Infraspinatus function impairment after arthroscopic Bankart repair with Hill Sachs remplissage. Isokinetic, functional, and radiographic analysis

PURPOSE

Arthroscopic Bankart repair with Hill Sachs remplissage (BHSR) is an option for anterior shoulder instability with humeral defect. Our hypothesis was that infraspinatus capsulo-tenodesis is an effective solution, with good clinical results and no consequences on shoulder strength and ranges of motion.

METHODS

We performed a retrospective case-control study involving 22 patients operated with arthroscopic BHSR. We compared isokinetic evaluation of both shoulders using a dynanometer in concentric, eccentric force and endurance. Ranges of motion were measured using a goniometer and compared to the contralateral unaffected side. Functional assessment included Constant, Rowe, Walch and Duplay and WOSI scores. Healing and fatty degeneration were analyzed with magnetic resonance imaging.

RESULTS

At mean 37.2 months follow-up, 21 patients (95.4%) were satisfied or very satisfied with the intervention. Range of motion in external rotation of the affected side decreased by 10.8° in adduction and 6° at 90° of abduction (p<0.05). Deficit in external rotation strength of the affected side greater than 15% was found in all isokinetic tests (p<0.05). Walch and Duplay, Rowe, WOSI and adjusted Constant average scores were respectively 71.05±14.1 (40-90), 67.63±19.7 (15-100), 34.6%±19.9 (8.43-76.23) and 69.8±13.57 (36.7-101). Postoperative MRI showed good capsulo-tenodesis healing without infraspinatus muscle fatty degeneration.

CONCLUSION

Arthroscopic BHSR provides satisfactory functional outcomes but significant infraspinatus functional impairments in both strength and ranges of motion in external rotation.

LEVEL OF EVIDENCE

III; case-control study.

Imaging Assessment of Nontraumatic Pathologic Conditions at the Craniovertebral Junction: A Comprehensive Review

Nontraumatic pathologic conditions of the craniovertebral junction encompass a range of conditions affecting the complex anatomy of this region without direct physical injury. These conditions include congenital syndromes that predispose individuals to ligamentous laxity, potentially leading to instability. Additionally, rare but noteworthy cases such as Grisel syndrome, a cause of pediatric torticollis, may arise without a traumatic trigger. Inflammatory diseases, including rheumatoid arthritis, ankylosing spondylitis, and crystal deposition, can lead to cervical instability and spinal cord compression. Infections at the upper cervical spine are dominated by tuberculosis, typically transmitted through hematologic or lymphatic routes with characteristic imaging findings. On the other hand, purulent bacterial infections in this area are rare. Furthermore, although tumors involving the structures of the craniovertebral junction are infrequent, they can lead to significant complications, albeit less frequently through cord compression and more commonly via pathologic fractures or subluxation. The craniocervical junction is a complex anatomic region comprising ligaments, bones, joints, and muscles that support the head's weight and enable its wide range of motion. Accurate recognition and understanding of the complex anatomy and the various nontraumatic pathologic conditions at the craniovertebral junction are pivotal for initiating timely and appropriate treatment strategies. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Finite element analysis of a customized coronoid prosthesis for traumatic coronoid deficiency

BACKGROUND

Traumatic coronoid deficiency with persistent elbow instability is a challenging condition. Autologous bone graft reconstruction is often associated with a range of additional clinical problems and the outcome is often unpredictable. The purpose of this study was to design a prosthetic device that can reconstruct coronoid deficiency of any height and to evaluate its mechanical properties using finite element analysis.

MATERIALS AND METHODS

A customized coronoid prosthesis was designed based on image registration, automatic measurement, and computer-aided design. After pilot study and sample size calculation, image data collected from 6 patients who underwent bilateral complete upper extremity CT scans were reconstructed. The test was divided into 3 groups: coronoid intact, prosthesis and autograft. Regan-Morrey type II and autologous olecranon osteotomy models were established. The prosthesis and autogenous olecranon were assembled to the coronoid base. Stress was applied axially along the proximal humeral diaphysis and implant micromotion and contact mechanics of the humeroulnar joint were measured at 30°, 45°, 60° and 90° of joint flexion respectively.

RESULTS

At all flexion angles, the maximum stress on the coronoid articular surface was significantly reduced in the prosthesis and autograft groups, with the reduction being more significant in the latter (P < .001). With increasing flexion, the maximum stress at the coronoid articular surface increased significantly after autograft reconstruction (7.2 to 68 MPa, P < .001), whereas the humeroulnar joint obtained a similar contact mechanics pattern to that of the control group after prosthetic reconstruction. As the flexion angle increased, the relative micromotion of both the prosthesis and autograft increased significantly (0.5-1.6 vs. 0.2-1.2, Pmeasure time < 0.001, Pgroups < 0.001). Contact pressure and center-of-force paths of the humeroulnar joint experience abrupt stress changes at approximately 60° of flexion.

CONCLUSION

The contact stress pattern in the humeroulnar joint is similar in prosthesis and intact coronoid groups. Autograft reconstruction increases contact stresses at the articular surface and alters the joint center-of-force path. The "stress surge phenomenon" in the humeroulnar joint surface before and after 60° of flexion may be one of the mechanisms of traumatic elbow degeneration.

Outcomes of surgical treatment of patellar instability in children with Down syndrome

BACKGROUND

patellar instability is a relatively frequent musculoskeletal disorder in children with Down syndrome (DS). However, such a condition has seldom been studied in the literature, even less its surgical treatment. Different techniques have been offered for this condition; the evidence for surgical options is scarce and primarily based on case reports or case series with few patients and heterogeneous techniques. Given this background, we aimed to evaluate the outcomes of a uniform kind of surgical procedure for such a condition that combined lateral soft tissue release, medial patellofemoral ligament (MPFL) reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty (if needed).

MATERIALS AND METHODS

This retrospective study involved 11 skeletally immature patients (12 knees; 9 males and 2 females), 5.5 to 14.1 years of age, with DS who had patellofemoral instability (PFI) and were managed by this technique between October 2018 and March 2020. Preoperative radiography, CT scan, and MRI were performed to evaluate the physis status, lower limb alignment, patellar height, trochlear morphology, and any associated knee pathology. A functional knee assessment was done by using the Kujala score and the modified Lysholm score.

RESULTS

The mean time of follow-up (± SD) was 47.7 ± 5.8 months (range: 39-56). Pre-operatively, the Kujala score (± SD) was 52.6 ± 14.3 (range: (31-74), and at final follow-up, it was 92.2 ± 4.4 (range: (88-98), showing a significant improvement (P < 0.001). The preoperative modified Lysholm score (± SD) was 54.3 ± 8.1 (range: 39-62), and at final follow-up it was 92.4 ± 5.3 (range: 82-96), showing a significant improvement (P < 0.001). All patients had a stable patella without a recurrence of instability and regained full ROM. There was no incidence of a patellar fracture or femoral physis injury.

CONCLUSIONS

Our proposed technique of combined soft tissue procedures, including lateral soft tissue release, MPFL reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty, was an effective method for treating patellar instability in children with DS while avoiding physeal injury and patellar fracture. Functional scores and radiological outcomes were improved.

LEVEL OF EVIDENCE

IV; retrospective case series.

Comparison of lumbar muscle morphology in patients with chronic nonspecific low back pain with and without clinical lumbar segmental instability

OBJECTIVES

Evaluation of spinal muscle morphology may be critical because of its impact on segmental stability and control of the lumbar spine in the subset of patients with clinical lumbar segmental instability (LSI). The purpose of this study was to compare lumbar muscle morphology in CNLBP patients with clinical LSI, CNLBP patients without clinical LSI.

METHODS

This case-control study included 30 patients with CNLBP (15 with clinical LSI and 15 without clinical LSI) and 15 subjects without LBP. Axial magnetic resonance images from the L2 to S1 lumbar levels were used to evaluate the morphology of the lumbar muscles.

RESULTS

A significant increase in the muscle-to-fat infiltration index and a significant decrease in the relative muscle cross-sectional area (rmCSA) of the multifidus muscle at the L3-L4 to L5-S1 levels were observed in both CNLBP groups compared to the control group (p<0.05). The mean erector spinae mean rmCSA was significantly greater in the clinical LSI group compared to the control group (SMD = 0.853, 95% CI = 0.105 to -1.6, P = 0.044) and also compared to the CNLBP without clinical LSI (SMD = 0.894, 95% CI = -1.645 to -0.144, P = 0.030) at the L4-L5 level.

CONCLUSIONS

The atrophic changes of the multifidus muscle, in CNLBP patients with or without clinical LSI was observed. However, hypertrophic changes of the erector spinae muscle at the L4-L5 lumbar level were observed only in the clinical LSI group. Psaos major did not show significant atrophic or hypertrophic changes.

Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation

PURPOSE

The present study aimed to assess the clinical efficacy and imaging results of reconstruction of the medial patellofemoral ligament through a double bundle of single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation.

METHODS

Twenty-three patients with recurrent patellar dislocation, including ten males and 13 females, with 23 knee joints were enrolled according to the relevant criteria. Reconstruction of the medial patellofemoral ligament was performed through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity. Knee function was evaluated using visual analog scale (VAS) score, International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score, and Kujala score at pre- and postoperative stages. Patellar stability was assessed by CT scans measuring tibial tuberosity-trochlear groove (TT-TG) distance, lateral patella displacement (LPD), congruence angle (CA), and patellar tilt angle (PTA).

RESULTS

All 23 patients were effectively followed up for 13-28 months (mean: 21.91 ± 4.14 months). At the last follow-up, the postoperative VAS score, IKDC score, Lysholm score, Tegner score, and Kujala score of 23 patients were 1.13 ± 0.82, 87.35 ± 3.17, 90.22 ± 1.28, 4.35 ± 0.65, and 89.26 ± 1.96, respectively, as compared to the preoperative values of 5.91 ± 1.13, 30.96 ± 5.09, 30.30 ± 2.98, 1.26 ± 0.62, and 27.87 ± 3.46, respectively, and these differences were statistically significant (P < 0.001). At the last follow-up, the postoperative TT-TG, LPD, CA, and PTA values of the 23 patients were 8.80 ± 1.85 mm, 6.01 ± 1.77 mm, 11.32 ± 6.18°, and 9.35 ± 2.88°, respectively, compared to the preoperative values of 18.77 ± 1.74 mm, 14.90 ± 4.07 mm, 37.82 ± 5.71°, and 23.58 ± 3.24°, respectively, and the differences were statistically significant (P < 0.001). No relevant complications were observed in the 23 patients.

CONCLUSIONS

Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation showed satisfactory medium-term efficacy, and further investigations are required to confirm the long-term efficacy of this approach.

