Reoperation risk of periprosthetic fracture after primary total hip arthroplasty using a collared cementless or a taper-slip cemented stem.

Aims: The aim of this study was to determine both the incidence of, and the reoperation rate for, postoperative periprosthetic femoral fracture (POPFF) after total hip arthroplasty (THA) with either a collared cementless (CC) femoral component or a cemented polished taper-slip (PTS) femoral component. Methods: We performed a retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All POPFFs were identified using regional radiograph archiving and electronic care systems. Results: A total of 11,018 THAs were implanted: 4,952 CC femoral components and 6,066 cemented PTS femoral components. Between groups, age, sex, and BMI did not differ. Overall, 91 patients (0.8%) sustained a POPFF. For all patients with a POPFF, 16.5% (15/91) were managed conservatively, 67.0% (61/91) underwent open reduction and internal fixation (ORIF), and 16.5% (15/91) underwent revision. The CC group had a lower POPFF rate compared to the PTS group (0.7% (36/4,952) vs 0.9% (55/6,066); p = 0.345). Fewer POPFFs in the CC group required surgery (0.4% (22/4,952) vs 0.9% (54/6,066); p = 0.005). Fewer POPFFs required surgery in males with a CC than males with a PTS (0.3% (7/2,121) vs 1.3% (36/2,674); p < 0.001). Conclusion: Male patients with a PTS femoral component were five times more likely to have a reoperation for POPFF. Female patients had the same incidence of reoperation with either component type. Of those having a reoperation, 80.3% (61/76) had an ORIF, which could greatly mask the size of this problem in many registries.

Risk factors for periprosthetic femoral fracture risk around a cemented polished taper-slip stem using an osteoporotic composite bone model.

This biomechanical study aimed to determine if variations in stem material, stem geometry, stem offset and cement viscosity affect mechanical resistance to postoperative periprosthetic fracture (PFF) after hip arthroplasty with a commonly used cemented polished taper-slip (PTS) stem (CPT, Zimmer Biomet) in a novel osteoporotic composite femoral bone model. Thirty-six osteoporotic composite femoral models were tested using a standardised in-vitro loading technique to simulate a typical PFF. Outcome measures were torque to failure (N), fracture energy (N/m2) and rotation to failure (°). Comparisons were made by stem material (cobalt chrome vs stainless steel), stem geometry (CPT stem vs Exeter stem), stem offset (standard offset vs extra extended offset) and cement viscosity (high viscosity vs low viscosity). Statistical comparisons were carried out with significance set at p < 0.05. All tested samples produced clinically representative fracture patterns with varying degrees of bone and cement comminution. There was no statistically significant difference in torque to failure, fracture energy or rotation to failure between any of the compared variables (all p > 0.05). This is the first biomechanical study on mechanical resistance to PFF using osteoporotic composite bone models. For the CPT stem, it confirms that stem material, stem offset, stem geometry and cement viscosity do not affect mechanical resistance to PFF in an osteoporotic bone model.

Cemented femoral stem design and postoperative periprosthetic fracture risk following total hip arthroplasty.

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.

Systematic Review and Meta-Analysis of Studies Comparing the Rate of Post-operative Periprosthetic Fracture Following Hip Arthroplasty With a Polished Taper Slip versus Composite Beam Stem.

BACKGROUND: We compared the incidence of postoperative periprosthetic femoral fractures (POPFF) following hip arthroplasty with either a cemented polished taper slip (PTS) stem or a cemented composite beam (CB) stem in comparative studies. METHODS: A systematic review of comparative studies, written in English and published in peer-reviewed journals since the year 2000, was conducted. Study quality was assessed using the Newcastle-Ottawa scale.The overall study qualities were good. There were 913,021 patients from 18 cohorts included in the meta-analysis. There were 294,540 patients who received a CB stem and 618,481 received a PTS stem. Cohorts were classified as high- or low-risk for POPFF based on patient risk factors. A metanalysis was performed using a random effects model, and the relative incidence with 95% confidence intervals (CIs) was reported. RESULTS: The patients at low risk of POPFF had an incidence rate ratio of 3.14 (CI: 2.48, 3.98) for the PTS group versus the CB group. Whereas, the patients at high risk of POPFF had an incidence rate ratio of 9.87 (CI: 3.63, 26.80) for the PTS group versus the CB group. CONCLUSIONS: The risk of POPFF is lower when hip arthroplasty was performed using a CB stem versus a PTS stem. This protective effect was greatest in patients who had a higher risk of POPFF. Surgeons should consider the effect of cemented stem choice on the risk of subsequent periprosthetic femur fracture, particularly in frail or elderly patients who are at a higher risk of postoperative periprosthetic femoral fracture.

