Simultaneous Hip Implant Segmentation and Gruen Landmarks Detection.

The assessment of implant status and complications of Total Hip Replacement (THR) relies mainly on the clinical evaluation of the X-ray images to analyse the implant and the surrounding rigid structures. Current clinical practise depends on the manual identification of important landmarks to define the implant boundary and to analyse many features in arthroplasty X-ray images, which is time-consuming and could be prone to human error. Semantic segmentation based on the Convolutional Neural Network (CNN) has demonstrated successful results in many medical segmentation tasks. However, these networks cannot define explicit properties that lead to inaccurate segmentation, especially with the limited size of image datasets. Our work integrates clinical knowledge with CNN to segment the implant and detect important features simultaneously. This is instrumental in the diagnosis of complications of arthroplasty, particularly for loose implant and implant-closed bone fractures, where the location of the fracture in relation to the implant must be accurately determined. In this work, we define the points of interest using Gruen zones that represent the interface of the implant with the surrounding bone to build a Statistical Shape Model (SSM). We propose a multitask CNN that combines regression of pose and shape parameters constructed from the SSM and semantic segmentation of the implant. This integrated approach has improved the estimation of implant shape, from 74% to 80% dice score, making segmentation realistic and allowing automatic detection of Gruen zones. To train and evaluate our method, we generated a dataset of annotated hip arthroplasty X-ray images that will be made available.

The Feasibility of Hinged Knee Arthrodiastasis for Cartilage Regeneration: A Systematic Review of the Literature.

Introduction: Knee joint distraction (KJD) is a potential technique for cartilage regeneration in young patients with osteoarthritis of the knee. Static distraction has been utilised typically; however, a significant proportion of patients complain of knee stiffness post-distractor removal. The use of a hinged distractor may reduce the duration and severity of post-treatment knee stiffness by maintaining the range of motion during distraction. Furthermore, improved cartilage regeneration has been demonstrated in hinged ankle joint distraction as compared to static, and this may also be demonstrated at the knee. An evidence review was undertaken to inform further research and a potential change in practice. Aim: A systematic review of all primary research on hinged knee joint distraction for cartilage regeneration. Methods: An online systematic search of citation databases was conducted. Quality assessment and data extraction were undertaken by two separate researchers. Results: The literature search returned a small number of relevant studies, of which 7 were included. Three of these were animal studies, two cadaveric and two case series. The study quality was low or very low. There was significant methodological heterogeneity with difficulties encountered in the transfer of constructs from animal and cadaveric studies to humans. Issues faced included difficulties with hinge placement and pin site pain in motion. Conclusion: The feasibility of hinged knee joint distraction has yet to be proven. Any further research attempting to establish the benefits of hinged-over static knee distraction will have to take construct design considerations into account. How to cite this article: Lineham B, van Duren B, Harwood P, et al. The Feasibility of Hinged Knee Arthrodiastasis for Cartilage Regeneration: A Systematic Review of the Literature. Strategies Trauma Limb Reconstr 2023;18(1):37-43.

Outcomes of ankle joint distraction in a paediatric and young adult cohort presenting with symptomatic ankle arthritis.

Ankle arthritis in paediatric and young adult patients causes significant morbidity; therefore, joint-preserving procedures are preferable. Ankle joint distraction (AJD) is a technique that preserves the native joint. However, only short-term outcomes are reported in paediatric patients. Therefore, this study reports on intermediate-term outcomes in a paediatric cohort. Demographics for all patients who underwent AJD at two centres were prospectively collected. Case records were reviewed retrospectively for complications and further intervention. Mean joint space at baseline and follow-up radiographs were evaluated by two independent observers. All patients were contacted for completion of a Foot and Ankle Outcome Score (FAOS). Seven patients received AJD between February 2016 and June 2019. Median age at surgery was 15 years (9.0-24.6 years). Complications included one superficial pin-site infection and one patient death due to complications from juvenile idiopathic arthritis 6.2 years post-operatively. Two patients were converted to fusion, at 12.6 months and 26.2 months following frame removal; one patient underwent spontaneous fusion at 9 months following frame removal. The four patients who continued without further intervention achieved 2.59 mm mean joint space at last follow-up (0.65-5.08 mm) and FAOS of 35-79%. Mean follow-up length was 4.3 years (2.9-6.3 years) with final radiographs at mean 2.6 years. While recognising the limitations of this retrospective review, several patients had significant, sustained improvements in joint space with good clinical outcome. Complications for this procedure are minimal, and it is a potential joint-preserving option for managing end-stage ankle arthritis in young patients.

