Similar Efficacy and Lower Cost Associated with Ceftazidime Compared to Tobramycin Coupled with Vancomycin in Antibiotic Spacers in the Treatment of Periprosthetic Joint Infection

BACKGROUND

Vancomycin and tobramycin have traditionally been used in antibiotic spacers. In 2020, our institution replaced tobramycin with ceftazidime. We hypothesized that the use of ceftazidime/vancomycin (CV) in antibiotic spacers would not lead to an increase in treatment failure compared to tobramycin/vancomycin (TV).

METHODS

From 2014 to 2022, we identified 243 patients who underwent a stage I revision for periprosthetic joint infection (PJI). The primary outcome was a recurrent infection requiring antibiotic spacer exchange. We were adequately powered to detect a 10% difference in recurrent infection. Patients who had a prior failed stage I or two-stage revision for infection, acute kidney injury (AKI) prior to surgery, or end-stage renal disease were excluded. Given no other changes to our spacer constructs, we estimated cost differences attributable to the antibiotic change. Chi-square and t-tests were used to compare the two groups. Multivariable logistic regressions were utilized for the outcomes.

RESULTS

The combination of TV was used in 127 patients; CV was used in 116 patients. Within one year of stage I, 9.8% of the TV group had a recurrence of infection versus 7.8% of the CV group (P = 0.60). By final follow-up, results were similar (12.6 versus 8.6%, respectively, P = 0.32). Adjusting for potential risk factors did not alter the results. Cost savings for ceftazidime versus tobramycin are estimated to be $68,550 per one hundred patients treated.

CONCLUSION

Replacing tobramycin with ceftazidime in antibiotic spacers yielded similar PJI eradication success at a lower cost. While larger studies are warranted to confirm these efficacy and cost-saving results, our data justifies the continued investigation and use of ceftazidime as an alternative to tobramycin in antibiotic spacers.

Discharge to a Skilled Nursing Facility After Hip Fracture Results in Higher Rates of Periprosthetic Joint Infection

BACKGROUND

Femoral neck fractures (FNFs) in elderly patients are associated with major morbidity and mortality. The influence of postoperative discharge location on recovery and outcomes after arthroplasty for hip fractures is not well understood.

METHODS

A multisite retrospective cohort from 9 academic centers identified patients who had FNF treated with hemiarthroplasty or total hip arthroplasty between 2010 and 2019. Patients who had diagnoses of dementia, stroke, age > 80 years, or high energy fracture were excluded. Discharge location was identified, including home-based health services (HHS), inpatient rehabilitation (IPR), or a skilled nursing facility (SNF). Rates of reoperation, periprosthetic joint infection (PJI), and mortality were compared between cohorts. Multivariate logistic regressions were performed, adjusting for age, American Society of Anesthesiologists (ASA) score, body mass index, sex, and tobacco use. Statistical significance was defined as P < .05.

RESULTS

A total of 672 patients (315 HHS, 144 IPR, and 213 SNF) were included in this study. The average follow-up was 30 months. The SNF cohort was significantly older (P < .0001) with higher ASA scores (P < .0001) than the HHS cohort. In a logistic regression model adjusting for age, ASA score, and body mass index, the SNF cohort had higher mortality rates than the HHS cohort (P = .0296) and were more likely to have PJI within 90 days (odds ratio = 4.55, 95% confidence interval = 1.40, 4.74) and within 1 year (odds ratio = 3.08, 95% confidence interval = 1.08, 8.78). Time to PJI was significantly shorter in the SNF cohort (SNF 38 versus HHS 231 days, P = .0155). No differences were seen in dislocation or reoperation rates between the SNF and HHS cohorts. No differences were seen in complication rates between the IPR and HHS cohorts.

CONCLUSIONS

Discharge to a SNF after arthroplasty for FNF is associated with increased mortality and higher rates of PJI. Hip fracture care pathways that uniformly discharge patients to SNFs may need to be re-evaluated, and surgeons should consider discharge to home with HHS when possible.

Risk Factors for Return to the Emergency Department and Readmission After Same-Day Discharge Total Joint Arthroplasty

INTRODUCTION

Same day discharge (SDD) after total joint arthroplasty (TJA) is safe and cost effective. However, benefits may be offset by the potential cost of emergency department (ED) visits and readmissions. We identified risk factors for return to the ED and readmission in patients who underwent SDD and inpatient (IP) stays after TJA.

METHODS

We performed a retrospective review of patients who underwent primary TJA at an academic institution over the course of one year. There were 1,708 consecutive TJAs (721 THA [total hip arthroplasty] and 987 TKA [total knee arthroplasty]) included. A SDD occurred after 1,199 (70%) TJAs, 523 THAs, and 676 TKAs. We compared the demographics and comorbidities of patients who have SDD or IP who stayed following TJA. We documented rates of return to the ED or readmission within 90 days of surgery. Cohorts were compared using the Student's t-test or Chi-squared test. Significant findings were those with P-value <0.05.

RESULTS

The SDD cohort had a significantly higher rate of young, non-White men who had a lower body mass index (BMI) and fewer comorbidities than the IP cohort. Rates of return to ED and readmission were similar between SDD and IP cohorts after TJA and similar between THA and TKA. Factors that significantly influenced return to ED included a higher American Society of Anaesthesiologists (ASA) score (SDD, IP), a higher Charlson Comorbidity Index (CCI) score (SDD, IP), a lower BMI (IP), and a psychological diagnosis (SDD, IP). Factors that significantly influenced readmission rates included a higher ASA score (SDD), older age (SDD), and psychological diagnosis (SDD, IP).

