The Empty Ischial Fossa Sign: A Visual Representation of Relative Inadequate Anteversion in the Posteriorly Tilted Pelvis.

Background: Instability is a known complication following total hip arthroplasty (THA) and is influenced by spinopelvic alignment. Radiographic markers have been investigated to optimize the acetabular cup position. This study evaluated if the empty ischial fossa (EIF) sign and the position of the trans-teardrop line were predictive of postoperative instability. Methods: All patients who underwent THA from 2011 to 2018 at a single institution were retrospectively reviewed. Pelvic tilt was measured using a trans-teardrop line compared to the superior aspect of the pubic symphysis on standing anteroposterior pelvis radiographs. Postoperative dislocations were identified through chart review and radiographic review. The EIF sign was determined by the presence of uncovered bone below the posterior inferior edge of the acetabular component at the level of the native ischium and posterior wall on standing postoperative anteroposterior radiographs. Results: One thousand seven hundred fifty patients (952 anterior approach and 798 posterior approach) were included. The EIF sign was present in 458 patients (26.2%) and associated with an increased dislocation rate (3.9% vs 0.9%, P < .0001). Patients with spondylosis/instrumented fusion, and positive EIF sign had a dislocation risk of 5.1% vs 1.3% (P = .001). A postoperative outlet pelvis was not significant for increased dislocation risk (odds ratio 2.16, P = .058). Patients with combined spondylosis/fusion, posterior approach, outlet pelvis, and EIF sign had a dislocation rate of 14.5%. Conclusions: The EIF sign was an independent risk factor for postoperative instability and may represent failure to account for pelvic tilt. Avoidance of the EIF sign during cup positioning may help reduce dislocations following THA.

A Novel Method to Calculate Functional Pelvic Tilt Using a Standing Anteroposterior Pelvis Radiograph.

Background: Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT. Methods: A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT. Results: There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r = 0.785, r2 = 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r = 0.864, r2 = 0.747, P < .001). Using regression analysis, a linear equation was created (PT = 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio. Conclusions: There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component.

Anterior-Based Approaches to Total Hip Arthroplasty: Beyond the Learning Curve.

BACKGROUND: Anterior-based approaches for total hip arthroplasty (THA) have gained popularity over the last decade. At our institution, anterior-based approaches are preferentially utilized, including both anterior-based muscle-sparing (ABMS) and direct anterior (DA) for primary THA. As there are higher complication rates during the transition to an anterior approach, we compared the outcomes and complications between ABMS and DA approaches beyond the learning curve. METHODS: A retrospective study of all ABMS and DA primary THA patients performed at a single institution was performed, excluding the first 100 anterior cases done by any surgeon. In total, 813 DA and 378 ABMS THA cases were included. Demographics, complications, and patient-reported outcomes (PROMIS and HOOS) were obtained for each patient. RESULTS: There was a 4.5% overall complication rate (4.1% in DA and 5.6% in ABMS, P = .248), with the most common complication being infection at 1.7% (1.5% vs 2.1%, P = .423). A revision was performed in 3.4% of cases overall (1.8% aseptic, 1.6% septic). There was no difference in complication rates between approaches. Length of surgery was shorter for ABMS (94.5 vs 116.0 minutes, P < .001). Both DA and ABMS had significant improvements in PROMIS and HOOS Jr. scores, without any significant difference between the groups. CONCLUSIONS: Anterior-based approaches for primary THA demonstrated excellent clinical results and low complication rates overall. Beyond the learning curve, excellent results can be obtained with either ABMS or DA approach for primary THA.

Increased Complications and Cost Associated With Hip Arthroplasty for Femoral Neck Fracture: Evaluation of 576,119 Medicare Patients Treated With Hip Arthroplasty.

