 2011 and 2019 at a single urban academic center was performed. Chart and radiographic review was completed. Between-group differences were assessed using analysis of variance, Kruskal-Wallis test, and Fisher exact test, as appropriate to variable distributions.

RESULTS

In total, 125 patients (82% male) were included, with a mean (SD) age of 10.7 (2) years (16 PSF, 51 IPF, 58 SLJS). There were no significant differences in patient characteristics between the 3 groups. One hundred percent of the patients with PSF (P < .001) and IPF (P < .001) had acute trauma, compared with 24% of patients with SLJS. Fewer patients with PSF had an intact straight leg raise (38%) compared with those with IPF (94%; P < .001) and SLJS (98%; P < .001). Fewer patients with SLJS had knee swelling (41%) compared with those with PSF (93%; P < .001) and IPF (94%; P < .001). More patients with PSF had knee effusion (81%) compared with those with IPF (37%; P = 0.011) and SLJS (3%; P < .001). More patients with SLJS were able to bear weight (88%) compared with those with IPF (12%; P < .001) and PSF (0; P < .001). Radiographically, compared with those with IPF and SLJS, patients with PSFs had increased mean prepatellar swelling (6.1 [P < .001] and 6.5 [P < .001] vs 12.9 mm), intra-articular effusion (6.1 [P = .014] and 4.9 [P = .001] vs 9.2 mm), maximum fragment size (26 [P = .004] and 17.7 [P < .001] vs 45.3 mm), and maximum fragment displacement (1.24 [P = .002] and 1.45 [P = .003] vs 13.30 mm), respectively. Compared with those with SLJS (1.10), patients with PSF (1.92; P < .001) and IPF (1.22; P < .001) had patella alta with higher mean Insall-Salvati ratios >1.2.

CONCLUSION

Differences in clinical features such as ability to straight leg raise, knee swelling, knee effusion, ability to bear weight, and radiographic features, such as prepatellar swelling, intra-articular effusion, fragment displacement/size/shape/location, and patellar height, can all be helpful in recognizing rare pediatric inferior patellar pathology, thus increasing efficiency in indicating for higher-level imaging to reach a prompt diagnosis and provide appropriate treatment.

Patella Sleeve Fracture with Medial Patellofemoral Ligament Tear and Lateral Femoral Condyle Fracture in an Adolescent: A Case Report

CASE

A 12-year-old boy sustained a patella sleeve fracture of the superior pole, medial patellofemoral ligament tear, and lateral femoral condyle fracture after a direct contact sledding injury. He was managed nonoperatively with 5 weeks of cylinder cast immobilization with transition to a hinged knee brace and physiotherapy. By 3 months, he returned to sport activity without patellar instability.

CONCLUSION

This is the first case to describe simultaneous development of these 3 injuries in an adolescent. We recommend that patients with patella sleeve fracture undergo magnetic resonance imaging to assess for local soft-tissue injury because this may influence treatment decisions.

Narrative Review - Knee Pain in the Pediatric Athlete

PURPOSE OF REVIEW

This review article seeks to highlight common youth athlete knee conditions due to overuse or trauma and elucidate differences from the adult populations.

RECENT FINDINGS

Overuse conditions presented include apophysitis, osteochondritis dissecans plica syndrome, and discoid meniscus. Traumatic conditions presented include patellar instability, patellar sleeve fracture, and patellofemoral osteochondral fractures. Knee injuries affect a significant proportion of youth athletes. These injuries place athletes at higher risk of chronic pain and potentially osteoarthritis. We have reviewed common overuse and traumatic knee injuries and differentiating factors between the adult population to improve and expedite the diagnosis, treatment, and prognosis for youth athletes with knee injuries.

Case Report on Sleeve Avulsion of Patella in Young Adult

Introduction:

Sleeve avulsion of patella is extremely rare, limited almost to children. However, few cases have been reported in adults. Rarity of this fracture makes the diagnosis and choice of treatment difficult. Inability to raise leg remains important clinical sign for quadriceps mechanism insufficiency. In the absence of standard treatment guidelines pullout sutures through patella provides a secure and stable fixation option. Our case remains the first to be reported ever in English literature in a 23-year-old male with a superior pole avulsion patella being treated with Krakow pullout suture.