CONCLUSION

Patients who discharge the same day after primary TJA have similar rates of return to the ED and readmission as those admitted as an inpatient. Patients who had a psychological diagnosis, and particularly a diagnosis of depression, are at higher risk for return to the ED and readmission after primary TJA, regardless of discharge the same-day or inpatient admission. Improved measures that attempt to further treat and optimize this patient population could reduce unnecessary postoperative ED visits.

Decreased Patellar Fractures and Subluxation with Patellar Component Replacement at Stage-One Spacer

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication of total knee arthroplasty (TKA) and is often treated with two-stage revision. We retrospectively assessed whether replacing the patellar component with articulating stage-one spacers was associated with improved outcomes compared to spacers without patellar component replacement.

METHODS

A total of 139 patients from a single academic institution were identified who underwent an articulating stage-one revision TKA and had at least 1-year follow-up. Of the 139 patients, 91 underwent patellar component removal without replacement, while 48 had a patellar component replaced at stage-one revision. Patellar fracture and reinfection at any point after stage-one were recorded. Knee range of motion (ROM), patellar thickness, lateral tilt, and lateral displacement were measured at six-weeks post stage-one. Chi-squared, Fisher's exact, and t-tests were utilized for comparisons. There were no significant demographic differences between groups.

RESULTS

Patellar component replacement at stage-one revision was associated with fewer patellar fractures (2.1 versus 12.1%, P = 0.046), less lateral patellar displacement (1.7 versus 16.0 mm, P < 0.01), and improved pre to postoperative knee ROM six weeks after stage-one (+5.9 versus -11.4°, P = 0.03). There was no difference in reinfections after stage-two revision for the replaced or unreplaced patellar groups (15.4 versus 15%, P = 1.000). While the mean time between stage-one and stage-two was not different (5.2 versus 4.5 months, P = 0.50), at one-year follow-up, significantly more patients in the patellar component replacement group were satisfied and refused stage-two revision (45.8% versus 3.3%, P < 0.001).

CONCLUSION

Replacing the patellar component at stage-one revision is associated with a decreased rate of patellar fracture and lateral patellar subluxation, improved ROM, and possible increased patient satisfaction, as reflected by nearly half of these patients electing to keep their spacer. There was no difference in reinfection rates between the cohorts.

Impact of Demographic Variables on Recovery After Total Hip Arthroplasty

BACKGROUND

Several patient factors affect recovery after total hip arthroplasty (THA). However, the impact of these variables on patient-reported outcome measure recovery curves following THA has not been defined. Our goal was to quantify the influence of multiple variables on recovery after primary THA.

METHODS

There were 1,724 patients in a multicenter study included. Variables included sex, race/ethnicity, anxiety/depression, body mass index, tobacco, and preoperative opioid use. The Hip disability and Osteoarthritis Score for Joint Replacement (HOOS JR) was recorded at multiple time points. Recovery curves were created using longitudinal estimating equations.

RESULTS

Patients who were women, obese, or smokers demonstrated lower HOOS JR scores at all time points. Preoperative opioid use was also correlated with lower HOOS JR scores, but this difference diminished after 6 months. Black patients demonstrated lower HOOS JR scores compared to Caucasians, and this relative difference increased out to 1-year postoperatively (P = .018). Hispanics also had lower HOOS JR scores, but scores recovered at similar rates compared to non-Hispanics. Patients who had only anxiety or depression had similar HOOS JR scores compared to patients who did not have anxiety or depression. However, patients who had both anxiety and depression had lower HOOS JR scores compared to patients who had neither (P = .049), and this relative difference became greater at 1-year postoperatively (P = .002).

CONCLUSIONS

Several factors including race/ethnicity, opioid use, and mental health influence recovery trajectory following THA. This information helps provide more individualized counseling about expectations after THA and focus targeted interventions to improve outcomes in at-risk groups.

A "Dry Tap" in Prosthetic Joint Infection Workup of Total Hip Arthroplasty Is Not Reassuring

BACKGROUND

Synovial fluid analysis is important in diagnosing prosthetic joint infection (PJI). The rate of culture-positive PJI in patients who have a dry tap of a total hip arthroplasty (THA) is not well described.

METHODS

We reviewed all image-guided THA aspirations, performed from 2014 to 2021 at a single academic institution. Aspirations were categorized as successful (≥ 0.5 mL) or unsuccessful (< 0.5 mL, "dry tap"). We analyzed culture data on all repeat aspirations and revision surgeries performed within 90 days of the initial dry tap.

RESULTS

We reviewed 275 consecutive attempted THA aspirations of which 100 (36.4%) resulted in a dry tap. The dry tap cohort had a significantly higher percentage of fluoroscopic-guided aspirations (64%) and fewer ultrasound-guided aspirations (36%) compared to the successful aspiration cohort (48.9% fluoroscopic, 53.1% ultrasound, P = .0061). Of the 100 patients who have dry taps, 48 underwent revision surgery within 90 days of the initial dry tap, and 15 resulted in 2 or more positive cultures. The rate of PJI defined by MusculoSkeletal Infection Society major criteria in the dry tap cohort was 16.0%.

CONCLUSIONS

Attempted aspiration of a THA resulted in a dry tap 36.4% of the time. Of those patients who had a dry tap, 16.0% were subsequently found to have PJI based on MusculoSkeletal Infection Society major criteria. Therefore, a "dry tap" does not exclude the diagnosis of infection and should not be considered reassuring for the absence of PJI.

