Glenoid loosening is a major problem in total shoulder arthroplasty. Failure of osteointegration, osteolysis and loosening are potential problems with concerning reports of these complications with earlier metal back designs. CT scans have been reported as more accurate than plain x-rays in examining fixation of components. This study examines the medium term osteointegration of the SMR (Lima) metal back glenoid component. 20 consecutive patients operated on by the same surgeon (KM) were evaluated at a mean of 3 years 9 months (range 3-5 years) using CT analysis. Films were read by a musculoskeletal radiologist (AS). 8 zones were described and the interface graded as ‘osteointergrated’, ‘lucent zone < 1mm’, ‘lucent zone 1-2mm’, ‘lucent zone > 2mm osteolysis’. Loosening was defined as lucent line on all zones > 1mm or migration of implant. No components were loose. All components were osteointegrated around the central peg. Osteointegration was observed in 85% of zones. 4% of the zones were graded as osteolysis, all in the one patient. This patient had osteolysis 4 years post-surgery with superior subluxation of the humeral head and polyethlylene and metal wear. The glenoid component was not loose at revision surgery. Problems with this technique of assessment include radiation exposure and artefact. Small lucent zones often had a well contoured margin suggesting that the component did not seat perfectly on the bone surface in these areas. These results confirm that reliable medium term osteointegration does occur with the SMR metal back glenoid in anatomical total shoulder replacement. Osteolysis can occur and longer term follow up is ongoing

Aims

Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA).

The glenoid is the ‘weak link’ in total shoulder arthroplasty. Concerns exist over loosening of all glenoid components. Metal back glenoid components have, in some reports, had early problems with liner dissociation, polyethylene wear, osteolysis and component fracture. In November 2003 the first metal back SMR total shoulder replacement was implanted in New Zealand (NZ). We reviewed the NZ joint registry information on anatomical total shoulder replacements over a 5-year period from the end of 2003. There were 192 metal back SMR prostheses (Lima) implanted and 484 cemented prostheses (all brands). 70% of patients in each group completed an Oxford score at 6 months. The mean score in both groups was 40.39. There was no statistically significant difference in the revision rate in this period for revisions of any kind (p=0.07). 6/192 metal back cases had a revision procedure, but none were for the glenoid component. 7/484 cemented cases had a revision procedure with 3 being for glenoid loosening. None of the metal back glenoids were revised in this period. 5 of the cemented glenoids were revised in this period. There was a higher revision rate for instability in the metal back group with 5 in the metal back group and 2 in the cemented group being revised for instability (p=0.01). In the metal back group there were 3 revisions to a reverse shoulder arthroplasty without removal of the metal back glenoid base plate. We have not identified an early cause for concern with the use of the metal back SMR prosthesis in anatomical total shoulder replacement in New Zealand. It is possible, but not proven, that the modularity of the implant may lower the revision threshold for some cases. Reassuringly, there were no revisions of the metal back glenoid in this early period

The 2021 Australian Orthopaedic Association National Joint Replacement Registry report indicated that total shoulder replacement using both mid head (TMH) length humeral components and reverse arthroplasty (RTSA) had a lower revision rate than stemmed humeral components in anatomical total shoulder arthroplasty (aTSA) - for all prosthesis types and diagnoses. The aim of this study was to assess the impact of component variables in the various primary total arthroplasty alternatives for osteoarthritis in the shoulder. Data from a large national arthroplasty registry were analysed for the period April 2004 to December 2020. The study population included all primary aTSA, RTSA, and TMH shoulder arthroplasty procedures undertaken for osteoarthritis (OA) using either cross-linked polyethylene (XLPE) or non-cross-linked polyethylene (non XLPE). Due to the previously documented and reported higher revision rate compared to other anatomical total shoulder replacement options, those using a cementless metal backed glenoid components were excluded. The rate of revision was determined by Kaplan-Meir estimates, with comparisons by Cox proportional hazard models. Reasons for revision were also assessed. For a primary diagnosis of OA, aTSA with a cemented XLPE glenoid component had the lowest revision rate with a 12-year cumulative revision rate of 4.7%, compared to aTSA with cemented non-XLPE glenoid component of 8.7%, and RTSA of 6.8%. The revision rate for TMH was lower than aTSA with cemented non-XLPE, but was similar to the other implants at the same length of follow-up. The reason for revision for cemented aTSR was most commonly component loosening, not rotator cuff deficiency. Long stem humeral components matched with XLPE in aTSA achieve a lower revision rate compared to shorter stems, long stems with conventional polyethylene, and RTSA when used to treat shoulder OA. In all these cohorts, loosening, not rotator cuff failure was the most common diagnosis for revision