Case Report:

A 23-year-old Indian male was admitted with left knee pain and swelling following fall from bike. He had knee pain, swelling, and inability to bear weight. Active straight leg raising was not possible. On X-ray he had small bony sleeve visible near proximal pole of patella. Magnetic resonance imaging (MRI) was done which showed sleeve avulsion of patella at proximal pole. Under spinal anesthesia fracture was exposed through midline approach. Pullout Krakow sutures were taken through quadriceps tendon and fracture fragments using 3 no Polyester suture. Transosseous tunnels were drilled in patella and tied distally. At 4 months patient had no extension lag with full range of movements. At 14 months follow-up patient is asymptomatic and able to run, squat, sit cross legged, and do his day-to-day activities.

Conclusion:

Sleeve avulsion of patella in adults is extremely rare with only few cases reported in literature. MRI is not only useful for diagnosis but also for deciding treatment modality. Krackow technique with Polyester suture through quadriceps tendon incorporating fracture fragment passed through patellar transosseous tunnel provides secure fixation with excellent results. Also avoids any future hardware problems in this subcutaneous bone.

Nonoperative Management of Minimally Displaced Patellar Sleeve Fractures

Patellar sleeve fractures primarily occur in the adolescent population from a rapid contraction of the quadriceps with the knee in a flexed position. Several small case reports describe operative reduction and fixation for displaced fractures. However, there is sparse literature on nonoperative management of these injuries. Retrospective review and prospective follow-up of all patients diagnosed with patellar sleeve fracture between 1991 and 2014 at a single institution. Patients with superior pole avulsion fractures, history of prior knee surgery, and fractures managed operatively were excluded. Patients with a clinical diagnosis without support of advanced imaging were also excluded. Radiographs and magnetic resonance imaging (MRI) were reviewed for initial fracture displacement, time until fracture union, and the presence of patellar tendon ossification. Outcome was assessed using the Tegner's activity scale, Kujala's Score and the International Knee Documentation Committee (IKDC) subjective knee evaluation score at final follow-up. Eighteen nonoperatively treated distal patellar pole sleeve fractures were identified, while five patients had advanced imaging to support their diagnosis. All were males with a mean age of 15.1 (range: 12-18). Traumatic and sport-related injuries were noted in the majority of patients. Only one patient had any appreciable displacement, but still < 2 mm. Final radiographic evaluation revealed fracture healing without patellar tendon ossification in all patients. All five patients had full terminal knee extension and symmetric range of motion. Mean IKDC score was 96.4 (range: 82-100) mean Tegner's activity score was 60 (range: 5-8), and mean Kujala's score was 89.7 (range: 63-100) at final follow-up. Of the five cases, three patients presented in a delayed fashion, and all went on to have surgical treatment. Two required arthroscopic loose body removal, while the other had an open patellar debridement and platelet-rich plasma (PRP) injection. Minimally displaced patellar sleeve fractures can be successfully managed nonoperatively with excellent clinical outcomes. However, delayed in presentation may be associated with worse outcome. This study of case series reflects level of evidence IV.

Superior pole patellar sleeve fracture after medial patellofemoral ligament reconstruction

A 13-year-old boy sustained a superior pole patellar sleeve fracture after a blunt trauma of the knee. A medial patellofemoral ligament reconstruction had been performed 4 weeks earlier. The patient underwent surgery to reinsert the quadriceps tendon in the superior pole of the patella using two bone suture anchors. One-year postoperative assessment revealed excellent functional outcomes. Sleeve fractures are easily misdiagnosed, and in our case, clinical examination was essential in order to perform the diagnosis.

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

Purpose

To highlight important diagnostic and treatment considerations in patients who present with bifocal patellar tendon avulsion fractures from the tibial tubercle and inferior patellar pole.

Methods

Radiographic 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.

Results

Five 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.

Conclusions

Advanced 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 Evidence

IV, therapeutic case series.

Patellar Sleeve Fracture in an Eight-Year-Old Girl

The patellar sleeve fracture is a rare entity in pediatric traumatology. Its diagnosis is challenging due to its rarity and subtle radiographic finding, and it is easily missed by emergency physicians. Early recognition and treatment of this fracture is of paramount importance in order to guarantee better outcomes. We present herein a case of severely displaced patellar sleeve fracture in an eight-year-old girl, which was treated successfully by open reduction and fixation of the osteochondral fragments using anchor sutures, yielding very positive clinical outcomes at the two-year follow-up.

