Faculty Bibliography

The number of total knee arthroplasties performed in the United States is growing, and a leading cause of failure is postoperative knee instability from suboptimal coronal or sagittal balancing. This article reviews native knee anatomy as well as several guiding principles of total knee arthroplasty such as limb axis, femoral referencing, and implant constraint. Next, techniques that can be used by the surgeon to achieve ideal sagittal balance and coronal balance are discussed in detail. Finally, due to the growing use of computer and robotic technologies in knee replacement, the impact of advanced technologies on total knee arthroplasty balancing and alignment is reviewed. An in-depth understanding of these topics will enable surgeons to optimize the outcome of their total knee arthroplasty patients.

AIMS/OBJECTIVE:non-anterior (NA) surgical approaches on prosthetic joint infection (PJI), and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution. PATIENTS AND METHODS/METHODS:(13.3 to 57.6, sd 6.1), respectively. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios (ORs) for risk of development of PJI with DA compared with NA approaches. In order to determine the effect of adopting a set of infection prevention protocols on PJI, we calculated ORs for PJI comparing patients undergoing THA for two distinct time periods: 2013 to 2014 and 2015 to 2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols. RESULTS:There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJIs in the DA group (1.22%) and 26 deep PJIs in the NA group (0.63%; p = 0.023). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (OR 2.2 (95% confidence interval 1.1 to 3.9); p = 0.006) for the overall study period. CONCLUSION/CONCLUSIONS:2019;101-B(6 Supple B):2-8.

AIMS/OBJECTIVE:Studying the indications for revision total hip arthroplasty (THA) may enable surgeons to change their practice during the initial procedure, thereby reducing the need for revision surgery. The aim of this study was to identify and describe the potentially avoidable indications for revision THA within five years of the initial procedure. PATIENTS AND METHODS/METHODS:A retrospective review of 117 patients (73 women, 44 men; mean age 61.5 years (27 to 88)) who met the inclusion criteria was conducted. Three adult reconstruction surgeons independently reviewed the radiographs and medical records, and they classified the revision THAs into two categories: potentially avoidable and unavoidable. Baseline demographics, perioperative details, and quality outcomes up to the last follow-up were recorded. RESULTS:A total of 60 revision THAs (51.3%) were deemed potentially avoidable and 57 (48.7%) were deemed unavoidable. The following were identified as avoidable factors: suboptimal positioning of the acetabular component (29; 48%), intraoperative fracture or a fracture missed on an intraoperative radiograph (20; 33%), early (less than two weeks) aseptic loosening (seven; 11.7%), and symptomatic leg length discrepancy of > 1 cm (four; 6.7%). CONCLUSION/CONCLUSIONS:2019;101-B(6 Supple B):97-103.

Two-stage exchange is most commonly used for treatment of prosthetic joint infections (PJI) but, this may fail to eradicate infections. C-reactive protein/albumin ratio (CAR) has been used to predict survival and operative success in other surgical subspecialties and so, we assess the association between CAR and reimplantation success during two-stage revision for PJI defined by the Musculoskeletal Infection Society following a primary total hip (THA) or knee (TKA) arthroplasty. From January, 2005 to December, 2015, two institutional databases were queried and patient demographics, antibiotic duration, C-reactive protein, and albumin were collected prior to reimplantation. Two-stage revisions were considered successful if patients were off of antibiotics and did not require a repeat surgery. CAR was available for 79 patients (34 hips and 46 knees) with 61 successful two-stage revisions and 18 failures. The average CAR for patients with successful reimplantation was 1.2 (0.2, 3.0) compared to 1.0 (0.4, 3.2) for treatment failure. However, this was not statistically significant (p=0.766). Therefore, CAR is not applicable in predicting the prognosis of two-stage revisions for PJI in total arthroplasty but other preoperative inflammatory-based prognostic scores should be explored.

AIMS/OBJECTIVE:A variety of surgical approaches are used for total hip arthroplasty (THA), all with reported advantages and disadvantages. A number of common complications can occur following THA regardless of the approach used. The purpose of this study was to compare five commonly used surgical approaches with respect to the incidence of surgery-related complications. PATIENTS AND METHODS/METHODS:-tests where appropriate and proportions were compared using the chi-squared test. RESULTS:A total of 248 patients had 263 complications related to the surgery, with an incidence of 6.94%. The anterior approach had the highest incidence of complications (8.5% (113/1329)) and the posterior approach had the lowest, at 5.85% (97/1657; p = 0.006). Most complications were due to deep infection (22.8%), periprosthetic fracture (22.4%), and prolonged wound drainage (21.3%). The rate of dislocation was 0.84% (14/1657) with the posterior approach and 1.28% (17/1329) with the anterior approach (p = 0.32). CONCLUSION/CONCLUSIONS:2019;101-B:646-651.

