Archive | January 2021

Halt Bisphosphonates in Patients with an Atypical Femoral Fracture

Osteoporosis is the major contributor to the increasing incidence of fragility fractures associated with low-energy falls. The other contributor is the populous baby-boomer generation that is entering its final decades of life. Our orthopaedic community has made some progress in “owning the bone” to prevent fragility fractures. For example, we have gotten better at identifying a first fragility fracture as a major risk for a subsequent fracture; we more frequently initiate medical treatment for osteoporosis, and we are more inclined to refer patients with a first fragility fracture to a fracture liaison service, if one exists (see related OrthoBuzz posts).

However, orthopaedic physicians treating patients with fragility fractures need to remember that osteoporosis-treatment complications are also within our scope of responsibility. In the January 20, 2021 issue of The Journal, Lee et al. retrospectively analyzed 53 patients (all women, with an average age of 72 years) who had a complete atypical femoral fracture (AFF), a phenomenon primarily related to bisphosphonate treatment for osteoporosis. More than 37% of these patients were given bisphosphonates after their first AFF, and among those 53 patients who went on to show radiographic progression toward a second AFF in the contralateral femur, 61% used bisphosphonates after surgery for the first AFF.

The most shocking aspect of the findings by Lee et al. is the unacceptably high percentage of patients who remained on bisphosphonate therapy after the initial AFF. I wholeheartedly agree with Anna Miller, MD, who writes in her Commentary on this study that “an atypical stress fracture while on bisphosphonates should be considered a failure of bisphosphonate treatment, and that therapy should be stopped immediately.” If there is ongoing osteoporosis in such cases, the orthopaedic surgeon should consider prescribing an anabolic drug such as teraparatide or abaloparatide–and should communicate with the patient’s endocrinologist or other physician who might still be prescribing bisphosphonates.

In my opinion, we have to improve more quickly on both of these clinical issues–secondary fragility fracture prevention and treatment of bisphosphonate-therapy complications–because the population dynamics in the US and worldwide are evolving rapidly.

Click here to view a 2-minute video summary of this study’s design and findings.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Pediatric Limb-Lengthening: A Cautionary Tale

JBJS Editor-in-Chief Dr. Marc Swiontkowski brought to OrthoBuzz’s attention a recent “Family Partnerships” essay published in Pediatrics. The 4 “speakers” in the essay chronicle the suffering and pain of Lindsay Ellingworth, who was born with a congenital lower-limb deficiency. Lindsay’s young parents opted for limb lengthening over amputation plus a prosthesis after several orthopaedic consultations and an agonizing, confusing decision-making process.

Orthopaedic surgeon Dr. David Hootnick entered the picture about 10 years ago, when he first saw Lindsay, who was by then a young nursing student with ongoing problems associated with the index procedure—including scoliosis and chronic neck and back pain. The extent of the original deformity (30% femur shortening at birth) made Lindsay a “nonideal candidate for lengthening,” says Dr. Hootnick, but he adds that “Lindsay had a normal-appearing foot, making it all the more understandable that her parents balked at removing an apparently healthy part of their beloved child.”

Lindsay describes her limb-lengthening and years of treatments for complications as “a living nightmare.” Now an adult, she has concluded that “the doctors put a pretty bow on limb lengthening.” Pediatrician and bioethicist Dr. Amy Caruso Brown acknowledges in the essay the untenable bind Lindsay’s parents found themselves in when having to make a decision before their child was old enough to express preferences. “It is difficult to accept that a procedure that sounds as drastic and anachronistic as amputation might have fewer complications than the seemingly more sophisticated alternative,” Dr. Brown said.

According to Lindsay’s mother Rene Mauchin, “Although she has endured so much, Lindsay still laughs and celebrates life.” When asked for a takeaway that might help other families in similar situations, Ms. Mauchin said, “You have a right to know everything the doctors know…Don’t hesitate to see several doctors, and ask for evidence to back up their recommendations.”

When Does I&D Beat 2-Stage Exchange in Second rTKA?

It’s hard to contemplate “conservative treatment” in the case of a revised total knee arthroplasty (rTKA) with extensive instrumentation that needs a reoperation due to periprosthetic joint infection (PJI), because all the treatment options in that scenario are pretty complex. In the January 6, 2021 issue of JBJS, Barry et al. report on a retrospective review of 87 revisions of extensively instrumented rTKAs that found that irrigation and debridement (I&D) with chronic antibiotic suppression was as effective as 2-stage exchange in preventing another reoperation for infection—and more effective in terms of maintaining knee function.

The average follow-up of the cases studied was 3.2 years, and the authors carefully defined “extensive instrumentation.” Among the 56 patients who were managed with I&D and suppression and the 31 who were managed with the initiation of 2-stage exchange (average age in both groups approximately 67 years), no significant differences were found in the rates of reoperation for infection or mortality. However, 9 of the 31 patients (29%) in the 2-stage group never underwent the second-stage reimplantation. Among those 9, 3 died prior to reimplantation and 2 underwent amputation due to failure of infection control.

