Heterotopic ossification after surface replacement arthroplasty and total hip arthroplasty: a randomized study

Resurfacing Hip Arthroplasty Is a Safe and Effective Alternative to Total Hip Arthroplasty in Young Patients: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed at comparing resurfacing hip arthroplasty (RHA) and total hip arthroplasty (THA) in terms of rate of complications, revisions, functional outcomes, blood loss, operative time and metal ions levels. The search was conducted on three databases (PubMed, Cochrane and Web of Science) updated until 13 October 2022. The inclusion criteria were RCTs) written in the English language, with no time limitation, comparing RHA and THA. Among the retrieved 4748 articles, 18 RCTs were eligible for a total of 776 patients (mean age 53.1 ± 5.0). A meta-analysis was performed. RHA reported significantly lower blood loss compared to THA (p < 0.001) but with longer operative time (p < 0.001). No statistically significant difference was found between RHA and THA in terms of complications (12.08% and 16.24%, respectively) and revisions (6.32% and 6.14%, respectively). Both RHA and THA provide excellent clinical results in a population of young and active patients. Functional outcomes were not significantly different between the groups. Moreover, no significant difference in metal ion levels was found. These findings provide evidence concerning the safety and clinical effectiveness of RHA. Because of its bone-preserving properties, the lack of drawbacks and good outcomes, RHA appears to be a valid alternative to THA in young and active patients.

Hip Resurfacing Compared with 28-mm Metal-on-Metal Total Hip Replacement: A Randomized Study with 15 Years of Follow-up

BACKGROUND

Bone stock conservation, hip anatomy preservation, and greater stability are among the promoted advantages of hip resurfacing (HR). However, the disappointing failure of some implants nearly led to its abandonment. The aim of this study was to compare clinical scores and revision and complication rates after HR with those after total hip arthroplasty (THA).

METHODS

Two hundred and three hips were randomized to 28-mm metal-on-metal (MoM) THA (99 hips) or to HR (104 hips). Main outcome measures compared between groups were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the revision rate, and the complication rates. The radiographic findings were also assessed.

RESULTS

After a mean follow-up of 15 years (range, 14 to 16 years), 9 (4.4%) of the 203 patients were lost to follow-up and 15 (7.4%) had died. The Kaplan-Meier survivorship, with revision for any reason as the end point, was 89.2% (95% confidence interval [CI], 82.3% to 96.1%) for HR and 94.2% (95% CI, 89.3% to 99.1%) for THA (p = 0.292). The reasons for revision included infection (3 patients), recurrent dislocation (1 patient), and adverse reaction to metal debris (ARMD) (1 patient) in the THA group and ARMD (2 patients) and femoral head loosening (7 patients) in the HR group. With aseptic revision as the end point, the Kaplan-Meier survivorship was significantly higher in the THA group (97.4% versus 89.2%; p = 0.033). No dislocation occurred in the HR group compared with 4 in the THA group (p = 0.058). Both groups achieved a similar mean WOMAC score (10.7 in the HR group and 8.8 in the THA group; p = 0.749), Forgotten Joint Score (87.1 and 85.3, respectively; p = 0.410), University of California Los Angeles (UCLA) activity score (6.3 and 6.4, respectively; p = 0.189), and overall joint perception (p = 0.251).

CONCLUSIONS

The specific HR and MoM 28-mm THA implants used in this study showed good long-term survival and function. The overall rates of complications and revisions were similar in both groups but were of different types. As it provides better femoral bone preservation and biomechanical reconstruction, HR may continue to have a role in selected patients when performed by experienced surgeons and using validated implants.

LEVEL OF EVIDENCE

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

Clinical and radiological evaluation of post total hip arthroplasty patients with acetabulum defect

BACKGROUND

Total Hip Arthroplasty (THA) is one of many therapies given to hip joint injury patients. The main indication for THA in elderly patients is degenerative diseases of the joints. One of the difficulties encountered in this THA procedure is to overcome the acetabulum deficiency, with Paprosky Classification. This study aims to evaluate patients with acetabulum defect that have undergone THA at Dr. Soetomo Hospital in 2014-2016.

METHODS

This was an observational retrospective study with descriptive analysis. The sample amount was 20 patients, from 80 patients who had THA procedure. Patients were evaluated based on the wear from acetabulum, migration from a cup, the presence of bone loss, heterotopic ossification, and also clinical condition based on Harris Hip Score. The presented results were analyzed by using Kruskal-Wallis on SPSS 19.0 for Windows Program.

RESULTS

Hypothesis testing was performed on THA patients based on acetabulum defect type I, II, and III in one, two, and three years after surgery respectively. Massin Score resulted no differences with p = 0.156, p = 0.574, and p = 0223. Bone Loss Classification resulted no differences with p = 0.296, p = 0.287, and p = 0223. No difference on Wear Rate with p = 0.072, p = 0.110, and p = 0.325. There was no difference of Harris Hip Score with p = 0.320, p = 0.082, and p = 0.472.

CONCLUSION

There were no significant differences in radiological evaluation of the Migration Rate, Heterotopic Ossification or Bone Loss, Wear Rate, and on clinical evaluation of Harris Hip Score in all three groups of evaluated acetabulum defects.

Comparison of revision risks and complication rates between total HIP replacement and HIP resurfacing within the similar age group

BACKGROUND AND PURPOSE

Currently it is not clear whether age is a factor affecting revisions in total hip replacement (THR) and hip resurfacing (HR). This study aimed to investigate which of THR or HR has a higher risk in terms of revision and complication within similar age groups.

METHODS

A systemic review was performed for published literature research databases and local data and compared the two procedures under the condition that both groups of patients were age matched. Meta-analysis techniques were used to analyse revision and complication rates. Twenty-seven literature studies were included along with local audit data. In total, 2520 HR procedures were compared with age-matched 2526 of THR procedures.

