Takehiko Takagi

Visualization of peripheral nerve degeneration and regeneration: monitoring with diffusion tensor tractography.

We applied diffusion tensor tractography (DTT), a recently developed MRI technique that reveals the microstructures of tissues based on its ability to monitor the random movements of water molecules, to the visualization of peripheral nerves after injury. The rat sciatic nerve was subjected to contusive injury, and the data obtained from diffusion tensor imaging (DTI) were used to determine the tracks of nerve fibers (DTT). The DTT images obtained using the fractional anisotropy (FA) threshold value of 0.4 clearly revealed the recovery process of the contused nerves. Immediately after the injury, fiber tracking from the designated proximal site could not be continued beyond the lesion epicenter, but the intensity improved thereafter, returning to its pre-injury level by 3 weeks later. We compared the FA value, a parameter computed from the DTT data, with the results of histological and functional examinations of the injured nerves, during recovery. The FA values of the peripheral nerves were more strongly correlated with axon-related (axon density and diameter) than with myelin-related (myelin density and thickness) parameters, supporting the theories that axonal membranes play a major role in anisotropic water diffusion and that myelination can modulate the degree of anisotropy. Moreover, restoration of the FA value at the lesion epicenter was strongly correlated with parameters of motor and sensory functional recovery. These correlations of the FA values with both the histological and functional changes demonstrate the potential usefulness of DTT for evaluating clinical events associated with Wallerian degeneration and the regeneration of peripheral nerves.

Supracondylar osteotomy of the humerus to correct cubitus varus: Do both internal rotation and extension deformities need to be corrected?

BACKGROUND A variety of osteotomies has been proposed to correct posttraumatic cubitus varus deformity as well as any associated hyperextension and/or rotational deformities. However, lateral closing-wedge osteotomy and step-cut osteotomy, both of which have been used extensively with satisfactory outcomes, correct only in the coronal plane. To date, no direct comparison has been made between three-dimensional and simple coronal plane osteotomies. METHODS Between 1983 and 2007, we treated eighty-six elbows with a posttraumatic varus deformity. We classified patients who underwent three-dimensional osteotomies as Group I and those who underwent simple coronal plane osteotomies as Group II, and we compared the outcomes between the groups. Clinical evaluation included an assessment of the carrying angle and measurement of the passive range of motion before surgery and at the time of the final follow-up. To evaluate the remodeling capacity of the bone to recover elbow flexion in Group II, we assessed the range of motion before surgery and at the time of the final follow-up in patients who were less than ten years old and those who were more than ten years old. RESULTS There was no significant difference between the groups with regard to the carrying angle or the elbow range of motion, either before surgery or at the time of the final follow-up. However, Group I had more significant loss of correction (p = 0.018). In Group II, elbow motion reached the physiological range by the time of the final follow-up in patients who were less than ten years old. CONCLUSIONS For osteotomies to correct cubitus varus deformity, correction of internal rotation is not needed. With a three-dimensional osteotomy, it is difficult to maintain correction and to acquire the planned carrying angle because of the small area of bone contact. It is necessary to correct hyperextension in patients older than ten years of age, as after that age bone remodeling is not expected to increase elbow flexion.

