Anaesthesia Considerations in a Case of Alkaptonuria Posted for Total Knee Arthroplasty.

Alkaptonuria is a rare hereditary condition in which homogentisic acid is deposited in collagenous tissues, leading to blackish discoloration, degenerative changes, restricted mobility, and pain in the affected part. The skeletal system is commonly affected, resulting in the stiffening of the vertebral spine, shoulders, knees, hip joints, and thoracic cage. Additionally, the degenerative process involves heart valves, endocardium, and kidneys, with associated pathophysiological changes. These patients present significant challenges in neuraxial anesthesia, airway management, and postoperative pain relief. In this report, we present the anesthetic management of a case of alkaptonuria undergoing total knee arthroplasty and discuss the encountered difficulties. We conclude that the perioperative anesthesia management of alkaptonuria patients requires thorough planning to effectively address the various challenges associated with the administration of anesthesia.

Joint replacement risk is markedly increased in alkaptonuria (AKU) in those with prior arthroplasty.

Background: Increased homogentisic acid (HGA) in alkaptonuria (AKU) causes severe arthritis. Nitisinone reduces the production of HGA, but whether it also decreases arthroplasty was examined in 237 AKU patients. Patients and methods: Patients attending the United Kingdom National Alkaptonuria Centre (NAC) and the Suitability of Nitisinone in Alkaptonuria 2 (SONIA 2) study were studied. Assessments included questionnaires eliciting details of arthroplasty. Nitisinone was administered from baseline, 2 mg in the NAC and 10 mg in SONIA 2. In SONIA 2, subgroups consisted of those with baseline arthroplasty on and not on nitisinone (BR + N+, BR + N-), as well as those without baseline arthroplasty on and not on nitisinone (BR-N+, BR-N-). Results: In the SONIA2 subgroups, new joint replacement (JR) probabilities after baseline were significantly different (BR + N+, BR + N-, BR-N+, BR-N-) (χ2 = 23.3, p < 0.001); mean (SD) was 3.8 (0.1) years in BR-N-, 3.7 (0.1) years in BR-N+, 3.4 (0.3) years in BR + N-, and 3.0 (0.3) years in BR + N+. Further, the BR + N- showed more JR than the BR-N- subgroup (p < 0.01), while BR + N+ similarly showed more JR than the BR-N+ subgroup (p < 0.001).In the NAC, the BR- group had a mean age of 51.6 (7.0) years at baseline but 57.7 (8.7) years at final follow up during nitisinone therapy and showed only 7 incident JR. The BR+ group had an age at baseline of 57.4 (8.5) years and had undergone 94 JRs at baseline. Conclusion: The incidence of arthroplasty was earlier and more frequent after the first JR and was not affected by nitisinone.

Alkaptonuria: From Molecular Insights to a Dedicated Digital Platform.

Alkaptonuria (AKU) is a genetic disorder that affects connective tissues of several body compartments causing cartilage degeneration, tendon calcification, heart problems, and an invalidating, early-onset form of osteoarthritis. The molecular mechanisms underlying AKU involve homogentisic acid (HGA) accumulation in cells and tissues. HGA is highly reactive, able to modify several macromolecules, and activates different pathways, mostly involved in the onset and propagation of oxidative stress and inflammation, with consequences spreading from the microscopic to the macroscopic level leading to irreversible damage. Gaining a deeper understanding of AKU molecular mechanisms may provide novel possible therapeutical approaches to counteract disease progression. In this review, we first describe inflammation and oxidative stress in AKU and discuss similarities with other more common disorders. Then, we focus on HGA reactivity and AKU molecular mechanisms. We finally describe a multi-purpose digital platform, named ApreciseKUre, created to facilitate data collection, integration, and analysis of AKU-related data.

Alkaptonuria with Fracture Neck of Femur - A Case Report.

Introduction: Alkaptonuria is a rare autosomal recessive genetic disorder found in 2-5/million live births. It results in dark brown pigmentation of connective tissues including cartilage and joint capsule that can often lead to arthropathy of large joints. However, bone fractures are unusual. This article describes a fracture neck of the femur in a patient with undiagnosed alkaptonuria managed at a rural center. Case Report: A 60-year-old daily wage laborer with previously pain-free hips presented with sudden onset pain in the left hip while walking with no prior history of trauma. Radiographs showed a displaced fracture of the neck of the left femur. She underwent Left hip hemiarthroplasty. Intraoperatively, her soft-tissue including the joint capsule and the femoral head had dark brown pigmentation. Postoperatively, her urine was tested and the same turned black supporting the clinical diagnosis of alkaptonuria. At her 1-year follow-up, she had a painless, stable, and mobile hip. Conclusion: We report a rare and unique case of neck of femur fracture in a patient with alkaptonuria treated with hemiarthroplasty in a resource-limited hospital in rural India. It is essential to consider the possibility of this condition when we come across a patient with an atypical fracture presentation. This article also presents an overview of alkaptonuria with a discussion on etiopathogenesis, clinical presentation, diagnosis, and management.

