Characterisation of barley resistance to rhynchosporium on chromosome 6HS

Key Message: Major resistance gene to rhynchosporium, Rrs18, maps close to the telomere on the short arm of chromosome 6H in barley. Rhynchosporium or barley scald caused by a fungal pathogen Rhynchosporium commune is one of the most destructive and economically important diseases of barley in the world. Testing of Steptoe × Morex and CIho 3515 × Alexis doubled haploid populations has revealed a large effect QTL for resistance to R. commune close to the telomere on the short arm of chromosome 6H, present in both populations. Mapping markers flanking the QTL from both populations onto the 2017 Morex genome assembly revealed a rhynchosporium resistance locus independent of Rrs13 that we named Rrs18. The causal gene was fine mapped to an interval of 660 Kb using Steptoe × Morex backcross 1 S₂ and S₃ lines with molecular markers developed from Steptoe exome capture variant calling. Sequencing RNA from CIho 3515 and Alexis revealed that only 4 genes within the Rrs18 interval were transcribed in leaf tissue with a serine/threonine protein kinase being the most likely candidate for Rrs18.Max Coulter, Bianca Büttner, Kerstin Hofmann, Micha Bayer, Luke Ramsay, Günther Schweizer, Robbie Waugh, Mark E. Looseley, Anna Avrov

Revision of Implant to Great Toe Fusion

Category: Midfoot/Forefoot Introduction/Purpose: A prospective, randomized, non-inferiority clinical trial demonstrated that first metatarsophalangeal joint (MTPJ1) hemiarthroplasty with a synthetic polyvinyl alcohol hydrogel implant (Cartiva®) had equivalent pain relief and functional outcomes to MTPJ1 arthrodesis at 2 years. Despite 91% success, there was a 9.2% rate of implant removal and conversion to fusion. Other implants with more bone resection have demonstrated poorer outcomes after conversion to fusion than if a primary arthrodesis was performed. Since bone loss with synthetic cartilage implant hemiarthroplasty is minimal, we hypothesized that outcomes following implant removal and conversion to fusion would be similar to those following primary arthrodesis. We determined the outcomes of revision of synthetic implant hemiarthroplasty of the great toe to MTPJ1 arthrodesis and compared these outcomes to the primary arthrodesis cohort. Methods: In the original pivotal trial, 152 patients >/=18 years diagnosed with hallux rigidus grade 2, 3, or 4 underwent synthetic cartilage implant MTPJ1 hemiarthroplasty, as previously described (Baumhauer et al., Foot Ankle Int. 2016;37(5):457-69). Outcome measures including the Foot and Ankle Ability Measure (FAAM), pain visual analogue scale (VAS), and Short Form-36 Physical Functioning (SF-36 PF) score were obtained preoperatively, and at 2 weeks, 6 weeks, and 3, 6, 12 and 24 months postoperatively. Revision surgery of the MTPJ1 was performed using the original surgical incision. The medial and lateral capsule was released, the metatarsal head was exposed to permit implant removal, and the void was filled with cancellous autograft or bone graft substitute. Joint compression was achieved using two crossed screws or a compression plate. Patients were non-weightbearing for six weeks. Union was confirmed on radiographs. Patients were followed post-conversion and assessed for pain and functional outcomes. Results: Fourteen patients (9.2%) underwent implant removal and conversion to MTPJ1 arthrodesis. Mean time to revision surgery was 12.8 (range: 1.8-24.2) months. The removed implants demonstrated no signs of wear, fragmentation, fracture or other defects; the cause for failure was patient-reported pain. Eleven revision patients were followed up for mean 11.6 (range 3.1- 22.9) months. Pain VAS decreased by mean 65.2 (range: 19.5-96.0) mm from baseline (i.e., prior to implant hemiarthroplasty). The FAAM ADL and Sports scores increased by mean 39.0 (range: 2.4-73.8) points and 49.2 (range: 5.8-90.6) points, respectively (Figure 1), compared to baseline, with minimal clinically important differences (MCIDs) of 8 and 9 points, respectively. The SF-36 PF subscore improved by mean 37.8 (range: 10-65) points from baseline, with MCID of 3.3 points. Conclusion: Patients who underwent implant removal and conversion to MTPJ1 arthrodesis exhibited outcome measure scores statistically similar (p>0.05 for all scores) to those of the MTPJ1 fusion cohort at 24 months in the original pivotal trial (Figure 1). These results indicate that removal of the synthetic cartilage implant does not “burn a bridge” to having excellent pain relief and a successful functional outcome with a subsequent fusion procedure, if needed. The amount of bone loss with synthetic implant hemiarthroplasty is minimal, as the original joint surface length is maintained