BACKGROUND: The benefit of total hip arthroplasty (THA) for treatment of osteoarthritis (OA) and femoral neck fractures (FNFs) in the geriatric population is well established. We compare perioperative complications and cost of THA for treatment of OA to hemiarthroplasty (HA) and THA for treatment of FNF. METHODS: Data from the Centers for Medicare & Medicaid Services were used to identify all patients 65 years and older undergoing primary hip arthroplasty between 2013 and 2017. Patients were divided into 3 cohorts: THA for OA (n = 326,313), HA for FNF (n = 223,811), and THA for FNF (n = 25,995). Generalized regressions were used to compare group mortality, 90-day readmission, thromboembolic events, and 90-day episode costs, controlling for age, gender, race, and comorbidities. RESULTS: Compared to patients treated for OA, FNF patients were older and had significantly more comorbidities (all P < .001). Even among the youngest age group (65-69 years) without comorbidities, FNF was associated with a greater risk of mortality at 90 days (THA-FNF odds ratio [OR] 9.3, HA-FNF OR 27.0, P < .001), 1 year (THA-FNF OR 7.8, HA-FNF OR 19.0, P < .001) and 5 years (THA-FNF hazard ratio 4.5, HA-FNF hazard ratio 10.0, P < .001). The average 90-day direct cost was $12,479 and $14,036 greater among THA and HA for FNF respectively compared to THA for OA (all P < .001). CONCLUSION: Among Centers for Medicare & Medicaid Services hip arthroplasty patients, those with an FNF had significantly higher rates of mortality, thromboembolic events, readmission, and greater direct cost. Reimbursement models for arthroplasty should account for the distinctly different perioperative complication and resource utilization for FNF patients.

Managing Hip-Spine Concepts in the Direct Anterior Approach With Use of Fluoroscopy.

BACKGROUND: The spinopelvic relationship in regard to total hip arthroplasty has become a topic of increasing interest in recent years. Hip arthritis and a stiff lumbar spine create a situation where the spinopelvic junction has decreased mobility, which in turn increases the risk of instability after total hip arthroplasty as the femoral acetabular joint must undergo increased motion. Regardless of the approach, surgeons should be aware of the risk of instability in patients with a stiff spinopelvic junction and the necessary modifications to component positioning to avoid postoperative instability. As many direct anterior approach surgeons use fluoroscopy for intraoperative navigation, anterior approach surgeons must also understand how to best use this technology to improve component positioning. METHODS: In this article, we address the basic concepts surrounding spinopelvic stiffness, the intraoperative component adjustments necessary for optimizing stability, and how to appropriately use fluoroscopy for navigation in the direct anterior approach. CONCLUSIONS: Appropriate use of intraoperative fluoroscopy includes understanding the impact of parallax and distortion, properly recreating the patient's standing functional pelvic plane intraoperatively and adjusting the cup's target position based on a preoperative understanding of the patient's spinopelvic motion.

Can a fibular malunion be corrected by a Z-shaped fibular osteotomy?

BACKGROUND: The aim of this study was to assess the short-term clinical and radiographic outcomes in patients who underwent realigning Z­shaped fibular osteotomy. METHODS: Between January 2007 and December 2014, 28 patients with a painful fibular malunion underwent a Z-shaped realignment fibular osteotomy. The mean age was 42.2 ± 14.1 years (range 19.1-67.8 years) and the mean follow-up was 7.0 ± 1.7 years (range 4.0-9.7 years), with no loss to follow-up. Weight-bearing radiographs were used to determine the distal fibula alignment based on Weber's criteria. Degenerative changes of the tibiotalar joint were assessed using the Kellgren-Lawrence scale. Clinical assessment included pain evaluation, measurement of ankle range of motion (ROM), sports activities, and quality of life outcomes. RESULTS: There were no intraoperative or perioperative complications. No delayed unions or nonunions were observed. One patient had radiographic progression of degenerative changes in the tibiotalar joint. Postoperative complications included removal of hardware (n = 15) and arthroscopic tibiotalar joint debridement (n = 2). At the last follow-up the mean visual analog scale (VAS) decreased from 6.5 ± 1.1 to 2.1 ± 1.1 (p < 0.001),the ROM improved from 39ºâ€¯± 6º to 45ºâ€¯± 4.5º (p < 0.001), the short form health survey questionnaire (SF-36) physical and mental outcome scores improved from 49 ± 8 to 84 ± 7 (p < 0.001) and from 61 ± 4 to 83 ± 5 (p < 0.001), respectively. CONCLUSION: The Z­shaped realignment osteotomy of the distal fibula can provide pain relief and functional improvement in the treatment of fibular malunion. Further studies are needed to address long-term outcomes in this patient cohort.