Ease of sutureless aortic valve replacement in a patient with unexpected ochronosis: a case report.

BACKGROUND: Alkaptonuria is a rare congenital metabolic disorder characterized by homogentisic acid accumulation in body cartilage and connective tissues due to a deficient homogentisic acid dioxygenase enzyme. This disorder manifests in various clinical symptoms, including spondyloarthropathy, ocular and dermal pigmentation, genitourinary tract obstruction by ochronosis stones, and cardiovascular system involvement. Cardiac ochronosis is a rare manifestation of alkaptonuria that may present as aortic stenosis, sometimes accompanied by other cardiovascular complications. CASE PRESENTATION: We report an unexpected case of ochronosis diagnosed during cardiac surgery. Due to the fragile, thin, and atheromatous nature of the ascending aorta in patients with ochronosis, we opted for a sutureless aortic valve replacement procedure. This approach appears to be more suitable for patients with ochronosis. CONCLUSIONS: Although cardiac ochronosis is rare, surgeons should remain vigilant and consider the possibility of this condition when examining patients with aortic valve stenosis, paying close attention to the clinical manifestations of alkaptonuria.

A shocking intraoperatively diagnosis of ochronotic knee arthropathy: a case report.

Introduction: Alkaptonuria is an autosomal extremely rare recessive metabolic disorder with incidence reported to occur as 1:100 000-1:250 000 live births worldwide. This rare metabolic disorder is characterized by the accumulation of homogentisic acid due to a deficiency in homogentisic acid 1,2 dioxygenase. Homogentisic acid subsequently oxidizes and accumulates in the connective tissue. The knee is the most significant peripheral joint to be affected by the disorder. The authors present the first case of ochronotic arthropathy in Syria. Case presentation: A 46-year-old male presented with bilateral pain in the knees. the pain was affecting his day-to-day activities, and not responding to conservative management. Anteroposterior standing radiographs demonstrated extensive degenerative disease. Intraoperatively, the diagnosis was done after noticing that the quadriceps tendon and the articular cartilage of the femur, tibia, and patella were blackened during cemented total knee replacement of the knee. Conclusion: Ochronotic arthropathy should be kept in mind in middle age patients with severe osteoarthritis to not be surprised by the rare alkaptonuria diagnosis if arthroplasty was indicated.

Arthroplasty in Ochronotic Arthropathy: 3 Replacements in a Single Patient with a Long-term Follow-up of 11 Years.

Introduction: Alkaptonuria is a rare autosomal recessive disorder caused by the defective metabolism of homogentisic acid, with a rare course and remained undetected even until adulthood. Ochronotic arthropathy is one of the manifestations of alkaptonuria, predominantly affecting weight bearing joints such as spine, hip, and knee. Total joint arthroplasty is treatment of choice in end-stage arthritis of hip and knee. Owing to the rarity of the disease, limited data is available in literature regarding surgical challenges and long-term functional outcomes. Case Report: Herein, we present a case of 43-year-old male with ochronotic arthropathy of bilateral hip, right knee, and bilateral elbow joints with involvement of spine, who was incidentally diagnosed with ochronotic arthropathy intraoperatively and underwent sequential arthroplasty for right hip followed by right knee and left hip over a period of 10 years. At 11 years' follow-up, the patient has full mobility with no loosening of implants. Conclusion: The long-term results of total joint arthroplasty in ochronotic arthropathy are good. Surgeon should be aware of the difficulty in soft tissue balancing and possible complications in the ochronotic arthropathy and require a conscientious approach to avoid complications.

Alkaptonuria Diagnosis Following a Discectomy: A Case Report.

