Indirect Head of the Rectus Femoris Tendon as a Graft for Segmental Hip Labral Reconstruction: An Anatomic, Radiographical, and Biomechanical Study in Comparison With Iliotibial Labral Reconstruction.

BACKGROUND: The indirect head of the rectus femoris (IHRF) tendon has been used as an autograft for segmental labral reconstruction. However, the biomechanical properties and anatomic characteristics of the IHRF, as they relate to surgical applications, have yet to be investigated. PURPOSE: To (1) quantitatively and qualitatively describe the anatomy of IHRF and its relationship with surrounding arthroscopically relevant landmarks; (2) detail radiographic findings pertinent to IHRF; (3) biomechanically assess segmental labral reconstruction with IHRF, including restoration of the suction seal and contact pressures in comparison with iliotibial band (ITB) reconstruction; and (4) assess potential donor-site morbidity caused by graft harvesting. STUDY DESIGN: Descriptive laboratory study. METHODS: A cadaveric study was performed using 8 fresh-frozen human cadaveric full pelvises and 7 hemipelvises. Three-dimensional anatomic measurements were collected using a 3-dimensional coordinate digitizer. Radiographic analysis was accomplished by securing radiopaque markers of different sizes to the evaluated anatomic structures of the assigned hip.Suction seal and contact pressure testing were performed over 3 trials on 6 pelvises under 4 different testing conditions for each specimen: intact, labral tear, segmental labral reconstruction with ITB, and segmental labral reconstruction with IHRF. After IHRF tendon harvest, each full pelvis had both the intact and contralateral hip tested under tension along its anatomic direction to assess potential site morbidity, such as tendon failure or bony avulsion. RESULTS: The centroid and posterior apex of the indirect rectus femoris attachment are respectively located 10.3 ± 2.6 mm and 21.0 ± 6.5 mm posteriorly, 2.5 ± 7.8 mm and 0.7 ± 8.0 mm superiorly, and 5.0 ± 2.8 mm and 22.2 ± 4.4 mm laterally to the 12:30 labral position. Radiographically, the mean distance of the IHRF to the following landmarks was determined as follows: anterior inferior iliac spine (8.8 ± 2.5 mm), direct head of the rectus femoris (8.0 ± 3.9 mm), 12-o'clock labral position (14.1 ± 2.8 mm), and 3-o'clock labral position (36.5 ± 4.4 mm). During suction seal testing, both the ITB and the IHRF reconstruction groups had significantly lower peak loads and lower energy to peak loads compared with both intact and tear groups (P = .01 to .02 for all comparisons). There were no significant differences between the reconstruction groups for peak loads, energy, and displacement at peak load. In 60° of flexion, there were no differences in normalized contact pressure and contact area between ITB or IHRF reconstruction groups (P > .99). There were no significant differences between intact and harvested specimen groups in donor-site morbidity testing. CONCLUSION: The IHRF tendon is within close anatomic proximity to arthroscopic acetabular landmarks. In the cadaveric model, harvesting of the IHRF tendon as an autograft does not lead to significant donor-site morbidity in the remaining tendon. Segmental labral reconstruction performed with the IHRF tendon exhibits similar biomechanical outcomes compared with that performed with ITB. CLINICAL RELEVANCE: This study demonstrates the viability of segmental labral reconstruction with an IHRF tendon and provides a detailed anatomic description of the tendon in the context of an arthroscopic labral reconstruction. Clinicians can use this information during the selection of a graft and as a guide during an arthroscopic graft harvest.

Short-Term Outcomes of Concomitant Patellofemoral Arthroplasty and Medial Patellofemoral Ligament Reconstruction to Treat Concurrent Patellofemoral Arthritis and Patellar Instability.

The purpose of this study was to evaluate the efficacy of combined patellofemoral arthroplasty (PFA) and medial patellofemoral ligament (MPFL) reconstruction in patients with patellofemoral arthritis in the setting of concomitant patellar instability. Patients who underwent single-stage, combined PFA and MPFL reconstruction by a single surgeon at a tertiary-care orthopaedic center between 2016 and 2021 were identified. Postoperative radiographic and clinical outcomes at a minimum of 6 months were recorded using patient-reported outcome measures, including International Knee Documentation Committee (IKDC), Kujala, and VR-12. Early complications and rates of recurrent instability were also recorded. Of the 16 patients who met inclusion and exclusion criteria, 13 patients were available for final follow-up (81%; 51.7 ± 7.2 years, 11 females, 2 males) with a mean clinical follow-up of 1.3 ± 0.5 years (range: 0.5-2.3 years). Patients experienced significant improvements in patellar tilt and multiple patient-reported outcome metrics postoperatively, including IKDC, Kujala, VR-12 Mental Health, and VR-12 Physical Health. At the time of the most recent follow-up, no patient had experienced a postoperative dislocation or subluxation event. The findings suggest that concurrent PFA and MPFL reconstruction are associated with significant improvements in multiple patient-reported outcomes. Further studies are needed to evaluate the duration of clinical benefits achieved with this combined intervention.