Purpose of the study: To assess the survivability of the metal backed glenoid component, to examine its mode of failure and to measure the range of movement, specifically rotation following Total Shoulder Arthroplasty. Patients and methods: 46 patients (55 shoulders) were prospectively followed up after Biomet biomodular Total Shoulder Arthroplasty using a metal backed glenoid component fixed with screws. 36 patients (43 shoulders) had Rheumatoid arthritis, 9 patients (11 shoulders) had Osteoarthritis and 1 patient had Psoriatic arthritis. Mean age at surgery was 58 years (range 37 to 79 years). Patients were followed up for a minimum of 5 years. Data was collected prospectively for a mean follow up of 84 months. 28 of the 46 patients had more than 10 years follow up. Range of movement including forward flexion and rotation was measured. Data was analysed by 3 independent observers. Intention to treat or revision of component was taken as failure. Paired t test comparison was carried out for statistical analysis. Results: One failure was noted in the Osteoarthritis group at 8 years follow up. Superior head migration and eccentric wear of polyethylene liner was noted in an otherwise well fixed glenoid component. Range of external rotation improved from a mean of 18.2 to 38.2 degrees. This improvement was statistically significant (p=0.01, 95% CI= 6.3 to 35.2). The range of forward flexion improved significantly from a mean of 80.5 to 110 degrees (p= .01, 95% CI= −42.6 to −5.9). 3 failures were noted in the Rheumatoid group. 2 patients needed revision to hemiarthroplasty within 4 years of surgery for rotator cuff insufficiency with superior head migration but without loosening of glenoid. One other shoulder was revised at 11 years for glenoid component loosening with a worn out polyethylene liner. All 3 failures occurred in patients more than 60 years of age. Rheumatoid patients under 60 had a significant improvement in the range of external rotation from a mean of 24.2 to 30.6 degrees (p= 0.03, 95% CI = −21.4 to −1.1). The range of forward flexion improved from a mean of 71.2 to 73.3 degrees which was not statistically significant (p=.767). Rheumatoid patients over 60 years of age did not have a statistically significant improvement in the range of external rotation( p= 0.712) or in their range of forward flexion (p=.757). Conclusion: Contrary to recent literature, in this study the metal backed glenoid component performed well in the medium to long term following Total Shoulder Arthroplasty particularly in patients with Osteoarthritis and in younger patients suffering with Rheumatoid arthritis

The metal backed glenoid component in total shoulder replacement (TSR) has been associated with high revision rates and some authors have suspended the use of this implant. The aim of this study was to evaluate the medium to long-term outcome of the metal backed glenoid component in rheumatoid patients. Thirty-nine patients (46 shoulders) with a mean age of 55 years (35–86 years) received a TSR with a screw fixed porous coated metal-back glenoid. Ten were lost or died before 8 years follow-up, of which none were revised. Twenty-nine patients (36 shoulders) were followed up for a mean of 132 months (96–168 months). A Constant score was measured preoperatively and annually from time of surgery, and independently at last follow-up. Radiographs were assessed for lucency, loosening and superior subluxation of the humeral head. The Constant score improved by 12.9 points (p=< 0.001). Implant survivorship at 10 years was 89%. Five were revised: 3 for pain secondary to superior subluxation, one for infection and one for aseptic loosing. All patients with lucent zones around the glenoid (four) had superior subluxation of the humeral head two to four years prior to their development. Survival rate however at 10 years was reduced, if judged by the development of superior subluxation on radiographs (33%). The uncemented glenoid performs well in the rheumatoid shoulder, giving pain relief and improved functional outcome. The survivorship is comparable to previously reported studies

Abstract. Shoulder replacements have evolved and current 4th generation implants allow intraoperative flexibility to perform anatomic, reverse, trauma, and revision shoulder arthroplasty. Despite high success rates with shoulder arthroplasty, complication rates high as 10–15% have been reported and progressive glenoid loosening remains a concern. Objectives. To report medium term outcomes following 4th generation VAIOS® shoulder replacement. Methods. We retrospectively analysed prospectively collected data following VAIOS® shoulder arthroplasty performed by the senior author between 2014–2020. This included anatomical (TSR), reverse(rTSR), revision and trauma shoulder replacements. The primary outcome was implant survival (Kaplan-Meier analysis). Secondary outcomes were Oxford Shoulder Scores (OSS), radiological outcomes and complications. Results. 172 patients met our inclusion criteria with 114 rTSR, 38 anatomical TSR, and 20 hemiarthroplasty. Reverse TSR- 55 primary, 31 revision, 28 for trauma. Primary rTSR- 0 revisions, average 3.35-year follow-up. Revision rTSR-1 revision (4.17%), average 3.52-year follow-up. Trauma rTSR- 1 revision (3.57%), average 4.56-year follow-up OSS: Average OSS improved from 15.39 to 33.8 (Primary rTSR) and from 15.11 to 29.1 (Revision rTSR). Trauma rTSR-Average post-operative OSS was 31.4 Anatomical TSR38 patients underwent primary anatomical TSR, 8 were revisions following hemiarthroplasty. In 16/38 patients, glenoid bone loss was addressed by bone grafting before implantation of the metal back glenoid component. Mean age at time of surgery was 68.3 years (53 – 81 years). Mean follow-up was 34 months (12 – 62 months). The average Oxford shoulder score improved from 14 (7–30) to 30 (9–48). There were 3 revisions (7.8%); two following subscapularis failure requiring revision conversion to reverse shoulder replacement and one for glenoid graft failure. Conclusions. The medium-term results of the VAIOS® system suggest much lower revision rates across multiple configurations of the system than previously reported, as well as a low incidence of scapular notching. This system allows conversion to rTSR during primary and revision surgery

