Neurofibroma

We describe a five-year-old child with neurofibromatosis type I who developed a Charcot knee. Infiltration of the joint by tissue associated with the disease caused damage to the proprioceptive mechanism and resulted in severe joint instability, accelerated destruction and development of neuropathic arthropathy.

J Bone Joint Surg [Br] 1998;80-B:468-70.

Neurofibromatosis is a genetically transmitted disorder characterised by abnormalities of the skin, nervous tissue and bone. These may include cafe-au-lait spots, neurofibromas, Lisch nodules, optic gliomas, osseous lesions, macrocephaly, short stature and mental retardation. Pseudarthrosis of the tibia and the ulna, dystrophic kyphoscoliosis, spinal manifestations, protrusio acetabuli, dislocation of the hip, hypertrophy of a limb, atlantoaxial dislocation and tendon ruptures may also occur.1-16

Neuropathic arthropathy with progressive destruction of weight-bearing joints was first described by Charcot in 1868.17 Many causes have been suggested including tabes dorsalis, injury of the spinal cord and peripheral nerves, syringomyelia, diabetes mellitus, congenital insensitivity to pain, amyloidosis, leprosy, myelomeningocele and nutritional deficiency.

Charcot joints are rare in children but may be found in association with neurological disorders such as congenital insensitivity to pain, peripheral nerve injuries, diabetic neuropathy and chronic diseases of the spinal cord which lead to sensory disturbances of the limb. 17-25

We describe a child who had neurofibromatosis complicated by the development of a Charcot knee due to an intraarticular neurofibroma.

Case report

A 5-year-old girl was seen because she had a limp and painless swelling of the left knee. Her mother and three of her four siblings had neurofibromatosis type I. The child had had several transient episodes of swelling of the knee during the past year accompanied by limping, which had all settled.

Clinical examination showed multiple cafe-au-lait spots and a mild lumbar scoliosis. The left leg was 2.5 cm shorter than the right. The left knee showed a large effusion, but the range of movement was normal, although with severe anteroposterior instability. There was no tenderness and all laboratory blood tests were normal. Plain radiographs showed severe degenerative changes with marked irregularity of the joint surfaces (Fig. 1).

^sup 99^Tc bone scanning showed a diffuse increase in uptake in the left knee. Electrophysiological studies of the legs were normal. MRI showed infiltration of the knee with abnormal tissue extending posteriorly into the popliteal fossa and invading the anterior cruciate ligament (ACL), the posterior cruciate ligament and the lateral meniscus (Fig. 2).

At arthroscopy, fibrofatty tissue was seen in the intercondylar notch and the ACL could not be identified. The articular surfaces of both tibia and femur showed severe degeneration and the lateral meniscus was detached anteriorly. This was reattached with sutures and an excisional biopsy was performed. Histological examination of this tissue showed evidence of neurofibromatosis with involvement of synovial tissue (Fig. 3). The immunohistochemical stain for S-100 protein was positive in these cells (Fig. 4).

The knee remained unstable and a knee brace was applied.

Discussion

Neurofibromatosis rarely affects a joint and infiltration of the knee with pathological tissue has not previously been reported. In this case the disease had affected the ACL, the nerve fibres of the synovial tissue and the longitudinal growth of both tibia and femur causing discrepancy in length and severe instability of the joint. Detachment of the lateral meniscus occurred, and there were early osteoarthritic changes due to complete absence of a sense of pain in the knee.

Infiltration of a joint and its structures by tissue associated with neurofibromatosis has been described in association with dislocation of the hip in children.8,14-16 This was accompanied by bony changes including narrowing of the neck of the femur, acetabular dysplasia, erosion of the acetabulum and deformities of the pubis and ischium, all caused by the invasion of neurofibromatosis tissue. McCann et al18 have described an adult male with neuropathic arthropathy of the knee due to involvement of a spinal nerve by neurofibromatosis leading to an insensitive knee.

In our patient there was a slow, progressive development of neuropathic arthropathy caused by destruction of the neural proprioceptive defence mechanisms in the knee.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

Received 4 November 1997; Accepted 2 December 1997

References

1. McCarroll HR. Clinical manifestations of congenital neurofibromatosis. J Bone Joint Surg [Am] 1950;32-A:601-17, 626.

2. McFarland B. Pseudarthrosis of the tibia in childhood. J Bone Joint Surg [Br] 1951;33-B:36-46.

3. Maffulli N, Fixsen JA. Pseudarthrosis of the ulna in neurofibromatosis: a report of four cases. Arch Orthop Trauma Surg 1991;110: 204-7.