The Effect of Deformity and Hindfoot Arthritis on Midterm Outcomes of Ankle Replacement and Fusion

Category: Ankle Arthritis Introduction/Purpose: Background: In 2014, Daniels et al reported the largest prospective comparison of clinical outcomes for Ankle Fusion (AF) and Replacement (TAR). Outcomes were comparable at 5.5 years mean F/U but were not stratified for potentially important factors including ipsilateral: Intra-articular deformity Significant foot deformity Hindfoot arthritis (or prior fusion) These factors define the Type and complexity of end stage ankle arthritis (ESAA) as described by the COFAS Classification. Since the effect of COFAS Type on outcomes is unknown, it remains unknown if TAR or AF might outperform the other in specific Types of ESAA and therefore be preferentially indicated. Purpose: Determine if outcomes for TAR and AF: vary with COFAS Type are different for ankles of the same COFAS Type. Methods: Prospective data from the COFAS multicenter database (3 sites, 5 surgeons) was used to compare outcomes in 890 consecutive non-randomized ankles with minimum 2 year F/U. TAR prostheses utilized were STAR, Hintegra, Infinity and InBone II. AF’s utilized open or arthroscopic techniques. Ankles were stratified according to the COFAS Classification of ESAA (1-isolated ankle arthritis; 2 - intra-articular ankle deformity (varus/valgus); 3 - foot or tibial deformity; 4 - hindfoot arthritis/fusion), creating 8 groups for comparison (AF1 – AF4; TAR1 – TAR4) A linear mixed-effects regression model (adjusted for significant variables identified by univariate analysis: Pre-operative Ankle Osteoarthritis Scale [AOS], age, diabetes status, BMI, surgeon) was used to compare the primary (AOS at latest F/U [AOS-LFU]) and secondary (SF-36 Physical Component Score at latest F/U [PCS-LFU]) outcome measures between groups. Reoperation & revision rates according to the COFAS Coding System were also compared. Results: There were 349 AF and 541 TAR cases with mean F/U of 5.4 years. Age averaged 55.9 (AF) and 64.3 (TAR) years. Analysis of raw AOS and PCS scores showed no difference pre-operatively between all 8 groups; all improved from pre-operative to LFU (p<0.05). Improvement was greater for TAR than AF in all COFAS Types, leading to significantly lower (better) AOS-LFU for TAR than AF in all COFAS Types (p <0.05). Multivariate analysis (see Figure) showed increasing (worsening) AOS-LFU for AF when progressing from Type 1 to 4, leading to better outcomes for TAR compared to AF in all Types, reaching statistical significance in Types 3 and 4. Revision rates were (6.3% [AF], 7.4% [TAR], NS); Non-revision reoperation rates were (14.6% [AF], 21.3% [TAR], p=0.01). Conclusion: At mid-term, patient reported outcomes for AF worsen with increasing ESAA complexity (as defined by COFAS Type), while outcomes for TAR are not affected by ESAA complexity. Both TAR and AF have similar revision rates, though non-revision reoperation rates are significantly higher for TAR. Both TAR and AF yield similar outcomes in non-complex ESAA (Types 1 and 2). However, for Complex ESAA (Types 3 and 4), TAR leads to significantly better outcomes, suggesting TAR may be indicated over AF in the presence of significant hindfoot deformity or hindfoot arthritis in patients who are otherwise candidates for either procedure