Dynamic assessment of scapholunate ligament status by real-time magnetic resonance imaging: an exploratory clinical study

OBJECTIVE

Clinical-standard MRI is the imaging modality of choice for the wrist, yet limited to static evaluation, thereby potentially missing dynamic instability patterns. We aimed to investigate the clinical benefit of (dynamic) real-time MRI, complemented by automatic analysis, in patients with complete or partial scapholunate ligament (SLL) tears.

MATERIAL AND METHODS

Both wrists of ten patients with unilateral SLL tears (six partial, four complete tears) as diagnosed by clinical-standard MRI were imaged during continuous active radioulnar motion using a 1.5-T MRI scanner in combination with a custom-made motion device. Following automatic segmentation of the wrist, the scapholunate and lunotriquetral joint widths were analyzed across the entire range of motion (ROM). Mixed-effects model analysis of variance (ANOVA) followed by Tukey's posthoc test and two-way ANOVA were used for statistical analysis.

RESULTS

With the increasing extent of SLL tear, the scapholunate joint widths in injured wrists were significantly larger over the entire ROM compared to those of the contralateral healthy wrists (p<0.001). Differences between partial and complete tears were most pronounced at 5°-15° ulnar abduction (p<0.001). Motion patterns and trajectories were altered. Complete SLL deficiency resulted in complex alterations of the lunotriquetral joint widths.

CONCLUSION

Real-time MRI may improve the functional diagnosis of SLL insufficiency and aid therapeutic decision-making by revealing dynamic forms of dissociative instability within the proximal carpus. Static MRI best differentiates SLL-injured wrists at 5°-15° of ulnar abduction.

One-Year Outcomes of the Anatomical Front and Back Reconstruction for Scapholunate Dissociation

PURPOSE

Anatomical front and back (ANAFAB) reconstruction addresses the critical volar and dorsal ligaments associated with scapholunate dissociation. We hypothesized that patients with symptomatic, chronic, late-stage scapholunate dissociation would demonstrate improvements in all radiographic parameters and patient-reported outcomes (PROMs) after ANAFAB reconstruction.

METHODS

From 2018 to 2021, 21 ANAFAB reconstructions performed by a single surgeon were followed prospectively, with 20 patients having a minimum follow-up of 12 months. In total, 17 men and four women were included, with an average age of 49 years. Three patients had modified Garcia-Elias stage 3 disease, eight stage 4, seven stage 5, and three stage 7. ANAFAB reconstruction of intrinsic and extrinsic ligament stabilizers was performed using a hybrid synthetic tape/tendon graft in a transosseous reconstruction. Pre- and postoperative radiographic parameters, grip, pinch strength, the Patient-Rated Wrist Evaluation, PROMIS Upper Extremity Function, and PROMIS Pain Interference outcome measures were compared.

RESULTS

Mean follow-up was 17.9 months (range: 12-38). Radiographic parameters were improved at follow-up, including the following: scapholunate angle (mean 75.3° preoperatively to 69.2°), scapholunate gap (5.9-4.2 mm), dorsal scaphoid translation (1.2-0.2 mm), and radiolunate angle (13.5° to 1.8°). Mean Patient-Rated Wrist Evaluation scores for pain and function decreased from 40.6 before surgery to 10.4. We were unable to detect a significant difference in grip or pinch strength or radioscaphoid angle with the numbers tested. There were two minor complications, and two complications required re-operations, one patient who was converted to a proximal row carpectomy for failure of fixation, and one who required tenolysis/arthrolysis for arthrofibrosis.

CONCLUSIONS

At 17.9-month average follow-up, radiographic and patient-reported outcome parameters improved after reconstruction of the critical dorsal and volar ligament stabilizers of the proximal carpal row with the ANAFAB technique.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Patellar Lateralization, Absence of Joint Hypermobility, and the Mechanism of Injury Are Associated With Osteochondral Fracture After First-time Acute Lateral Patellar Dislocation in Adolescents: An MRI-based Evaluation

BACKGROUND

Although the risk factors for patellofemoral dislocation are clearly defined, risk factors for osteochondral fracture (OCF) after patellar dislocation are not as well defined. The aim of this study was to investigate the risk factors for OCF by evaluating patients with and without OCF after first-time acute patellar dislocation.

METHODS

This multicenter study was conducted as a retrospective examination of the radiologic measurements on the magnetic resonance imaging of 306 patients. The patients were divided into the OCF group and non-OCF group, and OCFs were grouped according to whether the fracture was in the patella or femur. Patellar height, patellar lateralization, trochlear morphology, patellofemoral matching, and patella types were evaluated on patient magnetic resonance imaging. The presence of joint hypermobility in the patients was determined according to the Beighton scale score. The injury mechanisms of the patients were grouped as sports-related injuries, injuries resulting from simple falls, and injuries during daily activities.

RESULTS

A total of 120 OCFs were detected in 108 (35.2%) patients, of which 96 (80%) were in the patella and 24 (20%) in the femur. The rate of OCF after sports-related injuries was found to be significantly higher than in other injury mechanisms ( P =0.001). More joint hypermobility was detected in patients without OCF ( P =0.041). The measurements of tibial tubercle-trochlear groove, tibial tubercle-posterior cruciate ligament distance and lateral patellar displacement were statistically higher in cases with OCF ( P =0.001). In patients with normal joint mobility, the rate of OCF localization in the patella was significantly higher ( P =0.035). No correlation was found between any other parameters and OCF ( P >0.05). The absence of joint hypermobility and the measurements of tibial tubercle-trochlear groove distance, tibial tubercle-posterior cruciate ligament distance, and lateral patellar displacement were independent risk factors for the incidence of OCF according to the logistic regression analysis.

CONCLUSIONS

The absence of joint hypermobility and patellar lateralization are independent risk factors for the occurrence of OCF after first-time patellar dislocation. Sports-related injury is a nonindependent risk factor for the presence of OCF. In patients with normal joint mobility, the incidence of OCF in the patella is higher than in the femur. These important factors should be considered when evaluating patients and starting their treatment.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

The Global Track Concept for Assessment of Engaging Hill-Sachs Defects in Anterior Shoulder Instability

BACKGROUND

The glenoid track concept is used to determine preoperatively whether a Hill-Sachs defect is engaging or not. Currently, the glenoid track concept relies on measurements of bony structures as well as on the confines and elasticity of the rotator cuff as a reference point, which varies extensively among individuals and therefore limits the reliability and accuracy of this concept.

PURPOSE

To evaluate the reliability of the global track concept, which determines the angular distance of the Hill-Sachs defect from the center of the articular surface of the humeral head as a new reference point with the help of an automated image analysis software and 3-dimensional analysis of the humeral head.

STUDY DESIGN

Controlled laboratory study.

METHODS

Computed tomography scans of 100 patients treated for anterior shoulder instability with different sizes of Hill-Sachs defects were evaluated manually by 2 orthopaedic surgeons independently using the software OsiriX as well as automatically by using a dedicated prototype software (ImFusion). Obtained manual and automated measurements included the Hill-Sachs length, Hill-Sachs width, and Hill-Sachs depth of the defect; the Hill-Sachs interval (HSI); and the glenoid width for the glenoid track concept, as well as the angular distance of the Hill-Sachs defect from the center of the articular surface of the humeral head (global track concept). The reliability of the different measurement techniques was compared by calculating intraclass correlation coefficients (ICCs).

RESULTS

There was a significant difference for all obtained parameters comparing manual and automatic measurements. For manually obtained parameters, measurements referring to bony boundaries (glenoid width, Hill-Sachs length, and Hill-Sachs width) showed good to excellent agreement (ICC, 0.86, 0.82, and 0.62, respectively), while measurements referring to soft tissue boundaries (HSI and glenoid track; ICC, 0.56 and 0.53, respectively) or not directly identifiable reference points (center of articular surface and global track) only showed fair reliability (ICC middle excursion, 0.42). When the same parameters were measured with the help of an automated software, good reliability for the glenoid track concept and excellent reliability for the global track concept in the middle excursion were achieved.

CONCLUSION

The present study showed that the more complex global track measurements of humeral defects are more reliable than the current standard HSI and glenoid track measurements. However, this is only true when automated software is used to perform the measurements.

CLINICAL RELEVANCE

Future studies using the new proposed method in combination with an automated software need to be conducted to determine critical threshold values for defects prone to engagement.

Semiquantitative index of symptomatic minor instability of the lateral elbow at CT arthrography (SMILE index): clinical applicability and reproducibility study

OBJECTIVE

To assess the applicability of a semiquantitative index for symptomatic minor instability of the lateral elbow (SMILE).

MATERIALS AND METHODS

CT arthrograms of consecutive patients with lateral elbow pain who underwent ultrasound-guided CT arthrography at our orthopedic center between April 2019 and May 2022 were included. Images were acquired at 100 kVp and 80 mAs. An expert radiologist (R1) and a radiology resident (R2) retrospectively performed an independent, blinded evaluation of the arthrograms to assess the presence of imaging findings suggestive of elbow instability. The SMILE index (0-8) was obtained adding (I) radial head chondromalacia (0 - 1); (II) humeral capitellum chondromalacia (0 - 1); (III) humeral trochlear ridge chondromalacia (0 - 1); (IV) annular ligament laxity (0 - 2); (V) synovial thickening (0 - 1); (VI) humeroradial joint asymmetry (0 - 1); and (VII) capsular tear (0 - 1). R1 repeated the assessment after 14 days. Cohen's weighted κ statistic and raw concordance were used to appraise reproducibility.

RESULTS

Eighty patients (median age 49 years, interquartile range 40-53 years, 49, 61% males) underwent CT arthrography at our center, and 10 (12%) of them underwent bilateral elbow examination, leading to 90 included CT arthrograms. Median SMILE index was 4 (IQR: 2-5) for R1, 4 (IQR: 2-5) for R2, and 4 (IQR: 2-5) for the second assessment by R1. Intra-reader agreement was excellent (κ = 0.94, concordance 87%), while inter-reader agreement was substantial (κ = 0.75, concordance 67%).

CONCLUSION

The proposed SMILE index showed good reproducibility; further studies are warranted to correlate our index with clinical and surgical data.

CLINICAL RELEVANCE STATEMENT

Our scoring system allows a standardized evaluation of patients with lateral elbow pain and instability suitable for application into clinical practice, complementing the orthopedic surgeon's clinical diagnosis with imaging findings that may aid treatment choices.

KEY POINTS

• Lateral elbow pain is often interpreted clinically as lateral epicondylitis, but it can also encompass intra-articular pathology. • The proposed arthrographic index allows comprehensive quantification of lateral elbow pathology with good reproducibility and application times. • Our index provides the orthopedic surgeon with information regarding intra-articular findings, aiding treatment choices.

Evaluation of Open Versus Arthroscopic Anterior Talofibular Ligament Reconstruction for Chronic Lateral Ankle Instability With Talar and Subtalar Cartilage MRI T2 Mapping: A 3-Year Prospective Study

BACKGROUND

Previous studies have examined patients with chronic lateral ankle instability (CLAI) undergoing open and arthroscopic anterior talofibular ligament (ATFL) reconstruction, reporting equivalent clinical results between the 2 procedures. However, data on the magnetic resonance imaging (MRI) outcomes on cartilage health after the 2 procedures are limited.

