Patellar Tendon Ruptures after Total Knee Arthroplasty.

Patellar tendon rupture following total knee arthroplasty (TKA) is a rare, but devastating complication. These injuries occur most frequently in the acute period following TKA due to trauma to the knee. Patellar tendon ruptures that disrupt the extensor mechanism create a marked functional deficit, impacting every facet of daily life. In complete ruptures of the patellar tendon, repair or reconstruction is typically indicated; however, complication rates following intervention remain high, between 25 to 63%. Operative intervention remains the mainstay of treatment, with only certain specific situations where nonoperative intervention is appropriate. Operative treatments include repair with or without augmentation or reconstruction. Augmentation does reduce the high risk of complications, bringing rates down from 63 to 25%. Augmentation options include autografts, allografts, synthetic grafts, or synthetic meshes. Despite advancements, outcomes are unpredictable, and complications are common, highlighting the need for further research to improve treatment protocols. Operative techniques are chosen based on the acuity, location of disruption, and status of the residual soft tissues. This article provides an overview of patellar tendon ruptures following TKA, the various treatment options, and the recommendations of the senior authors for each common type of patellar tendon injury encountered.

Staying Ahead of the Curve: The Case for Recovery Curves in Total Knee Arthroplasty.

BACKGROUND: Sensor technology embedded within the total knee arthroplasty (TKA) implant has the potential to record data that can track recovery and provide diagnostic information. In this study, we introduce the concept of physical function recovery curve analytics, which are created from daily spatial-temporal gait metrics and step counts from a large cohort of TKA patients. METHODS: In our study population, 258 patients underwent a primary TKA with a smart implanted tibial extension between October 4, 2021, and July 15, 2022, by 33 surgeons. The average age was 63 years, with 138 (54%) women. All kinematic data was collected on a Health Insurance Portability and Accountability Act (HIPAA)-compliant cloud data management platform. RESULTS: Summaries of the gait parameters at 6 weeks are suggestive of differences between people over and under 65 years, with the older patients walking more slowly and having shorter stride lengths. The 6-week percentiles demonstrated a strong, linear correlation to the 12-week percentiles for each gait parameter, with correlation coefficients ranging from 0.87 to 0.92. CONCLUSIONS: A novel screening gait test at 6 weeks shows promising results for predicting patients who will likely have poor recovery based on at least 1 gait parameter recovery curve at 12 weeks with high sensitivity and specificity. A future study is needed to validate the screening tool with an independent set of patients.

A Comparison of Proximal Patellar Realignment vs. Medial Patellofemoral Ligament Reconstruction: A Review of the Literature.

¼ Patellar instability is challenging to address, and although there are many surgical options, proximal patellar realignment (PPR) and medial patellofemoral ligament (MPFL) reconstruction are both used-recently, the MPFL reconstruction has become more popularized.¼ Both procedures have demonstrated similar recurrent dislocation rates and rates of arthritic progression.¼ PPR is a cost-efficient procedure using just suture alone as compared with MPFL reconstruction, which uses different grafts and methods of fixation.¼ PPR has demonstrated durable results, with a lower overall complication rate, much of which is caused by the MPFL reconstruction having unique complications due to fixation methods.¼ The PPR is a beneficial procedure and should still be considered when dealing with patellar instability.

Managing Post-Traumatic Arthritis of the Knee with Total Knee Arthroplasty.

Post-traumatic arthritis (PTA) of the knee is a complex problem, requiring foresight and careful preoperative planning. Each case of PTA is unique, requiring understanding of the altered anatomy, management of any retained hardware, and also the ability to provide the appropriate stability for each affected knee. Successful treatment of PTA with total knee arthroplasty (TKA) requires the creation of stable and well-balanced joint. TKA for PTA provides comparable improvements in pain and function when compared with primary osteoarthritis, however, these patients are at increased risk of post-operative complications, including instability and infection.

Patella Fractures after Total Knee Arthroplasty.

Periprosthetic patella fractures are a rare complication that can lead to severe disability following total knee arthroplasty (TKA). There are several factors that increase the risk of this injury, including patient comorbidities, anatomic considerations, and surgical technique. With these factors limiting healing ability in the area, periprosthetic patellar fractures can pose a major challenge to treat, with potentially lasting morbidity for affected patients. These fractures can occur at any time following TKA and are classified based on their associated implant stability and disruption of the extensor mechanism using the Ortiguera and Berry classification system. Each of the three types of fractures can be managed in their own unique way; however, outcomes remain poor, and the complication rates remain high regardless of fracture type. This article provides an overview of the current literature and the recommended management of periprosthetic patella fractures.

Patients with Osteoporosis Are at Higher Risk for Periprosthetic Femoral Fractures and Aseptic Loosening Following Total Hip Arthroplasty.