Superior Pole Sleeve Fracture of the Patella in an Adolescent: A Case Report

CASE

We describe a case of a superior pole sleeve fracture of the patella in a healthy 12-year-old boy and provide a review of the literature. Patella pole sleeve fractures occur primarily in the paediatric population, with inferior pole fractures more commonly seen. Superior pole fractures are rare, which may make adequate diagnosis and treatment difficult.

CONCLUSION

This case report aims to inform surgeons to be diligent of superior patella pole sleeve fractures and demonstrate the effective use of ultrasound imaging (as opposed to magnetic resonance imaging) in the diagnosis of the injury. Furthermore, this case report provides insight on diagnosis, treatments, and outcomes.

Patellar sleeve avulsion fracture in a patient with Sinding-Larsen-Johansson syndrome: a case report

BACKGROUND

Patellar sleeve avulsion (PSA) fractures are rare injuries that occur in in skeletally immature patients. Initial diagnosis is key to a successful outcome, as these injuries are easily overlooked on plain radiographs with poor results well documented from delayed management. High index of suspicion from the mechanism of injury, thorough clinical examination and Magnetic Resonance Imaging (MRI) help to avoid misdiagnosis.

CASE PRESENTATION

The case of a 12-year-old male athlete with an acute PSA after a conservative treatment of a SLJ syndrome is described. The patient was referred to our clinic due to severe pain and loss of function after performing a high jump. Plain radiographs (X-ray) and MRI confirmed an inferior pole PSA which was fixed with double trans osseous ultra-high strength tapes. At the 3-month follow- up visit the patient was able to ambulate brace free. At 2-years follow up the patient was able to play soccer and ice hockey. To our knowledge, there are no case reports of inferior pole PSA with prior SLJ syndrome described in literature.

CONCLUSIONS

Early clinical suspicion and distinguishing this PSA from other enchondral ossification disorders around the knee is critical to avoid misdiagnosis. Whether SLJ syndrome increases the risk of sustaining a PSA is still not clear. Trans osseous fixation with suture tapes leads to good functional results in a young athlete with inferior pole PSA.

Paediatric injuries around the knee: Bony injuries

The aim of this article is to discuss the diagnosis, management and pitfalls of bony injuries around the skeletally immature knee. Each within their own right is a relatively uncommon injury but associated with potential complications. Distal femoral physeal fractures can result in growth arrest and vascular injury. Tibial spine avulsions can result in an unstable knee. Tibial tubercle fractures can be associated with compartment syndrome and pose a risk to the extensor mechanism of the knee. Fixation can be complicated by growth arrest and subsequent recurvatum deformity. Finally, patella sleeve injuries are often missed and this can also threaten the extensor mechanism. We discuss the approach to clinical and radiological assessment of these injuries, and evidence based recommendations as to how they are best managed to avoid complications.

Screw osteosynthesis of transverse fracture of the patella in children

Objective

Patella fractures in children are rare, with an incidence of less than 1% of all pediatric fractures. Literature describes different surgical techniques and outcomes, but there is not a specified superior technique for children. The aim of this study is to assess the functional outcome after screw fixation of transverse patella fractures in children.

Methods

Two boys at 11 years of age were presented with a transverse fracture of the patella within the same week. Open reduction and fixation of the fractured patella with periost sutures and a 4.0 mm titanium screw inserted from the distal fragment. Afterward, the quadriceps expansion was meticulously repaired with sutures.

Results

The patients could fully weight bear immediately on a fully extended knee in an orthosis. After 4 weeks, radiological healing was obtained. At the 8-week and 6-month follow-up, the modified Hospital of Special Surgery knee score was 100 points in both patients.

Conclusion

Single screw fixation provides an excellent outcome after 8 weeks with a full range of motion and full weight bearing, providing a faster recovery.

[Bony knee injuries in childhood and adolescence]

While fractures around the knee are known to be rare, physicians have encountered a rise in the frequency due to the increased participation of children and adolescents in high-impact sports at a younger age. Even if the treatment of fractures in some cases resembles that in adults, the diagnostics and treatment in childhood and adolescence require a hígh level of experience in order avoid possible sequelae and to enable early recognition. Thorough diagnostics using clinical and imaging investigations as well as a precise weighing up of the treatment are essential to minimize differences in leg length and axial malpositioning of the leg. A decision between conservative and operative treatment is made for both the femur and tibia depending on the type of fracture. Decisive is the degree of dislocation of the fracture. In operative treatment, the axis conform reduction and subsequent stress stable treatment are particularly decisive. Avulsion trauma, bony avulsions of the intercondylar eminence and patellar injuries are also treated conservatively with immobilization or surgically with the aid of various fixation techniques, depending on the degree of dislocation.

