Accuracy of cup placement compared with preoperative surgeon targets in primary total hip arthroplasty using standard instrumentation and techniques: a global, multicenter study.

BACKGROUND: Acetabular cup positioning in total hip arthroplasty (THA) is closely related to outcomes. The literature has suggested cup parameters defined by the Lewinnek safe zone; however, the validity of such measures is in question. Several studies have raised concerns about the benefits of using the Lewinnek safe zone as a predictor of success. In this study we elected to use prospective surgeon targets as the basis for comparison to see how successful surgeons are positioning their cup using standard instruments and techniques. METHODS: A prospective, global, multicenter study was conducted. Cup positioning success was defined as a composite endpoint. Both cup inclination and version needed to be within 10° of the surgeon target to be considered a success. Radiographic analysis was conducted by a third-party reviewer. RESULTS: In 170 subjects, inclination, target versus actual, was 44.8° [standard deviation (SD 0.9°)] and 43.1° (SD 7.6°), respectively (p = 0.0029). Inclination was considered successful in 84.1% of cases. Mean version, target versus actual, was 19.4° (SD 3.9°) and 27.2° (SD 5.6°), respectively (p < 0.0001). Version was considered successful in 63.4% of cases, and combined position (inclination and version) was considered successful in 53.1%. CONCLUSION: This study shows that with traditional methods of placing the cup intraoperatively, surgeons are only accurate 53.1% of the time compared with a predicted preoperative plan. This study suggests that the inconsistency in cup positioning based on the surgeon's planned target is potentially another important variable to consider while using a mechanical guide or in freehand techniques for cup placement in THA. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03189303.

Associations between presence of diabetes, mortality and fracture type in individuals with a hip fracture.

AIMS: An overlooked aspect of diabetes is an increased risk of hip fractures, with associated mortality. We investigated whether fracture type and/or burden of comorbidities explains the increased risk of mortality in diabetes after hip fracture. METHODS: For this cohort study, we used a de-identified data set of hip fracture patients registered in a quality-of-care registry (2017/2018) included in Maastricht University Medical Centre. RESULTS: Among 594 hip fracture patients, 90 (15.2 %) had diabetes. Median (IQR) age was 82 (71-87) years and 63.8 % were women. Compared to patients without, patients with diabetes had higher median Charlson Comorbidity Index [1 (0-2) vs 0 (0-2), P < 0.001)] and were more likely to sustain intertrochanteric/subtrochanteric fractures [54.4 vs 38.7 %, P = 0.02]. Over a median follow-up of 2.7 (1.6-3.3) years, crude mortality rate was 30.8 % in patients without and 50.0 % in patients with diabetes. This association remained unaltered after adjustment for age, sex, BMI, fracture type or burden of co-morbidities. CONCLUSION: Individuals with diabetes display a greatly increased absolute mortality risk after hip fracture. This association was not attenuated after adjustment for fracture type or non-diabetes associated co-morbidity. These findings have important implications for diabetes care in hip fracture patients, and underline the importance of fracture prevention.

Failure Mode Analysis of an Exeter Stem Fracture Initiated at the Introducer Hole: Time for a Design Change?

The fracturing of a hip prosthesis stem at its neck, in the absence of a trauma, is an extremely rare but serious adverse event. The patient in our case was young, active, and tall, thereby putting high mechanical loads on the prosthesis. Radiographs of the initial procedure and blood and synovium analysis showed no abnormalities. Analysis of the stem revealed niobium-rich precipitates, that is, alloy artifacts, at the introducer stud hole. The mechanically vulnerable location of the introducer stud hole, combined with alloy artifacts at that location and high mechanical stress, ultimately led to failure of the prosthesis. As younger and heavier patients will demand hip arthroplasty in the future, simple stem design adaptations should be considered to prevent stem fractures at the introducer stud hole.

Mortality in hip fracture patients after implementation of a nurse practitioner-led orthogeriatric care program: results of a 1-year follow-up.

