Long-term Results of Hemiarthroplasty for Osteoarthritis of the First Metatarsophalangeal Joint
Authors: Beekhuizen Stefan , Onstenk Ron 
Published: September 2017

Category: Big toe, MTP-1 joint osteoarthritis Introduction/Purpose: Osteoarthritis of the first metatarsophalangeal joint is the second most common disorder affecting the hallux. If non-operative treatment is not efficacious, operative treatment should be considered. Arthrodesis is considered standard care for grade III and IV osteoarthritis of the first metatarsophalangeal joint. If preservation of joint mobility is preferred, implant arthroplasty could be considered. Total arthroplasty is less recommendable because of high failure rates. However, recent studies showed similar short term results after arthrodesis and hemi joint replacement with greater satisfaction rates, as well as low postoperative pain, after hemiarthroplasty. In our study we mainly focussed on long-term subjective results like patient satisfaction as well as patient recommendation for the performed procedure including our primary outcome; the postoperative AOFAS HMI score. Methods: We therefore evaluated primary arthrodesis and hemiarthroplasty as treatment for arthritis of the first metatarsophalangeal joint. All 102 patients operated between January 2005 and December 2011 were asked to participate in our study, sixty-seven patients responded and were included. Forty-seven arthrodesis were performed in 40 patients using different fixation techniques and thirty-one hemiarthroplasties were performed in 27 patients using the BiopPro® First MPJ implant. Both procedures performed for stage 3 or 4 osteoarthritis and patients had been followed for at least five years, the American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal (AOFAS-HMI) scale score was measured as primary outcome. Secondary outcomes addressed satisfaction rates, recommendation of the performed procedure, number of unplanned surgical repeat procedures, return to daily activities (work as well as sports), and influence of smoking and diabetes mellitus on postoperative results. Finally, financial costs for both procedures were calculated. Results: The 47 primary arthrodeses and 31 hemiarthroplasties performed between January 2005 and December 2011 were evaluated. After a mean follow-up of 8.3 years (range 5-11.8) the mean AOFAS-HMI scale score after arthrodesis and after hemiarthroplasty were 72.8±14.5 and 89.7±6.6 respectively (p =.001). Patients were significantly more pleased after hemiarthroplasty (p<.001) and this procedure was better recommended (p<.001). The number of unplanned repeat surgical procedures did not differ between the two groups. No differences were found in postoperative work resumption, but patients returned to sports significantly sooner after hemiarthroplasty (p=.002). No association was found between smoking and the total AOFAS-HMI score. Overall costs, the sum of procedure costs as wel as additional costs, were quite similar for both procedures. Conclusion: Higher postoperative AOFAS HMI scores after a long-term follow-up (mean 8.3 years, range 5-11.8 years) were found after hemiarthroplasty compared to arthrodesis of the MTP-1 joint. Also greater patient satisfaction and better recommendation is seen after hemiarthroplasty. However return to work showed no differences, a significantly faster return to sports was seen after hemiarthoplasty. Based on these long-term results we could recommend hemiarthroplasty in future patient with osteoarthritis of the MTP-1 joint, with modest preference for the younger, more active patients.