MAIN FINDINGS

It was found that revision risk of HR is significantly higher than THR (risk ratio 1.65, 95% CI 1.28-2.31, p < 0.0001), highlighting that HR has a slightly higher chance of reoperation when compared to THR within the similar age group population. In terms of complications, HR was found to have an advantage over THR (risk ratio 0.84, 95% CI 0.73-0.96, p < 0.01).

CONCLUSION

THR had a lower revision risk but a slightly higher complication risk than HR under the condition that the two surgical procedures were applied to similar age groups of patients. In other words, age has not played an important role in revision and complication. Survivorship cannot be measured as follow-up periods were different in the studies used.

Extensive Surgical Wound Lavage Reduces the Incidence and Severity of Heterotopic Ossification in Primary Total Hip Replacement: A Study of 175 Hip Replacements

Purpose

One of the local factors contributing to the formation of heterotopic ossification includes bone debris generated during the surgery. This risk can be partially nullified by use of saline wash. Our research aim was to ascertain if extensive intraoperative lavage can reduce the incidence and severity of heterotopic ossification in primary total hip arthroplasty.

Materials and Methods

A retrospective case control radiological study of 145 patients (175 hip replacements). The control group received minimal intra-operative lavage (<1,000 mL); consisted of 90 primary hip replacements. The index group received extensive saline lavage (>3,000 mL), and included 85 primary hip replacements. Brooker classification was used to grade radiographs at one year for development of heterotopic ossification.

Results

Sixty-six patients in control group had heterotopic ossification, with six showing a significant grade (grade 3 or 4). Thirty-five patients in the index group had heterotopic ossification with no incidence of severe grade. Majority patients in the index group showed a predominantly grade 1 heterotopic ossification; 28 out of 35, as compared to 37 out of 66 in control group. There was a statistically significant difference in the incidence (P<0.05) as well as severity of heterotopic ossification between the groups (P<0.05).

Conclusion

We conclude that use of extensive lavage during total hip replacement reduces the incidence as well as severity of heterotopic ossification.

Comparison of Outcomes of Total Hip Arthroplasty between Patients with Ankylosing Spondylitis and Avascular Necrosis of the Femoral Head

BACKGROUND

The objective of this study was to compare clinical and radiological outcomes of total hip arthroplasty (THA) between ankylosing spondylitis (AS) of the hip joint and avascular necrosis (AVN) of the femoral head.

METHODS

Thirty patients (30 hips) underwent cementless THA for AS between 2003 and 2012. They were compared to 30 patients (30 hips) who underwent the same procedure for AVN of the femoral head. Each group was matched for age and gender, and both groups had similar preoperative demographic characteristics. All cases were followed for minimum 4 postoperative years. Clinical evaluation was based on operation time, intraoperative blood loss, quantity of postoperative drainage, Harris Hip Score (HHS), and range of motion (ROM). Radiological results were evaluated by acetabular cup anteversion and inclination, femoral stem orientation, pre- and postoperative leg length discrepancy, and postoperative complications.

RESULTS

The operation time was significantly longer in the AS group (120.2 ± 26.2 min) than in the AVN group (79.5 ± 11.1 min). The volume of postoperative drainage was significantly greater in the AS group (764.5 ± 355.4 mL vs. 510.5 ± 195.6 mL). Preoperative HHS was lower in the AS group (55.6 ± 13.8 vs. 59.2 ± 2.8). Similarly, postoperative HHS was significantly lower in the AS group (92.8 ± 2.7 vs. 97.4 ± 2.6). The arc of ROM was improved from 146.5° ± 13.2° preoperatively to 254.7° ± 17.2° postoperatively in the AS group and from 182.6° ± 15.5° to 260.4° ± 13.7° in the AVN group. Implant position and postoperative leg length discrepancy were not different between the groups. However, three cases of heterotopic ossification was observed in the AS group, whereas only 1 case was found in the AVN group. One deep infection and one aseptic stem loosening were found in the AS group, whereas none was observed in the AVN group.

CONCLUSIONS

Cementless THA showed satisfactory clinical and radiological results in both groups, despite the longer operation time, larger blood loss volume, and lower HHS score of the AS group. Our findings suggest that cementless THA is an effective and reliable treatment for both AS and AVN.

Anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for two contiguous levels cervical disc degenerative disease: a meta-analysis of randomized controlled trials

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) has been considered as a gold standard for symptomatic cervical disc degeneration (CDD), which may result in progressive degeneration of the adjacent segments. The artificial cervical disc was designed to reduce the number of lesions in the adjacent segments. Clinical studies have demonstrated equivalence of cervical disc arthroplasty (CDA) for anterior cervical discectomy and fusion in single segment cervical disc degeneration. But for two contiguous levels cervical disc degeneration (CDD), which kind of treatment method is better is controversial.

PURPOSE

To evaluate the clinical effects requiring surgical intervention between anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) at two contiguous levels cervical disc degeneration.

METHODS

We conducted a comprehensive search in multiple databases, including PubMed, Cochrane Central Register of Controlled Trials, EBSCO and EMBASE. We identified that six reports meet inclusion criteria. Two independent reviewers performed the data extraction from archives. Data analysis was conducted with RevMan 5.3.

