Modular fluted tapered stems in two-stage reimplantation of previously infected total hip arthroplasties

Aims

Uncemented implants are now commonly used at reimplantation of a two-stage revision total hip arthoplasty (THA) following periprosthetic joint infection (PJI). However, there is a paucity of data on the performance of the most commonly used uncemented femoral implants - modular fluted tapered (MFT) femoral components - in this setting. This study evaluated implant survival, radiological results, and clinical outcomes in a large cohort of reimplantation THAs using MFT components.

Methods

We identified 236 reimplantation THAs from a single tertiary care academic institution from September 2000 to September 2020. Two designs of MFT femoral components were used as part of an established two-stage exchange protocol for the treatment of PJI. Mean age at reimplantation was 65 years (SD 11), mean BMI was 32 kg/m2 (SD 7), and 46% (n = 109) were female. Mean follow-up was seven years (SD 4). A competing risk model accounting for death was used.

Results

The 15-year cumulative incidence of any revision was 24%. There were 48 revisions, with the most common reasons being dislocation (n = 25) and infection (n = 16). The 15-year cumulative incidence of any reoperation was 28%. Only 13 revisions involved the fluted tapered component (FTC), for a 15-year cumulative incidence of any FTC revision of 8%. Only two FTCs were revised for aseptic loosening, resulting in a 15-year cumulative incidence of FTC revision for aseptic loosening of 1%. Stem subsidence ≥ 5 mm occurred in 2% of unrevised cases. All stems were radiologically stable at most recent follow-up. Mean Harris Hip Score was 69 (SD 20) at most recent follow-up.

Conclusion

This series demonstrated that MFT components were durable and reliable in the setting of two-stage reimplantation THA for infection. While the incidence of aseptic loosening was very low, the incidence of any revision was 24% at 15 years, primarily due to dislocation and recurrent PJI.

Contemporary Aseptic Revision Total Hip Arthroplasty in Patients ≤50 Years of Age: Results of >500 Cases

BACKGROUND

There has been a paucity of long-term outcomes data on aseptic revision total hip arthroplasties (THAs) in the young adult population. The purpose of this study was to evaluate implant survivorship, complications, and clinical outcomes in a large cohort of contemporary aseptic revision THAs in patients ≤50 years of age at the time of the surgical procedure.

METHODS

We identified 545 aseptic revision THAs performed at a single academic institution from 2000 to 2020 in patients who were 18 to 50 years of age. Patients who underwent conversion THAs and patients with a history of any ipsilateral hip infection were excluded. The mean age was 43 years, the mean body mass index (BMI) was 29 kg/m2, and 63% were female. The index indication for revision THA was aseptic loosening in 46% of cases, polyethylene wear or osteolysis in 28% of cases (all revisions of conventional polyethylene), and dislocation in 11% of cases. There were 126 hips (23%) that had undergone at least 1 previous revision (median, 1 revision [range, 1 to 5 revisions]). The mean follow-up was 10 years.

RESULTS

In the entire cohort, the 20-year survivorship free of any re-revision was 76% (95% confidence interval [95% CI], 69% to 82%). There were 87 re-revisions, with 31 dislocations, 18 cases of aseptic loosening of the femoral component, and 16 periprosthetic joint infections (PJIs) being the most common reasons for re-revision. Dislocation as the indication for the index revision was associated with an increased risk of re-revision (hazard ratio, 2.9; p < 0.001). The 20-year survivorship free of any reoperation was 73% (95% CI, 66% to 78%). There were 75 nonoperative complications (14%), including 32 dislocations. The mean Harris hip score significantly improved (p < 0.001) from 65 preoperatively to 81 at 10 years postoperatively.

CONCLUSIONS

Contemporary aseptic revision THAs in patients ≤50 years of age demonstrated a re-revision risk of approximately 1 in 4 at 20 years. Dislocation, aseptic loosening of the femoral component, and PJI were the most common reasons for re-revision. Index revision THAs for dislocation had a 3 times higher risk of re-revision.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Marlex Mesh Reconstruction of the Extensor Mechanism: A Concise 5-Year Follow-up of 2 Previous Reports

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Obesity and Primary Total Hip Arthroplasty: The Absolute versus Relative Risk of Periprosthetic Joint Infection at 15 Years

BACKGROUND

To make an informed decision about total hip arthroplasty (THA), surgeons and patients need to understand the absolute and relative risks of periprosthetic joint infection (PJI). We sought to evaluate the long-term risk of PJI following primary THA stratified by body mass index (BMI) and PJI-related risk factors.

METHODS

We identified 21,550 primary THAs performed from 2000 to 2021 at a single institution. Patients were stratified as having 0, 1, or ≥ 2 PJI risk factors (diabetes, chronic kidney disease, nonprimary osteoarthritis, immunosuppression, or active smoking) and into BMI categories. The 15-year cumulative risk of PJI was evaluated by BMI and PJI risk factors.

RESULTS

For the entire cohort, the 15-year absolute risk of PJI was 2%. For patients who did not have PJI risk factors, the absolute risk of PJI at 15 years was 1% in normal weight, 2% in class III obesity, and 4% in class IV obesity. Patients who had class III and IV obesity had a 3-times and 9-times higher relative risk of PJI, respectively (P = .03, P < .001). Among patients who had ≥ 2 PJI risk factors, the absolute risk of PJI at 15 years was 2% in normal weight, 4% in class III obesity, and 18% in class IV obesity.

CONCLUSIONS

Healthy patients who had class III and IV obesity had a 3-times and 9-times increased risk of PJI at 15 years relative to normal weight patients. However, the absolute risk of PJI at 15 years was 2 and 4%, respectively. Given emerging data questioning whether BMI modification decreases PJI risk, surgeons and patients must consider both a 3-times to 9-times increased relative risk of PJI and a 2 to 4% absolute risk of PJI at 15 years for healthy patients who had a BMI ≥ 40.

LEVEL OF EVIDENCE

IV.

Outcomes After Successful Debridement, Antibiotic, and Implant Retention Therapy for Periprosthetic Joint Infection in Total Knee Arthroplasty

BACKGROUND

Controversy surrounds debridement, antibiotic and implant retention (DAIR) for treatment of acute periprosthetic joint infection (PJI). Data regarding DAIR's rate of infection resolution is variable with little investigation of functional outcomes.

METHODS

We identified 191 DAIR cases at a single institution from 2008 to 2020. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Patient Reported Outcome Measurement Information System-10 (PROMIS) scores were collected. Patient Reported Outcome Scores were obtained from 60 cases. Median follow-up (IQR) was 4.5 (2.1 to 7.6) versus 3.0 (1.2 to 5.3) years for the control group. Mean scores were compared to a cohort of uncomplicated total knee arthroplasties matched by age, body mass index, and sex using generalized linear models adjusted for follow-up duration. Kaplan-Meier survivorship curves for PJI were constructed.

RESULTS

Mean Patient Reported Outcome Scores for the DAIR cohort were 57.2 ± 19.7 for KOOS-JR, 41.6 ± 7.1 for PROMIS physical health (PH), and 46.6 ± 8.7 for PROMIS mental health (MH). Mean control group values were 65.8 ± 21.0 for KOOS-JR, 44.6 ± 8.4 for PROMIS PH, and 49.2 ± 9.2 for PROMIS MH. No difference was observed in KOOS-JR (P = .83) or PROMIS MH (P = .11). PROMIS PH was lower in the DAIR cohort compared to the control group (P = .048). Median follow-up (years) for all 191 cases was 5.9 (range, 0.5 to 13.1). Survivorship (years) without subsequent operation for infection was 84% at 1, 82% at 2, and 79% at 5.

CONCLUSION

Knee and MH outcomes in successful DAIR procedures were similar to uncomplicated total knee arthroplasty. DAIR's success rate was 79% in treating acute PJI at 5 years.

LEVEL OF EVIDENCE

Level III.

Did Rapid Expansion of Same Day Discharge Hip and Knee Arthroplasty During the COVID-19 Pandemic Increase Early Complications?

Background

The COVID-19 pandemic has had a lasting impact on patients seeking total hip and knee arthroplasty (THA, TKA) including more patients undergoing same day discharge (SDD) following total joint arthroplasty (TJA). The purpose of this study was to assess whether expansion of SDD TJA during the COVID-19 pandemic resulted in more early complications following TJA. We anticipated that as many institutions quickly launched SDD TJA programs there may be an increase in 30-day complications.

Methods

We retrospectively queried the ACS-NSQIP database for all patients undergoing primary elective TJA from January 1, 2018, to December 31, 2020. Participants who underwent THA or TKA between January 1, 2018 and March 1, 2020 were grouped into pre-COVID and between March 1, 2020 and December 31, 2020 were grouped into post-COVID categories. Patients with length of stay greater than 0 were excluded. Primary outcome was any complication at 30 days. Secondary outcomes included readmission and re-operation 30 days.

Results

A total of 14,438 patients underwent TKA, with 9,580 occurring pre-COVID and 4,858 post-COVID. There was no difference in rates of total complication between the pre-COVID (3.55%) and post-COVID (3.99%) groups (p=0.197). Rates of readmissions for were similar for the pre-COVID (1.75%) and post-COVID (1.98%) groups (p=0.381). There was no statistically significant difference in respiratory complications between the pre-COVID (0.41%) and post-COVID group (0.23%, p=0.03). A total of 12,265 patients underwent THA, with 7,680 occurring pre-COVID and 4,585 post-COVID. There was no difference in rates of total complication between the pre-COVID (3.25%) and post-COVID (3.49%) groups (p=0.52). Rates of readmissions for were similar for the pre-COVID (1.77%) and post-COVID (1.68%) groups (p=0.381). There was no statistically significant difference in respiratory complications between the pre-COVID (0.16%) and post-COVID group (0.07%, p=0.26). Combined data to include THA and TKA patients did not find a statistical difference in the rate of complications or readmission but did note a decrease in the rate of combined respiratory complications in the post-COVID group (0.15% vs. 0.30%, p=0.028).

