Regional distribution prevalence of heterotopic ossification in the elbow joint: a 3D study of patients after surgery for traumatic elbow injury

BACKGROUND

Heterotopic ossification (HO) is a common complication after elbow fracture surgery and can lead to severe upper extremity disability. The radiographic localization of postoperative HO has been reported previously. However, there is no literature examining the distribution of postoperative HO at the three-dimensional (3D) level. This study aimed to investigate 1) the distribution characteristics of postoperative HO and 2) the possible risk factors affecting the severity of postoperative HO at a 3D level.

METHODS

A retrospective review was conducted of patients who presented to our institution with HO secondary to elbow fracture between 13 January 2020 and 16 February 2023. Computed tomography scans of 56 elbows before elbow release surgery were reconstructed in 3D. HO was identified using density thresholds combined with manual identification and segmentation. The elbow joint and HO were divided into six regions according to three planes: the transepicondylar plane, the lateral ridge of the trochlear plane, and the radiocapitellar joint and coronoid facet plane. The differences in the volume of regional HO associated with different initial injuries were analyzed.

RESULTS

Postoperative HO was predominantly present in the medial aspect of the capsule in 52 patients (93%), in the lateral aspect of the capsule in 45 patients (80%), in the medial supracondylar in 32 patients (57%), and in the lateral supracondylar, radial head, and ulnar region in the same number of 28 patients (50%). The median and interquartile range volume of total postoperative HO was 1683 (777-4894) mm3. The median and interquartile range volume of regional postoperative HO were: 584 (121-1454) mm3 at medial aspect of capsule, 207 (5-568) mm3 at lateral aspect of capsule, 25 (0-449) mm3 at medial supracondylar, 1 (0-288) at lateral supracondylar, 2 (0-478) at proximal radius and 7 (0-203) mm3 at the proximal ulna. In the subgroups with Injury Severity Score > or = 16, Gustilo-Anderson II, normal uric acid levels, elevated alkaline phosphatase, and body mass index > or = 24, the median HO volume exceeds that of the respective control groups.

CONCLUSION

The medial aspect of the capsule was the area with the highest frequency and median volume of postoperative HO among all initial elbow injury types. Patients with higher Gustilo-Anderson grade, Injury Severity Score, alkaline phosphatase or Body Mass Index had higher median volume of postoperative HO.

Heterotopic ossification, osteolysis and implant failure following cervical total disc replacement with the M6-C™ artificial disc

INTRODUCTION

A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc.

METHODS

We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015.

RESULTS

In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5-11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03).

CONCLUSION

We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level.

Incidence and Risk Factors of Heterotopic Ossification in the Knee After Reamed Tibial Nailing

INTRODUCTION

Heterotopic ossification (HO) in the knee after tibial intramedullary nailing (IMN) has yet to be thoroughly investigated. Our aim was to assess frequency and associated factors for HO in the knee after tibial IMN.

METHODS

This is a retrospective review at a single level 1 urban trauma center of 213 patients who underwent reamed tibial IMN. Plain radiographs were reviewed postoperatively and on final follow-up (≥6 weeks). Chart review was performed for surgical approach (suprapatellar versus infrapatellar), demographics, injury characteristics, and clinical follow-up. The primary outcome was frequency of HO.

RESULTS

HO on final follow-up (mean: 41.43 weeks) was recorded in 15% cases. Postsurgical retroinfrapatellar reaming debris (odds ratio [OR], 4.73), Injury Severity Score (OR, 1.05), intensive care unit admission (OR, 2.89), chest injury (OR, 3.4), and ipsilateral retrograde femoral IMN (OR, 5.08) showed a notable association with HO development. No association was observed in HO formation between surgical approach, knee pain, or range-of-motion deficits.

DISCUSSION

Radiographic evidence of HO in the knee after reamed tibial IMN is not uncommon and is associated with retained reaming debris, Injury Severity Score, chest injury, intensive care unit admission, and ipsilateral retrograde femoral nailing. No differences were noted in HO formation between approaches. HO was not associated with knee pain or range-of-motion deficits.

Eagle jugular syndrome accompanied by de novo brainstem cavernous malformation: a case-based systematic review

BACKGROUND

Eagle jugular syndrome (EJS), recently identified as a cause of cerebrovascular disease (CVD) due to venous obstruction by an elongated styloid process (SP), is reported here alongside a case of concurrent de novo cerebral cavernous malformation (CCM). This study aims to explore the potential causal relationship between EJS and de novo CCM through a comprehensive literature review.

METHOD

Systematic literature reviews, spanning from 1995 to 2023, focused on EJS cases with definitive signs and symptoms and de novo CCM cases with detailed clinical characteristics. Data on the pathophysiology and clinical manifestations of EJS, as well as potential risk factors preceding de novo CCM, were collected to assess the relationship between the two conditions.

RESULT

Among 14 patients from 11 articles on EJS, the most common presentation was increased intracranial hypertension (IIH), observed in 10 patients (71.4%), followed by dural sinus thrombosis in four patients (28.6%). In contrast, 30 patients from 28 articles were identified with de novo CCM, involving 37 lesions. In these cases, 13 patients developed CCM subsequent to developmental venous anomalies (43%), seven following dural arteriovenous fistula (dAVF) (23%), and two after sinus thrombosis (6%). In a specific case of de novo brainstem CCM, the development of an enlarged condylar emissary vein, indicative of venous congestion due to IJV compression by the elongated SP, was noted before the emergence of CCM.

CONCLUSION

This study underscores that venous congestion, a primary result of symptomatic EJS, might lead to the development of de novo CCM. Thus, EJS could potentially be an indicator of CCM development. Further epidemiological and pathophysiological investigations focusing on venous circulation are necessary to clarify the causal relationship between EJS and CCM.

Chemoprophylaxis for heterotopic ossification following hip arthroscopy: A systematic review

INTRODUCTION

Heterotopic ossification (HO) is a known complication diagnosed following hip arthroscopy.

PURPOSE/HYPOTHESIS

This study sought to review the current literature on chemoprophylaxis for HO following hip arthroscopy and to describe what agents and doses are being utilized.

STUDY DESIGN

Systematic Review.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines on the use of chemoprophylactic medications for HO prevention following hip arthroscopy. Mechanical and radiation prophylaxis were not included in the current analysis.

RESULTS

A total of 203 studies were identified, of which 15 were included with 6463 patients. There was one randomized control trial (RCT) and 4 additional comparative studies. The most commonly utilized chemoprophylactic agents were the following: naproxen (n ​= ​8), celecoxib (n ​= ​3), indomethacin (n ​= ​3), aspirin (n ​= ​1), etoricoxib (n ​= ​1), and etodolac (n ​= ​1), and non-specific non-steroidal anti-inflammatory drugs (NSAIDs) (n ​= ​1). Naproxen was either given at a dose of 500 ​mg once or twice daily for 2-4 weeks. RCTs and additional comparative studies showed significant HO prevention using chemoprophylactic agents following hip arthroscopy.

CONCLUSIONS

HO is a known and common complication following hip arthroscopy. The current systematic review found significant heterogeneity across the literature with respect to specific chemoprophylactic agents and their dosing regimens aimed to reduce the incidence and severity of HO following hip arthroscopy. Additionally, this review demonstrates that most studies that utilize chemoprophylaxis use NSAIDs with successful reduction in the incidence of HO.

LEVEL OF EVIDENCE

Level IV Evidence.

Heterotopic Ossification Formation in Military Beneficiaries Following Hip- and Pelvic-Level Amputations

INTRODUCTION

Traumatic hip and pelvic level amputations are uncommon but devastating injuries and associated with numerous complications that can significantly affect quality of life for these patients. While heterotopic ossification (HO) formation has been reported at rates of up to 90% following traumatic, combat-related amputations, previous studies included few patients with more proximal hip and pelvic level amputations.

MATERIALS AND METHODS

We conducted a retrospective review of the Military Health System medical record and identified patients with both traumatic and disease-related hip- and pelvic-level amputations performed between 2001 and 2017. We reviewed the most recent pelvis radiograph at least 3 months following amputation to determine bony resection level and the association between HO formation and reason for amputation (trauma versus disease related).

RESULTS

Of 93 patients with post-amputation pelvis radiographs available, 66% (n = 61) had hip-level amputations and 34% (n = 32) had a hemipelvectomy. The median duration from the initial injury or surgery to the most recent radiograph was 393 days (interquartile range, 73-1,094). HO occurred in 75% of patients. Amputation secondary to trauma was a significant predictor of HO formation (χ2 = 24.58; P < .0001); however, there was no apparent relationship between the severity of HO and traumatic versus non-traumatic etiology (χ2 = 2.92; P = .09).

CONCLUSIONS

Amputations at the hip were more common than pelvic-level amputations in this study population, and three-fourths of hip- and pelvic-level amputation patients had radiographic evidence of HO. The rate of HO formation following blast injuries and other trauma was significantly higher compared with patients with non-traumatic amputations.

Prevalence, Timing, Locational Distribution, and Risk Factors for Heterotopic Ossification After Elbow Arthroscopy

BACKGROUND

Arthroscopic techniques aim to reduce complications and accelerate recovery of the elbow after treatments for posttraumatic stiffness, arthritis diseases, lateral epicondylitis, ligament reconstruction, and elbow trauma. However, data on the true prevalence and characteristics of heterotopic ossification (HO) formation after elbow arthroscopy are limited.

PURPOSE

To investigate the prevalence, timing, locational distribution, and risk factors of HO after elbow arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 4.

METHODS

Data on 205 patients undergoing elbow arthroscopy by a single senior elbow surgeon at a single institution between May 2011 and January 2022 were retrospectively reviewed. The patients were evaluated at 2 weeks, 8 weeks, 6 months, and then annually after surgery or more frequently if HO developed, with a minimum of 1 year of postoperative follow-up. Postoperative anteroposterior and lateral elbow radiographs were taken at 2 weeks to rule out fracture and at 8 weeks to identify HO. The clinical outcomes were evaluated based on the pain visual analog scale; the shortened version of the Disabilities of the Arm, Shoulder and Hand score; Mayo Elbow Performance Score; and the Single Assessment Numeric Evaluation scores before and after surgery. Bivariate logistic regression analyses were used to determine factors affecting HO prevalence.