Outpatient Total Joint Arthroplasty at a High-Volume Academic Center: An Analysis of Failure to Launch

BACKGROUND

Unanticipated failure to discharge home (failure to launch, FTL) following scheduled same-day discharge (SDD) total joint arthroplasty (TJA) is problematic for the surgical facility with respect to staffing, care coordination, and reimbursement concerns. The aim of this study was to review rates, etiologies, and contributing factors for FTL in SDD TJA at an inpatient academic medical center.

METHODS

All patients who underwent primary TJA between February 2021 and February 2023 were retrospectively reviewed. Of those scheduled for SDD, risk factors for FTL were compared with successful SDD. Readmission and emergency department (ED) visits were compared with historical cohorts. There were 3,093 consecutive primary joint arthroplasties performed, of which 2,411 (78%) were scheduled for SDD.

RESULTS

Overall, SDD was successful in 94.2% (n = 2,272) of patients who had an FTL rate of 5.8%. Specifically, SDD was successful in 91.4% with total hip arthroplasty, 96.0% with total knee arthroplasty, and 98.6% with unicompartmental knee arthroplasty. Factors that significantly increased the risk of FTL included general anesthesia versus spinal anesthesia (P < .0001), later surgery start time (P < .0001), longer surgical time (P = .0043), higher estimated blood loss (P < .0001), women (P = .0102), younger age (P = .0079), and lower preoperative mental health patient-reported outcomes scores (P = .0039). Readmission and ED visit rates were not higher in the SDD group when compared to historical controls (P = .6830).

CONCLUSIONS

With a comprehensive multidisciplinary approach dedicated to improving SDDs at an academic medical center, we have seen successful SDD in nearly 80% of primary TJA, with an FTL rate of 5.8%, and no increased risk of readmission or ED visits. Without adding many personnel, hospital recovery units, or other resources, simple interventions to help decrease FTL have included enhanced preoperative education and expectation settings, improved perioperative communications, reallocating personnel from the inpatient to the outpatient setting, the use of short-acting spinal anesthetics, and earlier scheduled surgery times.

Metallosis and Corrosion Associated With Revision Total Knee Arthroplasties With Metaphyseal Sleeves

Metallosis and corrosion have been associated with metal-on-metal and modular total hip arthroplasty but are rarely described in the setting of primary or revision total knee arthroplasty (TKA). In this series, we report on cases of metallosis due to mechanically assisted crevice corrosion at modular junctions of machined trunnion-bore tapers in a revision TKA system with metaphyseal sleeves. The unique design of metal modular junctions used in sleeve-based revision TKA, along with potential patient and surgical factors, may predispose these designs to fretting, corrosion, and adverse reaction to metal debris. We now consider metallosis and corrosion in the workup of painful or failed revision TKAs with sleeves. Future studies that investigate the incidence of this phenomenon may be warranted.

Recovery Curves for Patient Reported Outcomes and Physical Function After Total Hip Arthroplasty

INTRODUCTION

Patient reported outcome measures (PROMs) are frequently used for evaluating patient satisfaction and function following total hip arthroplasty (THA). Functional measures along with chronologic modeling may help set expectations perioperatively. Our goal was to define the trajectory of recovery and function in the first year following THA.

METHODS

Prospective data from 1,898 patients in a multicenter study was analyzed. The PROMs included the Hip disability and Osteoarthritis Score for Joint Replacement (HOOS-JR) and EuroQol-5 dimension (EQ5D). Physical activity was recorded on a wearable technology. Data was collected pre-operatively and at one, three, six, and twelve months post-operatively. Generalized estimating equations were used to evaluate outcomes over time.

RESULTS

Significant improvement occurred between pre- and post-operative time points for all PROMs. The PROMs showed the greatest proportional recovery within the first month post-operatively, each improving by at least one minimal clinically important difference (MCID). Daily steps and flights of stairs took longer to reach at least one MCID (three months and one year, respectively). Gait speed and walking asymmetry returned to baseline by three months, but did not reach a MCID of improvement by one-year.

CONCLUSION

Patients can be counseled that the greatest proportional improvement in PROMs is within one month after THA, while function surpasses pre-operative baselines by three-months, and gait quality may not improve until after one-year. This can help set realistic expectations and target interventions toward patients deviating from the norm.

Recovery Curve for Patient Reported Outcomes and Objective Physical Activity After Primary Total Knee Arthroplasty - A Multicenter Study Using Wearable Technology

BACKGROUND

This study aimed to describe the trajectory of recovery based on patient reported outcomes (PROs) and objective metrics of physical activity measures over the first 12 months post-total knee arthroplasty (TKA).

METHODS

In total, 1,005 participants who underwent a primary unilateral TKA surgery between November 2018 and September 2021 from a multi-site prospective study were analyzed. Generalized estimating equations were used to evaluate PROs and objective physical activity measures over time.

RESULTS

All Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), EuroQol-5D (EQ-5D) and steps per day scores were greater than pre-operative scores (P<0.05). The flights of stairs per day, gait speed and walking asymmetry all declined at 1-month (all, P<0.001). However, all subsequent scores improved by 6 months (all, P<0.01). The greatest clinically important differences from previous visit in KOOS JR (β=18.1; 95% Confidence Interval (CI)=17.2, 19.0), EQ-5D (β=0.11; 95% CI=0.10, 0.12), steps per day (β=1169.3; 95% CI=1012.7, 1325.9), gait speed (β=-0.05; 95% CI=-0.06, -0.03), and walking asymmetry (β=0.00; 95% CI=-0.03, 0.03) were observed at 3 months.

