PURPOSE:To compare the anterior-posterior distance ratio of the lateral-to-medial tibial plateau (LTP/MTP) among 3 patient groups: those with intact anterior cruciate ligaments (ACLi), primary ACL tears (ACLp), and failed ACL reconstructions (ACLf). METHODS:We retrospectively identified skeletally mature patients (16-40 years) who underwent knee magnetic resonance imaging between May 2013 and March 2022. Patients were included if they had adequate radiographs and magnetic resonance imaging available and were required to have a minimum of 2 years of follow-up for confirmation of ACL status. The anterior to posterior distance of the LTP and anterior to posterior distance of the MTP were measured on axial T1 magnetic resonance imaging to compute LTP/MTP. Tibial eminence width was measured between tibial spine peaks on coronal T1 magnetic resonance imaging. Posterior tibial slope (PTS) was calculated on lateral knee radiographs. Multivariate logistic regression identified predictors of ACLp and ACLf. RESULTS:Demographic characteristics: age, sex, and body mass index were no different between groups. The intraclass correlation coefficients for the morphometric measurements ranged from 0.750 to 0.902 indicating good to excellent agreement among the 3 raters and intrarater reliability testing. Mean PTS was significantly higher in ACLf (12.1 ± 2.9°) compared with ACLi (10.3 ± 2.0°) and ACLp (10.6 ± 2.6°) (P < .001). The mean LTP/MTP ratio was significantly lower in ACLp (0.79 ± 0.06) and ACLf (0.77 ± 0.06) versus ACLi (0.84 ± 0.06) (P < .001). In logistic regression comparing ACLp to ACLi, a lower LTP/MTP ratio was the only significant morphologic predictor (odds ratio [OR], 0.87; 95% confidence interval [CI]: 0.80-0.95). In contrast, when compared with ACLi, ACLf were significantly predicted by a lower LTP/MTP ratio (OR, 0.82; 95% CI: 0.74-0.91), higher PTS (OR, 1.38; 95% CI: 1.14-1.73), and narrower tibial eminence width (OR, 0.70; 95% CI: 0.51-0.94). A direct comparison found that higher PTS, narrower tibial eminence width, and higher body mass index were significantly associated with ACLf versus a ACLp. For every 1-degree increase in PTS, the odds of a retear versus ACL increased by 38%. CONCLUSIONS:This study identifies the LTP/MTP ratio as a key anatomical risk factor for ACL injury. Specifically, a smaller LTP/MTP ratio was associated with a significantly higher odds of both primary ACL tears and subsequent retears relative to individuals without ACL injury. LEVEL OF EVIDENCE:Level III, retrospective comparative study.

BACKGROUND:The identification of the medial patellofemoral ligament (MPFL) insertion site relies heavily on the use of radiographic landmarks such as the Schöttle point. However, little is known on how the variation in condylar alignment and beam directionality affects this perceived location. PURPOSE:To quantify changes in the perceived MPFL insertion site when posterior proximal or posterior distal condylar alignment is optimized and when fluoroscopic beam directionality alters. STUDY DESIGN:Controlled laboratory study. METHODS:A total of 16 cadaveric knees were included. The femoral insertion of the MPFL was identified and fixed with a radiopaque metal marker after dissection. Fluoroscopic images in the medial-to-lateral (ML) direction were taken with the posterior proximal condyles aligned and then with the posterior distal condyles aligned. Beam directionality was flipped to the lateral-to-medial (LM) direction, and images with posterior proximal and posterior distal condylar alignment were taken. Images were then superimposed onto the reference image, with discrepancies between marker locations quantified in the x- and y-axis. The 2-tailed Student t test was performed on all obtained variations. RESULTS:In the ML direction, proximal versus distal alignment resulted in a mean proximal displacement of 0.43 ± 1.86 mm (P = .37) and a mean posterior displacement of -0.11 ± 0.55 mm (P = .42). In the LM direction, proximal versus distal alignment resulted in a mean proximal displacement of 1.95 ± 2.37 mm (P = .005) and a mean anterior displacement of 0.22 ± 1.95 mm (P = .67). When comparing ML to LM beam directionality with optimized proximal condylar alignment, there was a mean distal displacement of -0.26 ± 1.73 mm (P = .56) and a mean anterior displacement of 2.22 ± 1.87 mm (P < .001). When comparing ML to LM beam directionality with optimized distal condylar alignment, there was a mean proximal displacement of 1.26 ± 2.53 mm (P = .07) and a mean anterior displacement of 2.55 ± 1.71 mm (P < .001). CONCLUSION:Beam directionality and condylar alignment affected the perceived location of the MPFL insertion. However, shooting in the ML direction and aligning the posterior proximal femoral condyles resulted in the least amount of total variation. Future studies are needed to determine the amount of variation in perceived MPFL insertion sites that are clinically significant. CLINICAL RELEVANCE:This information provides surgeons with the insight that beam directionality and condylar alignment significantly affect the perceived location of the MPFL insertion site and that surgeons can use fluoroscopic imaging in the ML direction with posterior proximal condylar alignment to minimize image variation.

