Hip & Pelvis

That all-important length of stay

With the worry of the potential impending implosion of funding within the majority of developed healthcare systems, and the spectre of rising costs and dramatically rising numbers of patients presenting with neck of femur (NOF) fractures, any intervention that has the added benefit of increased quality and decreased costs is a welcome innovation. Researchers in Rotterdam (the Netherlands) have evaluated the effects the implementation of a new clinical pathway for NOF care has had on hospital length of stay (HLOS). The authors report a retrospective cohort-based study (Level III evidence), examining the HLOS related to the implementation of a new NOF treatment pathway. This before-and-after study included 212 ‘before’ patients and 314 ‘after’ patients. The researchers used the hospitals’ electronic patient records, and recorded demographics, diagnosis, HLOS, mortality, complications and readmissions. There were some slight differences in demographics with a slightly higher intracapsular fracture rate (53% versus 57%) and an increased incidence of treatment with hemiarthroplasty in the ‘after’ cohort. Pertrochanteric fractures remained treated with a gamma nail in the majority of cases in both timeframes. The introduction of a comprehensive care pathway for NOF fracture patients in this series resulted in a decrease from a median of nine to six days HLOS. Within the hemiarthroplasty group itself (which had grown in size considerably) this reduction was less marked although still a significant improvement from a median of nine to seven days. There were no statistically significant differences in HLOS for the internal fixation group although the gamma nails benefited by a median decrease of four days (from ten to six days). There were no significant differences in complications as a whole, although there was a significant decrease in the gamma nail group in readmissions or mortality as a result of the introduction of the care pathway.¹ Care pathways have transformed orthopaedic care for NOF fracture patients, resulting in massive leaps in care. The UK system of incentivised best practice has identified benefits in mortality in addition to the benefits of HLOS outlined here.

Cementless metaphyseal fixation effective in the elderly

The ultra-short metaphyseal-fit hips (mini cementless stems) have risen in popularity over the past decade. With improvements in stem surface treatments and evolution of the prosthesis, the option of improved proximal loading and preservation of bone stock for potential revision surgery offers an attractive option. Despite the enthusiasm of proponents there is a lack of evidence for the use of these stems, particularly in the elderly. Reasoning that the metaphyseal bone may be of poorer quality and less able to provide reliable fixation in the elderly, researchers in Seoul (Korea) have set out to establish (or otherwise) the effectiveness of ultra-short metaphyseal-fitting anatomic cementless stems without diaphyseal fixation in both elderly and younger patients. The researchers designed a prospective cohort study (Level II evidence) to investigate the functional results, bone preservation, complication rates and radiological evidence of fixation for an ultra-short, metaphyseal-fitting anatomic cementless femoral stem. Their impressive comparative case series included 226 arthroplasties performed in 200 patients, divided equally between the younger and older group. The mean age was 43.9 years (31 to 65) in the younger group and 78.9 years (66 to 91) in the older patient group, with follow-up achieved to a mean of around 7.5 years (6 to 9) in both groups. There were no statistically significant differences in functional scores (Harris hip scores 95 versus 91, WOMAC score 11 versus 15, thigh pain incidence or UCLA activity scores 6.5 versus 4.5 points) nor in radiological outcomes between the two groups. Surprisingly, despite the relatively large series, there were no cases of aseptic loosening or adverse ceramic bearing features (clicking, squeaking or fracture).² The authors of this case series have established that this technique is reliable and equally effective in the elderly. Concerns about metaphyseal-fit stems in elderly patients certainly seem to have no founding based on the results presented here.

Mortality trends in over 400,000 total hip replacements

In one of the few orthopaedic publications to grace the pages of the Lancet this year, researchers from Bristol (UK) have performed an important analysis of 409,096 total joint replacements over an eight-year period. The authors comment that although death following planned hip replacement is rare, these deaths, following planned procedures where there is appropriate pre-operative assessment and which are undertaken in a controlled elective environment, are likely avoidable. They used the data collated as part of the National Joint Registry for England and Wales to establish if death caused by hip replacement has reduced in frequency and what, if any, modifiable peri-operative factors exist that could reduce deaths. The study includes all patients who underwent total hip replacement in England and Wales between April 2003 and December 2011. The primary endpoint was death within 90 days of the study using data linkage between the National Joint Registry and the Hospital Episode Statistics data. The investigators used Kaplan-Meier analysis and Cox proportional hazards modelling to establish linkage between comorbidities, peri-operative factors and death. This study is likely the largest population study of peri-operative patients of any variety and includes data on 409,096 patients, all undergoing primary hip replacements for osteoarthritis. There were 1743 deaths within 90 days of surgery. There was a significant decrease in death during the eight years of the study from 0.56% to 0.29% and this difference remained after adjustment for age, sex, and comorbidity. The authors identified a number of factors associated with lower mortality: posterior surgical approach (hazard ratio [HR] 0.82, 95% CI 0.73 to 0.92) mechanical thromboprophylaxis (HR 0.85, 95% CI 0.74-0.99), chemical thromboprophylaxis (HR 0.79, 95% CI 0.66 to 0.93), and spinal versus general anaesthetic (HR 0.85, 95% CI 0.74 to 0.97).³ While the authors conclude that “several modifiable clinical factors were associated with decreased mortality according to an adjusted model” and that “widespread adoption of four simple clinical management strategies (posterior surgical approach, mechanical and chemical prophylaxis, and spinal anaesthesia) could, if causally related, reduce mortality further”, they do seem to have forgotten slightly how the data have been collected. By definition there is selection bias in large registry studies like this. A posterior approach is in general performed by high volume hip surgeons, raising the question: is it the approach or the skill of the surgeon affecting death rates? Similarly, anaesthetists tend to select an anaesthesia method based on patient-related factors. While the authors have adjusted for age and co-morbidity based on HES data, we do know that population-level billing data is not always an accurate method of assessing clinical co-morbidity. We commend the authors for their powerful study here at 360 but we won’t be condemning surgeons using differing surgical approaches just yet.