Comparison of femoral component migration between Refobacin bone cement R and Palacos R + G in cemented total hip arthroplasty: A randomised controlled roentgen stereophotogrammetric analysis and clinical study

AIMS

The widely used and well-proven Palacos R (a.k.a. Refobacin Palacos R) bone cement is no longer commercially available and was superseded by Refobacin bone cement R and Palacos R + G in 2005. However, the performance of these newly introduced bone cements have not been tested in a phased evidence-based manner, including roentgen stereophotogrammetric analysis (RSA).

PATIENTS AND METHODS

In this blinded, randomised, clinical RSA study, the migration of the Stanmore femoral component was compared between Refobacin bone cement R and Palacos R + G in 62 consecutive total hip arthroplasties. The primary outcome measure was femoral component migration measured using RSA and secondary outcomes were Harris hip score (HHS), Hip disability and Osteoarthritis Outcome Score (HOOS), EuroQol 5D (EQ-5D) and Short Form 36 (SF-36).

RESULTS

Femoral component migration was comparable between Refobacin bone cement R and Palacos R + G during the two-year follow-up period with an estimated mean difference of 0.06 mm of subsidence (p = 0.56) and 0.08° of retroversion (p = 0.82). Five hips (three Refobacin bone cement R and two Palacos R + G) showed non-stabilising, continuous migration; the femoral cement mantle in these hips, was mean 0.7 mm thicker (p = 0.02) and there were more radiolucencies at the bone-cement interface (p = 0.004) in comparison to hips showing stabilising migration. Post-operative HHS was comparable throughout the follow-up period (p = 0.62). HOOS, EQ5D, and SF-36 scores were also comparable (p-values > 0.05) at the two-year follow-up point.

CONCLUSION

Refobacin bone cement R and Palacos R + G show comparable component migration and clinical outcome during the first two post-operative years. Hips showing continuous migration are at risk for early failure. However, this seems to be unrelated to cement type, but rather to cementing technique. Cite this article: Bone Joint J 2016;98-B:1333-41.

Serial casting for elbow flexion contractures in neonatal brachial plexus palsy

PURPOSE

The objective of this study was to evaluate the effectiveness of serial casting of elbow flexion contractures in neonatal brachial plexus palsy.

METHODS

A prospective consecutive cohort study was performed with a median follow-up of 5 years. Forty-one patients with elbow flexion contractures ≥ 30° were treated with serial casting until the contracture was ≤ 10°, for a maximum of 8 weeks. Range of motion, number of recurrences and patient satisfaction were recorded and analyzed using Wilcoxon signed-rank and Cox regression tests.

RESULTS

Passive extension increased from a median of -40° (IQR -50 to -30) to -15° (IQR -10 to -20, p < 0.001). Twenty patients showed 37 recurrences. The baseline severity of passive elbow extension had a hazard ratio of 0.93 (95% CI 0.89 to 0.96, p < 0.001) for first recurrence. Median patient satisfaction was moderate. Four patients showed loss of flexion mobility and in two patients serial casting had to be prematurely replaced by night splinting due to complaints.

CONCLUSION

Serial casting improved elbow flexion contractures, although recurrences were frequent. The severity of elbow flexion contracture is a predictor of recurrence. We recommend more research on muscle degeneration and determinants involved in elbow flexion contractures to improve treatment strategies and prevent side-effects.

Three dimensional measurement of minimum joint space width in the knee from stereo radiographs using statistical shape models

Objectives

An important measure for the diagnosis and monitoring of knee osteoarthritis is the minimum joint space width (mJSW). This requires accurate alignment of the x-ray beam with the tibial plateau, which may not be accomplished in practice. We investigate the feasibility of a new mJSW measurement method from stereo radiographs using 3D statistical shape models (SSM) and evaluate its sensitivity to changes in the mJSW and its robustness to variations in patient positioning and bone geometry.

Materials and Methods

A validation study was performed using five cadaver specimens. The actual mJSW was varied and images were acquired with variation in the cadaver positioning. For comparison purposes, the mJSW was also assessed from plain radiographs. To study the influence of SSM model accuracy, the 3D mJSW measurement was repeated with models from the actual bones, obtained from CT scans.

Results

The SSM-based measurement method was more robust (consistent output for a wide range of input data/consistent output under varying measurement circumstances) than the conventional 2D method, showing that the 3D reconstruction indeed reduces the influence of patient positioning. However, the SSM-based method showed comparable sensitivity to changes in the mJSW with respect to the conventional method. The CT-based measurement was more accurate than the SSM-based measurement (smallest detectable differences 0.55 mm versus 0. 82 mm, respectively).

