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JBJS Essential Surgical Techniques Awards

JBJS Essential Surgical Techniques (EST) and The Journal of Bone and Joint Surgery (JBJS) give out two annual awards–one for the best Subspecialty Procedure (SP) video article, and the other for the best Key Procedures (KP) video article published during each calendar year.  

We are pleased to spotlight the 2020 Award Winners: 

Editor’s Choice Subspecialty Procedures Award 

Minimally Invasive Sacroiliac Joint Fusion: A Lateral Approach Using Triangular Titanium Implants and Navigation
by David W. Polly Jr., MD, and Kenneth J. Holton, MD 

Editor’s Choice Key Procedures Award 

Computerized Navigation: A Useful Tool in Total Knee Replacement
by Oystein Gothesen, MD, PhD; Oystein Skaden, MD; Gro S. Dyrhovden, MD; Gunnar Petursson, MD, PhD; and Ove N. Furnes, MD, PhD 

Both articles are freely available online. 

Submissions for the 2021 EST Awards are currently being accepted. 

BMI Differentially Moderates Heritability of THA and TKA for Osteoarthritis

Genetic susceptibility to orthopaedic conditions is of interest to clinicians and patients alike. While the link between genetics and certain pediatric conditions is known, studies of sets of twins are providing new insights into adult issues, such as osteoarthritis, and the impact that genetics may have.

In the current issue of JBJS, Hailer et al. report on an investigation in Sweden in which they analyzed genetic susceptibility to hip and knee osteoarthritis necessitating total hip arthroplasty (THA) or total knee arthroplasty (TKA), and whether body mass index (BMI) moderates the heritability of these outcomes. They linked nearly 30,000 twin pairs with BMI information in the Swedish Twin Registry with the Swedish National Patient Register to identify twins who had undergone THA or TKA with a primary diagnosis of osteoarthritis. Structural equation modeling was then used to calculate the heritability of osteoarthritis treated with THA or TKA and how it related to BMI, age, and sex.

The authors note that, for radiographically defined knee osteoarthritis, previous twin studies have shown that the genetic susceptibility (“the proportion of the variation of a trait that can be attributed to the variation of genetic factors”) is between 0.4 to 0.8. In twin studies using total joint replacement as the outcome, heritability has been estimated to be 0.2 for TKA and 0.5 for THA.

Hailer et al. found that, on average in their cohort, approximately half of the susceptibility to undergo THA or TKA for osteoarthritis was explained by heritability, with similar estimates demonstrated for the 2 procedures: THA, 0.65 (95% CI, 0.59 to 0.70) and TKA, 0.57 (95% CI, 0.50 to 0.64). Of note, heritability decreased with higher BMI in both men and women for THA and in men for TKA. But in women, heritability for TKA increased with higher BMI (0.37 for a BMI of 20 kg/m2 and 0.87 for a BMI of 35 kg/m2).

Although the need for THA or TKA is not a perfect indicator of osteoarthritis (plenty of osteoarthritis does not become symptomatic enough to warrant total joint arthroplasty), this large study offers further data on the question of genetic susceptibility to the development of osteoarthritis. Understanding the influence of obesity (a modifiable risk factor) becomes increasingly important and warrants continued investigation in studies exploring heritability in relation to orthopaedic conditions. 

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Ten-Year Results of the BIRMINGHAM HIP Resurfacing Implant System 

There have been 3 historic cycles of interest in surface replacement of the hip in the last 40 years. The second cycle occurred in the 1980s into the 1990s, when very high failure rates were reported. Biomaterial and design advancements fueled the most recent cycle of interest, which began 12 to 15 years ago. However, the enthusiasm that occurred at the advent of this most recent cycle ebbed as it became increasingly apparent that patient selection is critical and that the fairly difficult hip resurfacing procedure requires experience to reproducibly place the implants correctly. 

In the latest issue of JBJS,  Su et al. report the 10-year results of the post-market-approval study of the BIRMINGHAM HIP Resurfacing (BHR) implant system, a metal-on-metal system approved by the U.S. Food and Drug Administration in 2006. The study included a cohort of 280 hips (253 patients) undergoing primary BHR procedures across 5 sites. The mean patient age at the time of surgery was 51 years; 74% of the BHRs were implanted in male patients, and 95% of the hips had a diagnosis of osteoarthritis.  

Among the findings: 

  • 10-year survivorship free from all-cause component revision was 92.9%. Among male patients <65 years of age at the time of the procedure, the rate was 96%. 
  • Twenty hips underwent revision (at a mean of 5 years).  
  • Whole-blood cobalt and chromium levels were higher at 1 year after surgery compared with preop levels; they remained stable through 5 years, and then decreased somewhat at 10 years.  
  • Improvements in the EQ-5D visual analogue scale score and Harris hip score were noted at 1 year and were maintained through 10 years.  

