Common radiographic indices used to measure patellar height do not consistently identify patella alta and lack interchangeability between measurements.

PURPOSE: Abnormal patellar height has been identified as a source of aberrant mechanical functioning within the patellofemoral joint. The purpose of this study is to examine the statistical agreement among three commonly used classification methods: Blackburne-Peel (BPI), Caton-Deschamps (CDI) and Insall-Salvati (ISR), by evaluating (1) the rates of patella alta identification and (2) the ability for one index to predict another. METHODS: One hundred lateral knee radiographs were evaluated using BPI, CDI and ISR to classify each knee as patella normal, patella alta or patella baja. Linear regression analysis was performed to evaluate the relationship between each index. Conversion equations were then derived using the reported linear regression best-fit line, comparing each pair of indices. RESULTS: Patella alta was identified in 15 knees using BPI, 15 using CDI and 25 using ISR. A total of seven knees were classified as patella alta by all BPI, CDI and ISR. Statistical analysis revealed significant correlation (p ≤ 0.001) among BPI and CDI (R2 = 0.706), BPI and ISR (R2 = 0.328) and CDI and ISR (R2 = 0.288). Wilcoxon Signed-Rank test between the three indices revealed no significant difference between the means of converted and original indices. CONCLUSION: Despite their significant correlations and adequate reproducibility, variability between common patellar height indices render predictions and conversions between BPI, CDI and ISR inequivalent. Users of these indices must be aware of their incongruent properties when considering application to patients in the clinical setting. Furthermore, it remains unclear which patellar height measurement technique is the correct index to use in a given knee. This study highlights the need for further investigation to create a reliable and standardised method for identifying patella height. LEVEL OF EVIDENCE: Level IV.

Relationship Between Hip Capsular Thickness and Instability After Previous Hip Arthroscopic Surgery: A Matched-Cohort Analysis.

Background: Thinner anterior hip capsules are associated with hip laxity, but there is little known about the impact of capsular thickness on the development of instability after primary hip arthroscopic surgery. Purpose: To investigate the relationship between hip capsular thickness as measured on preoperative magnetic resonance imaging (MRI) and the development of hip instability after hip arthroscopic surgery for femoroacetabular impingement. Study Design: Case-control study; Level of evidence, 3. Methods: We reviewed revision hip arthroscopic procedures performed between January 1, 2019, and May 1, 2021, at a single institution. Inclusion criteria were preoperative MRI/magnetic resonance arthrography, completion of the study traction protocol, and asymmetric distraction between the hips of ≥3 mm on examination under anesthesia. A comparison group of patients treated for femoroacetabular impingement with primary hip arthroscopic surgery who did not develop capsular instability were matched 1:1 to the patients with instability. Superolateral hip capsular thickness was measured on MRI before index surgery. Analysis was conducted using independent-samples t tests and multivariable linear regression. Results: A total of 44 patients were included, with 22 patients each in the instability and no-instability groups. The mean capsular thickness was lower in the patients with hip instability than in those without (1.9 ± 0.6 vs 3.4 ± 1.1 mm, respectively; P < .001). Decreased capsular thickness was significantly associated with hips with instability versus no-instability (ß = -1.468 [95% CI, -2.049 to -0.887]; P < .001). Conclusion: Thinner preoperative hip capsules in the region of the iliofemoral ligament were seen in patients who subsequently underwent revision arthroscopic surgery for hip instability compared to patients who underwent primary hip arthroscopic surgery without subsequent revision. Patients at a higher risk for the development of postoperative hip instability had a superolateral hip capsular thickness of <2 mm.

Magnetic Resonance Imaging and Magnetic Resonance Arthrography Are Both Reliable and Similar When Measuring Hip Capsule Thickness in Patients With Femoroacetabular Impingement Syndrome.

Purpose: To propose an accurate method of measuring hip capsular thickness in patients with femoroacetabular impingement syndrome and to compare the reliability of these measurements between magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA). Methods: A previously established database of patients with femoroacetabular impingement syndrome (FAIS) was used to identify candidates with preoperative MRI or MRA from November 2018 to June 2021. Two reviewers independently examined preoperative imaging for 85 patients. Capsular thickness was measured in 12 standardized locations. Intraclass correlation coefficients (ICCs) were calculated using an absolute-agreement, 2-way random-effects model. Using the same method, 30 patients were randomly selected for repeat measurements by 1 reviewer following a washout period. Ten additional patients with preoperative MRI and MRA of the same hip were identified to compare measurements between modalities using paired samples t test. Results: ICCs for measurements on MRIs and MRAs using these proposed measurements to compare inter-rater reliability were 0.981 and 0.985. ICCs calculated using measurements by a single reviewer following a washout period for intrarater reliability were 0.998 and 0.991. When comparing MRI and MRA measurements in the same patient, t test for all pooled measurements found no difference between modality (P = .283), and breakdown of measurements by quadrant found no difference in measurements (P > .05), with the exception of the inferior aspect of the capsule on coronal sequences (P = .023). Conclusions: In patients with FAIS, both MRI and MRA have excellent reliability for quantifying hip capsular thickness. A difference in capsular thickness was found only when comparing MRI and MRA on inferior coronal aspects of the hip capsule, indicating interchangeability of these imaging modalities when measuring the clinically important aspects of the hip capsule. Level of Evidence: Level IV, diagnostic case series.