Conclusion

The proposed measurement method is not a substitute for the conventional 2D measurement due to limitations in the SSM model accuracy. However, further improvement of the model accuracy and optimisation technique can be obtained. Combined with the promising options for applications using quantitative information on bone morphology, SSM based 3D reconstructions of natural knees are attractive for further development.

Cite this article: E. A. van IJsseldijk, E. R. Valstar, B. C. Stoel, R. G. H. H. Nelissen, N. Baka, R. van’t Klooster, B. L. Kaptein. Three dimensional measurement of minimum joint space width in the knee from stereo radiographs using statistical shape models. Bone Joint Res 2016;320–327. DOI: 10.1302/2046-3758.58.2000626.

Neo-cartilage engineered from primary chondrocytes is epigenetically similar to autologous cartilage, in contrast to using mesenchymal stem cells

OBJECTIVES

To compare the epigenetic landscape of 3D cell models of human primary articular chondrocytes (hPACs) and human bone-marrow derived mesenchymal stem cells (hBMSCs) and their respective autologous articular cartilage.

DESIGN

Using Illumina Infinium HumanMethylation450 BeadChip arrays, the DNA methylation landscape of the different cell sources and autologous cartilage was determined. Pathway enrichment was analyzed using DAVID.

RESULTS

Principal Component Analysis (PCA) of methylation data revealed separate clustering of hBMSC samples. Between hBMSCs and autologous cartilage 86,881 cytosine-phosphate-guanine dinucleotides (CpGs) (20.2%), comprising 3,034 differentially methylated regions (DMRs; Δβ > 0.1; with the same direction of effect), were significantly differentially methylated. In contrast, between hPACs and autologous cartilage only 5,706 CpGs (1.33%) were differentially methylated. Of interest was the finding of the transcriptionally active, hyper-methylation of a Cartilage Intermediate Layer Protein (CILP) annotated DMR (Δβ = 0.16) in PAC-cartilage, corresponding to a profound decrease in CILP expression after in vitro culturing of hPACs as compared to autologous cartilage.

CONCLUSIONS

In vitro engineered neo-cartilage tissue from primary chondrocytes, hPACs, exhibits a DNA methylation landscape that is almost identical (99% similarity) to autologous cartilage, in contrast to neo-cartilage engineered from bone marrow-derived mesenchymal stem cells (MSCs). Although hBMSCs are widely used for cartilage engineering purposes the effects of these vast differences on cartilage regeneration and long term consequences of implantation, are not known. The use of hBMSCs or hPACs for future cartilage tissue regeneration purposes should therefore be investigated in more depth in future endeavors to better understand the consequences of the differential methylome on neo-cartilage.

Increased Mortality in Metal-on-Metal versus Non-Metal-on-Metal Primary Total Hip Arthroplasty at 10 Years and Longer Follow-Up: A Systematic Review and Meta-Analysis

IMPORTANCE

There are concerns about increased mortality in patients with metal-on-metal bearings in total hip arthroplasty (THA).

OBJECTIVE

To determine the mortality and the morbidity in patients with metal-on-metal articulations (MOM THA) compared to patients with non-metal-on-metal articulations (non-MOM THA) after primary total hip arthroplasty.

DATA SOURCES

Search of PubMed, MEDLINE, EMBASE, Web of Science, Cochrane, CINAHL, AcademicSearchPremier, ScienceDirect, Wiley and clinical trial registers through March 2015, augmented by a hand search of references from the included articles. No language restrictions were applied.

STUDY SELECTION

Two reviewers screened and identified randomised controlled trials and observational studies of primary total hip arthroplasty comparing MOM THA with non-MOM THA.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted study data and assessed risk of bias. Risk differences (RD) were calculated with random effect models. Meta-regression was used to explore modifying factors.

MAIN OUTCOMES AND MEASURES

Difference in mortality and difference in morbidity expressed as revisions and medical complications between patients with MOM THA and non-MOM THA.

RESULTS

Forty-seven studies were included, comprising 4,000 THA in randomised trials and over 500,000 THA in observational studies. For mortality, random effects analysis revealed a higher pooled RD of 0.7%, 95%, confidence interval (CI) [0.0%, 2.3%], I-square 42%; the heterogeneity was explained by differences in follow-up. When restricted to studies with long term follow-up (i.e. 10 years or more), the RD for mortality was 8.5%, 95%, CI [5.8%, 11.2%]; number needed to treat was 12. Further subgroup analyses and meta-regression random effects models revealed no evidence for other moderator variables (study level covariates, e.g. resurfacing vs. non-resurfacing MOM) than follow-up duration. The quality of the evidence presented in this meta-analysis was characterized as moderate according to the CLEAR-NPT (for non-pharmacological trials) and Cochrane risk of bias Table.

