Augmented Ulnar Collateral Ligament Repair With Structural Bioinductive Scaffold: A Biomechanical Study.

BACKGROUND: Elbow ulnar collateral ligament (UCL) repair with suture brace augmentation shows good time-zero biomechanical strength and a more rapid return to play compared with UCL reconstruction. However, there are concerns about overconstraint or stress shielding with nonabsorbable suture tape. Recently, a collagen-based bioinductive absorbable structural scaffold has been approved by the Food and Drug Administration for augmentation of soft tissue repair. PURPOSE/HYPOTHESIS: This study aimed to assess the initial biomechanical performance of UCL repair augmented with this scaffold. We hypothesized that adding the bioinductive absorbable structural scaffold to primary UCL repair would impart additional time-zero restraint to the valgus opening. STUDY DESIGN: Controlled laboratory study. METHODS: Eight cadaveric elbow specimens-from midforearm to midhumerus-were utilized. In the native state, elbows underwent valgus stress testing at 30o, 60o, and 90o of flexion, with a cyclical valgus rotational torque. Changes in valgus rotation from 2- to 5-N·m torque were recorded as valgus gapping. Testing was then performed in 4 states: (1) native intact UCL-with dissection through skin, fascia, and muscle down to an intact UCL complex; (2) UCL-transected-distal transection of the ligament off the sublime tubercle; (3) augmented repair with bioinductive absorbable scaffold; and (4) repair alone without scaffold. The order of testing of repair states was alternated to account for possible plastic deformation during testing. RESULTS: The UCL-transected state showed the greatest increase in valgus gapping of all states at all flexion angles. Repair alone showed similar valgus gapping to that of the UCL-transected state at 30° (P = .62) and 60° of flexion (P = .11). Bioinductive absorbable scaffold-augmented repair showed less valgus gapping compared with repair alone at all flexion angles (P = .021, P = .024, and P = .024 at 30°, 60°, and 90°, respectively). Scaffold-augmented repair showed greater gapping compared with the native state at 30° (P = .021) and 90° (P = .039) but not at 60° of flexion (P = .059). There was no difference when testing augmented repair or repair alone first. CONCLUSION: UCL repair augmented with a bioinductive, biocomposite absorbable structural scaffold imparts additional biomechanical strength to UCL repair alone, without overconstraint beyond the native state. Further comparative studies are warranted. CLINICAL RELEVANCE: As augmented primary UCL repair becomes more commonly performed, use of an absorbable bioinductive scaffold may allow for improved time-zero mechanical strength, and thus more rapid rehabilitation, while avoiding long-term overconstraint or stress shielding.

High accuracy of intra-articular needle position during anterior landmark guided glenohumeral injections.

OBJECTIVES: Image-guided ultrasound or fluoroscopic glenohumeral injections have high accuracy rates but require training, equipment, cost, and radiation exposure (fluoroscopy). In contrast, landmark-guided glenohumeral injections do not require additional subspecialist referrals or equipment. An optimal technique would be safe and accurate and have few barriers to implementation. The purpose of this study was to define the accuracy of glenohumeral needle placement via an anterior landmark-guided approach as assessed by direct arthroscopic visualization. METHODS: A consecutive series of adult patients undergoing shoulder arthroscopy in the beach chair position were included in this study. Demographic and procedural data were collected. The time required to perform the injection, the precise location of the needle tip, and factors that affected the accuracy of the injection were also assessed. RESULTS: A standardized anterior landmark-guided glenohumeral joint injection was performed in the operating room prior to surgery, and the location of the needle tip was documented by arthroscopic visualization with a low complication profile and few barriers to implementation. A total of 81 patients were enrolled. Successful intra-articular glenohumeral needle placement by sports medicine and shoulder/elbow fellowship-trained orthopedic surgeons was confirmed in 93.8% (76/81) of patients. The average time to complete the procedure was 24.8 â€‹s. There were no patient-related variables associated with nonintra-articular injections in the cohort. CONCLUSIONS: This study demonstrated that the technique of anterior landmark-guided glenohumeral injection has an accuracy of 93.8% and requires less than 30 â€‹s to perform. This method is safe, yields similar accuracy to image-guided procedures, has improved cost and time efficiency, and requires less radiation exposure. No patient-related factors were associated with inaccurate needle placement. Anterior landmark-guided glenohumeral injections may be utilized with confidence by providers in the clinical setting. LEVEL OF EVIDENCE: Level 5. IRB: Approved under Stanford IRB-56323.