RESULTS

Thirteen (12 male, 1 female) of 205 (6.3%) patients developed HO, with 10 (76.9%) with HO that formed on the medial compartment of the elbow. Ten (76.9%) patients were diagnosed at 8 weeks after arthroscopic surgery, 1 (7.7%) at 6 months after surgery, and 2 (15.4%) at 12 months after surgery. HO was not found at 2 weeks after surgery in any patient. The mean follow-up time was 3.5 years (range, 1.0-11.8 years). Eleven asymptomatic patients were treated nonoperatively, and 2 symptomatic patients underwent HO excision arthroscopically or had a combination of open surgery and arthroscopy. Age was a protective factor for HO formation (odds ratio [OR], 0.953; 95% CI, 0.910-0.999; P = .047). The risk factors for HO formation were tourniquet time (OR, 1.042; 95% CI, 1.019-1.065; P < .001) and surgical time (OR, 1.026; 95% CI, 1.011-1.041; P < .001).

CONCLUSION

Among 205 patients who underwent elbow arthroscopy, HO was a minor complication of elbow arthroscopy, with a prevalence rate of 6.3%, and was usually located on the medial compartment of the elbow. Although the presence of HO may not affect the clinical outcomes in most patients, it should be carefully monitored for a minimum of 8 weeks postoperatively. Younger age, longer tourniquet time, and longer surgical time contributed to HO formation after elbow arthroscopy.

Association Between Tranexamic Acid Use and Heterotopic Ossification Prevalence After Elbow Trauma Surgery: A Propensity-Score-Matched Cohort Study

BACKGROUND

Heterotopic ossification (HO) is a common complication of elbow trauma that can affect limb mobility. Inflammation is an initiating factor for HO formation. Tranexamic acid (TXA) can reduce the inflammatory response after orthopaedic surgery. However, evidence regarding the effectiveness of TXA use for HO prevention after elbow trauma surgery is lacking.

METHODS

This retrospective observational propensity-score-matched (PSM) cohort study was conducted from July 1, 2019, to June 30, 2021, at the National Orthopedics Clinical Medical Center, Shanghai, People's Republic of China. A total of 640 patients who underwent surgery following elbow trauma were evaluated. The present study excluded patients with an age of <18 years; those with a history of elbow fracture; those with a central nervous system injury, spinal cord injury, burn injury, or destructive injury; and those who had been lost to follow-up. After 1:1 matching on the basis of sex, age, dominant arm, injury type, open injury, comminuted fracture, ipsilateral trauma, time from injury to surgery, and nonsteroidal anti-inflammatory drug use, the TXA group and the no-TXA group comprised 241 patients each.

RESULTS

In the PSM population, the prevalence of HO was 8.71% in the TXA group and 16.18% in the no-TXA group (with rates of 2.07% and 5.80% for clinically important HO, respectively). Logistic regression analyses showed that TXA use was associated with a lower rate of HO (odds ratio [OR], 0.49; 95% CI, 0.28 to 0.86; p = 0.014) than no TXA use, as well as with a lower rate of clinically important HO (OR, 0.34; 95% CI, 0.11 to 0.91; p = 0.044). None of the baseline covariates significantly affected the relationship between TXA use and HO rate (p > 0.05 for all). Sensitivity analyses supported these findings.

CONCLUSIONS

TXA prophylaxis may be an appropriate method for the prevention of HO following elbow trauma.

LEVEL OF EVIDENCE

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

Incidence of Heterotopic Ossification at 10 years After Cervical Disk Replacement: A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

This study aimed to assess the incidence of heterotopic ossification (HO) 10 years after cervical disk replacement (CDR).

SUMMARY OF BACKGROUND DATA

HO is a common complication after CDR and may limit the range of motion of the artificial disk. As HO usually progresses slowly, a long-term follow-up is required to better understand its incidence. In recent years, the increasing number of original articles reporting 10-year outcomes gives us the opportunity to better understand the long-term incidence of HO.

MATERIALS AND METHODS

We searched PubMed, Medline, Embase, and Cochrane Library databases to identify eligible studies. The incidence of HO was pooled, and subgroup analysis was performed. Meta-regression analyses were conducted to identify factors contributing to heterogeneity.

RESULTS

Eleven studies with at least 10 years of follow-up comprising 1140 patients who underwent CDR were included. The pooled incidence of overall HO was 70% (95% CI, 60%-81%) at 10 years postoperatively, 60% (95% CI, 44%-75%) at five or six years postoperatively, and 50% (95% CI, 27%-72%) at one or two years postoperatively. The pooled incidence of severe HO (grade 3 or 4) was 37% (95% CI, 29%-45%), and mild HO (grade 1 to 2) was 30% (95% CI, 17%-44%) at 10 years of follow-up. Pooled range of motion decreased from 8.59° before surgery to 7.40° 10 years after surgery. Subgroup analysis showed that HO incidence differed according to the prosthesis type. The earlier publication was associated with a higher pooled incidence of severe HO in the meta-regression analysis.

CONCLUSIONS

This is the first meta-analysis providing detailed information on the pooled 10-year incidence of HO after CDR. The incidence of HO seems to increase with the length of follow-up.

LEVEL OF EVIDENCE

3.

Incidence and risk factors of dural ossification in patients with thoracic ossification of the ligamentum flavum

OBJECTIVE

Dural ossification (DO) is a common clinical feature in patients with thoracic ossification of the ligamentum flavum (OLF) and associated with the increased risk of perioperative complications. However, few studies have been conducted to determine the incidence and independent risk factors of DO in patients with thoracic OLF. The aim of this retrospective study was to determine the incidence and independent risk factors of DO in patients with thoracic OLF.

METHODS

A total of 107 patients with thoracic OLF who were admitted to the authors' hospital from December 2020 to December 2021 were included in this study. The independent risk factors of DO in patients with thoracic OLF were determined through univariate analysis followed by multivariate logistic regression analysis with p < 0.05. The diagnostic efficacy of the DO in OLF (DO-OLF) risk classification model was determined on the basis of independent risk factors and evaluated on the basis of sensitivity, specificity, and agreement rate.

RESULTS

The incidence of DO in patients with thoracic OLF was 35% (37/107 patients). The tuberous type according to the Sato classification (OR 9.75, p < 0.01) and larger (≥ 9°) supine local kyphosis angle (LKA) (OR 8.13, p < 0.01) were two independent risk factors of DO in thoracic OLF. The DO-OLF risk classification, a novel approach for the diagnosis of DO in patients with thoracic OLF, was established on the basis of the combination of the tuberous type according to the Sato classification and larger supine LKA. The sensitivity, specificity, and agreement rate of this approach for distinguishing between patients with thoracic OLF at high and low risk of DO were 87%, 93%, and 91%, respectively.

CONCLUSIONS

The incidence of DO in patients with thoracic OLF was 35%. The tuberous type according to the Sato classification and larger supine LKA (≥ 9°) were independent risk factors of DO in patients with thoracic OLF. The novel DO-OLF risk classification approach could serve as an efficient method for predicting DO in patients with thoracic OLF.

Heterotopic Ossification Prophylaxis in Acetabular Fracture Surgery: A Systematic Review

Heterotopic ossification (HO) following acetabular fracture surgery is relatively common. The purpose of this study was to perform a systematic review of the literature regarding HO rates following acetabular surgery and the effectiveness of the various prophylactic measures taken to prevent its occurrence. A search of PubMed, MEDLINE, and Cochrane Database of Systematic Reviews was performed using the search terms ("Acetabular" OR "Acetabulum") AND ("Heterotopic Ossification" OR "HO" OR "Ectopic Ossification"). Inclusion criteria included articles published in English reporting on HO in acetabular fracture surgery. Descriptive statistics were calculated with categorical data presented as frequency with percentages and continuous data as means. Standard weighted means were calculated for all parameters. Sixty-six articles were included in this study with a total of 5,028 patients. HO was identified in 1,511 (30%) of fractures. Indomethacin (27%) and radiation therapy (24%) demonstrated decreased rates of HO formation versus no prophylaxis (36%). In particular, rates of severe HO formation were substantially decreased with radiation therapy (3%) and indomethacin (7%) compared to no prophylaxis (18%). Indomethacin and radiation therapy both appear to decrease HO formation and severity without substantially increasing surgical morbidity. (Journal of Surgical Orthopaedic Advances 32(4):217-224, 2023).

Heterotopic ossification after total hip arthroplasty: radiological comparison between a direct anterior approach without an orthopaedic table and a posterior approach

INTRODUCTION

Heterotopic ossification (HO) occurs in almost ⅓ of total hip arthroplasties (THAs). A direct anterior approach (DAA) with an orthopaedic table is less likely to cause HO than a posterior approach. Without an orthopaedic table, the exposure of the femur requires additional soft tissue release. Soft tissue trauma leads to the production of HO inductors. Our study evaluated the incidence of HO 6 months after THA and compared the results between DAAs without an orthopaedic table and posterior approaches.

METHODS

Retrospectively, 164 consecutive, primary THAs were included: 76 through a posterior approach and 88 through a DAA. The main objective was to measure the presence of HO on pelvis radiography 6 months after surgery.

RESULTS

The incidence of HO was significantly higher in the DAA group than in the posterior approach group (47.7% vs. 27.6%, respectively; p < 0.01). The overall incidence of HO was 38.4%. No significant difference was found between the 2 approaches regarding the severity of HO. No significant risk factor for HO was identified other than the surgical approach.

DISCUSSION

In our study, the incidence of HO after THA in patients undergoing DAA without an orthopaedic table was higher than in patients undergoing a posterior approach after 6 months of follow-up. This result is closely related to the surgical trauma. It suggests that the minimally invasive feature of a surgical approach cannot be dissociated from the overall conditions in which it is performed.