CONCLUSIONS AND RELEVANCE

Meta-analysis suggests there may be an increased long-term risk of mortality and revision surgery for patients with MOM THA compared to patients with non-MOM THA.

REGISTRATION

PROSPERO 2014:CRD42014007417.

Effectiveness of exercise therapy for meniscal lesions in adults: A systematic review and meta-analysis

OBJECTIVES

This study evaluated the effectiveness of exercise therapy in patients with meniscal lesions.

DESIGN

Systematic review and meta-analysis.

METHODS

Nine databases were searched up to July 2015, including EMBASE and Medline OvidSP. Randomized and controlled clinical trials in adults with traumatic or degenerative meniscal lesions were considered for inclusion. Interventions had to consist of exercise therapy in non-surgical patients or after meniscectomy, and had to be compared with meniscectomy, no exercise therapy, or to a different type of exercise therapy. Primary outcomes were pain and function on short term (≤3 months) and long term (>3 months). Two researchers independently selected the studies, assessed the risk of bias, and extracted data.

RESULTS

Of the 1415 identified articles 14 articles describing 12 studies were included; all had some concerns about the risk of bias. There was no significant difference between exercise therapy and meniscectomy for pain (MD 0.27 [-4.30,4.83]) and function (SMD -0.32 [-0.68,0.03]). After meniscectomy, there was conflicting evidence for the effectiveness of exercise therapy when compared to no exercise therapy for pain and function. There was no significant difference between various types of exercise therapy for pain (MD 19.30 [-6.60,45.20]) and function (SMD 0.01 [-0.27,0.28]).

CONCLUSIONS

Exercise therapy and meniscectomy yielded comparable results on pain and function. Exercise therapy compared to no exercise therapy after meniscectomy showed conflicting evidence at short term, but was more effective on function at long term. The preferable type/frequency/intensity of exercise therapy remains unclear. The strength of the evidence was low to very low.

Characterization of synovial mast cells in knee osteoarthritis: association with clinical parameters

OBJECTIVE

To investigate the presence of mast cells in the osteoarthritic (OA) synovium and their association with clinical parameters in comparison with rheumatoid arthritis (RA) samples.

METHOD

Synovial tissues of 56 symptomatic OA and 49 RA patients were obtained. Two to three paraffin slides were used to quantify inflammation using haematoxylin and eosin (H&E) staining (synovitis score 0-9), and numbers of mast cells (per 10 high-power fields) using double immunofluorescence for CD117 and tryptase. Average scores per patient were used for analysis. Knee radiographs of OA patients were scored according to the Kellgren and Lawrence (KL) system and pain was determined in OA patients at baseline by visual analogue scale (VAS).

RESULTS

Median (range) of mast cells was significantly higher in OA samples 45 (1-168) compared to RA samples 4 (1-47) (P-value < 0.001), despite a lower median (range) synovitis score in OA (2.5 (0-6.0)) compared to 4.6 (0-8.0) in RA samples. The synovitis score was significantly correlated with the number of mast cells (in OA Spearman's rho (P-value) 0.3 (0.023) and RA 0.5 (P-value < 0.001)). Interestingly, we observed a trend towards an association between the number of mast cells and an increased KL-grade (P-value 0.05) in OA patients, independently of synovitis. No associations were found with self-reported pain.

CONCLUSION

Prevalence of mast cells in OA synovial tissue is relatively high and associates with structural damage in OA patients, suggesting a role of mast cells in this disease.

[Persistent shoulder symptoms in calcific tendinitis: clinical and radiological predictors]

OBJECTIVE

We assessed the most important demographics and radiological characteristics at the time of diagnosis of rotator cuff calcific tendinitis (RCCT), and their associations with long-term clinical outcome.

DESIGN

Observational study.

METHOD

Baseline characteristics and treatment were evaluated in 342 patients in whom RCCT had been diagnosed. Interobserver agreement of the radiological investigations was analysed. Patients were sent a general questionnaire and 2 shoulder questionnaires, the "Western Ontario rotator cuff" (WORC) and the "Disabilities of the arm, shoulder and hand" (DASH) for evaluation of long-term clinical outcome. Associations between baseline characteristics and long-term outcomes were analysed using logistic regression.

