Total knee arthroplasty (TKA) continues to be a widely successful procedure by alleviating pain and restoring function for patients with degenerative disease of the knee. However, a significant number of patients continue to be dissatisfied with their TKA. Although patient dissatisfaction is multifactorial, the inability of total knee implants to restore native knee kinematics is likely a contributing factor.

Historically, the orthopedic world has debated between two main camps of knee design: posterior-stabilized and cruciate-retaining. Traditional posterior-stabilized total knee implant designs use a cam and post mechanism, which promotes roll back of the femur on the tibia during knee flexion. In contrast, traditional cruciate-retaining knee implants have a round-on-flat articulation that relies on an intact posterior cruciate ligament (PCL).

Read more

Unicompartmental knee arthroplasty (UKA), or partial knee replacement, is a technically demanding procedure vulnerable to errors in component positioning, alignment, and soft-tissue balancing. Early failures have been linked to excessive posterior tibial slope and placement of tibial components in a high degree of varus. To address these vulnerabilities, robotics has been marketed and increasingly adopted.

The orthopedic community has been inundated with messaging suggesting that robotic-assisted UKA improves the accuracy and precision of bone preparation and component alignment. But this technology comes at a steep price. Initial capital investment for robotic arthroplasty systems is estimated to range from $800,000 to $1,200,000, and disposable costs are estimated to range from $750 to $1,000 per case. In an era where reducing healthcare costs is paramount, we have to ask: Does everyone need a million-dollar robot, or does surgical experience still matter?

Read more

Despite the clinical success of primary total knee arthroplasty (TKA), complications requiring revision TKA (rTKA) persist. Treatment goals in rTKA are to perform a durable reconstruction that alleviates a patient’s pain and improves function. In rTKA, joint line elevation may occur when bone lost from the distal femur is not replaced, leading to historical recommendations that distal femoral augments be used to restore a native joint line.

The consequences of an elevated joint line were postulated to be inferior patient outcomes, decreased range of motion, less extensor strength, and anterior knee pain. However, interestingly, many “symptoms” of an elevated joint line can also be explained by instability, which has recently been described as one of the leading reasons for additional revisions of rTKAs. This study’s purpose was to evaluate the effect of joint line height elevation on validated patient-reported outcome measures (PROMs) using modern revision implants.

Read more

Despite the clinical success of primary total knee arthroplasty (TKA), complications requiring revision TKA (rTKA) persist. Treatment goals in rTKA are to perform a durable reconstruction that alleviates a patient’s pain and improves function. In rTKA, joint line elevation may occur when bone lost from the distal femur is not replaced, leading to historical recommendations that distal femoral augments be used to restore a native joint line.

The consequences of an elevated joint line were postulated to be inferior patient outcomes, decreased range of motion, less extensor strength, and anterior knee pain. However, interestingly, many “symptoms” of an elevated joint line can also be explained by instability, which has recently been described as one of the leading reasons for additional revisions of rTKAs. This study’s purpose was to evaluate the effect of joint line height elevation on validated patient-reported outcome measures (PROMs) using modern revision implants.

Read more

Despite the clinical success of primary total knee arthroplasty (TKA), complications requiring revision TKA (rTKA) persist. Treatment goals in rTKA are to perform a durable reconstruction that alleviates a patient’s pain and improves function. In rTKA, joint line elevation may occur when bone lost from the distal femur is not replaced, leading to historical recommendations that distal femoral augments be used to restore a native joint line.

The consequences of an elevated joint line were postulated to be inferior patient outcomes, decreased range of motion, less extensor strength, and anterior knee pain. However, interestingly, many “symptoms” of an elevated joint line can also be explained by instability, which has recently been described as one of the leading reasons for additional revisions of rTKAs. This study’s purpose was to evaluate the effect of joint line height elevation on validated patient-reported outcome measures (PROMs) using modern revision implants.

