Table 3 Summary of radiological outcome for each of the studies enrolled in this review.

Zampelis et al (2020) [17]

Inclination, anteversion, rotation, COR

There was a median deviation in postoperative position versus planned in inclination of 3.6° (IQR 1.0 to 5.4)

There was a median deviation in postoperative position versus planned in anteversion of –2.8° (IQR –7.5 to 1.2)

There was a median deviation in postoperative position versus planned in rotation of –1.2° (IQR –3.3 to 0.0)

The median deviation in position of COR was –0.5 mm (IQR –2.9 to 0.7) in the AP plane, –0.6 mm (IQR –1.8 to –0.1) in the ML plane, and 1.1 mm (IQR –1.6 to 2.8) in the SI plane

Tetreault et al (2020) [18]

Knee society radiological evaluation criteria

Follow-up radiographs showed evidence of osseointegration with reactive osseous trabeculation at the interface in 98% (119/122) of unrevised cases

Three unrevised femoral-sided cones were considered radiological failures with evidence of loosening

All four instances of cone loosening occurred in patients with type 2B or 3 defects in the presence of a hinged implant

Durand et al (2020) [19]

COR, component rotation, inclination and version cup angles

All components (100%) were positioned within 10mm of planned COR (in the three planes). Eighteen (95%) components were not rotated by more than 10° compared to plan. Eleven (58%) components were positioned within 5° of planned cup angle (inclination and version)

The mean difference, between planned and achieved, COR was -0.1 mm (95% CI -8.7, 8.6) in the AP plane, -1.4mm (95% CI-7.6, 4.8) in the SI plane and 0.1 mm (95% CI-9.4, 9.5) in the ML plane

The mean deviation of component rotation from planned was 2.2° (-6.4, 10.8)

Planned inclination had a mean of 40.3°(95% CI 29.2,51.5) and 40.5°(95% CI 26.6,54.4) postoperatively, the difference between the planned and postoperative inclination was 0.2°(95% CI -10.2 to 10.7)

The mean planned version was 14.2° (95% CI -3.5, 31.9), version post-operatively was 17.0° (95% CI -0.7, 33.3) with a mean difference between planned and postoperative version of 2.8° (95% CI -10.5, 16.1)

Wan et al (2019) [20]

The DeLee and Charnley zoning method, the bone growth evaluation criteria of the Anderson Orthopaedic Institute

There was no change in displacement and abduction angle in the observation group

None of the patients showed a bright line at the last follow up

Revision failed in one patient, 18 patients had no loosening at 6 months after surgery and 18 patients had continuous trabecular passage at the junction of prosthesis and host bone

Li et al (2019) [21]

Acetabular cup anteversion angle, acetabular cup abduction angle, COR, safe zone

11 of 18 (61.1%) patients were positioned within the safe zone

Percentage of outliers was corrected from 77.78% (14/18) preoperatively to 38.89% (7/18) postoperatively, with statistical significance (p = 0.040)

Ratio of vertical position of COR in surgical site/contralateral site was corrected from 1.15±0.19 to 1.09 ± 0.20 postoperatively (p = 0.185)

Ratio of horizontal position of COR in surgical site/contralateral site was changed from 0.97 ± 0.21 to 1.00 ± 0.18 postoperatively (p = 0.193)

The mean planned cup anteversion value did not differ from the postoperative value (−1.39 ± 4.1; p= 0.168), and a strong correlation was found (r = 0.894; p < 0.001)

There was deviation between the mean planned abduction and the postoperative value (2.24 ± 3.02; p=0.006), but a strong correlation between these two values was found (r=0.921, p< 0.001)

Kieser et al (2018) [22]

Moore criteria, migration of hip center, asymmetrical wear

All other patients had stable implants with evidence of osteointegration. No patients experienced radiographically apparent premature liner wear. The average change in Brooker score, at 2-years, was 0.3 (range 0-3, p=0.090).

Li et al (2016) [23]

Inclination of the cage, COR, component migration

Individualized custom cages resulted in generally reliable restoration of the hip center

The mean vertical distance was 25 mm (SD, 5 mm; range, 19–40 mm) on the revised side and 24 mm (SD, 5 mm; range, 18–40 mm) on the contralateral side (p=0.265)

The mean horizontal distance was 106 mm (SD, 9 mm; range, 90–119 mm) on the revised side and 109 mm (SD, 9 mm; range, 94–123 mm) on the other side (p=0.75)

Radiographic analysis showed the mean inclination of the cage was 46° (SD, 6°; range, 38°–58°)

No definite migration of any of the acetabular cups was observed

Mao et al (2015) [24]

The DeLee and Charnley zoning method, the stability of the cage

22 of the 23 cages (including the re-revision case) were considered stable and without migration based on the radiographic data

The overall incidence of radiolucent lines was 13% (three hips)

In all cases, the radiolucency was partial and nonprogressive, and the lines were<2mm in width

Incorporation of the graft complete in 19 hips. No screw fractures were observed