Does patient sex affect the anatomic relationships between the sternoclavicular joint and posterior vascular structures?

Normative Values for Sternoclavicular Joint and Clavicle Anatomy Based on MR Imaging: A Comprehensive Analysis of 1591 Healthy Participants

Background: The clavicle remains one of the most fractured bones in the human body, despite the fact that little is known about the MR imaging of it and the adjacent sternoclavicular joint. This study aims to establish standardized values for the diameters of the clavicle as well as the angles of the sternoclavicular joint using whole-body MRI scans of a large and healthy population and to examine further possible correlations between diameters and angles and influencing factors like BMI, weight, height, sex, and age. Methods: This study reviewed whole-body MRI scans from the Study of Health in Pomerania (SHIP), a German population-based cross-sectional study in Mecklenburg-Western Pomerania. Descriptive statistics, as well as median-based regression models, were used to evaluate the results. Results: We could establish reference values based on a shoulder-healthy population for each clavicle parameter. Substantial differences were found for sex. Small impacts were found for height, weight, and BMI. Less to no impact was found for age. Conclusions: This study provides valuable reference values for clavicle and sternoclavicular joint-related parameters and shows the effects of epidemiological features, laying the groundwork for future studies. Further research is mandatory to determine the clinical implications of these findings.

Sternoclavicular Joint Reconstruction With Gracilis Tendon Autograft

Clinical instability of the sternoclavicular (SC) joint is a challenging problem. Recurrent subluxation and pain can lead to significant functional limitations. Although many patients respond positively to conservative treatment, chronic dislocations often require operative intervention. The complex anatomy of the diarthrodial SC joint and the existence of concomitant SC joint degenerative changes compounded with close-by neurovascular structures present a surgical challenge. The purpose of this Technical Note is to describe a technique for the open management of symptomatic sternoclavicular joint instability using a figure-of-8 reconstruction with a gracilis autograft. The present authors believe this technique provides a technically safe and reproducible method for reconstructing the SC joint without compromising biomechanical strength.

Plunging Dangerously: A Quantitative Assessment of Drilling the Clavicle

Bicortical drilling of the clavicle is associated with risk of iatrogenic damage from plunging given the close proximity of neurovascular structures. This study determined plunge depth during superior-to-inferior clavicle drilling using a standard drill vs drill-sensing technology. Two orthopedic surgeons drilled 10 holes in a fresh cadaveric clavicle with drill-sensing technology in freehand mode (functions as standard orthopedic drill) and another 10 holes with drill-sensing technology in bicortical mode (drill motor stops when the second cortex is breached and depth is measured in real time). The drill-measured depths were compared with computed tomography-measured depths. Distances to the neurovascular structures were also measured. The surgeons' plunge depths were compared using an independent t test. With freehand (standard) drilling, the mean plunge depth was 8.8 mm. For surgeon 1, the range was 5.6 to 15.8 mm (mean, 10.9 mm). For surgeon 2, the range was 3.3 to 11.0 mm (mean, 6.4 mm). The surgeons' plunge depths were significantly different. In bicortical mode, the drill motor stopped when the second cortex was penetrated. Drill-measured depths were verified by computed tomography scan, with a mean difference of 0.8 mm. Mean distances from the clavicle to the neurovascular structures were 15.5 mm for the subclavian vein, 18.0 mm for the subclavian artery, and 8.0 mm for the brachial plexus. Plunge depths differed between surgeons. However, both surgeons' plunge depths were greater than distances to the neurovascular structures, indicating a risk of injury due to plunging. Although a nonspinning drill bit may still cause soft tissue damage, drill-sensing technology may decrease the risk of penetrating soft tissue structures due to plunging. [Orthopedics. 2021;44(1):e36-e42.].

Minimum 5-Year Clinical Outcomes, Survivorship, and Return to Sports After Hamstring Tendon Autograft Reconstruction for Sternoclavicular Joint Instability

BACKGROUND

Instability of the sternoclavicular (SC) joint is a rare but potentially devastating pathologic condition, particularly when it occurs in young or active patients, where it can lead to persistent pain and impairment of shoulder function. SC joint reconstruction using a hamstring tendon autograft is a commonly used treatment option, but midterm results are still lacking.

PURPOSE/HYPOTHESIS

The purpose of this study was to assess the clinical outcomes, survivorship, and return-to-sports rate after SC joint reconstruction using a hamstring tendon autograft in patients suffering from SC joint instability. We hypothesized that SC joint reconstruction would result in good clinical outcomes, high rate of survivorship, and a high rate of return to sports.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent SC joint reconstruction with a hamstring tendon autograft for SC joint instability, with a minimum 5-year follow-up, were included. Patient-reported outcomes were assessed prospectively by the use of the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numerical Evaluation (SANE) score, short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, 12-Item Short Form Health Survey (SF-12) physical component summary (PCS), and patient satisfaction. Survivorship of reconstruction was defined as no further revision surgery or clinical failure such as recurrent instability or subluxation events. Return to sports and pain were assessed using a customized questionnaire.

