Jaiyoung Ryu

An approach to Kienböck's disease: Triscaphe arthrodesis

Sixteen patients with Kienböcks disease were treated with triscaphe arthrodesis (fusion of the scaphoid, trapezium, and trapezoid) with or without silicone rubber lunate arthroplasty. This approach removes compressive stress from the diseased lunate and treats the accompanying rotary subluxation of the scaphoid. Five patients were treated with triscaphe arthrodesis together with silicone rubber lunate arthroplasty. Three patients, who were symptomatic, after receiving silicone rubber lunate arthroplasty elsewhere, were treated with triscaphe arthrodesis. Eight patients were treated with triscaphe arthrodesis alone, without silicone rubber lunate arthroplasty. Two of these eight patients later required silicone rubber lunate arthroplasty. Radial styloidectomy and small lunate fragment excision were performed later on one patient. After an average follow-up of 20.5 months, relief of pain was satisfactory in all 16 patients. There was neither nonunion nor surgical infection. We believe that triscaphe arthrodesis with a silicone rubber lunate provides a means for load transference and heavy stress use capability of the hand. Triscaphe arthrodesis alone may suffice to bear the wrist load and can be used in an effort to preserve the diseased lunate. A silicone rubber lunate can easily be added at a later date if necessary.

Sterility of surgical site marking

BACKGROUND Over the past decade, wrong-site surgery has been a popular topic of discussion, not only in medical and legal journals but also in the mainstream press. Marking of the surgical site according to the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) Universal Protocol was implemented at our institution to help reduce the number of wrong-site operations. In this study, we determined whether marking of the site affected the sterility of the surgical field. METHODS The study included twenty volunteers. The right forearm was used as the experimental (marked) arm and the left forearm, as the control arm. The experimental forearms were marked with a surgical marker as described by the protocol. Both upper extremities were then sterilized from the antecubital fossa to the phalanges with a 7.5% povidone-iodine scrub followed by the application of a 10% povidone-iodine paint. Swabs were used to obtain samples from the experimental and control arms as well as from the marker and were sent for microbiological culture and analysis. RESULTS No growth was seen in the cultures of the swabs used on the experimental or control arms or on the marking pens. CONCLUSIONS Preoperative marking of surgical sites in accordance with the JCAHO Universal Protocol did not affect the sterility of the surgical field, a finding that provides support for the safety of surgical site marking.

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.)

The triangular fibrocartilage complex: an important component of the pulley for the ulnar wrist extensor.

The extensor carpi ulnaris (ECU) tendon is the only wrist motor tendon that broadly connects with the triangular fibrocartilage complex (TFCC) of the wrist. The goal of this study was to determine the biomechanical effect of the TFCC on the function of the ECU. The effect of avulsion of the TFCC on the changes in mechanics of the ulnar wrist extensor tendon was investigated in 8 fresh-frozen cadaver forearms. Excursion of the ECU tendon was continuously recorded over the functional range of wrist extension and ulnar deviation in intact wrists, wrists with ulnar styloid fractures, wrists with TFCC release from the distal ulna, and after excising the distal ECU tendon sheath. The ECU tendon demonstrated a 30% increase in excursion during wrist extension after release of the TFCC from its attachment on the distal ulna. During 60 degrees of wrist extension, excursion of the ECU tendon was 4.8+/-1.9 mm in the intact wrists and 6.3+/-2.0 mm after TFCC release. This change in excursion represented 1.4 mm of bowstringing for the ECU tendon during 60 degrees of wrist extension. Further incision of the distal part of the extensor sheath produced only 6% increase in excursion of the ECU. Results of this study suggest that the TFCC is an important component of the pulley for the ulnar wrist extensor. These findings imply that disturbance of the wrist extensor after TFCC injury may potentially contribute to abnormal loading and force transmission through the ulnar wrist and the TFCC, and support the growing consensus that integrity of the TFCC should be restored in the presence of TFCC injuries.

Wrist kinetics after scapholunate dissociation: the effect of scapholunate interosseous ligament injury and persistent scapholunate gaps

The purpose of this study was to investigate the effects of cutting of the scapholunate interosseous ligament (SLIL) and persistent widening of the scapholunate (SL) joint on changes in moment arms of the principal wrist motor tendons. In seven fresh frozen cadaveric upper extremities, excursions of the extensor carpi radialis longus (ECRL) and brevis (ECRB), extensor carpi ulnaris (ECU), flexor carpi radialis (FCR), and flexor carpi ulnaris (FCU) were recorded simultaneously with wrist joint angulation during wrist flexion–extension and radioulnar deviation. Tendon excursions were measured in intact wrists, then in the wrists with complete SLIL sectioning and in those with moderate or severe persistent SL joint widening. The data were converted to moment arms of the tendons. The results showed that moment arms of the ECRL and ECRB tendons after SLIL sectioning were, respectively, 110 ± 6% and 105 ± 3% of those in the intact wrist. In the wrists with moderate or severe SL joint widening, moment arms of the flexors significantly increased (P < 0.01 and P < 0.001, respectively). During radioulnar deviation, moment arms of the ECRL, ECRB, ECU, and FCU tendons decreased after SLIL sectioning and the SL joint widening. However, moment arms of the FCR tendon significantly increased 122 ± 23% after the SLIL section, 133 ± 28% after the moderate SL joint widening, and 138 ± 24% after the severe SL joint widening compared with those of the intact wrists. This study demonstrated that integrity of the SLIL and appropriate SL joint space are important for mechanics of wrist motor tendons. Loss of integrity of the SLIL and persistent SL joint widening increase mechanical effects of the radial side wrist motor tendons, which may contribute to the pathomechanics of scaphoid malrotation, scapholunate advanced collapse, and early osteoarthritis in the radioscaphoid joint interface seen in SL dissociation. The results also suggest that reduction of the displaced SL joint is imperative to the recovery of wrist kinetics after SL dissociation.