PURPOSE

To compare the cartilage MRI T2 values of the talar and subtalar joints between patients with CLAI undergoing open and arthroscopic ATFL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A prospective study was conducted on patients who underwent open or arthroscopic ATFL reconstruction between January 2018 and December 2019, with a mean follow-up duration of 3 years. MRI scans and American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner score estimations were completed by patients ≤1 week before surgery, as a baseline measurement, and at a 3-year follow-up. A total of 21 healthy volunteers were included who underwent MRI at baseline. Cartilage health was evaluated using MRI T2 mapping. The talar and subtalar cartilage regions were segmented into 14 subregions.

RESULTS

At baseline, patients with CLAI had substantially higher T2 values in the medial anterior, medial center, medial posterior, and lateral center regions on the talus compared with the healthy controls (P = .009, .003, .001, and .025, respectively). Remarkable increases in T2 values in the lateral posterior region on the talus were observed from baseline to follow-up in the open group (P = .007). Furthermore, T2 values were considerably higher in the medial center, medial posterior, lateral posterior, and lateral posterior calcaneal facets of the posterior subtalar joint at follow-up in the arthroscopic group compared with the baseline values (P = .025, .002, .006, and .044, respectively). No obvious differences in ΔT2 values were noted between the 2 groups at follow-up. The AOFAS and Tegner scores remarkably improved from baseline to follow-up for the 2 groups (open: 3.25 ± 0.58 vs 5.13 ± 0.81, P < .001; arthroscopic: 3.11 ± 0.90 vs 5.11 ± 1.08, P < .001), with no considerable difference between them.

CONCLUSION

The elevated T2 values of cartilage could not be fully recovered after open or arthroscopic ATFL reconstruction. Both arthroscopic and open ATFL reconstruction displayed similar effects on cartilage health concerning ΔT2, but the arthroscopic group demonstrated more degenerative cartilage subregions than the open group.

C1 Transposterior Arch Lateral Mass Screws Combined With C2 Pedicle Screw and Rod Fixation for Pediatric Atlantoaxial Subluxation: A Minimal 10-Year Follow-up Outcome Analysis

BACKGROUND AND OBJECTIVES

Although the short-term outcomes of the 1-step reduction and fixation technique using C1 transposterior arch lateral mass screws combined with C2 pedicle screw and rod fixation system for the treatment of pediatric atlantoaxial subluxation (AAS) have been satisfactory, its long-term outcomes and impact on spinal development are not well studied. This study was intended to assess the long-term reliability of this technique for pediatric AAS.

METHODS

A retrospective case series study was conducted to analyze the minimum 10-year follow-up outcomes from 7 pediatric patients with AAS who underwent atlantoaxial fusion using the aforementioned technique. Quality of life and cervical range of motion were both measured thoroughly. In addition, vertical growth within the fusion construct (C1-2), overall cervical alignment, and subaxial cervical spine degeneration were evaluated radiographically.

RESULTS

The mean age of the 7 patients was 8.14 ± 2.41 (6-12) years at the time of surgery. The mean follow-up period was 11.00 ± 1.15 (10-13) years. No patients presented identifiable intervertebral disk degeneration or segmental instability in the subaxial cervical spine except for 1 patient who showed mild intervertebral disk degeneration. Vertical growth did continue within the atlantoaxial complex after surgery (11.90% ± 2.37%); however, there was a decrease in the percentage of vertical growth compared with the corresponding normal populations of the same age and sex. Moreover, there was a significant decrease in the range of cervical extension and rotation motion, and the overall cervical alignment straightened at the latest follow-up.

CONCLUSION

The 1-step reduction and fixation technique is a relatively reliable surgical technique for pediatric AAS, which does not adversely affect the postoperative quality of life or the subaxial cervical degeneration. Nevertheless, certain limitations, such as decreased cervical range of motion and changes in cervical alignment, should be concerned.

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

OBJECTIVE

To compare MRI features of medial and lateral patellar stabilizers in patients with and without patellar instability.

METHODS

Retrospective study of 196 patients (mean age, 33.1 ± 18.5 years; 119 women) after diagnosis of patellar instability (cohort-1, acute patellar dislocation; cohort-2, chronic patellar maltracking) or no patellar instability (cohort-3, acute ACL rupture; cohort-4, chronic medial meniscus tear). On MRI, four medial and four lateral stabilizers were evaluated for visibility and injury by three readers independently. Inter- and intra-reader agreement was determined.

RESULTS

Medial and lateral patellofemoral ligaments (MPFL and LPFL) were mostly or fully visualized in all cases (100%). Of the secondary patellar stabilizers, the medial patellotibial ligament was mostly or fully visualized in 166 cases (84.7%). Other secondary stabilizers were mostly or fully visualized in only a minority of cases (range, 0.5-32.1%). Injury scores for all four medial stabilizers were higher in patients with acute patellar dislocation than the other 3 cohorts (p < .05). Visibility inter- and intra-reader agreement was good for medial stabilizers (κ 0.61-0.78) and moderate-to-good for lateral stabilizers (κ 0.40-0.72). Injury inter- and intra-reader agreement was moderate-to-excellent for medial stabilizers (κ 0.43-0.90) and poor-to-moderate for lateral stabilizers (κ 0-0.50).

CONCLUSION

The MPFL and LPFL were well visualized on MRI while the secondary stabilizers were less frequently visualized. The secondary stabilizers were more frequently visualized medially than laterally, and patellotibial ligaments were more frequently visualized compared to the other secondary stabilizers. Injury to the medial stabilizers was more common with acute patellar dislocation than with chronic patellar maltracking or other knee injuries.

Dynamic Stress Ultrasound Assessment of Professional Baseball Players' Elbows After Ulnar Collateral Ligament Reconstruction

BACKGROUND

There is a paucity of data analyzing dynamic stress ultrasound (SUS) findings in elite pitchers who have undergone ulnar collateral ligament (UCL) reconstruction (UCLR) and returned to sport.

PURPOSE

To identify longitudinal, perioperative changes in the elbows of professional baseball pitchers who have undergone UCLR and to compare these findings with a matched cohort of healthy pitchers.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study used prospectively collected data from dynamic elbow SUS analyses of professional baseball pitchers within a single Major League Baseball organization. Pitchers were divided into 2 cohorts: a UCLR cohort and healthy cohort. The UCLR cohort eligibility included availability of (1) SUS from preseason of injury/UCLR and (2) SUS from ≥2 years after surgery. These players were 1:1 matched to players with no history of upper extremity injury to form the healthy cohort. Ligament thickness and ulnohumeral joint space at rest and under stress were directly measured. Joint laxity was calculated by subtracting joint space at rest from joint space under stress. The term "relative" was used to describe calculated differences where nondominant measurements were subtracted from dominant-side measurements.

RESULTS

Eight pitchers were included in the UCLR group and matched to 8 healthy pitchers (mean age at initial SUS examination, 19.6 years). At a minimum follow-up of 2 years, there were no significant differences between groups in terms of relative or dominant arm rest space, stress space, or laxity. Longitudinally (final measurements - baseline measurements), the mean relative ulnohumeral rest space decreased in the UCLR group and increased in the healthy group (-0.36 mm vs +0.50 mm; P = .032). The finding of increased UCL thickness in the UCLR group was expected, as UCL grafts are typically thicker than native ligaments.

CONCLUSION

Ulnhohumeral joint stability was achieved after UCLR as indicated by similar rest space, stress space, and joint laxity in dominant arms compared with a matched healthy cohort. A significant decrease in relative rest space after UCLR may represent the achievement of stability in surgery patients. Alternatively, the increase in ulnohumeral rest space seen in the healthy cohort may represent adaptive changes from pitching at a professional level.

Incidence of Medial Deltoid Ligament Instability in 226 Patients With Chronic Ankle Instability

The deltoid ligament is vitally important in the stability of the ankle and preventing excessive medial ankle movement. Historically, the impact of medial ankle instability has not been well understood in the setting of chronic ankle instability. A retrospective review of 226 patients treated for ankle instability between 2017 and 2022 identified 40 patients who required both medial and lateral repair. Decision for medial deltoid repair was based upon patient presentation, MRI findings, intraoperative fluoroscopy and final confirmation via arthroscopic positive "drive-through sign". Preoperative and postoperative American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle scores, Patient-Recorded Outcomes Measurement Information System (PROMIS) scores, and Karlsson-Peterson Ankle Function (K&P) scores were obtained and compared. There were statistically significant improvements found in all 3 scoring systems at a mean follow-up time of 11.7 months postoperatively. In the setting of chronic ankle instability, consideration should be given to the evaluation and potential repair of the deltoid ligament in order to provide sufficient stability to the medial ankle.

Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two-Thirds Glenoid Height Technique Compared to the "Best-fit Circle"

PURPOSE

To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy.

METHODS

The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, 2 reviewers independently estimated glenoid size using the two-thirds technique and the "best-fit circle" technique at 2 different times. A Student t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients.

RESULTS

This study included 112 patients. Using the results of glenoid height and "best-fit circle" diameter, the diameter of the "best-fit circle" was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the 2 measures of glenoid diameter (27.6 vs 27.9, P = .456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The interclass and intraclass coefficients for the perfect circle methods were 0.84 and 0.73, respectively.

CONCLUSIONS

We determined that the diameter of a circle placed on the inferior glenoid using the "best-fit circle" technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intraclass reliability.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

MRI Assessment of Tendon Graft After Lateral Ankle Ligament Reconstruction: Does Ligamentization Exist?

BACKGROUND

No description exists in the literature about the normal evolution of tendon graft after a lateral ankle ligament (LAL) reconstruction.

PURPOSE

To assess the magnetic resonance imaging (MRI) characteristics and the evolution of the tendon graft during different moments in the follow-up after an endoscopic reconstruction of the LAL.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This prospective study included 37 consecutive patients who underwent an endoscopic reconstruction of the LAL with an autograft using the gracilis tendon to treat chronic ankle instability (CAI) resistant to nonoperative treatment (CAI group) and 16 patients without ankle instability (control group). All patients in the CAI group underwent a postoperative assessment at 6, 12, and 24 months using the Karlsson score and MRI examination. Only patients with good and excellent results were included in the study. Graft assessment consisted of qualitative measurements and quantitative evaluations of the reconstructed anterior talofibular ligament (RATFL) and reconstructed calcaneofibular ligament (RCFL), including signal-to-noise quotient (SNQ) and contrast-to-noise quotient (CNQ) measurements in proton density-fat suppressed (PD-FS) and T1-weighted sequences. The analysis of variance test was used to compare the SNQ and the CNQ at different time points for each sequence.

