Anakinra in cerebral haemorrhage to target secondary injury resulting from neuroinflammation (ACTION): Study protocol of a phase II randomised clinical trial

BACKGROUND

Inflammation plays a vital role in the development of secondary brain injury after spontaneous intracerebral haemorrhage (ICH). Interleukin-1 beta is an early pro-inflammatory cytokine and a potential therapeutic target.

AIM

To determine the effect of treatment with recombinant human interleukin-1 receptor antagonist anakinra on perihematomal oedema (PHO) formation in patients with spontaneous ICH compared to standard medical management, and investigate whether this effect is dose-dependent.

METHODS

ACTION is a phase-II, prospective, randomised, three-armed (1:1:1) trial with open-label treatment and blinded end-point assessment (PROBE) at three hospitals in The Netherlands. We will include 75 patients with a supratentorial spontaneous ICH admitted within 8 h after symptom onset. Participants will receive anakinra in a high dose (loading dose 500 mg intravenously, followed by infusion with 2 mg/kg/h over 72 h; n = 25) or in a low dose (loading dose 100 mg subcutaneously, followed by 100 mg subcutaneous twice daily for 72 h; n = 25), plus standard care. The control group (n = 25) will receive standard medical management.

OUTCOMES

Primary outcome is PHO, measured as oedema extension distance on MRI at day 7 ± 1. Secondary outcomes include the safety profile of anakinra, the effect of anakinra on serum inflammation markers, MRI measures of blood brain barrier integrity, and functional outcome at 90 ± 7 days.

DISCUSSION

The ACTION trial will provide insight into whether targeting interleukin-1 beta in the early time window after ICH onset could ameliorate secondary brain injury. This may contribute to the development of new treatment options to improve clinical outcome after ICH.

Development and External Validation of a Model to Predict Overall Survival in Patients With Resected Gallbladder Cancer

OBJECTIVE

The aim of this study was to develop and validate a clinical prediction model to predict overall survival in patients with nonmetastatic, resected gallbladder cancer (GBC).

BACKGROUND

Although several tools are available, no optimal method has been identified to assess survival in patients with resected GBC.

METHODS

Data from a Dutch, nation-wide cohort of patients with resected GBC was used to develop a prediction model for overall survival. The model was internally validated and a cohort of Australian GBC patients who underwent resection was used for external validation. The performance of the American Joint Committee on Cancer (AJCC) staging system and the present model were compared.

RESULTS

In total, 446 patients were included; 380 patients in the development cohort and 66 patients in the validation cohort. In the development cohort median survival was 22 months (median follow-up 75 months). Age, T/N classification, resection margin, differentiation grade, and vascular invasion were independent predictors of survival. The externally validated C-index was 0.75 (95%CI: 0.69-0.80), implying good discriminatory capacity. The discriminative ability of the present model after internal validation was superior to the ability of the AJCC staging system (Harrell C-index 0.71, [95%CI: 0.69-0.72) vs. 0.59 (95% CI: 0.57-0.60)].

CONCLUSION

The proposed model for the prediction of overall survival in patients with resected GBC demonstrates good discriminatory capacity, reasonable calibration and outperforms the authoritative AJCC staging system. This model can be a useful tool for physicians and patients to obtain information about survival after resection and is available from https:// gallbladderresearch.shinyapps.io/Predict_GBC_survival/.

Arthroscopic partial meniscectomy vs non-surgical or sham treatment in patients with MRI-confirmed degenerative meniscus tears: a systematic review and meta-analysis with individual participant data from 605 randomised patients

OBJECTIVE

To identify subgroups of patients with magnetic resonance imaging (MRI)-confirmed degenerative meniscus tears who may benefit from arthroscopic partial meniscectomy (APM) in comparison with non-surgical or sham treatment.

METHODS

Individual participant data (IPD) from four RCTs were pooled (605 patients, mean age: 55 (SD: 7.5), 52.4% female) as to investigate the effectiveness of APM in patients with MRI-confirmed degenerative meniscus tears compared to non-surgical or sham treatment. Primary outcomes were knee pain, overall knee function, and health-related quality of life, at 24 months follow-up (0-100). The IPD were analysed in a one- and two-stage meta-analyses. Identification of potential subgroups was performed by testing interaction effects of predefined patient characteristics (e.g., age, gender, mechanical symptoms) and APM for each outcome. Additionally, generalized linear mixed-model trees were used for subgroup detection.

RESULTS

The APM group showed a small improvement over the non-surgical or sham group on knee pain at 24 months follow-up (2.5 points (95% CI: 0.8-4.2) and 2.2 points (95% CI: 0.9-3.6), one- and two-stage analysis, respectively). Overall knee function and health-related quality of life did not differ between the two groups. Across all outcomes, no relevant subgroup of patients who benefitted from APM was detected. The generalized linear mixed-model trees did also not identify a subgroup.

CONCLUSIONS

No relevant subgroup of patients was identified that benefitted from APM compared to non-surgical or sham treatment. Since we were not able to identify any subgroup that benefitted from APM, we recommend a restrained policy regarding meniscectomy in patients with degenerative meniscus tears.

Sustained inflammation, coagulation activation and elevated endothelin-1 levels without macrovascular dysfunction at 3 months after COVID-19

INTRODUCTION

Endothelial damage and thrombosis caused by COVID-19 may imperil cardiovascular health. More than a year since the WHO declared COVID-19 pandemic, information on its effects beyond the acute phase is lacking. We investigate endothelial dysfunction, coagulation and inflammation, 3 months post-COVID-19.

MATERIALS AND METHODS

A cohort study was conducted including 203 patients with prior COVID-19. Macrovascular dysfunction was assessed by measuring the carotid artery diameter in response to hand immersion in ice-water. A historic cohort of 312 subjects served as controls. Propensity score matching corrected for baseline differences. Plasma concentrations of endothelin-1 were measured in patients post-COVID-19, during the acute phase, and in matched controls. Coagulation enzyme:inhibitor complexes and inflammatory cytokines were studied.