Identification of Risk Factors in the Development of Heterotopic Ossification After Primary Total Hip Arthroplasty

PURPOSE

Heterotopic ossification (HO) is a process by which bone forms abnormally in soft tissues. Known risk factors for developing HO include male sex, spinal cord injury, trauma, and surgery. We investigated additional risk factors in the development of HO after hip arthroplasty.

METHODS

We performed a retrospective review of electronic medical records of 4070 individuals who underwent hip arthroplasty from September 2010 to October 2019 at the University of California, San Francisco Hospital. Demographics, anthropometrics, medications, and comorbid conditions were used in logistic regression analysis to identify factors associated with the development of HO.

RESULTS

A total of 2541 patients underwent primary hip arthroplasty in the analyzed timeframe (46.04% men, mean age at procedure: 62.13 ± 13.29 years). The incidence of postsurgical HO was 3% (n = 80). A larger proportion of individuals who developed HO had underlying osteoporosis (P < 0.001), vitamin D deficiency (P < 0.001), spine disease (P < 0.001), type 1 or 2 diabetes (P < 0.001), amenorrhea (P = 0.037), postmenopausal status (P < 0.001), parathyroid disorders (P = 0.011), and history of pathologic fracture (P = 0.005). Significant predictors for HO development were Black/African American race [odds ratio (OR) 2.97, P = 0.005], preexisting osteoporosis (OR 2.72, P = 0.001), spine disease (OR 2.04, P = 0.036), and low estrogen states (OR 1.99, P = 0.025). In the overall group, 75.64% received perioperative nonsteroidal anti-inflammatory drugs (NSAIDs), which negatively correlated with HO formation (OR 0.39, P = 0.001).

CONCLUSIONS

We identified new factors potentially associated with an increased risk of developing HO after primary hip arthroplasty, including African American race, osteoporosis, and low estrogen states. These patients may benefit from HO prophylaxis, such as perioperative NSAIDs.

Incidence and Risk Factors for Heterotopic Ossification in a Matched Cohort Adolescent Population Undergoing Hip Arthroscopy

BACKGROUND

Heterotopic ossification (HO) is a known complication after hip arthroscopy in adults, positively associated with larger cam resection, male sex, older age, and obesity, and negatively associated with nonsteroidal anti-inflammatory drug (NSAID) use and capsular closure. However, it has not been well-documented in adolescents. The purpose of this study was to determine the incidence and risk factors for the development of HO in adolescent patients undergoing hip arthroscopy.

METHODS

Clinical and operative records from a pediatric institution were queried to identify patients aged 21 years or younger who underwent hip arthroscopy between 2008 and 2018. The 27 cases that developed HO were matched 1:4 on age and sex with 107 controls. The bivariate analysis assessed the relationship between demographic and perioperative factors on the development of HO. Multivariable logistic regression evaluated the association between prophylactic NSAID use (indomethacin 75 mg, 3 wk) and HO, controlling for surgeon and extent of cam resection (change in alpha angle).

RESULTS

Twenty-seven of 595 (4.5%) hips that underwent hip arthroscopy developed HO within 2 years of surgery. Prophylactic indomethacin was not significantly associated with developing HO [30% (8/27), P=0.83], after controlling for surgeon and extent of cam resection-nor were age, sex, and body mass index percentile. Of patients who developed HO, a smaller proportion underwent reoperation for HO excision among those who received prophylactic indomethacin than those who did not [13% (1/8) vs. 63% (12/19), P=0.03].

CONCLUSIONS

The incidence of HO within 2 years of hip arthroscopy in this adolescent population was 4.5%. Although studies in the adult hip arthroscopy population have pointed to a protective role of NSAIDs (eg, indomethacin) in radiographic HO, the effect was less certain in this adolescent sample. Larger studies are important to further evaluate the role of prophylactic NSAIDs and variations in arthroscopic technique in developing HO.

LEVEL OF EVIDENCE

Level III-therapeutic, case-control study.

Association between obesity and ossification of spinal ligaments in 622 asymptomatic subjects: a cross-sectional study

INTRODUCTION

Previous studies on patients with symptoms of spinal ligament ossification, including ossification of the posterior longitudinal ligament (OPLL) and ligamentum flavum (OLF), have not clarified whether obesity is a cause or consequence of these diseases and were limited by selection bias. Thus, we investigated the association between obesity and the prevalence of spinal ligament ossification in randomly selected asymptomatic subjects.

MATERIALS AND METHODS

Between April 2020 and March 2021, 622 asymptomatic Japanese subjects who underwent computed tomography of neck to pelvis for medical check-up purposes were included. All subjects were divided into the following three groups: normal weight (body mass index [BMI] < 25 kg/m²), obese I (25 ≤ BMI < 30 kg/m²), and obese II (BMI ≥ 30 kg/m²). The relationship between factors affecting the presence of each spinal ligament ossification was evaluated using multivariate logistic regression analysis.

RESULTS

The proportion of subjects with thoracic OPLL was significantly higher in the obese II group than in the other two groups (vs. normal weight, P < 0.001; vs. obese I, P < 0.001). BMI was associated with the prevalence of OLF, cervical OPLL, thoracic OPLL, and ossification of the anterior longitudinal ligament (OALL). BMI was most significantly associated with the prevalence of thoracic OPLL (β, 0.28; 95% confidence interval, 0.17-0.39).

CONCLUSION

BMI was associated with the prevalence of OALL, cervical OPLL, thoracic OPLL, and OLF in asymptomatic subjects, suggesting that obesity is associated with the development of heterotopic ossification of the spinal ligaments.

Incidence of Complications in 25 Adult Patients With X-linked Hypophosphatemia

CONTEXT

Adults with X-linked hypophosphatemia (XLH) present complications other than osteomalacia.

OBJECTIVE

To describe the incidence and severity of comorbidities in adults with XLH.

METHODS

This observational retrospective study included a total of 25 adults with XLH with thorough investigations, including spinal computed tomography scans, x-rays of hip/knee joints and Achilles tendons, abdominal ultrasounds, and audiograms. The index of ossification of the anterior/posterior longitudinal ligament and yellow ligament (OA/OP/OY index) and the sum of OA/OP/OY index (OS index) were utilized to evaluate the severity of spinal ligament ossification. The Kellgren-Lawrence (KL) classification was adopted to evaluate the severity of the hip/knee osteophytes.

RESULTS

The participants consisted of 13 male patients and 12 female patients from 21 families, with a median age of 43 (range, 18-72) years. In all, 20 patients (80%) showed spinal ligament ossification. The median OA/OP/OY/OS indices were 2 (0-22), 0 (0-15), 6 (0-13), and 12 (0-41), respectively. Hip/knee osteophytes were reported in 24 (96%) and 17 cases (68%). The median KL grade was 3 in the hip joint and 2 in the knee joint, and 18 cases (72%) developed enthesopathy in the Achilles tendon. Nephrocalcinosis and hearing impairment were observed in 18 (72%) and 8 (32%) cases.

CONCLUSION

This study revealed a high prevalence and severity of ectopic ossification and disclosed the incidence of nephrocalcinosis and hearing impairment in adults with XLH. In cases with severe spinal ligament ossification or noticeable osteophytes around the hip/knee joints, undiagnosed XLH should be considered as a possible underlying condition.

An Unrecognized Ligament and its Ossification in the Craniocervical Junction: Prevalence, Patient Characteristics, and Anatomic Evidence

BACKGROUND

In the craniocervical junction, the ligaments between the anterior foramen magnum and the anterior arch of the atlas are not well defined, and ossification of the ligaments in this region has rarely been reported. Characterizing the anatomy and ossification of these ligaments may help in the diagnosis and treatment of disorders in this region.

QUESTIONS/PURPOSES

(1) What is the prevalence of an unrecognized ossification at the craniocervical junction in patients with cervical spine disorders, and what are the patient characteristics associated with this ossification? (2) Do patients with this ossification have a greater risk of ossification of other structures at the craniocervical junction or cervical spine? (3) Is there an unreported ligament at this ossified site?

METHODS

We conducted a retrospective study of 578 hospitalized patients who underwent CT for cervical spine disorders between January 2016 and July 2020. Based on the inclusion criteria, 11% (66 of 578) were excluded because of a cervical or craniocervical tumor, deformity, infection, fracture or dislocation, or prior surgery, leaving 89% (512 of 578) for analysis. These 512 patients had diagnoses of cervical radiculopathy, cervical myelopathy, cervical spondylotic amyotrophy, cervical spinal cord injury without a radiographic abnormality, or axial neck pain. Their mean age was 57 years (range 22-90 years), and 60% of the patients were men. Patient characteristics including age, gender, and diagnosis were retrieved from a longitudinally maintained institutional database. CT images were used to assess the presence of a previously unrecognized ossification and ossification of other structures in the craniocervical junction and cervical spine, including the posterior longitudinal ligament, anterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, and apical ligament, as well as diffuse idiopathic skeletal hyperostosis (DISH). The association between these structures was also assessed. This unreported ossification was called the capped dens sign. It was defined and graded from 1 to 3. Grade 3 was defined as the typical capped dens sign. Cervical spine MRI was used to assess whether there was an unreported structure in the same region as where the capped dens sign was detected on CT images. In the database of a recent study, there were 33 patients younger than 41 years. Nine percent (three of 33) were excluded because they did not have cervical spine MRI. MRIs of the remaining 30 patients were assessed. Their mean age was 35 years (range 22-40 years), and 58% were men. All cervical spine CT images and MRIs were reviewed by one senior spine surgeon and one junior spine surgeon twice with a 2-week interval. Blinding was accomplished by removing identifying information from the radiographs and randomly assigning them to each examiner. Any discrepancy with respect to the grade of the capped dens sign was adjudicated by a third blinded senior spine surgeon. Intrarater and interrater reliabilities were assessed by calculating weighted kappa statistics. No ligament or membrane was reported at this site. MRI is not sensitive to identify thin tissue in this region, especially when severe degeneration has occurred. A cadaveric study was conducted to discover a potential ligament between the inferior margin of the foramen magnum and the anterior arch of the atlas, as prompted by the newly discovered ossification in the clinical analysis of this study. Six embalmed human cadaveric craniocervical regions (three male and three female cadavers; median age 56 years, range 45-78 years) were dissected by a senior anatomist and a senior anatomy technician. A mid-sagittal section of the craniocervical junction was created, allowing us to explore the interval between the anterior foramen magnum and anterior arch of the atlas. A histologic analysis was conducted in two of the six cadavers (a male cadaver, 45 years; and a female cadaver, 51 years). Slides were made with 4-µm sections and stained with hematoxylin and eosin.