CONCLUSION

The KOOS JR, EQ-5D, and steps per day measures showed earlier improvements than other physical activity metrics, with the greatest magnitude of improvement within the first 3 months post-TKA. The greatest magnitude of improvement in walking asymmetry was not observed until 6 months, while gait speed and flights of stairs per day were not observed until 12 months. This data may further help provide expectation setting information to patients prior to surgery, and may aid in identifying outliers to the normal recovery curve who may benefit from targeted interventions.

Trends in Total Knee Arthroplasty Cementing Technique Among Arthroplasty Surgeons-A Survey of the American Association of Hip and Knee Surgeons Members

BACKGROUND

Aseptic loosening persists as one of the leading causes of failure following cemented primary total knee arthroplasty (TKA). Cement technique may impact implant fixation. We hypothesized that there is variability in TKA cement technique among arthroplasty surgeons.

METHODS

A 28-question survey regarding variables in surgeons' preferred TKA cementation technique was distributed to 2,791 current American Association of Hip and Knee Surgeons (AAHKS) members with a response rate of 30.8% (903 respondents). Patterns of responses were analyzed by grouping respondents by their answers to certain questions including cementing technique, tibial cement location, and femoral cement location.

RESULTS

A total of 73.5% reported performing at least 7 of 8 of the highest consensus techniques, including vacuum mixing (79.9%), using two bags (76.1%), tibial implant first (95.2%), single-stage cementing (96.9%), compression of the implants in extension (91.7%), and use of a tourniquet (84.3%). Medium and high viscosity cement was most commonly used (37.9 and 37.8%, respectively). Finger pressurization was most common (76.1%) compared to a gun (29.8%). There were 26.5% of respondents performing 6 or fewer of the most common majority techniques and seemed to perform other less common techniques (eg, use of a single bag of cement, trialing or closure prior to cement curing, and heating to accelerate cement curing). Cement was most commonly applied to the entire bone and implant surface on both the tibia (46.4%) and femur (47.7%), leaving much variation in the remaining cement application location responses.

DISCUSSION

There appears to be variability in cemented TKA technique among arthroplasty surgeons. There were 26.5% of respondents performing less of the majority techniques and also performed other additional low-response rate techniques. Further studies that look at the impacts of variation in techniques on outcomes may be warranted. Our study demonstrates the need for defining best practices for cement technique given the substantial variability identified.

Bilateral Erosive Septic Hip Arthritis Following Pregnancy

We report on a 34-year-old female whose normal spontaneous vaginal delivery was complicated by Group B streptococcus (GBS) colonization. She developed postpartum, bilateral, rapidly destructive septic hip arthritis. She was treated with bilateral articulating, antibiotic-impregnated spacers, 6 weeks of parenteral antibiotics, and subsequent conversion to total hip arthroplasties. In pregnant women, GBS can result in bacteremia, urinary tract infection, endometritis, and pneumonia. Less commonly, GBS can lead to endocarditis, sacroiliitis, or septic arthritis. Septic arthritis of the hip following pregnancy has been described in a limited number of case reports, yet none, to our knowledge, with rapid bilateral destruction requiring two-staged conversion to total hip replacement.

Prospective, Randomized, Surgeon-Blinded Comparison of Standard Magnification Assumption vs Magnification Marker Usage for Preoperative Templating in Total Hip Arthroplasty

BACKGROUND

We undertook this prospective, randomized, surgeon-blinded study to compare the accuracy of using of a magnification marker on preoperative radiographs for templating vs using a standard 21% magnification.

METHODS

One hundred consecutive total hip arthroplasties were randomized to preoperative templating using a 25-mm magnification marker (50 patients) or a standard 21% magnification (50 patients). Intraoperative data were collected regarding the actual and predicted size of the femoral and acetabular components.

RESULTS

The 2 groups were found to be comparable with respect to body mass index (28.9 vs 27.9, P = .26) and gender (P = .69). In the magnification marker group, we predicted the femoral size within 1 size in 80% of the cases and the acetabular component in 94%. In the group of a standard 21% magnification, we predicted the femoral size within 1 size in 90% of the cases and the acetabular component in 96%. These proportions did not statistically differ (femur: χ²P = .16, odds ratio = 2.3, 95% confidence interval = 0.7-7.1; acetabulum: χ²P = .65, odds ratio = 1.5, 95% confidence interval = 0.3-9.6).

CONCLUSION

We did not detect a statistically significant difference in accuracy by using one method over the other when comparing the accuracy of component size selection. As the use of the magnification marker adds to the time and expense of preoperative radiographic acquisition, we feel using a standard 21% magnification is an equally accurate technique.

Inaccuracies in the Use of Magnification Markers in Digital Hip Radiographs

BACKGROUND

With the ubiquity of digital radiographs, the use of digital templating for arthroplasty has become commonplace. Although improved accuracy with digital radiographs and magnification markers is assumed, it has not been shown.

QUESTIONS/PURPOSES

We wanted to (1) evaluate the accuracy of magnification markers in estimating the magnification of the true hip and (2) determine if the use of magnification markers improves on older techniques of assuming a magnification of 20% for all patients.

METHODS

Between April 2013 and September 2013 we collected 100 AP pelvis radiographs of patients who had a THA prosthesis in situ and a magnification marker placed per the manufacturer's instructions. Radiographs seen during our standard radiographic review process, which met our inclusion criteria (AP pelvic view that included a well-positioned and observed magnification marker, and a prior total hip replacement with a known femoral head size), were included in the analysis. We then used OrthoView(TM) software program to calculate magnification of the radiograph using the magnification marker (measured magnification) and the femoral head of known size (true magnification).

