Osseointegration of minimally invasive sacroiliac joint fixation implants-A human retrieval study.

Minimally invasive sacroiliac joint fusion has become increasingly prevalent and is described to reduce pain and improve function. In some patients, pain can recur several months after primary surgery. Lack of early implant osseointegration might be a cause of pain and hence an indication for revision surgery. Triangular titanium implants are the most documented implant for minimally invasive sacroiliac joint fusion. There is, however, no knowledge of how triangular titanium implants osseointegrate in humans and whether fusion is induced over the sacroiliac joint. During planned revision surgery due to recurrent pain, six triangular titanium implants were retrieved from six different patients at median 9 months from primary surgery. All six implants were scanned using microcomputed tomography. The presence or absence of bone in-growth, on-growth, and through-growth of the implants was evaluated as an indication of implant osseointegration. Three of six implants showed no or minor signs of osseointegration. Of the three remaining implants, one showed partial osseointegration and two implants showed high degrees of osseointegration. This study showed that triangular titanium implants can osseointegrate into host bone in humans. When osseointegration occurs, triangular titanium implants can give fusion across the sacroiliac joint.

The effect of minimally invasive sacroiliac joint fusion compared to sham operation: a double-blind randomized placebo-controlled trial.

Background: Minimally invasive fusion of the sacroiliac joint as treatment for low back pain may reduce pain and improve function compared to non-operative treatment, although clear evidence is lacking. The aim of this trial was to evaluate the effect of minimally invasive sacroiliac joint fusion compared to sham surgery on sacroiliac joint pain reduction. Methods: In this double-blind randomized sham surgery-controlled trial patients with clinical diagnosis of sacroiliac joint pain confirmed with sacroiliac joint injection were included at two university hospitals in Sweden and Norway. Patients were randomized by the operating surgeon at each site to minimally invasive sacroiliac joint fusion or sham surgery. The primary endpoint was group difference in sacroiliac joint pain on the operated side at six months postoperatively, measured by the Numeric Rating Scale (0-10). Un-blinding and primary analysis were performed when all patients had completed six months follow-up. The trial is closed for new participants and was registered at clinicaltrials.gov: NCT03507049. Findings: Between September 1st, 2018 and October 22nd, 2021, 63 patients were randomized, 32 to the surgical group, 31 to the sham group. Mean age was 45 years (range 26-63) and 59 of 63 (94%) patients were female. The mean reduction in the operated sacroiliac joint from baseline to six months postoperative was 2.6 Numeric Rating Scale points in the surgical group and 1.7 points in the sham group (mean between groups difference -1.0 points; 95% CI, -2.2 to 0.3; p = 0.13). Interpretation: This double-blind randomized controlled trial could not prove that minimally invasive fusion of the sacroiliac joint was superior to sham surgery at six months postoperative. Funding: Sophies Minde Ortopedi supported a clinical research position for Engelke Marie Randers. Region Stockholm supported the cost for the Swedish ethical application and a clinical research appointment for Paul Gerdhem.

Long-term follow-up and survival of delayed total hip arthroplasty following acetabular fracture: a matched cohort study of 552 cases from the Norwegian Arthroplasty Register.

BACKGROUND: Operative treatment of acetabular fractures generally yields good results, but several authors report up to 15-20% of patients developing post-traumatic osteoarthritis (OA). Previous studies have shown that total hip arthroplasty (THA) following post-traumatic OA have inferior results compared to THA for primary OA. The aim of this study was to report on long-term outcome of THA following acetabular fracture, compared to primary OA. MATERIALS AND METHODS: We performed a matched cohort study with data from the Norwegian Arthroplasty Register (NAR). All patients receiving THA following an acetabular fracture between 1987 and 2018 were identified. A 3:1 matched cohort consisting of patients treated for primary OA with THA was selected using propensity scores and matched for age, gender and year of surgery. Survival analysis was performed with revision of any cause as endpoint. Cox regression was used to identify factors associated with risk of revision surgery. RESULTS: 552 cases were identified, 397 men and 155 women. Mean age was 58.8 (11-91) years. 224 had previously been operated for the acetabular fracture, 328 had been treated non-operatively. Mean follow up time was 8.7 (1-29) years. Implant survival at 10 years was 79.7% (75.6-83.3) and at 20 years 62.4% (55.5-69.3). The hazard ratio for revision was 1.38 (1.07-1.77, p < 0.001) compared to the OA cohort, regardless of operative or non-operative treatment of the index acetabular fracture. Uncemented acetabular components had an increased risk of revision with hazard ratio for revision 1.61 (p = 0.012). CONCLUSIONS: THA following an acetabular fracture can be performed with acceptable results regarding implant survival, however, we report an increased risk for revision when compared to primary OA. Our results indicate that previous operative fracture treatment does not increase the risk for THA revision compared to cases treated non-operatively.