Alkaptonuria is a rare genetic disorder characterized by the excessive production of homogentisic acid, leading to the formation and deposition of pigment polymers throughout the body. It is extremely rare, affecting only around one in 100,000 individuals. Despite the normal life expectancy, it can cause severe morbidities. Alkaptonuria is typically managed supportively with pain medication, dietary modifications, and surgical interventions, which are considered to be the gold standard of therapy. Here we present a case of a 33-year-old male with no previous medical or surgical history who presented with severe acute back pain radiating to the left leg. Genetic testing confirmed a homozygous pathogenic variant for alkaptonuria. This case highlights the challenges in diagnosing alkaptonuria, emphasizing the significance of early detection, and clinical evaluation for improved outcomes. Furthermore, it underscores the need to consider alkaptonuria as a multidimensional disease, necessitating further research to enhance our understanding and develop effective management. Therefore, this study serves as an opportunity for future trials and studies aimed at digging deeper into the intricacies of alkaptonuria to increase our understanding and establish comprehensive management plans for affected individuals.

Alkaptonuria Presenting With Lumbar Disc Herniation: A Case Report.

Alkaptonuria is a rare autosomal recessive trait. Symptomatic lumbar disc herniation warranting surgical intervention is a rare scenario in alkaptonuria and only a few cases have been described in the literature. We present one such rare case of alkaptonuria in a 31-year-old female presenting with low back pain and left leg radiculopathy not relieved with conservative management. Roentgenograms of the lumbar spine revealed wafer-like disc calcifications and MRI showed a herniated disc at the L4-L5 level with deeply hypointense disc spaces in T2 suggestive of disc calcification and associated modic type 2 changes. During the surgery, the disc material removed was black in color, which raised a clinical suspicion of alkaptonuria. Postoperatively, the patient was re-examined and urine homogentisic acid was found to be raised. This, along with a histopathological examination, was diagnostic of alkaptonuria. The patient had excellent relief of symptoms postoperatively. In conclusion, if a 'black disc' is found during surgery, retrospective analysis and re-examination of patient clinical features and urine examination have to be done to diagnose alkaptonuria. While making a differential diagnosis of degenerative disc disease in patients with a calcified disc seen on radiography, a high index of suspicion for alkaptonuria has to be maintained.

Ochronotic Chondropathy: A Case Report.

Endogenous ochronosis, also known as alkaptonuria, is a rare disease known for its bluish-black discoloration of the skin, sclerae, and pinnae, as well as urine that turns black upon standing. Though rarely fatal, joint degradation is a common sequela, and many patients require multiple large joint arthroplasties throughout their lifetime. Though many aspects of the pathophysiological mechanisms of the disease have been described, questions remain, such as how the initiation of ochronotic pigmentation is prompted and the specific circumstances that make some tissues more resistant to pigmentation-related damage than others. In this report, we present the case of an 83-year-old female previously diagnosed with alkaptonuria including high-quality arthroscopic images displaying the fraying of articular cartilage. We also offer a summary of the latest literature on the pathophysiological mechanisms of the disease, including cellular-level changes observed in ochronotic chondrocytes, biochemical and mechanical alterations to the cartilaginous extracellular matrix, and patterns of pigmentation and joint degradation observed in humans and mice models. With these, we present an overview of the mechanisms of ochronotic chondropathy and joint degradation as the processes are currently understood. While alkaptonuria itself is rare, it has been termed a "fundamental disease," implying that its study and greater understanding have the potential to lead to insights in skeletal biology in general, as well as more common pathologies such as osteoarthritis and their potential treatment mechanisms.

Minocycline-Induced Ocular Ochronosis.

We report a case of minocycline-induced ocular ochronosis with scleral, retinal, and cutaneous manifestations. A 65-year-old male who had taken minocycline for four years to treat hidradenitis suppurativa, an inflammatory skin condition affecting the apocrine sweat glands and hair follicles, presented for evaluation of discoloration of bilateral sclera, nail beds, and gingiva. Ophthalmic evaluation revealed intact visual acuity, diffuse blue-gray hyperpigmentation of the sclera, more pronounced overlying insertions of the horizontal muscles, without any scleral thinning. Macular optical coherence tomography and fundus exam revealed a blue hue to the underlying choroid with dark deposits in the retinal pigment epithelium. Despite drug discontinuation, after six years the discoloration persisted. Management was directed towards patient tolerability.

Black Bone Disease: Ochronotic Arthritis Detected during Knee Arthroplasty.

Alkaptonuria is an extremely rare autosomal recessive metabolic disorder characterized by dark urine, ochronosis, and arthritis of the spine and major joints. We report a case of ochronotic arthritis observed during total knee replacement surgery in a 65-year-old male patient with no relevant medical history. Based on a literature review, this is the first case of ochronotic arthritis reported in Korea.

Exogenous Ochronosis: Characterizing a Rare Disorder in Skin of Color.