Subpectoral proximal humeral anatomy: Guidance to decrease risk of fracture following subpectoral biceps tenodesis.

Background: Biceps tenodesis is used for a variety of shoulder and biceps pathologies. Humeral fracture is a significant complication of this procedure. This cadaveric anatomy study sought to determine the cortical thickness of the humeral proximal shaft to identify the optimal technique to decrease unicortical drilling and reduce the risk of fracture. Methods: A computed tomography (CT) of eight cadaveric humeral specimens was obtained with a metallic marker placed at the site of subpectoral tenodesis. These scans were examined to define the cortical thickness of the subpectoral region of the humerus and determine angular safe zones for reaming. Results: At the standard point of a subpectoral tenodesis, a mean angle relative to the coronal plane of 29.2° medially and 21.6° laterally from the deepest portion of the bicipital groove avoided unicortical drilling with a 7 mm reamer. These values varied slightly 1 cm proximal and distal to this level. The thickest regions of cortex in the subpectoral humerus correspond to the ridges of the bicipital groove. Discussion: To avoid unicortical tunnels, surgeons should limit deviation from the perpendicular approach to no more than 23° relative to the coronal plane medially and 11° relative to the coronal plane laterally.

Patient-reported outcomes measurement information system depression psychometrically underperforms compared to legacy measures and is poorly associated with postoperative functional outcomes in shoulder arthroplasty patients.

Background: The purpose of this study was to investigate the associations between each mental health patient-reported outcome measure with postoperative functional outcomes following shoulder arthroplasty, and to compare psychometric properties of patient-reported outcomes measurement information system depression to the legacy (VR-12 Mental) patient-reported outcome measure. Methods: Patients who underwent primary shoulder arthroplasty from July 2018 to February 2019 were retrospectively reviewed. Patient-reported outcomes measurement information system depression and VR-12 Mental were administered preoperatively; American Shoulder and Elbow Surgeons and Single Assessment Numeric Evaluation were administered at 6-month and 1-year postoperatively. Rasch partial credit modeling analysis was used to compare psychometric properties of legacy versus patient-reported outcomes measurement information system instruments in assessing mental health. Results: Ninety-three patients who underwent total shoulder arthroplasty (n = 52), reverse total shoulder arthroplasty (n = 39), or hemiarthroplasty (n = 2) were included. Preoperative VR-12 Mental scores were moderately associated with American Shoulder and Elbow Surgeons at 6-months (coefficient: 0.52, P = 0.026) and 1-year (coefficient: 0.65, P = 0.002), while preoperative patient-reported outcomes measurement information system depression scores were not. Patient-reported outcomes measurement information system depression demonstrated significant floor effects (16%); VR-12 Mental demonstrated minimal floor and ceiling effects (1.1% for both). VR-12 Mental demonstrated broader coverage of mental outlook on Rasch modeling than patient-reported outcomes measurement information system depression and had adequate model fit after one round of reiterative item elimination. Discussion: Patient-reported outcomes measurement information system depression was poorly associated with postoperative American Shoulder and Elbow Surgeons scores, demonstrated significant floor effects, and had limited coverage of mental health on Rasch modeling with reiterative elimination. Level of Evidence: IV.

PROMIS physical function and pain perform poorly psychometrically in patients undergoing medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to assess the validity, floor and ceiling effects, and dimensionality of PROMIS Physical Function (PF) and Pain compared to legacy patient reported outcome (PRO) measures in patients undergoing medial patellofemoral ligament (MPFL) reconstruction. METHODS: Patients who underwent MPFL reconstruction between 2018 to 2020 were retrospectively reviewed. Preoperatively, patients completed the IKDC, VR-12, Kujala, SF-12, KOOS JR, PROMIS PF and Pain surveys. Inter-survey convergence was assessed with Spearman correlations. Psychometric analysis included investigations of inter-survey convergent validity, intra-survey floor and ceiling effects, and Rasch analyses with person-item fit and iterative question elimination model fit testing. RESULTS: A total of 76 patients (mean age: 22.6 ± 8.4 years) who completed preoperative surveys were included (compliance: 91.7-96.2%). Preoperatively, age was significantly associated with both PROMIS PF (coefficient: - 0.291, P = 0.005) and Pain scores (coefficient: 0.294, P = 0.002). PROMIS PF had a Very Good correlation with IKDC and PROMIS Pain had a Very Good correlation with KOOS JR. Other correlations ranged from Poor to Good. No significant floor or ceiling effects were observed for any PRO. On iterative question elimination Rasch modelling, only two questions from PROMIS PF remained after 6 rounds of elimination while PROMIS Pain had no questions remaining after 3 rounds of elimination. CONCLUSION: Preoperative PROMIS PF and Pain provided only Fair to Good correlations with most legacy PROs. Although no significant floor and ceiling effects were observed, PROMIS PF and Pain did not perform well psychometrically in this population of patients undergoing MPFL reconstruction. These results suggest PROMIS questionnaires should be used with caution in this population, especially if used in isolation, when discussing clinical expectations with patients. The authors recommend continued use of legacy PROs specific to assessment of patellar instability and function that have established validity in patellar instability populations. LEVEL OF EVIDENCE: Level IV.

