---

- See:
      - Boutonniere Injuries - Menu
      - Thumb Boutonniere Deformity

- Discussion:
    - rheumatoid boutonniere deformity begins w/ PIP synovitis & elongation capsule;
    - inflammation leads to lengthening of central extensor slip and triangular ligament (becoming dysfunctional) and volar displacement of the lateral bands (which leads to subsequent contracture of transverse retinacular fibers);
    - later there is attenutation of central slip & triangular ligament to allow volar subluxation of lateral bands;
            - lateral bands then become flexors of PIP joint;

- Stage 1:
    - 10-15 deg flexion deformity & extensor lag of PIP joint is passively correctable;
    - as PIP joint deformity is corrected, limited flexion of DIP will be noted;
    - consider dynamic splinting, & lateral band reconstruction (relocation dorsal to axis of rotation);
    - consider terminal extensor tendon tenotomy to improve DIP flexion;
            - this procedure is based on idea that oblique retinacular ligament acts to extend the DIP joint;

- Stage 2:
    - moderate deformity (PIP flexion deformity 30-40 degrees, flexible joint, preservation of joint space on X-ray);
    - pts w/ this deformity may compensate w/ MCP joint hyperextension;
    - terminal extensor tendon tenotomy to allow DIP flexion;
    - consider synovectomy;
    - central slip reconstruction and shortening;
    - lateral band reconstruction w/ release of transverse retinacular ligament;
    - postoperatively, PIP is held in extension w/ a K wire for 3 weeks;

- Stage 3:
    - fixed deformity w/ retinacular ligament tightness;
    - contracture and tightness of ORL and TRL;
    - deformity:
           - ORL: maintains DIP extension, blocks flexion;
           - TRL: maintains volar subluxation of lateral bands, PIP flexion
    - these patients may or may not feel that they have a functional deficit;
           - be careful to replace a functional flexion contracture with a poorly functioning stiff extended finger;
    - treatment spinting to restore PIP to full passive extension (may require serial casting);
           - active and passive ORL stretching, proceed as in stage II when the PIP is fully extended;
           - no reconstructive procedures should be tried, until passive ROM is restored;
    - if there is loss of articular cartilage, consider fusion for this deformity;

- Arthoplasty;
    - indicated for painful & stiff joint w/ x-ray evidence of joint destruction;
    - for deformities of more ulnar PIP joints;
    - PIP joint of the index finger does better w/ fusion in 20 to 40 deg flexion;
          - more stable index finger can be used in pinch and the more flexible middle finger can be used in grasp

---

Reference

Surgical treatment of the boutonniere deformity in rheumatoid arthritis.