The aim of the study was to report the survival of open reduction and internal fixation (ORIF) of Vancouver B fractures associated with the Exeter Stem (ES) at a minimum of 5 years.

This retrospective cohort study assessed 129 consecutive patients with Vancouver B type fractures treated with ORIF from 2008-2016 at a minimum of 5 years. Patient records were examined, and the following recorded: details of primary prosthesis, details of injury, Vancouver classification, details of operative management, complications, and requirement for reoperation. Data was analysed using SPSS. Survival analysis was undertaken using the endpoint ‘reoperation for any reason’.

Mean age at fracture was 78.2 (SD10.6, 46-96) and 54 (43%) were female. Vancouver subclassifications were: 24% B1, 70.5% B2 and 5.5% B3. For all Vancouver B fractures, Kaplan Meier analysis demonstrated a 5 year survival free from reoperation of 88.8% (82.0-94.7 95%CI). Fourteen patients required reoperation, most commonly within the first year for non-union and plate fracture (5.4%). Five-year survival for any reoperation differed significantly according to fracture type (p=0.016) and was worst in B1s: B1 76.6% (61.3-91.9); B2 92.6% 986.9-98.3); and 100% of B3. Univariate analysis identified B1 type (p=0.008) and a transverse fracture pattern (p=0.003) to be significantly associated with the need for reoperation.

Adopting a strategy of fixation of all Vancouver B fractures involving the ES where the fracture was anatomically reducible and the bone cement interface was well-fixed was associated with a 5 year survival, free from reoperation of 88.8%.

This study aims to determine the lifetime risk of revision surgery after primary knee arthroplasty (KA).

The Scottish Arthroplasty Project dataset was utilised to identify all patients undergoing primary KA during the period 1998–2019. The cumulative incidence function for revision and death was calculated and adjusted analyses utilised cause-specific Cox regression modelling to determine the influence of patient-factors. The lifetime risk was calculated for patients aged between 45–99 years using multiple decrement lifetable methodology.

The lifetime risk of revision ranged between 32.7% (95% Confidence Interval (CI) 22.62–47.31) for patients aged 45–49 years and 0.63% (95%CI 0.1–4.5) for patients aged over 90 years. Adjusted analyses demonstrated the converse effect of age on revision (Hazard Ratio (HR) 0.5, 95%CI 0.5–0.6) and death (HR 3.5, 95%CI 3.4–3.7). Male sex was associated with increased risks of revision (HR 1.1, 95%CI 1.1–1.2) and death (HR 1.4, 95%CI 1.3–1.4). Patients with inflammatory arthropathy had a higher risk of death (HR 1.7, 95%CI 1.7–1.8), but were less likely to be revised (HR 0.85, 95%CI 0.74–0.98) than those treated for osteoarthritis. Patients with greater number of comorbidities and greater levels of socio-economic deprivation were at increased risk of death, but neither increased the risk of revision.

The lifetime risk of revision knee arthroplasty varies depending on patient sex, age at surgery and underlying diagnosis. Patients aged between 45 and 49 years have a one in three probability of revision surgery within their lifetime. Conversely, patients aged 90 years or over were very unlikely to experience revision.

This study aims to determine satisfaction rates after hip and knee arthroplasty in patients who did not initially respond to PROMs, characteristics of non-responders, and contact preferences to maximise response rates. We performed a prospective cohort study of 709 patients undergoing THA and 737 patients undergoing TKA in a single centre in 2018. EQ-5D health related quality of life score and Oxford Hip/knee scores (OHS/OKS) were completed preoperatively and at 1year postoperatively via post when satisfaction was also assessed. Univariate, multivariate and receiver operator curve analysis were performed.

151/709 (21.2%) hip patients were non-responders, 83 (55.0%) of whom were contactable. 108/737 (14.6%) knee patients were non-responders, 91 (84.3%) of whom were contactable. There was no difference in satisfaction after arthroplasty between initial non-responders and responders for hips (74/81 vs 476/516, p=0.847) or knees (81/93 vs 470/561, p=0.480). Initial and persistent non-response was associated with younger age, higher BMIs and significantly worse preoperative PROMS for both hip and knee patients (p=0.05). Multivariate analysis demonstrated that younger age, higher BMI and poorer pre-operative OHS were independently associated with persistent non-response to hip PROMs (p<0.05). For the entire cohort (n=1352) patients <67 years were less likely to respond to postal PROMs with OR 0.63 (0.558 to 0.711). Using a threshold of >66.4 years predicted a preference for contact by post with 65.4% sensitivity and 68.1% specificity (AUC 0.723 (0.647-0.799 95%CI, p<0.001)).

