Heterotopic ossification in total hip arthroplasty. The influence of the approach

Heterotopic Ossification After Shoulder Arthroplasty: A Systematic Review

INTRODUCTION

Shoulder arthroplasty is increasing in incidence over time. One potential complication that is not well studied following shoulder arthroplasty is heterotopic ossification (HO), the abnormal growth of extraskeletal bone in soft tissue. HO has been described as a complication in total hip arthroplasty literature but less described in the setting of shoulder arthroplasty. The aim of this systematic review is to present available evidence regarding the incidence, risk factors, and potential management of HO after shoulder arthroplasty.

METHODS

A systematic search was conducted in June 2023 using Pubmed, Embase, and Ovid Medline databases to retrieve all relevant studies evaluating the occurrence of HO after shoulder arthroplasty. The search was done in duplicate, and a quality assessment of all studies was included.

RESULTS

A total of 170 studies were retrieved, of which 6 were included, involving 1,028 patients undergoing shoulder arthroplasty with 1,038 operated shoulders. HO developed postoperatively in 28% of the included shoulders and was symptomatic in 12% with most cases occurring in shoulders that developed osteoarthritis and cuff tear arthropathy. Men appear to have an increased risk of developing HO post shoulder arthroplasty. Fewer than 2% of HO shoulders went on to have revision surgery, and no notable differences were observed in the postoperative mean elevation and external rotation angles of non-HO and HO shoulders. In addition, no reported benefit of the use of nonsteroidal anti-inflammatory drugs was found against the formation of HO after shoulder arthroplasty.

CONCLUSION

HO occurs in 28% of shoulder arthroplasties in our review. Most of these were asymptomatic in the reviewed articles. Male patients and revision surgery with osteoarthritis and cuff tear arthroplasty seem to be at higher risk of developing HO post shoulder arthroplasty. Nonsteroidal anti-inflammatory drugs seem to not prevent the development of HO after shoulder arthroplasty; yet, future studies are needed to verify this claim.

LEVEL OF EVIDENCE

Level III; Systematic Review.

Risk Factors for the Development of Heterotopic Ossification Following Acetabular Fractures: A Systematic Review

BACKGROUND

Heterotopic ossification (HO) following acetabular fractures is a common complication that may affect clinical outcomes. However, the effects of prophylactic treatment with nonsteroidal anti-inflammatory drugs or radiation therapy remain controversial. While several factors have been related to the development of HO, there is considerable uncertainty regarding their importance or effect size in the setting of acetabular surgery. Therefore, this systematic review aims to summarize the risk factors for HO following the operative fixation of acetabular fractures and clarify their interrelationships.

METHODS

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, PubMed, MEDLINE, Embase, and CINAHL databases were searched from inception to February 2021. Studies that assessed factors related to HO development among patients with operatively repaired acetabular fractures were included. Outcomes were risk factors and their effect size (p values, odds ratios, and 95% confidence intervals).

RESULTS

Twenty-five studies and 1 conference abstract with a total of 3,940 patients were included. The following risk factors for HO were identified. Patient factors were increased body mass index, male sex, and increased age. Injury factors were intensive care unit (ICU) admission and length of stay, non-ICU hospitalization for >10 days, the need for mechanical ventilation for ≥2 days, abdominal and/or chest injuries, the number and type of associated fractures, traumatic brain injuries, T-type acetabular fractures, pelvic ring injuries, and hip dislocation. Care factors were a delay to surgery, extensile and posterior surgical approaches to the hip, trochanteric osteotomy, postoperative step-off of >3 mm, and a delay to prophylaxis following injury or surgery. Ethnicity, Injury Severity Score, cause of the fracture, femoral head injuries, degloving injuries, comminution, intra-articular debris, the type of bone void filler, gluteus minimus muscle preservation, prolonged operative time, and intraoperative patient position were not risk factors for developing HO.

CONCLUSIONS

HO following operative fixation of acetabular fractures is not uncommon, with severe-grade HO associated with substantial disability. Careful consideration of the risk factor effect sizes and interdependencies could aid physicians in identifying patients at risk for developing HO and guide their prophylactic management. The results of this study could establish a framework for future studies.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Heterotopic ossification in primary total hip arthroplasty using the posterolateral compared to the direct lateral approach

PURPOSE

Total hip arthroplasty (THA) is a successful procedure. However, in time, heterotopic ossification (HO) can form due to, amongst others, soft tissue damage. This can lead to pain and impairment. This study compares the formations of HO between patients who underwent either THA with the posterolateral approach (PA) or with the direct lateral approach (DLA). Our hypothesis is that patients who underwent THA with a PA form less HO compared to THA patients who underwent DLA.