Can Dislocation Rates Be Decreased Using the Anterior Approach in Patients With Lumbar Spondylosis or Lumbar Instrumented Fusion?

BACKGROUND: Although spinopelvic stiffness is known to contribute to instability following total hip arthroplasty (THA), it is unknown whether use of an anterior surgical approach is associated with decreased postoperative instability rates in patients with lumbar spondylosis or fusion. METHODS: A retrospective review was performed of 1750 patients who underwent primary THA at our institution over an 8-year time period. Radiographic and chart review was performed evaluating for dislocations. Lumbar and pelvic radiographs were used to identify the presence of spondylosis and/or instrumented fusion. Patients were then divided into non-spondylosis and spondylosis or fusion groups to compare dislocation rates by surgical approach. RESULTS: In total, 54.4% of THA patients had an anterior approach (n = 952) and 54.6% had lumbar spondylosis or instrumented fusion (n = 956). There were 29 dislocations in total (1.7%), with less occurring in anterior approach patients (0.6% vs 2.9%, P < .001). In the patients without lumbar spondylosis, there were less dislocations in the anterior approach group (0.2% vs 1.7%, P = .048). Likewise, in patients with lumbar spondylosis or fusion, there were less dislocations in the anterior approach group (1.0% vs 3.8%, P = .004). Using logistic regression, there was a 4.1× increased risk of dislocation with a posterior approach vs an anterior approach in the spondylosis or fusion group (P = .011). CONCLUSION: Patients with lumbar spondylosis or fusion have high rates of instability. At our institution, we found that utilization of an anterior surgical approach substantially mitigated this risk.

A Narrow Posterior Joint Space on a False Profile Radiograph Does Not Correlate With Posterior Joint Cartilage Degeneration in Hip Preservation Patients.

PURPOSE: To evaluate whether a narrow posterior joint space (<2 mm) correlated with posterior joint cartilage degeneration in the hip preservation patient population. METHODS: A retrospective chart review of 155 consecutive hip arthroscopy cases by a single surgeon (SKA) from March 2012 to February 2013 was performed. Patients were included in the study if they had an adequate perioperative false profile radiograph and clear intraoperative arthroscopic images of the posterior hip joint. The narrowest posterior joint space (NPJS) width and the directly posterior, posterosuperior, superior, and anterosuperior joint space widths were measured on the false profile radiograph. Femoral and acetabular cartilage of the posterior hip joint were graded according to the International Cartilage Repair Society (ICRS) classification system using arthroscopic images obtained at the time of surgery. The cartilage grades of patients with <2 mm NPJS were compared with cartilage grades of patients with ≥2 mm NPJS. RESULTS: There was no difference in cartilage grading between patients with <2 mm NPJS (19 patients) and those with ≥2 mm NPJS (81 patients) (P = .905). The mean age of patients with NPJS ≥2 mm and <2 mm was 34.0 (median 31.2; interquartile range [IQR] 23.7, 42.9) and 38.7 (median 43.0; IQR 26.1, 50.9) respectively, and was not statistically different (P = .183). No correlation between cartilage grade and NPJS measurement was found (P = .374). CONCLUSION: In this predominantly cam-type femoroacetabular impingement patient cohort, our findings indicate there is no correlation between a <2 mm posterior hip joint narrowing seen on false profile radiographs and posterior hip cartilage degeneration confirmed with arthroscopy. Although posterior arthritis can be visualized on a false profile radiograph, a posterior joint space measurement <2 mm should not be interpreted as isolated posterior joint wear and should not be considered a hip arthroscopy contraindication. LEVEL OF EVIDENCE: Level IV, case series.

