Bone health and the masters runner.

Masters runners are often defined as those ages 35 years and older who train and compete in running events. These runners represent a growing population of the overall running community and experience running-related injuries including bone stress injuries (BSIs). Similar to younger runners, health considerations in masters runners include the goal to optimize bone health with focus on mitigating age-associated loss of bone strength and preventing BSIs through a combination of ensuring appropriate physical activity, optimizing nutrition, and correcting faulty biomechanics. Importantly, BSIs in masters runners may include characteristics of both overuse injury from insufficient recovery and failure of bone weakened by age-related loss of bone (insufficiency fractures). This narrative review covers the limited available research on strategies to optimize bone health in masters runners. Applying knowledge on masters athletes and extrapolating from other populations, we propose strategies on treatment and prevention of BSIs. Finally, the review highlights gaps in knowledge that require further age-specific discoveries to advance treatment and prevention.

Multifocal stress fractures in a patient with rheumatoid arthritis.

Stress fractures are often associated to activities that requires repetitive stress such as running. However, insufficiency-type stress fractures can also occur in patients with risk factors such as rheumatoid arthritis. Diagnosis of stress fracture would require a thorough clinical evaluation along with radiological imaging. However, this may be difficult due to how it mimics other musculoskeletal problems. The case of a woman in her 60s presenting with 2 months of severe ipsilateral right knee and ankle pain is used as an example. Based on initial clinical assessment and plain radiograph, her provisional diagnosis was osteoarthritis or inflammatory arthritis secondary to rheumatoid disease. However, MRI scan revealed that she had multifocal stress fractures in her knee, ankle and foot. Hence, we hope that this case study can allow clinicians to consider multifocal stress fracture as a possible diagnosis in patients with risk factors and to have lower threshold in performing MRI scans.

Long-term results of arthroscopic repair of type II SLAP lesions in sports: assessment of return to pre-injury playing level and critical risk factors for complication.

PURPOSE: The management of isolated SLAP lesions is still debated especially in athletes. Aims of the study were: 1. to analyse our algorithm to treat SLAP lesions starting from the selection of patients for surgery and 2. to correlate the familiarity for diabetes and hypothyroid disorders with post-operative results. METHODS: Seventy-eight patients with isolated SLAP lesion were arthroscopically treated using knotless anchors and microfractures. All patients had a pre-operative and post-operative clinical examination according to Walch-Duplay, Constant, Rowe and Dash scores and interviewed for familiarity to diabetes and hypothyroid disorders. RESULTS: About 68.8% of patients solved pain with rehabilitation. About 29% of patients returned to the sports activities. About 32% of patients were no responder to physiotherapy and were arthroscopically treated. About 53.9% of patients responded excellent, 34.7% good, 3.8% medium and 7.6% poor results according to Walch-Duplay score. The Constant score increased from 64 to 95, the Rowe score from 48 to 96. The outcomes were significantly worse in patients with familiarity for diabetes. CONCLUSIONS: Microfractures and knotless anchor give long-term good results for the treatment of SLAP lesions in athletes. The familiarity for diabetes is an important risk factor that can lead to decreased outcomes.

Sacral insufficiency fractures are a frequent and painful consequence of pubic symphysis osteomyelitis.

BACKGROUND: Pubic symphysis osteomyelitis can result from urosymphyseal fistula formation. High rates of sacropelvic insufficiency fractures have been reported in this population. The aim of this study was to describe the presentation and risk factors for sacral insufficiency fractures (SIF) associated with surgical treatment of pubic symphysis osteomyelitis. METHODS: A retrospective review was performed for 54 patients who underwent surgery for pubic symphysis osteomyelitis associated with a urosymphyseal fistula at a single institution from 2009 to 2022. Average age was 71 years and 53 patients (98%) were male. All patients underwent debridement or partial resection of the pubic symphysis at the time of fistula treatment. Average width of the symphyseal defect was 65 mm (range 9-122) after treatment. RESULTS: Twenty patients (37%) developed SIF at a mean time of 4 months from osteomyelitis diagnosis. Rate of sacral fracture on Kaplan-Meier analysis was 31% at 6 months, 39% at 12 months, and 41% at 2 years. Eleven patients developed SIF prior to pubic debridement and 12 patients developed new or worsening of pre-existing SIF following surgery. Width of pubic resection was higher in patients who developed SIF (76 mm vs. 62 mm), but this did not meet statistical significance (p = 0.18). CONCLUSION: Sacral insufficiency fracture is a common sequela of pubic symphysis osteomyelitis. These fractures are often multifocal within the pelvis and can occur even prior to pubic resection. Pubectomy further predisposes these patients to fracture. Clinicians should maintain a high index of suspicion for these injuries in patients with symphyseal osteomyelitis.