RESULTS

A novel capped dens sign was detected in 39% (198 of 512) of the patients and the most typical capped dens sign was detected in 19% (96 of 512) of patients. The prevalence of this sign was the highest in patients with cervical spondylotic amyotrophy (12 of 25 patients). The prevalence of ossification of the anterior longitudinal ligament, ligamentum nuchae, and apical ligament, as well as DISH, was higher in patients with a capped dens sign than in those without (p = 0.04, p < 0.001, p < 0.001, and p = 0.001, respectively). The capped dens sign was identified in 69% (18 of 26) of the patients with DISH. A thin and short band-like structure or osteophyte was detected on MRI in 87% (26 of 30), in the same region as the capped dens sign. In the cadaveric study, an unreported, distinct ligamentous structure was identified at this ossified site. It originated from the posterosuperior rim of the anterior arch of the atlas to the inferior margin of the foramen magnum, which we called the inter-atlanto-occipital ligament. It was found in all six dissected craniocervical junctions. The histologic analysis revealed dense connective tissue.

CONCLUSION

More than one-third of the patients in this series demonstrated CT evidence of a previously unrecognized ossification in the craniocervical junction, which we called the capped dens sign. Anatomic evidence of this sign, which was a previously unidentified ligament, was also newly discovered in this region. This study was conducted among Asian patients and specimens. Further studies among diverse ethnic groups may be needed to generalize the results. An additional well-designed prospective study will be needed to provide further evidence regarding the potential pathophysiology and clinical relevance of the capped dens sign. Furthermore, the cadaveric analysis in this study was only a preliminary report of the ligament; further biomechanical research is needed to investigate its function.

CLINICAL RELEVANCE

Knowledge of this novel ligament may improve the diagnosis and treatment of craniocervical stability and dislocation. Ossification of this ligament is correlated with age, cervical spondylotic amyotrophy, and DISH. We wonder whether patients with cervical degenerative disorders who also have a capped dens sign may be at risk for the formation of osteophytes of an uncovertebral joint, which may result in palsy of the upper limb muscles. The capped dens sign may be the craniocervical manifestation of DISH. This possible association between the capped dens sign and DISH should be considered when performing surgery on patients with the capped dens sign.

Heterotopic Ossification Negatively Influences Range of Motion After Revision Total Knee Arthroplasty

BACKGROUND

The incidence of heterotopic ossification (HO) after total knee arthroplasty (TKA) varies and is of unclear clinical significance. This study aimed to identify the incidence of HO in patients undergoing revision TKA for either stiffness or aseptic loosening/instability and determine if the presence of HO is associated with inferior absolute range of motion (ROM) and ROM gains.

METHODS

Eighty-seven patients were prospectively enrolled and separated into 2 cohorts to evaluate ROM after revision TKA (2017-2019). Group 1 (N = 40) patients were revised for stiffness, while group 2 (N = 47) patients were revised for either aseptic loosening or instability. Goniometer-measured ROM values were obtained preoperatively and at 6 weeks, 6 months, and 1 year postoperatively. Statistical analysis included a Fisher's exact test to assess for an association between preoperative HO and final ROM at 1 year after revision TKA.

RESULTS

HO was identified on preoperative radiographs in 17 patients (20%). There was a significantly higher rate of preoperative HO in patients revised for stiffness compared to patients revised for instability or loosening (30% vs 11%; P = .03). Five cases of HO qualitatively identified as most clinically severe were associated with lower ROM at each time point compared to the remainder of HO cases in this study cohort (P < .02).

CONCLUSION

The presence of HO is greater in patients undergoing revision TKA for stiffness. Additionally, HO severity appears to have a major effect on preoperative and postoperative ROM trajectory. This information should help guide patient expectations and highlight the need for a comprehensive, standardized classification system for HO.

Relatively Low Rate of Heterotopic Ossification Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-analysis

BACKGROUND

Heterotopic ossification (HO) is abnormal growth of ectopic bone and negatively affects the outcomes after total knee arthroplasty (TKA). This systematic review and meta-analysis were performed to characterize the prevalence and severity of HO after primary TKA.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Patient demographics, publication year, and HO prevalence after a primary TKA were recorded. A meta-analysis was performed to determine the overall prevalence of HO formation, and a subanalysis compared the studies published in different timeframes to determine whether a temporal effect exists for HO prevalence.

RESULTS

Two thousand nine hundred eighty-eight patients underwent primary TKA across the included studies. Fourteen percent of patients (9% to 20%; I2: 93.68%) developed HO postoperatively during a mean follow-up of 40.1 months (11 to 108 months). HO rates seemed to decrease in studies published in more recent years, with a pooled HO prevalence of 5% (0% to 13%; I2: 92.26%) among studies published in the past 15 years compared with 18% (12% to 25%; I2: 92.49%) among studies published before then.

CONCLUSION

Although studies reported a relatively low overall rate of HO after a primary TKA, the absence of a single, standardized classification system precludes the comparisons of HO severity between studies. Overall, HO prevalence seems to have decreased over time, likely reflecting the changes in perioperative medication protocols.

Heterotopic Ossification After Elbow Fractures

Heterotopic ossification (HO), a complication after surgical repair of elbow fractures, can result in pain, decreased range of motion, or complete ankylosis of the joint. This updated systematic review focused on compiling incidence and prevalence rates of HO after surgical repair of various types of elbow fractures. The overall incidence of HO after surgical repair was calculated to be 28.7%, a result comparable with rates in the literature. Further analysis suggested that the odds of having HO may be less after distal humerus fractures than after proximal radius fractures, terrible triad injuries, and elbow fractures/dislocations. [Orthopedics. 2021;44(1):10-16.].

[Tranexamic Acid Reduces the Incidence of Heterotopic Ossifications after Elective Primary Total Hip Arthroplasty]

PURPOSE OF THE STUDY Heterotopic ossification is a frequent and a well-known complication after elective primary total hip arthroplasty. Prophylaxis is crucial since once the ossification is mature, the only treatment option is its surgical removal during revision hip surgery. There are pre-, peri- and postoperative prophylactic modalities. Ranking among the perioperative possibilities is the application of tranexamic acid in blood control management. The aim of our study is to prove the positive side effect of tranexamic acid application on reducing the heterotopic ossification ratio. MATERIAL AND METHODS A cohort of 401 total hip replacements was assessed retrospectively in the period from 2012 to 2016. Particular degrees were stratified based on the Brooker classification, sex, laterality and type of implant fixation. The average follow-up period is 6.10 years (range 40 m to 113 m). The hips treated in 2012 are taken as reference and the hips treated in 2016 are exposed to tranexamic acid protocol. Other secondary prophylactic modalities (pharmacological prophylaxis or radiotherapy), tertiary modalities (revision surgery) and trauma patients were excluded from the study. The acquired data were then statistically assessed. RESULTS Tranexamic acid protocol significantly reduces the incidence of heterotopic ossification after elective primary total hip replacement. In our cohort of 401 hips, the overall incidence of HO is 40.6%. The difference between the control group - 49.7% and the exposed group - 30.2% is statistically significant. More importantly, the clinically relevant types (III and IV) were also significantly reduced (12.7% vs. 4.2%). Other associated parameters such as uncemented implant, female sex and right-sided surgery further reduced the incidence of ossifications. DISCUSSION Identification of the risk patient, risk factors and subsequent care to maintain the range of motion, analgesia or potential removal of ossifications remain to be the priority in managing heterotopic ossifications after THA. Preoperative options to reduce the incidence of this complication are limited. Moreover, both the pharmacological prophylaxis and radiotherapy are associated with major complications and strict patient compliance is fundamental. Inclusion of simple tranexamic acid protocol in surgery management significantly reduces the risk of heterotopic ossification. CONCLUSIONS Development and maturation of heterotopic ossification is still intensively explored, but the main biochemical pathways are still unclear. Therefore, there is no causal treatment option nowadays. Individualisation of prophylactic treatment modalities leads to reduction in ossification development. It has been proven that one of these effective modalities is the tranexamic acid application before and after the procedure. This reduction is statistically significant and clinically relevant. Key words: tranexamic acid, total hip replacement, heterotopic ossification, prophylaxis, fixation type.

A proposed extension to the elongated styloid process definition: A morphological study with high-resolution tomography computer

The objective of the present study was to evaluate the morphology and angulation of the styloid process (SP), analyzing results stratified by gender, side and age on asymptomatic patients. We retrospectively analyzed 99 high-resolution computed tomography study images from asymptomatic patients. The images were assessed intra-observatory by a head and neck expert radiologist. Data for length, morphology, and angulation in a coronal and sagittal plane were recorded and stratified by age and gender. Morphology was classified according to the Langlais modified by Guimares classification. The mean lengths were 31.67±0.97mm and 31.64±0.90mm for the right and left sides respectively. Using the Langlais modified by Guimares classification, the normal type was the most prevalent and without a statistically significant difference when comparing between genders. A total of 27.6% presented a morphologically elongated SP (>25mm of continuous process), 49.5% presented a radiologically elongated SP (>30mm), and a total of 9.59% had a longer length than the proposed≤45mm. The right transverse angle was greater in men than women, and a statistically significant difference was found (P=0.010). We show the morphological variability of the SP. Although our results are reported with the traditional definition, the high prevalence supports the need for a new definition of elongated SP and a normal angulation ranges.

