Rates of superficial infection after DA-THA range from 0.6% to 1.6% in 3 large observational studies (combined deep infection rate, 0.43%).8,14,15 In 2 of these studies, all patients with superficial infection underwent formal débridement, though none developed deep infection. A prospective randomized study of 221 patients who underwent colorectal surgery—where perioperative infectious morbidity ranges from 25% to 50%—found that ring retractor use significantly reduced superficial wound infection rates (8.1% vs 0%). A significant reduction in wound infection was shown in a similarly designed study involving 48 patients who had open appendectomy (14.6% vs 1.6%). The device had no effect on deep infection in either general surgery study. The wound infection rates reported in these general surgery studies are markedly higher than those in our study population. As a result, the effect of the ring retractor on wound infection in DA-THA may be less. Regardless of the effect on deep infection, fewer superficial infections, which often require operative intervention, would be of considerable benefit.
Below-threshold albumin level and absolute lymphocyte count have been associated with wound-healing complications after hip replacement.21 In the present study, pre-albumin level under 20 mg/L was the only nutritional marker predictive of poor wound appearance, but this finding was seen only in SBSES scores from surgeon A. Subgroup analysis did not reveal any relationship between wound appearance and any of the recorded demographic or perioperative variables, but for a small predictive influence with age over 65 years.
This study had some limitations. Our findings cannot be generalized to all patients who undergo THA, as only DA incisions were studied. Results also may not be generalizable to non-fellowship-trained orthopedists. In addition, selection bias likely resulted from including patients already selected for the DA approach. Using digital images for evaluation (vs real-life evaluation) may have affected reliability as well. Last, by not incorporating texture, we omitted a potentially informative feature from scoring.
It is paramount that surgeons undergo diligent training before undertaking this approach for minimizing unwanted results; furthermore, higher early complication rates level off with increased surgeon experience.14,36,37 We recommend meticulous soft-tissue handling, cautious retraction, and careful patient selection (relative contraindication for patients with an abdominal pannus overlying the incision) as primary measures for minimizing incisional trauma and potential wound-healing complications.38 Preservation of the tensor fascia is also crucial,39 as it is the only closable layer separating deep and superficial compartments. Without good closure of the tensor fascia, there is no containment or tamponade of deep bleeding, which can facilitate hematoma formation.
In the population studied, we found no significant long-term differences in cosmetic appearance (based on clinician or patient evaluation) between wounds managed with and without the ring retractor. Our data do not support routine use of the ring retractor, during DA-THA, for improved wound cosmesis. Whether the device has any significant role in reducing the number of wound complications in THA is yet to be determined. Last, the ring retractor may have a role in other areas of orthopedic surgery, such as hip fractures in the elderly or orthopedic oncology. In situations like these, where adequate nutrition and immunocompetency may be lacking, the added protection provided by the device may translate into a more notable benefit than in elective THA.