410 likes | 652 Views
ACL Injuries In the Skeletally Immature. Jason W. Folk, MD Steadman Hawkins Clinic of the Carolinas February 2012. Disclosures. Consultant Smith & Nephew Endoscopy. Objectives.
E N D
ACL Injuries In the Skeletally Immature • Jason W. Folk, MD • Steadman Hawkins Clinic of the Carolinas • February 2012
Disclosures Consultant Smith & Nephew Endoscopy
Objectives • Describe the epidemiology, pathophysiology, and treatment principles of ACL injuries in skeletally immature patients
ACL Injuries: Introduction • Epidemiology: • Intrasubstance tears once considered rare in pediatric population • Tibial eminence fx considered pediatric ACL equivalent • Typically under 12yo • Increasing numbers over past decade • Increased attention
ACL Injuries: Introduction • Reasons for increased incidence: • Increased participation in sports • Higher competitive levels early on • Increased awareness of injury • Decreased conditioning
ACL Injuries: Introduction • ACL Injuries in Soccer Players 5-18 (Shea, et al. JPO 2004.) • Based on insurance data from 6 million player-years • 6.7% of total injury claims • 30.8% of all knee injury claims • True incidence unknown
ACL Injuries: Introduction • Differences in pediatric population • Often lack fully developed complex motor skills • May have temporary decline in motor and balance during puberty • Open physes • Higher strength of ligaments vs. bone-ligament interface
ACL Injuries:Diagnosis • History: • Patient describes a characteristic “Pop” • Effusion forms quickly after injury • 47% of patient’s aged 7-12 with traumatic effusion had ACL disruption • 65% in 13-18 year old group. (Stanitski et al. 1993) • Approximately 60% partial tears
ACL Injuries: Diagnosis • Physical Exam • Often more difficult in kids than adults • Acute pain • Frightened • Unable to relax • Examine uninjured leg for baseline laxity or congenital absence of ACL
ACL Injuries: Imaging • Plain Radiographs (4 views) • For anyone suspected of having an ACL injury • Bony avulsions • Osteochondral fractures • Physeal fractures • Patellar dislocation/subluxation • Degree of physeal closure • CT scan also used for evaluation of physeal closure.
Tibial Eminence Fracture • In skeletally immature, chondroepiphysis is weaker than the ligament. • Mechanism of injury typically hyperflexion • Most commonly 8-12yo • Present w/ pain and limited ROM • Dx on x-ray and CT
Tibial Eminence Fracture • Type I: LLC x 3-6 weeks in 20degrees flexion • Type II/III: Attempted closed reduction, +aspiration of hemarthrosis (may help reduction), LLC in extension x 4-6 weeks • Irreducible Type II/III or IV: arthrocopic vs open ORIF with suture, retrograde wire, or screw fixation • Some argue all Types II-IV should be fixed anatomically with countersinking of fragment because of residual laxity • Results of fixation usually excellent
ACL Injuries: Imaging • MRI • Should not be used as replacement for physical exam and routine radiographs • Look for ACL tear, meniscal injury, chondral injury • Indications • Failing to improve ROM • Persistent effusion • Physical exam difficult to interpret. • Help define anatomy of physis
ACL Injuries: Etiology • Can occur with fractures • Distal femoral physeal fractures (25-45%) • Salter-Harris III fxs at increased risk because frequently exits intra-articularly at notch • Proximal tibial physeal fractures
The Physis • Concern about iatrogenic injury to physis is what drives the debate about treatment strategies
The Physis • Distal femoral and prox tibial physis • Contribute more to limb length than hip and ankle • DF 1.2 cm/yr • PT 0.9 cm/yr • Overall 65% of length contributed to knee • Closure typically occurs • M=16 • F=14
Anatomy of Physis • MRI closure of Physis • 0% at 11 years • 5% at 12 years • 34% at 13 years • 53% at 14 years • 94% at 15 years • 100% at 16 years • Central tibial physis closes prior to peripheral physis • ?More central tunnel • ?Smaller tunnel Sasaki et al., J Knee Surg 2002
ACL Injuries:Treatment • Concern for possible growth abnormality fuels debate on treatment • Non-operative • Operative • Direct Repair • Extra-articular • Intra-articular • Intra/Extra articular reconstructions • Physeal sparing • Partial Transphyseal • Complete transphyseal • Trans epiphyseal