Direct anterior total hip arthroplasty: a retrospective study

BACKGROUND

The quest for less invasive surgical approaches for total hip arthroplasty has gained much attention recently. There is very little information regarding differences about the main surgical access. The purpose of this study was to collect data regarding patients' subjective perceptions of the direct anterior hip arthroplasty, heterotopic ossification degrees, range of movement and complication and comparing these satisfaction results with the other surgical techniques.

METHODS

The study involved 51 patients operated in our Orthopedic clinic with direct anterior total hip arthroplasty between 2016 and 2017. We recorded and compared clinical and radiographic data at 1 year with anterolateral hip arthroplasty.

RESULT

Only one patient described less than an 8/10 satisfaction; 5.45% of the patients restored the physiological ROM and 21.82 % lost only 5° of range of motion. According to Brooker Classification 58.33 % did not develop any Heterotopic Ossification.

CONCLUSION

All standard approaches to the hip have been shown to be safe and efficacious, with particular advantages and disadvantages for each approach. DAA has some short term advantages like a faster recovery, less blood loss and less heterotopic ossification. Long term studies are required to demonstrate a cost benefit or quality of care advantage to other hip approaches.

Incidence and risk factors for heterotopic ossification following periprosthetic joint infection of the hip

INTRODUCTION

Heterotopic ossifications (HOs) commonly occur following total hip arthroplasty. Data regarding the appearance of HO after periprosthetic joint infection (PJI) of the hip are rare. Therefore, the aim of this study was to analyze the incidence and potential risk factors for the development of HO in patients with PJI of the hip.

MATERIALS AND METHODS

We performed a single-center, retrospective study including patients treated with a two- or multistage operation and patients undergoing salvage procedure in cases of PJI of the hip with a minimum follow-up of 6 months. A total of 150 patients were included in the analysis. The Brooker-scale was used to classify HO. Patients were divided in three groups: (1) No HO, (2) HO Brooker type 1-4, and (3) high-grade HO (HO Brooker type 3 and 4). In each group, we checked possible risk factors for the development of HO for statistical significance.

RESULTS

Patients included in our study had a mean age of 70.4 ± 12.1 years. Of all patients, 75 were women (50%). HOs could be found in 70 patients (46.7%). Twenty-seven patients showed HO Brooker type 1, 23 type 2, 15 type 3 and 5 type 4. Male gender [odds ratio (OR) 2.14; p = 0.022], smoking (OR 5.75; p = 0.025) were significant risk factors for HO. A chronic infection (OR 3.54; p = 0.029) and a higher number of procedures (p = 0.009) were significant risk factors for the development of high-grade HO.

CONCLUSIONS

HOs often occur following surgical care of PJI. Male gender, smoking, a chronic infection and high number of operations are risk factors for developing HO after PJI.

Incidence and characteristics of heterotopic ossification after spinal cord injury: a single institution study in India

Study design

This was a single-centre, retrospective, descriptive, hospital-based study in persons with spinal cord injuries (SCI) patients.

Objectives

To study the incidence and characteristics of heterotopic ossification (HO) after SCI.

Setting

The in-patient services of the Department of Physical Medicine and Rehabilitation of a tertiary care institute in India between January 2001 and December 2017.

Methods

Medical records of all consecutive patients with diagnosis of SCI in the age group of 15-60 years were reviewed for presence of HO (diagnosed by clinical signs, laboratory investigations (ALP, ESR and X-rays)) and characteristics of HO. R-Ver 3.4.2 was used for analysis and correlations. Results were considered significant at P < 0.05.

Results

A total of 303 patients satisfied inclusion criteria. Nineteen individuals (6.3%) had developed HO. Seven (37%) were diagnosed within 3 months of SCI. Twelve (63%) patients developed unilateral HO. The most common site for HO was hip joint (73%). A significant association was found between the presence of a pressure ulcer and development of HO (P = 0.01).

Conclusions

The incidence of HO was 6.3% in our institution and the hip joint is the most common site. Due to the presence of limited treatment options it is important to diagnose HO early in patients with SCI based on clinical features and later confirmed with laboratory tests and imaging.

Influence of Fusion on the Behavior of Adjacent Disc Arthroplasty in Contiguous 2-Level Hybrid Surgery In Vivo

OBJECTIVE

To investigate whether the behavior of disc arthroplasty in 2-level hybrid surgery (HS) was affected by adjacent fusion in vivo compared with cervical disc arthroplasty (CDA) alone.

METHODS

Seventy-nine patients undergoing either a 1-level CDA or contiguous 2-level HS were retrospectively reviewed. Radiologic assessments included segmental lordosis (SL), intervertebral disc height (IDH), changes in SL and IDH, range of motion (ROM) of the disc replacement and its adjacent segments, migration and subsidence of the prosthesis, heterotopic ossification (HO), and adjacent segment degeneration (ASD) adjacent to the arthroplasty level. Clinical features and outcome scores were also recorded.

RESULTS

Compared with 1-level CDA, the increased SL and IDH immediately after surgery in 2-level HS were more likely to be lost throughout the follow-up period. However, both groups generally maintained the SL and IDH of the arthroplasty segment postoperatively. Two-level HS did not exhibit hypermobility of the disc prosthesis and preserved preoperative ROM of the adjacent segment of the device. The HS group showed adverse effects on the prosthesis stability, but there was no significant difference in the number of cases of obvious migration or subsidence between the groups. The differences in HO, ASD, and clinical outcomes between the groups were not significant at the final follow-up.

CONCLUSIONS

Although the fusion in 2-level HS partially affected the behavior of adjacent disc arthroplasty compared with CDA alone, it did not cause severe complications and adverse clinical outcomes. However, large-scale and long follow-up trials are warranted.

Critical Illness Polyneuropathy (CIP): a multicenter study on functional outcome

OBJECTIVES

To describe the functional recovery of consecutive inpatients with Critical Illness Polyneuropathy (CIP) at the time-point of the discharge from rehabilitation units according to Barthel Index scores. To examine whether age, gender, pre-ICU admission diagnosis, tracheostomy performance, heterotopic ossification development and duration of neuro-rehabilitation treatment are among the prognostic factors that can predict the functional outcome in studied patients.

METHODS

A retrospective observational clinical study from January 2010 to December 2014 in three rehabilitation units in Greece.

RESULTS

Sixteen subjects (57.1%) had >60 BI discharge scores, showing a prospect in gaining further independence. Females presented a tendency for better functional outcome vs males (73.8 ± 12.6 vs 58.6 ± 23.4, p=0.082). Respiratory, septic and neurologic patients demonstrated better rates of functional improvement after the rehabilitation process vs cardiac patients (p minor than 0.001, p=0.009 and p=0.019, respectively vs p=0,072). Heterotopic ossification development proved to be an adverse independent prognostic factor of functional outcome (47.8 ± 25.7 vs 68.8 ± 17.7, p=0.023).

CONCLUSIONS

A proportion of included patients experienced severe disability with poor prospect of further functional development and return to work at the discharge from the rehabilitation units. According to the present study, which is the first that focuses only on CIP and its outcome, specific prognostic factors can be defined. Our results can be used as pilot data for larger studies, so that firmer conclusions can be drawn.

Optimal strategies for the prevention of heterotopic ossification after total hip arthroplasty: A network meta-analysis

BACKGROUND

Nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), selective NSAIDs, and radiation are widely used for the prevention of heterotopic ossification (HO) after total hip arthroplasty (THA). Previous studies have suggested that nonselective NSAIDs, selective NSAIDs and radiation can prevent HO after THA, though the results are conflicting. In this network meta-analysis, we aimed to comprehensively analyze the efficacy and safety of three strategies for preventing HO after THA compared to a placebo.

PATIENTS AND METHODS

Relevant studies about nonselective NSAIDs, selective NSAIDs, radiation and controls that were used to prevent HO after THA were collected. Data were extracted independently by two reviewers. Network meta-analysis was applied to assess treatment efficacy and safety. The surface under the cumulative ranking curve (SUCRA) method was used to assess which treatment was ranked the highest. The node-splitting method was used to calculate inconsistency.

RESULTS

Radiation was found to be the most efficient option for preventing overall incidence of HO and Brooker IV, I, II and III HO after THA. Selective NSAIDs were the safest option, and radiation was ranked second for preventing HO after THA, as the treatments were ranked taking discontinuation caused by nongastrointestinal side effects (DNGSE) and the incidence of complications into consideration.

CONCLUSIONS

A network meta-analysis concluded that radiation is the most efficacious method for preventing HO after THA.

Infection Precedes Heterotopic Ossification in Combat Wounded

Heterotopic ossification is the formation of ossified bone in soft tissue, particularly after soft tissue trauma. Heterotopic ossification is known cause of pain, prosthetic/orthotic malfit, and reoperation following combat extremity injury. The purpose of this research was to examine injury and treatment characteristics that are associated with heterotopic ossification in a broader population of deployment-injured subjects. The Department of Defense Trauma Registry and Military Orthopaedic Trauma Registry was queried for a sample of deployment-injured subjects and the complication of heterotopic ossification. Heterotopic ossification was identified in 15% of subjects following 5% of all injuries. Symptoms attributed to the heterotopic bone were present in 40% of subjects with diagnosed with heterotopic ossification. Heterotopic ossification was not associated with injury severity or aggressiveness of open wound treatment. However, infection was the only positive predictor of heterotopic ossification resulting in two-times greater odds of heterotopic bone formation. This finding is consistent with prior research suggesting that heterotopic ossification requires persistent inflammation to be present in at-risk soft tissue. Among all wounds sustained during deployment injury, heterotopic may not be abundantly common; however, the risk may be further minimized by focused infection control.

Non-steroidal anti-inflammatory drugs for heterotopic ossification prophylaxis after total hip arthroplasty: a systematic review and meta-analysis

Aims

The aim of this study was to assess the efficacy of non-selective and selective non-steroidal anti-inflammatory drugs (NSAIDs) in preventing heterotopic ossification (HO) after total hip arthroplasty (THA).