RESULTS

Mean age at diagnosis was 49.0 years (SD = 10.0), and 60% were female. The dominant arm was affected in 66%, and 21% had bilateral RCCT. Calcifications were on average 18.7 mm in size (SD = 10.1, ICC = 0.84 (p < 0.001)) and located 10.1 mm (SD = 11.8) medially to the acromion (ICC = 0.77 (p < 0.001)). 32% of the calcifications had a Gärtner type I classification (κ: 0.47 (p<0.001)). After a mean follow-up of 14 years (SD =7.1), median WORC score was 72.5 (range: 3.0-100.0) and median DASH score 17.0 (range: 0.0-82.0). Female gender, dominant arm involvement, bilateral disease, longer duration of symptoms at presentation, and presence of multiple calcifications were associated with inferior long-term outcomes.

CONCLUSION

RCCT is not self-limiting. Radiological variations have no significant predictive value. We identified specific prognostic factors for inferior long-term outcome; more intensive follow-up and treatment should be considered in patients with these characteristics.

The reason why orthopaedic surgeons perform total knee replacement: results of a randomised study using case vignettes

PURPOSE

End-stage knee osteoarthritis (OA) results in total knee arthroplasty (TKA) surgery. The decision to perform TKA is not well defined, resulting in variation of indications among orthopaedic surgeons. Non-operative treatment measures are often not extensively used. Aim of this study was to investigate factors influencing the decision to perform TKA by Dutch orthopaedic surgeons.

METHODS

Three case vignettes, each case divided into two versions, being identical except for information on age (younger and older age), pain (mild and severe pain) or radiological OA (low and high grade) were developed. A questionnaire including these three case vignettes was sent to 599 Dutch orthopaedic surgeons, who were randomised to either one of the two versions. The orthopaedic surgeons were asked whether TKA would be the next step in treatment. Furthermore, from a list of patient factors they were asked how strong these factors would influence the decision to perform TKA.

RESULTS

54 % of the orthopaedic surgeons completed the questionnaire (n = 326). Orthopaedic surgeons indicated to perform TKA significantly more often at higher age (73.3 vs. 45.5 %, p < 0.001). In the presence of mild pain, orthopaedic surgeons were slightly more reluctant to perform a TKA compared to severe pain (57.0 vs. 64.0 %, n.s.). Mild radiological OA made surgeons more reluctant to perform TKA compared to severe OA (9.7 vs. 96.9 %, p < 0.001).

CONCLUSION

Old age and severe radiological OA are variables which are considered to be important in the decision to perform a TKA. Pain symptoms of moderate or severe pain are unequivocal when considering a TKA.

LEVEL OF EVIDENCE

Economic/decision analysis, Level III.

Return to work after total hip and knee arthroplasty: results from a clinical study

The aim of this study was to measure return to work and duration until return to work in patients undergoing total hip or knee arthroplasty (THA or TKA). This prospective study included patients under 65 years of age, undergoing THA or TKA, who provided information on their work status preoperatively (paid work yes/no and working hours) and 1 year thereafter (paid work yes/no, working hours and time until return to work). Seventy-one THA and 64 TKA patients had a paid job preoperatively. The employment rates 1 year postoperatively were 64/71 (90 %) after THA and 53/64 (83 %) after TKA. Of those who returned to work, 9/64 (14 %) of THA patients and 10/53 (19 %) of TKA patients worked less hours than preoperatively [mean decrease of 16 (SD 11.5) and 14 (SD 13.0) hours, respectively]. The mean time to return to work was 12.5 (SD 7.6) and 12.9 (SD 8.0) weeks in THA and TKA, respectively. The majority of working patients who underwent THA or TKA returned to work, after approximately 12 weeks. A considerable proportion of the patients returning to work worked less hours than preoperatively. More research into patients who do not return or decrease their working hours is needed.

Healthcare costs and loss of productivity in patients with trapeziometacarpal osteoarthritis

The objective of this study was to analyse healthcare and productivity costs in patients with trapeziometacarpal osteoarthritis. We included 161 patients who received surgery or steroid injection and calculated their healthcare costs in Euro (€) over 1 year. Patients filled out the Work Productivity and Activity Impairment Questionnaire to assess loss of productivity at baseline, and after 3, and 12 months. In the surgical group, loss of productivity among employed patients first increased and then decreased (50%, 64%, and 25% at 0, 3, and 12 months). Productivity was more stable over time in the injection group (52%, 38%, and 48%). In the surgical group, estimated total annual healthcare and productivity costs were €5770 and €5548, respectively. In the injection group, healthcare and productivity costs were €348 and €3503. These findings highlight the need for assessing productivity costs to get a comprehensive view of the costs associated with a treatment.Level of Evidence III.

