Effect of Price Capitation on Implant Selection for Primary Total Hip and Knee Arthroplasty

While price capitation strategies may help to control total hip (THA) and knee arthroplasty (TKA) implant costs, its effect on premium implant selection is unclear. Primary THA and TKA cases 6 months before and after capitated pricing implementation were retrospectively identified. After exclusions, 716 THA and 981 TKA from a large academic hospital and 2 midsize private practice community hospitals were reviewed. Academic hospital surgeons increased premium THA implant usage (66.5% to 70.6%; P = 0.28), while community surgeons selected fewer premium implants (36.4%) compared to academic surgeons, with no practice change (P = 0.95). Conversely, premium TKA implant usage significantly increased (73.4% to 89.4%; P < 0.001) for academic surgeons. Community surgeons used premium TKA implants at greater rates in both periods, with all cases having ≥ 1 premium criterion.     

Minimum 10 Year Survivorship Analysis of a Partially Coated Hydroxyapatite Tapered Femoral Stem in Elderly Patients With an Average Age Over 75

This is a retrospective, non-comparative study of 212 consecutive patients who underwent Total Hip Arthroplasty with an uncemented hydroxyapatite (HA) coated stem system from November 1997 to March 2000. The objective of the study was to analyze the performance of the implant at a minimum of 10 years in older patients (mean age 79.6 years). The Kaplan-Meier survivorship of the femoral stem at 10 years was 100%, and 97.5% for the whole prosthesis. The mean Merle d'Aubigné clinical score improved from 4.4 ± 2.1 points pre-operatively to 13.39 ± 3.77 points at final follow-up (p < 0.05), and the mean VAS score for thigh pain was 1.25. The radiographic analysis showed that there were no significant radiolucent lines or osteolysis compromising the fixation of the implant.     

Long-Term Survival of Semi-Constrained Total Knee Arthroplasty for Revision Surgery

Semi-constrained implants provide stability in the setting of soft-tissue deficiency in revision total knee arthroplasty (TKA). This study evaluated our institution’s long-term survival results with a semi-constrained implant used in the revision TKA setting. 234 semi-constrained revision total knee arthroplasties were performed in 209 patients. The average follow-up was 9 years. Forty repeat revisions were performed. 5-year survival was 91% and 10-year survival was 81%. Male gender significantly increased the risk of revision. At 10 years the average range of motion, pain level, and Knee Society score improved significantly (P < 0.001). Ninety percent of patients reported an improvement in their knee. The semi-constrained implant used in revision knee arthroplasty has acceptable implant survival and functional outcomes in the long-term follow-up period.     

Intra-Operative Periprosthetic Fractures Associated With Press Fit Stems in Revision Total Knee Arthroplasty : Incidence,Management, and Outcomes

The purpose of this study is to report the incidence, management, and outcomes of periprosthetic fractures associated with the insertion of press-fit stems during revision total knee arthroplasty (TKA). Immediate and six week post-operative radiographs from 634 stemmed implants (307 femoral, 327 tibial) from 420 consecutive revision TKAs were reviewed. Sixteen tibial (4.9%) and 3 femoral (1%) fractures (combined incidence 3.0%) were identified. All healed uneventfully without operative intervention, with no evidence of implant loosening at a mean of 23 months (range 12 to 47 months). The technique of tightly press fitting stems into the diaphysis is associated with a small rate (3%) of periprosthetic fractures; most were non or minimally displaced, all healed uneventfully with non-operative management and were not associated with implant loosening.     

Detecting total hip replacement prosthesis design on plain radiographs using deep convolutional neural network

Identifying the design of a failed implant is a key step in the preoperative planning of revision total joint arthroplasty. Manual identification of the implant design from radiographic images is time-consuming and prone to error. Failure to identify the implant design preoperatively can lead to increased operating room time, more complex surgery, increased blood loss, increased bone loss, increased recovery time, and overall increased healthcare costs. In this study, we present a novel, fully automatic and interpretable approach to identify the design of total hip replacement (THR) implants from plain radiographs using deep convolutional neural network (CNN). CNN achieved 100% accuracy in the identification of three commonly used THR implant designs. Such CNN can be used to automatically identify the design of a failed THR implant preoperatively in just a few seconds, saving time and improving the identification accuracy. This can potentially improve patient outcomes, free practitioners' time, and reduce healthcare costs.     

