Minimally invasive surgery versus an arthroscopic procedure for the first metatarsophalangeal arthrodesis: A comparative study of the effectiveness and safety profile.

INTRODUCTION

First metatarsophalangeal (MTP) arthrodesis is a common procedure for treating degeneration in the MTP joint. Open arthrodesis is a conventional procedure that provides acceptable results but is more invasive than minimally invasive or arthroscopic arthrodesis. However, little is known about the different outcomes between minimally invasive surgery (MIS) and arthroscopic surgery (AS) for MTP arthrodesis. This study was performed to compare the outcomes of the first MTP joint preparation for arthrodesis regarding the effectiveness of articular surface preparation and safety between MIS and the arthroscopic procedure in cadaveric specimens.

METHODS

Sixteen cadaveric feet were collected in this study from eight cadavers. The potential exclusion criteria were significantly decomposed or deformed joint. All feet were randomly allocated into two groups, eight feet for the MIS (under fluoroscopic control) group and eight feet for the arthroscopic group. One foot in the AS group was excluded because the position of an arthroscopic portal was incorrect. All feet were operated on by four fellowship-trained foot and ankle orthopedic surgeons who also had prior clinical experience with the arthroscopic and minimal invasive procedure. Following a complete procedure in each specimen, all feet were dissected and the areas of joint preparation on the metatarsal and phalangeal sides were recorded via photography and the ImageJ program. Injury to the adjacent structure was noted in each specimen. All data were analyzed via the IBM SPSS program version 22 and GraphPad to compare the outcomes between the two groups.

RESULTS

The average age of the cadavers was 68.6 ± 12.3 years. The average areas of joint preparation on the metatarsal and phalangeal sides were 136.97 and 99.08 mm, respectively. The average areas of joint preparation on the metatarsal sides were 154.26 and 117.21 mm in the MIS and arthroscopic groups, respectively (p value = 0.353). The average areas of joint preparation on the phalangeal sides were 82.46 and 118.08 mm in the MIS and arthroscopic groups, respectively (p value = 0.151). Regarding the ratio of prepared area/mean estimated fusion contact area, there was no significant difference of a ratio on metatarsal side with p value as 0.285. However, a higher level of ratio on phalangeal side was found in the arthroscopic group with p value as 0.085. For the safety profiles, the rate of adjacent injury was insignificantly higher in the MIS group (37.5%) than the arthroscopic group (0%) (p value = 0.20). All injuries were found at the extensor hallucis longus tendon.

CONCLUSIONS

There were no significant differences of the effectiveness of articular surface preparation between the MIS and arthroscopic groups. However, the arthroscopic procedure seemed to provide higher rate of prepared surface area on phalangeal side and be safer to the adjacent structures than MIS for this arthrodesis.