Does temporary bridge plate fixation preserve joint motion after an unstable Lisfranc injury?

BACKGROUND: Recently, temporary bridge plate fixation has gained popularity in the treatment of unstable Lisfranc injuries. The technique aims to reduce the risk of posttraumatic osteoarthritis, and after plate removal, the goal is to regain joint mobility. Here we explore marker-based radiostereometric analysis (RSA) to measure motion in the 1st tarsometatarsal (TMT) joint and asses the radiological outcome in patients treated with this surgical technique. METHOD: Ten patients with an unstable Lisfranc injury were included. All were treated with a dorsal bridge plate over the 1st TMT joint and primary arthrodesis of the 2nd and 3rd TMT joints. The plate was removed four months postoperatively. Non- and weight-bearing RSA images were obtained one and five years postinjury to assess joint mobility and signs of osteoarthritis. RESULTS: Detectable 1st TMT joint motion was observed in 2/10 patients after one year, and 6/9 patients after five years. At the final follow-up, mean 1st TMT dorsiflexion was 2.0°. Radiologically, the incidence of posttraumatic osteoarthritis was present in 4/10 patients after one year, and 5/9 patients after five years. All patients had observed TMT joint stability throughout the follow-up period. CONCLUSION: Preservation of joint motion can be achieved with a temporary bridge plate fixation over the 1st TMT joint. TYPE OF STUDY/LEVEL OF EVIDENCE: Prospective cohort study/Therapeutically level IV.

Predicting total knee arthroplasty from ultrasonography using machine learning.

Objective: To investigate the value of ultrasonographic data in predicting total knee replacement (TKR). Design: Data from the Musculoskeletal Pain in Ullensaker study (MUST) was linked to the Norwegian Arthroplasty Register to form a 5-7 year prospective cohort study of 630 persons (69% women, mean (SD) age 64 (8.7) years). We examined the predictive power of ultrasound (US) features, i.e. osteophytes, meniscal extrusion, synovitis in the suprapatellar recess, femoral cartilage thickness, and quality for future knee osteoarthritis (OA) surgery. We investigated 4 main settings for multivariate predictive modeling: 1) clinical predictors (age, sex, body mass index, knee injury, familial OA and workload), 2) radiographic data (assessed by the Kellgren Lawrence grade, KL) with clinical predictors, 3) US features and clinical predictors. Finally, we also considered an ensemble of models 2) and 3) and used it as our fifth model. All models were compared using the Average Precision (AP) and the Area Under Receiver Operating Characteristic Curve (AUC) metrics. Results: Clinical predictors yielded AP of 0.11 (95% confidence interval [CI] 0.05-0.23) and AUC of 0.69 (0.58-0.79). Clinical predictors with KL grade yielded AP of 0.20 (0.12-0.33) and AUC of 0.81 (0.67-0.90). The clinical variables with ultrasound yielded AP of 0.17 (0.08-0.30) and AUC of 0.79 (0.69-0.86). Conclusion: Ultrasonographic examination of the knee may provide added value to basic clinical and demographic descriptors when predicting TKR. While it does not achieve the same predictive performance as radiography, it can provide additional value to the radiographic examination.

60% Reduction of reoperations and complications for elderly patients with hip fracture through the implementation of a six-item improvement programme.