Distal femoral hemiepiphysiodesis is a minimally invasive procedure used to correct pediatric knee angular deformities by guiding growth across an open physis. Intraoperative fluoroscopy is used to estimate the physeal midpoint for hardware placement; however, no standardized radiographic method has been established to identify this landmark. The purpose of this study was to determine the accuracy and reliability of three novel radiographic landmarks for approximating the distal femoral physeal midpoint. Perfect lateral digitally reconstructed radiographs of the knee were generated from computed tomography scans of pediatric patients using open-source image computing software. The physeal midpoint was identified and compared with three radiographic landmarks: the diaphyseal midpoint, the apex of the physeal undulation, and the inferior point of Blumensaat's line. The anteroposterior distance between each landmark and the physeal midpoint was measured, and intraclass correlation coefficients (ICCs) were calculated to assess reliability. Twenty-seven (71% male and 29% female) patients with a mean age of 13.6 ± 1.7 years were included. Relative to the physeal midpoint, the diaphyseal midpoint was 4.0 ± 2.4 mm anterior, the apex undulation was 1.6 ± 1.2 mm anterior, and the inferior Blumensaat's point was 1.2 ± 1.3 mm posterior. Reliability was good for the diaphyseal midpoint (ICC = 0.799) and apex undulation methods (ICC = 0.889), and excellent for the Blumensaat landmark (ICC = 0.987). These findings suggest that multiple radiographic landmarks can reliably approximate the distal femoral physeal midpoint on perfect lateral radiographs. The inferior point of Blumensaat's line demonstrated the greatest accuracy and reliability and may serve as a useful intraoperative guide for hardware placement during distal femoral guided growth procedures. LEVEL OF EVIDENCE:Level III.

Background: Graft selection in anterior cruciate ligament reconstruction (ACLR) may lead to long-term, graft-specific muscle adaptations, yet their effect on functional outcomes remains poorly understood. Magnetic resonance imaging (MRI)–based 3D modeling enables precise quantification of muscle volume changes, offering insight into the relationship between postoperative muscle preservation and patient-reported outcomes. Purpose: To radiologically evaluate thigh muscle volume changes and patient-reported outcomes at minimum 5-year follow-up among patients after primary anterior cruciate ligament reconstruction (ACLR) using allograft, bone–patellar tendon–bone autograft (BPTB), or hamstring autograft (gracilis and semitendinosus; HS) with MRI-based 3D modeling. Study Design: Cohort study; Level of evidence, 3. Methods: Patients aged 18 to 45 years (mean ± SD age, 26.9 ± 7.2 years) with a body mass index (BMI) <30 who underwent primary ACLR with either allograft, BPTB, or HS with minimum 5-year follow-up were identified via retrospective chart review. Exclusion criteria were any history of a knee flexor or extensor injury/surgery, revision ACLR procedures, any concomitant surgical procedures other than chondral debridement and/or meniscectomy/repair, or any subsequent lower extremity surgery since the index ACLR. Bilateral thigh 3.0-T MRI scans were obtained, and images were rendered using 3D modeling software. Volume measurements were performed for (1) the individual muscles, (2) each compartment, and (3) the entire thigh. Specific individual muscles analyzed included the quadriceps (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius) and sartorius in the anterior compartment; the hamstrings (biceps femoris long and short heads, semitendinosus, semimembranosus) in the posterior compartment; and the gracilis and combined adductor muscle group in the medial compartment. Individual muscle volumes were calculated for each thigh and then normalized as a percentage of the total volume of their respective muscle compartments. These compartment-relative percentages in the operative thigh were subsequently compared with the corresponding percentages in the contralateral, nonoperative thigh. Multivariable linear regression linked ratios of injured to contralateral muscle preservation (total and compartmental) to International Knee Documentation Committee (IKDC) scores, adjusting for age, sex, BMI, and graft type. Paired Student t tests and chi-square tests were used for statistical analysis. Results: A total of 30 patients were included: 10 allograft, 10 BPTB, and 10 HS. The cohort consisted of 18 male patients (60%) and 12 female patients (40%), with a higher proportion of male patients in the BPTB group (9/10 male). Allograft patients (mean age, 34.6 years; range, 31-40 years) were significantly older at surgery than BPTB (mean age, 23.4 years; range, 17-33 years) and HS cohorts (mean age, 22.7 years; range, 16-28 years) ( P < .001). The mean time interval from surgery to follow-up MRI was 6.7 ± 1.2 years. No significant differences in total thigh or individual muscle volumes were found between operative and nonoperative limbs with allograft. BPTB demonstrated a significant reduction in mean muscle volume percentage of the vastus intermedius in the operative thigh compared with the nonoperative thigh (13.98% vs 16.48%; P < .001). With HS, significant reductions were observed in mean muscle volume percentages of the gracilis (15.61% vs 27.35%; P < .001) and semitendinosus (7.49% vs 17.49%; P = .001) muscles in the operative thigh. Conversely, the semimembranosus exhibited a significant increase in mean muscle volume percentage in the operative thigh relative to the nonoperative thigh (42.50% vs 36.57%; P = .006). Across graft types, greater preservation of operative-limb muscle volume predicted better function: Total-thigh preservation correlated with higher IKDC scores ( B = 61.8; P = .043), and anterior-compartment preservation showed the strongest association ( B = 110.3; P = .004; model R 2 = 0.48). No covariate (age, sex, BMI, graft type) independently influenced IKDC score. Conclusion: Five years after ACLR, thigh muscle adaptation depended on graft choice and carried meaningful functional consequences. Hamstring autografts were associated with lasting atrophy of the semitendinosus and gracilis with compensatory hypertrophy of the semimembranosus, whereas BPTB autografts were associated with selective loss of the vastus intermedius and no compensatory enlargement in the remaining quadriceps. Across all patients, larger differences in muscle volume between limbs, especially in the anterior compartment, were linked to lower IKDC scores.