[Patellar sleeve fractures : Bracing and augmentation technique with suture tape]

OBJECTIVE

Transosseous augmentation of patellar sleeve fractures (PSF) with suture tape in young athletes.

INDICATIONS

Acute avulsions of the proximal or distal patellar pol with clinical relevant deficit of knee extension.

CONTRAINDICATIONS

Local infections, severe soft tissue damage (relative contraindication), fractures of the patella or tibial tuberosity.

SURGICAL TECHNIQUE

Direct longitudinal anterior approach to the patella. Debridement of the proximal patellar tendon insertion. Anatomic reduction of any osteochondral fragments. Transosseous augmentation of the tendon with FiberTapes® (Arthrex, Naples, FL, USA).

POSTOPERATIVE MANAGEMENT

Passive motion exercise to 30° of flexion from day 1; increase to 60° from week 3; 90° from week 5. Partial load-bearing of 20 kg with knee in locked full extension brace during first 2 weeks. Isometric exercises from week 3. Free active ROM and full weight bearing from week 7.

RESULTS

If diagnosis and treatment is early and sufficient augmentation of the tendon and periosteum is provided, good to excellent functional outcome can be expected.

Socioeconomic factors and individual lifestyles influencing the incidence of patella fractures: a national population-based survey in China

BACKGROUND

We aimed to do a national survey on the population-based incidence of patella fractures and related risk factors fracture in China.

METHODS

All the data on patella fractures were available from the China National Fracture Survey (CNFS) between January and May in 2015. And in the CNFS, all eligible household members were selected from 24 urban cities and 24 rural counties of eight provinces of China, with stratified random sampling and the probability proportional to size method used. Questionnaire was sent to every participant for data collection and quality control was accomplished by our research team members.

RESULTS

A total of 512,187 valid questionnaires were collected, and relevant data were abstracted. There were a total of 69 patients with 69 patella fractures that occurred in 2014, indicating that the incidence was 13.5 (95% CI, 10.3-16.7))/100,000 person-years. Slip, trip, or fall from standing height was the most common cause, leading to 69.6% (48/69) of patella factures, followed by traffic accidents (18.8%, 13/69). Home and road were the first two most common places, where 86.9% of the overall injuries occurred. Age of 45-64 and 65-74 years, alcohol consumption and previous history of fractures were identified as independent risk factors for patella fracture.

CONCLUSIONS

Specific public health policies focusing on decreasing alcohol consumption should be implemented. Individuals aged 45-64 and 65-74 should pay more attention to bone mass density and prevention of falls, especially those with previous history of fracture.

Sleeve fracture of the adult patella: Case report and review of the literature

RATIONALE

The patellar fractures are common in adults, but rare in children. As a particular type of patellar fracture, however, sleeve fractures are almost always limited to children in the under 16's group.

PATIENT CONCERNS

Herein, we report a rare case of a 19-year-old healthy adult female who presented sleeve fracture at the superior pole of the left patella. The clinical and radiological features are found including joint effusion, anterior tilt of the patella and a shell of bone lying proximally to the patella.

DIAGNOSES

Computed tomography and magnetic resonance imaging examination have been performed to further confirm the diagnosis of sleeve fracture, rupture of the quadriceps tendon and the cartilaginous injury.

INTERVENTIONS

Under general anaesthesia, she underwent open surgical procedures for reconstituting anatomically the fracture and repairing the rupture of the quadriceps tendon.

OUTCOMES

Six months after the operation, she could fully use her left knee without any pain and disability.

LESSONS

Sleeve fractures of the patellar in adults are extremely rare, and our case is of interest for the first time occurring in healthy female adults. Our case report and literature review was aim to describe the clinic and imaging characteristics of superior pole sleeve fractures in adults, and highlight that physicians must be aware of this entity in adults so as to reduce misdiagnosis due to unfamiliarity.

