Mismatch 'never events' in hip and knee arthroplasty: a cohort and intervention study

AIMS

The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check.

MATERIALS AND METHODS

Intraoperative barcode registration of arthroplasty implants was introduced in Denmark in 2013. We developed a compatibility database and, from May 2017, real-time compatibility checking was implemented and became part of the registration. We defined four classes of component incompatibility: A-I, A-II, B-I, and B-II, depending on an assessment of the level of risk to the patient (A/B), and on whether incompatibility was knowingly accepted (I/II).

RESULTS

A total of 26 524 arthroplasties were analyzed. From 12 307 procedures that were undertaken before implementation of the compatibility check, 21 class A incompatibilities were identified (real- or high-risk combinations; 0.17%; 95% confidence interval (CI) 0.11 to 0.26). From 5692 hip and 6615 knee procedures prior to implementation of the compatibility check, we found rates of class A-I incompatibility (real- or high-risk combinations unknowingly inserted) of 0.14% (95% CI 0.06 to 0.28) and 0.17% (95% CI 0.08 to 0.30), respectively. From 14 217 procedures after the introduction of compatibility checking (7187 hips and 7030 knees), eight class A incompatibilities (0.06%; 95% CI 0.02 to 0.11) were identified. This difference was statistically significant (p = 0.008).

CONCLUSION

Our data presents validated estimates of the baseline incidence of incompatibility events for hip and knee arthroplasty procedures and shows that a significant reduction in class A incompatibility events is possible using a web-based recording system. Cite this article: Bone Joint J 2019;101-B:960-969.

Incidence and Risk Factors for Stroke in Fast-Track Hip and Knee Arthroplasty-A Clinical Registry Study of 24,862 Procedures

BACKGROUND

Postoperative stroke is a severe complication with a reported 30-day incidence of 0.4%-0.6% after total hip (THA) and knee arthroplasty (TKA). However, most data are based on diagnostic codes and with limited details on perioperative care, including the use of fast-track protocols. We investigated the incidence of and preoperative and postoperative factors for stroke after fast-track THA/TKA.

METHODS

We used an observational study design of elective fast-track THA/TKA patients with prospective collection of comorbidity and complete 90-day follow-up. Medical records were evaluated for events potentially disposing to stroke. Identification of relevant preoperative risk factors was done by multivariable logistic regression. Incidence of stroke was compared with a Danish background population.

RESULTS

Of 24,862 procedures with a median length of stay of 2 (interquartile range, 2-3) days, we found 27 (0.11%; 95% confidence interval [CI], 0.08%-0.16%) and 43 strokes (0.17%, 95% CI, 0.13%-0.23%) ≤30 and ≤90 days after surgery, respectively. Preoperative risk factors for stroke ≤30 days were age ≥ 85 years (odds ratio [OR], 4.3; 95% CI, 1.1-16.3) and anticoagulant treatment (OR, 3.1; 95% CI, 1.2-7.9). Preoperative anemia was near significant (OR, 2.1; 95% CI, 0.98-4.6, P = .055). Eight strokes ≤30 days were preceded by a cardiovascular event within the second postoperative day. Incidence of stroke after postoperative day 30 was similar to a Danish background population.

CONCLUSION

Risk of postoperative stroke in fast-track THA and TKA was low but may be further reduced with increased focus on avoiding perioperative cardiovascular events and in patients with preoperative anticoagulants or anemia.

Bone remodelling of the proximal femur after total hip arthroplasty with 2 different hip implant designs: 15 years follow-up of the thrust plate prosthesis and the Bi-Metric stem

INTRODUCTION

The thrust plate prosthesis (TPP) was introduced to preserve bone in patients undergoing total hip arthroplasty. We assessed the long-term results of hip arthroplasty in patients who received the TPP compared to a traditional intramedullary stem (Bi-Metric).

METHODS

In this prospective observational cohort study, we evaluated bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA), radiological imaging and clinical outcome using Harris Hip Score (HHS). Twenty patients received the TPP (group A) and 18 patients received the Bi-Metric stem (group B). Baseline was the 1st postoperative day, and subsequent follow-up was performed at 6 months, 1, 2, 8, 12 and 15 years after surgery. A four regions of interest (ROI) protocol was developed to assess BMD.