The Effects of Primary Implant Bearing Design on the Complexity of Revision Unicondylar Knee Arthroplasty

Comparisons of fixed- (FB) and mobile-bearing (MB) implants have failed to demonstrate a superiority of one design over the other. Despite showing equally successful outcomes, the wear patterns and small particulate debris associated with MB implants have been linked to an increased prevalence of osteolysis. This study compared the complexity of revision surgery for both bearing types. Operative time, use of augmentation and/or bone grafts, and the level of constraint required during revision were used to assess complexity. It was found that MB knees more frequently required tibial augmentation in our sample population (P = 0.020), but overall surgical complexity was equivalent for revisions of both implant designs. These data suggest that additional research pertaining to the potential differences between implants be investigated.     

The effect of Er:YAG laser irradiation on the scanning electron microscopic structure and surface roughness of various implant surfaces: an in vitro study

The purpose of this study was to evaluate the surface roughness (R_a) and microscopic change to irradiated dental implant surfaces in vitro and ultimately to determine the proper pulse energy power and application time for the clinical use of Er:YAG lasers. Anodic oxidized surface implants and sand-blasted, large-grit, and acid-etched (SLA) surface implants were used. Each experimental group of implant surfaces included ten implants. Nine implants were used for the laser irradiation test groups and one for the control group. Each test group was equally divided into three subgroups by irradiated pulse energy power. Using an Er:YAG laser, each subgroup of anodic oxidized surface implants was split into 60-, 100-, and 140-mJ/pulse groups, with each subgroup of SLA surface implants irradiated with a 100-, 140-, or 180-mJ/pulse. Three implants in every test subgroup were respectively irradiated for 1, 1.5, and 2 min. The R_a values for each specimen were recorded and every specimen was observed by SEM. Irradiation by Er:YAG laser led to a decrease in implant surface roughness that was not statistically significant. In anodic oxidized surfaces, the oxidized layer peeled off of the surface, and cracks appeared on implant surfaces in the 100- and 140-mJ/pulse subgroups. However, with SLA surfaces, no significant change in surface texture could be found on any implant surface in the 100- and 140-mJ/pulse subgroups. The melting and fusion phenomena of implant surfaces were observed with all application times with 180 mJ/pulse irradiation. The SLA implant surfaces are stable with laser intensities of less than 140 mJ/pulse and an irradiation time of less than 2 min. The anodic oxidized surfaces were not stable with laser intensities of 100 mJ/pulse when an Er:YAG laser was used to detoxify implant surfaces.     

Gentamycin delivered from a PDLLA coating of metallic implants: In vivo and in vitro characterisation for local prophylaxis of implant-related osteomyelitis

Locally applied antibiotics support prophylaxis of highly feared implant associated infections. Implant coatings with poly(d,l-lactide) (PDLLA)/gentamicin seem to be a promising approach. Aims of this study were to analyse the release kinetics of gentamicin in vivo, in vitro, to analyse the antibacterial efficacy, the resistance development and its impact on osteoblasts. For the in vitro release experiments titanium implants were coated with PDLLA/gentamicin and the antibiotic release in aqueous solution was analysed at 20 time points (from 10 s to 110 days). For the in vivo experiments PDLLA/gentamicin-coated kirschner wires were implanted in the tibiae of 18 rats. Gentamicin concentration in the bone was analysed at several time points (n = 3 each, 1 h to 7 days). Bactericidal efficacy, bacterial adhesion on the implants and resistance development were tested. AP activity, cell count and CICP expression of osteoblasts were analysed. Gentamicin was released rapidly with an initial burst in aqueous solution and followed by a slow release. Similarly, in vivo gentamicin concentration reached a high peak initially followed by a decrease to a low level. No development of resistance was observed in the investigated setting, the antibacterial efficacy was not affected by the coating process and significantly fewer bacteria were attached to the implant. Osteoblasts were not negatively affected by the gentamicin released from the coating. PDLLA/gentamicin coating resulted in a desired antibiotic peak concentration within the bone. Bacterial adhesion was successfully prevented. No bacterial resistances were developed. This coating seems to be a suitable supplement for prophylaxis of implant-associated infections.     

Total Joint Arthroplasty: Trends in Medicare Reimbursement and Implant Prices

Total joint arthroplasty (TJA) continues to be a popular target of cost control efforts. In order to provide a unique overview of financial trends facing TJA, we analyzed Medicare databases including 100% of beneficiaries, as well as industry surveys of implant list prices. Although there was a substantial increase in TJA utilization over the period 2000–2011 (+ 26.9%), growth has been stagnant since 2005. New coding schemes have made complicated cases more lucrative for hospitals (+ 2.5% to 6.5% per year), while reimbursements for uncomplicated cases have fallen (− 0.7% to − 0.6%). Physician reimbursements have declined on all case types (− 2.5% to − 2.1% per year), while list prices of orthopedic implants have risen (+ 4.8% to 5.5%). These trends should be kept in mind while contemplating future changes to TJA payment.     

