Advertisement for orthosearch.org.uk
Results 1 - 20 of 4225
Results per page:
Bone & Joint Research
Vol. 13, Issue 11 | Pages 682 - 693
26 Nov 2024
Wahl P Heuberger R Pascucci A Imwinkelried T Fürstner M Icken N Schläppi M Pourzal R Gautier E

Aims

Highly cross-linked polyethylene (HXLPE) greatly reduces wear in total hip arthroplasty, compared to conventional polyethylene (CPE). Cross-linking is commonly achieved by irradiation. This study aimed to compare the degree of cross-linking and in vitro wear rates across a cohort of retrieved and unused polyethylene cups/liners from various brands.

Methods

Polyethylene acetabular cups/liners were collected at one centre from 1 April 2021 to 30 April 2022. The trans-vinylene index (TVI) and oxidation index (OI) were determined by Fourier-transform infrared spectrometry. Wear was measured using a pin-on-disk test.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 62 - 62
22 Nov 2024
Mueller MM Kowald B Gerlach U Grimme C Schulz A Frosch K Schoop-Schmetgens R
Full Access

Aim. Aim of this study was to establish the first clinical results after implantation of ultrathin silver-polysiloxane-coated. 1. plates in the treatment of infected non-union of the femoral shaft. Method. As part of the REFECT study, a prospective, non-interventional analysis was conducted encompassing all patients who received internal stabilization with a silver-coated. 1. plate from 01/2023 to 09/2024 as part of the treatment for infected non-union of the femur. Standardized clinical follow-ups including PROMs (WOMAC-Index, LEF-S, EQ-5D, VAS) and X-rays were performed 3, 6, 12 (and 24) months postoperatively. For comparison, a retrospective analysis of 76 patients with infected femoral non-union, who had received a stabilization with an uncoated plate in the past 10 years, was performed. Results. The mean follow-up of the 8 included patients (mean bone defect: 3.6 cm) was 9 months (as of 04/24). Multiresistant bacteria were found in the intraoperative samples of 5 patients. The concentration of silver ions in blood serum reached a maximum of 0.014 mg/l in the laboratory controls. All patients showed a positive healing process with no sign of re-infection and no adverse procedure-associated events. Full weight bearing was achieved after an average of 4 months (n=6) with improved WOMAC-, LEF-S-, EQ-5D and VAS-score at 1-year FU. In the reference group (uncoated, mean FU: 3.5 years), there was a re-infection rate of 25 %, mostly in the first 2 years. Difficult-to-treat bacteria were detected in 22%, multiresistant Staph. epidermidis in 28% of cases. Conclusions. -. The silver-coated. 1. implants showed good biocompatibility with no evidence of procedure-associated complications. -. The use of silver-coated. 1. implants could reduce the risk of re-infection. -. Further clinical data with longer follow-up are needed to assess the long-term value of the procedure


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 8 - 8
14 Nov 2024
Bhat SS Mathai NJ Raghavendra R Hodgson P
Full Access

Introduction. As per national guidelines for Ankle fractures in the United Kingdom, fractures considered stable can be treated with analgesia, splinting and allowed to weight bear as tolerated. The guidelines also suggest further follow-up not mandatory. This study was aimed at evaluating the current clinical practice of managing stable ankle fractures at a university hospital against national guidelines. Method. The study was undertaken using retrospectively collected data, the inclusion criteria being all adults with stable ankle fracture pattern treated non-operatively between December 2022 and April 2023. Collected data included age of patient, date of injury, type of immobilization, number of clinical visits and any complications. Results. 41 cases were identified and analyzed. The mean age of the cohort was 49.8 years (Standard deviation 20.01). Twelve percent (n = 5) were reviewed in clinic, treated and discharged as stable Weber B type fracture pattern as per national guidelines after the first visit. About 52% (n = 21) were seen in clinic twice before discharge, first visit between 1-2 weeks and the last clinic visit between 5-7 weeks. About a third of patients (30%, n = 12) were seen in clinic on more than two occasions. At the first clinic visit 87% (n = 36) were given a boot and allowed to weight bear as tolerated. Two patients were diagnosed with deep vein thrombosis/pulmonary embolism during the treatment duration. Three patients had extended duration of follow up for ongoing symptoms. None discharged after first or second visit needed surgery for displaced or malunited fracture. Conclusion. Patients discharged from clinic after first or second visit did not need any further surgery. As per national guidelines, patients deemed stable weber B lateral malleolus fracture pattern after weight bearing radiograph can be treated safely with a weight bearing walking boot with no further follow up


