The CCJR® Charles A. Engh, Sr, MD. Excellence in Hip Research Award: The Evolution of Revision Hip Arthroplasty and Impact on the Trainee's Experience.

BACKGROUND: Advances in total hip arthroplasty (THA) have resulted in evolving revision indications and intraoperative techniques, which can influence the exposure of trainees to complex cases. We report 3 decades of revision experience from a tertiary referral center that trains fellows, comparing the reasons for revision and the complexity of revisions over time. METHODS: We retrospectively reviewed all revision THAs performed at our institution from 1990 to 2022. Revision diagnoses, components revised, types of revision implants used, and exposure techniques were collected. A "complex" revision was defined as a case that involved an extended trochanteric osteotomy, triflange and cup-cage construct, or acetabular augment. RESULTS: A total of 3,556 THA revisions were identified (108 revisions/year). Aseptic loosening was the most common indication in 1990 to 1999 (45 per year), but decreased to 28.3/year in 2010 to 2019. From 1990 to 1999 and 2010 to 2019, fracture increased from 3.1 to 7.3 per year, infection from 2.9/year to 16.9/year, and metallosis from 0.1 to 13.2 per year. Both component revision were common from 1990 to 1994 (42.6 per year), while polyethylene exchange was most common in 2010 to 2019 (43.3 per year). A decrease was observed in "complex" cases over time: 14.8 extended trochanteric osteotomies/year in 2000 to 2004 compared to 5.4 per year in 2018 to 2022, 4.5 triflange and cup-cage constructs/year in 2004 to 2007 compared to 0.8 per year in 2018 to 2022, and 4 acetabular augments per year in 2009 to 2012 compared to 1 per year in 2018 to 2022. CONCLUSIONS: Indications for revision have changed over the decades, while the number of "complex" revisions has gradually decreased, presumably due to advances in implants and materials. If this trend extends to other training institutions, the next generation of arthroplasty surgeons will have less exposure to complex revisions during their training.

Non-Inferiority of Aspirin for Venous Thromboembolism Prophylaxis After Hip Arthroplasty in a Statewide Registry.

BACKGROUND: Uncertainty remains surrounding the use of aspirin as a sole chemoprophylactic agent to reduce the risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) and bleeding after primary total hip arthroplasty. METHODS: We performed a non-inferiority analysis of a retrospective cohort of patients undergoing total hip arthroplasty from April 1, 2013 to December 31, 2018. Cases were retrieved from the Michigan Arthroplasty Registry Collaborative Quality Initiative database and performed by 355 surgeons at 61 hospitals throughout Michigan. Surgical setting ranged from small community hospitals to large academic and non-academic centers. The primary outcomes were post-operative venous thromboembolism event or death and bleeding event. RESULTS: Of the 59,747 patients included, 32,878 (55.03%) were female, and the mean age was 64.5. A total of 462 (0.77%) composite venous thromboembolism events occurred. There were 221 (0.71%) and 129 (0.80%) venous thromboembolism events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for composite venous thromboembolism events (odds ratio 0.99, 95% confidence interval 0.79-1.26, P < .001). Bleeding events occurred in 767 (1.28%) patients, with 304 (0.97%) and 281 (1.74%) bleeding events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for bleeding events (odds ratio 0.62, 95% confidence interval 0.52-0.74, P < .001). CONCLUSION: Aspirin is not inferior to other anticoagulants as pharmacologic venous thromboembolism prophylaxis with regards to post-operative risk of venous thromboembolism or bleeding. Sole use of aspirin for venous thromboembolism prophylaxis after total hip arthroplasty should be considered in the appropriate patient.

Association of Mechanical Axis With Osteochondritis Dissecans of the Femoral Condyle.

BACKGROUND: Osteochondritis dissecans (OCD) is a condition characterized by abnormal subchondral bone with disturbance of overlying articular cartilage. The role of weightbearing alignment in the pathophysiology of OCD lesion development is not fully understood. HYPOTHESIS: Lower extremity mechanical axis would be concordant with femoral condylar OCD lesion location. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Cases were identified from a single, large academic institutional database using International Classification of Diseases, Ninth Revision and Tenth Revision and Current Procedural Terminology codes associated with OCD. Patients were included if they had a magnetic resonance imaging scan demonstrating the OCD lesion and lower extremity alignment radiographs. OCD lesion location was identified using Cahill and Berg zones. The primary outcome was the association of OCD lesion location with weightbearing mechanical axis. Secondary outcomes included the association of mechanical axis with skeletal maturity, OCD lesion stability, and treatment. For unilateral OCD lesions, mechanical axis was compared between affected and unaffected lower extremities. RESULTS: A total of 86 patients (95 knees) with an OCD lesion of the femoral condyle were identified. The population was 74% male, and the mean age was 21 years. In total, 65% of knees had closed physes, 82% of lesions were unstable, and 85% underwent a surgical procedure. Mechanical axis was located in the same zone as the OCD lesion in 48% of cases and within the same compartment in 56% of cases. Spearman correlation coefficient demonstrated a moderate positive correlation (rs = 0.59). No significant differences were found in the association of mechanical axis and OCD lesion location in subgroup analysis of medial versus lateral femoral condylar OCD lesions, skeletal maturity, stability of the lesion, or treatment group. For patients with varus alignment and medial femoral condylar OCD lesions, the mean lateral distal femoral angle was 89.9°, and medial proximal tibial angle was 85.4°; for valgus alignment and lateral femoral condylar lesions, the lateral distal femoral angle was 84.8°, and medial proximal tibial angle was 88.8°. Patients with unilateral medial femoral condylar OCD lesions were more likely to have varus alignment of the affected extremity compared with the contralateral extremity (59% vs 36%; P = .01). CONCLUSION: This study demonstrated a relationship between lower extremity mechanical weightbearing axis and femoral condylar OCD location. Patients with unilateral medial femoral condylar OCD lesions frequently had asymmetric varus alignment in the affected extremity.

