Olof Wolf

A randomized study using DXA and RSA in 38 patients followed for 5 years

Background and purpose There is no consensus on the best rehabilitation regime after uncemented total hip arthroplasty. Theoretically, bone ingrowth into the implant should benefit from initial partial weight bearing. We investigated whether the degree of postoperative weight bearing influences the periprosthetic bone mineral density (BMD) and/or the stability of the CLS stem. Patients and methods 38 patients received an uncemented CLS stem and were randomized to either unrestricted postoperative weight bearing or to partial weight bearing for 3 months. Periprosthetic BMD was measured in the 7 Gruen zones with DXA and the stability of the femoral stem was assessed by radiostereometric analysis (RSA) after surgery and at 3, 12, 24, and 60 months. Results Periprosthetic BMD was not influenced by the type of postoperative weight bearing. BMD was reduced by 8–15% in all Gruen zones at 3 months. Restoration toward initial BMD was observed in all zones except in zone 7 (calcar region), where BMD was reduced by 22% at 5 years. Immediate weight bearing after surgery had no influence on the stability of the CLS stem, as assessed by RSA. Interpretation Immediate full weight bearing after uncemented total hip arthroplasty is safe. There is no difference in the periprosthetic BMD or in stability of the stem as measured by RSA compared to partial weight bearing for 3 months. BMD is reduced by more than 20% in the calcar region around a CLS stem after 5 years.Background and purpose There is no consensus on the best rehabilitation regime after uncemented total hip arthroplasty. Theoretically, bone ingrowth into the implant should benefit from initial partial weight bearing. We investigated whether the degree of postoperative weight bearing influences the periprosthetic bone mineral density (BMD) and/or the stability of the CLS stem. Patients and methods 38 patients received an uncemented CLS stem and were randomized to either unrestricted postoperative weight bearing or to partial weight bearing for 3 months. Periprosthetic BMD was measured in the 7 Gruen zones with DXA and the stability of the femoral stem was assessed by radiostereometric analysis (RSA) after surgery and at 3, 12, 24, and 60 months. Results Periprosthetic BMD was not influenced by the type of postoperative weight bearing. BMD was reduced by 8–15% in all Gruen zones at 3 months. Restoration toward initial BMD was observed in all zones except in zone 7 (calcar region), where BMD was reduced by 22% at 5 years. Immediate weight bearing after surgery had no influence on the stability of the CLS stem, as assessed by RSA. Interpretation Immediate full weight bearing after uncemented total hip arthroplasty is safe. There is no difference in the periprosthetic BMD or in stability of the stem as measured by RSA compared to partial weight bearing for 3 months. BMD is reduced by more than 20% in the calcar region around a CLS stem after 5 years.

Periprosthetic bone mineral density and fixation of the uncemented CLS stem related to different weight bearing regimes: A randomized study using DXA and RSA in 38 patients followed for 5 years

