Take-Home Points
- Thorough preoperative planning is imperative and inclusive of history, physical examination, radiographs, and MRI and potentially CT scan.
- Plan carefully for needed graft sources (autografts and allografts).
- Rehabilitation starts preoperatively and a detailed individualized plan is often warranted.
- Indicated ligamentous repair or augmented repair with reconstruction is more likely to succeed when performed within 2 weeks of injury.
- Complex combined knee restoration surgery can be safely performed in an outpatient setting.
Complex combined knee restoration surgery can be safely performed in an outpatient setting. The term complex knee restoration is used to describe management of knee injuries that are more involved—that is, there is damage to the menisci, cartilage, ligaments, and bones. Management entails not only determining the best treatment options but navigating the more complex logistics of making sure all necessary grafts (fresh and frozen allografts and autografts), implants, and instrumentation are readily available as these cases come to fruition.
The military healthcare paradigm often involves the added logistics of transporting the service member to the correct military treatment facility at the correct time and ensuring the patient’s work-up is complete before he or she arrives for the complex knee restoration. Such cases require significant rehabilitation and time away from family and work, so anything that reduces the morbidity of the surgical undertaking and the overall “morbidity footprint” of time away and that helps the patient return to normal function are value-added and worthy of our attention and diligence in developing an efficient system for managing complex cases.
The globally integrated military healthcare system that is in place has matured over the past decades to allow for the significant majority of the necessary preoperative work-up to be performed at a soldier’s current duty station, wherever in the world that may be, under the guidance of local healthcare providers with specific inputs from the knee restoration surgeon who eventually receives the patient for the planned surgical intervention.
Algorithm for Knee Restoration Planning
Alignment Issues
The first task is to confirm the realignment indication. Realignment may be performed with a proximal opening-wedge medial tibial osteotomy (OWMTO), a distal opening-wedge lateral femoral osteotomy (OWLFO), or a tibial tubercle osteotomy (TTO).1 Given the reproducible clinical improvement achieved and the robust nature of the fixation, these osteotomies are often the first surgical step in complex knee restorations.2 The final determination, made by the surgeon in consultation with the patient, is whether to perform the indicated osteotomy alone or in combination with the rest of the planned restoration surgery. In the vast majority of cases I have managed over the past 2 decades, I have performed the entire knee restoration in a single operation.3 Within the past 5 years, combining the procedures has become even more feasible with the important progress made in multimodal pain management and with the close collaboration of anesthesiologists.4
Meniscus and Cartilage Status
The integration status of meniscus and cartilage within the medial and lateral tibiofemoral compartments is crucial to the comprehensive restoration plan. In fact, the success of the restoration can be said to be dependent on the functional status and health of meniscus and cartilage—which either succeed together or fail apart.
Important covariables are age, prior surgical interventions, activity level expected or allowed after surgery, and size, location, and depth of cartilage injury.5 Whether a cartilage injury is monopolar or bipolar is determined with advanced imaging (magnetic resonance imaging [MRI], computed tomography [CT], weight-bearing radiography) along with analysis of a thorough history (including a review of prior operative reports and arthroscopic images) and a knee examination. Bipolar injuries that involve the condyle and juxtaposed plateau often bode poorly for good clinical outcomes—compared with unipolar lesions, which usually involve the condylar surfaces in isolation. The same thinking regarding the patellofemoral compartment is appropriate. Cartilage lesions that involve the juxtaposed surfaces of the patellar and trochlear groove do poorer than isolated lesions, which are more amenable to cartilage restoration options. The literature on potential cartilage restoration options for the patella and trochlea is expanding. I use the 3-dimensional cartilage restoration option of a fresh patellar osteochondral allograft (OCA) for high-grade cartilage lesions thought to be clinically significant. Other options, such as microfracture, cell-based cartilage restoration, and Osteochondral Autograft Transfer System (Arthrex) procedures (from the thinner condylar cartilage), have varied in their outcomes for patellar lesions. According to more recent literature and a review of my clinical results, fresh patellar OCAs are a good option for patellar lesions.6 Similarly, trochlear lesions can be managed with microfracture, cell-based therapies, or fresh OCAs, depending on surgeon preference.
