A Comparative Study of Tensile Strength of Three Operative Fixation Techniques for Metacarpal Shaft Fractures in Adults: A Cadaver Study

BACKGROUND: We sought to estimate the ultimate tensile strength after metacarpal shaft fracture repair in adults using three operative fixation methods: plate fixation, Kirschner wire (K-wire) fixation, and intramedullary headless compression screw fixation. We also compared the advantages and disadvantages of each operative technique. METHODS: We acquired 30 metacarpal bones from four Korean adult cadavers without trauma, operative history, or deformities. The 30 metacarpal bones were divided into ten groups consisting of three metacarpal bones each with matching sizes and lengths. They were fractured, reduced, and fixed with plate and screws, K-wires, or headless compression screws. We performed force testing, collected ultimate tensile strength data, and created a stress-strain graph. RESULTS: The ultimate tensile strength of ten groups according to the fixation method was as follows: late and screw fixation, 246.1 N (range, 175.3 to 452.4 N); K-wire fixation, 134.6 N (62.7 to 175.0 N); and intramedullary headless compression screw fixation, 181.2 N (119.2 to 211.7 N). The median tensile strength of each fixation method was significantly different. In addition, the post-hoc test showed significant difference between the plate and screw fixation and K-wire fixation, between the headless compression screw fixation and K-wire fixation, and between the headless compression screw fixation and plate and screw fixation. CONCLUSIONS: The tensile strength median values decreased in the following order showing significant differences among the fixation methods: plate and screw fixation, headless compression screw fixation, K-wire fixation. Significant differences were also observed between the plate and screw fixation and K-wire fixation, between the headless compression screw fixation and K-wire fixation, and between the headless compression screw fixation and plate and screw fixation.

Percutaneous Retrograde Intramedullary Pin Fixation for Isolated Metacarpal Shaft Fracture of the Little Finger

PURPOSE: To evaluate the anatomic and functional outcome of retrograde intramedullary single wire fixation for metacarpal shaft fractures of the little finger. MATERIALS AND METHODS: hirty one consecutive patients with closed metacarpal shaft fractures of the little finger who have been treated with retrograde intramedullary single wire fixation were evaluated. Fracture union and angulation were analyzed radiologically, and clinical evaluations were performed including range of motion, DASH score and complications. RESULTS: Fracture union was achieved in all cases and callus formation was obvious at postoperative 41 days. Average angulation of fracture site was 3degrees in the coronal plane and 1.2degrees in the sagittal plane at the last follow up and no measurable metacarpal shortening was observed. Mean TAM was 253degrees and DASH score was 2.6. There were two cases of pin migration as intermediate complications. CONCLUSION: Closed reduction with subsequent percutaneous retrograde K-wire fixation produced good radiological and functional results. We recommend this minimally invasive technique which provides adequate fixation of displaced little finger metacarpal shaft fractures with good functional results and low morbidity.

Treatment of Metacarpal Shaft Fractures with Retrograde Intramedullary Kirschner-Wire Fixation

PURPOSE: The purpose of this study is to evaluate the clinical results of retrograde intramedullary fixation of metacarpal shaft fractures using two pre-bent Kirschner wires. MATERIALS AND METHODS: Between March 2006 and May 2008, 19 cases (17 patients) of metacarpal shaft fractures were treated with the retrograde intramedullary Kirschner-wire fixation and followed at least one year. The exclusion criteria were thumb metacarpal fractures, comminuted fractures and irreducible metacarpal spiral shaft fracture by closed manipulation. At final follow up all the cases were assessed with total active motion(TAM), rotational deformity, bony union and angular deformity based on the plain radiographes. RESULTS: At the last follow-up, all cases achieved bony union. Five cases showed less than 5degrees of dorsal angular deformity. The average union period was 6.3 weeks (range, 5-9weeks). Fifteen cases (79%) showed excellent results, four cases good results based on TAM. No case showed rotational deformity. Two cases had skin irritation by distal wire end, which was subsided after wire removal. CONCLUSIONS: In patients with a metacarpal shaft fracture, retrograde intramedullary fixation using two pre-bent K-wires can provide satisfactory clinical results.

Operative Treatment of Metacarpal Shaft Fracture>: Comparision of Low-Profile Miniplating System and Kirschner Wire Fixation

PURPOSE: To compare Kirschner wire fixation and low profile miniplating system in metacarpal shaft fracture. MATERIALS AND METHODS: Patients, available at least 1 year, who received the operative treatment after being diagnosed as metacarpal shaft fracture from 1997 May to 2003 May were the subjects with the exclusion of thumb fracture and intraarticular metacarpal bone fracture and also cases involving Kirschner wire fixation on severe laceration or open fracture. On the last follow up total action motion (TAM) and plain radiographes was checked. RESULTS: In 7 cases (38.9%) where closed reduction and Kirschner wire fixation were carried out, 8 cases (61.5%) where open reduction and Kirschner wire fixation were carried out and 24 cases (88.9%) where open reduction using miniplate and screw showed either excellent or good results on TAM. 5 cases of dorsal angulation occured in closed reduction and Kirschner wire fixation group and 4 cases of dorsal angulation in open reduction and Kirschner wire fixation group however no cases of dorsal angulation occured in open reduction and miniplate and screw fixation group, and in all cases no rotational deformity, complications through ulnar or radial angulation occured. Internal fixation was carried out on 2 cases of nonunion which had closed reduction and Kirschner wire fixation carried out, while the rest all showed bony union. CONCLUSION: Selective use of low profile miniplate and screw fixation in the metacarpal shaft fracture is more effective than in cases of comminuted fracture which can not be achieved firm fixation by Kirschner wire fixation. Low profile miniplate and screw fixation can get more precise anatomical reduction and firm fixation so it allow early return to daily living activity and show low complication rate.