RESULTS AND CONCLUSIONS

The prevalence of macrovascular dysfunction did not differ between the COVID-19 (18.6%) and the historic cohort (22.5%, RD -4%, 95%CI: -15-7, p = 0.49). Endothelin-1 levels were significantly higher in acute COVID-19 (1.67 ± 0.64 pg/mL) as compared to controls (1.24 ± 0.37, p < 0.001), and further elevated 3 months post-COVID-19 (2.74 ± 1.81, p < 0.001). Thrombin:antithrombin(AT) was high in 48.3%. Markers of contact activation were increased in 16-30%. FVIIa:AT (35%) and Von Willebrand Factor:antigen (80.8%) were elevated. Inflammatory cytokine levels were high in a majority: interleukin(IL)-18 (73.9%), IL-6 (47.7%), and IL-1ra (48.9%). At 3 months after acute COVID-19 there was no indication of macrovascular dysfunction; there was evidence, however, of sustained endothelial cell involvement, coagulation activity and inflammation. Our data highlight the importance of further studies on SARS-CoV-2 related vascular inflammation and thrombosis, as well as longer follow-up in recovered patients.

Septoplasty versus non-surgical management for nasal obstruction in adults with a deviated septum: economic evaluation alongside a randomized controlled trial

BACKGROUND

For years, the benefits of septoplasty have been questioned. Due to the scarce and inconclusive literature, several National Health Service (NHS) Clinical Commissioning Groups in England decided to add septal surgery to their list of restricted procedures with low clinical value. Recently, evidence was obtained that septoplasty is actually more effective than non-surgical management for nasal obstruction in adults with a deviated septum. However, the relation between costs and effects of septoplasty remains unknown.

METHODS

We conducted an economic evaluation alongside an open, multicenter, pragmatic randomized controlled trial in two tertiary and 16 secondary referral hospitals in the Netherlands. Adults with nasal obstruction and a deviated septum were randomized to (1) septoplasty with or without concurrent turbinate surgery or (2) non-surgical management consisting of (a combination of) medical treatment and watchful waiting. Analyses were performed on an intention-to-treat basis. Single imputation nested in the bootstrap percentile method (using 5000 bootstrap replications) was performed to assess the effect of missing data. After 12 and 24 months, we assessed the incremental costs per quality-adjusted life year (QALY) gained from a healthcare and a societal perspective.

RESULTS

A total of 203 adults were randomly assigned to septoplasty (N = 102) or non-surgical management (N = 101). After 12 months, the mean cost difference between septoplasty and non-surgical management using a healthcare or societal perspective was €1181 (95%CI €1038 to €1323) or €2192 per patient (95%CI €1714 to €2670), respectively. The mean QALY difference was 0.03 per patient (95%CI - 0.01 to 0.07). Incremental costs per QALY gained from a healthcare or societal perspective were €41,763 or €77,525, respectively. After 24 months, the mean cost difference between the two groups using a healthcare or societal perspective decreased to €936 (95%CI €719 to €1153) or €1671 per patient (95%CI €952 to €2390), respectively. The mean QALY difference increased to 0.05 per patient (95%CI - 0.03 to 0.14). Incremental costs per QALY gained from a healthcare or societal perspective became €17,374 or €31,024, respectively. Analyses of imputed data did not alter our findings.

CONCLUSIONS

Depending on the selected perspective, cost-effectiveness threshold, and time horizon, septoplasty has the potential to be cost-effective. Despite considerable uncertainty, septoplasty seems to be cost-effective from a healthcare perspective, after 24 months against a threshold of €20,000 per QALY. From a societal perspective, septoplasty is not yet cost-effective after 24 months, but it comes closer to the cost-effectiveness threshold as time passes by.

TRIAL REGISTRATION

Nederlands Trial Register, NTR3868 (https://www.trialregister.nl/trial/3698). Prospectively registered on February 21, 2013.

Near-infrared fluorescence imaging for sentinel lymph node identification in colon cancer: a prospective single-center study and systematic review with meta-analysis

Background

Near-infrared (NIR) fluorescence imaging has the potential to overcome the current drawbacks of sentinel lymph node mapping (SLNM) in colon cancer. Our aim was to provide an overview of current SLNM performance and of factors influencing successful sentinel lymph node (SLN) identification using NIR fluorescence imaging in colon cancer.

Methods

A systematic review and meta-analysis was conducted to identify currently used methods and results. Additionally, we performed a single-center study using indocyanine green (ICG) as SLNM dye in colon cancer patients scheduled for a laparoscopic colectomy. SLNs were analyzed with conventional hematoxylin-and-eosin staining and additionally with serial sectioning and immunohistochemistry (extended histopathological assessment). A true-positive procedure was defined as a tumor-positive SLN either by conventional hematoxylin-and-eosin staining or by extended histopathological assessment, independently of regional lymph node status. SLN procedures were determined to be true negatives if SLNs and regional lymph nodes revealed no metastases after conventional and advanced histopathology. SLN procedures yielding tumor-negative SLNs in combination with tumor-positive regional lymph nodes were classified as false negatives. Sensitivity, negative predictive value and detection rate were calculated.

Results

This systematic review and meta-analysis included 8 studies describing 227 SLN procedures. A pooled sensitivity of 0.63 (95% CI 0.51–0.74), negative predictive value 0.81 (95% CI 0.73–0.86) and detection rate of 0.94 (95% CI 0.85–0.97) were found. Upstaging as a result of extended histopathological assessment was 0.15 (95% CI 0.07–0.25). In our single-center study, we included 30 patients. Five false-negative SLNs were identified, resulting in a sensitivity of 44% and negative predictive value of 80%, with a detection rate of 89.7%. Eight patients had lymph node metastases, in three cases detected after extended pathological assessment, resulting in an upstaging of 13% (3 of 23 patients with negative nodes by conventional hematoxylin and eosin staining).