Read more

Dislocation remains a challenging and relatively common complication following total hip arthroplasty (THA). Instability is the leading cause of revision following THA, which can lead to poor patient outcomes and increased economic burden. To combat this, surgeon-controlled factors for the prevention and treatment of instability often include maximizing femoral head diameter and the use of dual mobility (DM) bearings.

DM femoral head bearings were approved for use in the United States in 2009. The use of this implant design has grown significantly over the last decade and is now commonly used in modern THA for both primary and revision cases. The DM design combines the low frictional torque principle of a smaller head size with the benefit of a large-diameter outer bearing to increase the head-neck ratio. However, it remains unclear from the literature what benefit DM provides compared to simply using large-diameter femoral heads. We wanted to find out if the complex, heavily marketed DM bearing was actually better than a traditional “jumbo” head of the same size.

Read more

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 virus presented unprecedented challenges to elective total joint arthroplasty (TJA) services. The impact of delaying surgery cannot be understated. Consequences include the progression of pain and decrease of function, increased anti-inflammatory and pain medication use, and deteriorating mental health, as well as further bone loss and osteolysis or recurrent instability leading to soft-tissue damage. Consequently, increasing safe and effective outpatient TJA has been recommended to minimize inpatient hospital burden while appropriately caring for patients in a timely manner.

Outpatient primary TJA has been adopted at a growing number of ambulatory surgical centers (ASCs) and hospital systems in the United States. More recently, early discharge following aseptic revision TJA has been investigated; however, only a few studies have been published to date, with only 2 studies focused specifically on same-day discharge (SDD). We wanted to know if we could safely push the boundary further and bring the benefits of same-day discharge to patients requiring complex aseptic revisions and conversions.

Read more

Postoperative urinary retention (POUR) after primary hip and knee total joint arthroplasty (TJA) ranges from 4% to 46%. POUR is associated with urological injury and urinary tract infection (UTI) with possible hematogenous periprosthetic joint infection. Because of these risks, and the fact that a patient cannot be safely sent home until they can void, POUR is a common barrier to rapid-discharge TJA.

When a patient experiences POUR, the clinical team must intervene. Consequently, catheterization with an indwelling catheter, treatment with intermittent catheterization, or both are routinely used. However, the choice is driven by provider preference, with both methods associated with undesirable consequences, including increased infection risk, discomfort and pain, and compromised dignity. We wanted to look at the hard data to determine which method is actually the safest and most effective for getting our patients home.

Read more

Technological advances in the field of orthopaedics are widely being adopted across subspecialty fields in an attempt to improve the outcome of various surgical procedures. The use of robotic assistance and computer navigation during total knee arthroplasty (TKA) has increased in recent years. However, despite these proposed benefits, the literature is devoid of high quality, level-1 studies rigorously comparing manual and robotic-assisted surgery.

Furthermore, the rise of robotic-assisted TKAs has created a new environment for surgical trainees. Use of robotic assistance for TKA requires a new set of skills when compared to conventional techniques. This raises a critical question: Could the addition of robotic technology in the operating room have a negative impact on residents’ surgical skills and understanding of fundamental concepts of TKA?

Read more

Despite the clinical success of primary total knee arthroplasty (TKA) , surgical site complications (SSCs) including surgical site infections (SSIs) and wound healing complications are a leading cause of morbidity, unplanned early readmission , delayed return to work, and economic burden. This is incredibly serious, as patients with superficial SSIs are also more likely to develop deep periprosthetic joint infection (PJI) , a devastating complication.

Concurrent with the increasing number of surgeries performed in the last 2 decades, the overall medical comorbidity burden of patients undergoing primary TKA has risen dramatically , resulting in a larger total “at-risk” population. Closed incision negative pressure wound therapy (ciNPWT) is one method for reducing SSCs. However, for uncomplicated cases, surgeons should recognize the significant up-front cost difference between the 2 dressings. At our institution, the silver impregnated dressing costs $35.22, whereas a similarly sized ciNPWT dressing costs $389.99, representing a nearly 10-fold greater up-front cost per surgery.