Functional total or subtotal meniscectomies are often best managed with meniscal allograft transplantation (MAT). An intact or replaced medial or lateral meniscus works synergistically with any planned anterior cruciate ligament (ACL) reconstruction. Again, the adage that meniscus and cartilage succeed together or fail apart is appropriate when planning complex knee restoration. Signs of extrusion or joint-space narrowing and root avulsion or significant loss of meniscal tissue, visualized on MRI or on prior surgical images, often help substantiate a MAT plan. MAT has had the best long-term results when performed in compartments with cartilage damage limited to grade I and grade II changes, in stable knees, and in knees that can be concurrently stabilized.5 Technological advances have increased the value of MAT by limiting the morbidity of the operation and thus allowing for other surgery to be performed concomitantly and safely as part of comprehensive knee restoration. Over the past 20 years, I have arthroscopically performed MAT with bone plugs for medial and lateral procedures, and my results with active-duty soldiers have been promising, paralleling the clinic success reported in the literature.5 Alignment must be considered when performing MAT or cartilage restoration. If the addition of meniscal transplantation or cartilage restoration leaves the knee with residual malalignment of 6° or more, corrective osteotomy is performed.
My view and practice have been to plan for an unloading chondroprotective osteotomy. The goal is a balanced mechanical axis, whether achieved with mere joint-space restoration or with an osteotomy added.
Ligament Status
A comprehensive plan for establishing ligamentous stability is paramount to the overall clinical success of complex knee restorations. Meniscus and cartilage restoration efforts are wasted if clinically significant ligamentous laxity is not concomitantly treated with reconstruction surgery. Revision ACL surgery is by far the most commonly performed surgery in complex knee cases. Diligence in interpreting advanced MRI and physical examination findings is required to make sure there are no concomitant patholaxities in the medial, lateral, posterior, posteromedial, and posterolateral ligamentous complexes. Appropriate ligamentous reconstruction is warranted to maximize clinical results in complex knee restorations. Such cases more commonly require allograft tissue, as the availability of autograft tissue is the limiting issue with 2 or more ligament reconstructions. Military treatment facilities, in which comprehensive knee restorations are performed, have soft-tissue allografts on hand at all times. Having tissue readily available makes it less imperative to determine the most appropriate combined ligamentous reconstruction surgery before the patient arrives—a process that is often difficult. This situation is in contradistinction to the need for specific matched-for-size allograft frozen meniscus and fresh cartilage tissues, both of which require tissue-form procurement in advance of planned restoration surgery.
Rehabilitation Plan
The rehabilitation plan is driven by the part of the complex knee restoration that demands the most caution with respect to weight-bearing and range of motion (ROM) during the first 6 weeks after surgery. The most limiting restorative surgeries involve meniscus and cartilage. Recent clinical trial results support weight-bearing soon after tibial osteotomy performed in the absence of meniscus and cartilage restoration that would otherwise limit weight-bearing for 6 weeks.7 Therefore, most of these complex knee restorations are appropriately managed with a hinged brace locked in extension for toe-touch weight-bearing ambulation, with ROM usually limited to 0° to 90° during the first 6 weeks. Quadriceps rehabilitation with straight-leg raises and isometric contractions is prescribed with a focus on maintaining full extension as the default resting knee position until normalized resting quadriceps tone returns. Full weight-bearing and advancement to full flexion are routinely allowed by 6 weeks.
Case Report
A 41-year-old male service member who was overseas was referred to my clinic for high tibial osteotomy consideration and possible revision ACL reconstruction. His symptoms were medial pain, recurrent instability, and patellofemoral crepitance. Three years earlier, he underwent autograft transtibial ACL reconstruction with significant débridement of the medial meniscus. Before his trip to the United States, I asked that new MRI scans, full-length standing hip–knee–ankle bilateral alignment radiographs, and a 4-view weight-bearing knee series (including a posteroanterior Rosenberg view) be obtained and sent for my review (Figure 1).
Review of the patient’s detailed preoperative imaging work-up and electronic medical record (available through the military’s healthcare system) made it clear that far more surgical intervention was needed than originally assumed. A significant full-thickness chondral lesion of the patella and a subtotal medial meniscectomy would necessitate patellar cartilage restoration and medial MAT in addition to the high tibial osteotomy and revision ACL reconstruction.
Had this patient been sent through the military medical evacuation system, he would have had to make 2 overseas trips—one trip for preoperative evaluation and advanced imaging, whereby he would have been placed on a match list and had to wait for a requested meniscal allograft and an appropriate graft for his patella, and the other trip for his complex surgery. Fortunately, the military’s integrated healthcare network with true 2-way communication and the collaborative use of integrated electronic medical records proved extremely valuable in making management of this complex knee restoration as efficient as possible. From the perspective of the soldier and his military unit, only 1 big overseas trip was needed; from the perspective of the military healthcare system, responsible use of healthcare personnel and monetary resources and well-planned complex knee restoration surgery saved a knee and allowed a soldier-athlete to rejoin the fields of friendly strife.