BACKGROUND:The periportal capsulotomy for hip arthroscopy minimizes iliofemoral ligament violation compared to T- and interportal capsulotomies, theoretically reducing the risk of postoperative instability secondary to capsular insufficiency. PURPOSE/HYPOTHESIS:The purpose of this study was to compare patient-reported outcomes (PROs) and revision rates between women without dysplasia who underwent an interportal versus a periportal capsulotomy approach for the treatment of femoroacetabular impingement syndrome (FAIS). It was hypothesized that women without dysplasia would achieve better outcomes and a lower revision rate through a periportal approach. STUDY DESIGN:Cohort study; Level of evidence, 3. METHODS:Consecutive female patients with normal acetabular coverage (lateral center-edge angle >25° and ≤40°) who underwent primary hip arthroscopy with complete capsular closure by a single surgeon for the treatment of FAIS between February 2020 and November 2022 were prospectively added to a database and their records retrospectively reviewed. An interportal capsulotomy was utilized in all patients before June 2021, and periportal capsulotomies were utilized thereafter. Femoral osteoplasty was performed in all patients, and a labral repair was performed when indicated. PROs were collected preoperatively and at a 2-year minimum follow-up, including pain scores at rest and activities of daily living (range, 0-10), single assessment numeric evaluation (SANE) scores, and Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF) scores. Minimal clinically important differences (MCIDs) were calculated using the distribution method. PROs, MCID achievement rates, and revision rates were compared between capsulotomy types. RESULTS:In total, 105 women without dysplasia (41 interportal, 64 periportal) were included. There were no differences in baseline demographic or radiographic characteristics between groups. Follow-up time was longer in the interportal group compared to the periportal group (3.52 ± 1.04 years vs 2.67 ± 0.62 years; P < .001). The periportal group had greater improvements in SANE (30.0 ± 20.2 vs 17.3 ± 21.3; P = .004) and PROMIS-PF (13.7 ± 9.61 vs 7.62 ± 9.04; P = .003) scores compared to the interportal group. The periportal group also had higher rates of MCID achievement with SANE (87% vs 69%; P = .037) and PROMIS-PF (90% vs 68%; P = .018) scores compared to the interportal group. Overall, the 2-year revision rate was 12% for the interportal group and 4.7% for the periportal group (P = .26). All patients who required additional surgery underwent revision hip arthroscopy for instability. CONCLUSION:In female patients without hip dysplasia who underwent primary hip arthroscopy for the treatment of FAIS, periportal capsulotomies with complete capsular closure provided higher rates of clinically meaningful improvements in subjective outcomes of SANE and PROMIS-PF scores compared to an interportal capsulotomy with complete closure at 2 years postoperatively.