An All-Suture-Based Technique for Meniscal Repair Is Cost-Effective in Comparison to Partial Meniscectomy for Horizontal Cleavage Tears.

Purpose: To determine the cost-effectiveness of meniscal repair (MR) using an all-suture-based technique when compared to partial meniscectomy (PM) for horizontal cleavage tears (HCTs) from a payor's perspective in the United States. Methods: A state-transition model and cost-utility analysis were developed from a US payor's perspective to project treatment costs and quality-adjusted life-years (QALYs) in a cohort of 35-year-old patients without osteoarthritis at baseline and presenting with either a lateral or medial HCT. Two outpatient costing perspectives were used, namely ambulatory surgical centers (ASCs) and hospitals. The state-transition model had 7 health states with transition probabilities, costs, and utilities obtained from the existing literature. Cost-effectiveness was assessed using a willingness-to-pay threshold of $100,000/QALY, and sensitivity analysis considered the effects of parameter uncertainty on model results. MR failure rates were focused on an all-suture-based technique; however, in a separate scenario, this study considered effectiveness data from various MR techniques and devices. Results: MR dominated PM over a lifetime horizon, increasing QALYs by 0.43 per patient and decreasing the cost by $12,227 per patient within a hospital setting (and by $12,570 within an ASC). MR with an all-suture-based technique continued to be the dominant treatment when age at primary treatment was varied between 30 and 60 years. Sensitivity analysis showed that MR was not cost-effective in year 1, was cost-effective from year 2, and was cost-saving from year 6 onward from both ASC and hospital perspectives. Probabilistic sensitivity analysis found that MR was cost-effective over a lifetime horizon in 99% of 10,000 iterations on base-case analysis. Conclusions: Using a lifetime horizon, this study found that from a payor's perspective, MR is a cost-saving intervention when compared with PM in patients with an HCT. Level of Evidence: Level III, economic analysis.

High Tibial Osteotomy in Knee Reconstruction and Joint Preservation.

High tibial osteotomy is a dynamic operation, used as an effective procedure in both joint preservation and knee stability. Applications and indications are expanding, with good results in the treatment of malalignment associated with arthrosis, knee instability, meniscus deficiency or transplants, and/or cartilage restoration. Appropriate patient selection and preoperative planning are critical to achieving good outcomes after surgery. Coronal and sagittal plane corrections made through the proximal tibia can effectively alter joint mechanics creating a more favorable environment for cartilage, meniscus, and ligamentous structures about the knee. Advancing techniques and technologies have allowed for more precise planning and execution of osteotomies.

MRI of patellar stabilizers: Anatomic visibility, inter-reader reliability, and intra-reader reproducibility of primary and secondary ligament anatomy.