Conclusion

Rapid expansion of SDD TJA during the COVID-19 pandemic did not increase overall complication, readmission, or re-operation rates. Level of Evidence: IV.

Current Practice Trends in Primary Hip and Knee Arthroplasties Among Members of the American Association of Hip and Knee Surgeons

During the 2022 Annual Meeting of the American Association of Hip and Knee Surgeons, an audience response poll was conducted to establish current practice patterns among American Association of Hip and Knee Surgeons members. There were 49 multiple-choice questions pertaining to routine practices surrounding primary total hip arthroplasties and primary total knee arthroplasties posed to over 4,000 in-person and 400 virtual meeting attendees. Responses were submitted via a mobile application (ie, app). Poll responses were collated and results from the 2022 poll were compared to poll results from 2009, 2018, and 2020.

What is the Impact of Social Deprivation on Mental and Physical Health Before and After Primary Total Knee Arthroplasty?

Background

The purpose of the present study was to investigate the relationship between socioeconomic status and Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) scores before and after primary total knee arthroplasty (TKA). We hypothesized that patients with greater social deprivation would have lower PROMIS-GH scores at 3 months and 1 year following primary TKA.

Methods

We retrospectively reviewed data from patients who underwent unilateral primary TKA and completed PROMIS-GH preoperatively and at 3 months (n = 257) or 1 year (n = 154) postoperatively. Area Deprivation Index (ADI), calculated from 9-digit zip codes, was used to measure social deprivation. Participants were grouped into quartiles by ADI score. Minimal clinically important difference in PROMIS-GH mental (PROMIS-MH) and physical health (PROMIS-PH) component scores were compared between ADI groups.

Results

Participants in the highest ADI quartile (most disadvantaged) had significantly lower PROMIS-MH and PROMIS-PH scores at every time point relative to the lowest ADI quartile (least disadvantaged) (P < .05 for all). Both ADI groups experienced significant improvements in PROMIS-PH following TKA (P < .001 for all), but not in PROMIS-MH (P > .05 for all) at 3-months and 1-year postoperatively. Magnitude of improvement in PROMIS-PH and rates of achievement of minimal clinically important difference did not significantly differ between ADI groups (P > .05 for all).

Conclusions

Socially disadvantaged patients benefit equally from primary TKA but are more likely to have persistently lower 1-year postoperative PROMIS-GH scores relative to less disadvantaged patients. Social deprivation should be accounted for when using PROMIS-GH to assess clinical outcomes for research and quality measures.

Level of Evidence

IV, retrospective cohort study.

What Is the Fate of Total Joint Arthroplasty Patients Who Are Asked to Quit Smoking Prior to Surgery?

Background

Smoking is a known risk factor for complications following primary total joint arthroplasty (TJA). Little is known regarding the fate of patients who are asked to quit smoking before surgery. The purpose of this study was to evaluate the success of smoking cessation prior to primary TJA and the impact of smoking cessation on perioperative outcomes.

Methods

This is a retrospective review of patients who presented between 2008 and 2020 to a single academic medical center with a documented smoking history and were asked to quit smoking prior to receiving a date for primary TJA. The cohort was surveyed about smoking cessation, smoking history, use of quit aids, seeking surgery elsewhere due to the cessation policy, and postoperative complications. Descriptive statistics evaluated the relationship between demographics, smoking cessation, and postoperative complications.

Results

A total of 101 patients completed the survey with an overall response rate of 48%. Sixty-two percent of patients quit smoking before surgery, and 51% of these patients reported remaining smoke-free at 6 months postoperatively. The average time to quit before TJA was 45 days (range: 1-365 days), and 62% quit without quit aids. The wound complication/infection rate was significantly higher for patients who did not stop smoking prior to TJA (4 of 16; 27%) than for those who did quit prior to surgery (3 of 63; 5%; P = .02).

Conclusions

This study demonstrates that most patients (62%) will stop smoking, if required, prior to primary TJA. Furthermore, 51% of patients reported abstinence from smoking at 6 months following TJA. TJA appears to be an effective motivator for smoking cessation.

Level of Evidence

III (retrospective cohort study).

Projected Prevalence of Obesity in Aseptic Revision Total Hip and Knee Arthroplasty

Background

The purpose of this study was to develop projections of the prevalence of obesity in aseptic revision THA and TKA patients through the year 2029.

Methods

The National Surgical Quality Improvement Project (NSQIP) was queried for years 2011-2019. Current procedural terminology (CPT) codes 27134, 27137, and 27138 were used to identify revision THA and CPT codes 27486 and 27487 were used to identify revision TKA. Revision THA/TKA for infectious, traumatic, or oncologic indications were excluded. Participant data were grouped according to body mass index (BMI) categories: underweight/normal weight, <25 kg/m2; overweight, 25-29.9 kg/m2; class I obesity, 30.034.9 kg/m2; class II obesity, 35.0-39.9 kg/m2; morbid obesity ≥ 40 kg/m2. Prevalence of each BMI category was estimated from year 2020 to year 2029 through multinomial regression analyses.

Results

38,325 cases were included (16,153 revision THA and 22,172 revision TKA). From 2011 to 2029, prevalence of class I obesity (24% to 25%), class II obesity (11% to 15%), and morbid obesity (7% to 9%) increased amongst aseptic revision THA patients. Similarly, prevalence of class I obesity (28% to 30%), class II obesity (17% to 29%), and morbid obesity (16% to 18%) increased in aseptic revision TKA patients.

Conclusion

Prevalence of class II obesity and morbid obesity demonstrated the largest increases in revision TKA and THA patients. By 2029, we estimate that approximately 49% of aseptic revision THA and 77% of aseptic revision TKA will have obesity and/or morbid obesity. Resources aimed at mitigating complications in this patient population are needed. Level of Evidence: III.

Outcomes Vary Significantly Using a Tiered Approach To Define Success After Total Hip Arthroplasty

Background

Clinical outcomes following primary total hip arthroplasty (THA) are commonly assessed through patient-reported outcome measures (PROM). The purpose of this study was to use progressively more stringent definitions of success to evaluate clinical outcomes of primary THA at 1-year postoperatively and to determine if demographic variables were associated with achievement of clinical success.

Methods

The American Joint Replacement Registry (AJRR) was queried from 2012-2020 for primary THA. Patients that completed the following PROMs preoperatively and 1-year postoperatively were included: Western Ontario and McMaster Universities Arthritis Index (WOMAC), Hip Injury and Osteoarthritis Outcome Score (HOOS) and HOOS for Joint Replacement (HOOS, JR). Mean PROM scores were determined for each visit and between-visit changes were evaluated using paired t-tests. Rates of achievement of minimal clinically important difference (MCID) by distribution-based and anchor-based criteria, patient acceptable symptom state (PASS), and substantial clinical benefit (SCB) were calculated. Logistic regression was used to evaluate associations between demographic variables and odds of success.

Results

7,001 THAs were included. Mean improvement in PROM scores were: HOOS, JR, 37; WOMAC-Pain, 39; WOMAC-Function, 41 (p<0.0001 for all). Rates of achievement of each metric were: distribution-based MCID, 88-93%; anchor-based MCID, 68-90%; PASS, 47-84%; SCB, 68-84%. Age and sex were the most influential demographic factors on achievement of clinical success.

Conclusion

There is significant variability in clinical outcomes at 1 year after primary THA when using a tiered approach to define success from the patient's perspective. Tiered approaches to interpretation of PROMs should be considered for future research and clinical assessment. Level of Evidence: III.

Presence of a Lateral Trochlear Osteophyte Predicts Medial Unicompartmental Arthroplasty Failure at Midterm Follow-up

Background

Specific clinical and radiographic risk factors for medial unicompartmental knee arthroplasty (UKA) failure are incompletely understood. The purpose of this study was to perform a midterm survivorship analysis of medial UKA from a single, nondesigner surgeon. Based on observations from clinical practice, we hypothesized that the presence of a lateral trochlear osteophyte on preoperative Merchant radiographs may be predictive of medial UKA failure secondary to progressive osteoarthritis (OA).

Methods

Patients who underwent a mobile-bearing medial UKA by a single surgeon with minimum 24 months of clinical follow-up from 2008 to 2019 were retrospectively identified. Radiographic parameters, including the presence of a lateral trochlear osteophyte, were measured. Kaplan-Meier survivorship analyses were performed. Cox proportional hazards models were used to evaluate variables as risk factors for UKA failure, defined as reoperation or component revision.

Results

A total of 233 UKAs were included. The mean age was 60 years, mean BMI 32 kg/m², and 53% of patients were male. The mean follow-up duration was 5.7 years (range, 2.0-13.1 years). Using any reoperation as an endpoint, the 10-year survival was 91%. Using any component revision as an endpoint, the 10-year survival was 93%. Using revision due to progressive OA as an endpoint, the 10-year survival was 95%. The presence of a lateral trochlear osteophyte was associated with an increased risk of any reoperation (hazard ratio 3.6; 95% confidence interval 1.3-9.5) and increased risk of revision due to progressive OA (hazard ratio 9.8; 95% confidence interval 2.9-32.7).

Conclusions

The presence of a lateral trochlear osteophyte on preoperative Merchant view radiographs was associated with an increased risk of medial UKA failure.

Rates of Antimicrobial Resistance With Extended Oral Antibiotic Prophylaxis After Total Joint Arthroplasty

Background

There is increased interest and utilization of extended oral antibiotic prophylaxis (EOAP) following primary and revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). The purpose of this study was to look for potential associations between EOAP and differential rates of antimicrobial resistance or epidemiology of organisms causing periprosthetic joint infection (PJI) following primary and aseptic revision THAs/TKAs.

Methods

Patients who developed PJI following a primary or aseptic revision TKA/THA at a single institution from 2009 to 2020 were retrospectively identified. Patients who received at least 7 days of EOAP following the surgery were noted. Rates of antimicrobial resistance were compared between standard antibiotic prophylaxis and EOAP cohorts using the Fisher's exact test.