PURPOSE:To determine if distraction distance changes on an axial traction examination between the time zero capsular repair state and a later follow-up traction examination in patients with staged bilateral hip arthroscopies for femoroacetabular impingement syndrome. METHODS:Patients between September 2022 and February 2025 who underwent staged, primary bilateral hip arthroscopies for femoroacetabular impingement syndrome with a closed periportal capsulotomy were included. Patients were excluded if they had prior hip surgery or had acetabular pathology beyond a labral tear. Fluoroscopic images were obtained at 0 and 100 pounds of axial traction force (lbf) at multiple time points: preinstrumentation, postcapsulotomy, postcapsular repair, and at follow-up during contralateral hip surgery. Linear regression assessed the change in distraction distance over time between time zero repair and the follow-up distraction distance, whereas logistic regression evaluated factors associated with substantial distraction increase, defined by the minimal detectable change. RESULTS:Forty-one patients (41 hips, mean age 25.7 ± 11.4 years, 66% female) were included. Mean lateral center edge angle was 28.5 ± 5.0° and mean alpha angle was 59.7 ± 7.4°. Mean time between surgeries was 248 ± 191 days [range 43-833]. Compared with the native state, a repaired periportal showed greater resistance to axial traction at 100 lbf (8.50 ± 2.35 mm vs 6.37 ± 2.67 mm; P = .01). Regression analysis showed a significant relationship between time since surgery and increase in distractibility (β = 0.003, 95% confidence interval [0.001-0.006], P = .01). Logistic regression identified female sex (β = 1.74, 95% confidence interval [1.02-31.9], P = .04) as a predictor of a substantial postoperative increases in distractibility (minimal detectable change ≥1.2 mm). CONCLUSIONS:A repaired periportal capsulotomy shows increased resistance to axial traction compared with the native state at time zero; however, this resistance progressively decreases over time and returns to the native state on follow-up testing. LEVEL OF EVIDENCE:Level IV, retrospective case series.

PURPOSE:To determine the angle of hip flexion at which femoral neck chondral lesions in patients with femoroacetabular impingement syndrome (FAIS) engage the labrum under direct arthroscopic visualization. METHODS:Primary hip arthroscopy patients between 2022 and 2024 with intraoperatively identified femoral neck chondral lesions were included. Patients were flexed at the hip with the lower extremity in neutral rotation until the labrum engaged the femoral neck chondral lesion. Lateral photographs of the patient on the operating table were taken at this position, and degree of hip flexion was calculated using an online goniometer. Comparisons between the angle of impingement and patient demographics were assessed via two-tailed t-tests and one-way analysis of variance. Regression analysis was performed to evaluate the relationship between the impingement angle and various radiographic measurements while controlling for age, sex, and body mass index (BMI). RESULTS:A total of 108 patients were analyzed in this study. Mean age was 31.0 ± 10.8 years, mean BMI was 26.4 ± 5.8 kg/m2, and 73 (68%) were females. Mean angle of hip flexion required to achieve impingement was 63.3° ± 11.5° (range: 39.8-94.9). Males engaged at higher flexion angles (66.5° ± 10.9°) compared to females (61.8 ± 11.6, P = .045). Regression analysis had inverse relationship between impingement angle and alpha angle on frog leg lateral (β = -0.291, 95% confidence interval [-0.427 to -0.153], P < .001) and anteroposterior radiographs (β = -0.393, 95% confidence interval [-0.567 to -0.231], P < .001), as well as a direct relationship between femoral version and impingement angle (β = 0.406, 95% confidence interval [0.395 to 0.985], P < .001). CONCLUSIONS:Hip impingement in those with FAIS may routinely occur at hip flexion angles below 90° in neutral rotation, with males engaging at higher flexion angles than females. Furthermore, the angle of impingement directly correlates with femoral version and inversely correlates with alpha angles on radiographs. LEVEL OF EVIDENCE:Level IV, case series.

