Collagen atomic scale molecular disorder in ochronotic cartilage from an alkaptonuria patient, observed by solid state NMR

In pilot studies of the usefulness of solid state nuclear magnetic resonance spectroscopy in characterizing chemical and molecular structural effects of alkaptonuria on connective tissue, we have obtained (13) C spectra from articular cartilage from an AKU patient. An apparently normal anatomical location yielded a cross polarization magic angle spinning spectrum resembling literature spectra and dominated by collagen and glycosaminoglycan signals. All spectral linewidths from strongly pigmented ochronotic cartilage however were considerably increased relative to the control indicating a marked increase in collagen molecular disorder. This disordering of cartilage structural protein parallels, at the atomic level, the disordering revealed at higher length scales by microscopy. We also demonstrate that the abnormal spectra from ochronotic cartilage fit with the abnormality in the structure of collagen fibres at the ultrastructural level, whereby large ochronotic deposits appear to alter the structure of the collagen fibre by invasion and cross linking.

SUMMARY

Increased signal linewidths in solid state NMR spectra of ochronotic articular cartilage from an AKU patient relative to linewidths in normal, control, cartilage reveals a marked decrease in collagen molecular order in the diseased tissue. This atomic level disordering parallels higher length scale disorder revealed by microscopic techniques.

Ochronosis in differential diagnosis of patients with chronic backache: a review of the literature

A 50-year-old man presented with a complaint of low-back pain and widespread joint pain for the previous 20 years. Conventional radiography revealed wide areas of calcification in the intervertebral discs and degenerative changes in the peripheral joints. A diagnosis of ochronosis was made by the observation of bluish-brown pigmentation in the nose and ears, dark urine colors following alkalization, and high levels of homogentisic acid in the urine. Ochronosis should be considered in the differential diagnosis of patients with chronic low-back pain regarding features of widespread calcification in the intervertebral discs at radiography and bluish-brown pigmentation in the nose and ears.

Orthopaedic problems in patients affected by alkaptonuria. A case report

Alkaptonuria is a rare congenital metabolic disorder. A defect of the enzyme homogentisic oxidase results in a block of the metabolic pathway of the amino acids phenylalanine and tyrosine. Deposits of homogentisic acid polymers in connective tissue cause various organ manifestations, including musculoskeletal symptomatology. A 66 year-old woman was twice admitted to our Department because of progressive knee and low back pain. Physical examination and accessory investigations confirmed that her various complaints were caused by underlying alkaptonuria. We use this case and a review of literature to discuss orthopaedic problems in patients with alkaptonuria and describe the cardinal signs and symptoms of this disease, its diagnosis and treatment.

Ochronotic arthropathy, an approach to osteoarthritis bone remodelling

The objective is to use hip ochronotic arthropathy for an indirect approach to osteoarthritis bone remodelling in a human joint via an identified causal chondropathy. The method is via radiology connecting pathology and nosology, based on the study of seven ochronotic femur heads excised in alcaptonuric patients. Due to the brittleness of ochronotic cartilage, bone remodelling similar to that of hip osteoarthritis exists with diffuse narrowing of the interarticular space and (except in one case modified by intermediary surgery) poorly developed osteophytes. Ochronotic arthropathy is only a privileged model of osteoarthritis bone remodelling, the pathology of which might well evidence the stages of the process, with marking by pigmented cartilage remnants Thus it may lead to various reflections in rheumatology, among others concerning the respective radiological hip images of osteoarthritis and rheumatoid arthritis. The use of the pathology-radiology files provided by hip surgery of ochronotic arthropathy might offer a useful reference model for investigating various aspects of osteoarthritis.

Ochronotic arthropathy: disappearance of alkaptonuria after liver transplantation for hepatitis B-related cirrhosis

The deficiency of homogentisic acid oxidase, an enzyme that is mainly found in hepatocytes, is associated with alkaptonuria and ochronosis. We report a patient with clinical and radiologic findings of ochronotic arthropathy in whom alkaptonuria disappeared and the progressive course of the disease stopped after liver transplantation for hepatitis B-related cirrhosis.

Radiographic and MRI findings in ochronosis

PURPOSE

Ochronotic arthropathy is the articular manifestation of alkaptonuria, a rare hereditary metabolic disease that leads to the deposition of homogentisic acid particularly in the joints where it causes articular degeneration and inflammation. We studied the radiological patterns of the disorder using both traditional X-rays both MRI and comparing the results obtained with the two techniques.

MATERIALS AND METHODS

The study included five patients (4 males, 1 female, mean age 51 years); we studied the most frequently affected sites, the knee, the shoulder and the spine. As regards the conventional study we used a radiographic score which considered the state of the articular space and the presence of calcifications. MRI of the peripheral joints was performed on the most symptomatic site or, if asymptomatic, on the most severely affected site as established by radiography; in all cases T1- and T2-weighted sequences in the axial, sagittal and coronal planes were acquired.