Moreover, at the time of the latest follow-up, a significantly higher percentage of patients in the I&D group were ambulatory (76.8% vs 54.8% in the 2-stage group) and were able to functionally bend their knee (85.7% vs 45.2% in the 2-stage group). The authors surmise that these 2 findings are related to the soft-tissue damage and bone loss that typically occur during stage-1 removal of rTKA components.

Barry et al. conclude that in similar situations “deviating from the so-called gold standard of 2-stage exchange and accepting the modest results of I&D may be in the best interest of the patient,” as long as there are no loose implants in the existing construct. But the “sobering” mortality rates in the study (39.3% in the I&D group and 38.7% in the 2-stage group) remind us that this clinical scenario is extremely challenging for patients and surgeons, no matter which option is selected.

Click here to view an “Author Insights” video about this study with co-author Jeffrey Barry, MD.

Same-Patient Trial Design Measures Incremental Improvements in TKA Outcomes

The clinical and functional outcomes after total knee arthroplasty (TKA) are generally very favorable. The 15% to 20% of subpar patient-reported outcomes are usually related to persistent pain. Orthopaedic researchers have exhaustively investigated patient factors and technical considerations to address dissatisfaction in this minority population of TKA patients.

Meanwhile, the orthopaedic community has focused on prosthetic design in its attempts to incrementally improve outcomes for the 80% to 85% of generally satisfied TKA patients. Clearly documenting those incremental improvements often requires elegant study design. That’s what we see in the January 6, 2021 issue of The Journal, where Kim et al. report findings from a randomized trial in which 2 different knee-implant designs were compared in the same patients after primary simultaneous bilateral TKA.

Each of the 50 patients (49 of them women) received a posterior-stabilized design in 1 knee and an ultracongruent prosthesis in the other. Kim et al. selected the Forgotten Joint Score (FJS) as the primary outcome. The FJS is a 12-item questionnaire that assesses patient awareness of the artificial joint during daily activities. At 2 years, the researchers found no between-knee differences in FJS. The ultracongruent knees showed more anteroposterior laxity and less femoral rollback than the posterior-stabilized knees, but there were, again, no between-group differences in following measures:

  • Range of motion
  • Knee Society and WOMAC scores
  • Side Preference and patient satisfaction

The ultracongruent advancement in prosthetic design does not appear to offer clinically important advantages over the posterior-stabilized design. But if additional TKA patients can be recruited into studies using clever and effective experimental designs like this one, the future is bright for more robust assessments of the incremental impact of prosthetic design on functional and clinical outcomes.

Click here to view an Infographic summarizing this study.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Bone-Preserving Stems in THA – Do They Work?

Total hip arthroplasty (THA) is a tried-and-true treatment for debilitating hip osteoarthritis. But as the number of patients undergoing THA continues to rise, so does the incidence of periprosthetic femoral fractures and the need for revision surgery. The increasing burden of periprosthetic fractures has led to the development of shorter-stemmed femoral components that theoretically preserve bone, decrease fracture risk, and make revision surgery easier if it is required. In the January 6, 2021 issue of The Journal, Slullitel et al. report on a randomized controlled trial that determined whether bone loss differed between patients who received a conventional stem and those who received a short, bone-preserving stem over 2 years following THA.

Forty-six patients received the short, proximally porous-coated stem (Depuy Synthes Tri-Lock bone-preservation stem), and 40 received the conventional stem (Depuy Synthes collarless Corail stem). The primary outcome–bone mineral density (BMD)–was analyzed at 12, 26, 52, and 104 weeks after surgery with dual x-ray absorptiometry region-free analysis (DXA-RFA), which revealed pixel-level resolution of BMD at the bone-implant interface.

Immediately after surgery, researchers found a similar amount of bone loss in both groups in the calcar region and the cancellous portion of the distal greater trochanter. But at all other subsequent time points, bone loss was significantly greater in patients with the bone-preserving stem (analysis of variance [ANOVA] p < 0.0001). In addition, over the full study period the small areas of bone gain that the researchers found were statistically greater in the conventional-stem group than in the Tri-Lock group. Notably, patient-reported outcomes and adverse events did not differ between the 2 groups at the 2-year follow-up.

These early results cast a shadow of doubt over whether a stem that is marketed to preserve bone actually accomplishes that objective. However, 2 years is a very short follow-up when looking at the lifetime of a hip arthroplasty, and the clinical implications of these findings will become clearer with longer-duration analysis.

Click here to read a JBJS Clinical Summary titled “Short-Stem Femoral Components in THA” by Tad Mabry, MD.

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