RESULTS

After applying inclusion and exclusion criteria, six papers were included in meta-analyses. The overall sample size at baseline was 650 patients (317 in the TDR group and 333 in the ACDF group). The results of the meta-analysis indicated that the CDA patients had significant superiorities in mean blood loss (P < 0.00001, standard mean differences (SMD) = -0.85, 95 % confidence interval (CI) = -1.22 to -0.48); reoperation (P = 0.0009, risk ratio (RR) = 0.28, 95 % confidence interval (CI) = 0.13-0.59), adjacent segment degeneration (P < 0.00001, risk ratio (RR) = 0.48, 95 % confidence interval (CI) = 0.40-0.58) and Neck Disability Index (P = 0.002, SMD = 0.31, 95 % CI = 0.12-0.50). No significant difference was identified between the two groups regarding mean surgical time (P = 0.84, SMD = -0.04, 95 % CI = -0.40 to 0.32), neck and arm pain scores (P = 0.52, SMD = 0.06, 95 % CI = -0.13 to 0.25) reported on a visual analog scale and rate of postoperative complications [risk ratio (RR) = 0.79; 95 % CI = 0.50-1.25; P = 0.31]. The CDA group of sagittal range of motion (ROM) of the operated and adjacent levels, functional segment units (FSU) and C2-7 is superior to ACDF group by radiographic data of peroperation, postoperation and follow-up.

CONCLUSION

We can learn from this meta-analysis that the cervical disc arthroplasty (CDA) group is equivalent and in some aspects has more significant clinical outcomes than the ACDF group at two contiguous levels CDD.

Clinical and radiological analysis of Bryan cervical disc arthroplasty: eight-year follow-up results compared with anterior cervical discectomy and fusion

PURPOSE

Bryan cervical disc arthroplasty has been reported with satisfactory short- and medium-term clinical results. However, the long-term clinical and radiographic outcomes are seldom reported. The purpose of this study was to compare the eight-year follow-up results in patients who underwent Bryan disc arthroplasty with patients received ACDF, and assess the incidence of heterotopic ossification (HO) and its effect on clinical outcome and mobility of the device.

METHODS

Thirty-one patients underwent Bryan disc arthroplasty, and 35 patients underwent ACDF were included in the study. The Japanese Orthopedic Association (JOA) scores, neck disability index (NDI), visual analogue scale (VAS) of neck and arm pain, and the radiographs were used to evaluate the outcomes. The heterotopic ossification (HO) was determined by CT scan and was classified into three subgroups to compare the related effect. Adjacent segment degeneration (ASD) was also observed.

RESULTS

At final follow-up, there were no significant differences in JOA scores between two groups, but the improvement in NDI and neck or arm VAS were significantly greater in the Bryan disc cohort. The range of motion at the index level was 7.0° in Bryan group, while 100 % bone fusion were achieved in ACDF group. HO was observed in 18 (51.4 %) levels. There were more restricted movement of the prosthesis and slight higher rate of axial pain in patients with severe-HO (grade III and IV). Fourteen (28.6 %) levels developed ASD in Bryan group, which was significantly lower than that (58.6 %) in ACDF group.

CONCLUSIONS

At eight year follow-up, the clinical and radiographic outcomes of Bryan cervical disc arthroplasty compared favorably to those of ACDF. It avoided accelerated adjacent segment degeneration by preserving motion. However, severe HO restricted the ROM of the index levels and maybe associated with post-operative axial pain.

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation

BACKGROUND

Total hip replacement (THR) involves the replacement of a damaged hip joint with an artificial hip prosthesis. Resurfacing arthroplasty (RS) involves replacement of the joint surface of the femoral head with a metal surface covering.

OBJECTIVES

To undertake clinical effectiveness and cost-effectiveness analysis of different types of THR and RS for the treatment of pain and disability in people with end-stage arthritis of the hip, in particular to compare the clinical effectiveness and cost-effectiveness of (1) different types of primary THR and RS for people in whom both procedures are suitable and (2) different types of primary THR for people who are not suitable for hip RS.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, The Cochrane Library, Current Controlled Trials and UK Clinical Research Network (UKCRN) Portfolio Database were searched in December 2012, with searches limited to publications from 2008 and sample sizes of ≥ 100 participants. Reference lists and websites of manufacturers and professional organisations were also screened.

REVIEW METHODS

Systematic reviews of the literature were undertaken to appraise the clinical effectiveness and cost-effectiveness of different types of THR and RS for people with end-stage arthritis of the hip. Included randomised controlled trials (RCTs) and systematic reviews were data extracted and risk of bias and methodological quality were independently assessed by two reviewers using the Cochrane Collaboration risk of bias tool and the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A Markov multistate model was developed for the economic evaluation of the technologies. Sensitivity analyses stratified by sex and controlled for age were carried out to assess the robustness of the results.

RESULTS

A total of 2469 records were screened of which 37 were included, representing 16 RCTs and eight systematic reviews. The mean post-THR Harris Hip Score measured at different follow-up times (from 6 months to 10 years) did not differ between THR groups, including between cross-linked polyethylene and traditional polyethylene cup liners (pooled mean difference 2.29, 95% confidence interval -0.88 to 5.45). Five systematic reviews reported evidence on different types of THR (cemented vs. cementless cup fixation and implant articulation materials) but these reviews were inconclusive. Eleven cost-effectiveness studies were included; four provided relevant cost and utility data for the model. Thirty registry studies were included, with no studies reporting better implant survival for RS than for all types of THR. For all analyses, mean costs for RS were higher than those for THR and mean quality-adjusted life-years (QALYs) were lower. The incremental cost-effectiveness ratio for RS was dominated by THR, that is, THR was cheaper and more effective than RS (for a lifetime horizon in the base-case analysis, the incremental cost of RS was £11,284 and the incremental QALYs were -0.0879). For all age and sex groups RS remained clearly dominated by THR. Cost-effectiveness acceptability curves showed that, for all patients, THR was almost 100% cost-effective at any willingness-to-pay level. There were age and sex differences in the populations with different types of THR and variations in revision rates (from 1.6% to 3.5% at 9 years). For the base-case analysis, for all age and sex groups and a lifetime horizon, mean costs for category E (cemented components with a polyethylene-on-ceramic articulation) were slightly lower and mean QALYs for category E were slightly higher than those for all other THR categories in both deterministic and probabilistic analyses. Hence, category E dominated the other four categories. Sensitivity analysis using an age- and sex-adjusted log-normal model demonstrated that, over a lifetime horizon and at a willingness-to-pay threshold of £20,000 per QALY, categories A and E were equally likely (50%) to be cost-effective.

