Neglected patellar tendon rupture. Reconstruction using semitendinosus-gracilis tendon grafts and FiberWire augmentation

Pre-operatively, lateral radiographs of both knees were performed in order to estimate the Insall– Salvati ratio and use the measurement from the uninjured side as a guide during the reconstruction. The Insall–Salvati ratio measured 1.0. The patient was consented for a patellar tendon reconstruction using hamstring graft and possible Z lengthening of the quadriceps tendon. The patient was placed under general anaesthesia in a supine position on the operating table and intravenous antibiotic prophylaxis was administered. Tourniquet ischemia was not applied as this may have caused tethering of the quadriceps, preventing adequate assessment of patellar height. During the examination under anaesthetic no restrictions of patellar mobility were identified and it was possible to bring the patella distally to its appropriate position. An anterior midline skin incision was made, with adequate exposure to allow for the anatomy to be fully defined. The ruptured patella tendon was identified and it was apparent that the tendon had ruptured off the distal pole of the patella. The scar tissue at the level of the rupture was excised to expose healthy tendon edges. An assessment of the ability to recreate the Insall– Salvati ratio was confirmed at this stage and the patella was mobilized distally without significant tension from the quadriceps. The pes anserinus was identified and the semitendinosus and gracilis tendons were harvested with an open tendon stripper, achieving maximum length of the tendon grafts and leaving the tendons attached distally at their tibial insertion. The free tendon edges were cleaned of remaining muscle and soft tissue and prepared with whipstitch sutures. Two transosseous tunnels were subsequently drilled following the general principles as described by Ecker et al.; first, a 5.5 mm transverse tunnel through the patella, just distal to the mid-patellar level and then a 4.5 mm oblique tunnel behind the tibial tubercle, beginning proximally on the lateral aspect and extending distally to the medial aspect (Figure 1). With the knee in full extension, a FiberWire suture (Arthrex, Florida, USA) was passed through the tibial and patellar tunnels and tensioned to bring the patella distally. The suture was used to set the height of the patella, using the previously calculated Insall–Salvati ratio of the uninjured knee. This was confirmed DECLARATIONS