Asymmetric Deficit of Knee Flexion: An Occasional Symptom of Discoid Lateral Meniscus in Children

PURPOSE

A knee flexion deficit can be the unique symptom and sign of discoid lateral meniscus (DLM) in children. The aim of this study was to investigate the accuracy of this clinical sign. The hypothesis was that deficit of knee flexion was associated with anterior rim disinsertion and posteriorly fixed DLM.

METHODS

A retrospective, single-center study was conducted in a larger series of 114 operated knees for symptomatic DLM from 2007 to 2018. A focus was done on 9 knees with a deficit of knee flexion without snapping. History and clinical examination with grading of instability, preoperative magnetic resonance imaging, and arthroscopic findings were studied.

RESULTS

Among 35 knees with DLM grade 3 of instability, 26 had an isolated extension deficit. Nine knees in 5 boys and 4 girls with a mean age of 9 years (range 6 to 12) had a flexion deficit. It was the only symptom of DLM in 6, and it was associated to extension deficit in 3. In the history, 8 knees were grade 2 (snapping knee) before evolving toward a flexion deficit. All had a complete DLM with posterocentral (n=7) or central (n=2) shift at magnetic resonance imaging analysis. All had DLM with posterior shift fixed during arthroscopic evaluation. Moreover, looking at the entire series, 1 knee was a false negative and had a full flexion despite a posterior and fixed DLM during arthroscopic evaluation. The sensitivity of asymmetrical knee flexion to predict posterior fixed DLM was 90%.

CONCLUSIONS

An asymmetric deficit in knee flexion is highly suggestive of DLM with anterior detachment and fixed posterior meniscal shift (specificity and positive predictive value of 100%). Given this could be the only clinical sign of DLM, specific attention therefore must be paid in the assessment of knee flexion by measuring the distance between heel and bottom on both sides, especially in a knee without snapping currently but with a history of snapping (grade 3).

LEVEL OF EVIDENCE

Level III.

Microcornea, cerebellar hypoplasia and hyperlax joints-unusual combo in rare Ehlers-Danlos syndrome-musculocontractural type 1

Ehlers-Danlos syndrome is a group of connective tissue disorders with 14 subtypes, involving joint hyperlaxity, tissue fragility, hypertensive skin and other systemic organs with an incidence of 1 in 1 000 000 worldwide. We report a middle childhood female born of second degree consanguineous marriage with limping gait with muscle weakness, with normal development and IQ. Examination revealed microcornea, distal joint laxity of fingers and wrist, hypotonia and broad-based limping gait. Fracture dislocation right hip was managed by fixation. With the atypical neuroimaging finding of cerebellar vermis hypoplasia, exome sequencing was ordered and confirmed as Ehlers-Danlos syndrome (musculocontractural type-1). Hence, genetic counselling was done and prognosis of the child was explained.

Patellar Instability: Imaging Findings

Patellofemoral instability results from impaired engagement of the patella in the trochlear groove at the start of flexion and may lead to pain and lateral patellar dislocation. It occurs most frequently in adolescents and young adults during sporting activities. Trochlear dysplasia, patella alta, and excessive lateralization of the tibial tuberosity are the most common risk factors for patellar instability. The main role of imaging is to depict and assess these anatomical factors and highlight features indicating previous lateral dislocation of the patella.

The Dejour classification for trochlear dysplasia shows slight interobserver and substantial intraobserver reliability

PURPOSE

Trochlear dysplasia is one of the main risk factors for recurrent patellar dislocation. The Dejour classification identifies four categories that can be used to classify trochlear dysplasia. The purpose of this study is to evaluate the inter- and intraobserver reliability of the Dejour classification for trochlear dysplasia. The hypothesis was that both intra- and interobserver reliability would be at least moderate.

