Association of Smaller Intercondylar Notch Size With Graft Failure After Anterior Cruciate Ligament Reconstruction.

Background: Smaller intercondylar notch sizes have been consistently associated with a predisposition for primary anterior cruciate ligament tears. Purpose: To evaluate the association between intercondylar notch size, graft size, and postoperative complications, including knee stiffness and return to the operating room, after primary anatomic anterior cruciate ligament reconstruction (ACLR). Study Design: Case-control study; Level of evidence, 3. Methods: This was a retrospective analysis of prospectively collected data from consecutive patients who underwent anatomic single-bundle primary ACLR using a bone-patellar tendon-bone or quadriceps tendon autograft performed by fellowship-trained orthopaedic sports medicine surgeons between April 2009 and August 2019. Graft failure was defined as patient report of instability, pathologic laxity on clinical examination, or graft rerupture confirmed by magnetic resonance imaging and/or subsequent arthroscopy. To ensure the purposeful selection of covariates, univariate analyses were conducted on the list of potential confounders selected a priori, and those with a significance value of P < .10 were considered for the multivariate regression model. Covariates found to be statistically significant with univariate analysis were patient age, notch size, and graft type. After validating all potential covariates, they were added to the regression model and then eliminated in a stepwise fashion. Results: In total, 252 patients were included for analysis (99 bone-patellar tendon-bone and 153 quadriceps tendon autograft; age, 22.2 ± 7.0 years; graft size, 9.8 ± 1.0 mm; time to follow-up, 50.4 ± 28.9 months). Knee stiffness developed in 23 patients (9.1%), and 15 grafts failed (6.0%). Smaller notch size on magnetic resonance imaging was significantly associated with graft failure (P = .005). There was a significantly higher risk of graft failure with notch size <16 versus ≥16 mm (17.6% vs 2.3%; P = .005) with an odds ratio (OR) of 5.0 (95% CI, 1.7-15.1; P = .004). Notch size <15 mm was associated with the highest risk of graft failure (22.2%; OR, 5.8; 95% CI, 1.6-20.6; P = .006). There was no significant association between notch size or graft-notch size ratio and knee stiffness, meniscal injury, or cartilage damage at the time of ACLR, regardless of graft type. Conclusion: Intercondylar notch size <16 mm was associated with a 5-fold increased risk of graft failure after primary anatomic ACLR.

Outcomes After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon in Adolescent Athletes at Mean Follow-up of 4 Years.

Background: Despite increasing use of quadriceps tendon (QT) autograft in anterior cruciate ligament (ACL) reconstruction (ACLR), limited data exist regarding its outcomes in high-risk adolescent athletes. Purpose: To (1) report the outcomes after QT ACLR in adolescent athletes and (2) identify patient-related and surgery-related factors that may influence failure rates after QT ACLR. Study Design: Case series; Level of evidence, 4. Methods: All patients aged 14 to 17 years who underwent primary anatomic, transphyseal, single-bundle QT ACLR between 2010 and 2021 with a minimum 2-year follow-up were included for analysis. Demographic and surgical data as well as preoperative International Knee Documentation Committee (IKDC) and Marx activity scores were collected retrospectively. All patients were also contacted to assess postoperative patient-reported outcomes (PROs), including IKDC and Marx activity scores, and return-to-sports (RTS) data. Outcomes of interest included rates of revision ACLR and ipsilateral complications, contralateral ACL tears, difference in pre- and postoperative PROs, and rates of RTS. Patient and surgical characteristics were compared between groups who required revision ACLR versus those who did not. Results: A total of 162 patients met inclusion criteria, of which 89 adolescent athletes (mean age 16.2 ± 1.1 years, 64% female) were included for analysis at mean follow-up of 4.0 years. Postoperative IKDC scores were significantly higher than preoperative scores (88.5 vs 37.5; P < .001), whereas Marx activity scores decreased postoperatively (14.3 vs 12.2; P = .011). Successful RTS occurred in 80% of patients at a mean time of 9.7 ± 6.9 months, and 85% of these patients returned to the same or higher level of sports. The most common reasons for failure to RTS included lack of time (n = 7, 70%) and fearing reinjury in the operative knee (n = 5, 50%). The overall revision ACLR rate was 10% (n = 9), and contralateral ACL tears occurred in 14% (n = 12) of patients. The overall ipsilateral knee reoperation rate was 22.5% (n = 20). No statistically significant differences in patient or surgical characteristics were observed between patients who underwent revision ACLR and those who did not. Conclusion: At a minimum 2-year follow-up after QT ACLR, adolescent athletes experienced significantly improved postoperative IKDC scores, high rates of RTS, and low rates of graft failure, despite a relatively high ipsilateral reoperation rate. Surgeons may utilize this information when identifying the optimal graft choice for adolescent athletes who have sustained an ACL injury and wish to return to high level of sporting activities.