Conclusions

Several anatomical and technical difficulties make SLNM with NIR fluorescence imaging in colon cancer particularly challenging when compared to other types of cancer. As a consequence, reports of SLNM accuracy vary widely. Future studies should try to standardize the SLNM procedure and focus on early-stage colon tumors, validation of tracer composition, injection mode and improvement of real-time optical guidance.

Electronic supplementary material

The online version of this article (10.1007/s10151-019-02107-6) contains supplementary material, which is available to authorized users.

The risk of revision after total hip arthroplasty in young patients depends on surgical approach, femoral head size and bearing type; an analysis of 19,682 operations in the Dutch arthroplasty register

Background

Total hip arthroplasty (THA) is used increasingly in younger patients. There is little knowledge about the effect of THA characteristics on risk of revision, especially in young patients. Therefore, we studied the influence of both patient-related and surgical factors on the risk of revision using data from the Dutch Arthroplasty Registry (LROI).

Methods

All patients younger than 55 years with a primary THA implanted in the Netherlands between 2007 and 2017 were selected (n = 19,682). The covariates age, sex, primary diagnosis, ASA-classification, surgical approach, fixation method, bearing type, head size and year of surgery were entered into Cox proportional hazards models to calculate hazard ratios for the risk of revision.

Results

The overall 5-year survival of primary THA was 95.3% (95% CI, 94.9–95.6). Use of the anterior approach resulted in a lower risk of revision than the use of the posterolateral approach (HR: 0.66, 95% CI: 0.47–0.92). THAs with a head diameter ≥ 38 mm had a higher risk of revision (HR: 1.90, 95% CI: 1.33–2.72) than THAs with 32 mm heads. Use of MoM bearings resulted in an increased risk when compared to C-PE (HR: 1.76, 95% CI: 1.27–2.43).

Conclusion

The risk of revision in patients younger than 55 years depends on surgical approach, head size and bearing type. The anterior approach resulted in a decreased risk of revision, whereas use of ≥38 mm heads and MoM bearings resulted in an increased risk of revision for any reason.

The effect of surgery in tenosynovial giant cell tumours as measured by patient-reported outcomes on quality of life and joint function

AIMS

The aim of this study was to evaluate health-related quality of life (HRQoL) and joint function in tenosynovial giant cell tumour (TGCT) patients before and after surgical treatment.

PATIENTS AND METHODS

This prospective cohort study run in two Dutch referral centres assessed patient-reported outcome measures (PROMs; 36-Item Short-Form Health Survey (SF-36), visual analogue scale (VAS) for pain, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)) in 359 consecutive patients with localized- and diffuse-type TGCT of large joints. Patients with recurrent disease (n = 121) and a wait-and-see policy (n = 32) were excluded. Collected data were analyzed at specified time intervals preoperatively (baseline) and/or postoperatively up to five years.

RESULTS

A total of 206 TGCT patients, 108 localized- and 98 diffuse-type, were analyzed. Median age at diagnosis of localized- and diffuse-type was 41 years (interquartile range (IQR) 29 to 49) and 37 years (IQR 27 to 47), respectively. SF-36 analyses showed statistically significant and clinically relevant deteriorated preoperative and immediate postoperative scores compared with general Dutch population means, depending on subscale and TGCT subtype. After three to six months of follow-up, these scores improved to general population means and continued to be fairly stable over the following years. VAS scores, for both subtypes, showed no statistically significant or clinically relevant differences pre- or postoperatively. In diffuse-type patients, the improvement in median WOMAC score was statistically significant and clinically relevant preoperatively versus six to 24 months postoperatively, and remained up to five years' follow-up.

CONCLUSION

Patients with TGCT report a better HRQoL and joint function after surgery. Pain scores, which vary hugely between patients and in patients over time, did not improve. A disease-specific PROM would help to decipher the impact of TGCT on patients' daily life and functioning in more detail. Cite this article: Bone Joint J 2019;101-B:272-280.

The protective effect of anterior cruciate ligament reconstruction on articular cartilage: a systematic review of animal studies

OBJECTIVE

It is unclear if anterior cruciate ligament (ACL) reconstruction can prevent the onset of degenerative changes in the knee. Previous studies were inconclusive on this subject. The aim of this study was to systematically review all studies on the effect of ACL reconstruction on articular cartilage in animals.

DESIGN

Pubmed and Embase were searched to identify all original articles concerning the effect of ACL reconstruction on articular cartilage compared with both its positive (ACL transection) and negative (sham and/or non-operated) control in animals. Subsequently a Risk of bias and meta analysis was conducted based on five outcomes (gross macroscopic assessment, medical imaging, histological histochemical grading, histomophometrics and biomechanical characterization) related to articular cartilage.

RESULTS

From the 19 included studies, 29 independent comparisons could be identified which underwent ACL reconstruction with an average timing of data collection of 23 weeks (range 1-104 weeks). Due to limited data availability meta-analysis could only be conducted for gross macroscopic damage. ACL reconstruction caused significant gross macroscopic damage compared with intact controls (SMD 2.0 [0.88; 3.13]). These findings were supported by individual studies reporting on histomorphometrics, histology and imaging. No significant gross macroscopic damage was found when ACL reconstruction was compared with ACL transection (SMD -0.64 [-1.85; 0.57]).

CONCLUSION

This systematic review with an average follow up of included studies of 23 weeks (range 1-104 weeks) demonstrates that, in animals, ACL reconstruction does not protect articular cartilage from degenerative changes. The consistency of the direction of effect, provides some reassurance that the direction of effect in humans might be the same.