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 33 - 33
14 Nov 2024
Fallahy M Shaker F Ghanbari F Aslani MA Mohammadi S Behrouzieh S
Full Access

Introduction. Knee Osteoarthritis (KOA) is a prevalent joint disease requiring accurate diagnosis and prompt management. The condition occurs due to cartilage deterioration and bone remodeling. Ultrasonography has emerged as a promising modality for diagnosing KOA. Medial meniscus extrusion (MME), characterized by displacement of medial meniscus beyond the joint line has been recognized as a significant marker of KOA progression. This study aimed to explore potentials Ultrasound findings in timely detection of MME and compare it to magnetic resonance imaging (MRI) as a reference standard. Method. A comprehensive literature search was performed in 4 databases from inception to May 1 2024. Two independent reviewers, initiated screening protocols and selected the articles based on inclusion and exclusion criteria and then extracted the data. Meta-analysis was conducted using R 4.3.2 packages mada and metafor. Result. A total of 2500 articles from 4 databases was retrieved; however, following the application of inclusion and exclusion criteria 23 articles were finally extracted. These studies collectively encompassed a total of 777 patients with mean age of 53.2±7.4. The mean BMI calculated for patients was 28.31 ± 2.45. All patients underwent non-weight bearing knee ultrasonography in supine position with 0° flexion. The reported medial meniscus extrusion was 2.58 mm for articles using MRI and 2.65 mm for those using Ultrasound (MD: 0.05 ± 0.12, P= 0.65, I. 2. : 54%). Our meta-analysis revealed insignificant difference between US and MRI. (SMD: 0.03, 95% CI: -0.18 _0.23, P= 0.77, I. 2. : 56%) Meta analysis for diagnostic accuracy measures yielded a pooled sensitivity and specificity of 90.8% and 77% (95% CI: 84.2% – 94.8%, 35.5% – 95.3%, respectively, I. 2. : 44%). Conclusion. Our results indicate a close alignment in the accuracy of measurements obtained using Ultrasound modality. The narrow range suggests a minimal discrepancy in MME values between MRI and ultrasound, highlighting their comparable precision in diagnostic assessments


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 73 - 73
14 Nov 2024
Pérez GV Rey EG Quero LS Díaz NV
Full Access

Introduction. The identification of biological markers associated to implant failure in THA (total hip arthroplasty) patients remains a challenge in orthopedic surgery. In this search, previous studies have been mainly focused on typical mediators associated to bone metabolism and inflammation. Our group has evaluated changes in serum levels of insulin-like growth factor binding protein-1 (IGFBP-1), a protein which is not directly related to bone homeostasis, in patients undergoing THA. Method. We assessed IGFBP-1 levels in serum obtained from 131 patients (58% female, 42 % male; age: 68 ± 13 years) who underwent THA in the Orthopedic Surgery and Traumatology Department of our institution. In this cohort, 57% of patients had metal on polyethylene (MoP) as hip-bearing surface combination, 17 % had ceramic on ceramic (CoC) and 26% of them did not have any prosthesis. A test based on an enzyme-linked immunosorbent assay (ELISA) was used to determine IGFBP-1 levels in serum obtained from these patients. Result. Our results showed a significant increase in IGFBP- 1 levels in MoP group as compared to CoC and control groups, in which no differences in quantified levels were detected. Further analysis revealed no significant differences in IGFBP-1 between cemented and non-cemented MoP bearings. We performed a ROC curve to evaluate the accuracy of serum IGFBP-1 in discriminating MoP from the rest of patients (area under the curve: 0.7; 95% confidence interval: 0,6-0.8; p<0.05) and established a cut-off value of 10.2 ng/ml, according to the Youden´s Index. Logistic regression analysis showed that patients with MoP bearing surfaces had a higher risk of increased IGFBP- 1 levels in serum (p<0.05, Odds Ratio: 6.7, 95% Confidence Interval 3.1 to 14.8). Conclusion. IGFBP- 1 levels are significantly elevated in THA patients with MoP bearing surfaces, suggesting that this protein might be a reliable biomarker for the outcome of patients implanted with MoP


