Opioid-Free Analgesia is Safe and Effective in Anterior Cervical Spine Surgery: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial (RCT).

OBJECTIVE

Compare the efficacy of a multimodal, opioid-free (OF) pain management pathway with a traditional opioid-containing (OC) pathway in patients undergoing anterior cervical procedures.

SUMMARY OF BACKGROUND DATA

Previous studies have compared opioid-based pain regimens to opioid-sparing regimens following cervical spine surgery, but have been limited by high rates of crossover, retrospective designs, reliance on indwelling pain catheters, opioid utilization for early postoperative analgesia, and/or a lack of patient-reported outcome measures.

METHODS

This is a RCT in which patients were allocated to either an OF or OC perioperative pain management protocol. Eligible study participants included adult (age up to 18 y) patients who underwent primary, 1-level or 2-level anterior cervical surgery [anterior cervical discectomy and fusion (ACDF), anterior cervical disc arthroplasty (ACDA), or hybrid (ACDF and ACDA at different levels)] for degenerative pathology. The primary outcome variable was subjective pain level at 24 hours postoperative. The final study cohort consisted of 50 patients (22 OF, 28 OC).

RESULTS

Patients in the OF group reported lower median postoperative pain levels at 6 hours (4 for OF vs. 7 for OC; P =0.041) and 24 hours (3 for OF vs. 5 for OC; P =0.032). At 2-week and 6-week follow-up, pain levels were similar between groups. Patients in the OF group reported greater comfort at 12 hours (9 for OF vs. 5 for OC; P =0.003) and 24 hours (9 for OF vs. 5 for OC; P =0.011) postoperatively. Notably, there were no significant differences in patients' reported pain satisfaction, overall surgical satisfaction, or overall sense of physical and mental well-being. In addition, there were no significant differences in falls, delirium, or constipation postoperatively.

CONCLUSIONS

A multimodal OF pain management pathway following anterior cervical surgery for degenerative disease results in statistically noninferior pain control and equivalent patient-reported outcome measures compared with a traditional OC pathway.

Opioid Prescribing Rate for Nonoperative Distal Radius Fractures and Clinician Response to a Clinical Decision Support Alert

BACKGROUND

Opioids are commonly prescribed for the management of acute orthopedic trauma pain, including nonoperative distal radius fractures.

OBJECTIVES

This prospective study aimed to determine if a clinical decision support intervention influenced prescribing decisions for patients with known risk factors. We sought to quantify frequency of opioid prescriptions for acute nonoperative distal radius fractures treated.

METHODS

We performed a prospective study at one large health care system. Utilizing umbrella code S52.5, we identified all distal radius fractures treated nonoperatively, and the encounters were merged with the Prescription Reporting with Immediate Medication Mapping (PRIMUM) database to identify encounters with opioid prescriptions and patients with risk factors for opioid use disorder. We used multivariable logistic regression to determine patient characteristics associated with the prescription of an opioid. Among encounters that triggered the PRIMUM alert, we calculated the percentage of encounters where the PRIMUM alert influenced the prescribing decision.

RESULTS

Of 2984 encounters, 1244 (41.7%) included an opioid prescription. Age increment is a significant factor to more likely receive opioid prescriptions (p < 0.0001) after adjusting for other factors. Among encounters where the physician received an alert, those that triggered the alert for early refill were more likely to influence physicians' opioid prescribing when compared with other risk factors (p = 0.0088).

CONCLUSION

Over 90% of patients (106/118) continued to receive an opioid medication despite having a known risk factor for abuse. Additionally, we found older patients were more likely to be prescribed opioids for nonoperatively managed distal radius fractures.

Can researchers trust ICD-10 coding of medical comorbidities in orthopaedic trauma patients?

Objectives

The 10th revision of the International Classification of Diseases (ICD-10) coding system may prove useful to orthopaedic trauma researchers to identify and document populations based on comorbidities. However, its use for research first necessitates determination of its reliability. The purpose of this study was to assess the reliability of electronic medical record (EMR) ICD-10 coding of nonorthopaedic diagnoses in orthopaedic trauma patients relative to the gold standard of prospective data collection.

Design

Nonexperimental cross-sectional study.

Setting

Level 1 Trauma Center.

Patients/Participants

Two hundred sixty-three orthopaedic trauma patients from 2 prior prospective studies from September 2018 to April 2022.

Intervention

Prospectively collected data were compared with EMR ICD-10 code abstraction for components of the Charlson Comorbidity Index (CCI), obesity, alcohol abuse, and tobacco use (retrospective data).

Main Outcome Measurements

Percent agreement and Cohen's kappa reliability.

Results

Percent agreement ranged from 86.7% to 96.9% for all CCI diagnoses and was as low as 72.6% for the diagnosis "overweight." Only 2 diagnoses, diabetes without end-organ damage (kappa = 0.794) and AIDS (kappa = 0.798) demonstrated Cohen's kappa values to indicate substantial agreement.

Conclusion

EMR diagnostic coding for medical comorbidities in orthopaedic trauma patients demonstrated variable reliability. Researchers may be able to rely on EMR coding to identify patients with diabetes without complications or AIDS. Chart review may still be necessary to confirm diagnoses. Low prevalence of most comorbidities led to high percentage agreement with low reliability.

Level of Evidence

Level 1 diagnostic.

Anterior capsulectomy versus repair in direct anterior total hip arthroplasty

BACKGROUND

Utilization of the direct anterior approach for total hip arthroplasty (DAA THA) has increased over the last ten years. The preservation and repair of the anterior hip capsule has been recommended, while anterior capsulectomy has been described by others. In contrast, the higher risk of posterior dislocation using the posterior approach improved significantly after capsular repair. No studies to date have investigated outcome scores based on capsular repair versus capsulectomy for the DAA.

METHODS

Patients randomized to anterior capsulectomy or anterior capsule repair. Patients were blinded to their randomization. Maximum hip flexion was measured both radiographically and clinically with a goniometer. Using a one-sided t test assuming equal variance with an effect size, Cohen's d, of 0.6 and an alpha of 0.05, 36 patients in each group (total 72 patients) needed for a minimum 80% power.

RESULTS

Median goniometer measurements preoperatively were 95° for repair (IQR 85-100) and 91° for capsulectomy (IQR 82-97.5) (p = 0.52). Four-month and one-year goniometer measurements also had no significant difference, 110° (IQR 105-120) and 110° (IQR 105-120) for repair and 105° (IQR 96-116) and 109° (IQR 102-120) for capsulectomy (p = 0.38 and p = 0.26). Median change in flexion as measured by goniometer at 4 months and one year was 12 and 9 degrees for repair and 9.5 and 3 degrees for capsulectomy (p = 0.53 and p = 0.46). X-ray analysis showed no differences in pre-op, 4-month, and one-year flexion with median one-year flexion of 105.5° (IQR 96-109.5) for repair and 100° (IQR 93.5-112) for capsulectomy (p = 0.35). VAS scores were the same for both groups at all three time points. HOOS scores improved equally for both groups. There are no differences in surgeon randomization, age, or gender.

CONCLUSIONS

Both capsular repair and capsulectomy used in direct anterior approach THA result in equal maximum clinical as well as radiographic hip flexion with no change in postoperative pain or HOOS scores.

Biomechanical Assessment of Bicortical Suspension Device Fixation for Proximal Tibiofibular Joint Instability: Single Versus Double Device

BACKGROUND

Bicortical suspension device (BCSD) fixation treats proximal tibiofibular joint (PTFJ) instability in both the anterolateral and posteromedial directions. However, biomechanical data are lacking as to whether this technique restores the native stability and strength of the joint.

PURPOSE

To test (1) if BCSD fixation restores the native stability and strength and (2) if using 2 devices is needed.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen pairs of fresh-frozen cadaveric specimens were obtained. Six pairs were assigned to the control group and 10 matched pairs assigned for transection to model PTFJ and subsequent BCSD fixation (one specimen with 1-device repair and the other with 2-device repair). Joint stability and strength were assessed by translating the fibular head relative to the fixed tibia either anterolaterally or posteromedially. Control specimens received 20 cycles of 0- to 2.5-mm joint displacement tests (subfailure) and then proceeded to load to failure (5 mm). For the experimental group, cyclic tests were repeated after ligament resection and after fixation. Forces and stiffness at 2.5- and 5-mm displacement were recorded for comparisons of joint strength and stability at subfailure and failure loads, respectively.