Results

One hundred twenty-eight cultures were obtained from 119 patients with PJI. Fourty-four cases (37%) developed PJI after EOAP. Staphylococcus aureus was the most frequently isolated organism (30% of all cultures; 78% were methicillin-sensitive). Rates of antimicrobial resistance were similar between standard antibiotic prophylaxis and EOAP cohorts in all but 2 instances: Increased resistance to erythromycin and trimethoprim-sulfamethoxazole was observed in coagulase-negative Staphylococci isolates in the EOAP cohort (89% vs 21%, P < .01; 44% vs 0%, P = .02). An increased frequency of gram-negative organisms was observed in the EOAP group (22% vs 8%, P = .03).

Conclusions

Rates of antimicrobial resistance were not significantly different between EOAP and standard antibiotic prophylaxis cohorts except in coagulase-negative Staphylococci. The increased frequency of gram-negative infections was present in the EOAP cohort. Larger, multicenter studies are needed to better understand the impact of EOAP on antimicrobial resistance and PJI epidemiology.

Level of Evidence

Level III; retrospective cohort study.

Analysis of New Orthopaedic Technologies in Large Database Research

Improvements in orthopaedic surgery go hand in hand with technological advances. The present article outlines the historical and current uses of large databases and registries for the evaluation of new orthopaedic technologies, providing insights for future utilization, with robotic-assisted surgery as the example technology.

Not all Total Hip and Knee Arthroplasties Are the Same: What Are the Implications in Large Database Studies?

BACKGROUND

The use of claims databases for research after total hip and knee arthroplasty (THA, TKA) has increased exponentially. These studies rely on accurate coding, and inadvertent inclusion of patients with nonroutine indications may influence results. The purpose of this study was to evaluate the complexity of THA and TKA captured by CPT code and determine if complication rates vary based on the indication.

METHODS

The NSQIP database was queried using CPT codes 21730 and 27447 to identify patients undergoing THA and TKA from 2018 to 2019. The surgical indication was classified based on the ICD-10 diagnosis code as routine primary, complex primary, inflammatory, fracture, oncologic, revision, infection, or indeterminant. Patient factors and 30-day complications, readmission, reoperation, and wound complications were compared.

RESULTS

A total of 86,009 THA patients had 703 ICD-10 diagnosis codes and 91.4% were routine primary indications. Complication rates were: routine primary 7.4%, complex primary 11.3%, inflammatory 12.5%, fracture 23.9%, oncologic 32.4%, revision 26.9%, infection 38.7%, and indeterminant 10.3% (P < .0001). 137,500 TKA patients had 552 ICD-10 diagnosis codes and 96.1% were routine primary cases. Complication rates were: routine primary 5.9%, complex primary 8.0%, inflammatory 7.2%, fracture 38.9%, oncologic 32.7%, revision 13.3%, infection 37.7%, and indeterminant 9.6% (P < .0001). Routine primary arthroplasty had significantly lower rates of reoperation, readmission, and wound complications.

CONCLUSION

Using CPT code alone captures 10% of THA and 4% of TKA patients with procedures for nonroutine primary indications. It is essential to recognize identification of patients simply by CPT code has the potential to inadvertently introduce bias, and surgeons should critically assess methods used to define the study populations.

Perioperative Opioid Counseling Reduces Opioid Use Following Primary Total Joint Arthroplasty

BACKGROUND

Preoperative counseling may reduce postoperative opioid requirements; however, there is a paucity of randomized controlled trials (RCTs) demonstrating efficacy. The purpose of this study was to perform an interventional, telehealth-based RCT evaluating the effect of peri-operative counseling on quantity and duration of opioid consumption following primary total joint arthroplasty (TJA).

METHODS

Participants were randomized into three groups: 1. Control group, no perioperative counseling; 2. Intervention group, preoperative educational video; 3. Intervention group, preoperative educational video and postoperative acceptance and commitment therapy (ACT). Opioid consumption was evaluated daily for 14 days and at 6 weeks postoperatively. Best-case and worse-case intention to treat analyses were performed to account for non-responses. Bonferroni corrections were applied.

RESULTS

183 participants were analyzed (63 in Group 1, 55 in Group 2, and 65 in Group 3). At 2 weeks postoperatively, there was no difference in opioid consumption between Groups 1, 2, and 3 (p>0.05 for all). At 6 weeks postoperatively, Groups 2 and 3 had consumed significantly less opioids than Group 1 (p=0.04, p<0.001) (Table 1). Group 3 participants were less likely to obtain an opioid refill relative to Group 1 participants (p=0.04). Participants in groups 2 and 3 ceased opioid consumption a median of 6 days and 2 days sooner than Group 1, respectively (p<0.001, p=0.03) (Table 2).

CONCLUSION

Perioperative opioid counseling significantly decreases the quantity and duration of opioid consumption at 6 weeks following primary TJA. Level of Evidence: I.

Operative Time and Risk of Surgical Site Infection and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis on the association between operative time and peri-prosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

PubMed, Embase, and Cochrane CENTRAL databases were searched for relevant articles dating 2000-2020. Relationship of operative time and PJI rate in primary total joint arthroplasty (TJA) was evaluated by pooled odds ratios (OR) and 95% confidence intervals.

RESULTS

Six studies were identified for meta-analysis. TJA lasting greater than 120 minutes had greater odds of PJI (OR, 1.63 [1.00-2.66], p=0.048). Similarly, there were greater odds of PJI for TJA procedures lasting greater than 90 minutes (OR, 1.65 [1.27-2.14]; p<0.001). Separate analyses of TKA (OR, 2.01 [0.76-5.30]) and THA (OR, 1.06 [0.80-1.39]) demonstrated no difference in rates of PJI in cases of operative time ≥ 120 minutes versus cases < 120 minutes (p>0.05 for all). Using any surgical site infection (SSI) as an endpoint, both TJA (OR, 1.47 [1.181.83], p<0.001) and TKA (OR, 1.50 [1.08-2.08]; p=0.016) procedures lasting more versus less than 120 minutes demonstrated significantly higher odds of SSI.

CONCLUSION

Following TJA, rates of SSI and PJI are significantly greater in procedures ≥120 minutes in duration relative to those < 120 minutes. When analyzing TKA separately, higher rates of SSI were observed in procedures ≥ 120 minutes in duration relative to those <120 minutes. Rates of PJI in TKA or THA procedures alone were not significantly impacted by operative time. Level of Evidence: V.

Who Is Still Receiving Blood Transfusions After Primary and Revision Total Joint Arthroplasty?

BACKGROUND

Incidence of blood transfusions after primary and revision total hip and knee arthroplasty (primary total hip arthroplasty [pTHA], revision THA [rTHA], primary total knee arthroplasty [pTKA], and revision TKA [rTKA]) has been decreasing for a multitude of reasons. The purpose of this study was to assess whether transfusion rates have continued to decline and evaluate patient factors associated with transfusions.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing pTHA, pTKA, rTHA, and rTKA between 2011 and 2019. Patients undergoing bilateral procedures and arthroplasty for fracture, infection, or tumor were excluded. Trends in blood transfusions were assessed. Patient factor association with blood transfusions was evaluated using 2018 and 2019 data.

RESULTS

Transfusion rates decreased from 21.4% in 2011 to 2.5% in 2019 for pTHA (P < .0001). For pTKA, transfusion rates declined from 17.6% to 0.7% (P < .0001). In rTHA, the transfusion rate decreased from 33.5% to 12.0% from 2011 to 2019 (P < .0001). Transfusion rates declined from 19.4% to 2.6% for rTKA during the study period (P < .0001). Transfusions were more frequent in patients who were older, female, with more comorbidities, with lower hematocrit, receiving nonspinal anesthesia, and with longer operative time. Lower preoperative hematocrit, history of bleeding disorders, and preoperative transfusion were associated with greater odds for postoperative transfusion after multivariate analysis.

CONCLUSION

Transfusions after both primary and revision total joint arthroplasty have continued to decrease. Studies of arthroplasty complications should account for decreasing transfusions when assessing overall complication rates. Future studies should consider interventions to further reduce transfusions in revision arthroplasty.

Are Body Mass Index Cutoffs Creating Racial, Ethnic, and Gender Disparities in Eligibility for Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Unabated increases in the prevalence of obesity among American adults have disproportionately affected women, Black persons, and Hispanic persons. The purpose of this study was to evaluate for disparity in rates of patient eligibility for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on race and ethnicity and gender by applying commonly used body mass index (BMI) eligibility criteria to two large national databases.

METHODS

We retrospectively reviewed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2015-2019 for primary THA and TKA and the National Health and Nutrition Examination Survey (NHANES) from 2011-2018. Designations of race and ethnicity were standardized between cohorts. BMI cutoffs of <50 kg/m², <45 kg/m², <40 kg/m², and <35 kg/m² were then applied. Rates of eligibility for surgery were examined for each respective BMI cutoff and stratified by age, race and ethnicity, and gender.

RESULTS

143,973 NSQIP THA patients, 242,518 NSQIP TKA patients, and 13,255 NHANES participants were analyzed. Female patients were more likely to be ineligible for surgery across all cohorts for all modeled BMI cutoffs (P < .001 for all). Black patients had relatively lower rates of eligibility across all cohorts for all modeled BMI cutoffs (P < .0001 for all). Hispanic patients had disproportionately lower rates of eligibility only at a BMI cutoff of <35 kg/m².