INTRODUCTION:Radiographic markers including the crossover sign (COS), ischial spine sign (ISS), and posterior wall sign (PWS) are commonly used to assess acetabular morphology. The aim of this study was to determine the vertical tilt or horizontal rotation needed to elicit sign changes on anterior-posterior (AP) digitally reconstructed radiographs (DRRs). METHODS:CT scans of the pelvis were retrospectively collected and imported into three-dimensional (3D) imaging software to create 3D AP digitally reconstructed radiographs (DRRs). Rendered pelvises were standardized to 0° of tilt and rotation and assessed for positive or negative findings of COS, ISS, and PWS. Then, the DRR was manipulated at 1° intervals (from 0° to 20° in each direction), progressively inducing pelvic tilt in the vertical axis, and the process was then repeated in the horizontal axis. The degree at which the sign changed from positive to negative or vice versa in each hip was recorded. RESULTS:A total of 20 hips were assessed (five men, five women). On the standardized AP pelvis radiographs, positive COS, ISS, and PWS were 45%, 25%, and 75% respectively. The mean rotation required to change COS, ISS, and PWS from positive to negative or vice versa was 7.92° ± 4.25°, 5.55° ± 2.63°, and 6.37° ± 3.89°, respectively. The mean tilt required to flip COS, ISS, and PWS was 8.80° ± 5.73°, 7.73° ± 3.65°, and 9.55° ± 4.98°. CONCLUSION:Close consideration should be given to pelvic position when assessing positive findings of COS, ISS, and PWS because all signs were noted to flip with small degrees of rotation and tilt.

PURPOSE:To evaluate the in vivo biomechanical effects of periportal capsulotomies, single (modified anterior portal [MAP]) portal repair, and complete (MAP + anterolateral portal [ALP]) repair on altering the resistance to axial distraction compared to the native state (i.e., precapsulotomy). METHODS:Consecutive patients undergoing primary hip arthroscopy with periportal capsulotomies received intraoperative axial distraction testing at 0, 50, and 100 pounds of force (lbf). Patients were excluded if they did not break their suction seal with 100 lbf. Distraction testing was performed prior to capsulotomy (native), postcapsulotomy, after repair of just the MAP (partial repair), and after repair of both the MAP and ALP (complete repair). Distraction distances were calculated in millimeters (mm) as the difference in joint space between 0 and 50 or 100 lbf on intraoperative fluoroscopy from the lateral sourcil edge of the acetabulum to the femoral head. Repeated measures analysis of variance and Bonferroni-corrected P values were used for comparison. RESULTS:Eighty-six patients were included (58% female; mean age, 33.6 ± 11.7 years). There was a significant increase in distraction distance in the unreparied capsulotomy state compared to the native state at 100 lbf (1.14 [0.33-1.96] mm, P = .03). After partial and complete repair, the distraction distance was significantly decreased compared to the native state at 100 pounds of traction by 1.09 mm (0.28-1.90, P < .001) and 2.84 mm (2.09-3.59, P < .001), respectively. In a subgroup analysis, males also had a substantial decrease in distraction distance with MAP closure alone compared to the native state at 100 lbf (1.33 [0.32-2.35] mm, P = .04), whereas females did not (0.92 [0.09-1.75] mm, P = .19). CONCLUSIONS:The periportal capsulotomy causes a significant increase in hip distractibility compared to the native state, and both partial and complete capsular repair restore distraction resistance to levels at or greater than the native state. LEVEL OF EVIDENCE:Level IV, retrospective case series.

The acetabular labrum has long been a centerpiece in the treatment of femoroacetabular impingement syndrome and in our understanding of hip biomechanics. The labrum has a number of biomechanically distinct functions, including increasing the overall contact area of the hip joint, preventing synovial fluid egress from the central compartment during compressive loading, and increasing hip stability via negative pressure generation during destabilizing movements. Despite the delineation of these functions, our understanding of the labrum's influence on outcomes in hip preservation procedures is yet evolving. Labral preservation, via labral repair/refixation, has been consistently associated with greater improvement in patient-reported outcomes when compared with labral debridement. The influence of the hypoplastic labrum, a less severe labral deficiency, on surgical outcomes is an active area of investigation.

BACKGROUND:Spinopelvic morphology and alignment have been theorized to play a role in causing femoroacetabular impingement syndrome symptoms in individuals with cam morphology. However, prior studies have used hip morphological and alignment measurements that are interdependent, limiting understanding of form-function relationships. METHODS:Statistical shape modeling and biplane videoradiography were used for accurate, 3D assessment of femur and pelvis morphology and in vivo standing hip and pelvis orientation among individuals with and without cam morphology and impingement symptoms. Group differences in standing posture and shape were assessed, along with correlations between shape and posture. FINDINGS:Patients stood with less anterior pelvic tilt and greater hip extension than asymptomatic individuals without cam morphology. A more patient-like proximal femur shape was correlated with less anterior pelvic tilt. Asymptomatic individuals with cam morphology showed no standing posture differences but had a unique pelvic shape featuring an internally rotated ilium. Further, femur and pelvis anatomical features, primarily describing changes at hip-crossing muscle attachment sites and the sacroiliac region, showed significant associations with hip and pelvis orientation in the sagittal and frontal planes. INTERPRETATION:Patients with symptomatic impingement due to cam morphology may preemptively adopt less anterior pelvic tilt to enable functional hip range of motion. The associations between shape and standing posture may identify patients best suited for treatment involving pelvic posture modification. Results support further investigation of hip crossing muscle characteristics and spinopelvic alignment during dynamic activities to strengthen understanding of the underlying mechanisms responsible for symptoms in patients with femoroacetabular impingement syndrome.