INTRODUCTION: Hip fractures are common, serious and costly fractures in the elderly population. Several guidelines seeking to ensure best practice have been introduced. Although our institution complied with national guidelines for early surgery of hip fractures, no assessment of other evidence-based measures existed. We wanted to assess, test, implement and measure the impact of a quality improvement (QI) programme consisting of key elements proven to be important in the treatment of hip fractures. METHODS: We formed a multidisciplinary QI team, consisting of several specialists in different fields. The QI team assessed multiple possible process measures for inclusion in the programme and selected six measurable interventions for implementation: early surgery, correct administration of prophylactic antibiotics, surgery using proven methods and expertise, a multidisciplinary patient pathway and secondary fracture prevention. The improvement process was monitored by a statistical process control chart (SPC). Complications, reoperations and mortality were compared before (n=293) and after (n=182) the intervention. RESULTS: The SPC analyses indicated increasing adherence with all interventions throughout the improvement programme, and sustainability 7 years later. The last four periods showed a stable adherence above 90%. We found 60% reduction in major complications after the implementation of the improvement programme, from 19.1% to 7.7% (HR: 0.38 (95% CI: 0.23 to 0.61, p=0.0007). The need for reoperations due to complications fell from 12.6% to 4.9% (HR: 0.37 (95% CI: 0.21 to 0.67, p=0.0054). We did not find a difference in post-operative mortality after the implementation of the QI programme (HR: 0.95 (95% CI: 0.74 to 1.2, p=0.645). CONCLUSION: Our multiprofessional improvement programme achieved almost full adherence within 2 years and was sustainable 7 years later. The quality and safety of the care process were improved and led to a substantial and sustainable decrease in complications and reoperations.

Risk factors for revision surgery due to dislocation within 1 year after 111,711 primary total hip arthroplasties from 2005 to 2019: a study from the Norwegian Arthroplasty Register.

BACKGROUND AND PURPOSE: Dislocation of a hip prosthesis is the 3rd most frequent cause (after loosening and infection) for hip revision in Norway. Recently there has been a shift in surgical practice including preferred head size, surgical approach, articulation, and fixation. We explored factors associated with the risk of revision due to dislocation within 1 year and analyzed the impact of changes in surgical practice. PATIENTS AND METHODS: 111,711 cases of primary total hip arthroplasty (THA) from the Norwegian Arthroplasty Register were included (2005-2019) after primary THA with either 28 mm, 32 mm, or 36 mm femoral heads, or dualmobility articulations. A flexible parametric survival model was used to calculate hazard ratios for risk factors. Kaplan-Meier survival rates were calculated. RESULTS: There was an increased risk of revision due to dislocation with 28 mm femoral heads (HR 2.6, 95% CI 2.0-3.3) compared with 32 mm heads. Furthermore, there was a reduced risk of cemented fixation (HR 0.6, CI 0.5-0.8) and reverse hybrid (HR 0.6, CI 0.5-0.8) compared with uncemented. Also, both anterolateral (HR 0.5, CI 0.4-0.7) and lateral (HR 0.6, CI 0.5-0.7) approaches were associated with a reduced risk compared with the posterior approach. The time-period 2010-2014 had the lowest risk of revision due to dislocation. The trend during the study period was towards using larger head sizes, a posterior approach, and uncemented fixation for primary THA. INTERPRETATION: Patients with 28 mm head size, a posterior approach, or uncemented fixation had an increased risk of revision due to dislocation within 1 year after primary THA. The shift from lateral to posterior approach and more uncemented fixation was a plausible explanation for the increased risk of revision due to dislocation observed in the most recent time-period. The increased risk of revision due to dislocation was not fully compensated for by increasing femoral head size from 28 to 32 mm.

Compliance with national guidelines for antibiotic prophylaxis in hip fracture patients: a quality assessment study of 13 329 patients in the Norwegian Hip Fracture Register.

OBJECTIVE: We assessed compliance with new guidelines for prophylactic antibiotics in hip fracture surgery in Norway introduced in 2013. DESIGN: The data from the Norwegian Hip Fracture Register was used to assess the proportion of antibiotics given according to the national guidelines. SETTING: All hospitals in Norway performing hip fracture surgery in the period from 2011 to 2016. PARTICIPANTS: We studied 13 329 hemiarthroplasties (HAs) for acute hip fracture. MAIN OUTCOME MEASURE: Type and timing between first and last dose of prophylactic antibiotics compared with the national guidelines. RESULTS: Before the guidelines were introduced, the recommended drugs cephalotin or clindamycin was used in only 86.2% of all HAs. In 2016, one of the two recommended drugs was administered in 99.2% of HAs. However, hospitals' adaption of the recommended administration of the two drugs improved slowly, and by the end of the study period, only three out of five HAs were performed with the correct drug administered in the correct manner. We found major differences in compliance between hospitals. CONCLUSIONS: The change towards correct administration of antibiotic prophylaxis was varied both when investigating university and non-university hospitals. We suggest that both hospital leaders and the national Directorate of Health need to investigate routines for better dissemination of information and education to involved parties. Strong leadership concerning evidence-based guidelines on antibiotic prophylaxis in surgery may take away some autonomy from executing healthcare professionals, but will result in better patient care and antibiotic stewardship.