Incidence, risk factors, and complications of acromial stress fractures after reverse total shoulder arthroplasty.

BACKGROUND: An acromial stress fracture (ASF) is an uncommon complication after reverse total shoulder arthroplasty (RTSA) that can have severe clinical consequences on shoulder function. Although patient-specific factors have been identified to influence the risk of ASF, it is unclear whether modifying these factors can minimize risk. Moreover, there is limited information on the treatment outcomes of these fractures. Therefore, the purpose of this study was to determine modifiable risk factors for ASFs and the complication and revision rates of conservatively and operatively managed ASFs. METHODS: The PearlDiver database was queried to identify a cohort of patients who underwent RTSA with minimum 2-year follow-up. Current Procedural Terminology and International Classification of Diseases codes were used to compare the demographic characteristics, comorbidities, and medication use of patients with and without ASFs. Surgical complication and revision rates were compared between operatively and conservatively treated fractures. RESULTS: The overall incidence of ASFs was 1.4%. Patient-specific factors that were independently associated with the occurrence of an ASF included osteoporosis, rheumatologic disease, shoulder corticosteroid injection within 3 months before surgery, and chronic oral corticosteroid use. Among patients with osteoporosis, the initiation of physical therapy within 6 weeks after surgery also increased the risk of ASF. Patients who underwent surgical treatment of ASFs had a revision arthroplasty rate of 7.0% compared to a rate of 3.2% among those with conservatively managed fractures. CONCLUSION: ASFs are infrequent complications that can occur after RTSA. Preoperative factors that affect the quality of bone independently increase the fracture risk. Moreover, this risk can be minimized by avoiding shoulder corticosteroid injections 3 months before surgery and delaying physical therapy exercises among patients with osteoporosis. Surgical fixation of these fractures should be reserved for instances when conservative management has failed given high rates of infection, instability, and revision shoulder arthroplasty.

Changes in the incidence of stress reactions and fractures among intercollegiate athletes after the COVID-19 pandemic.

PURPOSE: The purpose of this study was to characterize the impact of detraining due to the COVID-19 pandemic on incidence of bony injuries and stress fractures in collegiate athletes. METHODS: A comprehensive collegiate athletic conference injury database was queried for all in-season, sport-related bony injuries (defined as all stress reactions and fractures) that occurred across all sports from January 2016 to June 2021. The bony injury rate per 1000 athlete exposure hours (AEH) was calculated and compared between the immediate post-hiatus season and historic rates from pre-hiatus seasons (2016-2019). Injury characteristics were also compared between the pre- and post-hiatus time periods. RESULTS: A total of 868 bony injuries across 23 sports were identified. The sports with highest overall baseline bony injury rates in historic seasons were women's cross country (0.57 injuries per 1000 AEH) and men's cross country (0.32). Compared to historic pre-hiatus rates, female cross-country runners demonstrated a significantly lower bony injury incidence rate in the post-hiatus season (0.24 vs. 0.57, p = 0.016) while male swimming athletes demonstrated a statistically significant increase in bony injury rate (0.09 vs. 0.01, p = 0.015). The proportion of bony injuries attributed to repetitive trauma increased; while, the proportion of injuries attributed to running decreased between the pre- and post-hiatus seasons. CONCLUSION: Across all sports, there was no consistent trend toward increased rates of bony injury in the immediate post-hiatus season. However, female cross-country runners demonstrated lower rates of bony injury in the post-hiatus season while male swimmers demonstrated higher rates. Furthermore, bony injuries in the post-hiatus season were more likely to be the result of repetitive trauma and less likely to be from running. LEVEL OF EVIDENCE: Level III, retrospective, cross sectional study.