4. Kameyama O, Ogawa R. Pseudarthrosis of the radius associated with neurofibromatosis: report of a case and review of the literature. J Pediatr Orthop 1990;10:128-31.

5. Kaempffe FA, Gillespie R. Pseudarthrosis of the radius after fracture through normal bone in a child who had neurofibromatosis: a case report. J Bone Joint Surg [Am] 1989;71-A:1419-21.

6. Rajaratnam K, Shanker J, Varughese S. Pseudarthrosis of the ulna due to neurofibromatosis: a case report. Injury 1989;20:239-40.

7. Joseph NK, Bowen JR, MacEwen GD. Unusual orthopaedic manifestations of neurofibromatosis. Clin Orthop 1992;278:17-28.

8. Haga N, Nakamura S, Taniguchi K, Iwaya T. Pathologic dislocation of the hip in Von Recklinghausen's disease: a report of two cases. J Pediatr Orthop 1994;14:674-6.

9. DiSimone RE, Berman AT, Schwentker EP. The orthopedic manifestation of neurofibromatosis: a clinical experience and review of the literature. Clm Orthop 1988;230:277-83.

10. Mandell GA, Harcke HT, Scott CL, et al. Protrusio acetabuli in neurofibromatosis: nondysplastic and dysplastic forms. Neurosurgery 1992;30:552-6.

11. Craigen MA, Clarke NM. Familial congenital pseudoarthrosis of the ulna. J Hand Surg [Br] 1995;20:331-2.

12. Isu T, Miyasaka K, Abe H, et al. Atlanto-axial dislocation associated with neurofibromatosis: report of three cases. J Neurosurg 1983; 58:451-3.

13. Kawabata H, Masada K, Kawai H, Masatomi T. Rupture of the flexor pollicis longus in Von Recklinghausen's disease. J Hand Surg [Am] 1991;16:666-9.

14. Lachiewicz PF, Salvati EA, Hely D, Ghelman B. Pathological dislocation of the hip in neurofibromatosis: a case report. J Bone Joint Surg [Am] 1983;65-A:414-5.

15. Nakasone S, Norimatsu H, Hamasaki N, et al. A case report of recurrent dislocation of the hip joint with neurofibromatosis. Seikeigeka to Saigaigeka 1989;38:511-4.

16. Phillips JE, McMaster MJ. Pathological dislocation of the hip in neurofibromatosis. J R Coll Surg Edinb 1987;32:180-2.

17. Charcot JM. Sur quelques arthropathies qui paraissent dependre d'une lesion du cerveau ou de la moelle epiniere. Arch Physiol Norm Pathol 1868;1:161.

18. McCann PD, Herbert J, Feldman F, Kelly MA. Neuropathic arthropathy associated with neurofibromatosis: a case report. J Bone Joint Surg [Am] 1992;74-A:1411-4.

19. Guidera KJ, Multhopp H, Ganey T, Ogden JA. Orthopaedic manifestations in congenitally insensate patients. J Pediatr Orthop 1990; 10:514-21

20. Bronfen C, Bensahel H, Teule JG. Orthopedic aspects of congenital insesitivity to pain. Chir Pediatr 1985;26:193-6.

21. Abell JM Jr, Hayes JT. Charcot knee dut to congenital insensitivity to pain. J Bone Joint Surg [Am] 1964;46-A:1287-91.

22. Brower AC, Allman RM. Pathogenesis of the neurotrophic joint: neurotraumatic vs neurovascular. Radiology 1981;139:349-54.

23. Johnson JTH. Neuropathic fractures and joint injuries: pathogenesis and rationale of prevention and treatment. J Bone Joint Surg [Am] 1967;49-A:1-30.

24. Resnick D. Neuroarthropathy. In: Resnick D, Niwayama G, eds. Diagnosis of bone and joint disorders. 2nd edition. Vol. 5, Philadelphia: W. B. Saunders Co,1988:3155-85.

25. Tachdjian MO. Neuropathic joint disease. Pediatric orthopedics. 2nd edition. vcl 2 Philadelohia W R. Saunders I99fl519-4

F. Lokiec, MD, Senior Orthopaedic Surgeon

R. Arbel, MD, Senior Orthopaedic Surgeon

S. Wientroub, MD, Professor and Head

Department of Paediatric Orthopaedics, Dana Children's Hospital, TelAviv Medical Centre, 6 Weizmann Street, 64239 Tel-Aviv, Israel. J. Isakov, MD, Senior Pathologist

Institute of Pathology and Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

Correspondence should be sent to Professor S. Wientroub.

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