Efficacy of periacetabular osteotomy followed by progressive resistance training compared to progressive resistance training as non-surgical treatment in patients with hip dysplasia (PreserveHip) - a protocol for a randomised controlled trial.

INTRODUCTION: Periacetabular osteotomy (PAO) is an established treatment for adolescent and adult patients with hip dysplasia. However, the efficacy of PAO has not been tested against another surgical intervention or conservative treatment in a randomised controlled trial before. We suggest that progressive resistance training (PRT) could be an alternative to PAO. The primary aim of this trial is therefore to examine the efficacy of PAO followed by 4 months of usual care followed by 8 months of PRT compared to 12 months of solely PRT in patients with hip dysplasia eligible for PAO in terms of patient-reported pain measured by The Copenhagen Hip and Groin Outcome Score (HAGOS). METHODS AND ANALYSIS: This trial is a single-blinded multicentre randomised controlled clinical trial, where patients with hip dysplasia, who are eligible for PAO, will be randomised to either PAO followed by usual care and PRT or PRT only. Primary outcome is patient-reported pain, measured on the subscale pain on the HAGOS questionnaire 12 months after initiation of PAO or PRT. The key secondary outcomes are the other subscales of the HAGOS, adverse and serious adverse events, usage of painkillers (yes/no) and type of analgesics. Based on the sample size calculation, the trial needs to include 96 patients. ETHICS AND DISSEMINATION: The trial is approved by the Central Denmark Region Committee on Biomedical Research Ethics (Journal No 1-10-72-234-18) and by the Danish Data Protection Agency (Journal No 1-16-02-120-19). The trial is also approved by The Regional Committee for Medical and Health Research Ethics, Region South-East Norway (Ref. 2018/1603). All results from this trial will be published in international peer-reviewed scientific journals regardless of whether the results are positive, negative or inconclusive. TRIAL REGISTRATION NUMBER: NCT03941171.

Component Placement in Direct Lateral vs Minimally Invasive Anterior Approach in Total Hip Arthroplasty: Radiographic Outcomes From a Prospective Randomized Controlled Trial.

BACKGROUND: End-stage coxarthrosis is increasingly common; however, limited evidence exists on the effect of direct lateral approach (DLA) and minimally invasive direct anterior approach (MIDA) on component placement in total hip arthroplasty (THA). We therefore conducted a prospective, randomized controlled trial to determine the component placement in DLA vs MIDA in THA. METHODS: Between January 2012 and June 2013, 164 patients with clinically and radiologically confirmed coxarthrosis aged 20-80 years were randomized to either DLA or MIDA (active comparator). Excluded were patients with previous ipsilateral hip surgery, a body mass index >35 kg/m2, and/or mental disability. Primary clinical outcomes have been published elsewhere. Secondary outcomes included radiographic assessment of the acetabular component (cement-mantle thickness, inclination, and anteversion), femoral stem position (varus/valgus and THA index), offset restoration, and leg length discrepancy. RESULTS: The mean cement-mantle was significantly thicker in zone 1 in the MIDA group (mean difference = 0.51 mm, 95% confidence interval [CI] 0.09-0.93, P = .018), and the mean degrees of inclination and anteversion were higher in the MIDA group (mean difference = 2.5°, 95% CI 0.3-4.6, P = .023 and mean difference = 3.6°, 95% CI 2.2-5.0, P < .0001, respectively). According to the defined reference range, cup inclination was more often adequate in the DLA group (67.9% (53/78) in the DLA group vs 52.4% (43/82) in the MIDA group, P = .045). There were no differences in frontal or lateral femoral stem position, global offset restoration, or leg length discrepancy. CONCLUSION: In this population of Norwegian patients with coxarthrosis, radiographic assessment showed limited differences in component placement between MIDA and DLA. The findings suggest that component placement is similar in the 2 surgical approaches.

Outcome of 881 total hip arthroplasties in 747 patients 21 years or younger: data from the Nordic Arthroplasty Register Association (NARA) 1995-2016.