Methodological considerations in assessing countermovement jumps with handheld accentuated eccentric loading.

This study aimed to compare the agreement between three-dimensional motion capture and vertical ground reaction force (vGRF) in identifying the point of dumbbell (DB) release during a countermovement jump with accentuated eccentric loading (CMJAEL), and to examine the influence of the vGRF analysis method on the reliability and magnitude of CMJAEL variables. Twenty participants (10 male, 10 female) completed five maximal effort CMJAEL at 20% and 30% of body mass (CMJAEL20 and CMJAEL30, respectively) using DBs. There was large variability between methods in both loading conditions, as indicated by the wide limits of agreement (CMJAEL20 = -0.22 to 0.07 s; CMJAEL30 = -0.29 to 0.14 s). Variables were calculated from the vGRF data, and compared between four methods (forward integration (FI), backward integration (BI), FI adjusted at bottom position (BP), FI adjusted at DB release point (DR)). Greater absolute reliability was observed for variables from DR (CV% ≤ 7.28) compared to BP (CV% ≤ 13.74), although relative reliability was superior following the BP method (ICC ≥ 0.781 vs ≥ 0.606, respectively). The vGRF method shows promise in pinpointing the DB release point when only force platforms are accessible, and a combination of FI and BI analyses is advised to understand CMJAEL dynamics.

Slope Osteotomies in the Setting of Anterior Cruciate Ligament Deficiency.

➤ Posterior tibial slope (PTS) of ≥12° represents an important risk factor for both anterior cruciate ligament (ACL) injury and ACL reconstruction failure.➤ PTS measurements can significantly differ on the basis of the imaging modality and the measurement technique used. PTS should be measured on strictly lateral radiographs, with a recommended proximal tibial length of 15 cm in the image. The PTS measurement can be made by placing 2 circles to define the proximal tibial axis, 1 just below the tibial tubercle and another 10 cm below it. PTS measurements are underestimated when made on magnetic resonance imaging and computed tomography.➤ Slope-reducing osteotomies can be performed using a (1) supratuberosity, (2) tubercle-reflecting transtuberosity, or (3) infratuberosity method. The correction target remains a topic of debate. Although it is controversial, some authors recommend overcorrecting the tibial slope slightly to a range of 4° to 6°. For instance, if the initial slope is 12°, a correction of 6° to 8° should be performed, given the target tibial slope of 4° to 6°.➤ Clinical outcomes following slope-reducing osteotomies have been favorable. However, potential complications, limited data with regard to the impact of slope-reducing osteotomies on osteoarthritis, and uncertainty with regard to the effects on the patellofemoral joint are notable concerns.➤ Patients with complex deformities may need biplanar osteotomies to comprehensively address the condition.

Nonanatomic femoral tunnel placement increases the risk of subsequent meniscal surgery after ACLR: Part II-Patients without recurrent ACL injury.

