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Risk Factors for Failure after FAI Treatment

Orthopaedic surgeons continually seek to refine techniques to improve their patients’ surgical outcomes. Surgical treatments for femoroacetabular impingement (FAI) syndrome are no exception, and careful patient selection is also critical to the success of these interventions. In the June 17, 2020 issue of The Journal, Ceylan et al. analyzed a single-surgeon prospective database to identify risk factors for treatment failure after a particular hip-preservation surgery known as mini-open femoroacetabular osteoplasty (FAO). In this study, the authors defined “failure” as the eventual need for a total hip arthroplasty (THA) over a minimum 2-year follow-up.

The 749 procedures studied were performed between 2004 and 2016 and involved treatment of the femur, acetabular rim, labrum, and chondral surfaces if necessary. Labral repair was performed on all hips that had adequate healthy tissue, while those that did not were treated with partial or total excision of the labrum.

Sixty-eight  hips (9%) underwent THA. The patients who did not need a hip replacement were significantly younger (mean age of 33 years vs nearly 42) and were operated on after the surgeon had more experience. Other significant differences among the failure group included the duration of symptoms (twice as long, at 3.6 years), higher preop alpha angles, and a higher percentage of total labral resections performed.

Radiographic evidence of hip dysplasia was also a significant risk factor for failure, along with labral hypertrophy and acetabular retroversion (both of which may be considered proxies for volume-deficient acetabuli). After adjusting for covariates, Ceylan et al. found that less surgeon experience, older patient age, prolonged preoperative symptoms, increased medial joint space narrowing and Tonnis grade, and developmental hip dysplasia were all associated with a higher risk of failure after FAO surgery.

Although these findings do not represent results using the most up-to-date arthroscopic techniques for FAI treatment, they do highlight characteristics that can and should be discussed with patients with FAI when the subject of expected surgical outcomes arises during shared decision making.

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

PROM ‘Crosswalks’ Are a Big Step Forward

Patient-reported outcome measures (PROMs) for orthopaedic procedures have long been used in clinical research. In the last decade, the use of PROMs has expanded to include quality-of-care assessments and, in some healthcare systems, to help calculate costs and reimbursements. All this has made PROMs increasingly visible to patients.

There are several validated and widely used PROMs for hip and knee arthroplasty. One problem with those is that the data from one PROM are not interchangeable with data from another. That disconnect limits the opportunity for meaningful data aggregation and thwarts large-scale population research.

In the June 3, 2020 issue of The Journal, Polascik et al. tackle this problem head-on. They report on a “crosswalk” system that allows back-and-forth conversion between 4 of the most commonly used PROMS—the Oxford hip and knee scores and the HOOS and KOOS short-form scores. The authors developed this tool by applying sophisticated statistical methods to data from a large cohort of hip and knee arthroplasty patients. The accuracy of the 4 crosswalks Polascik et al. developed was substantiated when they found minimal differences between the means of the known and crosswalk-derived scores.

This practical tool for converting scores is a substantial advance in patient-reported outcomes research. It will further facilitate the pooling of data for use in future clinical research, quality-of-care initiatives, and reimbursement systems. Patients, surgeons, researchers, and health systems alike all stand to benefit greatly.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Surgery to Repair the Hip’s ‘Rotator Cuff’

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.

Symptoms from gluteus medius tendon tears are common in people older than 50 years, but they are hard to distinguish from referred pain due to lumbar spine conditions or hip disorders such as osteoarthritis and femoroacetabular impingement. Because conservative measures are often effective, surgical remedies are not commonly discussed in the literature.

An anatomical study of the gluteus medius tendon found that the posterior part of the tendon has a fan-like shape and converges onto the superoposterior facet of the greater trochanter. The anterolateral part runs posteroinferiorly toward the lateral facet of the greater trochanter. Both the posterior and anterolateral parts insert via fibrocartilage. Given the nonuniform structure of this tendon, the thin anterolateral part may be more prone to tears than the thick posterior part.

In another recent study, a single surgeon described his experience with 185 consecutive gluteus medius tendon tear repairs.1 Tendon changes were confirmed preoperatively on MRI. Roughening of all appropriate surfaces preceded multiple-suture repair through bone holes, with sutures in line with the tendon segment being attached. Of the 185 patients, 165 completed 5- to 10-year phone follow-ups. The average age was 69 and 92% were female. There was no histological evidence of bursitis in any case. Only 9 patients reported worse Oxford Hip Scores at the 5-year follow-up; deep vein thrombotic events occurred in 4% of patients despite prophylaxis. Other common gluteus medius tendon repair techniques include utilization of suture anchors through a mini-open2 or arthroscopic approach.

Unlike degenerative rotator cuff tears of the shoulder, both incomplete and complete acute tears of the gluteus medius respond well to repair surgery. More advanced degenerative gluteus medius tendon changes do not respond as well. It is not clear what the differences are in the mechanical and biochemical mechanisms of rotator cuff and gluteal tendon changes that make surgery to repair the former seemingly less successful than surgery to repair the latter. Nevertheless, these four studies show promise for surgical interventions that have a reasonable chance of being effective, with relatively low risk.

References

  1. Fox OJK, Wertheimer G, Walsh MJ. Primary Open Abductor Reconstruction: A 5 to 10-Year Study. J Arthroplasty. 2020 Apr;35(4):941-944. doi: 10.1016/j.arth.2019.11.012. Epub 2019 Nov 14. PMID: 31813815
  2. Caleb M Gulledge, Eric C Makhni. Open Gluteus Medius and Minimus Repair With Double-Row Technique and Bioinductive Implant Augmentation. Arthrosc Tech 2019 May 17;8(6):e585-e589. doi: 10.1016/j.eats.2019.01.019. eCollection 2019 Jun. PMID: 31334014 PMCID: PMC6620622

Preop Nerve Blocks for Hip Fractures – Sooner Is Better

The benefits of peripheral nerve blocks for pain control and decreased use of opioids has been well-established for several orthopaedic procedures. In the May 20, 2020 issue of The Journal, a prospective cohort study by Garlich et al. shows that administering such a block earlier rather than later significantly benefits elderly patients awaiting surgery for a hip fracture.