Background and purpose There is no consensus on the best rehabilitation regime after uncemented total hip arthroplasty. Theoretically, bone ingrowth into the implant should benefit from initial partial weight bearing. We investigated whether the degree of postoperative weight bearing influences the periprosthetic bone mineral density (BMD) and/or the stability of the CLS stem. Patients and methods 38 patients received an uncemented CLS stem and were randomized to either unrestricted postoperative weight bearing or to partial weight bearing for 3 months. Periprosthetic BMD was measured in the 7 Gruen zones with DXA and the stability of the femoral stem was assessed by radiostereometric analysis (RSA) after surgery and at 3, 12, 24, and 60 months. Results Periprosthetic BMD was not influenced by the type of postoperative weight bearing. BMD was reduced by 8–15% in all Gruen zones at 3 months. Restoration toward initial BMD was observed in all zones except in zone 7 (calcar region), where BMD was reduced by 22% at 5 years. Immediate weight bearing after surgery had no influence on the stability of the CLS stem, as assessed by RSA. Interpretation Immediate full weight bearing after uncemented total hip arthroplasty is safe. There is no difference in the periprosthetic BMD or in stability of the stem as measured by RSA compared to partial weight bearing for 3 months. BMD is reduced by more than 20% in the calcar region around a CLS stem after 5 years.Background and purpose There is no consensus on the best rehabilitation regime after uncemented total hip arthroplasty. Theoretically, bone ingrowth into the implant should benefit from initial partial weight bearing. We investigated whether the degree of postoperative weight bearing influences the periprosthetic bone mineral density (BMD) and/or the stability of the CLS stem. Patients and methods 38 patients received an uncemented CLS stem and were randomized to either unrestricted postoperative weight bearing or to partial weight bearing for 3 months. Periprosthetic BMD was measured in the 7 Gruen zones with DXA and the stability of the femoral stem was assessed by radiostereometric analysis (RSA) after surgery and at 3, 12, 24, and 60 months. Results Periprosthetic BMD was not influenced by the type of postoperative weight bearing. BMD was reduced by 8–15% in all Gruen zones at 3 months. Restoration toward initial BMD was observed in all zones except in zone 7 (calcar region), where BMD was reduced by 22% at 5 years. Immediate weight bearing after surgery had no influence on the stability of the CLS stem, as assessed by RSA. Interpretation Immediate full weight bearing after uncemented total hip arthroplasty is safe. There is no difference in the periprosthetic BMD or in stability of the stem as measured by RSA compared to partial weight bearing for 3 months. BMD is reduced by more than 20% in the calcar region around a CLS stem after 5 years.

The effects of different weight-bearing regimes on press-fit cup stability: a randomised study with five years of follow-up using radiostereometry

PurposeThere is little evidence to support immediate weight bearing after uncemented total hip arthroplasty (THA).MethodsThirty-seven patients with unilateral osteoarthritis of the hip received a press-fit cup. Cup stability was assessed with radiostereometry (RSA) over five years. Patients were randomised to immediate full weight bearing, or partial weight bearing for three months.ResultsAt five years, we found no difference in micromotion as assessed with radiostereometry. Numerically, there was more proximal translation and increased inclination with immediate weight bearing, but these values barely exceeded the precision limit for the method. Pooled data for the two groups revealed translations of 0.1-0.3 mm and rotations of 0.2-0.3° over the five year follow-up period.ConclusionsWe found no adverse effects of immediate weight bearing after THA in relation to stability of these press-fit cups. Early mobilisation might have other advantages.

Differences in hip bone mineral density may explain the hip fracture pattern in osteoarthritic hips

Introduction In patients with osteoarthritis of the hip (OAH), trochanteric fractures are much more common than femoral neck fractures. One reason may be altered bone composition in the proximal femurs. OAH often leads to a fixed external rotation of the hip, leading to difficulties in positioning during DXA measurements. We compared BMD in OAH-affected legs and healthy legs. Patients and methods 40 patients with strictly unilateral OAH were cross-sectionally investigated with DXA at the hips and heels bilaterally as well as body composition of the legs. 3 regions of interest in the proximal femur were measured: femoral neck (FN), trochanter (TR), and total hip (TH). The design of the study allowed us to perform paired t-test between the OAH side and the healthy side. Results BMD was increased by 4.1% in FN, and reduced by 8.3% in TR and 4.1% in TH (p < 0.001 for all comparisons). Interpretation The differences in BMD, with decrease in the trochanter and increase in the femoral neck, may offer an explanation for the pattern of hip fractures seen in osteoarthritis. External rotation of the hip cannot explain the differences in BMD.

Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [ 11 C]-D-deprenyl PET/CT

Graphical Abstract Abstract Background and aims Positron emission tomography (PET) with the radioligand [11C]-D-deprenyl has shown increased signal at location of pain in patients with rheumatoid arthritis and chronic whiplash injury. The binding site of [11C]-D-deprenyl in peripheral tissues is suggested to be mitochondrial monoamine oxidase in cells engaged in post-traumatic inflammation and tissue repair processes. The association between [11C]-D-deprenyl uptake and the transition from acute to chronic pain remain unknown. Further imaging studies of musculoskeletal pain at the molecular level would benefit from establishing a clinical model in a common and well-defined injury in otherwise healthy and drug-naive subjects. The aim of this study was to investigate if [11C]-D-deprenyl uptake would be acutely elevated in unilateral ankle sprain and if tracer uptake would be reduced as a function of healing, and correlated with pain localizations and pain experience. Methods Eight otherwise healthy patients with unilateral ankle sprain were recruited at the emergency department. All underwent [11 C]-D-deprenyl PET/CT in the acute phase, at one month and 6-14 months after injury. Results Acute [11C]-D-deprenyl uptake at the injury site was a factor of 10.7 (range 2.9-37.3) higher than the intact ankle. During healing, [11C]-D-deprenyl uptake decreased, but did not normalize until after 11 months. Patients experiencing persistent pain had prolonged [11C]-D-deprenyl uptake in painful locations. Conclusions and implications The data provide further support that [11C]-D-deprenyl PET can visualize, quantify and follow processes in peripheral tissue that may relate to soft tissue injuries, inflammation and associated nociceptive signaling. Such an objective correlate would represent a progress in pain research, as well as in clinical pain diagnostics and management.

Do Orthogeriatric Inpatients Have a Correct Medication List? A Pharmacist-Led Assessment of 254 Patients in a Swedish University Hospital

Introduction: Comorbidities and polypharmacy complicate the treatment of geriatric patients with acute orthopedic injuries. A correct medication history and an updated medication list are a prerequisite for safe treatment of these debilitated patients. Published evidence suggests favorable outcomes with comanaged care. The aim of this study was to assess the accuracy of the inpatient medication lists generated at admission and investigate the efficacy of a dedicated ward-based pharmacist to find and correct mistakes in these lists. Methods: A total of 254 patients were enrolled. The ward-based pharmacist performed the assessment regarding the accuracy of the medication list generated at admission by the method of medication reconciliation. Number of discrepancies and types of discrepancy were noted. Results: The 254 patients (176 women) had a mean age of 85 years (standard deviation 7.4 years, range 42-100 years). The most common reason for orthopedic admission was hip fracture. The mean number of discrepancies was 2.1 for all patients (range 0-13). Omission of a prescribed drug was the most common mistake. Fifty-six (22%) of the 254 assessed patients had a correct medication list. Discussion: The many discrepancies in our study may have several explanations but highlight the difficulties in taking a correct medication history of patients in a stressful environment with an extremely high workload. Moreover, electronic medication lists create challenges. Implementing new electronic tools for health care requires feedback, redesign, and adaptation to meet various needs of the users. Conclusion: In conclusion, orthogeriatric patients have an unsatisfactory high number of discrepancies in their medication lists. Clinical pharmacists can accurately identify many of these mistakes.

EFFEctS oF PoStoPERAtIvE WEIgHt-BEARIng on BoDy coMPoSItIon AnD BonE MInERAl DEnSIty AFtER uncEMEntED totAl HIP ARtHRoPlASty

OBJECTIVE To investigate whether a postoperative weight-bearing regimen affects changes in bone mineral density and body composition after uncemented total hip arthroplasty, and to investigate the changes over a 5-year period after the surgical procedure. DESIGN Secondary analysis of a previous randomized controlled trial. METHODS A total of 39 patients were randomized to immediate full weight-bearing or partial weight-bearing for 3 months. Dual-energy X-ray absorptiometry was used to measure bone mineral density of the contralateral hip and both heels and to measure body composition. RESULTS The weight-bearing regimen had no effect on change in bone mineral density or body composition after 3 and 12 months. At 5 years, there was a decrease in bone mineral density of 3% in the total body and 2-3% in the contralateral hip regions. At 5 years we found a decrease in total body bone mineral content of 5%, but no changes in fat mass or lean mass compared with preoperative values. CONCLUSION The postoperative weight-bearing regimen had no effect on changes in body composition or bone mineral density. Five years after total hip arthroplasty there was a decrease in bone mineral content and bone mineral density, but no changes in lean mass or fat mass.