RESULTS

After repair of anterolateral instability, both the single- and double-device fixations successfully restored near-native states, with no significant differences as compared with the intact group for forces at subfailure load (P = .410) or failure load (P = .397). Regarding posteromedial instability, single-device repair did not restore forces to the near-native state at subfailure load (intact: 92.9 N vs single: 37.4 N; P = .001) or failure load (intact: 170.7 N vs single: 70.4 N; P = .024). However, the double-device repair successfully restored near-native posteromedial forces at both subfailure load (P = .066) and failure load (P = .723).

CONCLUSION

For treatment of the most common form of PTFJ instability (anterolateral), this cadaveric study suggests that 1 BCSD is sufficient to restore stability and strength. The current biomechanical results also suggest that 2 devices are needed for restoring PTFJ posteromedial stability and strength. Using 2 devices addresses both types of instability and provides more PTFJ posteromedial stability.

CLINICAL RELEVANCE

The results suggest that 1 device should be used for treating anterolateral instability and 2 devices used for posteromedial instability based on the biomechanical study.

Patients with glenohumeral arthritis are more likely to be prescribed opioids in the emergency department or urgent care setting

OBJECTIVE

The objective is to quantify the rate of opioid and benzodiazepine prescribing for the diagnosis of shoulder osteoarthritis across a large healthcare system and to describe the impact of a clinical decision support intervention on prescribing patterns.

DESIGN

A prospective observational study.

SETTING

One large healthcare system.

PATIENTS AND PARTICIPANTS

Adult patients presenting with shoulder osteoarthritis.

INTERVENTIONS

A clinical decision support intervention that presents an alert to prescribers when patients meet criteria for increased risk of opioid use disorder.

MAIN OUTCOME MEASURE

The percentage of patients receiving an opioid or benzodiazepine, the percentage who had at least one risk factor for misuse, and the percent of encounters in which the prescribing decision was influenced by the alert were the main outcome measures.

RESULTS

A total of 5,380 outpatient encounters with a diagnosis of shoulder osteoarthritis were included. Twenty-nine percent (n = 1,548) of these encounters resulted in an opioid or benzodiazepine prescription. One-third of those who received a prescription had at least one risk factor for prescription misuse. Patients were more likely to receive opioids from the emergency department or urgent care facilities (40 percent of encounters) compared to outpatient facilities (28 percent) (p < .0001). Forty-four percent of the opioid prescriptions were for "potent opioids" (morphine milliequivalent conversion factor > 1). Of the 612 encounters triggering an alert, the prescribing decision was influenced (modified or not prescribed) in 53 encounters (8.7 percent). All but four (0.65 percent) of these encounters resulted in an opioid prescription.

CONCLUSION

Despite evidence against routine opioid use for osteoarthritis, one-third of patients with a primary diagnosis of glenohumeral osteoarthritis received an opioid prescription. Of those who received a prescription, over one-third had a risk factor for opioid misuse. An electronic clinic decision support tool influenced the prescription in less than 10 percent of encounters.

Adherence to legislation limiting opioid prescription duration following musculoskeletal injury

OBJECTIVES

North Carolina had implemented legislation (Strengthen Opioid Misuse Prevention (STOP) Act) limiting opioid prescriptions to 5 days for acute pain and 7 days for post-operative pain. This study aimed to identify patient, prescriber, and facility characteristics associated with STOP Act adherence for patients with acute or post-surgical musculoskeletal (MSK) conditions.

DESIGN

A three-level hierarchical logistic regression model was used to predict odds of adherence with STOP Act duration limits, accounting for fixed and random effects at the patient, prescriber, and facility levels.

SETTING

A large healthcare system in North Carolina.

PATIENTS AND PARTICIPANTS

Patients (N = 6,849) presenting from 2018 to 2020 with a diagnosis of an acute MSK injury.

INTERVENTIONS

The STOP Act limited the duration of opioid prescriptions in North Carolina.

MAIN OUTCOME MEASURE

Prescriptions adhering to the STOP Act duration limits of 5 days (nonoperative) or 7 days (operative) were the primary outcome.

RESULTS

Opioids were compliant with STOP Act duration limits in 69.3 percent of encounters, with 33 percent of variation accounted for by clinician and 29 percent by facility. Patients prescribed >1 opioid (odds ratio (OR) 0.46, 95 percent confidence interval (CI): 0.36, 0.58) had reduced odds of a compliant prescription; surgical patients had increased odds of a compliant prescription (outpatient surgery: OR 5.89, 95 percent CI: 2.43-14.29; inpatient surgery: OR 7.71, 95 percent CI: 3.04-19.56). Primary care sports medicine clinicians adhered to legislation less frequently than orthopedic surgeons (OR 0.38, 95 percent CI: 0.15, 0.97).

CONCLUSIONS

Most prescriptions adhered to STOP Act legislation. Tailored interventions to improve adherence among targeted groups of prescribers, eg, those treating nonoperative injuries and sport medicine clinicians, could be useful.

Opioid Prescribing for Chronic Musculoskeletal Conditions: Trends over Time and Implementation of Safe Opioid-Prescribing Practices

OBJECTIVES

This study aimed (1) to determine the impact of a clinical decision support (CDS) tool on rate of opioid prescribing and opioid dose for patients with chronic musculoskeletal conditions and (2) to identify prescriber and facility characteristics associated with adherence to the Centers for Disease Control and Prevention guideline for prescribing opioids for chronic pain in this population.We conducted an interrupted time series analysis to assess trends in percentage of patients from 2016 to 2020, receiving an opioid and the average opioid dose, as well as the change associated with implementation of the CDS toolkit. We conducted a retrospective cohort study to assess the association between prescriber and facility characteristics and safe opioid-prescribing practices.

METHODS

We assessed the impact of the CDS intervention on percent of patients receiving an opioid and average opioid dose (morphine milligram equivalents). We operationalized safe opioid prescribing as a composite score of several behaviors (i.e., prescribing naloxone, initiating a pain agreement, prescribing <90 MME, avoiding extended-release prescriptions for opioid-naïve patients, and avoiding coprescribing opioids and benzodiazepines) and used a hierarchical linear regression model to assess associations between prescriber and facility characteristics and safe opioid prescribing.

RESULTS

This CDS intervention had a modest but statistically significant 1.6% reduction on the percent of patients (n = 1,290,746) receiving an opioid (mean: 15% preintervention; 10% postintervention). The average dose of opioid prescriptions did not significantly change. Advanced practice providers and prescribers with higher percentages of patients aged 18 to 64 exhibited safer opioid prescribing, while prescribers with higher percentages of white patients and larger numbers of patients on opioids exhibited less safe opioid prescribing.

CONCLUSION

A CDS intervention was associated with a small improvement in percent of patients receiving an opioid, but not on average dose. Clinicians are not prescribing opioids for chronic musculoskeletal conditions frequently, when they do, they are generally adhering to guidelines.

The Influence of Patient Sex on Outcomes Following One-Stage and Two-Stage Revision for Periprosthetic Joint Infection in Total Joint Arthroplasty

Although females have a higher rate of primary total joint arthroplasty (TJA), males have a higher rate of revision. The literature lacks studies examining the relationship between sex and outcomes following single and two-stage exchange for periprosthetic joint infection (PJI). The purpose of this study was to examine if differences exist in outcomes following revision for chronic PJI between sexes. A retrospective review was performed on all patients with an MSIS confirmed PJI who underwent a single or two-stage exchange at our institution from January 2010 to January 2021. Patient demographics, comorbidity characteristics, and outcomes were collected and compared between males and females. The primary outcome variable was disease-free survival at 1 year following definitive revision. Multivariable logistic regression analysis was performed to determine risk factors for failure. Of the 470 patients meeting final eligibility criteria, 250 were male and 226 were female (2 males and 4 females had a joint infection of either the contralateral side or a different joint and were treated as separate records). Of the patients in the cohort, 80% of the males (200/250) and 80% of the females (181/226) were found to be disease-free at 1-year follow-up (p > 0.99). Multivariable logistic regression analysis showed that nicotine use and diabetes, but not sex, were significant predictors of failure. Our study did not find a relationship between sex and outcome of revision for PJI. Further research is required to determine whether differences exist between males and females in the expression of PJI and outcomes following treatment.

