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CURRENT CONCEPTS
Historically, nonsurgical treatment options for skeletally
immature patients with ACL tears consisted of activity
modification, functional bracing, and physical rehabilitation.
The rationale for this approach was to allow the patient to
achieve skeletal maturity before performing a transphyseal
ACL reconstruction, thereby minimizing the risk of physeal
violation and potential growth deformity. This nonsurgical
approach should be best used in the highly compliant,
low-demand patient who has no additional intra-articular
pathologies or who has a partial ACL tear. Nevertheless
nonoperative management is an appealing option given
the increased healing potential of children and the risk of
physeal damage with surgical reconstruction, clinical results
following nonoperative management have not been favorable.
Partial ACL injuries represent one-quarter to one-half of the
midsubstance ACL tears that occur in children. Although
children tend to have better healing capacity than adults,
animal studies have demonstrated mixed results regarding
the precise healing potential after partial ACL transection.
Kocher et al. showed that approximately one-third of children
with a partial ACL tear who were treated nonoperatively
01
with a hinged knee brace, partial weight-bearing for six to
However due to a incomplete development of proprioception eight weeks, and a progressive ACL rehabilitation protocol
most of these patients do not complain of any knee instability ultimately required surgical reconstruction for persistent
but they are frequently referred to the physician by the instability. The authors noted several risk factors for failure
parents reporting recurrent episodes of pain and swelling of nonoperative management and developed an algorithm
after sports activities. A gentle palpation is used to detect for acute treatment. Overall, they recommended surgical
any underlying effusion. Stability tests should be performed management for patients with a tear greater than one-half of
first in the uninjured knee and then in the injured knee in the thickness of the ACL, a tear of the posterolateral bundle,
order to reassure the young patient. When a restriction in a pivot-shift examination result of grade B or greater, or a
the range of motion is recorded, a concomitant injury to the skeletal age of more than fourteen years. Recent papers
meniscus and/or cartilage should be suspected. A proper on nonoperative management of a complete ACL rupture
Lachman test is critical to assess an abnormal anterior tibial generally report a poor outcome. Additionally, it is associated
translation and the lack of a firm end point. Imaging of the with a high rate of sport dropout because of recurrent
injured knee is essential in devising a treatment plan. Initial instability, as studies have demonstrated that up to 50%
AP, lateral, notch, and sunrise radiographs of the injured of children treated nonoperatively do not return to athletic
knee are helpful in assessing osseous structures and skeletal activity. Progressive instability can result in progressive
maturity. Magnetic resonance imaging (MRI) is indicated meniscal and articular cartilage damage as well as Fairbanks
to evaluate for partial versus complete ACL injuries, define changes (e.g., condylar squaring and joint space narrowing
associated ligamentous pathology, and assess for suspected on an anteroposterior radiograph) in 61% of knees. Instability
meniscal derangement. MRI is 95% sensitive and 88% and cartilage degeneration are typically observed in patients
specific for detecting ACL tears in children. In addition to the who do not modify their post-injury activity level, as is often
standard radiographic evaluation performed in adults, some the case in active children and adolescents.
authors suggest to additionally obtain fifty-one-inch standing There has been considerable debate in the literature
(130-cm) anteroposterior hip-to-ankle radiographs. This
regarding the optimal time to perform ACL reconstruction
allows for accurate preoperative assessment of subtle limb- in skeletally immature patients. Concerns regarding physeal
length discrepancy and angular deformity.
damage, growth arrest, and subsequent sequelae including
Skeletal maturity is traditionally assessed using the Tanner angular deformity and limb-length discrepancy have led
staging system and with the use of a posteroanterior some surgeons to delay surgical management until skeletal
radiograph of the left hand, with reference to the Greulich maturity. Delayed reconstruction, however, has its own
and Pyle atlas. Child athletes who are being considered for important drawbacks including the possible development of
ACL reconstruction can be classified as either prepubescent progressive intraarticular pathology. These poor results have
or pubescent. The prepubescent patient has physiologic resulted in the development of modern operative techniques
findings consistent with Tanner stages 1 and 2 and a for pediatric ACL reconstruction.
bone age of <12 years in boys and <11 years in girls. The
pubescent patient has physiologic findings consistent with
Tanner stages 3 and 4 and a bone age of 13 to 16 years in
boys and 12 to 14 years in girls.
ISAKOS NEWSLETTER 2014: Volume II 21