Authors: Luke V. Tollefson, Evan P. Shoemaker, Matthew T. Rasmussen, Dustin R. Lee, Robert F. LaPrade
Categories: Technical Note
Source: Arthroscopy Techniques
Authors: Luke V. Tollefson, Evan P. Shoemaker, Matthew T. Rasmussen, Dustin R. Lee, Robert F. LaPrade
Patellar tendon ruptures are traumatic injuries disrupting the extensor mechanism. Common presentations include patellar alta, knee extension deficits, and a tendon gap. Although nonoperative treatment can be considered for partial tears or microtearing, full patellar tendon ruptures should be treated surgically. Acute treatment is also critical to prevent the patella from scarring in a proximal position. This technique describes an augmented repair of an acute patellar tendon midsubstance tear. Hamstring autografts, routed through the tibial tubercle and patella, are used to augment a repair of the patellar tendon.
Patellar tendon tears are traumatic injuries that typically present with patella alta, deficits in knee extension, and a tendon gap and are usually caused from overload to the extensor mechanism, typically with the knee flexed and a during a forceful quadriceps contracture.^1^ These tears can also be caused by degeneration, or microtearing, of the tendon, eventually leading to a full disruption of the patellar tendon.^1^^,^^2^ Although nonoperative management can be considered with partial or microtearing, a complex tear should be treated surgically.^3^ Acute treatment of patellar tendon ruptures is recommended, because chronic cases typically have fixed patella alta caused by scarring and lack of function of the extensor mechanism.^4^^,^^5^ Typically, in the acute phase, a full patellar tendon reconstruction is not required because the patella can still be reduced to anatomic position and healing can still occur with a repair.^1^^,^^3^^,^^4^ However, augmentation techniques, including using hamstring autografts, help reinforce the patellar tendon repair and facilitate improved healing and outcomes.^6^^,^^7^ This technical note describes a patellar tendon repair with subsequent hamstring autograft augmentation in the setting of a primary patellar tendon tear.
This is a technical note for the repair of a primary patellar tendon tear with hamstring autograft augmentation. The step-by-step guide and surgical pearls are listed in Table 1, and a detailed video of the technique is highlighted in Video 1.Table 1Step-by-Step Guide and Surgical Pearls for a Primary Patellar Tendon Rupture Augmentation and RepairStep-by-Step GuideSurgical PearlsAnterior incision from 2 cm proximal to patella to the tibial tubercle.A long incision is required for hamstring graft harvest, visualization of patellar tendon tear, and repair and augmentation technique.Dissection is carried down to the pes anserine bursa, and both the semitendinosus and gracilis hamstring tendons are harvested. These tendons are left attached to the tibia.A combination of a Cobb elevator, Metzbaum scissors, and the physicians’ fingers should be used to remove all adhesions and prevent graft amputation.The tibial tubercle is now identified, and an ACL guide is used to drill a guide pin across the tibial tubercle.This tunnel should be drilled 1 cm distal to the patellar tendon attachment on the tibial tubercle.A 4.5-mm reamer is used to over-ream the guide pin.Care should be taken to ensure the bone around the tunnel does not fracture.A hamstring tendon is passed from medial to lateral across the tunnel.The longer of the 2 hamstring tendons should be passed through the tibial tubercle tunnel.Two Q-Fix anchors are now placed, 1 at each side of the tibial tubercle tunnel.Both hamstring tendons will be fixed to the medial Q-Fix anchor, whereas only the graft passed from medial to lateral will be fixed at the lateral Q-Fix anchor.The patellar tunnel is now approached. A guide pin is drilled across the midpoint of the patella using an ACL guide.Spinal needles can be used to mark the proximal and distal ends of the patella to find the midpoint.A 4.5-mm reamer is used to over-ream the guide pin.This tunnel should be in the middle of the patella both proximal to distal and anterior to posterior to avoid fracture.Both hamstring grafts are whipstitched at their ends and passed proximally along the medial and lateral aspects of the patellar tendon to the patellar tunnels.The whipstitches in the grafts should be tight to facilitate smooth passage of both grafts through the patellar tunnel.The lateral graft is passed from medial to lateral across the patellar tunnel, and the medial graft is passed from medial to lateral across the tunnel.The order of passage may need to be reversed to facilitate the smoothest passage possible.The grafts are tensioned to restore the proper height of the patella.The patella should be positioned evenly. This can be adjusted by individually tensioning the medial or lateral grafts.The grafts are sewn to each other at the apertures of the tunnels.If extra graft remains, it can be whipstitched to the other graft.The patellar tendon tear can now be repaired using suture.Knee range of motion should be checked to ensure no limitations exist and to verify a safe initial postoperative range of motion.The deep and superficial tissues are closed with suture.This includes part of the retinaculum that may have been disrupted because of the initial tear.ACL, anterior cruciate ligament.