ACL InjuriesNonoperative Management • Avoids risk of physeal damage • Sometimes used as a temporizing measure until skeletal maturity • Very difficult to reasonably limit young patient’s activities
ACL Injuries:Nonoperative management • So what if we don’t treat these injuries? • Angel et al. Arthroscopy 1989 • 27 children with arthroscopically documented ACL tears • 22 patients at 51mo f/u • None able to return to sports at preinjury level
Non-op ACL Open Physis • 40 pts under 14 y/o open physis • 16 conservative • 6 scope for meniscal tears • Only 7 return to sports • All recur giving way, swelling, pain McCarroll et al., AJSM 1988
Non-op ACL Open Physis • 18 pts ACL injury open physis • Only one returned to preinjury level of sports • Initial scope 13 meniscal tears • Later secondary meniscal tears in 9 • Degen changes 11 of 18 pts by Xray Mizuta et al., JBJS Br 1995
Non-op ACL Open Physis • 60 children with ACL tear • 23 nonop • Nat Hx continued instability, further meniscal and chondral damage • 25 % secondary meniscal tears • Few able to participate in sports Aichroth et al., JBJS BR, 2002
Non-op ACL Open Physis • ? Effect of delay in treatment • 39 pt < 14 y/o • Sig increase in MMT with delay in treatment > 6 weeks • 36% chronic vs 11% in acute Rx • No diff in rate of LMT Millett et al., Arthroscopy 2002
ACL InjuriesNonoperative Management • Graf et al: • 12 skeletally immature patients with ACL tears • 8 patients underwent non-op and no restriction management. • 7 of the 8 had new meniscal tear at follow up
ACL Injury:Long Term Results • Kannus et al. JBJS-B. 1988 • 8 year F/U – 4/7 Pediatric Patients that had Untreated ACL Tears showed Advancing OA radiographically
Nonoperative Rx in Children • Non-op treatment has not resulted in good outcomes
ACL Injuries:Physeal Concerns • Fear disruption of open physes • Risk of epiphysiodesis, LLD, angular deformity • Caused by crossing physis with bone plug and/or fixation devices
ACL Injuries:Physeal Concerns • History • Campbell et al. (1959) • Large holes drilled through the physis have maximal retardation of growth plate • Insertion of cortical bone across physis causes arrest • Makel et al (1988) • Destruction of >7% of physis causes growth arrest • Destruction of 3% or less…no arrest • Stadelmeir et al (1995) • Soft tissue graft placed in drill hole did not cause physeal bar.
Factors Influencing Physeal Arrest • Diameter of drill hole • Soft tissue graft within tunnel • Tension of graft across physis • Tunnel location? (Central and vertical)
ACL Injuries: Operative Managment • Direct Repair: • A historic treatment modality • Inflammatory changes and degeneration begins within 48 hours after injury • Metalloproteases and cytokine inflammatory factors affect healing potential of direct repair • Poor results • Delee and Curtis, CORR 1983 • Engebretsen, et al. Acta Orthop Scand 1988
ACL Injuries:Operative Management • Extra-Articular repair • Temporizing method • Non-anatomic reconstruction • Poor results • Dahlstedt , et al. Acta Orthop Scand 1988 • McCarroll et al. AJSM 1998 • Graf, et al. Arthrsocopy 1992
ACL Injuries: Assessment of maturity • Tanner et al. : • Adolescent growth spurt begins at 12.5 years in boys and 10.5 years in girls. • Peak Growth velocity 1 year later • Menarche is good indication of maturity in girls • In athletic girls, menarche may be delayed. • Axillary and pubic hair appear in boys after growth spurt • Bone age: Most accurate method to determine skeletal maturity
General Guidelines • Think about physis if: • Male • Tanner stage 1 or 2 • Not shaving • Not reached growth spurt • 14 y/o or less • Female • Premenarchal • Tanner stage 1 or 2 • Not reached growth spurt • 12 y/o or less
ACL Injury:Physeal Sparing Reconstruction • Intra-articular, non-anatomic, extra-physeal Stanitski. JAAOS 1985
ACL Injury:Kocher Technique Physeal-Sparring Combined Intra- and Extra-articular Reconstruction
ACL Injury:Partial Transphyseal • Hybrid of physeal sparing and adult-type reconstruction • Femoral physis left intact • Graft: Hamstring or patella • Passed through 6-8mm tunnel • <5% physeal X-sectional area • Fixed in over the top position