Risk of venous thrombosis after arthroscopy of the knee: results from a large population-based case-control study

BACKGROUND

From the currently available evidence, the risk of venous thrombosis after knee arthroscopy remains unclear.

OBJECTIVES

To estimate the risk of venous thrombosis after arthroscopy of the knee, and to identify high-risk groups.

PATIENTS AND METHODS

We used data from a large population-based case-control study (the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis [MEGA] study) on the etiology of venous thrombosis (4416 cases; 6150 controls). Odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for age, sex, body mass index, rheumatic disease, and regular exercise, were calculated.

RESULTS

One hundred and three patients and 24 controls had a knee arthroscopy in the year before the index date, resulting in a six-fold increased risk (OR 5.9, 95% CI 3.7-9.3). Ligament reconstructions led to a higher risk (OR 17.2, 95% CI 2.2-136) than meniscal surgery, diagnostic arthroscopy, or chondroplasty (OR 5.4, 95% CI 3.4-8.7). An additionally increased risk was found for combinations with genetic and acquired risk factors: with oral contraceptives (OR 46.6, 95% CI 6.1-353); and with factor V Leiden, factor II G20210A mutation, or non-O blood type (OR 15.3, 95% CI 8.1-28.5). The risk of venous thrombosis was particularly high in the first 3 months after knee arthroscopy, with an 18-fold increased risk (OR 16.2, 95% CI 7.8-33.7).

CONCLUSIONS

We observed a strongly increased risk of venous thrombosis after knee arthroscopy, especially in the first months after the procedure. The risk was particularly high in the presence of other acquired or genetic risk factors, making knee arthroscopy a high-risk intervention in certain individuals.

Association of pain in knee osteoarthritis with distinct patterns of synovitis

OBJECTIVE

To determine possible patterns of synovitis on contrast-enhanced magnetic resonance imaging (CE-MRI) and its relation to pain and severity in patients with radiographic knee osteoarthritis (OA).

METHODS

In total, 86 patients (mean age 62 years, 66% women, median body mass index 29 kg/m(2) ) with symptomatic knee OA (Kellgren/Lawrence radiographic score 3) were included. T1-weighted, gadolinium-chelate-enhanced MRI with fat suppression was used to semiquantitatively score the extent of synovitis at 11 knee sites (total score range 0-22). Self-reported pain was assessed with 3 standardized questionnaires. Principal components analysis (PCA) was used to investigate patterns (the location and severity) of synovitis. Subsequently, these patterns were assessed for associations with pain measures and radiographic severity in adjusted logistic regression models.

RESULTS

Synovitis was observed in 86 patients and was found to be generally mild on CE-MRI (median total synovitis score 7, range 0-16). The median pain scores were 53 (range 0-96) on the visual analog scale for pain, 51.4 (range 2.8-97.2) on the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain, 35 (range 0-75) on the Intermittent and Constant Osteoarthritis Pain (ICOAP) score for constant pain, and 40.6 (range 0-87.5) on the ICOAP score for intermittent pain. PCA resulted in extraction of 3 components, explaining 53.4% of the variance. Component 1 was characterized by synovitis at 7 sites (mainly medial parapatellar involvement) and was associated with scores on the KOOS pain subscale and the ICOAP constant pain subscale. Component 2 was characterized by synovitis at 4 sites (mainly the site adjacent to the anterior cruciate ligament), but was not associated with pain measures or with radiographic severity. Component 3, characterized by synovitis at 3 sites (mainly at the loose body site), was associated with radiographic severity.

CONCLUSION

Different patterns of synovitis in knee OA were observed. The pattern that included several patellar sites was associated with pain, whereas other patterns showed no association, suggesting that pain perception in patients with knee OA is a localized response.

The stability of fixation of proximal femoral fractures

The aim of this study was to quantify the stability of fracture-implant complex in fractures after fixation. A total of 15 patients with an undisplaced fracture of the femoral neck, treated with either a dynamic hip screw or three cannulated hip screws, and 16 patients with an AO31-A2 trochanteric fracture treated with a dynamic hip screw or a Gamma Nail, were included. Radiostereometric analysis was used at six weeks, four months and 12 months post-operatively to evaluate shortening and rotation.