Lateral rim mesh in primary total hip arthroplasty

Aims

The aim of this study was to analyze the effect of a lateral rim mesh on the survival of primary total hip arthroplasty (THA) in young patients, aged 50 years or younger.

Patients and Methods

We compared a study group of 235 patients (257 hips) who received a primary THA with the use of impaction bone grafting (IBG) with an additional lateral rim mesh with a group of 306 patients (343 hips) who received IBG in the absence of a lateral rim mesh during the same period from 1988 to 2015. In the mesh group, there were 74 male and 183 female patients, with a mean age of 35 years (13 to 50). In the no-mesh group, there were 173 male and 170 female patients, with a mean age of 38 years (12.6 to 50). Cox regression analyses were performed to study the effect of a lateral rim mesh on acetabular component survival. Kaplan–Meier analyses with 95% confidence intervals (CIs) were performed to estimate the survival of the acetabular implant.

Results

The hazard ratio for the use of lateral rim mesh, adjusted for potential confounders, for acetabular revision for any reason was 0.50 (95% CI 0.13 to 1.93; p = 0.31) and for acetabular revision for aseptic loosening was 0.29 (95% CI 0.020 to 4.04; p = 0.35). The Kaplan–Meier analysis showed a ten-year survival for aseptic loosening of the acetabular of 98% (95% CI 95 to 100, n = 65 at risk) in the mesh group and 94% (89 to 98, n = 76 at risk) in the no-mesh group. The 15-year survival for aseptic acetabular loosening was 90% (81 to 100, n = 35 at risk) in the mesh group and 85% (77 to 94, n = 45 at risk) in the no-mesh group (p = 0.23).

Conclusion

This study shows that the use of a lateral rim mesh in primary THA in young patients is not associated with a higher risk of revision of the acetabular component. Therefore, we consider a lateral rim mesh combined with IBG to be effective in reconstructing segmental acetabular defects in primary THA.

Arthroscopic meniscectomy for degenerative meniscal tears reduces knee pain but is not cost-effective in a routine health care setting: a multi-center longitudinal observational study using data from the osteoarthritis initiative

OBJECTIVES

It is disputed whether arthroscopic meniscectomy is an (cost-) effective treatment for degenerative meniscus tears in day-to-day clinical practice. The objective of this study was to assess the cost-effectiveness of arthroscopic meniscectomy in subjects with knee osteoarthritis, in routine clinical practice, while taking into account the increased risk for future knee replacement surgery. We compared cost-effectiveness of arthroscopic meniscectomy compared to no surgery.

DESIGN

We used a state transition (Markov) simulation model to evaluate the cost-effectiveness of arthroscopic meniscectomy compared to no surgery in subjects with knee osteoarthritis (age range 45-79 years). Data used in the preparation of the current study were obtained from the Osteoarthritis Initiative (AOI) database. We applied a 9 years' time horizon (which is equal to the current OAI study follow up period), and evaluated cost-effectiveness from a societal perspective. The main outcome measure was the incremental cost-effectiveness ratio (Euros per quality adjusted life-year (QALY) gained).

RESULTS

Arthroscopic meniscectomy was associated with 8.09 (SD ± 0.07) QALYs at a cost of € 21,345 (SD ± 841), whereas the no surgery was associated with 8.05 (SD ± 0.07) QALYs at a cost of € 16,284 (SD ± 855). For arthroscopic meniscectomy, the incremental cost per QALY gained was € 150,754.

CONCLUSIONS

In day-to-day clinical practice, arthroscopic meniscectomy in subjects with knee osteoarthritis is associated with € 150,754 per QALY gained, which exceeds the generally accepted willingness to pay (WTP) (range € 20,000-€ 80,000).

External rotation of the femoral component increases asymmetry of the posterior condyles

AIMS

The morphometry of the distal femur was largely studied to improve bone-implant fit in total knee arthroplasty (TKA), but little is known about the asymmetry of the posterior condyles. This study aimed to investigate the dimensions of the posterior condyles and the influence of externally rotating the femoral component on potential prosthetic overhang or under-coverage.

PATIENTS AND METHODS

We analysed the shape of 110 arthritic knees at the time of primary TKA using pre-operative CT scans. The height and width of each condyle were measured at the posterior femoral cut in neutral position, and in 3º and 5º of external rotation, using both central and medial referencing systems. We compared the morphological characteristics with those of 14 TKA models.

RESULTS

In the neutral position, the dimensions of the condyles were nearly equal. Externally rotating the femoral cut by 3º and 5º with 'central referencing' induced width asymmetry > 3 mm in 23 (21%) and 33 (30%) knees respectively, while with 'medial referencing' it induced width asymmetry > 3 mm in 43 (39%) and 75 (68%) knees respectively. The asymmetries induced by rotations were not associated with gender, aetiology or varus-valgus alignment.

CONCLUSION

External rotation may amplify the asymmetry between the medial and lateral condyles, and exacerbate prosthetic overhang, particularly in the superolateral zone. 'Central referencing' guides result in less potential prosthetic overhang than 'medial referencing' guides. Cite this article: Bone Joint J 2017;99-B:894-903.