METHODS

This is a cross-sectional, reliability study. Twenty-eight examiners from the International Patellofemoral Study Group 2022 meeting evaluated lateral radiographs of the knee and axial magnetic resonance images from 15 cases of patellofemoral instability with trochlear dysplasia. They classified each case according to Dejour's classification for trochlear dysplasia (A-D). There were three rounds: one with only computed radiograph (CR), one with only magnetic resonance imaging (MRI) and one with both. Inter- and intraobserver reliability were calculated using κ coefficient (0-1).

RESULTS

The mean age of patients was: 14.6 years; 60% were female and 53% had open physis. The interobserver reliability κ probabilities were 0.2 (CR), 0.13 (MRI) and 0.12 (CR and MRI). The intraobserver reliability κ probabilities were 0.45 (CR), 0.44 (MRI) and 0.65 (CR and MRI).

CONCLUSION

The Dejour classification for trochlear dysplasia has slight interobserver reliability and substantial intraobserver reliability.

LEVEL OF EVIDENCE

Level I.

Editorial Commentary: Both 3-Dimensional Magnetic Resonance Imaging and Computed Tomography Are Valuable for Determination of Glenoid and Humeral Bone Loss in Patients With On- and Off-Track Shoulder Instability

Improving the modalities for advanced glenohumeral joint imaging has been an important area to address in the field of orthopaedic surgery. The current gold standard for imaging glenoid and humeral bone loss in patients with shoulder instability, 3-dimensional (3D) computed tomography (CT), provides high-quality 3D images of bones but comes with a cost of extra time, additional imaging because of the need for an additional magnetic resonance imaging (MRI) scan, and exposure to radiation. Three-dimensional MRI is a promising solution that can produce high-contrast images depicting both bony structures and soft tissues. Multiple 3D MRI sequences have been studied, with the FRACTURE (fast field echo resembling a CT using restricted echo-spacing) sequence showing high comparability of bony measurements to 3D CT scans, as well as the ability for widespread clinical use. Recent research has shown minimal differences in 3D CT and 3D MRI and has confirmed that 3D imaging does provide clinically relevant data for determination of on- and off-track instability. Finally, the gold standard for determination of bone loss is the measurement of deficiencies in the surface area of the glenoid using the best-fit circle with a diameter line measurement. This is most practical for day-to-day clinical use.

Demystifying the "Dark Side of the Knee": An Update on Imaging of the Posterolateral Corner

The posterolateral corner (PLC) of the knee is a complex anatomical-functional unit that includes ligamentous and tendinous structures that are crucial for joint stability. This review discusses the intricate anatomy, biomechanics, and imaging modalities, as well as the current challenges in diagnosing PLC injuries, with an emphasis on magnetic resonance imaging (MRI). Recognizing the normal MRI anatomy is critical in identifying abnormalities and guiding effective treatment strategies. Identification of the smaller structures of the PLC, traditionally difficult to depict on imaging, may not be necessary to diagnose a clinically significant PLC injury. Injuries to the PLC, often associated with cruciate ligament tears, should be promptly identified because failure to recognize them may result in persistent instability, secondary osteoarthritis, and cruciate graft failure.

A New Computed Tomography-Based Measure that Provides Insight Into Hip Stability in Patients With Posterior Wall Acetabular Fractures

OBJECTIVES

To describe the technique and results of a new sagittal plane computed tomography (CT)-based angular measure for predicting stability after posterior wall acetabular fractures (PWF).

METHODS

DESIGN

Retrospective review.

SETTING

Academic Level II trauma center.

PATIENT SELECTION CRITERIA

Fifty-eight consecutive patients with PWF (AO/OTA class 62A.1), 98% were high-energy injuries.

INTERVENTION

A new sagittal CT measure of PWF based on the angle subtending the joint center, cranial and caudal fracture exits.

OUTCOME MEASURES AND COMPARISONS

Hip incongruity or dislocation demonstrated using gold standard test, examination under anesthesia (EUA), or instability on static images. Prediction of hip instability using a sagittal CT angular measure based on cranial and caudal fracture exits was compared with previous axial CT measures suggestive of increased risk for instability including posterior wall size >50%, and those with cranial exit within 5.0 mm of the acetabular dome.