RESULTS

The MRI signal at 6 months was increased compared with that of the control group. Next, a significant signal decrease from 6 to 24 months was noted on PD-FS and T1-weighted images. SNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P = .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months. Similarly, CNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P < .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months.

CONCLUSION

The present study demonstrated an evolution of the MRI characteristics, suggesting a process of graft maturation toward ligamentization. This is important for clinical practice, as it suggests an evolution in graft properties and supports the possibility of creating a viable ligament.

Clinical and Radiological Outcomes After Combined ACL and MPFL Reconstruction Versus Isolated ACL Reconstruction for ACL Injury With Patellar Instability

BACKGROUND

An anterior cruciate ligament (ACL) injury accompanied by patellar instability (PI) is a topic that has gained orthopaedic surgeons' attention recently. Untreated PI is reportedly associated with worse clinical outcomes after isolated ACL reconstruction (ACLR) in patients after an ACL injury with PI. Nevertheless, the appropriate surgical approach and its long-term therapeutic effects in these patients remain unclear.

PURPOSE

(1) To compare the clinical and radiological outcomes between isolated ACLR (iACLR) and combined ACLR and medial patellofemoral ligament reconstruction (cAMR) in patients after an ACL injury with PI and (2) to explore the correlations between these 2 procedures and clinical and radiological outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 106 patients diagnosed with an ACL injury accompanied by PI between January 2016 and April 2021 were analyzed in this study. There were 34 patients excluded because of missing postoperative radiological data. Among the remaining 72 patients, 34 patients underwent iACLR, while 38 patients underwent cAMR. Demographic characteristics, intraoperative findings, and patient-reported outcomes (Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity score) were prospectively collected. Patellar alignment parameters and worsening patellofemoral osteoarthritis (PFOA) features (evaluated with the modified Whole-Organ Magnetic Resonance Imaging Score) were analyzed longitudinally on magnetic resonance imaging. The Kujala score was used to evaluate the functional recovery of the patellofemoral joint, and redislocations of the patella were prospectively recorded. Finally, multivariate logistic regression analysis was used to explore the correlations between these 2 procedures and clinical (not achieving the minimal detectable change [MDC] for the Lysholm score) and radiological (worsening PFOA features) outcomes.

RESULTS

The mean follow-up duration was 28.9 ± 6.2 and 27.1 ± 6.8 months for the iACLR and cAMR groups, respectively (P = .231). Significantly higher Lysholm scores (88.3 ± 9.9 vs 82.1 ± 11.1, respectively; P = .016) and subjective International Knee Documentation Committee scores (83.6 ± 11.9 vs 78.3 ± 10.2, respectively; P = .046) were detected in the cAMR group compared with the iACLR group postoperatively. The rates of return to preinjury sports were 20.6% and 44.7% in the iACLR and cAMR groups, respectively (difference, 24.1% [95% CI, 3.3%-45.0%]; P = .030). Moreover, the rates of worsening PFOA features were 44.1% and 18.4% in the iACLR and cAMR groups, respectively (difference, 25.7% [95% CI, 4.9%-46.4%]; P = .018). In addition, significantly higher Kujala scores (87.9 ± 11.3 vs 80.1 ± 12.0, respectively; P = .006), lower redislocation rates (0.0% vs 11.8%, respectively; difference, 11.8% [95% CI, 0.9%-22.6%]; P = .045), and significantly better patellar alignment were detected in the cAMR group compared with the iACLR group postoperatively. Furthermore, multivariate logistic regression analysis determined that iACLR and partial lateral meniscectomy were significantly correlated with not achieving the MDC for the Lysholm score and worsening PFOA features in our study population.

CONCLUSION

In patients after an ACL injury with PI, cAMR yielded better clinical and radiological outcomes compared with iACLR, with better patellar stability and a lower proportion of worsening PFOA features. Furthermore, not achieving the MDC for the Lysholm score and worsening PFOA features were significantly correlated with iACLR and partial lateral meniscectomy. Our study suggests that cAMR may be a more appropriate procedure for patients after an ACL injury with PI, which warrants further high-level clinical evidence.

Comparison of the distraction index and Norberg angle with radiographic grading of canine hip dysplasia

The Orthopedic Foundation for Animals (OFA) radiographic grading system stands as a well-established benchmark for categorizing hip dysplasia in canines. Although more objective techniques to quantify early hip laxity in young dogs, such as the Norberg angle (NA) and distraction index (DI), have been documented, there is a scarcity of published studies that directly compare these radiographic measures. The primary objectives of this prospective, analytical study were to assess and compare the NA and DI measures with OFA grades within a cohort of dogs. Thirty dogs (57 hip joints) were evaluated, with a mean age of 5.4 ± 2.9 years and a mean body weight of 34.3 ± 7.1 kg. The discriminative power of hip dysplasia for DI and NA used OFA as a reference were compared by multivariate discriminant analysis test. Using the DI (≤0.3) 12 joints were classified as normal, using NA (≥105°) 24 joints and using OFA (≤3) 29. When comparing the discriminant power of NA with OFA resulting similar (P = .8324) with correct classifications of 81% using cross validation, however, the discriminant power of dysplasia of the DI resulted significantly greater (P = .0034) than OFA with correct classifications of only 59% using cross-validation, consequently it was possible determined that of 29 patients with OFA ≤ 3, 20 had DI > 0.3. These findings demonstrated that phenotypic healthy dogs according to OFA grading can present passive hip joint laxity, as demonstrated by radiographic evaluation with distraction. Furthermore, DI can contribute to the screening of CHD when evaluated in conjunction with OFA grading.

Comparison of Clinical Outcomes With Arthroscopic ATFL Repair With the CFL Repair and Open ATFL and CFL Repair in Chronic Lateral Ankle Instability

It is important to eliminate instability related to chronic lateral ankle instability (CLAI) to prevent osteoarthritis progression. We performed arthroscopic anterior talofibular ligament (ATFL) repair and performed calcaneofibular ligament (CFL) repair if instability remained. This study aimed to assess the clinical outcomes of our arthroscopic procedure compared to that of open surgery. Forty ankles underwent arthroscopic surgery and 23 ankles underwent open surgery to repair the lateral ankle ligaments for CLAI. In the arthroscopic surgery, varus stress was applied under fluoroscopy after ATFL repair, and CFL repair was performed if instability remained. Open surgery was performed using the Broström procedure with ATFL and CFL repair. To assess clinical outcomes, American Orthopaedic Foot & Ankle Society (AOFAS) and Karlsson-Peterson (KP) scores were collected preoperatively and at the final follow-up. The talar tilt angle (TTA) was measured preoperatively and 1 year postoperatively. The arthroscopic group showed significantly higher AOFAS and KP scores at the final follow-up compared to the open surgery group. There was no significant difference in TTA at 1 year between the groups. In open surgery, 2 patients required revision surgery. There were no major complications, but scar-related pain in 2 cases of open surgery was reported. Arthroscopic ATFL repair with the CFL repair gave satisfactory clinical outcomes compared to open surgery in CLAI because of low invasive to soft tissue including the joint capsule. It is important to minimize soft tissue dissection in repairing the lateral ankle ligament in patients with CLAI.

Teres minor denervation and pathologies resulting in shoulder joint instability and rotator cuff tears: A retrospective cross-sectional MRI study

Teres minor denervation (TMD) has gained increasing attention in recent years, particularly with the advent of magnetic resonance imaging (MRI). The potential association between TMD and shoulder instability or rotator cuff tear remains a subject of interest in the orthopedic community. In this retrospective and cross-sectional study, authors aim to investigate the potential association between TMD and shoulder instability or rotator cuff tears. Authors retrospectively analyzed MRI findings from 105 patients with TMD, focusing on rotator cuff pathologies, posterior labrocapsular complex (PLCC) tears, and posteroinferior glenohumeral joint capsule alterations. Authors assessed the association between TMD and rotator cuff and PLCC tears. For the multivariate analysis, partial proportional odds models were constructed for subscapularis (SSC) and SSP tears. Rotator cuff tears were present in 82.9% of subjects, with subscapularis (SSC) tears being the most frequent (77.1%). A significant association was observed between TMD and rotator cuff pathology (P = .002). PLCC tears were found in 82.3% of patients, and humeral position relative to the osseous glenoid was noted in 60% of patients with TMD. A significant association was identified between TMD and shoulder instability or labral/capsular abnormalities (P < .001). More than half of the cases exhibited a long tethering appearance toward the axillary neurovascular bundle on T1-weighted sagittal images. Our findings suggest that TMD is significantly associated with rotator cuff tears and shoulder instability. This study highlights the importance of identifying and treating PLCC tears in patients with TMD to address shoulder instability. Further research is needed to elucidate the role of TMD in the pathogenesis of shoulder instability and rotator cuff pathology.

Craniocervical fusion in the paediatric population - case series of 21 patients

PURPOSE

Craniocervical junction instability in a paediatric population presents a formidable challenge to the neurosurgeon. With a variety of anatomical variations, diminutive bony and ligamentous structures, possible superimposed syndromic abnormalities, the craniocervical junction is a technically challenging region to operate within. We aimed to review our series of patients to identify the common pathologies necessitating craniocervical fusion along with the use of intraoperative image guidance.

METHODS

We performed a retrospective review of twenty-one patients, with a mean age of 8.1 years, undergoing craniocervical fixations, involving either occipitocervical fusion or atlantoaxial fixation, from a single institution over a twelve-year period. The presentation, preoperative investigations, indication for surgery, surgical procedure, use of intraoperative navigation and clinical and radiological results were examined.

RESULTS

Twelve patients underwent primary C1-2 fixation, with the remaining 9 undergoing occipitocervical fusion. Five patients underwent surgery for traumatic instability, seven for os odontoideum, six for congenital anomalies and three for post-infectious instability. Follow up for 20 patients averaged 34 months (range 2-93 months). Five patients had Trisomy 21 and all underwent C1-2 fixation. Frameless stereotactic image guidance was utilised in five patients. No patients suffered immediate complications resulting from craniocervical junction fusion. Patients were observed to either neurologically improve (n = 6), or arrest their neurological deterioration following surgical intervention (n = 14), with concomitant radiological evidence of osseous fusion at follow up in 18 of 20 patients (90%). Two patients (10%) had radiological evidence of screw lucency, but neither required intervention because of being asymptomatic.

CONCLUSIONS

Craniocervical fixation in a paediatric population is a viable and safe treatment modality for the management of disorders requiring stabilisation at the craniocervical junction. Our experience of utilising frameless stereotaxy in the setting of grossly distorted anatomical landmarks is also reported.