The patient is brought into the operating room and induced under general anesthesia. An examination under anesthesia is performed to check range of motion, assess the patella, and check for ligament stability. A high thigh tourniquet is placed, the nonsurgical leg is placed in a leg holder (Mizho OSI, Union City, CA), and the foot of the bed is left up for the surgical limb. The patient is draped in a normal sterile manner. For prophylaxis against infection, 2 g preoperative Ancef are administered.
An anterior midline incision is created from 2 cm proximal to the patella to the tibial tubercle (Fig 1). Dissection is carried down to expose the extensor mechanism. The patellar tendon tear is confirmed, and the location of the tear is visualized. A midsubstance tear should have patellar tendon tissue still attached to the tibial tubercle and patella (Fig 2). Through this same anterior incision, dissection is carried down to the pes anserine bursa. The semitendinosus and gracilis hamstring tendons are identified and isolated. All adhesions should be removed to facilitate a smooth harvest and avoid amputation using an open hamstring harvester. The hamstring autografts should be left attached to the tibia. Adequate hamstring tendon length is required for this procedure (Fig 3).Fig 1Anterior incision (purple arrow) in a right knee primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. The incision should extend from 2 cm proximal to the patella to just distal to the tibial tubercle. This incision will allow for access to the hamstring tendon graft harvest, the graft passage of the hamstring tendons, and the patellar tendon repair.Fig 2Patellar tendon tear confirmation in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. The patellar tendon tear should be visualized and confirmed through this anterior incision. For a midsubstance tear, patellar tendon tissue should still be attached to the patella and the tibial tubercle (black arrows). These tissues will be sutured back together later in the case.Fig 3Hamstring autograft harvest in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. At the pes anserine bursa, both the gracilis and semitendinosus hamstring tendons should be identified and isolated. The gracilis tendon (black arrow) should be harvested first, followed by the semitendinosus tendon (white arrow). For both tendons, adhesions should be removed via a combination of scissors, Cobb elevator, and the physicians’ fingers. An open hamstring harvester is used to harvest the tendon. Adequate hamstring graft length is required for the augmentation procedure.
