Early death following revision total knee arthroplasty.

All patients from our institution who underwent revision total knee arthroplasty (TKA) or were added to the waiting list for revision TKA between 2003 and 2013 were analysed to describe the timing and degree of excess early surgical mortality. We measured the excess surgical mortality at 90-days for the revision TKA group compared to the waiting list group as 0.37% (95% CI 0.10%-0.65%, p = 0.075). A larger sample size will be required to give a more accurate measurement and thus we encourage other authors with access to larger cohorts to use our methods to quantify excess mortality after revision TKA.

Long-term Outcomes Following Multilevel Surgery in Cerebral Palsy.

BACKGROUND: This long-term consecutive, retrospective single-center cohort study evaluates long-term outcomes of single-event multilevel surgery in diplegic cerebral palsy with respect to functional status, gait, and patient satisfaction. METHODS: All patients with diplegic cerebral palsy who underwent single-event multilevel surgery >10 years previously were included. Retrospective gait assessment was performed using the Edinburgh Visual Gait Score (EVGS) and Gillette Functional Assessment Questionnaire Walking Scale (FAQWS) preoperatively and at midterm postoperative follow-up (median 2.6 y) and prospectively at most recent review [median 18 y, interquartile (IQ) range: 14.4 to 20.5 y]. The Short Form-36 (SF-36) was used prospectively to evaluate outcome compared with population norms for adults from the UK. RESULTS: The complete assessment was possible in 26 of 39 patients who met the inclusion criteria. There was a statistically significant improvement at most recent follow-up compared with the preoperative assessment for EVGS and FAQWS [Wilcoxon Matched Pairs Signed Rank test -4.42 (P<0.0001) and 3.98 (P=0.0001), respectively]. The median Physical Health and Mental Health Component Summary scores for the SF-36 were 43.0 (IQ range: 32.8 to 46.8) and 55.3 (IQ range: 46.1 to 61.1), respectively. CONCLUSIONS: This study demonstrates significant long-term improvements in function, independence and patient satisfaction that continue into adulthood. This will inform discussions with patients and families considering this treatment option. LEVEL OF EVIDENCE: Level IV-Retrospective cohort study.

Early death following revision total hip arthroplasty.

INTRODUCTION: The frequency of primary total hip arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and surgical mortality associated with revision total hip arthroplasty (THA) compared to those on the waiting list. METHODS: All patients from a single institution who underwent revision total hip arthroplasty or were added to the waiting list for the same procedure between 2003 and 2013 were recorded. Mortality rates were calculated at 30 and 90 days following surgery or addition to the waiting list. RESULTS: 561 patients were available for the survivorship analysis in the surgical group. Following exclusion, 901 and 484 patients were available for the 30 and the 90-day analysis in the revision THA waiting list group. 30- and 90-day mortality rates were significantly greater for the revision THA group compared to the waiting list group (excess surgical mortality at 30 days = 0.357%, p = 0.037; odds ratio of 5.22, excess surgical mortality at 90 days = 0.863%, p = 0.045). CONCLUSIONS: Revision total hip arthroplasty is associated with a significant excess surgical mortality rate until 90 days post-operation when compared to the waiting list population. We would encourage other authors with access to larger samples to use our method to quantify excess mortality after both primary and revision arthroplasty procedures.

Retrograde femoral nailing of periprosthetic fractures around total knee replacements.

INTRODUCTION: The incidence of primary total knee replacement (TKR) is increasing with a resultant rise in those patients sustaining distal femoral periprosthetic fractures around TKRs. The management of these fractures pose a significant challenge. The compatibility of retrograde femoral intramedullary (IM) nails with femoral TKR components needs to be considered preoperatively when this complex pathology is addressed. The aim of this study was to update the literature and assess the compatibility of the most commonly used primary TKR prostheses and retrograde femoral IM nails using a Sawbone anatomical model. METHODS AND MATERIALS: Eight of the most commonly used primary TKR prostheses and four of the most commonly used retrograde femoral IM nails were identified. The femoral components of the TKRs were implanted onto left sided femoral Sawbones using the manufacturer's guides and cutting blocks and positioned appropriately. The retrograde IM nails were inserted using the conventional entry point and a nail was deemed compatible if this was possible through the femoral prosthesis. Details of whether a posterior entry point was required to allow insertion, whether the femoral nail was scratched by the femoral TKR prosthesis on insertion and whether excess force was required to insert the retrograde femoral IM nail were recorded. RESULTS: The Biomet AGC Cruciate Retaining (CR) and Posterior Stabilised (PS) TKR were the only prostheses that were compatible with all the nails used. The other TKR prostheses were not compatible because of the force required to gain entry, scratching of the retrograde femoral IM nail or because a posterior entry point was required to gain entry through the intercondylar notch. CONCLUSION: The majority of standard sized retrograde femoral nails are technically feasible for insertion through most femoral TKR components but this study has found that they are not compatible due to excessive force required for insertion, damage to the nail during insertion or the risk of anterior cortex perforation. Further studies are required to update the compatibility table and cadaveric studies would confirm the findings and allow further mechanical testing.