Outcome of Surgical Reconstruction After Traumatic Total Brachial Plexus Palsy

BACKGROUND Double free muscle transfer for the treatment of traumatic total brachial plexus injury provides useful prehensile function. We studied the outcome of this muscle transfer procedure, including the changes in disability and quality-of-life scores. METHODS Thirty-six patients with traumatic total brachial plexus injury who underwent double free muscle transfer for reconstruction from 2002 to 2008 and had a minimum follow-up of twenty-four months after the second free muscle transfer were studied. All were evaluated preoperatively and postoperatively with use of the Disabilities of the Arm, Shoulder and Hand (DASH) and Short Form-36 (SF-36) questionnaires. A separate questionnaire was used to determine job status, pain, use of the reconstructed hand, and satisfaction with the procedure. RESULTS The mean patient age was twenty-nine years (range, sixteen to forty-nine years), and the mean duration of follow-up was thirty-six months (range, twenty-four to seventy-nine months). The mean active range of motion was 23° (range, 0° to 80°) for shoulder flexion, 31° (range, 0° to 90°) for shoulder abduction, -18° (range, -80° to 40°) for shoulder external rotation, 62° (range, 0° to 130°) for the shoulder rotation arc, 119° (range, 90° to 150°) for elbow flexion, and -33° (range, -60° to -20°) for elbow extension. The power of elbow flexion was M4 in twenty-five patients and M3 in eleven. Twenty-three patients had triceps nerve reconstruction; extension was M0 in two of these patients, M1 in seven, M2 in ten, and M3 in four. Total active motion of the fingers was 46° (range, 0° to 98°), with a mean hook grip strength of 4 kg (range, 0 to 12 kg). Wilcoxon tests revealed significant improvements in the DASH score and the SF-36 physical functioning, role physical, and physical component summary scores. The majority of patients worked but had changed their type of work, used the reconstructed hand in activities of daily living that required both hands, and were satisfied with the procedure. CONCLUSIONS Double free muscle transfer yielded satisfactory function and allowed use of the reconstructed hand in activities that required both hands. The improvement in the DASH score was greater than that in the SF-36 score.

Sustained bFGF-release tubes for peripheral nerve regeneration: Comparison with autograft

Background: Despite numerous articles on the use of artificial nerve conduits, autologous nerve transplants remain the most effective for nerve repair. To improve this technique, the authors examined conduits containing gelatin hydrogel as a carrier enabling the sustained release of basic fibroblast growth factor (bFGF). Methods: To confirm sustained bFGF release in vivo, nerve-guide tubes containing iodine-125–labeled bFGF with or without gelatin hydrogel were implanted under the skin of mice, and the remaining radioactivity was measured. Next, a 15-mm segment of the sciatic nerve was resected and repaired with autologous nerve (group 1), a tube with gelatin hydrogel and bFGF (group 2), a tube with bFGF alone (group 3), or a tube only (group 4). Histologic and functional analyses were performed for 16 weeks after surgery. Results: The radioactivity from iodine-125–labeled bFGF incorporated into gelatin hydrogel decreased more slowly than iodine-125–labeled bFGF alone. Four weeks after surgery, significantly more regenerating axons were detected in group 2 than in groups 3 and 4, but the axonal density in group 2 was lower than in group 1. Similarly, the animals in group 2 showed significantly better motor performance than those in groups 3 and 4, but worse than those in group 1. The animals in groups 1 and 2 showed significantly better sensory recovery than those in groups 3 and 4. Conclusions: The nerve-guide tube containing gelatin hydrogel and bFGF promoted axonal regeneration after peripheral nerve injury, but not as well as autologous transplants. Understanding the limitations of this technique will facilitate its improvement for clinical applications.

Elbow and forearm reconstruction in patients with ulnar dimelia can improve activities of daily living

Ulnar dimelia (mirror hand with double ulna) is a rare congenital anomaly in which both forearm bones develop as a normal ulna and polydactyly is present in the hand, the thumb and radius bone being absent. Elbow and forearm problems remain after removal of excess digits and reconstruction of a radial finger to serve as a thumb to allow prehensile movement in all cases reported in the literature. No reports of elbow reconstruction have been identified, although reports of hand and thumb reconstruction have been published. We present our experience of improved activities of daily living (ADLs) after elbow reconstruction for a patient with ulnar dimelia. The elbow reconstruction led to better forearm range of motion but no significant improvement in elbow flexion.