Leg dominance as a risk factor for femoroacetabular impingement syndrome.

One etiological factor of femoroacetabular impingement syndrome (FAIS) is high impact athletics involving deep hip flexion, axial loading and jumping during skeletal development. Previous work has established that there is physiologic asymmetry of the lower limbs regarding function, with the dominant limb being primarily responsible for propulsion and kicking while the non-dominant limb is responsible for stability and planting. The authors hypothesize that the dominant limb will be more likely to undergo hip arthroscopy for symptomatic FAIS. Four hundred and sixty-nine patients at a single surgical center who underwent primary or revision hip arthroscopy for cam-type FAIS were identified. Patients were asked to identify their dominant lower extremity, defined as the lower extremity preferred for kicking. Sixty patients who indicated bilateral leg dominance were excluded. It was assumed that with no association between limb dominance and the need for surgery, the dominant side would have surgery 50% of the time. Enrichment for surgery in the dominant limb was tested for using a one-sample test of proportions, determining whether the rate differed from 50%. The enrichment for surgery on the dominant side was 57% (95% confidence interval 52-62%) which was significantly different from the rate expected by chance (50%), P = 0.003. No other significant differences were noted between groups. Limb dominance appears to be an etiological factor in the development of cam-type FAIS. Patients are more likely to undergo arthroscopic treatment of FAIS on their dominant lower extremity, although the non-dominant lower extremity frequently develops FAIS as well.

Reverse total shoulder arthroplasty and resting radiographic scapular rotation.

BACKGROUND: It remains unclear whether changes in scapular rotation influence the surgeon's ability to achieve resting radiographic neutral or inferior baseplate tilt at final follow-up. The purposes of this study were (1) to determine whether reverse total shoulder arthroplasty (RTSA) changes the resting scapular rotation, (2) to determine the association between glenoid inclination with respect to the scapula (ß angle) and resting scapular rotation, and (3) to determine the ß angle threshold that will most likely lead to resting radiographic neutral or inferior baseplate tilt relative to the thorax. METHODS: This was a retrospective radiographic study. Patients with adequate-quality standing anteroposterior and Grashey radiographs obtained preoperatively and after primary RTSA at a minimum of 1 year were included. Glenoid inclination (ß angle) was measured between the supraspinatus fossa and the glenoid. Resting scapular rotation was measured between the supraspinatus fossa and a vertical line. Baseplate tilt was then calculated as the angle between the glenoid and a vertical line. RESULTS: The study included 74 patients with a mean follow-up period of 3 years (range, 1-9 years). Scapular rotation changed 2° ± 12° (mean ± standard deviation) into upward rotation (P = .048). No association was found between the ß angle and scapular rotation. In 71% of patients with a neutral or inferior baseplate tilt, a postoperative ß angle greater than 85° was found. CONCLUSIONS: Resting radiographic scapular rotation changed 2° into upward rotation with RTSA and was not associated with the ß angle. If the ß angle is greater than 85°, resting radiographic baseplate tilt will most likely be inferior or neutral.

Open reconstruction with autologous spongiosa grafts and matrix-induced chondrogenesis for osteochondral lesions of the talus can be performed without medial malleolar osteotomy.

