Shinichiro Takayama

Origins and Insertions of the Triangular Fibrocartilage Complex: A Histological Study:

The origins and insertions of the triangular fibrocartilage complex (TFCC) were examined histologically in serially sectioned fresh-frozen cadaver wrists. The radioulnar ligament arose vertically through Sharpey’s fibres from a broad area in the ulnar fovea and more horizontally from a narrow area at the base of the ulnar styloid. The floor of the extensor carpi ulnaris sheath also originated firmly from the dorsal side of the fovea of the ulna, through an arrangement of Sharpey’s fibres. Loose ulnocarpally oriented fibres, corresponding to a thickened ulnar joint capsule, arose from the hyaline-like cartilage matrix at the tip of the ulnar styloid and inserted onto the triquetrum without Sharpey’s fibres. The ulnolunate and ulnotriquetral ligaments originated not from the ulna, but from the palmar side of the TFCC. The insertion of the TFCC into the sigmoid notch of the radius demonstrated a central transition from the fibrocartilaginous disc into hyaline cartilage and a firmer fibroosseous transition of the dorsal and palmar portions of the radioulnar ligament at the periphery.

MAGNETIC RESONANCE MYELOGRAPHY IN BRACHIAL PLEXUS INJURY

We used magnetic resonance (MR) myelography in ten patients with injuries to the brachial plexus and compared the findings with those obtained by conventional myelography and postmyelographic CT (CTM). In the presence of complete nerve-root avulsion (seven cases), a post-traumatic meningocele was detected by MR myelography. In injuries to the upper roots (three cases) MR myelography showed abnormal findings with a high signal intensity in the nerve root, obliteration of the damaged nerve root, or enlargement and obliteration of the root sleeve. No pseudomeningoceles were detected in these upper-root injuries by MR myelography and CTM. The overall accuracy of detection of damaged nerve roots or root sleeves was better with MR myelography than with conventional myelography and was similar to that of CTM. MR myelography is non-invasive, relatively quick, requires no contrast medium, provides imaging in multiple projections, and is comparable in diagnostic ability to the more invasive, time-consuming techniques of conventional myelography and CTM.

Open repair of the ulnar disruption of the triangular fibrocartilage complex with double three-dimensional mattress suturing technique.

Open repair technique of the ulnar disruption of the triangular fibrocartilage complex is described. This technique is indicated for a fresh or a relatively fresh (less than 1 year after the initial injury) ulnar foveal detachment tear, horizontal tear, and proximal slit tear of the triangular fibrocartilage complex, all of which are accompanied by severe dorsal, palmar, or multidirectional instability of the distal radioulnar joint. A chronic tear greater than 1 year from initial injury and a fresh triangular fibrocartilage complex tear without distal radioulnar joint instability, such as central slit tear, are excluded from our indications. A dorsal C-shaped skin incision, a longitudinal incision of the radial edge of the extensor carpi ulnaris subsheath and the dorsal distal radioulnar joint capsule, exposes the distal radioulnar joint. A small, 5-mm longitudinal incision at the origin of the radioulnar ligament exposes its fovea detachment and/or the proximal slit tear of the triangular fibrocartilage complex. The disrupted radioulnar ligament is sutured in a pullout fashion to the ulna with a 3-dimensional double mattress technique through 2 bone tunnels that is precisely made at the central portion of the fovea with 1.2-mm K-wire. An additional horizontal mattress suture is used for closure of the small incision made at the radioulnar ligament, then the extensor carpi ulnaris is repaired. This open-repair technique is complex and requires precise technical skills; however, early results have been more rewarding than the conservative treatment.

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.

Cubital tunnel release with lift-type endoscopic surgery.

A new technique of endoscopic release of the ulnar nerve at the elbow was designed for cubital tunnel syndrome. After three 5 mm incisions were made along the line of the ulnar nerve, the skin and subcutaneous tissue were lifted up using a fine tape to produce a provisional space. An endoscope was inserted through the one incision, and the constricting ligaments and fascia were released using a retrograde knife inserted through the other incision under endoscopic vision. Eight patients were treated using this method, and successful results were achieved. No neurovascular complications occurred, and all pre-operative complaints were resolved within three weeks. Our surgical series indicated an earlier return to work and daily activity due to early healing of incisions and minimal post-operative pain.

