Shohei Omokawa

Sagittal alignment of cervical flexion and extension: lateral radiographic analysis.

Study Design. An analysis of lateral radiographs in the upright, flexion–extension position. Objectives. To document and define the differences in cervical flexion–extension kinematics as they relate to changes of alignment in upright cervical lordosis. Summary of Background Data. No previous study has reported the association between sagittal plane cervical rotation kinematics and changes of alignment in upright cervical lordosis. Methods. Lateral radiographs were classified into five groups (Group A, lordosis; Group B, straight; Group C, kyphosis; Group D, S-curve with lordotic upper cervical and kyphotic lower cervical spine; and Group E, S-curve with kyphotic upper cervical and lordotic lower cervical spine) by changes of alignment in upright position. Sagittal cervical rotation angles were measured by a computer-assisted method in the fully flexed and extended positions. Results. Group A revealed the largest angle of lordosis at extension and the smallest angle of kyphosis at flexion, whereas Group C revealed the smallest angle of lordosis at extension and the largest angle of kyphosis at flexion. When Group D adopted the flexion–extension position, the curvature of the upper cervical spine was the same as Group A, whereas the lower cervical spine showed the same curve as Group C. Similarly, the cervical rotation kinematics in Group E were a combination of motion of upper cervical spine in Group C and that of lower spine in Group A. Conclusion. The results suggest that alterations in the static alignment of the cervical curvature cause alterations in the dynamic kinematics of the cervical spine during cervical flexion–extension. This information should aid in the interpretation of kinematic studies of the cervical spine.

Vascular and neural anatomy of the thenar area of the hand: its surgical applications.

&NA; Thirty fresh cadaver hands were injected with a silicone rubber compound (Microfil) and dissected to examine the vascular and neural supplies of the thenar area. In 10 specimens, a selective injection technique was used to determine the extent of skin territory nourished by the superficial palmar branch of the radial artery. The purpose of this study was to clarify the anatomic basis for clinical applications of vascularized free‐ or island‐Hap transfers from the thenar area. The superficial palmar branch of the radial artery was found in all hands; the average diameter of the branch measured at its bifurcation site was 1.4 mm (0.8 to 3.0 mm). The constant area nourished by the superficial palmar branch was an area approximately 4 × 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. These results indicate that a fasciocutaneous flap from the radial thenar region can be raised based on the superficial palmar branch and consistently transferred as a free flap. In 63 percent of the hands dissected, the superficial palmar branch was connected to other arteries in the palm, suggesting that the flap can be transferred as a reverse‐pedicle island flap in such hands. Innervation of the flap was provided chiefly by a branch of the superficial radial nerve. The radial aspect of the thenar eminence can provide a new and useful donor source for an innervated and vascularized free‐ or island‐flap transfer for reconstruction of various skin defects of the volar side of the fingers.

Prospective Outcomes of Comminuted Periarticular Metacarpal and Phalangeal Fractures Treated Using a Titanium Plate System

PURPOSE The purpose of this study was to prospectively evaluate clinical results for open reduction and internal fixation of unstable metaphyseal fractures of the metacarpal and phalangeal bones using a miniature titanium plate. METHODS Fifty-one consecutive patients with periarticular fractures with metaphyseal comminution and displacement were enrolled. Intra-articular involvement with a split or depression fracture was identified in 22 hands. Minimum follow-up was 1 year. There were 37 male and 14 female patients; average age was 38 years (range, 14-63). Of the 51 fractures, 15 were open; 8 of these had additional soft tissue injury, involving neurovascular injury in 4 and extensor tendon injury in 6. The average duration from injury to surgery was 6 days (range, 2-40 days). RESULTS Bone union was successfully achieved in all patients over an average period of 2.6 months. The final range of total active motion (%TAM) was excellent (>85%) for 26, good (70%-84%) for 17, fair (50%-69%) for 5, and poor (<49%) for 3. Postoperative complications occurred in 5 patients, including fracture redisplacement in 2, a collapse or absorption of the condylar head in 2, and superficial infection due to hardware exposure in one. Subsequently, 2 of these patients had malrotation deformities or osteoarthritic changes in the injured finger. Plates were removed in 30 cases, and additional surgery was required in 20 cases. Postoperative grip strength averaged 87% of the contralateral side. Statistical analysis revealed that patient age was significantly correlated with %TAM of the injured finger at 1-year follow-up (p < .01), and intra-articular (p < .05) and phalangeal bone (p < .01) involvement, as well as associated soft tissue injury (p < .05), significantly affected the range of finger motion. CONCLUSIONS Despite the technical demands of plating for comminuted metacarpal and phalangeal fractures, the low-profile titanium plate system was highly effective in maintaining anatomic reduction. The postoperative complication rate was relatively low, and the objective outcomes approached a reasonable level at 1-year follow-up. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Predictors of distal radioulnar joint instability in distal radius fractures.