A systematic review demonstrating correlation of MRI compositional parameters with clinical outcomes following articular cartilage repair interventions in the knee.

Objective: Compositional-MRI parameters enable the assessment of cartilage ultrastructure. Correlation of these parameters with clinical outcomes is unclear. This systematic review investigated the correlation of various compositional- MRI parameters with clinical outcome measures following cartilage repair or regeneration interventions in the knee. Design: This study was registered with PROSPERO and reported in accordance with PRISMA. PubMed, Institute of Science Index, Scopus, Cochrane Central Register of Controlled Trials, and Embase databases were searched. All studies, regardless of type, that presented correlation of compositional- MRI parameters with clinical outcome measures were included. Two researchers independently performed data extraction and QUADAS-2 analysis. Compositional-MRI parameter change following intervention and correlation with clinical outcome measures were evaluated. Results: 19 studies were included. Risk of bias was generally low. 5 different compositional parameters were observed from the included studies. However, due to the significant variability in the reporting of compositional-MRI parameters across studies, meta-analyses were possible only for T2 values and T2 index values (T2 value of repair cartilage relative to normal cartilage). Correlation of T2 values of repair cartilage with clinical outcome score was r â€‹= â€‹0.33 [0.15, 0.52]. Correlation of T2 index with clinical outcome score was r â€‹= â€‹0.52 [0.32, 0.77]. Conclusions: Correlation between T2 values and clinical outcome scores following knee cartilage repair were found. The heterogeneity of the correlations extracted from the included studies limited the scope for the meta-analysis. Thus, standardised, high-quality studies are required for better assessment of correlation between compositional MRI parameters and clinical outcome measures after cartilage repair. Registration number: PROSPERO CRD42021287364.Study protocol available on PROSPERO website.

Surgical treatment of spinal stenosis in achondroplasia: Literature review comparing results in adults and paediatrics.

BACKGROUND: This study aims to assess the quantity and quality of available literature on surgical treatment outcomes of spinal stenosis in adult and paediatric achondroplasia patients through a systematic review of literature and to investigate the suitability of conducting a meta-analysis on outcomes of surgical treatment. METHODS: Online databases were searched according to PRISMA guidelines. No restrictions regarding study design, sample size, previous treatment, or publication date were implemented. The following terms: "Spinal stenosis", "Spinal Decompression", "Spinal fusion", each term separately combined with the term "Achondroplasia" were used. Quality of the included studies were assessed used the Modified Coleman method. RESULTS: Five adult and four paediatric single-sample non-comparative studies were identified for inclusion (176 adult and 102 paediatric patients). Meta-analyses assessed the proportion of patients achieving full resolution of symptoms to be 0.51 (95% CI 0.00 to 1.00); the proportion of patients achieving full or partial resolution of symptoms to be 0.90 (95% CI 0.84 to 0.97); the proportion of procedures requiring re-operation to be 0.42 (95% CI 0.34 to 0.50; and the proportion of procedures involving dural tears to be 0.20 (95% CI 0.02 to 0.39). Statistical heterogeneity was very high for full resolution of symptoms and requirement for dural repair; and very low for other outcomes. CONCLUSIONS: The available literature on this population and condition is sparse, highly heterogenous, and is generally of low quality limiting the value of meta-analysis. Overall, outcomes of surgical decompression of symptomatic spinal stenosis in achondroplasia patients show consistent degree of resolution of symptoms. Duration of symptoms prior to surgical treatment appears to play an important role in the overall outcome of treatment. Therefore, a delay in diagnosis and treatment can potentially be detrimental in achieving a better outcome.

Comparison of Mechanical Performance between Circular Frames and Biplanar Distraction Devices for Knee Joint Distraction.

AIM AND OBJECTIVE: This study was designed to test and compare the mechanical performance of the biplanar ArthroSave KneeReviver and a circular frame construct with the intended use of providing a mechanically favourable environment for cartilage regeneration across a knee joint. MATERIALS AND METHODS: Three similar constructs of the two devices were applied to biomechanical testing sawbones, with the knee distracted by 8 mm. The constructs were vertically loaded to 800 N in an Instron testing machine at 20 mm/minute. Tests were conducted in neutral hip flexion and at 12° of hip flexion and extension, to mimic leg position in gait. Displacement measurements were taken from the Instron machine, and three-dimensional joint motion was recorded using an Optotrak Certus motion capture system. RESULTS: Overall axial rigidity was similar between the two devices (circular frame, 81.6 N/mm ± 5.9; and KneeReviver, 79.5 N/mm ± 25.1 with hip neutral) and similar in different hip positions. At the point of joint contact, the overall rigidity of the circular frame increased significantly more than the KneeReviver (491 N/mm ± 27 and 93 N/mm ± 32, respectively, p <0.001). There was more variability between models in the KneeReviver. There was more off-axis motion in the KneeReviver, mainly due to increasing knee flexion on loading. This was exacerbated with the hip in flexion and extension but remained small, with the maximal off-axis displacement being 7 mm/3°. CONCLUSION: The circular frame provides a similar mechanical environment to the novel KneeReviver device, for which most clinical data are available. These findings suggest that both devices appear a viable option for knee joint distraction (KJD). Further clinical data will help inform mode of application. CLINICAL SIGNIFICANCE: KJD is a relatively novel technique for use in osteoarthritis (OA), and it remains unclear which distraction devices provide appropriate mechanics. Our testing gives evidence to support either option for further use. HOW TO CITE THIS ARTICLE: Chowdhury JMY, Lineham B, Pallett M, et al. Comparison of Mechanical Performance between Circular Frames and Biplanar Distraction Devices for Knee Joint Distraction. Strategies Trauma Limb Reconstr 2021;16(2):71-77.

Measurement of Wire Deflection on Loading may Indicate Union in Ilizarov Constructs: A Pilot Study.

INTRODUCTION: No entirely reliable method to assess union during Ilizarov treatment exists. Premature frame removal results in treatment failure, and alternative methods of assessment warrant investigation. Wire deflection might provide an indication of fracture site deformation on weight-bearing, indicating progress towards union. A previous in vitro study from our group demonstrated this approach may be clinically applicable. We investigated translation of this method into clinical practice in an observational pilot study. MATERIALS AND METHODS: Patients with tibial shaft fractures treated with Ilizarov frames were recruited. A prototype depth gauge was used to measure wire deflection on weight-bearing. Investigators undertaking the measurement were blinded to the clinical stage of treatment, and clinicians caring for the patient were blinded to deflection results. Patient records were reviewed at the end of treatment to determine likely fracture stability at each time point. Deflection per kg of weight applied, per mm from the ring was compared between stable and unstable situations. RESULTS: Thirty-one measurements were obtained in 14 patients. The situation was deemed stable at 13 and unstable at 18 measurements. The median deflection in the stable group was 0.030 microns/kg/mm (IQR 0.005-0.104) and 0.165 microns/kg/mm (IQR 0.072-0.328) in the unstable group. This difference was statistically significant (Wilcoxon Mann-Whitney test p = 0.0014). ROC curve analysis revealed that wire deflection was able to predict clinical stability (AUC 0.84, p <0.0001). Various technical problems were encountered when using the device which would potentially limit its clinical utility in its current form. CONCLUSION: In this set of observations, wire deflection was significantly associated with clinically and radiologically determined stability. Though various practical limitations were encountered in using the prototype measurement device, this proof-of-concept study supports further development of this approach. The research group plan to develop a smaller, more reliable device for further clinical testing in a larger group of patients. HOW TO CITE THIS ARTICLE: Lineham B, Stewart T, Ward J, et al. Measurement of Wire Deflection on Loading may Indicate Union in Ilizarov Constructs: A Pilot Study. Strategies Trauma Limb Reconstr 2021;16(3):132-137.