RESULTS

A total of 22 shoulders that underwent SC joint reconstruction, with a mean patient age of 31.3 years (range, 15.8-57.0 years) at the time of surgery, were included. At the final evaluation, 18 shoulders, with a mean follow-up of 6.0 years (range, 5.0-7.3 years), completed a minimum 5-year follow-up. All clinical outcome scores improved significantly from preoperatively to postoperatively: ASES (50.0 to 91.0; P = .005), SANE (45.9 to 86.0; P = .007), QuickDASH (44.2 to 12.1; P = .003), and SF-12 PCS (39.4 to 50.9; P = .001). Median postoperative satisfaction was 9 (range, 7-10). The construct survivorship was 90% at 5-year follow-up. There were 2 patients with failed treatment at 82 and 336 days postoperatively because of instability or pain who underwent revision SC joint reconstruction and capsulorrhaphy. Another patient had a superficial wound infection, which was debrided once and resulted in a good clinical outcome. Of the patients who answered optional sports activity questions, 15 (17 shoulders, 77%) participated in recreational or professional sports before the injury. At final follow-up, 14 patients (16 of 17 shoulders, 94%) returned to their preinjury level of sports. The visual analog scale score for pain today (P = .004) and pain at its worst (P = .004) improved significantly from preoperatively to postoperatively.

CONCLUSION

SC joint reconstruction with a hamstring tendon autograft for SC joint instability resulted in significantly improved clinical outcomes with high patient satisfaction and 90% survivorship at midterm follow-up. Furthermore, 94% of this young and high-demand patient population returned to their previous level of sports. Concerns in terms of advanced postinstability arthritis were not confirmed because a significant decrease in pain was found after a minimum 5-year follow-up.

Medial Clavicle Osseous Dimensions with Implication on Plate Fixation

Significantly displaced medial clavicle fractures are associated with high rates of painful nonunion. Operative fixation can be challenging due to limited medial bone stock and adjacent vital vascular structures. Twenty-one consecutive chest computer topography (CT) scans were analyzed to measure anterior-posterior and superior-inferior dimensions of the medial clavicle. Correlation between height and clavicular dimensions were assessed by Pearson correlation coefficient. Two cases using dual T-locking plates are described. From anterior to posterior, the medial clavicle typically measures 1.44 (SD 0.26 cm) and 2.51 cm (SD 0.38 cm) at its narrowest and widest points, respectively. The mean superior-inferior width was 1.56 cm (SD 0.21 cm) and 2.76 cm (SD 0.39 cm) at its narrowest and widest points, respectively. Inter-observer reliability was 0.986 with combined intra-observer reliability between two time points of 0.984. Surgeons may use CT to reliably evaluate the amount of bone available for screw purchase and pre-operatively determine expected screw lengths. Locking plates using both unicortical locking screws and bicortical screws can be used for fracture fixation. Both patients healed fractures with dual T-locking plates without a short-term hardware complication. Dual T-locking plates may be a consideration for medial clavicle fracture fixation when medial bone purchase is a concern.

MEASURING THE DISTANCE BETWEEN STERNOCLAVICULAR JOINT AND HILAR STRUCTURES WITH TOMOGRAPHY

OBJECTIVES

To evaluate the tomographic distance between the sternoclavicular joints and the nearest hilar structures.

METHODS

Computed tomography images (axial and sagittal slices) in 120 healthy individuals (60 men and 60 women) between 18 and 60 years old were prospectively analyzed. The distances from both sternoclavicular joints to the respective brachiocephalic veins, trachea, esophagus, and lung apexes were measured and related to age, sex, and body mass index.

RESULTS

Statistically significant differences were found in the distance from the right and left sternoclavicular joint distances and the corresponding brachiocephalic vein, esophagus, and lung apexes. In women, both sides were closer to the noble structures. In patients with body mass index <25, the distances were significantly less than in heavier patients.

CONCLUSION

The left sternoclavicular joint is closer to the hilar structures than the contralateral side. In women, both sternoclavicular joints are closer to the brachiocephalic veins, esophagus, and lung apexes than in men. Patients with body mass index <25 have shorter distances between these joints and the brachiocephalic veins and esophagus. Level of Evidence II; Prognostic studies - Investigating the effect of a patient characteristic on the outcome of disease.

Minimum 2-year outcomes and return to sport following resection arthroplasty for the treatment of sternoclavicular osteoarthritis

HYPOTHESIS

The aim of this study was to assess the effect of open resection arthroplasty for osteoarthritis of the sternoclavicular (SC) joint on pain levels, functional outcomes, and return to sport.

METHODS

Patients from a single surgeon's practice who underwent open resection arthroplasty (maximum 10-mm resection) for SC osteoarthritis or prearthritic changes between November 2006 and November 2013 were retrospectively reviewed. This was an outcomes study with prospectively collected data. Preoperative and postoperative American Shoulder and Elbow Surgeons score, Quick Disabilities of the Arm, Shoulder, and Hand score, Single Assessment Numeric Evaluation score, several pain scores, and level of sport intensity were assessed.