A Radiographic Method for Evaluation of the Index-Hypoplastic Thumb Angle

PURPOSE Thumb metacarpophalangeal joint radial instability occurs during the pinch motion in patients with hypoplastic thumb because of thumb-index web narrowing. We devised a radiographic technique to measure the thumb-index angle, applied while the patient holds a styrene foam cone, to evaluate the relationship between the thumb and the index finger. We used this technique to compare different types of thumb hypoplasia and the groups before and after surgery. METHODS Twenty patients with hypoplastic thumbs held the styrene foam cone. The average age of the patients was 6.5 years (range, 1.6 to 12.0 y). We obtained an overhead radiograph while the patient held the cone and evaluated the apparent thumb-index web angle, the thumb to index finger metacarpal angle (1-2MCA), and the first metacarpophalangeal angle (1MPA). RESULTS In the 9 unilateral cases, no significant difference was detected between the unaffected side and the affected side in terms of thumb-index web angle, but the data showed meaningful differences in terms of 1-2MCA and 1MPA. In addition, the data showed meaningful differences between the groups before surgery and 2 years after surgery in terms of 1-2MCA and 1MPA. CONCLUSIONS Measuring both 1-2MCA and 1MPA enables evaluation of the severity of the deformity, and these parameters allowed for comparative evaluation of the severity of preoperative and postoperative narrowing of thumb-index web space and the radial instability of the thumb metacarpophalangeal joint. By focusing on these characteristics, we devised a novel approach for imaging of the thumb-index web space.

Modified step-cut osteotomy for correction of post-traumatic cubitus varus deformity: a report of 19 cases.

We reviewed the outcomes of post-traumatic varus deformity treated with modified step-cut osteotomy in 19 patients (average age, 7.4 years; range, 4.3–16.8 years at time of surgery). The average follow-up period was 29.6 months. The mean range of motion was 15.0°/124.7° (extension/flexion) before surgery and 6.8°/132.6° at final follow-up. The humerus–elbow–wrist angle was −21.1° before surgery and 4.2° at final follow-up, with a loss of 4.4° from the value of the humerus–elbow–wrist angle after the surgery. Osteotomy was fixed with Kirschner wires, and, in five cases, chips of excised bone could be inserted to avoid elbow extension. However, in eight cases, usually concerning younger patients, the elbow was fixed in hyperextension higher than 5°. No patient developed postoperative infections or later complications. Only one patient had transient nerve palsy. The modified step-cut osteotomy can precisely and stably correct the varus deformity in the coronal plane, especially in patients under 10 years of age. To avoid radial nerve palsy, we recommend that the retractors be removed sometimes during the operation.

A Modified Step-Cut (Reverse V) Osteotomy to Treat Posttraumatic Cubitus Varus Deformity

[Introduction][1] It is sufficient to correct posttraumatic cubitus varus deformity in only the coronal plane in children under the age of ten years to allow more precise and stable correction, and a modified step-cut (reverse V) osteotomy is one of the best methods. ![Figure][2] [Step 1: Expose the Distal Part of the Humerus][3] With the patient in a lateral decubitus position, expose the distal part of the humerus both medially and laterally, using gentle retraction to avoid radial nerve palsy. ![Figure][2] ![Figure][2] [Step 2: Resect Bone][4] Using a triangular template made prior to surgery, perform the osteotomy. ![Figure][2] [Step 3: Reduce Deformity][5] Increase the degree of correction to reduce the deformity. ![Figure][2] ![Figure][2] [Step 4: Fixation and Skin Closure][6] Cross-pin with Kirschner wires, taking care to avoid hyperextension at the osteotomy site. [Step 5: Postoperative Management][7] Immobilize the elbow with a splint, and permit active motion two to three weeks after surgery. ![Figure][2] ![Figure][2] [Results & Preop./Postop. Images][8] Our case series included eight patients (four male and four female). The average age of the patients at the time of the osteotomy was 6.8 years (range, four to fourteen years). [What to Watch For][9] [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [Introduction][1] It is sufficient to correct posttraumatic cubitus varus deformity in only the coronal plane in children under the age of ten years to allow more precise and stable correction, and a modified step-cut (reverse V) osteotomy is one of the best methods. ![Figure][2] [Step 1: Expose the Distal Part of the Humerus][3] With the patient in a lateral decubitus position, expose the distal part of the humerus both medially and laterally, using gentle retraction to avoid radial nerve palsy. ![Figure][2] ![Figure][2] [Step 2: Resect Bone][4] Using a triangular template made prior to surgery, perform the osteotomy. ![Figure][2] [Step 3: Reduce Deformity][5] Increase the degree of correction to reduce the deformity. ![Figure][2] ![Figure][2] [Step 4: Fixation and Skin Closure][6] Cross-pin with Kirschner wires, taking care to avoid hyperextension at the osteotomy site. [Step 5: Postoperative Management][7] Immobilize the elbow with a splint, and permit active motion two to three weeks after surgery. ![Figure][2] ![Figure][2] [Results & Preop./Postop. Images][8] Our case series included eight patients (four male and four female). The average age of the patients at the time of the osteotomy was 6.8 years (range, four to fourteen years). [What to Watch For][9] [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [1]: #sec-10 [2]: pending:yes [3]: #sec-11 [4]: #sec-12 [5]: #sec-13 [6]: #sec-14 [7]: #sec-15 [8]: #sec-16 [9]: #sec-17 [10]: #sec-18 [11]: #sec-19 [12]: #sec-20