Bone & Joint Open
Vol. 5, Issue 11 | Pages 971 - 976
5 Nov 2024
Baker G Hill J O'Neill F McChesney J Stevenson M Beverland D

Aims. In 2015, we published the results of our ceramic-on-metal (CoM) total hip arthroplasties (THAs) performed between October 2007 and July 2009 with a mean follow-up of 34 months (23 to 45) and a revision rate of 3.1%. The aim of this paper is to present the longer-term outcomes. Methods. A total of 264 patients were reviewed at a mean of 5.8 years (4.6 to 7.2) and 10.1 years (9.2 to 10.6) to determine revision rate, pain, outcome scores, radiological analysis, and blood ion levels. Those who were unwilling or unable to travel were contacted by telephone. Results. The all-cause revision rate at six years was 3.1% (eight THAs), increasing to 8.8% (18 THAs) at ten years. Of these, there were four and then seven bearing-related revisions at six and ten years, respectively. There was a statistically significant deterioration in the visual analogue scale pain score and Oxford Hip Score (OHS) between six and ten years. There were 18 CoM THAs in 17 patients who had a cobalt or chromium level over 4 ppb and ten CoM THAs in nine patients who had a cobalt or chromium level higher than 7 ppb with a statistically significant increase in chromium levels only between the two timepoints. Overall, 84 stems (39.1%) had significant radiolucent lines at ten years compared to 65 (25.5%) at six years. Conclusion. When compared to the original review, there has been a significant deterioration in pain score, OHS, radiograph appearance, and, most critically, survival has fallen to 91.2%, which does not meet the Orthopaedic Data Evaluation Panel (ODEP) 10 A* 95% threshold. Although this bearing is no longer on the market, 2.5% were bearing-related revisions, which have relevance to the discussion around modular dual-mobility implants that have a similar metal interface


The Bone & Joint Journal
Vol. 106-B, Issue 11 | Pages 1273 - 1283
1 Nov 2024
Mahmud H Wang D Topan-Rat A Bull AMJ Heinrichs CH Reilly P Emery R Amis AA Hansen UN

Aims

The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this study was to assess the in vitro wear performance of ceramic and metal humeral hemiarthroplasties on natural glenoids.

Methods

Intact right cadaveric shoulders from donors aged between 50 and 65 years were assigned to a ceramic group (n = 8, four male cadavers) and a metal group (n = 9, four male cadavers). A dedicated shoulder wear simulator was used to simulate daily activity by replicating the relevant joint motion and loading profiles. During testing, the joint was kept lubricated with diluted calf serum at room temperature. Each test of wear was performed for 500,000 cycles at 1.2 Hz. At intervals of 125,000 cycles, micro-CT scans of each glenoid were taken to characterize and quantify glenoid wear by calculating the change in the thickness of its articular cartilage.


The Bone & Joint Journal
Vol. 106-B, Issue 11 | Pages 1199 - 1202
1 Nov 2024
Watts AC Tennent TD Haddad FS


Bone & Joint Open
Vol. 5, Issue 10 | Pages 937 - 943
22 Oct 2024
Gregor RH Hooper GJ Frampton C

Aims

The aim of this study was to determine whether obesity had a detrimental effect on the long-term performance and survival of medial unicompartmental knee arthroplasties (UKAs).

Methods

This study reviewed prospectively collected functional outcome scores and revision rates of all medial UKA patients with recorded BMI performed in Christchurch, New Zealand, from January 2011 to September 2021. Patient-reported outcome measures (PROMs) were the primary outcome of this study, with all-cause revision rate analyzed as a secondary outcome. PROMs were taken preoperatively, at six months, one year, five years, and ten years postoperatively. There were 873 patients who had functional scores recorded at five years and 164 patients had scores recorded at ten years. Further sub-group analysis was performed based on the patient’s BMI. Revision data were available through the New Zealand Joint Registry for 2,323 UKAs performed during this time period.


