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Does Hip Arthroscopy Really Help?

Menge_Image_for_O'Buzz.pngOver the past 15 to 20 years, the use of arthroscopic procedures for hip pathologies has rapidly increased. Leaders in sports medicine have standardized many arthroscopic techniques, including methods of joint distraction, portal location, approaches to labral repair or debridement, and management of cartilage lesions.

Many in the orthopaedic community have wondered whether this expansive  use of  hip arthroscopy is justified by significant improvement in patient function or is simply a first (and perhaps overused) step toward inevitable hip arthroplasty. To help answer that question, in the June 21, 2017 issue of The Journal, Menge et al. document the 10-year outcomes of arthroscopic labral repair or debridement in 145 patients who originally presented with femoroacetabular impingement (FAI).

Whether these patients were treated with debridement or repair, their functional outcomes and improvement in symptoms were excellent over the 10-year time frame, and the median satisfaction score (10) indicates that these patients were very satisfied overall. However, as seen in other similar studies in the peer-reviewed literature, the results in older patients with significant cartilage injury or radiographic joint space narrowing were inferior, and most of the patients with these characteristics ended up with a hip replacement.

The Menge et al. study helps confirm that arthroscopic repair or debridement in well-selected FAI patients yields excellent longer-term outcomes, and it provides concrete criteria for patient selection.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Good Outcomes with After-Hours Hip Fracture Surgery

marc-swiontkowski-2In the June 7, 2017 issue of The Journal of Bone & Joint Surgery, Pincus et al. report on a careful analysis comparing outcomes from hip fracture surgery occurring “after hours” (defined by the authors as weekday evenings between 5 PM and 12 AM) with surgeries occurring during “normal hours” (weekdays from 7 AM to 5 PM). In the busy Ontario trauma center where this study was performed, it is common for patients with blunt trauma to take precedence over seniors who are relatively stable but in need of hip fracture care.

Pincus et al. found that adverse outcomes, in terms of surgical and medical complications, were similar whether the hip surgery occurred during normal hours or after hours.  Interestingly, there was a higher rate of inpatient complications in the normal-hours group, and fewer patients in the after-hours group were discharged to a rehab after surgery than in the normal-hours group.

It has been my impression that highly skilled professional surgeons and their teams are going to put forward their best efforts for all patients—no matter what time of day or night they operate. Concentration, focus, and high standards can generally overcome fatigue. However, the Pincus et al. study should not be viewed as justification for hospital decision makers to forget their commitment to optimize management of all resources, including surgical teams. After-hours care should never become “routine,” and there should be continuous attention on developing alternative solutions, such as moving elective surgery to other facilities or true shift scheduling that provides all members of the team with occasional daytime hours off for rest and management of personal lives.

The authors note that in their Canadian jurisdiction, there are hospital and surgeon-reimbursement incentives that may work to promote after-hours surgery, but the long-term focus must always put patient outcomes first. And we must always remember that good patient outcomes rely on maintaining surgical teams who are experienced and not burnt out.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

JBJS Classics: Porous-Coated Hip Components

JBJS Classics Logo.pngOrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these articles have had on the practice of orthopaedics. Please feel free to join the conversation by clicking on the “Leave a Comment” button in the box to the left.

In their classic 1987 publication, Drs. Charles Engh, Dennis Bobyn, and Andrew Glassman described clinical and radiographic results of a series of 307 hips with 2-year follow-up, and 89 hips with 5-year follow-up after total hip arthroplasty in which the patients had received an extensively porous-coated femoral stem. The authors also described histologic evaluation of 11 hips retrieved at autopsy or revision.

By 1987 the same authors as well as other investigators had already published observations concerning the influence of femoral stem size, shape, stiffness, and porosity on clinical and radiographic evidence of fixation and stress shielding in humans and animal models.1,2 But this study, which so far has been cited more than 1500 times, goes “above and beyond” by carefully correlating previous observations with histologic sections obtained through human femora.

Among other achievements, Engh et al. described radiographic criteria for categorizing a femoral implant as either stable by bone ingrowth, stable by fibrous tissue ingrowth, or unstable. Implants thought to be stable by fibrous ingrowth had a prominent radio-opaque line around the stem, separated from the implant by a radiolucent space up to 1 mm in thickness. This line was thought to represent a shell of bone with load-carrying capability. However, histology demonstrated that the space between the shell and the implant was composed of dense fibrous tissue. When the shell was present, there tended to be little hypertrophy or atrophy of the adjacent femoral cortex.

Engh et al. noted that radiographs and histology of hips with extensive ingrowth from the endosteum often showed parallel increased porosity of the adjacent cortex – an early manifestation of stress shielding. Overall, 259 (84%) of the femoral stems had radiographic findings suggestive of bone ingrowth, 42 (13%) had findings interpreted as stable fibrous ingrowth, and 2% were thought to be unstable (but not yet revised at the time of the study). Stress shielding was much more common in larger-diameter stems and those with good bone ingrowth compared to smaller implants or those with stable fibrous fixation.