RESULTS

In ROI1, bone resorption was significantly higher for group A at 6 months with a mean difference of 10% (95% confidence interval [CI], 4-16; p = 0.003) and 8% (95% CI, 1-15; p = 0.03) at 8 years. Regarding ROI4, group A had a lesser decrease in general compared to group B. The radiological findings did not reveal any subsidence or detectable implant migration. HHS improved from 53 (23-69) to 93 (55-100) in group A and from 51 (24-72) to 94 (78-100) in group B.

CONCLUSION

The TPP was not found to be inferior to the Bi-Metric stem regarding bone preservation. The decrease in BMD in ROI4 was greater in group B. Clinical and radiological results also revealed that the TPP was not inferior to the Bi-Metric stem.

Total knee replacement and non-surgical treatment of knee osteoarthritis: 2-year outcome from two parallel randomized controlled trials

OBJECTIVES

To compare 2-year outcomes of total knee replacement (TKR) followed by non-surgical treatment to that of non-surgical treatment alone and outcomes of the same non-surgical treatment to that of written advice.

DESIGN

In two randomized trials, 200 (mean age 66) adults with moderate to severe knee osteoarthritis (OA), 100 eligible for TKR and 100 not eligible for TKR, were randomized to TKR followed by non-surgical treatment, non-surgical treatment alone, or written advice. Non-surgical treatment consisted of 12 weeks of supervised exercise, education, dietary advice, use of insoles, and pain medication. The primary outcome was the mean score of the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, covering pain, symptoms, activities of daily living (ADL), and quality of life (QOL).

RESULTS

Patients randomized to TKR had greater improvements than patients randomized to non-surgical treatment alone (difference of 18.3 points (95% CI; 11.3 to 25.3)), who in turn improved more than patients randomized to written advice (difference of 7.0 points (95% CI; 0.4 to 13.5)). Among patients eligible for TKR, 16 (32%) from the non-surgical group underwent TKR during 2 years and among those initially ineligible, seven patients (14%) from the non-surgical group and ten (20%) from the written advice group underwent TKR.

CONCLUSIONS

TKR followed by non-surgical treatment is more effective on pain and function than non-surgical treatment alone, which in turn is more effective than written advice. Two out of three patients with moderate to severe knee OA eligible for TKR delayed surgery for at least 2 years following non-surgical treatment.

TRIAL REGISTRATION

ClinicalTrials.gov numbers NCT01410409 and NCT01535001.

Vitamin E diffused highly cross-linked polyethylene in total hip arthroplasty at five years: a randomised controlled trial using radiostereometric analysis

AIMS

The objective of this five-year prospective, blinded, randomised controlled trial (RCT) was to compare femoral head penetration into a vitamin E diffused highly cross-linked polyethylene (HXLPE) liner with penetration into a medium cross-linked polyethylene control liner using radiostereometric analysis.

PATIENTS AND METHODS

Patients scheduled for total hip arthroplasty (THA) were randomised to receive either the study E1 (32 patients) or the control ArComXL polyethylene (35 patients). The median age (range) of the overall cohort was 66 years (40 to 76).

RESULTS

The five-year median (interquartile range) proximal femoral head penetration into the E1 was -0.05 mm (-0.13 to -0.02) and 0.07 mm (-0.03 to 0.16) for ArComXL. At three and five years, the penetration was significantly greater in the ArComXL group compared with the E1 group (p = 0.029 and p = 0.019, respectively). All patient-reported outcomes (PROs) improved significantly from the pre-operative interval compared with those at one year, and remained favourable at five years. There were no differences between the two groups at any interval.

CONCLUSION

The five-year results showed that E1 polyethylene does not wear more than the control, ArComXL. This is the longest-term RCT comparing the wear performance and clinical outcome of vitamin E diffused HXLPE with a previous generation of medium cross-linked polyethylene. Cite this article: Bone Joint J 2017;99-B:577-84.