CONCLUSION

Using BMI cutoffs alone to determine the eligibility for primary THA and TKA may disproportionally exclude women, Black persons, and Hispanic persons. These data raise concerns regarding further disparity and restriction of arthroplasty care to vulnerable populations that are already marginalized.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Utilization of Arthroscopy During Ankle Fracture Fixation Among Early Career Surgeons: An Evaluation of the American Board of Orthopaedic Surgery Part II Oral Examination Database

BACKGROUND

Rotational ankle fractures are common injuries associated with high rates of intra-articular injury. Traditional ankle fracture open reduction and internal fixation (ORIF) techniques provide limited capacity for evaluation of intra-articular pathology. Ankle arthroscopy represents a minimally invasive technique to directly visualize the articular cartilage and syndesmosis while aiding with reduction and allowing joint debridement, loose body removal, and treatment of chondral injuries. The purpose of this study was to evaluate temporal trends in concomitant ankle arthroscopy during ankle fracture ORIF surgery amongst early-career orthopaedic surgeons while examining the influence of subspecialty fellowship training on utilization.

METHODS

The American Board of Orthopaedic Surgery (ABOS) Part II Oral Examination database was queried to identify all candidates performing at least one ankle fracture ORIF from examination years 2010 to 2019. All ORIF cases were examined to identify those that carried a concomitant CPT code for ankle arthroscopy. Concomitant ankle arthroscopy cases were categorized by candidates self-reported fellowship training status and examination year. Descriptive statistics were performed to report relevant data and linear regression analyses were utilized to assess temporal trends in concomitant ankle arthroscopy with ORIF for ankle fractures. Statistical significance was defined as p<0.05.

RESULTS

During the study period, there were 36,113 cases of ankle fracture ORIF performed of which 388 cases (1.1%) were performed with concomitant ankle arthroscopy. Ankle fracture ORIF was most frequently performed by trauma fellowship trained ABOS Part II candidates (n=8,888; 24.6%), followed by sports medicine (n=7,493; 20.8%) and foot and ankle (n=6,563; 18.2%). Arthroscopy was most frequently utilized by foot and ankle fellowship trained surgeons (293/6,270 cases; 4.5%) followed by sports medicine (29/7,464 cases; 0.4%) and trauma (4/8,884 cases; 0.1%). With respect to arthroscopic cases, 293 cases (75.5%) were performed by foot and ankle fellowship trained surgeons, 29 (7.5%) sports medicine, and 4 (1.0%) trauma. Ankle arthroscopy utilization significantly increased from 3.65 cases per 1,000 ankle fractures in 2010 to 13.91 cases per 1,000 ankle fractures in 2019 (p=0.010). Specifically, foot and ankle fellowship trained surgeons demonstrated a significant increase in arthroscopy utilization during ankle fracture ORIF over time (p<0.001; OR: 1.101; CI: 1.054-1.151).

CONCLUSION

Ankle arthroscopy utilization during ankle fracture ORIF has increased over the past decade. Foot and ankle fellowship trained surgeons contribute most significantly to this trend. Level of Evidence: IV.

Projected Prevalence of Obesity in Primary Total Hip Arthroplasty: How Big Will the Problem Get?

BACKGROUND

Obesity is associated with higher rates of adverse outcomes following primary total hip arthroplasty (THA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary THA patients in the United States through 2029.

METHODS

Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27130 was used to identify primary THA patients in NSQIP. Individuals were categorized according to body mass index (kg/m²) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029.

RESULTS

A total of 8,222,013 individuals were included (7,986,414 BRFSS, 235,599 NSQIP THA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary THA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary THA from 42% to 49%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 55% of primary THA will be obese/morbidly obese.

CONCLUSION

By 2029, we estimate ≥55% of primary THA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort Study.

Increased Risk of Short-Term Complications in Smokers Undergoing Primary Unicompartmental Knee Arthroplasty

The effects of smoking on unicompartmental knee arthroplasty (UKA) are unknown. The purpose of this study was to evaluate the effects of smoking on short-term outcomes following primary UKA. A query of the National Surgical Quality Improvement Project (NSQIP) database was used to identify cases of primary UKA performed during years 2006 to 2017. Patient demographics, operative times, and postoperative complications were compared between smoking and nonsmoking cohorts. Descriptive statistics, univariate analyses, and multivariate analyses were conducted to evaluate the effects of smoking on primary UKA. A total of 10,593 cases of UKA were identified; 1,046 of these patients were smokers. Univariate analysis demonstrated smokers to have higher rates of any complication (4.6 vs. 3.3%, p = 0.031), any wound complication (1.82 vs. 0.94%, p = 0.008), deep wound infection (0.57 vs. 0.13%, p = 0.006), and reoperation (1.34 vs. 0.68%, p = 0.018) relative to nonsmokers. Multivariate analysis demonstrated smokers to have higher rates of any wound complication (odds ratio [OR] = 1.79; 95% confidence interval [CI]: 1.06-2.95) and reoperation (OR = 2.11; 95% CI: 1.12-3.97). Smokers undergoing primary UKA are at higher risk for any wound complication and reoperation relative to nonsmokers in the first 30 days postoperatively. Further studies evaluating the long-term effects of smoking on outcome following UKA, as well as the impact of smoking cessation on outcomes following UKA, are needed.

What is the Impact of Body Mass Index Cutoffs on Total Knee Arthroplasty Complications?

BACKGROUND

Body mass index (BMI) cutoffs are commonly used to decide whether to offer obese patients elective total knee arthroplasty (TKA). However, weight loss goals may be unachievable for many patients who are consequentially denied complication-free surgery. The purpose of this study was to assess the impact of different BMI cutoffs on the rates of complication-free surgery after TKA.

METHODS

Patients undergoing elective, primary TKA from 2015 to 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database using Common Procedural Terminology code 27447. The BMI and rates of any thirty-day complication were collected. BMI cutoffs of 30, 35, 40, 45, and 50 kg/m² were applied to model the incidence of complications if TKA would have been allowed or denied based on the BMI.

RESULTS

A total of 314,719 patients underwent TKA, and 46,386 (14.7%) had a BMI ≥40 kg/m². With a BMI cutoff of 40 kg/m², 268,333 (85.3%) patients would have undergone TKA. A total of 282,552 (94.8%) would experience complication-free surgery, and 17.3% of all complications would be prevented. TKA would proceed for 309,479 (98.3%) patients at a BMI cutoff of 50 kg/m². A total of 293,108 (94.7%) would not experience a complication, and 2.8% of complications would be prevented. A BMI cutoff of 35 kg/m² would prevent 36.6% of all complications while allowing 94.8% of complication-free surgeries to proceed.

CONCLUSION

Lower BMI cutoffs can reduce complications, but will limit access to complication-free TKA for many patients. These data do not indicate TKA should be performed without consideration of risks from obesity; however, a holistic assessment and shared decision-making may be more valuable when deciding on appropriate goal weight reduction.

Can Abnormal Spinopelvic Relationships be Identified by Anteroposterior Pelvic Radiographs?

BACKGROUND

Abnormal spinopelvic relationships may place patients at an increased risk for instability after primary total hip arthroplasty. The purpose of this study was to determine if radiographic markers on a standing anteroposterior (AP) pelvis radiograph could identify patients with sagittal spinopelvic imbalance or spinal stiffness.

METHODS

Patients undergoing primary total hip arthroplasty at a single institution from 2017 to 2020 with standing AP pelvis radiographs and sitting/standing lateral radiographs were identified. AP pelvis radiographs were assessed for the following: lumbosacral hardware, spine osteophytes, disc space narrowing, scoliosis>5°, pelvic obliquity>5°, and overlap of the sacrococcygeal junction/pubic symphysis. Patients with spinopelvic imbalance and/or spinopelvic stiffness were identified. Univariate and multivariate analyses were performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Four hundred eighty-six patients were included. Prevalence of isolated sagittal spinopelvic imbalance and isolated spinopelvic stiffness was 12% and 21%, respectively; 11% of patients had sagittal imbalance and stiffness. Overlap of the sacrococcygeal junction/pubic symphysis (OR = 10.2, 95% CI = 5.3-19.8) and presence of lumbosacral hardware (OR = 4.4, 95% CI = 2.0-9.4) were markers of an increased risk of combined sagittal imbalance and stiffness. Seventy-nine percent of patients with overlap of the sacrococcygeal junction and pubic symphysis and 82% of patients with lumbosacral hardware had an abnormal spinopelvic relationship.

CONCLUSION

Isolated sagittal imbalance and stiffness were difficult to predict on standing AP pelvis radiographs. Overlap of the sacrococcygeal junction/pubic symphysis and presence of lumbosacral hardware associated with a higher risk of combined sagittal imbalance/stiffness and were present in ≥79% of patients with an abnormal spinopelvic relationship.

LEVEL OF EVIDENCE

IV; retrospective cohort study.

Are Morbidly Obese Patients Equally Benefitting From Care Improvements in Total Hip Arthroplasty?

BACKGROUND

Morbidly obese patients have increased rates of complications following primary total hip arthroplasty (THA) and it is not clear whether improvements in THA care pathways are equally benefitting these patients. The purpose of this study is to assess if reductions in complications have similarly improved for both morbidly obese and non-morbidly obese patients after THA.

METHODS

Patients undergoing primary THA between 2011 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by body mass index (BMI) <40 and ≥40 kg/m². Thirty-day rates of infectious complications, readmissions, reoperation, and any complication were assessed. Trends in complications were compared utilizing odds ratios and multivariate analyses.

RESULTS

In total, 234,334 patients underwent THA and 16,979 (7.8%) had BMI ≥40 kg/m². Patients with BMI ≥40 kg/m² were at significantly higher odds for readmission, reoperation, and infectious complications. Odds for any complication were lower for morbidly obese patients in 2011, not different from 2012 to 2014, and higher from 2015 to 2019 compared to lower BMI patients. Odds for any non-transfusion complication were higher for morbidly obese patients and there was no improvement for either group over the study period. There were improvements in rates of readmission and reoperation for patients with BMI <40 kg/m² and readmission for BMI >40 kg/m².

CONCLUSION

Odds for readmission and reoperation for non-morbidly obese patients and readmission for morbidly obese patients improved from 2011 to 2019. Reductions in transfusions are largely responsible for improvements in overall complication rates. Although morbidly obese patients remain at higher risk for complications, there does not appear to be a growing disparity in outcomes between morbidly obese and non-morbidly obese patients.