Correlation of Tibial Tubercle Overgrowth With Increased Posterior Tibial Slope: A Novel Radiographic Assessment.

Background: An elevated posterior tibial slope (PTS) is associated with an increased risk for anterior cruciate ligament and meniscal injury. Recent evidence suggests that the PTS is elevated in patients with Osgood-Schlatter disease. Purpose: To determine whether there is an association between objective measures of anterior tibial tubercle growth and PTS. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 100 radiographs were randomly selected from a sample of patients who had received a lateral knee radiograph that captured at least 15 cm of the tibia distal to the knee joint line at a single institution between December 2020 and March 2022. The PTS was measured, and tibial tubercle growth was quantified with 2 novel measurements. For these measurements, a line was drawn on the radiograph from the most anterosuperior point on the tibia to the point on the anterior cortex of the tibia 10 cm distal from the starting point. The tibial tubercle height (TTH) was measured as the perpendicular distance from this line to the most prominent portion of the anterior tibia. The anterior tibial tubercle angle (TTA) was measured as the angle between the endpoints of the line made previously and the most prominent portion of the tibial tubercle, with a more acute angle indicating a more prominent tibial tubercle. The relationship between TTA, TTH, and PTS was evaluated using a univariate linear regression model. Results: The mean patient age was 33.1 ± 14.1 years. The mean TTA was 158.6°± 4.7°, the mean TTH was 8.8 ± 2.0 mm, and the mean PTS was 9.7°± 2.6°. A significant correlation was found between PTS and TTA (r = -0.46; ß = -0.46; P < .001) as well as TTH (r = 0.43; ß = 0.43; P < .001). Conclusion: Objective measures of anterior tibial tubercle overgrowth correlated with an elevated PTS. Every 2.2° of anterior TTA deviation from the mean and every 2.3 mm in TTH deviation from the mean correlated with a 1° difference in the PTS. This suggests a link between the development of the tibial tubercle and PTS, and it potentially helps to explain why the PTS is elevated in certain patients.

Association of Relative Skeletal Immaturity of the Triradiate Cartilage with Increased Proximal Femoral Deformity in Prophylactic Fixation for Slipped Capital Femoral Epiphysis: A Radiographic Study.

INTRODUCTION: The purpose of this study was to describe proximal femoral deformity after contralateral hip prophylactic fixation of slipped capital femoral epiphysis (SCFE) in patients and the association of relative skeletal immaturity with this deformity. METHODS: A retrospective review of patients presenting with a SCFE was conducted from 2009 to 2015. Inclusion criteria were (1) radiographic evidence of a unilateral SCFE treated with in situ fixation, (2) contralateral prophylactic fixation of an unslipped hip, and (3) at least 3 years of follow-up. Measurements were made on radiographs and included greater trochanter height relative to the center of the femoral head, femoral head-neck offset, and femoral neck length. Skeletal maturity was evaluated by assessing the status of the proximal femoral physis and triradiate cartilage (TRC) of the hip, in addition to the length of time to closure of these physes. Values were compared from initial presentation to final follow-up. Statistical analysis included descriptive statistics and linear regression. RESULTS: Twenty-seven patients were included. Bivariable linear regression demonstrated that an increased relative trochanteric overgrowth was associated with TRC width (ß = 3.048, R = 0.585, P = 0.001) and an open TRC (ß = -11.400, R = 0.227, P = 0.012). Time to proximal femoral physis closure (ß = 1.963, R = 0.444, P = 0.020) and TRC closure (ß = 1.983, R = 0.486, P = 0.010) were predictive of increased deformity. In addition, multivariable elimination linear regression demonstrated that TRC width (ß = 3.048, R = 0.585, P = 0.001) was predictive of an increased relative trochanteric overgrowth. DISCUSSION: Patients with an open TRC and increased TRC width are associated with increased relative trochanteric overgrowth when undergoing prophylactic fixation for a unilateral SCFE. Increased caution should be exercised when considering contralateral hip prophylactic fixation in skeletally immature patients presenting with a unilateral SCFE. LEVEL OF EVIDENCE: Level IV, case series.

Mid-term outcomes of temporary medial distal femoral hemiepiphysiodesis with and without medial patellofemoral ligament repair for recurrent patellar instability in skeletally immature patients with genu valgum.