Comparison of axial-rotational postoperative periprosthetic fracture of the femur in composite osteoporotic femur versus human cadaveric specimens: A validation study.

Postoperative periprosthetic femoral fracture following hip replacement has been the subject of many varied experimental approaches. Cadaveric samples offer realistic fit and fracture patterns but are subject to large between-sample variation. Composite femurs have not yet been validated for this purpose. We compared the results of composite femurs to cadaveric femurs using an established methodology. In vitro postoperative periprosthetic fracture results using axial-rotational loading were compared between 12 composite femurs and nine fresh frozen femurs, which were implanted with an otherwise identical collarless (6 composite vs 4 cadaveric) or collared (6 composite vs 5 cadaveric) cementless femoral stem using identical methodology. Fracture torque and rotational displacement were measured and torsional stiffness and rotational work prior to fracture were estimated. Fractures patterns were graded according to the Unified Classification System. Fracture torque, displacement, torsional stiffness and fracture patterns for cadaveric and composite femurs were similar between groups. There was a trend for a greater rotational displacement in the cadaveric groups, which lead to a decrease in torsional stiffness and a significantly greater rotational work prior to fracture for all cadaveric specimens (collarless stems: 10.51 [9.71 to 12.57] vs 5.21 [4.25 to 6.04], p = 0.01 and for collared stems: 15.38 [14.01 to 17.05] vs 5.76 [4.92 to 6.64], p = 0.01). Given comparable fracture torque and the similarity in fracture patterns for fracture trials using composite samples versus cadaveric femurs, the use of composite femur models may be a reasonable choice for postoperative periprosthetic femoral fracture studies within certain limitations.

Mortality After Postoperative Periprosthetic Fracture of the Femur After Hip Arthroplasty in the Last Decade: Meta-Analysis of 35 Cohort Studies Including 4841 Patients.

BACKGROUND: Postoperative periprosthetic fracture of the femur (POPFF) is associated with increased mortality. There is a lack of general estimates of mortality after POPFF and a need for higher-level evidence in this area. The aim of this study was to estimate mortality after POPFF using data reported in cohort studies from the last decade. METHODS: Literature search was conducted using Medline and Embase. The primary outcome was all-cause mortality during time as an inpatient, within 30 days, within 90 days, and within one year of POPFF. Mortality (95% confidence interval [CI]) was estimated using metaregression. RESULTS: A total of 4841 patients from 35 cohort studies were included. Study quality was generally low. The weighted mean follow-up was 2.3 years, and the most common POPFF was Vancouver B. The pooled mortality as an inpatient was 2.4% (95% CI 1.6% to 3.4%). The pooled mortality within 30 days was 3.3% (95% CI 2.0% to 5.0%). The pooled mortality within 90 days was 4.8% (95% CI 3.6% to 6.1%). The pooled mortality within one year was 13.4% (95% CI 11.9% to 14.8%). Mortality after POPFF was like that of neck of femur fracture up to 30 days, but better at one year. CONCLUSION: Mortality is like that experienced by patients after neck of femur fracture up to 30 days, but better at one year, which may represent the lower underlying risk of death in the POPFF cohort. These results may form the basis for evaluation of services treating POPFF in the future.

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures.

BACKGROUND: This multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. METHODS: Data were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. RESULTS: Median (IQR) age of IPFF patients was 81.75 (76.57-85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407). CONCLUSION: The presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.

Reliability and validity of the Unified Classification System for postoperative periprosthetic femoral fractures around cemented polished taper-slip stems.

