Factors Associated with Range of Motion Recovery Following Manipulation Under Anesthesia.

INTRODUCTION: Stiffness and loss of motion following total knee arthroplasty (TKA) is a complex and multifactorial complication that may require manipulation under anesthesia (MUA). However, patient and surgical factors that potentially influence the development of knee stiffness following TKA are not fully understood. The purpose of this study was to identify patient and surgical factors that may influence range of motion loss following TKA by assessing a cohort of patients that underwent MUA and comparing them to a matched cohort of patients without complications.

MATERIALS AND METHODS: The joints registry was searched for patients who underwent MUA following primary TKA between 2004 and 2013. Demographic and surgical information was obtained from the electronic medical record including range of motion (ROM), comorbidities and timing of MUA. Patients who underwent MUA were then double-matched by baseline (prior to primary TKA) knee ROM to patients who underwent primary TKA with normal postoperative range of motion recovery during the same time period.

RESULTS: Fifty-two patients (fifty-six knees) (66% female, mean BMI 32.4 kg/m2) underwent MUA after TKA during the study period. MUA was performed a mean of 13.6 weeks after primary TKA. Study patients were double-matched by baseline flexion (mean 107º±2º) to 111 patients (112 knees) with a similar mean baseline flexion (104º±2º, p=0.138). Patients requiring MUA were younger (mean age 56 vs. 64 years, p<0.001), had more comorbidities (5 vs. 3, p<0.001), and a higher number of previous knee surgeries (56% vs. 21%, p<0.001) compared with controls. The risk for requiring MUA following primary TKA was significantly higher (2.4, p<0.001) in patients with previous knee surgery (arthroscopy for meniscal pathology, ACL reconstruction, osteotomies). Tourniquet time, length of stay, number of physical therapy sessions, blood loss >50 mL, and any complication during the hospital stay were not found to be associated with an increased risk of requiring MUA.

CONCLUSION: Younger patients with more comorbidities and a history of previous knee surgery were found to have significantly higher risk for developing stiffness and loss of motion requiring MUA after primary TKA in the current study. Patients with this risk profile need to be counseled regarding the risk for postoperative knee stiffness and range of motion loss possibly requiring MUA after primary TKA.