Most initial non-responders were ultimately contactable with effort. Satisfaction rates were not inferior in patients who did not initially respond to PROMs.

Though knee osteoarthritis (OA) is diagnosed and monitored radiographically, full thickness cartilage loss (FTCL) has rarely been correlated with radiographic classification. This study aims to analyse which classification system correlates best with FTCL and assessing their reliability.

Prospective study of 300 consecutive patients undergoing total knee arthroplasty (TKA) for OA. Two blinded examiners independently graded preoperative radiographs using 5 systems: Kellgren-Lawrence (KL); International Knee Documentation Committee (IKDC); Fairbank; Brandt; and Ahlback. Interobserver agreement was assessed using the intraclass correlation coefficient. Intraoperatively, anterior cruciate ligament (ACL) status and FTCL in 16 regions of interest were recorded. Radiographic classification and FTCL were correlated using the Spearman correlation coefficient.

On average, each knee had 6.8±3.1 regions of FTCL, most common medially. The commonest patterns of FTCL were medial with patellofemoral (48%) and tricompartmental (30%). ACL status was associated with pattern of FTCL (p=0.02). All classification systems demonstrated moderate ICC, but this was highest for IKDC: whole knee 0.68 (95%CI 0.60–0.74); medial compartment 0.84 (0.80–0.87); and lateral compartment 0.79 (0.73–0.83). Correlation with FTCL was strongest for Ahlback (Spearman rho 0.27–0.39) and KL (0.30–0.33), though all systems demonstrated medium correlation. The Ahlback was the most discriminating in severe OA. Osteophyte presence in the medial compartment had high positive predictive value for FTCL, but not in the lateral compartment.

The Ahlback and KL systems had the highest correlation with confirmed cartilage loss. However, the IKDC system displayed best interobserver reliability, with favourable correlation with FTCL in medial and lateral compartments, though less discriminating in severe disease.

Successful return to work (RTW) is a crucial outcome after primary total knee arthroplasty (TKA) in patients under 65 years old. We aimed to determine whether TKA facilitated RTW in patients <65 years, whose intention was to return preoperatively.

We prospectively assessed 106 TKA patients under 65 years over a 1 year period both preoperatively and at 1 year following surgery. Patient demographics were collected including Oxford knee score, Oxford-APQ, VAS pain/health scores and EQ-5D. A novel questionnaire was distributed to delineate pre-operative employment status and post-operative intentions. This included questions on nature of pre and post-operative occupation, whether joint disease affected their ability to work and details of retirement plans and how this was affected by their knee.

69 patients intended to return to work following their TKA. Following arthroplasty, 57/69 patients (82.6%) returned to work at a mean of 16.4 weeks (SD 16.6). Univariate analysis showed significant factors facilitating RTW included, pre-operative oxford knee score, pre-operative Oxford-APQ score and pre-operative EQ-5D score. These were not predictive on multivariate analysis.

This study finds that TKA facilitates return to work in 83% of those who intend to return to work following their surgery. This could have significant positive and health and financial cost implications for the individual, health system and society.

Anterior knee pain (AKP) is the commonest complication of total knee arthroplasty (TKA). This study aims to assess whether sagittal femoral component position is an independent predictor of AKP after cruciate retaining single radius TKA without primary patellofemoral resurfacing.

From a prospective cohort of 297 consecutive TKAs, 73 (25%) patients reported AKP and 89 (30%) reported no pain at 10 years. Patients were assessed pre-operatively and at 1, 5 and 10 years using the short form 12 and Oxford Knee Score (OKS). Variables assessed included demographic data, indication, reoperation, patella resurfacing, and radiographic criteria.