RESULTS

There were 32 operative and 26 nonoperatively treated fractures. Thirty fractures were determined to be unstable, and 28 were stable after EUA. Measurements of >70 degrees using the sagittal CT angular measure predicted instability in 28 of 28 patients, and ≤70 degrees predicted stability in 30 of 30 patients (sensitivity 100% and specificity 100%). Prevalence of EUA confirmed instability for subgroups with PWF based on prior axial CT measures were as follows: ≥50% wall involvement (11/16; sensitivity 67% and specificity 60%; 95% CI, 45%-89%/45%-75%), fracture within 5.0 mm of dome (5/18; sensitivity 86% and specificity 73%; 95% CI, 71%-100%/59%-87%), fracture within 5.0 mm of dome and ≥50% involvement (1/9; sensitivity 89% and specificity 56%; 95% CI, 69%-100%/24%-88%).

CONCLUSIONS

In a sample of 58 mostly high energy posterior wall fractures all having had an EUA, a new sagittal angular CT measurement of ≤70 degrees predicted hip stability and >70 degrees predicted instability with 100% sensitivity and specificity.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparative analysis of arthroscopic technique for anterior talofibular and calcaneofibular ligament reconstruction versus open modified brostrom-gould procedure in chronic lateral ankle instability management

BACKGROUND

Chronic Lateral Ankle Instability (CLAI) is a common condition treated using either Anterior Talofibular and Calcaneofibular Ligament (ATFL and CFL) reconstruction or Modified Brostrom Procedure (MBP). However, the comparative efficacy of these approaches is not well-studied.

METHODS

In this study, clinical data were retrospectively collected from 101 patients diagnosed with CLAI who underwent either ATFL and CFL reconstruction (n = 51) or the MBP (n = 50). Patients were comparable in terms of age, sex, Body Mass Index (BMI), post-injury duration, preoperative American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, Visual Analog Score (VAS), Anterior Talar Translation, and Talar Tilt Angle.

RESULTS

The post-operative measures showed no significant differences in AOFAS Score, Karlsson Score, and VAS between both treatment groups. However, patients who underwent ATFL and CFL reconstruction showed significantly lower follow-up Anterior Talar Translation (mean = 4.1667 ± 1.3991 mm) and Talar Tilt Angle (mean = 5.0549 ± 1.6173°) compared to those who underwent MBP. Further, patients treated with ATFL and CFL reconstruction experienced a significantly longer postoperative recovery time (median = 6 weeks) compared to MBP (median = 3 weeks).

CONCLUSIONS

Although both therapeutic techniques were generally effective in treating CLAI, the ATFL and CFL reconstruction approach delivered superior control of Anterior Talar Translation and Talar Tilt Angle. However, its longer recovery time merits further study to optimize the balance between therapeutic efficacy and recovery speed.

Three-dimensional magnetic resonance imaging-based statistical shape analysis and machine learning-based prediction of patellofemoral instability

This study performed three-dimensional (3D) magnetic resonance imaging (MRI)-based statistical shape analysis (SSA) by comparing patellofemoral instability (PFI) and normal femur models, and developed a machine learning (ML)-based prediction model. Twenty (19 patients) and 31 MRI scans (30 patients) of femurs with PFI and normal femurs, respectively, were used. Bone and cartilage segmentation of the distal femurs was performed and subsequently converted into 3D reconstructed models. The pointwise distance map showed anterior elevation of the trochlea, particularly at the central floor of the proximal trochlea, in the PFI models compared with the normal models. Principal component analysis examined shape variations in the PFI group, and several principal components exhibited shape variations in the trochlear floor and intercondylar width. Multivariate analysis showed that these shape components were significantly correlated with the PFI/non-PFI distinction after adjusting for age and sex. Our ML-based prediction model for PFI achieved a strong predictive performance with an accuracy of 0.909 ± 0.015, and an area under the curve of 0.939 ± 0.009 when using a support vector machine with a linear kernel. This study demonstrated that 3D MRI-based SSA can realistically visualize statistical results on surface models and may facilitate the understanding of complex shape features.