Healthcare costs of failed rotator cuff repairs

Background

The goal of this study was to estimate the short-term (∼2 years) healthcare costs of failed primary arthroscopic rotator cuff repair (RCR) in the United States.

Methods

A review of current literature was performed to estimate the number of RCR performed in the United States in the year 2022 and the rate of progression of these patients to lose repair continuity, reach clinical failure, and progress to nonoperative intervention and revision procedures. A review of the current literature was performed to estimate the costs incurred by these failures over the ensuing 2-year postoperative time period.

Results

The direct and indirect healthcare costs of structural and clinical failure of primary RCR performed in 2022 are estimated to reach $438,892,670 in the short-term postoperative period. The majority of the costs come from the estimated $229,390,898 in nonoperative management that these patients undergo after they reach clinical failure.

Conclusion

The short-term healthcare costs of failed arthroscopic RCR performed in the United States in 2022 are predicted to be $438,892,670. Although RCR improves quality of life, pain, function, and is cost-effective, there remains great potential for reducing the economic burden of failed RCR repairs on the US society. Investments into research aimed to improve RCR healing rates are warranted.

Clinical Relevance

Although RCR improves quality of life, pain, function, and is cost-effective, this study provides evidence that there remains great potential for reducing the economic burden of failed RCR repairs on the US society. Investments into research aimed to improve RCR healing rates are warranted.

Changes in opioid prescription duration for musculoskeletal injury associated with the North Carolina Strengthen Opioid Misuse Prevention (STOP) Act

OBJECTIVES

To assess whether implementation of the Strengthen Opioid Misuse Prevention (STOP) Act was associated with an increase in the percentage of opioid prescriptions written for 7 days or fewer among patients with acute or postsurgical musculoskeletal conditions.

DESIGN

An interrupted time-series study was conducted to determine the change in duration of opioid prescriptions associated with the STOP Act.

SETTING

Data were extracted from the electronic health record of a large health care system in North Carolina.

SUBJECTS

Patients presenting from 2016 to 2020 with an acute musculoskeletal injury and the clinicians treating them were included in an interrupted time-series study (n = 12 839).

METHODS

Trends were assessed over time, including the change in trend associated with implementation of the STOP Act, for the percentage of prescriptions written for ≤7 days.

RESULTS

Among patients with acute musculoskeletal injury, less than 30% of prescriptions were written for ≤7 days in January of 2016; by December of 2020, almost 90% of prescriptions were written for ≤7 days. Prescriptions written for ≤7 days increased 17.7% after the STOP Act was implemented (P < .001), after adjustment for the existing trend.

CONCLUSIONS

These results demonstrate significant potential for legislation to influence opioid prescribing behavior.

Implementation of required sedation assessment in nursing workflow to address naloxone utilization

OBJECTIVE

Opioid-related adverse drug events continue to occur. This study aimed to characterize the patient population receiving naloxone to inform future intervention efforts.

DESIGN

We describe a case series of patients who received naloxone in the hospital during a 16-week time frame in 2016. Data were collected on other administered medications, reason for admission to the hospital, pre-existing diagnoses, comorbidities, and demographics.

SETTING

Twelve hospitals within a large healthcare system.

PATIENTS

46,952 patients were admitted during the study period. 31.01 percent (n = 14,558) of patients received opioids, of which 158 received naloxone.

INTERVENTION

Administration of naloxone. Main outcome of interest: Sedation assessment via Pasero Opioid-Induced Sedation Scale (POSS), administration of sedating medications.

RESULTS

POSS score was documented prior to opioid administration in 93 (58.9 percent) patients. Less than half of patients had a POSS documented prior to naloxone administration with 36.8 percent documented 4 hours prior. 58.2 percent of patients received multimodal pain therapy with other nonopioid medications. Most patients received more than one sedating medication concurrently (n = 142, 89.9 percent).

CONCLUSIONS

Our findings highlight areas for intervention to prevent opioid oversedation. Investing in electronic clinical decision support mechanisms, such as sedation assessment, could detect patients at risk for oversedation and ultimately prevent the need for naloxone. Coordinated order sets for pain management can reduce the percentage of patients receiving multiple sedating medications and promote the use of multimodal pain management in efforts to reduce opioid reliance while optimizing pain control.

Ability of Countermovement Jumps to Detect Bilateral Asymmetry in Hip and Knee Strength in Elite Youth Soccer Players

Clinicians frequently assess asymmetry in strength, flexibility, and performance characteristics as a method of screening for potential musculoskeletal injury. The identification of asymmetry in countermovement jumps may be an ideal method to reveal asymmetry in other lower extremity characteristics such as strength that otherwise may require additional testing, potentially reducing the time and burden on both the athlete and clinicians. The present study aims to examine the ability of asymmetry in both the single-leg and two-leg countermovement jump tests to accurately detect hip abduction, hip adduction, and eccentric hamstring strength asymmetry. Fifty-eight young male elite soccer players from the same professional academy performed a full battery of functional performance tests which included an assessment of hip adductor and abductor strength profiles, eccentric hamstring strength profiles, and neuromuscular performance and asymmetries during countermovement jumps. Bilateral variables attained from both the single-leg and two-leg countermovement jump tests included concentric impulse (Ns), eccentric mean force (N), and concentric mean force (N) computed by the VALD ForceDecks software. Average maximal force (N) was calculated bilaterally for the strength assessments. Asymmetry was calculated for each variable using 100 × |(right leg − left leg)/(right leg)| and grouped into three categories: 0 to <10%, 10% to <20%, and 20% or greater. Analyses were performed for the two higher asymmetry groups. The accuracy to detect strength asymmetry was assessed as the sensitivity, specificity, and predictive values for positive and negative tests. The outcomes from the accuracy assessments suggest that the single-leg countermovement jump concentric impulse variable at the 20% threshold is indicative of a youth male soccer player having hip adduction strength asymmetry while also demonstrating more accuracy and applicability than the two-leg countermovement jump concentric impulse variable.

Biomechanical comparison of Tibial-sided supplemental fixation techniques in Bone-Patellar Tendon-Bone anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to compare the biomechanical properties of a commercially available suture anchor and a screw post for supplemental tibial fixation of a bone-patellar tendon-bone (BTB) graft at time zero. We hypothesized that supplemental fixation using a suture anchor would demonstrate similar biomechanical performance in comparison with a screw post.

METHODS

Sixteen fresh frozen, healthy human cadaveric knees underwent BTB autograft harvest, placement, and primary tibial-sided interference screw fixation using a standardized technique performed by a single surgeon. Specimens were randomly assigned to one of two tibial-sided supplemental fixation groups (suture anchor or screw post), yielding eight specimens in each group. Each specimen was affixed to a custom loading apparatus, with the tibial tunnel aligned in a vertical position that allowed for parallel "worst-case scenario" loading and eliminated loading variation due to tibial tunnel angle. Grafts were pretensioned to 30 N and biomechanical performance was compared with respect to cyclical loading between 50-250 N for 500 cycles at 0.5 Hz and pull-to-failure loading at 60 mm/min.

RESULTS

The suture anchor and screw post supplemental constructs demonstrated similar performance with respect to all biomechanical parameters assessed, including yield strength (294.0 N [IQR 267.2-304.2 N] versus 332.1 N [IQR 313.8-350.4 N]; P = 0.079) and ultimate strength (330.1 N [IQR 306.9-418.7 N] versus 374.7 N [IQR 362.0-387.3 N]; P = 0.3798). However, of the eight original specimens in each group, one suture anchor specimen (12.5%) and six metallic screw post specimens (75%) failed during cyclical testing and were unable to undergo displacement and load to failure testing.

CONCLUSION

This study provides preliminary evidence that supplemental tibial-sided fixation of a BTB ACL graft with a suture anchor has similar loading characteristics or load-to-failure strength when compared to supplemental fixation with a screw post construct.

STUDY DESIGN

Laboratory Controlled Study.

LEVEL OF EVIDENCE

Basic Science Study.

Balancing Safety, Comfort, and Fall Risk: An Intervention to Limit Opioid and Benzodiazepine Prescriptions for Geriatric Patients

Introduction

This study reports on the impact of a clinical decision support tool embedded in the electronic medical record and characterizes the demographics, prescribing patterns, and risk factors associated with opioid and benzodiazepine misuse in the older adult population.

