Does severe osteoarthritis in knees with varus deformity alter the adductor ratio?

Abstract

ObjectiveIn our retrospective study, we aimed to investigate the differences between the adductor ratio (AR) in knees with and without osteoarthritis, and its validity in determining the articular level.MethodsData from 80 knees of 80 patients were retrospectively evaluated. Anteroposterior weight-bearing knee radiographs of the patients with and without osteoarthritis (40 knees in each group) were obtained. The adductor ratio was determined using the following formula: ATJL/FW (adductor tubercle-joint line distance/femoral width). All radiographs were evaluated at the baseline and at one-month intervals afterwards. Intraobserver reliability of the two measurements was assessed using interclass correlations (ICC). Pearson's correlation test was used to evaluate the correlation between the ATJL and the FW. The differences between the adductor ratios of the two groups were evaluated by the independent samples two-tailed t-test.ResultsMost of the ICC values were well above 0.95, indicating a very high intraobserver reliability. The adductor ratio was significantly greater in Group 2 in comparison to Group 1 (Mean AR in Group 2: 0.522 ± 0.031 and Mean AR in Group 1: 0.502 ± 0.032; p = 0.005). There was a significant correlation between the ATJL and FW in the groups when assessed both separately and combined.ConclusionIn conclusion, we can assert that if the AR is used to determine the articular level in revision arthroplasty cases, it may be sensible to measure the FW intraoperatively rather than measuring it on primary or contralateral radiographs of arthritic patients.Level of evidenceLevel III, Diagnostic study.

The reliability of adductor tubercle as an anatomical landmark for joint line restoration in revision knee arthroplasty: a systematic review

“…A total of 13 papers (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21), published between 2013 and 2019, were included in the present review (Figure 1). Qualitative data synthesis is presented in Table 1.…”

“…Only three papers (10,11,20) reported the power analysis performed to calculate the sample size of radiographic exams/patients to be included. Anyway, based on the significant results achieved, it is reasonable to assume that all trials included a sufficient sample size.…”

“…With regard to the number of observers, in two studies just one observer performed the measurements (12,20), in other two studies (11,17) there is no mention on the number of observers. In ten studies (9,10,(12)(13)(14)(15)(16)18,19,21) observers were independent from each other.…”

“…(11,13,14,16,17). Intra-and inter-observers reliability data were reported in 11 out of 13 studies (9-11, [13][14][15][16][18][19][20][21].…”

“…Boya et al (20) in 2017 analyzed 80 patients, 40 with and 40 without knee OA: the authors raised the problem of JL narrowing, which is a common feature in knees with severe OA: AR was significantly greater in the non-arthritic group in comparison to the arthritic group on plan radiographs. Therefore, they suggest that, in case of advanced OA, surgeons should remove the medial and lateral femoral osteophytes before measuring the FW.…”