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.

A new etiology of nontraumatic C0-C1-C2-Complex instability - abnormality of musculus rectus capitis posterior minor: a case report

PURPOSE

This study presents an abnormality of the musculus rectus capitis posterior minor (RCPmi) as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex, with a focus on identifying the absence or atrophy of RCPmi on both sides.

METHODS

A 36-year-old male patient presented with recurring neck pain (VAS 8/10) and tingling paresthesia in the entire left hand over a six-month period, without significant neurological deficits. Radiated arm pain was not reported. Imaging examinations revealed sagittal plane instability in the C0-C1-C2-complex, spinal canal stenosis (SCS), and myelopathy at the C1 level. Subsequently, a dorsal C0-1 reposition and fusion with laminectomy were performed.

RESULTS

The congenital absence or atrophy of RCPmi, leading to the lack of cephalad-rearward traction on the C1-tuberculum-posterius, induced a developmental failure of the C1 posterior arch. Consequently, the oblate-shaped C1 posterior arch lost support from the underlying C2 posterior arch and the necessary cephalad-rearward traction throughout the patient's 36-year life. This gradual loss of support and traction caused the C1 posterior arch to shift gradually to the anterior side of the C2 posterior arch, resulting in a rotational subluxation centered on the C0/1 joints in the sagittal plane. Ultimately, this led to SCS and myelopathy. Traumatic factors were ruled out from birth to the present, and typical degenerative changes were not found in the upper cervical spine, neck muscles, and ligaments.

CONCLUSION

In this case, we not only report the atrophy or absence of RCPmi as a new etiological factor for nontraumatic sagittal plane instability in the C0-C1-C2-complex but also discovered a new function of RCPmi. The cephalad-rearward traction exerted by RCPmi on the C1 posterior arch is essential for the development of a normal C1 anterior-posterior diameter.

Relationships among hip instability, iliofemoral ligament, and pain in patients with developmental dysplasia of the hip

BACKGROUND

To evaluate the relationships among hip instability, pain, and morphology of the iliofemoral ligament (ILFL) in patients with developmental dysplasia of the hip (DDH) using ultrasonography (US).

METHODS

We reviewed 86 patients (109 hips) with DDH (Group D), 40 patients (46 hips) with borderline hip dysplasia (BDDH) (Group B) and 20 patients (23 hips) without hip pain and bony abnormality (control group). Group D was classified into three subgroups-the severe (group SP), moderate (group MP), and none/mild (group NMP) hip pain groups-using the visual analogue scale (VAS). For evaluating hip instability and ILFL morphology, the distance between the anterior edge of the anterior inferior iliac spine (AIIS) and the horizontal line to the femoral head, and ILFL thickness were measured using US. The difference between the distance in the neutral position and Patrick position was calculated and defined as the femoral head translation distance (FTD).

RESULTS

FTD and ILFL thickness in group D were significantly larger than those in the control group and group B (P < 0.05). There was a significant positive correlation between FTD and ILFL thickness in three groups (r = 0.57, P < 0.05; r = 0.55, P < 0.05; r = 0.62, P < 0.05, respectively). FTD and ILFL thickness in group SP were significantly larger than those in group NMP (P < 0.05). FTD and ILFL thickness in group D had significantly negative correlations with the lateral center edge (r = -0.54, P < 0.05; r = -0.40, P < 0.05, respectively) and vertical-center-anterior angle (r = -0.51, P < 0.05; r = -0.43, P < 0.05, respectively).

CONCLUSIONS

Acetabular bony deficiency, especially in the anterior and lateral region can result in antero-posterior hip instability, leading to thickened ILFL and hip pain, even in patients with BDDH. These findings may facilitate our understanding and treatment of patients with DDH. When hip instability is suspected, hip US examination may help confirm the diagnosis and assist in providing objective clinical diagnostic evidence.

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.

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.

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.

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.