Shockwave Treatment vs Surgery for Proximal Fifth Metatarsal Stress Fractures in Soccer Players: A Pilot Study.

BACKGROUND: To compare the clinical, radiologic, and functional outcomes between shockwave and operative treatments for proximal fifth metatarsal stress fractures in soccer players in a pilot study. METHODS: Between 2017 and 2019, 18 soccer players with fifth metatarsal stress fractures attended at Mutualidad de Futbolistas Españoles-Delegación Catalana were included. Patients were randomly assigned into 2 groups receiving either surgery with an intramedullary screw (group 1) or high-energy focused extracorporeal shockwave treatment (group 2 performed once a week for 3 weeks using 2000 impulses at an energy flux density of 0.21 mJ/mm2 and 4 Hz frequency). Clinical (pain), radiologic (bone healing), and functional (Tegner Activity Scale and American Orthopaedic Foot & Ankle Society [AOFAS] ankle-hindfoot scales) outcomes before and after receiving the treatment were compared between both groups. In addition, ability and time to return to play was also compared between groups. RESULTS: No patients were lost to follow-up. There were no statistically significant differences at last follow-up between surgery and extracorporeal shockwave treatment for bone healing, pain relief, AOFAS ankle-hindfoot score, Tegner score, and time return to play. No complications were reported in either of the 2 groups. CONCLUSION: In this pilot study, extracorporeal shockwave treatment and operative treatment were found to be equally effective at reducing pain, achieving bone healing, and allowing the soccer players to return to play after proximal fifth metatarsal stress fractures. This study suggests that ESWT may be a good option for the management of proximal fifth metatarsal stress fractures in soccer players. If this approach proves successful in larger trials, the shockwave approach might help avoid known complications of the surgical treatment like wound problems, nerve injury, and hardware intolerance. Further investigations with larger sample size should be conducted in order to confirm the present conclusions. LEVEL OF EVIDENCE: Level II, therapeutic, pilot randomized controlled trial.

Stress Fractures of the Distal Phalanx in Skeletally Immature Sport Climbers.

Stress fractures in the distal phalanx of skeletally immature patients are rare and previously unreported clinical occurrences. We report on 2 adolescent sport climbers with such fractures of the dorsal metaphysis of the distal phalanx at the point where parts of the extensor tendon insert. A conservative treatment approach alone was sufficient in healing this fracture type in both patients after 12 wk. Clinicians should be informed of the existence of this rare clinical phenomenon and counsel patients that a conservative treatment approach may result in complete healing without the need for an invasive procedure.

Pelvic insufficiency fractures and pelvic bone metastases after neoadjuvant (chemo)radiotherapy for rectal cancer.

BACKGROUND: Pelvic insufficiency fractures (PIFs) are a late complication of radiotherapy for pelvic malignancies. We evaluated the incidence, radiologic findings, clinical course, and outcome of PIFs in patients treated with neoadjuvant (chemo)radiotherapy ((C)RT) for rectal cancer. MATERIAL AND METHODS: Data of patients diagnosed with rectal cancer from a large teaching hospital treated from 2002 to 2012 were extracted from the Dutch Cancer Registry. All hospital records were reviewed for the diagnosis of PIFs or pelvic bone metastases. An expert radiologist reassessed all imaging procedures of the lower back, abdomen, and pelvis. RESULTS: A total of 513 rectal cancer patients were identified of whom 300 patients (58.5%) were treated with neoadjuvant (C)RT (long- vs. short-course radiotherapy: 91 patients [17.7%] vs. 209 [40.7%], respectively). Twelve PIFs were diagnosed initially according to hospital records and imaging reports of all 513 patients. These 12 patients were treated with neoadjuvant (C)RT. After reassessment of all pelvic imaging procedures done in this patient group (432 patients (84.2%)), 20 additional PIFs were detected in patients treated with neoadjuvant (C)RT, resulting in a 10.7% PIF rate in irradiated patients. One PIF was detected in the group of patients not treated with neoadjuvant (C)RT for rectal cancer. This patient had palliative radiotherapy for prostate cancer and is left out of the analysis. Median follow-up time of 32 PIF patients was 49 months. Median time between start of neoadjuvant (C)RT and diagnosis of PIF was 17 months (IQR 9-28). Overall median survival for patients with PIF was 63.5 months (IQR 44-120). CONCLUSION: PIFs are a relatively common late complication of neoadjuvant (C)RT for rectal cancer but are often missed or misdiagnosed as pelvic bone metastases. The differentiation of PIFs from pelvic bone metastases is important because of a different treatment and disease outcome.