Background and purpose - The literature is scarce on the outcome of the youngest patients with total hip arthroplasties (THAs). We analyzed register data, revision risk, and related factors in patients 21 years or younger with THAs in the Nordic Arthroplasty Register Association (NARA). Patients and methods - We included all THA patients 21 years or younger reported during 1995 through 2016 to the Danish, Finnish, Norwegian, and Swedish hip arthroplasty registers and merged these into the NARA dataset. Primary outcome was any implant revision. Results - We identified 881 THAs in 747 patients. Mean age at primary surgery was 18 years (9-21). The indications for THA were pediatric hip diseases (33%), systemic inflammatory disease (23%), osteoarthritis (4%), avascular necrosis (12%), hip fracture sequelae (7%), and other diagnoses (21%). Unadjusted 10-year survival for all THAs was 86%. Comparison between indications showed no differences in survival. Uncemented implants were used most frequently. Survival for uncemented and cemented implants was the same adjusted for sex, indication, head size, and time period for primary surgery. Aseptic loosening was the main cause of revision. Interpretation - Both cemented and uncemented fixations seem to be a viable option in this age group, but with a lower implant survival than in older patient groups.

Do Postoperative Results Differ in a Randomized Trial Between a Direct Anterior and a Direct Lateral Approach in THA?

BACKGROUND: The direct lateral approach to THA provides good exposure and is associated with a low risk of dislocations, but can result in damage to the abductor muscles. The direct anterior approach does not incise muscle, and so recovery after surgery may be faster, but it has been associated with complications (including fractures and nerve injuries), and it involves a learning curve for surgeons who are unfamiliar with it. Few randomized trials have compared these approaches with respect to objective endpoints as well as validated outcome scores. QUESTIONS/PURPOSES: The purpose of this study was to compare the direct anterior approach with the direct lateral approach to THA with respect to (1) patient-reported and validated outcomes scores; (2) frequency and persistence of abductor weakness, as demonstrated by the Trendelenburg test; and (3) major complications such as infection, dislocation, reoperation, or neurovascular injury. METHODS: We performed a randomized controlled trial recruiting patients from January 2012 to June 2013. One hundred sixty-four patients with end-stage osteoarthritis were included and randomized to either the direct anterior or direct lateral approach. Before surgery and at 3, 6, 12, and 24 months, a physiotherapist recorded the Harris hip score (HHS), 6-minute walk distance (6MWD), and performed the Trendelenburg test directly after the 6MWD. The patients completed the Oxford Hip Score (OHS) and the EQ-5D. The groups were not different at baseline with respect to demographic data and preoperative scores. Both groups received the same pre- and postoperative regimes. Assessors were blinded to the approach used. One hundred fifty-four patients (94%) completed the 2-year followup; five patients from each group were lost to followup. RESULTS: There were few statistical differences and no clinically important differences in terms of validated or patient-reported outcomes scores (including the HHS, 6MWD, OHS, or EQ-5D) between the direct anterior and the lateral approach at any time point. A higher proportion of patients had a persistently positive Trendelenburg test 24 months after surgery in the lateral approach than the direct anterior approach (16% [12 of 75] versus 1% [one of 79]; odds ratio, 15; p = 0.001). Irrespective of approach, those with a positive Trendelenburg test had statistically and clinically important worse HHS, OHS, and EQ-5D scores than those with a negative Trendelenburg test. There were four major nerve injuries in the direct anterior group (three transient femoral nerve injuries, resolved by 3 months after surgery, and one tibial nerve injury with symptoms that persist 24 months after surgery) and none in the lateral approach. CONCLUSIONS: Based on our findings, no case for superiority of one approach over the other can be made, except for the reduction in postoperative Trendelenburg test-positive patients using the direct anterior approach compared with when using the direct lateral approach. Irrespective of approach, patients with a positive Trendelenburg test had clinically worse scores than those with a negative test, indicating the importance of ensuring good abductor function when performing THA. The direct anterior approach was associated with nerve injuries that were not seen in the group treated with the lateral approach. LEVEL OF EVIDENCE: Level I, therapeutic study.

Preoperative incipient osteoarthritis predicts failure after periacetabular osteotomy: 69 hips operated through the anterior intrapelvic approach.