Intermediate Outcomes of Hydrogel Implant for Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus is the most common arthritic condition of the foot. Although a variety of great toe implants have been tried in an attempt to maintain toe motion, the majority have failed. In these cases, salvage to arthrodesis is more complicated and with a prolonged recovery. This prospective study assesses the intermediate efficacy and safety of a small (8/10 mm) hydrogel implant requiring minimal bone resection for moderate to severe hallux rigidus. Methods: Patients who underwent 1st MTP hemiarthroplasty with an organic polymer-based biomaterial implant (Cartiva), with at least five-year follow-up were contacted. Patients underwent a physical exam, and completed a pain visual analog scale (VAS) scale, SF-36, patient satisfaction questions, and the Foot and Ankle Ability Measure (FAAM). Results: Twenty-nine patients were available, with two lost to follow-up. The average time of follow-up was 5.3±0.5 years. The average age was 55.6±8.4, with 24(80%) females. The average VAS for pain improved from 64.6(±11.8) to 5.2(± 9.4) (p < 0.001). The average FAAM scores were: ADL subscale: 62.1(±16.4) to 95.8%(± 7.2) (p < 0.001); and Sports subscale: 40.2(±15.1) to 91.3%(±11.2) (p < 0.001); The average FAAM scores at follow-up for: Level of function during sports: 91.9%(±10.7); and Current level of function: 92.5%(±10.6). 69.2% of patients reported their level of function as normal, 26.9% nearly normal, and 3.8% abnormal function. Patients had 17.7 degrees of dorsiflexion, with a range of 12.7 to 22.7 degrees. Average peak dorsiflexion was 28.2°(±8.8). 92.3% stated they would undergo the procedure again. Conclusion: This study reports the mid-term results of an organic polymer-based biomaterial hemiarthroplasty implant for the management of hallux rigidus. Overall patients were very satisfied with the procedure. At an average of five years, patients are functioning very well, with limited pain and maintained motion of the 1st MTP joint. These results are promising as a viable alternative to fusion of the 1st MTP joint for management of moderate to severe hallux rigidus

Validity of a Revision Surgery Classification System for Ankle Arthritis Surgery

Category: Ankle Arthritis Introduction/Purpose: Reoperations may be a better way of tracking adverse outcomes than complications. Repeat surgery causes cost to the system, and often indicate failure of the primary procedure resulting in the patient not achieving the expected improvement in pain and function. Understanding the cause of repeat surgery at the primary site may result in design improvements to implants or improvements to fusion techniques resulting in better outcomes in the future. Repeat operations around the primary site may also be relevant to the primary surgery. The COFAS group have designed a reoperation classification system. The purpose of this study was to outline the inter and intra observer reliability of this classification scheme. Methods: To verify the inter- and intra-observer reliability of this new coding system, six fellow ship trained practicing foot and ankle Orthopaedic surgeons were asked to classify 61 repeat surgeries. The six surgeons read the operation reports in random order, and reread the reports 2 weeks later in a different order. Reliability was determined using regression analysis and intraclass correlation coefficients (ICC) were calculated and proportions of agreement. The agreement between pairs of readings (915 for inter observer for the first and second read; 61 readings with 15 comparisons) was determined by seeing how often each observer agreed. This was repeated for the 366 ratings for intra observer readings (61 times 6). Results: The inter-observer reliability test on the first read had a mean intra-class correlation coefficient (ICC) of 0.89, range 0.80 to 0.96. For 61 cases, 45 (74%) observations that were given the same code across all six observers for the first read. The inter-observer reliability test on the second read had a mean ICC of 0.94, range .90 to to 1.0. There were 43 (72%) observations that were the same across all six observers. Of all pairs (915 in total) there was agreement in 804 pairs for the first reading (88%). For the second reading there was agreement in 801 pairs (86%). The observers agreed with themselves in the intra-observer observation 324 times out of 366 paired readings (89% agreement of pairs). Conclusion: The COFAS classification of reoperations for end stage ankle arthritis was reliable. This scheme potentially could be applied to other areas of Orthopaedic surgery and should replace the Claiden Dindo modifications that do not accurately reflect Orthopaedic outcomes. As complications are hard to define and lack consistent terminology (Mercer) reoperations and resource utilization (extra clinic visits, extra days in hospital and extra hours of surgery may be more reliable measures of the negative effects of surgery