For the augmentation of the patellar tendon repair, the hamstring autografts will be passed into tunnels reamed through the tibial tubercle and patella. An ACL guide (Arthrex, Naples, FL) is used to drill a guide pin across the tibial tubercle 1 cm distal to the normal patellar tendon attachment on the tibia. This guide pin is over-reamed with a 4.5-mm reamer (Fig 4). The longer of the 2 hamstring autografts, which is usually the semitendinosus autograft, is passed from medial to lateral across the tibial tubercle tunnel (Fig 5). Two Q-Fix suture anchors (Smith & Nephew, London, UK) are placed, 1 at each end of the tibial tubercle tunnel. The gracilis and semitendinosus autografts are both fixed to the medial Q-Fix (Fig 6), and the semitendinosus autograft is fixed to the lateral Q-Fix (Fig 7).Fig 4Tibial tubercle tunnel in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. For the hamstring tendon augmentation, a tunnel is drilled across the tibial tubercle. An ACL guide (Arthrex, Naples, FL) is used to drill a guide pin through the tibial tubercle, 1 cm distal to the normal patellar tendon attachment on the tibia. The guide pin is drilled from medial to lateral (white arrows). The guide pin is over-reamed with a 4.5-mm reamer. The longer of the 2 hamstring tendon autografts should be pulled through this tunnel.Fig 5Hamstring graft passage through the tibial tubercle in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. A passing stitch (black arrow) should be passed through the tibial tubercle tunnel to facilitate graft passage. The longer of the 2 hamstring tendon autografts, in this case the semitendinosus tendon (white arrow), should be passed from medial to lateral across the tibial tubercle.Fig 6Medial graft fixation at the tibial tubercle in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. A Q-fix anchor (Smith & Nephew, London, UK) is placed at the tunnel entry site on the tibial tubercle (white arrow). This Q-Fix anchor will be used to fixate the semitendinosus (blue arrow) and gracilis (black arrow) autografts. Tension should be placed on the graft to ensure secure fixation.Fig 7Lateral graft fixation at the tibial tubercle in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. A Q-Fix anchor (Smith & Nephew, London, UK) is placed at the exit site of the tibial tubercle tunnel (black arrows). This Q-Fix anchor will only fixate the semitendinosus tendon (white arrow) (or the longer of the 2 tendons that is pulled through the tibial tubercle tunnel). The hamstring autograft should be tensioned to ensure secure fixation.
The patellar tunnel is now approached. The proximal and distal borders of the patella are marked with spinal needles, and the midpoint of the patella is found. The same ACL guide is used to drill a guide pin across the patella, and this is over-reamed with a 4.5-mm reamer (Fig 8).Fig 8Patellar tunnel in a right knee during a primary patellar tendon rupture repair with hamstring autograft augmentation with the patient in the supine position. The proximal border of the patella is marked with a spinal needle (yellow arrow), and the midpoint of the patella is found. A bone clamp is used to hold the patella in place, and an ACL guide is used to drill a guide pin horizontally across the patella (white arrow). This guide pin is over-reamed with a 4.5-mm reamer (black arrow).
Both hamstring autografts are whipstitched at their ends and passed proximally along the medial and lateral aspects of the normal position of the patellar tendon to the patellar tunnel (Fig 9). The semitendinosus autograft is then passed from lateral to medial through the patellar tendon tunnel, and the gracilis autograft is passed from medial to lateral through the same tunnel (Fig 10). The grafts are tensioned so that the patellar tendon height is restored, and the patella is positioned evenly. The grafts are then sewn to each other at the apertures of the patellar tunnel (Fig 11). Any extra grafts can be passed back down distally and sewn back into the existing autograft.Fig 9Graft passage from tibial tubercle tunnel to patellar tendon tunnel in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. The shorter of the 2 grafts, in this case the gracilis graft (white arrow), is passed under the superficial tissues along the medial side of the torn patellar tendon. The longer of the 2 grafts, which has already been passed through the tibial tubercle tunnel and in this case is the semitendinosus tendon (yellow arrow), is passed under the superficial tissues along the lateral side of the patellar tendon.Fig 10Graft passage through the patellar tendon tunnel in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. The ends of both grafts are whipstitched to help facilitate graft passage through the tunnels (white arrows). The semitendinosus graft (yellow arrow), or the longer of the 2 grafts, is passed first from lateral to medial across the patellar tendon. The gracilis graft (black arrow), or the shorter of the 2 grafts, is passed second from medial to lateral across the patellar tendon tunnel.Fig 11Graft fixation after passage through the patellar tendon tunnel in a right knee during a primary patellar tendon tear repair with hamstring autograft augmentation with the patient in the supine position. Prior to final hamstring graft fixation, the grafts should be tensioned, and the patellar height should be established. The gracilis tendon autograft was the graft passed from medial to lateral across the lateral, and the semitendinosus autograft was the graft passed from lateral to medial across the patellar tendon tunnel. The gracilis graft is sewn into the semitendinosus graft on the lateral side (black arrow), and the semitendinosus graft is sewn into the gracilis graft on the medial side (white arrow).
