Effect of carbon fiber type on monotonic and fatigue properties of orthopedic grade PEEK

Carbon-fiber reinforced (CFR) PEEK implants are used in orthopedic applications ranging from fracture fixation plates to spinal fusion cages. Documented implant failures and increasing volume and variety of CFR PEEK implants warrant a clearer understanding of material behavior under monotonic and cyclic loading. To address this issue, we conducted monotonic and fatigue crack propagation (FCP) experiments on orthopedic grade unfilled PEEK and two formulations of CFR PEEK (PAN- and pitch-based carbon fibers). The effect of annealing on FCP behavior was also studied. Under monotonic loading, fiber type had a statistically significant effect on elastic modulus (12.5 ± 1.3 versus 18.5 ± 2.3 GPa, pitch versus PAN CFR PEEK, AVG ± SD) and on ultimate tensile strength (145 ± 9 versus 192 ± 17 MPa, pitch versus PAN CFR PEEK, AVG ± SD). Fiber type did not have a significant effect on failure strain. Under cyclic loading, PAN CFR PEEK demonstrated an increased resistance to FCP compared with unfilled and pitch CFR PEEK, and this improvement was enhanced following annealing. Pitch CFR PEEK exhibited FCP behavior similar to unfilled PEEK, and neither material was appreciably affected by annealing. The improvements in monotonic and FCP behavior of PAN CFR PEEK is attributed to a compound effect of inherent fiber properties, increased fiber number for an equivalent wt% reinforcement, and fiber aspect ratio. FCP was shown to proceed via cyclic modes during stable crack growth, which transitioned to static modes (more akin to monotonic fracture) at longer crack lengths. The mechanisms of fatigue crack propagation appear similar between carbon-fiber types.

Comparison of a highly porous titanium cup (Tritanium) and a conventional hydroxyapatite-coated porous titanium cup: A retrospective analysis of clinical and radiological outcomes in hip arthroplasty among Japanese patients

BACKGROUND

The use of 3-dimensional highly porous acetabular cups is increasing. Their structure and mechanical properties mimic those of natural bone; therefore, they should promote stronger biological fixation. In our experience with total hip arthroplasty, radiolucent lines are observed when a 3-dimensional highly porous cup (Stryker Tritanium) is used. We compared the clinical and radiographic results between a Tritanium cup and a conventional cup (Stryker Trident HA) over a short time period.

METHOD

We retrospectively compared consecutive cases of primary total hip arthroplasty using a Tritanium cup (130 cases in 118 patients) and a matched cohort using a Trident cap (130 cases in 130 patients) between January 2011 and December 2014.

RESULTS

The mean follow-up duration was 41.3 and 38.1 months (p = 0.06) for the Tritanium and Trident groups, respectively. There were significant differences between the groups for radiolucent lines, cup abduction angle, and cup-center-edge angle. There were no significant differences in the clinical results. Radiolucent lines increased in the Tritanium group (36.1% at 3 months and 60.7% at final follow-up), whereas they decreased in the Trident group (2.5% at 3 months and 0.8% at final follow-up). The occurrence of radiolucent lines was significantly higher in the Tritanium group than in the Trident group at each follow-up period. Radiolucent lines were seen in 36.1% of patients in the Tritanium group during follow-up, without initial gaps. One cup loosening in the Tritanium group was identified at the final follow-up evaluation.

CONCLUSION

Both groups showed successful clinical results over short-term follow-up; however, the Tritanium group had a significantly higher rate of radiolucent line occurrence around the cups than did the Trident group. Thus, radiolucent lines can occur when using highly porous titanium cups; these lines indicate the possibility of future cup loosening. Longer follow-up and assessment of the results of using this implant are necessary.

Tests for predicting reimplantation success of two-stage revision for periprosthetic joint infection: A systematic review and meta-analysis

BACKGROUND

Several tests are used before reimplantation to detect persistent infection in patients with periprosthetic joint infection (PJI) undergoing two-stage revision. However, there is no consensus as to the optimal tests for excluding persistent infection or predicting successful reimplantation by stage. We aimed to determine the accuracy of different tests used to detect persistent infection after the first stage, and/or predicting failure following reimplantation in patients with PJI.

METHODS

We conducted a systematic review and meta-analysis of PubMed, Embase and the Cochrane Library databases. Two reviewers independently conducted quality assessments and data extractions to estimate pooled sensitivity and specificity, diagnostic odds ratio and area under the receiver operating characteristic curves (AUSROC) for each test.

RESULTS

We included 24 studies published between May 1999 and September 2017. Synovial fluid polymorphonuclear neutrophils (PMN)% had the highest sensitivity of 0.70, followed by serum erythrocyte sedimentation rate (0.57) and spacer sonication fluid culture (0.53). Synovial fluid culture had the highest specificity of 0.97, followed by frozen section (0.93) and the Musculoskeletal Infection Society criteria (0.92). Spacer sonication fluid culture was the most accurate test with an AUSROC of 0.8089, followed by synovial fluid culture (0.7749) and frozen section (0.7819).

DISCUSSION

Spacer sonication fluid culture had a relatively high diagnostic accuracy. We emphasize that no test can be used alone to exclude persistent infection beyond the first stage and/or predict failed reimplantation beyond the second stage.

LEVEL OF EVIDENCE

II, systematic review and meta-analysis of level 2 to level 4 studies with inconsistent results.

Intra-articular injections of expanded mesenchymal stem cells with and without addition of platelet-rich plasma are safe and effective for knee osteoarthritis

PURPOSE

To compare the effectiveness and safety of intra-articular injections of autologous expanded mesenchymal stromal stem cells alone (MSCs), or in combination with platelet-rich plasma (MSCs + PRP), in patients with knee osteoarthritis.

METHODS

Eighteen patients (57.6 ± 9.6 years) with radiographic symptomatic knee osteoarthritis (Dejour grades II-IV) were randomized to receive intra-articular injections of MSCs (n = 9) or MSCs + PRP (n = 9). Injections were performed 2-3 weeks after bone marrow aspiration (± 80-100 ml) which was obtained from both posterior iliac crests.

RESULTS

The Knee Injury and Osteoarthritis Outcome Score (KOOS) improved significantly throughout the 12 months for both groups (p < 0.05). No statistically significant differences between groups were found in KOOS subscales and global score improvements at 12-month end-point (n.s.). The MSCs group showed significant improvements in the pain, function and daily living activities, and sports and recreational activities subscales (p < 0.05). Similarly, the MSCs + PRP group showed significant improvements in the pain, function and daily living activities and quality of life subscales (p < 0.05). The average number of fibroblast colony forming units (CFU-F) was 56.8 + 21.9 for MSCs group and 50.7 ± 21.7 for MSCs + PRP group. Minimal adverse effects were seen in both groups (10 adverse events, in 5 patients).

CONCLUSIONS

Intra-articular injections of expanded MSCs alone or in combination with PRP are safe and have a beneficial effect on symptoms in patients with symptomatic knee osteoarthritis. Adding PRP to the MSCs injections did not provide additional benefit. These results are encouraging and support the recommendation of this minimally invasive procedure in patients with knee osteoarthritis, without requiring hospitalization. The CFU-F results may be used as reference for future research.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Proceedings of the signature series symposium "cellular therapies for orthopaedics and musculoskeletal disease proven and unproven therapies-promise, facts and fantasy," international society for cellular therapies, montreal, canada, may 2, 2018

The Signature Series Symposium "Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies-Promise, Facts and Fantasy" was held as a pre-meeting of the 26^th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions.