There is nothing going to ruin your day like a complication after shoulder arthroplasty, either hemiarthroplasty (HA) anatomical (TSA) or reverse arthroplasty (RTSA). While complications are fortunately uncommon with anatomical shoulder arthroplasty (approximately 8% but as high as 40%), the complication rate for RTSA has been reported as high as 70%. Most complications are multifactorial and cannot all be blamed on the patient. Basically you do not want to operate upon a young patient who is an insulin dependent diabetic, has an ASA of 3 or 4, who smokes, has HIV disease and has a BMI over 40. The most common predictors of failure are determined by the indication for surgery, the type of implant used and the skill of the surgeon. The major risk factors for HA are eccentric glenoids, young age and rotator cuff failure. The biggest risk factors for TSA are metal backed glenoid components, younger age of the patient, rotator cuff pathology and insufficient glenoid bone. The major risk factors for RTSA are the type of component used (Grammont type versus lateral center of rotation designs) and the indication for surgery. Infection risks include previous infected arthroplasty, previous joint infection, immunosuppression (e.g. steroid use, insulin dependent diabetes, HIV disease), ASA 3 or 4 and higher BMI (i.e. over 40). Not all of these risk factors can be prevented in patients but informed consent is critical to the patient understanding the potential outcomes of their surgery

The aim of this study was to assess the results of bone ingrowth into the glenoid component of one design of Total Shoulder Arthroplasty (TSA) in which hydroxyapatite (HA) coating of the glenoid baseplate was introduced since 1997. Glenoid loosening is one of the most important complications of both cemented and uncemented TSA. Between May 1993 and April 1997 over 140 uncemented, porous coated, metal backed glenoid component were used in our Unit. By 1997 it had become clear that a significant number of these glenoid components had developed mechanical loosening and some required revision. We therefore started using an HA coated glenoid component for our TSAs from April 1997. One hundred and seventy-four shoulder arthroplasty procedures were performed between April 1997 and October 1999 of which 37 were TSAs using the HA coated uncemented glenoid. The indications included osteoarthritis (22), rheumatoid arthritis (nine), revision TSA (three), avascular necrosis (two) and cuff arthropathy with cuff reconstruction (one). The minimum follow-up was 18 months. The X rays were evaluated using the MLS (Migration, Lucent lines, Screw problems) system, which had been developed and reported previously. This system of evaluation has been shown to be reproducible for assessment of glenoid fixation. There was one case in which the glenoid liner became displaced and had to be replaced. Our early results at a mean FU of approximately 2 years show an improved radiological fixation compared with those glenoids inserted without HA

It is estimated that there will be over 12,000 total shoulder replacements implanted this year. In the best series, the survivorships of these devices are 90% at 7 years. However, there are radiographic indications that the long term success will be limited to wear and damage to the polyethylene glenoid components. Like tibial insert in total knee replacements, the glenoid is subjected to both rolling sliding motions of a metal counterface. Additionally, the compressive loads on the glenoid have been estimated to be as high as 2800N under ‘normal’ conditions. In contrast to tibial inserts, glenoid components are all typically less than 6 mm thick. In metal backed glenoid devices, the polyethylene thickness is often < 3 mm. The effect of these parameters and kinematics on polyethylene damage has not previously described. Although total shoulder replacements have been in use for over 25 years, there have been no reports describing the nature and extent of glenoid polyethylene wear and damage. We report the determination of polyethylene damage type and severity of 38 retrieved glenoid components of at least 4 different designs. Wear and damage were considered significant when either 80% of the glenoid surface was damaged or if over 25% of the component was worn away. Abrasion, burnishing and pitting were the main modes of damage. There were 2 fractured components. There was significant UHMWPE wear and damage in 17 (45%) components. In nine of these, the component was completely worn through.. These findings are consistent with high stress, high wear conditions and thin polyethylene components. These results indicate polyethylene wear and damage is expected to be a key factor in limiting the survivor-ship total shoulder replacements and that polyethylene damage and wear in total shoulder replacements may be higher than that found for either total hip or knee replacements

Aims

We evaluated clinical and radiographic outcomes of total shoulder arthroplasty (TSA) using the second-generation Trabecular Metal (TM) Glenoid component. The first generation component was withdrawn in 2005 after a series of failures were reported. Between 2009 and 2012, 40 consecutive patients with unilateral TSA using the second-generation component were enrolled in this clinical study. The mean age of the patients was 63.8 years (40 to 75) and the mean follow-up was 38 months (24 to 42).

In the UK we have many surgeon inventors – surgeons who innovate and create new ways of doing things, who invent operations, who design new instruments to facilitate surgery or design new implants for using in patients. However truly successful surgeon inventors are a rare breed and they need to develop additional knowledge and skills during their career in order to push forward their devices and innovations. This article reviews my own experiences as a surgeon inventor and the highs and lows over the whole of my surgical career.