RESUMO
BACKGROUND: In anterior cruciate ligament reconstruction performed using cortical button fixation on the femur, we have observed a "wobble" effect that can occur when a cannulated femoral drill is used over a guide pin that is not securely fixed in bone. Our study assessed the effect of drill "wobble" on femoral tunnel aperture in sawbones. METHODS: Femoral tunnels were drilled in sawbones, which had been divided in two groups of 10 each, per drilling technique. The "wobble" technique group had the smaller cortical button drill passed before drilling the graft socket with the bigger diameter femoral drill. In contrast, in the "non-wobble" technique group, the smaller cortical button drill was passed after drilling the graft socket. The aperture dimensions: antero-posterior, proximo-distal and oblique, as well as the length of each tunnel, were measured. RESULTS: While the average dimensions of the tunnels were similar between the two techniques, there was significantly more variation in the antero-posterior measurements for the wobble technique as compared to the non-wobble technique (mean 7.3 mm, SD 0.28 mm, and mean 7.3 mm, SD 0.11 mm, respectively; Brown-Forsythe test, p 0.02). CONCLUSION: We conclude that using the "socket first" "non-wobble" technique is a single surgical technical step surgeons can employ to decrease variability in tunnel aperture and size.
RESUMO
BACKGROUND: Meniscal tears have been associated with meniscal cysts and fullness of the knee joint line on physical examination. HYPOTHESIS: Joint line fullness is an accurate, sensitive, and specific test to detect meniscal tears. STUDY DESIGN: Prospective cohort study. METHODS: One hundred consecutive patients undergoing knee arthroscopy were included. All had physical examinations documenting the presence of joint line fullness, joint line tenderness, and the McMurray sign. Arthroscopy was the gold standard for tears. Accuracy, sensitivity, and specificity were calculated and correlated with type of tear. Sixty-one patients had a magnetic resonance imaging preoperatively (the gold standard for determining the presence of a cyst). RESULTS: Meniscal tears were found in 67 patients at arthroscopy. The accuracy, sensitivity, and specificity of joint line fullness were, respectively, 73%, 70%, and 82% in detecting meniscal tears; 68%, 87%, and 30% for joint line tenderness; and 47%, 32%, and 78% for the McMurray sign. The highest positive predictive value for detecting a tear was 88% for joint line fullness, compared with 77% for joint line tenderness and 76% for the McMurray sign. However, joint line fullness did not correlate well with the presence of a cyst, with a low positive predictive value (29%). Of those patients with joint line fullness on physical examination, 89% had a horizontal cleavage component of their tear at arthroscopy. CONCLUSION: Joint line fullness is an accurate, sensitive, and specific test to detect meniscal tears. CLINICAL RELEVANCE: The findings support the routine use of joint line fullness during physical examination along with other common tests to improve the accuracy of clinically diagnosing meniscal tears.
