Tag Archive | total hip arthroplasty

Treating Developmental Hip Dislocations Diagnosed after Walking Age

There is a wry saying in academic medicine that “nothing ruins good results like long-term follow-up.” But long-term follow-up helps us truly understand how our orthopaedic interventions affect patients. This is especially important with procedures on children, and the orthopaedic surgeons at the University of Iowa have been masterful with long-term outcome analysis in pediatric orthopaedics. They demonstrate that again in the August 5, 2020 issue of The Journal, as Scott et al. present their results comparing outcomes among 2 cohorts of patients who underwent treatment for developmental hip dislocations between the ages of 18 months and 5 years—and who were followed for a minimum of 40 years.

Seventy-eight hips in 58 patients underwent open reduction with Salter innominate osteotomy, and 58 hips in 45 patients were treated with closed reduction. At 48 years after reduction, 29 (50%) of the hips in the closed reduction cohort had undergone total hip arthroplasty (THA), compared to 24 (31%) of hips in the open reduction + osteotomy group. This rate of progression to THA nearly doubled compared to previously reported results at 40 years of follow-up, when 29% of hips in the closed reduction group and 14% of hips in the open reduction group had been replaced.

In addition, the authors found that patient age at the time of reduction and presence of unilateral or bilateral disease affected outcomes. Patients with bilateral disease who were treated at 18 months of age had a much lower rate of progression to THA when treated with closed reduction, compared to those treated with open reduction—but the opposite was true among patients with bilateral disease treated at 36 months of age. Treatment type and age did not seem to substantially affect hip survival among those with unilateral disease.

I commend the authors for their dedication to analyzing truly long-term follow-up data to help us understand treatment outcomes among late-diagnosed developmental hip dislocations in kids. Long-term follow-up may “ruin” good results, but it gives us more accurate and useful results. And, in this case, the findings reminded us how important it is to diagnose and treat developmental hip dislocations as early in a child’s life as possible.

Read the JBJS Clinical Summary about this topic.

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

Questions About Survival of Ultraporous Cups in THA

Acetabular components for primary total hip arthroplasty (THA) made with ultraporous surfaces were developed to enhance osseointegration and biological fixation. In the July 1, 2020 issue of The Journal of Bone & Joint Surgery, Palomaki et al. report on a registry study that suggests that implant survival with these components over an average follow-up of 3.6 years is not so “ultra.”

The authors evaluated >6,000 primary THAs that used a Tritanium ultraporous cup and >25,000 THAs that used a conventional cup, all performed between 2009 and 2017. When they compared the two groups for revision for any reason, the 5-year Kaplan-Meier survivorship of the Tritanium group (94.7%) was inferior to that of the conventional-cup group (96.0%). When revision for aseptic loosening was examined, the 5-year survivorship was also inferior for the Tritanium group (99.0%) compared with the conventional group (99.9%). Regression analysis revealed that the Tritanium group had a much higher risk of revision for aseptic loosening 2 to 4 years after surgery (hazard ratio, 11.2; p <0.001). Interestingly, these survivorship and risk-of-revision differences disappeared when the authors analyzed data for the period from May 15, 2014 to December 31, 2017–when the registry was updated to include patient BMI and ASA-class data.

The authors cite several caveats that readers should apply to these findings. The registry did not capture radiographic findings for these patients, so potentially relevant imaging data could not be analyzed. And, despite the database upgrade in 2014, there was a dearth of available data on patient comorbidities. Finally, wide confidence intervals for some of the hazard-ratio calculations suggest the need to confirm revision-risk findings with further research.

Limitations notwithstanding, the study by Palomaki et al. suggests that the performance of ultraporous cups may not meet the hopes and expectations of hip surgeons and their patients.

What’s New in Orthopaedic Trauma 2020

Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of OrthoBuzz summaries of these “What’s New” articles. This month, co-author Niloofar Dehghan, MD, selected the 5 most clinically compelling findings from the >20 studies summarized in the July 1, 2020 “What’s New in Orthopaedic Trauma.

