Metallosis in Total Hip Arthroplasty.

¼ Metallosis is a rare but significant complication that can occur after total hip arthroplasty (THA) for a variety of reasons but most commonly in patients with metal-on-metal implants.¼ It is characterized by the visible staining, necrosis, and fibrosis of the periprosthetic soft tissues, along with the variable presence of aseptic cysts and solid soft tissue masses called pseudotumors secondary to the corrosion and deposition of metal debris.¼ Metallosis can present with a spectrum of complications ranging from pain and inflammation to more severe symptoms such as osteolysis, soft tissue damage, and pseudotumor formation.¼ Workup of metallosis includes a clinical evaluation of the patient's symptoms, imaging studies, serum metal-ion levels, and intraoperative visualization of the staining of tissues. Inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein along with intraoperative frozen slice analysis may be useful in certain cases to rule out concurrent periprosthetic joint infection.¼ Management depends on the severity and extent of the condition; however, revision THA is often required to prevent rapid progression of bone loss and tissue necrosis.

Higher Complication Rate in COVID-19 Recovered Patients Undergoing Primary Total Joint Arthroplasty.

BACKGROUND: There is limited data reviewing complication risks associated with total joint arthroplasty (TJA) after recovering from COVID-19. This study evaluated complications within 90 days of TJA in patients who had a COVID-19 diagnosis at varying intervals prior to surgery versus a non-COVID-19 cohort. METHODS: A large national database was used to identify patients diagnosed with COVID-19 in the six months prior to total hip arthroplasty (THA) or total knee arthroplasty. The incidence of complications within 90 days of surgery was recorded and compared to a COVID-19 negative control group matched 1:3 for age range in 5-year intervals, Charlson Comorbidity Index, and sex. There were 7,780 patients included in the study; 5,840 (75.1%) never diagnosed with COVID-19, 1,390 (17.9%) who had a COVID-19 diagnosis 0 to 3 months prior to surgery, and 550 (7.1%) who had a COVID-19 diagnosis 3 to 6 months prior to surgery. RESULTS: When compared to their COVID negative controls, patients who had a COVID-19 diagnosis 0 to 3 months prior to surgery had significantly higher rates of readmission (14.0 versus 11.1%, P = .001), pneumonia (2.2 versus 0.7%, P < .001), deep vein thrombosis (DVT) (3.3 versus 1.9%, P = .001), kidney failure (2.4 versus 1.4%, P = .006), and acute respiratory distress syndrome (1.4 versus 0.7%, P = .01). Patients who had a COVID-19 diagnosis 3 to 6 months prior to surgery had significantly higher rates of pneumonia (2.0 versus 0.7%, P = .002) and DVT (3.6 versus 1.9%, P = .005) when compared to their COVID negative controls. CONCLUSION: Patients diagnosed with COVID-19 within three months prior to TJA have an increased risk of 90-day postoperative complications. Risk for pneumonia and DVT remains elevated even when surgery was performed as far as 3 to 6 months after COVID-19 diagnosis.

Revision total knee arthroplasty for arthrofibrosis improves range of motion.

PURPOSE: Arthrofibrosis after primary total knee arthroplasty (TKA) is a significant contributor to patient dissatisfaction. While treatment algorithms involve early physical therapy and manipulation under anaesthesia (MUA), some patients ultimately require revision TKA. It is unclear whether revision TKA can consistently improve these patient's range of motion (ROM). The purpose of this study was to evaluate ROM when revision TKA was performed for arthrofibrosis. METHODS: A retrospective study of 42 TKA's diagnosed with arthrofibrosis from 2013 to 2019 at a single institution with a minimum 2-year follow-up was performed. The primary outcome was ROM (flexion, extension, and total arc of motion) before and after revision TKA, and secondary outcomes included patient reported outcomes information system (PROMIS) scores. Categorical data were compared using chi-squared analysis, and paired samples t tests were performed to compare ROM at three different times: pre-primary TKA, pre-revision TKA, and post-revision TKA. A multivariable linear regression analysis was performed to assess for effect modification on total ROM. RESULTS: The patient's pre-revision mean flexion was 85.6 degrees, and mean extension was 10.1 degrees. At the time of the revision, the mean age of the cohort was 64.7 years, the average body mass index (BMI) was 29.8, and 62% were female. At a mean follow-up of 4.5 years, revision TKA significantly improved terminal flexion by 18.4 degrees (p < 0.001), terminal extension by 6.8 degrees (p = 0.007), and total arc of motion by 25.2 degrees (p < 0.001). The final ROM after revision TKA was not significantly different from the patient's pre-primary TKA ROM (p = 0.759). PROMIS physical function, depression, and pain interference scores were 39 (SD = 7.72), 49 (SD = 8.39), and 62 (SD = 7.25), respectively. CONCLUSION: Revision TKA for arthrofibrosis significantly improved ROM at a mean follow-up of 4.5 years with over 25 degrees of improvement in the total arc of motion, resulting in final ROM similar to pre-primary TKA ROM. PROMIS physical function and pain scores showed moderate dysfunction, while depression scores were within normal limits. While physical therapy and MUA remain the gold standard for the early treatment of stiffness after TKA, revision TKA can improve ROM. LEVEL OF EVIDENCE: IV.

Digital Radiography in Total Hip Arthroplasty: Technique and Radiographic Results.

BACKGROUND: Obtaining the ideal acetabular cup position in total hip arthroplasty remains a challenge. Advancements in digital radiography and image analysis software allow the assessment of the cup position during the surgical procedure. This study describes a validated technique for evaluating cup position during total hip arthroplasty using digital radiography. METHODS: Three hundred and sixty-nine consecutive patients undergoing total hip arthroplasty were prospectively enrolled. Preoperative supine anteroposterior pelvic radiographs were made. Intraoperative anteroposterior pelvic radiographs were made with the patient in the lateral decubitus position. Radiographic beam angle adjustments and operative table adjustments were made to approximate rotation and tilt of the preoperative radiograph. The target for cup position was 30° to 50° abduction and 15° to 35° anteversion. Intraoperative radiographic measurements were calculated and final cup position was determined after strict impingement and range-of-motion testing. Postoperative anteroposterior pelvic radiographs were made. Two independent observers remeasured all abduction and anteversion angles. RESULTS: Of the cups, 97.8% were placed within 30° to 50° of abduction, with a mean angle (and standard deviation) of 39.5° ± 4.6°. The 2.2% of cups placed outside the target zone were placed so purposefully on the basis of intraoperative range-of-motion testing and patient factors, and 97.6% of cups were placed between 15° and 35° of anteversion, with a mean angle of 26.6° ± 4.7°. Twenty-eight percent of cups were repositioned on the basis of intraoperative measurements. Subluxation during range-of-motion testing occurred in 3% of hips despite acceptable measurements, necessitating cup repositioning. There was 1 early anterior dislocation. CONCLUSIONS: Placing the acetabular component within a target range is a critical component to minimizing dislocation and polyethylene wear in total hip arthroplasty. Using digital radiography, we positioned the acetabular component in our desired target zone in 97.8% of cases and outside the target zone, purposefully, in 2.2% of cases. When used in conjunction with strict impingement testing, digital radiography allows for predictable cup placement in total hip arthroplasty.