Criteria used when deciding on eligibility for total knee arthroplasty--Between thinking and doing

BACKGROUND

Clinical decision-making in total knee arthroplasty (TKA) is a complex process needing further clarification. The aim of this study was to compare TKA eligibility criteria considered most important by orthopedic surgeons (OSs) to characteristics of patients with knee osteoarthritis (OA) eventually found eligible for TKA.

METHODS

Nine OSs chose the five criteria most important when deciding on TKA eligibility. Cross-sectional data from 200 patients found either eligible (n=100) or not eligible (n=100) for TKA by one of the nine OS, were analyzed in a regression analyses with TKA eligibility as the dependent variable.

RESULTS

Radiographic severity (n=8), pain (n=9), functional disability (n=8) and not responding to the recommended non-surgical treatment (n=7) were considered most important by OSs. Associations (P<0.25) between TKA eligibility and criteria found important by the OS were demonstrated for worse radiographic severity and more functional limitations, but not for pain and not responding to the recommended non-surgical treatment. Furthermore, more comorbidities and higher Body Mass Index (BMI) were associated with TKA-eligibility, but not found important for TKA eligibility by the OS.

CONCLUSION

Radiographic severity and functional limitations were confirmed as drivers for TKA eligibility, while pain was not. Not responding to non-surgical treatment was not included in the decision-making, suggesting low uptake of clinical guidelines in clinical practice. This study highlights the complexity of the decision-making with some overlap between the criteria that OSs think they apply and what is actually applied in clinical practice.

Subchondral bone turnover, but not bone volume, is increased in early stage osteoarthritic lesions in the human hip joint

OBJECTIVE

The pathogenesis of osteoarthritis (OA) is not fully understood, but bone changes are suggested to be important. Bone turnover and bone volume (BV) in human hip OA were investigated in relation to the overlying cartilage degeneration using design-based stereological estimators.

MATERIALS AND METHODS

Femoral heads were obtained from 25 end-stage OA patients and 24 controls (CTL). Design-based stereological methods were used for sampling and quantification to obtain absolute estimates of volume and surface in the central trabecular and the subarticular bone region. The subarticular bone was further subdivided into regions according to the OARSI-score of the overlying articular cartilage in which erosion and osteoid surfaces were estimated.

RESULTS

In the subarticular region, bone volume (BV/TV) was 15.0% higher in OA patients compared to CTL; The fraction of erosive (ES/BS) and osteoid surfaces (OS/BS) were 56.2% and 72.8% higher in OA compared to CTL. In subarticular regions with none to mild cartilage degeneration (OARSI grade 0-2), ES/BS and OS/BS were 48.6% and 59.9% higher in OA compared to CTL, whereas BV/TV did not differ between OA and CTL.

CONCLUSION

In human end-stage hip OA, BV and bone turnover correlate with the degree of local cartilage degeneration. Subarticular bone sclerosis was only present in regions corresponding to end-stage OA. However, in regions with only none to mild cartilage degeneration the underlying bone had significantly higher turnover in OA patients compared to the control group, suggesting that high bone turnover may contribute to the early pathogenesis of OA.

Absence of a Tourniquet Does Not Affect Fixation of Cemented TKA: A Randomized RSA Study of 70 Patients

We aimed to determine whether not using a tourniquet in cemented TKA would affect migration of the tibial component measured by radiosterometric analysis (RSA). Seventy patients were randomized into a tourniquet group and a non-tourniquet group and using model-based RSA, the migration of the tibial component was analyzed. Primary and secondary outcome measures were maximum total point motion (MTPM) and translations and rotations. Follow-up period was 2 years. The tibial component was well fixated in both groups and no significant difference in migration between the two groups was detected (P=0.632). Mean MTPM (SD) was 0.47 mm (0.16) in the tourniquet group and 0.45 mm (0.21) in the non-tourniquet group. Absence of tourniquet indicates that stable fixation of the tibial component can be achieved in cemented TKA.

A Randomized, Controlled Trial of Total Knee Replacement

BACKGROUND

More than 670,000 total knee replacements are performed annually in the United States; however, high-quality evidence to support the effectiveness of the procedure, as compared with nonsurgical interventions, is lacking.