BACKGROUND: Untreated developmental hip dysplasia may result in pain, loss of function and is a common cause of osteoarthritis (OA). The periacetabular osteotomy (PAO) was developed to relieve symptoms and postpone further degeneration of the hip. We aimed to assess preoperative clinical and radiographic prognostic factors and evaluate survivorship of PAO after medium-term follow-up of 7.4 (2-15) years. METHODS: 59 patients (69 hips) operated with a PAO through an anterior intrapelvic approach from 1999 to 2011 were retrospectively identified. The patients were evaluated radiographically and clinically with Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index and 15D quality of life questionnaires. Survival analyses identified native hip joint survival predictors. RESULTS: 9 hips (9 patients) were converted to a total hip arthroplasty (THA). Of the 50 remaining patients (60 hips), 44 patients (54 hips) were examined at medium-term follow-up. 3 patients were lost to follow-up or declined participation and 3 were interviewed by telephone. Patient age at time of surgery was 32 (14-44) years. Survival analyses showed 84.3% (95% confidence interval [CI], 68.7-92.5%) survival of the native hip at 8 years follow-up (number at risk 32) (worst case scenario 80% survival at 8 years, 95% CI, 63.9-89.2%, number at risk 32). Cox regression with presence of preoperative OA (Tönnis ⩾1), showed a crude hazard ratio for conversion to THA with preoperative OA of 13.73, p < 0.001. CONCLUSIONS: Periacetabular osteotomy through the anterior intrapelvic approach can be performed safely and with satisfactory results at medium-term follow-up. The presence of preoperative incipient OA (Tönnis ⩾1) is the most important predictor for poor hip joint survival.

Arthroscopic Surgical Procedures Versus Sham Surgery for Patients With Femoroacetabular Impingement and/or Labral Tears: Study Protocol for a Randomized Controlled Trial (HIPARTI) and a Prospective Cohort Study (HARP).

Study Design Study protocol for a randomized controlled trial and a prospective cohort. Background The number of arthroscopic surgical procedures for patients with femoroacetabular impingement syndrome (FAIS) has significantly increased worldwide, but high-quality evidence of the effect of such interventions is lacking. Objectives The primary objective will be to determine the efficacy of hip arthroscopic procedures compared to sham surgery on patient-reported outcomes for patients with FAIS (HIP ARThroscopy International [HIPARTI] Study). The secondary objective will be to evaluate prognostic factors for long-term outcome after arthroscopic surgical interventions in patients with FAIS (Hip ARthroscopy Prospective [HARP] Study). Methods The HIPARTI Study will include 140 patients and the HARP Study will include 100 patients. The international Hip Outcome Tool-33 will be the primary outcome measure at 1 year. Secondary outcome measures will be the Hip disability and Osteoarthritis Outcome Score, Arthritis Self-Efficacy Scale, fear of movement (Tampa Scale of Kinesiophobia), Patient-Specific Functional Scale, global rating of change score, and expectations. Other outcomes will include active hip range of motion, hip muscle strength tests, functional performance tests, as well as radiological assessments using radiographs and magnetic resonance imaging. Conclusion To determine the true effect of surgery, beyond that of placebo, double-blinded placebo-controlled trials including sham surgery are needed. The HIPARTI Study will direct future evidence-based treatment of FAIS. Predictors for long-term development and progression of degenerative changes in the hip are also needed for this young patient group with FAIS; hence, responders and nonresponders to treatment could be determined. J Orthop Sports Phys Ther 2018;48(4):325-335. doi:10.2519/jospt.2018.7931.

Metabolic syndrome as a risk factor for total hip or knee replacement due to primary osteoarthritis: a prospective cohort study (the HUNT study and the Norwegian Arthroplasty Register).

