Article
Localized and adaptive synoviocyte proliferation characteristics in rat knee joint contractures secondary to immobility 1☆,

https://doi.org/10.1016/S0003-9993(03)00233-8Get rights and content

Abstract

Trudel G, Jabi M, Uhthoff HK. Localized and adaptive synoviocyte proliferation characteristics in rat knee joint contractures secondary to immobility. Arch Phys Med Rehabil 2003;84:1350–6.

Objective: To investigate the proliferative activity of synoviocytes in joint contracture.

Design: Experimental controlled trial.

Setting: Laboratory in vivo study.

Animals: Adult male Sprague-Dawley rats (avg weight, 340g).

Interventions: Not applicable.

Main Outcome Measures: We immobilized the knee joints of 24 rats, in 135° of flexion, for up to 32 weeks. Controls were 24 sham-operated and 5 unoperated rats. On sagittal sections, synoviocytes that stained with a proliferating cell nuclear antigen antibody were counted over the anterior and posterior synovial intima. The length of the synovial intima was also measured.

Results: The absolute number of proliferating synoviocytes decreased markedly in the posterior capsule of knee joints immobilized for more than 2 weeks (2.4±1.0 vs 22.7±7.1 at week 16, P<.05), and so did the synovial intima length (1.4±0.1mm vs 8.6±0.5mm at week 16, P<.05). No change occurred anteriorly.

Conclusion: A decreased number of proliferating synoviocytes and increased intima adhesion in the posterior capsule characterized joint contractures. The data further suggest that the synovial intima adapted to the new position of the joint. Phenomena of mechanotransduction could explain the fact that adaptations were restricted to the posterior synovial intima.

Section snippets

Methods

The protocol for this experiment was approved by the University Animal Care Committee. Sixty-two adult male Sprague-Dawley rats, average weight 340g, were used. Seven immobilized and 7 sham-operated animals formed a 1-time cohort. Four-time cohorts were observed relative to the time after intervention, and they were 2, 4, 16, and 32 weeks. In addition, 9 knees from 5 rats had no intervention and were used to distinguish the effect of the surgery.

Results

The histochemical and immunohistologic methods provided a clear distinction of both (1) the boundary between synovial intima and subintima and (2) the synoviocytes staining and those not staining with the anti-PCNA antibody (fig 1). Nine animals were excluded due to fracture, loosening of the screws, or infection. One animal was added to replace 1 excluded animal (time, 32wk). The final number of joints was 24 each in the immobilized and sham-operated groups and 9 in the nonoperated group Table

Discussion

Suppression of mobility around a joint causes a contracture. The prominent pathophysiologic hypothesis to explain the capsule stiffness and cartilage degeneration in contractures has assumed pannus proliferating and invading the intra-articular space.15, 16, 17, 18, 19, 20, 21 Our first histomorphometric study of contractured joints challenged this hypothesis: neither capsule thickening nor pannus was found.26 Therefore, measuring synoviocyte proliferation became a key to investigating the

Conclusion

Joint contracture is not a proliferative disease in nature. It is characterized by decreased synoviocyte proliferation and by synovial intima adhesion in contractured parts of the joint. Furthermore, we showed that these characteristics are adaptive to the imposed mechanical conditions. The completely different responses of synoviocytes and intima, based on their location in the joint, are novel and contribute conceptual advances to the pathophysiology and therapeutics of joint contractures.

Acknowledgements

We thank Clare Booth for her expert technical assistance, Dorothyann Curran for her help with the statistical analysis, and Drs David Jackson and Odette Laneuville for their review of the manuscript.

References (45)

  • R.R. Campbell et al.

    Limited joint mobility in diabetes mellitus

    Ann Rheum Dis

    (1985)
  • E.M. Eekhoff et al.

    Flexion contractures associated with a malignant neoplasm‘a paraneoplastic syndrome?’

    Clin Rheumatol

    (1998)
  • R.M. Braun et al.

    Treatment of shoulder deformity in acquired spasticity

    Clin Orthop

    (1999)
  • G.M. Yarkony et al.

    Contractures complicating spinal cord injuryincidence and comparison between spinal cord centre and general hospital acute care

    Paraplegia

    (1985)
  • M. Dalyan et al.

    Factors associated with contractures in acute spinal cord injury

    Spinal Cord

    (1998)
  • K. Tanaka et al.

    Autosomal dominant limb-girdle muscular dystrophy with ankle joint contracture

    Acta Neurol Scand

    (1999)
  • M.S. Gilbert et al.

    Management of fixed flexion contracture of the elbow in haemophilia

    Haemophilia

    (1999)
  • M.T. Hu et al.

    Limb contractures in levodopa-responsive parkinsonisma clinical and investigational study of seven new cases

    J Neurol

    (1999)
  • L. Jacobson et al.

    Plasma from human mothers of fetuses with severe arthrogryposis multiplex congenita causes deformities in mice

    J Clin Invest

    (1999)
  • R.A. Bank et al.

    Defective collagen crosslinking in bone, but not in ligament or cartilage, in Bruck syndromeindications for a bone-specific telopeptide lysyl hydroxylase on chromosome 17

    Proc Natl Acad Sci U S A

    (1999)
  • E.M. Halar et al.

    Immobility. Physiological and functional changes and effects of inactivity on body functions

  • K.M. Means

    Rehabilitation of joint contractures

    • Cited by (0)

    ☆

    Supported in part by the physicians of Ontario through The PSI Foundation and The Royal Ottawa Health Care Foundation.

    1

    No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.

    View full text
    Copyright © 2003 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.