Nicotine Acts on Growth Plate Chondrocytes to Delay Skeletal Growth through the α7 Neuronal Nicotinic Acetylcholine Receptor

Background Cigarette smoking adversely affects endochondral ossification during the course of skeletal growth. Among a plethora of cigarette chemicals, nicotine is one of the primary candidate compounds responsible for the cause of smoking-induced delayed skeletal growth. However, the possible mechanism of delayed skeletal growth caused by nicotine remains unclarified. In the last decade, localization of neuronal nicotinic acetylcholine receptor (nAChR), a specific receptor of nicotine, has been widely detected in non-excitable cells. Therefore, we hypothesized that nicotine affect growth plate chondrocytes directly and specifically through nAChR to delay skeletal growth. Methodology/Principal Findings We investigated the effect of nicotine on human growth plate chondrocytes, a major component of endochondral ossification. The chondrocytes were derived from extra human fingers. Nicotine inhibited matrix synthesis and hypertrophic differentiation in human growth plate chondrocytes in suspension culture in a concentration-dependent manner. Both human and murine growth plate chondrocytes expressed alpha7 nAChR, which constitutes functional homopentameric receptors. Methyllycaconitine (MLA), a specific antagonist of alpha7 nAChR, reversed the inhibition of matrix synthesis and functional calcium signal by nicotine in human growth plate chondrocytes in vitro. To study the effect of nicotine on growth plate in vivo, ovulation-controlled pregnant alpha7 nAChR +/− mice were given drinking water with or without nicotine during pregnancy, and skeletal growth of their fetuses was observed. Maternal nicotine exposure resulted in delayed skeletal growth of alpha7 nAChR +/+ fetuses but not in alpha7 nAChR −/− fetuses, implying that skeletal growth retardation by nicotine is specifically mediated via fetal alpha7 nAChR. Conclusions/Significance These results suggest that nicotine, from cigarette smoking, acts directly on growth plate chondrocytes to decrease matrix synthesis, suppress hypertrophic differentiation via alpha7 nAChR, leading to delayed skeletal growth.

Corrective Osteotomy for Volarly Malunited Distal Radius Fracture

PURPOSE To retrospectively analyze consecutive cases with opening wedge corrective osteotomy of the volarly malunited distal radius with iliac bone graft, including preoperative and postoperative comparison of symptoms, visual analog scale (VAS), Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand (DASH-JSSH) questionnaires, radiographic indices, clinical results as evaluated by modified Mayo wrist score, and complications. METHODS Subjects were 28 patients with volarly malunited distal radius fracture treated by transverse opening wedge osteotomy with oblique iliac bone graft. Preoperative symptoms included wrist deformity, weakness of grip strength, and marked restriction of supination range. Postoperative symptoms, radiographic parameters, clinical results, and complications were analyzed at an average of 25 months of follow-up. We also analyzed the union period of the radius in younger patients (< or =45 years old) and older patients (>45 years old). RESULTS Mean preoperative visual analog scale was 45, improving significantly to 3 postoperatively. Range of wrist motion improved in all 28 patients, with supination range improving from 16 degrees preoperatively to 80 degrees postoperatively. Mean preoperative DASH-JSSH score was 55, improving to 9 postoperatively. Radiography revealed that volar tilt improved from 32 degrees preoperatively to 10 degrees postoperatively, and radial inclination increased from 17 degrees to 21 degrees . Preoperative ulnar variance of +5.9 mm was corrected to -0.1 mm postoperatively. All 28 wrists demonstrated bony union at the osteotomy site after an average of 52 days (younger patients, 51 days; older patients, 54 days). No complications, significant radiographic correction loss, or nonunion were seen after at least 2 years of follow-up. Modified Mayo wrist score was excellent in 16 patients, good in 10 patients, and fair in 2 patients. CONCLUSIONS Opening wedge osteotomy for volarly malunited distal radius fracture restored bony configuration of the distal radius, decreased pain, and improved grip strength and range of wrist motion, particularly for forearm supination. No complications or noteworthy correction loss were noted after surgery, even in older patients. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Muscle repair after a transsection injury with development of a gap : An experimental study in rats

