Postoperative Care/Rehabilitation

Introduction

Postoperative care and rehabilitation for tibial plateau fractures remain areas of surgical management with little standardization. While a significant amount of research has focused on diagnosis, classification, surgical techniques, and operative outcomes of tibial plateau fractures, far less has evaluated appropriate postoperative care. Hence, there are a wide range of postoperative management protocols implemented by orthopedic trauma surgeons worldwide. An ideal postoperative regimen would minimize the risk of losing fracture reduction while also minimizing the risk of wound complications, loss of range of motion, patient deconditioning, and long-term sequelae of these injuries. These at times represent competing interests, with extended immobilization possibly minimizing fracture displacement, while consequently increasing the likelihood of postoperative stiffness in addition to precipitating cartilage loss and subsequent posttraumatic arthritis. The goal of this chapter is to discuss these factors and help guide orthopedic traumatologists to select the appropriate, evidence-based postoperative management protocol.

Wound Care

Tibial plateau fractures are high-energy injuries that often present with concomitant soft-tissue sequelae. High-energy plateau fractures often present significant swelling, with rates of compartment syndrome reported to be as high as 28% in bicondylar tibial plateau fractures. Furthermore, surgical site infection rates for tibial plateau fractures treated surgically have been reported as 9.9% in a recent meta-analysis and have been reported to be as high as 13.8%. ^, This must be kept in mind when addressing postoperative wound closure and wound care options.

Extensive open injuries with soft-tissue stripping and/or contaminated wounds may require second-look procedures given the high risk of infection. Options for coverage in those scenarios include negative pressure wound therapy (NPWT) followed by secondary closure, skin grafting, and flap coverage, with optimal soft-tissue coverage within 7 days to decrease complications. Details regarding choice of coverage are outside of the scope of this chapter. For a wound to be an optimal candidate for primary closure, it must be free from contamination, contain a viable soft-tissue envelope, and be able to be closed without unnecessary tension. In clean wounds with a viable soft-tissue envelope that have too much tension to be primarily closed after the index surgery, delayed primary closure via gradually tightened subcuticular stitches and the vessel loop shoe-lace method are both options.

When amenable to primary closure, wounds should be closed in a layered fashion. For skin closure, vertical mattress and horizontal mattress stitches are preferred for wounds with higher concern for tension as these suture patterns distribute the tension over a greater surface area. A 2008 study by Sagi et al. used a porcine model to explore the effect of suture patterns on cutaneous blood flow, finding that the Allgower-Donati pattern had the least effect on cutaneous blood flow for all levels of tension applied to the repair. More recently, a 2020 study by Shorten and colleagues used laser angiography to measure incisional skin perfusion in patients immediately after ankle fracture surgery. They found that vertical mattress stitches had equivalent performance to Allgower-Donati stitches and that both allowed for better perfusion than sutures in a horizontal or simple pattern. Finally, a similar study from the Mayo Clinic found vertical mattress stitches to demonstrate superior wound perfusion to staples. However, several trials, systematic reviews, and meta-analysis studies have shown no difference in clinical outcomes between the use of sutures or staples in surgical wound closure. Running subcuticular stitch, the pattern that allows for the most robust wound perfusion in both studies, would not be appropriate for the high-tension wounds seen in tibial plateau fractures. In this author’s experience, nylon suture thrown in a vertical mattress fashion provides a secure, strong closure for the vast majority of surgical wounds following fixation of tibial plateau fractures.

After closure, the ideal dressing provides a barrier against potential sources of contamination to prevent infection while also optimizing wound healing. Prior studies have shown that a moist environment helps improve wound healing by preventing tissue dehydration, promoting breakdown of dead tissue and fibrin, and stimulating faster epithelialization than a purely dry dressing. ^, A standard three-layer dressing of impregnated gauze (e.g., Xeroform (Covidien, Dublin, Ireland)), standard gauze, and waterproof outer dressing (e.g., Tegaderm (3M, Saint Paul, MN, USA)) provides an ideal healing environment while also wicking away exudate and providing a waterproof barrier on the outside. While research from the arthroplasty literature has suggested that silver-impregnated occlusive dressings are highly effective for wounds with significant drainage and may decrease acute periprosthetic joint infection rates, tibial plateau wounds are far less exudative. Dressings with such high absorptive properties are poorer options for dry wounds.

