Patients Achieving 90°/45°/0° Intraoperative Stability Do Not Require Hip Precautions Following Posterior Approach Total Hip Arthroplasty: A Prospective Randomized Study.

BACKGROUND: Hip precautions are traditionally employed after posterior total hip arthroplasty (THA). The primary purpose was to investigate the necessity of hip precautions after posterior approach THA. We hypothesized that eliminating precautions in patients that achieved appropriate intraoperative stability would not increase the dislocation rate. METHODS: Randomized controlled trial of 346 consecutive eligible patients undergoing primary THA with a mean follow-up of 2.3 years (range 11 months to 3.7 years). EXCLUSION CRITERIA: lumbar fusion, scoliosis, abductor insufficiency, inability to achieve intraoperative stability with combined 90° flexion and 45° internal rotation in 0° adduction. Fisher's exact test was used to compare dislocation rates between the hip precaution (HP) control group and no hip precaution (NP) study group. In addition, Mann-Whitney U test was used to compare differences in HOOS JR scores at 2, 6, 12 weeks between groups. RESULTS: The dislocation rate was not increased in the NP (0/172: 0%) group compared to the HP group 4/174 (2.29%) (P = .418). All dislocations occurred in the precautions group, two of which required revision. There were no differences in mean HOOS Jr. scores at any 2, 6, or 12 weeks (P > .05 at all timepoints) (secondary outcome). CONCLUSION: Eliminating hip precautions in patients undergoing posterior approach THA that achieve 90°/45°/0° intraoperative stability does not increase the rate of dislocation. In fact, every dislocation occurred in patients receiving hip precautions. Short-term patient-reported outcome measures were not affected by hip precautions. Surgeons may discontinue the use of hip precautions as the standard of care in patients achieving 90°/45°/0° stability.

Better accuracy and reproducibility of a new robotically-assisted system for total knee arthroplasty compared to conventional instrumentation: a cadaveric study.

PURPOSE: Robotically-assisted total knee arthroplasty (TKA) has been shown to improve alignment and decrease outliers, an important goal in TKA procedures. The purpose of this cadaveric study was to compare the accuracy and reproducibility of a recently introduced TKA robotic system to conventional instrumentation for bone resections. METHODS: This cadaveric study compared 14 robotically-assisted TKA with 20 conventional TKAs. Four board-certified high volume arthroplasty surgeons with no prior experience in robotics (except one) performed the procedures with three different implant systems. Angle and level of bone resections obtained from optical navigation or calliper measurements were compared to the intra-operative plan to determine accuracy. Group comparison was performed using Student t test (mean) and F test (variance), with significance at p < 0.05. RESULTS: The robotic group demonstrated statistically more accurate results (p < 0.05) and fewer outliers (p < 0.05) than conventional instrumentation when aiming for neutral alignment. Final limb alignment (HKA) had an accuracy of 0.8° ± 0.6° vs 2.0° ± 1.6°, with 100% vs 75% of cases within 3° and 93% vs 60% within 2°. For the robotically-assisted knees, the accuracy of bone resection angles was below 0.6° with standard deviations below 0.4°, except for the femur flexion (1.3° ± 1.0°), and below 0.7 mm with standard deviations below 0.7 mm for bone resection levels. CONCLUSION: This in vitro study has demonstrated that this novel TKA robotic system produces more accurate and more reproducible bone resections than conventional instrumentation. It supports the clinical use of this new robotic system. LEVEL OF EVIDENCE: Cadaveric study, Level V.

A Smartwatch Paired With A Mobile Application Provides Postoperative Self-Directed Rehabilitation Without Compromising Total Knee Arthroplasty Outcomes: A Randomized Controlled Trial.

BACKGROUND: Self-directed rehabilitation (SDR) after total knee arthroplasty (TKA) has not been traditionally recommended. The purpose of this study was to determine if there was an impact on postoperative outcomes with the use of an SDR program after primary TKA. METHODS: In this prospective, randomized, multicenter, controlled trial, we paired a smartwatch with a mobile application, providing an SDR program after TKA. Three groups were examined in this level I study: (1) control group (formal physical therapy [PT]), (2) high exercise compliance group, and (3) low exercise compliance group. Patient-reported outcome measures (PROMs) of knee injury and osteoarthritis outcome scores, joint replacement (KOOS, JR), and EuroQol five-dimension five-level (EQ-5D-5L) along with range of motion (ROM) and manipulation rates were evaluated. RESULTS: Three hundred thirty-seven patients were enrolled in two groups with 184 in the control group and 153 in the study groups (90 in the high-compliance group and 63 in the low-compliance group). The KOOS, JR score was statistically lower in the low-compliance group in net change from preoperative scores at 3 months (P = .046) and 6 months (P = .032) than that in the control group; difference was noted at 6 months for the high-compliance group, P = .036. However, these did not meet the threshold of 8.02 units for KOOS JR minimal clinically important difference. No differences were seen in PROMs at other time intervals and in manipulation rates or ROM. CONCLUSION: Postoperative outcomes including manipulation under anesthesia, ROM, and PROMs were not different when a smartwatch paired with a self-directed PT mobile application was compared with traditional formal PT. Surgeons can consider this an appropriate alternative to traditional PT programs after TKA.

