Validation of inertial measurement units with optical tracking system in patients operated with Total hip arthroplasty.

BACKGROUND: Patient reported outcome measurement (PROMs) will not capture in detail the functional joint motion before and after total hip arthroplasty (THA). Therefore, methods more specifically aimed to analyse joint movements may be of interest. An analysis method that addresses these issues should be readily accessible and easy to use especially if applied to large groups of patients, who you want to study both before and after a surgical intervention such as THA. Our aim was to evaluate the accuracy of inertial measurement units (IMU) by comparison with an optical tracking system (OTS) to record pelvic tilt, hip and knee flexion in patients who had undergone THA. METHODS: 49 subjects, 25 males 24 females, mean age of 73 years (range 51-80) with THA participated. All patients were measured with a portable IMU system, with sensors attached lateral to the pelvis, the thigh and the lower leg. For validation, a 12-camera motion capture system was used to determine the positions of 15 skin markers (Oqus 4, Qualisys AB, Sweden). Comparison of sagittal pelvic rotations, and hip and knee flexion-extension motions measured with the two systems was performed. The mean values of the IMU's on the left and right sides were compared with OTS data. RESULTS: The comparison between the two gait analysis methods showed no significant difference for mean pelvic tilt range (4.9-5.4 degrees) or mean knee flexion range (54.4-55.1 degrees) on either side (p > 0.7). The IMU system did however record slightly less hip flexion on both sides (36.7-37.7 degrees for the OTS compared to 34.0-34.4 degrees for the IMU, p < 0.001). CONCLUSIONS: We found that inertial measurement units can produce valid kinematic data of pelvis- and knee flexion-extension range. Slightly less hip flexion was however recorded with the inertial measurement units which may be due to the difference in the modelling of the pelvis, soft tissue artefacts, and malalignment between the two methods or misplacement of the inertial measurement units. TRIAL REGISTRATION: The study has ethical approval from the ethical committee "Regionala etikprövningsnämnden i Göteborg" (Dnr: 611-15, 2015-08-27) and all study participants have submitted written approval for participation in the study.

Linking Swedish health data registers to establish a research database and a shared decision-making tool in hip replacement.

BACKGROUND: Sweden offers a unique opportunity to researchers to construct comprehensive databases that encompass a wide variety of healthcare related data. Statistics Sweden and the National Board of Health and Welfare collect individual level data for all Swedish residents that ranges from medical diagnoses to socioeconomic information. In addition to the information collected by governmental agencies the medical profession has initiated nationwide Quality Registers that collect data on specific diagnoses and interventions. The Quality Registers analyze activity within healthcare institutions, with the aims of improving clinical care and fostering clinical research. MAIN BODY: The Swedish Hip Arthroplasty Register (SHAR) has been collecting data since 1979. Joint replacement in general and hip replacement in particular is considered a success story with low mortality and complication rate. It is credited to the pioneering work of the SHAR that the revision rate following hip replacement surgery in Sweden is amongst the lowest in the world. This has been accomplished by the diligent follow-up of patients with feedback of outcomes to the providers of the healthcare along with post market surveillance of individual implant performance. During its existence SHAR has experienced a constant organic growth. One major development was the introduction of the Patient Reported Outcome Measures program, giving a voice to the patients in healthcare performance evaluation. The next aim for SHAR is to integrate patients' wishes and expectations with the surgeons' expertise in the form of a Shared Decision-Making (SDM) instrument. The first step in building such an instrument is to assemble the necessary data. This involves linking the SHARs database with the two aforementioned governmental agencies. The linkage is done by the 10-digit personal identity number assigned at birth (or immigration) for every Swedish resident. The anonymized data is stored on encrypted serves and can only be accessed after double identification. CONCLUSION: This data will serve as starting point for several research projects and clinical improvement work.

Extended trochanteric osteotomy followed by cemented impaction allografting in revision hip arthroplasty.