LIMITATIONS

A large proportion of the included studies were inconclusive because of poor reporting, missing data, inconsistent results and/or great uncertainty in the treatment effect estimates. This warrants cautious interpretation of the findings. The evidence on complications was scarce, which may be because of the absence or rarity of these events or because of under-reporting. The poor reporting meant that it was not possible to explore contextual factors that might have influenced study results and also reduced the applicability of the findings to routine clinical practice in the UK. The scope of the review was limited to evidence published in English in 2008 or later, which could be interpreted as a weakness; however, systematic reviews would provide summary evidence for studies published before 2008.

CONCLUSIONS

Compared with THR, revision rates for RS were higher, mean costs for RS were higher and mean QALYs gained were lower; RS was dominated by THR. Similar results were obtained in the deterministic and probabilistic analyses and for all age and sex groups THR was almost 100% cost-effective at any willingness-to-pay level. Revision rates for all types of THR were low. Category A THR (cemented components with a polyethylene-on-metal articulation) was more cost-effective for older age groups. However, across all age-sex groups combined, the mean cost for category E THR (cemented components with a polyethylene-on-ceramic articulation) was slightly lower and the mean QALYs gained were slightly higher. Category E therefore dominated the other four categories. Certain types of THR appeared to confer some benefit, including larger femoral head sizes, use of a cemented cup, use of a cross-linked polyethylene cup liner and a ceramic-on-ceramic as opposed to a metal-on-polyethylene articulation. Further RCTs with long-term follow-up are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013003924.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Metal-on-metal hip resurfacing compared with 28-mm diameter metal-on-metal total hip replacement: a randomised study with six to nine years' follow-up

A total of 219 hips in 192 patients aged between 18 and 65 years were randomised to 28-mm metal-on-metal uncemented total hip replacements (THRs, 107 hips) or hybrid hip resurfacing (HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3) there was no significant difference between the THR and HR groups regarding rate of revision (4.0% (4 of 99) vs 5.8% (6 of 104), p = 0.569) or re-operation rates without revision (5.1% (5 of 99) vs 2.9% (3 of 104), p = 0.428). In the THR group one recurrent dislocation, two late deep infections and one peri-prosthetic fracture required revision, whereas in the HR group five patients underwent revision for femoral head loosening and one for adverse reaction to metal debris. The mean University of California, Los Angeles activity scores were significantly higher in HR (7.5 (sd 1.7) vs 6.9 (sd 1.7), p = 0.035), but similar mean Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained (5.8 (sd 9.5) in HR vs 5.1 (sd 8.9) in THR, p = 0.615) at the last follow-up. Osteolysis was found in 30 of 81 THR patients (37.4%), mostly in the proximal femur, compared with two of 83 HR patients (2.4%) (p < 0.001). At five years the mean metal ion levels were < 2.5 μg/l for cobalt and chromium in both groups; only titanium was significantly higher in the HR group (p = 0.001). Although revision rates and functional scores were similar in both groups at mid-term, long-term survival analysis is necessary to determine whether one procedure is more advantageous than the other.

Incidence of heterotopic ossification after surface and conventional total hip arthroplasty: a comparative study using anterolateral approach and indomethacin prophylaxis

The incidence and severity of heterotopic ossification (HO) in two homogeneous groups of patients that received surface replacement arthroplasty (SRA) and conventional total hip arthroplasty (THA) were evaluated retrospectively. Thirty-nine patients undergoing 42 hip resurfacing procedures and 41 primary cementless THAs through an anterolateral approach received a 10-day course of 150 mg/die of indomethacin postoperatively. The median surgical time was 190 minutes and 156 minutes, respectively (P < 0.003). At a minimum 1-year followup, the development of HO was assessed on standard X-ray using Brooker grading. Ectopic bone formation was detected in five cases (11.9%, two Brooker grade I and three grade II) in the SRA group and in 14 hips (34.1%, 12 grade I and two grade II) treated with conventional THA, but the difference was not significant (P < 0.11). No clinically relevant periprosthetic ossification (Brooker III or IV) occurred in both groups. Although the difference was not statistically significant, the incidence of HO after SRA was lower than conventional THA. More extensive soft tissue trauma, bone debris, and longer operative time in hip resurfacing are not likely to be absolute risk factors for HO. Further investigations including larger patient populations are needed to confirm these findings.

Recovery of function following hip resurfacing arthroplasty: a randomized controlled trial comparing an accelerated versus standard physiotherapy rehabilitation programme

Objective:

To identify if a tailored rehabilitation programme is more effective than standard practice at improving function in patients undergoing metal-on-metal hip resurfacing arthroplasty.

Design:

Randomized controlled trial.

Setting:

Specialist orthopaedic hospital.

Subjects:

80 men with a median age of 56 years.

Interventions:

Tailored post-operative physiotherapy programme compared with standard physiotherapy.

Main Outcomes:

Primary outcome – Oxford Hip Score (OHS), Secondary outcomes: Hip disability and Osteoarthritis Outcome Score (HOOS), EuroQol (EQ-5D-3L) and UCLA activity score. Hip range of motion, hip muscle strength and patient selected goals were also assessed.