OBJECTIVE: To compare MRI features of medial and lateral patellar stabilizers in patients with and without patellar instability. METHODS: Retrospective study of 196 patients (mean age, 33.1 ± 18.5 years; 119 women) after diagnosis of patellar instability (cohort-1, acute patellar dislocation; cohort-2, chronic patellar maltracking) or no patellar instability (cohort-3, acute ACL rupture; cohort-4, chronic medial meniscus tear). On MRI, four medial and four lateral stabilizers were evaluated for visibility and injury by three readers independently. Inter- and intra-reader agreement was determined. RESULTS: Medial and lateral patellofemoral ligaments (MPFL and LPFL) were mostly or fully visualized in all cases (100%). Of the secondary patellar stabilizers, the medial patellotibial ligament was mostly or fully visualized in 166 cases (84.7%). Other secondary stabilizers were mostly or fully visualized in only a minority of cases (range, 0.5-32.1%). Injury scores for all four medial stabilizers were higher in patients with acute patellar dislocation than the other 3 cohorts (p < .05). Visibility inter- and intra-reader agreement was good for medial stabilizers (κ 0.61-0.78) and moderate-to-good for lateral stabilizers (κ 0.40-0.72). Injury inter- and intra-reader agreement was moderate-to-excellent for medial stabilizers (κ 0.43-0.90) and poor-to-moderate for lateral stabilizers (κ 0-0.50). CONCLUSION: The MPFL and LPFL were well visualized on MRI while the secondary stabilizers were less frequently visualized. The secondary stabilizers were more frequently visualized medially than laterally, and patellotibial ligaments were more frequently visualized compared to the other secondary stabilizers. Injury to the medial stabilizers was more common with acute patellar dislocation than with chronic patellar maltracking or other knee injuries.

Experts Achieve Consensus on a Majority of Statements Regarding Platelet-Rich Plasma Treatments for Treatment of Musculoskeletal Pathology.

PURPOSE: To establish consensus statements on platelet-rich plasma (PRP) for the treatment of musculoskeletal pathologies. METHODS: A consensus process on the treatment of PRP using a modified Delphi technique was conducted. Thirty-five orthopaedic surgeons and sports medicine physicians participated in these consensus statements on PRP. The participants were composed of representatives of the Biologic Association, representing 9 international orthopaedic and musculoskeletal professional societies invited due to their active interest in the study of orthobiologics. Consensus was defined as achieving 80% to 89% agreement, strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: There was consensus on 62% of statements about PRP. CONCLUSIONS: (1) PRP should be classified based on platelet count, leukocyte count, red blood count, activation method, and pure-plasma versus fibrin matrix; (2) PRP characteristics for reporting in research studies are platelet count, leukocyte count, neutrophil count, red blood cell count, total volume, the volume of injection, delivery method, and the number of injections; (3) the prognostic factors for those undergoing PRP injections are age, body mass index, severity/grade of pathology, chronicity of pathology, prior injections and response, primary diagnosis (primary vs postsurgery vs post-trauma vs psoriatic), comorbidities, and smoking; (4) regarding age and body mass index, there is no minimum or maximum, but clinical judgment should be used at extremes of either; (5) the ideal dose of PRP is undetermined; and (6) the minimal volume required is unclear and may depend on the pathology. LEVEL OF EVIDENCE: Level V, expert opinion.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous. Results: Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus. Conclusion: Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

Editorial Commentary: Evaluation of Patellofemoral Instability Is Complex and Multifactorial.

The work-up of patellofemoral instability is complex and multifactorial. Patient factors (i.e., age, activity demand, goals/expectations), clinical presentation (pain, instability, or both), and physical examination (i.e., J-sign, apprehension into flexion), must be correlated with imaging findings (radiographs, magnetic resonance imaging, computed tomography) and anatomic risk factors, including patella alta, trochlear dysplasia, patellar tilt, lateralized force vector, valgus, femoral anteversion, and tibial torsion. Thus, developing a standard battery of reliable and reproducible radiographic measures of patellofemoral instability is a challenge. Imaging cut-offs provide insight into relative risk of recurrent instability. We still fall short in using imaging parameters to predict when to operate, what procedure(s) to perform, and how the patient might do. Future directions include the use of artificial intelligence and 3-dimensional measurements to help simplify a complex problem.

Association of Hip Dysplasia With Trochlear Dysplasia in Skeletally Mature Patients.