The Utilization of Formal Physical Therapy After Shoulder Arthroplasty

BACKGROUND

It is widely believed that structured rehabilitation programs by professional therapists help guide patients through the various recovery periods after shoulder arthroplasty, speeding up their recovery and improving their final functional gains. However, to our knowledge, there are no studies providing information about the current state of physical rehabilitation use after shoulder arthroplasty.

OBJECTIVES

To describe the variation in physical rehabilitation utilization after total shoulder arthroplasty (TSA) and reverse shoulder arthroplasty (RSA), and to identify differences in utilization based on type of insurance (private versus public), sex, age, and region of the country.

METHODS

This epidemiological retrospective database study utilized a commercially available database, PearlDiver, with longitudinal patient tracking linking all patients' Current Procedural Terminology and International Classification of Diseases-Ninth Revision codes to their specific records to analyze patterns of physical rehabilitation usage after TSA and RSA in the United States. Two main patient populations were analyzed within the PearlDiver database, the Humana private insurance population and the Medicare insurance population. The period analyzed was 2010 to 2015.

RESULTS

There was significantly higher utilization of physical rehabilitation in the Humana population when compared to the Medicare population (P<.001, Cramer's V = 0.270). In the Humana population, 36% of patients had 5 or fewer physical rehabilitation visits in the 6 months following their operation, while in the Medicare population, 56% of patients had 5 or fewer physical rehabilitation visits in the same period. Those with TSA had a higher utilization rate than those with RSA in the Humana (P<.001, V = 0.104; TSA, 31% had 5 or fewer physical rehabilitation visits; RSA, 40% had 5 or fewer physical rehabilitation visits within 6 months) and Medicare populations (P<.001, V = 0.135; TSA, 51% had 5 or fewer physical rehabilitation visits; RSA, 61% had 5 or fewer physical rehabilitation visits within 6 months).

CONCLUSION

Postoperative utilization of physical rehabilitation after anatomic TSA and RSA is markedly higher in privately insured patients than in patients with Medicare, regardless of age, sex, diagnosis, or region of country. These findings have important implications, from the individual patient's experience and outcomes to system-wide resource utilization.

LEVEL OF EVIDENCE

Economic and decision analyses, level 4. J Orthop Sports Phys Ther 2018;48(11):856-863. Epub 8 May 2018. doi:10.2519/jospt.2018.8176.

A minimum 20-year outcome of 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon

BACKGROUND:

Ceramic-on-ceramic (CoC) is currently a viable bearing combination in primary total hip arthroplasty (THA) and, due to its mechanical properties, it can be used in young patients requiring a long-lasting implant. The aim of this study is to report the results of a series of CoC THAs at a minimum 20 years follow-up.

METHODS:

A retrospective study was conducted on the 1st 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon on 51 females and 40 males with an average age of 60.7 years. The mean preoperative Harris Hip Score was 35. The press-fit cup consisted of a pure titanium core with a titanium alloy mesh. Both the inlay and the head were made of dense polycrystalline surgical-grade alumina. The 32-mm femoral head was anchored on 3 different femoral components.

RESULTS:

19 patients with 22 THAs were died or lost, 2 anatomic cementless stems were revised due to sinking, 1 THA was revised for periprosthetic infection. 2 patients sustained a Vancouver B1 periprosthetic femoral fracture. None of the 78 THAs eligible for this study were revised for wear, breakage, noise of the ceramic components. None of the cups, none of the cemented stems, none of the cementless straight stems failed. HHS raised up to a mean value of 95.

CONCLUSIONS:

The present report demonstrates that CoC coupling offers minimal wear at a long-term follow-up. Further studies are needed to evaluate whether the modern ceramic composites will confirm such excellent results in total hip replacement.

Deformity correction with total knee arthroplasty for severe knee osteoarthritis accompanying extra-articular femoral deformity: the results are promising

PURPOSE

This study aimed to evaluate patients with severe degenerative osteoarthritis of the knee and extra-articular femoral deformities treated with total knee arthroplasty (TKA) and acute deformity correction.

METHODS

Ten patients with severe degenerative osteoarthritis of the knee and extra-articular femoral deformities were included, and the median age was 63 years (range 38-67). The etiology was post-traumatic malunion in four patients, rickets sequelae in four patients, and surgical sequelae due to multiple epiphyseal dysplasia in two patients. The severity of degenerative osteoarthritis and deformity analyses were assessed according to the Kellgren-Lawrence and Paley criteria, respectively. The median number of previous operations the patients had undergone was two (range 0-3), and the median Oxford Knee Society score was 9 (range 5-13) before treatment. All patients were treated with primary TKA and deformity correction in the same surgery. The TKA was completed first, followed by an osteotomy at the apex of the deformity. Finally, a retrograde intramedullary nail was inserted.

RESULTS

The median follow-up period was 44 (31-60) months. A stable and functional knee joint, a physiological mechanical axis, and solid osseous union were achieved in all patients. Late prosthetic failure was seen in one patient due to deep infection. The median Oxford Knee Society score was 42 (range 37-47) at the final follow-up.

CONCLUSIONS

Combining several procedures in single setting for the treatment of severe knee osteoarthritis accompanied by extra-articular deformity may eliminate the need for multiple surgeries. Furthermore, a proper physiological mechanical axis can be obtained without causing substantial bone loss.

LEVEL OF EVIDENCE

IV.

Cefazolin Prophylaxis for Total Joint Arthroplasty: Obese Patients Are Frequently Underdosed and at Increased Risk of Periprosthetic Joint Infection

BACKGROUND

One of the most effective prophylactic strategies against periprosthetic joint infection (PJI) is administration of perioperative antibiotics. Many orthopedic surgeons are unaware of the weight-based dosing protocol for cefazolin. This study aimed at elucidating what proportion of patients receiving cefazolin prophylaxis are underdosed and whether this increases the risk of PJI.

METHODS

A retrospective study of 17,393 primary total joint arthroplasties receiving cefazolin as perioperative prophylaxis from 2005 to 2017 was performed. Patients were stratified into 2 groups (underdosed and adequately dosed) based on patient weight and antibiotic dosage. Patients who developed PJI within 1 year following index procedure were identified. A bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify risk factors for PJI.

RESULTS

The majority of patients weighing greater than 120 kg (95.9%, 944/984) were underdosed. Underdosed patients had a higher rate of PJI at 1 year compared with adequately dosed patients (1.51% vs 0.86%, P = .002). Patients weighing greater than 120 kg had higher 1-year PJI rate than patients weighing less than 120 kg (3.25% vs 0.83%, P < .001). Patients who were underdosed (odds ratio, 1.665; P = .006) with greater comorbidities (odds ratio, 1.259; P < .001) were more likely to develop PJI at 1 year.

CONCLUSION

Cefazolin underdosing is common, especially for patients weighing more than 120 kg. Our study reports that underdosed patients were more likely to develop PJI. Orthopedic surgeons should pay attention to the weight-based dosing of antibiotics in the perioperative period to avoid increasing risk of PJI.

Total Hip and Knee Arthroplasty in Patients with Multiple Sclerosis

Background

Hip and knee replacements for osteoarthritis are established procedures for improving joint pain and function, yet their safety in patients with multiple sclerosis (MS) is unknown. Patients with MS face unique surgical challenges due to underlying neurologic dysfunction. Current literature on arthroplasty in MS is limited to case reports focusing on adverse events.

