1.Highly Crosslinked Polyethylene Tibial Post Fracture in the Unafflicted Limb of a Patient with Unilateral Lower Limb Poliomyelitis: A Case Report
Malaysian Orthopaedic Journal 2019;13(1):42-44
We present a unique case of tibial post fracture of a posteriorstabilised total knee arthroplasty (PS-TKA) using highly crosslinked polyethylene (HXLPE) in the unafflicted limb of a patient who had poliomyelitis. The tibial post is an upright structure perpendicular to the PE insert articular surface which articulates with the cam of the femoral component to prevent excessive posterior translation of the tibia. We explore the choice of PS polyethylene (PE) inserts in patients with neuromuscular disorders (NMD). A 74-year old gentleman presented with recurrent knee pain seven years after the index PS-TKA with HXLPE. The TKA was performed on the unafflicted left limb (contralateral to the weak side affected by poliomyelitis). The posterior drawer test was positive. During the single-stage revision surgery, the HXLPE tibial post was noted to be broken. The liner was replaced with a thicker non-HXLPE. The patient achieved an excellent outcome at one-year post-surgery. This is the first report of HXLPE tibial post fracture in the unaffected knee of a patient with NMD affecting the lower limb. The HXLPE’s reduced resistance to fatigue crack propagation might not be suitable in PS-TKA where there might be focal stress points on the tibial post, which was amplified in this case as it was the limb that the patient most depended on. When managing end-stage osteoarthritis with TKA in the unafflicted knee of a patient with NMD causing lower limb weakness, the selection of polyethylene material in PS-TKA may need more consideration than previously thought.
2.Surgical Fixation and Inter-phalangeal Arthrodesis of Symptomatic Non-union of Fracture of a Lesser Toe Distal Phalanx: A Case Report
Malaysian Orthopaedic Journal 2019;13(3):69-71
Distal phalanx fractures of the toes are common injuries. The majority of them are treated conservatively with good outcome. We present the case of a painful non-union fracture of the distal phalanx of the 4th toe in a 60-year-old female patient with symphalangism of the 4th and 5th toes. She underwent surgical fixation of the fracture with concomitant inter-phalangeal joint (IPJ) arthrodesis for better stability. A transverse dorsal incision was made just distal to the IPJ to allow preparation of both the fracture site and IPJ. Fibrous tissue at the fracture non-union site was removed and the opposing surfaces drilled with a 0.88mm Kwire. Cartilaginous tissue at the IPJ was removed and similarly drilled with the 0.88mm K-wire. Stabilisation was achieved with a percutaneous headless compression screw. Radiographic union was achieved and the patient had resolution of symptoms 16 weeks after the surgery. The patient continued to be symptom-free at one year follow-up. This is the first case report of a surgically treated symptomatic non-union of distal phalanx fracture of a lesser toe in the literature.