The aim of this study is to present the medium- to long-term results of all cases of femoral impaction allografting revision at our institution that required an extended trochanteric osteotomy (ETO) at the time of surgery. Eighteen patients with a mean age of 60 years were evaluated. Indication for revision was aseptic loosening in all cases. The mean follow-up was 123 months (51-170). Charnley-D'Aubigné-Postel scores, stem length, ETO length, ETO healing, and complications were recorded. No patient was lost to follow-up. Signs of clinical healing were noted within the first 6 postoperative months. The difference between the preoperative and postoperative clinical scores was statistically significant. No nonunion of the ETO was observed in any case. These results give support to the combined use of these techniques.

Effects of a modified muscle sparing posterior technique in hip hemiarthroplasty for displaced intracapsular fractures on postoperative function compared to a standard lateral approach (HemiSPAIRE): protocol for a randomised controlled trial.

INTRODUCTION: Currently National Institute for Health and Care Excellence clinical guidelines in the UK suggest that surgeons performing partial hip replacements (hemiarthroplasty) should consider using the lateral approach. Alternatively, a newer, modified posterior approach using a muscle sparing technique named 'Save Piriformis and Internus, Repairing Externus' (SPAIRE) can be used leaving the major muscles intact. This randomised controlled trial (RCT) aims to compare the SPAIRE approach to the standard lateral approach, to determine if it allows patients to mobilise better and experience improved function after surgery. METHODS AND ANALYSIS: HemiSPAIRE is a two-arm, assessor-blinded, definitive pragmatic RCT with nested pilot and qualitative studies. Two hundred and twenty-eight participants with displaced intracapsular fractures requiring hip hemiarthroplasty will be individually randomised 1:1 to either the SPAIRE, or control (standard lateral approach) surgical procedure. Outcomes will be assessed at postoperative day 3 (POD3) and 120 (POD120). The primary outcome measure will be level of function and mobility using the Oxford Hip Score at POD120. Secondary outcomes include: De Morton Mobility Index (DEMMI), Cumulated Ambulatory Score and Numeric Pain Rating Scale (NPRS) at POD3; DEMMI, NPRS and EQ-5D-5L at POD120, complications, acute and total length of hospital stay, and mortality. Primary analysis will be on an intention-to-treat basis. Participant experiences of the impact of surgery and recovery period will be examined via up to 20 semi-structured telephone interviews. ETHICS AND DISSEMINATION: The protocol has been approved by Yorkshire and the Humber-Bradford Leeds Research Ethics Committee. Recruitment commenced in November 2019. Findings will be disseminated via research articles in peer-reviewed journals, presentations at conferences, public involvement events, patient groups and media releases. A summary of the trial findings will be shared with participants at the end of the study. TRIAL REGISTRATION NUMBER: NCT04095611.

Sport after total hip arthroplasty: undoubted progress but still some unknowns.

In this review, we discuss the evidence for patients returning to sport after hip arthroplasty. This includes the choices regarding level of sporting activity and revision or complications, the type of implant, fixation and techniques of implantation, and how these choices relate to health economics. It is apparent that despite its success over six decades, hip arthroplasty has now evolved to accommodate and support ever-increasing patient demands and may therefore face new challenges. Cite this article: Bone Joint J 2020;102-B(6):661-663.

Contemporary cementing technique and mortality during and after Exeter total hip arthroplasty.

The Exeter universal stem implanted with contemporary cementing technique has shown an excellent survivorship at 15 years. The technique used for implantation calls for prolonged pressurization preventing blood from the femur exiting into the femoral canal, but this technique is not accepted widely as some surgeons believe it is associated with significant morbidity. This concern prompted this review. From 1988 to 2005, 9082 primary total hip arthroplasty (THA) were implanted. We identified all patients who died within 30 days from surgery. When available, the postmortem results were reviewed. Twenty-one patients died within 30 days from their primary THA (prevalence, 0.23%). There was one intraoperative death (prevalence, 0.01%). The postmortem report was consistent with fat embolism. Two additional patients died the same day of surgery from cardiac processes. No other deaths could be linked to cement. Sudden death during cemented THA with a current contemporary cementing technique and a specialized anesthetic protocol is nearly zero.

Trends in hip replacements between 1999 and 2012 in Sweden.