AIMS: This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems. METHODS: Radiographs of 71 patients with a PFF admitted consecutively at two centres between 25 February 2012 and 19 May 2020 were collated by an independent investigator. Six observers (three hip consultants and three trainees) were familiarized with the UCS. Each PFF was classified on two separate occasions, with a mean time between assessments of 22.7 days (16 to 29). Interobserver reliability for more than two observers was assessed using percentage agreement and Fleiss' kappa statistic. Intraobserver reliability between two observers was calculated with Cohen kappa statistic. Validity was tested on surgically managed UCS type B PFFs where stem stability was documented in operation notes (n = 50). Validity was assessed using percentage agreement and Cohen kappa statistic between radiological assessment and intraoperative findings. Kappa statistics were interpreted using Landis and Koch criteria. All six observers were blinded to operation notes and postoperative radiographs. RESULTS: Interobserver reliability percentage agreement was 58.5% and the overall kappa value was 0.442 (moderate agreement). Lowest kappa values were seen for type B fractures (0.095 to 0.360). The mean intraobserver reliability kappa value was 0.672 (0.447 to 0.867), indicating substantial agreement. Validity percentage agreement was 65.7% and the mean kappa value was 0.300 (0.160 to 0.4400) indicating only fair agreement. CONCLUSION: This study demonstrates that the UCS is unsatisfactory for the classification of PFFs around PTS stems, and that it has considerably lower reliability and validity than previously described for other stem types. Radiological PTS stem loosening in the presence of PFF is poorly defined and formal intraoperative testing of stem stability is recommended. Cite this article: Bone Joint J 2021;103-B(8):1339-1344.

Calcar-collar contact during simulated periprosthetic femoral fractures increases resistance to fracture and depends on the initial separation on implantation: A composite femur in vitro study.

BACKGROUND: A calcar collar may reduce risk of periprosthetic fracture of the femur, through collar contact. We estimated the effect of collar contact on periprosthetic fracture mechanics using a collared fully coated cementless femoral stem and then estimated the effect of initial calcar-collar separation on the likelihood of collar contact. METHODS: Three groups of six composite left femurs with increasing calcar-collar separation in each group, underwent periprosthetic fracture simulation in a materials testing machine. Fracture torque and rotational displacement were measured and torsional stiffness and rotational work prior to fracture were estimated. Calcar collar contact prior to fracture was identified using high speed camera footage. FINDINGS: Where calcar-collar contact occurred fracture torque was greater (47.33 [41.03 to 50.45] Nm versus 38.26 [33.70 to 43.60] Nm, p = 0.05), Rotational displacement was less (16.6 [15.5 to 22.3] degrees versus 21.2 [18.9 to 28.1] degrees, p = 0.07), torsional stiffness was greater (151.38 [123.04 to 160.42] rad.Nm-1 versus 96.86 [84.65 to 112.98] rad.Nm-1, p < 0.01) and rotational work was similar (5.88 [4.67, 6.90] J versus 5.31 [4.40, 6.56] J, p = 0.6). Odds ratio (OR) of not achieving collar contact (95% confidence interval) increased 3.8 fold (95% CI 1.6 to 30.2, p < 0.05) for each millimetre of separation in the regression model. 95% chance of collar contact was associated with a separation of 1 mm or less. INTERPRETATION: Surgeons should reduce calcar-collar separation at stem implantation to a maximum of 1 mm to increase the chance of calcar-collar contact during injury and reduce the risk of early post-operative femoral fracture.

Can the use of an inclinometer improve acetabular cup inclination in total hip arthroplasty? A review of the literature.

INTRODUCTION: The angle of acetabular (cup) radiographic inclination is an important measurement in total hip arthroplasty (THA) procedures. Abnormal radiographic inclination is associated with dislocation, edge loading and higher failure rates. Consistently achieving a satisfactory radiographic inclination remains a challenge. Inclinometers have been increasingly used over the last decade. This paper reviews the literature to determine whether using an inclinometer improves the accuracy of acetabular cup inclination in THA. METHODS: A systematic literature search was performed. The following search terms were used: ('hip' OR 'hip replacement' OR 'hip arthroplasty' OR 'primary hip replacement' OR 'THR' OR 'THA' OR 'Acetabular cup Inclination') AND ('Inclinometer'). Titles and abstracts were screened for relevance. Both radiographic and operative inclination comparisons were included. RESULTS: 7 studies met the inclusion criteria. 2 were randomised control trials with level I evidence, and the remaining studies were cohort studies with level III/IV evidence. 5 were clinical and 2 experimental. In total there were 16 cohorts: 7 using an inclinometer, 6 freehand, and 3 using MAG techniques. All studies comparing radiographic inclination and 1 of 2 studies comparing operative inclination showed an improvement in the attainment of the optimal inclination. Similarly, the use of an inclinometer showed a reduction in the number of outliers when compared to MAG and freehand techniques. DISCUSSION: This review demonstrates that using an inclinometer improved the surgeon's ability to achieve their intended inclination (both operative and radiographic) and reduced the incidence of positioning outside the safe-zone. However, only 2 of the studies were randomised control trials and these resulted in opposing conclusions. Therefore, further studies looking at the use of inclinometers would prove useful in understanding their true benefit.

