Isato Sekiya

The Treatment of Enchondromas in the Hand by Endoscopic Curettage without Bone Grafting

Nine patients with enchondromas in the hand were treated by endoscopic curettage of the tumour without bone grafting. The procedure was performed on an out-patient basis using axillary block anaesthesia. New bone formation and remodelling of the lesions were observed in all patients. There were no postoperative fractures, infections, recurrences or other complications. Functional recovery was rapid. We conclude that endoscopic curettage without bone grafting is an effective treatment of enchondroma in the hand.

Recovery process of sciatic nerve defect with novel bioabsorbable collagen tubes packed with collagen filaments in dogs.

Autologous nerve graft is the most commonly applied treatment for the patients with peripheral nerve defect, while application is limited because of tissue availability and unfavorable donor site morbidity. To overcome this problem, peripheral nerve regeneration using a nerve conduit has been studied. Especially, nerve conduit using biodegradable materials has been considered promising. In this study, a potential of collagen nerve conduit has been studied with special reference to the regenerating process of a peripheral nerve. Twelve adult female Beagle dogs weighting 10-12 kg were used. The peroneal nerve was cut to make a 30-mm defect. The nerve defect was bridged by the collagen artificial nerve conduit. Comprehensive functional, electrophysiological, morphometrical, and histological analyses were performed until one year after operation. The wet weight of tibialis anterior muscles was only 32.4% of the healthy side at 24 weeks, which was recovered to 77.4% at 52 weeks after denervation. Electrophysiological evaluation of tibialis anterior muscle belly showed polyphasic wave at 52 weeks after implantation, which was almost half amplitude as compared with that of control. The diameters of myelinated nerve fibers thickened day by day, and the average diameter was 5.16 microm at PFN, 3.91 microm at CG, and 3.75 microm at DFN, and average thickness of myelin sheath was 0.94 microm at PFN, 0.46 microm at CG, and 0.55 microm at DFN after 52 weeks. The distribution of myelinated nerve fiber size in the 52 weeks group was distinctly bimodal with the major peak at approximately 2-4 microm and the minor peak at 10-12 microm. These findings were consistent with the distribution of the normal nerve fiber. This study proves the feasibility of the collagen artificial nerve conduit for promoting nerve regeneration, raises new possibilities of seeking alternatives to autograft for nerve repair. The results from this study showed detailed process of morphological, electrophysiological, and functional recovery of the regenerated nerve, which would provide scientific background for this novel therapy.

Arthroscopic Synovectomy of the Metacarpophalangeal and Proximal Interphalangeal Joints

Few reports about clinical experience in arthroscopy of finger joints exist. Furthermore, little attention has been given to arthroscopic synovectomy of rheumatoid fingers. Herein, we describe our experience with arthroscopic synovectomy of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in patients with rheumatoid arthritis. Arthroscopic synovectomy was performed in 45 finger joints (18 MCP joints, 26 PIP joints, and 1 interphalangeal thumb joint) of 23 patients with rheumatoid arthritis. All procedures were performed on an outpatient basis under regional anesthesia. The diameter of the arthroscope for small joints was 1.5 mm, and a mini shaver system with a 2.5-mm cutter was used for synovectomy. We developed new portals for PIP joints that were established on the dorsolateral aspect at a position more lateral than previously reported portals. Intraarticular structures of finger joints were well visualized, and magnified observation of the articular cartilage and synovial membrane was possible. Because insertion of the instruments into the palmar cavity was not possible without causing damage to the articular surfaces, synovectomy of the palmar capsule could not be performed. However, arthroscopic synovectomy of the dorsal capsule under visual control could be safely performed using the 2-portal technique. None of the patients experienced postprocedural complications. Swelling of each joint disappeared after the procedure and did not return in many cases for a long period. Furthermore, no joints required reoperation. We conclude that arthroscopy of MCP and PIP joints is useful not only for the assessment of articular cartilage and synovium but also for synovectomy in rheumatoid arthritis.

Anatomical basis of the medial sural artery perforator flap in Asians

Forty-four lower limbs preserved in formaldehyde from cadavers of adult Asians were used. In all specimens 1–5 perforating branches from the medial sural artery were found. No perforators were found higher than 5 cm or lower than 17.5 cm from the popliteal crease. In the most common place (16/44, 36%) in which 2 perforators were found, the proximal one was a mean of 9.6 cm away from the popliteal crease, and the distant one 12.8 cm. All perforators were in an area between 0.5 cm and 4.5 cm from the midline of the gastrocnemius muscles. Because of the differences in the length of the muscle belly, the distribution of perforators may differ between white people and Asians. It should be safe to raise this flap in Asians, because the anatomical comparison of the perforators of the medial sural artery between Asians and white people is now clear.

Relationship between screw trajectory of C1 lateral mass screw and internal carotid artery.