Outcomes of conservative treatment of acromial and scapular spine stress fracture post reverse shoulder arthroplasty: a systematic review with meta-analysis.

INTRODUCTION: Acromial and scapular spine stress fractures are common complications post reverse shoulder arthroplasty. A systematic review with meta-analysis was conducted to evaluate the clinical outcomes of conservatively treated acromial and scapular spine stress fractures post reverse shoulder arthroplasty in comparison to nonfracture control. METHODS: Embase, MEDLINE, and Web of Science were searched on September 9, 2022, using various terms related to fracture, acromion, scapula, and reverse shoulder arthroplasty. Meta-analysis using a random effects model was performed on common outcome scores. Risk of bias was assessed using the Joanna Briggs Institute tools for case-controlled studies. Sensitivity analysis was performed for imputed standard deviations and studies with <20 participants. RESULTS: Thirteen studies with a total of 339 fracture and 3142 control patients were included in the systematic review. Meta-analysis was performed on 12 studies assessing active forward flexion, abduction, external rotation, Constant-Murley score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, pain score, Simple Shoulder Test, and Single Assessment Numeric Evaluation. Fracture patients experienced significantly poorer functional outcome compared with control patients when the fractures were managed conservatively. Levy III fractures tend to experience worse outcomes. Pain score did not demonstrate a statistically significant difference between the fracture and nonfracture cohort. DISCUSSION: Currently, literature regarding surgical management is lacking, partially because of a dearth of high-quality literature but also hindered by a lack of standardized techniques. This review was limited by inclusion of studies of low evidence, small sample sizes, and inconsistency in outcome measurement and follow-up period. Overall, patients with acromial and scapular spine stress fractures treated conservatively are expected to have reduced shoulder function compared to nonfracture patients, with the spine of scapula fracture patients suffering the poorest outcomes. Future studies should aim to use the same sets of outcomes parameters to assess the patients at fixed time intervals and report outcomes stratified by Levy classification. This will enable interinstitutional collaboration and pooling of results.

Total Hip Arthroplasty is the Most Effective Treatment for Atraumatic Subchondral Insufficiency Fractures of the Femoral Head.

BACKGROUND: Subchondral insufficiency fracture of the femoral head (SIFH) is a relatively newly used diagnosisfollowing an insidious onset of hip pain in individuals without apparent antecedent trauma. The aim of this study was to investigate the outcomes of a consecutive series of patients with SIFH treated at one institution. METHODS: A total of 93 patients aged 23 to 91 years who were treated for SIFH in the outpatient clinics at one academic, urban medical center between August 2012 and August 2019 were identified. The diagnosis was made by magnetic resonance imaging or radiograph of the hip and was confirmed by a radiologist specialized in orthopedic surgery. Patient demographics, injury history, duration of pain, treatment type, and persistence of pain were recorded. RESULTS: Sixty-five (69.9%) patients with a mean age of 64.2 ± 9.4 years ultimately underwent total hip arthroplasty (THA). Twenty-eight (30.1%) patients chose no surgical intervention. Patients who underwent THA had less pain at their final follow-up appointment than patients who elected non-operative treatment (p < 0.001). At their final follow-up appointments, 92.9% of patients treated non-operatively reported pain, compared to only 13.8% of patients who underwent THA who had pain. Age, body mass index, and duration of pain prior to initial complaint did not affect presence of continued pain at final follow-up appointments, regardless of treatment type (p > 0.05). CONCLUSION: In the majority of patients, SIFH is often not sufficiently managed with non-operative treatments. Pain reported among patients with confirmed or suspected SIFH is usually severe and interferes with patients' ability to perform their activities of daily life. Total hip arthroplasty seems to be the most reliable method of treatment for this condition. Physicians who treat patients with SIFH should counsel them as to the expectations of recovery and the potential for poorer outcome if treated without THA.