Use of Cementless Metaphyseal Fixation in Revision Total Knee Arthroplasty in the United States

BACKGROUND

Fixation options for revision total knee arthroplasty (rTKA) have expanded and now include cementless metaphyseal fixation. The utilization rates of these implants in the United States are not well known. The purpose of this study was to analyze trends in cementless metaphyseal fixation for rTKA within the American Joint Replacement Registry (AJRR).

METHODS

The AJRR was queried for the years 2015-2019 to identify all rTKA with implant data. Trends in the use of cementless sleeves, metaphyseal cones, and any cementless metaphyseal fixation (sleeves + cones) were examined over the study period using logistic regression analysis.

RESULTS

Twenty thousand two hundred and eighty rTKA were analyzed. Cementless metaphyseal fixation was used in 16% of rTKA and significantly increased over the study period (14% to 19%, P < .0001). Cementless metaphyseal fixation was more frequently utilized during revision for aseptic loosening than other diagnoses (OR 1.014, 95% CI 1.001-1.027). Cementless sleeve utilization decreased over time (11% to 9%, P = .004), driven by decreased use on the femur (4% to 2%, P < .0001). The use of cones increased significantly over time (3% to 9%, P < .0001), driven by increased use on the tibia (2% to 9%, P < .0001). Cones were 22 times more likely to be utilized on the tibia relative to the femur (P < .0001) and were more likely to be used in revisions for infection (OR 1.103, 95% CI 1.089-1.117) and aseptic loosening (OR 1.764, 95% CI 1.728-1.800).

CONCLUSION

Cementless metaphyseal fixation has grown in popularity yet, still comprised only 16% of rTKA over a 5-year period. Most of the increase was due to the utilization of tibial metaphyseal cones.

Unicompartmental Knee Arthroplasty Utilization among Early Career Surgeons: An Evaluation of the American Board of Orthopaedic Surgery Part-II Database

An updated understanding of unicompartmental knee arthroplasty (UKA) utilization is needed. The purpose of this study was to evaluate temporal trends in volume and utilization of UKA among early-career surgeons and to examine the influence of fellowship training status on utilization of UKA. The American Board of Orthopaedic Surgery (ABOS) Part-II database was queried from 2010 to 2019 to identify candidates who reported ≥1 total knee arthroplasty (TKA) or UKA. Self-reported history of fellowship training experiences was recorded. "High-volume" surgeons were defined as performing ≥7 UKA over the ABOS Part-II collection period. Trends were evaluated with the Cochrane-Armitage test and generalized linear models. From 2010 to 2019, a total of 2,045 candidates (28.1%) reported ≥1 TKA, while 585 candidates (8.0%) reported ≥1 UKA. The number of candidates reporting ≥1 UKA significantly increased (p = 0.001). An increase in UKA volume was observed over the study period (p < 0.001). Rates of utilization of UKA relative to TKA did not change significantly over the study period (p = 0.11). Sixty-three (2.4%) candidates met the study definition for high-volume UKA utilization. UKA procedure volume increased among ABOS Part-II candidates over the study period; however, rates of UKA utilization relative to TKA volume remained unchanged. Increasing volume of UKA performed by early-career surgeons is likely secondary to an increased number of surgeons trained in adult reconstruction. Only 2.4% of candidates who reported performing at least one knee arthroplasty procedure met the threshold for a high-volume UKA practice. Early-career surgeons should remain conscientious of UKA volume in their practice.

Patient Resilience Influences Opioid Consumption in Primary Total Joint Arthroplasty Patients

Background

Resilience and depression may influence opioid consumption in patients undergoing primary hip and knee arthroplasty (TJA); however, data evaluating these relationships are limited.

Methods

We retrospectively identified 119 patients undergoing TJA who completed preoperative questionnaires to measure resilience (Brief Resilience Scale) and depression (PHQ-9) from 2017 to 2018 at a single institution. Patients were stratified into high, normal, and low resilience groups as well as no, mild, and major depression groups. Opioid use was recorded in morphine milligram equivalents (MMEs). Nonparametric statistical testing was performed with significance level at P < 0.05.

Results

Higher levels of resilience correlated with less postoperative inpatient opioid use (P = 0.003). Patients with high resilience were less likely to use preoperative opioids compared to those with low resilience (OR = 6.08, 95% CI [1.230.5]). There was no difference in postoperative outpatient opioid prescriptions between resilience groups. Lower levels of depression correlated with less postoperative inpatient opioid use, though this did not reach statistical significance (P = 0.058). Additionally, there was no significant difference in preoperative opioid use or postoperative outpatient opioid prescriptions between depression groups.

Conclusion

Patients with higher levels of resilience are less likely to use opioids before TJA and utilize lower amounts of opioids while inpatient following surgery. Depression correlated with higher postoperative inpatient opioid use; however, the present findings regarding this relationship are inconclusive. Resilience is a psychological trait that may impact opioid use in patients undergoing TJA and should be viewed as a modifiable risk factor. Level of Evidence: III.

Longer Length of Stay Is Associated With More Early Complications After Total Knee Arthroplasty

Background

Length of stay (LOS) following total knee arthroplasty (TKA) has decreased over recently years. In 2018, the Centers for Medicare and Medicaid Services removed TKA from Inpatient-Only List (IPO), incentivizing further expansion of outpatient TKA. However, many patients may still require postsurgical hospitalization. The purpose of this study was to assess early outcomes for TKA based on length of stay (LOS).

Methods

We identified patients undergoing elective, primary TKA in the National Surgical Quality Improvement Program database using CPT code 27447 between 2015 and 2018. Patients were stratified by length of stay (LOS) 0 days, 1-2 days, and ≥3 days. Thirty-day rates of any complication, wound complications, readmission, and reoperation were assessed. Multivariate analysis was performed to adjust for confounding variables.

Results

5,655 (3%) patients underwent outpatient TKA, 130,543 (59%) had LOS 1-2 days, and 84,986 (38%) had LOS ≥3 days. Any complication was experienced in 4.1% of those with LOS 0 days, 4.3% for those with LOS of 1-2 days, and 10.5% for patients with LOS ≥3 days (p<0.0001). Readmission occurred in 2.2%, 2.6%, and 4.0% for the 3 groups, respectively (p<0.0001). After multivariate analysis, there was no significant difference in any outcome measure between patients with LOS 0 and 1-2 days, however those with LOS ≥3 days had higher odds of complications, reoperation, and readmission.

Conclusion

A significant number of patients had LOS ≥3 days following TKA and had more comorbidities and complications. Outpatient TKA was not associated with increased early complication compared to those with LOS of 1-2 days. Despite expansion of outpatient surgery, postsurgical hospitalization remains an integral part of care following TKA. Level of Evidence: III.

Do Extended Oral Postoperative Antibiotics Prevent Early Periprosthetic Joint Infection in Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty?

BACKGROUND

Extended oral antibiotic prophylaxis after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) in patients with body mass index (BMI) ≥40 kg/m² may reduce the rate of early periprosthetic joint infection (PJI); however, existing data are limited. The purpose of this study was to examine rates of wound complications and PJI in patients with BMI ≥40 kg/m² treated with and without extended oral antibiotic prophylaxis after surgery.

METHODS

We retrospectively identified all primary THA and TKA performed since 2015 in patients with a BMI ≥40 kg/m² at a single institution. Extended oral antibiotic prophylaxis for 7-14 days after surgery was prescribed at the discretion of each surgeon. Wound complications and PJI were examined at 90 days postoperatively.

RESULTS

In total, 650 cases (205 THA and 445 TKA) were analyzed. Mean age was 58 years and 62% were women. Mean BMI was 44 kg/m². Extended oral antibiotic prophylaxis was prescribed in 177 cases (27%). At 90 days, there was no difference between prophylaxis and nonprophylaxis groups in rate of wound complications (11% vs 8%; P = .41) or PJI (1.7% vs 0.6%; P = .35). The univariate analysis demonstrated increased operative time (odds ratio (OR) 1.01; 95% confidence interval (95% CI) 1.01-1.02) and diabetes mellitus (OR 1.88; 95% CI 1.03-3.46) to be associated with increased risk of 90-day wound complications. No patient factors were associated with increased risk of PJI at 90 days postoperatively.

CONCLUSION

Extended oral antibiotic prophylaxis after primary THA and TKA did not reduce rates of wound complications or early PJI in a morbidly obese patient population.

Has Removal From the Inpatient-Only List Increased Complications After Outpatient Total Knee Arthroplasty?

BACKGROUND

On 1/1/2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) list. This change allowed expansion of outpatient TKA, potentially to include older, more frail patients at greater risk for perioperative complications. The purpose of this study was to evaluate the impact of removing TKA from the IPO list on early complications.

METHODS

Patients undergoing TKA in the National Surgical Quality Improvement Program database were identified using CPT code 27447. Only cases with length of stay of zero days were included. Rates of 30-day complications, readmissions, and reoperation were compared before and after TKA was removed from the IPO list (2015-2017 vs 2018). The analysis was performed both with and without propensity score matching.

RESULTS

212,313 patients underwent TKA during the study period. 2466 (1.5%) were outpatient TKA in 2015-2017 and 3189 (5.6%) in 2018. After propensity matching, there were 2458 patients in each cohort. Rates of total 30-day complications were significantly lower in 2018 (3.7%) than the years TKA remained on the IPO (4.5%, P = .04). Similarly, rates of any reoperation decreased from 1.2% during 2015-2017 to 0.6% in 2018 (P = .03). There were no significant changes in rates of readmission (2.5% vs 2.2%, P = .5) or wound complications (0.8% vs 0.8%, P = 1.0).

CONCLUSION

Removal of TKA from the IPO list did not result in an increase in complications or readmissions. These data suggest, despite the regulatory change, surgeons have continued to exercise sound judgment as to what patients can safely undergo outpatient TKA.

Are surgeons still performing primary total knee arthroplasty in the morbidly obese?