METHODS

In this prospective cohort study, 296 consecutive patients were included who underwent THA. A total of 127 patients underwent THA with the PA and 169 with the DLA. This was dependent on the surgeon's preference and experience. More than 95% of patients had primary osteoarthritis as the primary diagnosis. Clinical outcomes were scored using the Numeric Rating Scale (NRS) and Harris Hip Score (HHS), radiological HO were scored using the Brooker classification. Follow-up was performed at 1 and 6 years postoperatively.

RESULTS

Two hundred and fifty-eight patients (87%) completed the 6-year follow-up. HO formation occurred more in patients who underwent DLA, compared to PA (43(30%) vs. 21(18%), p = 0.024) after 6 years. However, the presence of severe HO (Brooker 3-4) was equal between the DLA and PA (7 vs. 5, p = 0.551). After 6 years the HHS and NRS for patient satisfaction were statistically significant higher after the PA (95.2 and 8.9, respectively) compared to the DLA (91.6 and 8.5, respectively) (p < 0.001 and p = 0.003, respectively). The NRS for load pain was statistically significant lower in the PA group (0.5) compared to the DLA group (1.2) (p = 0.004). The NRS for rest pain was equal: 0.3 in the PA group and 0.5 in the DLA group.

CONCLUSION

THA with the PA causes less HO formation than the DLA.

TRIAL REGISTRATION

Registrated as HipVit trial, NL 32832.100.10, R-10.17D/HIPVIT 1. Central Commission Human-Related research (CCMO) Registry.

Incidence of Heterotopic Ossification in Anterior Based Muscle Sparing Total Hip Arthroplasty: A Retrospective Radiographic Review

Heterotopic ossification (HO) is a known complication following total hip arthroplasty (THA). The anterior based muscle sparing (ABMS) approach is a variation of a direct anterior approach through the Watson–Jones interval. To date, few studies have evaluated HO formation following this surgery. We examine the incidence of HO in a consecutive series of THAs using this approach by three different surgeons at a single center. Standard preoperative radiographs were examined to determine the type of degenerative arthritis, and follow-up radiographs a minimum of 9 months after surgery were evaluated for the presence and classification of HO. The overall incidence of HO after ABMS THA in this study was 86/233, or 36.9%, which is comparable to recent studies of direct anterior and traditional approaches. Class III and IV HO is uncommon in ABMS surgery (3.9% and 1.3%, respectively) and appears to decrease with increased surgical experience with this technique.

Early results of displaced femoral neck fragility fractures treated with supercapsular percutaneous-assisted total hip arthroplasty

Background

Total hip arthroplasty (THA) is the preferred treatment for displaced femoral neck fractures in select patients, although dislocation remains a concern. In some studies, the supercapsular percutaneously assisted (SuperPATH) approach has demonstrated early mobilization, short hospital stay, and low dislocation rates in primary THA, but there are little data on its use for fractures. This study describes the perioperative outcomes and early dislocation rate of SuperPATH THA for displaced femoral neck fragility fractures.

Methods

A retrospective review was performed of previous ambulatory patients with a displaced femoral neck fragility fracture treated with THA using the SuperPATH approach. Demographic data, time to ambulation, length of stay, and in-hospital complications during the hospital stay and follow-up period were recorded. Phone interviews were conducted to check for dislocations 1 year after surgery.

Results

Thirty-seven consecutive patients were included with an average age of 75.0 years. Hospital stay averaged 5.5 days, and patients were discharged on average postoperative day 3.6. About 83.8% of patients were ambulatory by postoperative day 1, and 94.6% ambulatory before discharge. Twenty-seven percent of patients were discharged home, 46% to inpatient rehabilitation, 24% to skilled nursing facility, and 1 patient to hospice. At follow-up, there was no symptomatic heterotopic ossification and no infections. Thirty-two patients were available for telephone interviews at 1 year, with no dislocations reported.

Conclusions

In this small cohort, the SuperPATH approach for THA appears to be safe and effective for use in femoral neck fragility fractures, resulting in early ambulation and a low dislocation rate.

Heterotopic ossification after total elbow arthroplasty: a systematic review

BACKGROUND

Heterotopic ossification (HO) is a known complication that can arise after total elbow arthroplasty (TEA). In most cases, it is asymptomatic; however, in some patients, it can limit range of motion and lead to poor outcomes. The objective of this review was to assess and report the incidence, risk factors, prophylaxis, and management of HO after TEA.

METHODS

A systematic search was conducted using MEDLINE, Embase, and PubMed to retrieve all relevant studies evaluating the occurrence of HO after TEA. The search was performed in duplicate, and a quality assessment of all included studies was performed.

RESULTS

A total of 1907 studies were retrieved, of which 45 were included involving 2256 TEA patients. HO was radiographically present in 10% of patients and was symptomatic in 3%. Fewer than 1% of patients went on to undergo surgical excision of HO, with outcomes after surgery reported as good or excellent as assessed by range of motion and the Mayo Elbow Performance Score. HO appears more likely to develop in patients undergoing TEA because of ankylosis, primary osteoarthritis, and distal humeral fractures. Surgical intervention is more likely to be required in patients in whom HO develops after TEA performed for ankylosis and post-traumatic osteoarthritis.

