Etiological factors in osteochondritis dissecans. An experimental study into the etiological factors in osteochondritis dissecans in the canine humeral head using overloading with and without somatotropin and thyrotropin hormone treatment and mechanical trauma

An Osteochondral Lesion of the Lateral Femoral Condyle with Arthroscopic Appearance Resembling a Fried Egg: A Case Report

CASE

We encountered an unusual case of an osteochondral lesion of the lateral femoral condyle with a detached osteochondral fragment that was reversed and became reattached to its bed; examination by arthroscopy depicted this lesion with a unique resemblance to a fried egg. Because the excised osteochondral fragment showed little damage or degeneration and had relatively good compatibility with the site of origin, we selected the treatment option of reduction and suture fixation.

CONCLUSION

The pathological presentation of this osteochondral lesion that resembled a fried egg was an unusual and rare occurrence.

Stifle osteochondritis dissecans in snow leopards (Uncia uncia)

Three snow leopard (Uncia uncia) cubs, female and male siblings and an unrelated female, had lameness attributed to osteochondritis dissecans (OCD) lesions noted at 6, 8, and 10 mo of age, respectively. All cubs were diagnosed with OCD via radiographs. The sibling cubs both had lesions of the right lateral femoral condyles, while the unrelated cub had bilateral lesions of the lateral femoral condyles. Subsequently, OCD was confirmed in all three cases during surgical correction of the lateral femoral condyle lesions via lateral stifle arthrotomies, flap removal, and debridement of the defect sites. Histopathology also supported the diagnosis of OCD. Postoperatively, the sibling cubs developed seromas at the incision sites and mild lameness, which resolved within a month. To date, two cubs have been orthopedically sound, while one of the sibling cubs has developed mild osteoarthritis. OCD has rarely been reported in domestic felids, and to the authors' knowledge these are the first reported cases of OCD in nondomestic felids.

Ultrasound evaluation of cartilage damage in osteochondral lesions of the talar dome and correlation with clinical etiology: a preliminary report

BACKGROUND

The current study aimed to determine whether the acoustic properties of living human cartilage during arthroscopy differ between damage from trauma and that from pigmented villonodular synovitis (PVNS).

METHODS

Nine patients were evaluated with ultrasound during arthroscopy. As a quantitative index of cartilage quality, the percentage maximal magnitude (maximal magnitude of the measurement area divided by that of the intact cartilage; %MM) was selected. After ultrasound evaluation, the measurement points were divided into two groups on the basis of the etiologic findings (group T: cartilage damage from trauma and group P: cartilage damage from PVNS) and analyzed for the presence of significant differences in ultrasound analysis.

RESULTS

In the ultrasound findings, the %MM values ranged from 34.4% to 92.3%. According to the etiologic differences, the mean %MM was 81.0% in group T and 39.3% in group P, and significantly higher in group T than in group P (p < 0.01).

CONCLUSIONS

This study showed a correlation between the ultrasound results and the cartilage lesion etiology. Ultrasound evaluation may be useful for elucidating the process of articular cartilage degeneration with trauma and PVNS.

Computed tomographic osteoabsorptiometry of the elbow joint in clinically normal dogs

OBJECTIVE

To evaluate subchondral bone density patterns in elbow joints of clinically normal dogs by use of computed tomographic (CT) osteoabsorptiometry.

SAMPLE POPULATION

20 cadaver forelimbs from 10 clinically normal dogs.

PROCEDURE

Each elbow joint was imaged in parasagittal and transverse planes of 1.5-mm thickness. Slice data were converted to dipotassium phosphate equivalent density (PPED) values. Sagittal, parasagittal, and transverse medial coronoid process topographic maps were constructed. Defined zones were created for each of the 3 CT planes, and confluence and peak PPED values were determined.

RESULTS

The lowest PPED value was 340 mg/ml (articular and subchondral confluence), and the highest was 1780 mg/ml (peak subchondral density). Detectable effects of joint laterality were not found in the confluence or peak PPED measurements or in the peak-to-confluence PPED ratio for all 3 CT planes. Significant differences were found among zones in all 3 planes for confluence and peak PPED measurements and between sagittal and transverse planes for peak-to-confluence PPED ratios. Subjectively, the pattern of density distribution among dogs was fairly consistent for the sagittal and parasagittal slices. Three specific patterns of density distribution were apparent on the transverse topographic maps of the medial coronoid process that corresponded to conformational differences.