Stable Fixation but Unpredictable Bone Remodelling Around the Lord Stem : Minimum 23-Year Follow-Up of 66 Total Hip Arthroplasties

Early designs of uncemented hip implants turned out to be failures mainly because the prerequisites for durable implant fixation were unknown. One exception was the chrome–cobalt stem of the Madreporic Lord prosthesis. We prospectively studied this prosthetic design in 107 hips that underwent surgery in 1979–1986. At the last follow-up, five stems and 54 cups had been revised, corresponding to stem and cup survival rates of 92% ± 3% and 45% ± 5% at 26 years. In all, 66 hips with remaining Lord stems were available for clinical follow-up 26 years (24–29) after the index operation. The mean total Harris hip and pain scores were 81 (SD 14) and 41 (SD 5).     

Impact of pelvic osteotomy on the incidence of inguinal hernias in classic bladder exstrophy

Background/purpose

The high prevalence of inguinal hernias in the bladder exstrophy population is well documented. The authors' aim is to determine whether pelvic osteotomy reduces the incidence of primary and recurrent inguinal hernias in patients with classic bladder exstrophy.

Methods

Using an institutionally-approved database, patients who underwent immediate or delayed primary bladder closure between 1974 and 2012 were identified and stratified by the use of pelvic osteotomy at the time of closure. Data were analyzed using Fisher's exact test and multivariate logistic regression analysis.

Results

One hundred thirty-six patients were identified with a median follow up of 8 years. The incidence of inguinal hernias following closure was 25% in the osteotomy group versus 46% in the non-osteotomy group (p = 0.017). Osteotomy was associated with a significant decrease in recurrence of inguinal hernias amongst patients who underwent previous repair (17% versus 47%, osteotomy versus non-osteotomy, p = 0.027) and the development of primary inguinal hernias in whom initial groin exploration was negative (20% versus 39%, p = 0.029). Osteotomy and female sex were associated with a decreased rate of inguinal hernia development after bladder closure while age at closure was not.

Conclusions

Pelvic osteotomy at the time of exstrophy closure decreases the likelihood of primary or recurrent inguinal hernia development.     

Identification of predictors of early infection in acute burn patients

Burn patients are at high risk for infections; however, common indicators of infection are unreliable in this population and can lead to unnecessary use of antibiotics. The study objective was to determine if predictors of early infection in adult acute burn patients are identified to provide clinicians with a practical tool to aid in the diagnosis of infection, thereby minimizing unnecessary exposure to antimicrobials. A retrospective chart review of all adult acute burn injury patients admitted over a 1 year period to the burn centre at Sunnybrook Health Sciences Centre was conducted. Early infection was defined as one that occurred within the first 10 days after injury and in accordance with American Burn Association guidelines. Those without infection were compared to patients with infection generally and also to patients with sepsis specifically. The period prevalence of early infection and sepsis in our patients was 50% (56/111) and 16% (18/111), respectively. It was determined that heart rate ≥110 bpm, systolic blood pressure ≤100 mmHg and intubation were the best predictors of sepsis (p < 0.05); and fraction of inhaled oxygen >25% and maximum temperature ≥39 °C were the best predictors of infection (p < 0.05). This pilot project identified significant predictors of early infection and sepsis in acute burns and will be validated in a prospective study.     

Proximal Femoral Replacement in the Management of Acute Periprosthetic Fractures of the Hip: A Competing Risks Survival Analysis

To examine the mortality and implant survivorship of proximal femoral replacement (PFR), revision total hip arthroplasty (REV) and open reduction internal fixation (ORIF) in the treatment of acute periprosthetic fractures of the proximal femur, we retrospectively reviewed 97 consecutive acute periprosthetic proximal femoral fractures from 2000 to 2010. Three groups were defined: PFR (n = 21), REV (n = 19), and ORIF (n = 57). Outcome measures were all-cause mortality, implant failure, and reoperation. Competing Risks survival analysis of overall mortality during the mean 35-month follow-up showed no statistical difference between the three groups (P = 0.65; 12 and 60 month mortality for PFR: 37%, 45%; REV: 16%, 46%; ORIF: 14%, 100%). Implant survival was worse for the PFR group (P = 0.03, 12 and 60-month implant failure rate for PFR: 5%, 39%; REV: 7%, 7%; ORIF 2%, 2%). We conclude that PFR as compared with REV or ORIF may have worse medium-term implant survival, primarily due to instability and dislocation.     

