Lengthening of knee flexor muscles by percutaneous needle tenotomy: Description of the technique and preliminary results.

Background: Knee flexion contractures occur frequently in non-ambulatory, aged persons and persons with central nervous system lesions, rendering positioning and nursing care difficult. There are often risks associated with surgical interventions.
Objective: To evaluate the effectiveness of percutaneous needle tenotomy to lengthen the knee flexor muscles and improve passive function.
Methods: This was a retrospective study of all patients who underwent percutaneous needle tenotomy between 2012 and 2014. Tenotomy was carried out in the semi-tendinosus, biceps femoris and gracillis muscles under local anesthesia. The procedure took no more than 40 minutes. Range of motion (ROM) was evaluated immediately post-operatively and 3 months later.
Results: Thirty-four needle tenotomies were carried out. Mean lack of knee extension was 94.2° (range 35-120°) pre-op, (range 15-90°; p<0.05) immediately post-op and 50.1° (range 10-90°; p<0.05) three months later, thus a mean increase of 44.1° knee extension (range 0-90°). All care and positioning objectives were achieved. There were no complications and procedure-related pain was rated as 3-4/ 10.
Conclusions: Needle tenotomy was well tolerated and yielded a significant increase in ROM with no unwanted effects. All objectives were achieved. This technique could be used in an ambulatory care setting or within institutions for severely disabled individuals.