CONCLUSIONS AND CLINICAL RELEVANCE

The use of CT osteoabsorptiometry provides a repeatable technique that can be used to noninvasively examine bone density and the effects of stress acting on joints in vivo. Variability in density values for any of the CT planes was not identified among clinically normal dogs.

Modulation of appositional and longitudinal bone growth in the rat ulna by applied static and dynamic force

Appositional and longitudinal growth of long bones are influenced by mechanical stimuli. Using the noninvasive rat ulna loading model, we tested the hypothesis that brief-duration (10 min/day) static loads have an inhibitory effect on appositional bone formation in the middiaphysis of growing rat ulnae. Several reports have shown that ulnar loading, when applied to growing rats, results in suppressed longitudinal growth. We tested a second hypothesis that load-induced longitudinal growth suppression in the growing rat ulna is proportional to time-averaged load, and that growth plate dimensions and chondrocyte populations are reduced in the loaded limbs. Growing male rats were divided into one of three groups receiving daily 10 min bouts of static loading at 17 N, static loading at 8.5 N, or dynamic loading at 17 N. Periosteal bone formation rates, measured 3 mm distal to the ulnar midshaft, were suppressed significantly (by 28-41%) by the brief static loading sessions despite normal (dynamic) limb use between the daily loading bouts. Static loading neither suppressed nor enhanced endocortical bone formation. Dynamic loading increased osteogenesis significantly on both surfaces. At the end of the 2 week loading experiment, loaded ulnae were approximately 4% shorter than the contralateral controls in the 17 N static and dynamic groups, and approximately 2% shorter than the control side in the 8.5 N static group, suggesting that growth suppression was proportional to peak load magnitude, regardless of whether the load was static or dynamic. The suppressed growth in loaded limbs was associated with thicker distal growth plates, particularly in the hypertrophic zone, and a concurrent retention of hypertrophic cell lacunae. Negligible effects were observed in the proximal growth plate. The results demonstrate that, in growing animals, even short periods of static loading can significantly suppress appositional growth; that dynamic loads trigger the adaptive response in bone; and that longitudinal growth suppression resulting from compressive end-loads is proportional to load magnitude and not average load.

Congenital conditions that lead to osteoarthritis in the dog

Several congenital arthropathies exist in the canine that can lead to the development of degenerative joint disease. Nevertheless, early diagnosis and treatment generally will afford the patient a favorable prognosis for limb function. There is still a great need to develop controlled studies to evaluate the long-term efficacy of many of the surgical and medical treatment modalities that are currently available and will be made available in the future to treat the patient with a congenital arthropathy.

Early changes of osteochondrosis in medial femoral condyles from rats

Osteochondrosis developed from the early growing process of articular cartilage at the caudal-central region of the medial femoral condyle in rats. Articular cartilage was thick at the region. Mineralization of the matrix in the thick deep zone was incomplete and major parts remained unmineralized. Cavity formation in the mineralized matrix resulting in osteochondrotic lesions was present in the deep zone at 6 weeks of age and was followed by an appearance of viable chondrocytes around it. Osteochondrotic lesions were present from the age of 10 weeks for females and 12 weeks for males. Cavities were expanded and increased in number, and eosinophilic necrotic foci were additionally seen. These changes were extended throughout the deep zone, and viable chondrocytes were also increased in number. The thick deep zone was retained and had no detectable invasions of blood vessels from the subchondral bone. At 20 weeks of age, necrotic areas containing large clefts were present in the basal layer of the thick deep zone and fibrotic lesions were seen beneath them. In normal cases, invasions of blood vessels were seen in the basal layer of the deep zone and also in the cavities of the cartilage; the deep zone was markedly thinned at 20 weeks of age.

Familial osteochondritis dissecans and dwarfism

We review four generations of a short statured family in whom 12 members have osteochondritis dissecans (O.D.) affecting the knees, elbow, or both, and other minor anomalies of bony development are recorded. Four of the family, unaffected by O.D., exhibit idiopathic scoliosis.

Osteochondritis dissecans in the dog

The diagnosis, aetiology, pathogenesis and treatment of osteochondritis dissecans in the shoulder, elbow, stifle and hock joints of the dog is reviewed. A technique of surgically exploring the shoulder joint with minimal exposure is described. Recommendations for preventing the development of osteochondritis dissecans are made.