Background: Developmental dysplasia of the hip (DDH) and trochlear dysplasia (TD) are distinct pathologies with several important features in common. In addition to shared risk factors, both forms of dysplasia cause abnormal joint kinematics and force transmission, predisposing patients to pain, injuries to cartilage and soft tissue stabilizers, and ultimately arthritis. Purpose: To evaluate for an association between hip dysplasia and TD in skeletally mature patients with symptomatic hip dysplasia. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 48 patients with DDH who underwent periacetabular osteotomy were compared with 48 sex-matched patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) between July 2014 and February 2021. All patients were skeletally mature. The Tönnis angle and lateral center-edge angle were measured on preoperative pelvis radiographs. Femoral version, trochlear depth, lateral trochlear inclination (LTI), tibial tubercle-trochlear groove distance (TTTG-d), and posterior lateral condylar angle (PLCA) were measured on preoperative magnetic resonance imaging scans of the symptomatic hip and ipsilateral knee. Continuous variables were compared between the patient groups using 2-sample t tests. Interobserver reliability was measured using the intraclass correlation coefficient. Results: Patients with DDH demonstrated a reduced trochlear depth compared with patients with FAI (3.6 vs 4.6 mm; P < .001). There were no differences between groups in femoral anteversion, LTI, TTTG-d, or PLCA. Two (4.2%) patients with FAI and 17 (35.4%) patients with DDH had a trochlear depth <3 mm (P < .001). One (2.1%) patient with FAI and 7 (14.6%) patients with DDH had an LTI <11° (P = .027). There was no difference between groups in frequency of a convex proximal trochlea, patient-reported ipsilateral knee pain, or ipsilateral knee procedures. Conclusion: Patients with DDH had reduced trochlear depth compared with patients with FAI, demonstrating a higher incidence of dysplastic trochlear features that may predispose patients to patellofemoral joint disease. Further research is needed to determine whether screening at-risk patients and treating TD will help to prevent symptomatic patellofemoral disease.

The Principles of Knee Joint Preservation: Operative Treatment Strategies.

➤ Joint alignment, meniscal status, and ligament stability are codependent factors involved in knee joint preservation, and any injury or imbalance can impact the knee articular cartilage status and can result in adverse clinical outcomes.➤ Cartilage preservation procedures in the knee will not result in optimal outcomes if there is joint malalignment, meniscal deficiency, or ligamentous instability.➤ Lower-extremity varus or valgus malalignment is a risk factor for the failure of an anterior cruciate ligament (ACL) reconstruction. It represents an indication for a high tibial osteotomy or distal femoral osteotomy in the setting of failed ACL reconstruction, and may even be considered in patients who have an initial ACL injury and severe malalignment.➤ An elevated posterior tibial slope increases the risk of failure of ACL reconstruction, whereas a decreased posterior tibial slope increases the risk of failure of posterior cruciate ligament reconstruction.

Bifocal avulsion fracture and fixation of the patellar tendon: a case report.

Acute distal patella tendon avulsion from the tibial tubercle (TT) is a relatively rare injury that is usually described in the adolescents or elderly population in their 7th or 8th decades. Bifocal avulsion fractures of the patella tendon from the TT and the distal pole of the patella are exceptionally rare in adults. In this case report, we present a 52-year-old healthy old male who was treated for bifocal avulsion of the patellar tendon with open reduction and internal fixation augmented with two ULTRATAPE sutures. To our knowledge, this is the first case report to describe this injury in a healthy middle-aged patient.

Biomechanical Forces of the Lateral Knee Joint Following Meniscectomy and Meniscus Transplantation in Pediatric Cadavers.

