You are in: eMedicine Specialties > Orthopedic Surgery > KNEE Intercondylar Eminence FracturesArticle Last Updated: Oct 30, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Brett D Owens, MD, Consulting Staff, Department of Orthopedics, Keller Army Hospital, West Point Brett D Owens is a member of the following medical societies: American Academy of Orthopaedic Surgeons and Society of Military Orthopaedic Surgeons Coauthor(s): Troilus Plante, MD, University of Massachusetts Medical School; Brian D Busconi, MD, Associate Professor, Department of Orthopedic Surgery, University of Massachusetts Memorial Health Care Editors: Robert D Bronstein, MD, Associate Professor, Department of Orthopedic Surgery, University of Rochester School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Thomas M DeBerardino, MD, Director, John A Feagin, Jr Sports Medicine Fellowship at West Point, Clinical Instructor in Surgery, Orthopedic Surgery Service, Keller Army Community Hospital at West Point; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: tibial eminence fractures, tibial spine fractures, anterior cruciate ligament avulsion injuries, ACL avulsion injuries, broken leg, knee injury, knee pain INTRODUCTIONSection 2 of 12
  Fractures of the tibial intercondylar eminence are observed mostly in children and adolescents, often after minimal trauma; good results are expected with treatment by anatomic reduction. Although adults also can sustain this type of injury, they will often have additional concurrent knee trauma and, despite anatomic reduction, frequently do poorly. History of the ProcedureIn 1875, Poncet first described intercondylar eminence fractures. In 1959, Meyers and McKeever surgically addressed only type III fractures. Since then, techniques have improved and awareness of the importance of anterior cruciate ligament (ACL) integrity has increased. Currently, many authorities recommend anatomic reduction and fixation for fractures displaced to any noticeable degree, including type II fractures. ProblemThe Meyers and McKeever classification system in use today is as follows (see Image 1):
Zaricznyj (1977) proposed another category, type IV fractures (displacement with a comminuted avulsed fragment). FrequencyDetermining the exact frequency of intercondylar eminence fractures is difficult. The occurrence of these injuries was initially believed to be rare; however, the incidence appears to be rising, possibly due in part to a greater awareness of the condition among physicians. It may also be related to an increase in sporting activities in early adolescence. EtiologyIntercondylar eminence fractures in skeletally immature patients usually result from injuries that would cause ACL tears in skeletally mature patients. Meyers and McKeever reported that a large number of bicycle falls produce this type of injury in children. However, intercondylar eminence fractures can be caused by a spectrum of sporting activities and by motor vehicle accidents. PathophysiologyAnterior displacement of the tibia on the femur (often with a rotational component) leads to stress through the ACL, which causes failure at the incompletely ossified tibial eminence before the ligament itself fails. Some controversy exists as to whether microtearing of the ACL is associated with an intercondylar eminence fracture and results in ACL laxity despite anatomic fixation of the fracture. Intercondylar eminence fractures can extend into either of the articular tibial plateaus. Associated meniscal or ligamentous injuries, such as a medial collateral ligament tear, also are possible. These types of complicating injuries are more often observed in adults, who frequently sustain higher-energy trauma (ie, injuries involving a large amount of kinetic energy, such as those suffered in motor vehicle accidents). ClinicalPatients with intercondylar eminence fractures present with knee pain and often the inability to bear weight. An effusion caused by the hemarthrosis is present. Although patients may keep the knee in a fixed position, range of motion of the knee should be possible once pain is controlled. The presence of a locked knee (usually determined upon examination under anesthesia) should alert the surgeon to the presence of concomitant knee pathology (eg, a meniscus tear) or to an incomplete reduction of the fracture because of an interposed meniscus or a transverse intermeniscal ligament. Neurovascular status should not be affected, and the skin should be intact. INDICATIONSSection 3 of 12
Although it is difficult to choose a clearly superior treatment option for intercondylar eminence fractures, most sources agree that significantly displaced intercondylar eminence fractures (including type II fractures) require anatomic reduction and fixation and that closed reduction is rarely effective. Arthroscopic reduction causes less morbidity than open reduction and internal fixation. The choice of fixation for intercondylar eminence fractures is still debated. Meyers and McKeever used sutures to tack the bone fragment onto the anterior horn of the medial meniscus. Zaricznyj reported the use of multiple Kirschner wires (K-wires). Others have reported good results with cannulated screw fixation, which is usually the fixation chosen for such injuries in adults. In skeletally immature patients, screw fixation is secure but may require hardware removal. Whether via open, mini-open, or arthroscopic approach, suture fixation does provide secure fixation but may limit the speed of rehabilitation. RELEVANT ANATOMYSection 4 of 12