BACKGROUND: Hip fractures are a major cause of mortality and disability in frail older adults. Therefore, orthogeriatrics has been embraced to improve patient outcomes. With the optimal template of orthogeriatric care still unknown, and to curtail rising healthcare expenditure we implemented a nurse practitioner-led orthogeriatric care program (NPOCP). The objective was to evaluate NPOCP by measuring 3-month and 1-year mortality, compared to usual care (UC). In addition, length of stay (LOS) and location of hospital discharge were reported. METHODS: An anonymised data set, of hip fracture patients (n = 300) who presented to Maastricht University Medical Centre, the Netherlands, a level-1 trauma centre, was used. NPOCP was implemented on one of two surgical wards, while the other ward received UC. Patient allocation to these wards was random. RESULTS: In total, 144 patients received NPOCP and 156 received UC. In the NPOCP, 3-month and 1-year mortality rates were 9.0% and 13.9%, compared to 24.4% and 34.0% in the UC group (P < 0.001). The adjusted hazard ratio (aHR) for 3-month (aHR 0.50 [95%CI: 0.26-0.97]) and 1-year mortality (aHR 0.50 [95%CI: 0.29-0.85]) remained lower in NPOCP compared to UC. Median LOS was 9 days [IQR 5-13] in patients receiving UC and 7 days [IQR 5-13] in patients receiving NPOCP (P = 0.08). Thirty-eight (27.5%) patients receiving UC and fifty-seven (40.4%) patients receiving NPOCP were discharged home (P = 0.023). CONCLUSION: Implementation of NPOCP was associated with significantly reduced mortality in hip fracture patients and may contribute positively to high-quality care and improve outcomes in the frail orthogeriatric population.

Survival and reasons for revision of the uncemented Symax hip stem: A Dutch Arthroplasty Register study.

AIMS: Previous studies have already shown early proximal ingrowth, fast osseous integration, and a stable fit of the uncemented Symax hip stem, with excellent clinical and radiographic performance. Aims were to evaluate cumulative revision rates and reasons for revision of the Symax hip stem using Dutch Arthroplasty Register (LROI) data and to assess possible associations between patient characteristics and revision rate of the Symax hip stem. PATIENTS AND METHODS: All total hip arthroplasties with the uncemented Symax hip stem registered in the LROI between 2007 and 2017 were included (n = 5,013). Kaplan-Meier survival analysis was performed to assess the cumulative 1, 5 and 7-year revision percentages. Cox proportional hazard regression analysis was performed to assess the association between patient and procedural characteristics, and revision arthroplasty of the stem. RESULTS: Cumulative 1, 5, and 7-year revision rates (with 95% confidence interval (CI)) for revision of any component were 1.5% (CI 1.2%-1.8%), 3.2% (CI 2.7%-3.7%), and 3.8% (CI 3.1%-4.4%) respectively. Cumulative 1, 5, and 7-year stem revision rates of the Symax hip stem were 0.9% (CI 0.6%-1.1%), 1.5% (CI 1.1%-1.9%), and 1.7% (CI 1.3%-2.1%) respectively. Periprosthetic fractures (n = 35) and loosening of the stem (n = 30) were the most common reasons for revision of the stem. Revision of the stem was associated with acute fracture as primary diagnosis (Hazard Ratio (HR) 2.4 (CI 1.3-4.3)), or history of a previous surgery to the affected hip (HR 2.7 (CI 1.4-5.2)). CONCLUSION: This population-based registry study shows revision rates for the Symax hip stem comparable to those for best performing uncemented total hip arthroplasties in the Netherlands. Primary diagnosis of an acute fracture, and history of previous surgery on the affected hip, were significantly associated risk factors for revision of the Symax hip stem, and we discourage the use of the Symax hip stem in these patients.

Early stabilization of the uncemented Symax hip stem in a 2-year RSA study.

Background and purpose - The uncemented Symax hip stem has shown early proximal ingrowth as result of the BONIT-hydroxyapatite (HA) coating and the distal DOTIZE surface treatment. We evaluated 2-year postoperative radiostereometric analysis (RSA) migration of the Symax hip stem in THA patients. We also investigated the correlation between migration at 4 weeks and clinical outcomes after 2 years.Patients and methods - Patients in a 2-year clinical follow-up single-centre RSA randomized controlled trial were randomized to 2 different cup designs. All 45 patients received a Symax hip stem. RSA migration patterns of the Symax hip stem is presented here as a single cohort. RSA examinations were performed postoperatively, but before weight-bearing, and subsequently after 1, 3, 6, 12, and 24 months. Clinical outcomes and radiographic evaluations were assessed 3, 6, 12, and 24 months postoperatively.Results - During the first 4 weeks, the Symax hip stem subsided, rotated into retroversion, and translated posteriorly, after which the migration ceased and the prosthesis stabilized. All clinical outcomes improved from preoperatively to 2 years. There was no clinically or statistically significant correlation between subsidence and retroversion at 4 weeks and clinical outcomes after 2 years.Interpretation - RSA evaluation of the uncemented Symax hip stem confirms that the design principles and coating properties lead to early stabilization of the stem, as early as 4 weeks postoperatively. There was no correlation between subsidence and retroversion at 4 weeks and clinical outcomes after 2 years. Based on the predictive potential of the RSA technique, we anticipate excellent long-term survival of this hip stem.

Long-term Patient-reported Quality of Life and Pain After a Multidisciplinary Clinical Pathway for Elderly Patients With Hip Fracture: A Retrospective Comparative Cohort Study.

