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

To evaluate the treatment outcomes of a four-corner arthrodesis concentrator of Ni-Ti memory alloy for carpal collapse.

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.

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.

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.