Results:

At one year the mean (SD) Oxford Hip Score of the intervention group was higher, 45.1 (5.3), than the control group, 39.6 (8.8). This was supported by a linear regression model, which detected a 5.8 unit change in Oxford Hip Score ( p < 0.001), effect size 0.76. There was a statistically significant increase in Hip disability and Osteoarthritis Outcome Score of 12.4% ( p < 0.0005), effect size 0.76; UCLA activity score differed by 0.66 points ( p < 0.019), effect size 0.43; EQ 5D showed an improvement of 0.85 ( p < 0.0005), effect size 0.76. A total of 80% (32 of 40) of the intervention group fully met their self-selected goal compared with 55% (22 of 40) of the control group. Hip range of motion increased significantly; hip flexion by a mean difference 17.9 degrees ( p < 0.0005), hip extension by 5.7 degrees ( p < 0.004) and abduction by 4 degrees ( p < 0.05). Muscle strength improved more in the intervention group but was not statistically significant.

Conclusions:

A tailored physiotherapy programme improved self-reported functional outcomes and hip range of motion in patients undergoing hip resurfacing.

Low rates of heterotopic ossification after resurfacing hip arthroplasty with use of prophylactic radiotherapy in select patients

Recent reports have noted higher rates of heterotopic ossification (HO) with surface replacement arthroplasty (SRA) than with traditional total hip arthroplasty in the absence of postoperative HO prophylaxis. This study reports rates and grades of HO in 44 SRA patients with at least 1 year of follow-up. Heterotopic ossification prophylaxis was used in 32 (73%) of 44 cases. Heterotopic ossification prophylaxis consisted of radiotherapy (22/32), nonsteroidal anti-inflammatory drugs (8/32), or both (2/32). One case of clinically significant HO was documented in the no-prophylaxis group. This strategy of selective HO prophylaxis in patients felt by orthopedic surgeons to be at high risk of HO resulted in low rates of clinically relevant HO after SRA (1/44, 2.3%). Further study is needed to establish optimal selection criteria for HO prophylaxis after SRA.

Heterotopic ossification in vertebral interlaminar/interspinous instrumentation: report of a case

We present here a rare case of heterotopic ossification in interspinous/interlaminar Coflex device. The classical surgical indications for these implants are degenerative canal stenosis, discogenic low back pain, disk herniations, facet syndrome, and instability. However, fractures of spinous processes are a potential risk after interspinous/interlaminar devices' implantation. Recently, heterotopic ossification, a well-known complication of hip and knee arthroplasty, has been reported after cervical and lumbar prosthesis. We performed undercutting and implantation of the dynamic interspinous/interlaminar device to treat an adult male patient with L4-L5 stenosis. The patient underwent 45-day imaging and clinical followup, and we observed both a neurological and imaging improvement. A CT bone scan, performed 3 years after surgery for recurrence of neurogenic claudication, showed a new stenosis due to an abnormal ossification all over the device. To our knowledge, this is the first reported case of heterotopic ossification in an interspinous/interlaminar dynamic device. Accordingly, we aim to suggest it as a new complication of interspinous/interlaminar devices.

Adherence to routine use of pharmacological prophylaxis of heterotopic ossification after total hip arthroplasty: results from an Italian multicenter, prospective, observational survey

BACKGROUND

In spite of the proven efficacy of pharmacological prophylaxis of heterotopic ossification following total hip arthroplasty, its routine use is still debated, and no data are available regarding the adherence to its administration in clinical practice.

MATERIALS AND METHODS

In this prospective, observational, multicenter study, 480 consecutive patients operated on for primary total hip arthroplasty during the year 2009 were followed radiographically for 12 months after surgery in order to assess the incidence of periprosthetic heterotopic ossification. Surgeons were free to choose whether to administer pharmacological prophylaxis, and were asked to keep a record of the duration of the prophylaxis (if used) or the reasons for not using it. To facilitate the statistical analysis, all of the participating centers agreed to use only one drug (celecoxib) that had already proven to be effective.

RESULTS

368 patients were administered celecoxib and 112 patients did not receive any prophylaxis. Reported reasons for not administering celecoxib prophylaxis were the surgeon's opinion that prophylaxis was not needed on a routine basis (84/112 patients, 75%), previous history of gastrointestinal bleeding (17.8%), and concomitant cardiorenal pathologies (7.1%). The overall incidence of heterotopic ossification in the celecoxib-treated patients was 23% (no cases of Brooker grade 3 or 4 ossifications), compared to 55% in the untreated patients (Brooker grade 3 and 4: 8.9%). Multivariate analysis showed that celecoxib prophylaxis was the single most important variable when predicting the occurrence of heterotopic ossification.

CONCLUSIONS

This study confirms the efficacy and tolerability of celecoxib for the prophylaxis of heterotopic ossification after total hip arthroplasty, and shows how the surgeon's belief that routine prevention is not required still plays an important role in the determination of this complication, together with the fear of possible unwanted side effects.

Hip resurfacing arthroplasty in inflammatory arthritis a 3- to 5-year follow-up study

The success of hip resurfacing in younger patients with primary osteoarthritis has paved the way for the trial of the procedure in patients with secondary osteoarthritis of the hip. We retrospectively reviewed the clinical and radiologic results in a cohort of 23 patients (32 hips) with inflammatory arthritis who were chosen for hip resurfacing after normalizing vitamin D levels and ruling out proximal femoral osteopenia using dual-energy x-ray absorptiometry. At a minimum follow-up of 3 years, there was failure in only 1 hip due to fracture of the femoral neck attributable to osteonecrosis of the remnant head. The clinical outcome was evaluated using Harris hip score and was found to be good to excellent in 30 of 31 hips. Hip resurfacing is a promising alternative in carefully chosen patients with inflammatory arthritis.

Prevalence of heterotopic ossification after cervical total disc arthroplasty: a meta-analysis

BACKGROUND

Heterotopic ossification (HO) is a well-known complication after total hip and knee arthroplasty. But limited studies have focused on prevalence of HO following cervical total disc arthroplasty (CTDA) and the published data show controversial results.

OBJECTIVE

The purpose of this review is to investigate the prevalence of HO following CTDA by meta-analysis.

METHODS

The literatures were collected from PubMed, Embase and Cochrane library by using keywords as ([disc or disk] and [arthroplasty or replacement]) and (HO or delayed fusion or spontaneous fusion). The original studies were eligible only if the prevalence of HO and of advanced HO (Grade 3-4 according to McAfee) were investigated. A meta-analysis was then performed on collected data. Statistical heterogeneity across the various trials was tested using Cochran's Q, statistic and in the case of heterogeneity a random effect model was used. Tests of publication bias and sensitivity analysis were also performed.

RESULTS

Our data showed that the pooled prevalence of HO was 44.6% (95% confidence interval (CI), 37.2-45.6%) 12 months after CTDA and 58.2% (95% CI, 29.7-86.8%) 24 months after CTDA, while the advanced HO was 11.1% (95% CI, 5.5-16.7%) and 16.7% (95% CI, 4.6-28.9%), respectively. A significant heterogeneity was obtained. There was no publication bias and individual study had no significant effect on the pooled prevalence estimate.

CONCLUSION

Higher prevalence of HO was observed following CTDA, although HO was reported to be unrelated to the clinical improvement. It suggests that cervical disc replacement should be performed cautiously before obtaining long-term supporting evidence.

LEVEL OF EVIDENCE

Prognostic level III.

[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.

Incorrect use of the student t test in randomized trials of bilateral hip and knee arthroplasty patients

The statistical analysis of a study's results is critical to its interpretation. Often confused, 2 types of t tests exist for dependent or independent samples. We reviewed randomized controlled trials that included patients undergoing bilateral total hip or knee arthroplasty (dependent samples) that used the t test for analysis. Our inclusion criteria resulted in 40 studies for review, 10 of which combined both unilateral and bilateral patients. Of the 30 studies that compared a pure sample of only bilateral patients, 18 (60%) incorrectly used the independent t test. Of the 10 studies with mixed samples, 8 (80%) used the independent t test. The extent to which the incorrect use of this statistical test led to misleading conclusions is uncertain; however, our findings highlight the misuse of statistical tests in the arthroplasty literature.

Aspirin decreases heterotopic ossification after hip resurfacing

BACKGROUND

Heterotopic ossification (HO) is a concern for patients undergoing hip surgery, especially surface replacement arthroplasty (SRA) who tend to be younger, more active, and anticipate good motion. It is unclear, however, whether HO occurs more frequently after SRA than traditional total hip arthroplasty (THA) and whether aspirin influences the risk.

QUESTIONS/PURPOSES

We therefore determined the incidence of HO after hip resurfacing compared with THA and determined whether aspirin influenced the incidence or severity of HO.

METHODS

Retrospectively we compared three patient cohorts: SRA with aspirin (176 hips; 160 patients), SRA with warfarin (60 hips; 57 patients), and THA with warfarin (240 hips; 222 patients). All patients satisfied the same selection criteria and all surgeries were performed through the posterolateral approach using spinal anesthesia. HO was classified using the technique of Brooker et al. comparing the preoperative, immediate postoperative, and 6- to 12-month followup radiographs (minimum, 1 year; mean, 2.7 years).

RESULTS

In the SRA with aspirin group, HO was detected in four of 151 hips (2.6%; two Grade I; one Grade II; one Grade III); in the SRA with warfarin group, eight of 46 hips (17.4%) had HO with four hips (8.7%) having severe HO (Grade III). All 12 patients with HO in both SRA groups were male. The HO incidence and severity was less for the SRA patients treated with aspirin compared with those treated with warfarin. In the THA with warfarin control group, HO was detected in five of 189 hips (2.6%; two Grade I; three Grade II). The HO incidence and severity were the same between the THA with warfarin and the SRA with aspirin cohorts.

CONCLUSIONS

The risk of HO is greater in SRA than in THA in patients treated with warfarin postoperatively; aspirin appears to decrease the incidence and severity of HO after hip resurfacing surgery to a similar level as total hip arthroplasty.

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.

Heterotopic ossification after primary total ankle arthroplasty

BACKGROUND

Heterotopic ossification following lower-limb joint arthroplasty is a challenging clinical problem. No comprehensive study has been conducted on heterotopic ossification after total ankle arthroplasty, to our knowledge. The purpose of this study was to evaluate the prevalence and location of heterotopic ossification after primary total ankle arthroplasty, predisposing factors, and effects on clinical outcomes, and to develop a method of classification.

METHODS

Eighty ankles in eighty patients with a primary total ankle arthroplasty were followed for a mean (and standard deviation) of 31.9 ± 11.3 months (range, twenty-four to sixty-five months). The prevalence and location of heterotopic ossification, predisposing factors, and outcomes were analyzed, and a method of classification was developed.

RESULTS

Twenty (25%) of the eighty ankles demonstrated postoperative heterotopic ossification, with the majority of the cases in the posterior aspect of the ankle. The heterotopic ossification was Class I in four cases (20%); Class II, in five (25%); Class III, in four (20%); and Class IV, in seven (35%). Symptomatic heterotopic ossification was reported in eight patients (10%), and two required surgical resection because of intractable pain. Ankles that developed heterotopic ossification had significantly longer operative times, less postoperative motion, and lower American Orthopaedic Foot & Ankle Society ankle-hindfoot scores at the six, twelve, and twenty-four-month follow-up examinations (p < 0.05 for all).