PURPOSE: The purpose of this study was to identify risk factors for subsequent meniscal surgery following anterior cruciate ligament (ACL) reconstruction (ACLR) in patients without recurrent ACL injury. METHODS: Patients aged ≥14 years who underwent primary ACLR with minimum 1-year follow-up and without recurrent ACL injury were retrospectively reviewed. Patient demographics and surgical data at the time of ACLR were collected. Postoperative radiographs were used to measure femoral and tibial tunnel position, and posterior tibial slope. Univariate and multivariate analyses were performed to identify risk factors for subsequent meniscal surgery. RESULTS: Of 629 ACLRs that fulfilled the inclusion criteria, subsequent meniscal surgery was performed in 65 [10.3%] patients. Multivariate analysis revealed that medial meniscal repair at the time of ACLR, younger age, anterior femoral tunnel position and distal femoral tunnel position were significantly associated with subsequent meniscal surgery (p < 0.001, p = 0.016, p = 0.015, p = 0.035, respectively). The frequency of femoral tunnel placement >10% outside of the literature-established anatomic position was significantly higher in those who underwent subsequent meniscal surgery compared to those who did not (38.3% vs. 20.3%, p = 0.006). Posterior tibial slope and ACL graft type were not significantly associated with subsequent meniscal surgery. CONCLUSION: Medial meniscal repair at the time of ACLR, younger age and nonanatomic femoral tunnel placement were risk factors for subsequent meniscal surgery in patients without recurrent ACL injury. Femoral tunnel placement <10% outside of the native anatomic position is important to reduce the risk of subsequent meniscal surgery. LEVEL OF EVIDENCE: Level IV.

Total Shoulder Arthroplasty is associated With Less Pain and Better Functional Outcomes, but Humeral Head Resurfacing may be Preferred in Younger, Higher Demand Patients: A Short-Term Outcomes Study in Patients with Glenohumeral Osteoarthritis.

Objectives: This study aimed to compare short-term outcomes following Total Shoulder Arthroplasty (TSA) and Humeral Head Resurfacing (HHR) in patients with glenohumeral osteoarthritis (GHOA). Methods: A retrospective analysis included patients who had undergone either TSA or HHR for GHOA at a single institution. Baseline demographics, complications, range of motion (active forward flexion, FF and active external rotation, ER), visual analog scores (VAS), and Subjective Shoulder Values (SSV) were collected. Results: A total of 69 TSA and 56 HHR patients were analyzed. More HHR patients were laborers (44% versus 21%, P=0.01). There were more smokers in the TSA group (25% versus 11%, P=0.04) and more cardiovascular disease in the HHR cohort (64% versus. 6%, p<0.0001). Postoperative FF was similar, but ER was greater in the HHR (47° ± 15°) vs. TSA group (40° ± 12°, P = 0.01). VAS was lower after TSA vs. HHR (median 0, IQR 1 versus median 3.7, IQR 6.9, p<0.0001), and SSV was higher after TSA (89% ± 13% vs. 75% ± 20% after HHR; p<0.0001). Post-operative impingement was more common after HHR (32% vs. 3% for TSA, p<0.0001). All other complications were equivalent. Conclusion: While younger patients and heavy laborers had improved ER following HHR, their pain relief was greater after TSA. Decisions on surgical technique should be based on patient-specific demographic and anatomic factors.

Revision Anterior Cruciate Ligament Reconstruction and Associated Procedures.

Failure of anterior cruciate ligament reconstruction (ACLR) is a common yet devastating complication due to inferior clinical outcomes associated with revision ACLR. Identifying the cause and associated risk factors for failure is the most important consideration during preoperative planning. Special attention to tunnel quality, concomitant injuries, and modifiable risk factors will help determine the optimal approach and staging for revision ACLR. Additional procedures including lateral extra-articular tenodesis and osteotomy may be considered for at-risk populations. The purpose of this review is to explore causes of ACLR failure, clinical indications and appropriate patient evaluation, and technical considerations when performing revision ACLR.

Higher odds of meniscectomy compared with meniscus repair in a young patient population with increased neighbourhood disadvantage.