These outcomes are encouraging, but as Su et al. point out, the cohort is not representative of typical total hip arthroplasty populations, who tend to be older and include a greater percentage of female patients. Moreover, the surgeons who performed the procedures were all experienced. Patient selection remains key, with younger male patients being the best candidates. Data such as these can help sharpen our focus as we refine arthroplasty concepts for further improvement in patient outcomes. 

For additional perspective on this study, see the commentary by Timothy S. Brown, MD 

Marc Swiontkowski, MD
JBJS Editor-in-Chief 

Decrease in Inflation-Adjusted Medicare Reimbursement for Revision THA 

In a study now reported in JBJS, Acuña et al. analyzed Medicare reimbursements associated with revision total hip arthroplasty (THA) procedures. After adjusting for inflation, they found that the mean physician fee reimbursement for revision THA due to aseptic complications declined by a mean of 27% for femoral component revision, 27% for acetabular component revision, and 28% for both-component revision from 2002 to 2019. For 2-stage revision due to infection, they found that mean reimbursement fell by 19% and 24% for the explantation and reimplantation stages, respectively.  

The total decline in reimbursement for revision THA due to infection ($1,020.64 ± $233.72) was significantly greater than that for revision due to aseptic complications ($580.72 ± $107.22) (p < 0.00001). 

Reflecting on their investigation, the authors note: 

In light of persistent cost pressures and discussions surrounding the future of total hip arthroplasty reimbursement, our study explores temporal trends in the Centers for Medicare & Medicaid Services (CMS) physician fee schedule for revision THA procedures. Our findings, showing a significantly larger decline for septic revision THA reimbursements compared to their aseptic counterpart, may have important implications for ongoing discussions surrounding the CMS physician fee schedule.” 

They conclude in their study that, “continuation of this trend [of decreased reimbursement] could create substantial disincentives for physicians to perform such procedures and limit access to care at the population level.” 

Click here for the full JBJS report. 

A recent OrthoBuzz post on reimbursement for revision TKA can be found here. 

 

What’s New in Orthopaedic Trauma 2021 

Every month, JBJS publishes a review of the most pertinent and impactful studies reported in the orthopaedic literature during the previous year in 14 subspecialties. Click here for a collection of all such OrthoBuzz specialty-update summaries.

This month, co-author Mai P. Nguyen, MD summarizes the 5 most compelling findings from the >30 studies highlighted in the recently published “What’s New in Orthopaedic Trauma.”

Proximal Humeral Fracture 

–The DelPhi (Delta prosthesis-PHILOS plate) study, a multicenter, single-blinded, randomized controlled trial (RCT), evaluated the outcomes of reverse shoulder arthroplasty vs open reduction and internal fixation for displaced proximal humeral fractures in elderly patients. The results favored reverse shoulder arthroplasty (mean 2-year Constant-Murley score of 68.0 vs. 54.6 points for the 2 groups, respectively).

Hip Fracture 

–An RCT comparing hemiarthroplasty with or without cement in elderly patients with a displaced intracapsular fracture of the hip found better results for cemented hemiarthroplasty1. The number of mortalities was slightly higher in the uncemented group, although not significantly so (64 patients compared with 51; p 0.18). Although pain scores and reoperations were similar between the groups, better recovery of mobility was noted for the cemented group.

Proximal Femoral Fracture 

–Another recent RCT investigated the efficacy of a preoperative fascia iliaca compartment block (FICB) for patients with proximal femoral fractures (neck, intertrochanteric, or subtrochanteric regions)2. Lower morphine consumption (0.4 vs 19.4 mg; p = 0.05) and greater patient-reported satisfaction (31%; p = 0.01) were noted for the FICB cohort.

Ankle Fracture

–Among patients treated for unstable, rotational-type ankle fractures, a prospective RCT compared weight-bearing at 2 vs 6 weeks postoperatively3. Early weight-bearing at 2 weeks was associated with higher EuroQol-5 Dimension (EQ-5D) visual analog scale (VAS) scores at the 6-week follow-up. No difference, however, was seen at later follow-up time points.

Recovery After Trauma 

–The impact of trauma recovery services (TRS), which provide education and psychosocial support to patients with trauma and their families, was assessed in a recent study4. A total of 294 patients with operatively treated extremity fractures were prospectively surveyed. Injury, social, and demographic characteristics were studied for a possible association with patient-satisfaction scores. Use of TRS was the greatest predictor of better overall care ratings.