Significance

This study reports on prescribing patterns for patients ≥65 years-old who presented to Emergency Departments (ED) or Urgent Care (UC) facilities across a large healthcare system following a fall (n = 34,334 encounters; n = 25,469 patients). This system implemented a clinical decision support intervention which provides an alert when the patient has an evidence-based risk factor for prescription drug misuse; prescribers can continue, amend or cancel the prescription.

Results

Of older adults presenting with a fall, 31.4% (N = 7986) received an opioid or benzodiazepine prescription. Women and younger patients (65-74) had a higher likelihood of receiving a prescription (P < .0001). 11% had ≥1 risk factor. Women were more likely to receive an early refill (P = .0002) and younger (65-74) men were more likely to have a past positive toxicology (P < .0001). A prescription was initiated in 8,591 encounters, and 946 (9.0%) triggered an alert. In 58 cases, the alert resulted in a prescription modification, and in 80 the prescription was canceled.

Conclusions

Documented risk for opioid misuse in the elderly was 10% among patients presenting to the ED/UC after a fall. The dangers associated with opioid/benzodiazepine use increase with age as does fall risk. Awareness of risk factors is an important first step; more work is needed to address potentially hazardous prescriptions in this population.

Central Slip Reconstruction With a Distally Based Flexor Digitorum Superficialis Slip: A Biomechanical Study

PURPOSE

The ideal method of central slip reconstruction is difficult to determine due to the multitude of techniques, nonstandardized outcome reporting, and small patient series in the literature. Although most boutonniere deformities may be treated with nonsurgical measures, chronic, subacute, or open injuries may require operative intervention. To aid surgeons in the choice of the ideal central slip reconstruction method, this biomechanical study compared the 3 most common methods performed at our institution: direct repair, lateral band centralization, and distally-based flexor digitorum superficialis (FDS) slip repair.

METHODS

A boutonniere deformity was induced in 35 fresh-frozen cadaver digits. The central slip was repaired in 9 digits using a primary suture repair, in 9 digits using a lateral band centralization technique, and in 9 digits using a distally-based FDS slip reconstruction. A control group without injury was tested in 8 digits. Following repair or reconstruction, each digit was tested for load to failure, strain, and stiffness at the repair.

RESULTS

The average load to failure after central slip reconstruction was significantly greater for a distally based FDS slip method at 82.1 ± 14.6 N (95% CI, 62.2-101.9 N) than all other repair types. Although the FDS slip reconstruction was not as strong as the intact state (82.1 N vs 156.2 N, respectively), it was 2.6 times stronger than the lateral band centralization (82.1 N vs 31.6 N, respectively) and 3 times stronger than a primary repair (82.1 N vs 27.6 N, respectively).

CONCLUSIONS

Reconstruction of the central slip using a distally-based FDS slip provided the greatest biomechanical strength compared with the direct repair or lateral band centralization.

CLINICAL RELEVANCE

The use of a distally based reconstruction using FDS may allow for safer early motion.

Complications in the treatment of periprosthetic joint infection of the hip: when do they occur?

Prosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty (THA). The common treatment in the USA is a two-stage exchange which can be associated with significant morbidity and mortality. The purpose of this study was to analyze complications in the treatment course of patients undergoing two-stage exchange for PJI THA and determine when they occur. Methods: We analyzed all patients that underwent two-stage exchange arthroplasty for treatment of PJI after THA from January 2005 to January 2018 at a single institution. Complications were categorized as medical or surgical and divided into interstage and post-reimplantation. Minimum follow-up was 1 year. Success was based on the MusculoSkeletal Infection Society (MSIS) definition. Results: 205 hips (203 patients) underwent first stage of planned two-stage exchange. The median age was 68 (interquartile range (IQR) 18). There were 97 males and 106 females. Overall, 73/205 (38 %) patients had at least one complication during treatment: 13.5 % (25/185) of patients experienced a medical complication and 28.1 % (52/185) a surgical complication; 2.4 % died within 1 year of surgery, and 4.9 % (15/203) had mortality at a median of 2.5 years (IQR 4.9); 27 % of patients had complications during the interstage period, most commonly being recurrence of infection requiring additional surgery (63 %); and 14 % of patients experienced a complication following reimplantation, most commonly persistence or recurrence of infection (59 %). While 92 % of patients that initiated treatment were ultimately reimplanted, only 69 % were infection free at 1 year and required no additional treatment. Conclusions: While two-stage exchanges for PJI in THA have been reported as successful, there are few reports of the complications during the process. In our series, significant numbers of patients experienced complications, often during the interstage period, highlighting the morbidity of this method of treatment.

Dental pain management with prescription opioids by nondental healthcare professionals in a healthcare system network

OBJECTIVES

Patients with dental pain seek treatment in Urgent and Emergency Care settings by physicians and advanced practice practitioners (APPs) unable to provide definitive care, often relying on prescriptions for pain management including opioids. In the face of an opioid epidemic, this study assessed the impact of an electronic health record (EHR) clinical decision support tool to identify patients at high risk for opioid misuse using objective, evidence-based criteria, and guide safer prescribing.

METHODS

Dental pain encounters occurring between January 2016 and June 2018 within our healthcare system were identified and linked to the database supporting a real-time clinical decision support intervention, Prescription Reporting with Immediate Medication Utilization Mapping (PRIMUM), to characterize opioid prescribing patterns and prescribers' response to alert. Descriptive analysis of the data was performed.

RESULTS

There were 30,649 dental pain encounters of which opioids were written in 45.5 percent (N = 13,957) encounters. A total of 16.6 percent of patients prescribed an opioid had a risk factor for misuse and triggered the PRIMUM alert at the point of care. In response to the PRIMUM alert (N = 2,501 encounters), clinician decision-making was influenced in 9.5 percent (N = 237) of encounters, which was defined by cancelation of the original opioid prescription. Of those 9.5 percent encounters, 48.1 percent (N = 114) resulted in no opioid prescription written.

CONCLUSIONS

There is potential for a clinical decision support tool embedded in the EHR to guide safer prescribing practice by alerting providers to objective, evidence-based risk characteristics at the point of care.

Pain and Anxiety due to the COVID-19 Pandemic: A Survey of Patients With Delayed Elective Hip and Knee Arthroplasty

Background

The COVID-19 pandemic led to cancelation of all elective surgeries for a time period in the vast majority of the United States. We compiled a questionnaire to determine the physical and mental toll of this delay on elective total joint arthroplasty patients.

Methods

All patients whose primary or revision total hip or knee arthroplasty was canceled because of the COVID-19 pandemic at a large academic-private practice were identified. An 11-question survey was administered to these patients via email. All data were deidentified and stored in a REDCAP database.

Results

Of 367 total patients identified, 113 responded to the survey. Seventy-seven percent of patients had their surgery postponed at least 5 weeks, and 20% were delayed longer than 12 weeks. Forty-one percent of patients reported an average visual analog scale pain score greater than 7.5. Forty percent of respondents experienced increased anxiety during the delay. Thirty-four percent of patients felt their surgery was not elective. Sixteen percent experienced a fall during the delay, and 1 patient sustained a hip fracture. Level of pain reported was significantly associated with negative emotions, negative effects of delay, and whether patients felt their surgery was indeed elective. Seventy-six percent reported trust in their surgeon's judgment regarding appropriate timing of surgery. Communication was listed as the number one way in which patients felt their surgeon could have improved during this time.

Conclusion

Surgical delay due to the COVID-19 pandemic resulted in increased pain and anxiety for many total joint arthroplasty patients. While most patients maintained trust in their surgeon during the delay, methods to improve communication may benefit the patient experience in future delays.

Level of Evidence

Level II.

Cheilectomy With or Without Cryopreserved Amniotic Membrane-Umbilical Cord Allograft for Hallux Rigidus

BACKGROUND

For hallux rigidus, dorsal cheilectomy remains a treatment option even with advances in interposition techniques and devices. Cheilectomy aims to alleviate dorsal impingement and improve pain and function as well as range of motion. Cryopreserved umbilical cord allograft, with properties to mitigate inflammation and scar formation, has theoretical benefit for improving outcomes following cheilectomy. In this first prospective randomized and blinded cheilectomy study reported, we aimed to compare outcomes between cheilectomy alone and cheilectomy with umbilical cord allograft.