Single Shot Adductor Canal Block for Postoperative Analgesia of Pediatric Patellar Dislocation Surgery: A Case-Series Report

Postoperative analgesia for the knee surgery in children can be challenging. Meanwhile acute pain management in pediatric patients is still often undertreated due to inadequate pain assessment or management. We reported the ultrasound-guided single-injection adductor canal block (ACB) with 0.2% ropivacaine and dexmedetomidine (0.5 μg/kg) in addition in a series of 6 children. Patients' age was range from 7 to 15 years old with right or left habitual patellar dislocation needing an open reduction and internal refixation. Pain assessments using Numeric Rating Scale scores on the operative limb were made preoperatively and at 12, 24, 36, and 48 h postoperatively at rest. Medication consumption was calculated as well. The possible complications, such as hemodynamic changes, nausea, vomiting, and dysesthesia, were also recorded at 12, 24, 36, and 48 h postoperatively at rest. The pain scores were low, and analgesic medication consumption was minimal. Meanwhile, no adverse events were recorded in any of the subject. Single-injection ACB might be an optimal analgesia strategy for patellar dislocation surgery in pediatric patients.

Staged treatment of a chronic patellar sleeve fracture using the Taylor spatial frame

Patellar sleeve fractures are easily missed injuries since plain radiographs may not show a bony fragment at the time of injury. Failure to diagnose these injuries can result in patellar instability, extensor lag, and anterior knee pain. We report a novel treatment using a Taylor spatial frame as part of a staged reconstruction to regain length of the extensor mechanism and maintain knee motion prior to performing primary repair of the avulsed patellar sleeve fragment. In our case, an 11-year-old male presented to our institution six months after sustaining a patellar sleeve fracture. Radiographic examination with the knee in extension revealed a 23-mm gap between the inferior patellar pole fragment and the remaining patella. The patient was ultimately taken to the operating room twelve months after the initial injury for placement of a Taylor spatial frame to regain length of the extensor mechanism. The patient began immediate knee range-of-motion exercises, and performed daily soft tissue lengthening of two millimeters. After four weeks of treatment the patient underwent removal of the fixator and primary repair of the patella. At final follow up six years after patellar reconstruction, the patient had an active knee range-of-motion from five degrees of hyperextension to 140° of flexion. Where current literature reports suboptimal results even when treatment is delayed for two months, in our case the patient was able to obtain a high level of function after treatment with a two-stage reconstruction using a Taylor spatial frame.

Inferior patellar pole fragmentation in children: just a normal variant?

BACKGROUND

Fragmentary ossification of the inferior patella is often dismissed as a normal variant in children younger than 10 years of age.

OBJECTIVE

The purpose of this study was to determine whether fragmentary inferior patellar pole ossification is a normal variant or is associated with symptoms or signs of pathology using MRI and clinical exam findings as reference.

MATERIALS AND METHODS

A retrospective review was performed on 150 patients ages 5-10 years who underwent 164 knee radiography and MRI exams (45.1% male, mean age: 7.8 years). The presence or absence of inferior patellar pole fragmentation on radiography was correlated with the presence or absence of edema-like signal on MR images. Clinical notes were reviewed for the presence of symptoms or signs referable to the inferior patellar pole. These data were compared with a 1:1 age- and sex-matched control group without inferior pole fragmentation. Statistical analysis was performed using two-tailed t-tests.

RESULTS

Forty of 164 (24.4%) knee radiographs showed fragmentary ossification of the inferior patella. Of these 40 knees, 62.5% (25/40) had edema-like signal of the inferior patellar bone marrow compared with 7.5% (3/40) of controls (P = 0.035). Patients with fragmentary ossification at the inferior patella had a significantly higher incidence of documented focal inferior patellar pain compared with controls (20% vs. 2.5%, P = 0.015).

CONCLUSION

Inferior patellar pole fragmentation in children 5 to 10 years of age may be associated with localized symptoms and bone marrow edema-like signal and should not be routinely dismissed as a normal variant of ossification.

Sleeve fracture of the patella with lateral slip of the retinaculum: a case report in an 11-year-old child

Adolescents are susceptible to patellar sleeve fractures. We present an interesting case of a patellar sleeve fracture in an 11-year-old child with lateral slip of the retinacular sleeve. Clinical assessment was difficult; however, an MRI scan confirmed the diagnosis. Surgical repair was undertaken, and the retinacular sleeve was repaired along with repair of the patellar tendon. The patient recovered well after surgery and underwent physiotherapy. A patellar sleeve fracture should always be suspected in patients less than 16 years of age, particularly in those with indirect acute trauma to the knee. Prompt surgical repair is important to achieve full functional recovery.