Genu valgum contributes to patellar instability, though outcomes following temporary hemiepiphysiodesis via eight plating are less understood. The purpose of this study was to evaluate the outcomes and need for additional procedures following temporary hemiepiphysiodesis for the treatment of pediatric genu valgum and patellar instability, as well as evaluating the utility of a concurrent medial patellofemoral ligament (MPFL) repair. Patients who underwent medial distal femoral epiphysiodesis for the treatment of genu valgum and recurrent patellar instability were identified. Inclusion criteria were minimum 1-year follow-up and lack of concurrent ligamentous reconstruction. Patients were contacted to complete a questionnaire which included the International Knee Documentation Committee (IKDC) form and questions pertaining to knee function and patient satisfaction. Thirty-one patients aged 12.0 ± 1.9 years underwent 47 guided growth procedures and were included in final analysis. Seventeen knees (36%) required subsequent surgery for patellar instability. All patients requiring subsequent surgery were female, compared with 70% of patients not requiring subsequent surgery ( P  = 0.017). The MPFL repair group underwent fewer subsequent procedures to address instability, though this difference was NS (17 vs. 46%, P  = 0.318). Mean IKDC score at 5.3 years follow-up among 18 survey respondents was 78.6. Medial distal femoral hemiepiphysiodesis may partially address recurrent patellar instability in skeletally immature patients with genu valgum. Concurrent MPFL repair may minimize the need for subsequent procedures to address recurrent instability. While correcting alignment may be helpful, patients should be aware of the potential need for further patellar instability surgery. Level of evidence: IV, case series.

Editorial Commentary: Superior Capsular Reconstruction Hybrid Grafts Include Autograft for Healing Plus Synthetics for Structural Integrity to Improve Outcomes.

Superior capsular reconstruction is a viable option for select patients with massive irreparable rotator cuff tears. Graft integrity at short- and mid-term follow-up directly correlates with range of motion, functional outcome, and radiographic outcome. Historically, various graft options have been proposed, including dermal allograft, fascia lata autograft, and synthetic graft choices. With a traditional dermal allograft and fascia lata autograft, the graft retear rates have been variably reported. Because of this uncertainty, newer techniques using the healing capabilities of autografts in conjunction with the structural integrity of synthetic materials have emerged in an effort to decrease graft failure rates. Preliminary results are promising; however, longer-term follow-up with head-to-head comparison with traditional techniques is required to understand their true efficacy.

Acetabular Labral Reconstruction: Review of Techniques and Outcomes.

PURPOSE OF REVIEW: To analyze advances in labral reconstruction, and to discuss the literature relating to efficacy, outcomes, and technical considerations of labral reconstruction. RECENT FINDINGS: The available evidence suggests that labral reconstruction is a safe and effective procedure that can improve pain and function in patients with severe and/or complex labral tears. The superiority of labral reconstruction over labral repair is uncertain, and it remains unclear what graft type and technique should be used in labral reconstructions. Labral reconstruction assists in restoring the function of the labrum of the hip. It consistently restores stability of the hip joint and demonstrates good clinical outcomes at follow-up. The optimal graft type, technique, and extent are still debated, and more research is needed. Ultimately, despite this uncertainty, labral reconstruction is proving to be a valuable tool for hip preservation specialists.

Hip Joint Venting Decreases the Traction Force Required to Access the Central Compartment During Hip Arthroscopy.

Purpose: To investigate the effect of hip joint venting on the magnitude of traction force required to arthroscopically access the central compartment of the hip. Methods: Patients who underwent hip arthroscopy for femoroacetabular impingement syndrome prospectively underwent an intraoperative traction protocol. Joint space was measured on fluoroscopic images obtained at 50 and 100 lbs of axial traction in the prevented and vented state, and joint space values were normalized to millimetric values using preoperative anteroposterior pelvis radiographs. Venting was performed by inserting a large gauge spinal needle into the hip joint through the hip capsule and removing the stylet. Joint space differences were compared with paired t-tests, Wilcoxon signed-rank tests, and McNemar tests. Results: Fifty hips in 46 patients were included. Mean joint space before venting was 7.4 ± 2.6 mm and 13.3 ± 2.8 mm at 50 and 100 lbs of traction, respectively. Mean joint space after venting was 13.9 ± 2.3 mm and 15.5 ± 2.4 mm at 50 and 100 lbs of traction, respectively. Mean differences in joint space at 50 and 100 lbs were 6.5 mm (P < .001) and 2.2 mm (P < .001), respectively. Mean joint space at 50 lbs in the vented state was significantly greater than in the pre-vented state at 100 lbs (13.9 mm vs. 13.3 mm; P = .002). The increase in joint space between 50 and 100 lbs of traction was significantly greater in the prevented state than in the vented state (5.9 mm vs 1.6 mm; P = .021). Conclusions: Venting the hip reduces the traction force necessary to arthroscopically visualize and instrument the central compartment of the hip by at least 50%. Further, residual negative pressurization of the hip joint remains after breaking the labral suction seal and venting effectively eliminates this phenomenon to aid in hip joint distraction at lower traction force. Level of Evidence: Level IV, case series.

