Soft Tissue Expansion in Total Knee Arthroplasty Due to Extensive Scarring and Fibrosis in Multiple-Operated Knee

Densely adhered scar tissue from a multiple-operated knee forms contractile tissue between the overlying skin and the anterior bony surface of the knee joint. Subsequent total knee arthroplasty (TKA) among patients with a tightly adhered skin envelope is associated with higher rates of ischemia and serious complications related to wound healing, such as soft tissue infections, skin necrosis, and dehiscence.^1,2 A high index of suspicion in the preoperative stage is required to identify surface anatomy that may result in inadequate wound coverage: namely, thin anterior knee skin and/or evidence of scarring from previous operations or local trauma.³

In such circumstances of soft tissue deficiency, the use of soft tissue expansion (STE) in preparation for TKA can be an attractive substitute to other, more complex wound coverage procedures such as rotational fasciocutaneous flaps, extensive cross-leg flaps, and microvascular free flaps. In addition to minimal donor-site morbidity, the use of STE allows for relatively unrestricted knee motion during the recovery process, whereas flap procedures require restriction of knee motion for protection of flap viability.⁴ Furthermore, using STE allows for the presence of optimally matched skin color, texture, hair-bearing qualities, and sensation, compared with the altered recipient-site skin features when using local distant or free flaps.⁵

This report presents a case of STE of the anterior knee before TKA.

A 47-year-old female with severe and progressive osteoarthritis of the right knee is scheduled for TKA because of continued pain and disability refractory to conservative treatment. X-ray imaging of the right knee demonstrates advanced degeneration with bone-on-bone contact in the medial compartment (Figure 1). The patient’s injury is complicated by a traumatic lawn mower accident during childhood that resulted in a below-the-knee amputation of the left knee and multiple injuries about the right knee, rendering the right knee unstable.

On physical examination, the right knee displayed an array of traumatic and surgical scars. During palpation of the surrounding skin and soft tissue of the anterior compartment, dense scar tissue was noted to be firmly adherent to the underlying structures (Figure 2).

First-Stage Procedure: Bilateral Flap Elevation and Pocket Creation

The patient initially was reluctant to undergo STE because of concerns of expander visibility in public. To address significant concern for viability of soft tissue coverage, the patient agreed to an operative plan including a delay procedure with elevation, SPYTM indocyanine green angiography evaluation of the soft tissue envelope, hyperbaric therapy, and future re-incision with simple flap closure over the total knee prosthesis.

An extension of the oblique scar was made with sharp dissection medially and laterally to release the underlying adhesions. The dissected pocket of dense scar tissue revealed a complex soft tissue envelope encasing the knee joint (Figure 3 and Figure 4). Then, using indocyanine green angiography evaluation with the SPYTM equipment, adequate perfusion was found in all but one small area (Figure 5), which was excised. Complex closure over a drain was performed.

Second-Stage Procedure: Pocket Elevation and Placement of Tissue Expander

Change in Operative Plan

After the delay procedure with elevation of the soft tissue capsule, the patient unexpectedly changed her mind and agreed to undergo subsequent STE. Planned for 6 weeks after the initial elevation procedure, a tissue expander with a remote port would be inserted for gradual tissue expansion to ensue over a 6-week period.

Placement of Tissue Expander

To avoid further soft tissue disruption of the anterior knee, the tissue expander was not inserted via additional pocket elevation. Alternatively, a vertical 5-cm incision was made proximally, and an 8 x 16–cm tissue expander was tunneled into the anterior knee pocket via blunt dissection in the subcutaneous plane. The remote port was placed in a small subcutaneous pocket reachable for injection but at an ample distance from the expander to avoid unintentional expander puncture. One subcutaneous drain was placed, and the insertion site was closed with absorbable sutures. Expansion was initiated immediately after wound closure, with approximately 20 mL of sterile saline solution injected into the port site (Figure 6). The knee was placed in an immobilizer, and the patient was scheduled for follow-up in clinic at 2 weeks postoperatively.

Expansion Period: Outpatient Port-Site Injections

At 2 weeks, the patient presented to the clinic with no signs of early wound complications. Under locally sterile conditions, a 23-gauge needle was used to inject sterile saline solution into the remote port site until palpable tension was felt at the expander site. To confirm whether adequate tension was achieved, capillary refill was tested at the expander site, with a quick refill (< 5 seconds) signaling the requirement for additional injection volume. After the initial 2-week visit, the patient was scheduled for weekly expansion injections for the ensuing 4 weeks. At 6 weeks’ post placement of the tissue expander, adequate expansion of the overlying skin and subcutaneous tissue was determined, and the patient was scheduled for TKA and expander removal.

Third-Stage Procedure: Expander Removal, TKA, and Closure

Access to the joint space for the TKA was through the large oblique scar (Figure 2 and Figure 4). The tissue expander was removed, and successful robot-assisted TKA was performed with soft tissue capsular closure (Figure 7 and Figure 8). The expanded subcutaneous tissue was closed over a drain in multiple layers (Figure 7, Figure 8, and Figure 9). Subsequent full range of motion was achieved in this reconstructed right knee.