INTRODUCTION: Lateral meniscus transplantation successfully treats symptomatic meniscus deficiency in children. Although clinical outcomes are well-characterized, joint forces in meniscus-deficient and transplant states are unknown. The purpose of this study was to characterize contact area (CA) and contact pressures (CP) of transplanted lateral meniscus in pediatric cadavers. We hypothesize that (1) compared with the intact state, meniscectomy will decrease femorotibial CA and increase CP, and increase contact pressure (CP) and (2) compared with the meniscectomy state, meniscus transplantation will improve contact biomechanics toward the intact meniscus state. METHODS: Pressure-mapping sensors were inserted underneath the lateral meniscus of eight cadaver knees aged 8 to 12 years. CA and CP on the lateral tibial plateau were measured in the intact, meniscectomy, and transplant states each at 0°, 30°, and 60° of knee flexion. Meniscus transplant was anchored with transosseous pull-out sutures and sutured to the joint capsule with vertical mattresses. The effects of meniscus states and flexion angle on CA and CP were measured by a two-way analysis of variance repeated measures model. One-way analysis of variance measured pairwise comparisons between meniscus states. RESULTS: Regarding CA, at 0°, no differences between the groups reached significance. Meniscectomy reduced CA at 30° ( P = 0.043) and 60° ( P = 0.001). Transplant and intact states were comparable at 30°. At 60°, transplant significantly increased CA ( P = 0.04). Regarding contact pressure, the average pressure increased with meniscectomy at all angles of flexion (0° P = 0.025; 30° P = 0.021; 60° P = 0.016) and decreased with transplant relative to respective intact values. Peak pressure increased with meniscectomy at 30° ( P = 0.009) and 60° ( P = 0.041), but only reached intact comparable values at 60°. Pairwise comparisons support restoration of average CP with transplant, but not peak CP. DISCUSSION: Pediatric meniscus transplantation improves average CP and CA more than peak CP, but does not completely restore baseline biomechanics. Net improvements in contact biomechanics after transplant, relative to the meniscectomy state, support meniscus transplant. STUDY DESIGN: Descriptive laboratory study, Level III.

Patellar Tracking: An Old Problem with New Insights.

Patellofemoral pain and instability are common indications for imaging that are encountered in everyday practice. The authors comprehensively review key aspects of patellofemoral instability pertinent to radiologists that can be seen before the onset of osteoarthritis, highlighting the anatomy, clinical evaluation, diagnostic imaging, and treatment. Regarding the anatomy, the medial patellofemoral ligament (MPFL) is the primary static soft-tissue restraint to lateral patellar displacement and is commonly reconstructed surgically in patients with MPFL dysfunction and patellar instability. Osteoarticular abnormalities that predispose individuals to patellar instability include patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Clinically, patients with patellar instability may be divided into two broad groups with imaging findings that sometimes overlap: patients with a history of overt patellar instability after a traumatic event (eg, dislocation, subluxation) and patients without such a history. In terms of imaging, radiography is generally the initial examination of choice, and MRI is the most common cross-sectional examination performed preoperatively. For all imaging techniques, there has been a proliferation of published radiologic measurement methods. The authors summarize the most common validated measurements for patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Given that static imaging is inherently limited in the evaluation of patellar motion, dynamic imaging with US, CT, or MRI may be requested by some surgeons. The primary treatment strategy for patellofemoral pain is conservative. Surgical treatment options include MPFL reconstruction with or without osseous corrections such as trochleoplasty and tibial tubercle osteotomy. Postoperative complications evaluated at imaging include patellar fracture, graft failure, graft malposition, and medial patellar subluxation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Knee MRI: Meniscus Roots, Ramps, Repairs, and Repercussions.