CONCLUSIONS

This study demonstrates that the prevalence of heterotopic ossification following primary total ankle arthroplasty is considerable, and that heterotopic ossification is associated with reduced ankle motion and a poor clinical outcome at a mean of two years postoperatively. Care is needed to attempt to reduce the occurrence of heterotopic ossification.

Imaging of metal-on-metal hip resurfacing

Conventional radiography is the primary imaging modality to evaluate the condition of hip resurfacing implants and the preferred method of assessing implant stability over time. Radiographs assess the angle of inclination of the femoral and acetabular components, implant stability, and femoral neck narrowing. Ultrasonography detects solid or soft tissue masses adjacent to the implant. Magnetic resonance imaging (MRI) detects osteolysis and complications in the periprosthetic soft tissues such as wear-induced synovitis, periprosthetic collections, neurovascular compression, and quality of the muscle and tendons of the rotator cuff of the hip. For pain after hip resurfacing, early use of optimized MRI is recommended.

Complications after metal-on-metal hip resurfacing arthroplasty

This article determines the incidence and cause of the complications commonly associated with metal-on-metal hip resurfacing implants and the proposed methods to prevent these complications. The literature available in PubMed was reviewed. Complication rates after hip resurfacing are low, and the procedure has shown both safety and efficacy in the hands of surgeons trained in specialized centers. Proper surgical technique can further reduce the incidence of femoral neck fracture, component loosening, and abnormal wear of the prosthesis. A more systematic detection of adverse local tissue reactions is needed to provide accurate assessments of their prevalence.

Heterotopic bone formation following resurfacing total hip arthroplasty

Heterotopic bone (HO), a rare association with total hip arthroplasty (THA), has recently been shown to be more of a problem with resurfacing hip arthroplasty (RHA). It has been speculated to be the result of greater soft tissue dissection required for this procedure. HO most commonly develops in males and patients with bilateral disease. To better understand if this problem does occur in RHA, groups of patients with RHA on one side and conventional THA on the other were evaluated. We retrospectively identified 45 patients that had RHA on one side and conventional cemented THA on the other. Follow-up has been up to 25 years. HO was graded at every clinical visit using the Brooker Classification. In the RHA group, there were 32 hips without evidence of HO, ten with grade 1, and three with grades 2 or 3. In the THA group, there were 36 hips without any HO, eight with grade 1, and one with grade 2. There was no statistical difference between either types of hip arthroplasty in HO formation overall or in the development of more severe grades. Motion was not significantly affected with the more severe grades. Our data obtained from a bilateral patient model suggests that RHA does not predispose to a greater development of HO. In doing a RHA, one should be aware that there might be an increased likelihood of HO in males with bilateral disease.

The clinical and radiological outcomes of hip resurfacing versus total hip arthroplasty: a meta-analysis and systematic review

BACKGROUND AND PURPOSE

Hip resurfacing (HRS) procedures have gained increasing popularity for younger, higher-demand patients with degenerative hip pathologies. However, with concerns regarding revision rates and possible adverse metal hypersensitivity reactions with metal-on-metal articulations, some authors have questioned the hypothesized superiority of hip resurfacing over total hip arthroplasty (THA). In this meta-analysis, we compared the clinical and radiological outcomes and complication rates of these 2 procedures.

METHODS

A systematic review was undertaken of all published (Medline, CINAHL, AMED, EMBASE) and unpublished or gray literature research databases up to January 2010. Clinical and radiological outcomes as well as complications of HRS were compared to those of THA using risk ratio, mean difference, and standardized mean difference statistics. Studies were critically appraised using the CASP appraisal tool.

RESULTS

46 studies were identified from 1,124 citations. These included 3,799 HRSs and 3,282 THAs. On meta-analysis, functional outcomes for subjects following HRS were better than or the same as for subjects with a THA, but there were statistically significantly greater incidences of heterotopic ossification, aseptic loosening, and revision surgery with HRS compared to THA. The evidence base showed a number of methodological inadequacies such as the limited use of power calculations and poor or absent blinding of both patients and assessors, possibly giving rise to assessor bias.

INTERPRETATION

On the basis of the current evidence base, HRS may have better functional outcomes than THA, but the increased risks of heterotopic ossification, aseptic loosening, and revision surgery following HRS indicate that THA is superior in terms of implant survival.

A comparison of clinical results of hip resurfacing arthroplasty and 28 mm metal on metal total hip arthroplasty: a randomised trial with 3-6 years follow-up

Two hundred and nine hips were randomised to receive either a 28 mm total hip athroplasty (THA, 100 hips) or hybrid hip resurfacing (HR, 109 hips). At 1 and 2 years post-operatively, patients with HR achieved statistically significantly better WOMAC functional scores. However, differences in scores were of slight clinical relevance with a difference of 2.2/100 and 3.3/100, at 1 and 2 years respectively (p=0.007). After an average follow-up of 56 months (range 36-72) there were similar re-operation rates 7/100 THA and 6/109 HR (p=0.655) and revision rates 2/100 THA and 4/109 HR (p=0.470). However, the types of complications were different. Higher early aseptic loosening rate was found in HR and long-term survival analysis of both patient cohorts is necessary to determine whether the potential bone preservation advantage offers by HR will overcome its earlier higher failure rate.

