Usefulness of bioabsorbable thread pins after resection arthroplasty for rheumatoid forefoot reconstruction.

BACKGROUND: Bioabsorbable thread pin has been used for internal fixation of bone. The results of resection arthroplasty of the lesser metatarsophalangeal (MTP) joints using internal intramedullary fixation with bioabsorbable pins have not been reported.

METHODS: Resection arthroplasty of the MTP joints of the lesser toes with poly-L-lactic acid (PLLA) thread pins or Kirschner wires was performed at random in reconstruction of the 87 rheumatoid forefeet (62 patients) with a grommet-protected silicone-rubber implant insertion of the first MTP joint. Clinical symptoms, the state of radiographic changes, and complications were assessed 5-10 years (average, 7.7 years) postoperatively.

RESULTS: The mean American Orthopaedic Foot and Ankle Society clinical scores at the preoperative and latest points were 31 and 91, respectively, in the operated patients with PLLA pins, while the mean scores were 32 and 82, respectively, in the operated patients with Kirschner wires. The lesser toes treated by bioabsorbable pins did not become rigid, although they were stable. Recurrent dorsal subluxation of the lesser MTP joints was visible on radiographs in three of the 46 feet with PLLA pins, while two feet had three dislocated MTP joints and one subluxated MTP joint postoperatively and recurrent dorsal subluxation of the lesser MTP joints was visible in four of the 41 feet with Kirschner wires. The postoperative hallux valgus did not progress to the preoperative level during the follow-up period in both groups. Two of the 46 feet with PLLA pins and two of the 41 feet with Kirschner wires had radiographic evidence of silicone synovitis without pathological fracture. Three patients with Kirschner wires had wire-track infection, and one patient had severe circulation disturbance of the corrected lesser toes necessitating wire removal.

CONCLUSIONS: A new trial of internal fixation with bioabsorbable pins may lead to the establishment of a safe method for enhancing stability of the lesser toes after resection arthroplasty of the lesser MTP joints.