Initial reports suggested a favorable role for incisional NPWT for major lower extremity trauma to decrease risk of surgical site infection. ^, A recent meta-analysis reported a decrease in infections and hospital stays with NPWT use. However, in a recent randomized controlled trial of 1548 adults with lower extremity fractures who underwent primary closure, there was no difference in the deep surgical site infection rate between standard wound dressing and incisional wound vacuum therapy.

Bracing

Postoperative bracing protocol plays a significant role in the recovering patient’s functional status after surgery. When considering tibial plateau bracing protocols, the goal is to maximize postoperative range of motion and prevent any loss of knee extension. A combination of locked and unlocked bracing to optimize both has been recommended.

There does appear to be good rationale behind locking the hinged knee brace in extension postoperatively. The expected inflammation and joint swelling after tibial plateau fracture repair cause the knee to rest in a position that maximizes knee joint volume. A position of 15 to 60 degrees of flexion maximizes joint volume and minimizes intraarticular pressure ; hence, knee bracing locked in extension is required to prevent the patient from resting in flexion. The elevated levels of inflammatory cytokines in the perioperative period led to arthrofibrosis and subsequent knee stiffness in this flexed position. A loss of even 5 degrees of extension causes a limp and significantly increases energy expenditure. Flexion contractures after tibial plateau fractures are often irreversible: mouse studies have shown that the length of the posterior capsule is permanently shortened even after 1 week of being held in flexion and is not reversible upon remobilization.

Immobilization in extension has its own risks, as the same inflammatory cytokines responsible for flexion contractures can also cause. There are significant benefits to early motion and keeping the knee brace unlocked. Rabbit studies have shown that mobilization of the knee joint postoperatively is associated with a fivefold decrease in proinflammatory interleukin-1 levels, subsequently decreasing release of transforming growth factor beta. Other inflammatory cytokines responsible for fibroblast proliferation. The downstream effects of fibroblast proliferation are significant: a 2015 study from the University of Utah showed that each day of fixed extension after tibial plateau fixation increased the odds of requiring manipulation under anesthesia by 10%. New research also suggests that the downstream effects of mobilization may extend to cartilage health as well. The proinflammatory environment driven by interleukin-1 is associated with chondrocyte death. However, even 8 hours of activity with 16 hours of rest was adequate to block the interleukin-1–mediated proinflammatory gene induction in articular chondrocytes.

In summary, during the immediate postoperative period, the authors recommend a protocol of unlocking the knee brace during the day while locking in −10 degrees of extension at night while the patient sleeps. This protocol yields the antiinflammatory and procartilage benefits of early knee mobilization while also preventing the development of irreversible knee flexion contractures. Patients should be able to maintain full knee extension during the entirety of their recovery period and should achieve 90 degrees of knee flexion by 6 weeks postoperatively. The brace may be discontinued at 6 weeks as there should be sufficient knee motion, especially extension, obtained at this postoperative juncture.

Weight Bearing

The official AO (Arbeitsgemeinschaft für Osteosynthesefragen) recommendation for postoperative weight bearing after tibial plateau repair is restricted weight bearing (nonweight bearing or partial-weight bearing) for roughly 12 weeks. A systematic review of published studies reporting postoperative management of tibial plateau fractures showed that on average surgeons recommend 4 to 6 weeks of nonweight bearing followed by 4 to 6 weeks of partial weight bearing, with increasing Schatzker type being correlated with delayed time to full weight bearing. These restrictions reduce the risk of malreduction by decreasing the amount of force applied to the healing fracture site. Historical studies support these guidelines and have shown that weight bearing in the first 6 weeks postoperatively is associated with increased risk of failure of fixation. Ali and colleagues reported that patients who began partial weight bearing prematurely during the first 6 weeks postoperatively had an 80% rate of loss of reduction compared to 25% of their patients who avoided full weight bearing until after 10 weeks. Other factors that have been associated with loss of reduction include age greater than 60, degree of comminution, and presence of a medial coronal fracture line.

