Tibial Condyle Valgus Osteotomy for Ipsilateral Knee Osteoarthritis after Hip Arthrodesis

We report a case of tibial condylar valgus osteotomy (TCVO) for ipsilateral knee osteoarthritis (OA) after hip arthrodesis. A 58-year-old woman developed right purulent hip arthritis at one month of age and underwent right hip fusion at 16 years old. She visited our department at the age of 57 because her right knee joint pain worsened. The range of motion for her right knee was 80° and -5° of flexion and extension, respectively, and she experienced medial weight-bearing pain. A plain X-ray image showed that the right knee joint had end-stage knee OA with a bone defect inside the tibia, and the tibial plateau shape was the pagoda type. There was a marked instability in her right knee with a valgus of 9° and varus of 7° on stress photography. She underwent TCVO on her right knee and was allowed full load four weeks after surgery. Computed tomography imaging showed bone union nine months after surgery. Two years after the operation, there was no correction loss, and she could walk independently without pain. In general, total knee arthroplasty (TKA) is indicated for end-stage knee OA; however, there are problems, such as early loosening due to the increased mechanical load on the knee after hip OA. In this case, since a good course was obtained, TCVO is considered a treatment option for terminal knee OA after hip arthrodesis.

Structure of elbow joint revision arthroplasty

Introduction Current operations of elbow arthroplasty are accompanied by an extremely high rate of complications in the early and long-term periods. Therefore, along with the widespread growth of primary arthroplasty, there is a growing need for revision interventions. Purpose To study the age groups of patients at the time of primary and revision arthroplasty, to investigate the reasons of the first and repeated revisions, the scope of interventions, as well as the time since the previous AP. Materials and methods A retrospective analysis of 133 cases of elbow revision arthroplasty (111 patients) treated from 2003 to 2019 was conducted. The rate of re-revisions was 16.5 %. The study investigated the age of patients, reasons for the first and repeated revisions, the scope of interventions, as well as the time passed since the previous elbow arthroplasty. Results In the structure of primary and revision arthroplasty, there was a significant dominance of patients aged 51 to 60 years (25.4 % and 33.3 %, respectively). However, the total rate of patients under 40 years old in the group of primary arthroplasty was 33.5 %, and in the revision group it was 34.2 %. The most frequent reason in the first and repeated revisions was aseptic loosening: 47 % and 50 %, respectively, followed by PJI (23 % in both groups), dislocation (10 % and 18 %, respectively) and breaks of the implant's components (8 % and 4 %). Other complications were less common (12 % and 5 %, respectively). Most of the revisions for PJI were performed in the first year since the previous arthroplasty (56.7 %). In terms of aseptic instability, early and late periods were identified. The ratio of early revisions to the total number of primary arthroplasty during the entire time of the surgical team's work decreased from 19.4 % to 3.5 %. Discussion The observed number of young people in the age structure of primary and revision AP in the long term is likely to lead to an increase in the number of patients with severe bone defects. The data of our study demonstrate a significant decrease in the number of revisions over the past 5 years performed for early loosening, despite the general increase in the number of primary APs. Conclusion The study identified a considerable number of young patients, which could potentially lead to an increase in the number of repeated revisions and related problems, including pronounced bone defects and recurrent infection. All this actualizes the need to improve the technique of revision arthroplasty.

An algorithmic approach to total hip arthroplasty in patient with post-polio paralysis and fixed pelvic obliquity

Aims Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening. Methods In all, ten hips in ten patients with PPRP with fixed pelvic obliquity who underwent THA as per an algorithmic approach in two centres from January 2014 to March 2018 were followed-up for a minimum of two years (2 to 6). All patients required one or more additional soft tissue procedures in a pre-determined sequence to correct the pelvic obliquity. All were invited for the latest clinical and radiological assessment. Results The mean Harris Hip Score at the latest follow-up was 79.2 (68 to 90). There was significant improvement in the coronal pelvic obliquity from 16.6o (SD 7.9o) to 1.8o (SD 2.4o; p < 0.001). Radiographs of all ten hips showed stable prostheses with no signs of loosening or migration, regardless of whether paralytic or non-paralytic hip was replaced. No complications, including dislocation or infection related to the surgery, were observed in any patient. The subtrochanteric shortening osteotomy done in two patients had united by nine months. Conclusion Simultaneous correction of soft tissue contractures is necessary for obtaining a stable hip with balanced pelvis while treating hip arthritis by THA in patients with PPRP and fixed pelvic obliquity. Cite this article: Bone Jt Open 2021;2(9):696–704.