Migration could be assessed in ten patients with a fracture of the femoral neck and seven with a trochanteric fracture. By four months post-operatively, a mean shortening of 5.4 mm (-0.04 to 16.1) had occurred in the fracture of the femoral neck group and 5.0 mm (-0.13 to 12.9) in the trochanteric fracture group. A wide range of rotation occurred in both types of fracture. Right-sided trochanteric fractures seem more rotationally stable than left-sided fractures.

This prospective study shows that migration at the fracture site occurs continuously during the first four post-operative months, after which stabilisation occurs. This information may allow the early recognition of patients at risk of failure of fixation.

Cite this article: Bone Joint J 2015;97-B:391–7.

The natural history of the rheumatoid shoulder: a prospective long-term follow-up study

The purpose of this study was to evaluate the natural history of rheumatoid disease of the shoulder over an eight-year period. Our hypothesis was that progression of the disease is associated with a decrease in function with time. A total of 22 patients (44 shoulders; 17 women, 5 men, (mean age 63)) with rheumatoid arthritis were followed for eight years. All shoulders were assessed using the Constant score, anteroposterior radiographs (Larsen score, Upward-Migration-Index (UMI)) and ultrasound (US). At final follow-up, the Short Form-36, disabilities of the arm, shoulder and hand (DASH) Score, erythrocyte sedimentation rate and use of anti-rheumatic medication were determined. The mean Constant score was 72 points (50 to 88) at baseline and 69 points (25 to 100) at final follow-up. Radiological evaluation showed progressive destruction of the peri-articular structures with time. This progression of joint and rotator cuff destruction was significantly associated with the Constant score. However, at baseline only the extent of rotator cuff disease and the UMI could predict the Constant score at final follow-up. A plain anteroposterior radiograph of the shoulder is sufficient to assess any progression of rheumatoid disease and to predict functional outcome in the long term by using the UMI as an indicator of rotator cuff degeneration.

Survey on the management of acute first-time anterior shoulder dislocation amongst Dutch public hospitals

INTRODUCTION

The primary aim of this study was to record how orthopaedic surgeons are currently managing acute first-time anterior shoulder dislocation (AFASD) 8 years after introduction of the Dutch national guideline: "acute primary shoulder dislocation, diagnostics and treatment" in 2005. The second aim was to evaluate how these surgeons treat recurrent instability after AFASD.

MATERIALS AND METHODS

An online questionnaire regarding the management of AFASD and recurrent shoulder instability was held amongst orthopaedic surgeons of all 98 Dutch hospitals.

RESULTS

The overall response rate was 60%. Of the respondents, 75% had a local protocol for managing AFASD, of which 28% had made changes in their treatment protocol after the introduction of the national guideline. The current survey showed wide variety in the overall treatment policies for AFASD. Twenty-seven percent of the orthopaedic surgeons were currently unaware of the national guideline. The variability in treatment for AFASD was present throughout the whole treatment from which policy at the emergency department; when to operate for recurrent instability; type of surgical technique for stabilization and type of fixation of the labrum. As for the treatment of recurrent instability, the same variability was seen: 36% of the surgeons perform only arthroscopic procedures, 7% only open and 57% perform both open and arthroscopic procedures.

CONCLUSIONS

Despite the introduction of the national guideline for the initial management of AFASD in 2005, still great variety among orthopaedic surgeons in the Netherlands was present. As for the surgical stabilization technique, the vast majority of the respondents are performing an arthroscopic shoulder stabilization procedure at the expense of the more traditional open procedure as a first treatment option for post-traumatic shoulder instability.

Validation of a model-based measurement of the minimum insert thickness of knee prostheses: a retrieval study

INTRODUCTION

Wear of polyethylene inserts plays an important role in failure of total knee replacement and can be monitored in vivo by measuring the minimum joint space width in anteroposterior radiographs. The objective of this retrospective cross-sectional study was to compare the accuracy and precision of a new model-based method with the conventional method by analysing the difference between the minimum joint space width measurements and the actual thickness of retrieved polyethylene tibial inserts.

METHOD

Before revision, the minimum joint space width values and their locations on the insert were measured in 15 fully weight-bearing radiographs. These measurements were compared with the actual minimum thickness values and locations of the retrieved tibial inserts after revision.

RESULTS

The mean error in the model-based minimum joint space width measurement was significantly smaller than the conventional method for medial condyles (0.50 vs 0.94 mm, p < 0.01) and for lateral condyles (0.06 vs 0.34 mm, p = 0.02). The precision (standard deviation of the error) of the methods was similar (0.84 vs 0.79 mm medially and both 0.46 mm laterally). The distance between the true minimum joint space width locations and the locations from the model-based measurements was less than 10 mm in the medial direction in 12 cases and less in the lateral direction in 13 cases.