RESULTS

Both the X-ray and MRI study revealed the typical alterations of ochronosis in the cases with a known diagnosis: articular space narrowing up to osseous ankylosis, calcifications, osteophytosis, reactive sclerosis of the articular surfaces; MRI was however more accurate in identifying the alterations and revealing lesions not visible at conventional radiology, such as ligament lesions. In the case of newly diagnosed ochronotic arthropathy MRI proved valuable for its ability to detect alterations that are poorly appreciable at conventional radiology.

CONCLUSIONS

Modern diagnostic imaging, above all MRI, allowed us to identify the peculiar characteristic features of ochronosis and is fundamental both for the diagnosis and for differentiating ochronosis from other articular disorders.

[Ochronotic arthropathy: the value of bone scintigraphy in alkaptonuria]

We report the case of a 62 year old man diagnosed of alkaptonuria who was referred to our department to undergo bone scintigraphy for polyarthralgia. The patient had a history of pain in lumbar and thoracic spine, right shoulder and left knee. Bone scintigraphy showed multiple joint disease with increased uptake in both shoulders, knees and spine. Higher uptake stood out in painful right shoulder and left knee joints. Ochronotic arthropathy that is developed in alkaptonuric patients is a degenerative joint disease. X-ray studies in this patient showed marked degenerative arthrosis in knees and shoulders, without more intense involvement in the symptomatic joints. Lumbar spine X-rays showed intervertebral disk calcification with disk collapse and fusion of the vertebral bodies with relative sparing of sacroiliac joint, which is a classic feature of ochronotic arthropathy. This case highlights the utility of bone scintigraphy in the evaluation of joint involvement as well as its correlation with clinical course and potential usefulness in the follow-up of this disease.

Spontaneous tendon ruptures in alkaptonuria

Ochronosis, the musculoskeletal manifestation of alkaptonuria, is known to lead to degenerative changes of the spine and weight-bearing joints. Symptoms related to degeneration of tendons or ligaments with spontaneous ruptures have not previously been reported. Three patients are described with four spontaneous ruptures of either the patellar tendon or tendo Achillis as the first symptom of alkaptonuria.

[A case of diagnosis of knee joint ochronosis in bone tuberculosis hospital]

The author presents a case of knee joint ochronosis or alcaptonuric osteoarthrosis, which is rarely encountered in clinical practice. The pathogenesis of the disease is attributable to the acculation of homogentisic acid derivatives in the body. There is a great similarity of clinical and X-ray manifestations of ochronosis and tuberculous arthritis.

[Ankylosis of the spine in a case with ochronosis]

A thirty-nine-year-old man presented with a complaint of low back pain with a history of 20 years. Cervical and thoracolumbar radiographs showed wide calcification areas and ankylosis in the intervertebral discs. Observation of blue-gray pigmentation around his nose and ears suggested a diagnosis of ochronosis, which was confirmed by the detection of high levels of homogentisic acid in the urine and dark urine color following alkalization. Ochronosis should be included in the differential diagnosis in patients with chronic low back pain, calcified intervertebral discs, and black pigmentation in cartilagenous and collagenous tissues.

Bilateral hip arthroplasty for ochronotic arthropathy

Ochronosis is a musculoskeletal manifestation of alkaptonuria, a rare hereditary metabolic disorder characterised by the absence of the enzyme homogentisic acid oxidase and associated with various systemic abnormalities related to the deposition of homogentisic acid pigment (ochronotic pigment). In this report, we describe a 53-year-old, HLA-B27(+) woman with ochronotic arthropathy. In addition to the typical clinical features of the disorder, she had bilateral hip involvement, which was improved by cementless total hip prosthesis.

[Ochronotic changes in alkaptonuria: a case report]

Alkaptonuria is a rare metabolic condition caused by congenital homogentisate oxidase deficiency of recessive autosomal inheritance. Homogentisate polymers are accumulated and cause urine darkening (alcaptonuria), brown/black pigmentation of connective tissue (ochronosis), articular cartilage pathology, osteoporosis and patomorphologic changes in internal organs. A case of 61 female with ochronotic polyarthropathy is presented. An early result of Weller THR is encouraging. Pathogenesis, clinical picture, diagnostics and treatment of alkaptonuria is presented on the ground of the literature.

Chiropractic care and ochronotic arthropathy

OBJECTIVE

To discuss the case of a patient with ochronotic arthropathy whose symptoms were treated with chiropractic care. An emphasis is placed on this condition's radiographic features.

CLINICAL FEATURES

A 59-year-old woman with pain in her low back, right knee, and left ankle sought chiropractic evaluation. Black pigmentation was found in the sclera of both eyes, and homogentisic acid was present in the urine. Orthopedic evaluation revealed uncomplicated, nonspecific joint pain, and radiographs demonstrated characteristic spinal changes.