Loading Effect of Prosthetic Feet’s Anthropomorphicity on Transtibial Osseointegrated Implant

ABSTRACT Introduction Osseointegrated implants for direct skeletal attachment of transtibial prosthesis carry risks that are yet to be fully resolved, such as early loosening, mechanical failure of percutaneous and medullar parts of implant, periprosthetic issues, and infections. Underloading could lead to early loosening and infection. Overloading might compromise the bone–implant interface. Therefore, Goldilocks loading regimen applied by transtibial bone-anchored prostheses is critical for safe and efficient development of osseointegration around the implant during rehabilitation and beyond. We hypothesized that Goldilocks loading could be achieved when ambulating with a so-called anthropomorphic prosthetic ankle showing moment–angle relationship similar to a sound ankle. Materials and Methods Quantitative characteristics of the moment–angle curve of the sound ankle during dorsiflexion phase of a free-pace walking were extracted for 4 able-bodied participants (experiment 1). A slope of the moment–angle curve (stiffness) was calculated twice: for the first half and for the second half of the moment–angle curve. The difference of stiffnesses (those at the second half minus at the first half) was called the index of anthropomorphicity (IA). By definition, positive IA is associated with concave shape of the moment–angle curve, and the negative IA is associated with convex shape. In experiment 2, the same recordings and calculations were performed for 3 participants fitted with transtibial osseointegrated fixation during walking with their usual feet and the Free-Flow Foot (Ohio Willow Wood). The Free-Flow Foot was selected for its anthropomorphicity demonstrated in the previous studies with amputees using traditional socket attachment. Results The IA was 5.88 ± 0.93 for the able-bodied participants, indicating that the stiffness during the first part of the dorsiflexion phase was substantially fewer than during the second parts, as the calf muscles resisted to angulation in ankle substantially less than during the second part of dorsiflexion phase. For amputees fitted with Free-Flow Foot, IA was 2.68 ± 1.09 and −2.97 ± 2.37 for the same amputees fitted with their usual feet. Conclusions Indexes of anthropomorphicity, while of different magnitude, were positive in control able-bodied group and in the amputee group wearing Free-Flow Foot, which was qualitatively associated with concave shape of their moment–angle curves. The 3 usual feet worn by the participants were classified as nonanthropomorphic as their individual moment–angle curves were convex and the corresponding IAs were negative. Furthermore, this study showed that a foot with anthropomorphic characteristics tends to decrease maximal loads at the bone–implant interface as compared to the nonanthropomorphic feet and possibly may minimize the risks to compromise the integrity of this interface.

Does vacuum mixing affect diameter shrinkage of a PMMA cement mantle during in vitro cemented acetabulum implantation?

Radiolucent lines on immediate postoperative cemented acetabular component radiographs between the PMMA bone cement mantle and bone are an indicator of an increased risk of early loosening. The cause of these lines has yet to be identified. Thermal and chemical necrosis, fluid interposition and cement shrinkage have all been suggested in the literature. The aim of the study reported here was to take an engineering approach – eliminating confounding variables present during surgery – to quantify the size of the interstice created by cement shrinkage when a 50 mm diameter flanged acetabular cup is implanted in a model acetabulum with a 52 mm hemispherical bore under controlled conditions using vacuum and non-vacuum mixed cement. Irrespective of the mixing method used, a significant interstice was created between the bone cement and the mock acetabulum. When the cement was mixed under vacuum the interstice created between the mock acetabulum and the cement mantle was 0.60 mm ± 0.09 mm; when the cement was mixed under non-vacuum conditions the interstice created was 0.39 mm ± 0.15 mm. Possible explanations for radiolucent lines are discussed.