The Schöttle Point Is Consistently Located Distal to the Medial Femoral Physis in Pediatric Patients: A Digitally Reconstructed Radiographic Study.

BACKGROUND: Significant controversy surrounds ideal tunnel position for medial patellofemoral ligament (MPFL) reconstruction (MPFLR) in the pediatric setting. The start point for femoral tunnel positioning (the Schöttle point) relative to the distal medial femoral physis is not well defined. Previous studies provide conflicting data regarding position of the MPFL origin and the Schöttle point relative to the distal femoral physis. HYPOTHESIS: The Schöttle point would be consistently distal to the distal medial femoral physis. STUDY DESIGN: Descriptive laboratory study. METHODS: The institutional picture archiving and communication system was queried for computed tomography (CT) imaging studies of pediatric knees. Data were imported to an open-source image computing platform. True lateral digitally reconstructed radiographs and 3-dimensional (3D) renderings were generated, and the Schöttle point was registered in 3D space. Then, 3D distance measurements were obtained from the Schöttle point to the distal medial femoral physis. RESULTS: A total of 49 pediatric knee CT scans were included. Mean age was 13.0 ± 2.3 years. Mean minimum distance from the medial physis to the Schöttle point was 9.9 ± 3.0 mm (range, 3.4-16.1 mm). In 49 of 49 cases (100%), the Schöttle point was distal to the physis. Using a 6-mm reaming diameter would result in 3 of 49 (6%) femurs having violation of the distal medial femoral physis. Moving the start point 3 mm distally would result in 0 of 49 (0%) sustaining physeal injury. CONCLUSION/CLINICAL RELEVANCE: The Schöttle point is consistently distal to the distal medial femoral physis. The mean minimum distance from the Schöttle point to the physis on the medial cortex is 9.9 mm. The Schöttle point provides a safe and reliable radiographic landmark for pediatric MPFLR, although reaming diameter should be considered.

Postoperative Pain Medication Utilization in Pediatric Patients Undergoing Sports Orthopaedic Surgery: Characterizing Patient Usage Patterns and Opioid Retention.

INTRODUCTION: Opioid overprescribing is a problem in orthopaedic surgery, with many patients having leftover opioid medications after surgery. The purpose of our study was to capture utilization patterns of opioids in pediatric patients undergoing orthopaedic sports medicine surgery, in addition to evaluating patient practices surrounding unutilized opioid medication. Our hypothesis was that there would be low utilization of opioids in this patient population and would in turn contribute to notable overprescribing of opioids and opioid retention in this population. METHODS: Pediatric patients undergoing orthopaedic surgery for knee and hip pathology were prospectively enrolled. A survey was administered 14 days postoperatively, with questions centered on the patient-reported number of opioids prescribed, number of opioids used, number of days opioids were used, and incidences of leftover opioid medication and disposal of leftover medication. The magnitude of opioid overprescribing was calculated using the reported prescribed and reported used number of opioid pills. Linear regression was used to examine associations between opioids and NSAIDs prescribed. RESULTS: One hundred fourteen patients reported a mean prescription of 12.0 ± 5.0 pills, with utilization of 4.4 ± 6.1 pills over 2.7 ± 5.1 days. Patients were prescribed 2.73 times the number of opioid pills required on average. One hundred patients (87.7%) reported having unused opioid medication after their surgery, with 71 (71.0%) reporting opioid retention. Regression results showed an association with opioids used and prescribed opioid amount (ß = 0.582, R = 0.471, P < 0.001). DISCUSSION: Overall, our study results help characterize the utilization patterns of opioid medications in the postsurgical pediatric sports orthopaedic population and suggest that orthopaedic surgeons may be able to provide smaller quantities of opioid pills for analgesia than is typically prescribed, which in turn may help reduce the amount of prescription opioid medications present in the community. LEVEL OF EVIDENCE: Level IV.

Rapid nickel(ii)-promoted cysteine S-arylation with arylboronic acids.

S-Arylation of cysteine residues is an increasingly powerful tool for site-specific modification of proteins, providing novel structure and electronic perturbation. The present work demonstrates an operationally-simple cysteine arylation reaction 2-nitro-substituted arylboronic acids, promoted by a simple nickel(ii) salt. The process exhibits strikingly fast reaction rates under physiological conditions in purely aqueous media with excellent selectivity toward cysteine residues. Cysteine arylation of natural proteins and peptides allows attachment of useful reactive handles for stapling, imaging, or further conjugation.