The authors looked at whether the time to block (TTB) with a fascia iliaca nerve block (FIB) in a cohort of 107 patients who sustained a hip fracture affected preoperative opioid consumption and postoperative pain scores. They also examined the relationship between TTB and length of stay and adverse events related to opioids. All FIBs were performed between the time of emergency department arrival and ≥4 hours prior to surgery. Those parameters allowed time for the block to work and also time for the patients in this cohort to request pain medication.

Preoperatively, 72% of all opioid consumption took place prior to block placement. Patients experiencing a faster TTB consumed fewer opioids preoperatively and also on postoperative days 1 and 2, although the day-2 differences were not statistically significant. More specifically, Garlich et al. found a 63.7% reduction in the median preoperative opioid consumption in those with a TTB <8.5 hours from the time of arrival, relative to those whose TTB was ≥8.5 hours.

In addition, patients with a TTB <8.5 hours had significantly lower pain scores on postoperative day 1, and their hospital stays were significantly shorter than those who received blocks ≥8.5 hours after arrival (4.0 days versus 5.5 days). There were no differences in opioid-related adverse events between the TTB groups, although commentator Dr. Patrick Schottel notes that the study was underpowered to definitively discern those between-cohort differences.

Overall, this important study shows that early preoperative FIB reduces perioperative opioid consumption in geriatric patients with hip fractures, in addition to decreasing their pain scores and length of hospital stay. Further investigation is needed to determine the optimal timing for administering preoperative blocks in this vulnerable population.

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

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

How to Conduct a Virtual Orthopaedic Examination

For obvious reasons, the use of telemedicine has surged during the COVID-19 pandemic. If you are wondering what a “virtual” orthopaedic physical exam looks like, Tanaka et al. explain the process in words and images in a recent fast-tracked JBJS article.

At the time they schedule their virtual visit, patients are asked to confirm their audiovisual capabilities, and they receive specific instructions about camera positioning, body positioning, setting, and attire to improve the efficiency of the visit.

Tanaka et al. give step-by-step instructions for virtually evaluating the knee, hip, shoulder, and elbow. They describe how they measure range of motion using a web-based goniometer (see Figure), and they explain how to conduct virtual strength tests for each joint. To enable post-exam follow-up discussions with patients, the authors recommend using “the screen-sharing function that is presumably available on all interactive telehealth platforms.”

The authors acknowledge the limitations inherent in a virtual orthopaedic exam, such as the inability to directly palpate the joint or perform provocative tests. They also admit that the patient population that would potentially benefit the most from televisits—older patients with limited mobility and who are at higher risk for infection during the pandemic—are also those who may have the most difficulty implementing the technology.

The rapid rise of telemedicine in orthopaedics has occurred due to unexpected necessity, but many expect that its widespread use will continue post-pandemic. Tanaka et al. cite future directions for the technology, including the development of validated, modified examination techniques and advancements that will improve interactivity during the physical examination. For now, though, these experience-based guidelines should help orthopaedists optimize the quality and efficiency of their upcoming virtual visits for common musculoskeletal conditions.

Romosozumab for Hip Fractures: All That Glitters Is Not Gold

We have all come to realize that promising results from lab studies or preclinical trials in animal models do not always translate into meaningful clinical benefits in humans. Yet it is vitally important to perform those human trials to ascertain that knowledge. This is demonstrated by Schemitsch et al. in the April 15, 2020 edition of The Journal. The authors performed a Level I, double-blinded, randomized controlled trial comparing varying doses of romosozumab to placebo in the treatment of older patients with a hip fracture.

Romosozumab is a sclerostin-inhibiting antibody that helps increase bone formation while decreasing resorption. It is indicated to treat osteoporosis in postmenopausal women, in whom the drug has been shown to increase bone mineral density and reduce the risk of fragility fractures. In multiple preclinical studies, romosozumab has increased bone mass and bone strength in rodent osteotomy models, suggesting it might possibly promote fracture healing in people.

In the current study, Schemitsch et al. randomized patients between 55 and 95 years old who had a low-energy hip fracture amenable to internal fixation to receive 3 postsurgical subcutaneous injections of romosozumab at doses of either 70 mg (60 patients), 140 mg (93 patients), or 210 mg (90 patients), or to receive 3 placebo injections (89 patients). The primary end point was the validated “timed Up and Go” (TUG) score. The authors also measured the Radiographic Union Scale for Hip (RUSH) score, and hip pain on a visual analog scale (VAS).

The authors enrolled 325 patients, with 263 (79.2%) reaching the 24-week follow up and 229 (69.0%) reaching the 52-week follow up. They found no statistically significant between-group differences in the TUG, with all patients improving and plateauing at week 20. Similarly, there were no differences between any of the treatment arms in time to radiographic healing, RUSH scores, or VAS. The safety profile of the medication was similar between the 3 romosozumab doses and the placebo.

Romosozumab may increase bone mineral density and reduce the risk of fragility fracture in patients with osteoporosis, but when it comes to helping heal hip fractures, it did not prove to be more advantageous than placebo. This shows, yet again, that what may glitter in animal studies may not necessarily shine like gold in clinical trials with people.

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

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