CONCLUSION

HO is an uncommon complication after TEA, with most patients in whom HO develops being asymptomatic and requiring no surgical management. Routine HO prophylaxis for TEA is not supported by the literature. The effectiveness of prophylaxis in high-risk patients is uncertain, and future studies are required to clarify its usefulness.

Heterotopic Ossification in Primary Total Hip Arthroplasty: which is the role of drainage?

Background and aim of the work: The Heterotopic Ossification (HO) is a common complication following Total Hip Arthroplasty (THA). Although there is no concordance in Literature regarding the etiopathogenic mechanism, various HO risk factors have been recognized, both related to the patient and associated with the surgical procedureLiterature does not consider the use of intra-articular drainage as a possible risk factor. Our hypothesis is that this item can contribute to the development of HO. Materials and Methods: 425 implants of hip arthroplasty performed between 2014 and 2017 at the Ortopedic Clinic of Udine were included in the study. No patient performed pre-operative or post-operative anti-HO prophylaxis during follow-up. Radiographs of preoperative and postoperative at 1 year were analyzed according to the Brooker Classification.Results: The incidence of HO in patients with intra-articular drainage is 24.6%, while the incidence of HO in patients without intra-articular drainage is 15.3%, with a statistically significant difference. Conclusions: The data obtained suggest to consider the use of intra-articular drainage as a possible intra-operative risk factor for HO. This is a retrospective cohort study, so we need more studies and more robust experimental designs to confirm these results. (www.actabiomedica.it)

Total hip arthroplasty in patients affected by poliomyelitis

Aims

The aims of this study were to determine the clinical and radiographic outcomes, implant survivorship, and complications of patients with a history of poliomyelitis undergoing total hip arthroplasty (THA) in affected limbs and unaffected limbs of this same population.

Patients and Methods

A retrospective review identified 51 patients (27 male and 24 female, 59 hips) with a mean age of 66 years (38 to 88) and with the history of poliomyelitis who underwent THA for degenerative arthritis between 1970 and 2012. Immigrant status, clinical outcomes, radiographic results, implant survival, and complications were recorded.

Results

In all, 32 THAs (63%) were performed on an affected limb, while 27 (37%) were performed on an unaffected limb. The overall ten-year survivorship free from aseptic loosening, any revision, or any reoperation were 91% (95% CI 0.76 to 0.99), 91% (95% CI 0.64 to 0.97) and 87% (95% CI 0.61 to 0.95), respectively. There were no revisions for prosthetic joint infection. There were no significant differences in any of the above parameters if THA was on the affected or unaffected control limbs.

Conclusion

Patients with a history of poliomyelitis who undergo THA on the affected or unaffected limbs have similar results with overall survivorship and complication rates to those reported results in patients undergoing THA for osteoarthritis. At long-term follow-up, previous clinical concerns about increased hip instability due to post-polio abductor weakness were not observed. Cite this article: Bone Joint J 2018;100-B:733–9.

Heterotopic Ossification in Primary Total Hip Arthroplasty Using the Direct Anterior vs Direct Lateral Approach

BACKGROUND

The formation and severity of heterotopic ossification (HO) may be influenced by type of surgical approach. Our hypothesis was that because of differences in soft tissue dissection, differences exist in HO formation in primary total hip arthroplasty using direct anterior (DA) vs direct lateral (DL) approach.

METHODS

A total of 1482 consecutive patients with DL (736) or DA (746) approach and similar perioperative care protocol during 2009-2011 were retrospectively studied. No patient received prophylactic radiotherapy. Preoperative and 6-month postoperative radiographs were reviewed based on Brooker classification.

RESULTS

The incidence of overall HO was higher in DL (36.1%) vs DA group (19.4%, P < .001) but high-grade HO (Brooker ≥3) was not significantly different among the groups (3.9% for DL and 3.0% for DA groups). No patient required further surgery for HO resection.

CONCLUSION

The type of approach (DA vs DL) did not seem to have a major influence on the short-term incidence of high-grade HO based on this radiographic analysis.

Incidence of heterotopic ossification in minimally invasive short-stem THA using the modified anterolateral approach

INTRODUCTION

Heterotopic ossification (HO) is known to be a common complication after total hip arthroplasty (THA). The minimal invasive (MIS) modified anterolateral approach has become popular in combination with a short stem. We analysed the incidence of HO following short-stem THA using this approach in combination with a postoperative administration of nonsteroidal anti-inflammatory drugs (NSAIDs).

MATERIALS AND METHODS

216 short stems were implanted in 162 patients. NSAIDs were administered for 2 weeks after surgery in 154 patients (95.1%). Standardised pre- and postoperative radiographic imaging was done at 2-year follow-up. HO was analysed according to the Brooker classification. Influence of age, gender, body mass index (BMI), and blood transfusion were analysed. Harris Hip Score (HHS) and visual analogue scale (VAS) of satisfaction were assessed. Operation time and blood-transfusion rate was documented. Short-term gastrointestinal side effects were recorded.