Aims

This study examined the relationship between obesity (OB) and osteoporosis (OP), aiming to identify shared genetic markers and molecular mechanisms to facilitate the development of therapies that target both conditions simultaneously.

Methods

Using weighted gene co-expression network analysis (WGCNA), we analyzed datasets from the Gene Expression Omnibus (GEO) database to identify co-expressed gene modules in OB and OP. These modules underwent Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and protein-protein interaction analysis to discover Hub genes. Machine learning refined the gene selection, with further validation using additional datasets. Single-cell analysis emphasized specific cell subpopulations, and enzyme-linked immunosorbent assay (ELISA), protein blotting, and cellular staining were used to investigate key genes.


Bone & Joint 360
Vol. 13, Issue 5 | Pages 28 - 30
1 Oct 2024

The October 2024 Foot & Ankle Roundup360 looks at: Hemiarthroplasty for hallux rigidus; Fixed or mobile-bearing ankle arthroplasty? A meta-analysis; Bone grafting for periprosthetic bone cysts following total ankle arthroplasty; Diabetic foot ulcer after first-ray amputation; Early motion after ankle surgery: the path to faster recovery?; Are podiatrists and orthopaedic surgeons approaching zone 2 fifth metatarsal fractures in the same way?.


The Bone & Joint Journal
Vol. 106-B, Issue 9 | Pages 916 - 923
1 Sep 2024
Fricka KB Wilson EJ Strait AV Ho H Hopper, Jr RH Hamilton WG Sershon RA

Aims. The optimal bearing surface design for medial unicompartmental knee arthroplasty (UKA) remains controversial. The aim of this study was to compare outcomes of fixed-bearing (FB) and mobile-bearing (MB) UKAs from a single high-volume institution. Methods. Prospectively collected data were reviewed for all primary cemented medial UKAs performed by seven surgeons from January 2006 to December 2022. A total of 2,999 UKAs were identified, including 2,315 FB and 684 MB cases. The primary outcome measure was implant survival. Secondary outcomes included 90-day and cumulative complications, reoperations, component revisions, conversion arthroplasties, range of motion, and patient-reported outcome measures. Overall mean age at surgery was 65.7 years (32.9 to 94.3), 53.1% (1,593/2,999) of UKAs were implanted in female patients, and demographics between groups were similar (p > 0.05). The mean follow-up for all UKAs was 3.7 years (0.0 to 15.6). Results. Using revision for any reason as an endpoint, five-year survival for FB UKAs was 97.2% (95% CI 96.4 to 98.1) compared to 96.0% for MB (95% CI 94.1 to 97.9; p = 0.008). The FB group experienced fewer component revisions (14/2,315, 0.6% vs 12/684, 1.8%; p < 0.001) and conversion arthroplasties (38/2315, 1.6% vs 24/684, 3.5%; p < 0.001). A greater number of MB UKAs underwent revision due to osteoarthritis progression (FB = 21/2,315, 0.9% vs MB = 16/684, 2.3%; p = 0.003). In the MB group, 12 (1.8%) subjects experienced bearing dislocations which required revision surgery. There were 15 early periprosthetic tibia fractures (0.6%) in the FB group compared to 0 for MB (p = 0.035). Conclusion. In similar patient populations, FB UKAs demonstrated slightly higher survival than a commonly used MB design. Adverse event profiles differed by bearing type, with an increased risk of bearing dislocation and OA progression with MB designs, and early periprosthetic tibia fractures for FB designs. Cite this article: Bone Joint J 2024;106-B(9):916–923


Bone & Joint Open
Vol. 5, Issue 8 | Pages 715 - 720
23 Aug 2024
Shen TS Cheng R Chiu Y McLawhorn AS Figgie MP Westrich GH

Aims

Implant waste during total hip arthroplasty (THA) represents a significant cost to the USA healthcare system. While studies have explored methods to improve THA cost-effectiveness, the literature comparing the proportions of implant waste by intraoperative technology used during THA is limited. The aims of this study were to: 1) examine whether the use of enabling technologies during THA results in a smaller proportion of wasted implants compared to navigation-guided and conventional manual THA; 2) determine the proportion of wasted implants by implant type; and 3) examine the effects of surgeon experience on rates of implant waste by technology used.