National Registers document changes in the circumstance, practice, and outcome of surgery with the passage of time. In the context of total hip replacement (THR), registers can help elucidate the relevant factors that affect the clinical outcome. We evaluated the evolution of factors related to patient, surgical procedure, socio-economy, and various outcome parameters after merging databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length-of-stay, mortality rate, adverse events, re-operation and revision rates, and Patient Reported Outcome Measures (PROMs). Throughout this time period the majority of patients were operated on with a diagnosis of primary osteoarthritis. Comorbidity indices increased each year observed. The share of all-cemented implants has dropped from 92% to 68%. More than 88% of the bearings were metal-on-polyethylene. Length-of-stay decreased by 50%. There was a reduction in 30- and 90-day mortality. Re-operation and revision rates at 2 years are decreasing. The post-operative PROMs improved despite the observation of worse pre-operative pain scores getting over time. The demographics of patients receiving a THR, their comorbidities, and their primary diagnosis are changing. Notwithstanding these changes, outcomes like mortality, re-operations, revisions, and PROMs have improved. The practice of hip arthroplasty has evolved, even in a country such as Sweden that is considered to be conservative with regard taking on new surgical practices. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:432-442, 2018.

Mammoth interatrial septal aneurysm in the ICE age.

BACKGROUND: Intracardiac echocardiography (ICE) is a useful imaging modality that is now being used more widely to assist in the percutaneous closure of atrial septal defects (ASD) and patent foramen ovales (PFO). CASE PRESENTATION: A 42 year old lady with a history of transient ischaemic attacks and migraine underwent percutaneous closure of an ASD. Intraprocedural ICE demonstrated a mammoth billowing multiperforated interatrial septal aneurysm in association with a secondum ASD. CONCLUSION: ICE provides excellent adjuvant imaging during percutaneous closure of intracardiac shunts, in this case demonstrating a 'mammoth' interatrial septal aneurysm.

Impaction allografting revision for B3 periprosthetic femoral fractures using a Mennen plate to contain the graft: a technical report.

We prospectively evaluated the long-term results of a technique using the Mennen plate to contain impacted allograft and support cemented Exeter stem revision fixation for the treatment of three B3 periprosthetic femoral fractures (PFFs). Three patients with a median age of 77 years were followed-up for a median of 84 months. In all cases the stem bypassed the distal fracture line by a median length of 85 mm (median ratio over femoral diameter = 2.13). The median postoperative Charnley-Merle d'Aubigné-Postel score for pain, function and range of movement was 5, 3 and 6 respectively. Impaction allografting revision could be used for B3 PFFs when the stem bypasses the most distal fracture line by at least two ipsilateral femoral diameters. The Mennen plate can aid to contain the impacted allograft and to maintain fracture reduction and short term stability thereafter, but the long stem is necessary for long-term stability and healing.

Is Preoperative Patient-Reported Health Status Associated with Mortality after Total Hip Replacement?

The influence of comorbidities and worse physical status on mortality following total hip replacement (THR) leads to the idea that patient-reported health status may also be a predictor of mortality. The aim of this study was to investigate the relationship between patient-reported health status before THR and the risk of dying up to 5 years post-operatively. For these analyses, we used register data on 42,862 THR patients with primary hip osteoarthritis operated between 2008 and 2012. The relative survival ratio was calculated by dividing the observed survival in the patient group by age- and sex-adjusted expected survival of the general population. Pre-operative responses to the five EQ-5D-3L (EuroQol Group) dimensions along with age, sex, education status, year of surgery, and hospital type were used as independent variables. Results shown that, as a group, THR patients had a better survival than the general population. Broken down by the five EQ-5D-3L dimensions we observed differentiated survival patters. For all dimensions, those reporting extreme problems had higher mortality than those reporting moderate or no problems. In conclusion, worse health status according to the EQ-5-3L before THR is associated with higher mortality up to five years after surgery. EQ-5D-3L responses may be useful in a multifactorial individualized risk assessment before THR.

A review of 202 periprosthetic fractures--stem revision and allograft improves outcome for type B fractures.

