Two-component implant more effective than K-wire fixation for hammertoe correction

LONG BEACH, Calif. — A modular two-component implant was found to be more effective both clinically and radiographically compared with standard K-wire fixation for hammertoe correction, pain reduction, quality of life improvement and ambulatory activity, according to data presented at the American Orthopaedic Foot & Ankle Society Annual Meeting.

According to Charles Zelen, DPM, radiographic union was observed in 83% of patients who received the modular two-component implant, compared with only 14% of patients who received K-wires.

“Why did the nonunion occur with the K-wires? Lack of compression, lack of rotational stability and thermal necrosis,” Zelen said.

Charles Zelen

Zelen and colleagues performed a prospective, randomized, comparative effectiveness trial to analyze 58 patients’ outcomes after undergoing two different procedures to correct hammertoes with arthrodesis of the proximal interphalangeal joint. Group one comprised 29 patients who were treated with standard arthrodesis including PIP joint resection followed by percutaneous stabilization using K-wire, and group two comprised 29 patients who underwent treatment with a unique modular two-component implant. Follow-up occurred at 1, 3 and 6 weeks and at 3 months and 6 months. The researchers recorded medication use and adverse events.

“Our primary outcome was radiographic evaluation. We actually had third-party validators evaluate the radiographs in order to assess position and osseous union,” Zelen said. Postoperative patient experience and satisfaction were evaluated with the Bristol Foot Score (BFS) and Foot Function Index (FFI).

The researchers noted complete osseous union in 24 patients (83%) in group two at the final radiographic evaluation compared with four patients from group one. According to Zelen, BFS and FFI were neither statistically nor significantly different between the two groups at baseline.

“For the BFS and FFI at 1 week, 3 weeks and 6 months, the patients with the two-component implants did do statistically significantly better than the K-wire group, but at 3 months, when patients were getting back to running and their regular activity, there was absolutely no difference between the groups,” Zelen said. “Once we got to 6 months, there was, again, a highly statistically significantly improvement in the patients that had the unique two-component implants vs. the K-wire.” – by Monica Jaramillo

Reference:

Zelen C. Prospective randomized multicenter comparative effectiveness study comparing two component modular digital implant versus K-wire fixation for surgical correction of hammertoes. Presented at: American Orthopaedic Foot & Ankle Society Annual Meeting; July 15-18, 2015; Long Beach, Calif.

Disclosures: Zelen reports no relevant financial disclosures.