Methods

We identified 104,420 implants either implanted or wasted during 18,329 primary THAs performed on 16,724 patients between January 2018 and June 2022 at our institution. THAs were separated by technology used: robotic-assisted (n = 4,171), imageless navigation (n = 6,887), and manual (n = 7,721). The primary outcome of interest was the rate of implant waste during primary THA.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 60 - 60
19 Aug 2024
Lau LCM Cheung MH Ng FY Fu H Chan PK Chiu P
Full Access

In total hip arthroplasty (THA), cementless cup without screw holes has the putative benefits of maximizing host bone contact and reducing osteolysis by eliminating channels to backside wear particles. However, supplemental trans-acetabular screws cannot be used. 74 hips in 60 patients receiving same model of cementless cup without screw holes (Depuy Duraloc 100 HA cup) from 6/1999 to 3/2003 were prospectively followed up. All patients were allowed to have immediate full weight bearing. Age at THA was 53 ± 13 (range 24–74) years. Osteonecrosis was the leading hip disease (45% of hips). Survivorship was assessed using revision of the cup as the end point. Radiological parameters, including lateral opening angle, vertical and horizontal migration distances of the cups were measured. Paired t-test was used to compare between the measurements in early postoperative period and at final follow up. 51 hips were assessed at minimum 20 years follow-up. The mean follow-up was 22.6 (range 21 – 25) years. All the cups were well fixed. There were two cup revisions. Conventional polyethylene (PE) was used in both hips; osteolysis occurred 17 and 18 years later. Both cups were well fixed but were revised, one due to cup mal-positioning, one due to need in upsizing the articulation. 14 other hips were revised but these cups were well fixed and not revised; 9 loosened stems (most were cemented Elite plus stems), 5 PE wear and osteolysis (all were conventional PE). At 20 years, the survivorship of cups was 96.1%. Changes in lateral opening angle, vertical and horizontal migration distances were 0.44±1.59°, 0.01±1.52mm and -0.32±1.47mm respectively, without statistical significance. This study provided evidence of excellent long-term survivorship of cementless cup without screw holes. Immediate postoperative weight-bearing also did not lead to cup migration in the long-term


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 39 - 39
19 Aug 2024
Zuke WA Hannon CP Kromka J Granger C Clohisy JC Barrack RL
Full Access

We previously reported the five to ten-year results of the Birmingham Hip Resurfacing (BHR) implant. The purpose of this study was to evaluate the survivorship, radiographic results, and clinical outcomes of the BHR at long-term follow-up. We retrospectively reviewed 250 patients from the original cohort of 324 BHRs performed from 2006 to 2013 who met contemporary BHR indications. Of these, 4 patients died and 4 withdrew. From the 242 patients, 224 patients (93%) were available for analysis. Modified Harris hip score (mHHS) and University of California, Los Angeles (UCLA) scores were collected and compared to a matched total hip arthroplasty (THA) cohort. Mean follow-up was 14 years. Survivorship free of aseptic revision was 97.4% and survivorship free of any revision was 96.0% at 15 years. Revisions included 3 periprosthetic joint infections, 2 for elevated metal ions and symptomatic pseudotumor, 2 for aseptic femoral loosening, and 1 for unexplained pain. The mean mHHS was 93 in BHR patients at final follow-up, similar to the THA cohort (p=0.44). The UCLA score was significantly higher for BHR patients (p=0.02), however there were equal proportions of patients who remained highly active (UCLA 9 or 10) in both groups, 60.5% and 52.2% (p=0.45) for BHR and THA respectively. Metal ion levels at long term follow-up were low (mean serum cobalt 1.8±1.5 ppb and mean serum chromium 2.2±2.0 ppb). BHR demonstrated excellent survivorship in males less than 60 years of age at time of surgery. Clinical outcomes and activity levels were similar to THA patients. Failures related to the metal-on-metal bearing were rare and metal levels were low at long-term follow-up. Level of evidence: III. Keywords: survivorship; hip arthroplasty; activity; metal-on-metal. Surface Replacement Arthroplasty demonstrates low revision rates and similar activity level compared to total hip arthroplasty at long-term follow-up