Hip Fracture
—An international randomized controlled trial (RCT) of hip fracture patients ≥45 years of age1 compared outcomes among 1,487 who underwent an “accelerated” surgical procedure (within 6 hours of diagnosis) and 1,483 who received “standard care” (surgery within 24 hours of diagnosis). Mortality and major complication percentages were similar in both groups, but it is important to note that even the standard-care group had a relatively rapid median time-to-surgery of 24 hours.

—An RCT of nearly 1,500 patients who were ≥50 years of age and followed for 2 years2 compared total hip arthroplasty (THA) with hemiarthroplasty for the treatment of displaced femoral neck fractures. There was no between-group difference in the need for secondary surgical procedures, but hip instability or dislocation occurred in 4.7% of the THA group versus 2.4% of the hemiarthroplasty group. Functional outcomes measured with the WOMAC index were slightly better (statistically, but not clinically) in the THA group. Serious adverse events were high in both groups (41.8% in the THA group and 36.7% in the hemiarthroplasty group). Although the authors conclude that the advantages of THA may not be as compelling as has been purported, THA’s benefits may become more pronounced with follow-up >2 years.

—A preplanned secondary analysis of data from the FAITH RCT examined the effect of posterior tilt on the need for subsequent arthroplasty among older patients with a Garden I or II femoral neck fracture who were treated with either a sliding hip screw or cannulated screws. Patients with a posterior tilt of ≥20° had a significantly higher risk of subsequent arthroplasty (22.4%) compared with those with a posterior tilt of <20° (11.9%). In light of these findings, instead of internal fixation, primary arthroplasty may be an appropriate treatment for older patients who have Garden I and II femoral neck fractures with posterior tilt of >20°.

Ankle Syndesmotic Injury
—An RCT that compared ankle syndesmosis fixation using a suture button with fixation using two 3.5-mm screws3 found a higher rate of malreduction at 3 months postoperatively with screw fixation (39%) than with suture button repair (15%). With the rate of reoperation also higher in the screw group due to implant removal, these findings add to the preponderance of recent evidence that the suture button technique is preferred.

Wound Management
—A 460-patient RCT examining the cost-effectiveness of negative-pressure wound therapy4 for initial wound management in severe open fractures of the lower extremity found the technique to  be associated with higher costs and only marginal improvement in quality-adjusted life-years for patients.

References

  1. HIP ATTACK Investigators. Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial. Lancet.2020 Feb 29;395(10225):698-708. Epub 2020 Feb 9.
  2. Bhandari M, Einhorn TA, Guyatt G, Schemitsch EH, Zura RD, Sprague S, Frihagen F, Guerra-Farfán E, Kleinlugtenbelt YV, Poolman RW, Rangan A, Bzovsky S, Heels-Ansdell D, Thabane L, Walter SD, Devereaux PJ; HEALTH Investigators. Total hip arthroplasty or hemiarthroplasty for hip fracture. N Engl J Med.2019 Dec 5;381(23):2199-208. Epub 2019 Sep 26.
  3. Sanders D, Schneider P, Taylor M, Tieszer C, Lawendy AR; Canadian Orthopaedic Trauma Society. Improved reduction of the tibiofibular syndesmosis with TightRope compared with screw fixation: results of a randomized controlled study. J Orthop Trauma.2019 Nov;33(11):531-7.
  4. Petrou S, Parker B, Masters J, Achten J, Bruce J, Lamb SE, Parsons N, Costa ML; WOLLF Trial Collaborators. Cost-effectiveness of negative-pressure wound therapy in adults with severe open fractures of the lower limb: evidence from the WOLLF randomized controlled trial. Bone Joint J.2019 Nov;101-B(11):1392-401.

Predictors of Prolonged Analgesic Use after Joint Replacement

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Eric Secrist, MD in response to a recent study in Arthritis Research & Therapy.

There has been a proliferation of research regarding postoperative opioid usage after joint arthroplasty due to the widespread opioid epidemic. But Rajamäki and colleagues from Tampere University in Finland took the unique approach of also analyzing acetaminophen and NSAID usage in addition to opioids. The authors used robust data from Finland’s nationwide Drug Prescription Register, which contains reliable information on all medications dispensed from pharmacies, including over-the-counter drugs.

