Diagnosis and Management of Distal Clavicle Osteolysis

Upper Extremity Stress Fractures

BACKGROUND

Stress injuries are often missed secondary to their insidious onset, milder symptoms, and subtle or initially absent findings when imaged.

MAIN BODY

This review aims to provide strategies for evaluating and treating upper extremity stress fractures. This article outlines the classic presentation of each fracture, the ages during which these injuries often occur, the relevant anatomy and biomechanics, and the mechanism of each injury. Diagnostic imaging and management principles are also discussed, including the use of conservative versus surgical management techniques.

SHORT CONCLUSION

Upper extremity stress fractures are often mild injuries that resolve with conservative management but can lead to more serious consequences if ignored. Given their increasing incidence, familiarity with diagnosis and management of these injuries is becoming increasingly pertinent.

Arthroscopic distal clavicle resection versus conservation in patients with combined rotator cuff tears and acromioclavicular joint osteoarthritis

PURPOSE

The most common cause of shoulder pain originating from the acromioclavicular (AC) joint is osteoarthritis, causing pain and disability. Operative Management of AC arthritis includes arthroscopic distal clavicle resection (DCR) and open clavicle resection. This study was conducted to evaluate the outcomes of isolated rotator cuff repair with conservative treatment of ACJ arthritis versus the combined resection of the distal clavicle with the repair of a rotator cuff tear, in cases with acromioclavicular arthritis.

METHODS

A total of 46 patients with unilateral or bilateral combined rotator cuff tear and acromioclavicular arthritis were included, they were classified into 2 independent groups: Conservative group (23 patients), and DCR group (23 patients). All patients were subjected to full history taking, examination, pre and post-operative University of California at Los Angeles shoulder scoring scale (UCLA), Antero-Posterior and Zanca X-rays views, early and late complications.

RESULTS

Mean age was (51 ± 9) years, males were predominant (56.5%). The average post-operative UCLA score was (31.1 ± 4.9), and the average time to return to work was (214 ± 22). (2.2%) of patients had early complications, (19.6%) had late complications, (32.6%) had > 24 h till 1st post-operative analgesia, and (87%) needed MgSO4 Injection. We found a highly significant increase in UCLA score measurements in the Conservative group, and a highly significant increase in UCLA score measurements in the DCR group (p < 0.01). But there was no difference between the 2 groups.

CONCLUSION

Conventional conservative approach with arthroscopic rotator cuff repair and subacromial decompression has proven to be as effective as arthroscopic rotator cuff repair and subacromial decompression with DCR, in terms of efficacy and safety profiles in short term, but with more risks of potential hazards and cost with the DCR.

Distal Clavicular Osteolysis Treated With Platelet-Rich Plasma: A Case Report

ABSTRACT

Atraumatic distal clavicular osteolysis (DCO) is a cause of shoulder pain in younger athletes, often resulting from weightlifting and activities with repetitive pressing and overhead lifting. Athletes will present with shoulder pain localized to the acromioclavicular (AC) joint, with tenderness to palpation over the joint exacerbated by provocative testing on examination. Conservative management often includes activity modification, oral analgesics, physical therapy, and corticosteroid injection. Distal clavicular osteolysis can be refractory to conservative management and these athletes are often referred for surgical consultation. Platelet-rich plasma (PRP) injections have been used to treat a wide variety of musculoskeletal injuries, but there have been no published studies assessing the efficacy of PRP injections specifically for distal clavicle osteolysis. We present a case of refractory DCO successfully treated with an ultrasound-guided PRP injection of the AC joint.

A Sports Medicine Clinician's Guide to the Diagnosis and Management of Distal Clavicular Osteolysis

ABSTRACT

Weightlifting associated shoulder injuries have seen a dramatic rise in the last 20 years. Distal clavicular osteolysis, coined weightlifter's shoulder, is one such condition caused by repetitive microtrauma to the distal clavicle with subsequent, painful development of bony erosions and resorption of the distal clavicle. Diagnosis, treatment, and prevention of this condition can be challenging. In this article, we highlight evidence-based clinical recommendations for the diagnosis and management of distal clavicular osteolysis, including specific considerations for atraumatic and posttraumatic etiologies, to help clinicians better care for their patients. Activity modification and rehabilitation are the mainstays of the initial treatment. Adjuvant treatments, such as injections or surgery, may be required in refractory cases or in certain patient populations. Early recognition and treatment of weightlifter's shoulder is essential to prevent progression to acromioclavicular joint pathology or instability and to allow for continued participation in sport-specific activities.

Acromioclavicular Joint Injury and Repair

The acromioclavicular (AC) joint is commonly injured in athletes participating in contact and overhead throwing sports. Injuries range from simple sprains to complete ligamentous disruption, and they are classified by the established Rockwood grading system. High-grade injuries are associated with fractures around the AC joint and disruption of the superior shoulder suspensory complex, a ring of osseous and ligamentous structures at the superior aspect of the shoulder. Radiographs are the mainstay of imaging of the AC joint, with magnetic resonance imaging reserved for high-grade injuries to aid classification and plan surgical management. Low-grade AC joint injuries tend to be managed conservatively, but a wide range of surgical procedures have been described for higher grade injuries and fractures around the AC joint. This review illustrates the anatomy of the AC joint and surrounding structures, the imaging features of AC joint injury, and the most commonly performed methods of reconstruction and their complications.

