Background: The role of arthroscopic débridement in the
treatment of osteoarthritis of the knee remains to be defined, and few
clinical and radiographic characteristics have been quantitatively associated
with the outcome. The hypothesis of this study was that the outcome of
arthroscopic débridement for osteoarthritis of the knee is associated
with preoperative clinical and radiographic features and intraoperative
characteristics and that there are subsets of patients who are more and less
likely to respond favorably to the treatment.
Methods: We performed a cross-sectional study of a consecutive
cohort of 122 patients who underwent arthroscopic débridement for the
treatment of osteoarthritis of the knee that had been unresponsive to
anti-inflammatory therapy. One hundred and ten patients were followed for a
mean of thirty-four months. Pain was assessed with the pain domain of the Knee
Society scoring system. Radiographs were scored with the Kellgren-Lawrence
method, and limb alignment and the widths of the medial and lateral joint
spaces were measured. The severity of cartilage lesions was scored
intraoperatively with a modified Noyes grading system. Specific methods of
data collection and analysis were incorporated to minimize bias.
Results: Fifty-two (90%) of fifty-eight knees with mild arthritis,
normal alignment, and a joint space width of =3 mm were improved after
arthroscopic débridement. Conversely, only five (25%) of twenty knees
with severe arthritis, limb malalignment, and a joint space width of <2 mm
had substantial relief of symptoms. Of seventy-two patients who had
improvement, forty-four (61%) had it within six months after the arthroscopy.
The severity of the lesion was highly predictive of the clinical outcome both
in patients with mild arthritis and in those with severe arthritis.
Conclusions: The severity of the arthritis, as assessed
preoperatively with radiography and intraoperatively by rating the severity of
cartilage lesions, influences the clinical outcome of arthroscopic
débridement of an osteoarthritic knee. Knees with severe arthritis fare
poorly, whereas those with mild arthritis fare well. We could not predict the
outcome for knees with moderate arthritis. We believe that these observations
are relevant for establishing indications for arthroscopy in patients with
osteoarthritis of the knee and may be useful for designing studies with a more
rigorous experimental design.
Level of Evidence: Prognostic Level II. See Instructions
to Authors for a complete description of levels of evidence.