Naohide Takeuchi

Asymmetric six-strand core sutures enhance tendon fatigue strength and the optimal asymmetry

Under cyclic loading, we recorded the fatigue strength of a six-strand tendon repair with different symmetry in the lengths of suture purchase in two stumps of 120 dental rolls and in 30 porcine tendons. First, the strengths of the repairs with 1, 2, 3, 4 and 5 mm asymmetry were screened using the dental rolls. The asymmetric core suture repairs were then made with a Kessler repair of equal suture purchase (10 mm) in two tendon stumps, and shifting two other Kessler repairs by 1, 3 or 5 mm, respectively, along the longitudinal axis of the tendon in relation to the first (symmetric) Kessler repair. The core repairs with 3 mm or more asymmetry in suture purchases in two tendon ends showed significantly greater fatigue strength and significantly smaller gaps compared with 1 mm asymmetry in core suture repair. Our results support that asymmetric placement of core sutures in two tendon ends favour resisting gapping at the repair site and 3 mm or more asymmetry is needed to produce such beneficial effects.

Strength enhancement of the interlocking mechanism in cross-stitch peripheral sutures for flexor tendon repair: Biomechanical comparisons by cyclic loading

The fatigue strength of three peripheral suture techniques for flexor tendon repair was compared by cyclic loading of repairs in a cotton dental roll tendon model. Thirty pairs of dental roll were sutured using only peripheral sutures with 6-0 polypropylene. An initial cyclic load of 5 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The fatigue strength of an interlocking cross-stitch suture was 113% greater than a running suture and 36% greater than a standard cross-stitch suture. Interlocking the cross-stitch prevented shortening of the transverse portions under load and appears to be a useful technique for increasing the strength of the peripheral suture.

The biomechanical assessment of gap formation after flexor tendon repair using partial interlocking cross-stitch peripheral sutures

The gap formation of five core plus peripheral suture techniques for flexor tendon repair was evaluated by cyclic load testing. Fifty pairs of dental roll tendon models were sutured using six-strand Pennington modified Kessler core suture with 4-0 Polypropylene. One-half or three-fourths circumferential interlocking cross-stitch, or three complete circumferential peripheral suture techniques were performed using 6-0 Polypropylene. An initial cyclic load of 10 N for 500 cycles was applied and increased by 5 N for an additional 500 cycles at each new load until rupture. The complete circumferential interlocking cross-stitch had the greatest fatigue strength. The partial circumferential cross-stitches resulted in significantly larger gap formations at both the repaired and unrepaired sides than the complete circumferential sutures, and were also associated with early rupture. The full circumference of the cut tendon must be sutured using an interlocking cross-stitch peripheral suture to improve strength and avoid gap formation.

In vivo dynamic acromiohumeral distance in shoulders with rotator cuff tears

Background: There are no previous studies on the acromiohumeral distance in shoulders with large‐to‐massive full‐thickness rotator cuff tears. In this study, the acromiohumeral distance in rotator cuff tear and healthy shoulders was measured using 3D‐to‐2D model‐to‐image registration techniques. Methods: The dynamic glenohumeral kinematics during scapular plane abduction and axial rotation were analyzed in 11 rotator cuff tear patients and 10 healthy control subjects. Periodic radiographic images of scapular plane abduction and axial rotation were taken using a flat‐panel radiograph image detector. Movements of the shoulder joint were assessed using radiographic images and computed tomography‐derived digitally reconstructed radiographs. The acromiohumeral distance was defined as the shortest 3D distance between the acromion and the proximal humerus. Findings: For scapular plane abduction, the rotator cuff tear group had significantly smaller acromiohumeral distance than the control group at 15°, 30°, 45°, 60°, 75°, 135°, and 150° of humeral abduction (P < 0.05 at each measured angle). For axial rotation in the adducted position, the rotator cuff tear group had significantly smaller acromiohumeral distance than the control group at each point between −20° and 40° of glenohumeral external rotation (P < 0.05 at each measured angle). Interpretation: The minimum measured acromiohumeral distance was 0.9 mm in the rotator cuff tear shoulders and 2.1 mm in the healthy shoulders at 90° of scapular plane abduction. The findings are of clinical relevance because quantitative evaluation of the dynamic acromiohumeral distances in rotator cuff tear and healthy shoulders might provide important insight into subacromial impingement. HighlightsAcromiohumeral distance in rotator cuff tear and healthy shoulders was measured.3D‐to‐2D model‐to‐image registration techniques were performed.Acromiohumeral distance was significantly smaller in rotator cuff tear shoulders.Quantitative evaluation of acromiohumeral distance might provide important insight.

Brodie’s Abscess of the Radius in a Child

We herein report an unusual case of Brodies abscess of the radius in a child. A 13-year-old boy presented with pain on his right distal forearm. A plain radiograph showed an 8 cm translucent lesion in the distal radius. MRI showed a penumbra sign on the T1-weighted image, hyperintensity on T2-weighted images, and ring enhancement on the contrast-enhanced T1 image. 18F-FDG PET/CT images showed an uptake at the margin of the radius. Curettage and iliac cancellous bone grafting were undertaken for Brodies abscess. Bacteriological examinations were found to be negative, however, the pathologic diagnosis showed chronic osteomyelitis. Eight months after surgery, the patient was asymptomatic and there was no sign of recurrence of infection. For Brodies abscess in a child, thorough debridement is mandatory in addition to cancellous bone grafting. Brodies abscess should be considered in the differential diagnosis of a patient who presents with forearm pain and exhibit the radiolucent osteolytic lesion on simple radiography.