Study Design. Evaluation of diagnostic imaging. Objective. To comprehend anatomic relationships between the internal carotid artery (ICA) and bicortical purchase of C1 lateral mass screws from the perspective of avoiding ICA injury. Summary of Background Data. No studies have evaluated safety trajectory of atlantal lateral mass screw that would avoid the ICA injury in relation to its location, although previous studies have indicated concern about ICA injury by the screw tip at the anterior surface of the lateral mass of the atlas. Methods. From 149 of 177 human 3-dimensional computed tomography reconstruction images, 6 distance and 2 angle parameters related to both atlas and ICA were measured on the plane 15° cephalad to the transverse plane. In addition, angle of error during screw insertion from intended trajectory was checked. Results. The ICA was located in front of the C1 lateral mass in 64.4% of cases and faced the lateral one third of the C1 lateral mass in 54.6% of cases. None were located in front of the medial one third of the C1 lateral mass. The maximum inward screw trajectory that would violate the ICA was 8.6°. Mean angle of preoperative C1/2 rotation and angle of error from intended trajectory was about 5°, respectively. Conclusion. The possibility of ICA injury can be excluded by correct insertion of the screw 10° inward. Although bicortical purchase with adequately medially angulated trajectory might be safe enough, we must remember the possibility to violate the ICA in bicortical purchase, because the intended screw trajectory never be assured.

Anatomical basis of distally based anterolateral thigh flap.

Abstract Soft tissue coverage around the knee has persisted as a challenge for plastic and reconstructive surgeons. The distally-based anterolateral thigh flap is often used for coverage. Nevertheless, few anatomical studies have investigated the retrograde vascular pedicle. This report clarifies the anatomy of the connection between the descending branch of the lateral circumflex femoral artery and the lateral superior genicular artery. This study examined 38 lower limbs from cadavers and recorded the numbers and locations of perforating vessels. Proximal and distal pivot points were also recorded. The proximal pivot point was 1.0–12.1 cm (average = 6.0 cm) from the inguinal ligament. The distal pivot point, found under the vastus lateralis muscle in all 38 specimens, was 4.0–13.6 cm (average = 9.8 cm) from the lateral superior edge of the patella. The most distal perforator was 8.2–28.0 cm (average = 18.9 cm) from the proximal pivot point. The most proximal perforator was 3.0–19.5 cm (average = 8.7 cm) from the distal pivot point. Details of the anastomosis of the descending branch and the superior lateral genicular artery were clarified. The distally-based anterolateral thigh flap presents one option for reconstruction around the knee.

Extensor tendon rupture related to calcium pyrophosphate crystal deposition disease

Abstract. We report a rare case of spontaneous rupture of the extensor tendons at the wrist which was shown histologically to be related to calcium pyrophosphate crystal deposition disease. The causes of tendon rupture were chronic synovitis with crystal deposition and a dorsal prominence of the ulnar head.

Treatment of an aneurysmal bone cyst of the second metatarsal using an endoscopic approach

An aneurysmal bone cyst is a benign solitary lesion of unknown etiology. A case report is presented of recurrence of an aneurysmal bone cyst in the foot that was treated with endoscopic curettage without bone grafting. Bone remodeling and bone formation were completed in the early stages postsurgically. At 2-year follow-up, the patient is asymptomatic with no radiographic evidence of recurrence.

Morphometric analysis of the peroneal tubercle using a three-dimensional computed tomography model

BACKGROUND The peroneal tubercle is a small bony ridge located on the lateral wall on the calcaneus immediately inferior to the lateral malleolus and separates the peroneus brevis and peroneus longus tendons. The size and configuration of the peroneal tubercle has been implicated in the pathogenesis of peroneal tendon tears and tenosynovitis and is the increasing object of clinical interest. However, the morphology of the tubercle is difficult to assess with precision. METHODS We utilized a new method to evaluate the three-dimensional (3D) geometry of 46 calcanei from 34 consecutive patients; average patient age was 48.0 years who underwent lower extremity computed tomography (CT) for clinical treatment of non-peroneal tubercle-related conditions. The 3D geometries of calcanei were reconstructed by using the computer software to calculate the surface 3D models. To measure the size of the peroneal tubercle, we virtually excised it from the 3D calcaneus model and made a precise measurement of the height. RESULTS Peroneal tubercles with measured heights of 1mm or more were detected in 65% of the feet, with an average tubercle height of 2.59mm. Peroneal tubercles were larger and more frequent in middle-aged or older than younger patients.

Effects of mechanical vibration on DNA and proteoglycan syntheses in cultured articular chondrocytes

Abstract The objective of this study was to determine the effects of mechanical vibration loading on DNA and proteoglycan syntheses in cultured rabbit articular chondrocytes. Chondrocyte culture plates were placed in a vibratory apparatus and subjected to a mechanical vibratory load at various frequencies and periods during culture. Mechanical vibration was applied at a sinusoidal waveform of 1.4 G-acceleration with frequencies of 200, 300, 400, 800, and 1600 Hz. 3H-thymidine and H2 35SO4 incorporation were used to detect radiolabeled DNA and proteoglycan syntheses, respectively. A frequency of 300 Hz showed a time-dependent augmentation of DNA synthesis and gave a maximal increase on day 3 with periodic vibration (8 h per day), and at 72 h or longer with continuous vibration. It also promoted proteoglycan synthesis in long-term cul-ture (from 3 to 15 days) by periodic vibration. However, frequencies above 400 Hz suppressed biosynthesis. These results suggest that mechanical vibration at certain frequencies may modulate the biosynthetic response of articular chondrocytes.