INTERVENTION AND OUTCOME

The patient was treated with chiropractic manipulation, physiotherapy modalities, bracing, and exercises. This type of therapy was successful in reducing the symptoms and helped decrease the severity and frequency of acute exacerbations.

CONCLUSION

Ochronotic arthropathY is a rare metabolic disorder that can be diagnosed from spinal radiographs. Chiropractic care is an appropriate tool for reducing its symptomatology.

Hereditary ochronosis: hyperpigmented skin overlying cartilaginous structures

Hereditary ochronosis, or alkaptonuria, results from deficiency of homogentisic acid oxidase. It is an autosomal recessive condition found in geographically isolated populations. The excess homogentisic acid deposits in collagenous structures, leading to unusual pigmentation of the skin overlying cartilaginous structures, but on occasion pigment is also seen in the sclera, in sweat after oxidation, and classically, in urine when left standing at room temperature. This case report highlights the pathogenesis and expression of this rare disorder.

[Ochronosis--case report and literature review]

A case of a patient with polyarthritis in the process of ochronosis is reported. Basic facts concerning etiology, epidemiology and clinical picture are recalled.

Ochronotic arthropathy: rapid destructive hip osteoarthritis associated with metabolic disease

Ochronosis is a musculoskeletal manifestation of alkaptonuria, an inherited metabolic disorder associated with various systemic abnormalities related to the deposition of homogentisic acid pigment in connective tissues. This report describes a 58-year-old woman with ochronotic arthropathy who, in addition to the typical clinical features of the disorder, presented with rapidly progressive hip osteoarthritis. The destruction of the joint architecture and the severe functional impairment necessitated a total hip replacement which resulted in a satisfactory outcome.

Spinal abnormalities similar to ankylosing spondylitis in a 58-year-old woman with ochronosis

Ochronotic arthropathy (spondylosis or peripheral arthropathy) is a late complication of alkaptonuria. There is a tendency for HLA-B27 positive patients with alkaptonuria to develop ochronotic spondylosis. A 58-year-old white woman, presented with ochronotic spondylosis. She was HLA-B27 positive. Her family history was positive for alkaptonuria. Ochronotic patients with HLA-B27 positivity develop spinal changes similar to ankylosing spondylitis (AS).

A case of alkaptonuria with root canal stenosis

Spinal involvement in alkaptonuria is common. Patients usually present in the third or fourth decade with spondylosis or acute intervertebral disc prolapse. Alkaptonuria with root canal stenosis has however hitherto not been reported. We wish to report one such patient.

The "whisker sign" as an indicator of ochronosis in skeletal scintigraphy

A patient with alkaptonuria and ochronotic arthrosis was imaged twice with technetium-99m dicarboxypropane diphosphonate (99mTc-DPD)--once during a bout of arthritic knee pain and once when symptom-free. There was a marked accumulation of radioactivity in the large joints. During the episode of arthritis the knee joints had a higher uptake than when the patient was without symptoms. The intervertebral discs showed a high uptake which extended laterally from the axial vertebral column; the finding gave an impression of whiskers, and this "whisker sign" may be characteristic of ochronosis.

Coexistence of ochronosis and ankylosing spondylitis

We describe a 65-year-old woman with ochronosis and ankylosing spondylitis. The coexistence of these 2 diseases has not previously been described. Differential radiological features of these conditions, which share some resemblances from the clinical point of view, are highlighted.

[Ochronotic arthropathy in alkaptonuria. Radiological manifestations and physiopathological signs]

Alkaptonuria is a rare autosomal recessive metabolic disease, due to the lack of homogentisic acid oxidase. The following accumulation of homogentisic acid brings about a black discoloration of both the urine (alkaptonuria) and connective tissue (ochronosis). The ochronotic alterations into joint cartilages cause degenerative arthropathy and osteopenia. The radiological features of three unrelated cases of alkaptonuria are reported. Radiographic abnormalities of ochronotic arthropathy are found in both the spine and the extraspinal joints. In the spine, the progressive calcification and "vacuum" phenomenon of disc spaces are the most characteristic findings. Disc space narrowing is associated with calcification and marginal sclerosis of vertebral bodies and is accentuated by osteopenia. Osteophytes are usually absent or of small size; nevertheless progressive formation of marginal intervertebral bridges and obliteration of disc spaces at multiple levels ("pseudoblock vertebrae") may occur. In extraspinal sites, space narrowing, bone sclerosis and fragmentation may also be observed. Diagnosis of ochronotic arthropathy is often suggested by radiographs of the spine, and it is confirmed afterwards by clinical and laboratory findings. The characteristic radiological findings of ochronotic spondylitis, in the final stage, include narrowing of at least four lumbar disc spaces, associated with their calcification and "vacuum" phenomenon, "pseudoblock vertebrae", marginal sclerosis and osteopenia of vertebral bodies.