The optimal timing of baseline radiostereometric analysis of uncemented press fit cups

Background and Aims: The baseline radiostereometric analysis (RSA) is usually performed during the first postoperative week. We investigated the micromotion of two uncemented press fit acetabular cups during the first week after total hip arthroplasty. Material and Methods: All study patients had unilateral osteoarthritis of the hip and received an uncemented THA combination consisting of a CLS stem and either an Allofit or an Interop acetabular cup. The study group consisted of 24 patients who underwent RSA within 1 hour after skin closure, and at 1 and 7 days after surgery. Results: The upper limit of the 95% confidence interval for micromotion was less than or close to the precision of the method for all studied directions during the first week after surgery. Mean values indicate proximal and medial translation of the uncemented cup at one week. Conclusions: We found only minimal micromotion, barely above the precision limit, measured as medial and proximal translations of these uncemented cups. This indicates that the first postoperative RSA measurement following a primary THA with an uncemented press fit acetabular cup should be made as early as possible after the first postoperative day.

Intraobserver and interobserver reliability of recategorized Neer classification in differentiating 2-part surgical neck fractures from multi-fragmented proximal humeral fractures in 116 patients

BACKGROUND Optimal fracture classification should be simple and reproducible and should guide treatment. For proximal humeral fractures, the Neer classification is commonly used. However, intraobserver and interobserver reliability of the Neer classification has been shown to be poor. In clinical practice, it is essential to differentiate 2-part surgical neck fractures from multi-fragmented fractures. Thus, the aim of this study was to evaluate whether surgeons can differentiate 2-part surgical neck fractures from multi-fragmented fractures using plain radiographs and/or computed tomography (CT). METHODS Three experienced upper limb specialists and trauma surgeons (B.O.S., A.P.L., and V.L.) independently reviewed and classified blinded plain radiographs and CT scans of 116 patients as showing 2-part surgical neck fractures or multi-fragmented fractures. Each imaging modality was reviewed and classified separately by each surgeon, after which each surgeon reviewed both modalities at the same time. This process was repeated by all surgeons after 24 weeks. Intraobserver and interobserver analyses were conducted using Cohen and Fleiss κ values, respectively. RESULTS The κ coefficient for interobserver reliability showed substantial correlation (0.61-0.73) and was as follows: 0.73 for radiographs alone, 0.61 for CT scans alone, and 0.72 for radiographs and CT scans viewed together. After 24 weeks, the process was repeated and intraobserver reliability was calculated.The κ coefficient for intraobserver reliability showed substantial correlation (0.62-0.75) and was as follows: 0.62 for radiographs alone, 0.64 for CT scans alone, and 0.75 for radiographs and CT scans viewed together. CONCLUSION Clinicians were able to differentiate 2-part surgical neck fractures from multi-fragmented fractures based on plain radiographs reliably.

Visualization of painful process in peripheral tissue using positron emission tomography and [11C]-d-deprenyl

Abstract Background/aims An objective correlate of ongoing painful process in peripheral tissue would represent a progress in the analysis of pain. The aim of this study was to investigate if the extent of the injury and inflammation in musculoskeletal injuries can be visualized, quantified and followed over time using positron emission tomography (PET) with the radioligand [11C]-D-deprenyl. Methods Eight otherwise healthy patients with unilateral ankle sprain were PET-imaged acutely and followed up twice, first a month and then up to over one year after injury. Results Acutely [11C]-D-deprenyl uptake was significantly increased by a factor 10.7 (range 2.9–37.3) in the injury sites as compared to the intact ankle. During healing [11C]-D-deprenyl uptake was reduced, but not normalized until after 11 months. Conclusions Patients experiencing persistent pain showed prolonged [11C]-D-deprenyl uptake in the injury sites. Thus, PET can be used to visualize, quantify and follow painful processes in peripheral tissue.