RESULTS

The mean true magnification using the femoral head was 21% (SD, 2%). The mean magnification using the marker was 15% (SD, 5%). The 95% CI for the mean difference between the two measurements was 6% to 7% (p < 0.001). The use of a magnification marker to estimate magnification at the level of the hip using standard radiographic techniques was shown in this study to routinely underestimate the magnification of the radiograph using an arthroplasty femoral head of known diameter as the reference. If we assume a magnification of 20%, this more closely approximated the true magnification routinely. With this assumption, we were within 2% magnification in 64 of the 100 hips and off by 4% or more in only four hips. In contrast, using the magnification marker we were within 2% of true magnification in only 20 hips and were off by 4% or more in 59 hips.

CONCLUSION

We found the use of a magnification marker with digital radiographs for preoperative templating to be generally inaccurate, with a mean error of 6% and range from -5% to 15%. Additionally, these data suggest that the use of a magnification marker while taking preoperative radiographs of the hip may be unnecessary, as simply setting the software to assume a 20% magnification actually was more accurate.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Modular Versus Nonmodular Femoral Necks for Primary Total Hip Arthroplasty

In total hip arthroplasty (THA), proximal femoral neck stem modularity (PFNSM) has theoretical advantages over nonmodular stems, including the ability to more closely reconstruct anatomy and improve stability. However, risks of metallosis and breakage at the junction must be considered. In this study, we compared the head centers of a modular neck system with that of its nonmodular counterpart. Of 463 primary THAs with a modular stem, 261 (56%) had a head center equivalent to that of its nonmodular counterpart, and an additional 132 (29%) had a head center within 4 mm in length and 2 mm of offset. Thus, only 70 stems (15%) had a head center that was more than 4 mm in length and more than 2 mm in offset different from the nonmodular stem. Only 12 stems had a verted neck. These findings suggest that, in a majority of primary THAs, use of a modular stem results in head center positions also achievable with a nonmodular stem. Given the risks of modularity, PFNSM should be used with caution. We recommend PFNSM in cases that cannot be reconstructed with the nonmodular option.

Lessons learned from managing a prospective, private practice joint replacement registry: a 25-year experience

BACKGROUND

In 1984, we developed a private practice joint replacement registry (JRR) to prospectively follow patients undergoing THA and TKA to assess clinical and radiographic outcomes, complications, and implant survival. Little has been reported in the literature regarding management of this type of database, and it is unclear whether and how the information can be useful for addressing longer-term questions.

QUESTIONS/PURPOSES

We answered the following questions: (1) What is the rate of followup for THA and TKA in our JRR? (2) What factors affect followup? (3) How successful is this JRR model in capturing data and what areas of improvement are identified? And (4) what costs are associated with maintaining this JRR?

METHODS

We collected clinical data on all 12,047 patients having primary THA and TKA since 1984. Clinical and radiographic data were collected at routine followup intervals and entered into a prospective database. We searched this database to assess the rate of successful followup and data collection and to compare the effect of patient variables on followup. Costs related to database management were evaluated.

RESULTS

Followup was poor at every time interval after surgery, with a tendency for worsening over time. Patients with a complication and those younger than 70 years tended to followup with greater frequency. There were difficulties with data capture and substantial expenses related to managing the database.

CONCLUSIONS

Our findings highlight the difficulties in managing a JRR. Followup is poor and data collection is often incomplete. Newer technologies that allow easier tracking of patients and facilitate data capture may streamline this process and control costs.

Total hip arthroplasty after failed internal fixation of proximal femoral fractures

Between February 1987 and October 2008, we performed 102 total hip arthroplasties (THAs) after failed internal fixation of a prior hip fracture. There were 39 intertrochanteric fractures and 63 femoral neck fractures. Etiology of failure included 35 cases of osteonecrosis, 32 cases of arthritis, 25 cases of early failure of fixation, and 10 cases of nonunion. There were 12 patients who had early surgical complications related to the procedure (11.8%, 12/102). These included 5 patients who had dislocations (4.9%), 4 periprosthetic fractures (3.9%), 2 hematomas (2.0%), and 1 infection (1%). Of these 102 THAs, 50 were available for at least 2 years of follow-up (mean, 3.2 years). At a minimum 2-year follow-up, THA after failed internal fixation of hip fracture in these patients was clinically successful with an elevated risk of periprosthetic fracture and dislocation.

Cost comparison of cementless versus cemented hemiarthroplasty for displaced femoral neck fractures

Hip hemiarthroplasties are frequently performed for displaced femoral neck fractures. The purpose of this study was to identify the costs associated with cementless and cemented hemiarthroplasties, compare operative times, and identify complications. The hypothesis was that cementless hemiarthroplasties cost less than cemented hemiarthroplasties, require less operative time, and have fewer perioperative complications. A retrospective review was conducted of 2 surgeons' patients admitted for displaced femoral neck fractures between 2006 and 2010. Group 1 included 45 patients who underwent monopolar hemiarthroplasties with cementless femoral components via a standard posterior approach by a single surgeon. Group 2 included 49 patients who underwent monopolar hemiarthroplasties with cemented femoral components via a modified lateral approach by a single surgeon. Surgical and anesthesia times and the cost of implants and accessories were recorded. The cost for cementless components was $3275.60 (femoral stem, $2800; monopolar head, $400; sleeve, $75.60), whereas the cost of cemented components was $3694.47 (femoral stem, $1800; monopolar head, $400; sleeve, $75.60, 3 Simplex with tobramycin cement packets, $1221; cement mixer/irrigator with tip/centralizer and plug/pressurizer, $197.87), a cost savings of 12.7% ($418.87). Operative time was significantly reduced in group 1 vs group 2 (mean, 32.9 vs 56.1 minutes, respectively; P<.01). Anesthesia time was also significantly reduced in group 1 (mean, 82.3 vs 102.9 minutes, respectively; P<.01). The difference in mean anesthetic times demonstrates an overall cost savings of 18.6%, or $1161.30. No difference in complications was noted between the groups perioperatively. Regional cost variances, vendor-hospital contracts, and surgeons' operative times are factors that may influence cost savings. This study demonstrates significantly lower operative and anesthetic times and observable cost savings with cementless femoral implants.

