MENISCAL INJURIES IN CHILDREN AND ADOLESCENTS

CHARLES J. ODGERS, IV, MD, Resident, Orthopaedic Surgery

BRIAN GALINAT, MD, Attending Orthopaedic Surgeon

May 8, 1996

CLINICAL CASE PRESENTATION

ORTHOPAEDIC DEPARTMENT

THE ALFRED I. DUPONT INSTITUTE

WILMINGTON, DELAWARE

CASE HISTORY:

A 13-year-old boy presented with left knee pain after sustaining an injury while wrestling three months prior to this visit. The patient stated that his left knee was in a hyperflexed position when it was twisted.

He felt a "pop" associated with pain on the lateral aspect of his knee. He stated that he had minimal knee swelling which had resolved, but his pain persisted. He had taken Advil for a few days after his injury which helped control the pain.

PHYSICAL EXAM: On physical exam he had full range of motion of his left knee with a trace effusion. There was lateral joint line tenderness, and he described a 'clunky' sensation as his knee was brought into extension from a hyperflexed position. There was a negative Lachman test and no instability to varus or valgus stress. Neurologic exam was normal.

IMAGING STUDIES: An MRI of his left knee showed no evidence of cruciate ligament injury. The lateral meniscus was not adequately visualized as the MRI was of poor quality. Plain radiographs were not obtained.

DISCUSSION:

Epidemiology

• 5% of meniscal injuries involve patients < 15 years of age
• Both menisci are equally vulnerable to injury
• Slightly higher incidence of lateral meniscal tears in youths because of high numbers of discoid menisci in the earlier studies
• Usually associated with high energy activities such as football, soccer, and basketball

Clinical Presentation

The Problem

• Difficult to diagnose meniscal tears in children- bad historians
• Clinical findings often subtle and nonspecific
• Often leads to delay in diagnosis and misdiagnosis

History

• Often describe a twisting event
• A 'pop' may be heard or felt
• Pain is usually significant with the majority of adolescents recalling a specific injury

Clinical Presentation

Symptoms

• Pain, intermittent swelling, locking, limping, and clicking
• Vahvanen and Aalto- series of 41 menisectomies in children- 95% presented with pain, 71% had intermittent effusions, 66% had snapping sensation, 63% giving way, 54% intermittent locking, and 7% with a locked knee

Physical Findings

• Most common signs- joint tenderness and effusion
• Chronic tears- often have quadriceps wasting
• Ligamentous laxity in children can cause false positive McMurray's test

Demographics

• Most common meniscal lesions - longitudinal vertical and peripheral tears
• Bucket handle tears common in older adolescents
• Radial and parrot-beak tears often associated with ACL injuries
• ACL injuries with meniscal injuries- need to evaluate for both

Differential diagnosis

• Discoid meniscus- presents as 'snapping knee syndrome' with pain and popping from lateral joint line- may be due to mechanical impingement of the thickened meniscus or a tear in the meniscus
• Popliteus tendinitis- diagnosis made clinically by tenderness over fibular collateral ligament with the knee in 'figure of 4' position
• Plica syndrome- can cause pseudolocking with the knee in semiflexed postion and pain with any motion
• Patellofemoral pain- frequently localized to anteromedial joint line
• Osteochondritis dessicans- routine radiographs can usually identify this

Evaluation

• Radiographs helpful to rule out OCD, bony tumor, or osseous loose body
• MRI- study of choice in detecting meniscal pathology
1. Noninvasive and painless- made arthrogram essentially obsolete
2. Frequently need sedation for children
3. Indications- when clinical evaluation is inconclusive
4. Can miss lateral meniscal tears, especially in children

Diagnostic Arthroscopy- Indications

1. Persistent pain and instability
2. Recurrent effusions
3. Obvious ACL injury or meniscal tear by clinical exam

Treatment

• Decision based on patients age, duration of symptoms, pattern of meniscal injury, and presence of concurrent injuries
• Meniscectomy
1. Mainly of historical importance
2. Most follow-up studies- poor result with progressive and clinical deterioration over time
3. Fairbaink's radiographic changes after total meniscectomy- squaring of the edge and flattening of the condyle, and narrowing of the joint space .

Partial Meniscectomy

1. Principle is to preserve as much of functioning rim of meniscus as possible
2. McGinty et al- compared 89 total with 39 partial meniscectomies with 5.6 year follow-up- better results with partial meniscectomy- too soon to tell
3. Indications- Tear patterns not amenable to repair-tears in avascular zone, small radial tears, and parrot-beak tears

Meniscal Repair

1. Collagen healing is possible in capsular third of meniscus- area where most meniscal injuries occur in children
2. Repairing tear in young individuals when technically feasible is prudent when considering the natural history of alternative treatments

Practical problem- Prolonged rehabilitation and time away from sports compared to partial meniscectomy

REFERENCES:

1. Busch MT: Meniscal injuries in children and adolescents. Clin Sports Med 9:661, 1990
2. DeHaven KE, Linter DM: Athletic injuries: Comparison by age, sport, and gender. Am J Sports Med 14:218-224, 1986.
3. Fairbank TJ: Knee joint changes after meniscectomy. J Bone Joint Surg 4B:664-670, 1948.
4. Jackson JP: Degenerative changes in the knee after meniscectomy. Br Med J 2:525-527.
5. King AG: Meniscal lesions in children and adolescents: a review of the pathology and clinical presentation. Injury 15:105-108, 1985.
6. McGinty JB, Geuss LF, Marvin RA: partial or total meniscectomy. J Bone joint Surg 59A: 763-766, 1977.
7. Medlar RC, Manidberg JJ, Lyne ED: Meniscectomies in children- report of long term results. Am J Sports Med 8:87-92, 1980.
8. Ritchie DM: Meniscectomy in children. Aust NZ J Surg 35:239-241, 1965.
9. Vahvanen V, Aalto K: Meniscectomy in children. Acta Orthop Scand 50:791-795, 1979.