Progressive glenoid bone loss caused by erosion in humeral head resurfacing. Orthopade. 2017;46:1028-1033. [PMID: 29063146 DOI: 10.1007/s00132-017-3483-6]

Glenoid wear and migration pattern of a humeral head resurfacing implant: a prospective study using radio stereometric analysis

Background

The humeral head resurfacing arthroplasty (HHR) is normally used as a hemi shoulder arthroplasty and has been in use for the treatment of Gleno-Humeral osteoarthritis (OA) of the shoulder for more than 30 years. Some studies, however, shows that anatomical total shoulder arthroplasty provides better improvement in function than a HHR for patients with OA. Reasons for this may be a progressive glenoid wear (GW) or loosening of the HHR. We, therefore, wanted to investigate the migration pattern of the HHR and also GW by using radio stereometric analysis (RSA).

Methods

21 patients (21 shoulders) with OA and a mean age of 64 years were enrolled in the study. They all received the Copeland humeral resurfacing head and were followed for 2 years with RSA. We evaluated the clinical outcome at 2 years with Western Ontario Osteoarthritis of the Shoulder (WOOS), EuroQol 5 dimension 3L and Constant Shoulder Score. In addition, we assessed data on WOOS and revisions until 5 years follow-up by using the local clinic data within the Swedish Shoulder Arthroplasty Register.

Results

After an initial migration at two months the implants were stable in relation to the humerus with no statistically significant difference between the 2 months and the 2 years value (P = .23). The GW continued to increase during the study period with an initial migration of mean 2.3 mm and at 2 years 3.5 mm with a statistically difference between the 6 months and 2 years value (P = .046). The WOOS, EuroQol 5 dimension 3L and Constant Shoulder Score were all improved at 2 years compared to the preoperative values. We found a weak correlation between GW at 2 years and the WOOS score at 2 and 5 years, but these did not reach statistical significance. There were 4 revisions within 5 years after the primary operation, all due to pain.

Conclusion

The marker-free RSA can be used in clinical studies for assessing migration in HHR implants and was also for the first time used to measure GW. The Copeland HHR seems to obtain a secure fixation in the humerus but shows continuous GW up to two years.

Pyrocarbon hemiprostheses show little glenoid erosion and good clinical function at 5.5 years of follow-up

BACKGROUND

The success of traditional shoulder hemiarthroplasty (HA) with cobalt-chromium heads is limited by painful glenoid erosion with problematic bone loss. Hemiprostheses with pyrolytic carbon (PyC) heads have shown reduced glenoid erosion in experimental laboratory studies. Few in vivo data are available.

METHODS

We performed a single-center consecutive cohort study of 31 of 34 patients (91%) who underwent PyC HA between September 2013 and June 2018. In 11 of these patients, concentric glenoid reaming was additionally performed. The mean follow-up period was 5.5 years (range, 3.5-7 years). Standardized radiographs were taken, and clinical function (Constant score) and pain (visual analog scale score) were recorded. Anteroposterior radiographs were analyzed according to an established method by 2 independent observers: A line parallel to the superior and inferior glenoid rim was translated to the most medial point of the glenoid surface. A further parallel line was placed on the spinoglenoid notch. The distance between these 2 lines was measured. Measurements were scaled using the known diameter of the implanted humeral head component. To assess eccentric erosion, anteroposterior and axial images were classified according to Favard and Walch, respectively.

RESULTS

Mean medial glenoid erosion measured 1.4 mm at an average of 5.5 years of follow-up. In the first year, 0.8 mm of erosion was observed, significantly more than the average erosion per year of 0.3 mm (P < .001). Mean erosion per year was 0.4 mm in patients with glenoid reaming vs. 0.2 mm in those without reaming (P = .09). An evolution of glenoid morphology was observed in 6 patients, of whom 4 had a progression of the erosion grade. The prosthesis survival rate was 100%. The Constant score improved from 45.0 preoperatively to 78.0 at 2-3 years postoperatively and 78.8 at latest follow-up (5.5 years postoperatively) (P < .001). The pain score on a visual analog scale decreased from 6.7 (range, 3-9) preoperatively to 2.2 (range, 0-8) at latest follow-up (P < .001). There was a weak correlation (r = 0.37) between erosion and pain improvement (P = .039) and no correlation between erosion and change in Constant score (r = 0.06).

