title: Painful pretibial pseudocyst at bioabsorbable interference screw aperture two years after anterior cruciate ligament reconstruction.
abstract: We report the case of a patient with a painful subcutaneous nodule, measuring 13 mm × 17 mm, at the pretibial graft aperture site, which presented two years after a successful anterior cruciate ligament reconstruction with an autologous hamstring graft. A bioabsorbable poly-L-lactide interference screw was used for graft fixation at the tibial aperture. The patient underwent surgical excision of the lesion and curettage at the tunnel aperture. Grossly, extruded fragments of the screw and a thick pseudocapsule of surrounding tissue were excised. There was no communication between the tunnel aperture and the knee joint. The graft was also intact. Histological analysis revealed fragments of the bioabsorbable material in association with fibrous and granulomatous chronic inflammatory cells. This was consistent with a foreign body reaction. The patient subsequently recovered and resumed preinjury level of activity. To the best of our knowledge, this is the first report describing a nodular granulomatous type reaction to foreign bioabsorbable poly-L-lactide screw material subsequent to an anterior cruciate reconstruction surgery.
authors.affiliation: Department of Orthopaedic Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433. sheny_mike@hotmail.com.
authors.forename: Michael Xuanrong
authors.initials: MX
authors.lastname: Shen
authors.forename: S S
authors.initials: SS
authors.lastname: Sathappan
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects* / Q000379:methods; D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology*; D001845:Bone Cysts / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D001863:Bone Screws / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint; D008279:Magnetic Resonance Imaging; D008297:Male; D011183:Postoperative Complications; D012086:Reoperation; D013977:Tibia; D055815:Young Adult