RESULTS

The overall incidence of HO was 7.8% (16 cases). HO Brooker type 3 and 4 occurred in only 1 case (0.5%). No correlation with age, gender or BMI was revealed. HHS improved largely from 45.8 (SD 15.9) before surgery to 98.1 (SD 4.7) after a minimum of 2 years. At that point VAS satisfaction was 9.7 (SD 0.9). Mean operative time was 45.8 minutes (SD 18.7). 12 patients (7.4%) received at least 1 blood-transfusion. Gastrointestinal side effects occurred in 13 of 154 patients (8.4%).

CONCLUSIONS

The combination of short-stem THA, the MIS modified anterolateral approach and a postoperative application of NSAIDs resulted in the effective prevention of HO and excellent clinical results.

Heterotopic ossification after hemiarthroplasty of the hip - A comparison of three common approaches

OBJECTIVE

Heterotopic ossification (HO) about the hip after total hip arthroplasty and internal fixation of the hip, pelvis, and acetabulum has been linked to surgical approach. However, no study has investigated surgical approach and HO in patients undergoing hemiarthroplasty. We therefore aimed to explore the influence of operative approach in patients undergoing hemiarthroplasty.

METHODS

Through a retrospective case series at an Urban level I trauma center, we found 80 patients over the age of 60 undergoing hemiarthroplasty for femoral neck fractures from 2000 to 2009. Patient charts, operative notes, and radiographs were reviewed for demographics, operative approach (anterior: A, anterior-lateral: AL, posterior: P), and any development of HO. Fisher's exact test compared rates of HO among the three approaches. Student's t-tests compared Brooker Classification levels of HO among the approaches.

RESULTS

82 hemiarthroplasties (26 A, 32 AL, 24 P) were included for analysis. 22 patients (27%) had HO. There was no significant difference in the development of HO based upon surgical approach: A: 19% (n = 5); AL: 34% (n = 11); P: 25% (n = 6). There was a significant difference in the grade of HO based on Brooker Classification (BC) with the posterior approach resulting in significantly lower grade of HO: A (BC: 2.60); AL (BC: 2.64); P (BC: 1.50) (p = 0.012).

CONCLUSIONS

Our data is the first to evaluate surgical approach and HO in patients with hemiarthroplasty. Patients have a significant risk of developing higher grade HO based on surgical approach (A or AL). Orthopedists should be mindful of these risks when considering A or AL approaches.

The fate of heterotopic ossification associated with cervical artificial disc replacement

STUDY DESIGN

This is a retrospective study designed to observe the progressive appearance of heterotopic ossification (HO) after cervical artificial disc replacement (ADR).

OBJECTIVE

To investigate the development and progressive appearance of HO at cervical ADR sites.

SUMMARY OF BACKGROUND DATA

HO is defined as the formation of bone outside the skeletal system. The reported HO occurrence rate in cervical ADR is high and varied. However, the long-term outcome of HO has not been investigated by longitudinal observation.

METHODS

Sixty-seven consecutive patients undergoing cervical ADR with complete radiological data were selected for this study. Cervical lateral radiographs and computed tomographic scans were obtained during the first and second studies and compared to identify any transitions in HO. The change in the HO occurrence rate, distribution, and grade of HO were investigated at 2 follow-up time points (18.6 and 36.9 mo postsurgery). To compare the amount of progression between participants' HO rates, the relative increase rate was calculated.

RESULTS

HO showed a progressive pattern. The grade of HO was redistributed toward a higher grade in the second study. The number of patients with HO had increased from 31 (46.3%) to 43 (64.2%) of 67 patients at the final follow-up with statistically significant difference (P = 0.037). Twenty-six patients (39.4%) had progressed toward a higher HO grade, but 41 patients (60.6%) showed no change in HO grade. The overall RI rate and the weighted RI rate were 39.4% and 48.7%, respectively.

CONCLUSION

This study found that HO has a progressive appearance and determined that HO is not a static but rather a dynamic phenomenon with progressive pattern. Future elucidation of the environmental factors affecting HO, including genetic or proteomic analyses, is recommended.

LEVEL OF EVIDENCE

3.

Incidence of heterotopic ossification in direct anterior total hip arthroplasty: a retrospective radiographic review

Heterotopic ossification (HO) is a complication following total hip arthroplasty (THA) with traditional approaches. The direct anterior approach (DAA) has become a popular approach for THA; however, no study has evaluated HO formation following DAA THA. We examined the incidence of HO in a consecutive series of THA using the DAA in two separate hospitals. Standard preoperative radiographs were examined to determine the type of degenerative arthritis, and follow-up radiographs of at least 6 months after surgery were evaluated for the presence and classification of HO. The overall incidence of HO after DAA THA in this study was 98/236, or 41.5%, which falls within the reported range from recent studies involving more traditional approaches to the hip.