Measurement of wire deflection on loading may indicate union in Ilizarov constructs, an in vitro model.

No entirely reliable method exists for assessing union during Ilizarov treatment. Premature removal results in potential treatment failure; hence, alternative methods warrant investigation. Wire deflection might provide an indication of fracture site deformation on weight bearing, indicating progress towards union. This study aimed to test a method for assessing wire deflection within an Ilizarov frame. (1) To assess the repeatability of our novel measurement method in measuring wire deflection within an Ilizarov frame in vitro. (2) To compare the amount of wire deflection in an unstable model with that in an intact bone model. (3) To assess accuracy of this method by comparing wire deflection measured with overall machine extension. Tests were performed on clinical grade-tensioned fine wire 4-ring Ilizarov constructs stabilising a simulated fracture, with and without an unstable defect. Models were sequentially loaded to 700 N using an Instron testing machine. A digital depth gauge attached to the superior ring measured relative wire displacement at the ring closest to the fracture. Tests were repeated 3 times. (1) Both unstable and stable bone models produced highly repeatable load deformation curves (R2 = 0.98 and 0.99). (2) In the unstable model, wires tensioned at 882 and 1274 N produced mean maximum deflections of 2.41 and 2.69 mm compared with 0.05 and 0.04 mm in the intact bone model (significant p < 0.0001). (3) Wire deflection and machine extension results were strongly correlated (r = 0.99). A measurable difference in wire deflection between stable and unstable situations exists using this method which appears accurate and repeatable, with clear correlation between displacement and load and displacement and machine extension. This approach might be clinically applicable, and further clinical testing is required.

Successful management of femoral trauma in a through-knee amputee with a previous malunited fracture: Implications and functional outcome.

BACKGROUND: After amputation patients are more likely to injure their residual limb. An injury of a previously amputated limb, especially if the residuum is not anatomically normal, poses a dilemma for management. Case Description and Methods: This case report discusses a femoral fracture sustained proximal to a through-knee amputation. Findings and outcomes: The fracture was at the site of a malunited fracture. A shortening osteotomy with bone graft was undertaken to improve alignment and prosthetic fit and remove poor-quality bone. This was stabilised using an intramedullary nail, supplemented with an anti-rotation plate. This fracture went on to uneventful union, and the patient was able to comfortably use a prosthesis with increased functionality compared with prior to the recent injury. DISCUSSION: This management enabled quick healing of the fracture without the need to resort to a more proximal amputation. CONCLUSION: In these unusual cases, careful planning is necessary to ensure all aspects of the problem is dealt with. Each case should be treated on its own merits. Clinical relevance This case demonstrates the difficulty in care of complex limb trauma and offers a solution for management of similar cases. Excellent results are possible when all surgical options are considered.

Case study: Correction of angular deformity post-trans-tibial amputation to improve prosthesis fit and comfort.

BACKGROUND: This case report describes the revision of a trans-tibial amputation complicated by a proximal malunited fracture. It demonstrates the complexity of decisions involved in revisions of this nature. CASE DESCRIPTION AND METHODS: The patient presented has a painful stump due to breakdown of soft tissues. She had been suffering for over a year with pressure sores and inability to use a prosthesis resulting from this, decreasing her quality of life. Malunion of a tibial fracture proximal to the amputation complicated her condition. FINDINGS AND OUTCOMES: Initially it was feared that the amputation level would be converted to a through-knee amputation, but wedge osteotomy of the tibia allowed coverage of the stump, increasing functionality for the patient, while still maintaining a below-knee stump. CONCLUSION: This report highlights the importance of addressing the cause of soft tissue problems in an amputation revision, which must be addressed on a case-by-case basis. CLINICAL RELEVANCE: This case offers an insight into the decision-making process in limb reconstruction and suggests a solution for similar cases. It is important that all surgical options are considered before amputation length is sacrificed.