Fractures of the patella in children

Evolution in the Management of Patella Fractures

Patella fractures usually occur as a result of direct trauma to the anterior knee joint, indirect injury as a result of eccentric muscle contraction, or rapid knee flexion against a contracted quadriceps muscle. The patella functions as part of the extensor mechanism of the knee, where large forces are transmitted, and its subcutaneous nature has made treatment of patella fractures a challenge. In this review article, we evaluate how the management of these fractures has evolved over time and the advantages associated with the various treatment techniques. There are few comparative studies looking at the different treatment types for fractures of the patella, with the goal of achieving a functional extensor mechanism with low rates of post-traumatic arthritis and metal-work irritation.

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.

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

An 11-year-old boy was admitted to our hospital due to severe pain in his right knee when he landed after jumping over a vaulting box. A plain X-ray image and computed tomography scan showed an avulsion fracture of the lower pole of the patella and patella alta. Furthermore, magnetic resonance imaging (MRI) revealed an articular cartilage lesion and rupture between the inferior pole of the patella and the patella tendon. We diagnosed a sleeve fracture of the patella and performed surgical treatment. Open reduction and internal fixation were performed by the pull-out technique using transosseous no. 2 MaxBraid™​​​​​​ ​(Zimmer Biomet, Tokyo, Japan) sutures. While postoperative weight-bearing was permitted, the knee joint was immobilized in a brace for four weeks. Three months of postoperative assessment revealed excellent functional outcomes.

Transosseous Repair of Patellar Sleeve Fractures: A Case Series and Surgical Technique Guide

The purpose of this study is to describe the surgical technique and outcomes of transosseous repair of patellar sleeve fractures in a pediatric cohort. A retrospective review was performed on patients younger than 16 years undergoing transosseous repair of distal patellar sleeve fractures. A chart review was performed on demographics, surgical repair technique, and postoperative care. Primary outcomes included intact extensor mechanism function and range of motion (ROM) at final follow-up. In this study, 20 patients, 17 males and 3 females, with a mean age of 11.7 years were included. ROM was initiated at a median of 27.5 days following surgery. All patients had a healed patellar sleeve fracture and intact extensor function at final follow-up. Final mean knee ROM among the 18 patients with minimum 3-month follow-up was 132 degrees. Thirteen patients (72%) achieved full ROM (≥ 130 degrees) and 5 patients (28%) achieved less than 130 degrees knee flexion. Duration of initial immobilization was found to be the only variable strongly associated with final postoperative ROM. Mean duration of immobilization for patients achieving ≥ 130 degrees was 24 days versus 44 days in those patients achieving < 130 degrees, p = 0.009. All patients who began knee ROM within 21 days of surgery obtained full knee ROM. No patients experienced construct failure or extensor lag. Operative management of displaced patellar sleeve fractures with anatomic transosseous suture repair of the sleeve fracture, brief immobilization no more than 21 days, and initiation range of early ROM results in excellent outcomes.

A rare case of an open transverse patella fracture in a 5-year-old child

Patella fractures in children are rare accounting for 1 % of all paediatric fractures. Rarer still are transverse patella fractures in children with only 1 case previously described in the literature of a child less than the age of 6. We present the second case in the literature of a transverse patella fracture in a child, and the only case of a transverse fracture in a partially ossified patella in a 5-year-old. Our patient suffered an open patella fracture following fall with a flexed knee onto a broken tile. The case was successfully managed with adult fixation principles of patella fractures with a tension band wire construct. The patient had regular follow-up with knee radiographs showing a well healed fracture and a good range of motion of the knee at 3 months. The hardware was subsequently removed with no complications. In conclusion, we present an extremely rare case of an open transverse patella fracture in a child, utilising adult fixation principles of a patella which resulted in a successful outcome for the patient.

Bilateral sleeve fracture of the inferior pole of the patella in children: A case report

Background

A patellar avulsion fracture is a unique fracture type in children with an extremely low incidence rate in knee joint injuries, most of which are unilateral. Cases of simultaneous bilateral fracture are rare. Due to the physiological and anatomical characteristics of patellar sleeve fractures in children, obvious avulsed bony fragments are seldom seen with plain radiography after trauma; thus, this fracture type is often misdiagnosed or missed on first evaluation. Early diagnosis of patellar sleeve fracture is the key to successful treatment.