Read more

Despite the clinical success of primary total knee arthroplasty (TKA), surgical site complications (SSCs) including surgical site infections (SSIs) and wound healing complications are a leading cause of morbidity, unplanned early readmission, delayed return to work, and economic burden. Patients with superficial SSIs are also more likely to develop deep periprosthetic joint infection (PJI), a devastating complication.

Concurrent with the increasing number of surgeries performed in the last two decades, the overall medical comorbidity burden of patients undergoing primary TKA has risen dramatically. Closed incision negative pressure wound therapy (ciNPWT) is one method for reducing SSCs. First introduced in 1997, in the form of vacuum-assisted closure, negative pressure therapy has long been considered the gold standard for treatment of acute and chronic open wounds. This technology has since been expanded to at-risk incisions in the form of ciNPWT.

However, a similarly sized ciNPWT dressing costs a hospital nearly 10 times as much as a standard occlusive silver impregnated dressing ($389.99 vs. $35.22). We wanted to know if this massive cost difference was truly justified for high-risk patients.

Read more

Periprosthetic joint infection (PJI) remains one of the most common causes of early revision total joint arthroplasty (TJA). It represents a staggering 14.8% of total hip arthroplasty (THA) and 25.5% of total knee arthroplasty (TKA) revisions performed in the United States. The financial burden is immense, with the direct costs of a single revision for infection ranging from $75,000 to $100,000.

Currently, clinical practice guidelines recommend utilizing serum tests like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), alongside synovial tests like polymorphonuclear percentage (PMN%), to diagnose PJI. However, no single test or scoring method has been shown to be 100% sensitive and specific in diagnosing PJI. While novel biomarkers like alpha-defensin and calprotectin offer potential for increased detection, they may not be readily available at every institution and can be costly.

This has driven researchers to ask a vital question: Could a synovial marker currently utilized in the standard workup of PJI, without requiring additional infrastructure or cost, be interpreted in a novel way to predict infection?

Read more

Periprosthetic joint infection (PJI) remains one of the most common causes of early revision total joint arthroplasty (TJA), representing 14.8% of total hip arthroplasty (THA) and 25.5% of total knee arthroplasty (TKA) revisions performed in the United States. The risk of PJI after THA and TKA is approximately 0.4%-2% in the United States. Revision takes a great toll on patients, surgeons, healthcare professionals, hospitals, and the healthcare system.

Currently, no single test or scoring method has been shown to be 100% sensitive and specific in diagnosing PJI. While new biomarkers offer potential for increased detection of PJI, they may not be readily available at every institution and can be costly. Therefore, it would be ideal if a synovial marker that is currently utilized in the standard workup of PJI, without requiring additional infrastructure or cost, could be interpreted in a novel way to predict infection.

There has been growing interest in interpreting known biomarkers in a novel way to aid in diagnosing infection, including Absolute Neutrophil Count (ANC) and Neutrophil-to-Lymphocyte Ratio (NLR).

Read more

In the fast-paced world of orthopedic surgery, peer-reviewed literature is the bedrock of clinical decision-making. Surgeons rely on published studies to refine their techniques, select implants, and ultimately improve patient outcomes. However, the integrity of this process depends on relentless scrutiny and the willingness of the medical community to challenge inconsistencies.

Recently, we read a study published in The Journal of Arthroplasty with great interest. The study, entitled “Are Kinematics an Indicator of Outcome After Total Knee Arthroplasty?” by Hodge and colleagues, investigated the relationship between in vivo knee kinematics data and patient-reported outcome measures (PROMs) during specific physical tasks. We commend the authors on a certainly onerous data collection and analysis process that few investigators are willing to undertake. However, upon a deep dive into the paper, we discovered several glaring inconsistencies that compelled us to submit a formal Letter to the Editor.