Patient Demographic Factors Are Not Associated With Mesenchymal Stromal Cell Concentration in Bone Marrow Aspirate Concentrate.

Purpose: To describe the capacity for concentration of a single processing machine for bone marrow aspirate concentrate (BMAC) production and investigate the effects of demographic factors on the number of mesenchymal stromal cells (MSCs) in BMAC. Methods: Patients enrolled in our institution's randomized control trials involving BMAC who had complete BMAC flow cytometry data were included. Multipotent MSC phenotype, defined as cell-surface coexpression of specific-identifying antigens (≥95% positive) and the absence of hematopoietic lineage markers (≤2% positive), was determined for both patient bone marrow aspirate (BMA) and BMAC samples. The ratio of cells in BMA:BMAC samples was calculated and Spearman correlations (i.e., body mass index [BMI]) and Kruskall-Wallis (i.e., age: <40, 40-60, >60 years) or Mann-Whitney (i.e., sex) tests were used to determine the relationship of cell concentration to demographic factors. Results: Eighty patients were included in analysis (49% male, mean age: 49.9 ± 12.2 years). Mean concentration of BMA and BMAC was 2,048.13 ± 2,004.14 MSCs/mL and 5,618.87 ± 7,568.54 MSC/mL, respectively, with a mean BMAC:BMA ratio of 4.35 ± 2.09. A significantly greater MSC concentration was observed in the BMAC samples when compared with BMA (P = .005). No patient demographic factors (age, sex, height, weight, BMI) were found to predict MSC concentration in the BMAC samples (P ≥ .01). Conclusions: Demographic factors, including age, sex, and BMI do not impact the final concentration of MSCs in BMAC when using a single harvest technique (anterior iliac crest) and a single processing system. Clinical Relevance: As the role of BMAC therapy expands in clinical application, it becomes increasingly important to understand the determinants of BMAC composition and how it is affected by different harvesting techniques, concentrating processes, and patient demographics.

Lateral Patellofemoral Ligament Reconstruction: A Biomechanical Comparison of 2 Techniques.

BACKGROUND: The importance of maintaining lateral patellar stabilizing structures has been demonstrated by the presence of iatrogenic medial patellar instability after lateral retinacular release (LRR) procedures. In patients with medial patellar instability, lateral patellofemoral ligament (LPFL) reconstruction has been clinically shown to restore patellar stability while improving patient-reported outcomes. However, the biomechanics associated with different LPFL reconstruction techniques remain largely unknown. PURPOSE: To (1) investigate whether LPFL reconstruction restores medial patellar translation compared with the intact state after LRR and (2) evaluate for any biomechanical differences between soft tissue and osseous LPFL reconstruction techniques. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 7 knees were included in the final analysis. The knees were dissected, and the tibia and femur were potted. An eye screw was then placed at the midpoint of the patella perpendicular to the medial surface. A custom jig was constructed to allow for a 1-kg load to be applied to the quadriceps muscle. Medial patellar displacement was investigated at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion using a tensile testing machine with a 20-N medial force applied to the patella. Medial patellar displacement was assessed in 4 states: intact, LRR, soft tissue LPFL reconstruction (inserted through incisions in the iliotibial band, quadriceps tendon, and patellar tendon), and osseous LPFL reconstruction. RESULTS: The LRR group had significantly greater medial patellar translation compared with the intact group throughout flexion (P < .01 to P = .029). The soft tissue LPFL reconstruction group demonstrated significantly greater medial patellar translation at 30° (P = .020) and 45° (P = .025) compared with the intact group, with less translation compared with the LRR group at all degrees of knee flexion except for 45° (P = .065). The osseous LPFL reconstruction group demonstrated significantly greater medial patellar translation compared with the intact group at 30° of flexion (P = .036), with significantly less translation compared with the LRR group from 0° to 30° (P < .01 to P = .013). The soft tissue LPFL reconstruction group (15.94 ± 2.55 mm) demonstrated significantly greater medial patellar translation at 10° of flexion compared with the osseous LPFL reconstruction group (14.16 ± 2.34 mm) (P = .033). CONCLUSION: Soft tissue LPFL reconstruction led to significantly greater medial patellar translation at 30° and 45° compared with the intact state, while osseous LPFL reconstruction produced significantly greater translation only at 30°. Both the soft tissue and the osseous reconstruction techniques resulted in comparable medial patellar translation at all degrees of knee flexion except for 10°, in which osseous reconstruction was more similar to the intact state. CLINICAL RELEVANCE: Compared with LRR, soft tissue LPFL reconstruction was able to restore stability against medial patellar translation at most degrees of knee flexion, while osseous LPFL reconstruction did not provide adequate stabilization beyond 30° of flexion. While the LPFL does appear to have osseous insertions, soft tissue reconstruction functioned more similarly to the intact state after LRR.