References

  1. Parker MJ, Cawley S. Cemented or uncemented hemiarthroplasty for displaced intracapsular fractures of the hip: a randomized trial of 400 patients. Bone Joint J. 2020 Jan;102-B(1):11-6.
  2. Thompson J, Long M, Rogers E, Pesso R, Galos D, Dengenis RC, Ruotolo C. Fascia iliaca block decreases hip fracture postoperative opioid consumption: a prospective randomized controlled trial. J Orthop Trauma. 2020 Jan;34(1):49-54.
  3. Schubert J, Lambers KTA, Kimber C, Denk K, Cho M, Doornberg JN, Jaarsma RL. Effect on overall health status with weightbearing at 2 weeks vs 6 weeks after open reduction and internal fixation of ankle fractures. Foot Ankle Int. 2020 Jun;41(6):658-65. Epub 2020 Mar 6.
  4. Simske NM, Benedick A, Rascoe AS, Hendrickson SB, Vallier HA. Patient satisfaction is improved with exposure to Trauma Recovery Services. J Am Acad Orthop Surg. 2020 Jul 15;28(14):597-605.

Changes in 24-Hour Physical Activity Patterns and Walking Gait Biomechanics After Primary Total Hip Arthroplasty

Together with improvements in self-reported pain and perceived physical function, patients had significantly improved gait function postoperatively.

Read the full article here.

Contralateral Limb Function Before THA: An Indicator of Postop Gait Speed 

In a prospective case-control study reported in JBJS, Ohmori et al. evaluated factors related to postoperative gait speed in patients with osteoarthritis undergoing total hip arthroplasty. They found that the preoperative, contralateral-side OLST (one-leg standing time) was a significant factor (p < 0.001) for postoperative comfortable gait speed. They also found that preoperative, contralateral-side knee extensor strength was a significant factor (p = 0.018) for postoperative maximum gait speed. 

Reflecting on their findings, the authors note: 

THA is a procedure that typically has a good a postoperative prognosis. However, some patients do not have sufficient satisfaction. Investigating reasons for this, we found that the functional status of the nonoperative lower limb is an important factor. 

Surgical intervention before lower-limb function on the contralateral side declines, or a preoperative rehabilitation intervention on the contralateral side, may improve the THA outcome.” 

Click here for the full JBJS report. 

Use of Machine Learning to Predict Improvement After Hip Arthroscopy 

The management of expectations is crucial when counseling patients undergoing treatment for a musculoskeletal injury or condition. In hip arthroscopy, this is especially critical when discussing with patients—including athletes seeking to return to play—their anticipated outcomes following surgical treatment for femoroacetabular impingement syndrome (FAIS).

In the latest issue of JBJS, Kunze et al. report on their investigative efforts to develop and internally validate machine learning algorithms that can yield patient-specific predictions of which athletes will reach clinically relevant improvement in function after arthroscopy for FAIS.

A total of 1,118 athletes, identified through a retrospective review of clinical registry data, met the inclusion criteria. The primary outcome was attaining the minimal clinically important difference (MCID) in the Hip Outcome Score-Sports Subscale (HOS-SS) at a minimum of 2 years postoperatively. Six machine learning algorithm models were tested.

The authors found that 23.1% of the athletes did not achieve the MCID for the HOS-SS. Six variables optimized algorithm performance, with the following cutoffs found to decrease the likelihood of achieving the MCID:

  • Preoperative HOS-SS score of ≥58.3
  • Tönnis grade of 1 (early osteoarthritis)
  • Alpha angle of ≥67.1° on anteroposterior radiograph
  • Body mass index (BMI) of >26.6 kg/m2
  • Tönnis angle of >9.7° (indicating subtle instability or dysplasia)
  • Patient age of >40 years

The elastic-net penalized logistic regression (ENPLR) model was the most accurate model in this study.

The findings suggest that patient selection is paramount to the ability to achieve clinically relevant improvements in outcomes for patients treated with arthroscopy for FAIS. Multiple studies have demonstrated that increasing arthritis level and age, along with BMI, are associated with inferior patient-reported outcomes. In addition, hip instability and increased Tönnis angle have been shown to be associated with worse outcomes following hip arthroscopy. A greater alpha angle indicates a larger “deformity” and thus the potential for more damage at the time of surgery that cannot be completely addressed with today’s surgical techniques. “Higher” preoperative HOS-SS (although on a scale of 0 to 100, 58 is not that high) may make it more difficult for a patient to achieve enough of an improvement in their outcome score to be considered as having attained the MCID.