A comparison of two implant systems in restoration of hip geometry in arthroplasty

BACKGROUND

Restoration of hip offset and leg length during THA is often limited by available implant geometries. The recent introduction of femoral components with a modular junction at the base of the neck (two modular junction components) has expanded the options to restore femoral offset and leg length.

QUESTIONS/PURPOSES

We asked (1) whether a femoral component with two modular junctions would predict by templating more frequent restoration of preoperative offset and leg length abnormalities than one with single modular junctions; and (2) how our use of these options compared with national sales data.

PATIENTS AND METHODS

We retrospectively reviewed the preoperative templating data in 100 primary THAs using single modular junction implants with only a neutral version stem and 100 THAs using two modular junction implants. We compared the frequency with which the desired leg length and offset were completely restored by preoperative templating in the two groups.

RESULTS

Offset and leg lengths were restored to within 1 mm in 85% of cases with two modular junction implants and 60% of cases with single modular junction implants. An anteverted or a retroverted neck was used in 25% of cases with the two modular junction stems. The national sales data revealed femoral neck components with version were used in 28% of cases.

CONCLUSIONS

The use of a femoral component with two modular junctions resulted in more frequent ability to restore femoral offset and leg length than a single modular junction. The advantage of clinical flexibility should be tempered by the potential concerns of prosthetic mechanical failure (which has been reported in another implant system with two modular junctions), increased third-body wear and corrosive debris, and increased prosthetic cost.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Polyethylene exchange in a second-generation cementless acetabular component

Some have suggested that isolated polyethylene exchange in a well-fixed Harris-Galante II acetabular component (Zimmer, Warsaw, Ind) necessitates cementing the liner or complete revision because the locking mechanism is suboptimal. We reviewed 29 hip revisions during which the polyethylene was exchanged using the native locking mechanism. Mean follow-up was 5.1 years (2-13 years). Of the 29 patients, one had a disengagement of the revision polyethylene at 2.5 years. At the time of this patient's original revision, one of the tines was fractured, but a direct exchange was performed. There were 4 other revisions (one for loosening and 3 for instability). There were no other complications attributable to the direct polyethylene exchange and no further reoperations. This series suggests that polyethylene exchange with the Harris-Galante II prosthesis can be performed safely using the native locking mechanism in the absence of fractured tines.

Cruciate-retaining total knee arthroplasty in patients with at least fifteen degrees of coronal plane deformity

There has been debate regarding the superiority of posterior stabilized (PS) or cruciate-retaining knee designs in total knee arthroplasty (TKA). The proponents of PS TKA argue that a relative contraindication to the use of cruciate-retaining total knee arthroplasty is that of significant coronal plane deformity. The purpose of this study is to compare our minimum 10-year results of posterior cruciate ligament-retaining TKAs in patients with preoperative coronal plane deformity of at least 15 degrees (> or =10 degrees of varus or > or =20 degrees of valgus) to historical results of PS TKA designs in similar patients. We found, at a minimum 10-year follow-up, very good results with a 93% (95% confidence interval, 87%-98%) revision-free survivorship at 10 years and no revisions for instability or loosening.

A second-generation cementless total hip arthroplasty mean 9-year results

Two hundred fifty-eight primary total hip arthroplasties in 231 patients were implanted using a circumferentially, proximally porous-coated, collared femoral component and a cementless, hemispherical, porous-coated acetabular component and followed up for a mean of 9 years (5-14 years). Four femoral components were revised (2 stems for infection and 2 stems for aseptic loosening). One additional femoral component was radiographically loose at last follow-up. Nine hips underwent acetabular revision (4 for instability, 2 for infection, 2 for loosening, and 1 for osteolysis). Ten-year survivorship with revision or loosening of any component as the end point was 92%; with femoral component aseptic loosening as end point, survivorship was 98%; with acetabular aseptic loosening as the end point, survivorship was 99%. Osteolysis was identified in 26 hips (13%).

Cementless total hip arthroplasty in patients 50 years or younger

This report examines the mean 9-year results of 100 second-generation cementless total hip arthroplasty in 91 patients 50 years or younger. The mean age at arthroplasty was 39 years (range, 14-50 years), and follow up averaged 9 years (range, 5-13 years). There were 13 revisions (7 related to polyethylene wear and/or osteolysis, 5 for instability, and 1 for infection). No femoral components were revised for loosening and none were radiographically loose. Two acetabular shells were revised for loosening secondary to extensive osteolysis. Ten-year survivorship using revision for any reason as the end point was 87.5%, using femoral component aseptic loosening as the end point was 100%, and using acetabular component aseptic loosening as the end point was 97.1%.