Symmetric Peripheral Running Sutures are Superior to Asymmetric Peripheral Running Sutures for Increasing the Tendon Strength in Flexor Tendon Repair

BACKGROUND The fatigue strength of three peripheral suture techniques for flexor tendon repair was compared by cyclic loading of the repairs in the porcine flexor digitorum tendon. METHODS Thirty-six tendons were sutured using only peripheral sutures with 6-0 Nylon. An initial cyclic load of 10 N for 500 cycles was applied and increased by 10 N for an additional 500 cycles at each new load until rupture. RESULTS The fatigue strength of the symmetric running peripheral suture was 85.0% and 144.8% greater than that of the two kinds of the asymmetric running peripheral sutures. CONCLUSIONS Symmetric running sutures can enhance the suture strength and appears to be a useful technique for increasing the strength of the peripheral suture.

Recovery of Wrist Function after Volar Locking Plate Fixation for Distal Radius Fractures.

BACKGROUND The purpose of our present study was to examine the recovery of the postoperative wrist function, and to compare the range of motion among each direction ofthe wrist joint during the same time periods after surgery for distal radius fractures. METHODS Twenty patients treated with a volar locking plate were evaluated. The active range of motion and grip strength were assessed at four weeks, six weeks, three months, six months and one year after surgery. RESULTS The ratio of the range of motion in pronation and supination recovered significantly earlier than for any other directions within six months after surgery (p = 0.0205), however, the ratio of the range of motion among the six directions was not significantly different at one year after surgery (p = 0.0823). The recovery of the range of motion in flexion was 96.8% compared with the contralateral wrist at one year after surgery, and it was not significantly lower than that in extension, radial deviation or ulnar deviation (97.8%, 93.5%, 94.4%, respectively). The grip strength of dominant hand recovered from 50% after four weeks to 66% after six weeks, 83% after three months, 91% after six months and 106% at the examination performed after one year compared with the uninjured non-dominant hand. The grip strength of non-dominant hand recovered from 52% after four weeks to 59% after six weeks, 79% after three months, 84% after six months and 94% at the examination performed after one year compared with the uninjured dominant hand. The mean DASH score was 5.3. CONCLUSIONS The range of motion in flexion can achieve similar improvement to that in the other directions by obtaining the appropriate postoperative parameters. The optimal postoperative radiographic parameters were thus identified to be essential for successfully obtaining a recovery of the wrist function for unstable distal radius fractures.

The Characteristics of Two Sizes of the JuggerKnot Mini 1.0 mm: 2-0 and 3-0

Background: This study was to investigate the characteristics and the basic data of two sizes of the JuggerKnot Mini 1.0 mm. Methods: Twenty-three 3-0 and thirty-four 2-0 anchors were inserted into synthetic bone, and we used twenty 3-0 and 2-0 anchors each which had been inserted correctly on the first attempt. After a preload of 10 N, cyclic testing was performed at 10-30 N for 200 cycles, after which destructive testing was performed. The parameters included the insertion form, the failure mode, the load to failure, and elongation at rupture. Findings: 3-0 suture was more likely to be completely inserted at first insertion compared with a 2-0 suture. The mean strength of each anchor was 73.0 N and 118.7 N for 3-0 and 2-0, respectively. The average elongation at rupture of the 3-0 and 2-0 anchors was 2.63 mm and 3.66 mm, respectively. Conclusions: These basic data and characteristics should be taken into account when using the JuggerKnot mini 1.0 mm in a clinical setting.

Avulsion Fracture of the Tibial Tuberosity Requiring Meniscal Repair : A Case Report

Avulsion fractures of the tibial tuberosity are uncommon injuries. A 16-year-old male sustained injuries to his right knee joint after jumping from stairs and landed on his feet with his right knee forced into flexion. X-ray photographs showed a type III avulsion fracture of the tibial tuberosity. On the next day of the injury, open reduction and internal fixation, followed by arthroscopy was performed. The fracture fragment was fixed with three 5.0mm cannulated cancellous screws. The torn anterior portion of medial meniscus was repaired with 3-0 Polydioxanone (PDS) using outside-in sutures and the torn midportion of medial meniscus was repaired using the FasT-Fix meniscal repair system. Eight months after the injury, removal of the screws and arthroscopy were undertaken. The medial meniscus was completely healed. The range of motion was full at the knee joint. Meniscal suture should be strongly considered for type III avulsion fractures of the tibial tuberosity in adolescents.

Open pelvic ring fracture and multiple fractures of the lower extremities: a case report.

A 73-year-old female was hit by a car, and transferred to our hospital. On examination, her consciousness was alert, but her vital signs were unstable. There are three 10-cm open wounds on her right buttock. X-rays showed an unstable pelvic ring fracture, a right femoral shaft, a right proximal tibia and a right tibial plafond fractures. One hour after the injury, transarterial embolization (TAE) followed by external fixation (EF), and retroperitoneal pelvic packing (RPP) was performed. Two days and five days after the injury, thorough debridement of the open wounds was performed. The skin defect on the right buttock and the lower abdomen had enlarged to 40 x 35 cm, therefore, negative pressure wound therapy was applied. On the same day, right femur was fixed using a retrograde intramedullary nailing. 12 days after the injury, the proximal tibial fracture was fixed using a plate, and the tibial plafond fracture was fixed using screws and external fixators. 28 days after the injury, the split-thickness skin graft was performed on the right buttock and the lower abdomen. Seven months after the injury, the open wounds were completely healed without infection. She was able to walk smoothly with a T-cane. For the management of open pelvic ring fractures, it is essential to perform TAE, EF and RPP as soon as possible. Providing aggressive management, including thorough debridement, is mandatory to prevent severe infection and sepsis. We achieved a good clinical outcome by using a combination of TAE, EF, RPP and staged surgery, including thorough debridement.