Suture Anchor-Based Quadriceps Tendon Repair May Result in Improved Patient-Reported Outcomes but Similar Failure Rates Compared to the Transosseous Tunnel Technique.

PURPOSE: The purpose of this study was to compare failure rates and patient-reported outcomes between transosseus (TO) suture and suture anchor (SA) quadriceps tendon repairs. METHODS: Following institutional review board approval, patients who underwent primary repair for quadriceps tendon rupture with TO or SA techniques between January 2009 and August 2018 were identified from an institutional database and retrospectively reviewed. Patients were contacted for satisfaction (1-10 scale), current function (0-100 scale), failure (retear), and revision surgeries; International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were also collected to achieve a minimum of 2-year follow-up. RESULTS: Sixty-four patients (34 SA, 30 TO) were available by phone or e-mail at a mean of 4.81 ± 2.60 years postoperatively. There were 10 failures, for an overall failure rate of 15.6%. Failure incidence did not significantly differ between treatment groups (P = .83). Twenty-seven patients (47% of nonfailed patients) had completed patient-reported outcomes. The SA group reported higher subjective function (SA: 90 [85-100] vs TO: 85 [60-93], 95% CI of difference: -19.9 to -2.1 × 10-5, P = .042), final IKDC (79.6 [50.0-93.6] vs 62.1 [44.3-65.5], 95% CI of difference: -33.0 to -0.48, P = .048), KOOS Pain (97.2 [84.7-97.2] vs 73.6 [50.7-88.2], 95% CI of difference: -36.1 to -3.6 × 10-5, P = .037), Quality of Life (81.3 [56.3-93.8] vs 50.0 [23.4-56.3], 95% CI of difference: -50.0 to -6.2, P = .026), and Sport (75.0 [52.5-90.0] vs 47.5 [31.3-67.5], 95% CI of the difference: -45.0 to -4.1 × 10-5, P = .048). CONCLUSIONS: There is no significant difference in failure rate between transosseus and suture anchor repairs for quadriceps tendon ruptures (P = .83). Most failures occur secondary to a traumatic reinjury within the first year postoperatively. Despite the lack of difference in failure rates, at final follow-up, patients who undergo suture anchor repair may report significantly greater subjective function and final IKDC, KOOS Pain, Quality of Life, and Sport scores. LEVEL OF EVIDENCE: III, retrospective cohort study.

Journal Discipline Plays a Significant Role in Academic Attention But Not in Social Media Attention in the Peripheral Nerve Literature.

Evaluating the impact of articles can be performed through bibliometric analysis or social media impact using the Altmetric Attention Score (AAS). The purpose of this study was to report on the social media impact of peripheral nerve studies; how article demographic factors, such as journal specialty (hand, orthopedics, plastic surgery), affect AAS; and how AAS correlates with bibliometrics, namely citation number. While orthopedic journals received the highest academic attention, there was no significant difference in social media attention between journal groups. These findings suggest AAS may be useful to authors in deciding which journal in which to pursue publication. [Orthopedics. 2023;46(3):e143-e148.].

Trends in Lateral Retinacular Release from 2010 to 2017.

Historically, lateral retinacular release (LRR) procedures have been utilized in the treatment of a variety of patellofemoral disorders, including lateral patellar instability. However, in the past decade, there has been an increasing awareness of the importance of the lateral stabilizers in patellar stability, as well as the complications of LRR, such as recurrent medial patellar instability. The purpose of this study was to investigate current trends in LRR procedures from 2010 through 2017 using a large national database. The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for arthroscopic LRR procedures (the Current Procedural Terminology [CPT] code, 29873) from 2010 to 2017. The number and incidence of lateral release procedures, both isolated and nonisolated, were analyzed and separated into cohorts for analysis. Age and gender of the LRR cohort was investigated and compared with all other orthopaedic procedures during the same time period in the NSQIP database. In addition, concomitant procedures and associated International Classification of Disease-9th Revision (ICD-9) and ICD-10th Revision (ICD-10) codes were analyzed over time and between LRR groups. From 2010 to 2017, 3,117 arthroscopic LRRs were performed. The incidence for LRR was 481.9 per 100,000 orthopaedic surgeries in 2010 and significantly decreased to 186.9 per 100,000 orthopaedic surgeries in 2017 (p < 0.01). LRR was more commonly performed in females (66%) and 58% of patients were under 44 years of age. In addition, LRR was most commonly performed with a concomitant meniscectomy (36%), synovectomy (19%), or microfracture (13%), and for a diagnosis of pain (22%). The overall incidence of LRR procedures significantly decreased from 2010 to 2017. LRRs were more commonly performed in younger, female patients for a diagnosis of pain with the most common concomitant procedure being meniscectomy, synovectomy, or microfracture.