INTRODUCTION: There is an increase in incidence of hip fractures in the ageing population. The implementation of multidisciplinary clinical pathways (MCP) has proven to be effective in improving the care for these frail patients, and MCP tends to be more effective than usual care (UC). The aim of this study was to analyze potential differences in patient-reported outcome among elderly patients with hip fractures who followed MCP versus those who followed UC. MATERIALS AND METHODS: This retrospective cohort study included patients aged 65 years or older with a low-energy hip fracture, who underwent surgery in the Maastricht University Medical Center, Maastricht, the Netherlands. Two cohorts were analyzed; the first one had patients who underwent UC in 2012 and the second one contained patients who followed MCP in 2015. Collected data regarded demographics, patient-reported outcomes (Short Form 12 [SF-12] and the Numeric Rating Scale [NRS] to measure pain), and patient outcome. RESULTS: This cohort study included 398 patients, 182 of them were included in the MCP group and 216 were in the UC group. No differences in gender, age, or American Society of Anesthesiologists classification were found between the groups. No significant differences were found in SF-12 and the NRS data between the MCP group and UC group. In the MCP group, significantly lower rates of postoperative complications were found than in the UC group, but mortality within 30 days and one year after the hip fracture was similar in both groups. DISCUSSION: Although the effects of hip fractures in the elderly on patient-reported outcome, pain and quality of life have been addressed in several recent studies, the effects of MCP on long-term outcome was unclear. CONCLUSION: A multidisciplinary clinical pathway approach for elderly patients with a hip fracture is associated with a reduced time to surgery and reduced postoperative complications, while no differences were found in quality of life, pain, or mortality.

The role of the Fracture Liaison Service (FLS) in subsequent fracture prevention in the extreme elderly.

BACKGROUND: Several guidelines recommend a bone and fall-related osteoporosis risk assessment in all patients with fracture and age > 50 years. In practice, however, there is no consensus whether screening > 85 years is useful. AIM: To evaluate the subsequent fracture risk in all patient > 85 years, comparing the two populations of Fracture Liaison Service (FLS) attenders and non-attenders. METHODS: All patients > 85 years that presented at the FLS with a non-vertebral fracture were included in the study during a 5-year period (September 2004 and December 2009). Excluded were pathologic fractures, death < 30 days, or patients on osteoporosis treatment. in patients that attended the FLS, assessment of bone mineral density and fall-risk factors were screened. In both the attenders and non-attenders groups, mortality and subsequent fracture rates were scored during a follow-up of 2 years. RESULTS: 282 patients fulfilled inclusion criteria for screening, of which 160 (57%) patients did not attend the FLS. 122 patients were screened for osteoporosis and fall-related risk of whom 72 were diagnosed with osteoporosis. Subsequent fracture risk in both groups was 19%. Medical treatment was started in 51 patients, of which 15 patients developed a subsequent fracture. Cox-regression analysis indicated a significantly lower mortality rate, but not a diminished subsequent fracture rate in the FLS screened population compared to the non-attenders. CONCLUSION: The advantage of a FLS in reducing subsequent fracture risk in patients > 85 years seems to be limited. In practice a large proportion of these patients are not screened.

One Week of Hospitalization Following Elective Hip Surgery Induces Substantial Muscle Atrophy in Older Patients.

OBJECTIVES: Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women. DESIGN AND PARTICIPANTS: Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study. MEASUREMENTS: On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type-specific CSA. RESULTS: An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (-3.4% ± 1.0%) and thigh muscle CSA (-4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 µm2 vs 4075 ± 279 µm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10). CONCLUSIONS: Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.

Acute Hospital Admissions Because of Health Care-Related Adverse Events: A Retrospective Study of 5 Specialist Departments.

BACKGROUND: Health care-related adverse events (HCRAEs), which should not be confused with (blameworthy) medical errors, are common; they can lead to hospital admissions and can have grave consequences. Although they are sometimes potentially preventable, information is lacking on HCRAEs leading to admission to different departments. AIM: This study aimed to gain insight into the incidence, type, severity, and preventability of HCRAEs (including adverse drug events) leading to hospitalization to the departments of internal medicine, surgery, orthopedics, neurology, and neurosurgery. Further, we explore if there are differences regarding these HCRAEs between these departments. METHODS: We retrospectively evaluated the medical records of all patients admitted through the emergency department (ED) in a 6-month period to the departments of internal medicine, surgery, orthopedics, neurology, and neurosurgery. All patients admitted because of HCRAEs were included. RESULTS: More than one-fifth (21.8%; range 12.0%-47.8%) of all admissions to the 5 departments were due to a HCRAE. Half (49.9%) of these HCRAEs were medication-related and 30.5% were procedure-related. In 6.5% of patients, the HCRAE led to permanent disability and another 4.4% of patients died during hospitalization. HCRAEs treated by internists and neurologists were usually medication-related, whereas HCRAEs treated by surgeons, orthopedic surgeons, and neurosurgeons were usually procedure-related. CONCLUSION: Hospital admissions to different departments are often caused by HCRAEs, which sometimes lead to permanent disability or even death. Gaining insight into similarities and differences in HCRAEs occurring in different specialties is a starting point for improving clinical outcomes.