At 6-month follow-up, the operated knee healed without complications and displayed full range of motion, and the patient was satisfied with the results (Figure 10).

Four years after Manders et al⁶ first described the use of STE in 1984, its use in the lower extremity—including thigh, buttocks, and at or below the knee—was successively described in 1988.⁷ It is worth noting that Weinz, Dowden, and Stulberg⁵ reported the successful use of STE prior to TKA in a 33-year-old woman with posttraumatic arthritis and severe arthrofibrosis in 1987, a year earlier. Nonetheless, only a limited amount of data exists to date.^2,4,5,7 It was not until 1994 that STE prior to TKA was again reported in the literature when Mahomed et al⁷ described 2 successful cases. In 1996, Gold et al³ described the use of STE prior to TKA in 10 consecutive knees, with the first case reported to occur in 1992. The study reported no complications and was the first prospective study to support the safety and effectiveness of STE prior to TKA.³ In 1997, Santore et al⁴ claimed to first describe the successful use of STE in revision TKA in a case report of a 76-year-old woman with an infected primary arthroplasty treated by multiple debridements and skin grafting resulting in inadequate soft tissue.

Despite low complication rates reported in the early literature, only a small number of institutions have reported use of STE as an alternative to flaps or skin grafts involving the knee.^2,8,9 In 2000, Manifold et al¹⁰ retrospectively reviewed the outcomes of 29 consecutive cases performed at a single institution. In that study, minor complications such as erythema, blistering, and wound breakdown occurred in 6 (21%) patients during the expansion stage and 5 (18%) patients during the subsequent arthroplasty stage. One patient experienced a major complication during the expansion stage, characterized by skin necrosis, that required return to the operating room and abandonment of the subsequent arthroplasty. It is worth noting that the major complication occurred in a patient with a history of radiation therapy to the skin of the knee.¹⁰ This study was the largest of its kind until 2011, when at the same institution, Long et al¹¹ conducted a 15-year review dating from the first case performed in 1992. The study reported minor complications occurring in 14 (22%) patients, all of which occurred during the expansion stage, and major complications—defined as those requiring return to the operating room—occurred in 7 (11%) patients. It is worth noting that 6 of the 14 minor complications (43%) and all cases of hematoma formation occurred among patients undergoing the procedure before the standard use of subcutaneous drains. It is also important to consider that 27 of the 64 patients (42%) were from the Manifold et al⁸ study. As of late, Piuzzi et al² reported 2 cases of STE, with both patients experiencing major complications requiring additional surgery: the first case resulted in explantation of an infected prosthesis with subsequent successful re-implantation, and the second was complicated by hematoma formation, requiring surgical evacuation 1 week after surgery. It is worth noting that despite the occurrence of major complications, no difficulty in generating viable soft tissue for satisfactory wound coverage was reported.²

There exists no other published literature on STE prior to TKA outside of the previously mentioned studies; thus, insufficient data exists to predict significant risk factors for poor outcomes. Nonetheless, in the largest study to date, Long et al¹¹ reported several patient characteristics associated with an increased likelihood of complication development. Based on a 15-year experience, the authors recommend not using STE on knees that lack a healthy plane for expansion: namely, any plane that includes previously irradiated tissue or presence of skin-grafted tissue that is densely adherent to bone. This recommendation is based on higher observed rates of wound breakdown, blistering, necrosis, soft tissue infection, and expander migration among patients with suboptimal planes of tissue at the expansion site. The authors also advise holding low molecular weight heparin during the postarthroplasty period until after subcutaneous drains are removed. By doing so, the authors reported a dramatic decrease in hematoma formation and persistent drainage; however, due to holding anticoagulation and the relative immobility during the expansion period, a history of deep vein thrombosis is relatively contraindicated in the use of tissue expanders prior to TKA.¹¹

In the present case, the described precautions were applied apart from holding low molecular weight heparin. The patient experienced no hematoma formation, persistent drainage, or complications to wound healing. This result mirrors the outcome of most patients in the literature, yet it is important to note that this is a single case report that simply describes a method to minimize the potential of ischemic soft tissue coverage over a knee prosthesis in a densely scarred skin envelope. This, along with the scarcity of cases reported in the literature, emphasizes the importance of publishing reports such as the present case.

In the multiply operated knee with excessive scar tissue and fibrosis causing uncertain soft tissue coverage, the use of STE prior to TKA can be a useful method in creating adequate wound closure and may reduce the risk of wound healing complications.

Affiliations: ¹Ochsner Clinic Foundation, Ochsner Health System, Jefferson, LA; ²Division of Plastic Surgery, Department of Surgery, Tulane University School of Medicine, New Orleans, LA; ³Department of Plastic and Reconstructive Surgery, Ochsner Clinic Foundation, New Orleans, LA; ⁴Tulane Medical Center, New Orleans, LA; ⁵Department of Surgery, Ochsner Clinic Foundation, New Orleans, LA

Correspondence: Salomon Puyana, MD, MS; salomonpuyana@gmail.com

Disclosures: The authors have no financial or proprietary interest in the subject matter of this article.