The Risk of Acute Infection Following Intra-articular Corticosteroid Injection Into a Pre-existing Total Knee Arthroplasty.

BACKGROUND: No previous studies have investigated the risk of infection following intra-articular corticosteroid injection (IACI) into a pre-existing total knee arthroplasty (TKA). The aim of this study is to determine the risk of acute infection following IACI into a pre-existing TKA. METHODS: A retrospective chart review identified all patients at a single institution between October 2009 and May 2015 that had an ipsilateral knee injection subsequent to a TKA. The risk of acute infection, as defined by development of an infection within 3 months of IACI, was determined via review of clinic notes, operative reports, laboratory records, and telephone interviews. RESULTS: A total of 1845 injections in 736 patients met the inclusion criteria. In total, 101 (4.8%) patients were lost to follow-up. Three infections in 3 patients occurred within 3 months of IACI, yielding an infection rate of 0.16% per injection, or 1 infection in every 625 IACIs following TKA. CONCLUSION: This study is the first to investigate the risk of acute infection following injection of corticosteroid into a pre-existing TKA. Given the dire consequences of infection following TKA, the routine use of IACI into a pre-existing TKA should be avoided, and a thorough workup should be performed in any patient with a painful TKA prior to consideration of IACI.

Arthrofibrosis Associated With Total Knee Arthroplasty.

BACKGROUND: Arthrofibrosis is a debilitating postoperative complication of total knee arthroplasty (TKA). It is one of the leading causes of hospital readmission and a predominant reason for TKA failure. The prevalence of arthrofibrosis will increase as the annual incidence of TKA in the United States rises into the millions. METHODS: In a narrative review of the literature, the etiology, economic burden, treatment strategies, and future research directions of arthrofibrosis after TKA are examined. RESULTS: Characterized by excessive proliferation of scar tissue during an impaired wound healing response, arthrofibrotic stiffness causes functional deficits in activities of daily living. Postoperative, supervised physiotherapy remains the first line of defense against the development of arthrofibrosis. Also, adjuncts to traditional physiotherapy such as splinting and augmented soft tissue mobilization can be beneficial. The effectiveness of rehabilitation on functional outcomes depends on the appropriate timing, intensity, and progression of the program, accounting for the patient's ability and level of pain. Invasive treatments such as manipulation under anesthesia, debridement, and revision arthroplasty improve range of motion, but can be traumatic and costly. Future studies investigating novel treatments, early diagnosis, and potential preoperative screening for risk of arthrofibrosis will help target those patients who will need additional attention and tailored rehabilitation to improve TKA outcomes. CONCLUSION: Arthrofibrosis is a multi-faceted complication of TKA, and is difficult to treat without an early, tailored, comprehensive rehabilitation program. Understanding the risk factors for its development and the benefits and shortcomings of various interventions are essential to best restore mobility and function.

Patient perception of physician reimbursement in elective shoulder surgery.

BACKGROUND: A previous study revealed that patients perceived physician reimbursement to be much higher than current Medicare schedules for hip and knee replacement. The purpose of this study was to evaluate patient perception of surgeon reimbursement for total shoulder replacement (TSA) and rotator cuff repair (RCR). METHODS: The study surveyed 250 patients. Patients were asked what they believe a surgeon should be reimbursed for performing TSA and RCR. Patients were then asked to estimate what Medicare reimbursed for each of these procedures. We then revealed the Medicare reimbursement rate for TSA and RCR, and patients were asked to comment. Finally, patients were asked whether surgeons with advanced shoulder training should receive additional payments. RESULTS: Patients thought that surgeons should receive $13,178 for TSA and $8459 for RCR. Patients estimated actual Medicare reimbursement was $7177 for TSA and $4692 for RCR. Eighty percent of patients stated that Medicare reimbursement was too low for TSA, 75% thought that payment for RCR was lower than what it should be. Less than 1% of patients felt that it was higher than it should be. A total of 87% of patients thought that surgeons with advanced shoulder training should be reimbursed at a higher rate. CONCLUSION: Patients perceived the values of TSA and RCR were much higher than current Medicare schedules. This is in agreement with prior surveys. Continued decreases in Medicare reimbursements may force surgeons to not participate in Medicare and create a potential access issue. Further investigation should focus on identifying how many surgeons may opt out.