Nutritionist Referral Modestly Improves Weight Loss and Increases Surgery Rate in Obese Patients Seeking Total Joint Arthroplasty.

Background: Obesity is associated with increased complications after total joint arthroplasty (TJA), leading some surgeons to recommend nutrition counseling and weight loss. We aim to evaluate the effect of preoperative nutritionist referral on weight loss and likelihood of surgery in obese patients seeking primary TJA. Methods: A retrospective cohort of patients seeking primary TJA who were referred to a licensed nutritionist for weight loss was matched by age, sex, and body mass index (BMI) to an unreferred control group. BMI change was compared between groups up to 1 year of follow-up. Differences were determined using 2-tailed t-tests and chi-squared tests with a significance cutoff of P < .05. Results: A total of 274 referred patients and 174 controls were included in our analysis. Patients who were referred to a nutritionist achieved significantly greater average BMI change (-1.5 kg/m2) than controls (-0.8 kg/m2) by 6 months after first contact (P = .01) although significance was lost at 1 year after first contact (P = .21). Thirty-eight percent of referred patients went on to TJA compared with 28% of controls (P < .01). Conclusions: Referral to a licensed nutritionist modestly improves early weight loss and is associated with a higher rate of surgery in obese patients seeking primary TJA.

Time for an Update? A Look at Current Guidelines for Venous Thromboembolism Prophylaxis After Hip and Knee Arthroplasty and Hip Fracture.

Venous thromboembolism is a well-established complication of total hip and knee arthroplasty and hip fracture surgery. Clinical practice guidelines have been proposed to help clinicians provide prophylaxis against this risk. However, most guidelines reference data that are becoming outdated because of new advances in perioperative protocols. Recent data would suggest that aspirin may be appropriate for most patients after total hip and knee replacement and a more potent chemoprophylaxis for higher risk patients. Low-molecular-weight heparin remains the recommended choice after hip fracture surgery, although there is a paucity of recent literature in this patient population. There are randomized trials currently underway in the arthroplasty population that may guide clinicians in the appropriate choice of chemoprophylaxis. These studies should inform updates to the current clinical practice guidelines.

Robotic navigation system utilization for percutaneous sacroiliac screw placement: surgical setup and technique.

Sacroiliac joint (SIJ) pathology is a common cause of significant pain and disability, and operative treatment consisting of SIJ fusion can be performed in cases where non-operative measures fail to provide sustained relief. Through the years, SIJ fusion has evolved from an open invasive procedure, to more recently, being performed through minimally invasive techniques. Intraoperative navigation systems and robotic guidance are becoming popularized for SIJ fusion, as well as other routine and complex spinal cases. The utility of navigation and robotics is the enhanced ability of the surgeon to place instrumentation more accurately, with less dissection, blood less, and overall operative time. We present a technique guide for robotic instrumented SIJ fusion with intraoperative navigation that we have put into practice at our institution and found to be very beneficial to patients for the above reasons. We describe the setup and utilization of these technologies intraoperatively, and provide specific case examples to highlight our technique. The described methods have been found to be effective and reproducible, allowing for minimally invasive SIJ screw placement with high accuracy and safety. We emphasize that utilizing intraoperative navigation and robotics is not meant to substitute for surgeon knowledge of case steps or anatomy, but rather to enhance safety and efficacy. To our knowledge, robotic SIJ fusion has not been previously described in the literature.

First Metatarsophalangeal Lateral Collateral Ligament Repair in an Athlete: A Case Report.

CASE: Evidence-based surgical strategies to reconstruct the collateral ligament complex of the first metatarsophalangeal (MTP) joint are not available. We report a case of first MTP lateral collateral ligament insufficiency in a young, female gymnast with varus laxity and subsequent satisfactory mid-term and long-term outcomes. CONCLUSION: This case report describes an efficient suture anchor technique for restoring stability of the first MTP joint because of chronic varus laxity with acceptable results both clinically and with patient-reported outcome scores at mid-term and long-term follow-ups. We suggest that our strategy is a viable option for addressing chronic varus laxity of the first MTP joint. LEVEL OF EVIDENCE: Level IV, case report.