Non-Ablative Fractional Resurfacing of Total Knee Replacement Scars

Patients undergoing unilateral, primary total knee replacement will be enrolled in the study in the treating surgeon's office at the time surgery is indicated and scheduled. Patient's will be asked to enroll in the study if they are indicated by the treating surgeon for primary total knee replacement, are 18 years of age or older, and, if they have no history of wound healing problems, chronic infection or connective tissue disorder and if they have a Fitzpatrick skin type between I and VI. Patients will be excluded from the study if they: have any prior history of surgery on the indicated knee; have a mental or psychological illness that prohibits them from consenting or completing the necessary forms; if they refuse to consent to be in the study; or, if they have a history of wound healing problems, or a diagnosed skin or connective tissue disease. Standard baseline health information and demographics will be collected at the time of enrollment (gender, age, co-morbidities, etc.).

On the day of surgery, patients will be randomized to have their surgical incision treated with the non-ablative fractional laser or treated with the placebo laser. Randomization will be computer-generated and stored in opaque sealed envelopes. For each patient, randomization will take place prior to surgery in the holding area on the day of surgery. At discharge, the laser technician will open the sealed envelope to reveal the allocation into control or experimental groups. The technician will then treat the patient appropriately as per the protocol. Proper randomization will be ensured by the technician, principal investigator and co-investigators. The patients, principal investigator and co-investigators collecting the data will be blinded to the randomization. The technician providing the laser therapy will not be blinded.

The incisional length will be determined by the treating surgeon at the time of surgery based on what he deems will be adequate given the patient's body habitus and the technical demands of the surgery. The skin incision will always be made with a new, sharp, sterile 10 blade. Subcutaneous dissection will be done with the scalpel as well.

Closure of the wound will be done with 0-vicryl sutures for the arthrotomy and deep subcutaneous tissue. The sutures will be tied in an interrupted simple pattern. The superficial subcutaneous tissue layer will be closed with interrupted buried 2.0-vicryl sutures. The skin will be closed with a 4.0 monocryl running subcuticular stitch. The wound will be dressed with a sterile dressing that will come off on post operative day two.

After the primary dressing is taken down, the wound will be left open to air unless there is active drainage. If active drainage is present, sterile gauze will be kept on the wound until it is dry.

As a dry wound is a pre-requisite for patient discharge, no patient will be discharged with a draining wound. On the day of discharge, the patient will have the first of the non-ablative, fractional laser treatments done in the hospital. This will be performed by a registered technician who has been trained in the use of the non-ablative, fractional laser. The technician will be trained by the company providing the device and will have completed the hospital's required laser training prior to using the device on patients.

The laser settings will be preset at 15 mjs and 50 mj. The number of passes used per patients will be 5 passes, and this is determined by the plastic surgeon included on the study and will be individualized to the patient's Fitzpatrick skin type. The technician will know the status of the patient's randomization and will either treat the patient with the laser or turn the laser on and apply it in the standard fashion without activating the device. The technician will also apply a Lidocaine patch in order to numb the area that will be treated by the laser device and keep the patient blinded from the treatment. The patients will be asked to wear opaque glasses that prevent them from seeing the technician using the laser so as to remain blinded to the treatment. Additionally, they will be asked to wear noise-cancelling headphones so as to minimize any sound the active laser makes.

On the day of discharge the patient will have the first of the non-ablative, fractional laser treatments performed in the hospital by the registered technician who has been trained in the use of the non-ablative fractional laser. The patients will be given strict instruction in a standardized wound care regimen. They will complete a standard post TKR rehabilitative course. At the 4-week and 8-week time points the patient will return to the clinic for a wound check and for the 2nd and 3rd laser therapy treatment. The patients will see the surgeon at the 4-week follow up visit, as this is standard of care. At week 8,the non-Standard of Care visit, the treating surgeon's nurse and the laser technician will see the patients. If the patient, nurse or technician has any concerns about the status of the wound, the Principle Investigator will be notified. Patients will not be charged for the 8-week visit.

At the 4 week, 8 week, 3 month and 1 year visits the surgical scar will be photographed in a standardized, controlled fashion. Dr. Rothaus, a plastic surgeon, has extensive experience with standardized cosmetic photography and will provide his expertise. Briefly, the same camera, lens, lighting and position will be used for all patients at all time points. The goal is to have the only variable be the appearance of the scar. At each of these visits, the patient will complete a validated scar assessment outcomes tool, the Patient and Observer Scar Assessment Scale (POSAS).(22) Additionally, one of three experts (Dr. Rothaus, Ms. Trezza, Dr. Cornell) trained in scar assessment will inspect the patient's scar and complete the observer portion of the scar assessment instrument. In addition to the POSAS, each patient will also complete a valid knee outcomes instrument, the Knee Injury and Osteoarthritis Outcome Score (KOOS)(23) at each visit. The data will be collected in the physician's private office prior to the scheduled surgery and after surgery at each visit. An identified co-investigator, with the appropriate HIPAA and human subjects research training will be responsible for administering the knee instruments, answering any of the patient's questions, and then collecting the instruments after they have been completed. This will ensure that the surgeon does not have access to the patient's responses.

The primary outcome will be the difference in POSAS score between patients treated with the laser and those treated with placebo. Secondary outcomes include the difference in POSAS observer score as well as the difference in KOOS score between the experimental and the control group.

While the investigators group is the first to use this technology on Total Knee Replacement scars, Vasily et al. in 2009 reported on the effectiveness of laser treatment of post-surgical and traumatic scars and found that relative to baseline, 73% of scars improved 50%, and 43% improved by 75% or more. Overall, all of the treated scars demonstrated some clinical improvement with a mean overall improvement of 52%. Side effects were minimal and included swelling (95%), erythema (94%) and purpura (5%).(9) All side effects completely resolved at the one-month follow-up visit.

Additionaly, the investigators pilot study has demonstrated that the laser treatment is safe, as the investigators have applied the treatments to ten patients, in the manor mentioned above, and have not seen any complications thus far. On the basis of this data and the pilot study, treatment with the non-ablative fractional laser has been deemed both safe and effective.