Rates of Deep Vein Thrombosis Occurring After Osteotomy About the Knee
We conducted a study to determine the rates of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) after high tibial osteotomy (HTO), distal femoral osteotomy (DFO), or tibial tubercle osteotomy (TTO) in patients who did not receive postoperative chemical prophylaxis. All patients who had HTO, DFO, or TTO performed by a single surgeon between 2009 and 2014 were identified. Charts were reviewed to determine presence or absence of DVT or PE. Patient age, smoking status, oral contraceptive (OC) use, and body mass index (BMI) were recorded. Patients received no chemical or mechanical prophylaxis after surgery. We identified 141 patients (44% male, 56% female) who underwent HTO, DFO, or TTO. Mean (SD) age was 34.28 (9.86) years, mean (SD) follow-up was 17.1 (4.1) months, and mean (SD) BMI was 26.88 (5.11) kg/m2. Overall, 36.7% of female patients used OCs, and 13.48% of all patients were smokers. After surgery, 2 patients (1.42%) developed below-knee DVT (unilateral in 1 case, bilateral in the other). The bilateral DVT case progressed to PE. Neither patient smoked, but the bilateral DVT/PE patient was using OCs. DVT patients’ mean (SD) age was 48.16 (8.24) years, and their mean (SD) BMI was 23.18 (0.18) kg/m2. HTO, DFO, and TTO patients who did not receive chemical prophylaxis had low rates of DVT (1.42%) and PE (0.71%). Administration of DVT/PE prophylaxis after these osteotomies may not be warranted.
Study Limitations
The strengths of this study include the large number of patients treated by a single surgeon using the same postoperative protocol. Limitations of this study include the lack of a control group. Although we found a DVT rate of 1.42% and a PE rate of 0.71%, the literature on the accepted risks for DVT and PE after HTO, DFO, and TTO is unclear. With our results stratified by procedure, the DVT rate was 2% in the HTO group, 0% in the DFO group, and 1% in the TTO group. However, we were unable to reliably stratify these results by each specific procedure, as the number of patients in each group would be too low. This study involved reviewing charts; as patients were not contacted, it is possible a patient developed DVT or PE, was treated at an outside facility, and then never followed up with the treating surgeon. Patients were identified by CPT codes, so, if a patient underwent HTO, DFO, or TTO that was recorded under a different CPT code, it is possible the patient was missed by our search. All patients were seen after surgery, and we reviewed the outpatient office notes that were taken, so unless the DVT or PE occurred after a patient’s final postoperative visit, it would have been recorded. Similarly, the DVT and PE rates reported here cannot be extrapolated to overall risks for DVT and PE after osteotomies about the knee in all patients—only in patients who did not receive DVT prophylaxis after surgery.
Conclusion
The rates of DVT and PE after HTO, DFO, and TTO in patients who did not receive chemical prophylaxis are low: 1.42% and 0.71%, respectively. After these osteotomies, DVT/PE prophylaxis in the absence of known risk factors may not be warranted.
Am J Orthop. 2017;46(1):E23-E27. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.