Patients with AKP (mean age 67.0 (38–82), 48 (66%) female) had mean Visual Analogue Scale (VAS) Pain scores of 34.3 (range 5–100). VAS scores were 0 in patients with no pain (mean age 66.5 (41–82), 60 (67%) female). Femoral component flexion (FCF), anterior femoral offset ratio, and medial proximal tibial angle all differed significantly between patients with AKP and no pain (p<0.001), p=0.007, p=0.009, respectively). All PROMs were worse in the AKP group at 10 years (p<0.05). OKSs were worse from 1 year (p<0.05). Multivariate analysis confirmed FCF and Insall ratio <0.8 as independent predictors of AKP (R² = 0.263). Extension of ≥0.5° predicted AKP with 87% sensitivity.

AKP affects 25% of patients following single radius cruciate retaining TKA, resulting in inferior patient-reported outcome measures at 10 years. Sagittal plane positioning and alignment of the femoral component are important determinants of long-term AKP with femoral component extension being a major risk factor.

To investigate predictors of periprosthetic fracture level (around stem (Vancouver B) or distal to stem (Vancouver C/D) in cemented polished tapered femoral stems.

Retrospective cohort study of 188 patients (mean age 79 (range 30–91); 99 (53%) male) with unilateral periprosthetic femoral fractures associated with CPT stems. Medical notes were reviewed and the following recorded: patient demographics, past medical history, drug history, date of prosthesis insertion, and date of injury. Radiographs analysis included Vancouver classification, cement restrictor type, cement mantle to implant tip distance, cortical thickness, femoral diameter and DORR classification. Univariate, multivariate and ROC curve analysis was performed.

Fractures occurred at mean 7.5 years following primary procedure: 152 (83%) were B fractures; and 36 (19%) C/D. On univariate analysis female gender, lower BMI, osteoporosis, NSAID use, Bisphosphonate therapy, cortical thickness, distal cement mantle length and distal cement mantle length:femoral diameter ratio were significantly associated with C level fractures (p<0.05). Distal cement mantle lengths of >19.6mm (AUC 0.688, p<0.001) were associate with C level fractures. Multivariate analysis demonstrated female gender and distal cement mantle length:femoral diameter ratio to be independent predictors of C level periprosthetic fractures.

Though female sex is the largest independent predictor of periprosthetic fractures distal to a CPT femoral stem, the relationship between cortical thickness and distal cement mantle length appears significant. As fractures distal to the stem are invariably managed by ORIF, whereas fractures around the stem frequently require revision arthroplasty, this has relevance at primary surgery in osteoporotic females to reduce the need for complex revisions.

Risk of revision following total knee replacement is relatively high in patients under 55 years of age, but little is reported regarding non-revision outcomes. This study aims to identify predictors of dissatisfaction following TKR in patients younger than 55 years of age.

We assessed 177 TKRs (157 consecutive patients) from 2008 to 2013. Data was collected on age, sex, implant, indication, BMI, social deprivation, range of motion, and prior knee surgery in addition to Oxford Knee Score (OKS) and SF-12 score. Postoperative data included knee range of motion, complications, and OKS, SF-12 score and satisfaction measures at one year.

Overall, 24.9% of patients (44/177) were unsure or dissatisfied with their TKR. Significant predictors of dissatisfaction on univariable analysis (p<0.05) included: Kellgren-Lawrence grade 1/2 osteoarthritis; indication; poor preoperative OKS; postoperative complications; and poor improvements in OKS and pain component score (PCS) of the SF-12. Odds ratios for dissatisfaction by indication compared to primary OA: OA with previous meniscectomy 2.86; OA in multiply operated knee 2.94; OA with other knee surgery 1.7; OA with BMI>40kgm-2 2; OA post-fracture 3.3; and inflammatory arthropathy 0.23. Multivariable analysis showed poor preoperative OKS, poor improvement in OKS and postoperative stiffness, particularly flexion of <90°, independently predicted dissatisfaction (p<0.005).

Patients coming to TKR when under 55 years of age differ from the ‘average’ arthroplasty population, often having complex knee histories and indications for surgery, and an elevated risk of dissatisfaction.