Methods

Of 40 identified patients who underwent hip or knee replacement, 30 had sufficient data for inclusion. We reviewed their medical records and recorded reasons for surgery, age at surgery, MS characteristics, surgical complications, and ambulatory aid status before and after surgery. We supplemented medical record review with questionnaires regarding preoperative and postoperative pain and satisfaction with surgical outcomes.

Results

Median follow-up was 26 months. Complications of surgery were reported in ten patients (33%), mostly mild and self-limited, although four patients (13%) required repeated operation. Six patients (20%) reported improvements in ambulatory aid use compared with presurgery baseline, ten (33%) worsened, and 14 (47%) were unchanged. In 20 patients who completed the questionnaire, mean ± SD joint pain scores (on 0-10 scale) decreased from 8.6 ± 2.0 preoperatively to 2.9 ± 2.4 postoperatively (P < .001). Five patients (25%) were free of joint pain at last follow-up.

Conclusions

These results suggest that pain reduction is a realistic outcome of total knee or hip arthroplasty in people with MS and that improved functional gait outcomes are possible in some patients. Prospective, multicenter, collaborative studies are needed to optimize selection and improve outcomes in people with MS considering arthroplasty.

Traumatic anterior dislocation of a prosthetic knee, from trauma to delayed onset of vascular injury

Anterior dislocation of a prosthetic knee is a rare event. Only few episodes have been described in the past and have never been linked with neurovascular injury. This could lead orthopaedic surgeons to focus on the implant instability factors and underrate other complications. The authors report a case of a patient who experienced popliteal artery dissection 80 hours after traumatic anterior knee dislocation of a previously well-functioning total knee arthroplasty. Given that there is a lack of clinical cases that have established guidelines for management of this problem, the authors have focused on the importance of performing computed tomography angiography in the management of an anterior traumatic knee dislocation of a prosthetic knee.

[Advances in total femur replacement]

Objective

To summarize the advances of total femur replacement in recent years.

Methods

The literature related to total femur replacement was reviewed, and the indications, techniques, prosthesis design, complications, rehabilitation, and function were summarized.

Results

The indication of total femur replacement is a wide involvement of the femur, skip lesions and a huge bone defect in revision. Watson-Jone is the main incision in the proximal, and then the full length of the thigh to the patella. Vascular and nerve bundle, abduction muscles are well protected, and combined or costumed prosthesis are replaced. The prosthesis design progresses, showing a diversified prostheses. Complication is frequent and varied. Rehabilitation in early stage is physical therapy, weight training is evolutionary. The main function evaluation system is Musculoskeletal Tumor Society (MSTS) score.

Conclusion

Total femur replacement is effective in limb salvage. Large sample size and long-term follow-up study should be carried out to unify indications and functional exercise standards and reduce postoperative complications.

The cost-effectiveness of dual mobility in a spinal deformity population with high risk of dislocation: a computer-based model

AIMS

The routine use of dual-mobility (DM) acetabular components in total hip arthroplasty (THA) may not be cost-effective, but an increasing number of patients undergoing THA have a coexisting spinal disorder, which increases the risk of postoperative instability, and these patients may benefit from DM articulations. This study seeks to examine the cost-effectiveness of DM components as an alternative to standard articulations in these patients.

PATIENTS AND METHODS

A decision analysis model was used to evaluate the cost-effectiveness of using DM components in patients who would be at high risk for dislocation within one year of THA. Direct and indirect costs of dislocation, incremental costs of using DM components, quality-adjusted life-year (QALY) values, and the probabilities of dislocation were derived from published data. The incremental cost-effectiveness ratio (ICER) was established with a willingness-to-pay threshold of $100 000/QALY. Sensitivity analysis was used to examine the impact of variation.

RESULTS

In the base case, patients with a spinal deformity were modelled to have an 8% probability of dislocation following primary THA based on published clinical ranges. Sensitivity analysis revealed that, at its current average price ($1000), DM is cost-effective if it reduces the probability of dislocation to 0.9%. The threshold cost at which DM ceased being cost-effective was $1180, while the ICER associated with a DM THA was $71 000 per QALY.

CONCLUSION

These results indicate that under specific clinical and economic thresholds, DM components are a cost-effective form of treatment for patients with spinal deformity who are at high risk of dislocation after THA. Cite this article: Bone Joint J 2018;100-B:1297-1302.

Antiseptic Irrigation as an Effective Interventional Strategy for Reducing the Risk of Surgical Site Infections

A surgical site infection (SSI) can occur at several anatomic sites related to a surgical procedure: Superficial or deep incisional or organ/space. The SSIs are the leading cause of health-care-associated infection (HAI) in industrialized Western nations. Patients in whom an SSI develops require longer hospitalization, incur significantly greater treatment costs and reduction in quality of life, and after selective surgical procedures experience higher mortality rates. Effective infection prevention and control requires the concept of the SSI care bundle, which is composed of a defined number of evidence-based interventional strategies, because of the many risk factors that can contribute to the development of an SSI. Intra-operative irrigation has been a mainstay of surgical practice for well over 100 years, but lacks standardization and compelling evidence-based data to validate its efficacy. In an era of antibiotic stewardship, with a widespread prevalence of bacterial resistance to multiple antibiotic agents, there has emerged an interest in using intra-operative antiseptic irrigation to reduce microbial contamination in the surgical site before closure and possibly reduce the need for antibiotic agents. This approach has gained added appeal in an era of biomedical device implantation, especially with the recognition that most, if not all, device-related infections are associated with biofilm formation. This review focuses on the limited, evidence-based rationale for the use of antiseptic agents as an effective risk reduction strategy for prevention of SSIs.

Weighing in on Body Mass Index and Infection After Total Joint Arthroplasty: Is There Evidence for a Body Mass Index Threshold?

BACKGROUND

Although morbid obesity is considered a modifiable risk factor for periprosthetic joint infection (PJI), there is no consensus regarding an appropriate threshold for body mass index (BMI) above which a high risk for infection may outweigh the benefits of surgery.

QUESTIONS/PURPOSES

(1) Is there a BMI cutoff threshold that is associated with increased risk for PJI? (2) Is the risk of PJI increased in higher obesity classes?

METHODS

A retrospective study was conducted of all primary THAs and TKAs performed at one institution between 2006 and 2015. Overall 19,226 patients were eligible to be included in the study; 1053 patients were excluded as a result of incomplete data, resulting in a final cohort of 18,173 patients (8757 TKAs and 9416 THAs). PJI was defined using the International Consensus Meeting criteria. To ensure accurate followup, and because there is evidence to support the association between obesity and early infection, we identified PJI within 90 days of the index surgery. This relationship was examined separately for BMI as a continuous variable and for each BMI category as defined by the Centers for Disease Control and Prevention (underweight ≤ 18.49 kg/m; normal 18.5-24.9 kg/m; overweight 25-29.9 kg/m; obese class I 30-34.9 kg/m; obese class II 35-39.9 kg/m; obese class III ≥ 40 kg/m). Analyses were performed with logistic regression, accounting for both patient and surgical risk factors. A BMI threshold was evaluated with a receiver operating characteristic (ROC) curve and the Youden index.

