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.

Evaluation of in vivo wear of vitamin E-diffused highly crosslinked polyethylene at five years: a multicentre radiostereometric analysis study.

AIMS: The primary aim of this study was to compare the wear properties of vitamin E-diffused, highly crosslinked polyethylene (VEPE) and one formulation of moderately crosslinked and mechanically annealed ultra-high molecular weight polyethylene (ModXLPE) in patients five years after primary total hip arthroplasty (THA). The secondary aim was to assess the clinical results of patients treated with VEPE by evaluating patient-reported outcome measures (PROMs), radiological evidence of fixation, and the incidence of mechanical failure. PATIENTS AND METHODS: A total of 208 patients (221 THAs) from four international centres were recruited into a prospective study involving radiostereometric analysis (RSA) and the assessment of clinical outcomes. A total of 193 hips (87%) were reviewed at the five-year follow-up. Of these, 136 (70%) received VEPE (vs ModXLPE) liners and 68 (35%) received ceramic (vs metal) femoral heads. PROMs and radiographs were collected preoperatively and at one, two, and five years postoperatively. In addition, RSA images were collected to measure PE wear postoperatively and at one, two, and five years after surgery. RESULTS: We observed similar bedding in one year postoperatively and wear two years postoperatively between the two types of liner. However, there was significantly more penetration of the femoral head in the ModXLPE cohort compared with the VEPE cohort five years postoperatively (p < 0.001). The only variables independently predictive of increased wear were ModXLPE (vs VEPE) liner type (ß = 0.22, p = 0.010) and metal (vs ceramic) femoral head (ß = 0.21, p = 0.013). There was no association between increased wear and the development of radiolucency (p = 0.866) or PROMs. No patient had evidence of osteolysis. CONCLUSION: Five years postoperatively, patients with VEPE (vs ModXLPE) and ceramic (vs metal) femoral heads had decreased wear. The rates of wear for both liners were very low and have not led to any osteolysis or implant failure due to aseptic loosening.

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.

Incidence and related factors for intraoperative failed spinal anaesthesia for lower limb arthroplasty.

BACKGROUND: Spinal anaesthesia is the preferred choice for total hip- and knee arthroplasty (THA/TKA), due to the claimed superior outcome profile, relative simple technique and without the need for advanced airway support. However, choosing and informing about spinal anaesthesia should also include the risk for intraoperative failed spinal anaesthesia with associated pain, discomfort and suboptimal settings for airway management. Small-scale studies suggest incidences from 1 to 17%; however, no multi-institutional large data exists on failed spinal incidence and related factors during THA/TKA, hindering evidence-based information and potential anaesthesia stratification. METHODS: In a sub-analysis, data from a prospective study on spinal anaesthesia for THA/TKA were examined for incidence of intraoperative conversion to general anaesthesia. Potential perioperative factors (age, gender, American Society of Anaesthesiologist (ASA) score, height, weight, BMI, procedure, bupivacaine dosage and duration of time from spinal administration until end of surgery) were analysed with logistic regression for relation to failed spinal anaesthesia. RESULTS: In all, 1451 patients were included for analysis, whereof 57 (3.9%) had failed spinal anaesthesia. Spinal failure patients were significantly younger (61 vs. 67 years, P = 0.003), and operation time longer in the failed spinal group vs no-failure, respectively (133 vs. 89 min, P < 0.001). No significant differences were found with regard to bupivacaine volume, gender, ASA-score, height, weight, BMI or THA vs. TKA. CONCLUSION: Failed spinal anaesthesia for THA and TKA is a relatively frequent occurrence and identification of risk patients is not feasible. These results should be considered when choosing anaesthesia and included in the information to patients.

Pain and sensitization after total knee replacement or nonsurgical treatment in patients with knee osteoarthritis: Identifying potential predictors of outcome at 12 months.

BACKGROUND: This study is a secondary analysis of 12-month follow-ups from two parallel, randomized controlled trials (RCT) in painful knee osteoarthritis patients. RCT1: Total knee replacement (TKR) followed by nonsurgical treatment compared with nonsurgical treatment. RCT2: Nonsurgical treatment compared with usual care. The aims were to investigate (1) possible predictors of treatment outcome after TKR and nonsurgical interventions at 12 months, (2) associations between pain intensity and pressure pain thresholds (PPTs) (pain sensitization) at baseline and after 12 months and (3) possible gender differences. METHOD: Each RCT included 100 patients. Pain intensities, PPTs and number of painful sites were assessed at baseline and after 12 months. RESULTS: In all groups, pain improved and pain sensitization decreased. In RCT1, the TKR group had the greatest improvements in pain. In RCT2 the nonsurgical group had the greatest improvement, with no between-group differences in PPTs. Lower PPTs at baseline predicted higher pain after TKR. Baseline pain intensity and PPT levels were associated with the number of painful sites. Subjects with the highest pain and lowest PPTs at baseline showed the largest relative improvement in pain and sensitization but were still experiencing highest absolute pain and lowest PPTs after 12 months (combined cohorts). CONCLUSION: Low PPTs at baseline predicted worse pain outcome after TKR, but did not predict outcome after nonsurgical interventions. The number of painful sites was weakly associated with pain and PPTs, and the higher pain/lower PPTs, the higher pain/lower PPTs at 12 months with females showing the lowest PPT values. SIGNIFICANCE: Human experimental pain assessment was used to assess the degree of pain sensitization in patients with painful knee osteoarthritis. High sensitization before TKR predicted worse outcome. Outcome after nonsurgical interventions could not be predicted.

