Indication for Knee Arthroplasty by Cartilage Analysis
The type of arthroplasty received (TKA, BKA or UKA) could be identified in 87 subjects from OAI database. Of those 87 subjects, 85 (97.7%) underwent TKA and 2 (2.3%) underwent UKA. There were no patients received BKA.
Table 3 shows the results of the relationship between knee components with G5+G6 (greater than 50% + full thickness) cartilage defect and arthroplasty. All three compartments (M+L+PF) were regarded as damaged in 33 subjects and the M+L compartments were damaged in 9 subjects. These 42 (TKA 40; UKA 2) subjects met the indication for TKA. The remaining 45 subjects (M+PF 20; L+PF 14; M 7; and L 4) who received TKA were subsequently assessed with regard to other factors such as ligamentous injuries, bone marrow edema, and subchondral cysts.
Figure 3 shows the optimal arthroplasty as determined by our operative indication in 45 subjects where TKAs were performed for M+PF, L+PF, M, or L compartmental cartilage defect. Four subjects with M+PF cartilage loss (Figure 3(a)) and one case with L+PF cartilage loss (Figure 3(b)) met the indication for TKA. The former included one subject with completely ruptured ACL and three with lateral compartmental factor, while the latter case had completely ruptured ACL and M compartmental factor. The remaining subjects with M+PF and L+PF cartilage loss met the indication for BKA. As shown in Figure 3(c, d), single compartment cartilage loss with G5+G6 demonstrated a total of 4 indications for TKA. The remaining subjects met the indication for partial arthroplasty (BKA or UKA). Two subjects for whom UKA was performed were classified as either M+L+PF or M+L compartmental cartilage loss and considered to meet the indication for TKA (Figure 4b).
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Figure 3.
Rate of optimal arthroplasty in the pattern of cartilage defect involvement for the subjects actually performed TKA; (a) M+PF, (b) L+PF, (c) M, and (d) L compartmental cartilage defect with G5+G6. M: medial, L: lateral, PF: patellofemoral, TKA: total knee arthroplasty, BKA: bicompartmental knee arthroplasty, and UKA: unicompartmental knee arthroplasty.
The constellation of the above results is shown in Figure 4. Among 85 TKA subjects, TKA was indicated for 49 subjects (57.6%), BKA for 31 subjects (36.5%: 17 medial and 14 lateral), and UKA for 5 subjects (5.9%: 4 medial and 1 lateral). Among all 87 subjects, the number (or proportion) of actually performed TKA (n=85, 97.7%) was significantly higher (p<0.001) than that estimated by our surgical indications criteria (n=51, 58.6%). Though there was no subject who underwent BKA, 31 subjects (35.6%) met the indication for BKA. With respect to UKA, 5 subjects (5.7%) who underwent TKA met the indication for UKA and 2 subjects (2.3%) who underwent UKA met the indication for TKA based on MR finding criteria.
(Enlarge Image)
Figure 4.
Differences in rate of optimal arthroplasty for subjects actually performed TKA and UKA. TKA: total knee arthroplasty, BKA: bicompartmental knee arthroplasty, and UKA: unicompartmental knee arthroplasty.
Results
The type of arthroplasty received (TKA, BKA or UKA) could be identified in 87 subjects from OAI database. Of those 87 subjects, 85 (97.7%) underwent TKA and 2 (2.3%) underwent UKA. There were no patients received BKA.
Relationship Between Cartilage Defects and Arthroplasty Received
Table 3 shows the results of the relationship between knee components with G5+G6 (greater than 50% + full thickness) cartilage defect and arthroplasty. All three compartments (M+L+PF) were regarded as damaged in 33 subjects and the M+L compartments were damaged in 9 subjects. These 42 (TKA 40; UKA 2) subjects met the indication for TKA. The remaining 45 subjects (M+PF 20; L+PF 14; M 7; and L 4) who received TKA were subsequently assessed with regard to other factors such as ligamentous injuries, bone marrow edema, and subchondral cysts.
Optimal Arthroplasty Due to the Pattern of Cartilage Defect
Figure 3 shows the optimal arthroplasty as determined by our operative indication in 45 subjects where TKAs were performed for M+PF, L+PF, M, or L compartmental cartilage defect. Four subjects with M+PF cartilage loss (Figure 3(a)) and one case with L+PF cartilage loss (Figure 3(b)) met the indication for TKA. The former included one subject with completely ruptured ACL and three with lateral compartmental factor, while the latter case had completely ruptured ACL and M compartmental factor. The remaining subjects with M+PF and L+PF cartilage loss met the indication for BKA. As shown in Figure 3(c, d), single compartment cartilage loss with G5+G6 demonstrated a total of 4 indications for TKA. The remaining subjects met the indication for partial arthroplasty (BKA or UKA). Two subjects for whom UKA was performed were classified as either M+L+PF or M+L compartmental cartilage loss and considered to meet the indication for TKA (Figure 4b).
(Enlarge Image)
Figure 3.
Rate of optimal arthroplasty in the pattern of cartilage defect involvement for the subjects actually performed TKA; (a) M+PF, (b) L+PF, (c) M, and (d) L compartmental cartilage defect with G5+G6. M: medial, L: lateral, PF: patellofemoral, TKA: total knee arthroplasty, BKA: bicompartmental knee arthroplasty, and UKA: unicompartmental knee arthroplasty.
Differences in Rate of Operative Methods Between Actually Performed and Estimated From MR Images
The constellation of the above results is shown in Figure 4. Among 85 TKA subjects, TKA was indicated for 49 subjects (57.6%), BKA for 31 subjects (36.5%: 17 medial and 14 lateral), and UKA for 5 subjects (5.9%: 4 medial and 1 lateral). Among all 87 subjects, the number (or proportion) of actually performed TKA (n=85, 97.7%) was significantly higher (p<0.001) than that estimated by our surgical indications criteria (n=51, 58.6%). Though there was no subject who underwent BKA, 31 subjects (35.6%) met the indication for BKA. With respect to UKA, 5 subjects (5.7%) who underwent TKA met the indication for UKA and 2 subjects (2.3%) who underwent UKA met the indication for TKA based on MR finding criteria.
(Enlarge Image)
Figure 4.
Differences in rate of optimal arthroplasty for subjects actually performed TKA and UKA. TKA: total knee arthroplasty, BKA: bicompartmental knee arthroplasty, and UKA: unicompartmental knee arthroplasty.
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