BACKGROUND:Lateral extra-articular tenodesis (LET) is used as an adjunct to anterior cruciate ligament reconstruction (ACLR) to enhance stability. However, understanding of the optimal fixation method is limited. PURPOSE/HYPOTHESIS:The purpose was to compare biomechanical knee stability using 3 femoral LET fixation methods before and after cyclic loading. It was hypothesized that the fixation achieved with a suture anchor or an interference screw would demonstrate greater stability than that achieved with a metallic staple. STUDY DESIGN:Controlled laboratory study. METHODS:Ten matched pairs of cadaveric knees (mean age 64 years) underwent modified Lemaire LET. Each pair received suture anchor fixation on 1 knee and either interference screw (arm A) or metallic staple (arm B) fixation on the contralateral knee. Specimens were tested in 4 states: intact (native), anterolateral knee lesion, modified Lemaire (LET) procedure, and modified Lemaire (LET) procedure after cyclic loading. Cyclic loading consisted of 2000 cycles of 5 N·m internal rotation at 1 Hz. Anterior translation was applied at 90 N of force using visual marker motion capture. Internal rotation was measured using a 5 N·m moment and a digital inclinometer. RESULTS:No significant differences in anterior translation were observed between the different states (anterolateral lesion, LET, and post-cyclic loading) for all constructs. The mean increase in internal rotation among the subgroups after undergoing anterolateral lesion ranged from 2.1° to 4.0°. No significant difference was found in mean internal rotation after samples underwent cyclic loading in both arms of the study (arm A [suture anchor vs screw], P = .262; arm B [suture anchor vs staple], P = .450). Specimen undergoing suture anchor fixation demonstrated significantly greater change in internal rotation from pre- to post-cyclic loading than those using screw fixation (arm A, 7.2% ± 2.3% vs -1.3% ± 2.6%, respectively; P = .011) but not staple fixation (arm B, 14.3% ± 16.7% vs 5.3% ± 3.1%; P = .338). Internal rotatory stability was restored by all LET methods even after undergoing cyclic loading. CONCLUSION:All fixation methods restored rotational stability to near-native levels even after loading. Suture anchor fixation appeared more vulnerable to cyclic loading than the other 2 methods. CLINICAL RELEVANCE:Suture anchors appeared most vulnerable to cyclic loading. No significant difference was found in absolute mean internal rotation values between suture anchors and screws or staples. Clinically, all 3 methods remain viable options for LET fixation. Staples and screw may better resist cyclic physiologic stress when compared with suture in controlled settings; however, this may not be clinically significant.

Background: Controversy exists surrounding the necessity of capsular repair in patients undergoing hip arthroscopy. In adults, studies show capsulotomy decreases the hip joint’s resistance to axial distraction, and capsular repair restores this resistance to native-state levels. However, no literature exists evaluating these distraction characteristics in pediatrics, particularly when utilizing a periportal approach. The purpose of this study is to assess whether periportal capsulotomy compromises the hip joint’s resistance to axial distraction, and whether capsular repair can restore native state resistance in the pediatric population. Methods: Patients undergoing primary hip arthroscopy for femoroacetabular impingement underwent intraoperative axial distraction testing. This was conducted in the native, capsulotomy, and repaired capsular states, using fluoroscopic imaging at 0-, 25-, 50-, 75-, and 100- lbs. of applied traction. Variables were assessed for normality using a Shapiro-Wilk test, and comparisons were made using a paired t-test for normally distributed data, and a Wilcoxon signed-rank test for non-normally distributed data. Results: Fifty hips were included for analysis with a mean age of 16.8±1.3 years. Relative to the native state, hips in the open capsulotomy state distracted to significantly greater distances at 25, 50, 75, and 100 lbs. (p<0.001). Once repaired, hips distracted to significantly lesser distances at 25, 50, 75, and 100 lbs. compared to the capsulotomy state (p≤0.001). When comparing the repaired versus native states, repaired hips distracted more at 25 lbs. (p<0.001), distracted similarly at 50 lbs. (p=0,751), and significantly less at 75 and 100 lbs. (p<0.001). Conclusion: This study provides the first in-vivo biomechanical data investigating intraoperative distraction in pediatric patients undergoing periportal capsulotomy with capsular repair. Despite minimizing iliofemoral ligament disruption with a periportal approach, the capsulotomy resulted in increased distraction compared to the native hip, with restoration of this resistance to distraction with capsular repair. To minimize the potential risk of iatrogenic hip instability after hip arthroscopy in pediatric patients, a capsular repair should be considered even when utilizing a periportal capsulotomy approach. Level of Evidence: Level IV, case series