PURPOSE A tear of the triangular fibrocartilage complex (TFCC) is the most frequent soft tissue injury associated with fractures of the distal radius, and repair of the deep ligamentous portion of the TFCC is considered when the tear contributes to instability of the distal radioulnar joint (DRUJ). The purpose of this prospective cohort study was to identify predictors of DRUJ instability accompanying unstable distal radius fractures. METHODS Between 2002 and 2007, we prospectively treated 163 consecutive patients with unstable distal radius fractures with the volar locking plating system. Complete radioulnar ligament tears representing DRUJ instability were present in 11 of 163 distal radius fractures. We tested univariate associations between DRUJ instability and potential predictors and conducted multivariate analysis to establish independent predictors of instability. We applied receiver operating characteristics curves within the significant risk factors to determine threshold values. RESULTS In univariate analyses, only the radial and sagittal translation ratios of the fracture site were significant predictors of DRUJ instability. Multivariate logistic regression analysis confirmed that the radial translation ratio, which corresponds to a normalized DRUJ gap, was a significant risk factor. According to the receiver operating characteristics curve for the radial translation ratio, the area under the curve was 0.89. A cutoff value of 15% for the radial translation ratio showed the highest diagnostic accuracy rate. CONCLUSIONS A radiographic finding of a normalized DRUJ gap on posteroanterior views was the most important predictor to identify DRUJ instability accompanying unstable distal radius fractures. The relative risk of instability increases by 50% when the ratio of DRUJ widening increases by 1%.

A reverse ulnar hypothenar flap for finger reconstruction

A reverse-flow island flap from the hypothenar eminence of the hand was applied in 11 patients to treat palmar skin defects, amputation injuries, or flexion contractures of the little finger. There were three female and eight male patients, and their ages at the time of surgery averaged 46 years. A 3 × 1.5 to 5 × 2 cm fasciocutaneous flap from the ulnar aspect of the hypothenar eminence, which was located over the abductor digiti minimi muscle, was designed and transferred in a retrograde fashion to cover the skin and soft-tissue defects of the little finger. The flap was based on the ulnar palmar digital artery of the little finger and in three patients was sensated by the dorsal branch of the ulnar nerve or by branches of the ulnar palmar digital nerve of the little finger. Follow-up periods averaged 42 months. The postoperative course was uneventful for all patients, and all of the flaps survived without complications. The donor site was closed primarily in all cases, and no patient complained of significant donor-site problems. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer, as indicated by 5 mm of moving two-point discrimination. A reverse island flap from the hypothenar eminence is easily elevated, contains durable fasciocutaneous structures, and has a good color and texture match to the finger pulp. This flap is a good alternative for reconstruction of palmar skin and soft-tissue defects of the little finger. (Plast. Reconstr. Surg. 106: 828, 2000.)

A long-term study of the donor-site ankle after vascularized fibula grafts in children

We reviewed the long‐term course of the donor‐site ankle after vascularized fibula grafts in 13 children. The preventive and therapeutic effects of the tibio‐fibular metaphyseal synostosis (T‐F synostosis) against valgus ankle deformity, which is one of the postoperative donor‐site problems, were evaluated based on three radiologic and clinical parameters. Thirteen patients were divided into two groups: patients with or without simultaneous T‐F synostosis when the fibula was taken. Three patients underwent T‐F synostosis secondarily after the development of the valgus deformity. Follow‐up periods averaged 12.4 years. In the patients with primary T‐F synostosis, valgus deformity was only observed in one case. No functional disorder of the ankle joints was observed after T‐F synostosis. In the patients without T‐F synostosis, all the patients younger than 8 years old showed valgus deformity, in which the tilting angle averaged 6.3 degrees. In the three patients who underwent T‐F synostosis secondarily, the tilting angle normalized in cases in which the fixation was performed when the lateral wedging was in a mild stage. There was a statistically significant difference in valgus tilt angle between the two groups (with or without T‐F synostosis).

Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

&NA; Primary soft‐tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions—the proximal and distal—according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 × 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches from the palmar digital nerve supplying the midpalmar area. From this study, two different reverse flaps were proposed. First, a 5 × 2 cm flap from the distal midpalmar region was elevated on the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal joint level and could cover the finger pulp of the digits. The second flap candidate was that from the radial aspect of the midpalm, which was supplied by the terminal branch of the superficial palmar arch. In studies with cadaver hands, connection of this artery with the deep arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft‐tissue loss of the fingers. (Plast. Reconstr. Surg. 108: 2020, 2001.)