AIMS

The purpose of this study was to assess total knee arthroplasty (TKA) volume and rates of early complications in morbidly obese patients over the last decade, where the introduction of quality models influencing perioperative care pathways occurred.

METHODS

Patients undergoing TKA between 2011 to 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by BMI < 40 kg/m² and ≥ 40 kg/m² and evaluated by the number of cases per year. The 30-day rates of any complication, wound complications, readmissions, and reoperation were assessed. Trends in these endpoints over the study period were compared between groups using odds ratios (ORs) and multivariate analyses.

RESULTS

In total, 314,695 patients underwent TKA and 46,362 (15%) had BMI ≥ 40 kg/m². The prevalence of morbid obesity among TKA patients did not change greatly, ranging between 14% and 16%. Reoperation rate decreased from 1.16% to 0.96% (odds ratio (OR) 0.81 (95% confidence interval (CI) 0.66 to 0.99)) for patients with BMI < 40 kg/m², as did rates of readmission (4.46% to 2.87%; OR 0.61 (0.55 to 0.69)). Patients with BMI ≥ 40 kg/m² also had fewer readmissions over the study period (4.87% to 3.34%; OR 0.64 (0.49 to 0.83)); however, the rate of reoperation did not change (1.37% to 1.41%; OR 0.99 (0.62 to 1.56)). Significant improvements were not observed for infective complications over time for either group; patients with BMI ≥ 40 kg/m² had increased risk of both deep infection and wound complications compared to non-morbidly obese patients. Rate of any complication decreased for all patients.

CONCLUSION

The proportion of TKAs in morbidly obese patients has not significantly changed over the past decade. Although readmission rates improved for all patients, reductions in reoperation in non-morbidly obese patients were not experienced by the morbidly obese, resulting in a widening of the complication gap between these cohorts. Care improvements have not lowered the differential risk of infective complications in the morbidly obese. Cite this article: Bone Joint J 2021;103-B(6 Supple A):38-44.

Radiographic Evaluation of Proximal Femoral Nutrient Arteries After Total Hip Arthroplasty With a Short Femoral Stem

BACKGROUND

The use of less invasive approaches and broach only press-fit femoral stems in total hip arthroplasty (THA) may increase the risk for periprosthetic fracture. Proximal femoral nutrient arteries (FNAs) can be mistaken for fractures after THA. Description of FNAs in relation to THA implants is important to better distinguish between FNAs and periprosthetic fractures. The purpose of this study was to evaluate the frequency, location, and morphology of FNAs visible on radiographs after primary THA with a broach-only stem design.

METHODS

A retrospective cohort study was performed. Patients ≥18 years who underwent primary THA with a cementless, broach-only stem, and had 6-week follow-up radiographs were included. Patient demographics were recorded. Anteroposterior and lateral radiographs at 6 weeks postoperatively were assessed for the presence of FNA; if present, measurements of vessel location and morphology were obtained. Descriptive statistics were reported. Univariate and multivariate analyses were performed to identify patient characteristics associated with the radiographic presence of perforating vessel.

RESULTS

A total of 378 hips were evaluated (332 patients). FNAs were identified radiographically in 46.3% (175 hips/378 hips). All FNAs were found to be unicortical, most observed in the posterior and lateral cortices. Gender, age, BMI, stem position, and surgical approach did not correlate with a presence of FNA on radiograph.

CONCLUSION

FNA was seen on postoperative radiographs in 46% of patients after THA with one broach-only stem design. The FNA was unicortical and present on preoperative radiographs. Surgeons should consider this when evaluating postoperative radiographs.

What is the Clinical Utility of Synovial Alpha Defensin Testing of Antibiotic Spacers Before Reimplantation?

BACKGROUND

The purpose of this study was to evaluate the diagnostic performance of standalone alpha defensin (AD) testing of antibiotic spacers during two stage exchange and to determine if the addition of AD testing to other commonly used laboratory tests improves the ability to detect persistent infection in an antibiotic spacer.

METHODS

Cases of two-stage exchange for periprosthetic joint infection from 2016 to 2019 at a single institution were retrospectively reviewed. Cases were classified as persistently infected or not infected in accordance with 2014 and 2018 Musculoskeletal Infection Society criteria to determine if AD provided any clinical utility beyond the other commonly used tests that make up both criteria. Delphi Consensus criteria at 1 year were used as the gold standard for determining recurrent periprosthetic joint infection.

RESULTS

Fifty-two spacers (25 hips and 27 knees) in 51 patients were included for analysis. Five spacers were persistently infected based on Musculoskeletal Infection Society criteria. One spacer underwent reresection and the remaining 4 underwent reimplantation with no subsequent infectious complications. All 48 patients who were categorized as not infected underwent reimplantation; at 1 year postoperatively, 7 (13%) had failed due to infection. Three spacers (6%) had a positive AD test. Two spacers with positive AD tests underwent reimplantation, neither had failed at 1 year postoperatively. Sensitivity of standalone AD testing was 0%, and specificity was 96%.

CONCLUSION

Standalone AD testing for the purpose of predicting repeat infection after two-stage exchange arthroplasty exhibits sensitivity of 0% and low predictive value. Addition of synovial AD testing did not increase the diagnostic performance of commonly used synovial and serologic markers of infection.

LEVEL OF EVIDENCE

IV-retrospective cohort study.

The Impact of Transitioning From International Classification of Diseases, Ninth Revision to International Classification of Diseases, Tenth Revision on Reported Complication Rates Following Primary Total Knee Arthroplasty

BACKGROUND

In 2015, the healthcare system transitioned from International Classification of Diseases, Ninth Revision (ICD-9) coding to the Tenth Revision (ICD-10). We sought to determine the effect of this change on the reported incidence of complications following total knee arthroplasty (TKA).

METHODS

The Humana administrative claims database was queried from 2 years prior to October 1, 2015 (ICD-9 cohort) and for 1 year after this date (ICD-10 cohort) to identify all TKA procedures. Complications occurring within 6 months of surgery were captured using the respective coding systems. Incidence of each complication was compared between cohorts using risk ratios (RR) and 95% confidence intervals.

RESULTS

There were 19,009 TKAs in the ICD-10 cohort and 38,172 TKAs in the ICD-9 cohort. The incidence of each complication analyzed was significantly higher in the ICD-9 cohort relative to the ICD-10 cohort. Periprosthetic joint infection occurred in 1.9% vs 1.3% (RR 1.5, 1.3-1.9), loosening in 0.3% vs 0.1% (RR 2.7, 1.8-4.9), periprosthetic fracture in 0.3% vs 0.1% (RR 3.0, 1.6-4.5), and other mechanical complications in 0.7% vs 0.4% (RR 2.0, 1.5-2.5) (P < .05 for all).

CONCLUSION

The transition from ICD-9 to ICD-10 coding has altered the reported incidence of complications following TKA. These results are likely due to the added complexity of ICD-10 which is joint and laterality specific. It is important to understand the differences between coding systems as this data is used for quality initiatives, risk adjustment models, and clinical research. Thoughtful methodology will be necessary when ICD-9 and ICD-10 data are being analyzed simultaneously.

Resilience and Depression Influence Clinical Outcomes Following Primary Total Joint Arthroplasty

BACKGROUND

Resilience and depression may impact clinical outcomes following primary total joint arthroplasty (TJA). This study aimed to quantify baseline resilience and depression prevalence in patients undergoing primary TJA and evaluate their influence on patient-reported clinical outcomes.

METHODS

We prospectively enrolled 98 patients undergoing primary TJA. Exclusion criteria included patients under 18 years of age, undergoing surgery for fracture, or who underwent additional surgery during the study period. Patients completed the Brief Resilience Scale to measure resilience, Patient Health Questionnaire-9 to measure depression, and Patient-Reported Outcomes Measurement Information System-10 to measure global physical and mental health preoperatively and 1 year postoperatively.

RESULTS

Preoperatively, 22% and 15% of patients demonstrated major and mild depression, respectively. High resilience was identified in 34% of patients, normal resilience in 55%, and low resilience in 11%. Preoperative depression correlated with lower resilience, global physical health, and global mental health scores preoperatively as well as at 1 year after surgery (P < .001). Higher levels of preoperative resilience correlated with higher global physical and mental health scores preoperatively and at 1 year postoperatively (P < .001).

CONCLUSION

Depression symptoms are common among patients undergoing primary TJA and are associated with worse patient-reported outcomes. Patients with higher levels of resilience have higher global physical and mental health scores before and after TJA. Psychological traits and depression impact clinical outcomes following TJA.

Home Discharge Has Increased After Total Hip Arthroplasty, However Rates Vary Between Large Databases

BACKGROUND

There have been significant advancements in perioperative total hip arthroplasty (THA) care and it is essential to quantify efforts made to better optimize patients and improve outcomes. The purpose of this study is to assess trends in discharge destination, length of stay (LOS), reoperations, and readmissions following THA.

METHODS

Patients undergoing primary THA were identified using International Statistical Classification of Diseases and Current Procedural Terminology codes in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and Humana claims databases. Discharge destinations were assessed and categorized as home or not home. Trends in discharge destination, LOS, readmissions, reoperation, and comorbidity burden were assessed.

RESULTS

In ACS NSQIP, 155,637 patients underwent THA and the percentage of patients discharging home increased from 72.2% in 2011 to 87.0% in 2017 (P < .0001). In Humana, 84,832 THA patients were identified, with an increase in home discharge from 56.6% to 72.8% (P < .0001). LOS decreased and proportion of patients with an American Society of Anesthesiologists score ≥3 or Charlson Comorbidity Index ≥2 increased significantly for both home and nonhome going patients. Patients discharged home had a decrease in readmissions in both databases.

CONCLUSION

Patients undergoing THA more often discharged home and had shorter hospital LOS with lower readmission rates, despite an increasingly comorbid patient population. It is likely these changes in disposition and LOS have resulted in significant cost savings for both payers and hospitals. The efforts necessary to maintain improvements should be considered when changes to reimbursement are being evaluated. ACS NSQIP hospitals had a larger proportion of patients discharged home and the source of data used to benchmark hospitals should be considered as findings may differ.