MPFL Reconstruction Combined with a Modified Elmslie-Trillat Procedure for Recurrent Patellofemoral Instability

Several combined procedures have been reported for treating recurrent patellofemoral instability (RPI) with various types and severity of morphological abnormalities, but none have identified absolute threshold values as indications for surgery. We performed medial patellofemoral ligament (MPFL) reconstruction combined with a modified Elmslie-Trillat (ET) procedure on 24 knees (10 male and 11 female patients) to treat RPI with morphological abnormalities corresponding to elevated tibial tubercle-trochlear groove (TT-TG) distance, significant patella alta, and trochlear dysplasia. The inclusion criteria were RPI with morphological abnormalities corresponding to one or more of the following: sulcus angle > 160 degrees, trochlear dysplasia of Dejour classification C or D, Caton-Deschamps index > 1.5, lateral shift ratio > 50%, congruence angle > 15 degrees, or TT-TG distance > 20 mm, including habitual dislocation of the patella. Skeletally immature patients and those with congenital dislocation of the patella were excluded. The Kujala score, International Knee Documentation Committee subjective score, Knee Injury and Osteoarthritis Outcome score (KOOS), and each item of the KOOS improved significantly after surgery. Patellar apprehension sign was present preoperatively in all cases, but all disappeared postoperatively. No instance of postoperative redislocation was observed. On radiographic examination, the mean Q angle, tilting angle, lateral shift ratio, congruence angle, Caton-Deschamps index, Insall-Salvati index, and TT-TG distance improved significantly after surgery. There were no significant differences in sulcus angle after surgery. These results suggest MPFL reconstruction combined with a modified ET procedure provides satisfactory outcomes based on radiological and clinical evaluations for RPI with morphological abnormalities corresponding to elevated TT-TG distance, significant patella alta, and trochlear dysplasia.

Radiographic Anatomy of the Lateral Ankle Ligament Complex: A Cadaveric Study

BACKGROUND

When lateral ankle sprains progress into chronic lateral ankle instability (CLAI), restoring precise anatomic relationships of the lateral ankle ligament complex (LALC) surgically is complex. This study quantifies the radiographic relationships between the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and prominent osseous landmarks visible under fluoroscopy to assist in perioperative practices for minimally invasive surgery for CLAI.

METHODS

Ten fresh frozen ankle specimens were dissected to expose the LALC and prepared by threading a radiopaque filament through the ligamentous footprints of the ATFL and CFL. Fluoroscopic images were digitally analyzed to define dimensional characteristics of the ATFL and CFL. Directional measurements of the ligamentous footprints relative to the lateral process of the talus and the apex of the posterior facet of the calcaneus were calculated.

RESULTS

Dimensional measurements of the ATFL were a mean length of 9.3 mm, fibular footprint of 9.4 mm, and talar footprint of 9.1 mm. Dimensional measurements of the CFL were a mean length of 19.4 mm, fibular footprint of 8.2 mm, and calcaneal footprint of 7.3 mm. From the radiographic apparent tip of the lateral process of the talus, the fibular attachment of the ATFL was found 13.3 mm superior and 4.4 mm posterior, whereas the talar attachment was found 11.5 mm superior and 4.8 mm anterior. From the radiographic apparent posterior apex of the posterior facet of the calcaneus, the fibular attachment of the CFL was found 0.2 mm inferior and 6.8 mm anterior, whereas the calcaneal attachment was found 14.3 mm inferior and 5.9 mm posterior.

CONCLUSION

The ATFL and CFL were radiographically analyzed using radiopaque filaments to outline the ligamentous footprints in their native locations. These ligaments were also localized with reference to 2 prominent osseous landmarks. These findings may assist in perioperative practices for keyhole incision placement and arthroscopic guidance. Perfect lateral ankle joint imaging with talar domes superimposed is required to be able to do this.

CLINICAL RELEVANCE

Radiographic evaluation of the ATFL and CFL with reference to prominent osseous landmarks identified under fluoroscopy may assist in perioperative practices for minimally invasive surgery to address CLAI for keyhole incision placement and arthroscopic guidance.

Radiographic evaluation of radial flexion osteotomy effect on static scapholunate instability: a preliminary cadaveric study

INTRODUCTION

The optimal treatment of chronic scapholunate instability has yet to be established. Scapholunate ligament grafts are still far from being the ideal solution. We conducted an experimental study to evaluate whether flexion-opening wedge osteotomy of the distal radius improves misalignment and avoids rotatory subluxation of the scaphoid in a cadaveric model of static scapholunate dissociative instability.

MATERIALS AND METHODS

Radiographic studies were performed on 15 cryopreserved specimens after recreating a model of scapholunate instability by division of the scapholunate interosseous ligament (SLIL) and secondary stabilizers, taking radiographs at baseline, after the instability model, and after distal radius osteotomy. Static and dynamic (under controlled tendon traction) anteroposterior and lateral views were obtained to measure the length (in mm) of the carpal scaphoid and scapholunate interval, scapholunate angle, radio-lunate angle, and palmar tilt of the distal joint surface of the radius and to measure the dorsal scaphoid translation by the concentric circles method. The Wilcoxon test was used for statistical comparisons.

RESULTS

The scapholunate interval was significantly decreased after osteotomy in all static anteroposterior views and in all lateral views under tendon traction. Dorsal scaphoid translation was significantly reduced in static lateral view in extension and in dynamic lateral view under 5-pound flexor carpi radialis tendon tension controlled by a digital dynamometer.

CONCLUSIONS

Flexion-addition osteotomy of the distal radius appears to improve carpal alignment parameters in a cadaveric model of static scapholunate instability, achieving similar values to those obtained before instability.

Measurement of TT-TG can change with sequential MRIs due to variations in tibiofemoral rotation in patellofemoral instability patients

PURPOSE

There are various anatomic risk factors for patellofemoral instability (PFI) that help guide surgical treatment, including the tibial tubercle to trochlear groove (TT-TG) distance. However, no study has analysed the temporal changes in TT-TG prior to surgical intervention. This study sought to understand the variations in TT-TG over time for pediatric patients suffering from PFI prior to surgical intervention. The authors hypothesised that the TT-TG would substantially change between time points.

METHODS

Patients undergoing medial patellofemoral ligament (MPFL) reconstruction between 2014 and 2019 by one of two fellowship-trained orthopaedic surgeons were identified. Patients were included if they had two preoperative magnetic resonance imaging (MRI) performed on the same knee within 7.5 months of each other prior to any surgical intervention and had an initial TT-TG greater than 10 mm.

RESULTS

After considering 251 patients for inclusion, 21 patients met the final inclusion criteria. The mean age was 14.5 ± 2.5 years and 61.9% were female. TT-TG was initially noted to be 15.1 ± 1.8 mm. At mean time after sequential MRIs of 5.0 ± 1.9 months, TT-TG was noted to be 16.7 ± 3.2 mm. The differences between initial and subsequent TT-TG ranged from a 21.2% decrease to a 61.1% increase, with a mean difference of an 11.3% increase. Comparison between initial and subsequent TT-TG values demonstrated a significant difference (p = 0.017). Change in tibiofemoral rotation ranged from -9.2° to 7.5°. When comparing the change in TT-TG to change in tibiofemoral rotation, a significant correlation was found (p = 0.019).

CONCLUSION

Despite only a mean time between MRIs of 5 months, variations in TT-TG ranged from a decrease of 21.2% to an increase of 61.1%. The significant relationship between the changes in TT-TG and changes in tibiofemoral rotation between MRIs suggest that TT-TG measurements may vary due to variations in tibiofemoral rotation at the time of individual MRIs.

LEVEL OF EVIDENCE

Level IV.

[Imaging of posttraumatic shoulder instability : Current concepts]

Posttraumatic instability accounts for more than 95% of all shoulder instabilities with the highest incidence in patients between 20 and 30 years of age. In this age group, lesions of the capsulolabral complex are the most common sequelae after the first shoulder dislocation. Typical acute findings are the Bankart and Perthes lesions and humeral avulsion of the glenohumeral ligament (HAGL). Chronic sequelae are anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions, and nonclassifiable lesions with deficient anterioinferior labrum and glenohumeral ligaments. Recently, quantification of Hill-Sachs and bony Bankart lesions with glenoid defects have become the focus of interest: bipolar bone loss has emerged to be one important factor of recurrent instability that has not been addressed during the first stabilizing operation. The glenoid track concept emphasizes the importance of bipolar bone loss, where the glenoid track refers to the contact area between the humeral head and the glenoid at the end-range of motion in abduction, extension and external rotation. Any lesion of the humeral head that extends beyond the glenoid track is considered high risk for engagement of the humeral head at the glenoid margin with subsequent dislocation. Both the Hill-Sachs interval and the glenoid track can be determined using computed tomography (CT) and magnetic resonance imaging and, thus, help to define the status of the shoulder (on-track vs. off-track), which is prerequisite for planning the appropriate operative procedure. Similar tendencies also exist for posttraumatic posterior instabilities which are much rarer.

Anterior talofibular ligament's superior fascicle as a cause of ankle microinstability can be routinely identified by ultrasound

PURPOSE

Chronic pain can affect up to 40% of patients after ankle inversion sprains. The current hypothesis to explain this high percentage of chronic pain is a partial/total rupture of anterior talofibular ligament (ATFL) superior fascicle, a structure that has recently been described as intra-articular and as having a different function than ATFL's inferior fascicle. This has created the need for diagnosing ATFL superior and inferior fascicles independently. Therefore, the objective of this study is to investigate if the ATFL's superior fascicle can be visualized on ultrasound, and to describe its ultrasonographic appearance.

METHODS

Twenty fresh-frozen ankle specimens were used in this 4-phases study. First, the specimens were scanned on US to identify what was believed to be ATFL's superior fascicle. Second, ATFL's superior fascicle was sutured under direct arthroscopic vision. Next, the specimens were scanned on US to obtain an image of the sutured structure. Finally, the specimens were dissected to confirm that the suture was indeed placed on ATFL's superior fascicle.

RESULTS

On the 20 specimens studied, full correlation was obtained between US, arthroscopic suture and specimen dissection. ATFL's superior fascicle US appearance is provided.

CONCLUSION

ATFL's superior fascicle can be visualized on US, which will allow to undergo diagnosis of isolated injuries to that fascicle, a common finding in ankle microinstability. The results of this study will facilitate the diagnosis of partial or complete rupture of ATFL's superior fascicle, likely increasing the amount of ankle microinstability diagnosis, impacting clinical management of ankle sprain consequences.

Medial Patellofemoral Ligament Reconstruction With or Without Tibial Tubercle Osteotomy in Carefully Selected Patients Results in a 5% Revision Rate: A Preliminary Analysis

PURPOSE

The purpose was to assess the outcomes of medial patellofemoral ligament (MPFL) allograft reconstruction with or without tibial tubercle osteotomy (TTO) in adolescents, with a focus on evaluating demographic and imaging characteristics on outcomes.

METHODS

A single-institution retrospective study was performed of patients ages 12 to 19 years who underwent MPFL reconstruction +/- TTO for the treatment of lateral patellar instability. Demographic, clinical, surgical, and postoperative information was collected. All x-ray and magnetic resonance imaging measurements were completed independently by 2 surgeons. Patients were contacted to complete patient-reported outcomes at a minimum of 2 years following surgery. The primary outcome measure was recurrent instability resulting in revision surgery.