METHODS

Patients were randomized to cheilectomy alone (CA) or cheilectomy with cryopreserved umbilical cord (ie, amniotic membrane-umbilical cord [AM-UC]). Patients were evaluated with American Orthopaedic Foot & Ankle Society (AOFAS), Foot Function Index (FFI), and visual analog scale (VAS) pain outcomes collected preoperatively and at 6 months and 1 year postoperatively. In addition, radiographic range of motion data were collected using stress radiographs. Fifty-one patients (26 AM-UC, 25 CA) completed the study, with 5 bilateral surgeries in the AM-UC group and 2 in the CA group, totaling 31 and 27 feet, respectively.

RESULTS

The AM-UC group had statistically significant improved AOFAS and FFI scores at 1 year compared with the CA group, but there was no difference at 6 months. There was no significant difference between groups for VAS-pain scores at any time point, but overall VAS-pain improved in both groups from preoperative values. There was no significant difference in range of motion (total arc) between groups and changes in range of motion (total arc) in both groups from preoperative to 1 year postoperative were small.

CONCLUSION

We present the results of the first randomized and blinded prospective study of cheilectomy surgery patients. When appropriately selected, cheilectomy remains a good option for patients with symptomatic hallux rigidus. Cryopreserved umbilical cord is a potential adjuvant to cheilectomy, with 1-year results showing improvements in functional outcome scores.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

No difference in patient compliance between full-strength versus low-dose aspirin for VTE prophylaxis following total hip and total knee replacement

INTRODUCTION

The utilization of aspirin for VTE prophylaxis following TJA has increased due to updated clinical practice guidelines. Aspirin is the only approved VTE prophylaxis medication that does not require a prescription, but adherence and tolerance remain unknown. We hypothesized decreased patient compliance utilizing full-strength 325 mg aspirin twice daily following TJA when compared to low-dose 81 mg twice daily. We also investigated the reasons why patients may elect to stop the medication earlier than 28 days.

METHODS

A consecutive series of patients undergoing primary total hip or knee arthroplasty utilizing 325 or 81 mg of EC aspirin twice daily for 4 weeks were surveyed to determine compliance with use and any adverse events related to the medication. Fisher's exact test was used to determine statistical significance.

RESULTS

404 patients were enrolled with 199 patients prescribed the 325 mg regimen. Fifty-two patients who were prescribed 325 mg missed a dose versus 51 patients who were prescribed 81 mg (p = 0.082). No significant difference in the frequency of missed doses (missing < 5 doses, 5-10 doses, > 10 doses) between the treatment regimens (p = 0.78, 0.39 and 0.83, respectively). Most commonly cited reason for stopping aspirin in both treatment groups was gastrointestinal issues (10.5% and 7%, respectively).

DISCUSSION AND CONCLUSIONS

By surveying patients on their use of aspirin we find no difference in adherence between full-strength and low-dose treatment regimens. Additionally, we have a better understanding of the reasons for noncompliance as GI upset was a relatively common complaint with both doses.

Ambulatory versus inpatient shoulder arthroplasty: a population-based analysis of trends, outcomes, and charges

Background

The purpose of this study was to evaluate the clinical outcomes and cost of shoulder arthroplasty (SA) performed in ambulatory surgery centers (ASCs) compared with SA performed in hospital-based surgery settings.

Methods

The State Inpatient Databases and the State Ambulatory Surgery Databases were queried for patients undergoing primary or reverse SA between 2010 and 2014 in 5 states in either the inpatient (IP), hospital outpatient department (HOPD), or ASC setting. Outcomes included all-cause readmissions, emergency department visits within the 90-day postoperative period, and charges. Covariates included patient demographic data and procedure details. Risk factors for readmission were calculated using logistic regression analysis.

Results

We identified 795 ASC (2%), 183 HOPD (0.5%), 38,114 (97.5%) SA procedures. The outpatient cohort was overall younger and healthier with a lower percentage of diabetes (14.1% vs. 20.2%), cardiopulmonary disease (11.4% vs. 20.4%), and obesity (10.7% vs. 15.6%). The US state and obesity were factors significantly (P < .0001) associated with readmission. The median IP charge was $62,905 (range, $41,327-$87,881) vs. $37,395 (range, $21,976-$61,775) for combined outpatient cases. When outpatient SA was stratified into ASC and HOPD cases, the median charges were $31,790 for ASC cases vs. $55,990 for HOPD cases (P < .0001). After adjustment for multiple covariates, the charges for combined outpatient SA surgery were 40% lower than those for IP SA surgery (P < .0001).

Conclusion

As the current health care climate shifts toward lower-cost and higher-quality care, this study demonstrates that SAs performed in ASCs have a comparable safety profile to and significant financial advantage over SAs performed in the hospital-based setting.

A Cost-Effectiveness Analysis of Isolated Meniscal Repair Versus Partial Meniscectomy for Red-Red Zone, Vertical Meniscal Tears in the Young Adult

PURPOSE

To evaluate the cost-effectiveness of treating isolated red-red zone, vertical meniscal tears with either isolated meniscal repair (IMR) or partial meniscectomy (PM) in the young adult using conservative modeling.

METHODS

A decision-analytic Markov disease progression model with a 40-year horizon was created simulating outcomes after IMR or PM for an isolated meniscal tear. Event probabilities, costs, and utilities were used for the index procedures, and the development of osteoarthritis (OA) and subsequent need for knee arthroplasty were calculated or selected from the published literature. Differences in cost, difference in quality-adjusted life years (QALYs), and the incremental cost effect ratio were calculated to determine which index procedure is most cost effective.

RESULTS

Total direct costs from PM were modeled at $38,648, and the total direct costs of IMR were $23,948, resulting in a projected cost savings of $14,700 with IMR. There was a modeled gain in QALYs of 17 for PM and 21 for IMR, resulting in an increase in 4 QALYs for the IMR treatment group. This results in an incremental cost effect ratio of $3,935 per QALY, favoring IMR as the dominant procedure.

CONCLUSIONS

Meniscal repair for isolated red-red zone, vertical meniscal tears was predicted to have lower direct costs and improve QALYs compared with partial meniscectomy over 40-year modeling, indicating isolated meniscal repair to be the cost-effective procedure in the treatment of an isolated meniscal tear in the young adult population.

LEVEL OF EVIDENCE

Level 3: economic and decision analysis.

Long-Term Screening is Necessary in Patients with Metal on Metal Total Hip Arthroplasty

Introduction: Adverse reactions to metal debris with catastrophic failures have been seen with a number of metal on metal (MoM) total hip designs. Understanding survivorship and factors associated with failure will allow for more targeted surveillance of those patients at highest risk for failure. The purpose of this study was to assess the mid to long term survivorship and specific factors associated with failure for a large cohort of a single modular MoM design.Methods: Consecutive patients treated with a modular metal on metal bearing with a five to fourteen year follow-up were included. Clinical outcome scores and radiographic data were prospectively collected.  Failure was defined as revision of either component for any reason during the study period. Multiple implant, surgical, and patient factors were analyzed for associations with elevated ion levels or revision due to adverse reactions to metal debris.Results: The average age at the time of surgery for the 253 patients included in the study was 55. There were 28 revisions (7.5%), eight due to metallosis (2%).   Survivorship was 89% at 12.6 years with revision for any reason as the end point. Survivorship was 93% when limited to revision for ALTR as the end point. Time in situ was the only variable that was statistically associated with an increased risk of failure due to ALTR (p<0.0001)Conclusion: In this large series of a single design modular metal-metal total hip we found relatively low rates of revision due to adverse reactions to metal debris.  The only variable associated with a statistically significant risk of ALTR was time in situ.   Therefore, long-term surveillance is necessary in patients with a MoM THA.

Effects of Cryopreserved Amniotic Membrane Allograft on Total Ankle Arthroplasty Wound Healing

Category:

Ankle, Ankle Arthritis, Basic Sciences/Biologics

Introduction/Purpose:

Despite improvements in newer-generation total ankle arthroplasty (TAA) implants, relatively high wound-healing complication rates continue to be reported with the anterior ankle incision. Only 66% heal without wound-healing complications, 25% have minor complications requiring local care and/or oral antibiotics, and 9% experience major complications requiring reoperation (Raikin et al., 2010). Recently, multiple regenerative adjuncts have been investigated to reduce postoperative complications by enhancing local healing factors and reducing risk of infection. The relatively novel use of adjunctive therapy utilizing cryopreserved amniotic membrane modulate wound healing by down-regulating inflammation and scar formation (Hanselman et al., 2015). The purpose of our study is to determine whether the local application of cryopreserved amniotic membrane wound allograft may enhance soft tissue wound healing of the TAA anterior ankle incision.