CONCLUSION

The model-based minimum joint space width measurement method is more accurate than the conventional measurement with the same precision. Cite this article: Bone Joint Res 2014;3:289-96.

Degree of synovitis on MRI by comprehensive whole knee semi-quantitative scoring method correlates with histologic and macroscopic features of synovial tissue inflammation in knee osteoarthritis

OBJECTIVE

To evaluate the association between synovitis on contrast enhanced (CE) MRI with microscopic and macroscopic features of synovial tissue inflammation.

METHOD

Forty-one patients (mean age 60 years, 61% women) with symptomatic radiographic knee OA were studied: twenty underwent arthroscopy (macroscopic features were scored (0-4), synovial biopsies obtained), twenty-one underwent arthroplasty (synovial tissues were collected). After haematoxylin and eosin staining, the lining cell layer, synovial stroma and inflammatory infiltrate of synovial tissues were scored (0-3). T1-weighted CE-MRI's (3 T) were used to semi-quantitatively score synovitis at 11 sites (0-22) according to Guermazi et al. Spearman's rank correlations were calculated.

RESULTS

The mean (SD) MRI synovitis score was 8.0 (3.7) and the total histology grade was 2.5 (1.6). Median (range) scores of macroscopic features were 2 (1-3) for neovascularization, 1 (0-3) for hyperplasia, 2 (0-4) for villi and 2 (0-3) for fibrin deposits. The MRI synovitis score was significantly correlated with total histology grade [r = 0.6], as well as with lining cell layer [r = 0.4], stroma [r = 0.3] and inflammatory infiltrate [r = 0.5] grades. Moreover, MRI synovitis score was also significantly correlated with macroscopic neovascularization [r = 0.6], hyperplasia [r = 0.6] and villi [r = 0.6], but not with fibrin [r = 0.3].

CONCLUSION

Synovitis severity on CE-MRI assessed by a new whole knee scoring system by Guermazi et al. is a valid, non-invasive method to determine synovitis as it is significantly correlated with both macroscopic and microscopic features of synovitis in knee OA patients.

Appraisal of evidence base for introduction of new implants in hip and knee replacement: a systematic review of five widely used device technologies

OBJECTIVE

To determine the evidence of effectiveness and safety for introduction of five recent and ostensibly high value implantable devices in major joint replacement to illustrate the need for change and inform guidance on evidence based introduction of new implants into healthcare.

DESIGN

Systematic review of clinical trials, comparative observational studies, and registries for comparative effectiveness and safety of five implantable device innovations.

DATA SOURCES

PubMed (Medline), Embase, Web of Science, Cochrane, CINAHL, reference lists of articles, annual reports of major registries, summaries of safety and effectiveness for pre-market application and mandated post-market studies at the US Food and Drug Administration.

STUDY SELECTION

The five selected innovations comprised three in total hip replacement (ceramic-on-ceramic bearings, modular femoral necks, and uncemented monoblock cups) and two in total knee replacement (high flexion knee replacement and gender specific knee replacement). All clinical studies of primary total hip or knee replacement for symptomatic osteoarthritis in adults that compared at least one of the clinical outcomes of interest (patient centred outcomes or complications, or both) in the new implant group and control implant group were considered. Data searching, abstraction, and analysis were independently performed and confirmed by at least two authors. Quantitative data syntheses were performed when feasible.

RESULTS

After assessment of 10,557 search hits, 118 studies (94 unique study cohorts) met the inclusion criteria and reported data related to 15,384 implants in 13,164 patients. Comparative evidence per device innovation varied from four low to moderate quality retrospective studies (modular femoral necks) to 56 studies of varying quality including seven high quality (randomised) studies (high flexion knee replacement). None of the five device innovations was found to improve functional or patient reported outcomes. National registries reported two to 12 year follow-up for revision occurrence related to more than 200,000 of these implants. Reported comparative data with well established alternative devices (over 1,200,000 implants) did not show improved device survival. Moreover, we found higher revision occurrence associated with modular femoral necks (hazard ratio 1.9) and ceramic-on-ceramic bearings (hazard ratio 1.0-1.6) in hip replacement and with high flexion knee implants (hazard ratio 1.0-1.8).

CONCLUSION

We did not find convincing high quality evidence supporting the use of five substantial, well known, and already implemented device innovations in orthopaedics. Moreover, existing devices may be safer to use in total hip or knee replacement. Improved regulation and professional society oversight are necessary to prevent patients from being further exposed to these and future innovations introduced without proper evidence of improved clinical efficacy and safety.