RESULTS

Seventeen SC joints in 16 patients (9 female, 7 male) met inclusion criteria. Mean age at time of surgery way 41.1 years (range, 12-66 years). One patient refused participation in the study. Three SC joint resections (17.7%) required SC joint revision surgery. Minimum 2-year outcomes data were available for 11 of the remaining 13 SC joints (84.6%). The mean time to follow-up was 3.3 years (range, 2.0-8.8 years). Pain at its worst (P = .026), pain at competition (P = .041), the Quick Disabilities of the Arm, Shoulder, and Hand score (P = .034), and the ability to sleep on the affected shoulder (P = .038) showed significant improvement postoperatively. The average postoperative American Shoulder and Elbow Surgeons score was 83.3. The level of sports participation (P = .042) as well as strength and endurance when participating in sport (P = .039) significantly increased postoperatively.

CONCLUSION

Resection arthroplasty of the medial end of the clavicle in patients with osteoarthritis of the SC joint without instability results in pain reduction, functional improvement, and a high rate of return to sport at midterm follow-up.

Biomechanical Comparison of Surgical Techniques for Resection Arthroplasty of the Sternoclavicular Joint

BACKGROUND

The optimal location and extent of medial clavicle resection for sternoclavicular (SC) joint resection arthroplasty are unknown.

HYPOTHESIS

Resection of the intra-articular disc alone cannot reliably decompress the SC joint, and a parallel resection technique will decompress the SC joint significantly more compared with the same amount with an oblique resection technique.

STUDY DESIGN

Controlled laboratory study.

METHODS

Force transmission through the SC joint was measured in 7 matched-pair human cadaveric SC joints in a dynamic tensile testing machine. The specimens were randomized to either a parallel or an oblique resection technique. An 80-N axial load was applied on the lateral clavicle toward the SC joint in each of the following 4 conditions: (1) intact joint, (2) after resecting the intra-articular disc, (3) after resecting 5 mm of the medial clavicle, and (4) after 10-mm resection.

RESULTS

Complete discectomy of all SC joints resulted in a significant reduction of force transmitted through the SC joint (P = .002). However, the varying anatomy of the disc was accompanied by a varying amount of joint decompression (95% CI, 29.8%-65.4%). Resecting 5 mm of the SC joint with the parallel technique decompressed the SC joint by a mean (±SD) of 76.7 ± 22.1 N compared with 37.8 ± 24.8 N with the oblique technique (P = .02). Decompression did not significantly differ between the groups after 10-mm resection (P = .18) using the parallel technique (89.4 ± 24.1 N) compared with the oblique technique (68.2 ± 31.6 N). Furthermore, 5-mm resection of the medial end of the clavicle with the parallel technique decompressed the SC joint by an amount similar to 10-mm resection with the oblique technique.

CONCLUSION

Resection of the disc alone did not reliably decompress each SC joint. Resection of 5 mm of the medial end of the clavicle with the parallel resection technique reliably decompressed the SC joint better than with the oblique resection technique.

CLINICAL RELEVANCE

This study provides baseline data on SC joint resection techniques and their mechanical effects. This knowledge can be implemented in clinical practice to treat patients with symptomatic posttraumatic arthritis of the SC joint.

Clinical outcomes after autograft reconstruction for sternoclavicular joint instability

BACKGROUND

Instability of the sternoclavicular (SC) joint is a rare condition. However, in some cases, SC joint instability may lead to persistent pain and impairment of shoulder function that requires surgical management. This study evaluated clinical outcomes after SC joint reconstruction with hamstring tendon autograft in patients with SC joint instability.

METHODS

From December 2010 to January 2014, 21 reconstructions of the SC joint with hamstring tendon autograft were performed. Outcomes data were prospectively collected and retrospectively reviewed. Data analyzed included American Shoulder and Elbow Surgeons score, Quick Disability of the Arm, Shoulder and Hand, physical component of the Short Form 12, and Single Assessment Numeric Evaluation scores. Pain with activities of daily living, work, and sleep were separately analyzed along with painless use of arm for activities. Patients were also questioned regarding postoperative satisfaction.

RESULTS

Nine women and 10 men (2 bilaterals), with a mean age of 30 years (range, 15-56 years), were monitored for a mean of 2 years (range, 12-36 months) postoperatively. Mean American Shoulder and Elbow Surgeons, Quick Disability of the Arm, Shoulder and Hand, and Single Assessment Numeric Evaluation scores significantly improved (P < .001). Pain scores also improved over preoperative baselines, including pain with activities of daily living, work, and sleep (P < .001). Median satisfaction at final follow-up was 8.5 (range, 7-10). There were no intraoperative or postoperative complications and no cases of recurrent instability.

CONCLUSION

Free hamstring tendon autograft reconstruction for SC joint instability resulted in significantly improved clinical outcomes with high patient satisfaction and no intraoperative or postoperative complications.