Swelling Results in Poor Outcome After Ankle Arthritis Surgery

Category: Ankle Arthritis Introduction/Purpose: Patients often comment on swelling after foot and ankle surgery. However the relationship between swelling and outcome has not been defined. Pinsker and Daniels demonstrated that swelling was an important aspect of outcome. The purpose of this paper was to determine the relationship between swelling score and outcome after ankle fusion and replacement. A secondary purpose was to determine how this relationship changed in time, how swelling score changed before and after surgery, and determine differences in swelling score between total ankle replacement (TAR), open ankle arthrodesis (OAA) and arthroscopic ankle arthrodesis (AAA). Methods: The MODEMS outcomes package from AAOS was used, with the validated ankle osteoarthritis score (AOS) score being used to assess outcomes in the pain and disability domains. The swelling score was indexed from 1 to 5, 1 being no swelling and five being severe swelling. Outcomes were recorded pre-operatively and annually up to 2010. Statistical analysis was performed using 95% confidence intervals and correlations being determined using Pearson’s correlation and r 2 values. Results: The swelling score was correlated with AOS score preoperatively. Postoperatively patients with a swelling score of 1 had an average AOS score of 15.1 (CI 13.3 to 16.9), a swelling score of 2 had an AOS score of 23 (CI 21.7 to 24.9), 3 an AOS of 31 (CI 29.6 to 33.1), 4 an AOS of 33.6 (CI 34.9 to 38.8), and 5 an AOS of 39 (CI 35.3 to 43.0). There was therefore a difference in outcome score for all groups of swelling score (i.e. 1 scored better than 2, 2 better than 3, 3 better than 4 and 4 better than 5). Swelling scores were the same for TAR, OAA and AAA preoperatively. Postoperatively swelling scores were lower for AAA (2.1, CI 1.9 to 2.2) compared to TAA (2.5, CI 2.4 to 2.6) and OAA (2.5, CI 2.4 t0 2.6). Conclusion: Swelling has a relationship with outcome. Swelling after surgery may result in poorer outcomes. Strategies to reduce swelling such as patient education about elevation, surgical technique and the use of compression stockings may improve outcomes. Arthroscopic surgery may have better outcomes because of the reduction in postoperative swelling

Is the Canadian Orthopaedic Foot and Ankle Society Ankle Arthritis Score (COFAS AAS) Associated with the Need for Revision Surgery?

Category: Ankle Arthritis Introduction/Purpose: There has been limited evidence to support the effective use of a patient reported outcome measure (PROM) for patients that have undergone surgical treatment for end-stage ankle arthritis (ESAA). This study used longitudinally collected patient-data from a cohort of patients in the Canadian Orthopaedic Foot and Ankle Society (COFAS) ankle arthritis study to evaluate whether the post-operative COFAS Ankle Arthritis Score (COFAS AAS), a patient-reported outcome (PROs), was associated with need for revision surgery. Methods: Between 2001 and 2010, a cohort of 623 patients and 653 ankles undergoing total ankle replacement or ankle arthrodesis were enrolled in a multicenter prospective ankle reconstruction study. At pre-surgical baseline, key patient level variables were collected including demographics, body mass index, and comorbidities. The COFAS AAS, a patient-reported outcome measure was collected at baseline and annually post-surgically. Time to revision surgery was modeled using a proportional hazards model which controlled for age, sex, BMI, diabetic status, smoking status, inflammatory arthritis, and surgery on the right or left side and time varying PROs. Results: 531 ankles in 509 patients with complete pre and post-operative data were included. Seventy of the cohort underwent metal component revision procedures during the follow up time period . The remaining 461 unrevised ankles had a minimum 2 year follow up (average of 3.4 years). Baseline COFAS AAS, age, sex, side, BMI, diabetic status, smoking status, and inflammatory arthritis were not statistically associated with the need for revision surgery. However, revision surgery was found to be associated with a higher post-operative COFAS AAS, and with a longer follow-up. The hazard ratio for the COFAS AAS indicates that for every one-point increase in the score, the rate of revision surgery was one percentage point higher at each post-operative time point. Conclusion: This study demonstrated that patients who reported higher levels of post-operative functional impairment, as indicated by a higher COFAS AAS, were more likely to undergo a revision surgery. This finding is also based on duration of follow-up, with the risk of revision surgery rising with length of follow up. This study provides further evidence for the utility of the COFAS AAS in the clinical setting. Further investigation is warranted to better understand the COFAS AAS’s ability to measure clinically meaningful change in an individual patient not requiring revision surgery