We report a retrospective review of the outcome of treatment of 202 periprosthetic fractures around total hip arthroplasty (THA) from two specialised arthroplasty centres. Fractures were classified according to the Vancouver classification. The aim was to evaluate treatment methods with respect to stem revision and grafting. Transverse B1 fractures treated with stem revision compared to those treated with open reduction and internal fixation (ORIF) with a plate showed a trend towards improved overall union rate (OR=2, p=0.6, 95% CI:0.14-28.4) and shorter times to union (p=0.038, mean 12 months SD 6.573 for ORIF versus 4.48 months SD 0.757 for stem revision). B2 fractures undergoing stem revision and grafting were significantly more likely to unite compared to ORIF alone (OR=17.3, p=0.018 95%CI:1.63-184.4). B3 fractures presented with significant variation in fracture configuration and bone loss and therefore their treatment was individualised. When treated with stem revision and grafting healing was achieved in a mean time of 7 months (n=81). Periprosthetic fractures of the femur are highly complex and challenging. Stem revision for transverse B1 fractures is now considered as a viable treatment modality as this fracture configuration is difficult to control with single plating, and fixation with a long stem bypassing the distal fracture line is necessary to achieve axial stability and healing. Bone allografting, whether used as a cortical onlay or in morselised impacted form for B2 and B3 fractures enhances fracture healing.

Acetabular impaction grafting in total hip replacement.

BACKGROUND AND PURPOSE: Acetabular impaction grafting has been shown to be very effective, but concerns regarding its suitability for larger defects have been highlighted. We report the use of this technique in a large cohort of patients, and address possible limitations of the technique. METHODS: We investigated a consecutive group of 339 cases of impaction grafting of the cup with morcellised impacted allograft bone for survivorship and mechanisms for early failure. RESULTS: Kaplan Meier survival was 89.1% (95% CI 83.2 to 95.0%) at 5.8 years for revision for any reason, and 91.6% (95% CI 85.9 to 97.3%) for revision for aseptic loosening of the cup. Of the 15 cases revised for aseptic cup loosening, nine were large rim mesh reconstructions, two were fractured Kerboull-Postel plates, two were migrating cages, one was a medial wall mesh failure and one had been treated by impaction alone. INTERPRETATION: In our series, results were disappointing where a large rim mesh or significant reconstruction was required. In light of these results, our technique has changed in that we now use predominantly larger chips of purely cancellous bone, 8-10 mm3 in size, to fill the cavity and larger diameter cups to better fill the aperture of the reconstructed acetabulum. In addition we now make greater use of i) implants made of a highly porous in-growth surface to constrain allograft chips and ii) bulk allografts combined with cages and morcellised chips in cases with very large segmental and cavitary defects.

The use of long cemented stems for femoral impaction grafting in revision total hip arthroplasty.

BACKGROUND: Following revision total hip arthroplasty involving femoral impaction grafting, fractures usually have occurred distal to a standard-length stem in an area of weakened bone that was left inadequately supported. The purpose of the present study was to determine whether the use of a long stem decreases the rate of femoral fracture after revision hip surgery. We hypothesized that the use of a long-stem femoral component would decrease the risk of these fractures. METHODS: From 1991 to 2000, 567 revision total hip arthroplasties were performed with use of femoral impaction grafting. Of these, forty-two procedures in forty patients (average age, 73.8 years) were performed with use of a stem that was > or = 220 mm in length. The average number of previous revisions was 1.85. Thirty-four of the forty hips with preoperative radiographs had preoperative bone loss that was classified as grade III or IV according to the Endo-Klinik system. Major complications were recorded, and survival analysis was performed. RESULTS: No patient was lost to follow-up. Sixteen patients (sixteen hips) died at an average of fifty-two months postoperatively. The average duration of clinical follow-up for the hips in which the implant survived for more than forty-eight months was 7.5 years. The rate of major postoperative complications was 29%. Two postoperative femoral fractures occurred. Six patients (six hips) required a femoral reoperation. The survival rate with revision hip surgery as the end point was 90% at both five and ten years. The rate of survival with any failure as the end point was 82% at five years and 64% at ten years. CONCLUSIONS: The use of a long stem for femoral impaction grafting did not completely resolve the problem of postoperative fractures in these patients with substantial loss of bone stock undergoing revision hip surgery. Poor bone stock, technical errors, and other patient-related factors continue to account for the high postoperative fracture rate.

