In vitro biomechanical evaluation of the double loop suture for flexor tendon repair.

Fifty-one fresh frozen human anatomic specimen flexor superficialis and profundus tendons that had been transected completely were repaired using the double loop, the single loop, and the modified Kessler techniques, and the resistances to mechanical distraction at 1, 2, and 3 mm and the ultimate load to failure were compared. The mechanical distraction at 1, 2, and 3 mm created nearly identical gaps at the tendon repair sites. There was no significant difference among the three repair techniques to resisting distraction at 1 and 2 mm. However, the double loop technique presented a mean resistance force of 22.0 N to distraction at 3 mm and 45.8 N in load to failure, which was significantly greater than the single loop (18.8 N at 3 mm distraction and 31.5 N failure load) and the modified Kessler (19.0 N at 3 mm distraction and 26.0 N failure load). This suggests the double loop technique may be superior to the single loop and the modified Kessler techniques in resisting gap in the range of forces generated in the early rehabilitation protocol.

Elbow ligament strain under valgus load: a biomechanical study.

This study assessed the importance of the anterior and posterior bundles of the medial collateral ligament in the elbow by measuring in situ strain in response to valgus loads at three positions of forearm rotation throughout a full arc of motion. Strain in the anterior bundle was significantly greater than in the posterior bundle and increased with more flexion. The anterior bundle developed strain at a lower flexion angle (30 degrees) than the posterior bundle (60 degrees). Strain ratio increased with load increase for all flexion angles. Forearm position minimally affected strain. These results indicate that the anterior bundle is important in resisting a valgus load, particularly in mid-flexion, while the importance of the posterior bundle increases as the elbow approaches full flexion.

Use of the medial intermuscular septum as a fascial sling during anterior transposition of the ulnar nerve.

A new technique using the released medial intramuscular septum as a fascial or fasciodermal sling to prevent posterior subluxation of the ulnar nerve following subcutaneous transposition is described. The technique is simple and prevents subluxation, yet it still allows free excursion of the ulnar nerve and postoperative rehabilitation is begun immediately.

Wrist arthrodesis. Technique and functional evaluation.

Wrist arthrodesis is a reliable procedure that, although it sacrifices motion for stability, provides the patient with relief from pain. This review of 26 wrist arthrodeses performed in 24 patients using the AO technique, with plate and screw fixation and iliac crest bone graft, shows a 100% union rate and high patient satisfaction. Using a questionnaire, the patients revealed that they adapted to their fused wrists but still had difficulty with some activities, such as getting the hand into tight places, heavy lifting, and positioning the hand for some specific activities. The most common complication was fracture at the ends of the plate. Removal of the plate after solid healing of the fusion is recommended strongly.

Effectiveness of the chevron arthrodesis in small joints of the hand.

The chevron arthrodesis technique for small joints in the hand was used in 98 joints in 71 operations on 53 patients. Successful fusion was obtained in all cases in an average of 9 weeks. There were 2 minor infections and 1 malunion. The chevron arthrodesis technique is technically easy while offering the advantage of a large surface area of cancellous bone for fusion.

Toxic gas exposures in ice arenas.

OBJECTIVE: To determine the number of states with laws monitoring toxic gases in ice arenas. To inform physicians who care for ice skaters of the dangers of carbon monoxide and nitrogen dioxide exposure in ice arenas. DESIGN: Survey, literature review. PARTICIPANTS: Health Departments of the 50 states and Washington D.C. ASSESSMENT OF RISK FACTORS: At risk are users of ice arenas. Vigorous exercise (hockey or competitive figure skating) and underlying pulmonary or cardiovascular disease increase the risk toxicity. Toxic gas concentration is determined by the amount of production from internal combustion engines, effectiveness and use of the ventilation system, and the "cold air pool" over the ice. MAIN OUTCOME MEASURES: Number of states with laws regulating toxic gases in ice arenas. RESULTS: Only two states (Minnesota and Rhode Island) have laws regulating toxic gases in indoor ice areas. CONCLUSIONS: Physicians and the public are generally unaware of this problem. Toxic gas exposure in ice arenas is under recognized and underreported. The risks are not documented in journals generally seen by physicians who care for skaters. Conversion to electric ice resurfacing machines--the best solution--is not economically practical; legislation on the monitoring of toxic gas levels offers a reasonable alternative.

Anomalous hand muscle found in the Guyon's canal at exploration for ulnar artery thrombosis. A case report.

A diagnosis of ulnar artery thrombosis should be considered when a patient reports symptoms of ulnar neuropathy, ischemia in the hand, or a mass in the hypothenar area. A history of repetitive blunt trauma to the hypothenar area is particularly suggestive of this. Ulnar artery thrombosis is possibly associated with an anomalous muscle in the Guyon's canal. The anomalous muscle in this case originated on the flexor carpi ulnaris muscle, was ulnarly innervated, and joined the flexor digiti minimi muscle distally. This patient had a history of blunt injury and a significant smoking history, thus, a causal relationship between the anomalous muscle and ulnar artery thrombosis cannot be stated with certainty.

The effect of the radial head and prosthetic radial head replacement on resisting valgus stress at the elbow.

Five fresh nonembalmed elbows were tested for resistance to valgus stress in their anatomic state, after radial head resection, and after insertion of Silastic and polymethylmethacrylate (PMMA) radial head replacements. The resistance to valgus stress was found to be reduced an average of 28% after radial head resection. The PMMA and Silastic implants restored valgus stiffness an average of 86% and 78% respectively, as compared to intact elbow values for corresponding flexion angles. Testing in pronation, supination and neutral forearm rotation demonstrated no difference in valgus stiffness. For each elbow, resistance to valgus stress was greatest at full extension and dropped approximately 30% at all other flexion angles as compared to corresponding full extension value. These data support the concept of the radial head as a stabilizer to valgus stress in the in vitro elbow. Further, this data demonstrated the ineffectiveness of current radial head replacement systems in restoring this biomechanical function and suggest that the use of a stiffer implant material may be beneficial in resisting valgus stress. Additional testing is indicated to determine the performance of a stiffer implant at the clinical and biological levels.