Late Periprosthetic Femoral Stress Fracture Associated with Extra-articular Deformity in a Patient with Fibrous Dysplasia: A Case Report.

CASE: In the setting of a total hip arthroplasty performed in a patient with a proximal femoral deformity, atraumatic periprosthetic femoral stress fracture may arise as a complication. We report a rare case of a late periprosthetic femoral stress fracture around a cemented stem in a patient with a history of fibrous dysplasia of the proximal femur. After a 10-year uneventful period, the patient complained about a subtle, subacute pain in his left thigh induced by exercise but not with daily axial load. Diagnosis of a nondisplaced, incomplete (i.e., only compromising the lateral femoral cortex) periprosthetic femoral stress fracture was made with plain radiographs, blood work, and bone scintigraphy. Surgical treatment consisted of a minimally invasive plate osteosynthesis bridging the femoral deformity plus percutaneous osteoperiosteal decortication. At 5-year follow-up, the patient was asymptomatic with full return to physical activity, with radiographs evidencing callus formation. CONCLUSION: Stress fractures around well-fixed femoral stems, while infrequent, should be addressed in patients with a history of severe proximal femur deformity experiencing atraumatic thigh pain.

Risk factors of acromial and scapular spine stress fractures differ by indication: a study by the ASES Complications of Reverse Shoulder Arthroplasty Multicenter Research Group.

BACKGROUND: Both patient and implant related variables have been implicated in the incidence of acromial (ASF) and scapular spine fractures (SSF) following reverse shoulder arthroplasty (RSA); however, previous studies have not characterized nor differentiated risk profiles for varying indications including primary glenohumeral arthritis with intact rotator cuff (GHOA), rotator cuff arthropathy (CTA), and massive irreparable rotator cuff tear (MCT). The purpose of this study was to determine patient factors predictive of cumulative ASF/SSF risk for varying preoperative diagnosis and rotator cuff status. METHODS: Patients consecutively receiving RSA between January 2013 and June 2019 from 15 institutions comprising 24 members of the American Shoulder and Elbow Surgeons (ASES) with primary, preoperative diagnoses of GHOA, CTA and MCT were included for study. Inclusion criteria, definitions, and inclusion of patient factors in a multivariate model to predict cumulative risk of ASF/SSF were determined through an iterative Delphi process. The CTA and MCT groups were combined for analysis. Consensus was defined as greater than 75% agreement amongst contributors. Only ASF/SSF confirmed by clinical and radiographic correlation were included for analysis. RESULTS: Our study cohort included 4764 patients with preoperative diagnoses of GHOA, CTA, or MCT with minimum follow-up of 3 months (range: 3-84). The incidence of cumulative stress fracture was 4.1% (n = 196). The incidence of stress fracture in the GHOA cohort was 2.1% (n = 34/1637) compared to 5.2% (n = 162/3127) (P < .001) in the CTA/MCT cohort. Presence of inflammatory arthritis (odds ratio [OR] 2.90, 95% confidence interval [CI] 1.08-7.78; P = .035) was the sole predictive factor of stress fractures in GHOA, compared with inflammatory arthritis (OR 1.86, 95% CI 1.19-2.89; P = .016), female sex (OR 1.81, 95% CI 1.20-2.72; P = .007), and osteoporosis (OR 1.56, 95% CI 1.02-2.37; P = .003) in the CTA/MCT cohort. CONCLUSION: Preoperative diagnosis of GHOA has a different risk profile for developing stress fractures after RSA than patients with CTA/MCT. Though rotator cuff integrity is likely protective against ASF/SSF, approximately 1/46 patients receiving RSA with primary GHOA will have this complication, primarily influenced by a history of inflammatory arthritis. Understanding risk profiles of patients undergoing RSA by varying diagnosis is important in counseling, expectation management, and treatment by surgeons.