Vascularized bone graft from the medial calcaneus for treatment of large osteochondral lesions of the medial talus

Background: Operative treatment of large osteochondral lesions of the talus is difficult because the blood supply is poor in the talar dome. The purpose of this study was to evaluate the results of a vascularized bone graft transfer from the medial calcaneus to the large osteochondral lesion. Methods: Four ankles in four patients with medial osteochondral lesions were treated through a medial transmalleolar approach. Vascularized bone graft was harvested from the medial calcaneus using the calcaneal branch of the posterior tibial artery and was placed through a fenestration of the medial aspect of the talar dome. The mean duration of postoperative followup was 34 (range 24 to 48) months. Clinical and radiographic evaluations were made before surgery and at final followup. Results: According to the AOFAS ankle-hindfoot scale, mean pain and function scores improved from 20 to 33 points and 30 to 43 points, respectively. The mean total score improved from 60 to 83 points. Plain radiography at followup showed slight osteosclerosis in all patients, but joint space narrowing was not seen in any patient. Cysts seen preoperatively on MRI or CT resolved after 12 months postoperatively, and MRI or CT did not reveal any findings indicative of osteonecrosis. Conclusions: Clinical and radiographic results were satisfactory. Vascularized bone grafts harvested from the calcaneus were successful for the treatment of large osteochondral lesions of the medial talus.

Validation of the Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome Instrument.

BackgroundThe Carpal Tunnel Syndrome Instrument (CTSI) is a disease-specific, self-administered questionnaire that consists of a symptom severity scale (SS) and a functional status scale (FS). The CTSI was cross-culturally adapted and developed by the Impairment Evaluation Committee, Japanese Society for Surgery of the Hand (JSSH). The purpose of this study was to test the reliability, validity, and responsiveness of the Japanese version of the CTSI (CTSI-JSSH).MethodsA consecutive series of 87 patients with carpal tunnel syndrome completed the CTSI-JSSH, the JSSH version of the Disability of the Arm, Shoulder, and Hand questionnaire (DASH-JSSH), and the 36-Item Short-Form Health Survey (SF-36). Seventy-two of the patients were reassessed for test–retest reliability 1 or 2 weeks later. Reliability was investigated by the reproducibility and the internal consistency. To analyze the validity, a factor analysis (principal axis factoring) of the CTSI-JSSH and the correlation coefficients between the CTSI-JSSH and DASH-JSSH were obtained. The responsiveness was examined by calculating the standardized response mean (SRM; mean change/SD) and effect size (mean change/SD of baseline value) after carpal tunnel release in 42 patients.ResultsCronbach’s alpha coefficients for the CTSI-JSSH-SS and the CTSI-JSSH-FS were 0.84 and 0.90, respectively, and the intraclass correlation coefficients were 0.82 and 0.83, respectively. The unidimensionality of the CTSI-JSSH-SS was barely confirmed; the unidimensionality of the CTSI-JSSH-FS was confirmed. The correlation coefficients between the CTSI-JSSH-FS and the CTSI-JSSH-SS or DASH-JSSH were 0.58 and 0.80, respectively. The correlation coefficient between the CTSI-JSSH-SS and DASH-JSSH was 0.54. The correlation coefficients between the subscales of SF-36 and the CTSI-JSSH-SS or the CTSI-JSSH-FS ranged from −0.23 to −0.66 and from −0.19 to −0.63, respectively. The SRMs/effect sizes of the CTSI-JSSH-SS and the CTSI-JSSH-FS were −0.85/−0.99 and −0.70/−0.61, which indicated that they were more than moderately sensitive.ConclusionsThe CTSI-JSSH has sufficient reliability, validity, and responsiveness to assess the health status in carpal tunnel syndrome.

Innervated radial thernar flap for sensory reconstruction of fingers

A radial thenar flap, which is supplied by the superficial palmar branch of the radial artery and innervated by the superficial branch of the radial nerve, was used in four patients for sensory reconstruction of the fingers. Two patients had degloving injuries of the hand and two had amputation injuries of the thumb. Three of the cases underwent free-flap transfers, and one case underwent a reverse-flow island flap. The size of these flaps was about 3 x 5 cm except in one case, where a 15 x 5 cm flap combined with a radial forearm flap was used. Sensory reinnervation was excellent and donor site morbidity was minimal in all four cases. An innervated radial thenar flap from the ipsilateral hand offers an alternative choice to reconstruct large palmar defects of the fingers.