Shoulder and Elbow Surgery in Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory arthropathy that manifests itself prior to the age of sixteen years with symptoms lasting six weeks or longer. As JIA frequently effects the upper extremities, activities of daily living become compromised during the stages of development when young adults are striving for independence. Symptomatology includes ankylosing, pain and early growth plate closure. Patients with joint involvement prior to growth plate closure have the most destruction in terms of joint abnormality and surgical complexity.Medical management of JIA has allowed for better non-surgical management, yet, there is a continued need to understand the appropriate surgical intervention and order for the greatest functional gains. Comparative studies have shown that varied results as to whether the shoulder replacement should supersede the elbow replacement or should that be reversed or both joint replacements done simultaneously. Our experience found a more significant functional improvement after total elbow replacement due to the unpredictable nature from the shoulder replacement outcomes and an inability for patients to do simple tasks such as bringing a cup to their mouths or handling a toothbrush. The exception to this occurs if the ipsilateral shoulder joint is severely limited to the point that the stressors placed on the elbow due to compensation will lead to early loosening or failure of the elbow joint replacement.Various methods for performing joint replacement of the shoulder and elbow in the JIA population will be discussed. Soft tissue integrity including the functional status of the rotator cuff will be a consideration for which surgical procedure should be considered. Surgical approaches for the elbow present fewer options for improving pain and function in this patient population. Pre, peri and postoperative management is reviewed as careful attention to irregular bony dimensions and dysmorphic anatomy precludes the use of standard implants.Total shoulder and total elbow arthroplasty should be considered in the JIA population where pain and significant functional compromise are present. The order of procedures is dependent on multiple factors and expected outcomes. Educating patients on postoperative expectations over the lifespan is an important part of surgical management for patients with JIA.

Scaphometacarpal arthroplasty: a report of ten cases of trapeziometacarpal prosthesis and trapeziectomy revision

Loosening of the trapezial component is a main cause of failure of trapeziometacarpal prostheses. This report presents the preliminary results of scaphometacarpal prostheses used for revision of trapeziometacarpal prostheses and failed trapeziectomies. A retrospective multicentre study was conducted on ten patients. Four had revision surgery after failure of trapeziometacarpal prostheses, five after trapeziectomy and one after a trapezial silicone implant. Pain, mobility, strength, QuickDASH, satisfaction score and radiographs were assessed. Nine patients were assessed (one was lost to follow-up), with a mean follow-up of 34 months. The mean pain score was 1.2/10, Quick-DASH was 39 and opposition according to the Kapandji score was 8.6. Strength was 3 kg for key pinch and 13.6 kg for power grip. One failure was observed, with early loosening of the scaphoid cup. Scaphometacarpal arthroplasty is a reliable medium-term solution for revision of the loosening of a trapeziometacarpal prosthesis with trapezial damage and for failed trapeziectomy. Level of evidence: IV

Neural Network as an Assisting Tool in Designing Talus Implant

The design of current talus implant are focusing too much on mechanical simplicity and usually based on certain population which tends to ignore the anatomically difference between populations. An anatomically talus implant design is known can reduce the contact pressure but one of the constraints for designing implant anatomically is to get bone parameters. This is due to the difficulty to get enough volunteers in getting bone parameters using hazardous method (X-ray or CT scan) .Thus, the talus implant (TI) for particular population was developed based on artificial neural network (ANN) prediction. By using Finite Element Method (FEM), numerical models that include mainly the talus bone and the talus implants are created to compare the contact pressure distribution of the newly develop talus implant with the three different kind of current talus implant designs (BOX, STAR & TNK). For FEM results, only BOX and the newly develop talus implant exceeded the contact stress recommended for the superior articular surface compared to the others. The results also showed that the stress increased near the resected surface. Thus, it is agreed that excessive bone resection may not support the force at the ankle which consequently may contribute to early loosening and subsidence of the talus implant. It is concluded that the excessive bone resection can be avoided by perfectly match talus implant which only can be achieved by designing talus implant for a particular population.