OBJECTIVES: To investigate the impact of demographic and socioeconomic factors on the management of isolated meniscus tears in young patients and to identify trends in surgical management of meniscus tears based on surgeon volume. METHODS: Data from a large healthcare system on patients aged 14-44 years who underwent isolated meniscus surgery between 2016 and 2022 were analysed. Patient demographics, socioeconomic factors and surgeon volume were recorded. Patient age was categorised as 14-29 years and 30-44 years old. Area Deprivation Index (ADI), a measure of neighbourhood disadvantage with increased ADI corresponding to more disadvantage, was grouped as <25th, 25-75th and >75th percentile. Multivariate comparisons were made between procedure groups while univariate comparisons were made between surgeon groups. RESULTS: The study included 1552 patients treated by 84 orthopaedic surgeons. Older age and higher ADI were associated with higher odds of undergoing meniscectomy. Patients of older age and with non-private insurance were more likely to undergo treatment by a lower-volume knee surgeon. Apart from the year 2022, higher-volume knee surgeons performed significantly higher rates of meniscus repair compared with lower-volume knee surgeons. When controlling for surgeon volume, higher ADI remained a significant predictor of undergoing meniscectomy over meniscus repair. CONCLUSION: Significant associations exist between patient factors and surgical choices for isolated meniscus tears in younger patients. Patients of older age and with increased neighbourhood disadvantage were more likely to undergo meniscectomy versus meniscus repair. While higher-volume knee surgeons favoured meniscus repair, a growing trend of meniscus repair rates was observed among lower-volume knee surgeons. LEVEL OF EVIDENCE: Retrospective cohort study, level III.

Surgical Techniques in Primary ACL Reconstruction: Getting It Right the First Time.

The ideal anterior cruciate ligament reconstruction (ACLR) is an individualized anatomic approach aimed at restoring the native structure and function of the knee. Surgeons are tasked with difficult decisions during operative planning, including the optimal graft choice for the patient and appropriate anatomic tunnel placement. Special considerations should additionally be given for skeletally immature patients and those at high-risk for failure, including younger, active patients participating in pivoting sports. The purpose of this review is to provide an overview of the individualized approach to ACLR, including the necessary preoperative and operative considerations to optimize patient outcomes.

Conversion to knee arthroplasty is more common after meniscectomy than meniscus repair in patients older than age 40.

PURPOSE: To describe rates of conversion to unicompartmental or total knee arthroplasty (KA) in patients over the age of 40 years (at initial surgery) after partial meniscectomy (ME) or meniscal repair (MR). METHODS: Patients over the age of 40 undergoing isolated ME or MR between 2016 and 2018 were extracted from a single healthcare provider database. Data on patient characteristics, type of initial surgery, number of returns to the operating room, as well as performed procedures, including conversion to KA, were recorded. Comparative group statistics as well as a Kaplan-Meier survival rate analysis were performed. RESULTS: A total of 3638 patients (47.8% female) were included, with 3520 (96.8%) undergoing ME and 118 (3.2%) MR. Overall, 378 (10.4%) patients returned to the OR at an average of 22.7 ± 17.3 months postoperatively. Conversion to KA was performed more frequently in patients after primary ME (n = 270, 7.7%) compared to those with MR (2.5%, n = 3, odds ratio [OR]: 3.2, p = 0.03). Compared to ME (2.3%, n = 82), two times as many patients undergoing MR returned for subsequent meniscus surgery (MR: 5.9%, n = 7, OR: 2.6, p = 0.02). Time from primary surgery to KA (ME: 22 ± 17 months, MR: 25 ± 15 months, p = 0.96) did not differ between the treatment groups. Survivorship was 95% for ME and 98.2% for MR after 24 months (p = 0.76) and 92.5% and 98.2% after 60 months (p = 0.07), respectively. CONCLUSION: The overall reoperation rate after meniscal surgery was 10.4% in patients over the age of 40 years. Patients treated with primary ME have over three times higher odds to undergo subsequent KA compared to those treated with MR. However, patients with primary MR have a higher rate of subsequent meniscus surgery compared to those undergoing primary ME. This information is important when considering and treating a patient over the age of 40 and meniscal injury. LEVEL OF EVIDENCE: Level III study.

'Real world' clinical implementation of blood flow restriction therapy does not increase quadriceps strength after quadriceps tendon autograft ACL reconstruction.