Intramedullary strut substitution and impaction allografting cemented revision for the treatment of a periprosthetic fracture in a severely compromised femur.

Revision for the treatment of a B3 periprosthetic femoral fracture often requires proximal femoral allograft arthroplasty in physiologically young or tumor prostheses in elderly patients. Extramedullary strut allograft augmentation can only be used when the host femur is structurally adequate for the insertion of the revision stem (periprosthetic femoral fractures type B2) and appears to be an attractive biological concept as early incorporation to the host bone results in a sound biomechanical construct. We report here the simultaneous use of whole femur intramedullary strut substitution along with an extramedullary strut graft placement, with impaction allografting revision to a long cemented femoral prosthesis, to augment the deficient metadiaphyseal bone stock (Paprosky type IV) for the treatment of a complex type B3 periprosthetic femoral fracture.

Mixing bone graft with OP-1 does not improve cup or stem fixation in revision surgery of the hip: 5-year follow-up of 10 acetabular and 11 femoral study cases and 40 control cases.

BACKGROUND: Bone morphogenetic proteins (BMPs) have the potential to improve incorporation of allograft bone in revision surgery. This could result in improved fixation and graft incorporation. PATIENTS AND METHODS: We evaluated the effect of mixing OP-1 (BMP-7) with morselized allograft in hip revisions. In a case-control study, 20 acetabular revisions (10 in the study group, 10 controls) and 41 femoral revisions (11 in study group, 30 controls) were done using impaction allografting. The migration of the cups and stems was studied with radiostereometric analysis (RSA) for up to 5 years. Changes of bone mineral density around the femoral component were measured with dual energy X-ray adsorptiometry for 2 years. Bone remodeling and the extent of radiolucent lines were evaluated on conventional radiographs after 5 years. The clinical results were documented using Harris hip score. RESULTS: In the cup study, there was no significant difference in implant migration between the study and control groups. 4 sockets in the study group were classified as radiographically loose after 5 years and 2 of them were revised after 5 years. After 2 years, the stems in the study group showed slightly increased posterior tilt (0.3 degrees , p = 0.03). 1 stem in the study group loosened and was revised during the third year of observation. INTERPRETATION: The sample size and study design in our evaluation did not allow any firm conclusions. Absence of any trend to improved fixation and early revisions in the study group prompted us to stop recruitment to this study.

Dynamic compression plates for Vancouver type B periprosthetic femoral fractures: a 3-year follow-up of 18 cases.

BACKGROUND: There is no consensus on the best surgical treatment of periprosthetic femoral fractures. We report our experience with a dynamic compression plate. PATIENTS AND METHODS: We reviewed the results of 18 periprosthetic femoral fractures treated with open reduction and internal fixation using the dynamic compression plate (DCP). There were 7 Vancouver type B1, 2 type B2 and 9 type B3 fractures. 16 cases had previously undergone at least one revision procedure. In addition to a DCP plate, all B2 and B3 fractures were revised to cemented prostheses, and all B3 fractures were revised with impaction grafting. Mean follow-up was 39 months. RESULTS: The mean healing time for those 11 cases that united was 13 months. One B1-type and one B3-type fracture with plate fracture within 8 months of surgery failed to heal. Furthermore, one B1-type fracture and one B2-type fracture failed and developed nonunion. 3 patients died, from causes not related to surgery, within 8 months after surgery without signs of healing. INTERPRETATION: Open reduction and internal fixation using DCPs seems to be a valid method for the treatment of postoperative periprosthetic femoral fractures with stable stem in place. If the stem is unstable, we suggest that DCPs may be used in association with femoral revision using a long stem. In cases with stable stem (B1), we are inclined to agree with other authors that additional fixation using an extramedullary cortical strut graft may be necessary to improve stability and promote final healing.