Bone Loss During Revision of Unicompartmental to Total Knee Arthroplasty : An Analysis of Implanted Polyethylene Thickness From the National Joint Registry Data

Using the National Joint Registry (UK) database, we compared the thickness of polyethylene (PE) and the level of constraint used during primary total knee arthroplasty (TKA) versus the revision of unicondylar knee arthroplasty (UKA) to TKA. A total of 251,803 TKA procedures and 374 revision UKA–TKA procedures between 2003 and 2009 were reviewed. The commonest PE size used in TKA was 10 mm, compared to 12.79 mm in the revision group. The use of constrained knee implant was required in 2.15% of primary TKA and 4.19% of UKA to TKA revisions. The revision of UKA to TKA is a more complex procedure compared to primary TKA, with a higher incidence of using constrained implants and thicker PE inserts. These findings may be useful for surgeons in their decision making.     

Establishing a Role for Vancomycin Powder Application for Prosthetic Joint Infection Prevention—Results of a Wear Simulation Study

Topical vancomycin powder (VP) has shown efficacy and safety in decreasing post-operative spine infections. VP use in arthroplasty has not been established. Concerns remain for third-body wear with the addition of crystalline substrate at the implant interface. The study's purpose was to compare wear behavior of CoCr on UHMWPE to identical wear couples with VP. A six-station wear simulator was utilized and cyclic articulations were run for 10 million cycles (Mc). UHMWPE wear was measured using photography, stereomicroscopy, and gravimetric measurement. There were no differences in wear mark length (P = 0.43), width (P = 0.49), or gravimetric wear at 10 Mc (P = 0.98). VP and control groups lost 0.32 and 0.33 mg, respectively. VP may have a role in PJI prevention. A well-designed clinical study is needed.     

Repérage de la membrane cricothyroïdienne en phase d’apprentissage : valeur ajoutée de l’échographie ?

Objectives

Emergency cricothyroidotomy is recommended as life-saving maneuver when mask ventilation and tracheal intubation are impossible. It requires the puncture of the cricothyroid membrane (CTM) whose clinical identification is difficult. The objective of this study is to evaluate if ultrasound can help locating the CTM by comparing palpation and ultrasonographic evaluation.

Patients and methods

After ultrasound localization of CTM by a referent physician in two overweight volunteers, twelve residents without prior anatomy recall, defined by palpation an entry point for CTM. After a rapid training in CTM ultrasound localization, residents identified an ultrasound-guided puncture point. For each puncture site were registered: relevance, time and ease to localization. Six months later, residents renewed clinical and ultrasound identification of CTM on the same subjects.

Results

The CTM was accurately identified by palpation and ultrasound by 46% and 100% of residents respectively (P < 0.05). Six months later, residents remained more effective identifying CTM with ultrasound than with palpation (78% vs. 33%) (P < 0.05). Time to localization of CTM by palpation in the 2 volunteers was 15 s [11–18] and 24 s [9–39] (average [CI 95%]) whereas it was 21 s [16–25 s] and 28 s [19–36] by ultrasound respectively (ns). The ultrasound identification of CTM was also considered easier than clinical identification.

Conclusion

Following a limited training phase, ultrasound allowed a more effective localization of CTM by residents when compared to clinical palpation in overweight patients. This benefit remained significant when assessment was repeated 6 months later.     

Eleven-Year Results of the Anatomic Coated CFP Stem in Primary Total Hip Arthroplasty

There is a paucity of intermediate term results relating to short stem prostheses. The current study represents the longest follow-up results of the CFP prosthesis to the authors’ best knowledge. Between January 1999 and December 2000, all total hip arthroplasty patients (n = 149), treated with this anatomic neck preserving stem in the authors’ institution were enrolled in this study. After a mean follow-up time period of 11.2 years 117 patients were available for the follow-up examination. The mean HHS increased from 53 to 93. Overall, revision surgery was required in 11 patients (9.4%), with implant-associated complications noted in only five cases (4.3%). Aseptic loosening leading to implant removal was noted in four patients (3.4%). The current study's data suggest that the CFP implant, used in young patients undergoing primary total hip arthroplasty, is safe and provides excellent results after 11 years.     

