Synovectomy of the knee in rheumatoid arthritis. I. Range of movement and guadriceps lag after surgery

Double blind glucocorticoid controlled trial of samarium-153 particulate hydroxyapatite radiation synovectomy for chronic knee synovitis

BACKGROUND

Samarium-153 particulate hydroxyapatite (Sm-153 PHYP) is a relatively new radiation synovectomy agent developed for the treatment of chronic synovitis. Although it has been shown that the levels of unwanted extra-articular radiation are lower after intra-articular injection of Sm-153 PHYP than yttrium-90 colloid, its clinical efficacy has not been rigorously studied.

OBJECTIVES

To establish whether Sm-153 PHYP radiation synovectomy results in a clinically useful benefit sustained at one year.

METHODS

In a randomised double blind study, patients received either intra-articular 40 mg triamcinolone hexacetonide alone or 40 mg triamcinolone hexacetonide combined with Sm-153 PHYP in an outpatient clinic.

RESULTS

Sixty patients (28 male, 32 female), median age 51 (18-75) with chronic knee synovitis were studied. Diagnoses included: rheumatoid arthritis (n=29); psoriatic arthritis (n=9); ankylosing spondylitis (n=3); reactive arthritis (n=2); undifferentiated seronegative oligoarthritis (n=13) and miscellaneous inflammatory conditions (n=4). More patients who received Sm-153 PHYP/triamcinolone hexacetonide sustained clinical benefit a year after treatment compared with patients who received corticosteroid alone (12 of 31 (39%) v 6 of 29 (21%), a difference of 18% more patients (95% CI -5% to 41%)) though the difference was not significant (chi(2)=2.31, 0.2>p>0.1, n=60). Despite the variation in injected activity (median 563 MBq, range 218-840 MBq), there was no obvious relation between low levels of injected activity (<555 MBq) and relapse within 12 months of treatment (chi(2) =2.61, 0.2>p>0.1, n=31).

CONCLUSIONS

There was no clear beneficial clinical effect of combined Sm-153 PHYP/triamcinolone hexacetonide injection over triamcinolone hexacetonide alone a year after treatment for chronic knee synovitis.

Treatment of rheumatoid arthritis using radiopharmaceuticals

One hundred and twenty one knees in 97 patients with seropositive rheumatoid arthritis and persistent knee synovitis were treated with the intra-articular injection of 270 mCi (30 GBq) of dysprosium-165 (165Dy) bound to ferric hydroxide macroaggregates. Of 81 knees evaluated at one year, 61% had good results, 23% had fair results and 16% had poor results. Of 44 knees evaluated at two years, 64% had good results, 16% had fair results and 20% had poor results. Knees with Stage I radiographic changes showed 72 and 81% good results at one and two years, respectively. Knees and Stage II radiographic changes showed 53 and 48% good results at one and two years, respectively. Leakage of radioactivity from the injected joint was minimal. Mean leakage to the venous blood was 0.15% of the injected dose. Mean leakage to the liver 24 h after injection was 0.64% of the injected dose. Mean leakage to the draining inguinal lymph nodes was 0.17% of the injected dose. These results indicate that 165Dy-ferric hydroxide macroaggregate is an effective agent for radiation synovectomy, particularly in knees with Stage I radiographic changes. The minimal leakage rates observed offer a definite advantage over previously used agents.

Treatment of rheumatoid synovitis of the knee with intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates

One hundred eight knees of 93 patients with seropositive rheumatoid arthritis and persistent synovitis of the knee were treated with an intraarticular injection of 270 mCi of dysprosium 165 bound to ferric hydroxide macroaggregate. Leakage of radioactivity from the injected joint was minimal. Mean leakage to the venous blood 3 hours after injection was 0.11% of the injected dose; this corresponds to a mean whole body dose of 0.2 rads. Mean leakage to the liver 24 hours after injection was 0.64% of the injected dose; this corresponds to a mean liver dose of 3.2 rads. In 7 additional patients examined, there was negligible or near negligible activity found in the draining inguinal lymph nodes. One-year followup was possible for 74 knees (63 patients). Sixty-one percent of the knees had good results, 23% had fair results, and 16% had poor results. There was a direct correlation between the radiographic stage and response to treatment. In knees with stage I radiographic changes, 72% showed good results; 93% showed improvement. In knees with stage II changes, 59% showed good results; 81% showed improvement. These preliminary results indicate that dysprosium 165-ferric hydroxide macroaggregate is an effective agent for radiation synovectomy. The low leakage rates observed offer a definite advantage over agents previously used.

Factors related to extension lag at the knee joint

Twenty patients were examined in an investigation of the relationships between extension lag at the knee and other measures taken from the injured and uninjured extremity. The results of the study show: 1) there were no significant correlations between extension lag and the depth of squat, the extension force or flexion force, the circumference at the joint line or the circumference 5 and 15 centimeters cephalad to the patella pole, and active or passive knee flexion; 2) that the mean for flexion force was greater than the mean for extension force in the injured extremity, and there was no difference between the means for flexion and extension force in the uninjured extremity; and 3) that the means of the measures for active and passive flexion, flexion force, and circumference measures of the thigh taken from a group of patients who had stiff rotational movements at the tibiofemoral joint.were different from the means of the same measures taken from a group of patients who had normal rotational movements. There is limited evidence to suggest that weakness of the quadriceps muscle may be a factor in extension lag at the knee, but the support for this conclusion is based on comparison between groups of patients and not from the correlations between other variables and extension lag. For future studies, it is recommended that an attempt be made to secure patients with extension lags greater than 3Oin an effort to improve the prospect of detecting any relationships.J Orthop Sports Phys Ther 1982;3(4):178-182.