TIBIAL SPINE FRACTURES

Frank Giacobetti, M.D. Orthopaedic Resident

September 20, 1995

CLINICAL CASE PRESENTATION

ORTHOPAEDIC DEPARTMENT

THE ALFRED I. DUPONT INSTITUTE

WILMINGTON, DELAWARE

CASE HISTORY:

• HISTORY: This is a 14 year old male who presented to the A.I duPont emergency room complaining of left knee pain after having fallen off his bicycle.
• PHYSICAL EXAM: Exam reveals a swollen left knee. Skin was intact. There was tenderness to palpation diffusely about the knee. Valgus stress at full extension and at 30 degrees revealed an increased laxity on the left. Anterior draw and Lachman tests were also asymmetric with an increased excursion on the left. Neurovascular exam was unremarkable.
• XRAYS: Type III Meyer's / McKeever tibial spine fracture

GENERAL:

• Avulsion fracture of the tibial spine is a relatively rare injury in children accounting for approximately 3 per 1 00,000 children's fx -Fracture of the tibial spine is seen primarily in children from the ages of 8 to 14 -The injury is virtually always to the anterior intercondylar eminence. The posterior intercondylar eminence is rarely fractured (10x less common), and when this occurs, it is generally in skeletally mature individuals.
• The anterior intercondylar eminence fracture is analogous to an injury to the ACL in the skeletally mature individual.

ETIOLOGY:

• Injury is caused by hyperextension of the knee associated with some lateral movement leading to increased stress on the ACL.
• The most common activity associated with this fracture is bicycle riding. Some authors say that if a knee injury with effusion occurs during a bike ride, a tibial spine fracture is present until proven otherwise.

CLASSIFICATION:

• Meyer's and McKeever have described three main types of intercondylar fractures in children based on the amount of displacement and the fracture pattern seen on the initial radiographs. Type I is nondisplaced and does not interfere with knee extension. The type II fracture has a posterior hinge with the anterior portion being elevated. In this type, knee extension is generally limited, and there is a possibility that the anterior horn of the meniscus is caught under the anterior fracture fragment. A type III fracture is fully displaced, usually with the knee held in a mildly flexed position.

SIGNS AND SYMPTOMS:

• Physical findings in acute injury include pain, effusion from associated hemarthrosis, and reluctance to bear weight.
• Extremes of motion are limited because of increasing pain.

RADIOGRAPHIC FINDINGS:

• Adequate AP and Lateral x-rays are essential to evaluate the degree of displacement of the anterior tibial spine.
• Fracture is best seen on the lateral radiograph.
• A displaced osteochondral fragment from the patella or femoral condyle may simulate a fracture of the tibial spine.
• If an MRI study is done, a concomitant partial tear of the ACL may be noted in some cases.

MANAGEMENT:

• Type I fractures can be treated using long leg cast immobilization in a few degrees of knee flexion for 5-6 weeks.
• in Type II fractures, with the child under general anesthesia, the knee is hyperextended to attempt fracture reduction by forcing the elevated anterior portion of the fracture fragment back into place through the contact pressure of the femoral condyles. Afterward the knee is brought back to a position of a few degrees of flexion for long leg cast immobilization. Casting in full extension or hyperextension should be avoided to prevent excessive popliteal artery stretch and a resultant lower leg compartment syndrome. If this closed maneuver is unsuccessful, operative reduction is needed.
• Operative reduction is indicated for all Type III fractures.
• The goal for operative treatment is to remove the soft tissue(usually the meniscus and blood clot) that is blocking reduction and to secure the reduction.
• A cast is used following this reduction and minimal internal fixation.
• Reduction can be accomplished by either arthroscopic means or by a limited anteromedial or anterolateral arthrotomy.
• A nonabsorbble suture can be woven through the ACL and out the distal end of the tibial spine fragment to strengthen the repair.
• After reduction and fixation, a long-leg cast is applied with the knee in neutral or slight flexion for 6-8 weeks.

PROGNOSIS AND COMPLICATIONS:

• With appropriate treatment, follow-up results are very good. Nonunion is rare. -Although mild, asymptomatic laxity of the ACL is often present after the final healing of the fracture. This is why most advocate countersinking the tibial spine fragment during reduction

REFERENCES:

1. Baxter, M.P.; Wiley, J.J. Fractures of the tibial spine in children. An evaluation of knee stability. J Bone Joint Surg 70-B:228-30, 1988.
2. 2)Fyfe, I.S.; Jackson,J.P. Tibial intercondylar fractures in children: A review of the classification and treatment of malunion. Injury 13:165-169, 1981.
3. 3)Meyers,M.H.; McKeever,F.M. Fracture of the intercondylar eminence of the tibia. J Bone Joint Surg 41 -A: 209-222, 1959.
4. 4)Meyers,M.H.; McKeever, F.M, Follow-up notes. Fracture of the intercondylar eminence of the tibia. J Bone Joint Surg 52-A: 1 677-1684, 1970.
5. 5)Nichols, J.N.; Tehranzadeh, J. A review of tibial spine fractures in bicycle injury. Am J Sports Med 15:172-174, 1987.