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.