Anatomical basis for a fasciocutaneous flap from the hypothenar eminence of the hand

Thirty-two fresh cadaver hands were perfused with a silicone rubber compound (Microfil) and dissected to explore the vascular and neural anatomy of the hypothenar eminence, in order to assess the possibility for free or pedicled island flaps from this area. In five specimens Microfil was selectively injected into the ulnar palmar digital artery of the little finger to determine the skin territory nourished by this artery. The hypothenar eminence was divided into three territories according to the type of nutrient artery supplying each territory. Among the three territories, the distal half of the ulnar aspect of the hypothenar eminence (approximately 3 x 2 cm), located over the abductor and flexor digiti minimi muscles, had a constant vascular and neural supply from the ulnar palmar digital artery of the little finger and the dorsal or palmar cutaneous branch of the ulnar nerve. This fasciocutaneous area provides a new and feasible donor site for free or pedicled island skin flaps to repair palmar skin defects of the fingers.

Long-term results of lateral calcaneal artery flap for hindfoot reconstruction.

The purpose of the present study was to analyze our long-term results of lateral calcaneal artery flap transfer for hindfoot reconstruction. A total of four patients (average age, 48 years) underwent lateral calcaneal artery flap transfer. The etiologies were heat injury of the lateral malleolus in one patient and skin necrosis over the Achilles tendon attachment site in three patients due to displaced calcaneal fracture, pyogenic tendinitis of the Achilles tendon, and vascular insufficiency of the wound after Achilles tendon surgery in a patient with Werner syndrome, respectively. The defect sizes ranged from 2 x 2 cm to 4 x 4 cm, and all of the patients had bone or tendon exposure. All of the flaps survived completely without any problems. The donor sites were closed by full-thickness skin grafts. Postoperative complications included delayed wound healing in one patient and transient restriction of ankle motion in another patient. No painful neuroma of the sural nerve was recorded. No recurrence of ulcers at the shoe-contacting area of the flaps was noted. Therefore, lateral calcaneal artery flap transfer is useful for reconstruction of skin and soft tissue defects with bone or tendon exposure over the calcaneus or lateral malleolus.

Anatomical basis for a vascular pedicled island flap from the dorsal area of the wrist.

We explored the cutaneous vascularity of the dorsal wrist area to examine the possibility of using reverse island flaps from this area for reconstruction of the hands and fingers. Four dominant arterial branches including the dorsal branches of the ulnar and radial arteries and terminal branches of the anterior and posterior interosseous arteries, which supplied the dorsal skin over the extensor retinaculum, were explored. The location, number, and diameter of skin perforators from these arteries were examined. The dorsal branches of the radial and ulnar arteries that passed along the dorsal cutaneous nerves gave off 2–4 skin perforators (diameter 0.1–0.2 mm) at the level of the carpal bone and always connected distally to perforating arteries from the palmar arterial system at the metacarpal head. Skin perforators from the anterior and posterior interosseous arteries were found passing through the extensor retinaculum in the second and third and fifth and sixth intercompartmental areas. The terminal branches of the anterior and posterior interosseous arteries always continued to the dorsal carpal arch, and lay over the distal carpal row. It may be anatomically possible to raise two different island flaps from the dorsum of the wrist.

The effects of cyclic loading on tensile properties of a rabbit femur–anterior cruciate ligament–tibia complex (FATC)

Abstract The purpose of this study was to investigate the effect of cyclic loading on tensile properties of femur–ACL–tibia complexes (FATCs). Paired FATCs of New Zealand white rabbits were tested. One specimen of each pair was designated as a control and loaded until failure. The contralateral specimen was cyclically loaded and then loaded until failure. In specimens cyclically loaded with 40% of control ultimate tensile strength (UTS), UTS decreased significantly compared to controls. Half the specimens of the 50% group were ruptured during cyclic loading. Load-to-failure of FATCs can be decreased by cyclic loading in the range of 40∼50% of their UTS. Cycled specimens had a significantly higher incidence of intrasubstance failure pattern as compared to controls. This result correlates well with clinical experience.

A new method for the representation of articular surfaces using the influence surface theory of plates

The traditional approach to the representation of an articular surface is by using piecewise polynomial functions with a limited continuity to fit the surface from ordered data points. In this study, we introduce a new method, which is based on the influence surface theory of plates, for the representation of articular surfaces. The most significant advantage of this method is that it can effectively represent an articular surface from non-ordered data points. The effectiveness of the present method was shown by reconstruction of a human femoral surface and a mathematical cone.