Improving peri-prosthetic bone adaptation around cementless hip stems: a clinical and finite element study.

This study assessed whether the Symax™ implant, a modification of the Omnifit(®) stem (in terms of shape, proximal coating and distal surface treatment), would yield improved bone remodelling in a clinical DEXA study, and if these results could be predicted in a finite element (FE) simulation study. In a randomized clinical trial, 2 year DEXA measurements between the uncemented Symax™ and Omnifit(®) stem (both n=25) showed bone mineral density (BMD) loss in Gruen zone 7 of 14% and 20%, respectively (p<0.05). In contrast, the FE models predicted a 28% (Symax™) and 26% (Omnifit(®)) bone loss. When the distal treatment to the Symax™ was not modelled in the simulation, bone loss of 35% was predicted, suggesting the benefit of this surface treatment for proximal bone maintenance. The theoretical concept for enhanced proximal bone loading by the Symax™, and the predicted remodelling pattern were confirmed by DEXA-results, but there was no quantitative match between clinical and FE findings. This was due to a simulation based on incomplete assumptions concerning the yet unknown biological and mechanical effects of the new coating and surface treatment. Study listed under ClinicalTrials.gov with number NCT01695213.

Randomised trial comparing bone remodelling around two uncemented stems using modified Gruen zones.

For assessment of bone remodelling around total hip arthroplasty using dual-emission X-ray absorptiometry (DEXA), a variety of different systems to identify regions of interest (ROI) have been used, making comparisons between stem designs difficult. The Gruen zones are now widely used for this purpose. We present the results of a randomised clinical trial comparing 2 uncemented stem designs with proximal coating, using a modification of the Gruen zones to allow improved representation of the effect of the implant on bone mineral density (BMD) over time. DEXA-data were used in a randomised trial with 2 years follow up, comparing the uncemented Symax(TM) (n=25) and Omnifit(®) (n=24) stems. The effect on BMD was determined using the 'standard' adapted Gruen zones, and a modification which studied an equal length and position for zones 1 and 7 around both stems, assuring that the same regions in terms of cancellous and cortical bone were compared. The 'modified' regions of interest give lower BMD values around the Omnifit(®) than using the 'standard' Gruen zones (3.6 % in zone 7, p<0.05). The difference with the Symax(TM) BMD values, which had been concealed using the standard Gruen zones, became statistically significant in favour of the Symax(TM) implant. This adaptation can detect a statistically significant difference in bone preservation in zone 7 between stems that would otherwise not have been revealed. We recommend the use of 'modified' Gruen zones for more valid comparison of remodelling caused by different implant designs.

Are periprosthetic tissue reactions observed after revision of total disc replacement comparable to the reactions observed after total hip or knee revision surgery?

STUDY DESIGN: Comparative study. OBJECTIVE: To compare periprosthetic tissue reactions observed after total disc replacement (TDR), total hip arthroplasty (THA), and total knee arthroplasty (TKA) revision surgery. SUMMARY OF BACKGROUND DATA: Prosthetic wear debris leading to particle disease, followed by osteolysis, is often observed after THA and TKA. Although the presence of polyethylene (PE) particles and periprosthetic inflammation after TDR has been proven recently, osteolysis is rarely observed. The clinical relevance of PE wear debris in the spine remains poorly understood. METHODS: The number, size, and shape of PE particles, as well as quantity and type of inflammatory cells in periprosthetic tissue retrieved during CHARITÉ TDR (n = 22), THA (n = 10), and TKA (n = 4) revision surgery were compared. Tissue samples were stained with hematoxylin/eosin and examined by using light microscopy with bright field and polarized light. RESULTS: After THA, large numbers of PE particles of size less than 6 µm were observed, which were mainly phagocytosed by macrophages. The TKA group had a broad size range with many larger PE particles and more giant cells. In TDR, the size range was similar to that observed in TKA. However, the smallest particles were the most prevalent with 75% of the particles being less than 6 µm, as seen in revision THA. In TDR, both macrophages and giant cells were present with a higher number of macrophages. CONCLUSION: Both small and large PE particles are present after TDR revision surgery compatible with both THA and TKA wear patterns. The similarities between periprosthetic tissue reactions in the different groups may give more insight into the clinical relevance of PE particles and inflammatory cells in the lumbar spine. The current findings may help to improve TDR design as applied from technologies previously developed in THA and TKA with the goal of a longer survival of TDR.