Evaluation of novel biodegradable three-armed- and hyper-branched tissue adhesives in a meniscus explant model

Current treatment methods to repair meniscal tears do not bring fully satisfactory results. Tissue adhesives are considered promising alternatives, since they are easy to apply and cause minimal tissue trauma. The first aim of this study was to analyze the adhesive properties of and tissue response to two recently developed biodegradable block copolymeric three-armed- and hyper-branched tissue adhesives. The second aim was to investigate if tissue surface modification with collagenase improves the attachment of the adhesives and increases the healing potential of the tissue. Cylindrical explants were harvested from bovine menisci. The central core of the explants was removed and glued back into the defect, with or without incubation in collagenase solution prior to gluing, using one of the novel glues, Dermabond® or fibrin glue. The repair constructs were cultured in vitro for 1 and 28 days. Adhesion tests and histology were performed to analyze the effects of the glue in combination with the additional treatment. The adhesive strength of the novel glues was 40-50 kPa, which was significantly higher than that of fibrin glue (15 kPa). Cells were present in direct contact with the glues, and the tissue remained vital during the whole culture period. Increased cellularity around the tear in the collagenase treated explants was observed after 1 day. The two newly developed tissue adhesives are attractive materials to be used for repair of meniscal tears. The beneficial influence of collagenase treatment in treating meniscal tears with glues still needs to be confirmed in more clinical relevant studies. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1405-1411, 2017.

Increased risk for knee replacement surgery after arthroscopic surgery for degenerative meniscal tears: a multi-center longitudinal observational study using data from the osteoarthritis initiative

OBJECTIVE

The primary objective was to assess whether patients with knee osteoarthritis and whom undergo arthroscopic meniscectomy have an increased risk for future knee replacement surgery.

DESIGN

Data used were obtained from the Osteoarthritis Initiative (OAI) study.

SETTING

Participants were enrolled, in four clinical centers, between February 2004 and May 2006 and were followed up on an annual basis up to and including 108-months from enrollment.

PARTICIPANTS

4674 participants (58.4% female), aged 45-79, of all ethnic groups, who had, and those who were at high risk for developing, symptomatic knee osteoarthritis were included, of which 3337 (71.4%) were included in the final follow up visit.

MAIN OUTCOME MEASURES

Hazard ratio of knee replacement surgery for participants who underwent arthroscopic meniscectomy during follow up compared to propensity score matched participants who did not undergo arthroscopic meniscectomy during follow up.

RESULTS

335 participants underwent arthroscopic meniscectomy during follow up, of which 63 (18.8%) underwent knee replacement surgery in the same knee. Of the 335 propensity score matched participants 38 (11.1%) underwent knee replacement surgery during follow up. Results from the Cox-proportional hazards model demonstrated that the hazard ratio of knee replacement surgery was 3.03 (95% CI (1.67-5.26)) for participants who underwent arthroscopic meniscectomy relative to the propensity score matched participants who did not undergo arthroscopic meniscectomy.

CONCLUSIONS

In patients with knee osteoarthritis arthroscopic knee surgery with meniscectomy is associated with a three fold increase in the risk for future knee replacement surgery.

Relaxation of the MCL after an Open-Wedge High Tibial Osteotomy results in decreasing contact pressures of the knee over time

PURPOSE

The objective of this study was to investigate the effect of a medial open-wedge osteotomy (OWO) and the release of the superficial medial collateral ligament (MCL) on the tibiofemoral cartilage pressure, the MCL tension and the valgus laxity of the knee.

METHODS

Seven fresh-frozen, human cadaveric knees were used. Medial and lateral mean contact pressure (CP), peak contact pressure (peakCP), and contact area (CA) were measured using a pressure-sensitive film (I-Scan; Tekscan, Boston, MA). The MCL tension was measured using a custom-made device. These measurements were continuously recorded for 5 min after an OWO of 10°. After the osteotomy, the valgus laxity was measured with a handheld Newtonmeter. For one knee, the measurements were continued for 24 h. At the end, a complete release of the superficial MCL was performed and the measurements were repeated at 10°.

RESULTS

There was relaxation of the MCL after the osteotomy; the tension dropped in 5 min with 10.7% (mean difference 20.5 N (95% CI 16.1-24.9)), and in 24 h, the tension decreased by 24.2% (absolute difference 38.8 N) (one knee). After the osteotomy, the mean CP, peakCP and CA increased in the medial compartment (absolute difference 0.17 MPa (95% CI 0.14-0.20), 0.27 MPa (95% CI 0.24-0.30), 132.9mm² (95% CI 67.7-198.2), respectively), and decreased in the lateral compartment (absolute difference 0.02 MPa (95% CI 0.03 -0.01), 0.08 MPa (95% CI 0.11 - 0.04), 47.0 mm² (95% CI -105.8 to 11.8), respectively). Only after a release of the superficial MCL, the mean CP, peak CP and CA significantly decreased in the medial compartment (absolute difference 0.17, 0.27 MPa, 119.8 mm², respectively), and increased in the lateral compartment (absolute difference 0.02, 0.11 MPa, 52.4 mm², respectively). After the release of the superficial MCL, a mean increase of 7.9° [mean difference - 0.1° (95% CI -1.9 to 1.6)] of the valgus laxity was found.

CONCLUSIONS

A release of the superficial MCL helps achieve the goal of reducing medial cartilage pressure in an OWO. There was considerable relaxation of the MCL after an OWO that resulted in a decrease of the mean CP in the medial and lateral compartments of the knee over time. However, cartilage pressure shifted from the medial to the lateral compartment only after release of the superficial MCL. The release of the superficial MCL caused a significant increase in the valgus laxity, which could influence stability after an OWO.

LEVEL OF EVIDENCE

I.

Short-term clinical results of revision elbow arthroplasty using the Latitude total elbow arthroplasty

Aims

Revision total elbow arthroplasty (TEA) is often challenging. The aim of this study was to report on the clinical and radiological results of revision arthroplasty of the elbow with the Latitude TEA.

Patients and Methods

Between 2006 and 2010 we used the Latitude TEA for revision in 18 consecutive elbows (17 patients); mean age 53 years (28 to 80); 14 women. A Kudo TEA was revised in 15 elbows and a Souter-Strathclyde TEA in three. Stability, range of movement (ROM), visual analogue score (VAS) for pain and functional scores, Elbow Functional Assessment Scale (EFAS), the Functional Rating Index of Broberg and Morrey (FRIBM) and the Modified Andrews’ Elbow Scoring System (MAESS) were assessed pre-operatively and at each post-operative follow-up visit (six, 12 months and biennially thereafter). Radiographs were analysed for loosening, fractures and dislocation. The mean follow-up was 59 months (26 to 89).

