We investigated whether a novel, real-time fluoroscopy based navigation system optimized component positioning and leg length in fluoroscopically aided Direct Anterior Approach Total Hip Arthroplasty (DAA-THA). We retrospectively reviewed 75 fluoroscopically assisted DAA-THA performed by a single surgeon: 37 procedures used the software intraoperatively to overlay anteversion, inclination, and leg length information over the existing fluoroscopic radiograph with the aim of enhancing component positioning. The control group consisted of 38 procedures from the single surgeon's patient pool who had undergone non-navigated fluoroscopic assisted DAA-THA one month prior to the system's trial. We used the software to compute each data point on an immediate post operative AP radiograph to replicate the intra operative measurement process. Our results demonstrate that the navigation group measurements were significantly closer to the target numbers with less variation. The mean values were significantly closer to target values anteversion (control: 14°, navigated: 19.1°), inclination (control: 37.7°, navigated: 40.8°) and leg length discrepancy (control: 4.7mm, navigated: 0.1mm). The mean difference from target value were also statistically significant: for anteversion (control: −6.0°, navigated: −0.9°), inclination (control: −2.3°, navigated: 0.8°) and leg length discrepancy (control: 2.7°, navigated: −1.9°). In addition, surgical time was shorter in the navigation group (75.7 vs. 74 minutes; p=0.001). The p values were all statistically significant (anteversion 0.0001, inclination 0.0019, LLD < 0.001 and surgical time 0.001). The real-time feedback and calculations provided by the navigation software provided a reproducible precision for component positioning and leg length measurement during DAA-THA.

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To validate the Modified Forgotten Joint Score (MFJS) as a new patient-reported outcome measure (PROM) in hip and knee arthroplasty (THR/TKR) against the UK's gold standard Oxford Hip and Knee Scores (OHS/OKS).

The MFJS is a new assessment tool devised to provide a greater discriminatory power, particularly in well performing patients. It measures an appealing concept; the ability of a patient to forget about their artificial joint in everyday life.

Postal questionnaires were sent out to 400 THR and TKR patients who were 1–2 years post-op. The data collected from the 212 returned questionnaires was analysed in relation to construct and content validity. 77 patients took part in a test-retest repeatability assessment.

The MFJS proved to have an increased discriminatory power in high-performing patients in comparison to the OHS and OKS, highlighted by its more normal frequency of distribution and reduced ceiling effects. 30.8% of patients (n=131) achieved excellent OHS/OKS scores of 42–48 this compared to just 7.69% of patients who achieved a proportionately equivalent MFJS score of 87.5–100. The MFJS proved to have an increased test-retest repeatability based upon its intra-class correlation coefficient of 0.97 compared to the Oxford's 0.85.

The MFJS provides a more sensitive tool in the assessment of well performing hip and knee arthroplasties in comparison to the OHS/OKS. The MFJS tests the concept of awareness of a prosthetic joint, rather than pain and function and therefore should be used as adjunct to the OKS/OHS.

To validate the Modified Forgotten Joint Score (MFJS) as a new patient-reported outcome measure (PROM) in hip and knee arthroplasty against the UK's gold standard Oxford Hip and Knee Scores (OHS/OKS).

The original Forgotten Joint Score was created by Behrend et al to assess post-op hip/knee arthroplasty patients. It is a new assessment tool devised to provide a greater discriminatory power, particularly in the well performing patients. It measures an appealing concept; the ability of a patient to forget about their artificial joint in everyday life. The original FJS was a 12-item questionnaire, which we have modified to 10-items to improve reliability and missing data.

Postal questionnaires were sent out to 400 total hip/knee replacement (THR/TKR) patients who were 1–2 years post-op, along with the OHS/OKS and a visual pain analog score. The data collected from the 212 returned questionnaires (53% return rate) was analysed in relation to construct and content validity. A sub-cohort of 77 patients took part in a test-retest repeatability study to assess reliability of the MFJS.

The MFJS proved to have an increased discriminatory power in high-performing patients in comparison to the OHS and OKS, highlighted by its more normal frequency of distribution and reduced ceiling effects in the MFJS. 30.8% of patients (n=131) scored 42–48 (equivalent to 87.5–100 in the MFJS) or more in the OKS compared to just 7.69% in the MFJS TKR patients. The MFJS proved to have an increased test-retest repeatability based upon its intra-class correlation coefficient of 0.968 compared to the Oxford's 0.845.

The MFJS provides a more sensitive tool in the assessment of well performing hip and knee arthroplasties in comparison to the OHS/OKS. The MFJS tests the concept of awareness of a prosthetic joint, rather than pain and function and therefore should be used as adjunct to the OKS/OHS.