After excluding patients who underwent revision surgery or had their knee or hip replaced for a diagnosis other than osteoarthritis, the authors analyzed 6,238 hip replacements in 5,657 patients and 7,501 knee replacements in 6,791 patients, all performed between 2002 and 2013. The mean patient age was 68.7 years and the mean BMI was 29.

One year postoperatively, 26.1% of patients were still filling prescriptions for one or more analgesics, including NSAIDs (15.5%), acetaminophen (10.1%), and opioids (6.7%). Obesity and preoperative analgesic use were the strongest predictors of prolonged analgesic medication usage 1 year following total joint arthroplasty. Other predictors of ongoing analgesic usage included older age, female gender, and higher number of comorbidities. Patients who underwent knee replacement used the 3 analgesics more often than those who underwent hip replacement.

This study had all of the limitations inherent in retrospective database analyses. Additionally, it was not possible for the authors to determine whether patients took analgesic medications for postoperative knee or hip pain or for pain elsewhere in their body. Finally, the authors utilized antidepressant reimbursement data as a surrogate marker for depression and other medications as a surrogate for a Charlson Comorbidity Index.

Figure 2 from this study (shown below) reveals 2 important findings. First, total joint arthroplasty resulted in a significant decrease in the proportion of patients taking an analgesic medication, regardless of BMI. Second, patients in lower BMI categories were less likely to use analgesics both preoperatively and postoperatively.

The findings from this study may be most useful during preoperative counseling for obese patients, who often present with severe joint pain but are frequently told they need to delay surgery to lose weight and improve their complication-risk profile. Based on this study, those patients can be counseled that losing weight will not only decrease their complication risk, but also decrease their reliance on medications for the pain that led them to seek surgery in the first place.

Eric Secrist, MD is a fourth-year orthopaedic resident at Atrium Health in Charlotte, North Carolina.

Stronger Hands Related to Better Outcomes in THA and TKA

This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.

Up to 33% of patients are dissatisfied with their outcome after a knee or hip replacement. It’s evident that successful recovery from lower-limb joint replacement is aided by leg strength and stamina, but handgrip strength has been proposed as a proxy for a person’s overall muscle strength. A recent prospective cohort study1 of 226 patients who underwent total hip arthroplasty (THA) and 246 patients who underwent total knee arthroplasty (TKA) investigated the association between handgrip strength measured preoperatively with a dynamometer and changes in preoperative versus 1-year postoperative patient-reported outcome scores. Researchers analyzed the data after adjusting for sex, body mass index, and baseline scores.

For both THA and TKA patients, handgrip strength was positively associated with most physical function, symptom, and quality-of-life scores measured with HOOS, KOOS, and SF-36 questionnaires. On the other hand, there was no association between grip strength and mental-component scores in either the THA or TKA group.

Based on a review of the literature and this study’s findings, the authors conclude that the association between handgrip strength and THA/TKA outcomes is partly dependent on the joint site. Although the mechanism to explain the association has not been elucidated, translating these findings into an informal dynamometer-based tool could help clinicians counsel prospective joint-replacement patients about the value of preoperative conditioning.

Reference
1. Meessen JMTA, Fiocco M, Tordoir RL, Sjer A, Verdegaal SHM, Slagboom PE, Vliet Vlieland TPM, Nelissen RGHH. Association of handgrip strength with patient-reported outcome measures after total hip and knee arthroplasty. Rheumatol Int. 2020 Apr;40(4):565-571. doi: 10.1007/s00296-020-04532-5. Epub 2020 Feb 18. PMID: 32072233

More Data on Periprosthetic Hip Infections

Among >100,000 total hip arthroplasty (THA) patients ≥55 years of age whose data resides in a Canadian arthroplasty database, the 15-year cumulative incidence of periprosthetic joint infection (PJI) was 1.44%, according to a study by the McMaster Arthroplasty Collaborative in the March 18, 2020 issue of JBJS.

In addition to finding that the overall risk of developing PJI after THA has not changed over the last 15 years in this cohort, the authors found the following factors associated with increased risk of developing a PJI:

  • Male sex (absolute increased risk of 0.48% at 10 years)
  • Type 2 diabetes (absolute increased risk of 0.64% at 10 years)
  • Discharge to a convalescent-care facility (absolute increased risk of 0.46% at 10 years)

The authors view the third bulleted item above as “a surrogate marker of frailty and poorer general health.”