Outcomes of Patellar Subchondroplasty Surgery: A Case Series.

A select subset of patients can present with anterior knee pain in the setting of normal patellar tracking, no significant cartilage damage, and the presence of a bone marrow lesion (BML) involving the patella on advanced imaging. One novel treatment option for this condition is patellar subchondroplasty, where calcium phosphate is injected into the subchondral bone under fluoroscopic guidance. The purpose of this study is to report preliminary outcomes of patients who have undergone subchondroplasty of the patella. The surgical log of the senior author was retrospectively reviewed to identify patients who had undergone patellar subchondroplasty from January 2014 to June 2019. Indications for surgery included the presence of retropatellar pain refractory to conservative management without significant arthritis with a related focal BML on magnetic resonance imaging. International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Veterans Rand 12-item Health Survey (VR-12) were obtained preoperatively, at 6 months and at final follow-up. Eight patients (nine knees) who underwent patellar subchondroplasty with minimum 1-year follow-up participated in the study. On preoperative magnetic resonance imaging, patients had a mean BML that was 2 cm in diameter. Patients had a median Kellgren-Lawrence grade of 2 both preoperatively and at final radiographic follow-up (15.50 ± 20.52 months). No patient underwent subsequent surgery or conversion to arthroplasty. Compared with baseline, VR-12 mental (p = 0.046) and physical (p = 0.003), KOOS joint replacement (p = 0.024), KOOS pain (p = 0.033), and KOOS sports (p = 0.034) scores were significantly increased at final follow-up (24.00 ± 13.55 months). In addition, on a scale of 0 to 100, patient-reported satisfaction was 73.88 ± 33.90. This study introduces patellar subchondroplasty as a surgical treatment for patients with symptomatic BMLs of the patella without significant arthritis after failure of conservative management. Our results demonstrated good outcomes and patient satisfaction. In addition, no patients converted to patellofemoral or total knee arthroplasty. This study suggests that patellar subchondroplasty may be a reasonable treatment option in the correct patient population.

Lateral Translation of the Patella in MPFC Reconstruction: A Biomechanical Study of Three Approaches.

The purpose of this study was to investigate whether differences exist in preventing lateral patellar translation between three distinct medial patellofemoral complex (MPFC) reconstruction procedures at varying knee flexion angles. Six cadaveric knee specimens were dissected, potted, and placed in a customized jig for testing. Lateral patellar displacement was measured at intervals between 0 and 90 degrees of knee flexion using a tensile testing machine with a 20 N lateral force applied to the patella. Each specimen was tested with the MPFC intact, sectioned, and after each of the three reconstruction techniques: MPFL, hybrid, and medial quadriceps-tendon femoral (MQTFL) reconstructions. There was significantly increased lateral patellar displacement following MPFC sectioning when compared with the intact state in early degrees of flexion (10-30 degrees) (p < 0.05). All three reconstruction groups restored patella stability and reduced lateral patellar displacement following sectioning from 0 to 30 degrees of flexion (p < 0.05). When compared with the intact group, all three reconstruction groups demonstrated reduced patella translation at full knee extension, while the MPFL and hybrid reconstruction groups additionally demonstrated significant reduction in patella translation at 10 degrees of flexion (p < 0.05). No significant differences were observed between the three reconstruction groups. This biomechanical study demonstrates the efficacy of three MPFC reconstruction techniques in patella stabilization following sectioning. Our results suggest that MPFL reconstruction may provide the most robust patella stabilization, whereas MQTFL reconstruction may be the most forgiving construct. This study suggests that MQTFL and hybrid reconstructions provide adequate resistance to lateral translation and may be used as an alternative to MPFL reconstruction.

The Effect of Aberrant Rotation on Radiographic Patellar Height Measurement Using Canton-Deschamps Index: A Cadaveric Analysis.