The inter-observer and intra-observer reliability of the Paprosky femoral bone loss classification system.

The Paprosky classification provides a straightforward algorithm for defining bone loss and directing treatment for femoral revision. The purpose of this study was to test the inter-observer and intra-observer reliability of this system. Four arthroplasty surgeons reviewed radiographs of 205 consecutive femoral revisions. For each radiograph, the pattern of femoral bone loss was classified by Paprosky type on two separate occasions. A kappa value was used to calculate the reliability, which demonstrated an inter-observer reliability of 0.61, indicating substantial agreement between surgeons. The intra-observer reliability for each of the 4 participating surgeons was 0.81, 0.78, 0.76, and 0.75, indicating substantial to almost perfect agreement. There is substantial agreement among experienced arthroplasty surgeons when using the Paprosky Classification to characterize femoral bone loss.

Long-term survivorship and failure modes of unicompartmental knee arthroplasty.

BACKGROUND: In a previously reported series of 51 patients with 62 cemented, fixed-bearing unicompartmental knee arthroplasties, we reported a 10-year, 98% survival rate with an average knee score of 92 points. The survivorship and modes of failure past 10 years are incompletely understood. QUESTIONS/PURPOSES: At 15-year followup we sought to determine (1) the overall durability and survivorship of this design; (2) modes of failure; and (3) the progression of arthritis in the nonresurfaced compartments. METHODS: Nineteen knees in 16 patients were available for study with 34 patients lost to death and one lost to followup. At 15 years, we analyzed the Kaplan-Meier survivorship as well as durability with regard to radiographic loosening and knee scores, determined modes of failure, and assessed radiographs for degeneration in the nonresurfaced compartments. RESULTS: Fifteen-year survivorship was 93% and 20-year survivorship was 90%. Four of 62 knees were revised to total knee arthroplasty at a mean of 144 months. One knee was revised for patellofemoral and lateral compartment degeneration, one for lateral compartment degeneration, one for polyethylene disengagement and metallosis, and one for pain of unclear etiology. No patients had aseptic loosening or osteolysis. The mean knee score was 78 at latest followup. Arthritic progression in the nonresurfaced compartments was common although symptomatic in only two patients. CONCLUSIONS: With this cemented, fixed-bearing design, the failure rates were low, there were no cases of failure secondary to wear or loosening, and the survivorship was similar to that reported for total knee arthroplasty.

Prevalence, risk factors, and management of proximal femoral remodeling in revision hip arthroplasty.

The prevalence of, risk factors, and management of proximal femoral remodeling in revision total hip arthroplasty is unknown. Therefore, we reviewed the files of 200 consecutive femoral revision arthroplasties to study this phenomenon. Remodeling was considered present if a properly sized diaphyseal-engaging acrylic template had appropriate distal canal fill but lied within 2mm of the proximal lateral endosteal cortex (definition 1) or completely outside the femoral canal (definition 2) on anteroposterior femoral radiographs. The prevalence of remodeling was 42% by definition 1 and 21% by definition 2. The strongest risk factors were loose femoral components and more severe femoral bone loss. Orthopedic surgeons performing revision arthroplasty should be prepared to encounter remodeling as its presence can complicate femoral component revision.

Protrusio acetabuli and total hip arthroplasty in patients with Marfan syndrome.

Our goals were (1) to quantify protrusio acetabuli in patients with Marfan syndrome who underwent total hip arthroplasty and (2) to identify clinical results and complications associated with total hip arthroplasty in those patients. We reviewed the preoperative radiographs of the 29 patients (38 hips) in our study and analyzed the related patient operative reports, postoperative records, and self-administered questionnaires (mean follow-up, 116 ± 102 months). The mean preoperative center-edge angle of Wiberg was 50.9° ± 14°. Loosening (3) and radiolucent lines (4) occurred in femoral but not acetabular components. The hips had 15 complications, including 8 reoperations. High questionnaire scores (82 ± 13 points) indicated good hip function regardless of preoperative protrusio severity.

Patient perception of physician reimbursement in elective total hip and knee arthroplasty.