METHODS

In this randomized, controlled trial, we enrolled 100 patients with moderate-to-severe knee osteoarthritis who were eligible for unilateral total knee replacement. Patients were randomly assigned to undergo total knee replacement followed by 12 weeks of nonsurgical treatment (total-knee-replacement group) or to receive only the 12 weeks of nonsurgical treatment (nonsurgical-treatment group), which was delivered by physiotherapists and dietitians and consisted of exercise, education, dietary advice, use of insoles, and pain medication. The primary outcome was the change from baseline to 12 months in the mean score on four Knee Injury and Osteoarthritis Outcome Score subscales, covering pain, symptoms, activities of daily living, and quality of life (KOOS4); scores range from 0 (worst) to 100 (best).

RESULTS

A total of 95 patients completed the 12-month follow-up assessment. In the nonsurgical-treatment group, 13 patients (26%) underwent total knee replacement before the 12-month follow-up; in the total-knee-replacement group, 1 patient (2%) received only nonsurgical treatment. In the intention-to-treat analysis, the total-knee-replacement group had greater improvement in the KOOS4 score than did the nonsurgical-treatment group (32.5 vs. 16.0; adjusted mean difference, 15.8 [95% confidence interval, 10.0 to 21.5]). The total-knee-replacement group had a higher number of serious adverse events than did the nonsurgical-treatment group (24 vs. 6, P=0.005).

CONCLUSIONS

In patients with knee osteoarthritis who were eligible for unilateral total knee replacement, treatment with total knee replacement followed by nonsurgical treatment resulted in greater pain relief and functional improvement after 12 months than did nonsurgical treatment alone. However, total knee replacement was associated with a higher number of serious adverse events than was nonsurgical treatment, and most patients who were assigned to receive nonsurgical treatment alone did not undergo total knee replacement before the 12-month follow-up. (Funded by the Obel Family Foundation and others; MEDIC ClinicalTrials.gov number, NCT01410409.).

The efficacy of 12 weeks non-surgical treatment for patients not eligible for total knee replacement: a randomized controlled trial with 1-year follow-up

OBJECTIVE

To compare the efficacy of a 12-week non-surgical treatment program with usual care in patients with knee osteoarthritis (OA) not eligible for total knee replacement (TKR).

METHOD

This two-arm parallel group assessor-blinded randomized controlled trial (RCT) included 100 adults from secondary care with knee OA, confirmed by radiography (Kellgren-Lawrence grade ≥1), but not eligible for a TKR. The 12-week non-surgical treatment program consisted of individualized progressed neuromuscular exercise, patient education, insoles, dietary advice and prescription of pain medication if indicated, while usual care comprised two leaflets with information and advice on knee OA and recommended treatments. The primary outcome was the change from baseline to 12 months in the Knee injury and Osteoarthritis Outcome Score (KOOS)4 defined as the average score for the KOOS subscales of pain, symptoms, activities of daily living (ADL), and quality of life (QOL).

RESULTS

91% of the patients completed the 12 months follow-up on the primary outcome. Compared with usual care, patients undergoing the treatment program improved more in KOOS4 (adjusted mean difference (95% CI) of 9.6 (4.4-14.8)) with no serious treatment-related adverse events (AE). The number needed to treat (NNT), defined as the number of patients needed to treat for one person to improve 15% was 7.2. Secondary outcomes supported the primary findings.

CONCLUSION

In patients with mostly moderate to severe knee OA not eligible for TKR, a 12-week individualized, non-surgical treatment program is more efficacious at 12 months compared with usual care and has few treatment-related AE.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01535001).

Faster recovery without the use of a tourniquet in total knee arthroplasty

BACKGROUND AND PURPOSE

Tourniquet application is still a common practice in total knee arthroplasty (TKA) surgery despite being associated with several adverse effects. We evaluated the effects of tourniquet use on functional and clinical outcome and on knee range of motion (ROM).

