A comprehensive analysis of the pre- and postoperative responses to each of the 12 Oxford knee score questions one year following knee arthroplasty.

AIMS: To assess the pre- and postoperative responses to each of the 12 individual Oxford Knee Score (OKS) questions and percentages of those that were better, same or worse after primary knee arthroplasty (KA). METHODS: A single centre retrospective cohort study conducted over a 24-month period which included 3259 patients with completed OKS preoperatively and 1-year after KA. There were 1286 males and 1973 females, with an overall mean age of 70.0 (range 34-94). The mean scores for each question of the OKS were compared between baseline and 1-year. The percentage of patients who reported better, the same or worse postoperative symptoms for each question were calculated and represented on a heatmap. RESULTS: There were significant (p < 0.001) improvements in all 12 questions, all of which demonstrated moderate (Q2, Q7) or large effect sizes. Improvements in individual question responses varied. Symptoms of pain and limping demonstrated the greatest improvement, with 86% of patients enjoying a positive change in their symptoms. Despite this improvement 1067 (41.4%) continued to have mild to severe pain in their knee, and 442 (17.3%) patients limped often to all the time when walking postoperatively. Whereas other questions that did not improve to the same extent for example washing and drying only improved in 53% of patients but only 347 (13.5%) had moderate/extreme trouble or found it impossible to do this postoperatively. Preoperatively four questions (Q1, Q6, Q7, Q8) demonstrated floor effects, postoperatively all questions apart from question 7 (kneeling) demonstrated ceiling effects. CONCLUSION: The mean improvement and outcome at 1-year for each of the 12 questions varied according to the patient's preoperative response. As a clinical tool, the heatmap (improvement, same and worse) will enable communication to patients about their potential change in their knee specific symptoms according to their preoperative responses. LEVEL OF EVIDENCE: Retrospective study, Level III.

The Oxford Knee Score is a reliable predictor of patients in a health state worse than death and awaiting total knee arthroplasty.

BACKGROUND: The health-related quality of life of patients awaiting a total knee arthroplasty (TKA) deteriorates with increasing time to surgery and identification of those with the worst quality of life may help to prioritize patients. The aims were to identify and validate independent variable(s) associated with a health state worse than death (WTD) in patients awaiting a TKA and whether these variables influenced patients-reported outcome measures. METHODS: A retrospective cohort of 5857 patients undergoing a primary TKA was identified from an established arthroplasty database. Patient demographics, body mass index (BMI), index of multiple deprivation, Oxford Knee Score (OKS), EuroQoL five dimension (EQ-5D) 3 level, and visual analogue scale (EQ-VAS) were collected preoperatively and one year postoperatively. An EQ-5D utility of less than zero was defined as WTD. A randomly selected subset of patients (n = 3076) was used to validate the variable that was most predictive of a state WTD and to assess the influence on patient-reported outcomes. RESULTS: There were 771 (13.2%) patients with a health state WTD. Increasing social deprivation (P = 0.050), worse preoperative OKS (P < 0.001), or EQ-VAS (P < 0.001) were independently associated with a health state WTD. The OKS was the most reliable predictor (area under curve 88.9%, 95% CI 87.8 to 90.1, P < 0.001) of a health state WTD. A threshold value of 16 or less, 80% sensitive and specific, was validated and confirmed to have a negative predictive value of 97.5%. Patients with an OKS of 16 or less had a significantly greater improvement in their OKS (difference 6.9, P < 0.001) and EQ-5D score (difference 0.257, P < 0.001). When adjusting for confounding factors, a health status WTD was not associated with worse postoperative OKS (difference -0.6, 95% CI -1.4 to 0.3, P = 0.177), EQ-5D (difference -0.016, 95% CI -0.036 to 0.003, P = 0.097) or patient satisfaction (difference -1.8, 95% CI -4.3 to 0.7, P = 0.162). CONCLUSION: A threshold score 16 or less in OKS was a reliable predictor of a health status WTD and was associated with a greater improvement in knee-specific and health-related quality of life following TKA.

Clinically insignificant association between anterior knee pain and patellofemoral lesions which are found incidentally.

BACKGROUND: Patellofemoral chondral lesions are frequently identified incidentally during the arthroscopic treatment of other knee pathologies. A role has been described for arthroscopic debridement when symptoms are known to originate from pathology of the patellofemoral joint. However, it remains unclear how to manage lesions which are found incidentally whilst tackling other pathologies. The purpose of this study was to establish the strength of association between anterior knee pain and patellofemoral lesions identified incidentally in a typical arthroscopic population. METHODS: A consecutive series of patients undergoing arthroscopy for a range of standard indications formed the basis of this cross section study. We excluded those with patellofemoral conditions in order to identify patellofemoral lesions which were solely incidental. Pre-operative assessments were performed on 64 patients, where anterior knee pain was sought by three methods: an annotated photographic knee pain map (PKPM), patient indication with one finger and by palpated tenderness. A single blinded surgeon, performed standard arthroscopies and recorded patellofemoral lesions. Statistical correlations were performed to identify the association magnitude. RESULTS: Associations were identified between incidental patellofemoral lesions and tenderness palpated on the medial patella (P = 0.007, χ(2) = 0.32) and the quadriceps tendon (P = 0.029, χ(2) = 0.26), but these associations were at best fair, which could be interpreted as clinically insignificant. CONCLUSION: Incidental patellofemoral lesions are not necessarily associated with anterior knee pain, we suggest that they could be left alone. This recommendation is only applicable to patellofemoral lesions which are found incidentally whilst addressing other pathology.

The relationship between quadriceps angle and tibial tuberosity-trochlear groove distance in patients with patellar instability.

PURPOSE: The quadriceps angle (Q-angle) represents the angle between the vector of action of the quadriceps and the patellar tendon. An increased Q-angle has been associated with an increased risk of patellar instability, although there is disagreement on its reliability and validity as it is affected by the position of the limb and contraction of the quadriceps. Tibial tuberosity-trochlear groove distance (TT-TG) is ascertained by axial CT scanning, with an increased value associated with patellar instability. This study aimed to determine whether the Q-angle correlates with the TT-TG distance in patients with patellar instability. METHODS: Q-angles were measured in 34 knees that had previously undergone CT scanning for assessment of patellar instability. Measurements were made with the patient supine, the knee extended and the lower limbs in neutral rotation with the quadriceps relaxed and contracted. TT-TG distance was measured on CT scanning in an identical position. RESULTS: Of the 34 knees measured, 24 had symptoms of patellar instability, and 10 were normal. A significant negative correlation between relaxed Q-angle and TT-TG in all knees was demonstrated (p = 0.028). In symptomatic knees, contracted Q-angle also demonstrated a significant negative correlation with TT-TG (p = 0.037). CONCLUSIONS: If TT-TG distance is regarded as the gold standard measurement, Q-angle is not a reliable indicator of patellar instability. There is a clear need to develop methods to more fully characterise the knee and factors contributing to patellar instability. LEVEL OF EVIDENCE: II.