Results

Descriptives

The meniscus videos contained 19 patients aged 19–46 years (32% female). Nine patients (47%) had a medial meniscal tear (Table 1). There were 12 posterior meniscal tears, 6 posterior-body tears, and one tear located at the body. There were no anteriorly located meniscal tears. The location and type of each individual meniscal tear are presented in Table 2.

Characteristic | Baseline value
Age, median (range) | 31 (19/46)
Sex, female, n (%) | 6 (32)
Left knee, n (%) | 7 (37)
Type of surgery performed
APM, n (%) | 9 (47)
Meniscal repair, n (%) | 6 (32)
APM and meniscal repair, n (%) | 4 (21)
Meniscal tear type
Bucket handle, n (%) | 3 (17)
Bucket handle complex, n (%) | 1 (5)
Complex: longitudinal + horizontal + flap, n (%) | 1 (5)
Degenerative with flaps, n (%) | 1 (5)
Degenerative complex, n (%) | 1 (5)
Flap, n (%) | 5 (26)
Horizontal, n (%) | 1 (5)
Horizontal complex, n (%) | 1 (5)
Longitudinal, n (%) | 3 (17)
Longitudinal with flap, n (%) | 1 (5)
Radial, n (%) | 1 (5)
Location of meniscal tear, medial, n (%) | 9 (47)

Case # | Meniscal tear type | Medial/lateral meniscal tear | Location of meniscal tear | Cooper classification | Meniscal surgery performed
1 | Complex: longitudinal + horizontal + flap | Lateral | Posterior | F2-3 | APM
2 | Flap | Medial | Posterior | A2-3 | APM
3 | Bucket-handle | Lateral | Body-posterior | EF1 | APM
4 | Longitudinal | Lateral | Posterior | F2 | APM
5 | Bucket-handle | Lateral | Posterior | F0-1 | Meniscal repair
6 | Horizontal | Lateral | Posterior | F1-3 | Meniscal repair and APM
7 | Bucket-handle complex | Medial | Body-posterior | AB1 | Meniscal repair
8 | Horizontal complex | Lateral | Body-posterior | EF2-3 | Meniscal repair and APM
9 | Longitudinal | Medial | Posterior | A0-1 | APM
10 | Flap | Medial | Body-posterior | AB2-3 | APM
11 | Degenerative with flaps | Medial | Posterior | A3 | APM
12 | Bucket-handle | Lateral | Posterior | F1 | APM
13 | Flap | Medial | Body | B3 | Meniscal repair
14 | Degenerative complex | Medial | Posterior | A3 | APM
15 | Flap | Lateral | Posterior | F3 | Meniscal repair
16 | Radial | Lateral | Body-posterior | EF2-3 | Meniscal repair
17 | Flap | Medial | Posterior | A2-3 | Meniscal repair and APM
18 | Longitudinal | Medial | Posterior | A0-1 | Meniscal repair and APM
19 | Longitudinal with flap | Lateral | Body-posterior | EF2-3 | Meniscal repair

In total, 27 orthopaedic knee surgeons from 17 different institutions (general hospitals, academic institutes, and private clinics) in The Netherlands and from one hospital in Sweden reviewed the meniscus videos. They had a median of 12 years of experience (range 1–32 years). Two surgeons only rated 18 meniscus videos, and another orthopaedic surgeon only rated 17 of the 19 meniscus videos as they felt unable to judge the meniscal tear shown. We observed much variation in the willingness-to-randomize between orthopaedic surgeons. For some meniscal tears, the choice of meniscal surgery was fairly consistent among surgeons. Results of the ratings for all three outcomes are shown in Table 3.

 | Willingness-to-randomize | Choice of meniscal surgery | Preferred treatment: Conservative
Case # | Yes | No | APM | Repair | No surgery | Yes | No
1 | 15 | 12 | 18 | 5 | 4 | 14 | 13
2 | 4 | 23 | 26 | 1 | 0 | 4 | 23
3 | 16 | 11 | 5 | 22 | 0 | 2 | 25
4 | 21 | 6 | 4 | 20 | 3 | 7 | 20
5 | 7 | 19 | 0 | 26 | 0 | 0 | 26
6 | 24 | 3 | 8 | 10 | 9 | 22 | 5
7 | 15 | 12 | 8 | 19 | 0 | 0 | 27
8 | 22 | 5 | 17 | 5 | 5 | 15 | 12
9 | 11 | 16 | 0 | 24 | 3 | 9 | 18
10 | 11 | 15 | 24 | 2 | 0 | 9 | 17
11 | 10 | 17 | 14 | 2 | 11 | 23 | 4
12 | 24 | 3 | 3 | 22 | 2 | 8 | 19
13 | 7 | 19 | 16 | 1 | 9 | 23 | 3
14 | 12 | 15 | 18 | 6 | 3 | 19 | 8
15 | 19 | 8 | 2 | 21 | 4 | 13 | 14
16 | 16 | 10 | 10 | 16 | 0 | 6 | 20
17 | 15 | 12 | 20 | 1 | 6 | 21 | 6
18 | 12 | 15 | 0 | 25 | 2 | 10 | 17
19 | 19 | 8 | 22 | 3 | 2 | 16 | 11

Agreement

The Fleiss Kappa for agreement on whether to randomize a meniscal tear was 0.14 (95% CI 0.03–0.26). Agreement for the choice of meniscal surgery (resection/repair/no surgery) was 0.38 (95% CI 0.25–0.51), and for preferred treatment option (conservative treatment vs surgery) 0.29 (95% CI 0.12–0.45).

The kappa coefficients and their CI indicate that the majority of meniscal tears were not consistently rated, in line with observed high variability in judgment between surgeons. The only exception was for meniscal tear cases #6 and #12, where almost all surgeons (n = 24) were willing to randomize the meniscal tear on the video (Fig. 1, Table A1 in Appendix). Although both are lateral posterior meniscal tears in a similar Cooper zone (F1), the performed surgery was for case #6 meniscal repair and APM, while case #12 only had APM. Also, the choice of treatment (APM, meniscal repair or no surgery) for these specific videos varied much across the surgeons (Fig. 2).

Fig. 1: Willingness-to-randomize meniscal tears by orthopaedic surgeons based on the meniscus videos.

Fig. 2: The distribution of the choice of treatment for the 19 included cases.

Although we observed considerable variation between the surgeons in the choice of meniscal surgery, we also noticed that for cases # 5, 9, and 18 the surgeons generally agreed on performing a meniscal repair (Fig. 2). The tears from cases #9 and #18 were very similar, with a longitudinal medial posterior meniscal tear in the vascularized area (red-red zone). Also, the meniscal tear from case #5 was in the red-red zone, although it was a lateral posterior bucket-handle tear. These meniscal tears were surgically treated differently; case #5 had meniscal repair, case #9 had APM, and case #18 had both meniscal repair and APM.

Except for two cases, at least a few orthopaedic surgeons preferred non-surgical treatment over a meniscal surgery based on the meniscal tear shown on the video.