Total Ankle Arthroplasty and Ankle Arthrodesis Use: An American Board of Orthopaedic Surgery Part II Database Study

Total ankle arthroplasty (TAA) use has increased during the past 20 years, whereas ankle arthrodesis (AAD) use has remained constant. The purpose of this study was to examine trends in TAA and AAD use in American Board of Orthopedic Surgery Part II candidates while considering the influence of fellowship training status on treatment of end-stage ankle arthritis. The American Board of Orthopedic Surgery Part II database was queried to identify all candidates who performed ≥1 TAA or AAD from examination years 2009 through 2018. Candidates were categorized by examination year and by self-reported fellowship training status. Descriptive statistical methods were used to report procedure volumes. Trends in use of TAA and AAD were examined by using log-modified regression analyses. From 2009through 2018, there was no significant change in TAA or AAD use among all candidates (p = .92, p = .20). Candidates reporting a foot and ankle fellowship trended toward increased use of TAA relative to AAD compared with non-foot and ankle fellowship candidates, but this failed to reach statistical significance (p = .06). The use of arthroscopic AAD increased over time (p < .01) among all candidates. TAA and AAD use did not change over the study period. Volume of TAA and AAD performed by early-career surgeons remains low. The findings in this study should serve as an important reference for orthopedic trainees, early-career surgeons, and orthopedic educators interested in optimizing training curriculum for surgical management of end-stage ankle arthritis.

Hip Arthroscopy Prior to Periacetabular Osteotomy Does Not Increase Operative Time or Complications: A Single Center Experience

BACKGROUND

Periacetabular osteotomy (PAO) is a well-established procedure to improve function and reduce pain in the non-arthritic dysplastic hip. PAO and hip arthroscopy are often performed together; however, there is concern that hip arthroscopy increases difficulty of PAO due to arthroscopic fluid extravasation. The purpose of the current study was to examine the effect of performing hip arthroscopy prior to PAO under the same anesthetic on PAO operative time and postoperative complications.

METHODS

A retrospective review of all PAO cases during a two-year period at a single academic institution was performed. Cases were stratified into two groups based on whether concomitant hip arthroscopy was performed. In the combined hip arthroscopy and PAO group, hip arthroscopy was performed prior to PAO under the same general anesthetic in all cases. Student t-test was utilized to compare the operative times between the two study groups and Chi Square was used to compare categorical variables.

RESULTS

During the two-year study period, 93 total PAO cases in 86 patients (mean age: 23.5 + 8.7 years; 81.4% female) were performed. Of these, 67 PAO surgeries (72.0%) were performed following hip arthroscopy. The total complication rate was 2.2% with one postoperative complication occurring in each group. There was no difference in mean PAO operative time between the two study groups (PAO: 127.6 + 18.0 minutes; PAO with hip arthroscopy: 125.4 + 16.8 minutes; p=0.570).

CONCLUSION

Performing hip arthroscopy prior to PAO under the same general anesthetic does not significantly increase PAO operative time or postoperative complications.Level of Evidence: IV.

Salvage of Distal Femoral Replacement Loosening with Massive Osteolysis Using Impaction Grafting: A Report of 2 Cases

CASE

Salvage of 2 cases of distal femoral replacement loosening with massive osteolysis using impaction grafting are presented with 9- and 11-year follow-ups.

CONCLUSION

Surgeons should keep impaction grafting in their armamentarium for cases of failed DFR with severe osteolysis. Doing so may allow for preservation of the native hip and deferment of more radical procedures (i.e. total femur replacement) that have high rates of complication and poor survivorship.

Common Peroneal Nerve Injury and Recovery after Total Knee Arthroplasty: A Systematic Review

Background

Common peroneal nerve palsy (CPNP) after total knee arthroplasty (TKA) may impact extremity pain and function. Incidence and rates of recovery of CPNP after TKA vary in the current literature. The purpose of this systematic review was to evaluate the incidence of incomplete and complete CPNP after TKA and rates of incomplete and complete recovery of nerve function in the absence of further surgical treatment.

Methods

PubMed, Embase, and Cochrane Central were searched for studies published in the years 1970-2019. Studies evaluating incidence and recovery rates of CPNP in the absence of further surgical treatment were screened according to inclusion and exclusion criteria. Outcomes of interest included incidence of complete and incomplete CPNP and rates of incomplete and complete nerve recovery.

Results

Eleven studies were included for qualitative analysis. In total, there were 47,585 TKAs performed, with 203 postoperative CPNPs, for a cumulative incidence of 0.4%. One hundred twenty-nine CPNPs were classified as complete or incomplete palsies. At a mean follow-up of 3.6 years (range, 0-11 years), 24 (39%) complete CPNPs had complete recovery, 34 (56%) had incomplete recovery, and 3 were lost to follow-up. In contrast, 45 (66%) with incomplete CPNPs had complete recovery, 18 (27%) had incomplete recovery, and 5 patients were lost to follow-up.

Conclusions

Incidence of CPNP after TKA was 0.4%. Recovery of nerve function after CPNP in the setting of TKA varies by the degree of initial nerve palsy. These data may be used to inform decisions on further interventions and for the purposes of perioperative patient counseling after TKA.

Do Patient Positioning and Portal Placement for Arthroscopic Subtalar Arthrodesis Matter?

Background

Arthroscopic subtalar arthrodesis was first described over 2 decades ago and originally performed in the lateral decubitus or supine position using anterolateral and posterolateral portals situated about the fibula. More recently, several authors have advocated for prone positioning utilizing posteromedial and posterolateral portals with an optional accessory lateral portal. To date, a comparison of these techniques has been limited.

Purpose

To determine the effect of patient positioning and portal placement on complication rates after arthroscopic subtalar arthrodesis.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Patients were placed into 1 of 3 groups: the lateral group if they were positioned lateral or supine with lateral-based portals; the 2-portal prone group if they were positioned prone with posteromedial and posterolateral portals; or the 3-portal prone group if posteromedial, posterolateral, and accessory lateral portals were utilized in the prone position. Inverse variance-weighted fixed-effects models were used to evaluate pooled estimates.

Results

A total of 20 studies examining 484 feet in 468 patients with a mean follow-up of 36.1 months were included for analysis. Overall, 8 studies examined patients in the prone position with 2 posterior portals (n = 111; 22.9%), 7 articles evaluated lateral portals (n = 182; 37.6%), and 5 studies examined patients in the prone position with 3 portals (n = 191; 39.5%). The total complication rate was similar (P = .620) between the 2-portal prone (18.9%), 3-portal prone (17.8%), and lateral (17.6%) groups. There was no difference observed in the rate of complications secondary to portal placement (P ≥ .334), rate of painful hardware (P ≥ .497), and rate of repeat surgery (P ≥ .304). The 2-portal prone group had a significantly higher rate of nonunion than the lateral group (8.1% vs 1.1%, respectively; P = .020) but not the 3-portal prone group (5.8%; P = .198).

Conclusion

The current study demonstrated a higher rate of nonunion following arthroscopic subtalar arthrodesis with prone patient positioning using posteromedial and posterolateral portals without an accessory lateral portal.

Nonoperative Treatment of a Pathologic Proximal Tibia Fracture in the Setting of Previous Total Knee Arthroplasty: A Case Report

CASE

We present the case of a super obese 51-year-old woman with a pathologic fracture of the proximal tibia in the setting of a previous total knee arthroplasty. Imaging demonstrated an osteolytic lesion distal to the keel and pathologic fracture of the proximal tibia. Nonoperative treatment with a 12-week course of nonweight-bearing resulted in fracture healing and ossification of osteolysis.

CONCLUSION

Pathologic fractures of the tibia secondary to osteolysis are frequently treated surgically. Patients may benefit from nonoperative management, even in the setting of super morbid obesity and significant osteolysis about the tibial component.

The Prevalence of Abnormal Spinopelvic Relationships in Patients Presenting for Primary Total Hip Arthroplasty

Background

The prevalence of an abnormal spinopelvic relationship in patients presenting for primary total hip arthroplasty (THA) is not well known. The purpose of this study was to identify the prevalence of abnormal spinopelvic relationships in patients presenting for primary THA.

Methods

A retrospective chart review of 338 consecutive, nonselected patients undergoing primary THA from the practice of 2 fellowship-trained adult reconstruction surgeons was performed (J.E.O. and T.S.B.). Sitting and standing radiographs were measured for lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS_stand), and pelvic tilt; the sacral slope was also measured on sitting radiographs (SS_sit). Patients were assessed for the presence of spinopelvic imbalance, defined as PI–LL>10°, and decreased spinopelvic motion, defined as SS_stand–SS_sit< 10°. Descriptive statistics were reported.

Results

A cohort of 338 patients was identified; 110 were excluded. In total, 228 unique patients underwent measurement. One hundred one of 228 patients (44.3%) in the cohort were female. The mean age of the cohort was 60.0 ± 13 years, with the mean body mass index of 31 ± 7 mg/kg². Spinopelvic imbalance (PI–LL > 10°) was present in 142 of 228 patients (62.3%). Decreased motion at the spinopelvic junction (SS_stand–SS_sit < 10°) was present in 78 of 228 patients (34.2%). Fifty (21.9%) patients had both spinopelvic imbalance and decreased spinopelvic motion.

Conclusions

In a cohort of 228 patients presenting for primary THA, the prevalence of spinopelvic imbalance was 62.3%, the prevalence of decreased spinopelvic motion was 34.2%, and the prevalence of both spinopelvic imbalance and decreased spinopelvic motion was 22%. Hip surgeons are likely to encounter patients with abnormal spinopelvic relationships.

Opioid Use After Total Knee Arthroplasty: Does Tramadol Have Lower Risk Than Traditional Opioids?