RESULTS

The area under the ROC curve for BMI and risk of PJI within 90 days was only 0.58 (confidence interval [CI], 0.52-0.63) suggesting such a cutoff was not much better than random chance. Among the BMI classes, patients with class III obesity (≥ 40 kg/m) were the only ones showing a higher risk for PJI within 90 days (odds ratio [OR], 3.09 [1.46-6.54]; p = 0.003). The risk of developing PJI was not greater for overweight (OR, 0.72; 95% CI, 0.38-1.4), class I obese (OR, 1.06; 95% CI, 0.57-2.0), or class II obese (OR, 1.08; 95% CI, 0.52-2.2) patients. Underweight patients also demonstrated no increased risk for PJI (OR, 1.80; 95% CI, 0.23-13.9).

CONCLUSIONS

The risk for infection increases gradually throughout the full range of BMI, but no threshold exists. Weight reduction before surgery may mitigate risk for infection for all patients with a BMI above normal. Of note, patients with a BMI > 40 kg/m carried a threefold higher risk for PJI and for these patients, the risks of surgery must be carefully weighed against its benefits.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Liposomal Bupivacaine Does Not Reduce Inpatient Opioid Prescription or Related Complications after Knee Arthroplasty: A Database Analysis

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

WHAT THIS MANUSCRIPT TELLS US THAT IS NEW: BACKGROUND:: Although some trials suggest benefits of liposomal bupivacaine, data on real-world use and effectiveness is lacking. This study analyzed the impact of liposomal bupivacaine use (regardless of administration route) on inpatient opioid prescription, resource utilization, and opioid-related complications among patients undergoing total knee arthroplasties with a peripheral nerve block. It was hypothesized that liposomal bupivacaine has limited clinical influence on the studied outcomes.

METHODS

The study included data on 88,830 total knee arthroplasties performed with a peripheral nerve block (Premier Healthcare Database 2013 to 2016). Multilevel multivariable regressions measured associations between use of liposomal bupivacaine and (1) inpatient opioid prescription (extracted from billing) and (2) length of stay, cost of hospitalization, as well as opioid-related complications. To reflect the difference between statistical and clinical significance, a relative change of -15% in outcomes was assumed to be clinically important.

RESULTS

Overall, liposomal bupivacaine was used in 21.2% (n = 18,817) of patients that underwent a total knee arthroplasty with a peripheral nerve block. Liposomal bupivacaine use was not associated with a clinically meaningful reduction in inpatient opioid prescription (group median, 253 mg of oral morphine equivalents, adjusted effect -9.3% CI -11.1%, -7.5%; P < 0.0001) and length of stay (group median, 3 days, adjusted effect -8.8% CI -10.1%, -7.5%; P < 0.0001) with no effect on cost of hospitalization. Most importantly, liposomal bupivacaine use was not associated with decreased odds for opioid-related complications.

CONCLUSIONS

Liposomal bupivacaine was not associated with a clinically relevant improvement in inpatient opioid prescription, resource utilization, or opioid-related complications in patients who received modern pain management including a peripheral nerve block.

Pain monitoring and management in a rehabilitation setting after total joint replacement

Total hip replacement (THR) and, particularly, total knee replacement (TKR), are painful surgical procedures. Effective postoperative pain management leads to a better and earlier functional recovery and prevents chronic pain. Studies on the control of pain during the postoperative rehabilitation period are not common. The aim of this study is to present results of a perioperative anesthetic protocol, and a pain treatment protocol in use in the Orthopaedic and the Rehabilitation intensive units of our Hospital. 100 patients (50 THR and 50 TKR) were retrospectively included in this observational study. Numeric Rating Scale (NRS) for pain at rest registered in the clinical sheet was retrieved for all patients and analyzed with respect to the spinal anaesthesia given for the surgery, local analgesia, analgesia protocol adopted during the postoperative days in the Orthopaedic Unit, the antalgic treatment given during the stay within the Rehabilitation Unit, the postoperative consumption of rescue pain medication, and any collateral effect due to the analgesic therapy. Patients reached standard functional abilities (walking at least 50 meters and climbing/descending stairs) at a mean length of 8 days without medication-related complications. Mean NRS during the time of stay was 1.3 ± 0.3 for THR and 1.3 ± 0.2 for TKR) and maximum mean NRS was 1.8 ± 0.5 for TKR and 1.8 ± 0.6 for THR. The use of rescue therapy in the rehabilitation guard was correlated with the mean NRS pain and the maximum NRS pain. A very good control of pain with the perioperative anesthetic protocol and pain treatment protocol in use was obtained.

Time-driven activity-based cost of outpatient total hip and knee arthroplasty in different set-ups

Background and purpose - Length of stay (LOS) following total hip and knee arthroplasty (THA and TKA) has been reduced over the years due to fast-track. Short stays of 2 days in fast-track departments in Denmark have resulted in low total costs of around US$2,550. Outpatient THA and TKA is gaining popularity, albeit in a limited and selected group of patients; however, the financial benefit of outpatient arthroplasty remains unknown. We present baseline detailed economic calculations of outpatient THA and TKA in 2 different settings: one from the hospital and another from the ambulatory surgery department. Patients and methods - Data from 6 patients (1 TKA, 1 uncemented THA, 1 cemented THA in each department) were collected prospectively using the Time Driven Activity Based Costing method (TDABC). Time consumed by different staff members involved in patient treatment in the perioperative period of outpatient THA and TKA was calculated in 2 different settings: one in the orthopedic department and one in the ambulatory surgery department. Results - LOS was around 11 h in the orthopedic department and around 7 h in the ambulatory surgery department, respectively. TDABC revealed minor differences in the operative settings between departments and similar expenses occurred during the short stay of US$777 and US$746, respectively. Adding the preoperative preparation and postoperative follow-up resulted in total cost of US$951 and US$942 for the ward and the ambulatory surgery department, respectively. Interpretation - Outpatient THA and TKA in hospital and ambulatory surgery departments results in similar cost using the TDABC method. Compared with the cost associated with 2-day stays, outpatient procedures are around two-thirds cheaper provided no increase occurs in complications or readmissions.

The Efficacy of Tranexamic Acid in Total Knee Arthroplasty: A Network Meta-Analysis

BACKGROUND

A growing body of published research on tranexamic acid (TXA) suggests that it is effective in reducing blood loss and the risk for transfusion in total knee arthroplasty (TKA). The purpose of this network meta-analysis was to evaluate TXA in primary TKA as the basis for the efficacy recommendations of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Medicine on the use of TXA in primary total joint arthroplasty.

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Reviews, Scopus, and Web of Science databases for publications before July 2017 on TXA in primary total joint arthroplasty. All included studies underwent qualitative and quantitative homogeneity testing. Direct and indirect comparisons were performed as a network meta-analysis, and results were tested for consistency.

RESULTS

After critical appraisal of the available 2113 publications, 67 articles were identified as representing the best available evidence. Topical, intravenous (IV), and oral TXA formulations were all superior to placebo in terms of decreasing blood loss and risk of transfusion, while no formulation was clearly superior. Use of repeat IV and oral TXA dosing and higher doses of IV and topical TXA did not significantly reduce blood loss or risk of transfusion. Preincision administration of IV TXA had inconsistent findings with a reduced risk of transfusion but no effect on volume of blood loss.

CONCLUSIONS

Strong evidence supports the efficacy of TXA to decrease blood loss and the risk of transfusion after primary TKA. No TXA formulation, dosage, or number of doses provided clearly improved blood-sparing properties for TKA. Moderate evidence supports preincision administration of IV TXA to improve efficacy.