Exogenous ochronosis is a rare dyschromia that primarily impacts those with skin of color. It is characterized by blue-black pigmentation and is associated with the long-term application of skin-lightening creams containing hydroquinone. Commonly confused with other dyschromias, the use of skin lightening topicals can cause paradoxical skin darkening in patients with known exogenous ochronosis. This is highly distressing to patients, often worsening the underlying dyschromia and making treatment more difficult. A 10-year retrospective analysis was conducted that revealed 25 patients with exogenous ochronosis. The average patient used a skin lightening cream for 9.2 years, with exogenous ochronosis most commonly arising on the cheeks (68%), forehead (24%), and temples (20%). Furthermore, this study identified that patients with exogenous ochronosis may respond well to treatment with Q-switched Alexandrite laser and microneedling. The incidence of exogenous ochronosis is likely to increase as demographics shift and access to a wide range of over-the-counter topicals becomes more available, both in the United States and worldwide. Therefore, it is imperative to better characterize exogenous ochronosis to identify best treatment practices for all patients.

Alkaptonuria - Past, present and future.

Alkaptonuria (AKU) is an ultra-rare inherited inborn error of metabolism that afflicts the tyrosine metabolic pathway, resulting in the accumulation of homogentisic acid (HGA) in the circulation, and significant excretion in urine. Clinical manifestations, typically observed from the third decade of life, are lifelong and significantly affect the quality of life. This review provides a comprehensive overview of the natural history of AKU, including clinical, biochemical and genetic perspectives. An update on the major advances on studies in murine models and human subjects, providing mechanistic insight into the molecular and biochemical processes that underlie pathophysiology and its response to treatment are presented. The impact of treatment with nitisinone is also presented with a specific emphasis on hypertyrosinemia, as uncertainty on this topic remains. Future perspectives are explored, such as novel approaches to treat hypertyrosinemia including the use of binding agents and amino acid transporter inhibitors, as well as advanced potentially curative gene and cell therapy initiatives.

Rare Case of Ochronosis with Fracture of Intracapsular Neck of Femur and Scoliosis: A Case Report.

Introduction: Ochronosis is a rare syndrome caused by accumulation of homogentisic acid in connective tissue due to deficiency of enzyme homogentisic acid oxidase. It characterized by blue-black pigmentation connective tissues such as sclera, cartilage of ear, and synovium of joints and it causes destruction of joints cartilage and early arthritis. Urine becomes dark coloured on prolonged standing. Some patient may develop rare cardiac manifestation due to accumulation of homogentisic acid on valves. Case Report: A 56-year-old female admitted with neck of femur fracture after history of fall at home. The patient was having chronic back ache and knee pain. Plain radiograph of knee and spine showed severe arthritic changes. Exposure during surgery was difficult due to hard and brittle tendons and capsule of joint. Femur head and acetabulum cartilage appeared dark brown. Dark brown pigmentation of sclera and hands was found on clinical examination postoperatively. Conclusion: Patients with ochronosis usually develop early osteoarthritis and spondylosis which should be differentiated from other causes of early arthritis such as rheumatoid arthritis and seronegative arthritis. It leads to destruction of joint cartilage and weaking subchondral bone which leads to pathological fracture. And due to the stiffness of soft-tissues around joint, surgical exposure can be challenging.

A Previously Undiagnosed Case of Alkaptonuria in an 80-Year-Old Patient: A Case Report.

Alkaptonuria is a rare genetic metabolic disorder of autosomal recessive inheritance characterised by the accumulation of homogentisic acid in the body. It is diagnosed upon identification of characteristic symptoms, using various biochemical investigations, radiographic pictures, and a variety of specialised tests. Here we are discussing the case of an 80-year-old female patient with incidental findings of alkaptonuria. It is crucial to understand the fundamental diagnostic investigations that can be used in low-income nations or facilities where investigations like genetic testing, gas chromatography, and mass spectrometry are not readily available for the diagnosis of alkaptonuria.

Total Knee Arthroplasty in Ochronosis: A Rare Condition.

Ochronosis is a rare metabolic disorder characterized by homogentisic acid deposition in the large joints and spine, resulting in progressive degeneration. We present two cases of ochronotic arthritis of the knee subjected to cemented total knee arthroplasty (TKA). These cases were diagnosed intraoperatively and later confirmed with a histopathologic examination. Orthopedic surgeons should be aware of the condition as the intraoperative finding of darkened cartilage might surprise them. After a five-year TKA follow-up, both of our cases showed better mobility and function.

Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders.

Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation.