The Utility of Postoperative Radiographs 2 Years After Primary Total Knee Arthroplasty

The Utility of Routine Postoperative Radiographs in the Asymptomatic Total Hip Arthroplasty Patient

BACKGROUND

Total hip arthroplasty (THA) patients often receive routine radiographs in the year following their index surgery. This study sought to investigate the clinical and economic value of obtaining routine postoperative hip radiographs for asymptomatic patients following primary elective THA.

METHODS

A retrospective cohort study of consecutive patients who underwent primary elective THA from 2016 to 2019 was conducted. Patients undergoing nonelective or revision THA, radiographic follow-up <10 months, and patients aged <18 years were excluded. All radiographs were reviewed for abnormalities in the first postoperative year by an arthroplasty fellowship-trained orthopaedic surgeon, blinded to the symptoms of the patient.

RESULTS

Of the 327 patients (351 hips) included, 57.2% were women and 68.2% were White, with an average age of 65 years (range, 22-97 years) and average body mass index of 29.1 kg/m² (range, 16.2-49.8 kg/m²). Only four (0.4%) radiographic series revealed abnormalities with the potential to alter postoperative management. One patient experienced a change in management directly related to their abnormal finding (closed reduction for dislocation at 10.2 months postoperatively). The remaining three abnormal radiographic findings included femoral stem subsidence, progressive radiolucencies around an acetabular component, and cement mantle fracture. The average cost for each radiographic series was $155.27, resulting in total direct charges of $167,691.60.

CONCLUSION

Routine postoperative radiographs may be of limited utility in the asymptomatic patient in the first year following elective primary THA. Consideration should be given to limit postoperative radiographs following standard elective THA, while reserving postoperative radiographic evaluation for patients who are symptomatic.

LEVEL OF EVIDENCE

Level III.

Clinical efficacy and cost-effectiveness of postoperative radiographs after total knee arthroplasty

BACKGROUND

Postoperative radiographs are commonly ordered after primary total knee arthroplasty (TKA), however, there is limited data on how often these films change management over the entire postoperative time course, and what should prompt imaging to maximize clinical utility.

METHODS

A retrospective cohort study was conducted of patients ≥ 18 years old who underwent a primary TKA at two level one trauma centers. Postoperative data were collected to determine the frequency of postoperative radiograph series, radiograph findings that did not suggest normal healing or alignment to radiologist and orthopedists, and changes in postoperative management. The total cost and radiation exposure values were calculated for all patient radiographs using estimates from previous literature.

RESULTS

From the 1258 patients included, 3831 postoperative radiographs were taken (mean ± 95% confidence interval [CI]: 3.05 ± 0.11 radiographs per patient). Of these 3831 radiographs, 44 (1.1%) contained a positive radiographic finding. Only 13 (0.3% of radiographs) of these positive radiographic findings were positive orthopaedic findings, 11 of which led to changes in management. For all but 1 of these patients (10/11, 91%), these radiographs were taken during a non-routine postoperative visit. Routine postoperative radiographs that did not change management cost $1,008,480 and administered 22.92 mSV of radiation to patients within this study.

CONCLUSION

Postoperative radiography obtained after primary TKA were of low clinical utility yet resulted in considerable healthcare costs and unnecessary radiation burden. Radiographs ordered during a non-routine visit, however, were a reliable indicator of when this imaging provided clinical utility.

Heterotopic Ossification Negatively Influences Range of Motion After Revision Total Knee Arthroplasty

BACKGROUND

The incidence of heterotopic ossification (HO) after total knee arthroplasty (TKA) varies and is of unclear clinical significance. This study aimed to identify the incidence of HO in patients undergoing revision TKA for either stiffness or aseptic loosening/instability and determine if the presence of HO is associated with inferior absolute range of motion (ROM) and ROM gains.

METHODS

Eighty-seven patients were prospectively enrolled and separated into 2 cohorts to evaluate ROM after revision TKA (2017-2019). Group 1 (N = 40) patients were revised for stiffness, while group 2 (N = 47) patients were revised for either aseptic loosening or instability. Goniometer-measured ROM values were obtained preoperatively and at 6 weeks, 6 months, and 1 year postoperatively. Statistical analysis included a Fisher's exact test to assess for an association between preoperative HO and final ROM at 1 year after revision TKA.

RESULTS

HO was identified on preoperative radiographs in 17 patients (20%). There was a significantly higher rate of preoperative HO in patients revised for stiffness compared to patients revised for instability or loosening (30% vs 11%; P = .03). Five cases of HO qualitatively identified as most clinically severe were associated with lower ROM at each time point compared to the remainder of HO cases in this study cohort (P < .02).

CONCLUSION

The presence of HO is greater in patients undergoing revision TKA for stiffness. Additionally, HO severity appears to have a major effect on preoperative and postoperative ROM trajectory. This information should help guide patient expectations and highlight the need for a comprehensive, standardized classification system for HO.

Relatively Low Rate of Heterotopic Ossification Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-analysis

BACKGROUND

Heterotopic ossification (HO) is abnormal growth of ectopic bone and negatively affects the outcomes after total knee arthroplasty (TKA). This systematic review and meta-analysis were performed to characterize the prevalence and severity of HO after primary TKA.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Patient demographics, publication year, and HO prevalence after a primary TKA were recorded. A meta-analysis was performed to determine the overall prevalence of HO formation, and a subanalysis compared the studies published in different timeframes to determine whether a temporal effect exists for HO prevalence.

RESULTS

Two thousand nine hundred eighty-eight patients underwent primary TKA across the included studies. Fourteen percent of patients (9% to 20%; I2: 93.68%) developed HO postoperatively during a mean follow-up of 40.1 months (11 to 108 months). HO rates seemed to decrease in studies published in more recent years, with a pooled HO prevalence of 5% (0% to 13%; I2: 92.26%) among studies published in the past 15 years compared with 18% (12% to 25%; I2: 92.49%) among studies published before then.

CONCLUSION

Although studies reported a relatively low overall rate of HO after a primary TKA, the absence of a single, standardized classification system precludes the comparisons of HO severity between studies. Overall, HO prevalence seems to have decreased over time, likely reflecting the changes in perioperative medication protocols.

Routine Radiographs After Total Joint Arthroplasty: Is There Clinical Value?

BACKGROUND

Routine radiographs have historically been obtained during routine care after total joint arthroplasty (TJA). However, substantial improvements in surgical technique, biomaterials, and changes in payment models placing greater emphasis on value have occurred. Recently, there has been interest in a transition to performing follow-up visits virtually. The purpose of this study was to assess how frequently patients attend postoperative appointments and the clinical utility of routine radiographs after TJA.

METHODS

Patients undergoing primary total hip arthroplasty and total knee arthroplasty at a single tertiary institution in 2018 were included. Patients attending scheduled follow-up at 6 to 12 weeks and 1 year were assessed. Retrospective chart review was conducted to determine whether abnormalities were noted on routine radiographic surveillance by the orthopedic surgeons or radiologist and if any radiographic findings altered clinical management.

RESULTS

A total of 938 TJAs were performed, and 885 met inclusion criteria, with 423 (47.8%) total hip arthroplasties and 462 (52.2%) total knee arthroplasties. Eight hundred sixty-five (97.7%) patients attended a follow-up visit at 6 or 12 weeks and 589 (66.6%) attended at 1 year postoperatively. A single radiographic abnormality was detected, occurring at the 6- to 12-week period by the radiologist and interpreted as being an artifact by the surgeon. No additional radiographic abnormalities were detected at 1 year. Information from radiographs did not change clinical management for any patients.

CONCLUSION

In a large cohort of patients, routine radiographic surveillance did not detect any true abnormalities during the first year after primary TJA. For patients without symptoms attributable to the TJA prosthesis, conducting virtual care visits without routine radiographs may be considered.

Is There a Need for Recovery Room Radiographs Following Uncomplicated Primary Total Knee Arthroplasty?

Introduction

Total knee arthroplasty (TKA) is one of the most common orthopedic procedures performed in the United States. Obtaining radiographs in the post-anesthesia care unit (PACU) has been the standard of care at most hospitals. The purpose of this study was to examine the utility and cost-effectiveness of immediate, postoperative radiographs in regards to operative decision-making to prevent complications within 90 days after primary TKA.

Methods

A retrospective review of 4,830 consecutive patients who underwent cemented or uncemented TKA between January 2016 and June 2019 at a large, regional medical center was performed. International Classification of Diseases, Tenth Revision (ICD-10) codes were used to track any readmissions within 90 days of TKA. If readmission was for a mechanical complication, including fracture, dislocation, or component loosening, PACU radiographs were reviewed for any abnormalities that may have prevented readmission.

Results

There were 195 readmissions (195 patients), of which 17 were due to mechanical complications. There was no evidence of fracture or abnormality appreciated on any of the reviewed PACU radiographs by either the reading radiologist or the senior authors. Assuming all fractures were noted on immediate, postoperative radiographs, the cost associated with identifying a single fracture in 2,415 patients was $1,072,260.

Conclusion

Routine radiographs in the recovery room after an uncomplicated primary TKA are not a reliable mechanism for preventing mechanical complications and do not alter patient care.

Radiographs are not sufficient for evaluation of component fit in subtle knee pain after total knee arthroplasty

PURPOSE

To determine the component fit by radiography or computed tomography after total knee arthroplasty and the relation of imaging with clinical examination of residual knee pain.

METHODS

The study was conducted in 172 patients with residual knee pain after total knee arthroplasty. The patients were examined to determine whether they experienced pain upon palpation at nine regions surrounding the tibial and femoral components, and the results were noted. The Knee Society Clinical Rating System and The Western Ontario and McMaster Universities Arthritis Index pain scale score forms were completed for all patients. Radiologic evaluation was performed using computed tomography and anteroposterior, lateral, and oblique radiographs to determine component overhang/underhang status at these nine regions. Overhang, underhang, and cortical fit groups were created based on the position of the component at the bone margin. A statistical relationship was sought between the clinical scores and the values measured to determine which imaging method showed the best correlation with clinical scores. Consistency of CT and Rx measurements was compared using the McNemar-Bowker test. Comparisons between groups were made using Student's t test for normally distributed data, and the Mann-Whitney U test.

RESULTS

Computed tomography and radiographic measurements were similar in the medial, anterior, and lateral tibial regions. However, no similarities were observed in the anteromedial, anterolateral, posteromedial, and posterolateral tibial regions, and in the distal-medial and distal-lateral aspects of the femur. Statistical relationships among decreased clinical scores, pain with palpation, and the presence of overhang/underhang were only observed in the medial tibial region for imaging using radiography. A statistically significant relationship was observed in the medial, posteromedial, and posterolateral tibial regions, and in the distal-medial region of the femur for imaging based on computed tomography.

CONCLUSIONS

Radiography could only aid in assessing the component fit in the anteromedial, medial, and lateral regions of the tibia in patients with residual knee pain following knee arthroplasty, but it was not sufficient in comparison with computed tomography in six other regions.

LEVEL OF EVIDENCE

Prospective study, level of evidence II.