Why do we consider this manuscript a classic? First, the authors include a careful correlation of histology with radiographic and clinical findings, helping illustrate the importance of tight press fit at the isthmus to achieve proximal fixation. The authors also document intracortical porosity as the morphologic manifestation of stress shielding and emphasize the impact of a small increase in stem diameter on axial rigidity.

Designs of femoral stems have evolved considerably since the 1980s,3 and the findings described in this paper helped validate fundamental principles related to load transmission and bone remodeling4-6 and thus helped advance that evolutionary process.

Thomas W. Bauer, MD, PhD
JBJS Deputy Editor

References

  1. Bobyn JD, Pilliar RM, Binnington AG, Szivek JA. The effect of proximally and fully porous-coated canine hip stem design on bone modeling. Journal of orthopaedic research : official publication of the Orthopaedic Research Society 1987;5:393-408.
  2. Bobyn JD, Pilliar RM, Cameron HU, Weatherly GC. The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone. Clinical orthopaedics and related research 1980:263-70.
  3. McAuley JP, Culpepper WJ, Engh CA. Total hip arthroplasty. Concerns with extensively porous coated femoral components. Clinical orthopaedics and related research 1998:182-8.
  4. Huiskes R. Validation of adaptive bone-remodeling simulation models. Stud Health Technol Inform 1997;40:33-48.
  5. Huiskes R, Weinans H, Dalstra M. Adaptive bone remodeling and biomechanical design considerations for noncemented total hip arthroplasty. Orthopedics 1989;12:1255-67.
  6. Weinans H, Huiskes R, Grootenboer HJ. Effects of fit and bonding characteristics of femoral stems on adaptive bone remodeling. J Biomech Eng 1994;116:393-400.

June 2017 Article Exchange with JOSPT

JOSPT_Article_Exchange_LogoIn 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.

During the month of June 2017, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis.”

Based on 17 studies included in the meta-analysis, the authors found that recreational runners had a lower occurrence of osteoarthritis compared with competitive runners and sedentary controls.

Sports Medicine Update

What's_New_Sports_Med_Image_for_O'Buzz.pngEvery month, JBJS publishes a Specialty Update—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 all OrthoBuzz Specialty Update summaries.

The May 17, 2017 JBJS Specialty Update on Sports Medicine reflects evidence in the field of sports medicine published from September 2015 to August 2016. Although this review is not exhaustive of all research that might be pertinent to sports medicine, it highlights many key articles that contribute to the existing evidence base in the field.

Topics covered include:

  • Prevention of Musculoskeletal Injuries
  • Autograft vs Allograft ACL Reconstruction
  • Anterior Shoulder Stabilization
  • Hip Arthroscopy

Fracture Liaison Service Boosts Patient Engagement with Secondary Prevention

fragility fractures for O'Buzz.pngOrthoBuzz has published several posts about osteoporosis, fragility fractures, and secondary fracture prevention. In the May 17, 2017 edition of JBJS, Bogoch et al. add to evidence suggesting that a coordinator-based fracture liaison service (FLS) improves engagement with secondary-prevention practices among inpatients and outpatients with a fragility fracture.

The Division of Orthopaedic Surgery at the University of Toronto initiated a coordinator-based FLS in 2002 to educate patients with a fragility fracture and refer them for BMD testing and management, including pharmacotherapy if appropriate. Bogoch et al. analyzed key clinical outcomes from 2002 to 2013 among a cohort of 2,191 patients who were not undergoing pharmacotherapy when they initially presented with a fragility fracture.

  • Eighty-four percent of inpatients and 85% of outpatients completed BMD tests as recommended.
  • Eighty-five percent of inpatients and 79% of outpatients who were referred to follow-up bone health management were assessed by a specialist or primary care physician.
  • Among those who attended the referral appointment, 73% of inpatients and 52% of outpatients received a prescription for anti-osteoporosis medication.

The authors conclude that “a coordinator-based fracture liaison service, with an engaged group of orthopaedic surgeons and consultants…achieved a relatively high rate of patient investigation and pharmacotherapy for patients with a fragility fracture.”

More Comparative Data on Surgical Approaches to THA

Implant Survival and THA Approach.jpegThe May 17, 2017 edition of The Journal of Bone & Joint Surgery features a registry-based study by Mjaaland et al. comparing implant-survival/revision outcomes in total hip arthroplasty (THA) among four different surgical approaches:

  • Minimally Invasive (MI) Anterior (n=2017)
  • MI Anterolateral (n=2087)
  • Conventional Posterior (n=5961)
  • Conventional Direct Lateral (n=11,795)

Although the authors analyzed a whopping 21,860 THAs from 2008 to 2013, the findings are limited by the fact that all of those procedures used an uncemented stem.

Overall, the revision rates and risk of revision with the MI approaches were similar to those of the conventional approaches. There was a higher risk of revision due to infection in THAs that used the direct lateral approach than in THAs using the other three approaches. “To our knowledge,” the authors write, “this finding has not been previously described in the literature, and we do not have an explanation for it.” The authors also found a reduced risk of revision due to dislocation in THAs that used the MI anterior, MI anterolateral, and direct lateral approaches, relative to those using the posterior approach.