Body Builder’s Shoulder: Posterior Labrum Periosteal Sleeve Avulsion (POLPSA) and Glenoid Posterior Rim Stress Fracture due to Intense Bench Pressing

Background

Shoulder overuse, both occupational and sports-related, is a major cause of shoulder pain with an estimated incidence of 0.9%-2.5% in the general population and a prevalence of 7%-27% in Europe and United States. We report on a young amateur bodybuilder presenting with a complex shoulder overuse lesion. A posterior labrum periosteal sleeve avulsion (POLPSA) with a chondral lesion of the posterior glenoid cavity and a SLAP lesion was diagnosed. Case presentation. A 33-year-old male construction worker complained of 9 months worsening right shoulder pain. He was an amateur body builder who would bench press heavy weights (up to 170 kg). A magnetic resonance arthrogram showed a posterior labrum sleeve avulsion, a stress chondral fracture of the posterior glenoid cavity and a SLAP lesion. Arthroscopic repair of the bicipital anchor, posterior labrum fixation and removal of the chondral fragment, proved successful and allowed the patient to return to his previous sports activity.

Conclusions

Bench press creates major forces along the anteroposter axis of the upper limbs, pushing the humeral head posteriorly and increasing joint reaction force on the posterior glenoid quadrant considerably as the scapula is locked resting on the bench. This may result in a tendency for the humeral head to subluxate posteriorly which, aggravated by the high number of repetitions, puts the posterior labrum and capsula under very high stress eventually leading to labrum failure. Arthroscopic repair was shown to restore shoulder function in these athletes.

Detailed management of post-traumatic distal clavicle osteolysis in a 24-year-old female: a case report

INTRODUCTION

Distal clavicular osteolysis (DCO) is a musculoskeletal pathology characterized by shoulder pain. Given the high prevalence of shoulder pain due to rotator cuff and subacromial injuries, DCO is often overlooked. Conservative therapy is indicated prior to surgical intervention. However, no literature has described conservative management of DCO in detail. This report will outline conservative management details for DCO to guide future research and clinicians.

CASE PRESENTATION

A 24-year-old female hockey player presented with trauma-induced injury, where she was diagnosed with type II acromio-clavicular joint separation. She presented 5-months later with residual pain and limitations in ranges of motion (ROM). Radiographic images revealed DCO.

MANAGEMENT AND OUTCOME

Management entailed strict rest from overhead activities followed by rehabilitation and manual therapy. 6-months later the patient reported resolution of symptoms, improved ROMs, and activities of daily living.

SUMMARY

DCO can be difficult to diagnose given its limited etiological understanding, low incidence, and poor radiographic sensitivity. DCO diagnosis should be considered in cases with unresolving shoulder pain.

Distal Clavicle Excision for Acromioclavicular Joint Osteoarthritis Using a Fluoroscopic Kirschner Wire Guide

Pathology of the acromioclavicular joint is common and often resistant to conservative treatment, requiring distal clavicle excision for definitive relief. First described as an open technique by Mumford and Gurd in 1941, distal clavicle excision has evolved greatly, with arthroscopic techniques currently predominating. No significant difference has been found in patient satisfaction or rate of complication between the techniques in a recent meta-analysis. Indeed, open excisions are still performed at a high rate, owing to the difficulty in technique and visualization with arthroscopic methods. One major critique of arthroscopic distal clavicle excision is difficulty safeguarding against under- and overexcision of the distal clavicle due to the lack of depth perception and visual reference points of the arthroscopic perspective. This Technical Note and accompanying video describe an indirect subacromial arthroscopic distal clavicle excision using a fluoroscopic Kirschner wire guide placed at the proximal border prior to resection to serve as a visual and mechanical reference to overexcision.

Arthroscopic Distal Clavicle Resection Through the Supraspinatus Fossa Portal

Disorders of the acromioclavicular (AC) joint quite often necessitate distal clavicle resection (DCR). Arthroscopic DCR is favored because of it is mini-invasive and convenient to treat concomitant intraarticular or subacromial lesions. In previous reports, arthroscopic DCR was performed through the anterior portal with the patient in beach chair position. However, when the patient is in the lateral decubitus position, it is inconvenient to perform DCR through the anterior portal. Thus, we introduce a special DCR technique through the supraspinatus fossa (SSF) portal. The critical point of this technique is viewing the acromioclavicular joint through the routine posterior portal, creating the SSF portal at the anterior edge of the scapular spine and the same medial-to-lateral level to the AC joint, and enough removal of the posterior edge of the distal clavicle. We believe the introduction of this technique will provide a special technical option when DCR is needed.

