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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 77 - 77
1 Feb 2020
Ramirez-Martinez I Smith S Trail I Joyce T
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Introduction

Despite the positive outcomes in shoulder joint replacements in the last two decades, polyethylene wear debris in metal-on-polyethylene artificial shoulder joints is well-known as a limitation in the long-term survival of shoulder arthroplasties systems. Consequently, there is an interest in the use of novel materials as an alternative to hard bearing surfaces such as pyrolytic carbon layer (PyroCarbon).

Materials and Methods

In the present study, the unique Newcastle Shoulder Wear Simulator was used (Smith et al., 2015; Smith et al., 2016) to evaluate the wear behavior of four commercially available PyroCarbon humeral heads 43 mm diameter, articulating against conventional ultra-high molecular weight polyethylene (UHMWPE) glenoid inserts with a radius of curvature of 17.5 mm to form an anatomic total shoulder arthroplasty.

A physiological combined cycled “Repeat-motion-load” (RML) (Ramirez-Martinez et al., 2019) obtained from the typical activities of daily life of patients with shoulder implants was applied as a simulator input. A fifth sample of the same size and design was used as a soak control and subjected to dynamic loading without motion during the wear test. The mean volumetric wear rate of PyroCarbon-on-polyethylene was evaluated over 5 million cycles gravimetrically and calculated on the basis of linear regression, as well as the change in surface roughness (Sa) of the components using a non-contacting white light profilometer throughout the test.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_27 | Pages 19 - 19
1 Jul 2013
Rashid M Butt U Birch A Crank S Temperley D Freemont A Trail I
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Our aim was to accurately determine whether muscle atrophy and fatty infiltration are reversible following cuff repair. Patients with a repairable cuff-tear were recruited and assessed clinically and radiologically (Magnetic Resonance Imaging). At surgery, supraspinatus was biopsied. Post-operatively, patients underwent clinical evaluation at standardised intervals, with further MRI and an ultrasound guided biopsy of supraspinatus at 12 months.

MRI was used to characterize cuff-tears and determine the degree of muscle atrophy and fatty infiltration. Biopsy samples were fixed on-site and transported for processing. Morphometric assessments of myofibres were made and mean cross-sectional areas calculated using validated techniques. The pathologist was blinded to sample details. Statistical analysis was performed to assess differences in mean myofibre area following cuff repair and correlated with radiological findings.

Eight patients were available for completed histological and radiological analysis. Six (two re-tears) demonstrated sizeable and highly statistically significant improvements in mean myofibre cross-sectional area (P=0.000–0.0253). Of the two not showing any increase in myofibre area, neither result was statistically significant (P=0.06, 0.2); one was a re-tear and one was a repair of a partial-thickness tear. Radiologically, the muscle and fatty changes had not demonstrably changed.

Our finding that myofibre cross-sectional area increases following cuff repair suggests muscle atrophy is a potentially reversible process. Even with re-tears, improvements were seen. MRI features of fatty infiltration and muscle atrophy were not seen to improve however. It is likely that radiological assessment is not sensitive enough to demonstrate the reversibility of muscle atrophy seen on histological analysis at one year.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 42 - 42
1 Feb 2012
Talwalkar S Edwards A Hayton M Stillwell J Trail I Stanley J
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One hundred and sixty-two patients with a diagnosis of scapholunate instability underwent a modified Brunelli procedure over a 7 year period. One hundred and seventeen were assessed with the help of a questionnaire and, of these, 55 patients attended for clinical evaluation. The mean follow-up was 4 (1-8) years. There were 72 patients with dynamic scapholunate instability and 45 patients with static instability. The average age was 38 years. There were 50 males and 67 females. 77 (62%) patients had no to mild pain with a mean visual analogue score of 3.67 (SD=2.5)). The loss in the arc of flexion-extension was due to a reduced range of flexion (mean 31% loss), while 80% of extension was maintained, compared with the contralateral side. The grip strength on the operated side was reduced by 20% of the non-operated side. There was no statistically significant difference (p>0.05) in the range of movement or the grip strength between the static and dynamic group or the claims and non-claims group. Ninety (79%) patients were satisfied with the result of the surgery (good to excellent) and 88% of the patients felt that they would have the same surgery again. We feel that these results compare favourably with the early results published from this unit and recommend this procedure for dynamic and static scapholunate instability


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 33 - 33
1 Feb 2012
Talwalkar S Roy N Hayton M Trail I Stanley J
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Between 1994 and 2002, 81 patients underwent ulnohumeral arthroplasty for elbow arthritis at our institution. All patients were sent a questionnaire with a request to attend for a clinical evaluation. Forty replied and 34 attended for clinical examination, 6 females and 34 males with an average age of 63 years (32-80) and a mean follow-up of 6 years (2-10). There were 22 (55%) patients with primary osteoarthritis, 14 (35%) with osteoarthritis secondary to trauma, two patients with rheumatoid arthritis and one patient each with arthrogryphosis multiplex congenital and post-septic arthritis of the elbow.

Using the VAS (0-10), the pain score was seen to improve from a mean pre-operative score of 8 (6-10) to 4 (0-9). 21 patients (50%) were on minimal or no analgesia and 31 (75%) patients felt they would have the surgery again for the same problem. The arc of motion as regards flexion/extension was found to increase by 19% while prono-supination was found to increase by 30%. There was one patient each with superficial infection, anterior interosseous nerve neuropathy and myositic ossificans while two patients had triceps rupture. Radiological examination showed that in 12 cases the trephine hole was partially obliterated while in 4 cases it was completely obliterated. This could not be correlated clinically. Patients with loose bodies seemed to do better in the post-operative phase.

Ulnohumeral arthroplasty has a role in the management of the arthritic elbow as it provides pain relief in the post-operative period; however, the improvement in the range of movement is limited particularly as regards the arc of extension.