Proximal fibular stress fracture in adolecent soccer player. A case report.

Fibular fractures are the third most common stress fractures in children and adolescents. Proximal fibular location is a very rare finding, with few reports in the literature and, frequently, careful investigations before a definitive diagnosis could be necessary. The authors report a case of an adolescent 13 years old soccer player with a proximal fibular fracture that was initially underestimated and misdiagnosed and ultimately confirmed as a stress lesion by MRI.

Current risks factors and emerging biomarkers for bone stress injuries in military personnel.

INTRODUCTION: Bone stress injuries (BSIs) have plagued the military for over 150 years; they afflict around 5 to 10% of military recruits, more so in women, and continue to place a medical and financial burden on defence. While the tibia generally adapts to the rigours of basic military training, the putative mechanisms for bone maladaptation are still unclear. METHODS: This paper provides a review of the published literature on current risk factors and emerging biomarkers for BSIs in military personnel; the potential for biochemical markers of bone metabolism to monitor the response to military training; and, the association of novel biochemical 'exerkines' with bone health. RESULTS: The primary risk factor for BSI in military (and athletic) populations is too much training, too soon. Appropriate physical preparation before training will likely be most protective, but routine biomarkers will not yet identify those at risk. Nutritional interventions will support a bone anabolic response to training, but exposure to stress, sleep loss, and medication is likely harmful to bone. Monitoring physiology using wearables-ovulation, sleep and stress-offer potential to inform prevention strategies. CONCLUSIONS: The risk factors for BSIs are well described, but their aetiology is very complex particularly in the multi-stressor military environment. Our understanding of the skeletal responses to military training is improving as technology advances, and potential biomarkers are constantly emerging, but sophisticated and integrated approaches to prevention of BSI are warranted.

Patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia.

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition. The study included 33 patients with TIO who were treated between January 2000 and June 2022. The causative tumour was detected in all patients. We investigated the symptoms and evaluated the radiological patterns of insufficiency fractures of the rib, spine, and limbs. The mean age of the patients was 57 years (24 to 87), and the mean duration of pain from onset to time of presentation was 3.9 years (0.75 to 23). The primary symptoms were low back pain (ten patients), chest wall pain (eight patients), and hip pain (eight patients). There were symptoms at more sites at the time of presentation compared with that at the time of the onset of symptoms. Bone scans showed the uptake of tracer in the rib (100%), thoracic and lumbar vertebrae (83%), proximal femur (62%), distal femur (66%), and proximal tibia (72%). Plain radiographs or MRI scans identified femoral neck fractures in 14 patients, subchondral insufficiency fractures of the femoral head and knee in ten and six patients, respectively, distal femoral fractures in nine patients, and proximal tibial fractures in 12 patients. Thoracic or lumbar vertebral fractures were identified in 23 of 29 patients (79.3%) when using any imaging study, and a biconcave deformity was the most common type of fracture. Insufficiency fractures in patients with TIO caused spinal pain, chest wall pain, and periarticular pain in the lower limbs. Vertebral fractures tended to be biconcave deformities, and periarticular fractures of the hips and knees included subchondral insufficiency fractures and epiphyseal or metaphyseal fractures. In patients with a tumour, the presence of one or more of these symptoms and an insufficiency fracture should suggest the diagnosis of TIO.

An 18-Year-Old Female Athlete Presenting with Knee Pain Following a Basketball Game and Diagnosed with Bilateral Patellar Stress Fractures.

BACKGROUND Stress fractures of the patella are rare, may result from overuse, and can be difficult to detect on imaging. Furthermore, the differential diagnosis of the anterior knee pain associated with most patellar stress fractures is broad, making it difficult to quickly reach the diagnosis. This report is of an 18-year-old female athlete presenting with knee pain after playing basketball and diagnosed with bilateral patellar stress fractures. CASE REPORT An 18-year-old female athlete with a history of bilateral anterior knee pain presented with left knee pain and swelling following a basketball game. X-ray images and magnetic resonance imaging (MRI) revealed a displaced inferior pole fracture of the left patella. The patient underwent surgical fixation of the patella. Approximately 4 months following surgical fixation of the left patella, right anterior knee pain persisted, and imaging demonstrated a stress reaction in the inferior pole of the right patella. The patient was ultimately treated with surgical fixation of the right patella as well. CONCLUSIONS This report demonstrates that, although stress fractures of the patella are rare, and bilateral stress fractures of the patella are even more rare, this condition may present with pain and usually with a history of high-impact exercise. Challenges remain in identifying patellar stress fractures early in their progression and determining the best course of treatment.