PURPOSE: To evaluate complication rates and postoperative outcomes in patients with osteochondral lesions of the talus who underwent an autologous matrix-induced chondrogenesis (AMIC) procedure with autologous spongiosa grafting without malleolar osteotomy. METHODS: A total of 23 patients with a mean age of 35.6 ± 13.9 years were included in this study. The mean follow-up was 33.5 ± 10.4 months (range 24-52.9 months). The clinical outcomes were evaluated using the visual analog scale (VAS) and the Foot Function Index (FFI). Postoperatively, lesion healing was assessed using the magnetic resonance observation of cartilage repair tissue (MOCART) protocol. RESULTS: There were no intraoperative or perioperative complications. In one patient, arthroscopic arthrolysis was performed due to painful arthrofibrosis. The mean VAS significantly decreased from 7.6 ± 1.1 (range 4.2-9.3) to 1.4 ± 2.2 (range 0-7.4) (P < 0.001). The mean FFI significantly improved from 46.8 ± 14.3 (range 24.3-80.8) to 15.9 ± 11.4 (range 10.0-51.7) (P < 0.001). The mean MOCART score at 1-year follow-up was 74.1 ± 12.4 (range 50-95). Both preoperative and postoperative pains were significantly higher for smokers when compared to non-smokers. CONCLUSIONS: The results of the present study study indicate that AMIC procedure can be performed through the anterolateral and anteromedial arthrotomy without malleolar osteotomy. Thus, the possible complications associated with malleolar osteotomy can be avoided. The AMIC procedure without a malleolar osteotomy can be considered a safe and reliable procedure in patients with osteochondral lesions localized anterior to the midline in the sagittal plane. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.

Debridement and hinged motion distraction is superior to debridement alone in patients with ankle osteoarthritis: a prospective randomized controlled trial.

PURPOSE: To evaluate and compare complication rates and postoperative outcomes in patients with ankle debridement alone vs. debridement and hinged ankle distraction arthroplasty. METHODS: A total of 50 patients with posttraumatic ankle osteoarthritis (OA) with a mean age of 40.0 ± 8.5 years were included into this prospective randomized study: 25 patients in ankle debridement alone group and 25 patients in debridement and hinged ankle distraction group. The mean follow-up was 46 ± 12 months (range 36-78 months). The clinical and radiographic outcomes were evaluated at the 6-month and 3-year follow-up using the visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, SF-36 quality of life score, and van Dijk OA classification. A Kaplan-Meier survival analysis was performed to calculate the 3-year and 5-year survival rates. RESULTS: Both patient groups experienced significant pain relief, functional improvement, and improvement in quality of life postoperatively. In total, 26 major secondary procedures were performed. The overall survival rates in the debridement and ankle distraction group were 19 of 25 (74%) and 15 of 25 (59%) at 3 years and 5 years, respectively. The overall survival rates in the ankle debridement alone group were 12 of 25 (49%) and 9 of 25 (34%) at 3 years and 5 years, respectively. CONCLUSIONS: The study demonstrated comparable postoperative functional outcome and quality of life. However, rate of postoperative revision surgery was substantially higher in ankle debridement alone group. LEVEL OF EVIDENCE: Randomized controlled study, Level I.

Extracapsular local infiltration analgesia in hip arthroscopy patients: a randomized, prospective study.

Hip arthroscopy patients can experience significant post-operative pain. Many strategies to combat this pain have been explored including nerve blocks, which can be costly. An alternative option for pain management is local infiltration analgesia (LIA) which has been studied in hip and knee arthroplasty, but its ability to decrease pain in the setting of hip arthroscopy remains uncertain. A prospective randomized controlled trial of 74 patients who underwent hip arthroscopy at a single medical center was performed. Thirty-seven patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure while 37 from the control group received no injection. Primary outcome measures were both maximum and discharge numeric rating scale (NRS) pain scores while in the post-anesthesia care unit (PACU). The LIA group had a statistically significant decrease in the maximum PACU NRS score (6.16 versus 7.35, P = 0.009), however this did not reach the level of minimal clinically important difference of 1.5. There was an insignificant difference in discharge PACU pain scores. This is the first randomized controlled trial studying extracapsular LIA in hip arthroscopy. While LIA offers an uncomplicated and low-cost approach to post-operative pain management, this specific technique did not reduce pain to a clinically significant level.

Extracapsular local infiltration analgesia in hip arthroscopy: a retrospective study.