PATIENTS AND METHODS

70 patients who underwent TKA were randomized into a tourniquet group (n = 35) and a non-tourniquet group (n = 35). All operations were performed by the same surgeon and follow-up was for 1 year. Primary outcomes were functional and clinical outcomes, as evaluated by KOOS and knee ROM. Secondary outcomes were intraoperative blood loss, surgical time and visibility, postoperative pain, analgesic consumption, and transfusion requirements.

RESULTS

Patients in the non-tourniquet group showed a better outcome in all KOOS subscores and better early knee ROM from surgery to week 8. No difference was detected at the 6- and 12-month follow-ups. Postoperative pain and analgesic consumption were less when a tourniquet was not used. Surgical time and visibility were similar between groups. Intraoperative blood loss was greater when not using a tourniquet, but no postoperative transfusions were required.

INTERPRETATION

This study shows that TKA without the use of a tourniquet results in faster recovery in terms of better functional outcome and improved knee ROM. Furthermore, reduced pain and analgesic use were registered and no intraoperative difficulties were encountered.

Thromboprophylaxis only during hospitalisation in fast-track hip and knee arthroplasty, a prospective cohort study

OBJECTIVES

International guidelines recommend thrombosis prophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) for up to 35 days. However, previous studies often have hospital stays (length of stay; LOS) of 8-12 days and not considering early mobilisation, which may reduce incidence of venous thromboembolic events (VTE). We investigated the incidence of any symptomatic thromboembolic events (TEEs) with only in-hospital prophylaxis if LOS ≤5 days after fast-track THA and TKA.

DESIGN

A prospective descriptive multicentre cohort study in fast-track THA and TKA from February 2010 to December 2011, with complete 90-day follow-up through the Danish National Patient Registry and patient files.

SETTING

6 Danish high-volume centres with a similar standardised fast-track setup, including spinal anaesthesia, opioid-sparing analgesia, early mobilisation, functional discharge criteria and discharge to own home.

PARTICIPANTS

4924 consecutive unselected unilateral primary THA and TKAs in patients ≥18 years with no preoperative use of continuous 'potent' anticoagulative therapy (vitamin K antagonists).

EXPOSURE

Prophylaxis with low-molecular-weight heparin or factor Xa-inhibitors only during hospitalisation when LOS ≤5 days.

OUTCOMES

Incidence of symptomatic TEE-related, VTE-related and VTE-related mortality ≤90 days postoperatively.

RESULTS

LOS ≤5 days and thromboprophylaxis only during hospitalisation occurred in 4659 procedures (94.6% of total). Median LOS and prophylaxis duration was 2 days (IQR 2-3) with 0.84% (95% CI 0.62% to 1.15%) TEE and 0.41% (0.26% to 0.64%) VTE during 90-day follow-up. VTE consisted of five pulmonary embolisms (0.11% (0.05% to 0.25%)) and 14 deep venous thrombosis (0.30% (0.18% to 0.50%)). There were four (0.09% (0.04% to 0.23%)) surgery-related deaths, of which 1 (0.02% (0.00% to 0.12%)) was due to pulmonary embolism, and 6 (0.13% (0.06% to 0.28%)) deaths of unknown causes after discharge.

CONCLUSIONS

The low incidence of TEE and VTE suggests that in-hospital prophylaxis only, is safe in fast-track THA and TKA patients with LOS of ≤5 days. Guidelines on thromboprophylaxis may need reconsideration in fast-track elective surgery.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01557725.

No superior performance of hydroxyapatite-coated acetabular cups over porous-coated cups

BACKGROUND AND PURPOSE

Hydroxyapatite (HA) coating is believed to improve bone-implant ingrowth and long-term survival of prostheses. Recent studies, however, have challenged this view. Furthermore, HA particles may produce third-body wear and initiate aseptic loosening of implants. We report the performance of HA- and porous-coated acetabular cups in a prospective randomized trial.