Menisci play an essential role in maintaining normal pain-free function of the knee. While there are decades of MRI literature on the tears involving the meniscus body and horns, there is now a surge in knowledge regarding injuries at the meniscus roots and periphery. The authors briefly highlight new insights into meniscus anatomy and then summarize recent developments in the understanding of meniscus injuries that matter, emphasizing meniscus injuries at the root and peripheral (eg, ramp) regions that may be missed easily at MRI and arthroscopy. Root and ramp tears are important to diagnose because they may be amenable to repair. However, if these tears are left untreated, ongoing pain and accelerated cartilage degeneration may ensue. The posterior roots of the medial and lateral menisci are most commonly affected by injury, and each of these injuries is associated with distinctive clinical profiles, MRI findings, and tear patterns. Specific diagnostic pitfalls can make the roots challenging to evaluate, including MRI artifacts and anatomic variations. As with root tears, MRI interpretation and orthopedic treatment have important differences for injuries at the medial versus lateral meniscus (LM) periphery (located at or near the meniscocapsular junction). Medially, ramp lesions typically occur in the setting of an anterior cruciate ligament rupture and are generally classified into five patterns. Laterally, the meniscocapsular junction may be injured in association with tibial plateau fractures, but disruption of the popliteomeniscal fascicles may also result in a hypermobile LM. Updated knowledge of the meniscus root and ramp tears is crucial in optimizing diagnostic imaging before repair and understanding the clinical repercussions. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available in the Online Learning Center.

Screws or Sutures? A Pediatric Cadaveric Study of Tibial Spine Fracture Repairs.

BACKGROUND: Tibial spine fractures are common in the pediatric population because of the biomechanical properties of children's subchondral epiphyseal bone. Most studies in porcine or adult human bone suggest that suture fixation performs better than screw fixation, but these tissues may be poor surrogates for pediatric bone. No previous study has evaluated fixation methods in human pediatric knees. PURPOSE: To quantify the biomechanical properties of 2-screw and 2-suture repair of tibial spine fracture in human pediatric knees. STUDY DESIGN: Controlled laboratory study. METHODS: Cadaveric specimens were randomly assigned to either 2-screw or 2-suture fixation. A standardized Meyers-Mckeever type 3 tibial spine fracture was induced. Screw-fixation fractures were reduced with two 4.0-mm cannulated screws and washers. Suture-fixation fractures were reduced by passing 2 No. 2 FiberWire sutures through the fracture fragment and the base of the anterior cruciate ligament. Sutures were secured through bony tunnels over a 1-cm tibial cortical bridge. Each specimen was mounted at 30° of flexion. A cyclic loading protocol was applied to each specimen, followed by a load-to-failure test. Outcome measures were ultimate failure load, stiffness, and fixation elongation. RESULTS: Twelve matched pediatric cadaveric knees were tested. Repair groups had identical mean (8.3 years) and median (8.5 years) ages and an identical number of samples of each laterality. Ultimate failure load did not significantly differ between screw (mean ± SD, 143.52 ± 41.9 7 N) and suture (135.35 ± 47.94 N) fixations (P = .760). Screws demonstrated increased stiffness and decreased elongation, although neither result was statistically significant at the .05 level (21.79 vs 13.83 N/mm and 5.02 vs 8.46 mm; P = .076 and P = .069, respectively). CONCLUSION: Screw fixation and suture fixation of tibial spine fractures in human pediatric tissue were biomechanically comparable. CLINICAL RELEVANCE: Suture fixations are not biomechanically superior to screw fixations in pediatric bone. Pediatric bone fails at lower loads, and in different modes, compared with adult cadaveric bone and porcine bone. Further investigation into optimal repair is warranted, including techniques that may reduce suture pullout and "cheese-wiring" through softer pediatric bone. This study provides new biomechanical data regarding the properties of different fixation types in pediatric tibial spine fractures to inform clinical management of these injuries.

Medial Patellofemoral Ligament Reconstruction in Obese Patients Results in Low Complication Rates and Improved Subjective Outcomes.