Many hip arthroscopy patients experience significant pain in the immediate postoperative period. Although peripheral nerve blocks have demonstrated efficacy in alleviating some of this pain, they come with significant costs. Local infiltration analgesia (LIA) may be a significantly cheaper and efficacious treatment modality. Although LIA has been well studied in hip and knee arthroplasty, its efficacy in hip arthroscopy is unclear. The purpose of this retrospective study is to determine the efficacy of a single extracapsular injection of bupivacaine-epinephrine during hip arthroscopy in reducing the rate of elective postoperative femoral nerve blocks. A retrospective review of 100 consecutive patients who underwent primary hip arthroscopy at a single medical center was performed. The control group consisted of 50 patients before the implementation of the current LIA protocol, whereas another 50 patients received a 20-ml extracapsular injection of 0.25% bupivacaine-epinephrine under direct arthroscopic visualization after capsular closure. In the post-anesthesia care unit (PACU), patients were offered a femoral nerve block for uncontrolled pain. The rate of femoral nerve block, and total opioid consumption, was compared between groups. The proportion of patients receiving elective femoral nerve blocks was significantly less in the LIA group (34%) as compared with the control group (56%; P = 0.027). There was no significant difference in total PACU opioid consumption between groups (P = 0.740). The decreased utilization of postoperative nerve blocks observed in the LIA group suggests that LIA may improve postoperative pain management and should be considered as a potentially cost-effective tool in pain management in hip arthroscopy patients. Level of Evidence: III.

Do Total Knee Arthroplasty Patients Have a Higher Activity Level Compared to Patients With Osteoarthritis?

BACKGROUND: Despite the alleviation of osteoarthritis (OA) symptoms that total knee arthroplasty (TKA) provides for patients with end-stage knee OA, recent studies have suggested that TKA may not increase physical activity levels. In this study, we compare the physical activity levels of patients with OA treated nonoperatively (non-TKA) with both patients who had received TKA (post-TKA) and patients who received TKA within 3 years of data collection (pre-TKA). METHODS: Utilizing the Osteoarthritis Initiative database, accelerometry data were collected from non-TKA, pre-TKA, and post-TKA patients. Accelerometry data were subdivided by physical activity intensity levels, yielding daily minutes of each level of activity. Physical activity levels were then compared between non-TKA and pre-TKA/post-TKA patients. Physical activity levels for each patient were also compared to the Department of Health and Human Services (DHHS) guidelines for physical activity. RESULTS: There was no difference in physical activity between non-TKA and pre-TKA patients, with the exception of non-TKA patients achieving more daily minutes of vigorous activity (P < .001). There was no difference in physical activity between non-TKA and post-TKA patients. Although 11.6% of non-TKA patients met DHHS guidelines, only 4.8% of pre-TKA and 5.3% of post-TKA patients met guidelines. CONCLUSION: Despite the improvements in patient-reported outcome measures following TKA, we found that TKA alone does not improve physical activity levels beyond those seen in the average patient with OA. In our study, the vast majority of patients with OA, treated nonoperatively or operatively, did not meet current DHHS guidelines for physical activity.

Does Body Mass Index Decrease Over Time Among Patients Who Undergo Total Knee Arthroplasty Compared to Patients With Osteoarthritis? Data From the Osteoarthritis Initiative.

BACKGROUND: Although total knee arthroplasty (TKA) is associated with improved patient-reported function, pain, and quality of life, the effects on weight loss are less certain. In this study, we use data from a large, prospective cohort study of osteoarthritis (OA) patients to compare the changes in body mass index (BMI) across 6 years in OA patients who received TKA compared with OA patients who did not receive TKA. METHODS: Using data from the Osteoarthritis Initiative, a prospective cohort study of patients with OA, our study divided patients into two groups: patients who received a TKA during the Osteoarthritis Initiative study (N = 140) and those who did not (N = 697). The initial BMI, final BMI, and change in weight over 72 months were compared between groups. Subgroup analysis was performed by dividing patients by their initial BMI, gender, and age. RESULTS: The TKA group's change in weight, initial BMI, and final BMI were not significantly different from the non-TKA group over 72 months (weight change: -0.763 kg vs +0.191 kg; P = .597). Subgroups of women and patients aged 51-60 years with TKA gained more weight than respective non-TKA OA patients. CONCLUSIONS: Overall, patients who received TKA did not lose or gain more weight than OA patients who did not receive TKA. Patients with longer follow-up after TKA (>2 years) still gained weight on average. Despite the improved patient-reported pain levels, function, and quality of life after TKA, it appears that TKA alone is not a sufficient intervention for obesity.