The Safety of Tranexamic Acid in Total Joint Arthroplasty: A Direct Meta-Analysis

BACKGROUND

Tranexamic acid (TXA) is effective in reducing blood loss in total joint arthroplasty (TJA), but concerns still remain regarding the drug's safety. The purpose of this direct meta-analysis was to evaluate and establish a basis for the safety recommendations of the combined clinical practice guidelines on the use of TXA in primary TJA.

METHODS

A search was completed for studies published before July 2017 on TXA in primary TJA. We performed qualitative and quantitative homogeneity testing and a direct comparison meta-analysis. We used the American Society of Anesthesiologists (ASA) score of 3 or greater as a proxy for patients at higher risk for complications in general and performed a meta-regression analysis to investigate the influence of comorbidity burden on the risk of arterial thromboembolic event and venous thromboembolic event (VTE).

RESULTS

Topical, intravenous, and oral TXA were not associated with an increased risk of VTE after TJA. In addition, meta-regression demonstrated that TXA use in patients with an ASA status of 3 or greater was not associated with an increased risk of VTE after total knee arthroplasty.

CONCLUSION

Although most studies included in our analysis excluded patients with a history of prior thromboembolic events, our findings support the lack of evidence of harm from TXA administration in patients undergoing TJA. Moderate evidence supports the safety of TXA in patients undergoing total knee arthroplasty with an ASA score of 3 or greater. The benefits of using TXA appear to outweigh the potential risks of thromboembolic events even in patients with a higher comorbidity.

What preoperative factors predict postoperative sitting pelvic position one year following total hip arthroplasty?

Aims

The aims of this study were to measure sagittal standing and sitting lumbar-pelvic-femoral alignment in patients before and following total hip arthroplasty (THA), and to consider what preoperative factors may influence a change in postoperative pelvic position.

Patients and Methods

A total of 161 patients were considered for inclusion. Patients had a mean age of the remaining 61 years (sd 11) with a mean body mass index (BMI) of 28 kg/m2 (sd 6). Of the 161 patients, 82 were male (51%). We excluded 17 patients (11%) with spinal conditions known to affect lumbar mobility as well as the rotational axis of the spine. Standing and sitting spine-to-lower-limb radiographs were taken of the remaining 144 patients before and one year following THA. Spinopelvic alignment measurements, including sacral slope, lumbar lordosis, and pelvic incidence, were measured. These angles were used to calculate lumbar spine flexion and femoroacetabular hip flexion from a standing to sitting position. A radiographic scoring system was used to identify those patients in the series who had lumbar degenerative disc disease (DDD) and compare spinopelvic parameters between those patients with DDD (n = 38) and those who did not (n = 106).

Results

Following THA, patients sat with more anterior pelvic tilt (mean increased sacral slope 18° preoperatively versus 23° postoperatively; p = 0.001) and more lumbar lordosis (mean 28° preoperatively versus 35° postoperatively; p = 0.001). Preoperative change in sacral slope from standing to sitting (p = 0.03) and the absence of DDD (p = 0.001) correlated to an increased change in postoperative sitting pelvic alignment.

Conclusion

Sitting lumbar-pelvic-femoral alignment following THA may be driven by hip arthritis and/or spinal deformity. Patients with DDD and fixed spinopelvic alignment have a predictable pelvic position one year following THA. Patients with normal spines have less predictable postoperative pelvic position, which is likely to be driven by hip stiffness. Cite this article: Bone Joint J 2018;100-B:1289–96.

A Wedge-Shaped Uncemented Femoral Component: Survivorship in Patients Younger Than 50 Years at a Mean Follow-Up of 22 Years

BACKGROUND

This study presents the results of the long-term survival of a wedge-shaped uncemented femoral component in a cohort of young patients with a follow-up of 20-25 years.

METHODS

In a consecutive series of 85 patients (100 hips), aged less than 50 years at the time of primary total hip arthroplasty, the long-term survival of the Cementless Spotorno femoral component was analyzed by performing a Kaplan-Meier survival analysis (95% confidence interval [CI]).

RESULTS

The mean follow-up was 22 years (range, 19.7-25.5). The clinical and radiographic outcomes were satisfactory. The overall survival rate of the femoral component was 93.4% after 23.8 years (95% CI, 85.9%-97.0%). Survival with revision for aseptic loosening as the end point was 94.4% (95% CI, 87.0%-97.6%) after 23.8 years.

CONCLUSION

This study shows an excellent long-term survival of this specific wedge-shaped uncemented femoral component after 20 to 25 years in patients younger than 50 years.

Surgery Before Subspecialty Referral for Periprosthetic Knee Infection Reduces the Likelihood of Infection Control

BACKGROUND

Failure to control a periprosthetic joint infection (PJI) often leads to referral of the patient to a tertiary care institution. However, there are no data regarding the effect of prior surgical intervention for PJI on subsequent infection control.

QUESTIONS/PURPOSES

(1) Is the likelihood of 2-year infection-free survival worse if an initial surgery for PJI was performed before referral to a tertiary care center when compared with after referral for definitive treatment? (2) Is the likelihood of identifying a causal organism during PJI worse if the initial surgery for PJI was performed before referral to a tertiary care center when compared with after referral for definitive treatment? (3) We calculated how many patients are harmed by the practice of surgically attempting to treat PJI before referral to a tertiary care center when compared with treatment after referral to a tertiary care center for definitive treatment.

METHODS

Among 179 patients (182 TKAs) who were referred for PJI between 2004 and 2014, we retrospectively studied 160 patients (163 TKAs) who had a minimum of 2 years of followup after surgical treatment or had failure of treatment within 2 years. Nineteen TKAs (19 patients) were excluded from the study; 13 patients (7%) had < 2-year followup, three patients had infected periprosthetic fractures, and three patients had infected extensor mechanism reconstruction. Eighty-six patients (88 TKAs, two bilateral [54%]) had no surgical treatment before referral to our institution for PJI management, and 75 patients (75 TKAs [46%]) had PJI surgery before referral. The mean followup was 2.4 ± 1.2 years for patients with PJI surgery before referral and 2.8 ± 1.3 years for patients with no surgery before referral (p = 0.065). Infection-free survival was defined as prosthesis retention without further surgical intervention or antibiotic suppression. During the period, further surgical intervention generally was performed after failure of irrigation and débridement, a one- or two-stage procedure, or between stages of a two-stage reimplantation without documentation of an eradiated infection, and antibiotic suppression generally was used when patients were not medically sound for surgical intervention or definitive implants were placed after the second of a two-stage procedure with positive cultures; these criteria were applied similarly to all patients during this time period in both study groups. Endpoints were assessed using a longitudinally maintained institutional database, and the treating surgeons were not involved in data abstraction. Relative and absolute risk reductions with 95% confidence intervals (CIs) as well as a Kaplan-Meier survival curve with a Cox proportional hazard model were used to evaluate survival adjusting for significant covariates. The number needed to harm is calculated as the number needed to treat. It is the reciprocal of the absolute risk reduction or production by an intervention.

RESULTS

The cumulative infection-free survival rate of TKAs at 2 years or longer was worse when PJI surgery was performed before referral to a tertiary center (80%; 95% CI, 69%-87%) compared with when no PJI surgery was performed before referral (94%; 95% CI, 87%-98%; log-rank test p = 0.006). Additionally, PJI surgery before referral resulted in a lower likelihood of causative microorganism identification (52 of 75 [69%]) compared with patients having surgery at the tertiary center (77 of 88 [88%]; odds ratio, 2.71; 95% CI, 1.28-4.70; p = 0.006). With regard to the infection-free survival rate of TKAs, the number needed to harm was 7.0 (95% CI, 4.1-22.5), meaning the referral of less than seven patients to a tertiary care center for definitive surgical management of PJI before intervention at the referring hospital prevents one infection-related failure. With regard to the culture negativity in PJI, the number needed to harm was 5.5 (95% CI, 3.3-16.7), meaning the referral of less than six patients to a tertiary care institution for PJI before surgery at the outside hospital prevents the diagnosis of one culture-negative infection.