RESULTS

Seventy-eight knees in 74 patients, with a median age of 15.3 years (interquartile range: 14.4, 16.1), were included. Forty-five knees underwent isolated MPFL reconstruction and 33 knees had a combined MPFL + TTO. The knees that underwent MPFL + TTO had significantly greater tibial tubercle-trochlear groove distance (19.0 mm vs. 15.4 mm, P =0.015) and patellar tendon-lateral trochlear ridge distance (10.9 mm vs. 5.9 mm, P =0.018) than the knees treated with isolated MPFL reconstruction. Four knees (5.1%) underwent revision stabilization surgery, including 3 knees in the MPFL cohort (6.7%) and 1 knee in the MPFL + TTO cohort (3.0%). The rate of failure between the MPFL and MPFL + TTO knees was not significantly different, P =0.634. There were no differences in age, sex, body mass index, number of dislocations, or any imaging characteristics in patients who underwent revision versus those who did not. Patient-reported outcomes were collected on 50 knees at a median of 36 months (interquartile range: 24, 54) after surgery, and no differences were noted between cohorts.

CONCLUSIONS

Patellar stabilization surgery, including MPFL reconstruction and TTO in carefully selected patients, had excellent revision-free outcomes in 95% of this adolescent cohort. In this case series, those patients whose treatment included TTO had greater tibial tubercle-trochlear groove and patellar tendon-lateral trochlear ridge as compared to the isolated MPFL cohort. Despite previous literature suggesting demographic and imaging characteristics as risks for recurrent instability, we identified no characteristics within these two distinct surgical treatment groups to be predictive of the need for revision stabilization, regardless of the treatment group.

LEVEL OF EVIDENCE

Level III-retrospective comparison study.

The distal tibiofibular joint effusion may be a reliable index for diagnosing the distal tibiofibular syndesmosis instability in ankle

PURPOSE

To analyze the accuracy of MRI in diagnosis of distal tibiofibular syndesmosis instability (DTSI) and construct new diagnostic parameters.

MATERIALS AND METHODS

This retrospective study evaluated 212 patients with history of ankle sprains and 3 T MRI and received a final diagnosis of distal tibiofibular syndesmosis instability by ankle arthroscopic surgery from October 2017 and December 2021. We compared the accuracy of syndesmotic injury, qualitative index of distal tibiofibular joint effusion (DTJE), and quantitative index of distal tibiofibular joint effusion (DTJE) in diagnosing distal tibiofibular syndesmosis instability. The criteria for syndesmotic injury were consistent with previous literature, and DTJE was grouped according to the pre-experimental results.

RESULTS

A total of 212 patients (mean age, 35.64 ± 11.79, 74 female and 138 male) were included. Independent predictive MRI features included syndesmotic injury, qualitative index of distal tibiofibular joint effusion, and quantitative index of DTJE including the height, projected area of equal-point method, and projected area of incremental-value method. The quantitative index of DTJE showed a higher area under the receiver operating characteristic curve (0.805/0.803/0.804/0.811/0.817/0.805 > 0.8, P < 0.05; in comparison with all other method). The height measurement method was simpler and easier to operate, that could be gotten only by measuring the DTJE distance of a MRI independent layer, and the cut-off value of the effusion height was 8.00 mm and the Youden index (0.56) was the best.

CONCLUSIONS

Our research translated a complicated string of MRI multi-dimensional spatial measurements into a simple measuring process, and established the significance of quantifying DTJE in the diagnosis of DTSI. We found that the 8-mm height of DTJE was a more specific indicator for DTSI and could serve as a novel MRI diagnostic cutoff in clinical practice.

The arthroscopic double-button Latarjet does not modify the static posterior translation of the humeral head

INTRODUCTION

The Latarjet procedure treats anterior instability of the shoulder and is based on a triple anterior lock, where the conjoint tendon straps the lower third of the subscapularis muscle. Excessive posterior translation of the humeral head is a known risk factor for shoulder osteoarthritis. No in vivo study has investigated the effect of the bone block on the posterior static translation of the humeral epiphysis. The purpose of this study was to evaluate the effect of the bone block on the static posterior translation of the humeral head. The hypothesis was that this procedure increased this translation.

MATERIALS AND METHODS

This retrospective study included patients treated arthroscopically for anterior shoulder instability by a double-button Latarjet. An independent examiner analyzed the CT scans preoperatively, at 15 days, and at least 6 months postoperatively according to a standardized protocol. The analysis focused on the position of the bone block in the axial and coronal planes relative to the glenoid. The posterior translation was automatically calculated using the Blueprint© planning software.

RESULTS

Thirty-five patients were included with a mean age of 25 years (16-43), according to a 4M/1F sex ratio. The graft was perfectly flush to the subchondral bone in 63% (n=22) of cases and subequatorial in 91% (n=32). Preoperative posterior humeral translation was 52%. The mean immediate postoperative posterior humeral translation was 56%, and 57% at more than 6 months. The change in mean posterior humeral translation between preoperative/6 months was +0.94% [-20%; +12%] (p=0.29) and immediate postoperative/6 months +0.34% [-18%; +15%] (p=0.84). Gender, hypermobility and the axial position of the bone block did not influence the change in posterior humeral translation. The equatorial position of the bone block appeared to increase posterior humeral translation by +10%±5.2% [-0.427; 20.823] (p=0.07).

CONCLUSION

This work refutes our initial hypothesis. The change in static posterior humeral translation after arthroscopic Latarjet bone block remains stable at more than 6 months of follow-up. This procedure does not alter the anatomical position of the humeral head in relation to the glenoid. On the other hand, a more cranial positioning of the bone block could have an influence.

LEVEL OF EVIDENCE

IV.

Comparison of short-term clinical outcomes between open-wedge high tibial osteotomy and tibial condylar valgus osteotomy

BACKGROUND

This study aimed to compare radiological features and short-term clinical outcomes between open-wedge high tibial osteotomy (OWHTO) and tibial condylar valgus osteotomy (TCVO), to provide information facilitating decision-making regarding those two procedures.

METHODS

Twenty-seven cases involving 30 knees that had undergone OWHTO (HTO group) and eighteen cases involving 19 knees that had undergone TCVO (TCVO group) for medial compartment knee osteoarthritis (OA) were retrospectively evaluated. Patient characteristics, severity of knee OA, lower limb alignment, joint congruity and instability were measured from standing full-length leg and knee radiographs obtained before and 1 year after surgery. Range of motion in the knee joint was measured and Knee Injury and Osteoarthritis Outcome Score (KOOS) was obtained to evaluate clinical results preoperatively and 1 year postoperatively.

RESULTS

Mean age was significantly higher in the TCVO group than in the HTO group. Radiological features in the TCVO group included greater frequencies of advanced knee OA, varus lower limb malalignment, higher joint line convergence angle, and varus-valgus joint instability compared to the HTO group before surgery. However, alignment of the lower limb and joint instability improved to comparable levels after surgery in both groups. Maximum flexion angles were significantly lower in the TCVO group than in the HTO group both pre- and postoperatively. Mean values in all KOOS subscales recovered similarly after surgery in both groups, although postoperative scores on three subscales (Symptom, Pain, and ADL) were lower in the TCVO group (Symptom: HTO, 79.0; TCVO, 67.5; Pain: HTO, 80.5; TCVO, 71.1; ADL: HTO, 86.9; TCVO, 78.0).

CONCLUSIONS

Both osteotomy procedures improved short-term clinical outcomes postoperatively. TCVO appears preferable in cases of advanced knee OA with incongruity and high varus-valgus joint instability. An appropriate choice of osteotomy procedure is important to obtain favorable clinical outcomes.

Standing on single foot-binding test yields satisfactory results as a novel method for the diagnosis of distal tibiofibular syndesmosis instability: a prospective, cross-sectional diagnostic-accuracy study

BACKGROUND

Non-invasive diagnosis of distal tibiofibular syndesmosis instability (DTSI) was a great challenge to clinicians. We designed a new method, the Standing on single foot-Binding test, and investigated the accuracy of the test in the diagnosis of distal tibiofibular syndesmosis instability in adults with a history of ankle injury.

METHODS

85 participants with ankle injury were subjected to the Standing on single foot-Binding test, MRI and palpation to detect the distal tibiofibular syndesmosis instability (DTSI) and the findings were compared with ankle arthroscopic results. Both participants and arthroscopist were blind to the predicted results of the clinical tests. Sensitivity, specificity, PPV, NPV, LR+, LR - and their 95% CIs were calculated for each of the clinical tests as well as for the positive clinical diagnosis.

RESULTS

The Standing on single foot-Binding test (SOSF-B test) outperformed MRI and palpation, in terms of sensitivity (87.5%/84.38%), specificity (86.79%/86.79%), PPV (80%/79.41%), NPV (92%/91.2%), LR+ (6.625/6.39), LR- (0.14/0.18) and diagnostic accuracy (87.06/85.88), among others, in the diagnosis of distal tibiofibular syndesmosis instability (DTSI). The diagnostic performance of 20° SOSF-B test was virtually identical to that of 0° SOSF-B test. According to the prevalence (28.7%) of DTSI and LR of four tests, the post-test probability could be used in clinical practice for the prediction of DTSI.

CONCLUSION

This prospective and double-blind diagnostic test showed that the SOSF-B test is clinically feasible for the diagnosis of distal tibiofibular syndesmosis instability (DTSI), and new diagnostic tools for rapid screening of distal tibiofibular syndesmosis instability (DTSI).

LEVEL OF EVIDENCE

II.

Unrecognized glenoid fracture in opposite shoulders with symptomatic anterior instability

BACKGROUND

The purpose of the present study was to investigate the characteristics of unrecognized glenoid fracture in opposite shoulders with symptomatic anterior instability.

METHODS

Participants were 38 patients, who had complaints of instability on only one side (symptomatic shoulder) and had no complaints despite of a glenoid fracture on the other shoulder (asymptomatic shoulder) from 2011 to 2020. Factors that could influence the onset of symptoms including glenoid rim morphology were retrospectively investigated.

RESULTS

Among the asymptomatic shoulders, 16 had a single traumatic event and 22 had no history of trauma. The glenoid morphology was normal in 6, erosion in 12 and bony Bankart in 20 on the symptomatic side, whereas the respective shoulders were 0, 16 and 22 on the asymptomatic side. Bone union of bony Bankart was complete in 9, partial in 3 and non-union in 8 on the symptomatic side, whereas the respective shoulders were 18, 3 and 1 on the asymptomatic side. The mean glenoid defect size was 10.4% and 7.8%, and the mean bone fragment size was 5.0% and 4.5%, respectively. The mean medial displacement of bone fragments was 2.6 mm and 1.0 mm, respectively (p < 0.001). A larger glenoid defect (≥10%) was recognized in 19 symptomatic shoulders and 10 asymptomatic shoulders. Among them, erosion was solely recognized in 5 symptomatic shoulders. In shoulders with bony Bankart, all 10 asymptomatic shoulders had a completely or partially united fragment with less than 2 mm displacement. On the other hand, among 14 symptomatic shoulders, united fragment was solely recognized in 8 shoulders, in which medial displacement was less than 2 mm in 3 shoulders.