Methods:

Patients with symptomatic ankle arthritis who failed conservative management underwent TAA by two senior foot and ankle surgeons at single tertiary hospital. Both senior surgeons were present and involved in all surgeries, and all patients underwent the same procedure as indicated by their pathology, postoperative regimen, and rehabilitation protocol. At skin closure, patients were either allocated to the treatment or control group strictly by the designated primary attending. The skin closure of the treatment group was performed in standard fashion with local application of cryopreserved amniotic membrane to the extensor retinacular layer and no allograft was used for the control group. Demographics, sagittal and coronal correction, and patient comorbidity information was collected. The primary outcome was time to skin healing as determined by suture removal and surgical site skin apposition without evidence of granulation tissue or eschar. Secondary outcomes were skin dehiscence, local wound care, and use of antibiotics.

Results:

Local application of amniotic membrane allograft significantly decreased overall time to skin healing (40 days to 28.5 days, p=0.0377). There were no reoperations for wound complications in either group. However, there was a trend in decreased dehiscence (13% to 6%, p=0.29) and antibiotic prescription (23% to 9%, p=0.09). There was no significant difference in treatment versus control group with respect to body mass index, sagittal or coronal correction, sex, history of smoking, prior arthrodesis, or primary or revision. There was a significantly higher percentage of patients with history of diabetes who received amniotic membrane than those who did not receive the adjunct therapy (20% versus 2%, p=0.01).

Conclusion:

Regenerative technology using local application of cryopreserved amniotic membrane allograft may enhance TAA outcomes by decreasing time to healing. Although there was a trend in decreased dehiscence and antibiotic usage, larger randomized controlled trials are necessary to determine whether local application of cryopreserved amniotic membrane allograft may enhance soft tissue wound healing and ultimately reduce the incidence of devastating soft tissue complications.

A Retrospective Review of Risk Factors and Conversion Rate of Transmetatarsal Amputations to Below or Above Knee Amputation

Category:

Diabetes

Introduction/Purpose:

Despite the presence of several studies examining the conversion from transmetatarsal amputation (TMA) to a more proximal amputation, few studies identified the possible predictors of failure. The objective of this study is to examine the rate of conversion of transmetatarsal amputation to below or above knee amputation, and to identify the risk factors for conversion.

Methods:

A retrospective cohort study was performed examining 71 transmetatarsal amputations performed by a single group of foot and ankle subspecialists within a single specialty group between October 1 2005 and August 25 2015. Demographic information and comorbidities were recorded, as were complications, readmission rate, and rate of conversion to a more proximal amputation.

Results:

Of the 71 patients who underwent transmetatarsal amputation during the study period, 74.7% progressed to a revision amputation or more proximal amputation at a mean of 9.7 months, but a median of only 3.2 months. 87.3% progressed to below knee amputation, 9.9% underwent revision transmetatarsal amputation, and 2.8% received an above knee amputation. Of the patients who progressed to more proximal amputation, 88.2% had diabetes mellitus, 72.4% had a pre-operative ulceration, and 81.7% had peripheral neuropathy. Only 52.7% had diagnosed peripheral vascular disease, 38.1% had a history of renal disease, and 35% were smokers.

Conclusion:

Transmetatarsal amputation has an extremely high short-term reamputation rate with the vast progressing to a below knee amputation. Comorbidities such as diabetes mellitus, neuropathy, and history of ulceration are often found in these patients, while renal and peripheral vascular disease as well as tobacco abuse are not necessarily present. This high rate of reamputation may bring into question the efficacy of performing transmetatarsal amputation as opposed to a more proximal amputation as a definitive procedure when lower extremity amputation is required.

High frequency of adverse local tissue reactions in asymptomatic patients with metal-on-metal THA

BACKGROUND

The key to successful management of patients with metal-on-metal (MOM) THAs is to diagnose adverse local tissue reactions (ALTRs) early. ALTRs have been described in asymptomatic patients with resurfacing arthroplasties. Whether this concerning finding applies to modular MOM THAs is unknown.

QUESTIONS/PURPOSES

We (1) determined the prevalence of ALTRs in asymptomatic patients with modular MOM THAs, (2) described any differences in the appearance of these lesions between symptomatic and asymptomatic patients, and (3) analyzed potential predictive factors for any associations with ALTR prevalence.

METHODS

We evaluated 114 patients with modular MOM THAs who had MRI with metal artifact reduction sequence software and metal ion laboratory results at a mean of 57 months postoperatively. There were 83 asymptomatic and 31 symptomatic patients. We defined ALTRs as abnormal fluid collections, solid or semisolid pseudotumors, or muscle or bone damage. Ion levels, lesion size, and cup abduction angles were analyzed.

RESULTS

Twenty-six (31%) asymptomatic patients had ALTR lesions, all of which were in the greater trochanteric area. Most lesions in symptomatic patients also were in that location, but there was more diversity of location in this group. The cup position among patients with ALTRs was generally good; the average abduction angle for the asymptomatic patients with ALTRs was 40°. In 24 (92%) and 22 (85%) of 26 asymptomatic patients with ALTRs, respectively, chromium and cobalt levels were below the 7-ppb threshold.

CONCLUSIONS

A 31% incidence of periarticular fluid collections in asymptomatic patients with modular MOM THAs is alarming and calls into question any algorithmic approach dependent on symptomatology. The presence of pain was insufficient to identify patients at risk for ALTRs. To determine whether routine cross-sectional imaging of all asymptomatic patients with MOM implants is necessary will require a larger study cohort, longer followup, and clearer understanding of the natural history of periarticular lesions in these patients.

Risk factors for periprosthetic joint infection following primary total hip arthroplasty: a case control study

The purpose of this study was to identify the specific comorbidities and demographic factors that are independently associated with an increased risk of periprosthetic joint infection (PJI) in total hip arthroplasty (THA) patients. A case-control study design was used to compare 88 patients who underwent unilateral primary THA and developed PJI with 499 unilateral primary THA patients who did not develop PJI. The impact of 18 comorbid conditions and other demographic factors on PJI was examined. Depression, obesity, cardiac arrhythmia, and male gender were found to be independently associated with an increased risk of PJI in THA patients. This information is important to consider when counseling patients on the risks associated with elective THA, and for risk-adjusting publicly reported THA outcomes.

Safe and accurate: learning the direct anterior total hip arthroplasty

Wear, instability, leg length, and muscle recovery are the major obstacles in total hip arthroplasty (THA). The direct anterior approach with fluoroscopic assistance has been proposed to address all four of these issues. The goal of this study was to assess the learning curve, safety, and accuracy of direct anterior THA. A retrospective review was completed on a single surgeon's initial consecutive series of 300 THAs performed via a direct anterior approach. Cases were grouped based on chronologic order (1-100, 101-200, 201-300). Operative time, fluoroscopy time, estimated blood loss, radiographic leg length discrepancy (LLD), radiographic cup abduction angle, and complications were recorded. Data were analyzed using an analysis of variance. Postoperatively, all patients were managed without dislocation precautions. The average age for the cohort was 58.9 years, and the average BMI was 29. All groups were similar with respect to age and BMI. Direct anterior THA demonstrated significant reductions inoperative and fluoroscopy after the first 100 cases. Mean surgery time was 132.8 minutes for group 1, 109.9 for group 2, and 106.1 for group 3 (P<.001). Mean fluoroscopy time was 32.1 seconds for group 1, 14.5 for group 2, and 14.5 for group 3 (P<.001). There was one dislocation in group 3 and three intraoperative calcar fractures in the first 100 cases. There were no infections. Direct anterior THA demonstrated a reduction in operative time and fluoroscopy time after the initial 100 cases. Calcar fracture did not occur after the first 62 cases. Cup abduction angle, dislocation rate, and LLD were excellent in all groups.