Results

The ROM of the elbow did not improve significantly. The mean EFAS and MAESS scores improved significantly six months post-operatively (18.6 points, standard deviation (sd) 7.7; p = 0.03 and 28.8 points, sd 8.6; p = 0.006, respectively) and continued to improve slightly or reached a plateau. The mean pain scores at rest (Z = -3.2, p = 0.001) and during activity (Z = -3.2, p = 0.001), and stability (Z = -3.0, p = 0.003) improved significantly six months post-operatively. Thereafter scores continued to improve slightly or a plateau was reached. There were no signs of loosening.

Conclusion

Revision surgery using the Latitude TEA results in improvement of functionality, reduced pain and better stability of the elbow. Improvement of ROM of the elbow should not be expected. Cite this article: Bone Joint J 2016;98-B:1086–92.

Tissue adhesives for meniscus tear repair: an overview of current advances and prospects for future clinical solutions

Menisci are crucial structures in the knee joint as they play important functions in load transfer, maintaining joint stability and in homeostasis of articular cartilage. Unfortunately, ones of the most frequently occurring knee injuries are meniscal tears. Particularly tears in the avascular zone of the meniscus usually do not heal spontaneously and lead to pain, swelling and locking of the knee joint. Eventually, after a (partial) meniscectomy, they will lead to osteoarthritis. Current treatment modalities to repair tears and by that restore the integrity of the native meniscus still carry their drawbacks and a new robust solution is desired. A strong tissue adhesive could provide such a solution and could potentially improve on sutures, which are the current gold standard. Moreover, a glue could serve as a carrier for biological compounds known to enhance tissue healing. Only few tissue adhesives, e.g., Dermabond(®) and fibrin glue, are already successfully used in clinical practice for other applications, but are not considered suitable for gluing meniscus tissue due to their sub-optimal mechanical properties or toxicity. There is a growing interest and research field focusing on the development of novel polymer-based tissue adhesives, but up to now, there is no material specially designed for the repair of meniscal tears. In this review, we discuss the current clinical gold standard treatment of meniscal tears and present an overview of new developments in this field. Moreover, we discuss the properties of different tissue adhesives for their potential use in meniscal tear repair. Finally, we formulate recommendations regarding the design criteria of material properties and adhesive strength for clinically applicable glues for meniscal tears.

Radiological characteristics of the knee joint in nail patella syndrome

Aim

Nail patella syndrome (NPS) is a skeletal dysplasia with patellofemoral dysfunction as a key symptom. We present the first in-depth radiological evaluation of the knee in a large series of NPS patients and describe the typical malformations.

Patients and Methods

Conventional radiological examination of 95 skeletally mature patients with NPS was performed. Patellar morphology was classified according to the Wiberg classification as modified by Baumgartl and Ficat criteria, and trochlear shape was classified according to the Dejour classification.

Results

Patellar aplasia was present in 4/90 (4%), and patellar hypoplasia in 77/90 (86%) of patients. The prevailing patellar shapes were type III, type IV and Hunter’s cap. No patellar shape genotype-phenotype association could be found. The malformations of the distal femur comprised shortening of the lateral femoral condyle in 46 out of 84 patients (55%), with a prominent anterior surface of the lateral femoral condyle in 47 out of 84 patients (56%) and a flat anterior surface of the medial femoral condyle in 78 out of 85 patients (92%). The trochlea was type A1 according to the Dejour classification in 79 out of 85 patients (93%).

Conclusion

An easily recognisable characteristic quartet of malformations consisting of patellar aplasiaor hypoplasia and the malformations of the distal femur was found in 22 out of 81 patients (27%), with the majority displaying at least three malformations. Take home message: The distinct malformations of the knee in nail patella syndrome are easily recognisable on conventional radiographs and lead to the correct interpretation of the aberrant morphology which is essential in the treatment of these patellofemoral disorders. Cite this article: Bone Joint J 2016;98-B:483–9.

Functional biomechanical performance of a novel anatomically shaped polycarbonate urethane total meniscus replacement

PURPOSE

To evaluate the functional biomechanical performance of a novel anatomically shaped, polycarbonate urethane total meniscus implant.

METHODS

Five human cadaveric knees were flexed between 0° and 90° under compressive loads mimicking a squat movement. Anteroposterior (AP) laxity tests were performed in 30° and 90° flexion. Meniscal kinematics and knee laxity were quantified using roentgen stereophotogrammetric analysis. Tibial cartilage contact mechanics were determined in 90° flexion. Measurements were repeated for the native medial meniscus, the implant, after total medial meniscectomy and allograft transplantation.

RESULTS

The implant and allograft displayed increased posterior and medial displacements compared to the native meniscus, yet no differences were found between the implant and allograft. Meniscal condition did not affect rotational laxity. Compared to the native joint, AP laxity for the implant was increased in 30° flexion, but not in 90°. The implant reduced the mean contact pressure compared to meniscectomy but could not restore contact pressures to native meniscus levels. Compared to the native meniscus, the implant significantly increased the peak pressure, while the contact area was reduced. Contact mechanics of the implant and allograft were never statistically different.

CONCLUSIONS

Biomechanical performance was similar for the implant and allograft. However, both meniscal replacements could not restore outcomes to native meniscus levels or sufficiently improve outcomes after meniscectomy. This was presumably caused by the mobility allowed by the suture-only horn fixation. The similarity of implant and allograft performance suggests that the novel implant has the biomechanical potential to serve as an alternative to meniscal allograft transplantation.