Current Concepts in Radial Club Hand

Radial club hand is a complex congenital abnormality of the radial or pre-axial border of the upper extremity. It has a wide range of phenotypes from hypoplasia of the thumb to complete absence of the radius and the first ray. Centralization with tendon transfer is a popular method for maintaining the correct position of radial club hand. On the other hand, various corrections were devised, e.g. radialization after distraction to emphasize the fact that the head of the ulna is positioned under the radial carpal bones and is no longer placed in a slot in the center of the carpus, microvascular epiphysis transfer, gradual correction using Ilizarov method, for Bayne Type III or Type IV. We should pay attention to the recurrence of radial deformity or circulatory impairment with the tension. Lunate excision or ulnar shortening can be selected for tension-free correction. Radialization can be indicated for avoiding the recurrence of radial flexion. However, we should pay attention of the radial protrusion of the ulnar head. For avoiding the recurrence of radial deformity or circulatory impairment, gradual correction using Ilizarov external fixation can be indicated, especially in the cases with severe radial deviation or with short forearm. In the mild cases, Bayne Type I or Type II, radius lengthening is accompanied by a soft-tissue distraction or release at the ulnar carpal joint with keeping wrist and forearm motion without producing growth plate damage.

Open Wedge Osteotomy with Ulnar Shortening for Madelung Deformity Using a Computer-Generated Template

A variety of osteotomies have been reported to correct Madelung deformity using plain radiographs. However, evaluation of the deformity using 2-dimensional plain radiography is difficult because of its complex 3-dimensional nature. Therefore, we performed corrective osteotomy using recently developed 3D simulation technology on an adult woman with Madelung deformity, and achieved an excellent outcome. In this study, we calculated the amount of parallel displacement as well as the rotational angle for more precise correction, and performed open wedge osteotomy. Furthermore, we performed concurrent ulnar shortening. An exaggerated radial inclination was observed in the posteroanterior radiograph. A palmar shift of the carpus and dorsal dislocation of the ulnar head were observed in the lateral radiograph. In the preoperative findings, radial inclination (RI), volar tilt (VT), and ulnar variance (UV) were 35°, 40°, and 12 mm, respectively. The wrist showed improvement, with an RI of 25°, VT of 14°, and UV of 0 mm. At present, 14 months after surgery, there has been no loss of correction, instability of the ulnar head, or pain on the ulnar side. The procedure resulted in improvements in the protrusion and pain in the ulnar portion of the patients wrist. Based on this result, we believe that accurate corrective osteotomy with ulnar shortening should be performed for Madelung deformity.