PURPOSE: To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. METHODS: A retrospective review of consecutive patients undergoing ACLR with QT autograft with a minimum of two quantitative postoperative isometric strength assessments via an electromechanical dynamometer (Biodex) was included. Demographics, surgical variables and strength measurement outcomes were compared between patients undergoing blood flow restriction therapy as part of postoperative rehabilitation versus those who did not. RESULTS: Eighty-one (81) patients met the inclusion criteria. No differences were found in demographic and surgical characteristics between those who received blood flow restriction compared with those who did not. While both groups had improvements in quadriceps peak torque and limb symmetry index (LSI; defined as peak torque of the operative limb divided by the peak torque of the nonoperative limb) over the study period, the blood flow restriction group had significantly lower mean peak torque of the operative limb at first Biodex strength measurement (95.6 vs. 111.2 Nm; p = 0.03). Additionally, the blood flow restriction group had a significantly lower mean LSI than those with no blood flow restriction at the second Biodex measurement timepoint (81% vs. 90%; p = 0.02). No other significant differences were found between the strength outcomes measured. CONCLUSIONS: Results of this study show that the 'real world' clinical implementation of blood flow restriction therapy to the postoperative rehabilitation protocol following QT autograft ACLR did not result in an increase in absolute or longitudinal changes in quadriceps strength measurements. A better understanding and standardisation of the use of blood flow restriction therapy in the rehabilitation setting is necessary to delineate the true effects of this modality on strength recovery after QT autograft ACLR. LEVEL OF EVIDENCE: Level III.

Lateral extra-articular tenodesis may be more cost-effective than independent anterolateral ligament reconstruction: A systematic review and economic analysis.

IMPORTANCE: Anterolateral augmentation during primary anterior cruciate ligament (ACL) reconstruction (ACLR) may lower rates of ACL graft failure. However, differences in costs between two techniques, lateral extra-articular tenodesis (LET) and anterolateral ligament reconstruction (ALLR), are unclear. OBJECTIVE: To perform a systematic review and subsequent cost-effectiveness analysis comparing LET versus ALLR in the setting of primary ACLR. The hypothesis was that LET is more cost-effective than ALLR. EVIDENCE REVIEW: A systematic review was conducted on studies in which patients underwent primary ACLR with a concomitant LET or ALLR with minimum 24 months follow-up published between January 2013 and July 2023. Primary outcomes included ACL graft failure rates and Knee Injury and Osteoarthritis Outcome Survey-Quality of Life (KOOS-QoL) subscale scores, which were used to determine health utilities measured by quality-adjusted life years (QALYs) gained. A decision tree model with one-way and two-way sensitivity analyses compared the cost of primary ACLR with a concomitant LET, independent autograft ALLR, or independent allograft ALLR. Costs were estimated using a combination of QALYs, institution prices, literature references, and a survey sent to 49 internationally recognized high-volume knee surgeons. FINDINGS: A total of 2505 knees undergoing primary ACLR with concomitant LET (n=1162) or ALLR (n=1343) were identified from 22 studies. There were 77 total ACL graft failures with comparable failure rates between patients receiving LET versus ALLR (2.9% vs. 3.2%, P=0.690). The average QALYs gained was slightly higher for those who received LET (0.77) compared to ALLR (0.75). Survey results revealed a 5 minute longer median self-reported operative time for ALLR (20 â€‹min) than LET (15 â€‹min). The estimated costs for LET, autograft ALLR, and allograft ALLR were $1,015, $1,295, and $3,068, respectively. CONCLUSIONS AND RELEVANCE: Anterolateral augmentation during primary ACLR with LET is more cost-effective than independent autograft and allograft ALLR given the lower costs and comparable clinical outcomes. Surgeons may utilize this information when determining the optimal approach to anterolateral augmentation during primary ACLR, although differences in preferred technique and health care systems may influence operative efficiency and material costs. LEVEL OF EVIDENCE: Systematic review; Level of evidence, IV.

Around-the-knee osteotomies part II: Surgical indications, techniques and outcomes - State of the art.

Recent advances in surgical techniques and planning for knee-based osteotomies have led to improvements in addressing lower extremity malalignment. Part 1 of this review presented the biomechanical and clinical rationale of osteotomies, emphasizing the importance of osteotomies for restoring normal knee kinematics. In Part 2 of this review, indications, surgical technique and outcomes of osteotomies to correct coronal, sagittal and axial plane deformities will be examined. Traditional high tibial and distal femoral osteotomies will be discussed in addition to more recent advanced techniques including biplanar corrections and double-level osteotomies, as well as slope-correcting osteotomies. Patient-specific instrumentation and its use in more complex corrections will also be addressed.