CONCLUSIONS

Even if a glenoid fracture occurred, symptom such as instability or pain was not always recognized by all patients. Regardless of glenoid defect size, shoulders with a completely or partially united bone fragment and with less than 2 mm displacement were found to be asymptomatic.

Occult, Incomplete, and Complete Posterior Labral Tears Without Glenohumeral Instability on Imaging Underestimate Labral Detachment

PURPOSE

To introduce a classification of posterior labral tear and describe clinical characteristics, magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) findings, arthroscopic findings, and outcomes after arthroscopic repair for patients with posterior labral tears without glenohumeral instability.

METHODS

Sixty patients with posterior labral tear who underwent arthroscopic repair were analyzed retrospectively. Patients with shoulder instability were excluded. Tear patterns were classified into 3 types; occult (type 1), incomplete (type 2), and complete (type 3) based on MRI/MRA studies. A visual analog scale score for pain, American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score for satisfaction, and return to sports were evaluated at a minimum follow-up of 2 years. Computed tomography arthrography was performed at a year follow-up for assess labral healing. The diagnosis was confirmed in arthroscopy, and arthroscopic labral repair without capsular plication was performed.

RESULTS

The mean patient age was 30.4 ± 6.9 years, and all patients were male. Forty-four patients (73.3%) were participating in sports. MRI/MRA studies identified 10 patients with type 1, 18 with type 2, and 32 with type 3 tears. Type 1 tear patients showed a significantly longer symptom duration than those with type 3 (32.5 ± 17.2 vs 18.2 ± 17.1 months; P = .015). In arthroscopic findings, 70% of type 1 tear was confirmed as incomplete or complete tears. The American Shoulder and Elbow Surgeons score improved from 79.6 ± 10.3 to 98.1 ± 3.7, and pain was relieved from 2.4 ± 0.7 to 0.2 ± 0.5 at the last follow-up visit with high labral healing rate (95%). Thirty-nine (88.6%) patients returned to sports at preinjury levels.

CONCLUSIONS

In active young men with shoulder pain during daily activities or sports despite programmed conservative treatment, posterior labral tears should be considered even when MRI/MRA findings are ambiguous. Arthroscopic posterior labral repair without capsular plication provided satisfactory clinical outcomes and a high labral healing rate.

LEVEL OF EVIDENCE

Level Ⅳ, case series.

Latarjet in women for anterior shoulder instability: a case series analysis

PURPOSE

The Latarjet procedure is traditionally used to treat chronic anterior shoulder instability associated with glenoid bone loss. However, few series have analyzed outcomes in a female-only population. The objective of this study was to evaluate the clinical and radiological outcomes of a Latarjet bone block in this specific population.

METHODS

This single-center retrospective study included 15 women (mean age 35 ± 11.3; 19-60) reviewed with a minimum follow-up of 2 years. The procedure was performed using the open bone block screw technique (n = 7) or by arthroscopy with cortical button (n = 8). Clinical evaluation was based on active range of motion measurements, Rowe and Walch-Duplay scores, and subjective shoulder value (SSV). Radiographic analysis explored bone block healing at the last follow-up.

RESULTS

At a mean follow-up of 48 months (32-86), no recurrence was reported. The mean Rowe score was 91 points (70-100), Walch-Duplay 90 points (60-100), and SSV 87% (70-100). The active mobilities reached 169° (± 9°) in elevation, 57° (± 15°) in external rotation at side, and 89° (± 6°) in abduction. The return-to-sport rate was 91%. Five patients experienced persistent anterior pain, with screws requiring hardware removal in 2 (p = 0.02). Radiological assessment detected one case of nonunion (7%).

CONCLUSION

Women treated with the Latarjet procedure experienced satisfactory midterm clinical outcomes. The arthroscopic technique using cortical button fixation seems to avoid residual anterior pain requiring hardware removal.

Quantifying the Stress in Stress Radiographs to Determine Sufficient Laxity of the Coxofemoral Joint: A Canine Hip Dysplasia Cadaveric Study

OBJECTIVE

 While it has been known for a long time that laxity in the hip joint is the primary cause of degenerative changes later on in canine hip dysplasia, limited data are available on the fundamental characteristics that define the procedure used to quantify this. The aim of this study was to evaluate the force-laxity relation to assess the repeatability of repeated cycles of stress on the hip joint and determine the force necessary tomeasure a sufficient proportion of laxity present in hip joints.

MATERIALS AND METHODS

 Thirty-four canine cadavers underwent a radiographic protocol including stress radiographs with increasing force using the Vezzoni modified Badertscher distension measuring device (VMBDmD). Three dogs underwent five repeat examinations. The laxity index (LI) and osteoarthritis were scored.

RESULTS AND CONCLUSION

 The curves and the maximal LI (LImax) were not significantly influenced by osteoarthritis, weight, gender, and side. The position of the VMBDmD influenced the curve but not the LImax. The force-laxity curve itself and the LImax were repeatable, which indicated that it did not cause permanent damage to the joint and also confirmed the practicability of the procedure. Ninety percent of hip joints reached sufficient laxity at a force of 95.32 N, which is realistically achievable. Further studies are necessary before extrapolating these results to patients and to further enlighten the biomechanics of stress radiographs.

Editorial Commentary: Patients May Have Posterior Glenoid Labral Tears in the Absence of Instability or Magnetic Resonance Imaging Findings

Posterior labral tears occur more often than imagined 25 years ago. Although such tears are generally identified in patients with posterior shoulder instability, the spectrum of labral tears in patients without instability creates a challenging diagnosis. Both physical examination and magnetic resonance imaging interpretation are difficult. Pathology encompassing posterior labral tears without instability notably reveals differences compared with throwers with posterior labral tears and patients with posterior instability. Recent research has identified 3 tear types: occult (type 1), incomplete (type 2), and complete (type 3). Attention to diagnosis deserves critical attention, in addition to tailoring of repair techniques to address the appropriate conditions in the shoulder. Even in patients without posterior instability and with ambiguous magnetic resonance imaging or magnetic resonance arthrography findings, posterior shoulder pain during daily activities or sports may indicate a posterior labral tear. Arthroscopic posterior labral repair without capsular plication provides good clinical outcomes and high rates of return to sport and labral healing.

Diagnostic value of measuring the talofibular space using stress sonography in chronic lateral ankle instability

OBJECTIVES

To investigate the diagnostic value of measuring the talofibular space using stress sonography for chronic lateral ankle instability (CLAI).

MATERIALS & METHODS

We recruited patients who were clinically diagnosed with CLAI between October 2018 and December 2019 (CLAI group). A control group of healthy volunteers was also included for this study. Both groups underwent a preliminary stress sonographic examination. First, the ultrasonic characteristics of the anterior talofibular ligament (ATFL), including length, thickness, relaxation, calcification, and rupture, were observed using conventional sonography. Second, the talofibular space at the passive neutral position (D1) and maximum varus position (D2) was measured (by stress sonographic images), and the difference (ΔD = D1-D2) between them was determined. Third, the parameters of the two groups were statistically compared. Finally, receiver operating characteristic (ROC) curves and area under the curve (AUC) analyses were performed for parameters with significant differences.

RESULTS

The CLAI group comprised 60 patients, yielding data on 60 ankles, whereas the control group comprised 35 participants, yielding data for 70 ankles. Differences in D1, D2, and ΔD of the talofibular space between the two groups were significant, with ΔD proving to be the best diagnostic indicator (P < 0.001). Its AUC, optimal cutoff value, sensitivity, and specificity were 0.922, 0.11 cm, 73 %, and 94 %, respectively, followed by D2 (0.850, 0.47 cm, 67 %, and 94 %, respectively; P < 0.001) and D1 (0.635, 0.47 cm, 67 %, and 94 %, respectively; P = 0.006).

CONCLUSION

Measurement of talofibular space in stress sonography is a valuable diagnostic indicator for CLAI, especially the ΔD between the neutral and stress position.

Normal Values for Distal Tibiofibular Syndesmotic Space With and Without Subject-Driven External Rotation Stress

BACKGROUND

The diagnosis and treatment of distal tibiofibular syndesmosis (DTFS) injury can be challenging, especially in cases of subtle instability that may be masked on 2-dimensional conventional radiographs. Weightbearing computed tomography (WBCT) has recently emerged as a useful diagnostic tool allowing direct assessment of distal tibiofibular area widening. The purpose of the current study was to examine and report normal threshold values for DTFS area measurements in a cohort of healthy volunteers, assessing the ankles in natural weightbearing position and under subject-driven external rotation stress.

METHODS

In this prospective study, we enrolled 25 healthy volunteers without a history of DTFS injury or high ankle sprain, previous foot and ankle surgery, or current ankle pain. Subjects with any prior ankle injuries were excluded. Study participants underwent bilateral standing nonstress and external rotation stress WBCT scans. The DTFS area (mm2) was semiautomatically quantified on axial-plane WBCT images 1 cm proximal to the apex of the talar dome using validated software. Syndesmosis area values were compared between "unstressed" and "stressed" ankles, as well as left and right ankles. Statistical analysis was performed using independent t tests/Wilcoxon analysis with statistical significance defined as P <.05.

RESULTS

The study cohort consisted of 50 ankles in 25 patients (12 males, 48%) with a mean age of 28.7 ± 9.3 years. In the unstressed ankle, the mean pooled DTFS area was determined to be 103.8 + 20.8 mm2. The mean syndesmosis area of unstressed left ankles (104.2 + 19.5 mm2) was similar to unstressed right ankles (109.2 + 17.2 mm2) in the cohort (P = .117). With external rotation stress, the DTFS area of left ankles (mean difference -0.304 mm2, CI -12.1 to 11.5; P = .082), right ankles (mean difference -5.5 mm2, CI 16.7-5.7; P = .132), and all ankles (mean difference -2.9 mm2, CI -10.8 to 5.1; P = .324) remained similar.

CONCLUSION

This study presents normal values and range for DTFS area calculation. In uninjured ankles with expected intact ligaments, subject-driven external rotation stress did not result in significant widening of the DTFS space as imaged on with WBCT.

LEVEL OF EVIDENCE

Level II, cross-sectional study.

Effect of Patient Characteristics on the Minimal Clinically Important Difference and Patient Acceptable Symptom State Thresholds After Arthroscopic Bankart Repair

BACKGROUND

There is scarce literature on clinically significant values after arthroscopic Bankart repair (ABR).

