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Clinical Faceoff: Suprapatellar Tibial Nailing for Tibia Fractures

2020; Lippincott Williams & Wilkins; Volume: 478; Issue: 6 Linguagem: Inglês

10.1097/corr.0000000000001254

1528-1132

Lisa K. Cannada, Hassan R. Mir, Stephen Kottmeier,

Knee injuries and reconstruction techniques

Tibial shaft fractures are common, often arise from high-energy trauma, and may be accompanied by soft-tissue injuries. Static, locked intramedullary nailing is one common approach that works well for many patients with these injuries. The conventional approach to tibial nailing involves an infrapatellar starting point, obtained with the knee in a flexed position, but it can result in anterior knee pain [1, 23, 28]. There have been multiple suggestions as to the etiology, including the position of the nail tip and angle of insertion [12, 15]. In addition, with certain fracture patterns such as proximal tibia fractures, a flexed position of the knee to obtain the starting point was felt to contribute to apex anterior deformity. Although approaches to minimize apex anterior and possible valgus deformities in proximal tibia fractures have been described, including mini-fragment plating, nailing in a semi-extended position, and the judicious use of blocking screws [10, 17, 19, 30, 35], some surgeons felt these techniques alone were not sufficient for easy insertion of intramedullary nails in proximal tibia fractures. An alternative to the conventional approach is suprapatellar nailing [15]. It is performed in a semi-extended position, which was believed to improve fracture alignment not only of proximal fractures, but also of more-distal injuries [1]. With a special insertion sleeve, this approach involves an incision through the quadriceps tendon, using a cannula device over a trocar and a protective sleeve to help protect the tendon during nail insertion [7]. Proponents of this technique have suggested it decreases knee pain, improves fracture alignment, and makes it easier to obtain fluoroscopic images [6, 8-11, 16, 20, 32, 37]. But others have raised concerns, including the possibility of cartilage injury to the knee and difficulty removing the nail, should a patient want it removed [22, 37]. This topic is controversial. It's also important, given the great frequency and potential morbidity of tibial shaft fractures. To help us sort through this, I've invited two international experts to debate the topic. Hassan R. Mir MD is the Director of Orthopaedic Trauma Research and the Orthopaedic Program Director at Tampa General Hospital in Florida. He has used this technique for several years and has published on it. Also joining us is Stephan A. Kottmeier MD, Professor and Chief of Orthopaedic Trauma at Stony Brook University in New York. He is known for his thoughtful insight into fracture care and supporting techniques in the care of injured patients. Lisa K. Cannada MD:The key purported benefit of suprapatellar nailing is decreased knee pain, but one large study [19] found no differences between treatment groups among patients followed for at least a year. In Dr. Mir's article [5], he also comments on the need for "mastery" of a new technique, as well as the need for special equipment. That being so, why choose suprapatellar nailing, which seems to have other potential disadvantages, such as possible cartilage damage and difficulty in nail removal? Hassan R. Mir MD: The theoretical disadvantages of the suprapatellar technique have not been borne out in the growing body of studies or with clinical experience. Cadaver studies have shown that the infrapatellar and suprapatellar techniques both increase intraarticular pressure but not to levels that are concerning for cartilage damage [17], and that there is less structural intraarticular damage with the suprapatellar technique [3, 13, 14]. Clinical studies have shown at worst no increase in knee pain [18], and in some series, less knee pain with suprapatellar nailing [24, 31]. In practice, many surgeons experienced in both techniques (including myself) have noted reduced knee pain. On the rare occasions when nail removal is performed (which in my practice is almost never for knee pain), I have found that the procedure is not difficult and can be done via either a suprapatellar or infrapatellar approach. There are several advantages to the suprapatellar technique [1, 6, 8, 9, 11, 17, 21, 32, 35-37]. Surgeons can obtain easier and better reductions for proximal and distal fractures, as well as less difficulty with fluoroscopic imaging. The suprapatellar technique is not difficult to learn. It benefits patients in terms of better-aligned fractures and less radiation exposure. It's a win-win for surgeons and patients alike. Stephen A. Kottmeier MD: The first portion of the question is directed towards clinically important (if any) sequelae to the extensor mechanism origin with either or both techniques. Numerous studies of different designs and varying degrees of "elegance" suggest, as does my own personal experience, that this is a nonissue in the short- and long-term [20]. Another nonissue is implant extraction. I see no purpose in employing a suprapatellar tactic. I have easily removed nails introduced via the suprapatellar technique by both myself and referral sources with an infrapatellar approach, each time without difficulty [22]. The question further poses "potential disadvantages" of suprapatellar nailing. A witnessed hardship associated with the suprapatellar technique includes the difficulty of assessing rotation because of decreased mobility to asses cortical thickness with a suprapatellar cannula in place. Another is the absence of an opportunity for impaction and, accordingly, the potential for distraction of the fracture site [6, 27]. I have observed that with the knee flexed and the foot firmly positioned against the operating room table, both of these concerns are more easily resolved with infrapatellar nailing. These attributes are, however, somewhat limited and the problems they resolve are easily overcome with suprapatellar nailing. In general, I believe it is a well-supported consensus that suprapatellar nailing affords superior reduction parameters and diminished operation and fluoroscopy times [36]. I also agree with Dr. Mir in that the technique has a learning curve that is easily mastered, and similar observations are supported in a previous study [33]. Dr. Cannada:With any new technique, there is a learning curve. What tricks can you offer the surgeon new to suprapatellar nailing to minimize the risk of intraoperative challenges and complications? In what situations do you consider suprapatellar nailing either contraindicated or especially difficult, such that you'd choose another intramedullary nailing approach? Dr. Mir: I recommend starting by positioning the injured leg on a foam (or blanket) leg ramp to aid with fluoroscopy. Use a sterile small stack of towels or a bump for additional knee flexion. Get good fluoroscopic images by using tibia-based referencing for AP and lateral imaging (a "twin-peaks" tibial spine profile and a flat-plateau image, respectively) [4]. The skin incision is 3 cm long, and it stops 1 cm above the patella. Expose and split the quadriceps tendon, but stop 5 mm proximal to the patella to allow for distal parapatellar extension, when necessary. Make sure the cannula stays in position behind the patella and protects the patellofemoral cartilage throughout the procedure. Most cannulas can be pinned to either the femur or the tibia. Many manufacturers have different-sized cannulas available for patients with different-sized patellofemoral joints. Remember it's semi-extended nailing, so there needs to be some flexion for a proper trajectory, but not too much flexion that tightens the joint, changes the wire's trajectory, and affects fracture alignment. If getting the wire into the correct trajectory through the cannula is difficult, you may try a modified Seldinger technique of inserting the wire first and then sliding the cannula over it. The remainder of the suprapatellar tibial nailing procedure (for example, reduction and instrumentation) is similar to infrapatellar nailing but much easier. Dr. Kottmeier: I agree with Dr. Mir's technical pearls. He comments on "distal parapatellar extension, when necessary." In my opinion, this cannot be overstated. Preexisting patella baja-related obstacles can often be anticipated preoperatively, and in such scenarios, I advocate for mini-open parapatellar exposures [29]. These are well-described and afford a desirable starting point and trajectory without likely short- or long-term detriment to the extensor mechanism of clinical consequence [2, 23]. I think it worth reiterating that most of the benefits of semi-extended nailing (supra- or lateral/medial patellar) have little to do with SP access [37]. They instead have more to do with the predictable and desirable trajectory, the starting point that all three approaches offer, and the avoidance of obstacles such as an apex anterior deformity with proximal tibia fracture nailing in a flexed position and starting point trajectory, which are evident with infrapatellar nailing [15]. Dr. Cannada:Initially, suprapatellar nailing with its semi-extended position was thought to be beneficial for the treatment of proximal tibia fractures. But now, some have suggested that suprapatellar nailing can provide improved alignment with distal tibia fractures and decreased anterior knee pain compared with traditional tibial nailing. Why might this be? Dr. Kottmeier: The unique reduction-related attributes suprapatellar nailing may offer in contrast to infrapatellar nailing are both indirect and direct. Manual manipulation of the distal limb to contribute favorably to reduction is facilitated with the leg relatively extended. This would favor suprapatellar nailing. Similarly, percutaneous reduction forceps and joysticks are applied with greater ease in the semi-extended position. Avilucea et al. [1] compared both nail insertion techniques and witnessed more-desirable alignment in patients with distal tibia fractures with suprapatellar nailing than in those with infrapatellar nailing, although they did not suggest a mechanism for this finding. I believe that suprapatellar nailing may contribute to a more-desirable and consistent nail insertion starting point. How or even whether these contribute to the quality of distal tibial fracture reduction is certainly arguable. Another study suggested the anatomic center of the distal tibia is just lateral and anterior to the center of the distal tibial articular surface in the coronal and sagittal planes, respectively [33]. That study further maintained that placement of the nail along this axis results in improved reduction parameters. Some of