Fate of the infrapatellar branch of the saphenous nerve post total knee arthroplasty.

Background: The infrapatellar branch of the saphenous nerve is a known cause of morbidity following knee surgery. The incidence of sensory changes following total knee arthroplasty, and its effect on patient satisfaction with arthroplasty surgery remain undocumented. Our aim was to document the incidence of infrapatellar nerve palsy following total knee arthroplasty and its effect on patient satisfaction.

Methods: Between 1 January 2002 and 31 December 2003 all patients attending outpatients clinic for primary total knee joint arthroplasty were prospectively tested for sensory defects. Patients were then assessed postoperatively and satisfaction was measured using the British Orthopaedic Satisfaction Score and a visual analogue scale.

Results: Thirty-one patients satisfied inclusion criteria of which 21 agreed to participate. One patient was excluded later in the study leaving 20 patients. Seventy per cent of patients had sensory changes in the area supplied by the infrapatellar branch of the saphenous nerve. Patient satisfaction scores did not correlate to the presence of a sensory deficit. Two patients stated that the sensory deficit was a significant factor in their dissatisfaction with their arthroplasty surgery.

Conclusions: Sensory changes due to damage to the infrapatellar branch of the saphenous nerve during total knee joint arthroplasty is a common occurrence and can interfere with patient satisfaction. Patients should be informed of this risk in the preoperative discussion.