Background:Multiligament knee injuries (MLKIs) are complex and challenging, with significant long-term consequences. While previous studies have examined chondral injuries in MLKI over time, there are limited data regarding their development during the interval between injury and surgery. Hypothesis:MLKIs with increased time interval between injury and surgery will be associated with an increased incidence of chondral injuries. Study Design:Case-control study; Level of evidence, 3. Methods:This retrospective review utilized a multisurgeon database, including patients with MLKI treated from April 2008 to October 2022. Inclusion criteria were MLKI requiring surgical intervention, available operative reports, and documented date of injury in the electronic medical record. MLKIs were categorized by time interval from injury to surgery (acute, 0-90 days; delayed, 91-365 days; late, >365 days). The location and pattern of meniscal and chondral injuries were evaluated accordingly. Compartment injury patterns were also analyzed based on cruciate ligament injury pattern. Results:A total of 206 patients were included (acute, n = 138; delayed, n = 54; late, n = 14). The delayed and late groups had significantly higher mean numbers of chondral surface injury (out of 6 total surfaces evaluated) compared with the acute group (delayed, 1.79; late, 1.52; acute, 0.70; P = .002). Trochlear cartilage injuries occurred significantly more frequently in the delayed (28%) compared with the acute group (9%; P = .003). Similarly, patellar cartilage injuries were more common in the delayed (30%) compared with acute patients (12%; P = .02). Medial femoral condylar chondral injuries were significantly increased in the delayed (30%) and late (50%) groups compared with acute (15%; P = .002). Medial tibial plateau cartilage injuries followed the same pattern (acute, 13%; delayed, 30%; late, 43%; P = .002). Patients with bicruciate MLKIs undergoing surgery after 90 days showed significantly higher trochlear (31% vs 8%; P = .04) and patellar cartilage injury rates (35% vs 11%; P = .03). ACL-based MLKIs operated beyond 90 days had increased rates of trochlear (22% vs 8%; P = .03), medial femoral condylar (30% vs 13%; P = .02), and medial tibial plateau (27% vs 11%; P = .03) cartilage injury. PCL-based MLKI patients undergoing delayed surgery (>90 days) also had significantly higher medial femoral condylar (71% vs 8%; P = .004) and medial tibial plateau (71% vs 8%; P = .01) cartilage injury rates. Meniscal injury rates did not differ significantly across time groups. Conclusion:Patients who underwent delayed surgery for their MLKI injuries had more medial and patellofemoral cartilage injuries at the time of surgery than those treated within 30 days of injury.

BACKGROUND:Intraoperative hip capsule management is increasingly recognized as an important component of hip arthroscopy for the prevention of capsular-related instability. The periportal capsulotomy, relative to the interportal capsulotomy, has been proposed as a minimally invasive technique for decreasing postarthroscopy hip instability; however, the biomechanical effects of this technique are not well established. PURPOSE/HYPOTHESIS:This study aimed to provide a biomechanical characterization of interportal and periportal capsulotomies, helping inform surgeon choice of capsulotomy type and repair, potentially guiding clinical practice in hip arthroscopy. The authors hypothesized that the periportal capsulotomy would demonstrate greater resistance to axial distraction in all capsular states. STUDY DESIGN:Cross-sectional study; Level of evidence, 3. METHODS:Patients undergoing primary hip arthroscopy by a single surgeon underwent intraoperative axial distraction testing at 25-, 50-, 75-, and 100-pound force intervals, with each axial distraction distance measured by standardized fluoroscopic evaluation. Propensity matching was conducted between the periportal group and the interportal group using native state distraction, lateral center-edge angle, and sex as covariates to achieve balance between groups. Between-group comparisons of distraction distances were then conducted using the Student t test and Fisher exact test. RESULTS:In total, 74 interportal capsulotomies and 124 periportal capsulotomies were identified. Propensity matching yielded 74 hips in each group. Demographic and radiographic characteristics were similar between matched cohorts (P > .05). An unrepaired interportal capsulotomy led to an increase in hip distraction of 2.74 mm at 100 lbf (P < .001) compared with the native state, whereas unrepaired periportal capsulotomy led to an increase of 2.43 mm at 100 lbf (P < .001). Distraction distances were similar between the interportal and periportal groups in both the capsulotomy and repair states (P > .05), while the periportal capsulotomy repair demonstrated decreased hip distraction distance when compared with the native state by 1.37 mm at 75 lbf and 1.45 mm at 100 lbf (P < .001). CONCLUSION:In a propensity-matched cohort analysis, an unrepaired periportal capsulotomy and interportal capsulotomy have similar effects on increasing hip axial distraction distance intraoperatively. Performing a capsular repair restores intraoperative resistance to axial distraction in both procedures. Despite the minimal disruption of the capsule with periportal techniques, repair is required for restoration of native biomechanics.