PURPOSE

To determine the minimal clinically important difference (MCID) and the patient acceptable symptom state (PASS) thresholds at 1 year for the Rowe and Athletic Shoulder Outcome Scoring System (ASOSS) scores after ABR and to determine the effect of patient characteristics on these metrics after ABR.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review of patients undergoing ABR from a single institution between January 2017 and January 2020 was performed. Patients with at least 1 episode of instability and a minimum follow-up of 12 months were included. The exclusion criteria were as follows: bony defects of >20% on the anteroinferior portion of the glenoid based on a preoperative computed tomography scan; engaging Hill-Sachs lesions at 90° of abduction and 90° of external rotation based on an arthroscopic examination; previous surgery on the same shoulder; multidirectional instability or concomitant repair of full-thickness rotator cuff tears; superior labral anterior to posterior lesions; posterior labral tears; or humeral avulsion of the glenohumeral ligament lesions. Patient-reported outcome measures were collected both preoperatively and 1-year postoperatively. Delta was defined as the change between preoperative and 1-year postoperative scores. Distribution-based (one-half the standard deviation of the difference between pre- and postoperative outcome scores) and anchored-based approaches (response to a satisfaction question at 1 year) were used to estimate the MCID and the PASS, respectively. The optimal cutoff point, where sensitivity and specificity were maximized, and the percentage of patients achieving those thresholds were also calculated.

RESULTS

Overall, 190 patients were included. The distribution-based MCID for the Rowe and ASOSS scores were calculated to be 8.2 and 8.7, respectively. The rate of patients who achieved MCID thresholds was 96% for the Rowe and 96% for ASOSS scores. The PASS threshold for the Rowe and ASOSS scores were ≥80 and ≥90, respectively. The rate of patients who achieved PASS scores after ABR were 86% and 83%, respectively. The MCID and PASS values showed great variability based on sex (men: 8.5 and ≥85 for Rowe / 8.9 and ≥90 for ASOSS, respectively, vs women: 6.7 and ≥73 for Rowe / 8.1 and ≥75 for ASOSS), age (≥21: 8.4 and ≥80 / 9.2 and ≥90 vs <21: 7.8 and ≥75 / 7.7 and ≥85), sports participation (sports: 8.8 and ≥85 / 9.5 and ≥90 vs no sports: 8.1 and ≥75 / 8.6 and ≥80), and type of athlete (competitive: 8.4 and ≥85 / 8.9 and ≥87 vs recreational: 7.5 and ≥73 / 8.1 and ≥68).

CONCLUSION

This study identified the MCID and PASS thresholds for the Rowe and ASOSS scores at 1 year after ABR. However, these values showed great variability when accounting for different patient characteristics such as sex, age, sports participation, and type of athlete, highlighting the importance of considering individual patient-specific characteristics for optimal treatment decision-making and ensuring treatment success tailored to each patient's unique needs and expectations.

Anatomical front and back reconstruction sustains radiographic alignment: a comparison to three-ligament tenodesis

Multiple techniques exist to reconstruct the scapholunate interosseous ligament, though none have demonstrated superiority. This study compares 1-year radiographic outcomes of the three-ligament tenodesis and the anatomical front and back reconstruction. All patients who underwent reconstruction of their scapholunate interosseous ligament at one institution with either anatomical front and back reconstruction or three-ligament tenodesis between 2011 and 2020 were retrospectively reviewed. At 52-week follow-up, anatomical front and back reconstruction maintained a statistically significant improvement in scapholunate gap, corrected radiolunate angle and dorsal scaphoid translation, while three-ligament tenodesis demonstrated no sustained improvement in any parameter. The improvement in dorsal scaphoid translation was significantly greater for patients undergoing anatomical front and back reconstruction compared with three-ligament tenodesis at the 16-weeks postoperative timepoint (-1.0 mm, -0.3 mm). Anatomical front and back reconstruction demonstrates sustained improvement in radiographic outcomes at 1 year when compared with three-ligament tenodesis. By addressing both volar and dorsal critical ligament restraints, adoption of anatomical front and back reconstruction for advanced stage scapholunate interosseous ligament injuries should be considered.Level of evidence: IV.

Association of Diaphragm Contractility and Postural Control in a Chronic Ankle Instability Population: A Preliminary Study

BACKGROUND

Altered reorganization of the sensorimotor system after an initial lateral ankle sprain may lead to a chronic neuromuscular maladaptation in multiple body locations. Specifically, decreased diaphragm contractility has been observed in patients with chronic ankle instability (CAI). The diaphragm has an essential role in postural control. Decreased diaphragm contractility could associate with diminished postural control commonly observed in patients with CAI. However, no study has determined if diaphragm contractility contributes to postural control in a CAI population.

HYPOTHESIS

Decreased diaphragm contractility would be negatively associated with static postural control in patients with CAI.

STUDY DESIGN

Cross-sectional study design.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 15 participants with CAI participated voluntarily. An ultrasonography assessment was performed to quantify the right and left hemidiaphragm thickness at the end of resting inspiration and expiration in supine while breathing quietly. The degree of diaphragm contractility was calculated from the diaphragm thickness. Participants performed 3 eyes-open trials of a 20-second single-leg balance task on the involved limb. Static postural control measures included the center of pressure velocity (COPV) and mean of time-to-boundary (TTB) minima in the anteroposterior (AP) and mediolateral directions.

RESULTS

Moderate correlations of the right hemidiaphragm contractility were observed with COPV (ρ = -0.54) and TTB mean minima (ρ = 0.56) (P < 0.05) in the AP direction. The left hemidiaphragm contractility was moderately correlated with COPV (ρ = -0.56) and TTB mean minima (ρ = 0.60) (P < 0.05) in the AP direction.

CONCLUSION

Lower diaphragm contractility may be associated with diminished static postural control in the AP direction in patients with CAI.

CLINICAL RELEVANCE

This study highlights diaphragm contractility could be a potential connection with diminished static postural control in patients with CAI. Our data raise new avenues for future exploration including potential beneficial effects of implementation of diaphragm breathing exercises and techniques for restoring static postural control in patients with CAI.

High incidence of osteoarthritic changes in patients with osteochondral lesions of the talus without chronic lateral ankle instability

BACKGROUND

It is unclear whether osteochondral lesions of the talus (OLTs) without chronic lateral ankle instability (CLAI) progress to osteoarthritis, which affects the therapeutic strategy. Especially, the efficacy of conservative treatment for OLT remains controversial. Since various anatomical abnormalities have been reported, there may be abnormal movement of the talus in the mortise, causing ankle instability. We hypothesized that OLTs have frequent osteoarthritic changes even without CLAI. This study aimed to evaluate the incidence of osteoarthritic changes and stress distribution on the talus in OLT.

METHODS

Fifty-eight ankles with medial OLT without CLAI were retrospectively reviewed. Osteophytes and joint space narrowing on radiographs were scored using Kraus's classification and compared to ankles without OLTs. OA scores were compared between over 18 years and less than 17 years in OLTs. On computed tomography images, the area of OLTs was measured. Besides, Hounsfield Units (HU) of the talus in patients with and without OLTs were measured and compared.

RESULTS

Osteoarthritic changes were observed in 54 of the 58 ankles (94.8%) in the OLT patients. Osteophytes were frequently observed at the medial gutter and anterior tibial plafond. The OA score in patients aged over 18 years was significantly higher than that in patients aged less than 17 years (P < 0.05). HU values in the talus were significantly higher than those in non-OLT patients. OLTs more than 100 mm2 had a significantly higher osteoarthritic score than those less than 100 mm2.

CONCLUSION

Medial OLT without CLAI has frequently osteoarthritic changes, especially large lesions. Osteoarthritic changes in OLTs will progress over time, which needs to be considered when deciding whether to perform the surgical or non-surgical treatment.

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.

Loosening of the anterolateral capsule affects the stability after arthroscopic lateral ankle ligament repair of chronic ankle instability

PURPOSE

Arthroscopic anterior talofibular ligament (ATFL) repair for chronic lateral ankle instability (CLAI) has been widely performed. The recurrence of the instability after the surgery sometimes occurs, which may cause the development of osteoarthritis. Therefore, it is important to elucidate the factors of the recurrence. This study aimed to evaluate the loosening of the capsule in the MRI and whether it affected clinical outcomes or not in arthroscopic ATFL repair.

MATERIALS AND METHODS

Thirty-eight ankles in 35 patients with CLAI treated by arthroscopic lateral ligament repair were included. The capsule protrusion area defined as the area that protruded ATFL laterally from the line connecting the fibula and talus attachment on MRI was measured. Capsule protrusion area in ankles with or without CLAI was compared and the relationships between it and clinical outcomes were assessed.

RESULTS

The capsule protrusion area in the CLAI group (74.2 ± 36.4 mm2) was significantly larger than that in the control (25.5 ± 14.3 mm2) (p < 0.01). The capsule protrusion area in the poor remnant group (93.8 ± 36.4 mm2) was significantly larger than that in the excellent (53.2 ± 40.3 mm2) (p < 0.05). The capsule protrusion area in the patients with recurrent instability (99.8 ± 35.2 mm2) was significantly larger than that without recurrent instability (62.4 ± 30.9 mm2) (p < 0.01). Clinical scores in the recurrent group were significantly lower than those in the non-recurrent group (p < 0.05).

CONCLUSIONS

Capsule loosening would be one of the causes of the recurrence of instability after arthroscopic lateral ankle ligament repair. Evaluation of the capsule protrusion area on MRI is helpful to choose appropriate surgical procedures for CLAI patients.

LEVEL OF EVIDENCE: 4

Joint instability in patients with borderline developmental dysplasia of the hip

BACKGROUND

The treatment strategy for developmental dysplasia of the hip is determined based on the lateral center-edge angle. Nonetheless, an evaluation of joint instability may be important in determining the treatment strategy. This study classified the displacement patterns of the femoral head center during hip abduction.

METHODS

Ten patients with borderline developmental dysplasia of the hip, 10 patients with developmental dysplasia of the hip, and 10 patients with normal hips were analyzed. Image matching was performed using X-ray images of hip abduction with a three-dimensional hip model. The displacement of the femoral head center and its trajectory length were measured. A cluster analysis was conducted to classify the displacement pattern of the femoral head center, and trajectory lengths were compared.

FINDINGS

Displacement was classified into three patterns: medialization, hinge abduction, and centering. Patients with borderline developmental hip dysplasia exhibited all three patterns. Almost all patients with developmental dysplasia of the hip showed medialization and hinge abduction, whereas all normal patients had the centering type. The mean trajectory length indices for the medialization and hinge abduction types were significantly longer than those for the centering type (P = 0.01 and P = 0.016, respectively).

INTERPRETATION

Borderline developmental dysplasia of the hip is a heterogeneous condition characterized by varying hip instability levels. Our findings suggest that uniform evaluation based on the lateral center-edge angle is inappropriate and that joint instability must be evaluated in each patient with borderline developmental dysplasia of the hip.