Rare sleeve fracture of the superior patella pole in an adult due to forceful passive physiotherapy following cast immobilization

Sleeve fractures are generally restricted to children or adolescents, and usually occur at the lower patella pole. Here we report on a superior pole sleeve fracture in an adult that occurred following forceful passive physiotherapy after cast immobilization. To our knowledge, this is the first report of a superior pole sleeve fracture in an otherwise healthy adult. The case highlighted that a diagnosis of a superior patella pole sleeve fracture in an adult can easily be missed because it is a rare injury, and hence is unlikely to be suspected by physicians.

[Avulsion fracture of the patella with intra-articular dislocation : a rare form of injury to the growing skeleton]

Sleeve avulsion fractures of the patella in children are a rare condition. We present a patient history of an unusual case of an irreducible avulsion fracture with intra-articular dislocation including the surgical management and a review of the literature.

Bilateral sleeve fracture of the inferior poles of the patella in a healthy child: case report and review of the literature

The initial diagnosis of a sleeve fracture of the patella is key to a successful outcome with poor results well documented in the literature from delayed management. Diagnosis is difficult due to the rarity of this injury and thus the low likelihood the admitting junior doctor would think of this injury in their differential. They are very uncommon in incidence and have features on plain radiography that are difficult to interpret unless the surgeon is familiar with the anatomy of the immature patella. Missing the diagnosis can be disastrous for the patient. In this paper we describe the presentation of bilateral sleeve fractures in a healthy child, our initial investigations and subsequent management. We chose to repair with 5 Ethibond via 3 transosseous tunnels, initially reinforced with a circlage wire. On last review the boy maintains stable, pain-free knees with a full range of motion. The authors hope that this case and literature review will provide a valuable teaching aid and so assist in early, accurate diagnosis and cover the management options to achieve a positive outcome.

Injury of a bipartite patella in a young upcoming sportsman

The aim of this study was to report the clinical features of a young athletic patient with bipartite patella, and review the literature to discuss the entity of this rare anomaly. In the course of an athletics competition, a 12-year-old top sportsman felt an intense pain around his left knee-cap while taking off from a jumping-board and broke down the competition. X-rays and magnetic resonance imaging showed an isolated distal pole of the patella with just minor diastasis; however, the X-rays did not suggest a recent fracture but rather hint at an atypically injured bipartite patella. A conservative therapy of 5 weeks with brace followed including a ban on sport activities for 12 weeks. Ten weeks later, the radiographs revealed a complete consolidation. Six months after the injury, MRI only presented a generally inconspicuous horizontal sclerosed structure. A fracture or separation of the bipartite patella was retrospectively diagnosed.

Superior pole sleeve fracture following patellar stabilisation

Sleeve fractures of the superior pole of the patella are rare. The importance of their diagnosis lies in the fact that the avulsed fragment contains a source of bone forming tissue which may lead to duplication or enlargement of the patella. We report a case in a 16 year old boy who underwent plication of the medial patellofemoral ligament, vastus medialis obliquus advancement and percutaneous lateral release, for recurrent instability. Interruption of the blood supply with subsequent avascular necrosis is one possible mechanism for this complication. Another more likely mechanism is that of failure of the repair and re-dislocation, which may have been contributed to by prolonged cast immobilization.

Sleeve fracture of the patella in children

PURPOSE

To report the diagnosis, treatment, and outcomes of sleeve patellar fractures in children.

METHODS

Records of a consecutive series of patients with sleeve patellar fractures were retrospectively reviewed.

RESULTS

Of the 11 children (8 boys and 3 girls; mean age, 12 years), 6 had minimally displaced fractures (1-2 mm) and were managed by cylindrical plaster of Paris immobilisation, whereas the other 5 with severely displaced fractures underwent open reduction with tension band wiring. The mean follow-up period was 10 (range, 3-36) months. All patients obtained full extension of the knee except one (with an extension lag of 10 degrees). No patient complained of pain or discomfort of the involved knee.