Methods

A thorough and systematic literature search was conducted and 29 studies were found that met inclusion criteria. Data were extracted and statistical analysis was carried out generating forest plots.

Results

Non-selective NSAIDs showed a significant decrease in the odds for forming HO after THA (odds ratio (OR) -1.35, confidence interval (CI) -1.83 to -0.86) when compared with placebo. Selective NSAIDs also showed a significant decrease in the odds for forming HO after THA when compared with placebo (OR -1.58, CI -2.41 to -0.75). When comparing non-selective NSAIDs with selective NSAIDs, there was no significant change in the odds for forming HO after THA (OR 0.22, CI -0.36 to 0.79).

Conclusion

Our meta-analyses of all available data suggest that both non-selective and selective NSAIDs are effective HO prophylaxis and can be used routinely after THA for pain control as well as prevention of HO. Indomethacin may serve as the benchmark among non-selective NSAIDs and celecoxib among selective NSAIDs. There was no difference in the incidence of HO between non-selective and selective NSAIDs, allowing physicians to choose either based on the clinical scenario and patient-specific factors. Cite this article: Bone Joint J 2018;100-B:915-22.

Clinical and Radiographic Outcomes of Unipolar and Bipolar Radial Head Prosthesis in Patients with Radial Head Fracture: A Systemic Review and Meta-Analysis

PURPOSE

To compare clinical outcomes of unipolar and bipolar radial head prosthesis in the treatment of patients with radial head fracture.

MATERIALS AND METHODS

Medline, Cochrane, EMBASE, Google Scholar databases were searched until April 18, 2016 using the following search terms: radial head fracture, elbow fracture, radial head arthroplasty, implants, prosthesis, unipolar, bipolar, cemented, and press-fit. Randomized controlled trials, retrospective, and cohort studies were included.

RESULTS

The Mayo elbow performance score (MEPS), disabilities of the arm, shoulder, and hand (DASH) score, radiologic assessment, ROM, and grip strength following elbow replacement were similar between prosthetic devices. The pooled mean excellent/good ranking of MEPS was 0.78 for unipolar and 0.73 for bipolar radial head arthroplasty, and the pooled mean MEPS was 86.9 and 79.9, respectively. DASH scores for unipolar and bipolar prosthesis were 19.0 and 16.3, respectively. Range of motion outcomes were similar between groups, with both groups have comparable risk of flexion arc, flexion, extension deficit, rotation arc, pronation, and supination (p values <0.001 for both unipolar and bipolar prosthesis). However, bipolar radial head prosthesis was associated with an increased chance of heterotopic ossification and lucency (p values ≤0.049) while unipolar prosthesis was not (p values ≥0.088). Both groups had risk for development of capitellar osteopenia or erosion/wear (p values ≤0.039).

CONCLUSION

Unipolar and bipolar radial head prostheses were similar with respect to clinical outcomes. Additional comparative studies are necessary to further compare different radial head prostheses used to treat radial head fracture.

The prevalence and morphometric analysis of ossified superior transverse scapular ligaments in patients with rotator cuff tears

BACKGROUND

The prevalence of ossified superior transverse scapular ligaments (OSTSLs) in rotator cuff tears (RCTs) has not yet been determined. The purposes of this study were to evaluate the prevalence of OSTSLs in RCTs and to investigate the correlation between OSTSL morphology and supraspinatus muscle atrophy.

METHODS

We analyzed a total of 213 patients with RCTs for whom 3-dimensional (3D) computed tomography (CT) and magnetic resonance imaging were performed prior to arthroscopic procedures. The mean age of the patients was 59.73 ± 8.43 years, and 103 patients were men. OSTSLs were identified based on 3D CT findings. The correlations between OSTSLs and age, sex, and RCT size were analyzed. The horizontal and vertical diameters, area, and circumference of the suprascapular foramen were measured. By use of the occupation ratio calculated from magnetic resonance imaging results, supraspinatus muscle atrophy was evaluated.

RESULTS

Of 213 patients with RCTs, 22 (10.3%) had OSTSLs. OSTSLs were found at a rate of 15.5% (16 of 103) in men, higher than that in women (P = .016). The rate of OSTSLs increased with age (P = .003). RCT size was not correlated with the prevalence of OSTSLs. As the horizontal diameter and circumference of the suprascapular foramen increased, muscle atrophy progressed (P = .001 and P = .046, respectively).

CONCLUSION

One of ten patients with RCTs had OSTSLs; the rate of OSTSLs was higher among men and increased with age. For patients with RCTs preparing to undergo arthroscopic superior transverse ligament resection, preoperatively identifying OSTSLs through 3D CT would be useful for the resection.

Fibrodysplasia ossificans progressiva: The patient voice

The following essays are the personal statements of two remarkable young individuals, Ian Cali and Laura Rossano, who candidly share their perspectives on living life with fibrodysplasia ossificans progressiva (FOP). These essays are excerpts from the opening comments that Ian and Laura delivered at The First and The Second International FOP Association Drug Development Forums in 2014 and 2016, respectively. We present these unedited essays in this special issue of BONE so that physicians, scientists, and researchers everywhere can glimpse the valiant challenges that envelop the lives of all individuals with FOP and can appreciate that diseases are not just biological processes but indelible human experiences. These last words belong to Ian and Laura. Frederick S. Kaplan M.D.; Eileen M. Shore Ph.D.; and Robert J. Pignolo M.D., Ph.D. - Guest Editors.

Incidence of Heterotopic Ossification Following a Multimodal Pain Protocol in Total Hip Arthroplasty With the Posterior Approach

Heterotopic ossification (HO) is prevalent after total hip arthroplasty (THA). Oral nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors have reduced the incidence of HO; however, to the authors' knowledge, no studies have reported the incidence and severity of HO with a pain protocol highlighted by celecoxib in the pre- and postoperative period with a posterolateral approach. Between October 2014 and October 2015, a retrospective study was conducted of 687 consecutive primary THAs with minimum 1-year follow-up performed between January 2009 and December 2013. All patients underwent a posterolateral THA with a multimodal pain protocol consisting of preoperative celecoxib; local steroid infiltration intraoperatively; postoperative celecoxib, dexamethasone, and ketorolac; and aspirin or warfarin thromboprophylaxis. For all patients, pre- and postoperative radiographs were examined and classified for HO using the Brooker classification. Interobserver reliability was calculated for both incidence of HO and Brooker classification. Overall, HO was present around 98 (14.3%) THAs. The incidence of Brooker I, II, and III HO was 38 (5.5%), 47 (6.8%), and 12 (1.7%), respectively. No patients required surgical excision or had radiographic evidence of Brooker IV HO. Multivariate logistic regression identified male sex and hypertrophic osteoarthritis as significant risk factors. The use of aspirin for thromboprophylaxis significantly reduced the incidence of HO. This study found the overall incidence of HO when using celecoxib during a posterior THA to be 14.3%, which is similar to what others have reported with the direct lateral approach and with other COX-2 inhibitors for a posterior approach. Risk factors include male sex and preoperative hypertrophic osteoarthritis. [Orthopedics. 2018; 41(1):e92-e97.].

The prevalence of heterotopic ossification among patients after cervical artificial disc replacement: A systematic review and meta-analysis

BACKGROUND

Prevalence estimates of heterotopic ossification (HO) following cervical artificial disc replacement (ADR) varied widely in previous studies. We conducted a systematic review and meta-analysis to summarize its point prevalence.

METHODS

Electronic searches of PubMed, Web of Science, Embase, and Cochrane Library databases were conducted to identify studies that reported prevalence of HO. Definitions of HO and severe HO were based on McAfee grading system. Random-effects model was used to estimate the pooled prevalence. We conducted subgroup analyses according to the different length of follow-up time, and performed univariate metaregression analyses to explore the effects of potential variables on the overall prevalence.

RESULTS

A total of 38 studies were included in this study. The pooled data showed that the prevalence of HO after cervical ADR within the 1 to 2 years, 2 to 5 years, and 5 to10 years of follow-up was 38.0% (95% confidence interval [CI], 30.2%-46.5%), 52.6% (95% CI, 43.1%-61.9%), and 53.6% (95% CI, 40.0%-66.7%), respectively, while the prevalence of severe HO was 10.9% (95% CI, 9.0%-13.2%), 22.2% (95% CI, 15.5%-30.7%), and 47.5% (95% CI, 30.0%-65.8%), respectively. Follow-up time was positively associated with the prevalence of severe HO (P < .01), and the 1-month growth of mean follow-up went with 0.63% increase of severe HO.

CONCLUSION

This meta-analysis reported data on the prevalence of HO and severe HO after cervical ADR, and provided information on its process of development. These should be useful to enable surgeons and patients to gain a better understanding of HO after cervical ADR.

Prevalence and pattern of the elongated styloid process among geriatric patients in Saudi Arabia

OBJECTIVE

The objectives of this study were to assess the elongation of the styloid process on digital panoramic radiographs and to evaluate the prevalence of the elongation according to age, sex and types.

PATIENTS AND METHODS

Digital panoramic radiographs of 198 geriatric edentulous patients were analyzed. The radiographic length of the styloid process was measured on both sides using the measurement toolbars on the accompanying analysis software. For statistical analysis, Student's t-test, chi-square test and analysis of variance test were used.

RESULTS

The elongated styloid process was seen in 87 of the 198 patients. It was observed that as age increased, elongation of the styloid process increased with a male predominance. Type I elongation was more common than other types of elongation. Bilateral elongation was most commonly found than unilateral elongation, and both types of elongation were frequently seen in males compared with females.

CONCLUSION

The prevalence of the elongated styloid process in the present study was higher in comparison to the other reports from edentulous patients.

Dural ossification associated with ossification of ligamentum flavum in the thoracic spine: a retrospective analysis

OBJECTIVES

To investigate the incidence, distribution and radiological characteristics of dural ossification (DO) associated with ossification of ligamentum flavum (OLF) in the thoracic spine.

DESIGN

A retrospective radiographical analysis.