Linking skeletal muscle aging with osteoporosis by lamin A/C deficiency

The nuclear lamina protein lamin A/C is a key component of the nuclear envelope. Mutations in the lamin A/C gene (LMNA) are identified in patients with various types of laminopathy-containing diseases, which have features of accelerated aging and osteoporosis. However, the underlying mechanisms for laminopathy-associated osteoporosis remain largely unclear. Here, we provide evidence that loss of lamin A/C in skeletal muscles, but not osteoblast (OB)-lineage cells, results in not only muscle aging-like deficit but also trabecular bone loss, a feature of osteoporosis. The latter is due in large part to elevated bone resorption. Further cellular studies show an increase of osteoclast (OC) differentiation in cocultures of bone marrow macrophages/monocytes (BMMs) and OBs after treatment with the conditioned medium (CM) from lamin A/C-deficient muscle cells. Antibody array screening analysis of the CM proteins identifies interleukin (IL)-6, whose expression is markedly increased in lamin A/C-deficient muscles. Inhibition of IL-6 by its blocking antibody in BMM-OB cocultures diminishes the increase of osteoclastogenesis. Knockout (KO) of IL-6 in muscle lamin A/C-KO mice diminishes the deficits in trabecular bone mass but not muscle. Further mechanistic studies reveal an elevation of cellular senescence marked by senescence-associated beta-galactosidase (SA-β-gal), p16Ink4a, and p53 in lamin A/C-deficient muscles and C2C12 muscle cells, and the p16Ink4a may induce senescence-associated secretory phenotype (SASP) and IL-6 expression. Taken together, these results suggest a critical role for skeletal muscle lamin A/C to prevent cellular senescence, IL-6 expression, hyperosteoclastogenesis, and trabecular bone loss, uncovering a pathological mechanism underlying the link between muscle aging/senescence and osteoporosis.

Cross-Species RNA-Seq Study Comparing Transcriptomes of Enriched Osteocyte Populations in the Tibia and Skull

Local site-specific differences between bones in different regions of the skeleton account for their different properties and functions. To identify mechanisms behind these differences, we have performed a cross-species study comparing RNA transcriptomes of cranial and tibial osteocytes, from bones with very different primary functions and physiological responses, collected from the same individual mouse, rat, and rhesus macaque. Bioinformatic analysis was performed to identify 32 genes changed in the same direction between sites and shared across all three species. Several well-established key genes in bone growth and remodeling were upregulated in the tibias of all three species (BMP7, DKK1, FGF1, FRZB, SOST). Many of them associate or crosstalk with the Wnt signaling pathway. These results suggest Wnt signaling-related candidates for different control of regulatory mechanisms in bone homeostasis in the skull and tibia and indicate a different balance between genetically determined structure and feedback mechanisms to strains induced by mechanical loading at the different sites.

Current evidence for nonpharmacological interventions and criteria for surgical management of persistent acromioclavicular joint osteoarthritis: A systematic review

BACKGROUND

The primary aim of this systematic review was to investigate the individual/combined effectiveness of nonpharmacological interventions in individuals with persistent acromioclavicular joint osteoarthritis. The secondary aims were to investigate the comparative effectiveness of nonpharmacological versus surgical interventions, and to identify the criteria used for defining failure of conservative interventions in individuals who require surgery for persistent acromioclavicular joint osteoarthritis.

METHOD

Major electronic databases were searched from inception until October 2018. Studies involving adults aged 16 years and older, diagnosed clinically and radiologically with isolated acromioclavicular joint osteoarthritis for at least three months or more were included. Studies must explicitly state the type and duration of conservative interventions. Methodological risk of bias was assessed using the Modified Downs and Black checklist.

RESULTS

Ten surgical intervention studies were included for final synthesis. No studies investigated the effectiveness of nonpharmacological interventions or compared them with surgical interventions. Common nonpharmacological interventions trialed from the 10 included studies were activity modification (n = 8) and physiotherapy (n = 4). Four to six months was the most often reported timeframe defining failure of conservative management (range 3-12 months).

CONCLUSIONS

Currently, there is no evidence to guide clinicians about the individual or combined effectiveness of nonpharmacological interventions for individuals with persistent acromioclavicular joint osteoarthritis.

Lamins and bone disorders: current understanding and perspectives

Lamin A/C is a major constituent of the nuclear lamina implicated in a number of genetic diseases, collectively known as laminopathies. The most severe forms of laminopathies feature, among other symptoms, congenital scoliosis, osteoporosis, osteolysis or delayed cranial ossification.

Importantly, specific bone districts are typically affected in laminopathies. Spine is severely affected in LMNA-linked congenital muscular dystrophy. Mandible, terminal phalanges and clavicles undergo osteolytic processes in progeroid laminopathies and Restrictive Dermopathy, a lethal developmental laminopathy. This specificity suggests that lamin A/C regulates fine mechanisms of bone turnover, as supported by data showing that lamin A/C mutations activate non-canonical pathways of osteoclastogenesis, as the one dependent on TGF beta 2.

Here, we review current knowledge on laminopathies affecting bone and LMNA involvement in bone turnover and highlight lamin-dependent mechanisms causing bone disorders. This knowledge can be exploited to identify new therapeutic approaches not only for laminopathies, but also for other rare diseases featuring bone abnormalities.