Incidence of Heterotopic Ossification in Patients Receiving Radiation Therapy following Total Hip Arthroplasty

Heterotopic ossification (HO) is a frequent complication of hip surgery. In this study the incidence of HO is analyzed in high risk patients who received radiation therapy (RT) after total hip replacement (THA) with regular and miniposterolateral hip approach. Two hundred and thirty five high risk patients received a single dose of 700 rad after THA. The incidence of HO was 15.7%. The incidence of HO in the high risk subgroup with the miniincision was lower (5.7%) but not significantly different (P=0.230). Hypertrophic osteoarthritis was demonstrated to be the consistent predisposing factor for HO formation (P=0.005).

The predisposing factors for the heterotopic ossification after cervical artificial disc replacement

BACKGROUND CONTEXT

Heterotopic ossification (HO) is defined as a formation of bone outside the skeletal system. The reported HO occurrence rate in cervical artificial disc replacement (ADR) is unexpectedly high and is known to vary. However, the predisposing factors for HO in cervical ADR have not yet been elucidated.

PURPOSE

Investigation of the predisposing factors of HO in cervical arthroplasty and the relationship between degeneration of the cervical spine and HO occurrence.

STUDY DESIGN

Retrospective study to discover predisposing factors of HO in cervical arthroplasty.

PATIENT SAMPLE

A total of 170 patients who underwent cervical ADR were enrolled including full follow-up clinical and radiologic data.

OUTCOME MEASURES

Radiologic outcomes were assessed by identification of HOs according to McAfee's classifications.

METHODS

This study enrolled a total of 170 patients who underwent cervical ADR. Pre-existing degenerative change included anterior or posterior osteophytes, ossification of the anterior longitudinal ligament, posterior longitudinal ligament, or ligamentum nuchae. The relationships between basic patient data, pre-existing degenerative change, and HO were investigated using linear logistic regression analysis.

RESULTS

Among all 170 patients, HO was found in 69 patients (40.6%). Among the postulated predisposing factors, only male gender and artificial disc device type were shown to be statistically significant. Unexpectedly, preoperative degenerative changes in the cervical spine exerted no significant influence on the occurrence of HOs. The odds ratio of male gender compared with female gender was 2.117. With regard to device type, the odds ratios of Mobi-C (LDR medical, Troyes, France) and ProDisc-C (Synthes, Inc., West Chester, PA, USA) were 5.262 and 7.449, respectively, compared with the Bryan disc.

CONCLUSIONS

Definite differences in occurrence rate according to the gender of patients and the prosthesis type were identified in this study. Moreover, factors indefinably expected to influence HO in the past were not shown to be risk factors thereof, the results of which may be meaningful to future studies.

Risk factors for heterotopic ossification in primary total hip arthroplasty

Heterotopic ossification (HO) is a recognised complication of total hip arthroplasty (THA). This study aims to correlate demographics, surgical approach and type of arthroplasty to the incidence of HO in an attempt to quantify patient risk. A total of 920 primary THAs in 893 patients were performed between 2006 and 2008 in a single arthroplasty centre. Radiographic evaluation was conducted and all cases of HO were classified using the Brooker classification. Age, sex, arthroplasty type and surgical approach were all considered as variables. Arthroplasty type was classified into four groups; total cemented (TC), total uncemented (TU), hybrid (H) and reverse hybrid (RH). Two-level logistic regression analysis was conducted. The overall incidence of HO was 24%. Male sex [OR=3.57, 95% CI (1.79-7.10); p=0.001], lateral approach [OR=2.47, (95% CI 1.23-4.95); p=0.001] and total cemented implants [OR=3.14, (95%CI 1.37-7.23); p=0.007] were significantly associated with HO. The intra-class correlation coefficient was 0.52 [95% CI (0.21, 0.81); p=0.004], demonstrating that patients with previous HO to one THA were very likely to suffer HO in subsequent THA. The results demonstrate very large effects for sex, surgical approach, and implant type on HO incidence. This raises a three arm hypotheses that reaming of the femoral canal for the insertion of cemented implants contaminates the surgical field with bone marrow increasing the risk of HO, whereas modern cementless implants generally employ impaction broaching. In addition surgical insult to the hip abductors during exposure, particularly in males due to higher muscle mass, may also predispose to HO.

Bone mineral density is not related to heterotopic ossification after total hip arthroplasty

PURPOSE

Heterotopic ossification (HO) after total hip arthroplasty (THA) is a frequent complication that compromises the success of this procedure; however, its precise pathogenesis is unknown. Patient-related risk factors have previously been investigated to predict patients likely to have HO. In this study, we compared bone mineral density (BMD) between patients with and without HO after THA.

