Perhaps you are tired of seeing loosening and pistoning with first metatarsophalangeal joint (MPJ) implants. Perhaps you are trying to alleviate the concerns of a patient who is apprehensive about a fusion procedure and wants to maintain some degree of motion in the first MPJ. Perhaps you are looking for an alternative implant that is technically straightforward.
One option is metatarsal resurfacing of the first MPJ with the HemiCAP Dorsiflexion Implant System (Arthrosurface). The company notes the implant offers a threaded taper post, a morse taper interlock and inlay design that ensure optimal fixation in the metatarsal bone and reduce shear forces that can lead to loosening.
“The technological design of the taper post is superior to other implant systems because it will not loosen, rotate or piston,” explains Randy Kittleson, DPM, who is affiliated with UW Health, a multispecialty group associated with the University of Wisconsin. “Additionally, the taper post allows the surgeon to decompress the joint and therefore the total peak height of the implant without compromising stability.”
“(The HemiCAP Dorsiflexion Implant) certainly holds better in the bone as you are screwing it into the medullary canal,” notes Daniel J. Tucker, DPM, FACFAS, who has performed more than 50 procedures with this implant.
Drs. Kittleson and Tucker both cite the straightforward design of the implant and its ease of use. The availability of multiple contours of the articular component of the implant allows for variability in the anatomy of the first MPJ, according to Dr. Kittleson.
The newer design with the HemiCAP Dosiflexion implant “allows better dorsal excursion of the hallux on the first metatarsal head,” points out Dr. Tucker, a Diplomate of the American Board of Podiatric Surgery. Dr. Kittleson adds that the HemiCAP device is also available with a dorsal flange, which prevents bone overgrowth of the implant.
Dr. Tucker notes that the implant is not only easy to place but it is easy to remove if you have to convert to a salvage procedure. He notes that implant removal wouldn’t remove any bone with it. Dr. Tucker adds that the HemiCAP Dorsiflexion implant works well in patients with questionable bone stock.
Dr. Tucker says the HemiCAP Dorsiflexion implant is for patients who are not ready to pursue fusion of the great toe joint but aren’t getting results from conservative therapy.
“This implant restores motion to the joint so people can hold on to some functional capacity,” notes Dr. Tucker.
In regard to appropriate indications, Dr. Tucker says the HemiCAP dorsiflexion implant is not for end-stage hallux rigidus or those with significant arthritic changes of the sesamoids. He notes that he also wouldn’t use the implant in marathon runners or those who engage in impact activities.
Overall, Dr. Tucker says he had not had any failures with the HemiCAP Dorsiflexion implant and has some patients who are three and four years out after undergoing the procedure. Dr. Kittleson has used the HemiCAP implant system for nearly six years.
“I would venture to say that collectively thousands of patients have benefited from the HemiCAP implant,” notes Dr. Kittleson.