Biomedical subjects

Fumito Komatsu

Publications and source records attributed to Fumito Komatsu.

4 recordsLinked to original sources

PubMed2006

Optimum location of knot for tendon surgery in side-locking loop technique.

BACKGROUND: Although various tendon repair techniques have been reported to achieve stronger repair, suture failures tend to occur near the knot. We experimentally investigated whether the location of a single core suture knot affects the biomechanical properties of the repair. METHODS: Transected bovine tendons (male Japanese black cattle, 24 months old) of the medial gastrocnemius (9-11 x 14-16 mm in diameter) were sutured with the side-locking loop technique using a USP2-sized polyethylene and polyester multifilament suture or polyester multifilament suture. The knot was made using 7 simple square ties (a surgeon's knot plus 5 ties) at three locations; on the loop, between the tendon stumps, or between the loops burying the knot in a tendon slit using a scalpel. A cyclical loading protocol from 10N to 100N was used and the loading was repeated 10,000 times. FINDINGS: The gap was most decreased and the ultimate strength was most increased when the knot was located between the loops when using a polyethylene and polyester multifilament suture. Cross-sectional area of the tendon showed the ratio of the buried knot relative to the tendon was only 1.6-2.3%, and the polyethylene and polyester multifilament suture was very durable against frictional abrasion. INTERPRETATION: We found that the knot between the loops, buried in the bovine tendon provided the optimum results.

Animals↗

PubMed2006

Optimum surgical suture material and methods to obtain high tensile strength at knots: problems of conventional knots and the reinforcement effect of adhesive agent.

BACKGROUND: Strong suture material and a firmly tight knot that never loosens are necessary for tendon suture, but the appropriate combination of suture materials and the methods to make a knot are matters of uncertainty. METHODS: The tensile strength of four conventional tendon suture materials (Surgilon, Ethibond, Ethilon, PDS II) and newly developed FiberWire were examined. An experienced orthopedic surgeon formed surgical knots with USP2 wire (0.5-0.599 mm in diameter) by making loops and then pulled them at 20 mm/min using Instron. RESULTS: With the conventional surgical suture method (the addition of one throw on a surgeon's knot), Surgilon proved to have the highest tensile strength (163.6 +/- 6.5 N). Other suture materials, when tied under the same conditions, slipped and did not reach the ultimate tensile strength. When four additional throws were made, FiberWire provided the highest tensile strength (316.6 +/- 12.2 N) among the five suture materials tested (others were 140-200 N). When an adhesive agent, cyanoacrylate, was applied to a knot, PDS II provided the highest tensile strength (182.0 +/- 10.1 N). CONCLUSIONS: Our study suggests three suitable combinations of suture materials and methods for suture knot formation, depending on the site of surgery, that provide optimum treatment outcomes. Surgilon provides the most stable strength for general suture techniques. FiberWire is the strongest suture material for a site where a large number of throws is clinically possible. PDS II provides a strong suture when combined with cyanoacrylate reinforcement.

Adhesives↗

PubMed2006

Reconstruction of lateral ligament with arthroscopic drilling for treatment of early-stage osteoarthritis in unstable ankles.

PURPOSE: The purpose of this study was to investigate the clinical, radiologic, and arthroscopic results of lateral stabilization with reconstruction of the lateral ligaments and cartilage regeneration with arthroscopic drilling for the treatment of moderate osteoarthritis of the ankle with simultaneous lateral instability of the ankle (LIA). METHODS: There were 16 cases with LIA, 7 of which had stage 2 osteoarthritis of the ankle according to the radiographic classification of Takakura et al. and 9 of which had stage 3 osteoarthritis. Arthroscopic drilling was performed with a motorized drill for the chondral defect, and anatomic reconstruction of the lateral ligament with an autologous gracilis tendon graft was performed for LIA. Clinical, radiologic, and arthroscopic evaluations were performed before surgery and at the most recent follow-up. RESULTS: In stage 2 cases the mean score on the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale was 42.5 +/- 6.8 points before surgery and 87.4 +/- 4.2 points at the most recent follow-up (P = .0002). In stage 3 cases the mean score was 41.4 +/- 8.0 points before surgery and 61.2 +/- 7.4 points at the most recent follow-up (P = .0001). The talar tilt angles on standard stress radiography in stage 2 cases were 17.4 degrees +/- 4.5 degrees before surgery and 3.4 degrees +/- 0.9 degrees at the most recent follow-up (P = .0009). In stage 3 cases the mean talar tilt angles were 18.2 degrees +/- 4.7 degrees before surgery and 3.6 degrees +/- 0.7 degrees at the most recent follow-up (P < .0001). In all cases the radiographic classification of Takakura et al. was unchanged between assessments before surgery and at the most recent follow-up. With regard to arthroscopic findings at 1 year after surgery, the International Cartilage Repair Society's cartilage repair assessment score showed 6 nearly normal and 1 abnormal stage 2 cases and 1 abnormal and 8 severely abnormal stage 3 cases. CONCLUSIONS: Reconstruction of the lateral ligament with arthroscopic drilling as a surgical procedure for the treatment of stage 2 osteoarthritis with LIA can be recommended. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Adult↗

PubMed2004

[Partial nephrectomy using microwave tissue coagulator--application for laparoscopic operation].

We report our clinical findings on 12 tumors (11 patients) successfully resected by partial nephrectomy with a microwave tissue coagulator (MTC) without renal pedicle clamping, including laparoscopic operation in 4 patients. All patients presented with a renal tumor detected incidentally by ultrasonography or computed tomography. The mean size of renal tumor was 1.9 (range 0.8-3.4) cm. Pathological diagnosis was renal cell carcinoma in 9 tumors and hemorrhagic cyst in 3 tumors. Mean operative time was 249 minutes. Mean blood loss was 183 ml in cases with a laparoscopic operation, that was statistically less than 486 ml in cases with an open operation (p<0.05), and 376 ml in all cases. There was no significant change in the creatinine clearance of cases with laparoscopic operation, compared with that of cases with an open operation. There were no other serious complications postoperatively. These findings suggested that partial nephrectomy with the MTC can be safely and successfully carried out while sparing renal function. Moreover, partial nephrectomy with the MTC for a laparoscopic operation may provide these patients with more benefits.

Adult↗