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.

The effects of total knee replacement and non-surgical treatment on pain sensitization and clinical pain.

BACKGROUND: The objective was to compare the effect of total knee replacement (TKR) followed by a 3-month non-surgical treatment with the non-surgical treatment alone in reducing pain sensitization and other pain-related measures in patients with knee osteoarthritis. METHODS: One hundred patients were randomized to (1) TKR followed by a non-surgical treatment of neuromuscular exercise, education, diet, insoles and pain medication or (2) the non-surgical treatment alone. Outcomes assessed at baseline and after 3 months were as follows: (1) pain sensitization assessed as pressure-pain thresholds (PPTs) at the knee (localized sensitization) and the lower leg (spreading sensitization), (2) peak pain intensity during the previous 24 h, (3) pain intensity after 30 min of walking, (4) pain location and pattern, (5) spreading of pain on a region-divided body chart and (6) the usage of pain medication. RESULTS: There was a statistical significant mean difference (95% CI) in change in PPTs from baseline to 3 months between groups in the crude analysis of 71 kPa (21-121) and of 75 kPa (33-117) when adjusting for baseline PPT, age, gender and body mass index, favouring the group having TKR. There were no significant between-group differences in change in the pain-related measures from baseline to 3 months (p = 0.15-0.27). Both groups improved in most of the pain-related measures (p < 0.05). CONCLUSIONS: At 3 months, TKR followed by non-surgical treatment is more effective in reducing localized and spreading pain sensitization than non-surgical treatment alone. Both treatments are equally efficacious in reducing the pain-related measures of this study. WHAT DOES THIS STUDY ADD?: Knee replacement followed by non-surgical treatment is more effective in reducing pain sensitization, but not other pain-related measures, as compared to non-surgical treatment alone at 3 months.

The efficacy of non-surgical treatment on pain and sensitization in patients with knee osteoarthritis: a pre-defined ancillary analysis from a randomized controlled trial.

OBJECTIVE: To report the efficacy of a 3-month treatment program consisting of neuromuscular exercise, education, diet, insoles and pain medication (MEDIC-treatment) compared to usual care (two leaflets with information and treatment advice) in reducing pain-related measures and sensitization in patients with knee osteoarthritis (OA) not eligible for total knee replacement (TKR). METHOD: A pre-defined ancillary analysis of the results at 3 months of a randomized controlled trial (RCT) of 100 patients randomized to MEDIC-treatment or usual care. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01535001). Outcomes were sensitization assessed at the knee, the lower leg and forearm using a handheld algometer, peak pain intensity in the previous 24 h, pain intensity after 30 min of walking, pain location and pattern, spreading of pain (a region-divided body chart) and the usage of pain medication. RESULTS: The MEDIC group had larger improvements from baseline to 3 months in peak pain intensity (P = 0.02) and pain after 30 min of walking (P < 0.001) and in the number of body sites with pain (P = 0.04). There was no difference in the change in sensitization from baseline to 3 months between groups (P = 0.87), but sensitization decreased in both groups (P < 0.001). CONCLUSION: A non-surgical treatment program is more efficacious in reducing pain-related measures than usual care, while both are equally efficacious in reducing sensitization, indicating that mechanisms other than pain sensitization contribute to the perceived pain. The patients did not have severe symptomatic knee OA and hence pain sensitization may not yet have developed into a clinically relevant parameter or subgroups with less sensitization may exist.

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.

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).

Facilitation of pain sensitization in knee osteoarthritis and persistent post-operative pain: a cross-sectional study.

BACKGROUND: Around 20% of patients with osteoarthritis (OA) have chronic post-operative pain after total knee arthroplasty (TKA) and often undergo revision surgery with unfavourable pain outcome. This study compared sensitization in pain patients with knee OA and after revision TKA (re-TKA). METHODS: Median pressure pain thresholds (PPTs) assessed from the most affected knee (localized sensitization) were used to subgroup 53 patients with OA pain and 20 patients with pain after re-TKA: group 1: OA and high-knee PPT; group 2: OA and low-knee PPT; group 3: re-TKA and high-knee PPT; group 4: re-TKA and low-knee PPT. Clinical pain intensity was assessed using a visual analogue scale (VAS). Bilateral PPTs were measured from the lower leg and forearm (spreading sensitization). Furthermore, the pain intensities evoked by 10 repeated pressure pain stimuli (temporal summation) at the knee and lower leg were assessed on an electronic VAS. RESULTS: The mean clinical pain intensity was not significantly different between groups. The PPTs from both lower leg and forearm were significantly lower in group 4 compared to groups 1, 2, and 3 and in groups 2 and 3 compared to group 1 (p < 0.05). Temporal summations from the knee and lower leg were significantly facilitated in groups 3 and 4 compared to groups 1 and 2 (p < 0.05). CONCLUSIONS: Despite similar pain intensities, facilitated temporal summation is worse in re-TKA than in OA and patients with high local knee hyperalgesia show more prominent spreading sensitization. The study suggests that sensitization should be considered in knee OA especially before re-TKA.

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.

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]. / Mange of patienterne i en åben skadestue kunne behandles hos vagtlaegen.

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]. / Fasciitis necroticans.

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.