Does Smoking Affect Outcome in Surgical Management of Ankle Arthritis? A COFAS Multicentre Study

Category: Ankle Arthritis Introduction/Purpose: Smoking has been shown to increase complication rates after ankle surgery. The aim of this study was to compare complication rates between smokers and non smokers undergoing surgery for ankle arthritis. Methods: Smokers (n=88) and non smokers (n=565) with ankle arthritis who had undergone ankle arthrodesis or ankle arthroplasty were included in the study. Multicentre, prospective data was used from the COFAS ankle arthritis database. Patients with information available on smoking habits and 2 year follow up were included Results: There was no significant difference in the overall re operation rates between smokers and non smokers. However, the amputation rate was higher in smokers (3.4%) as compared to non smokers (0.7%). AOS scores and SF 36 scores were similar in the 2 groups. A higher proportion of smokers underwent fusion (46.5%) as compared to non smokers (28.8%). Amputation rate after ankle arthrodesis was higher in smokers (4.9%) as compared to non smokers (0.6%). Conclusion: Smokers have a higher amputation rate after ankle arthrodesis or ankle arthroplasty as compared to non smokers. Information from this study can be used during counselling of surgical patient

The Influence of Patient Factors on the Outcome of Synthetic Cartilage Implant Hemiarthroplasty versus First Metatarsophalangeal Joint Arthrodesis

Category: Midfoot/Forefoot Introduction/Purpose: Many studies have compared the outcomes of MTPJ1 hemiarthroplasty and arthrodesis, but there is a paucity of data on the influence of patient factors on clinical outcomes. A prior prospective, randomized, clinical trial compared the efficacy and safety of first metatarsophalangeal joint (MTPJ1) hemiarthroplasty with a synthetic polyvinyl alcohol hydrogel implant (Cartiva®) and MTPJ1 arthrodesis for moderate to severe hallux rigidus. The current study evaluated the data from this clinical trial to determine the impact of numerous patient variables, including osteoarthritis grade, hallux valgus angle, preoperative range of motion (ROM), gender, body mass index (BMI), preoperative duration of symptoms, and preoperative pain level, on the success or failure of MTPJ1 hemiarthroplasty and arthrodesis. Methods: Patients =18 years diagnosed with hallux rigidus grade 2, 3, or 4 were randomized and treated with synthetic cartilage implant MTPJ1 hemiarthroplasty (n=129) or arthrodesis (n=47). Outcome measures included a pain visual analogue scale (VAS), Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) scores, and Short Form-36 Physical Functioning (SF-36 PF) subscore, obtained preoperatively and at 2, 6, 12, 24, 52 and 104 weeks postoperatively. Great toe active dorsiflexion motion, secondary procedures, radiographs and safety parameters were evaluated. A patient’s outcome was deemed successful if composite primary endpoint criteria for clinical success (pain, function and safety) were met at 24 months. Predictor variables included: osteoarthritis grade; hallux valgus angle; preoperative ROM; gender; body mass index (BMI); preoperative symptom duration; prior surgery; and preoperative pain level. Two-sided Fisher’s Exact test was used to assess the impact of these variables on success of surgery (p0.05) in success rates (i.e., VAS pain reduction ≥ 30%, maintenance/improvement in function, freedom from radiographic complications, and no secondary surgical intervention) between synthetic cartilage implant MTPJ1 hemiarthroplasty and arthrodesis when stratified by osteoarthritis grade, degree of preoperative hallux valgus, extent of preoperative ROM, gender, BMI, duration of symptoms, prior MTPJ1 surgery status, and preoperative pain VAS score (Table 1). Notably, patients with minimal ROM and mild hallux valgus had equivalent success rates for both procedures. Males tended to have greater clinical success with implant hemiarthroplasty versus arthrodesis, but this difference was not statistically significant. 1Baumhauer et al., FAI, 2016;37(5):457-69. Conclusion: Synthetic cartilage implant hemiarthroplasty is an appropriate treatment for patients with hallux rigidus of Coughlin grade 2, 3 or 4. Its results in those with associated mild hallux valgus (<20 degrees) and in those with a high degree of preoperative stiffness are equivalent to MTPJ1 fusion, irrespective of gender, BMI, osteoarthritis grade, or preoperative pain or duration of symptoms, in contrast to what might have been expected