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 13 - 13
19 Aug 2024
DeBenedetti A Weintraub MT Valle CJD Jacobs JJ Nam D
Full Access

The purpose of this randomized controlled trial was to evaluate serum metal levels in patients undergoing total hip arthroplasty (THA) with a conventional compared to a modular dual-mobility bearing. Patients undergoing primary THA for osteoarthritis were randomized to receive either a modular dual-mobility or conventional polyethylene bearing. All patients received the same titanium acetabular and femoral component and a ceramic femoral head. Serum metal levels were drawn pre-operatively then annually for a minimum of two years postoperatively. An a priori power analysis determined that 40 patients (20 per cohort) were needed to identify a clinically relevant difference in serum cobalt of 0.35 ng/ml (ppb) at 90% power. Forty-six patients were randomized to a modular dual-mobility (n=25) or conventional bearing (n=21) with 40 at a minimum follow-up of two years. No differences in serum cobalt (mean 0.14 ppb [range, 0.075–0.29] vs. 0.20 ppb [range, 0.075–0.57], p=0.39) or chromium levels (mean 0.14 ppb [range, 0.05–0.50] vs. 0.12 ppb [range, 0.05–0.35], p=0.65) were identified between the modular dual-mobility and conventional cohorts, respectively. There was no statistically significant difference in serum Co or Cr at two years postoperatively in subjects implanted with a ceramic head and this particular dual mobility bearing in comparison to a ceramic head and a conventional acetabular component. While modest expected elevations in serum Co and Cr were observed in the dual mobility group, in no case did the Co level exceed the laboratory reference range nor the threshold of one part per billion that has been associated with adverse local tissue reactions to mechanically-assisted crevice corrosion


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 62 - 62
19 Aug 2024
Devane PA Horne JG Chu A
Full Access

We present minimum 20 year results of a randomized, prospective double blinded trial (RCT) of cross-linked versus conventional polyethylene (PE), using a computer assisted method of PE wear measurement. After Ethics Committee approval, 122 patients were enrolled into an RCT comparing Enduron (non cross-linked PE) and highly cross-linked Marathon PE (DePuy, Leeds, UK). Other than the PE liners, identical components were used, a Duraloc 300 metal shell with one screw, a 28mm CoCr femoral head and a cemented Charnley Elite femoral stem. All patients were followed with anteroposterior (A∼P) and lateral radiographs at 3 days, 6 weeks, 3 months, 6 months, 1, 2, 3, 4, 5, 10 and 20 years. PE wear was measured with PolyMig, which has a phantom validated accuracy of ± 0.09mm. At minimum 20 year follow-up, 47 patients had died, 5 of which had been revised prior to their death. Another 32 patients were revised and alive, leaving 43 patients unrevised and alive (15 Enduron, 28 Marathon). No patients were lost to follow-up, but 2 were not able to be radiographed (dementia), leaving 41 patients (15 Enduron, 26 Marathon) available for PE wear measurement. After the bedding-in period, Enduron liners had a wear rate of 0.182 mm/year, and Marathon liners had a wear rate of 0.028 mm/year. At 20 years follow-up, 37 patients had required revision. Patients with conventional PE had three times the revision rate (28/37) of those who received XLPE (9/37). This is the longest term RCT showing substantially improved clinical and radiological results when XLPE is used as the bearing surface


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 61 - 61
19 Aug 2024
Whitehouse MR Patel R French J Beswick A Navvuga P Marques E Blom A Lenguerrand E
Full Access

We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by types of bearing surfaces used. We analysed THR procedures across all orthopaedic units in England and Wales. Our analyses estimated all-cause and cause-specific revision rates. We identified primary THRs with heads and monobloc cups or modular acetabular component THRs with head and shell/liner combinations. We used flexible parametric survival models to estimate adjusted hazard ratios (HR). A total of 1,026,481 primary THRs performed between 2003–2019 are included in the primary analysis (Monobloc: n=378,979 and Modular: n=647,502) with 20,869 (2%) of these primary THRs subsequently undergoing a revision episode (Monobloc: n=7,381 and Modular: n=13,488). Compared to implants with a cobalt chrome head and highly crosslinked polyethylene (HCLPE) cup, the all-cause risk of revision for monobloc acetabular implant was higher for patients with cobalt chrome or stainless steel head and non-HCLPE cup. The risk of revision was lower for patients with a delta ceramic head and HCLPE cup implant, at any post-operative period. Compared to patients with a cobalt chrome head and HCLPE liner primary THR, the all-cause risk of revision for modular acetabular implant varied non-constantly. THRs with a delta ceramic or oxidised zirconium head and HCLPE liner had a lower risk of revision throughout the entire post-operative period. The all-cause and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is lower for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup than commonly used alternatives such as cobalt chrome heads and HCLPE liner/cup