The purpose of this study was to evaluate patient perception of orthopedic surgeon reimbursement for total hip (THA) and knee (TKA) arthroplasty. A total of 1120 consecutive patients were asked what they believed a surgeon should be paid for performing THA and TKA. Patients were then asked to estimate what Medicare actually reimbursed for each of these procedures. On average, patients thought that surgeons should receive $14,358 for THA and $13,332 for TKA. Patients estimated actual Medicare reimbursement to be $8212 for THA and $7196 for TKA. Most of the patients stated that Medicare reimbursement was "much lower" than what it should be. Many patients commented that given this discrepancy, surgeons may drop Medicare, which may decrease access to quality hip and knee arthroplasties.

Multimodal conservative management of arthrofibrosis after total knee arthroplasty compared to manipulation under anesthesia: a feasibility study with retrospective cohort comparison.

BACKGROUND: The ideal treatment of early-stage arthrofibrosis after total knee arthroplasty is unclear. The purpose of this study was to determine the treatment effect, including variability, and feasibility of a multimodal physical therapy program as compared to manipulation under anesthesia. METHODS: This was a prospective feasibility study with a retrospective cohort comparison. Ten consecutive patients (aged 64 ± 9 years, 7 females) with early-stage arthrofibrosis were enrolled 6 weeks after primary total knee arthroplasty and participated in the multimodal physical therapy program. The multimodal physical therapy program consisted of manual therapy, therapeutic exercise, and static progressive splinting delivered over 4 weeks. The outcomes included knee range of motion (ROM), adherence, patient satisfaction, and safety. Data were compared to a retrospective cohort of 31 patients with arthrofibrosis (aged 65 ± 9 years, 20 females) who underwent manipulation under anesthesia followed by physical therapy. RESULTS: Overall, knee ROM outcomes were similar between multimodal physical therapy (110° ± 14) and manipulation under anesthesia (109° ± 11). Seven out of ten patients achieved functional ROM (≥ 110°) and avoided manipulation under anesthesia with the multimodal physical therapy program. Three out of 10 multimodal physical therapy patients required manipulation under anesthesia secondary to failure to demonstrate progress within 4 weeks of the multimodal physical therapy program. Adherence to the multimodal physical therapy program was 87 ± 9%. The median patient satisfaction with the multimodal physical therapy program was "very satisfied." Safety concerns were minimal. CONCLUSION: The use of the multimodal physical therapy program is feasible for treating early-stage arthrofibrosis after total knee arthroplasty, with 70% of patients avoiding manipulation under anesthesia. Randomized controlled trials are needed to determine the efficacy of the multimodal physical therapy program and to determine the optimal patient selection for the multimodal physical therapy program versus manipulation under anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04837872 .

Recurrent Hemarthrosis Secondary to Erosive Patellofemoral Arthritis Treated with Arthroplasty: A Report of 3 Cases.

CASE: Three patients presented with recurrent hemarthrosis secondary to erosive patellofemoral arthritis. Recurrent hemarthrosis from the eroded patellofemoral subchondral bone has not been well described. Each patient presented with symptoms secondary to painful effusions that were identified by aspiration. Each patient was successfully treated with patellofemoral or total knee arthroplasty. CONCLUSION: Spontaneous or recurrent effusions in the setting of erosive patellofemoral arthritis should prompt orthopaedic surgeons to consider hemarthrosis as the cause of such effusions. Patellofemoral or total knee arthroplasty is effective in resolving the hemarthroses, resolving pain, and restoring function in these patients.

Early aseptic loosening with a precoated low-profile tibial component: a case series.

Between March 2007 and December 2008, we performed 529 consecutive total knee arthroplasties in 460 patients with the Zimmer (Warsaw, IN) NexGen MIS Tibial Component using a minimally invasive approach. Eight knees in 8 patients (1.5%) were revised for early aseptic loosening of the tibial component despite normal initial postoperative radiographs. Several additional patients have concerning radiographic signs of pending failure. The mean time to revision was 17 months (range, 9-31 months). Intraoperatively, in all cases, more than 50% of the tibial tray was devoid of cement and factory-applied polymethylmethacrylate. Our experience with early aseptic loosening of this tibial component has led us to discontinue its use until the etiology of the high early failure rate is able to be determined.

Giardia lamblia Reactive Arthritis Mimicking Acute Periprosthetic Knee Infection: A Case Report.

CASE: A healthy 49-year-old man with a well-functioning total knee replacement developed a painful swollen knee. The erythrocyte sedimentation rate was 12 mm/hour, and C-reactive protein was 20.3 mg/L. Aspiration revealed 24,440 white blood cells and 5% neutrophils. His 2018 International Consensus Meeting (ICM) definition score of 5 met criteria for "possibly infected." He was diagnosed with reactive arthritis (ReA) secondary to Giardia lamblia, mimicking acute periprosthetic infection. He was successfully treated with a 10-week course of multiple oral antiparasitic medications. CONCLUSION: Systemic parasitic infectious ReA can mimic acute infection in the presence of total knee arthroplasty. Careful application of the 2018 ICM criteria can be critical for workup and the treatment of suspected periprosthetic infection.