METHODS

We measured BMD of the lumbar spine, radius, and calcaneus using dual-energy X-ray absorptiometry in 98 females who were scheduled to undergo THA. Radiographs were graded for the presence of HO according to the criteria of Brooker at a minimum follow-up of two years following THA. BMD were compared between those with HO and those without.

RESULTS

In total, HO was observed in 20 of 98 hips. There were no significant differences in age, height, weight, body mass index, and pre-operative total hip score between the HO and non-HO groups. No significant difference was observed in BMD of the lumbar spine, distal radius, mid-radius, and calcaneus between the two groups.

CONCLUSIONS

Our findings suggest that generalized BMD is not related to the occurrence of HO after THA in women.

[Heterotopic ossifications in total hip arthroplasty: prophylaxis and therapy]

Heterotopic ossification (HO) is a frequent and occasionally severe complication after total hip arthroplasty. Clinical symptoms of this benign abnormal bone formation are loss of mobility and local pain. The etiology and pathomechanisms are not yet completely understood. Overexpression of bone morphogenetic proteins and dysregulation of prostaglandin metabolism seem to be relevant. Medication with non-steroidal anti-inflammatory drugs (NSAIDs) and perioperative single dose radiotherapy are used for prophylaxis, whereby radiotherapy should only be performed in patients with a history of HO or additionally after resection of HO. From currently available data selective cyclooxygenase-2 inhibitors seem to have a preventive efficacy equal to the classical NSAIDs diclofenac and indometacin. This work discusses current knowledge about the pathophysiology, risk factors and the clinical approach for prevention and treatment of HO.

Does a plastic drape reduce incidence of heterotopic ossification after hip resurfacing?

BACKGROUND

High rates of heterotopic ossification have been associated with hip resurfacing as compared to THA. Bone debris from femoral head reamings is cited as one of the risk factors linked to increased rates of heterotopic ossification.

QUESTIONS/PURPOSES

We therefore asked whether (1) the incidence of heterotopic ossification differed with and without the use of a plastic drape used to collect bone debris and (2) any of a number of variables (age, gender, diagnosis, previous hip surgery, operative time, and blood loss) related to the occurrence of HO.

METHODS

We retrospectively reviewed 136 hip resurfacings performed using one of two techniques: Group 1 contained 64 hip resurfacings performed using a sterile drape around the femoral neck while reaming the femoral head to collect bone debris; Group 2 contained 72 hip resurfacings carried out with manually removing bone debris and utilizing a pulse lavage. Data were collected with respect to diagnosis, gender, previous surgery, postoperative complications, operative time, and blood loss to rule out confounding variables. The amount of heterotopic ossification was measured radiographically in hips after undergoing resurfacing arthroplasty. The minimum followup was 6 months (mean, 15 months; range, 6-27 months).

RESULTS

No patient had heterotopic ossification of clinical importance and none had resection of the heterotopic ossification. Group 1 had a lower overall incidence of minor heterotopic ossification (32%) than Group 2 (58%). Risk factors linked to heterotopic ossification include male gender and operative time.

CONCLUSIONS

The use of a plastic drape to collect bone debris from femoral head reamings decreased the incidence of heterotopic ossification in resurfacing arthroplasty of the hip.

The predictive power of preoperative hip range of motion for the development of heterotopic ossification

Postoperative development of heterotopic ossification can compromise the success of total hip arthroplasty (THA). Heterotopic ossification has been associated with decreased postoperative hip range of motion (ROM), potentially leading to poor patient satisfaction with outcome. Many risk factors predisposing to heterotopic ossification have been discussed in the literature, including sex, age, operative time, surgical approach, and preoperative function. The goal of this study was to examine if preoperative ROM is a risk factor for the development of severe heterotopic ossification after THA, and the impact of severe heterotopic ossification formation on the gain in ROM following THA. In a retrospective study of a single surgeon's 20-year experience, all patients who developed type III heterotopic ossification after THA were evaluated for hip ROM preoperatively and at 1-year follow-up. Total ROM was classified according to the modified Merle d'Aubigne score, and Harris Hip Scores were calculated. A statistically significant difference was found in preoperative external rotation in the study group compared to the control group (P<.001). At 1 year postoperatively, hip ROM differences were significant in external rotation (P<.001), internal rotation (P<.001), and abduction (P<.05). The modified Merle d'Aubigne score was significantly different between the groups (P<.001). Although many factors have been shown to influence the development of heterotopic ossification following THA, we found that a decrease in preoperative external rotation may point to an increased risk. Surgeons should consider this data when considering the use of prophylactic treatment to avoid the development of heterotopic ossification.