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 6 - 6
19 Aug 2024
Lausmann C Luck S Beil FT Citak M Gehrke T
Full Access

Mechanical failure due to dislocation, fracture and acetabular wear as well as persistence of infection are the main complications associated with the use of hip spacers in the treatment of periprosthetic joint infections (PJI). We have developed a novel, custom-made spacer as part of two-stage septic hip replacement and present the two- to five-year results after reimplantation. We prospectively examined a total of 73 patients over our study period in whom our new spacer technique was used. The technique includes a dual mobility inlay and a cemented straight stem in combination with antibiotic-loaded PMMA bone cement which allows full weight bearing meanwhile the interim period. The follow-up ranged between 24 and 60 months after reimplantation as second stage of a two-stage approach. The patients were contacted as part of the follow-up using a questionnaire concerning reoperation, reinfection as well as hip function by using the Harris Hip Score. 72 patients (98,6%) could be reimplanted, one patient is still using the spacer prothesis for 45 months because of excellent functional results with a Harris Hip Score of 95, nevertheless reimplantation is planned. The reinfection rate was less than 7% after reimplantation. The dislocation rate was 5%, and in total there was an overall complication rate of less than 10%. The Harris Hip Score was significantly improved. The ENDO spacer surgical technique is a promising option in the treatment of periprosthetic joint infections (PJI) for two-stage septic exchange with a low dislocation rate and good infection control after reimplantation. In addition, it enables early mobilization with the possibility of full weight-bearing in the interval between spacer implantation and reimplantation


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 66 - 66
19 Aug 2024
Terhune EB Sutter EG Balkissoon R Pallante GD Specht L Leikin JB Kwon YM Lewallen DG Gerlinger TL Jacobs JJ
Full Access

Ceramic-on-ceramic (CoC) articulations in total hip arthroplasty (THA) have low wear, but the unique risk of fracture. After revision for CoC fracture, ceramic third bodies can lead to runaway wear of cobalt chrome (CoCr) causing extremely elevated blood cobalt. We present five cases of ceramic liner fractures revised to a CoCr head associated with the rapid development of severe cobalt toxicity.

We identified 5 cases of fractured CoC THA treated with revision to CoCr on highly cross-linked polyethylene (HXLPE) – three to conventional bearings and two to modular dual mobility bearings (CoCr acetabular liner, CoCr femoral head, and HXLPE). Mean follow up was 2.5 years after CoCr/HXLPE re-revision.

Symptoms of cobalt toxicity occurred at average 9.5 months after revision for ceramic fracture (range 6–12). All patients developed vision and hearing loss, balance difficulties, and peripheral neuropathy. Several had cardiomyopathy, endocrinopathy, and local skin discoloration. Two reported hip pain. Re-revision for cobalt toxicity occurred at an average of 22 months (range 10–36) after revision for ceramic fracture. Average serum cobalt level at re-revision was 991 μg/L (range 734–1302, normal <1 μg/L). All CoCr heads exhibited massive wear with asphericity; deep tissues exhibited prominent metallosis. Treatment consisted of debridement and revision to a ceramic head with HXLPE. Serum cobalt improved to an average of 25 μg/L at final follow up. All patients reported partial improvement in vision and hearing; peripheral neuropathy and balance did not recover.

Systemic cobalt toxicity is a rare but devastating complication of ceramic fracture in THA treated with cobalt-alloy bearings. Cobalt alloy bearings should be avoided in this setting. The diagnosis of systemic cobalt toxicity requires a high index of suspicion and was typically delayed following systemic symptoms. Debridement and revision to a ceramic-on-HXLPE leads to improvement but not resolution of cobalt toxicity complications.