The Caton-Deschamps Index (CDI) is a measurement used to evaluate patella alta based on true lateral radiographs; however, no prior study has investigated how altering the degree of radiograph aberrancy affects CDI measurement. The primary and secondary purpose of this study was to evaluate effects of rotational radiographic changes on patella height measurements and compare these findings to MRI measurements, respectively. Five cadaver knees (n = 5) were utilized in this study. True lateral radiographs were obtained for each specimen by using a fluoroscopic C-arm machine. The C-arm was then altered in two planes (axial and coronal) in both the clockwise and counterclockwise direction and radiographs were taken at 5, 10, and 15 degrees of error from the true lateral position. A CDI measurement of each specimen was performed based on sagittal magnetic resonance imaging (MRI) slices and compared with radiographic CDI measurements. Three orthopedic surgeons measured the CDI for each radiograph and MRI performed. Interrater reliability and changes in CDI were analyzed. Clinically significant difference in CDI was set to 0.1. Mean intraclass correlation coefficient was high (≥0.7) at true lateral and at all varying degrees of error. When performing a pairwise comparison of mean CDI from the true lateral position to increasing degrees of error, statistically significant differences were observed in the axial plane. The largest change in CDI measurements was seen with rotational malposition in the axial plane and counterclockwise direction. No statistically significant differences in mean CDI were observed in the coronal plane. The change in CDI from the true lateral position reached an absolute maximum of at least 0.1 in all four scenarios at each tested degree of error. This study found that aberrant radiographic rotation in the axial plane resulted in a significantly different mean CDI measurement when compared with true lateral radiographs. All degrees of error in both directions and in both planes could have a clinically significant effect on CDI (≥0.1). Our findings confirm the importance of a perfect true lateral radiograph when measuring patella height.

Negative Ulnar Variance Lessens DRUJ Instability After DRUJ Disruption: A Biomechanical Analysis.

BACKGROUND: The purpose of this study was to perform a biomechanical investigation on the effect of ulnar variance (UV) on the stability of the distal radioulnar joint (DRUJ) prior to and after DRUJ sectioning. METHODS: Ten cadaveric forearm specimens were included in the study and baseline UV was assessed radiographically. Radial motion relative to the ulna was evaluated using Intel real sense cameras and a custom developed program. The forearms were dissected, and a radial osteotomy was performed. Using a custom-made plate, radial stability was assessed with an UV of + 4, 0, and -4 mm by measuring the maximum and minimum radial position relative to the ulna during a simulated Shuck test. The volar radioulnar ligaments and triangular fibrocartilage complex (TFCC) were then sectioned, and testing was repeated at each UV state. RESULTS: Sectioning significantly increased radial translation at neutral (P = .008), +4 mm UV (P = .008), and -4 mm UV (P = .018). There were no significant differences in translation between the 3 UV groups with the DRUJ intact (P = .124). The ulnar negative (-4 mm) state had significantly lower translation compared to the positive (+4 mm) (P < .001) and the neutral (0 mm) (P = .026) UV states. There were no significant differences between the positive and neutral UV groups with the DRUJ sectioned. CONCLUSIONS: Fixating the radius in -4 mm of ulnar negativity significantly decreased radial translation after sectioning the volar radioulnar ligament and TFCC. Ulnar variance had no effect on stability with an intact DRUJ. STUDY TYPE: Biomechanical Study.

Accuracy and Precision of Acetabular Component Position Does Not Differ Between the Anterior and Posterior Approaches to Total Hip Arthroplasty With Robotic Assistance: A Matched-Pair Analysis.

Background: Deviation from planned component placement with robot-assisted total hip arthroplasty (RA-THA) may differ based on surgical approach. The purpose of this study was to compare radiographic accuracy and precision of acetabular component position using RA-THA with the direct anterior approach (DAA) or posterior approach (PA). Methods: Between 2016 and 2019, 134 PA RA-THA patients were matched to 134 DAA RA-THA patients based on age (±10 years), body mass index (±5 kg/m2), and sex (exact). Acetabular component position was assessed using (1) planned position on preoperative computed tomography, (2) intraoperative position, and (3) position on 6-week postoperative radiographs using the digital Ein Bild Röntgen Analyse system. Results: Accuracy of acetabular component inclination in the PA cohort was lower than that in the DAA cohort (PA: 4.3° ± 2.8° vs DAA: 3.1° ± 2.4°, P = .001). Inclination precision was not statistically different (PA: 3° ± 2.4° vs DAA: 2.5° ± 1.8°, P = .071). Anteversion accuracy was not statistically different (PA: 4.1° ± 3.7° vs DAA: 3.5° ± 2.5°, P = .091). Acetabular component anteversion was more precise with DAA (PA: 4.1° ± 3.7° vs DAA: 2.9° ± 2.0°, P = .001). Radiographic outliers (anteversion or inclination was >10° or <-10° from the planned target) were significantly more prevalent in the PA cohort than in the DAA cohort (12 vs 3, P = .016). Conclusions: The acetabular component can be positioned with excellent precision and accuracy when using RA-THA regardless of approach. Although the DAA resulted in a slight increase in precise placement of cup anteversion and more accurate placement of cup abduction with fewer outliers, these small differences may not be clinically meaningful.

Proximal Row Carpectomy Does Not Alter Contact Pressures of the Lunate Fossa: A Cadaveric Study.