The protective effect of meniscus allograft transplantation on articular cartilage: a systematic review of animal studies

Despite widespread reporting on clinical results, the effect of meniscus allograft transplantation on the development of osteoarthritis is still unclear. The aim of this study was to systematically review all studies on the effect of meniscus allograft transplantation on articular cartilage in animals. Pubmed and Embase were searched for original articles concerning the effect of meniscus allograft transplantation on articular cartilage compared with both its positive (meniscectomy) and negative (either sham or non-operated) control in healthy animals. Outcome measures related to assessment of damage to articular cartilage were divided in five principal outcome categories. Standardized mean differences (SMD) were calculated and pooled to obtain an overall SMD and 95% confidence interval. 17 articles were identified, representing 14 original animal cohorts with an average timing of data collection of 24 weeks [range 4 weeks; 30 months]. Compared to a negative control, meniscus allograft transplantation caused gross macroscopic (1.45 [0.95; 1.95]), histological (3.43 [2.25; 4.61]) damage to articular cartilage, and osteoarthritic changes on radiographs (3.12 [1.42; 4.82]). Moreover, results on histomorphometrics and cartilage biomechanics are supportive of this detrimental effect on cartilage. On the other hand, meniscus allograft transplantation caused significantly less gross macroscopic (-1.19 [-1.84; -0.54]) and histological (-1.70 [-2.67; -0.74]) damage to articular cartilage when compared to meniscectomy. However, there was no difference in osteoarthritic changes on plain radiographs (0.04 [-0.48; 0.57]), and results on histomorphometrics and biomechanics did neither show a difference in effect between meniscus allograft transplantation and meniscectomy. In conclusion, although meniscus allograft transplantation does not protect articular cartilage from damage, it reduces the extent of it when compared with meniscectomy.

Short Term Evaluation of an Anatomically Shaped Polycarbonate Urethane Total Meniscus Replacement in a Goat Model

Purpose

Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed. This study evaluates the in vivo performance of the implant in a goat model, with a specific focus on the implant location in the joint, geometrical integrity of the implant and the effect of the implant on synovial membrane and articular cartilage histopathological condition.

Methods

The right medial meniscus of seven Saanen goats was replaced by the implant. Sham surgery (transection of the MCL, arthrotomy and MCL suturing) was performed in six animals. The contralateral knee joints of both groups served as control groups. After three months follow-up the following aspects of implant performance were evaluated: implant position, implant deformation and the histopathological condition of the synovium and cartilage.

Results

Implant geometry was well maintained during the three month implantation period. No signs of PCU wear were found and the implant did not induce an inflammatory response in the knee joint. In all animals, implant fixation was compromised due to suture breakage, wear or elongation, likely causing the increase in extrusion observed in the implant group. Both the femoral cartilage and tibial cartilage in direct contact with the implant showed increased damage compared to the sham and sham-control groups.

Conclusion

This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading. Failure of the fixation sutures may have increased implant mobility, which probably induced implant extrusion and potentially stimulated cartilage degeneration. Evidently, redesigning the fixation method is necessary. Future animal studies should evaluate the improved fixation method and compare implant performance to current treatment standards, such as allografts.

Mid-term clinical results of a modern convertible total elbow arthroplasty

Unlinked, linked and convertible total elbow arthroplasties (TEAs) are currently available. This study is the first to report the clinical results of the convertible Latitude TEA. This was a retrospective study of a consecutive cohort of 63 patients (69 primary TEAs) with a mean age of 60 years (23 to 87). Between 2006 and 2008 a total of 19 men and 50 women underwent surgery. The mean follow-up was 43 months (8 to 84). The range of movement, function and pain all improved six months post-operatively and either continued to improve slightly or reached a plateau thereafter. The complication rate is similar to that reported for other TEA systems. No loosening was seen. Remarkable is the disengagement of the radial head component in 13 TEAs (31%) with a radial head component implanted.

Implantation of both the linked and the unlinked versions of the Latitude TEA results in improvement of function and decreased pain, and shows high patient satisfaction at mid-term follow-up.

Cite this article: Bone Joint J 2015; 97-B:681–8.

Which patient characteristics influence length of hospital stay after primary total hip arthroplasty in a ‘fast-track’ setting?

After implementation of a ‘fast-track’ rehabilitation protocol in our hospital, mean length of hospital stay for primary total hip arthroplasty decreased from 4.6 to 2.9 nights for unselected patients. However, despite this reduction there was still a wide range across the patients’ hospital duration. The purpose of this study was to identify which specific patient characteristics influence length of stay after successful implementation of a ‘fast-track’ rehabilitation protocol. A total of 477 patients (317 female and 160 male, mean age 71.0 years; 39.3 to 92.6, mean BMI 27.0 kg/m2;18.8 to 45.2) who underwent primary total hip arthroplasty between 1 February 2011 and 31 January 2013, were included in this retrospective cohort study. A length of stay greater than the median was considered as an increased duration. Logistic regression analyses were performed to identify potential factors associated with increased durations. Median length of stay was two nights (interquartile range 1), and the mean length of stay 2.9 nights (1 to 75). In all, 266 patients had a length of stay ≤ two nights. Age (odds ratio (OR) 2.46; 95% confidence intervals (CI) 1.72 to 3.51; p <  0.001), living situation (alone vs living together with cohabitants, OR 2.09; 95% CI 1.33 to 3.30; p = 0.002) and approach (anterior approach vs lateral, OR 0.29; 95% CI 0.19 to 0.46; p <  0.001) (posterolateral approach vs lateral, OR 0.24; 95% CI 0.10 to 0.55; p < 0.001) were factors that were significantly associated with increased length of stay in the multivariable logistic regression model.

Cite this article: Bone Joint J 2015;97-B:19–23.