Below-knee cast immobilization and the risk of venous thrombosis: results from a large population-based case-control study

BACKGROUND

From the available evidence, the risk of venous thrombosis in patients with below-knee cast immobilization remains unclear.

OBJECTIVES

To estimate the risk of venous thrombosis after below-knee cast immobilization and to identify high-risk groups.

PATIENTS AND METHODS

We used data from a large population-based case-control study (MEGA study) on the etiology of venous thrombosis (4418 cases; 6149 controls). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated, and adjusted for age, sex, body mass index, and regular exercise. Absolute risks were estimated from the ORs.

RESULTS

One hundred and thirty-four patients and 23 controls had below-knee plaster cast immobilization in the year before the index date, resulting in an eight-fold increased risk (OR 8.3 [95% CI 5.3-12.9]). Traumatic indications led to a higher risk than non-traumatic indications: OR 12.7 (95% CI 6.6-24.6) vs. OR 7.6 (95% CI 0.9-66.4). An additionally increased risk was found for combinations with genetic or acquired risk factors: oral contraceptives (OR 18.2 [95% CI 6.2-53.4]); obesity (OR 17.2 [95% CI 5.4-55.2]); factor V Leiden, factor II 20210A mutation, and/or non-O blood group (OR 23.0 [95% CI 11.5-46.0]); all for a period of 1 year. Ninety per cent of the events occurred in the first 3 months after cast application. This led to a 56-fold increased risk (OR 56.3 [95% CI 17.9-177.3]) in this period.

CONCLUSIONS

Below-knee cast immobilization strongly increases the risk of venous thrombosis. We found distinct differences in intrinsic risk between individuals with respect to indication for cast immobilization and the presence of genetic or acquired risk factors.

Feasibility of osteosynthesis of fractured cadaveric hips following preventive elastomer femoroplasty

BACKGROUND

In vitro cadaveric studies showed that elastomer femoroplasty prevents displacement of fracture parts after proximal hip fracture allowing for conservative treatment. In the event that secondary displacement does occur, the purpose of this present study was to determine the feasibility of performing osteosynthesis of a fractured hip after preventive treatment with elastomer femoroplasty.

METHODS

Ten pairs of human cadaveric femurs were fractured in a simulated fall configuration. From each pair, one femur was randomly selected for elastomer femoroplasty prior to fracture generation and the contralateral femur was used as control. Following hip fracture generation, osteosynthesis was performed in all femurs. The operative time per case, technical difficulties during the procedure, and postoperative energy-to-failure load were recorded.

RESULTS

The mean (SD) time to perform osteosynthesis was 20 (6) minutes in the control-group and 19 (5) minutes in the elastomer femoroplasty-group (P=0.69). During osteosynthesis of the fractured hip in the elastomer femoroplasty-group, no difficulties including the need for additional instruments to remove elastomer from the proximal femur were recorded. Postoperative energy-to-failure load was similar in the control-group and the elastomer femoroplasty-group.

CONCLUSION

Fixation with routine osteosynthesis of displaced cadaveric hip fractures is not hindered by the presence of previously injected elastomer.

Autologous wound drains have no effect on allogeneic blood transfusions in primary total hip and knee replacement: a three-arm randomised trial

We hypothesised there was no clinical value in using an autologous blood transfusion (ABT) drain in either primary total hip (THR) or total knee replacement (TKR) in terms of limiting allogeneic blood transfusions when a modern restrictive blood management regime was followed. A total of 575 patients (65.2% men), with a mean age of 68.9 years (36 to 94) were randomised in this three-arm study to no drainage (group A), or to wound drainage with an ABT drain for either six hours (group B) or 24 hours (group C). The primary outcome was the number of patients receiving allogeneic blood transfusion. Secondary outcomes were post-operative haemoglobin (Hb) levels, length of hospital stay and adverse events. This study identified only 41 transfused patients, with no significant difference in distribution between the three groups (p = 0.857). The mean pre-operative haemoglobin (Hb) value in the transfused group was 12.8 g/dL (9.8 to 15.5) versus 14.3 g/dL (10.6 to 18.0) in the non-transfused group (p < 0.001, 95% confidence interval: 1.08 to 1.86). Post-operatively, the median of re-transfused shed blood in patients with a THR was 280 mL (Interquartile range (IQR) 150 to 400) and in TKR patients 500 mL (IQR 350 to 650) (p < 0.001). ABT drains had no effect on the proportion of transfused patients in primary THR and TKR. The secondary outcomes were also comparable between groups.