AIMS/OBJECTIVE:With an ageing population of patients who are infected with hepatitis C virus (HCV), the demand for total knee arthroplasty (TKA) in this high-risk group continues to grow. It has previously been shown that HCV infection predisposes to poor outcomes following TKA. However, there is little information about the outcome of TKA in patients with HCV who have been treated successfully. The purpose of this study was to compare the outcomes of TKA in untreated HCV patients and those with HCV who have been successfully treated and have a serologically confirmed remission. PATIENTS AND METHODS/METHODS:A retrospective review of all patients diagnosed with HCV who underwent primary TKA between November 2011 and April 2018 was conducted. HCV patients were divided into two groups: 1) those whose HCV was cured (HCV-C); and 2) those in whom it was untreated (HCV-UT). All variables including demographics, HCV infection characteristics, surgical details, and postoperative medical and surgical outcomes were evaluated. There were 64 patients (70 TKAs) in the HCV-C group and 63 patients (71 TKAs) in the HCV-UT cohort. The mean age at the time of surgery was 63.0 years (sd 7.5; 44 to 79) in the HCV-C group and 61.7 years (sd 6.9; 47 to 88) in the HCV-UT group. RESULTS:1.4%; p < 0.01) than HCV-C patients. CONCLUSION/CONCLUSIONS:2019;101-B:667-674.

AIMS:Revision total knee arthroplasty (rTKA) accounts for approximately 5% to 10% of all TKAs. Although the complexity of these procedures is well recognized, few investigators have evaluated the cost and value-added with the implementation of a dedicated revision arthroplasty service. The aim of the present study is to compare and contrast surgeon productivity in several differing models of activity. MATERIALS AND METHODS:rTKA with a single OT; and 3) primary TKA with two OTs versus rTKA with a single OT. RESULTS:In total, 4570 procedures were performed: 4128 primary TKAs, 51 TKA liner exchanges, and 391 full rTKAs. Surgical time was significantly different between the primary TKA, liner exchange, and rTKA cohorts (100.6, 97.1, and 141.7 minutes, respectively; p < 0.001). Primary TKA yielded a mean of 7.1% more RVU/min per procedure than rTKA. Our one-OT model demonstrated that primary TKA (n = 4) had a 1.9% RVU/day advantage over rTKA (n = 3). If two OTs are used for primary TKA (n = 6), the outcome strongly favours primary TKA by an added 34.6% RVUs/day. CONCLUSION:Our results suggest that a dedicated rTKA service would lead to lower surgeon remuneration based on the current RVU paradigm. Revision arthroplasty specialists may need additional or alternative incentives to promote the development of a dedicated revision service. Through such an approach, healthcare organizations could enhance the quality of care provided, but surgeon productivity measures would need to be adjusted to reflect the burden of these cases. Cite this article: Bone Joint J 2019;101-B:675-681.

BACKGROUND:The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) is a nationally standardized tool to assess patient experience between hospitals. The HCAHPS survey can affect hospital reimbursement. This study aims to determine if HCAHPS scores vary by a number of demographic variables in patients undergoing primary total knee arthroplasty (TKA). METHODS:Patients who underwent primary TKA and returned a completed HCAHPS survey were included in this study. HCAHPS surveys were collected from our institution's Center for Quality and Patient Safety department, which was cross-referenced with our hospital's electronic data warehouse. Patient demographics, surgical factors, and quality outcomes were queried, and multivariable linear regression was performed. RESULTS:. Sixty-nine percent of the patients (1287 patients) were discharged home versus 10.3% (106 patients) to another facility. Mean length of stay was 2.9 ± 1.4 days. Age was correlated with a 0.3% decrease in top-box response rate (P < .01) for each 1-year increase in age. Compared to Caucasian race, African American race was correlated with a 5.6% increased rate for top-box response (P < .01), while Asian race (P = .42) and unknown race (P = 1.00) demonstrated no significant difference. Marital status demonstrated that divorced/separated status resulted in a significant 5.4% decrease in top-box response rates (P < .05). Similarly, single (P = .12) and widowed (P = .09) statuses also demonstrated a trend toward lower top-box response rates when compared to married or partnered patients. For each day increase in length of stay, HCAHPS top-box response rates decrease by 1.6% (P < .01). Gender, body mass index, smoking status, insurance type, and discharge disposition were not found to be significantly correlated with HCHAPS top-box response rate (P > .05). CONCLUSION/CONCLUSIONS:HCAHPS scores in patients undergoing primary TKA are influenced not just by hospital and surgeon factors such as length of stay but by demographic variables such as age, race, and marital status. As surgeons become more involved with the burden of improving patient experience, they should be aware that static demographic variables can have a significant effect on HCAHPS scores.

Arthrofibrosis is the pathologic stiffening of a joint caused by an exaggerated inflammatory response. As a common complication following total knee arthroplasty (TKA), this benign-appearing connective tissue hyperplasia can cause significant disability among patients because the concomitant knee pain and restricted range of motion severely hinder postoperative rehabilitation, clinical outcomes, and basic activities of daily living. The most effective management for arthrofibrosis in the setting of TKA is prevention, including preoperative patient education programs, aggressive postoperative physical therapy regimens, and anti-inflammatory medications. Operative treatments include manipulation under anesthesia, arthroscopic debridement, and quadricepsplasty.