CONCLUSION

PyC HA caused little glenoid erosion and a sustained improvement in clinical function in our cohort at mid-term follow-up. PyC demonstrates a biphasic development of glenoid erosion, with a reduced rate after the first year. PyC HA should therefore be considered as an alternative to cobalt-chromium HA and to anatomical total shoulder arthroplasty for patients with a high risk of glenoid component complications.

Humeral Head Resurfacing for Isolated Primary Humeral Osteoarthritis With a Large Chondral Defect

Primary, isolated humeral head arthritis or focal chondral defects are uncommon and difficult to diagnose preoperatively. While these lesions have traditionally been treated with total shoulder arthroplasty, shoulder hemiarthroplasty is a viable option for patients with isolated humeral head disease and minimal degenerative changes in the glenoid. This approach can be performed in a minimally invasive fashion, which preserves bone stock and native biomechanics, and can be beneficial if conversion to total shoulder arthroplasty is required in the future and avoids risk of glenoid loosening or failure in younger and more active individuals. In this Technical Note and accompanying video, we describe our technique of humeral head resurfacing in a patient with isolated primary humeral osteoarthritis with a large focal chondral defect in the humeral head.

Mid-term outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared with metal humeral resurfacing and metal stemmed hemiarthroplasty for osteoarthritis in young patients: analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The optimal surgical management of glenohumeral osteoarthritis in young patients remains an unsolved problem. Humeral resurfacing hemiarthroplasty and stemmed hemiarthroplasty using metallic heads are 2 surgical options that avoid the complications of loosening or wear of the glenoid component seen in total shoulder arthroplasty. Despite the potential benefits, improvement in survivorship has not been demonstrated from joint registry studies or other studies at mid-term follow-up. This is predominantly because of glenoid erosion and pain that occur when the metal resurfaced head articulates with the native glenoid. The use of pyrolytic carbon (pyrocarbon) as a resurfacing material has been proposed as an alternative bearing surface thought to reduce glenoid erosion owing to a marked reduction in wear rates in vitro. This study aimed to compare the survivorship of shoulder hemi-resurfacing using pyrocarbon with shoulder hemi-resurfacing and stemmed hemiarthroplasty using metallic heads.

METHODS

Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed for all patients aged <55 years who had undergone a primary shoulder replacement for osteoarthritis from April 16, 2004, to December 31, 2019. The outcomes of shoulder procedures using pyrocarbon hemi-resurfacing were compared with procedures using metal hemi-resurfacing and metal stemmed hemiarthroplasty. The reasons for revision in each arthroplasty class were analyzed. The analyses were undertaken using Kaplan-Meier estimates of survivorship and hazard ratios (HRs) from Cox proportional hazards models.

RESULTS

We analyzed 393 primary shoulder procedures, of which 163 were pyrocarbon hemi-resurfacing procedures, 163 were metal hemi-resurfacing procedures, and 67 were metal stemmed hemiarthroplasties.The cumulative percentage of revision at 6 years was 8.9% for pyrocarbon hemi-resurfacing, 17.1% for metal hemi-resurfacing, and 17.5% for metal stemmed hemiarthroplasty. Pyrocarbon hemi-resurfacing prostheses had a statistically lower revision rate than other hemi-resurfacing prostheses (HR, 0.41; 95% confidence interval, 0.18-0.93; P = .032). Pain, prosthesis fracture, and infection were the key reasons for revision. No pyrocarbon hemi-resurfacing cases were revised for glenoid erosion. In male patients, pyrocarbon humeral resurfacing had a lower cumulative percentage of revision compared with metal stemmed hemiarthroplasty (HR, 0.32; 95% confidence interval, 0.11-0.93; P = .037).