Does Total Knee Arthroplasty Affect Physical Activity Levels? Data from the Osteoarthritis Initiative.

Total knee arthroplasty (TKA) is associated with improved patient-reported pain levels, function, and quality of life; however, it is poorly understood whether there is increased physical activity following TKA. Using data from the Osteoarthritis Initiative (OAI), we compare physical activity, as measured using an accelerometer, and patient-reported outcome measures of 60 patients who had already received a TKA with 63 patients who eventually received a TKA during the OAI study. There was no significant difference in activity levels between the two groups as measured by the accelerometer. Total WOMAC, KOOS Quality of Life, KOOS Knee Pain, and KOOS Function scores improved in the post-TKA compared to the pre-TKA group. In both pre-TKA and post-TKA groups, physical activity guidelines were met in only 5% or less.

Patient risk taking and spending habits correlate with willingness to pay for novel total joint arthroplasty implants.

In this study, we compare patients' risk-taking and spending behaviors to their willingness to pay (WTP) for novel implants in a joint arthroplasty. 210 patients were surveyed regarding risk-taking and spending behavior, and WTP for novel implants with either increased-longevity, increased-longevity with higher risk of complications, or decreased risk of complications compared to a standard implant. Patients with increased recreational risk-taking behavior were more WTP for increased-longevity. Patients who "rarely" take health-risks were more WTP for decreased risk of complications. Patients with higher combined risk scores were more WTP for all novel implants. Patients who paid more than $50,000 for their current car were more WTP for decreased complications. This study shows that patients' risk taking and spending behavior influences their WTP for novel implants.

Poor WOMAC scores in contralateral knee negatively impact TKA outcomes: data from the osteoarthritis initiative.

While total knee arthroplasty (TKA) has been shown to have excellent outcomes, a significant proportion of patients experience relatively poor post-operative function. In this study, we test the hypothesis that the level of osteoarthritic symptoms in the contralateral knee at the time of TKA is associated with poorer post-operative outcomes in the operated knee. Using longitudinal cohort data from the Osteoarthritis Initiative (OAI), we included 171 patients who received a unilateral TKA. We compared pre-operative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores in the contralateral knee to post-operative WOMAC scores in the index knee. Pre-operative contralateral knee WOMAC scores were associated with post-operative index knee WOMAC Total scores, indicating that the health of the pre-operative contralateral knee is a significant factor in TKA outcomes.

Success of different knee arthrodesis techniques after failed total knee arthroplasty: is there a preferred technique?

Arthrodesis is a widely accepted treatment for failed total knee arthroplasty when further revision is contraindicated. In this study, we retrospectively review the pre-operative characteristics, operation techniques, treatment plans, and eventual outcomes in 42 consecutive patients (43 knees) who underwent knee arthrodesis at a single institution. Femorotibial fusion was achieved in 30 cases (75.0%). No cases of implant failure were recorded. Post-operative complications occurred in 20 cases (46.5%). Repeat arthrodesis was performed in 4 cases, and 2 patients eventually required above-the-knee amputation. Comparing the cases with successful vs. unsuccessful outcomes, there was a significant difference in days until hospital discharge following arthrodesis (P = .026), mean erythrocyte sedimentation rate prior to arthrodesis (P = .012), and the proportion of patients with post-operative wound complications (P = .021).