Severe depletion of mitochondrial DNA in spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disorder in childhood leading to a dramatic loss of muscle strength. Functional investigations with high-resolution polarography and enzyme measurements of the respiratory chain revealed lowered activities in muscle tissue of SMA patients. To gain a better understanding of this low energy supply we analyzed the amount of mitochondrial DNA (mtDNA) in skeletal muscle of 20 unrelated children with genetically proven SMA and 31 controls. Quantitative Southern blot analysis revealed a severe and homogeneous decrease in the content of muscle mtDNA in relation to nuclear DNA in SMA patients (90.3+/-7.8%), whereas by immunofluorescence no decrease in the number of mitochondria was detected. In addition, a two- to threefold reduction of the nuclear-encoded complex II (succinate dehydrogenase) activity was detected in SMA muscle tissue. Western blot analysis showed a significant reduction of both mitochondrial- and nuclear-encoded cytochrome c oxidase subunits. Our results indicate that mtDNA depletion in SMA is a consequence of severe atrophy, and has to be differentiated by measurement of complex II from an isolated reduction of mtDNA as found in patients with mitochondriocytopathies and the so-called mtDNA depletion syndrome.

[Anterior intertrochanteric ossification after total hip arthroplasty]

AIM

Heterotopic paraarticular ossifications are usually identified by an anterior-posterior radiograph of the corresponding hip and are consecutively classified by the well accepted methods of Brooker, Arcq or deLee. In these methods ossifications are solely evaluated by the means of a single a-p radiograph, hence a major part of ossifications located in the anterior intertrochanteric region cannot be evaluated. Our study deals with the incidence of ossifications exclusively verifiable by an axial radiograph.

METHOD

In the present study 209 patients' axial radiographs were retrospectively analysed by using our simple method of classification. In the axial projection these ossifications are situated anterior of the intertrochanteric region, therefore we created the term "anterior intertrochanteric ossification (AIO)". After developing a simple topographic scheme we classified these appearances by localisation and size.

RESULTS

After total hip arthroplasty by using the transgluteal approach ossifications situated in the anterior intertrochanteric region can develop. These ossifications appear as bone islands, shield or clip like (without fixed connection to the femoral cortical bone) or as solid exostoses. Due to their strict anterior localisation these formations are often solely verifiable by the means of an axial (Lauenstein) radiograph. We were able to identify anterior intertrochanteric ossifications (AIO) in 97 out of 209 patients (48.4 %), 27 patients (13 %) developing an anterior intertrochanteric ossification were classified grade 0 according to the methods of Brooker, Arcq and deLee.

CONCLUSION

According to the widely accepted methods of classification of paraarticular ossifications depending on a single a-p radiograph of the corresponding hip, 13 % of paraarticular ossifications would remain undocumented because of their strict anterior intertrochanteric position.

[Prophylaxis of heterotopic ossification in hip revisions with 7 Gy single-dose radiation]

AIM OF STUDY

Radiation therapy is an established method for the prevention of heterotopic ossification. The aim of this study was to assess whether radiation therapy is also effective in revision arthroplasties.

METHOD

143 hips were irradiated with 7 Gy anterior-posterior applied single dose radiation, on one of the first four days after revision surgery.

RESULTS

After an average follow-up of 18 months, 107 hips were evaluated radiographically using Brooker's criteria. In comparison to the immediate postoperative findings (26 % showed no heterotopic ossification, 66 % had Brooker I, 5 % Brooker II, and 3 % Brooker III), at final follow-up 19 % showed no heterotopic ossification, 66 % had Brooker I, and 7.5 % Brooker II and III. New ossification or an increase of one grade was found in 12 %, of two grades in 4 %. Grade 0 showed significantly more ossifications. Gender (p = 0.43), age (p = 0.43), the type of revision surgery (p = 0.36), the day of radiation (1st day vs. 2nd, 3rd, 4th day; p = 0.46) had no significant influence on this increase. There was no correlation between pain score and Brooker grades (p = 0.755). There was a significantly (p < 0.01) negative correlation (r = - 0.31) between the Brooker grades and flexion.

CONCLUSION

Radiation therapy with 7 Gy single dose effectively prevents the new formation of heterotopic ossification or the progression of ossifications after revision surgery. To prevent a decrease in the range of motion due to HO after revision surgery, HO should be removed intraoperatively.