Factors Associated With Knee Extension Strength Symmetry After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft.

Background: Diminished postoperative knee extension strength may occur after anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) autograft. Factors influencing the restoration of knee extensor strength after ACLR with QT autograft remain undefined. Purpose: To identify factors that influence knee extensor strength after ACLR with QT autograft. Study Design: Case-control study; Level of evidence, 3. Methods: The authors performed a retrospective review of patients who underwent primary ACLR with QT autograft at a single institution between 2010 and 2021. Patients were included if they completed electromechanical dynamometer testing at least 6 months after surgery. Exclusion criteria consisted of revision ACLR, <6 months of follow-up, concomitant procedure (osteotomy, cartilage restoration), and concomitant ligamentous injury requiring surgery. Knee extension limb symmetry index (LSI) was obtained by comparing the peak torque of the operated and nonoperated extremities. Univariable and multivariable analyses were performed to identify factors associated with knee extension LSI in the patient, injury, rehabilitation, and preoperative patient-reported outcomes score domains. Results: A total of 107 patients (58 male; mean age, 22.8 years) were included. Mean knee extension LSI of the overall cohort was 0.82 ± 0.18 at 7.5 ± 2.0 months; 35 patients (33%) had a value of ≥0.90. Multivariable analysis demonstrated significant negative associations between knee extension LSI and female sex (-0.12; P < .001), increased age at the time of surgery (-0.01; P = .018), and larger QT graft width (-0.049; P = .053). Conclusion: Factors influencing knee extensor LSI after ACLR with QT autograft in this study population spanned patient and surgical factors, including female sex, older age at the time of surgery, and wider graft harvest. Surgeons should consider the association between these factors and lower postoperative knee extensor LSI to optimize patient outcomes.

Bipolar bone loss and distance to dislocation.

Studies have shown that glenoid- and humeral-sided bone loss may be present in up to 73-93% of individuals with recurrent anterior shoulder instability. As such, bone loss must be addressed appropriately, as the amount of bone loss drives surgical decision making and influences outcomes. Methods to describe and measure bone loss have changed over time. Originally, glenoid and humeral bone loss were viewed separately. However, the concepts of bipolar bone loss, the glenoid track (GT), and "on/off-track" lesions arose, highlighting the interplay between the two entities in contributing to recurrent instability. Classically, "off-track" lesions have been described as those Hill-Sachs interval (HSI) greater than the GT, and have been shown to result in higher rates of re-instability when addressed nonoperatively or with Bankart repair alone. More recently, further attention has been given to "on-track" lesions (HSI < GT). The new concept of "distance to dislocation" (DTD) has gained popularity. DTD is calculated as the difference between the GT and HSI, and literature evaluating DTD suggests that not all "on-track" lesions should be treated in the same manner. The purpose of this concept review article is twofold: (I) describe glenoid, humeral, and bipolar bone loss in the setting of anterior shoulder instability; and (II) elaborate on the new concept of "DTD" and its use in guidance of management.

Around-the-knee osteotomies part 1: definitions, rationale and planning-state of the art.

Knee osteotomies are essential orthopedic procedures with the ability to preserve the joint and correct ligament instabilities. Literature supports the correlation between lower limb malalignment and outcomes after knee ligament reconstruction and cartilage procedures. Concepts such as joint line obliquity, posterior tibial slope angle, and intra-articular deformity correction are integral components of both preoperative planning and postoperative evaluations. The concept of preserving and/or restoring joint line congruence during simultaneous correction of varus or valgus deformity can be achieved through several different approaches. With advancements in osteotomy research and surgical planning technology, the surgical decision-making has increased in complexity. Based upon a patient's specific deformity, decisions need to be made whether to perform a single-level (proximal tibia or distal femur) versus double-level (both proximal tibia and distal femur) osteotomy, and whether to correct deformity in a single plane (coronal or sagittal) or perform a biplanar osteotomy, correcting two of the malalignments in either coronal, sagittal, or axial planes. Osteotomy procedures prioritize safety, reproducibility, precision, and meticulous planning. Equally important is the proactive management of possible complications and the implementation of preventive strategies for complications such as hinge fractures and unintentional changes to alignment in other planes. This review navigates the intricate landscape of lower limb alignment, commencing with foundational definitions and rationale for performing osteotomies, progressing through the planning phase, and addressing the critical aspect of complication prevention, all while looking ahead to anticipate future advancements in this field. However, rotational osteotomies and tibial tubercle osteotomies in isolation or as an adjunct procedure are beyond the scope of this review.