Postoperative periprosthetic femoral fracture around total hip replacements: current concepts and clinical outcomes.

The rising incidence of postoperative periprosthetic femoral fracture (PFF) presents a significant clinical and economic burden.A detailed understanding of risk factors is required in order to guide preventative strategies.Different femoral stems have unique characteristics and management strategies must be tailored appropriately.Consensus regarding treatment of PFFs around well-fixed stems is lacking, but revision surgery may provide more predictable outcomes for unstable fracture patterns and fractures around polished taper-slip stems.Future research should focus on implant-related risk factors, treatment of concurrent metabolic bone disease and the use of large endoprostheses. Cite this article: EFORT Open Rev 2020;5:558-567. DOI: 10.1302/2058-5241.5.200003.

Current State of Undergraduate Trauma and Orthopaedics Training in United Kingdom: A Survey-based Study of Undergraduate Teaching Experience and Subjective Clinical Competence in Final-year Medical Students.

OBJECTIVE: To assess the quality and duration of trauma and orthopedics (T&O) training in medical schools in United Kingdom (UK), and to evaluate final-year students' self-perceived level of competence in essential T&O skills. DESIGN: This was a survey-based study of final-year medical students that attended 1-day undergraduate T&O courses held between Feb'17 and Feb'19. Outcome measures were duration and perceived quality of undergraduate T&O placements, students' self-rated competence in essential T&O skills, and impact of teaching methods on their subjective future competence. SETTING: Four courses held at education centers in 3 different locations in UK (London, Nottingham, and Leeds) PARTICIPANTS: All 414 course attendees from 13 UK medical schools completed the questionnaire. RESULTS: 19.3% of students had not experienced a placement in T&O. Mean duration of T&O placements was 2.5 weeks. 37.4% described their training as "poor". Majority of students attended 1-5 sessions of: lectures (50.5%), small group teaching (58.7%), trauma meetings (58.7%), clinics (65.7%), and theatres (72.5%). Lowest competency scores were reported in management of T&O emergencies, fracture management, and interpretation of T&O radiographs. Self-rated competence in essential T&O skills was significantly higher in students with previous experience of a T&O placement (p < 0.05). There was a strongly positive correlation between small group teaching attendance and perceived competence in management of T&O patients in different clinical settings (p < 0.001). CONCLUSIONS: Medical schools in UK are currently failing to adequately train medical graduates to manage T&O patients, with students reporting low competency scores in all basic T&O skills. To mitigate the current situation, a minimum duration of a T&O placement for all students must be implemented nationally. Educational boards and medical schools must work in collaboration to improve the delivery of undergraduate T&O curriculum, the structure of the clinical T&O placement, and efficacy of the commonly encountered learning environments.

Patient and implant survival following intraoperative periprosthetic femoral fractures during primary total hip arthroplasty: an analysis from the national joint registry for England, Wales, Northern Ireland and the Isle of Man.

AIMS: We compared implant and patient survival following intraoperative periprosthetic femoral fractures (IOPFFs) during primary total hip arthroplasty (THA) with matched controls. PATIENTS AND METHODS: This retrospective cohort study compared 4831 hips with IOPFF and 48 154 propensity score matched primary THAs without IOPFF implanted between 2004 and 2016, which had been recorded on a national joint registry. Implant and patient survival rates were compared between groups using Cox regression. RESULTS: Ten-year stem survival was worse in the IOPFF group (p < 0.001). Risk of revision for aseptic loosening increased 7.2-fold following shaft fracture and almost 2.8-fold after trochanteric fracture (p < 0.001). Risk of periprosthetic fracture of the femur revision increased 4.3-fold following calcar-crack and 3.6-fold after trochanteric fracture (p < 0.01). Risk of instability revision was 3.6-fold after trochanteric fracture and 2.4-fold after calcar crack (p < 0.001). Risk of 90-day mortality following IOPFF without revision was 1.7-fold and 4.0-fold after IOPFF with early revision surgery versus uncomplicated THA (p < 0.001). CONCLUSION: IOPFF increases risk of stem revision and mortality up to ten years following surgery. The risk of revision depends on IOPFF subtype and mortality risk increases with subsequent revision surgery. Surgeons should carefully diagnose and treat IOPFF to minimize fracture progression and implant failure. Cite this article: Bone Joint J 2019;101-B:1199-1208.

