Surface replacement of the humeral head in the rheumatoid shoulder

Cementless Metal-Free Ceramic-Coated Shoulder Resurfacing

Shoulder resurfacing is a versatile, bone-conserving procedure to treat arthritis, avascular necrosis, and rotator cuff arthropathy. Shoulder resurfacing is of interest to young patients who are concerned about implant survivorship and those in need of a high level of physical activity. Using a ceramic surface reduces wear and metal sensitivity to clinically unimportant levels. Between 1989 and 2018, 586 patients received cementless, ceramic-coated shoulder resurfacing implants for arthritis, avascular necrosis, or rotator cuff arthropathy. They were followed for a mean of 11 years and were assessed using the Simple Shoulder Test (SST) and Patient Acceptable Symptom State (PASS). CT scans were used in 51 hemiarthroplasty patients to assess the glenoid cartilage wear. Seventy-five patients had a stemmed or stemless implant in the contralateral extremity. A total of 94% of patients had excellent or good clinical results and 92% achieved PASS. 6% of patients required a revision. A total of 86% of patients preferred their shoulder resurfacing prosthesis over a stemmed or stemless shoulder replacement. The glenoid cartilage wear at a mean of 10 years was 0.6 mm by a CT scan. There were no instances of implant sensitivity. Only one implant was removed due to a deep infection. Shoulder resurfacing is an exacting procedure. It is clinically successful, with excellent long-term survivorship in young and active patients. The ceramic surface has no metal sensitivity, very low wear, and, therefore, it is successful as a hemiarthroplasty.

Correlação entre posicionamento do implante das artroplastias parciais de recobrimento do ombro e os resultados funcionais

Objective  The present study aimed to correlate functional outcomes and implant positioning in a case series of partial shoulder resurfacing arthroplasties.

Methods  A total of 25 patients were assessed for range of motion, functional outcome per the University of California at Los Angeles (UCLA) score and radiographic findings. Pre- and postoperative data were compared. In addition, patients were grouped according to the cervical-diaphyseal angle (CDA) determined by an anteroposterior radiography and to the retroversion angle (RVA) determined by an axillary radiography. A CDA from 130° to 140° and a RVA from 20° to 40° consisted in ideal positioning (anatomical standard). Data were analyzed using the Wilcoxon signed-rank test, analysis of variance (ANOVA) followed by the Kruskal-Wallis test or the Mann-Whitney test as appropriate.

Results  The mean follow-up time was 48.3 months (12 to 67 months). The postoperative functional score (31.5) was higher than the preoperative score (15.5) ( p  < 0.001). In 6 patients, the implant was in anatomical positioning, while implant positioning was considered “nonstandard” in 19 subjects. Seven patients had a CDA < 130°, and 14 patients had a CDA ranging from 130° to 140°; in addition, the CDA was > 140° in 4 subjects. The RVA was up to 20° in 15 patients and ranged from 20° to 40° in 10 subjects. Using these criteria to group patients, the postoperative clinical-functional parameters were not statistically different from the preoperative findings ( p  > 0.05).

Conclusion  Partial shoulder resurfacing results in significant postoperative functional recovery in patients with degenerative joint diseases. However, implant positioning assessed by CDA and RVA does not correlate with clinical-functional outcomes and, therefore, it is an inaccurate indicator of surgical success.

Level of Evidence IV; Case Series.

Getting back in the game after humeral head resurfacing

Background

Aim of this investigation was to analyze whether patients undergoing humeral head resurfacing (HHR) surgery are able to successfully return to their sports and occupation afterwards.

Materials and methods

Fifty patients treated with CUP (HHR) arthroplasty were included. Two groups were built: Patients who have participated in sports less than 5 years prior surgery (Group 1: n = 42 (84%)) and patients who have never participated in sports (Group 2: n = 8 (16%)). Evaluation was based on a questionnaire asking for types of sports, frequency, time to return to sports and work as well as limitations in work life.

Results

Mean age at the time of surgery was 58.6 (36-84) years in Group 1 and 65 (56-75) years in Group 2. Mean time follow-up was 5.5 years (2.5-12) years. Twenty-seven (64%) patients in Group 1 participated in sports right before surgery. Twenty-one patients (50%) returned to sports after surgery. The returning rate was 78%. Seven (17%) patients in Group 1 stated that the reason they underwent shoulder replacement surgery was to continue to participate in sports. Swimming and skiing were two of the most favorable sports. Two (4%) patients had to change their profession due to surgery. Most of the patients were retired at follow-up.

Conclusion

Most of the active patients undergoing HHR surgery are successfully able to return to their sports activities after surgery. Patients employed were able to return to their occupation after surgery. Many patients were already retired at the time of follow up.

Cementless humeral head resurfacing for degenerative glenohumeral osteoarthritis fails at a high rate

Purpose

The aim of the study was to examine clinical and radiographic results of a cementless humeral surface and to evaluate prognostic parameters for implant failure.