Cyclooxygenase-2 inhibitor for pain management in osteoid osteoma

Thirteen patients with osteoid osteoma were enrolled in a prospective trial to test whether rofecoxib, a selective cyclooxygenase-2 inhibitor, is as effective for pain control as acetylsalicylic acid. Each patient documented the pain level using a visual analog scale, with 0 being no pain and 10 being unbearable pain, during 2 days of no pain medication, 4 days of 500 mg acetylsalicylic acid three times a day, and 10 days of 25 mg rofecoxib once a day. Oral administration of 500 mg acetylsalicylic acid three times a day led to a significant decrease in pain at night, pain at rest, and pain induced by exercise. Twenty-five milligrams rofecoxib given once a day at midday showed the same remarkable improvement in pain at night, pain at rest, and pain induced by exercise. Rofecoxib in comparison with acetylsalicylic acid showed a trend toward lower pain levels in all categories. Rofecoxib offered a significantly better reduction in pain at rest during the day than did acetylsalicylic acid. Results of the current study suggest that pain induction in osteoid osteoma is related to cyclooxygenase-2, an enzyme that is blocked by acetylsalicylic acid and rofecoxib. Conservative medical treatment with rofecoxib for osteoid osteoma is recommended when percutaneous intervention is associated with significant morbidity.

Poor storage and handling of tissue mimics mitochondrial DNA depletion

Analysis of the mitochondrial DNA (mtDNA) is an important part in the diagnosis of mitochondrial disorders. Besides point mutations and deletions in the mitochondrial genome a reduction in the amount of mtDNA molecules (mtDNA depletion) can also be the reason for mitochondrial defects. The DNA stability in clinical samples is essential for proper performance and interpretation of DNA based diagnosis. The stability of mtDNA was compared with that of nuclear DNA under poor handling and storage conditions. Fresh and thawed muscle tissue specimens were kept at different temperatures for a certain period of time before DNA isolation. Quantitative Southern blot analysis revealed a time-dependent decrease in the amount of mtDNA compared with nuclear DNA in thawed tissue specimens. Therefore, the current study demonstrates that proper specimen storage is a critical issue in quantitative mtDNA analysis and that poor handling and storage of tissue may mimic a severe mtDNA depletion.

Postoperative aneurysm of the popliteal artery after arthroscopic meniscectomy

We report a case of a 14-year-old girl who underwent arthroscopic subtotal meniscectomy after a bucket-handle tear of the lateral meniscus followed by a pseudoaneurysm of the popliteal artery. A revision surgery and reconstruction of the artery with a saphena magna patch was necessary to repair the defect. At 1-year follow-up, excellent range of motion, function of the knee, and a normal quality of life was achieved.

[Ultrasound diagnosis of iliopectineal bursitis--contribution to differential diagnosis of leg swelling]

PURPOSE

To describe the pathognomic sonographic morphology of iliopectineal bursitis as a contribution to the differential diagnosis of leg swelling.

METHODS

Characterization of the enlarged iliopectineal bursa by sonography (including CCDS) (n = 6) and comparison with CT (n = 4) and MRI findings (n = 1).

RESULTS

There were 6 enlarged iliopectineal bursas in 5 female patients which exhibited an elongated oval form and were typically located in the groin region lateral and dorsal of the vessels and in the pelvis lateral to the iliac vessels. On sonography, cystic structures with echo-free contents (n = 1) in arthrosis, homogeneous echoic contents (n = 3) in abrasive reactions after hip TEP, and with inhomogeneous, pseudo-tumorous contents (n = 2) in PCP.

CONCLUSIONS

Sonography enables the reliable diagnosis of an iliopectineal bursitis by means of its elongated oval from and extension from the groin region in continuity to the pelvis with medial displacement of the femoral and iliac vessels. It can thus help to avoid unnecessary operations or biopsies. In cases of doubt, use of CT or MRT enables a certain anatomical assignment.

Indomethacin for prevention of heterotopic ossification after hip arthroplasty. A randomized comparison between 4 and 8 days of treatment

In a randomized, parallel group study, we evaluated the efficacy of a 4-day versus an 8-day course of indomethacin (50 mg, 3 times per day), given as prophylaxis against heterotopic ossification after cementless total hip arthroplasty in 209 patients with arthrosis. Patients receiving the prophylaxis for 8 days had less (p = 0.03) severe heterotopic bone formation.