Four-corner arthrodesis concentrator of nickel-titanium memory alloy for carpal collapse: a report on 18 cases.

PURPOSE: To evaluate the treatment of carpal collapse using a four-corner arthrodesis concentrator of nickel-titanium memory alloy. METHODS: From August 2006 to August 2010, 18 patients with carpal collapse had scaphoid excision and four-corner (capitate, lunate, triquetrum, and hamate) arthrodesis using a nickel-titanium memory alloy four-corner arthrodesis concentrator. The mean follow-up time was 30 months (range, 12-48). Various wrist parameters, including grip strength, wrist motion, and degree of pain were recorded and compared before and after surgery. RESULTS: The average fusion time was 2.3 months (range, 2-4). Neither nonunion nor wound infection was found in any of the patients. At one year follow-up, the grip strength had reached 80% of that of the healthy side, whereas the range of motion was greater than 50% of the contralateral side. After the surgery, the mean pain scores were improved. CONCLUSIONS: Four-corner arthrodesis using a nickel-titanium memory alloy four-corner arthrodesis concentrator effectively treated carpal collapse and preserved most wrist function.

Four-corner arthrodesis concentrator of Ni-Ti memory alloy for carpal collapse.

OBJECTIVE: To evaluate the treatment outcomes of a four-corner arthrodesis concentrator of Ni-Ti memory alloy for carpal collapse. METHODS: From August 2006 to November 2009, 13 patients with carpal collapse underwent scaphoid excision and four-corner (capitate, lunate, triquetrum and hamate) arthrodesis using a four-corner arthrodesis concentrator of Ni-Ti memory alloy. The mean follow-up time was 26.5 months (range, 7-38 months). Various wrist parameters, including the grip strength, range of wrist movements and degree of pain (visual analogue scales) were recorded and compared before and after surgery. RESULTS: The average fusion time was 2.3 months (range, 2-4 months). Neither non-union nor wound infection was found in any of the patients. By the sixth month postoperatively, the grip strength had reached an average of 32.49 ± 6.21 kg with a range of 22.3-39.7 kg, this being 80.8% of that found on the healthy side. The range of motion reached over 53.0% of that of the healthy side. Preoperatively and at 6 months postoperatively, the mean pain scores were (4.46 ± 1.27) and 1.31 ± 0.95, respectively, when resting (P < 0.05), and 7.00 ± 1.41 and 2.62 ± 1.26, respectively, when weight-bearing (P < 0.05). The mean value of the Krimmer wrist score was 79.2 (range, 64-84). The rate of excellent and fine results was 84.6% (11/13), being excellent in three cases, good in eight and fair in two. CONCLUSION: Four-corner arthrodesis using a four-corner arthrodesis concentrator of Ni-Ti memory alloy is an effective method for treating carpal collapse and preserving most wrist function.