Magnetic Resonance Arthrogram Outperforms Standard Magnetic Resonance Imaging 2 Weeks After First Shoulder Dislocation for Labral Tear Diagnosis.

PURPOSE: To determine the comparative accuracy and precision of routine magnetic resonance imaging (MRI) versus magnetic resonance (MR) arthrogram in measuring labral tear size as a function of time from a shoulder dislocation. METHODS: We retrospectively evaluated consecutive patients who underwent primary arthroscopic stabilization between 2012 and 2021 in a single academic center. All patients completed a preoperative MRI or MR arthrogram of the shoulder within 60 days of injury and subsequently underwent arthroscopic repair within 6 months of imaging. Intraoperative labral tear size and location were used as standards for comparison. Three musculoskeletal radiologists independently interpreted tear extent using a clock-face convention. Accuracy and precision of MR labral tear measurements were defined based on location and size of the tear, respectively. Accuracy and precision were compared between MRI and MR arthrogram as a function of time from dislocation. RESULTS: In total, 32 MRIs and 65 MR arthrograms (total n = 97) were assessed. Multivariate analysis demonstrated that intraoperative tear size, early imaging, and arthrogram status were associated with increased MR accuracy and precision (P < .05). Ordering surgeons preferred arthrogram for delayed imaging (P = .018). For routine MRI, error in accuracy increased by 3.4° per day and error in precision increased by 2.3° per day (P < .001) from time of injury. MR arthrogram, however, was not temporally influenced. Significant loss of accuracy and precision of MRI compared with MR arthrogram occurred at 2 weeks after an acute shoulder dislocation. CONCLUSIONS: Compared with MR arthrogram, conventional MRI demonstrates time-dependent loss of accuracy and precision in determining shoulder labral tear extent after dislocation, with statistical divergence occurring at 2 weeks. LEVEL OF EVIDENCE: Level II, retrospective radiographic diagnostic study.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair.

BACKGROUND: The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied. HYPOTHESIS: Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability. RESULTS: In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions. CONCLUSION: Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Bone loss in shoulder instability: putting it all together.

Glenohumeral bone loss is frequently observed in cases of recurrent anterior and posterior shoulder instability and represents a risk factor for failure of nonoperative treatment. Patients with suspected glenoid or humeral bone loss in the setting of recurrent instability should be evaluated with a thorough history and physical examination, as well as advanced imaging including computed tomography (CT) and/or magnetic resonance imaging (MRI). In cases of both anterior and posterior instability, the magnitude and location of bone loss should be determined, as well as the relationship between the glenoid track (GT) and any humeral defects. While the degree and pattern of osseous deficiency help guide treatment, patient-specific risk factors for recurrent instability must also be considered when determining patient management. Treatment options for subcritical anterior bone loss include labral repair and capsular plication, while more severe deficiency should prompt consideration of bony augmentation including coracoid transfer or free bone block procedures. Concomitant humeral lesions are treated according to the degree of engagement with the glenoid rim and may be addressed with soft tissue remplissage or bony augmentation procedures. While critical and subcritical thresholds of glenoid bone loss guide the management of anterior instability, such thresholds are less defined in the setting of posterior instability. Furthermore, current treatment algorithms are limited by a lack of long-term comparative studies. Future high-quality studies as well as possible modifications in indications and surgical technique are required to elucidate the optimal treatment of anterior, posterior, and bipolar glenohumeral bone loss in the setting of recurrent shoulder instability.