the advantages so often ascribed to suprapatellar nailing have little to do with introducing a nail above (and behind) the patella. They are instead the virtues of nailing a tibia in semi-extension of the leg. The options are not limited to suprapatellar and infrapatellar nailing. Current peripatellar insertion methods (performed in semi-extension) continue to be refined and may offer the advantages of suprapatellar nailing while obviating some of its shortcomings. Dr. Mir: I agree that our study mainly found that acceptable alignment was much more reliably obtained with distal tibia fractures treated with suprapatellar nailing (96.2%) than with infrapatellar nailing (73.9%) at two busy Level 1 trauma centers [1]. However, with the distal tibia, we know that function (and outcome) follows form, and if a technique offers the benefit of reliably obtaining anatomic alignment without an increased risk of harm, then prudence would argue in favor of that technique. While semi-extended positioning of the limb may be one of the major contributors to alignment with distal tibial nailing, the reproducibility of the suprapatellar nailing technique when performed with attention to detail and with specialized instrumentation for performing semi-extended nailing offers the treating surgeon the ability to obtain desired alignment more easily and reproducibly. Other techniques of semi-extended nailing either employ a full arthrotomy with a larger incision or smaller incisions adjacent to the patella that involve patellar subluxation. These are alternatives that can be considered if suprapatellar nailing equipment is not available or the surgeon is not familiar with or comfortable with this technique, with two available studies on the outcomes [25, 26]. Unlike suprapatellar nailing, I am unaware of cadaver studies examining the safety of these alternative approaches with regard to joint forces or intraarticular damage. Dr. Cannada:Because suprapatellar nailing is relatively new, less is known about its potential benefits of decreased knee pain and need for removal of the nail and decreased incidence of malunion and harms regarding long-term results. Two meta-analyses found no difference in complications between suprapatellar nailing and infrapatellar nailing[9, 16]. With no differences, I understand you have reservations about the safety of suprapatellar nailing and the complications associated with it over the longer run. Why is that? Dr. Kottmeier: The question regarding my perception of "safety" vis-à-vis suprapatellar nailing is perhaps better considered in terms of the relative strengths and disadvantages of that approach when compared specifically with infrapatellar nailing. One scenario certainly is a "floating knee" in which both femoral and tibial fractures are suitable for intramedullary fixation and the pathoanatomic characteristics of the tibial fracture suitable to infrapatellar nailing. Another would be the risk (if any) of knee sepsis with suprapatellar nailing in the presence of an open tibial fracture. While several studies suggest the risk is "limited," it is not nonexistent, and it certainly has been observed [21]. For patients in whom the potential for fracture-related infection remains high, one might choose infrapatellar nailing. The question also asks about my concerns regarding long-term functional outcomes. My personal observations and those supported by good-quality studies (cadaveric, biomechanical, and clinical [3, 14, 15, 18, 38]) do not demonstrate any clinically relevant sequelae to regional starting-point anatomy and the patellofemoral articulation. Although sequelae related to the extensor mechanism are unlikely, motion-restricting heterotopic ossification has been described [24]. Dr. Mir: I have used suprapatellar nailing for numerous open tibial shaft fractures, and I have also used retrograde femoral nailing for numerous open femoral shaft fractures, and I cannot recall having more than a few septic knees treated with either technique over the past several years. I note that infrapatellar nailing may also "seed" the knee, because the approach frequently becomes contiguous with the joint. Speaking of nailing both femurs and tibias in the same surgical session ("floating knees"), my standard approach for these is a retrograde femoral nail, followed by suprapatellar nailing via two separate incisions, and I have observed no complications in my practice from using the two approaches on the same knee. The challenges with starting point and trajectory because of anatomic variants of the patellofemoral joint can be addressed via several published tips and tricks with suprapatellar nails [4, 5, 7, 16, 20, 31, 34, 36]. All tibial nailing procedures, and especially those of proximal and distal fractures, I believe, are more easily performed with a suprapatellar nailing technique. If it's applicable to challenging procedures, then it is applicable in simpler procedures, which is why I use the suprapatellar nailing technique for all of my tibial nailing. The short- and mid-term clinical outcomes regarding alignment and decreased knee pain in suprapatellar nailing are very favorable [1, 2, 6, 21, 33] and surpass those of infrapatellar nailing in many regards [8, 9, 11, 17, 19, 32, 35, 37]. I hope that many centers will continue to follow these patients and publish long-term results, which is certainly challenging in trauma populations.