Patient age, surgical approach, surgical setting (academic versus rural), use of cement, and patient income were not associated with an increased risk of PJI. Nearly two-thirds of PJI cases occurred within 2 years after surgery, and 98% occurred within 10 years postoperatively.

The authors conclude that these and other substantiated findings about PJI risk factors “should be reviewed with the patient during preoperative risk counseling.”

THA in the Very Young: Midterm Results

Orthopaedic surgeons work hard to find good alternatives to total hip arthroplasty (THA) in patients <50 years old. That’s because the high functional demands and longer remaining lifespan in these patients can result in excessive wear of the bearing surfaces and loosening of the components—both of which have been documented in multiple publications. But what happens when THA is the most viable solution for a posttraumatic or congenital hip problem in a very young patient because arthrodesis or other osteotomies are not feasible?

In the March 18, 2020 issue of The Journal, Pallante et al. report medium-term outcomes of THA in 78 patients who were ≤20 years of age at the time of surgery, with follow-ups ranging from 2 to 18 years. The findings included the following:

  • 10-year survivorship for reoperation of 95.0%
  • 10-year survivorship for revision of 97.2%
  • 10-year survivorship for complications of 89.5%

Overall, the linear articular wear averaged 0.019 mm/yr in the ceramic-on-ceramic, ceramic-on-highly cross-linked polyethylene, and metal-on-highly cross-linked polyethylene bearings studied, and the average modified Harris hip score in the cohort was 92.

However, despite these impressive clinical and survivorship outcomes, I advise orthopaedists not to lower their resistance to performing THA on these very young patients, many of whom present with hip problems caused by deforming conditions such as Legg-Calve-Perthes disease. We really need 30 to 40 years of outcome data to truly  understand what happens with function, revision rates, and wear characteristics in this population. Having said that, I am confident that this group from Mayo will continue reporting on this patient cohort at 5- to 10-year intervals, so that the worldwide orthopaedic community can keep learning from this experience.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Are Tantalum Hip Implants Safe?

I have been told that daytime TV is punctuated by a continual stream of ads for personal-injury lawyers asking if you have been injured by a particular medication or medical device.  Since 2002, billions of dollars have been paid out in lawsuits over metal-on-metal hip replacements containing cobalt and/or chromium, the “loose” ions of which increase the risk for aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL)—which are sometimes referred to as “pseudotumors.” So orthopaedic surgeons understandably want to know more about the potential long-term implications of newer metal technologies such as tantalum.

“Trabecular Metal” is a trade name for tantalum-based bone-ingrowth material that is now quite common in acetabular cups and revision shells used for total hip arthroplasty (THA). In the March 4, 2020 issue of the The Journal, Brüggemann et al. investigated the safety of these tantalum components. They retrospectively reviewed blood tantalum levels in 30 patients who underwent primary THA with no tantalum components, 30 patients who received a tantalum cup during a primary THA, and 84 patients who received a tantalum shell during a revision. Tantalum levels in 59 blood-donor volunteers served as controls. The authors also measured subsets of lymphocytes (CD8+ and CD4+ T-cells) that are thought to be associated with the immunologic cascade causing ALVAL.

At an average follow-up of 4 years, Brüggemann et al. found that median tantalum concentrations were 0.051 µg/L  in those receiving primary tantalum implants and 0.05 µg/L in those receiving primary implants without tantalum. (The “detection limit” for tantalum used in this study was 0.05 µg/L.) Patients receiving revision tantalum shells had median serum tantalum levels of 0.091 µg/L.  Time since surgery did not affect tantalum levels.

The authors also found a weak negative correlation between increased tantalum concentration and lower concentrations of CD8+ T-cells. Clinically, none of the hips in this series was deemed loose, and the Harris hip scores among all subjects were good to excellent.

It seems that with stable tantalum implants, any increase in serum concentrations of tantalum is small, but we don’t yet know the longer-term implications of these small increases. While it’s also reassuring that the lymphocyte activation associated with ALVAL does not seem to occur with these tantalum implants, I agree with the authors’ conclusion that this study “cannot exclude the possibility that even low tantalum concentrations confer a risk to patients’ health.”  Clearly, longer-term studies are needed.