OBJECTIVE: Biochemical changes associated with obesity may accelerate osteoarthritis beyond the effect of mechanical factors. This study investigated whether metabolic syndrome and its components (visceral obesity, hypertension, dyslipidemia and insulin resistance) were risk factors for subsequent total hip replacement (THR) or total knee replacement (TKR) due to primary osteoarthritis. DESIGN: In this prospective cohort study, data from the second survey of the Nord-Trøndelag Health Study 2 (HUNT2) were linked to the Norwegian Arthroplasty Register for identification of the outcome of THR or TKR. The analyses were stratified by age (<50, 50-69.9 and ≥70 years) and adjusted for gender, body mass index, smoking, physical activity and education. RESULTS: Of the 62,661 participants, 12,593 (20.1%) were identified as having metabolic syndrome, and we recorded 1,840 (2.9%) THRs and 1,111 (1.8%) TKRs during a mean follow-up time of 15.4 years. Cox regression analyses did not show any association between full metabolic syndrome and THR or TKR, except in persons <50 years with metabolic syndrome who had a decreased risk of THR (hazard ratio [HR] 0.58, 95% CI 0.40-0.83). However, when including only participants whose exposure status did not change during follow-up, this protective association was no longer significant. Increased waist circumference was associated with increased risk of TKR in participants <50 years (HR 1.62, 95% CI 1.10-2.39) and 50-69.9 years (HR 1.43, 95% CI 1.14-1.80). Hypertension significantly increased the risk of TKR in participants <50 years (HR 1.38, 95% CI 1.05-1.81), and this risk was greater for men. CONCLUSION: This study found an increased risk of TKR in men <50 years with hypertension and persons <70 years with increased waist circumference. Apart from this, neither metabolic syndrome nor its components were associated with increased risk of THR or TKR due to primary osteoarthritis.

The direct anterior minimal invasive approach in total hip replacement: a prospective departmental study on the learning curve.

INTRODUCTION: Introduction of new surgical techniques is normal, but seldom monitored in real time. The purpose of this study was to monitor the learning curve when introducing a new surgical technique to a department. We did a prospective evaluation of the learning curve when introducing the minimally invasive direct anterior approach in total hip arthroplasty. We wish to investigate whether there is a learning curve for the direct anterior minimal invasive approach in total hip replacement and what are the early complications to this approach. METHODS: The department changed from the direct lateral approach to the minimally invasive direct anterior approach. We monitored the first 522 patients operated using this approach with regards to patient outcome scores and complications 6 months postoperatively. RESULTS: The last 250 patients operated all had significantly better results with regard to patient outcome scores and cup placement. We investigated 100 patients at a time and compared them with the rest of the patient and found the same pattern. This pattern ends when we reach patients somewhere between 200-300. DISCUSSIONS: We established the learning curve on a departmental level with regards to introduction of the minimal invasive direct anterior approach. We see a steady improvement in scores with regards to patient outcome scores and cup positioning until we reach a steady-state. The learning curve here flattens out. Departments must understand that one should expect early complications and somewhat less than optimal results at first when introducing this new surgical technique.

The mediating effect of body mass index on the relationship between smoking and hip or knee replacement due to primary osteoarthritis. A population-based cohort study (the HUNT Study).

To investigate the total effect of smoking on total hip or knee replacement (THR/TKR) due to primary osteoarthritis (OA) and to quantify the indirect effect of smoking through body mass index (BMI). Participants from the Nord-Trøndelag Health Study (the HUNT Study) were linked to the Norwegian Arthroplasty Register to detect the first THR or TKR due to primary OA. A mediation analysis was used to decompose the total effect of smoking into a direct and indirect effect. BMI was considered a mediator in the analysis. All effects were estimated as hazard ratios (HRs) with 95% confidence intervals (CIs). The indirect effect of smoking mediated through BMI was expressed as a percentage (proportion*100). In total 55 188 participants were followed up during 17.2 years (median). We identified 1322 THRs and 754 TKRs. For men, the total effect of current vs. never smoking revealed a decreased risk of THR (HR 0.59, 95% CI 0.46-0.76) and TKR (HR 0.47, 95% CI 0.32-0.66). For women, current smoking increased the risk of THR (HR 1.34, 95% CI 1.11-1.60). For men, 6% and 7% of the risk reduction for THR and TKR, respectively, was mediated by BMI. We found a negative association between smoking and THR or TKR for men. On the contrary, smoking was associated with increased risk of THR for women. Most of the effect of smoking on joint replacement risk remained unexplained by BMI.

Adverse Health Outcomes and Associations with Self-Reported General Health in Childhood Lymphoma Survivors.

