Neglected patellar tendon rupture. Reconstruction using semitendinosus-gracilis tendon grafts and FiberWire augmentation
A fit and well, non-smoker, 23-year-old male motorbike courier was referred to the senior author (DC) for the management of a neglected patellar tendon rupture, 10 weeks following a low-speed road traffic collision.\nPre-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.\nThe 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.\n; 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 (). 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 using C-arm image intensifier with the knee at 30° of flexion (). The free end of the semitendinosus tendon was passed medio-laterally through the oblique tunnel behind the tibial tubercle using the whipstitch and a suture passer. It was then passed latero-medially through the transverse patellar tunnel, again using a suture passer. The free end of the gracilis tendon was then passed medio-laterally through the transverse tunnel in the patella. The remaining tendons were then overlapped and sutured to each other. The tendon edges at the site of the original tendon rupture were also sutured (Ethibond suture, Ethicon, Gargrave, UK). After the repair was completed, the knee could be flexed to 90° passively without any gapping at the rupture site and the final patellar height was assessed at 60° of knee flexion and found to be symmetrical to the uninjured side. The wound was closed in layers (Vicryl and Monocryl sutures, Ethicon, Livingston, UK), after repair and reefing of the injured extensor retinaculum.\nPostoperatively, the knee was immobilized in a plaster cast at 20° of flexion. The patient was discharged the second postoperative day, not weight bearing. At the two-week follow-up, the cast and sutures were removed and the knee was placed in a hinged brace allowing flexion from 0 to 20°. Quadriceps isometric exercises were initiated at this stage. Further follow-up appointments were arranged at two weekly intervals with a 20° increase of the knee flexion on every occasion, ultimately achieving 120° of flexion in 12 weeks. At the three-month follow-up, initiation of weight bearing was permitted along with closed chain knee exercises under the supervision of a physiotherapist. At the six-month follow-up, the patient was able to walk unaided and without a limp. He had full active knee extension and 130° of flexion, achieving pre-injury functional levels, including return to sport. His Lysholm knee score was 87 points.