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

So Far, Bundled Payments Not Affecting Patient Selection for Joint Replacement

Many people predicted that the mandatory “bundling” of payments for knee and hip arthroplasty by the Centers for Medicare and Medicaid Services (CMS) that began on April 1, 2016 in several US metropolitan areas would lead to  “cherry-picking” and ”lemon-dropping.” In other words, hospitals and surgeons wouldn’t take on more complex and sicker patients for joint replacement for fear that the bundled payment would be insufficient (lemon-dropping), and would instead select the healthier patients (cherry-picking). See related OrthoBuzz post.

In the February 19, 2020 issue of The Journal, Humbyrd et al. compare the characteristics of patients who underwent hip and knee replacement (HKR) from April to December 2015 with those of HKR patients during the same period in 2016, after CMS mandated the bundled-payment program in 67 metropolitan statistical areas (MSAs). The patients were matched so that those treated in bundled and non-bundled settings had similar socioeconomic backgrounds.

The matched groups included 12,388 HKR episodes in 40 bundled MSAs and 20,288 HKRs in 115 nonbundled MSAs. The authors also evaluated pre- and post-policy case-mix changes among 1,549 hip hemiarthroplasties, which are not subject to bundling, in the bundled MSAs.

Among patients who underwent HKR, Humbyrd et al. found no significant differences in patient characteristics—including race, dual Medicare-Medicaid eligibility, tobacco use, obesity, diabetes, and Charlson Comorbidity Index (CCI)—after the bundled-payment policy was implemented. Also, they found that patients in bundled MSAs undergoing hemiarthroplasty had significantly higher CCI values and were more likely to have diabetes than those who underwent HKR. This suggests that some surgeons opt for hemiarthroplasty over total hip replacement in less-healthy patients to avoid treating such patients under a bundled program.

From the MSA perspective, these results suggest that cherry picking and lemon dropping are not occurring in the short term. But we would do well as a profession to ensure that those controversial patient-selection practices are not happening at the individual surgeon level, and that the short-term results demonstrated here by Humbyrd et al. persist over the longer term. Even our sickest joint replacement patients deserve the best surgical care.

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

Safe Retractor Placement during Direct Anterior THA

One of my residency mentors always stressed that orthopaedic surgeons should be “masters of musculoskeletal anatomy.” During his first lecture each July, he would grill the junior residents on muscle origins and insertions, along with innervations. Knowing safe surgical planes helps us avoid complications from neural or vascular injury and increases the likelihood of a successful orthopaedic procedure. With the increased popularity of the direct anterior approach (DAA) for total hip arthroplasty (THA), it is crucial that orthopaedists understand the anatomical implications of that technique.

One key to a successful DAA hip replacement is adequate visualization, which is aided by retractors. However, malpositioned retractors can cause femoral nerve palsy, a potentially serious neurological complication that can delay postoperative rehabilitation. In the January 15, 2020 issue of The Journal, Yoshino et al. report on a cadaveric study that quantifies the distance between the femoral nerve and the acetabular rim at varying points along the rim. Knowing these precise distances could help surgeons make safer decisions about where—and where not—to place retractors.

The authors dissected 84 cadaveric hips from 44 formalin-embalmed cadavers and measured the distance from the femoral nerve to various points along the acetabular rim by using a reference line drawn from the anterior superior iliac spine (ASIS) to the center of the acetabulum. They found the femoral nerve was closest to the rim (only 16.6 mm away) at the 90° point.

In addition, at 90°, the thickness of the iliopsoas muscle and the femoral length (a probable proxy for size of the patient) were positively associated with increased distance to the nerve. Other anatomic factors such as inguinal ligament length, femoral head diameter, and thickness of the capsule were not associated with the nerve-rim distance.

The degree nomenclature used by Yoshino et al. can be correlated to a clock-face representation of the acetabulum, with the 60° point at the 3 o’clock (anterior) position; the 30° point represents a relatively safe  location for placement of the anterior inferior iliac spine retractor (see Figure above).

This important anatomic study can help us improve our mastery of musculoskeletal anatomy—and avoid, if possible, placement of retractors at 90° relative to a line drawn from the ASIS to the center of the acetabulum.

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