Early death following primary total hip arthroplasty.

This study aims to describe the timing, cause of death, and excess surgical mortality associated with primary total hip arthroplasty when compared to a population awaiting primary total hip arthroplasty. Mortality rates were calculated at cutoffs of 30 and 90 days post-operation or following the addition to the waiting list. Cause of death was recorded from the death certificate. An excess surgical mortality of 0.256% at 30 days (P = 0.002) and 0.025% at 90 days post-operation (P = 0.892), unaffected by age or gender, was seen with myocardial infarction and pneumonia the cause of death in the majority of cases. By using a more appropriate control population, an excess surgical mortality at 30 days post-operation is demonstrated; the effect diminishes at 90 days post-operation.

Relationship of serum markers of cartilage metabolism to imaging and clinical outcome measures of knee joint structure.

BACKGROUND: Biomarkers of cartilage metabolism have prognostic potential. OBJECTIVE: To examine whether serum cartilage biomarkers, cartilage oligomeric matrix protein (COMP), N-propeptide of type IIA procollagen (PIIANP), type II collagen breakdown product (collagen type-II cleavage (C2C)) predict cartilage volume loss and knee joint replacement. METHODS: 117 subjects with knee osteoarthritis (OA) had MRI at baseline and 2 years. Cartilage biomarkers were measured at baseline. Change in knee cartilage volume over 2 years and knee joint replacement over 4 years was determined. The population was divided into subgroups with high or low cartilage biomarkers (based on biomarker levels greater than or equal to, or less than, the mean, respectively). The relationships between biomarkers and outcome measures were examined in the whole population, and separately in marker subgroups. RESULTS: The relationship between cartilage biomarkers and cartilage volume loss was not linear across the whole population. In the low (regression coefficient B=-9.7, 95% CI -0.01 to 0.003, p=0.01), but not high (B=-0.46, 95% CI -8.9 to 8.0, p=0.92) COMP subgroup, COMP was significantly associated with a reduced rate of medial cartilage volume loss (p for difference between groups=0.05). Similarly, in the low (B=-8.2, 95% CI -12.9 to -3.5, p=0.001) but not high (B=2.6, 95% CI -3.3 to 8.5, p=0.38) PIIANP subgroup, PIIANP was associated with a significantly reduced rate of medial volume cartilage loss (p for difference=0.003). C2C was not significantly associated with rate of cartilage volume loss. PIIANP was associated with a reduced risk of joint replacement (odds ratio (OR)=0.28, 95% CI 0.10 to 0.93, p=0.04). CONCLUSION: Cartilage biomarkers may be used to identify subgroups among those with clinical knee OA in whom disease progresses at different rates. This may facilitate our understanding of the pathogenesis of disease and allow us to differentiate phenotypes of disease within a heterogeneous knee OA population.

Markers of bone formation and resorption identify subgroups of patients with clinical knee osteoarthritis who have reduced rates of cartilage loss.

OBJECTIVE: To determine whether serum markers of bone formation and resorption, used individually or in combination, can be used to identify subgroups who lose cartilage volume at different rates over 2 years within a knee osteoarthritis (OA) population. METHODS: Changes in cartilage volume over 2 years were measured in 117 subjects with knee OA using magnetic resonance imaging. We examined relationships between change in cartilage volume and baseline serum markers of bone formation [intact N-terminal propeptide of type I procollagen (PINP) and osteocalcin] and resorption [N-telopeptide of type I collagen (NTX-I), C-telopeptide of type I collagen (CTX-I), and C-telopeptide of type I collagen (ICTP). RESULTS: The baseline markers of bone formation, PINP and osteocalcin (p = 0.02, p = 0.01, respectively), and the baseline markers of bone resorption, CTX-I and NTX-I (p = 0.02 for both), were significantly associated with reduced cartilage loss. There were no significant associations between baseline ratios of bone formation to resorption markers and cartilage loss. However, when subjects were divided into subgroups with high or low bone formation markers (based on levels of marker >or= mean or < mean for the population, respectively), in the subgroup with high PINP there was a significant association between increasing bone resorption markers CTX-I and NTX-I and reduced cartilage loss (p = 0.02, p = 0.001, respectively). Similarly, in the subgroup with high osteocalcin, there was a significant association between increasing CTX-I and NTX-I and reduced cartilage loss (p = 0.02, p = 0.003, respectively). In contrast, in subgroups with low bone formation markers, no significant associations were obtained between markers of bone resorption and cartilage loss. CONCLUSION: Overall, the results suggest that higher bone remodeling (i.e., higher serum levels of bone formation and resorption) is associated with reduced cartilage loss. Considering markers of bone formation and resorption together, it is possible to identify subgroups within the OA population who have reduced rates of cartilage loss.