Incomplete seating of press-fit porous-coated acetabular components: the fate of zone 2 lucencies

The purpose of this study was to asses the fate of incomplete seating of press-fit acetabular components. From 1990 to 2002, 587 hip arthroplasties were performed using a single-design acetabular component inserted with a press-fit technique with no additional fixation. Complete radiographic follow-up at a mean 9.2 years was available for 343 cases. One hundred thirty-three acetabular components had incomplete seating on the initial postoperative radiograph and 210 cases had complete seating. Of 133 components, 125 (94%) had evidence of complete zone 2 filling. Zone 2 focal osteolysis was present in 22 patients. There were no intraoperative fractures. No acetabular components were revised for loosening. Incomplete seating of press-fit acetabular components is safe and effective in achieving initial and long-term fixation. Zone 2 lucencies when present initially are not associated with increased failure risks. Vigorous attempts to completely seat the acetabular component appear to be unwarranted.

Why do revision knee arthroplasties fail?

This study identified the mechanisms of failure and the variables associated with failure after revision knee arthroplasty. Five hundred sixty-six index revision knee arthroplasties were studied. Of index revisions, 12.0% failed at an average of 40.1 months. Predominant revision failure modes included infection (46%), aseptic loosening (19%), and instability (13%). Only 4.3% of knees revised for aseptic loosening required rerevision as compared to 21% of knees revised for infection. Revision knee arthroplasty was more likely to fail in younger patients and in those who underwent polyethylene exchanges. Mechanisms of failure for revision arthroplasties are different than for primary knee arthroplasties. Revisions for infection are 4 times more likely to fail than revisions for aseptic loosening. The survivorship for the entire cohort, with revision for any reason as an end point, was 82% at 12 years.

Hip instability in 2-stage reimplantation without an articulating spacer

Hip instability is a common postoperative complication after revision surgery. This study sought to define the prevalence of hip instability after 2-stage reimplantation without an articulating spacer. A joint registry review identified 110 patients undergoing 2-stage reimplantation. Fifty-five patients (56 hips) were alive at the time of data collection. Instability was documented and risk factors were analyzed. Of the 56 hips, 14 (25%) dislocated. Five of these 14 patients had chronic abduction insufficiency. Six patients required rerevision to attain stability. There were no significant differences between dislocators and nondislocators in abduction angle, head size, cup size, liner type, or leg length. The 25% (14/56) dislocation rate reported here is unacceptable. Interim articulating spacers, postoperative bracing, large head technology, and constrained liners are treatment methods that should be considered in this group of patients.

Importance of a balanced-gap technique in rotating-platform knees

Rotating-platform knees are constructed of highly conforming polyethylene to reduce contact pressures that potentially cause wear. The mobile nature of the rotating platform can lead to bearing spin-out. The purpose of this study was to determine the prevalence of spin-out in a single series. A total of 426 knees in 393 patients were included in the study. All knees were implanted using a balanced-gap technique. The average follow up was 3.2 years. There were no cases of bearing spin-out. The author concludes that the balanced-gap technique reliably prevents spin-out in mobile-bearing total knee implantation. This implantation technique provides the potential wear benefits of the rotating platform design with a nominal bearing spin-out rate.

Acetabular component deformation with press-fit fixation

Acetabular component deformation secondary to forces encountered during insertion is a potential consequence of the press-fit technique. This study characterized the stiffness of Pinnacle 100 cups (DePuy, Warsaw, Ind) via mechanical testing and used this information with intraoperative measurements of cup deformation to calculate the in vivo forces acting on cups inserted during hip arthroplasty in 21 patients. We found that 90.5% of cups had measurable compression deformity, averaging 0.16 +/- 0.16 mm. The corresponding forces acting on these cups averaged 414 +/- 421 N. For hard-on-hard bearing surfaces, such in vivo deformation of acetabular shells may result in negative clinical consequences such as equatorial loading with increased wear and potential seizing of components, chipping of ceramic inserts, or locking mechanism damage.

Early failure in total hip arthroplasty

Although some patients experience a success rate greater than 90% after total hip arthroplasty, others require revision surgery within 5 years after the index procedure. The purpose of our study was to analyze the failure mechanisms in patients who had revision surgery within 5 years after index total hip arthroplasty. We retrospectively reviewed 824 revision total hip arthroplasties performed in 692 patients from 1986-2001. Seven hundred forty-five patients had adequate data. Two hundred ninety-one (39%) patients had revisions within 5 years after index arthroplasty. Ninety-six (33%) patients had revision surgery for instability, 88 (30%) for aseptic loosening, 41 (14%) for infection, 14 (5%) for osteolysis, 44 (15%) for failed painful hemiarthroplasties, and eight (3%) for periprosthetic fractures. Early revisions for aseptic loosening decreased from 38% in the early period to 24% in the current period, whereas revisions for instability increased from 9% to 42%. We were alarmed that 39% of the revisions at our institution were performed during the first 5 years after index surgery. Although improved fixation methods decreased early revisions for loosening, early revisions for instability increased substantially during the same time. Steps to avoid short-term failure must be taken.

Outcome comparison of partial and full component revision TKA

We compare the clinical and radiographic results of partial-component versus full-component revision total knee arthroplasty. A retrospective review was used to identify patients who had partial revision total knee arthroplasty. Only isolated femoral or tibial revisions were included. From 1986 to 2000, 448 revision total knee arthroplasties were done. Seventy-seven partial revisions were done. Three were excluded for a diagnosis of infection. The average followup was 63 months. The average Knee Society score for full component revisions was 85 compared with 79 for partial revisions. This difference was significant (p = 0.0001). The average Knee Society score for those patients who had a full revision for instability was 85 compared with 63 for partial revision (p = 0.0001). The average Knee Society score for those patients who had a full revision for wear-related problems was 88 compared with 78 for partial revisions (p = 0.03). Although the advantages of partial revision in hip replacement are well-documented, the efficacy of this treatment strategy has not been established in revision total knee arthroplasty. Care should be taken when considering partial revision for instability or wear-related problems.

LEVEL OF EVIDENCE

Therapeutic study, Level III (retrospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.

Failure of femoral surface replacement for femoral head avascular necrosis

The appropriate treatment for the young patient with post-collapse avascular necrosis (AVN) of the femoral head continues to be controversial. Femoral surface replacement (FSR) has emerged as a potential strategy to delay total hip arthroplasty in these patients. Between 1997 and 2003, 37 FSR procedures were performed. Success was defined as patients not requiring revision surgery or having a Harris hip pain score of 30 or greater. Failure was defined as patients having revision surgery or a Harris hip pain score of 20 or less. The overall failure rate based on Harris hip pain scores and revision surgery was 64.8% (24/37 procedures). Fifteen (40.5%) procedures required revision surgery, whereas 9 (24.3%) patients were considered failures based on their pain scores. The purpose of this study was to determine if FSR is a viable option for post-collapse AVN. We conclude that hemiresurfacing for AVN is an unpredictable procedure. This procedure is no longer offered as a treatment option for post-collapse AVN at our institution.

Cementless revision total hip arthroplasty without allograft in severe proximal femoral defects

This study evaluates the difficult reconstructive challenge of severe proximal femoral bone loss. We present intermediate-term results of 46 hips with extensive proximal femoral bone loss that underwent revision total hip arthroplasty using cementless distal fixation without supplemental allograft. All were evaluated with the Harris hip score at a minimum of 2 years. Radiographs were assessed using the Engh fixation scale. At a mean of 6.4 (range 2-12) years, 43 of the 46 prostheses were functioning well. Two patients required revision for symptomatic loosening, and 1 prosthesis remains radiographically loose with a fair clinical score. Mean Harris hip score was 77 at last follow-up. There were 6 intraoperative femur fractures, 9 dislocations, 10 cases of severe stress shielding, and no infections.

Early morbidity of modular exchange for polyethylene wear and osteolysis

This study assessed the early morbidity associated with modular component exchange surgery for the treatment of accelerated polyethylene wear and osteolysis in 55 patients. Review of the surgical records revealed no significant intraoperative complications, little intraoperative blood loss (mean 333 mL), no allogenic blood transfusions, and no recorded postoperative deep vein thromboses. Eighteen percent of patients, however, experienced postoperative dislocation. Five patients dislocated multiple times, 3 of which required rerevision surgery. Two patients required rerevision for femoral implant fractures related to osteolysis and 1 additional patient required rerevision due to catastrophic failure of the acetabular component 5 years postoperatively. With an average follow-up of 30 months, 6 of the 55 patients treated with modular exchange required rerevision. The results of this study suggest that instability is the most prevalent early complication associated with modular component exchange. As such, we believe that more stable constructs should be emphasized, possibly at the expense of polyethylene thickness.