The Utility of Obtaining a Complete Blood Count After Total Knee Arthroplasty in the Era of Tranexamic Acid.

Questioning the routine use of postoperative laboratory tests is a strategy to combat rising health care costs. The goal of this study was to determine the utility and cost of routine postoperative complete blood count (CBC) testing after primary total knee arthroplasty (TKA) in the era of tranexamic acid (TXA). This retrospective chart review identified patients who underwent primary TKA performed by a single surgeon at a single private institution during a 2-year period. All patients received TXA intraoperatively. Exact tests were used to determine whether there was a significant difference in transfusion rates between patients with and without preoperative anemia. Of 628 primary TKA procedures, 390 patients (62.10%) had anemia postoperatively. However, only 1 patient (0.16%) required transfusion. A total of 956 CBC tests were performed without intervention, at a total cost of $116,804.08. In addition, 1 of 26 patients with preoperative anemia vs 0 of 602 patients without preoperative anemia required transfusion (P=.04). Healthy patients undergoing primary TKA who receive TXA do not require postoperative CBC. This change has the potential to reduce this laboratory cost by more than 97% compared with the current practice of obtaining postoperative CBC testing for every patient undergoing TKA. Only patients with preoperative anemia should undergo postoperative CBC testing to help to identify those who require transfusion. The potential health care savings associated with eliminating routine postoperative CBC testing are substantial and should be considered by arthroplasty surgeons. [Orthopedics. 2021;44(1):e26-e30.].

Postsurgical bleeding following treatment of a chronic Morel-Lavallée lesion.

Morel-Lavallée lesions are closed soft-tissue degloving injuries that occur when the skin and subcutaneous tissues are separated from underlying fascia as a result of a sudden shearing force. The space that is created has the potential to be filled with a mixture of blood, lymph fluid, or necrotic fat, which may easily become infected. The optimal treatment of Morel-Lavallée lesions is controversial. We present a case of a 29-year-old man who sustained pelvic fractures in a motorcycle accident and 1 year later presented with a painless, slowly expanding left thigh mass. Treatment, consisting of open debridement and primary closure, was complicated by significant postoperative bleeding requiring reoperation. The patient was followed clinically as an outpatient, and at 6-month follow-up he was doing well and had no evidence of recurrence of the lesion. Morel-Lavallée lesions are rare complications that are often missed or underappreciated at the time of initial injury. In many cases these lesions can persist for months before they are recognized. For long-standing Morel-Lavallée lesions, it is important to determine the nature of the fluid in the cavity before planning treatment. In the current case, it was unclear based on the official radiographic interpretation whether the lesion was filled with frank blood versus serous or serosanguineous fluid.

Early High-Intensity Versus Low-Intensity Rehabilitation After Total Knee Arthroplasty: A Randomized Controlled Trial.

OBJECTIVE: To examine the safety and efficacy of a high-intensity (HI) progressive rehabilitation protocol beginning 4 days after total knee arthroplasty (TKA) compared to a low-intensity (LI) rehabilitation protocol. METHODS: A total of 162 participants (mean ± SD ages 63 ± 7 years; 89 women) were randomized to either the HI group or LI group after TKA. Key components of the HI intervention were the use of progressive resistance exercises and a rapid progression to weight-bearing exercises and activities. Both groups were treated in an outpatient setting 2 to 3 times per week for 11 weeks (26 total sessions). Outcomes included the stair climbing test (SCT; primary outcome), timed-up-and-go (TUG) test, 6-minute walk (6MW) test, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), 12-item Short Form health survey (SF-12), knee range of motion (ROM), quadriceps and hamstring strength, and quadriceps activation. Outcomes were assessed preoperatively and at 1, 2, 3 (primary end point), 6, and 12 months postoperatively. RESULTS: There were no significant differences between groups at 3 or 12 months in SCT, TUG, 6MW, WOMAC scores, knee ROM, quadriceps and hamstrings strength, quadriceps activation, or adverse event rates. By 12 months, outcomes on the 6MW, TUG, WOMAC, SF-12, quadriceps and hamstring strength, and quadriceps activation had improved beyond baseline performance in both groups. CONCLUSION: Both the HI and LI interventions were effective in improving strength and function after TKA. HI progressive rehabilitation is safe for individuals after TKA. However, its effectiveness may be limited by arthrogenic muscular inhibition in the early postoperative period.