Background and aims: The interpositional arthroplasty was developed to retain foot function and to relieve pain due to the arthritis of the first metatarsophalangeal joint. The bioabsorbable poly-L-D-lactic acid RegJoint® interpositional implant provides temporary support to the joint, and the implant is subsequently replaced by the patient's own tissue. In this study, we retrospectively examined the results of the poly-L-D-lactic acid interpositional arthroplasty in a 9-year follow-up study among patients with hallux valgus with end-stage arthrosis or hallux rigidus.
Material and methods: Eighteen patients and 21 joints underwent interpositional arthroplasty using the poly-L-D-lactic acid implant between February 1997 and October 2002 at Tampere University Hospital. Of these, 15 (83.3%) (21 joints) patients were compliant with clinical examination and radiographic examination in long-term (average 9.4 years) follow-up. The mean age of the patients was 48.3 (from 28 to 67) years at the time of the operation. Six patients underwent the operation due to arthritic hallux valgus and nine patients due to hallux rigidus.
Results: The mean Ankle Society Hallux Metatarsophalangeal-Interphalangeal Scale and visual analogue scale (VAS) for pain scores improved after the operation in all patients. The decrease of pain (visual analogue scale) after the operation was statistically significant (77.5 vs 10.0; p < 0.001). Postoperative complications were observed in 3 (14.3%) joints of two hallux rigidus patients. For these patients, surgery had only temporarily relieved the pain, and they underwent reoperation with arthrodesis.
Conclusion: In conclusion, interpositional arthroplasty using a poly-L-D-lactic acid implant yielded good results. This study indicates that the poly-L-D-lactic acid interpositional implant may be a good alternative for arthrodesis for treatment of end-stage degeneration of the first metatarsophalangeal joint.
Keywords: Interposition arthroplasty; hallux rigidus; hallux valgus; long-term follow-up; operative technique; poly-L-D-lactic acid implant.