Risk Factors for Intraoperative Periprosthetic Femoral Fractures During Primary Total Hip Arthroplasty. An Analysis From the National Joint Registry for England and Wales and the Isle of Man.

BACKGROUND: The aim of this study is to estimate risk factors for intraoperative periprosthetic femoral fractures (IOPFF) and each anatomic subtype (calcar crack, trochanteric fracture, femoral shaft fracture) during primary total hip arthroplasty. METHODS: This retrospective cohort study included 793,823 primary total hip arthroplasties between 2004 and 2016. Multivariable regression modeling was used to estimate relative risk of patient, surgical, and implant factors for any IOPFF and for all anatomic subtypes of IOPFF. Clinically important interactions were assessed using multivariable regression. RESULTS: Patient factors significantly increasing the risk of fracture were female gender, American Society of Anesthesiologists grade 3 to 5, and preoperative diagnosis including avascular necrosis of the hip, previous trauma, inflammatory disease, pediatric disease, and previous infection. Overall risk of IOPFF associated with age was greatest in patients below 50 years and above 80 years. Risk of any fracture reduced with computer-guided surgery and in non-National Health Service hospitals. Nonposterior approaches increased the risk of shaft and trochanteric fracture only. Cementless implants significantly increased the risk of only calcar cracks and shaft fractures and not trochanteric fractures. CONCLUSION: Fracture risk increases in patients younger than 50 and older than 80 years, females, American Society of Anesthesiologists grade 3 to 5, and indications other than primary osteoarthritis. Large cumulative reduction in IOPFF risk may occur with use of cemented implants, posterior approach, and computer-guided surgery. LEVEL OF EVIDENCE: Level 3b (cohort study).

Periprosthetic femoral fractures following total hip and total knee arthroplasty.

Total joint arthroplasties are increasing worldwide in both frequency and prevalence. When successful, they offer great improvements in quality of life. However, fractures around implants are often difficult to manage and require prolonged inpatient stays in tertiary hospitals. Management may differ between surgeons, but most patients will be managed surgically if mobility or joint stability is threatened. Those affected are often at higher risk from surgery, are frailer and at higher risk of mortality and a lifelong reduction in mobility. The incidence of these fractures is increasing, and patients should appreciate the risk and implications of this recognised complication of joint arthroplasty.

Delays in treating patients with good grade subarachnoid haemorrhage in London.

BACKGROUND AND PURPOSE: Spontaneous aneurysmal subarachnoid haemorrhage (SAH) is managed as a neurosurgical priority with guidelines and published literature emphasising the identification and the treatment of the ruptured aneurysm within 48 h of ictus. We audited the timing of management of good grade (WFNS 1 & 2) SAH in a neurosurgical unit in Greater London. We also reviewed the available services for treating SAH within Greater London. MATERIALS AND METHODS: Retrospective audit of patients admitted with SAH to St. George's Hospital between 31 May 2007 and 31 May 2009 was performed. Prospective telephone and public record review of the catchment area and neurovascular provisions of the seven London neurosurgical units were assessed. RESULTS: There were 141 WFNS grade 1 and 2 SAH patients admitted. Only a quarter were treated within 48 h of ictus. Patients destined for endovascular treatment waited significantly longer periods until treatment when compared with that of clipping group patients. The day of the week on which diagnostic angiography occurred was critical in determining treatment delays, probably due to the lack of routine provision of clipping at weekends and next day coiling services. We estimated that 440 good grade SAH are admitted per annum in Greater London. There are 20 neurovascular surgeons and 16 interventional neuroradiologists across seven neurosurgical units that routinely treat SAH. CONCLUSIONS: We have identified significant delays in treating three quarters of good grade SAH patients in London. This appears to be due to a lack of next day treatment availability. A collaborative strategy between the seven London neurosurgical units could reduce treatment delays.