CONCLUSIONS

Surgical treatment of a PJI before referral for subspecialty surgical management increases the risk of failure of subsequent surgical management. The prevalence of culture-negative PJI was much higher if surgery was attempted before referral to a tertiary care center when compared with referral before treatment. This suggests that surgical treatment of PJI before referral to a treating center with specialized expertise in PJI compromises the infection-free survival and impacts infecting organism isolation.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does Surgeon Volume Affect Outcomes Following Primary Total Hip Arthroplasty? A Systematic Review

BACKGROUND

Surgeon volume has been identified as an important factor impacting postoperative outcome in patients undergoing orthopedic surgeries. With an absence of a detailed systematic review, we sought to collate evidence on the impact of surgeon volume on postoperative outcomes in patients undergoing primary total hip arthroplasty.

METHODS

PubMed (MEDLINE) and Google Scholar databases were queried for articles using the following search criteria: ("Surgeon Volume" OR "Provider Volume" OR "Volume Outcome") AND ("THA" OR "Total hip replacement" OR "THR" OR "Total hip arthroplasty"). Studies investigating total hip arthroplasty being performed for malignancy or hip fractures were excluded from the review. Twenty-eight studies were included in the final review. All studies underwent a quality appraisal using the GRADE tool. The systematic review was performed in accordance with the PRISMA guidelines.

RESULTS

Increasing surgeon volume was associated with a shorter length of stay, lower costs, and lower dislocation rates. Studies showed a significant association between an increasing surgeon volume and higher odds of early-term and midterm survivorship, but not long-term survivorships. Although complications were reported and recorded differently in studies, there was a general trend toward a lower postoperative morbidity with regard to complications following surgeries by a high-volume surgeon.

CONCLUSION

This systematic review shows evidence of a trend toward better postoperative outcomes with high-volume surgeons. Future prospective studies are needed to better determine long-term postoperative outcomes such as survivorship before healthcare policies such as regionalization and/or equal-access healthcare systems can be considered.

Cutaneous Hypesthesia and Kneeling Ability After Total Knee Arthroplasty: A Randomized Controlled Trial Comparing Anterolateral and Anteromedial Skin Incision

BACKGROUND

Anterolateral skin incision can preserve the skin sensory of the anterior aspect of the knee and may improve kneeling ability after total knee arthroplasty (TKA).

METHODS

This is a prospective, 2-arm, parallel-group, randomized, controlled trial involving patients scheduled for TKA. A total of 118 patients (162 knees) were randomly assigned to receive anterolateral skin incision or anteromedial skin incision with 1:1 treatment allocation. The surgical techniques other than skin incision were identical in both groups. The area of cutaneous hypesthesia was measured by a nonblinded assessor, and kneeling ability was evaluated by 2 blinded assessors at 12 months after surgery.

RESULTS

The area of cutaneous hypesthesia was significantly smaller in the anterolateral skin incision group than the anteromedial skin incision group (3.0 ± 8.7 cm² vs 10.6 ± 18.6 cm²; 95% confidence interval, 2.8-12.3 cm²; P = .0019). The rates of patients judged to be able to kneel were significantly higher in the anterolateral skin incision group by both assessors (81% vs 60%; P = .025 and 81% vs 59%; P = .015, respectively) with almost perfect agreement between the 2 assessors (kappa value = 0.94). There were no significant differences in terms of complication rate, including wound complications, between the 2 groups (P > .05).

CONCLUSION

Compared with anteromedial skin incision, anterolateral skin incision may provide less cutaneous hypesthesia and better kneeling ability after TKA without increasing complication rate.

Differential toxicity of processed and non-processed states of CoCrMo degradation products generated from a hip simulator on neural cells

Physico-chemical characteristics of the CoCrMo degradation products have played an important role in cytotoxicity and clinical complications on the orthopedic patients who have metal implants. Previous studies have limited reflection on the physicochemical characteristics of the degradation products generated in vivo, which are very different from individual metal particles and/or ions obtained from different commercial sources. In this study, we aimed to understand the differences in toxicity induced by the degradation products in as-synthesized form as well as those obtained after post-processing. The degradation products were generated using a hip-simulator by maintaining physiological conditions closer to in vivo and separated into two batches, one with processing by washing and drying called processed degradation products (PDP) and another batch as 'as-synthesized' degradation product (DP). We studied the dose-dependent toxicity response by neural cells derived from induced pluripotent stem cells. The results of the study show that as-synthesized DPs are more toxic to neural cells even at lower concentrations studied with evident low TC50 (1-5 μg/ml) concentrations compared to PDP (25 μg/ml). Flow cytometric analysis showed a significant (p<.01) increase in uptake of the particles after 24 h and corresponding ROS production in DP-treated cells. RT-PCR analysis of oxidative specific gene expression showed, elevated mRNA levels of NADPH oxidase-1, nuclear transcription factor, superoxide dismutase-2 and glutaredoxin-2 in DP-treated cells after 6 h. The results of the study provided a clear evidence of the differential response of neural cells on the degradation products as a function of concentrations and their chemical nature.

Blood management in total knee arthroplasty: state-of-the-art review

Total blood loss from primary total knee arthroplasty may exceed 2 L with greater blood loss during revision procedures. Blood loss and allogeneic transfusion are strongly associated with adverse outcomes from surgery including postoperative mortality, thromboembolic events and infection. Strategies to reduce blood loss and transfusion rates improve patient outcomes and reduce healthcare costs. Interventions are employed preoperatively, intraoperatively and postoperatively. The strongest predictor for allogeneic blood transfusion is preoperative anaemia. Over 35% of patients are anaemic when scheduled for primary and revision knee arthroplasty, defined as haemoglobin <130 g/L for men and women, and the majority of cases are secondary to iron deficiency. Early identification and treatment of anaemia can reduce postoperative transfusions and complications. Anticoagulation must be carefully managed perioperatively to balance the risk of thromboembolic event versus the risk of haemorrhage. Intraoperatively, tranexamic acid reduces blood loss and is recommended for all knee arthroplasty surgery; however, the optimal route, dose or timing of administration remains uncertain. Cell salvage is a valuable adjunct to surgery with significant expected blood loss, such as revision knee arthroplasty. Autologous blood donation is not recommended in routine care, sealants may be beneficial in select cases but further evidence of benefit is required, and the use of a tourniquet remains at the discretion of the surgeon. Postoperatively, restrictive transfusion protocols should be followed with a transfusion threshold haemoglobin of 70 g/L, except in the presence of acute coronary syndrome. Recent studies report no allogeneic transfusions after primary knee arthroplasty surgery after employing blood conservation strategies. The current challenge is to select and integrate different blood conserving interventions to deliver an optimal patient pathway with a multidisciplinary approach.