Purpose: To compare outcomes, activity scores, and complication rates of obese and non-obese patients undergoing medial patellofemoral ligament (MPFL) reconstruction. Methods: A retrospective review identified patients undergoing MPFL reconstruction for recurrent patellofemoral instability. Patients were included if they had undergone MPFL reconstruction and had follow-up for a minimum of 6 months. Patients were excluded if they underwent surgery less than 6 months earlier, had no outcome data recorded, or underwent concomitant bony procedures. Patients were divided into 2 groups based on body mass index (BMI): BMI of 30 or greater and BMI less than 30. Presurgical and postsurgical patient-reported outcomes including Knee Injury and Osteoarthritis Outcome Score (KOOS) domains and the Tegner score were collected. Complications requiring reoperation were recorded. P < .05 was defined as a statistically significant difference. Results: A total of 55 patients (57 knees) were included. There were 26 knees with a BMI of 30 or greater and 31 knees with a BMI less than 30. There were no differences in patient demographic characteristics between the 2 groups. Preoperatively, no significant differences were found in KOOS subscores or Tegner scores (P = .21) between groups. At minimum 6-month follow-up (range, 6.1-70.5 months), patients with a BMI of 30 or greater showed statistically significant improvements in the KOOS Pain, Activities of Daily Living, Symptoms, and Sport/Recreation subscores. Patients with a BMI less than 30 showed a statistically significant improvement in the KOOS Quality of Life subscore. The group with a BMI of 30 or greater had significantly lower KOOS Quality of Life (33.34 ± 19.10 vs 54.47 ± 28.00, P = .03) and Tegner (2.56 ± 1.59 vs 4.78 ± 2.68, P = .05) scores. Complication rates were low, with 2 knees (7.69%) requiring reoperation in the cohort with a BMI of 30 or greater and 4 knees (12.90%) requiring reoperation in the cohort with a BMI less than 30, including 1 reoperation for recurrent patellofemoral instability (P = .68). Conclusions: In this study, MPFL reconstruction in obese patients was safe and effective, with low complication rates and improvements in most patient-reported outcomes. Compared with patients with a BMI less than 30, obese patients had lower quality-of-life and activity scores at final follow-up. Level of Evidence: Level III, retrospective cohort study.

Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis.

¼: Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA. ¼: HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO. ¼: UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.

A scoping review of portable sensing for out-of-lab anterior cruciate ligament injury prevention and rehabilitation.

Anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) surgery are common. Laboratory-based biomechanical assessment can evaluate ACL injury risk and rehabilitation progress after ACLR; however, lab-based measurements are expensive and inaccessible to most people. Portable sensors such as wearables and cameras can be deployed during sporting activities, in clinics, and in patient homes. Although many portable sensing approaches have demonstrated promising results during various assessments related to ACL injury, they have not yet been widely adopted as tools for out-of-lab assessment. The purpose of this review is to summarize research on out-of-lab portable sensing applied to ACL and ACLR and offer our perspectives on new opportunities for future research and development. We identified 49 original research articles on out-of-lab ACL-related assessment; the most common sensing modalities were inertial measurement units, depth cameras, and RGB cameras. The studies combined portable sensors with direct feature extraction, physics-based modeling, or machine learning to estimate a range of biomechanical parameters (e.g., knee kinematics and kinetics) during jump-landing tasks, cutting, squats, and gait. Many of the reviewed studies depict proof-of-concept methods for potential future clinical applications including ACL injury risk screening, injury prevention training, and rehabilitation assessment. By synthesizing these results, we describe important opportunities that exist for clinical validation of existing approaches, using sophisticated modeling techniques, standardization of data collection, and creation of large benchmark datasets. If successful, these advances will enable widespread use of portable-sensing approaches to identify ACL injury risk factors, mitigate high-risk movements prior to injury, and optimize rehabilitation paradigms.

Survival analyses and their applications in orthopaedics.

Survival analyses are a powerful statistical tool used to analyse data when the outcome of interest involves the time until an event. There is an array of models fit for this goal; however, there are subtle differences in assumptions, as well as a number of pitfalls, that can lead to biased results if researchers are unaware of the subtleties. As larger amounts of data become available, and more survival analyses are published every year, it is important that healthcare professionals understand how to evaluate these models and apply them into their practice. Therefore, the purpose of this study was to present an overview of survival analyses, including required assumptions and important pitfalls, as well as examples of their use within orthopaedic surgery.