CONCLUSION

Pyrocarbon humeral resurfacing arthroplasty had statistically lower revision rates at mid-term follow-up in patients aged <55 years compared with other hemi-resurfacing procedures.

Outcome and revision rate of uncemented humeral head resurfacing: Mid-term follow-up study

BACKGROUND

Glenohumeral osteoarthritis (OA) is a common cause of pain and disability affecting nearly a third of the world’s population over 60 years of age. As in other joints, shoulder arthroplasty appears to be the most effective treatment. The implant design has evolved during time transitioning to shorter humeral stem lengths or even stemless components.

AIM

To evaluate the medium-term outcome and survival of a cementless humeral head resurfacing (HHR) in a group of patients affected with OA or avascular necrosis.

METHODS

This is a retrospective study of prospectively collected data using HHR in 23 patients (15 female and 8 male) after a 7.4 year follow-up. The collected data included clinical and radiographical evaluation. The Constant score, the visual analogue scale, and a clinical evaluation of range of motion were registered pre- and postoperatively. Fifteen patients affected with OA (2 cases of mild, 6 moderate, and 7 severe) and 10 with avascular necrosis (stage III according to Cruess classification) were enrolled. X-rays were evaluated to detect loosening signs, degenerative changes, and superior humeral head migration. Magnetic resonance preoperatively was also performed to assess the rotator cuff status. Tendon integrity was mandatory to implant the HHR.

RESULTS

In total, 19 patients (21 shoulders) completed the follow-up. Data on 4 shoulders, in 4 patients, were lost because of prosthesis failure. The global revision rate was 16%. A statistically significant improvement in the mean Constant score, visual analogue scale, and range of motion have been reported. No signs of loosening were registered, while in 12 cases a glenoid erosion was found. The osteophytes appeared 7 times on the humeral side and 12 on the glenoid. Superior humeral migration was recorded in only 1 case.

CONCLUSION

HHR remains a reasonable option in patients with an intact rotator cuff for the treatment of OA and avascular necrosis.

Clinical and radiological outcomes of 17 reverse shoulder arthroplasty cases performed after failed humeral head resurfacing

INTRODUCTION

Despite the good outcomes with shoulder resurfacing procedures reported by some authors, our team has documented several failures caused by glenoid erosion and rotator cuff rupture, likely due to implant overstuffing. The aim of this study was to evaluate the clinical and radiological outcomes of reverse shoulder arthroplasty (RSA) performed after failed humeral head resurfacing (HHR).

MATERIAL AND METHODS

This was a retrospective, single-center study of 17 patients who underwent RSA after failed HHR between January 2011 and February 2016. The mean patient age was 69.4 years and the mean time between HHR and surgical revision was 41 months (14.7-73.5±18.8). Preoperative ultrasonography and CT were used to evaluate the condition of the rotator cuff, extent of glenoid erosion and to look for signs of humeral cup loosening. The clinical outcomes were evaluated pre- and postoperatively using the simple shoulder test (SST), DASH (Disabilities of the Arm, Shoulder and Hand) and the Constant-Murley score. Pain was estimated using a visual analog scale (VAS). The range of motion (ROM) was determined pre- and postoperatively. All patients had standard AP and lateral X-ray views of the shoulder taken as part of their postoperative follow-up protocol to look for implant loosening.

RESULTS

The mean follow-up was 35.9 months (24-59±10.7). There were no intraoperative or postoperative complications. All the functional scores were improved after RSA. The median weighted Constant score preoperatively was 46% (36; 62) while it was 92% postoperatively (78; 100) (p<0.0001). The active ROM improved by 65° in forward flexion (p=0.0003) and by 30° in external rotation (p=0.002). On X-rays, we identified one patient with Sirveaux stage 4 glenoid notching and one patient with a humeral periprosthetic radiolucent line less than 2mm thick in zone 6, with no clinical consequences.

CONCLUSION

The excellent outcomes after RSA for failed HHR in our study are similar to the ones reported when RSA is performed for cuff tear arthropathy.