Low back pain and ochronosis

We have examined the presentation of low back pain in three patients with ochronosis, and have reviewed the literature. Low back pain and/or stiffness is the first presenting feature and usually appears after the age of 30. Discolouration of the ear is almost always present. Characteristic radiographic changes in the lumbar spine include calcification of the intervertebral discs and lucencies in the discs. The process gradually extends to the entire spine.

Radiologic manifestations in alcaptonuria

Alcaptonuria is a rare, hereditary disorder of amino acid metabolism, secondary to lack of homogentisic acid oxydase . As a consequence, there is an accumulation of homogentisic acid, which is excreted in the urine and deposited in the connective tissues. This deposition results in ochronotic pigmentation and arthropathy, of which some characteristic radiological findings are demonstrated.

Tendon involvement in a case of ochronosis

A patient with severe skeletal and systemic involvement due to ochronosis is reported. On radiographic examination there was a linear density attached to the left lesser trochanter. The possible role of ochronotic pigment deposition in tendon, leading to metaplastic bone formation, is discussed.

Hip arthropathy in ochronosis: anatomical and radiological study

Anatomical and radiological studies of four cases of ochronotic arthropathy of the hip were based on the examination of a total of six surgically removed femoral heads. One of these had undergone a surgical biopsy 10 years previously. The impregnation of the articular cartilage by the ochronotic pigment causes it to break into small fragments in the weight-bearing zone. This results in a similar osteoarthrotic remodeling to that commonly attributed to the histologically different "degenerative chondropathy". The labelling of the cartilage in ochronotic arthropathies offers an opportunity for better understanding of the main nonspecific components of osteoarthrotic remodeling. An anatomico-pathological approach explains why their radiological images in the hip may simulate those of rheumatoid arthritis.

The concept of osteoarthrotic remodelling as illustrated by ochronotic arthropathy of the hip. An anatomico-radiological approach

This report is an anatomico-radiological study of six femoral heads excised from four patients with diffused ochronotic arthropathy. In one case a biopsy specimen taken eleven years earlier was also studied. The deterioration of the ochronotic cartilage involves a fragmentation process reflected by histological characteristics that are different from those observed in common "cartilaginous degeneration". The fragments resulting from this process become embedded in the remodelled bone-marrow tissue of the weight-bearing zone and in the synovial membrane. Except for the presence of pigmented cartilage, the intrinsic osteogenic remodelling and the extrinsic osteophytic remodelling (the latter often appearing in the form of minor equivalents) are similar to that of the common form of osteoarthrotic remodelling. The pigment labelling of the ochronotic cartilage provides a particularly favorable opportunity to study the general problem of osteoarthrotic remodelling; it facilitates the differentiation between newly formed and preexisting tissue and consequently our understanding of the entire process. An anatomico-radiological approach provides an explanation for the similarity frequently observed on X-rays between ochronotic and rheumatoid hip arthropathies.

Biochemical identification of homogentisic acid pigment in an ochronotic egyptian mummy

Roentgenograms of an Egyptian mummy, dating from 1500 B.C., showed extensive calcification of the intervertebral discs and articular narrowing in both hip and knee joints. Biopsy cores from the right hip showed parallel black zones in the region of the articular surfaces, leading to a clinical diagnosis of ochrinosis. The black pigment was extracted, analyzed, and compared to an air-oxidized homogentistic acid polymer. The two substances apparently were identical. The chemical evidence thus confirms the clinical finding of ochronosis, an autosomal recessive disorder. This is, so far as known, the earliest verified case of this disorder.

[Ochronotic hip disease. Radiological and scintigraphic study (author's transl)]

A radiological and scintigraphic study of hte femoral head removed from a patient at the time of insertion of a total prosthesis of the hip in a patient with ochronotic rheumatic disease. The images obtained differ from those seen in aseptic osteonecrosis and confirm the hypotheses of Lagier, who has described several forms of arthrotic remodelling in ochronotic hip disease.

Multiple vacuum discs, and early sign of ochronosis. Radiologic findings in two brothers

Two brothers with ochronosis are reported and the radiological features of ochronotic vertebral disease are reviewed. A striking feature was the presence of multiple vacuum discs. This "vacuum phenomenon" constitutes one of the earliest radiologic changes in the spine and presumably represents areas of severe degeneration within the intervertebral discs. Other features included a dark pigmentation of the urine after standing or following the addition of sodium hydroxide, and calcification within the cartilages of the ears and intervertebral discs. There was no abnormality of the peripheral joints and pigmentary deposits in the ears, sclerae, or skin were not observed.

Vertebral changes in ochronosis

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