Bipolar clavicular injury.

While clavicular injuries are fairly common, bipolar clavicular injuries are not. They may involve dislocations at both ends of the clavicle, or a fracture at one end and a dislocation at the other. We present two cases; a patient with a bipolar clavicular dislocation, and another with a fracture in both medial and lateral ends of the clavicle with anterior dislocation of the sternoclavicular joint. Both were treated conservatively, with fairly good range of motion and return to normal activity.

Open reduction and temporary rigid internal fixation of Lisfranc fracture-dislocations.

AIM: To review the results of open reduction and temporary rigid screw fixation of Lisfranc fracture-dislocations performed in Singapore General Hospital (SGH) from 1996 to 1998. METHODS: A retrospective review of II cases of Lisfranc injuries treated with temporary rigid internal screw fixation with a minimum follow up of six months was carried out. Radiological assessment was made at follow up to ascertain the anatomical reduction achieved and complications such as post-traumatic arthritis. In addition, the patients were evaluated with a functional assessment with relation to pain, interference to usual activities and the time to resumption of work. RESULTS: Anatomical reduction was achieved in all cases. None of the cases showed loss of reduction at follow up after the temporary implants were removed. No longitudinal arch collapse or other deformities were seen. All the patients had good or excellent functional outcomes. CONCLUSIONS: Results of treatment of Lisfranc injuries are related to anatomical correction. Temporary screw fixation allows rigid internal fixation with stability to allow anatomical correction. Screws also maintain their stability longer, allowing ligamentous injuries the longer period necessary for healing. In conclusion, temporary rigid screw fixation of Lisfranc fracture maintains anatomical reduction and gives excellent functional outcomes for the patients.

Optimizing arthroscopic knots using braided or monofilament suture.

Surgeons need to know how the material properties of a suture affect the security of a surgical knot. The purpose of this study was to compare the security of some clinically important arthroscopic knots when tied using a braided multifilament suture and to draw comparisons with results of similar knots tied with monofilament suture. Permanent braided polyester suture was used to test 10 knot configurations. Eight of the knots included (1) two types of initial cinching knots followed by (2) one of four combinations of half-hitches. We also tested the taut-line hitch locked with half-hitches and the original Revo knot. Each knot was subjected to cyclic loading followed by an ultimate load to failure. Clinical failure was defined as the maximum force that resulted in 3 mm of loop displacement. Force versus displacement data were obtained, and the maximal loop holding capacities were compared statistically. The Duncan loop with switched-post half-hitches and the Revo knot (Linvatec, Largo, FL) showed the highest knot-holding capacities (mean, 87N and 92N, respectively) when compared with all other configurations (P < .0001) for braided suture. A similar knot-holding capacity was described for monofilament suture using the Duncan loop locked with switched-post, reversed-direction half-hitches (mean, 81 N). All knots without post switching slipped completely at significantly lower loads than knots with post switching (monofilament, P < .001; braided, P < .0001). When compared with results of knots tied with monofilament suture, the braided switched-post configurations had smaller cyclic displacements (braided, 0.7 mm; monofilament, 1.7 mm). Although the Revo knot showed good strength for braided suture, it was significantly weaker than other configurations when tied with monofilament suture. Therefore, it is important to test the knot strength for a given suture material before applying it clinically.

Practical guidelines to safe surgery about the subscapularis.

Surgical mobilization of an adherent or retracted subscapularis tendon is often necessary whenever an attempt is made to restore function to the glenohumeral joint subsequent to failed anterior reconstructive surgery. Surgical guidelines drawn from this study emphasize how a surgeon might accomplish this task effectively and avoid denervating the subscapularis, a muscle that is essential to anterior glenohumeral stability and strength. In this study we examined subscapularis innervation in 11 fresh-frozen cadaveric shoulders. The position of the subscapular nerve insertion points were recorded relative to easily identified surgical landmarks such as the axillary nerve, the conjoined tendon, and the anterior glenoid rim. The palpable anterior border of the glenoid rim deep to the subscapularis along with the medical border of the conjoined tendon can serve as guides to the subscapularis nerve insertion points, because all the nerves are no closer than 1.5 cm medial to these landmarks for all positions of humeral rotation in the unelevated arm. The lower subscapular nerve was found immediately posterior or just lateral to the axillary nerve. During a standard deltopectoral approach potential injury to the subscapularis innervation can be minimized by locating and protecting the axillary nerve, because it serves as a guide to the insertion point of the lower subscapularis nerve, the nerve closet to the surgical field.

Congenital perforations of the triangular fibrocartilage of the wrist.

A cadaveric study of the triangular fibrocartilage of the wrist in the foetus and infant revealed a high incidence of congenital perforation. In the second half of the study, wrist arthrography in foetal and infant cadavers with crown-rump length of more than 20 cm followed by dissection of the wrist joints showed good correlation between the two. In 60 cadavers there were 11 with bilateral perforations and five had unilateral perforation. This gave a total of 27 perforations in 120 wrist joints studied.

Optimizing arthroscopic knots.

Arthroscopic repairs, such as those for shoulder instability, are commonly performed. However, the failure rate after arthroscopic repair appears to be higher than with open surgery. These failures may relate to the challenge of tying secure knots arthroscopically. Many knots tied arthroscopically commonly consist of an initial slip knot to remove slack, and a series of half-hitches. Half-hitches, instead of square throws, are difficult to avoid and result when asymmetrical tension is applied to the strands. For this reason, the security of knots tied arthroscopically may not be equivalent to square knots and a greater rate of failure may occur. The purpose of this study was to determine (1) the security of various arthroscopic knots under cyclic and peak loading conditions, (2) how the surgeon can modify the method or sequence of half-hitch throws to minimize knot slippage or breakage, and (3) whether using an arthroscopic knot pusher affects the security of the same knot tied by hand. The most secure knot configurations were achieved by reversing the half-hitch throws and alternating the posts. These knots performed significantly better than all other knots tested (P < .002). Thus the surgeon can control the holding capacity and minimize suture loop displacement by proper alternation of the tying strands and reversal of the loop when placing the hitches.(ABSTRACT TRUNCATED AT 250 WORDS)