25–40% of unicompartmental knee replacement (UKR) revisions are performed for unexplained pain possibly secondary to elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on cancellous bone strain in a finite element model (FEM) of a cemented fixed bearing medial UKR, validated using previously published acoustic emission data (AE).

FEMs of composite tibiae implanted with an all-polyethylene tibial component (AP) and a metal backed one (MB) were created. Polyethylene of thickness 6–10mm in 2mm increments was loaded to a medial load of 2500N. The volume of cancellous bone exposed to <−3000 (pathological overloading) and <−7000 (failure limit) minimum principal (compressive) microstrain (µ∊) and >3000 and >7000 maximum principal (tensile) microstrain was measured.

Linear regression analysis showed good correlation between measured AE hits and volume of cancellous bone elements with compressive strain <−3000µ∊: correlation coefficients (R= 0.947, R2 = 0.847), standard error of the estimate (12.6 AE hits) and percentage error (12.5%) (p<0.001). AP implants displayed greater cancellous bone strains than MB implants for all strain variables at all loads. Patterns of strain differed between implants: MB concentrations at the lateral edge; AP concentrations at the keel, peg and at the region of load application. AP implants had 2.2 (10mm) to 3.2 (6mm) times the volume of cancellous bone compressively strained <−7000µ∊ than the MB implants. Altering MB polyethylene insert thickness had no effect. We advocate using caution with all-polyethylene UKR implants especially in large or active patients where loads are higher.

Joint registries report that 25–40% of UKR revisions are performed for pain. Proximal tibial strain and microdamage are possible causes of this “unexplained” pain. The aim of this study was to examine the effect of UKR implant design and material on proximal tibial cortical strain and cancellous microdamage.

Composite Sawbone tibias were implanted with cemented UKR components: 5 fixed bearing all-polyethylene (FB-AP), 5 fixed bearing metal backed (FB-MB), and 5 mobile bearing metal backed implants (MB-MB). Five intact tibias were used as controls. Tibias were loaded in 500N increments to 2500N. Cortical surface strain was measured using digital image correlation (DIC). Cancellous microdamage was measured using acoustic emission (AE), a technique which detects elastic waves produced by the rapid release of energy during microdamage events.

DIC showed significant differences in anteromedial cortical strain between implants at 1500N and 2500N in the proximal 10mm only (p<0.001) with strain shielding in metal backed implants. AE showed significant differences in cancellous microdamage (AE hits), between implants at all loads (p=0.001). FB-AP implants displayed significantly more hits at all loads than both controls and metal backed implants (p<0.001). FB-AP implants also differed significantly by displaying AE hits on unloading (p=0.01), reflecting a lack of implant stiffness. Compared to controls, the FB-AP implant displayed 15x the total AE hits, the FB-MB 6x and the MB-MB 2.7x. All-polyethylene medial UKR implants are associated with greater cancellous bone microdamage than metal backed implants even at low loads.

Unicompartmental knee replacements (UKRs) have inconsistent and variable survivorships reported in the literature. It has been suggested that many are revised for ongoing pain with no other mode of failure identified. Using a medial UKR with an all-polyethylene non-congruent tibial component from 2004–7, we noted a revision rate of 9/98 cases (9.2%) at a mean of 39 months. Subchondral sclerosis was noted under the tibial component in 3/9 revisions with well fixed implants, and the aim of this study was to investigate this as a mode of failure. 89 UKRs in 77 patients were investigated radiographically (at mean 50 months) and with SF-12 and Oxford Knee scores at mean follow up 55 months. Subjectively 23/89 cases (25%) had sclerosis under the tibial component. We describe a method of quantifying this sclerosis as a greyscale ratio (GSR), which was significantly correlated with presence/absence of sclerosis (p<0.001). Significant predictors of elevated GSR (increasing sclerosis) were female sex (p<0.001) and elevated BMI (P=0.010) on both univariate and multivariate analysis. In turn, elevated GSR was significantly associated with poorer improvement in OKS (p<0.05) at the time of final follow up. We hypothesise that this sclerosis results from repetitive microfracture and adaptive remodelling in the proximal tibia due to increased strain. Finite element analysis is required to investigate this further, but we suggest caution should be employed when considering all polyethylene UKR implants in older women and in those with BMI >35.