SETTING

This study was conducted at a single institution in China.

PARTICIPANTS

53 patients with OLF who underwent posterior decompression surgery between January 2011 and July 2015 in a single institution were enrolled in this study. The decompression segments were grouped according to imaging evaluation and intraoperative evidences.

OUTCOME MEASURES

The demographic distribution, radiological data and detailed surgical records were collected. First, preoperative CT images of decompressed segments were evaluated to identify imaging signs of DO. The 'tram tack sign' (TTS), 'comma sign' and 'bridge sign' were considered as characteristic imaging findings of DO in OLF. 4 kinds of confusing signs (false TTS) were identified and excluded. Then detailed surgical records were reviewed to finally identify segments with DO.

RESULTS

The incidence of DO in patients with OLF was 43.4%. The incidence of DO in OLF segments was 21.5%. OLF was more common in the lower thoracic spine, and more than half (53.8%) of the DO was located in T9-T12. TTS was the most common sign, but it might be misdiagnosed. After excluding 4 kinds of false TTS, the sensitivity and specificity of imaging diagnosis were 94.23% and 94.21%, respectively.

CONCLUSIONS

DO was relatively common in thoracic OLF, especially in T9-T12. TTS might be misdiagnosed. After excluding 4 kinds of false TTS, the accuracy of imaging diagnosis was relatively high.

Total hip arthroplasty in patients with ankylosing spondylitis: Midterm radiologic and functional results

Introduction

The aim of this study was to evaluate the clinical and radiological outcomes of total hip arthroplasty (THA) in patients with Ankylosing Spondylitis (AS).

Patients and methods

One hundred five hips of 61 AS patients (mean age: 41.3 ± 10.2 years) who underwent THA between 1997 and 2012 were included into the study. Dorr's classification of proximal femoral geometry, acetabular protrusio, bone ankylosis, acetabular protrusion, Brooker classification of heterotopic ossification (HO), Gruen and Charnley classifications of implant loosening were used in radiographic assessments. Patients were called back to return for an additional long-term follow-up for functional assessment.

Results

Cementless total hip arthroplasty was used in 83 hips (79%) and cemented TKA was used in 22 hips (21%). The overall rate of aseptic loosening was 7.6% at a mean follow-up of 5.4 years. Femoral loosening was statistically similar in cemented and cementless femoral components (14% vs. 8%, p = 0.089). Acetabular component loosening was statistically higher in patients with any degree of HO (p = 0.04). Regardless of the type of femoral implant (cemented or cementless), femoral component loosening was higher in Dorr's type C patients (p = 0.005). The average pre-operative HSS was 46.6 ± 16.3, and it improved to 80.7 ± 18.7 at last follow-up (p < 0.01).

Conclusion

Revision incidence was similar in between ankylosed and non-ankylosed hips. While complication rates are high, significant functional improvement can be achieved after THA in patients with AS.

Anterior approach versus posterior approach for Pipkin I and II femoral head fractures: A systemic review and meta-analysis

PURPOSE

We performed a meta-analysis, pooling the results from controlled clinical trials to compare the efficiency of anterior and posterior surgical approaches to Pipkin I and II fractures of the femoral head.

METHODS

Potential academic articles were identified from the Cochrane Library, Medline (1966-2015.5), PubMed (1966-2015.5), Embase (1980-2015.5) and ScienceDirect (1966-2015.5) databases. Gray studies were identified from the references of the included literature. Pooling of the data was performed and analyzed by RevMan software, version 5.1.

RESULTS

Five case-control trials (CCTs) met the inclusion criteria. There were significant differences in the incidence of heterotopic ossification (HO) between the approaches, but no significant differences were found between the two groups regarding functional outcomes of the hip, general postoperative complications, osteonecrosis of the femoral head or post-traumatic arthritis.

CONCLUSION

The present meta-analysis indicated that the posterior approach decreased the risk of heterotopic ossification compared with the anterior approach for the treatment of Pipkin I and II femoral head fractures. No other complications were related to anterior and posterior approaches. Future high-quality randomized, controlled trials (RCTs) are needed to determine the optimal surgical approach and to predict other postoperative complications.

LEVEL OF EVIDENCE

III.

Subacute complications during recovery from severe traumatic brain injury: frequency and associations with outcome

BACKGROUND

Medical complications after severe traumatic brain injury (S-TBI) may delay or prevent transfer to rehabilitation units and impact on long-term outcome.

OBJECTIVE

Mapping of medical complications in the subacute period after S-TBI and the impact of these complications on 1-year outcome to inform healthcare planning and discussion of prognosis with relatives.

SETTING

Prospective multicentre observational study. Recruitment from 6 neurosurgical centres in Sweden and Iceland.

PARTICIPANTS AND ASSESSMENTS

Patients aged 18-65 years with S-TBI and acute Glasgow Coma Scale 3-8, who were admitted to neurointensive care. Assessment of medical complications 3 weeks and 3 months after injury. Follow-up to 1 year. 114 patients recruited with follow-up at 1 year as follows: 100 assessed, 7 dead and 7 dropped out.

OUTCOME MEASURE

Glasgow Outcome Scale Extended.

RESULTS

68 patients had ≥1 complication 3 weeks after injury. 3 weeks after injury, factors associated with unfavourable outcome at 1 year were: tracheostomy, assisted ventilation, on-going infection, epilepsy and nutrition via nasogastric tube or percutaneous endoscopic gastroscopy (PEG) tube (univariate logistic regression analyses). Multivariate analysis demonstrated that tracheostomy and epilepsy retained significance even after incorporating acute injury severity into the model. 3 months after injury, factors associated with unfavourable outcome were tracheostomy and heterotopic ossification (Fisher's test), infection, hydrocephalus, autonomic instability, PEG feeding and weight loss (univariate logistic regression). PEG feeding and weight loss at 3 months were retained in a multivariate model.

CONCLUSIONS

Subacute complications occurred in two-thirds of patients. Presence of a tracheostomy or epilepsy at 3 weeks, and of PEG feeding and weight loss at 3 months, had robust associations with unfavourable outcome that were incompletely explained by acute injury severity.

Risk factors for the development of heterotopic ossification after acetabular fracture fixation

BACKGROUND

Heterotopic ossification (HO) is a common complication of the operative treatment of acetabular fractures. Although the surgical approach has been shown to correlate with the development of ectopic bone, specific risk factors have not been elucidated.

QUESTIONS/PURPOSES

The purposes of this study were to determine specific risk factors associated with the development of severe HO and the frequency with which patients develop severe HO after acetabular fracture fixation through an isolated Kocher-Langenbeck approach.

METHODS

Using an institutional orthopaedic trauma database at a regional Level I trauma center, patients undergoing open treatment of acetabular fractures during the study period (January 2000 to January 2010) were identified. A review of medical records and imaging studies was performed on 508 patients who were treated by the senior author (MR) through an isolated Kocher-Langenbeck approach. During the study period, the senior author used indomethacin for HO prophylaxis in patients who had ipsilateral femur fracture treated with antegrade reamed medullary nailing or severe local soft tissue injury; 49 (10%) of the patients he treated with the Kocher-Langenbeck approach received prophylaxis, and they were excluded from this study, leaving a total of 459 patients who met inclusion criteria. Of those, 147 (29%) were lost to followup or did not have radiographs both before and at a minimum of 6 weeks (median, 1 week; range, 0-3 weeks), leaving 312 (61% of the patients treated with the Kocher-Langenbeck approach during this time) available for this analysis. Demographic data as well as information related to cause of injury, associated periacetabular findings, other system injuries, and treatment were gathered. Final followup radiographs were assessed for the presence of ectopic bone by two of the authors (TJO, AS) using the modified Brooker classification. Logistic regression was performed to identify possible predictors of development of severe ectopic bone.

RESULTS

The only predictor we identified for the development of severe HO was the need for prolonged mechanical ventilation (odds ratio, 7.1; 95% confidence interval, 2.9-17.3; p=0.001). Injury Severity Score, sex, presence of comminution, femoral head impaction, dislocation, degloving injury, debris in the joint, number of other fractures, and head and chest Abbreviated Injury Score>2 did not correlate with severe HO. Severe HO (Brooker Class III or IV) developed in 38 of 312 patients (12%).

CONCLUSIONS

Patients with prolonged mechanical ventilation might benefit from HO prophylaxis given the increased risk of developing severe HO in this patient population. However, future prospective studies need to be performed to verify this finding given the fact that a considerable number of patients were prophylactically treated in this study.

LEVEL OF EVIDENCE

Level IV, prognosticstudy. See Guidelines for Authors for a complete description of levels of evidence.

Risk factors for the development of heterotopic ossification after knee dislocation

BACKGROUND

Results of treatment for acute knee dislocations and multiligament knee injuries may be influenced by a multitude of patient- and injury-related factors, including neurologic function, vascular status, ipsilateral fractures, and joint stability. The development of heterotopic ossification (HO) may nullify any benefits of reconstruction, because it can cause stiffness and discomfort. Identifying factors associated with HO after knee dislocation may help identify patients who might benefit from prophylaxis.

QUESTIONS/PURPOSES

The purposes of this study were (1) to identify specific risk factors for the development of HO in patients with knee dislocation; and (2) to elucidate the relationship between the presence of absence of HO and postoperative range of motion.

METHODS

Between 2005 and 2010, we performed 101 multiligament reconstructions for patients with knee dislocations, of which 91 (90%) in 91 patients were available for followup at a minimum of 6 months (mean, 18 months; range, 6-44 months), and were reviewed here. AP and lateral radiographs were reviewed for all patients and HO was classified according to the Mills and Tejwani classification system. This knee dislocation cohort was separated into two groups based on the presence or absence of HO for comparison. Using a significance level of p < 0.05 for factors in the univariate analyses, we identified potential variables for a multivariate logistic regression model to identify risk factors predicting development of HO in patients with multiligament knee injuries; multivariate analysis then was performed to mitigate the influence of potentially confounding variables. Thirty patients (34%) developed HO after multiligament knee injury in our series.