With the patella back in anatomic position from the hamstring autografts, the 2 ends of the patellar tendon tear are sewn together using 0-Vicryl (Johnson & Johnson, New Brunswick, NJ) (Fig 12). This tissue is typically quite disrupted by the tear and is thus a tenuous repair in isolation. The knee is flexed from 0° to 90° to ensure there is no significant tension on the repair or the hamstring autograft augmentation. The tourniquet is let down. The medial and lateral aspects of the retinaculum that were disrupted by the tear are sutured. The deep and superficial tissues are closed.Fig 12Patellar tendon repair in a right knee during a primary patellar tendon rupture repair with hamstring autograft augmentation with the patient in the supine position. The patellar tendon should be repaired after the hamstring autograft augmentation is complete (black arrow). The hamstring tendons help hold the patella at the correct height while the repair occurs (purple arrow). The 2 ends of the native patellar tendon rupture are sewn together using 0-Vicryl (Johnson & Johnson, New Brunswick, NJ). Any tissues of the capsule around the patellar tendon should also be repaired at this time (yellow arrow).
The patient is nonweightbearing on the surgical limb for 6 weeks. Their flexion is limited to 60° for 2 weeks, then 90° for the next 2 weeks, after which they may progress as tolerated. Radiographs should be obtained at day 1 and 6 weeks postoperatively to obtain a baseline and then assess healing, respectively.
In the setting of a patellar tendon tear, surgical intervention ideally should be performed acutely. A previous study by Roudet et al.^5^ reported on early and late outcomes of 38 patients with patellar tendon tears treated in the acute phase with repair and augmentation. They reported significant improvements in range of motion at early follow-up and average Lysholm score of 93.7 points and 95% satisfaction rate at 9.3 years follow-up. In another study, Belhaj et al.^8^ reported improved outcomes scores in Knee Society Scores and Visual Analog Scores compared with preoperative values for both acute and chronic repairs. They also noted that there was significantly decreased knee extensor strength in the surgical limb, and this was worse for those treated in the chronic phase compared with the acute phase. With proper surgical intervention, good outcomes can be achieved for patellar tendon repair with augmentation.
The advantages of the aforementioned technique include the use of autograft for the augmentation procedure, the acute timing of the surgery, and the repair of the native tissues and structures. The disadvantages of this technique include potential for attenuation of the repair over time owing to significant disruption of the patellar tendon at its midpoint, potential for patellar and tibial tubercle fracture if the tunnels are malpositioned, and potential for patella baja if the augmentation with the hamstrings is tensioned too tight. The full list of advantages and disadvantages is presented in Table 2.Table 2Advantages and DisadvantagesAdvantagesDisadvantagesThe augmentation technique helps solidify the fragile tendon repair.Because of the disruption of the patellar tendon as a result of the repair, the tissue may be quite attenuated and difficult to repair.The use of hamstring autografts reduces surgical costs.Potential iatrogenic damage during drilling of tunnels across patella and tibial tubercle.The independent tensioning of the hamstring grafts can help properly restore patellar height.Potential iatrogenic damage with hamstring autograft harvest.Open incisions facilitate full visualization of the tear and surrounding tissues that may be damaged.Care should be taken to ensure hamstring grafts are not too tight or too loose.Acute timing of surgery prevents scar tissue buildup.
The authors declare the following financial interests/personal relationships which may be considered as potential competing R.F.L. consults, advises, and receives funding grants and patent royalties from Ossur; consults, advises, and receives funding grants and travel reimbursement from Smith and Nephew; consults and advises Responsive Arthroscopy; receives funding grants from the Arthroscopy Association of North America; receives funding grants from the American Orthopaedic Society for Sports Medicine; and receives speaking and lecture fees from Foundation Medical. All other authors (L.V.T., E.P.S., M.T.R., D.R.L.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.