Heterotopic ossification after total hip arthroplasty: our experience

Heterotopic ossification is a condition characterized by the presence of mature lamellar bone and often bone marrow in soft tissues surrounding a major joint. It represents a common complication after total hip arthroplasty (THA). The etiology and predisposing factors are not completely known, but some authors reported that the implant of a non-cemented prosthesis seems to be associated with a greater incidence of HO. Two hundred and two non-cemented total hip arthroplasties were performed between October 1997 and February 2002. The mean age was 70.2 years. The average follow-up for 181 hips included in the study was 96 months (range, 72-120 months). A standard lateral approach (Hardinge) was performed for the implant of a non-cemented femoral component and a non-cemented acetabular component. Radiographs were done before and after surgery, at 1, 4 and 12 months postop, then every year. The incidence of HO was assessed in the antero-posterior view at each interval and graded according to Brooker classification. Out of 181 implants, HO was observed in 52 hips (28,7%). Heterotopic bone was graded as class I in 32 (17.7%) hips, class II in 14 (7.73%) hips, class III in 6 (3,3%) hips and class IV in none (0%). The mean preoperative Harris hip score was 48; at the last follow-up, the mean postoperative score was preoperatively to a mean of 89 points (range, 76-97 points) in HO Hip and of 91 points (range, 78-100 points) in the other Hip. In our experience, non-cemented THA led to a higher incidence of class I and II HO according to Brooker Classification, the incidence of HO is comparable to the rates reported in recent studies about the HO finding after a non-cemented THA, the importance of clinical symptoms in the presence of HO is very low.

Aspirin decreases the prevalence and severity of heterotopic ossification after 1-stage bilateral total hip arthroplasty for osteoarthrosis

Heterotopic ossification (HO) is a frequent complication after total hip arthroplasty (THA). We retrospectively evaluated the prevalence and severity of HO in patients with osteoarthrosis who underwent 1-stage bilateral THA (OSBTHA) and compared those who received aspirin with those who received Coumadin for postoperative chemothromboprophylaxis. The aspirin group consisted of 66 patients (132 hips), with a mean age of 64 years (SD, 8.5). The Coumadin group consisted of 67 patients (134 hips), with a mean age of 60 years (SD, 10.2). Overall, HO was detected in 124 hips (46.6%). There were 43 hips (32.5%) with HO in the aspirin group and 81 (60.4%) in the Coumadin group (P < .00005). Aspirin significantly decreases the prevalence and severity of HO in comparison to Coumadin after OSBTHA.

Incidence of heterotopic ossification after hip resurfacing

BACKGROUND

Heterotopic ossification has been noted around total hip arthoplasty in numerous studies. With hip resurfacing growing in popularity, we have prospectively evaluated the incidence in a cohort undergoing hip resurfacing.

METHODS

Two hundred and twenty consecutive hip-resurfacing procedures were prospectively reviewed at a minimum of 2 years follow up to assess the incidence of heterotopic ossification and its effect on function and clinical outcome. We also reviewed the preoperative diagnosis, age, sex and previous surgery.

RESULTS

The overall percentage of heterotopic ossification was 58.63%. The incidence of Brooker 1 was 37.27%, Brooker 2 was 13.18% and Brooker 3 was 8.18%. Male osteoarthritis had the highest incidence of heterotopic bone formation (HBF). Three men underwent excision of heterotopic bone, two for pain and stiffness and one for decreased range of movement. Both anteroposterior and lateral radiographs were reviewed for evidence of HBF. In all, 12.7% had no evidence of HBF in the first view but clearly had in the second view.

CONCLUSIONS

Overall, we found no evidence that HBF affected the clinical or functional outcome of the hip resurfacing at a mean of 3 years follow up. However, in light of the high incidence of HBF seen in a yet unproven long-term prosthesis, we conclude that the Cochrane database recommendations with regard to prophylaxis should be implemented.

Effects of heterotopic bone formation on outcome after hip arthroplasty

BACKGROUND

Heterotopic bone formation (HBF) is well established as a frequent complication of major hip surgery, but its importance as a cause of impaired postoperative outcome is uncertain.

METHODS

A systematic overview of all studies that reported the association of HBF with the risk of impaired range of movement, pain or poor function, late after hip arthroplasty.

RESULTS

A computer-based search identified 37 relevant studies that included 10,826 individuals. There were 30 studies (8305 participants) that assessed the association between HBF and range of movement, 14 studies (7420 participants) that assessed the association between HBF and pain and 16 studies (5918 participants) that assessed the association between HBF and function. Overall, there was a clear positive association of HBF with the risk of an impaired range of movement at the hip joint and with the risk of a poor functional outcome. The association of HBF with pain was unclear. There was evidence of effects of mild-to-moderate HBF on the postoperative range of movement.

CONCLUSIONS

These results suggest that mild-to-moderate HBF, not just severe HBF, can influence outcome after major hip surgery. HBF may therefore be a more frequent cause of postoperative symptomatology than is generally believed. It is possible that effective prophylactic regimens will improve outcomes in large numbers of patients.