Methods

34 shoulders were examined preoperatively and after a mean 2.7 years. Radiographic parameters, Constant scores (CS) and complications were recorded.

Results

The mean CS improved from 27 to 51 points. Eight patients (24%) had an implant revision for secondary glenoid erosion. In the revision group was an increase of the LGHO of 8.4%.

Conclusions

The study shows a high revision-rate (24%). Predictor for an implant failure was an operative changing of the LGHO.

Radiological and functional 24-month outcomes of resurfacing versus stemmed anatomic total shoulder arthroplasty

PURPOSE

This study compared clinical and radiographic outcomes of patients undergoing resurfacing total shoulder arthroplasty (TSA) with those treated with a stemmed TSA.

METHODS

Patients with primary osteoarthritis who underwent humeral resurfacing (RES) or stemmed (STA) TSA were identified in our shoulder arthroplasty register for retrospective analysis. Standard radiographs and clinical/patient-rated assessments were made up to 24 months post-surgery. Implant revisions were assessed. Patients were frequency-matched in a 1:1 (RES:STA) ratio based on gender and age, and compared with regard to operation time and shoulder function (Constant, SPADI and Quick DASH scores). Mixed models with statistical adjustments were applied.

RESULTS

From 2006 to 2014, 44 RES and 137 STA operations were performed in 157 patients; one and two revisions were recorded in the RES and STA group, respectively. The final matched cohort included a total of 69 patients and 37 operations per treatment group. Resurfacing TSA was 17 min shorter (95%CI: 5-28) compared to the stemmed procedure (p = 0.005). RES and STA patients showed significant functional improvement six months post-implantation, yet all measured scores did not differ between the groups at 2 years (p ≥ 0.131). The status of static centering of the humeral head, acromiohumeral distance, and a lack of signs of implant loosening were also similar between treatments.

CONCLUSION

Similar 24-month post-operative radiological and functional outcome is achieved by RES and STA patients, even with a shorter RES surgery time. Larger cohorts and longer follow-up are required to better assess implant survival.

Radiostereographic analysis of a shoulder surface replacement: does hydroxyapatite have a place?

Resurfacing of the humeral head is commonly used within the UK to treat osteoarthritis (OA) of the shoulder. We present the results of a small prospective randomised study of this procedure using the Global CAP prosthesis with two different coatings, Porocoat and DuoFix hydroxyapatite (HA). We followed two groups of ten patients with OA of the shoulder for two years after insertion of the prosthesis with tantalum marker beads, recording pain, Constant-Murley and American Shoulder and Elbow Surgeons (ASES) outcome scores, and using radiostereometric analysis to assess migration. The outcomes were similar to those of other series, with significant reductions in pain (p = 0.003) and an improvement in the Constant (p = 0.001) and ASES scores (p = 0.006). The mean migration of the prosthesis three months post-operatively was 0.78 mm (0.51 to 1.69) and 0.72 mm (0.33 to 1.45) for the Porocoat and DuoFix groups, respectively. Analysis of variance indicated that the rate of migration reached a plateau after three months post-operatively in both groups. At follow-up of two years the mean migration was 1 mm (sd 1 (0.25 to 3.32)); in the Porocoat group and 0.8 mm (sd 0.4 (0.27 to 1.45)) in the DuoFix HA group. Significant migration of the prosthesis was seen in one patient who had received an anterior humeral bone graft. This prosthesis was later revised after 2.7 years. The addition of a coating of HA to the sintered surface does not improve fixation of this prosthesis.

Thermal damage during humeral reaming in total shoulder resurfacing

INTRODUCTION

Total shoulder resurfacing (TSR) provides a reliable solution for the treatment of glenohumeral arthritis. It confers a number of advantages over traditional joint replacement with stemmed humeral components, in terms of bone preservation and improved joint kinematics. This study aimed to determine if humeral reaming instruments produce a thermal insult to subchondral bone during TSR.

PATIENTS AND METHODS

This was tested in vivo on 13 patients (8 with rheumatoid arthritis and 5 with osteoarthritis) with a single reaming system and in vitro with three different humeral reaming systems on saw bone models. Real-time infrared thermal video imaging was used to assess the temperatures generated.

RESULTS

Synthes (Epoca) instruments generated average temperatures of 40.7°C (SD 0.9°C) in the rheumatoid group and 56.5°C (SD 0.87°C) in the osteoarthritis group (P = 0.001). Irrigation with room temperature saline cooled the humeral head to 30°C (SD 1.2°C). Saw bone analysis generated temperatures of 58.2°C (SD 0.79°C) in the Synthes (Epoca) 59.9°C (SD 0.81°C) in Biomet (Copeland) and 58.4°C (SD 0.88°C) in the Depuy Conservative Anatomic Prosthesis (CAP) reamers (P = 0.12).