Case report

This paper presents a case of bilateral patellar sleeve fracture in a 10-year-old girl that was missed in another hospital and treated successfully by open reduction and fixation of the osteochondral fragments after the patient was transferred to our hospital, yielding good clinical outcomes at the one-year follow-up.

Conclusion

Overall, this case report described the clinical and imaging characteristics of inferior pole sleeve fractures in children and highlight clinicians’ awareness of this injury to assist in early, accurate diagnosis and reduce the incidence of misdiagnosis and missed diagnosis due to unfamiliarity.

Consecutive ipsilateral inferior pole patella and superior patella sleeve fractures

We present a rare, previously undescribed case of a superior patella sleeve fracture in a skeletally immature adolescent male, just 1 month following surgery for an ipsilateral traumatic inferior pole patella fracture. This was initially missed resulting in a delay to surgery. We recommend a high index of suspicion is key in these patients who re-present following subsequent trauma and alternative X-ray views such as a flexed lateral can be extremely beneficial.

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.

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.

Epidemiology of paediatric lower extremity fractures in a tertiary care center in Switzerland

PURPOSE

About 20% of all fractures in children occur at the lower extremity. This study aims to investigate the epidemiology and injury pattern of lower extremity fractures within the pediatric population consulting a tertiary referral hospital in Switzerland.

METHODS

Study population included all patients up to 16 years presenting with a lower extremity fracture over a period of one year. Recorded data were age, gender, side, season of the year, mechanism, type of fracture and applied treatment.

RESULTS

Fractures of the lower extremity represent 23% of all fractures with a mean age of 9 years and 6 months. The tibia, with 94 fractures (38%), represents the most frequently injured bone. Peak incidence is seen in winter and 24% of tibia shaft fractures were due to board sports. Overall, 82% of fractures were treated by cast with or without closed reduction, and only 18% requested surgery.

CONCLUSION

Board sports seems to be a leading cause of tibial shaft fracture in our region. Nevertheless, only 18% of fractures had recourse to an orthopedic surgeon, hence the importance of the teaching quality of pediatric residents for conservative fracture treatment.

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.

Evaluation and management of traumatic knee injuries in the emergency department

Posttraumatic knee pain is a common presentation in the emergency department (ED). The use of clinical decision rules can rule out reliably fractures of the knee and reduce the unnecessary cost and radiation exposure associated with plain radiographs. If ligamentous or meniscal injury to the knee is suspected, the ED physician should arrange for expedited follow- up with the patient's primary care physician or an orthopedic specialist for consideration of an MRI and further management. Patients presenting after high-energy mechanisms are at risk for occult fracture and vascular injuries. ED providers must consider these injuries in the proper clinical setting.

Assessment and treatment of knee pain in the child and adolescent athlete

Knee pain in children and adolescents is one of the most prevalent complaints in a pediatric practice, accounting for at least a third of musculoskeletal complaints. Accurate diagnosis requires an understanding of knee anatomy and patterns of knee injuries and skill in physical examination. This review covers the most common causes of knee pain in children and adolescents, including overuse issues, such as Osgood-Schlatter and osteochondritis dissecans, as well as traumatic injuries, including tibial spine fractures and anterior cruciate ligament injuries.

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.

An Isolated Articular Surface Fracture of the Distal Patella: An Unusual and Previously Unreported Paediatric Injury

Paediatric patella fractures are uncommon, accounting for less than 1% of all paediatric fractures. This case report describes a previously undocumented patella fracture in a child, with a clear mechanism of injury. We present a case of a previously healthy 14-year-old boy who fell directly onto his right knee after coming off his pushbike. He sustained an isolated fracture involving the articular surface of the distal part of the patella with minimal displacement. The patient was managed conservatively in a Richard splint for three weeks, followed by a knee brace with gradually increasing degrees of flexion. He was instructed to be nonweight bearing for two weeks and then partial weight bearing for six weeks. At the final followup, after 9 weeks, the patient had full return of function and standard radiographs show the fracture to be healed. This case report has demonstrated how direct compression to the paediatric patella can cause a fracture isolated to its articular surface. It has detailed the natural progression of this injury to radiographic union, using a conservative management strategy. The authors believe that this case report provides an interesting insight into the variation of paediatric patella fractures and their contrasting management strategies.

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.

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.