Comparison of complications after transtrochanteric and posterolateral approaches for primary total hip arthroplasty

For this study, 100 total hip arthroplasties (THAs) in a transtrochanteric approach group and 100 THAs in a posterolateral approach group were performed at one university hospital by a single, experienced surgeon. These THAs were then followed up for a minimum of 2 years to determine the incidence of postoperative complications. In our study, patients undergoing primary THA by the posterolateral approach were 18.4 times more likely to be complication free than patients in whom the transtrochanteric approach was used. This benefit, combined with a shortened surgical time, decreased blood loss, and technical ease, shows the advantages of the posterolateral approach for THA.

Heterotopic ossification after hip and knee arthroplasty: risk factors, prevention, and treatment

Symptomatic heterotopic ossification (HO) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is relatively rare. Patients at high risk for developing HO after THA include men with bilateral hypertrophic osteoarthritis, patients with a history of HO in either hip, and patients with posttraumatic arthritis characterized by hypertrophic osteophytosis. Patients at moderate risk are those with ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis, Paget's disease, or unilateral hypertrophic osteoarthritis. Patients at high risk for developing HO after TKA include those with limited postoperative knee flexion, increased lumbar bone mineral density, hypertrophic arthrosis, excessive periosteal trauma and/or notching of the anterior femur, and those who require forced manipulation after TKA. Preoperative radiation is effective for preventing HO after THA, as are post-operative prophylactic drug regimens and single-dose radiation treatments. Recurrence of HO after surgical excision should be expected unless prophylaxis is administered. Prophylactic measures against HO after THA and TKA should be administered before the fifth postoperative day, optimally within 24 to 48 hours.

Incidence of heterotopic bone formation after major hip surgery

BACKGROUND

Heterotopic bone formation is a well-established complication of major hip surgery, but traditional reviews of the published literature may have underestimated its frequency.

METHODS

A systematic overview of all the relevant studies was performed to determine reliably the incidence of any heterotopic bone formation and the incidence of each Brooker equivalent grade. Separate estimates were made for patients with total hip replacement and patients with acetabular fracture repair.

RESULTS

A computer-based search identified 218 studies with data on the incidence of heterotopic bone formation after either hip replacement or acetabular fracture repair. These studies included data from an estimated 59 121 operated hips among patients that received total hip replacement and an estimated 998 hips among patients that underwent acetabular fracture repair. In these studies, the incidence of any heterotopic bone formation was 43% after total hip replacement and 51% after acetabular fracture repair. The incidence of severe heterotopic bone formation was 9% and 19%, respectively.

CONCLUSIONS

These results suggest that heterotopic bone formation occurs more frequently after total hip replacement than is generally believed. It is possible that heterotopic bone formation is a more important cause of postoperative disability than has previously been recognized and that effective prophylactic regimens might improve outcome in substantial numbers of patients.

Outcomes of surgical management of total HIP replacement in patients aged 65 years and older: cemented versus cementless femoral components and lateral or anterolateral versus posterior anatomical approach

This observational study compared the outcomes of 271 cases of hip osteoarthritis receiving primary total hip replacement (patients 65 years of age and older) from numerous surgeons in 12 Baltimore region hospitals from 1991-1993. The independent variables studied were: (a) totally non-cemented prostheses (non-cemented femoral component, non-cemented acetabular component) versus hybrid prostheses (cemented femoral component, non-cemented acetabular component), and (b) lateral or anterolateral surgical approach versus posterior surgical approach. Outcomes included complications during the initial hospitalization, hospital length of stay, hospital cost, readmission, and reported and/or observed physical, instrumental, neuromuscular and affective functioning and pain at 2, 6, and 12 months post surgery. Results indicated that, while the totally non-cemented prosthesis was more costly, there were no statistically significant differences in clinical or functional outcomes between the non-cemented and the hybrid prostheses up to 12 months post surgery. Also, while the posterior surgical approach was associated with a non-statistically significant higher rate of dislocation, overall, there was improved function and reduced pain in the first 12 months post-surgery associated with this approach.

The effect of pulsed irrigation on the incidence of heterotopic ossification after total hip arthroplasty

Heterotopic ossification (HO) is a common complication of total hip arthroplasty (THA). Pulsed lavage is being used with increasing frequency for THA. A prospective randomized, double-blind trial was initiated to determine if pulsed lavage affected the incidence of HO. A total of 94 THAs in 91 patients were analyzed. No significant difference in the incidence of HO was found between the 2 groups. Hypertrophic osteoarthritis was found to be a significant risk factor for HO. The findings suggest that the osteogenic precursor cells thought to be involved in the pathogenesis of HO possibly are derived from within the local soft tissues in the proximity of the hip joint.

Polyarticular heterotopic ossification complicating critical illness

A patient with generalized heterotopic ossification (HO) complicating critical illness due to necrotizing pancreatitis is described; data on two other cases with HO are briefly presented. The clinical features, prevention and therapy of HO are discussed. The effect of surgical therapy of the HO in our three patients was good.