Developing a standardized test for the assessment of suturing skill in novice microsurgeons.

Suturing performance was assessed for 13 novice microsurgeons throughout a 4-5 day microsurgical training course. Time to complete a suture (from needle insertion to completion of tie-off) was assessed on a standardized suture task, for two sutures at the beginning and end of each training day. For days 2-4, suturing performance with actual tissue was also assessed at both the beginning and end of each day. An average learning curve for suturing performance on the standardized test was developed and demonstrated huge performance improvement. A consistent and significant relationship existed between trainees' performance on the standardized suturing test and suturing of actual tissue. Thus the standardized test appears both to reflect actual suturing performance and to be sensitive to improvements in suturing skill that result from practice.

Perichondrial arthroplasty in a canine elbow model: comparison of vascularized and nonvascularized techniques.

The purpose of this study was to use a canine model to compare the ability of vascularized and nonvascularized perichondrial grafts to resurface an experimental joint defect. In five adult mongrel dogs, a 3 x 2 cm segment of perichondrium, subtended by the intercostal-internal mammary vessels, was harvested and transplanted to a surgically created defect on the ulnar condyle of the humerus. A similar defect in the opposite elbow was repaired with a 3 x 2 cm standard perichondrial graft. Five untreated dogs acted as normal controls. The dogs were allowed to mobilize freely for a period of 6 months. At that time, angiography demonstrated that all microvascular anastomoses were patent. There was no statistical difference in the range of motion of the two elbows, in the radiographic appearance, or in bone density of the two groups of joints. Histologic assessment demonstrated that the vascularized perichondrium formed an articular cartilage with an average thickness of 21.8 microns as compared with 38.5 microns for the nonvascularized perichondrium (p < 0.05). The cartilage in both grafts was morphologically hyaline in type. There were degenerative changes in the grafts with partial separation of the graft from the underlying bone and formation of surface clefts or pits, villous projections, and synovial proliferation. Degenerative changes also were observed on the articular surface opposite the grafted humeral condyle. In two animals the grafts displaced from the recipient condyle, which instead became resurfaced by greater amounts of hyaline-type cartilage with lesser degrees of degeneration and subarticular fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

The free medial scapular osteofasciocutaneous flap for head and neck reconstruction.

A modification of the scapular free flap has been developed using the medial ridge of the scapula. This variation preserves the advantages of the previously described lateral scapular flap, providing abundant hairless skin and soft tissue, adequate bone for mandibular reconstruction, and a primarily closed asymptomatic and inconspicuous donor site. It adds the advantage of a longer vascular pedicle and enhanced versatility because it is independent of the parascapular artery. Furthermore, it eliminates the disadvantage of rotator cuff muscle weakness associated with the lateral scapular flap. Multiple skin paddles subtended by the common circumflex cutaneous scapular artery and the interconnecting dorsal thoracic fascia were used in 4 of the 9 patients in our series. The ability of this somewhat thinner bone to incorporate biointegrable implants is unproven.

Differential staining of different types of peripheral nerve and muscle.

We modified Ungewitter's (1951) and Beermann and Cassens' (1976) non-selective silver methods for peripheral nerve axons and their terminals by lengthening the time for the prestaining treatment of sections, adjusting the times of various stages of the staining procedures and selecting reagents with minimal chloride and sulphate impurities. These methods were applied to Bouin's fixed material embedded in wax with serial sections up to 100 micron thick, cut longitudinally. The Ungewitter modification stained sensory axons and their terminals very well but failed to give good impregnations of motor fibres. In addition, it marked intrafusal muscle fibres with a peppery silver deposit while sparing extrafusal fibres. The Beermann and Cassens method yielded excellent details of motor axons and their terminals but results were very poor on sensory fibres. Both sensory and motor methods worked regardless of whether the neural elements were mature, regenerating, or neonatal. Both methods consistently yielded pale backgrounds in these thick sections.