Rapid Complete Acetabular Destruction in Metal-on-Metal Total Hip Arthroplasty

Adverse local tissue reaction, osteolysis, and subsequent increased incidence of failure have been associated with metal-on-metal (MoM) total hip arthroplasty (THA). We present the case of a 68-year-old woman with rheumatoid arthritis who has undergone left THA with a MoM bearing. Seven years postoperatively, she presented with 6 weeks of severe left hip pain. Sequential radiographs and advanced imaging demonstrated a rapid onset of extensive acetabular osteolysis with pelvic discontinuity and pseudotumor formation. She underwent revision THA using a cup-cage construct with a satisfactory outcome. In this article, we review current evidence-based management options for pelvic discontinuity, as well as other complications related to MoM THA.

Fracture of an S-ROM stem at the sleeve-stem junction

Fracture of a well-ingrown femoral component is a rare and often challenging complication. Modular junctions and sleeve interfaces have been identified as one potential point of weakness with corrosion and fretting being contributing factors to ultimate femoral component fracture. Stem fractures at the sleeve interface were reported occasionally for the proximal ingrowth modular Emperion System (Smith and Nephew, Memphis, TN). However, this failure mechanism has been reported infrequently, often associated with corrosion at the modular junction, for the similarly designed S-ROM system (DePuy Orthopedics Inc., Warsaw, IN). We present the case of a 52-year-old patient, with a body weight of 84 kg (185 lbs) and a body mass index of 30.6 kg/m², who suffered a fatigue fracture of a 14 × 09 × 130 mm S-ROM stem 42 months after implantation. The present study presents the results of the surface analysis, discusses possible failure mechanisms, provides treatment guidelines, and a review of the literature revealing 15 cases of failure at the level of the stem-sleeve junction. In particular, modifiable risk factors for potential stem failure, including stem diameter, stem offset, and the resulting cantilever bending forces on the proximal sleeve-stem junction, are discussed in detail.

Health professionals' perceptions of the allied health role in the acute setting following hip and knee joint replacement surgery: a qualitative study

Purpose: To describe health professionals' perceptions of the role of allied health during the acute phase following elective lower limb joint replacement surgery to inform the development of efficient allied health service models.Methods: This was a qualitative descriptive study conducted using semi-structured focus groups and thematic analysis. Participants were 25 medical, nursing, and allied health professionals working on two orthopaedic wards in a tertiary hospital in Victoria, Australia. Focus groups elicited staff perceptions regarding the aims and roles of acute allied health intervention following hip and knee replacement, how these services are currently provided, and how these services can best be provided. This study was undertaken alongside two stepped wedge cluster randomised controlled trials during which existing weekend allied health services were to be temporarily removed with opportunity to contribute to a stakeholder-driven model of these services.Results: The main theme that emerged was a sense of unrealised potential amongst health professionals in terms of patient outcomes following hip and knee joint replacement surgery arising from tension between perceptions of actual versus ideal allied health practice. Assessing function and planning for discharge accordingly was perceived to be a higher priority than intervening to improve functional independence.Conclusion: Prioritising allied health intervention to low functioning and complex patients could be a more efficient use of allied health expertise in patients following lower limb replacement surgery than current practice in this setting that prioritises discharge.Implications for RehabilitationAllied health service delivery in the acute phase following hip and knee joint replacement needs to balance the needs of the health service with those of the patients.Prioritising allied health intervention to low functioning and complex patients could be a more efficient use of allied health expertise in this population than current practice, which is to prioritise discharge.There may be more scope for nurses to be involved in promoting early postoperative mobilisation following joint replacement surgery, especially in uncomplicated cases.

New Innovations in the Treatment of PJI and Biofilms-Clinical and Preclinical Topics

PURPOSE OF REVIEW

Periprosthetic joint infection (PJI) is a devastating complication after total joint replacement. A main source for antibiotic tolerance and treatment failure is bacterial production of biofilm-a resilient barrier against antibiotics, immune system, and mechanical debridement. The purpose of this review is to explore some novel approaches to treat PJI and biofilm-related infections.

RECENT FINDINGS

Innovative treatment strategies of bacterial and biofilm infections revolve around (a) augmenting current therapies, such as improving the delivery and efficiency of conventional antibiotics and enhancing the efficacy of antiseptics and (b) administrating completely new therapeutic modalities, such as using immunotherapy, nanoparticles, lytic bacteriophages, photodynamic therapy, novel antibiotics, and antimicrobial peptides. Several promising treatment strategies for PJI are available to be tested further. The next requirement for most of the novel treatments is reproducing their effects in clinically representative animal models of PJI against clinical isolates of relevant bacteria.

Timed Up and Go test is predictive of Patient-Reported Outcomes Measurement Information System physical function in patients awaiting total knee arthroplasty

Background

The Patient Reported Outcomes Measurement Information System (PROMIS) Computerized Adaptive Test (CAT) physical function rapidly assesses self-reported function capability. The Timed Up and Go (TUG) test is often used in clinical practice, but administration may be impeded by space and patient limitations. PROMIS CAT can potentially address these limitations, but we lack evidence if TUG and health indicators are predictors of PROMIS CAT. This study assessed whether TUG, body mass index (BMI), numeric pain rating scale (NPRS), and smoking status were predictors of PROMIS CAT in total knee arthroplasty (TKA) candidates.

Methods

Sixty-five TKA candidates completed the PROMIS CAT physical function test using an iPad application. TUG, NPRS, BMI, and smoking status were obtained at the clinic visit or from medical records. Univariate and multiple regression analyses identified the strongest predictors of PROMIS CAT.

Results

TUG was the best predictor of PROMIS CAT physical function based on simple regression (r = −0.43, 95% CI = −0.62 to −0.20) or multiple regression (βˆ = −0.45, 95% CI = −0.73 to −0.17) analyses. BMI and NPRS did not incrementally help predict the PROMIS score beyond TUG. Smoking status did not contribute to the prediction of the PROMIS CAT score.

Conclusions

The findings suggest that the PROMIS CAT physical function is not a surrogate for the TUG performance-based measure in candidates for TKA. However, TUG was the best predictor of PROMIS physical function compared with BMI, NPRS, and smoking status. Clinicians should consider both patient-reported and performance-based measures when evaluating function for TKA outcomes.

Cementless Total Knee Arthroplasty: A Comprehensive Review of the Literature

This review evaluated (1) original and newer cementless implants; (2) outcomes of newer designs; (3) risks and benefits; and (4) newer cementless vs cemented total knee arthroplasties. A search for all reports on cementless total knee arthroplasties published from January 2010 to April 2017 was performed, and 31 studies were included for final analysis. Newer cementless total knee arthroplasty designs have shown excellent survivorship, functional outcomes, and satisfaction rates in both young and elderly populations. Compared with cement fixation, there may be potential benefits with the newer cementless implants. However, these findings need to be further substantiated with additional studies reporting longer-term results. [Orthopedics. 2018; 41(5):263-273.].

Implant Survival and Patient-Reported Outcomes After Total Hip Arthroplasty in Young Patients

BACKGROUND

Younger patients are undergoing total hip arthroplasty (THA) for various conditions that affect the hip joint. This study evaluates the implant survival and long-term patient-reported outcomes of THA in patients aged 35 years or younger.

METHODS

Data were collected through a retrospective chart review, and follow-up surveys were conducted to determine implant survival and patient-reported outcomes. Kaplan-Meier survival analysis was performed to evaluate implant survival, and the hip disability and osteoarthritis outcome score (HOOS) was used to describe patient-reported outcomes. Descriptive statistics were used to summarize baseline and follow-up data, and univariate and multivariate analyses were used to compare implant survival and patient-reported outcomes.