BACKGROUND

Preoperative opioid use has been shown to increase postoperative opioid use following total knee arthroplasty (TKA). Tramadol is recommended for symptomatic treatment of osteoarthritis; however, it acts on opioid receptors and may confer similar adverse effects. The purpose of this study is to assess postoperative opioid use with preoperative opioid and tramadol use.

METHODS

Patients undergoing primary TKA were identified in the Humana administrative claims database. Patients were stratified by whether they filled a prescription for an opioid, tramadol, either, or neither within 3 months of TKA. Prescription claims were tracked for 12 months postoperatively and relative risk for each group was calculated.

RESULTS

In total, 107,973 patients undergoing TKA were identified. Preoperatively, 29,890 (27.7%) patients filled a prescription for opioids, 8049 (7.5%) for tramadol, 44,403 (41.1%) for tramadol or opioids, and 63,570 (58.9%) did not fill a prescription for either. At 12 months postoperatively, an opioid prescription was filled by 6.0% of preoperative narcotic-free patients, 35.2% opioid users (relative risk [RR] 5.83 [5.63-6.03]), 9.2% tramadol users (RR 1.52 [1.40-1.63]), and 29.5% opioid or tramadol users (RR 4.88 [4.72-5.05]). Opioid or tramadol prescriptions were filled by 7.7% of preoperative narcotic-free patients, 37.3% opioid users (RR 4.84 [4.70-4.99]), 26.2% tramadol users (RR 3.40 [3.26-3.57]), and 35.7% opioid or tramadol users (RR 4.64 [4.50-4.78]) at 12 months.

CONCLUSION

Patients taking tramadol preoperatively were found to be at lower risk for prolonged postoperative opioid use following TKA. Patients taking either narcotics preoperatively continued use of these medications at a higher rate than those who were not.

Preoperative Validation of the Patient-Reported Outcomes Measurement Information System in Patients With Articular Cartilage Defects of the Knee

PURPOSE

To validate the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function computer adaptive test (PF CAT) with current patient-reported outcome (PRO) instruments in patients with cartilage injuries of the knee.

METHODS

Patients scheduled for osteochondral autograft or allograft transplant, microfracture, autologous chondrocyte implantation, allograft cartilage resurfacing, and chondroplasty were prospectively enrolled in the study and completed PROMIS PF CAT, Knee Injury and Osteoarthritis Outcome Score (KOOS activities of daily living, pain, symptoms, sport, and quality of life), Short Form-36 Health Survey (SF-36 physical function [PF] and Physical Component Summary), and EuroQol-5 Dimension questionnaires. The Spearman correlation coefficient was used to compare instruments. Instrument correlations were defined as excellent (>0.7), excellent to good (0.61-0.69), good (0.4 to 0.6), and poor (<0.39), with significance defined as P < .05.

RESULTS

A total of 293 knees in 275 patients (54.5% male) undergoing 319 cartilage procedures were analyzed. The most commonly performed cartilage procedure was chondroplasty (n = 118; 37.0%), followed by microfracture (n = 100; 31.3%). The mean age was 34.0 ± 14.7 and the mean body mass index was 30.0 ± 6.9. The PROMIS PF CAT had an excellent correlation with the SF-36 PF (r = 0.819; P < .001), SF-36 Physical Component Summary (r = 0.766; P < .001), KOOS activities of daily living (r = 0.733; P < .001), KOOS Sport (r = 0.709; P < .001), and EuroQol-5 Dimension (r = 0.752; P < .001) instruments; an excellent-good correlation with the KOOS pain (r = 0.662; P < .001), and KOOS quality of life (r = 0.640; P < .001) scores; and a good correlation with the KOOS symptoms (r = 0.519; P < .001) scale. The PROMIS PF CAT had no floor or ceiling effects and the smallest question burden (mean 4.17 ± 0.93 questions). Dimensionality analyses demonstrated that the smallest amount of unexplained variance was present in the PROMIS PF CAT (3.6%).

CONCLUSION

The PROMIS PF CAT is an effective tool for preoperative outcome assessment in patients with cartilage defects of the knee. It correlates strongly with legacy PRO measures of physical function with no ceiling and floor effects and a minimal time burden for completion. Further study is warranted to determine postoperative performance and to evaluate the responsiveness of PROMIS to change within a patient.

LEVEL OF EVIDENCE

III; Prognostic retrospective comparative study.

Is Bony Knee Alignment Representative of the True Joint Surface in Skeletally Immature Patients? A Magnetic Resonance Imaging Study

Aim and objective

In deformity correction around the knee, the mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA) are used in surgical planning routinely. While plain radiographs are generally adequate, some surgeons utilise intraoperative arthrograms to visualise the articular contours and assess a younger child's true joint alignment, often with findings that these are discrepant from that measured just using bone alignment. The age cutoff for a discrepancy between the two is not defined.

Materials and methods

We queried our picture archiving and communication systems (PACS) database for MRIs with a radiological read of “normal” for patients between the ages of 4 and 16 years at the time of the study. Anatomic axes were used to determine the anatomic LDFA (aLDFA) and MPTA angles using end-cartilage and end-bone landmarks independently.

Results

We reviewed 116 MRIs, 56% male, with approximately 9 studies per year of age. There were no significant overall differences between aLDFA and MPTA when measured at the bone vs cartilage surfaces (p = 0.42 and p = 0.53, respectively). In the 4- to 6-year age range, there was a significant difference between bony and cartilaginous aLDFA (p = 0.02) but not MPTA (p = 0.88).

Conclusion

In children 6 years of age and younger, intraoperative arthrogram should be considered while treating knee deformity, as plain films may not fully represent the true deformity of the distal femur in particular.

Clinical significance

Supports the need for advanced imaging or intraoperative arthrogram for joint corrective surgery in young patients.

Level of evidence

Level 3 diagnostic.

How to cite this article

Bigach SD, Carender CN, Liu RW. Is Bony Knee Alignment Representative of the True Joint Surface in Skeletally Immature Patients? A Magnetic Resonance Imaging Study. Strategies Trauma Limb Reconstr 2020;15(2):79–83.

Utilization and Short-Term Outcomes of Computer Navigation in Unicompartmental Knee Arthroplasty

BACKGROUND

The use of navigation remains a controversial topic in knee arthroplasty. The purpose of this study is to evaluate current rates of utilization of navigation in unicompartmental knee arthroplasty (UKA) in the United States, as well as the incidence of short-term complications and operative times between navigated and non-navigated UKA.

METHODS

A query of the National Surgical Quality Improvement Project (NSQIP) database was used to identify cases of primary UKA during years 2006-2017. Additional common procedural terminology (CPT) codes were used to identify cases in which navigation was utilized. Operative time, length of stay, and short-term outcomes were compared. Propensity score matching was used to minimize differences in demographics and comorbidities between the navigation and non-navigation cohorts.

RESULTS

A total of 10,586 cases of UKA were identified; 343 of these cases (3.2%) utilized navigation. The unadjusted rate of any complication for the entire cohort was 3.6%. Navigated UKA had mean operative times 8 minutes longer than non-navigated UKA (92.1 min vs. 84.3 min; p<0.001). There was no difference in overall complication rates between the matched navigated (3.5%) and non-navigated (3.2%) cohorts (p=0.65). There was no difference in rates of readmission (0.31% vs. 0.58%; p=0.31), reoperation (0.29% vs. 0.29%; p=1.00), and mean length of stay (1.3 ± 1.6 days vs. 1.2 ± 1.9 days; p=0.15).

CONCLUSION

UKA utilizing navigation had a mean operative time 8 minutes longer than non-navigated UKA. We found no difference in rates of short-term complications, readmission, reoperation, or mean length of stay between navigated and non-navigated UKA.Level of Evidence: III.

Preoperative Performance of PROMIS in Patients With Patellofemoral Malalignment and Chondral Disease

BACKGROUND

Use of the Patient-Reported Outcomes Measurement Information System (PROMIS) instrument has not yet been validated in patients undergoing operative treatment for patellofemoral malalignment and chondral disease.

PURPOSE

To evaluate the PROMIS Physical Function Computer Adaptive Testing (PF CAT) instrument in a population of patients with patellofemoral malalignment and chondral disease relative to established patient-reported outcome (PRO) instruments.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Eligible patients were prospectively enrolled at the time of indication for surgery and completed 5 PRO instruments preoperatively: 36-Item Short Form Health Survey (SF-36); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); Marx activity rating scale (Marx); EuroQol 5-dimension, 5-level instrument (EQ-5D-5L); and PROMIS PF CAT. Convergent and discriminant validity was assessed by measuring correlations between PROMIS PF CAT and other PRO instruments, including the Knee injury and Osteoarthritis Outcome Score (KOOS). Strength of correlation was measured by use of Spearman correlation coefficients.

RESULTS

In total, 37 patients (40 knees) were enrolled in the study. All knees underwent Fulkerson osteotomy and concomitant cartilage procedure (29 chondroplasty, 6 allograft, 5 microfracture). Mean patient age was 33.4 years, and 73% of knees were in female patients. Correlations (r) between PROMIS PF CAT and knee PRO instruments were as follows: SF-36 PF (r = 0.80; P < .01); KOOS Pain (r = 0.74; P < .01); KOOS Symptoms (r = 0.47; P < .01); KOOS Quality of Life (r = 0.68; P < .01); KOOS Sports and Recreation (r = 0.72; P < .01); KOOS Activities of Daily Living (ADL) (r = 0.80; P < .01); WOMAC Function (r = 0.80; P < .01); WOMAC Pain (r = 0.72; P < .01); WOMAC Stiffness (r = 0.38; P = .02); Marx (r = 0.22; P = .31); and EQ-5D-5L (r = 0.72; P < .01). Neither floor nor ceiling effects were observed in PROMIS PF CAT or KOOS ADL. Mean (±SD) question burden with PROMIS PF CAT was 5.6 ± 0.6 questions.

CONCLUSION

In patients with patellofemoral malalignment and chondral disease, PROMIS PF CAT is an efficient and reliable PRO instrument to preoperatively assess patients across a spectrum of knee function without floor or ceiling effects.