The tibial eminence consists of the eminent confluence of the tibial plateaus and contains 2 spines. The medial spine serves as the attachment of the ACL. The ACL, which has a broad insertion onto the tibial eminence, fans out and coalesces with the attaching fibers of the anterior horn of the medial meniscus anteriorly and the anterior horn of the lateral meniscus posteriorly. These meniscal attachments or the transverse intermeniscal ligament may be interposed between the fracture and its bed, thereby blocking a reduction, although this is controversial. CONTRAINDICATIONSSection 5 of 12
No true contraindications exist for surgical fixation of intercondylar eminence fractures except for contraindications to surgery in general that relate to systemic medical issues. WORKUPSection 6 of 12
Imaging Studies
TREATMENTSection 7 of 12
Medical therapyMost authors recommend aspiration of the hemarthrosis and casting for nondisplaced type I intercondylar eminence fractures. This is also the initial management used for displaced fractures. The position of immobilization is still controversial. It was initially thought that the immobilization should be in full extension so that the fracture fragment is reduced by condylar contact. However, because full extension is the tightest position for the ACL, this method may result in increased tension and displacement at the fracture site. Surgical therapyAlthough most authors agree that displaced intercondylar eminence fractures need repair, the choice of fixation is still debated. Meyers and McKeever used sutures to tack the fragment onto the anterior horn of the medial meniscus. Zaricznyj reported the use of multiple K-wires. Others have reported good results with cannulated screw fixation, which is usually the fixation chosen for adults. In skeletally immature patients, screw fixation is secure but may require hardware removal. Whether via open, mini-open, or arthroscopic approach, suture fixation does provide secure fixation but may limit the speed of rehabilitation. Intraoperative detailsThe details of intercondylar eminence fracture reduction depend mainly on the approach used. However, the basic steps are the same. The fracture bed is cleared of any hematoma and debris. Because the attachments of the medial and lateral menisci also may inhibit reduction, these are retracted out of the way as the avulsed tibial eminence is reduced to its bed. The avulsed tibial eminence can be held by sutures to the medial meniscus or through a drill hole or held by K-wires or a cannulated screw (depending on the level of comminution). Postoperative detailsThe traditional approach to postoperative care for intercondylar eminence fractures has been long leg casting in extension (or slight flexion) for 4 weeks, followed by a rehabilitation program. Recent studies have reported use of early ACL rehabilitation protocols, with excellent results achieved. Follow-upPatients with intercondylar eminence fractures should be monitored at least until bony union is seen radiographically. At that point, hardware may need to be removed. Continued follow-up is warranted as patients resume their preinjury levels of activity, because ACL laxity can become symptomatic. COMPLICATIONSSection 8 of 12
The most devastating complication of open or arthroscopic fixation of a displaced intercondylar eminence fracture is infection. Sterile technique and implants, intraoperative antibiotics, and proper wound closure should keep this complication to a minimum. Another concern with acute surgery is fluid extravasation, leading to the potential for lower-extremity compartment syndrome. The use of the arthroscopy fluid pump should be avoided in this situation. The most often reported complication is ACL laxity. The cause of this laxity could be fixation in a nonanatomic position (thereby functionally lengthening the ACL) or microtearing of the ACL prior to eminence fracture. Although many studies report an increase in KT1000 knee ligament arthrometer measurements, patients do not report associated symptoms of instability. Another complication is diminished range of motion, caused by immobilization. Most authors report an extensor lag, which can be minimized by secure fixation and an early, aggressive rehabilitation program. OUTCOME AND PROGNOSISSection 9 of 12
Most studies report good results from the use of open or arthroscopic reduction and fixation of displaced intercondylar eminence fractures, or, in the case of minimal displacement, from the employment of closed treatment. Although some studies have demonstrated an increased, treatment-related ACL laxity by objective measures, these results do not correlate with patients' symptoms. FUTURE AND CONTROVERSIESSection 10 of 12
The future of surgical management of displaced intercondylar eminence fractures is the arthroscopic approach. As arthroscopic skills advance, the need for an arthrotomy to fix these types of fractures will decrease. Another future direction is the use of bioabsorbable implants for fixation of such injuries, which would provide rigid fixation but eliminate the need for hardware removal. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Intercondylar Eminence Fractures excerpt Article Last Updated: Oct 30, 2006 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