Releasing the circumferential fixation of the medial meniscus does not affect its kinematics

BACKGROUND

Meniscal functioning depends on the fixation between the meniscal horns and the surrounding tissues. It is unknown, however, whether the integration between the outer circumference of the medial meniscus and the knee capsule/medial collateral ligament also influences the biomechanical behavior of the meniscus. Therefore, we aimed to determine whether detaching and resuturing the circumferential fixation of the medial meniscus influence its kinematic pattern.

METHODS

Human cadaveric knee joints were flexed (0°-30°-60°-90°) in a knee loading rig, in neutral orientation and under internal and external tibial torques. Roentgen stereophotogrammetric analysis was used to determine the motion of the meniscus in anteroposterior (AP) and mediolateral (ML) directions. Three fixation conditions were evaluated: (I) intact, (II) detached and (III) resutured.

RESULTS

Detaching and resuturing the circumferential fixation did not alter the meniscal motion pattern in either the AP or ML direction. Applying an additional internal tibial torque caused the medial meniscus to move slightly anteriorly, and an external torque caused a little posterior translation with respect to the neutral situation. These patterns did not change when the circumferential fixation condition was altered.

CONCLUSIONS

This study demonstrated that the motion pattern of the medial meniscus is independent of its fixation to the knee capsule and medial collateral ligament.

CLINICAL RELEVANCE

The outcomes of this study can be deployed to design the fixation strategy of a permanent meniscus prosthesis. As peripheral fixation is a complicated step during meniscal replacement, the surgical procedure is considerably simplified when non-resorbable implants do not require circumferential fixation.

Bone ingrowth potential of electron beam and selective laser melting produced trabecular-like implant surfaces with and without a biomimetic coating

The bone ingrowth potential of trabecular-like implant surfaces produced by either selective laser melting (SLM) or electron beam melting (EBM), with or without a biomimetic calciumphosphate coating, was examined in goats. For histological analysis and histomorphometry of bone ingrowth depth and bone implant contact specimens were implanted in the femoral condyle of goats. For mechanical push out tests to analyse mechanical implant fixation specimens were implanted in the iliac crest. The follow up periods were 4 (7 goats) and 15 weeks (7 goats). Both the SLM and EBM produced trabecular-like structures showed a variable bone ingrowth after 4 weeks. After 15 weeks good bone ingrowth was found in both implant types. Irrespective to the follow up period, and the presence of a coating, no histological differences in tissue reaction around SLM and EBM produced specimens was found. Histological no coating was detected at 4 and 15 weeks follow up. At both follow up periods the mechanical push out strength at the bone implant interface was significantly lower for the coated SLM specimens compared to the uncoated SLM specimens. The expected better ingrowth characteristics and mechanical fixation strength induced by the coating were not found. The lower mechanical strength of the coated specimens produced by SLM is a remarkable result, which might be influenced by the gross morphology of the specimens or the coating characteristics, indicating that further research is necessary.

The effect of E-beam engineered surface structures on attachment, proliferation and differentiation of human mesenchymal stem cells

Electron beam melting (E-beam) is a new technology to produce 3-dimensional surface topographies for cementless orthopedic implants. The effect of two newly designed highly porous E-beam engineered surface structures (cubic and star) on attachment, proliferation and differentiation of human mesenchymal stem cells (hMSCs) was investigated and compared to a solid sandblasted control. SEM analysis showed that the E-beam structures allowed cells to attach and spread. Proliferation on the new surface structures was comparable to the solid control. Furthermore, differentiation on the 3D structures was comparable to the control specimen. When culturing 300,000 cells for 10 days, the cubic structure showed a significantly higher differentiation rate compared to the sandblasted specimen. We conclude that the results for attachment, proliferation and differentiation of mesenchymal stem cells on the newly engineered 3-dimensional E-beam surface topographies are promising. In vivo experiments are necessary to assess the bone ingrowth potential of the new surface structures.

The effect of bone ingrowth depth on the tensile and shear strength of the implant-bone e-beam produced interface

New technologies, such as selective electron beam melting, allow to create complex interface structures to enhance bone ingrowth in cementless implants. The efficacy of such structures can be tested in animal experiments. Although animal studies provide insight into the biological response of new structures, it remains unclear how ingrowth depth is related to interface strength. Theoretically, there could be a threshold of ingrowth, above which the interface strength does not further increase. To test the relationship between depth and strength we performed a finite element study on micro models with simulated uncoated and hydroxyapatite (HA) coated surfaces. We examined whether complete ingrowth is necessary to obtain a maximal interface strength. An increase in bone ingrowth depth did not always enhance the bone-implant interface strength. For the uncoated specimens a plateau was reached at 1,500 μm of ingrowth depth. For the specimens with a simulated HA coating, a bone ingrowth depth of 500 μm already yielded a substantial interface strength, and deeper ingrowth did not enhance the interface strength considerably. These findings may assist in optimizing interface morphology (its depth) and in judging the effect of bone ingrowth depth on interface strength.

Cortical bone development under the growth plate is regulated by mechanical load transfer

Longitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the development of cortical bone is governed by mechanical stimuli. We also hypothesize that trabecular and cortical bone share the same regulatory mechanisms for adaptation to mechanical loads. To test these hypotheses, we monitored the development of the tibial cortex in growing pigs, using micro-computer tomography and histology. We then tested the concept that regulatory mechanisms for trabecular bone adaptation can also explain cortical bone development using our mechanical stimulation theory, which could explain trabecular bone (re)modelling. The main results showed that, from the growth plate towards the diaphysis, the pores of the trabecular structure were gradually filled in with bone, which resulted in increased density and cortical bone. The computer model largely predicted this morphological development. We conclude that merging of metaphyseal trabeculae into cortex is likely to be governed by mechanical stimuli. Furthermore, cortex development of growing long bones can be explained as a form of trabecular bone adaptation, without the need for different regulatory mechanisms for cortical and trabecular bone.