Lacerated muscle needs fusion with muscle fibres to regain good function, but it often lose its elasticity and the repair seems poor. We think that the scar healing is caused by the development of a gap. In this study in 20 rats we made silicone tube models to keep a constant distance between the muscle ends, and examined the repair inside the silicone tube. In the short gap (1 mm), aligned collagen fibres and muscle fibres bridged both ends. However, when the gap was long (4 mm) they could not bridge both ends and collagen fibres covered the cut ends of muscle. Muscle contains a large fibrous component and will regenerate simultaneously after transsection injury. This result suggests that fibrous repair influences the muscle repair and muscle regeneration will be disturbed as the gap widens.Lacerated muscle needs fusion with muscle fibres to regain good function, but it often lose its elasticity and the repair seems poor. We think that the scar healing is caused by the development of a gap. In this study in 20 rats we made silicone tube models to keep a constant distance between the muscle ends, and examined the repair inside the silicone tube. In the short gap (1 mm), aligned collagen fibres and muscle fibres bridged both ends. However, when the gap was long (4 mm) they could not bridge both ends and collagen fibres covered the cut ends of muscle. Muscle contains a large fibrous component and will regenerate simultaneously after transsection injury. This result suggests that fibrous repair influences the muscle repair and muscle regeneration will be disturbed as the gap widens.

Surgical treatment of spontaneous posterior interosseous nerve palsy: a retrospective study of 50 cases.

We have reviewed 38 surgically treated cases of spontaneous posterior interosseous nerve palsy in 38 patients with a mean age of 43 years (13 to 68) in order to identify clinical factors associated with its prognosis. Interfascicular neurolysis was performed at a mean of 13 months (1 to 187) after the onset of symptoms. The mean follow-up was 21 months (5.5 to 221). Medical Research Council muscle power of more than grade 4 was considered to be a good result. A further 12 cases in ten patients were treated conservatively and assessed similarly. Of the 30 cases treated surgically with available outcome data, the result of interfascicular neurolysis was significantly better in patients < 50 years old (younger group (18 nerves); good: 13 nerves (72%), poor: five nerves (28%)) than in cases > 50 years old (older group (12 nerves); good: one nerve (8%), poor: 11 nerves (92%)) (p < 0.001). A pre-operative period of less than seven months was also associated with a good result in the younger group (p = 0.01). The older group had a poor result regardless of the pre-operative delay. Our recommended therapeutic approach therefore is to perform interfascicular neurolysis if the patient is < 50 years of age, and the pre-operative delay is < seven months. If the patient is > 50 years of age with no sign of recovery for seven months, or in the younger group with a pre-operative delay of more than a year, we advise interfascicular neurolysis together with tendon transfer as the primary surgical procedure.

An experimental study on the perineurial window

Abstract  Neurological symptoms of herniated nerve fibers resulting from limited perineurial injury from sharp materials such as needles have become a recent topic in clinical practice. However, the mechanism of this disorder, which is known as a perineurial window, has not been clarified. To investigate the mechanism of nerve damage in the perineurial window, we designed small (1‐mm length) and large (5‐mm length) perineurial windows using tibial nerves of Wistar rats. In the 1‐mm group, a marked hernia of the endoneurial contents developed soon and decreased in size with time, but protrusion of nerve fibers was still observed after 12 weeks. Nerve fibers in both the herniated portion and under the edge of the window were damaged. Even after 12 weeks, regeneration of the nerve fibers and the perineurium was incomplete. In contrast, in the 5‐mm group, the initial endoneurial edema was remarkable, but herniated nerve fibers were not seen after 12 weeks. Neurological impairment in the 5‐mm group was marked in the early stage but rapidly recovered. The repair of the perineurium and nerve fibers in the 1‐mm group was slower than in the 5‐mm group. Persistent neurological symptoms in the perineurial window appeared to be more closely associated with entrapment of nerve fibers at the window edge rather than with disruption of endoneurial homeostasis.