METHODS

This was an 8-year follow-up study of our previously published prospective randomized study to compare clinical outcomes, survival, periprosthetic bone mineral density, migration, and wear rates of HA- and porous-coated acetabular cups. Dual X-ray absorptiometry (DXA) and Ein Bild Roentgen Analyse (EBRA) measurements were used. 100 patients who underwent unilateral cementless total hip arthroplasty were randomized to either porous-coated cups or HA-coated cups. Patients were examined preoperatively and at 3, 6, and 9 months, and also 1, 3, and 8 years after surgery. 81 patients were available for 8-year follow-up, 40 with porous-coated cups and 41 with HA-coated cups.

RESULTS

Age, sex, bone mineral density, and clinical results (Harris hip score) were similar in the 2 groups. The survival, wear, and migration patterns of the cups were also similar in both groups. The results of periprosthetic bone mineral density scans in region of interest 2 was in favor of the porous-coated cups, but there were no differences between the 2 groups in all the remaining regions of interest.

INTERPRETATION

HA coating had no statistically significant effect on clinical results, survival, wear, or migration at the 8-year follow-up.

Relating clinical measures of pain with experimentally assessed pain mechanisms in patients with knee osteoarthritis

Background Peripheral and central sensitisation is prominent in knee osteoarthritis (KOA) and could be important for the reduced efficacy in some cases after as well surgery as pharmacological interventions. Although sensitisation is important in KOA it is not known to what degree it contributes to the overall clinical pain problem. The aim was therefore to investigate how much a combination of quantitative pain measures assessing various pain mechanisms (local and spreading hyperalgesia, temporal and spatial summation, descending inhibition) could predict peak pain intensity in patients with KOA. Methods While resting in a comfortable recumbent position the pressure pain thresholds (PPT) in the peripatellar region (eight locations) and at the tibialis anterior muscle (TA) were assessed by handheld pressure algometry, computer-controlled pressure algometry and cuff-algometry in the affected leg of 17 KOA patients without pain or sensory dysfunctions in other regions than the knee. Cuff-algometry was used to detect spatial pain summation of the lower leg. Temporal pain summation was assessed by repeated pressure stimulation on the TA muscle. The conditioning pain modulation (CPM) was evaluated by conditioning tonic arm pain and by PPT from the peripatellar region. The participants rated their peak pain intensity in the previous 24 h using on a 10 cm visual analogue scale. Results A multiple-regression model based on TA pressure pain sensitivity (spreading sensitisation) and temporal pain summation on the lower leg accounted for 55% of the variance in peak pain intensity experienced by the patients (P=0.001). Significant correlations (P< 0.05) were found between PPTs assessed by handheld pressure algometry in the peripatellar region and at TA (R = 0.94), PPTs assessed by computer-controlled pressure algometry and handheld pressure algometry in the peripatellar region (R = 0.71), PPTs assessed by computer-controlled pressure algometry in the peripatellar region and handheld pressure algometry at TA (R = 0.71) and temporal summation at the knee and at TA (R = 0.73). Conclusion Based on the multiple regression model 55% variance of the perceived maximal pain intensity in painful KOA could be explained by the quantitative experimental pain measures reflecting central pain mechanisms (spreading sensitisation, temporal summation). The lack of other correlations between the methods used in assessing pain mechanisms in this study highlights the importance of applying different tests and different pain modalities when assessing the sensitised pain system as different methods add complementary information. Implications Clinical pain intensity can be explained by influences of different central pain mechanisms in KOA. This has implications for pain management in KOA where treatment addressing central pain components may be more important than previously acknowledged.

Total knee replacement plus physical and medical therapy or treatment with physical and medical therapy alone: a randomised controlled trial in patients with knee osteoarthritis (the MEDIC-study)

Background

There is a lack of high quality evidence concerning the efficacy of total knee arthroplasty (TKA). According to international evidence-based guidelines, treatment of knee osteoarthritis (KOA) should include patient education, exercise and weight loss. Insoles and pharmacological treatment can be included as supplementary treatments. If the combination of these non-surgical treatment modalities is ineffective, TKA may be indicated. The purpose of this randomised controlled trial is to examine whether TKA provides further improvement in pain, function and quality of life in addition to optimised non-surgical treatment in patients with KOA defined as definite radiographic OA and up to moderate pain.