BACKGROUND: The increased incidence of physical and psychosocial adverse health outcomes (AHOs) in childhood lymphoma survivors (CLSs) is well known, but these AHOs' association with self-reported general health is rarely described. AIM: We explored this association among long-term CLSs. METHODS: In 124 CLSs (Hodgkin: 81; non-Hodgkin: 43; median age: 33 years), physical AHOs were graded based on slightly modified common toxicity criteria for adverse effects (CTCAE)-4 recommendations (Grade 0-3). Psychosocial AHOs (pain, work inability, fatigue, and mental distress) were mainly assessed by validated patient-reported questionnaires (Grade 0-2). The results were related to contemporary self-reported general health. Statistical significance: p < 0.01. RESULTS: At least one physical AHO was found in 120 CLSs, being of Grades 1, 2, and 3, respectively, in 43, 43, and 34 survivors. The prevalence of psychosocial AHOs (Grades 1 or 2) was 63%, being Grade 2 in 62 CLSs. The CLSs described their general health as significantly reduced compared with controls, with the greatest reduction for survivors in whom physical AHOs were combined with moderate to severe psychosocial AHOs. CONCLUSION: Psychosocial more than physical AHOs impact on CLSs' current self-reported general health. Clinicians responsible for follow-up of CLSs should be aware of the strong reduction of contemporary general health by Grade 2 psychosocial AHOs. The study challenges the use of the physician-assessed CTCAE-4 categories in long-term cancer survivors and emphasizes the need to develop instruments, which reflect both physical and psychosocial AHOs in these individuals.

Implant Survival After Minimally Invasive Anterior or Anterolateral Vs. Conventional Posterior or Direct Lateral Approach: An Analysis of 21,860 Total Hip Arthroplasties from the Norwegian Arthroplasty Register (2008 to 2013).

BACKGROUND: Since 2008, there has been an increase in the use of minimally invasive surgery (MIS) through an anterior or anterolateral approach for total hip arthroplasty (THA) in Norway. We compared the MIS approaches with the conventional posterior and direct lateral approaches in terms of revision rates and risk of revision. METHODS: On the basis of data in the Norwegian Arthroplasty Register, 21,860 THAs with an uncemented stem, performed between 2008 and 2013, were identified and included in the cohort. Of these THAs, 2,017 were done through an MIS anterior approach; 2,087, through an MIS anterolateral approach; 5,961, through a posterior approach; and 11,795, through a direct lateral approach. Follow-up ended on December 31, 2015. Two and 5-year survival rates were calculated using Kaplan-Meier survival analysis. Relative risk (RR) was calculated using Cox regression analysis, with adjustment for age, sex, primary diagnosis, American Society of Anesthesiologists (ASA) grade, femoral head size, cup fixation, type of articulation, and duration of surgery and using 6 revision end points based on cause: any cause, infection, dislocation, femoral fracture, aseptic loosening, and other/unknown cause. The median duration of follow-up was 4.3 years. RESULTS: There were no significant differences among the surgical approaches with regard to the 2 and 5-year survival rates or RR of revision due to any cause. The RR of revision due to infection was 0.53 (95% confidence interval [CI] = 0.36 to 0.80, p = 0.002) for the MIS anterior and anterolateral approaches and 0.57 (95% CI = 0.40 to 0.80, p = 0.001) for the posterior approach compared with the direct lateral approach. The RR of revision due to dislocation was 2.1 (95% CI = 1.5 to 3.1, p < 0.001) for the posterior approach compared with the direct lateral approach but no significant difference in risk was found when the MIS anterior and anterolateral approaches were compared with the direct lateral approach (RR = 0.71, 95% CI = 0.40 to 1.3, p = 0.25). CONCLUSIONS: The revision rates and risk of revision associated with the MIS anterior and anterolateral approaches were not increased compared with those of the conventional posterior and direct lateral approaches. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incidence of total hip or knee replacement due to osteoarthritis in relation to thyroid function: a prospective cohort study (The Nord-Trøndelag Health Study).

BACKGROUND: To study whether thyroid function was associated with risk of hip or knee replacement due to primary osteoarthritis. METHODS: In a prospective cohort study, data from the second and third survey of the Nord-Trøndelag Health Study were linked to the Norwegian Arthroplasty Register in order to identify total hip or knee replacement as a result of primary osteoarthritis. RESULTS: Among 37 891 participants without previously known thyroid disease we recorded 978 total hip replacements (THRs) and 538 total knee replacements (TKRs) during a median follow-up time of 15.7 years. The analyses were adjusted for sex, age, BMI (body mass index), smoking, physical activity and diabetes. We did not find any association between TSH (thyroid stimulating hormone) and THR or TKR due to osteoarthritis. Neither were changes in TSH over time, or overt hypo- or hyperthyroidism, associated with incidence of THR or TKR. CONCLUSION: No association was found between thyroid function and hip or knee joint replacement due to osteoarthritis.