While the authors found all-cause risk of revision to be similar among all four approaches, they note that the follow-up in the study was relatively short (mean of 4.3 years) and that “additional studies are needed to determine whether there are long-term differences in implant survival.”

Don’t Delay DDH Treatment to Wait for Ossific Nucleus

Ossific_Nucleus_for_OBuzz.pngThe exact cause of osteonecrosis in the setting of developmental dysplasia of the hip (DDH) is unknown. However, some pediatric orthopaedists are concerned that DDH treatment in the absence of the ossific nucleus of the femoral head increases the risk of subsequent osteonecrosis. That concern has to be weighed against evidence that delayed DDH treatment may lead to more difficult reduction and potentially necessitate additional procedures.

In the May 3, 2017 issue of JBJS, Chen et al. performed a meta-analysis of cohort and case-control studies to clarify this potential “conflict of interests” in DDH treatment. Twenty-one observational studies were included. Of the 969 hips with an ossific nucleus present before reduction, 198 hips (20.4%) had eventual osteonecrosis events; among the 608 hips without an ossific nucleus, 129 (21.2%) had osteonecrosis events. The authors state that this difference “is neither clinically important nor [statistically] significant.”

A sub-analysis determined that the presence of the ossific nucleus was not associated with significantly decreased odds of osteonecrosis even among patients who later developed more severe (grades II to IV) osteonecrosis. Chen et al. also performed a “meta-regression” of studies with short- and long-term follow-ups, finding “no evidence for a protective effect of the ossific nucleus with either short or long-term follow-up.”

Although 11 of the 21 studies in the meta-analysis were deemed high quality and 10 were of moderate quality, the inherent limitations of a meta-analysis derived predominantly from retrospective data prompted the authors to call for “further prospective studies with long-term follow-up and blinded outcome assessors.” Nevertheless, these findings lend additional support to the belief that treatment for DDH should not be delayed based on the absence of the femoral head ossific nucleus.

After THA, Self-Directed Home Exercise Yielded Same Benefits as Formal PT

THA3 for OBuzz.jpegAn estimated 40% of total costs from a total hip arthroplasty (THA) episode are accrued from post-discharge services.  With that in mind, Austin et al. embarked on a randomized controlled trial comparing outcomes among two groups of primary THA patients: those who followed a 10-week self-directed home exercise regimen (n=54) and those who received a combination of in-home and outpatient physical therapy (PT) for 10 weeks (n=54). The results were published in the April 19, 2017 edition of The Journal of Bone & Joint Surgery.

At 1 month and 6 to 12 months after surgery, patients in both groups showed significant preoperative-to-postoperative improvements in function as measured by all administered instruments (Harris Hip Score, WOMAC Index, and SF-36 Physical Health Survey). However, there was no difference in any of the measured functional outcomes between the two groups.

In addition, a total of 30 patients (28%) crossed over between groups: 20 (37%) from the formal physical therapy group and 10 (19%) from the home exercise group.  The 10 patients who crossed over from home exercise to formal PT were not meeting progress goals; they tended to be older and had worse preoperative function than those in that cohort who did not cross over.

So, while this study provides evidence that unsupervised home exercise can be as effective as a structured rehabilitation program for most patients, the authors say the following patient characteristics might be indications for a referral to formal PT:

  • Older age
  • Poorer preoperative function
  • Severe preoperative gait imbalance
  • Postoperative neurological complications
  • Expectations for quick return to high-level activity

Follow Preop Heart-Testing Guidelines with Elderly Hip Fracture Patients

Heart Ultrasound.jpgFrom the perspective of a geriatric patient with a hip fracture, having a preoperative echocardiogram may not seem like a big deal, especially since it’s a noninvasive test. However, as Adair et al. reveal in an April 19, 2017 JBJS study, following clinical guidelines established by the American College of Cardiology (ACC) and the American Heart Association (AHA) could have prevented “cardiac echoes” from being done in 34% of 100 elderly hip fracture patients without missing any disease. Such unnecessary testing not only adds cost to the health care system, but can also delay surgical treatment for an operation that evidence suggests is best performed within 24 to 48 hours.

A single reviewer blinded to the later results of the tests assessed whether the ACC/AHA guidelines were followed in each case of an ordered echo; when ≥1 of the criteria were met, the echo was considered ordered in accordance with the guidelines. The rate of adherence to the guidelines was 66% over the 3.5-year study period. No important heart disease was found in any of the 34 patients who underwent an echocardiogram that had not been indicated by the guideline criteria, and 14 of the 66 patients (21%) for whom an echo was indicated by the criteria were found to have heart conditions serious enough to modify anesthesia or medical management.

The most common documented reasons for ordering an echo outside the guideline criteria were dementia that prevented evaluation of preoperative cardiac condition and generic “evaluation of cardiac function,” even though those patients had no history, physical exam findings, or work-ups that suggested heart disease.

Adair et al. conclude that these findings “suggest that integration of [clinical practice guidelines] into a perioperative protocol has the potential to improve the efficiency of preoperative evaluation, reduce resource utilization, and reduce the time to surgery without sacrificing patient safety.”