Methods/Design

The study will be conducted in The North Denmark Region. 100 participants with radiographic KOA (K-L grade ≥2) and mean pain during the previous week of ≤ 60 mm (0–100, best to worst scale) who are considered eligible for TKA by an orthopaedic surgeon will be included. The treatment will consist of 12 weeks of optimised non-surgical treatment consisting of patient education, exercise, diet, insoles, analgesics and/or NSAIDs. Patients will be randomised to either receiving or not receiving a TKA in addition to the optimised non-surgical treatment. The primary outcome will be the change from baseline to 12 months on the Knee Injury and Osteoarthritis Outcome Score (KOOS)₄ defined as the average score for the subscale scores for pain, symptoms, activities of daily living, and quality of life. Secondary outcomes include the five individual KOOS subscale scores, EQ-5D, pain on a 100 mm Visual Analogue Scale, self-efficacy, pain pressure thresholds, and isometric knee flexion and knee extension strength.

Discussion

This is the first randomised controlled trial to investigate the efficacy of TKA as an adjunct treatment to optimised non-surgical treatment in patients with KOA. The results will significantly contribute to evidence-based recommendations for the treatment of patients with KOA.

Trial registration

Clinicaltrials.gov reference: NCT01410409

Sensitization in patients with painful knee osteoarthritis

Pain is the dominant symptom in osteoarthritis (OA) and sensitization may contribute to the pain severity. This study investigated the role of sensitization in patients with painful knee OA by measuring (1) pressure pain thresholds (PPTs); (2) spreading sensitization; (3) temporal summation to repeated pressure pain stimulation; (4) pain responses after intramuscular hypertonic saline; and (5) pressure pain modulation by heterotopic descending noxious inhibitory control (DNIC). Forty-eight patients with different degrees of knee OA and twenty-four age- and sex-matched control subjects participated. The patients were separated into strong/severe (VAS>or=6) and mild/moderate pain (VAS<6) groups. PPTs were measured from the peripatellar region, tibialis anterior (TA) and extensor carpi radialis longus muscles before, during and after DNIC. Temporal summation to pressure was measured at the most painful site in the peripatellar region and over TA. Patients with severely painful OA pain have significantly lower PPT than controls. For all locations (knee, leg, and arm) significantly negative correlations between VAS and PPT were found (more pain, more sensitization). OA patients showed a significant facilitation of temporal summation from both the knee and TA and had significantly less DNIC as compared with controls. No correlations were found between standard radiological findings and clinical/experimental pain parameters. However, patients with lesions in the lateral tibiofemoral knee compartment had higher pain ratings compared with those with intercondylar and medial lesions. This study highlights the importance of central sensitization as an important manifestation in knee OA.

Bone remodelling around HA-coated acetabular cups : a DEXA study with a 3-year follow-up in a randomised trial

This study was designed to investigate bone remodelling around the cup in cementless THA. Previous studies indicate an advantage of better sealing of the bone-prosthesis interface by HA/TCP coating of implants, inhibiting polyethylene-induced osteolysis. One hundred patients gave informed consent to participate in a controlled randomized study between porous coated Trilogy versus Trilogy Calcicoat (HA/TCP coated). The cup was inserted in press-fit fixation. The femoral component was a cementless porous coated titanium alloy stem (Bi-Metric), with a modular 28-mm CrCo head. The Harris Hip Score (HHS) and bone mineral density (BMD) determined by DEXA scanning were used to study the effect. Measurements revealed no difference between the two groups after 3 years either in the clinical outcome or in terms of periprosthetic bone density. Patients with a body mass index above normal regained more bone mineral than patients with normal weight. This finding supports the assumption that load is beneficial to bone remodelling.

Detection of bony defects around cementless acetabular components in total hip arthroplasty: a DEXA study on 10 human cadavers

BACKGROUND

We studied the ability of DEXA to detect bony defects around cementless acetabular components in total hip arthroplasty. The aim of our study was to provide a tool for detection and quantification of osteolytic lesions for the planning of revision cases.

METHODS

We measured BMC in 10 human pelvis specimens retrieved from post mortem. We created standardized defects behind inserted acetabular components and compared the ash weights of the removed bone to the corresponding BMC measurements.

