Ta-Wei Liu, Chih-Hao Chiu, Alvin Chao-Yu Chen, Shih-Sheng Chang, and Yi-Sheng Chan

Journal of Clinical Medicine, 2021, 10, 1727
https://doi.org/10.3390/jcm10081727

Summary by Ryan Paul, BS

Clinicians perform medial open wedge high tibial tubercle osteotomy (TTO) to decrease the load on the medial compartment of the knee and to fix malalignment.^1,2 Clinicians have been begun performing TTO with cartilage restoration, ligament reconstruction, and meniscal repairs in order to minimize the load of the reconstructed/repaired structure; however, there are infrequent yet significant risks with TTO.³ Patients with a deep surgical site infection (SSI) suffer very poor post-operative outcomes, which can lead to revision surgery and nonunion.⁴

The authors of this study sought to identify risk factors for superficial and deep SSI in patients that underwent TTO with concomitant arthroscopic procedures. The authors enrolled 59 patients over a 3-year period who underwent TTO with another arthroscopic knee procedure. Patients were contacted for follow-up regarding complications and reoperations 1-4 years after surgery. Deep SSIs were considered any infection that required surgical debridement.

Eleven patients (18%) had SSIs, with 8 (13.1%) being superficial SSIs and 3 (4.9%) being deep SSIs. All 3 patients with deep SSIs were treated successfully, as plate fixation was preserved and bony union was achieved within 8 months. Multivariate analysis found that patients who were current smokers (odds ratio: 18.1, p=0.02) and older in age (odds ratio: 1.2, p=0.025) were more likely to experience a SSI. Patients with diabetes mellitus were also likely to be at a higher risk (odds ratio: 11.2, p=0.051).

A large retrospective review of a Japanese national database (n=12,853 patients) found that smoking status, male sex, and longer anesthesia time are associated with SSIs, while younger age is a protective factor.⁵ These results are similar to those of the current study, with both studies finding smoking status and age to affect SSI incidence. However, despite the benefits of a prospective study design, this current study had a relatively small sample size (n=59 patients, 61 knees) for evaluation of risk factors. Several of the cohorts had less than 10 patients, such as 5 patients with diabetes mellitus and 8 patients with Hepatitis B or C. Therefore, larger prospective studies should be completed before definitive risk factors are implemented clinically. Until then, clinicians should be aware that smoking status and age may affect SSI incidence in patients after TTO with concomitant arthroscopic procedures.

References:

1. Konopka, J. F., Gomoll, A. H., Thornhill, T. S., Katz, J. N. & Losina, E. The cost-effectiveness of surgical treatment of medial unicompartmental knee osteoarthritis in younger patients: a computer model-based evaluation. J. Bone Joint Surg. Am. 97, 807–817 (2015).
2. Rossi, R., Bonasia, D. E. & Amendola, A. The role of high tibial osteotomy in the varus knee. J. Am. Acad. Orthop. Surg. 19, 590–599 (2011).
3. Schuster, P. et al. Open-Wedge High Tibial Osteotomy and Combined Abrasion/Microfracture in Severe Medial Osteoarthritis and Varus Malalignment: 5-Year Results and Arthroscopic Findings After 2 Years. Arthroscopy. 31, 1279–1288 (2015).
4. Seki, K. et al. Treatment for Staphylococcus aureus infection following open wedge high tibial osteotomy using antibiotic-impregnated calcium phosphate cement. Knee Surg. Sports Traumatol Arthrosc. 22, 2614–2617 (2014).
5. Kawata, M. et al. Type of bone graft and primary diagnosis were associated with nosocomial surgical site infection after high tibial osteotomy: analysis of a national database. Knee Surg. Sports Traumatol Arthrosc. 29, 429–436 (2021).