CONCLUSION

Sleeve patellar fractures in children are uncommon. Diagnosis can be missed, especially in those with a very small avulsed bony fragment. For undisplaced fracture, conservative management can achieve good results. For severely displaced fractures, early surgical intervention is effective.

Sleeve fracture at the superior pole of the patella

We present a sleeve fracture at the superior pole of the patella in a 12-year-old boy. Sleeve fractures at the inferior pole of the patella have been well described in the orthopedic and radiologic literature. However, a similar injury at the superior pole of the patella is relatively rare. We hope that awareness of this unusual injury and its imaging findings will allow timely diagnosis and intervention.

Avulsionsfrakturen des unteren Patellapols

Fractures of the lower pole of the patella are rare and occur typically in children. In these types of fractures an extensive sleeve of cartilage is pulled off with a small bony fragment. The so-called sleeve fractures are often overlooked in plain radiographs. We describe the operative treatment and outcomes in two patients with sleeve fractures, one receiving early and one delayed treatment.A 12-year-old boy (case 1) sustained an indirect injury to the left knee while playing ball. Clinical examination showed a lag of active extension of the left knee without decrease in passive range of motion. At 9 years of age, a 12-year-old girl (case 2) sustained a direct blunt trauma to her right knee while playing ball. The lesion of the lower pole of the patella was not diagnosed in time. During the following 3 years a lag of extension of the right knee developed.The sleeve fracture diagnosed early was treated by open reduction and internal fixation with transosseous suturing. At the 6-month follow-up the knee had regained full range of motion. The sleeve fracture diagnosed late showed a nonunion of the patella resulting in a lag of extension. Even after 3 years a shortening osteotomy of the patella resulted in full range of motion of the right knee.

Sleeve fracture of the superior pole of patella: a case report

The growing patella is more vulnerable to osteochondral or avulsion fractures. Avulsion or sleeve fractures can occur at the superior or lower pole. Superior pole fractures are very rare. A case of superior pole sleeve facture of the patella is presented and the treatment described.

Pediatric knee fractures

PURPOSE OF REVIEW

Fractures about the knee are a common occurrence in children, and characteristics of the growing skeleton make children susceptible to specific fractures that do not occur in adults. The purpose of this review is to help the clinician to recognize, understand, and appropriately treat these injuries.

RECENT FINDINGS

Pediatric knee fractures are diagnosed by a comprehensive history and physical examination supplemented with appropriate imaging modalities. Depending on the injury, treatment may include immobilization, arthroscopic treatment, or open reduction and internal fixation.

SUMMARY

A thorough understanding of pediatric knee fractures will enable clinicians to appropriately manage these injuries and provide patients with a rapid return to preinjury activities.

A review of sleeve fractures of the patella in children

Patella fractures are rare in children and the sleeve fracture is a particular form of fracture that only occurs in children where it is the most common patella fracture. It is caused by rapid muscle contraction. Diagnosis may be difficult both clinically and on the X-ray which may look normal if there is no bony fragment. Patella alta is the best sign and ultrasound is very helpful. Awareness of the existence of the injury is all important. This fracture differs from straightforward avulsion because of the "sleeve" of periosteum which is pulled off the patella and will continue to form bone if not treated thus enlarging or even duplicating the patella. Treatment involves prompt reduction and, usually, internal fixation of the disrupted patella tendon.

Fractures around the knee in children

Traumatic forces applied to the immature knee result in fracture patterns different from those in adults. The relative abundance of cartilage in the knee of the growing child may make the diagnosis of certain injuries more challenging. If plain radiographs fail to reveal a fracture, a stress radiograph, computed tomography scan, or magnetic resonance imaging study may help to establish the diagnosis. Certain fractures, such as hyperextension injuries to the distal femoral or proximal tibial epiphysis, or displaced tibial tuberosity fractures, may be especially susceptible to neurovascular problems. Although the use of appropriate treatment techniques may minimize the occurrence of late complications such as malunion and physeal bridging, not all problems are preventable. A careful discussion of the injury with both patient and parents should stress the importance of follow-up so that any problems that do occur can be promptly addressed.

Children's sports injuries

Sports injuries in children are common. They range from very serious and even, occasionally, fatal accidents, to trivial sprains and bruises. Sports medicine is a burgeoning field. Parallel with this there has been an increased understanding of the radiology of these lesions. Lesions in the immature skeleton differ greatly to those in the mature skeleton. This review describes the most frequent sports injuries in children.