Bipolar reconstruction for recurrent instability of the hip

Between 1986 and 1998, 81 total hip revisions were performed for recurrent instability. Twenty-three revisions were fixed cups to bipolars. Average follow-up was 50 months. Radiographic evaluation showed no significant osteolysis and average migration of 1.7 mm. The average postoperative Harris hip score was 74. All patients who underwent revision to a bipolar prosthesis had no further instability. Acetabular revision to a bipolar prosthesis provides stability in recurrent prosthetic hip instability.

Kyphoplasty: report of eighty-two thoracolumbar osteoporotic vertebral fractures

OBJECTIVES

Document initial outcomes of balloon kyphoplasty.

DESIGN

Retrospective analysis of the first 52 patients with 82 painful vertebral body compression fractures secondary to osteoporosis treated at our institution.

SETTING

Operation on subacute painful fractures with office follow-up.

PATIENTS/PARTICIPANTS

First 82 fractures in 52 patients treated. All patients had failed nonoperative treatment and had magnetic resonance imaging scans documenting edematous changes of the vertebral body. Forty-nine out of 52 patients presented for follow-up at an average of 37 weeks.

INTERVENTION

Minimally invasive balloon reduction via bilateral transpedicular or extrapedicular approaches followed by polymethyl methacrylate fixation.

MAIN OUTCOME MEASURES

Vertebral body height, Cobb angle, visual analogue pain scale, Roland-Morris Disability Survey, and complication rate.

RESULTS

Mean length of follow-up was 9 months (37 weeks, range 4-99 weeks); improved height 4.6 and 3.9 mm in the anterior and medial columns, respectively (P > 0.05); Cobb angle increased 14% (P < 0.05), visual analogue pain scale score improved 7 points (P < 0.05); Roland-Morris Disability Survey improved 11 points (P < 0.05); no adverse medical or procedural complications; 9.8% cement leakage rate.

CONCLUSION

Balloon kyphoplasty safely improves vertebral body height and patient quality of life.

MIC mitigation in a 100 MW district heating peak load unit

During inspection of AISI316 stainless steel plate heat exchangers in a district heating peak load unit, localised corrosion attacks along with indications of microbiological activity were found on the boiler side beneath patches of sturdy black deposits. Bacteria and sulphide were detected within black deposits. Thorough investigation of the boiler system revealed several incidents of localised corrosion on low alloy steel along with deposits of organic matter and bacteria primarily in places with stagnant water or places operating at a low flow rate. A relatively large amount of bacteria was detected within the system, primarily in deposits and around corrosion sites. The observations suggested the combination of deposits and bacterial activity, being the major reason for the observed corrosion. Prior to the investigation, the boiler system had operated with cat-/anion-exchanged, de-aerated water for 3 years, during which the water fulfilled strict chemical limits set to minimise corrosion. Based on these findings, the system has been modified in order to minimise the risk of microbiologically influenced corrosion and a monitoring program for fouling and corrosion has been established.

Stem fixation in revision total knee arthroplasty: a comparative analysis

Methods of stem fixation are a controversial aspect of revision TKA. We sought to determine which technique was superior by reviewing 475 revision TKAs done between 1986 and 2000. Of these 475 revisions, 286 major component revisions were done using 484 extended stems for fixation. Patients who died, patients who had less than 2 years follow up, or patients who had diaphyseal engaging stems were excluded from the study. The final data set included 113 revision TKAs with 202 metaphyseal engaging stems. Of the 202 stems, 107 were cemented whereas 95 were press-fit metaphyseal engaging stems. One hundred one of these were femoral stems and 101 were tibial stems. Using a modified Knee Society radiographic scoring system, 100 (93%) of the 107 implants with cemented stems were considered stable, seven (7%) were categorized as possibly loose requiring close followup, and none were loose. Of the 95 implants placed with cementless stems, only 67 (71%) were categorized as stable. Eighteen (19%) were possibly loose requiring close followup and 10 (10%) were loose (two tibial and eight femoral implants). We currently would urge caution in using cementless metaphyseal engaging stems for fixation in revision TKA.

Monitoring and characterisation of bacteria in corroding district heating systems using fluorescence in situ hybridisation and microautoradiography

Presence of biofilm and biocorrosion has been observed in Danish district heating (DH) systems despite very good water quality that was expected to prevent significant microbial growth. The microbiological water quality was investigated in order to identify the dominating bacterial groups on surfaces with corrosion problems. Water samples from 29 DH systems were investigated for the total number of bacteria and presence of sulphate reducing bacteria (SRBs). SRBs were found to be present in more than 80% of the DH systems. The microbial population in samples from 2 DH system (biofilm from a test coupon and an in situ sample from a heat exchanger) was investigated with fluorescence in situ hybridisation, and the results showed significant differences in population composition. Betaproteobacteria was the dominant population in both samples. SRBs were present in both samples but were most numerous in the biofilm from the test coupon. Examination of functional groups based on uptake of radiolabelled acetate (microautoradiography) showed presence of both aerobic and anaerobic bacteria despite the fact that oxygen is not anticipated in DH systems.

Success rate of modular component exchange for the treatment of an unstable total hip arthroplasty

Hip instability is the leading cause of morbidity after total hip arthroplasty. Surgical strategies that have been used to eliminate recurrent instability include component revision, trochanteric advancement, or the use of constrained components. Between 1986 and 1997, 731 revision total hip arthroplasties were performed at our institution. A total of 29 patients underwent modular component exchange to treat hip instability. After revision surgery, 16 of 29 (55%) patients experienced redislocation. Nine (31% overall) patients dislocated repeatedly after modular component exchange. Five of the 9 patients who dislocated repeatedly (17% overall) ultimately required rerevision to obtain stability. Modular component exchange is an unpredictable procedure in definitively solving hip stability problems. The limitations of this procedure in treating this complex multifactorial problem must be understood by patient and surgeon alike.

Patella inversion method for exposure in revision total knee arthroplasty

Satisfactory performance of revision total knee arthroplasty (TKA) requires adequate exposure. This article shows the patella inversion method of exposure in a large consecutive series of revision TKAs.Between 1987 and 1999, 420 revision TKAs were performed. Exposure was facilitated by the patella inversion method. No attempt was made to evert the patella. This technique of exposure was used in 95% (397 of 420) of patients. There were no episodes of patellar tendon avulsion in this series. Multiple exposure options are available in revision TKA. Extensile techniques violate the extensor mechanism. For most patients, these methods were unnecessary. The patella inversion method afforded adequate exposure in most patients without violating the extensor mechanism.

Early failures in total knee arthroplasty

Total knee arthroplasty is a predictable operation. Unfortunately, there is a subset of patients who do not do well and require revision surgery within the first 5 years. The purpose of the current study was to analyze the mechanisms of failure in patients who had revision surgery within 5 years of their index arthroplasty. Between 1986 and 1999, 440 patients with total knee arthroplasties were referred for revision surgery. An analysis of patients in whom the arthroplasties failed within 5 years of the index arthroplasty and the reasons for early failure were documented. Of the 440 patients who had revision surgery, 279 (63%) had revision surgery within 5 years of their index arthroplasty: 105 of the 279 patients with early failures (38%) had revision surgery because of infection; 74 (27%) had revision surgery because of instability; 37 (13%) had revision surgery because of failure of ingrowth of a porous-coated implant; 22 (8%) had revision surgery because of patellofemoral problems; and 21 (7%) had revision surgery because of wear or osteolysis. Only eight of the 279 patients with early failures (3%) had revision surgery because of aseptic loosening of a cemented implant. The remaining 12 patients had revision surgery because of miscellaneous problems. Host factors may prevent infection from ever being eradicated totally. The two other major patterns of failure in this series were failure of cementless fixation and instability. If all of the arthroplasties in the patients in this early failure group would have been cemented routinely and balanced carefully, the total number of early revisions would have decreased by approximately 40%, and the overall failures would have been reduced by 25%.