RESULTS

This study included 400 patients (548 THAs). The average age at the time of surgery was 27 (range: 8-35) years, and the mean time to follow-up was 14 (range: 2-29.7) years. The 10- and 20-year implant survival was 87% and 61%, respectively. Implant survival differed based on primary diagnosis (P = .05), and it was significantly better in patients aged 25 years or older at the time of surgery, male patients, and patients with ceramic-on-ceramic or ceramic-on-plastic implants (P < .05). Mean HOOS scores at follow-up were 86 for pain, 84 for symptoms, 86 for ADLs, and 77 for sports. All HOOS scores were significantly worse after revision THA (P < .01).

CONCLUSION

Young patients have good implant survival and favorable long-term outcomes after THA. There are several predictors of implant survival and patient-reported outcomes after THA in young patients.

Enhanced Recovery After Shoulder Arthroplasty

Enhanced recovery after surgery (ERAS) protocols depend on multidisciplinary care and should be peer-reviewed and data-driven. ERAS has reduced hospital length of stay and complications, simultaneously improving patient outcomes. ERAS protocol after shoulder arthroplasty features multidisciplinary collaboration among different perioperative services and multimodal analgesia with a focus on regional anesthesia. Despite success, adoption is not universal because ERAS protocols are resource intensive. They require clinicians invested in the success of these programs and patients who can take charge of their own health. Future protocols need to include quality of life and functional outcome measures to gauge success from the patient perspective.

Postdischarge Unscheduled Care Burden After Lower Limb Arthroplasty

BACKGROUND

In contrast to postdischarge arthroplasty readmission rates, the unscheduled reattendance burden to primary care is under-reported. Understanding reasons for reattendance would allow for implementation of strategies to reduce this burden. The present study aims to quantify the out-of-hours (OOH) general practitioner and emergency department (ED) service reattendance burden and readmission rate after primary total hip arthroplasty and total knee arthroplasty, with estimation of the associated costs.

METHODS

This is a prospective consecutive cohort study. A prospective audit of all total hip arthroplasty and total knee arthroplasty patients in 2016 in a single high-volume UK arthroplasty unit was performed. Incidence and reasons for reattendance to OOH and ED service, as well as readmission rates, at both 30 and 90 days following discharge are reported. A multivariate analysis was performed to determine patient characteristics, which results in increased reattendance and readmission rates.

RESULTS

A total of 2351 procedures resulted in 374 attendances of OOH service and 665 to ED with a total estimated cost of £190,000 within 90 days. The readmission rate was 6.8%. Risk factors for reattendance and readmission were increasing age and a prolonged length of stay. The use of a 5-day postdischarge phone call and a dedicated Arthroplasty Care Practitioner favors reduced reattendances but not the readmission rate, with the additional benefit of being cost-effective.

CONCLUSION

The postdischarge arthroplasty reattendance burden is associated with significant costs, and strategies to reduce this should be developed. Further research is required to assess the effectiveness and cost-effectiveness of multicomponent strategies to reduce reattendance operating at scale.

Dislocation of the Hip: A Review of Types, Causes, and Treatment

Background

Dislocation of the hip is a well-described event that occurs in conjunction with high-energy trauma or postoperatively after total hip replacement.

Methods

In this review, the types, causes, and treatment modalities of hip dislocation are discussed and illustrated, with particular emphasis on the assessment, treatment, and complications of dislocations following total hip replacement.

Results

Hip dislocations are commonly classified according to the direction of dislocation of the femoral head, either anterior or posterior, and are treated with specific techniques for reduction. Generally, closed reduction is the initial treatment method, usually occurring in the emergency room. Bigelow first described closed treatment of a dislocated hip in 1870, and since then many reduction techniques have been proposed. Each method has unique advantages and disadvantages. Anterior hip dislocation is commonly reduced by inline traction and external rotation, with an assistant pushing on the femoral head or pulling the femur laterally to assist reduction. Posterior hip dislocations are the most common type and are reduced by placing longitudinal traction with internal rotation on the hip.

Conclusion

Patients with hip dislocations must receive careful diagnostic workup, and the treating physician must be well versed in the different ways to treat the injury and possible complications. Timely evaluation and treatment, including recognizing the potential complications, are necessary to offer the best outcome for the patient.

Primary Hip and Knee Arthroplasty in a Safety Net Hospital: Substance Abuse and Other Factors Affecting Short-term Complications

BACKGROUND

Arthroplasty outcomes and patient risk factors have not been studied in detail in safety net hospital settings. This study examines the relationship between selected risk factors and short-term complications in such a population, including a large subgroup with treated substance abuse.

METHODS

This retrospective cohort study contains 486 consecutive patients after primary hip and knee arthroplasty. One hundred three of these had a history of substance abuse and completed a 1-year sobriety pathway preoperatively. Primary outcomes included the presence of any complication, deep infection, and reoperation. Bivariable analyses were used to compare outcomes with demographic and health risk factors. A multivariate analysis was performed to identify independent risk factors.

RESULTS

Adverse outcomes were more common in patients with higher rates of substance abuse, mental illness, and infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). Substance abuse alone was not an independent risk factor for the occurrence of complications, but infections with HIV and HCV were. In the substance abuse subgroup, with its higher prevalence of risk factors, complications were more frequent (31.1% vs 16.4%, P = .0009), and, in particular, deep infections (5.8% vs 1.8%, P = .0256).

CONCLUSIONS

Specific risk factors were associated with short-term complications in safety net arthroplasty patients. Despite having completed a preoperative sobriety pathway, substance abuse patients had more complications than did others. However, substance abuse alone was not an independent risk factor for adverse surgical outcomes. Other factors, notably HCV and HIV infection that were more common in patients with substance abuse, were most closely associated with adverse outcomes.

Intraoperative Considerations for Treatment/Prevention of Prosthetic Joint Infection

PURPOSE OF REVIEW

Innovative measures have recently been proposed to prevent periprosthetic joint infection following total hip and knee arthroplasty. We sought to review these recent innovations to determine the reported reduction in periprosthetic joint infection.

RECENT FINDINGS

The most recent literature demonstrates promising results in regard to hydrofiber dressings as an independent risk factor for primary prosthetic joint infection reduction, which in turn is also linked with cost savings. As our understanding of safe yet effective concentrations of antiseptic solutions develops, dilute betadine in particular has demonstrated encouraging efficacy which warrants continued investigation through controlled trials. In summary, we found that the application of a hydrofiber dressing may prove beneficial in decreasing the risk of prosthetic joint infection following primary total hip and knee arthroplasty. The gold standard for an infection prevention protocol continues to be explored and optimized.

Two-Stage Revision Arthroplasty for the Treatment of Prosthetic Joint Infection

PURPOSE OF REVIEW

To review the diagnosis and treatment of prosthetic joint infection (PJI) with a focus on two-stage revision arthroplasty. The text will discuss different spacer constructs in total knee and total hip arthroplasty and will present clinical outcome data for these various options.

RECENT FINDINGS

There is no appreciable difference in infection eradication between mobile and static antibiotic spacers. Mobile spacers have shown improved knee range of motion after second-stage re-implantation. Two-stage revision arthroplasty is the gold standard treatment for PJI. The first stage involves removal of all components, cement, and compromised soft tissues with placement of an antibiotic-impregnated spacer. Spacer options include both mobile and static spacers. Mobile spacers offer maintenance of ambulation and joint range of motion between staged procedures and have shown to be as effective in eradicating infection as static spacers.