BACKGROUND: Previous studies have suggested that proximal row carpectomy (PRC) results in increased contact pressures and decreased contact areas in the radiocarpal joint. Such experiments, however, used older technologies that may be associated with considerable measurement errors. The purpose of this study was to determine whether there was a significant difference in contact pressure and contact area before and after PRC using Tekscan, a newer pressure sensing technology. METHODS: Ten nonpaired cadaveric specimens were dissected proximal to the carpal row and potted. An ultra-thin Tekscan sensor was secured in the lunate fossa of the radius. The wrists were loaded with 200 N of force for 60 seconds to simulate clenched-fist grip; contact pressure and area was assessed before and after PRC. RESULTS: Performing a PRC did not significantly increase mean contact pressure at the lunate fossa compared to the native state (mean increase of 17.4 ± 43.2 N/cm2, P = .184). Similarly, the PRC did not significantly alter peak contact pressures at the lunate fossa (intact: 617.2 ± 233.46 N/cm2, median = 637.5 N/cm2; PRC: 707.8 ± 156.6 N/cm2, median = 728.5 N/cm2; P = .169). In addition, the PRC (0.46 ± 0.15 cm2, median = 0.48 cm2) and intact states (0.49 ± 0.25 cm2, median = 0.44 cm2) demonstrated similar contact areas (P = .681). CONCLUSIONS: In contrast to prior studies that demonstrated significant increases in contact pressure and decreases in contact area after PRC, our findings propose that performing a PRC does not significantly alter the contact pressures or area of the lunate fossa of the radiocarpal joint.

Radiocarpal Contact Pressures Are Not Altered after Scapholunate Ligament Tears.

Background The scapholunate interosseous ligament (SLIL) couples the scaphoid and lunate, preventing motion and instability. Prior studies suggest that damage to the SLIL may significantly alter contact pressures of the radiocarpal joint. Questions/Purposes The purpose of this study was to investigate the contact pressure and contact area in the scaphoid and lunate fossae of the radius prior to and after sectioning the SLIL. Methods Ten cadaveric forearms were dissected distal to 1-cm proximal to the radiocarpal joint and a Tekscan sensor was placed in the radiocarpal joint. The potted specimen was mounted and an axial load of 200 N was applied over 60 seconds. Results Sectioning of the SLIL did neither significantly alter mean contact pressure at the lunate fossa ( p = 0.842) nor scaphoid fossa ( p = 0.760). Peak pressures were similar between both states at the lunate and scaphoid fossae ( p = 0.301-0.959). Contact areas were similar at the lunate fossa ( p = 0.508) but trended toward an increase in the SLIL sectioned state in the scaphoid fossa ( p = 0.055). No significant differences in the distribution of contact pressure ( p = 0.799), peak pressure ( p = 0.445), and contact area ( p = 0.203) between the scaphoid and lunate fossae after sectioning were observed. Conclusion Complete sectioning of the SLIL in isolation may not be sufficient to alter the contact pressures of the wrist. Clinical Relevance Injury to the secondary stabilizers of the SL joint, in addition to complete sectioning of the SLIL, may be needed to induce altered biomechanics and ultimately degenerative changes of the radiocarpal joint.

Time to Achieving Clinically Significant Outcomes After Meniscal Allograft Transplantation.

PURPOSE: To determine the time to achieving minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for commonly administered patient-reported outcome (PRO) measures and risk factors affecting achievement of clinically significant outcomes in patients undergoing meniscal allograft transplantation (MAT). METHODS: A prospectively maintained MAT registry was retrospectively reviewed from April 2014 to May 2019. Patients who underwent revision MAT or did not complete preoperative PROs or one post operative time point were excluded. Patients who underwent concomitant procedures were included in the analysis. PROs were administered preoperatively and at 6 months, 1 year, and 2 years postoperatively. Previously defined MCID and PASS thresholds were utilized and Kaplan-Meier survival curve analysis with interval censoring was used to calculate the cumulative percentages of MCID and PASS achievement at each follow-up time interval (5-7, 11-13, and 23-25 months). RESULTS: Eighty patients (age: 28.35 ± 9.76, 50% male) who completed preoperative, 6-month (n = 69, 86% compliance), and 1-year (n = 76, 95% compliance) PROs were included. The majority of patients (>50%) achieved MCID and PASS on most included PROs. Workers' compensation status was found to significantly delay achievement of MCID and PASS on all PROs except for PASS on Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life (QoL). Higher body mass index (BMI) significantly delayed time to achieving MCID on KOOS Pain and activities of daily living (ADL), as well as PASS on KOOS Symptoms and KOOS QoL. CONCLUSION: This study suggests that the majority of patients have clinically significant improvements in pain and function after MAT, with more than 50% of patients experiencing clinically significant improvement within the first postoperative year. Workers' compensation status and high BMI may prolong time to achievement of MCID and PASS after MAT.

Effect of Mechanical Mincing on Minimally Manipulated Articular Cartilage for Surgical Transplantation.