Metal ion release from bearing wear and corrosion with 28 mm and large-diameter metal-on-metal bearing articulations: a follow-up study

We have updated our previous randomised controlled trial comparing release of chromium (Cr) and cobalt (Co) ions and included levels of titanium (Ti) ions. We have compared the findings from 28 mm metal-on-metal total hip replacement, performed using titanium CLS/Spotorno femoral components and titanium AlloFit acetabular components with Metasul bearings, with Durom hip resurfacing using a Metasul articulation or bearing and a titanium plasma-sprayed coating for fixation of the acetabular component. Although significantly higher blood ion levels of Cr and Co were observed at three months in the resurfaced group than in total hip replacement, no significant difference was found at two years post-operatively for Cr, 1.58 microg/L and 1.62 microg/L respectively (p = 0.819) and for Co, 0.67 microg/L and 0.94 microg/L respectively (p = 0.207). A steady state was reached at one year in the resurfaced group and after three months in the total hip replacement group. Interestingly, Ti, which is not part of the bearing surfaces with its release resulting from metal corrosion, had significantly elevated ion levels after implantation in both groups. The hip resurfacing group had significantly higher Ti levels than the total hip replacement group for all periods of follow-up. At two years the mean blood levels of Ti ions were 1.87 microg/L in hip resurfacing and and 1.30 microg/L in total hip replacement (p = 0.001). The study confirms even with different bearing diameters and clearances, hip replacement and 28 mm metal-on-metal total hip replacement produced similar Cr and Co metal ion levels in this randomised controlled trial study design, but apart from wear on bearing surfaces, passive corrosion of exposed metallic surfaces is a factor which influences ion concentrations. Ti plasma spray coating the acetabular components for hip resurfacing produces significantly higher release of Ti than Ti grit-blasted surfaces in total hip replacement.

[Hip joint arthrolysis due to heterotopic ossification]

OBJECTIVE

Restoration of joint mobility with preservation of femoral head perfusion and warranty of joint stability. Pain reduction. Enhancement of the autonomous daily mobility (if possible regarding the cognitive status) as well as the ability to sit. For nonambulatory, bedridden patients ease of sanitary tasks and improvement of patients' convenience.

INDICATIONS

Joint stiffness with limitation of the quality of life. Pain. Joint deformity, especially in cases of progressive subluxation.

CONTRAINDICATIONS

Relative: radiologically and scintigraphically immature heterotopic ossification (HO) with moderate limitation of motion and patients who are not able to tolerate the demanding postoperative management.

SURGICAL TECHNIQUE

The patient is positioned depending on size and location of ectopic bone. Ectopic bone is released from surrounding soft tissue or by making use of a gap between original bone and ectopic bone from the femur or pelvis. If ectopic bone is close to neurovascular structures, these have to be identified and protected.

POSTOPERATIVE MANAGEMENT

Postoperative irradiation in patients > 50 years. Generally, medicamentous prevention for recurrent cases with nonsteroidal anti-inflammatory drugs. Intensive and aggressive physical therapy, especially in patients with neurologic disorders. Depending on the extent of arthrolysis and the cause of HO, full, partial, or no weight bearing of the extremity over the first 6 postoperative weeks.

RESULTS

The literature does not allow to draw firm conclusions regarding the occurrence of HO. The incidence of HO after primary total hip arthroplasty is estimated at 42%. In 9% of these cases, a severe HO with major limitation of motion or ankylosis occurs. In patients with neurologic injuries (brain injuries, spinal cord injuries) the incidence varies between 20-40%, but only one third of these patients show limited function or ankylosis. After surgical arthrolysis, the recurrence rate amounts to 25-30% at a mean follow-up of 6 years.

Articular Surface Replacement of the hip: a prospective single-surgeon series

We present the early clinical and radiological results of Articular Surface Replacement (ASR) resurfacings in 214 hips (192 patients) with a mean follow-up of 43 months (30 to 57). The mean age of the patients was 56 years (28 to 74) and 85 hips (40%) were in 78 women.

The mean Harris hip score improved from 52 (11 to 81) to 95 (27 to 100) at two years and the mean University of California, Los Angeles activity score from 3.9 (1 to 10) to 7.4 (2 to 10) in the same period. Narrowing of the neck (to a maximum of 9%) was noted in 124 of 209 hips (60%). There were 12 revisions (5.6%) involving four (1.9%) early fractures of the femoral neck and two (0.9%) episodes of collapse of the femoral head secondary to avascular necrosis. Six patients (2.8%) had failure related to metal wear debris. The overall survival for our series was 93% (95% confidence interval 80 to 98) and 89% (95% confidence interval 82 to 96) for hips with acetabular components smaller than 56 mm in diameter.

The ASR implant has a lower diametrical clearance and a subhemispherical acetabular component when compared with other more frequently implanted metal-on-metal hip resurfacings. These changes may contribute to the higher failure rate than in other series, compared with other designs. Given our poor results with the small components we are no longer implanting the smaller size.

Clinical significance of the heterotopic ossification after total hip arthroplasty

Heterotopic ossification represents one of the most frequent complications following any type of hip arthroplasty. However, disagreement exists regarding the clinical significance of heterotopic ossification after total hip arthroplasty (THA). This study evaluated the effect of different grades of heterotopic ossification on range of hip motion, pain, and the clinical outcome in patients after THA. The study included 198 patients with primary THA because of unilateral hip osteoarthritis, followed for a minimum of 1 year after THA. Diagnosis and classification of heterotopic ossification according to Brooker was achieved on anteroposterior radiograph of the hips 1 year postoperatively. The clinical outcome was assessed at 1-year follow-up with the use of the Harris hip score. Pain was assessed as the pain component of the Harris hip score. Hip range of motion was measured passively in the lying position with a goniometer and recorded in degrees according to the method suggested by the American Academy of Orthopaedic Surgeons 1988. The incidence of heterotopic ossification was 47% and the incidence of severe ossification was 11%. The severe heterotopic ossification significantly reduced clinical outcome, overall range of hip motion and certain components such as flexion, abduction and external rotation, but had no significant effect on pain, while the lower degree of ossification did not significantly influence the clinical outcome, hip motion and pain. This study has shown that only severe heterotopic ossification is of clinical significance.