Subchondral insufficiency fracture of the femoral head in a patient with ankylosing spondylitis: Case report and literature review.

Subchondral insufficiency fracture (SIF) of the femoral head occurs in patients with osteoporosis, elderly women, and renal or liver transplant recipients. Although SIF has been reported in several patients with rheumatic disease, SIF of the femoral head has not been reported in patients with ankylosing spondylitis (AS), and the association between AS and SIF has not been determined. A 48-year-old man with AS presented with pain in his left hip for 2 months. He had been diagnosed with AS and radiographic bilateral grade 3 sacroiliitis 11 years earlier. He had been treated with subcutaneous adalimumab 40 mg biweekly for more than 10 years, during which time his condition remained stable. This patient was obese but had no other known predisposing conditions, such as old age, overexertion, osteoporosis, steroid use, or transplantation. He had never taken steroids. X-rays showed no specific findings, other than mild osteoarthritis in both hips. However, pelvic magnetic resonance imaging demonstrated flattening and subchondral irregularity with a large amount of bone marrow edema, confirming a diagnosis of SIF of the femoral head. Thus, even in patients with AS having no significant risk factors, SIF should be considered as part of the differential diagnosis of hip pain.

First Rib Stress Fracture in an Adolescent Elite Tennis Player: A Case Report.

CASE: A 16-year-old, right-hand-dominant, Asian male, elite tennis player presented to the clinic with a 1-month history of left shoulder pain. Originally, the pathology was believed to be shoulder-based, but lack of improvement after several weeks of therapy warranted further imaging, which ultimately revealed a nondisplaced fracture of the posterior left first rib. CONCLUSION: Stress injuries are not uncommon in the sport of tennis, but atraumatic rib fractures are rare. Given the increase in youth sports specialization and overtraining and other risk factors such as adolescent age and race, it is important to keep rib stress fracture on the differential.

Effect of reverse shoulder arthroplasty humeral component retroversion on acromial strain.

INTRODUCTION: Acromion and scapular spine stress fractures can be catastrophic complications following reverse shoulder arthroplasty (RSA). A variety of host, implant, and technical factors have been identified that increase the risk of this complication. The glenoid component in particular has been closely evaluated for its impact on rates of stress fractures following RSA. The goal of this biomechanical study is to evaluate if humeral stem version has an impact on acromion and scapular spine strain after RSA. METHODS: Eight cadaveric specimens were tested on a custom dynamic shoulder frame. Commercially available RSA components were implanted with the humeral component inserted in 0° of retroversion. Acromion and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes secured to the acromion and scapular spine in the typical locations for Levy type II and type III stress fractures, respectively. The humeral stem was then removed and reimplanted in 30° of retroversion and the measurements were repeated. Student t test was performed to analyze the relationship between humeral stem version and acromion and scapular spine strain at various abduction angles. RESULTS: Strain at the both the acromion and scapular spine were found to have no significant difference at any abduction angle when comparing 0° and 30° version of the humeral stem. With 0° and 30° versions pooled together, there is significantly lower acromion and scapular spine strain at 60° of abduction when compared to 0° of abduction (strain at 0° abduction - strain at 60° abduction: acromion 313.1 µêœª; P = .0409, Scapular spine 304.9 µêœª; P = .0407). There was no significant difference in strain at either location when comparing 0° of abduction to 30° of abduction and when comparing 30° of abduction to 60° of abduction. CONCLUSIONS: This biomechanical study found no significant difference in scapular spine and acromion strain after RSA when comparing variations in humeral stem version. There does appear to be lower strain at both the acromion and scapular spine at 60° of abduction when compared to 0° of abduction regardless of stem version.