BACKGROUND: Point-of-care treatment options for medium to large symptomatic articular cartilage defects are limited. Minced cartilage implantation is an encouraging single-stage option, providing fresh viable autologous tissue with minimal morbidity and cost. PURPOSE: To determine the histological properties of mechanically minced versus minimally manipulated articular cartilage. STUDY DESIGN: Controlled laboratory study. METHODS: Remnant articular cartilage was collected from fresh femoral condylar allografts. Cartilage samples were divided into 4 groups: cartilage explants with or without fibrin glue and mechanically minced cartilage with or without fibrin glue. Samples were cultured for 42 days. Chondrocyte viability was assessed using live/dead assay. Cellular migration and outgrowth were monitored using bright-field microscopy. Extracellular matrix deposition was assessed via histological staining. Proteoglycan content and synthesis were assessed using dimethylmethylene blue assay and radiolabeled 35S-sulfate, respectively. Type II collagen (COL2A1) gene expression was analyzed via polymerase chain reaction. RESULTS: The mean viability of minced cartilage particles (34% ± 14%) was not significantly reduced compared with baseline (46% ± 13%) on day 0 (P = .90). After culture, no significant difference in the percentage of live cells was appreciated between mechanically minced (58% ± 23%) and explant (73% ± 14%) cartilage in the presence of fibrin glue (P = .52). The addition of fibrin glue did not significantly affect the viability of cartilage samples. The qualitative assessment revealed comparable cellular migration and outgrowth between groups. Proteoglycan synthesis was not significantly different between groups. Histological analysis findings were positive for COL2A1 in all groups, and matrix formation was appreciated in all groups. COL2A1 expression in minced cartilage (1.72 ± 1.88) was significantly higher than in explant cartilage (0.15 ± 0.07) in the presence of fibrin glue (P = .01). CONCLUSION: Mechanically minced articular cartilage remained viable after 42 days of culture in vitro and was comparable with cartilage explants with regard to cellular migration, outgrowth, and extracellular matrix synthesis. CLINICAL RELEVANCE: Mechanically minced articular cartilage is an encouraging intervention for the treatment of symptomatic cartilage defects. Further translational work is warranted to determine the viability of minced cartilage implantation as a single-stage therapeutic intervention in vivo.

The Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient-Acceptable Symptomatic State after Medial Patellofemoral Ligament Reconstruction.

Purpose: To define the minimal clinically important difference (MCID), substantial clinical benefit (SCB) and patient-acceptable symptomatic state (PASS) for patient-reported outcome measures (PROMs) after medial patellofemoral ligament reconstruction (MPFLR) and to investigate the role of preoperative, demographic, and intraoperative variables for predicting achievement of these thresholds. Methods: This retrospective cohort study used a prospectively maintained database of patients undergoing primary MPFLR between August 2015 and December 2019. PROMs included the International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS joint replacement (JR), and Kujala. Anchor-based and distribution-based methods were used to calculate the MCID, SCB, and PASS. Regression analyses were performed to identify prognosticators for achievement of clinically significant thresholds. Results: 139 patients met inclusion criteria (mean age: 21.7± 8.2 years). At 6 months, the MCID values were 8.3 (KOOS-Pain) and 8.5/13.5 (Kujala); SCB values were 1.4 (KOOS-Pain) and 43.7 (KOOS-QOL); and PASS values were 64.9 (IKDC), 83.3 (KOOS-Symptom), 76.8 (KOOS-Pain), 91.2 (KOOS-ADL), 47.5 (KOOS-Sport), 40.6 (KOOS-QOL), and 78.1 (KOOS-JR). At 1 year, the MCID values were 4.2 (KOOS-Pain), 7.2 (KOOS-ADL), 12.4 (KOOS-QOL) and 25.2 (KOOS-JR); SCB were 23.6 (IKDC), 4.2 (KOOS-Symptom), 19.7 (KOOS-Pain), 6.5 (KOOS-ADL), 55.0 (KOOS-Sport), 6.3 (KOOS-QOL), and 19.6/25.2 (KOOS-JR); and PASS were 65.5 (IKDC), 80.4 (KOOS-Symptom), 84.7 (KOOS-Pain), 99.3 (KOOS-ADL), 57.5 (KOOS-Sport), 53.1 (KOOS-QOL), and 76.3 (KOOS-JR). In regression analysis, greater age, body mass index, and preoperative PROMs were negative prognosticators for achieving clinically significant thresholds. Conversely, male gender increased the likelihood of achieving PASS for Kujala at 6 months and KOOS-ADL at 1 year. Conclusions: This study established thresholds for the MCID, SCB, and PASS at 6 months and 1 year after MPFLR, providing physicians an evidence-based method to advise patients and assess outcomes with this surgery. Older patients and those with higher preoperative outcome scores are less likely to report improvement and satisfaction with MPFLR, while male patients are more likely to report some satisfaction. Level of Evidence: Level III, retrospective cohort study (diagnosis).