RESULTS

Posterior cruciate ligament reconstruction was the only independent predictor of HO that we identified (odds ratio, 6.3; 95% confidence interval, 1.2-34.6). Patients who developed HO were more likely to develop stiff knees and undergo surgery (50%; 15 of 30 patients) versus those without HO (12%; seven of 58 patients) to attempt to restore functional range of motion (p < 0.001).

CONCLUSIONS

HO is a common complication after knee dislocation and can diminish range of motion and cause patients to undergo further surgery. Posterior cruciate ligament reconstruction is an independent risk factor for the development of HO. Strategies to identify risk factors for, and safe prevention of, HO after multiple ligament injury and surgery should be investigated going forward.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Prevalence and risk-factors of neurogenic heterotopic ossification in traumatic spinal cord and traumatic brain injured patients admitted to specialised units in Australia

OBJECTIVES

To identify the prevalence and risk factors in the development of Neurogenic Heterotopic Ossification (NHO) in traumatic brain and spinal cord injured patients admitted to specialised units.

METHODS

An audit protocol was used to gather all clinically relevant data, in specific patient groups, relating to the prevalence of NHO, and was statistically analysed to identify traumatic brain injury (TBI) and traumatic spinal cord injury (TSCI) patients at high risk of developing NHO.

RESULTS

262 TBI and 151 TSCI patients were identified. NHO was diagnosed in 10 and 16 patients with TBI and TSCI, respectively; 18 clinically relevant characteristics were analysed for association with NHO in these patient groups. The only common variables associated with NHO in both neurological conditions were deep vein thrombosis and/or pulmonary emboli (DVT/PE).

CONCLUSIONS

The prevalence of NHO in TBI patients is less than one-third of that found in TSCI patients, ~4% and 11%, respectively. This study also suggests that the risk factors associated with NHO in TBI patients are distinct from those identified as risk factors in TSCI patients.

Incidence and risk factors analysis of heterotopic ossification after cervical disc replacement

BACKGROUND

Cervical disc replacement (CDR) as a substitute for traditional fusion surgery has been widely used in treating degenerative cervical disc diseases. The objectives of this study were to assess the clinical and radiological findings for patients with heterotopic ossification (HO) following CDR and to detect the risk factors of HO after CDR.

METHODS

A total of 125 patients with symptomatic cervical single- or double-level disc diseases, who underwent CDR procedure with Discover prosthesis in Department of Spine Surgery, Changzheng Orthopedics Hospital from March 2009 to March 2011, were enrolled in this retrospective study. Occurrence of HO was defined by the McAfee classification on cervical lateral X-rays in this study. Prosthesis vertebral ratio (PVR) was used to determine the matching degree between the cervical disc prosthesis and cervical vertebra. Logistic regression analyses were performed to determine the risk factors of HO. Variables evaluated for their association with HO occurrence included age, gender, high-intensity signal in spinal cord, preoperative range of motion (ROM), postoperative ROM, operation level number, and PVR.

RESULTS

Mean follow-up time was (26.4±5.8) months. All the patients had significant symptoms and neurological function improvements during the follow-up period. The ROM of the operated segment from the preoperative period to the last follow-up was relatively well maintained. The rate of HO in this cohort of patients, who underwent Discover disc, was 27.92% per surgical level and 24.8% per patient by the last follow-up. There were 19 patients (19.79%) with HO in the single-level group while 12 patients (41.38%) in the double-level group.

CONCLUSIONS

We identified preoperative high-intensity signal in spinal cord, postoperative ROM of surgical level, number of operation level, and PVR as significant risk factors for postoperative HO occurrence.

Direct anterior total hip arthroplasty: complications and early outcome in a series of 300 cases

The direct anterior approach for total hip arthroplasty has gained popularity throughout the last decade. Early reports showed successful results with rapid functional recovery and low dislocation rates. However there is some concern about the high number of complications induced by the technique. The aim of this study was to examine the early radiological outcome and perioperative complications in a consecutive series of 300 total hip arthroplasties performed through a minimal invasive anterior approach with the aid of a positioning table. We observed 9(3%) intra-operative complications : two femoral perforations, 4 calcar fractures and 3 greater trochanter fractures. There were 42 (14%) postoperative complications and 20 (6.7%) patients required a surgical re-intervention. Our major finding was early peri-prosthetic femoral fracture in 5 patients, not noticed during surgery. The dislocation ratio (2 cases, 0.66%) was low. The complication ratio decreased throughout our series, but statistical significance could not be shown (p = 0.26). Surgeons should be aware of the high risk of occult intra-operative fractures when starting with this technique.

Ossification of the ligamentum flavum of the lumbosacral spine in the Polish hospitalized population - a prospective cohort study

AIM

The aim of this study was to assess the prevalence, clinical features and distribution of lumbosacral ossifications of the ligamentum flavum (OLF), using MRI, CT and microCT, in hospitalized Polish patients.

METHODS

Patients were recruited prospectively between January 2011 and January 2013. Patients were further qualified to the study group only if CT or MRI of the lumbosacral region detected OLF. Level of OLF excision was determined by the localization of spinal stenosis. After excision the LF fragments containing OLF were stored in a 4% solution of formaldehyde until microCT assessment.

RESULTS

A total of 184 agreed to take part in the study. In 50 patients (27.2%) OLF were found. Thus, the study group consisted of 17 women (34%) and 33 men, with a mean age of 55.4 ± 17.2 years. OLF occurred more often in men (66%) than in women (34%) (p = 0.0014). The most common site for the localization of OLF in women, as well as in men was the L5/S1 level (60% and 53.3% respectively). The mean volume of OLF was 3.87 ± 5.27 mm3 (4.66 ± 5.71 mm3 vs. 1.27 ± 2.19 mm3, in men and women respectively; p = 0.023). The LF were thickened in 21 (42%) patients. The mean volume of OLF in patients with normal LF was 4.78 ± 5.95 mm3 and in patients with thickened LF 5.33 ± 6.10 mm3 (p = 0.75).

CONCLUSIONS

The prevalence of lumbosacral OLF in the Polish hospitalized population is very high. The most common site of their localization is the L5/S1 level. LF thickening is not associated with OLF formation.

Uncovertebral hypertrophy is a significant risk factor for the occurrence of heterotopic ossification after cervical disc replacement: survivorship analysis of Bryan disc for single-level cervical arthroplasty

OBJECTIVES

The purpose of this study is to investigate the incidence of heterotopic ossification (HO) in the Bryan cervical arthroplasty group and to identify associations between preoperative factors and the development of HO.

METHODS

We performed a retrospective review of clinical and radiological data on patients who underwent single-level cervical arthroplasty with Bryan prosthesis between January 2005 and September 2007. Patients were postoperatively followed-up at 1, 3, 6, 12 months and every year thereafter. The clinical assessment was conducted using Odom's criteria. The presence of HO was evaluated on the basis of X-ray at each time-point according to the McAfee classification. In this study, we focused on survivorship of Bryan prosthesis for single-level arthroplasty. The occurrence of ROM-affecting HO was defined as a functional failure and was used as an endpoint for determining survivorship.

RESULTS

Through the analysis of 19 cases of Bryan disc arthroplasty for cervical radiculopathy and/or myelopathy, we revealed that ROM-affecting HO occurs in as many as 36.8% of cases and found that 37% of patients had ROM-affecting HO within 24 months following surgery. The overall survival time to the occurrence of ROM-affecting HO was 36.4 ± 4.4 months. Survival time of the prosthesis in the patient group without preoperative uncovertebral hypertrophy was significantly longer than that in the patient group with preoperative uncovertebral hypertrophy (47.2 months vs 25.5 months, p = 0.02). Cox regression proportional hazard analysis illustrated that preoperative uncovertebral hypertrophy was determined as a significant risk factor for the occurrence of ROM-affecting HO (hazard ratio = 12.30; 95% confidential interval = 1.10-137.03; p = 0.04).

CONCLUSION

These findings suggest that the condition of the uncovertebral joint must be evaluated in preoperative planning for Bryan cervical arthroplasty.

[Analysis of effectiveness and incidence of heterotopic ossification after single-level Bryan cervical artificial disc replacement]

OBJECTIVE

To evaluate the incidence of heterotopic ossification (HO) after single-level Bryan cervical artificial disc replacement, and to identify the relationship between HO and the effectiveness.

METHODS

The clinical data of 48 patients undergoing single-level Bryan cervical artificial disc replacement between October 2005 and October 2007 were reviewed retrospectively. There were 27 males and 21 females with an average age of 40.5 years (range, 33-51 years), including 8 cases of cervical myelopathy, 27 cases of nerve root cervical spondylosis, and 13 cases of mixed cervical spondylosis with an average disease duration of 10.3 months (range, 2-14 months). The involved segments included C3,4 in 3 cases, C4,5 in 6 cases, C5,6 in 30 cases, and C6,7 in 9 cases. The outcomes were evaluated using Visual Analogue Scale (VAS) score, the neck disability index (NDI), and cervical range of motion (ROM). According to patients with or without HO, 48 patients were divided into 2 groups (HO group and no HO group). VAS score, NDI, and cervical ROM were compared between 2 groups at 1, 2, 3, and 4 years after operation.

RESULTS

No severe complication occurred during and after operation in all patients. Forty-eight patients were followed up 48-72 months (mean, 56.6 months). VAS score and NDI were significantly improved when compared with preoperative values at all time points (P < 0.05); except at 3 days after operation, no significant difference was found in cervical ROM at the other time points when compared with preoperation (P > 0.05). Thirteen patients (27.08%) had HO at 4 years after operation, including 8 cases of grade 1, 3 cases of grade 2, and 2 cases of grade 3. There was no significant difference in VAS score, NDI, and cervical ROM between 2 groups at 1, 2, 3, and 4 years (P > 0.05).

CONCLUSION

The incidence of HO after single-level Bryan cervical artificial disc replacement is relatively high. However, HO has no effect on the cervical ROM and the effectiveness.