Background:For patients who have patellar instability with patella alta, distalizing the patella via tibial tubercle osteotomy (TTO-d) is one method used to surgically restore stability. Although this procedure is generally associated with favorable outcomes, the effects on maintaining postoperative patellar height remain inadequately understood. Purpose/Hypothesis:This study aimed to assess changes in patellar height after TTO-d in skeletally mature patients. It was hypothesized that the patella would eventually return to a state of alta after TTO-d. Study Design:Case series; Level of evidence, 4. Methods:Skeletally mature patients who underwent a TTO-d procedure with a follow-up lateral knee radiograph at ≥3 months after surgery were included. Caton-Deschamp (CD) and Blackburne-Peele (BP) indices were calculated at various time intervals: preoperative, immediate postoperative, 3-month, 6-month, and ≥1-year follow-up on lateral knee radiographs as available. Paired Student t tests were used to compare patellar height indices at different time points. Result:A total of 35 knees in 28 patients were included in this study, 20 of which had imaging ≥1 year postoperatively. The mean age of the cohort was 22.3 ± 7.95 years (range, 15.5-43.0 years), mean body mass index was 28.0 ± 7.86, mean tibial tubercle distalization was 10.8 ± 4.83 mm at time of surgery, and mean follow-up using the latest available lateral knee radiographs occurred at 2.83 ± 2.96 years postoperatively. Mean preoperative CD and BP indices were 1.46 ± 0.193 and 1.24 ± 0.196, respectively, which decreased to 1.13 ± 0.189 (P < .001) and 0.855 ± 0.209 (P < .001) on immediate postoperative films. In those with imaging ≥1 year out from surgery, mean CD and BP indices increased to 1.34 ± 0.196 (P < .001) and 1.13 ± 0.131, respectively. Additionally, 88% (15/17) of patients with a minimum 1-year radiographic follow-up transitioned from normal CD and BP indices immediately postoperatively to patella alta at latest follow-up. Conclusion:Nearly all patients who underwent TTO-d had progressive increases in both CD and BP indices over time, suggesting a return to a state of patella alta over time. Further studies are needed to compare clinical outcomes of patients who have a confirmed return to alta versus those who do not in order to better understand the clinical significance of this observation.

Purpose To examine the relationship of labral height measured on magnetic resonance imaging and resistance to axial distraction in patients with cam-type femoroacetabular impingement (FAI) syndrome. Methods Patients who underwent primary hip arthroscopy for FAI syndrome between March 2020 and August 2020 were enrolled in the study traction protocol. Before any operative instrumentation, fluoroscopic images were taken of the native hip joint at 12.5-lb intervals between 0 and 100 lbs of axial traction on a postless traction table. Distraction was calculated as the difference between the total joint space at each traction interval and the baseline joint space. Labral height was measured on magnetic resonance imaging sagittal reformats at approximately 1:30 on the acetabular clockface by a musculoskeletal fellowship-trained radiologist blinded to the traction data. Descriptive statistics, independent samples t tests, Pearson χ2 tests, and Fisher exact tests were utilized in analysis. Results Forty-three hips in 42 patients were included. Labral height was <6 mm in 19 (44%) patients and ≥6 mm in 24 (56%) patients. No statistically significant differences in age, sex, body mass index, alpha angle, Tönnis grade, lateral center edge angle, Beighton score, or presence of labral tears were observed between patients with <6 and ≥6 mm of labral height (P > .05). A greater percentage of patients with a labral height <6 mm broke their suction seal relative to patients with a labral height of ≥6 mm at 62.5 lbs (42% vs 4%; P = .003) and 100 lbs (95% vs 67%; P = .027). Conclusions Anterosuperior labral height ≥6 mm is associated with increased resistance to axial distraction on an examination under anesthesia in patients undergoing primary hip arthroscopy for FAI syndrome. Level of Evidence Level III, retrospective cohort study.