RESULTS

We found a good correlation between the BMC differences measured and the corresponding ash weights.

INTERPRETATION

We conclude that DEXA can detect even small defects in the bone adjacent to the cup.

DXA scanning of acetabulum in patients with cementless total hip arthroplasty

The aim of this study was to evaluate the reproducibility of bone mineral density (BMD) measurements of the periprosthetic bone in patients with hemispherical acetabular cups in cementless total hip arthroplasty (THA). Thirty patients were treated for primary osteoarthrosis with cementless THA. Dual-energy X-ray absorptiometry (DXA) scanning was performed with a pencil-beam bone densitometer (Norland XR-36). Accuracy and reproducibility was determined by double measurements of BMD in four regions of interest (ROI). The influence of patient postures including various pelvic inclination angles was evaluated as well. Pitman test for a combined netROI revealed a standard deviation ratio of 3.2 for the anterio-posterior scans related to the lateral position. The Wilkinson ROIs showed a high intraobserver agreement. With pelvic tilt increasing until 20 degrees , the precision of DXA scanning decreased. In conclusion, reproducibility of DXA scanning was high. This study demonstrated that the patients can be scanned in the supine position, and BMD measurement of the periacetabular bone can be performed using the Wilkinson model with four rectangular ROIs.

Ilizarov treatment of tibial nonunions results in 16 cases

Treatment with the Ilizarov technique was performed in 16 patients with complex tibial nonunions. Two years post treatment the functional stage and patient satisfaction were recorded. There were 4 hypertrophic, 3 atrophic and 9 infected nonunions. Eleven patients had segmental bone loss. Fifteen nonunions united, and limb length discrepancy was reduced within 1.5 cm of the contralateral leg. Average time in the frame was 182 days. Fifteen of the 16 patients were satisfied with the treatment. One patient demanded an amputation after 3 months of treatment, despite good signs of healing. There were no refractures or recurrent infections. In conclusion the Ilizarov technique for complex nonunions has a high rate of success in achieving union and eradicating infection, bone loss and malalignment. The treatment is demanding both to the surgeon and to the patient, but we strongly recommend the Ilizarov treatment for tibial nonunion, especially in cases with chronic infection and severe bone loss.

Clavicular nonunions treated with compression plate fixation and cancellous bone grafting: the functional outcome

We evaluated fracture healing and functional outcome after surgery in 16 patients with midshaft clavicular nonunion. The operative treatment consisted of compression plate fixation and autologous cancellous bone graft. The follow-up examination took place at an average of 54 months (range 26 to 90 months) after surgery. Radiographs were reviewed, and 12 patients underwent clinical review. All fractures united successfully. Two patients had a second operation because of loosening of the screws shortly after the first operation. Eleven of 12 patients had a good or excellent Constant score (>70 points). Nine of 12 patients returned to their preinjury activity level. Treatment with compression plate and autologous cancellous bone graft yields a high rate of healing and an acceptable functional outcome.

[Many patients treated in the emergency department could be treated by a general practitioner on call]

Misuse of accident and emergency (A&E) departments is a problem throughout the world. Staffing A&E departments with general practitioners has been reported as successful in a few prospective studies. A medical audit of all A&E charts during one week was carried out. The audit-panel included two orthopaedic surgeons and two general practitioners. The charts were divided in two groups: 1) true A&E cases, 2) inappropriate A&E users, who should have visited the general practitioners' acute consultation instead. There was substantial agreement between audit-panel groups that 57% of attenders could visit the general practitioner instead. Ten percent of attenders received no treatment in the A&E department, but were transferred to other departments within the hospital. It is concluded that two-thirds of the A&E department attenders could have visited the general practitioners instead, for treatment or for referral to the relevant hospital department.

[Necrotizing fasciitis]

Necrotizing fasciitis is a rare soft tissue infection with a high rate of mortality. Decreased capacity of the immune response is the overall disposing factor. Necrotizing fasciitis can develop very rapidly, and a rapid diagnosis and aggressive surgery provides the best prognosis.