Read more

Despite excellent long-term survivorship and outcomes after total knee arthroplasty (TKA) , patient satisfaction stubbornly lags behind that of total hip arthroplasty, with approximately 20% of unsatisfied patients. Unsatisfied patients experience pain, functional limitations, and describe an unnatural feel to the knee. To help close the gap on the subset of unsatisfied patients, there is increased interest in knee kinematics before and after TKA related to kinematic pivot patterns, which may help optimize patient-reported outcomes.

Traditionally, it was hypothesized that the optimal kinematic pivot pattern was predominantly medial through the range of motion. However, a modern understanding of kinematic pivot patterns in healthy knees and post-TKA knees may be nuanced with a more accurate description of a dual-pivot kinematic pivot pattern characterized by a lateral pivot in early flexion, which transitions to a medial pivot in mid to late flexion. Recently, this dual-pivot kinematic pivot pattern has shown superior patient-reported outcomes related to satisfaction and patients reporting their knee to always feel normal at 1-year after TKA compared with various other patterns.

Read more

Unicompartmental knee arthroplasty (UKA) is an attractive treatment option for unicompartmental osteoarthritis (OA) due to preservation of cruciate ligaments and bone stock, expedited recovery, reduced blood loss, and fewer complications compared to other surgical interventions. However, the decision of who is a good candidate for this procedure has been heavily influenced by historical guidelines.

In 1989, criteria were developed by Kozinn and Scott to guide surgeons with patient selection for UKA. Since its introduction, pre-existing patellofemoral arthropathy has been widely considered a contraindication by many surgeons. This means that for decades, if a patient had arthritis under their kneecap (the patellofemoral joint), they were typically disqualified from receiving a partial knee replacement and steered toward a total knee replacement instead.

More recently, some studies have argued that patellofemoral disease can be ignored in UKA; however, this supporting research is predominantly in mobile-bearing designs. We wanted to evaluate the effect of patellofemoral OA severity on the latest outcomes after fixed-bearing medial UKA.

Read more

A painful hip following total hip arthroplasty (THA) is concerning to patients and surgeons, particularly in the setting of satisfactory postoperative radiographs. Traditionally, most painful hips are caused by periprosthetic joint infection, component loosening, and instability. However, when these major mechanical issues are ruled out, both the patient and the physician can be left searching for answers.

Other less commonly reported causes of painful THAs persist and can be related to musculotendinous deficiencies, which include iliopsoas tendinitis and abductor mechanism disruption. These frequently underdiagnosed deficiencies are poorly understood in the literature and therefore challenging to resolve.

Read more

In the United States, same-day discharge (SDD) after primary hip and knee total joint arthroplasty (TJA) has evolved into an increasingly common practice. We know that when properly executed, SDD is highly effective. Nonetheless, failure to achieve planned SDD for primary TJA occurs in as many as 7% to 49% of patients in the United States.

As we push for more efficient, patient-friendly recovery pathways, it is critical to understand why these failures happen. To find out, we performed a retrospective analysis of prospectively collected data from 466 primary TJAs with planned SDD to home. Surgeries were performed at an academic tertiary care center comprising a hospital facility and a stand-alone ambulatory surgery center (ASC) on the same campus.

Read more

Enhancement of primary total joint arthroplasty (TJA) clinical and surgical protocols, cost containment, and recent shifts in Medicare policies have coalesced to promote the rapid growth of outpatient TJA. Identification of patients who can safely undergo outpatient TJA remains a top priority.

The Outpatient Arthroplasty Risk Assessment (OARA) score was previously developed to assign points to 52 comorbidities across 9 medical areas to generate a threshold score for safe patient selection.

Read more

Total joint arthroplasty (TJA) is among the most successful of orthopedic procedures performed. However, the exponentially increased demand for TJA has imposed an enormous economic burden on the healthcare system, accounting for more Medicare expenses than any other inpatient procedure. Not surprisingly, cost containment has become a focus of policy and research in TJA.

In 2016, a pilot study triggered by Anthem insurance found the average intraservice times for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) to be less than the Centers for Medicare and Medicaid Services (CMS) benchmark of 100 minutes.

Read more