This report provides an updated analysis for patients with osteoporosis following total hip arthroplasty (THA). The comorbidities of alcohol abuse, chronic kidney disease, cerebrovascular disease, obesity, and rheumatoid arthritis continue to be significant risk factors for periprosthetic femur fracture (PPFFx) and aseptic loosening in the population with osteoporosis. Patients with dual-energy x-ray absorptiometric (DEXA) scans were at risk for PPFFx regardless of femoral fixation method, and patients with DEXA scans with cementless fixation were at risk of aseptic loosening after THA. The patient population with severe osteoporosis may have higher risks for aseptic loosening and PPFFx than previously recognized.

Anatomic Referencing of the Distal Femur in Total Knee Arthroplasty: The Impact of Orientation on Femoral Component Size.

BACKGROUND: Anatomic referencing in total knee arthroplasty places the femoral component flush to the anterior cortex while maintaining posterior condylar offset (PCO). The intent of this study was to evaluate how component position influences the femoral component size. METHODS: Digital surface models were created using 446 femora from an established computed tomography database. Virtual bone resections, component sizing, and component placement were performed assuming neutral (0°) flexion and neutral (3°) rotation relative to the posterior condyles. The appropriately sized femoral component, which had 2 mm of incremental size, was placed flush with the anterior cortex for optimal restoration of the PCO. Sizing and placement were repeated using 3 and 6° flexion and 0, 5, and 7° external rotation (ER). RESULTS: At 0° flexion, decreasing ER from 3 to 0° resulted in an average decreased anterior-posterior height (APH) of 1.9 mm, corresponding to a component size decrease of 1 for 88% of patients. At 7° ER, component size increased by an average of 2.5 mm, corresponding to a size increase for 80% of patients. Flexing the femoral component to 3° with ER at 3° resulted in a decrease in APH of 2.2 mm (1 size decrease in 93% of patients). At 3° flexion and 3° ER, 86% had the same component size as at 0° flexion and 0° ER. Increasing ER at 3° flexion increased APH by 1.2 mm at 5° and 3.1 mm at 7° on average, relative to 3° ER. Increasing flexion from 3 to 6° extended this effect. CONCLUSIONS: Flexion decreases the APH when the ER is held constant. The ER of the femoral component increases the APH across all tested flexion angles, causing an increase in the ideal femoral component size to maintain PCO. With anatomic referencing, alterations in femoral component positioning and subsequent changes in component size can be accounted for.

Antibiotic prophylaxis prior to colonoscopy with biopsy does not decrease risk of prosthetic joint infection in total knee arthroplasty recipients.

Introduction: Prosthetic joint infection (PJI) risk continues to receive much attention given its associated morbidity and costs to patients and healthcare systems. It has been hypothesized that invasive colonoscopies may increase the risk of PJI. However, the decision to administer antibiotic prophylaxis lacks clinical guidance. In this study we aimed to compare PJI rates in patients undergoing colonoscopies with and without antibiotic prophylaxis against a control group, analyzing PJI occurrences at 90 days, 6 months, 9 months, and 1-year post-procedure and (2) assess the impact of antibiotic prophylaxis on PJI rates to inform clinical guidelines. Methods: We queried a national, all-payer database to identify all primary total knee arthroplasty procedures without prior history of PJI between January 2010 and October 2020 (n = 1.9 million). All patients who had a diagnosis of PJI within one year of index procedure were excluded. There were three cohorts identified: colonoscopy with biopsy without antibiotic prophylaxis; colonoscopy with biopsy with antibiotic prophylaxis; and a control of no prior colonoscopy. Both colonoscopy cohorts were slightly younger and had higher comorbidities than the controls. The PJI diagnoses were identified at four separate time intervals within one-year after colonoscopy: 90-days; 6-months; 9-months; and 1-year. Chi-square analyses with odds ratios (ORs) and 95% confidence intervals were conducted for PJI rates between groups at all time-points. Results: Among all cohorts, no significant differences in PJI rates were found at 90-days (P = 0.459), 6-months (P = 0.608), 9-months (P = 0.598), and 1-year (P = 0.330). Similarly, direct comparison of both colonoscopy groups, with and without antibiotic prophylaxis, demonstrated no PJI rate differences at 90-day (P = 0.540), 6-months (P = 0.812), 9-months (P = 0.958), and 1-year (P = 0.207). Ranges of ORs between the colonoscopy cohorts were 1.07-1.43. Conclusion: Invasive colonoscopy does not increase the risk of PJI in patients who have pre-existing knee implants. Furthermore, antibiotic prophylaxis may not be warranted in patients undergoing colonoscopy who have a planned biopsy.