The ENPLR  model was converted into an open-source application, although as Kunze et al. point out, external validation is necessary before wider adoption of the application. Nonetheless, the model demonstrates the potential to help hip surgeons better educate our patients on expected outcomes and to assist with proper patient selection for the ever-evolving treatment of FAIS.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

Co-author Kyle N. Kunze, MD discusses this study in an “Author Insights” video, found here.

Isoelastic Monoblock vs Modular Press-Fit Cup 

As the volume of total hip arthroplasty (THA) cases continues to rise, so too will the need for revision surgery. Revision THA can be complicated by insufficient bone stock on either the femoral or acetabular side, and researchers are gaining further insight into bone loss potentially related to implant design, such as loss that may occur through stress-shielding from press-fit implants.  

 In a randomized controlled trial recently reported in JBJS, Brodt et al. evaluated reduction in bone mineral density (BMD), primarily periacetabular BMD, as measured in 2 groups: patients who received a press-fit isoelastic monoblock cup (24 patients analyzed) and those who received a modular titanium press-fit cup (23 patients analyzed). At question was whether an isoelastic monoblock cup, with an elastic modulus similar to that of bone, would lead to less stress-shielding and thus less bone loss compared with a conventional modular titanium cup. 

Periprosthetic BMD was assessed at 1 week postoperatively (baseline) and at 4 years postoperatively using dual x-ray absorptiometry (DXA). The authors evaluated 4 regions of interest (ROIs) around the acetabular component and 7 ROIs around the femoral component based on regions previously described in the literature for assessing periprosthetic bone loss. 

Baseline patient characteristics, operative time, and improvement in clinical outcome scores did not differ between the groups.  A decrease in overall periacetabular BMD was found in both groups, but the difference between the groups was not significant. 

However, the researchers found a significant difference between the groups in BMD changes in certain periprosthetic regions. On the acetabular side, the group with the modular titanium cup had a 15.9% decrease in BMD in zone 2 (the superior pole of the acetabulum) compared with a decrease of 4.9% in the group with the isoelastic monoblock cup. And on the femoral side, the group with the modular titanium cup had a 15.4% decrease in BMD in zone 1 (along the greater trochanter) compared with a loss of 7% in the group with the isoelastic monoblock cup. None of the other regions differed significantly between the groups.   

Despite the relatively short follow-up and small (but adequately powered) numbers, these results are worthy of our consideration. I agree with the authors that longer follow-up is needed before conclusions can be drawn. As implant design can impact component longevity, it is critical that we evaluate differences to better understand the long-term implications. 

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media 

 

“Normal” Ultrasound May Not Rule Out DDH Later in Childhood

Some years ago, we moved away from calling hip dysplasia “congenital” and started using the term “developmental dysplasia of the hip” (DDH). Indeed, it is developmental. As a surgeon specializing in pediatric orthopaedics and hip preservation, I see not only infants when DDH is of potential concern but also young adults with more mature manifestations of hip dysplasia not previously diagnosed or treated.

Screening protocols have successfully helped in the early identification of DDH and dislocation, but what is the likelihood that infants with risk factors for dysplasia but normal ultrasound results will go on to experience DDH in childhood? And which risk factors are predictive?

In a recent report in JBJS Open Access, Humphry et al. provide new insight into these challenging questions. This study from the UK included 1,053 children from a cohort of 2,191 children who had been assessed as newborns and had at least 1 of 9 perinatal risk factors for DDH. All had undergone ultrasound at a mean of 8 weeks and were followed clinically.

The mean age of the children in the current study was 4.4 years (range, 2.0 to 6.6 years). Thirty-seven of the participants had been treated for DDH in the postnatal period, predominantly with a harness.

Assessing the acetabular index (AI) on pelvic radiographs, the authors found that:

  • 27 of the children had “severe” hip dysplasia (an AI of >2 standard deviations above age and sex reference values). Girls were more likely to have this outcome. Only 3 of the 27 received treatment for DDH in infancy.
  • 146 (13.9%) of the children had an AI of >20°, only 12 of whom had been treated during infancy; 92% had no prior diagnosis of DDH. On multivariate analysis, female sex and breech presentation at birth were significantly predictive of this “mild” dysplasia (breech presentation demonstrated a nearly twofold increased odds of an AI of >20° at ≥3 years of age), while first-born status had a protective effect.

The findings of this study lend support to radiographic monitoring later in childhood for patients with risk factors such as breech positioning at birth. While the exact algorithm of ultrasound and radiographic workup still needs to be elucidated, it appears that a “normal” ultrasound in infancy does not necessarily rule out the development of hip dysplasia in children with select risk factors.

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media