Learning curve for the two-incision total hip replacement

Recently there has been increased interest in doing total hip replacement through small incisions. One such technique is the two-incision approach. After initial investigations into its feasibility, Zimmer developed a training program for surgeons interested in doing the so called MIS 2-Incision Hip Procedure. An "index case" study was initiated to track the early experiences of trained surgeons, which includes 159 surgeons who have completed such training and recorded data on their initial cases. The purpose of this report is to present the data available from this index case study regarding the process of developing proficiency with the two-incision total hip replacement. We found a significant decrease in the mean operative time and fluoroscopy time from the first to tenth case. Key complications did not show a systematic decrease as a function of case number for the first ten cases. Clarification of the entire learning curve for this technique requires further investigation but may last beyond case ten for many surgeons. In addition, data from this study suggests that patient characteristics and surgeon experience have a significant effect on the prevalence of complications with the two-incision technique. The evolution of minimally invasive joint replacement is clearly in its infancy. Complication rates and the demonstrated learning curve may be altered by changes in training and surgical techniques.

A comparison of cementless acetabular components of the same design: spiked versus supplemental screws

The purpose of this report was to compare the results of a series of otherwise-identical, cementless acetabular components with screws to a group with spikes in primary total hip arthroplasty. Between April 1993 and August 1997, 339 primary total hip arthroplasties were performed using a cementless acetabular component in 312 patients. There were 227 acetabular components with screws and 112 with spikes only. Radiographic evaluation was performed at a mean of 4.8 years' postarthroplasty (range, 2-8.6 years). No significant difference was identified between the 2 groups in regard to radiographic or clinical parameters.

Indications for lateral retinacular release in total knee replacement

The rule of no thumb test was compared with the towel clip test in determining the need for lateral retinacular release in 200 consecutive primary total knee replacements. The towel clip test was positive in 13 knees (6.5%) and the rule of no thumb test was positive in 78 knees (39%). Using a positive towel clip test as the indication for lateral retinacular release, there was no radiographic evidence of patellar tilt, subluxation, or dislocation in any knee at 6 months postoperatively. Therefore, the rule of no thumb test falsely predicted the need for lateral release in 65 knees (32.5%). The authors advocate the towel clip test to determine the need for lateral retinacular release.

Trochanteric osteotomy and fixation during total hip arthroplasty

Once used routinely, trochanteric osteotomy in total hip arthroplasty now is usually limited to difficult primary and revision cases. There are three types: the standard trochanteric osteotomy and its variations, the trochanteric slide, and the extended trochanteric osteotomy. Each has unique indications, fixation techniques, and complications. Primary total hip arthroplasty procedures requiring the enhanced exposure provided by trochanteric osteotomy may be needed in patients with hip ankylosis or fusion, protrusio acetabuli, proximal femoral deformities, developmental dysplasia, or abductor muscle laxity. Trochanteric osteotomies in revision arthroplasties, primarily the extended trochanteric osteotomy, facilitate the removal of well-fixed femoral components, provide direct access to the diaphysis for distal fixation, and enhance acetabular exposure.

Second-generation cementless total hip arthroplasty. Eight to eleven-year results

BACKGROUND

Second-generation cementless femoral components were designed to provide more reliable ingrowth and to limit distal osteolysis by incorporating circumferential proximal ingrowth surfaces. We examined the eight to eleven-year results of total hip arthroplasty with a cementless, anatomically designed femoral component and a cementless hemispheric acetabular component.

METHODS

Ninety-two consecutive primary total hip arthroplasties with implantation of a femoral component with a circumferential proximal porous coating (Anatomic Hip) and a cementless hemispheric porous-coated acetabular component (Harris-Galante II) were performed in eighty-five patients. These patients were prospectively followed clinically and radiographically. Six patients (seven hips) died and five patients (seven hips) were lost to follow-up, leaving seventy-four patients (seventy-eight hips) who had been followed for a mean of ten years (range, eight to eleven years). The mean age at the time of the arthroplasty was fifty-two years.

RESULTS

The mean preoperative Harris hip score of 51 points improved to 94 points at the time of final follow-up; 86% of the hips had a good or excellent result. Thigh pain was reported as mild to severe after seven hip arthroplasties. No femoral component was revised for any reason, and none were loose radiographically at the time of the last follow-up. Two hips underwent acetabular revision (one because of dislocation and one because of loosening). Kaplan-Meier survivorship analysis was performed with revision or loosening of any component as the end point. The ten-year survival rate was 96.4% +/- 2.1% for the total hip prosthesis, 100% for the femoral component, and 96.4% +/- 2.1% for the acetabular component. Radiolucencies adjacent to the nonporous portion of the femoral component were seen in sixty-eight (93%) of the -seventy-three hips with complete radiographic follow-up. Femoral osteolysis proximal to the lesser trochanter was noted in four hips (5%). No osteolysis was identified distal to the lesser trochanter. Periacetabular osteolysis was identified in twelve hips (16%). Five patients underwent exchange of the acetabular liner because of polyethylene wear.

CONCLUSIONS

This second-generation cementless, anatomically designed femoral component provided excellent clinical and radiographic results with a 100% survival rate at ten years. The circumferential porous coating of this implant improved ingrowth and prevented distal osteolysis at a mean of ten years after the arthroplasty.

Gout-induced arthropathy after total knee arthroplasty: a report of two cases

Gout, although relatively rare in joint replacements, can present as an acute or chronic painful knee or hip arthroplasty. Gout and acute infection of a joint replacement can be difficult to differentiate, with the physical examination and laboratory study results frequently being similar. Both conditions can present with a rapid onset of joint pain, swelling, erythema, and constitutional symptoms, including fevers and malaise. Laboratory findings in both conditions often include an elevated leukocyte count, erythrocyte sedimentation rate, and C-reactive protein level. Negatively birefringent, needle-shaped crystals in the synovial fluid confirm the diagnosis of gout. The mistaken diagnosis of septic arthritis in a joint replacement with crystal-induced synovitis can lead to inappropriate open debridement or component removal. The current study includes a review of the literature and presents two cases of gout after total knee arthroplasty. These cases suggest that in situations of suspected sepsis without synovial fluid crystals, operative intervention is indicated with a presumed diagnosis of septic arthritis. The identification of chalky white or yellow deposits in the synovium or bone is highly suggestive of gout. The definitive diagnosis is made by polarized light histologic evaluation of these tissues. If these deposits are present in the absence of a positive preoperative culture, positive Gram stain for bacteria, or component loosening, component retention is indicated.

Posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis

BACKGROUND

Although initial reports on posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis have been encouraging, a high rate of late instability necessitating revision has been reported recently. The purpose of the present prospective study was to analyze the results of posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis.

METHODS

Seventy-two posterior cruciate ligament-retaining total knee arthroplasties in fifty-one patients with rheumatoid arthritis were studied prospectively. All procedures were performed with the Miller-Galante I prosthesis. Eighteen patients (twenty-four knees) died before the eight-year follow-up and one patient (two knees) was lost to follow-up, leaving forty-six knees (thirty-two patients) for review. These forty-six knees were evaluated clinically (with particular attention to posterior instability) and radiographically at annual intervals for a mean of 10.5 years (range, eight to fourteen years).

RESULTS

Forty-four (95%) of forty-six knees had a good or excellent result at a mean of 10.5 years. However, nine (13%) of the original seventy-two knees had revision of the implant, with six of the revisions performed because of failure of a metal-backed patellar component. The rate of survival at ten years was 93% 4% with femoral or tibial revision for any reason as the end point and 81% 5% with any reoperation as the end point. There was no aseptic loosening in any knee. Posterior instability was identified clinically and/or radiographically in two (2.8%) of the original seventy-two knees; both unstable knees were in the same patient.

CONCLUSION

Posterior cruciate ligament-retaining total knee arthroplasty yielded satisfactory clinical and radiographic results in patients with rheumatoid arthritis at intermediate-term follow-up (mean, 10.5 years). Therefore, we believe that it remains an excellent treatment option for these patients.

The basic science of periprosthetic osteolysis

Despite improvements in the techniques, materials, and fixation of total joint replacements, wear and its sequelae continue to be the main factors limiting the longevity and clinical success of arthroplasty. Since Charnley first recognized aseptic loosening in the early 1960s, a tremendous amount of information has been gained on the basic science of osteolysis. Tissue explant, animal, and cell culture studies have allowed development of an appreciation of the complexity of cellular interactions and chemical mediators involved in these processes. Cellular participants have been shown to include the macrophage, osteoblast, fibroblast, and osteoclast. The plethora of chemical mediators that are responsible for the cellular interactions and effects on bone primarily include PGE2, TNF-alpha, IL-1, and IL-6. Recent and ongoing work in the field of signaling pathways will continue to advance our understanding of the mechanisms of periprosthetic bone loss. Although initial animal studies are promising for the development of possible pharmacologic agents for the treatment and prevention of osteolysis, well controlled human trials are required.

Alternate bearing surfaces in total joint arthroplasty: biologic considerations

The problem of periprosthetic osteolysis is currently the major limiting factor in joint arthroplasty longevity. Because this process has been shown to be primarily a biologic response to wear particles, corrosion products, or both, efforts to reduce particle generation are being undertaken. These efforts include the development of modified polyethylene and alternative articulating surfaces. These alternate bearing surfaces currently include ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal. Although these alternate bearings diminish or eliminate the generation of polyethylene particles, ceramic and metal particles are produced. The purpose of the current review is to discuss the literature that addresses the biologic response to these particles, locally and systemically.

Femoral-shaft fractures in children: a comparison of immediate casting and traction

Two hundred fifty-three femoral-shaft fractures in 246 pediatric patients treated between 1976 and 1986 were retrospectively reviewed, and 186 fractures in 181 patients were available for demographic review. Fifty-nine patients underwent spica casting within 48 h of injury, whereas 127 were placed in traction and underwent delayed casting (>48 h from injury). Fifty-five patients in the traction group and 33 in the immediate-casting group were locatable for long-term follow-up of 8.9 years average (range, 4-20 years). There was no clinically significant difference in limb-length inequalities, or rotational or angular deformities between the two groups at initial casting or at final follow-up. Hospital stay averaged 17.3 days in the traction group and 2.2 days in the immediate-casting group (p < 0.001). Total estimated charges, at current rates, demonstrated an 83% greater patient charge in the traction group than in the immediate-casting group.

Brachialis muscle entrapment in displaced supracondylar humerus fractures: a technique of closed reduction and report of initial results

A retrospective review was conducted of 152 extension-type supracondylar humerus fractures in 151 children. Ninety-two (61%) of 152 of these fractures were displaced (Gartland type III). Initial irreducibility was present in 20 of the 92 displaced fractures. Brachialis muscle interposition was diagnosed by physical examination or intraoperative findings in 18 (90%) of the 20 initially irreducible fractures. Sixteen of the fractures with brachialis muscle interposition underwent an attempt at freeing the impaled proximal fragment by the described "milking maneuver." The maneuver was successful in 15 of the 16 patients and was followed by closed reduction and percutaneous pinning. Three of the remaining four cases required open reduction and pinning. We identify the incidence of initial irreducibility in displaced supracondylar humerus fractures, describe clinical findings suggestive of brachialis entrapment, and demonstrate the milking maneuver to be a valuable technique in the treatment of displaced supracondylar fractures with brachialis interposition.