Documentation of hip prostheses used in NorwayA critical review of the literature from 1996–2000

We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of prostheses used for primary total hip replacement (THR) in Norway. The study is based on two Health Technology Assessment reports from the UK (Faulkner et al. 1998, Fitzpatrick et al. 1998), reviewing the literature from 1980 to 1995. Using a similar search strategy, we have evaluated the literature from 1996 through 2000. We included 129 scientific and medical publications which were assessed according to a specific appraisal protocol. The majority (72%) were observational studies, whereas only 9% were randomized studies. We could not retrieve any peer-reviewed documentation for one third of the implants. The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90% implant survival after about 10 years. Survival of the Charnley prosthesis declines by about 10% during each of the two following decades. Except for the Charnley and Lubinus IP, no other prosthesis on the market in Norway has given long-term results (> 15 years). 5 other cemented implants have given comparable results at about 10 years of follow-up. Some uncemented stems have shown promising medium-term outcome, but no combination of uncemented cup and stem fulfilled the benchmark criterion of ≥ 90% implant survival at 10 years, which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR. New or undocumented implants should be introduced through a four-step model including preclinical testing, small series evaluated by radiosterometry, randomized clinical trial involving comparison with a well-documented prosthesis, and finally, surveillance of clinical use through registers.     

Mid-term outcomes after intramedullary fixation of peritrochanteric femoral fractures using the new proximal femoral nail antirotation (PFNA)

Background

Controversy persists concerning the preferred treatment of peritrochanteric femoral fractures. The purpose of the present study was to evaluate the mid-term outcomes of the newly developed implants - proximal femoral nail antirotation (PFNA) for the stabilisation of this type of fracture.

Methods

Between April 2006 and March 2008, 169 patients with peritrochanteric femoral fractures were treated with PFNA. As many as 26 patients were excluded from the study. According to the Orthopaedic Trauma Association (OTA) classification system, the remaining 143 fractures were classified as 19 cases of AO/OTA 31A1 fractures, 83 cases of 31A2 fractures, 28 cases of 31A3 fractures and 13 cases of 31A combined with proximal 32 fracture or separate proximal 32 fracture. The mean age of these patients was 67 years (range, 20-93 years). The operative time, the overall fluoroscopy time, the duration of hospitalisation and the surgical complications were noted. Patients were followed up for a mean of 21 months (range, 12-36 months). Functional outcomes were assessed according to the Harris hip scoring system.

Results

Fifteen patients (10%) required open reduction. The mean duration of surgery (from the beginning of close reduction to wound closure) was 72 min with a range between 45 and 170 min. The mean fluoroscopy time was 164 s with a range between 92 and 396 s. The mean time of hospital stay was 15 days. Postoperative X-rays showed a good or acceptable reduction in 134 cases (94%), and an ideal implant position in 131 cases (92%). There were 12 (8%) postoperative complications. All patients except one healed their fractures without any implant-specific complication (bending, breaking of the implant, cut out of the PFNA blade, femoral head penetration of the blade or ipsilateral fractures of the femoral shaft at the tip of the implant). The average time to bone healing was 16 weeks (range, 12-25 weeks). At the time of the latest follow-up, 106 patients (74%) were restored to their preoperative mobility. The mean Harris hip score was 84 points (range, 46-100 points). A total of 106 patients (74%) had an excellent or good outcome. According to the patients and/or their caregivers, outcome was described as satisfactory in 120(84%) of the 143 patients, and 36(90%) of the 40 patients, who were more than 80 years old.

Conclusion

The results suggest that PFNA is a very effective and safe method in the treatment of different patterns of peritrochanteric femoral fractures. The fixation is adequate to maintain reduction over time even in osteoporotic bones.     

Trends in Total Hip Arthroplasty Implant Utilization in the United States

Total hip arthroplasty (THA) implant usage has evolved as experience has been gained with newer implant designs. The purpose of this study was to characterize trends in THA implant usage between 2001 and 2012. The Orthopedic Research Network, which includes 174 hospitals and ~ 105,000 THA, was used to evaluate trends in fixation, bearings, acetabular cup and liner, and femoral head usage. In 2012, 93% of THAs were cementless; 56% of THA bearings were metal-HXLPE; and 35% were ceramic-HXLPE. 99% of acetabular cups were modular. 61% of femoral heads were metal, 39% were ceramic, 51% were 36 mm, and 28% were 32 mm. THA implant usage trends favor cementless fixation, metal-on-polyethylene or ceramic-on-polyethylene bearings, modular acetabular cups, and large diameter femoral heads.