It is important to note that there are potential downsides to limiting weight bearing in patients. Restricted weight bearing necessitates increased energy expenditure and changes gait mechanics. Basic scientific studies have shown that joint unloading significantly affects cartilage health and thickness. Historical studies from the 1970s showed that within weeks, knee cartilage thickness was reduced by 50% in dogs with hindlimbs immobilized. Researchers at Kobe University subjected mice to 2, 4, and 8 weeks of hind-limb unloading and found that cartilage thickness was decreased at all time points compared to the control group. Nonweight bearing also contributes to increased muscle atrophy that may contribute to further delays in return to preinjury level of function. Fortunately, these effects are reversible: cartilage can be rebuilt with progressive loading and muscle mass can be recovered with physical therapy.

Recent clinical studies suggest that early weight bearing may not be as detrimental to surgical fixation as previously reported. Haak and colleagues compared immediate weight-bearing protocol to 6 to 8 weeks of initial nonweight bearing in 32 patients with lateral plateau fractures. They found that the immediate weight-bearing group had no increased loss of reduction, fracture displacement, or need for reoperation. A similar study out of the United Kingdom expanded inclusion criteria to include all types of plateau fractures and found that early weight bearing was not associated with joint depression or loss of fixation when compared to 6 weeks of restricted weight bearing. With ever-expanding evidence that postoperative weight bearing may be liberalized past the current guidelines, it may be unsurprising that a recent European survey revealed that many current orthopedic surgeons deviate from official AO guidelines and favor earlier weight bearing.

Despite these recent studies supporting early weight bearing, this author recommends a conservative approach with patients until further conclusive evidence suggests limited risks. Further caution should be used when fractures demonstrate high-risk factors including increased patient age, significant comminution, or presence of a medial coronal fracture line. Overall, randomized clinical trials are required to adequately demonstrate that early weight bearing is not associated with increased risk of fracture malunion or loss of reduction.

Exercises and Rehabilitation

Tibial plateau fractures and the subsequent period of decreased weight bearing and mobilization cause significant weakening of the associated musculature. A study by Gaston et al. in 2005 measured muscle strength in 51 patients who underwent repair of tibial plateau fractures and showed that only 14% returned to baseline quadriceps strength 12 months after surgery. This likely played a large role in their finding that almost one in five patients had sustained flexion contracture of greater than 5 degrees. Aside from helping maintain full extension, quadriceps strengthening also plays a part in knee forces during the gait cycle. As the quadriceps serves to decelerate the leg during the heel strike phase, acting as a shock absorber, weakness in the quadriceps causes an increase in force that ends up being transmitted into the knee and newly repaired tibial plateau.

Hence, the focus of postoperative rehabilitation and exercise should be on maintaining quadriceps and hamstring strength to maximize postoperative range of motion. Unlocking the brace during the day allows the patient to immediately begin active range of motion, delaying quadriceps and hamstring atrophy.

The specific type of exercise used to prevent joint stiffness and strengthen the surrounding muscles depends on stage of weight bearing. During the nonweight bearing stage or the first 4 to 6 weeks, patients and physical therapists should focus on passive and active range of motion, straight leg raises, and stretching. While basic scientific studies have shown decreased arthrofibrosis and improved cartilage healing with continuous passive movement (CPM) machines, these findings have not been replicated in clinical studies. Multiple studies looking at the effect of CPM on total knee replacement patients have found no significant benefit in range of motion or functional outcomes with its use. ^, Hence, barring new evidence, we do not see a role for CPM in postoperative rehabilitation. During the partial weight-bearing stage, physical therapists may expand to more intensive strengthening exercises that keep joint reactive forces low such as stationary cycling, aquatic exercises, and rowing. Finally, once the patient has been advanced to full weight bearing, they may progress to closed chain lower body strength exercises such as squats and lunges.

It is crucial for the surgeon to clearly document their weight-bearing recommendations based on the most recent physical examination and radiographs during the rehabilitation process. As each individual has a different fracture pattern and heals at a different rate, communication between the surgeon and physical therapist is crucial to optimize muscle strength while minimizing risk of injury or loss of reduction by progressing with therapy too rapidly.