CONCLUSION

Humeral reaming with power driven instruments generates considerable temperatures both in vivo and in vitro. This paper demonstrates that a significant thermal effect beyond the 47°C threshold needed to induce osteonecrosis is observed with humeral reamers, with little variation seen between manufacturers. Irrigation with room temperature saline cools the reamed bone to physiological levels and should be performed regularly during this step in TSR.

Resurfacing humeral prosthesis: do we really reconstruct the anatomy?

BACKGROUND

The goal of a resurfacing shoulder arthroplasty is to reproduce the individual's anatomy while preserving the bone stock of the humeral head. This study investigated the hypothesis that resurfacing the humeral prosthesis restores normal glenohumeral relationships and correlates with the final clinical results.

MATERIALS AND METHODS

A resurfacing shoulder implant was performed in 61 patients (64 shoulders). Indications were primary osteoarthritis in 26, secondary osteoarthritis in 21, avascular necrosis in 4, rheumatoid arthritis in 4, dysplasia in 4, and for others indications in 5.

RESULTS

At an average of 36 months (range, 24-65) of follow-up , the Constant score reached 68 points and the Quick-Disabilities of Arm, Shoulder and Hand score reached 28 points. Preoperative and postoperative radiographic analysis showed a decrease of the humeral head diameter (51 ± 5 vs 48 ± 5 mm) and of the height of the humeral head (21 ± 4 vs 19 ± 2 mm), without modification of the radius of curvature or the height of the center of rotation. The medial humeral offset increased from 3.3 ± 3.5 to 6.4 ± 3 mm and the lateral offset from 6.8 ± 9 to 10.4 ± 9 mm. The implant was mainly in varus postoperatively compared with preoperative values (122° ± 11° vs 134° ± 7°). Postoperative radiographic analysis and at the last follow-up did not show any significant difference, except for the increase of the depth of the glenoid from 4.2 ± 1.4 to 4.9 ± 1.8 mm.

CONCLUSIONS

The resurfacing shoulder arthroplasty reproduces the normal anatomy and compensates glenohumeral wear. However, there was a tendency to position the prosthesis in varus because of technical imperfections. With follow-up, medialization of the humerus with glenoid wear was observed and was correlated in some patients with reappearance of pain.

Long-term results and patient satisfaction after shoulder resurfacing

BACKGROUND

Shoulder resurfacing has regained popularity in recent years. This report presents the long-term (>20 years) results of this procedure with regard to patient satisfaction and implant survival.

MATERIALS AND METHODS

We followed up 61 patients who underwent shoulder resurfacing procedures (74 shoulders) for a minimum of 20 years or until death (7 additional patients were lost to follow-up). The mean patient age at the time of surgery was 58 years. There were 41 total resurfacing procedures and 33 hemi-resurfacing procedures. The humeral component consisted of a cup with a short central peg that was placed either with or without cement. The glenoid was resurfaced with a cemented polyethylene or polyurethane component.

RESULTS

Patient satisfaction was 95%, and the survivorship of the humeral prostheses was 96%. There were no periprosthetic fractures, dislocations, or infections. Two humeral components were revised to stemmed prostheses (one for loosening and one for unexplained pain), and one was revised from a cementless to a cemented resurfacing prosthesis. Twelve cemented polyethylene glenoid prostheses had radiolucencies, but only three produced symptoms requiring revision surgery; three polyurethane glenoid prostheses showed severe wear radiographically, but none was loose or required revision surgery. There were 7 revision procedures, 6 with good results.

CONCLUSIONS

Shoulder resurfacing is a successful procedure for the majority of patients, with high rates of patient satisfaction, long-term survivorship of the humeral prosthesis, and few complications.

SURFACE ARTHROPLASTY FOR TREATING PRIMARY AND/OR SECONDARY SHOULDER OSTEOARTHROSIS BY MEANS OF THE HEMICAP-ARTHROSURFACE(®) SYSTEM

Objective: To present the surgical technique for the He-miCAP-Arthrosurface^® system and evaluate our results from this technique for treating primary and/or secondary shoulder osteoarthrosis. Method: Between June 2007 and June 2009, 10 shoulders of 10 patients (nine with primary osteoarthrosis and one with avascular necrosis of the humeral head) underwent surface arthroplasty using the HemiCAP-Arthrosurface^® system to correct the problem. The follow-up time ranged from six to 29 months (mean of 17 months). The patients’ ages ranged from 62 to 73 years (mean of 67.5 years). Six patients were female and four patients were male. The patients were followed up weekly for the first month after the surgical procedure and every three months thereafter. The clinic evaluation was done using the criteria of the University of California at Los Angeles (UCLA) and a visual analogue pain scale. Results: All the patients said that they were satisfied with the results from the surgical treatment, with a mean UCLA score of 30 points and a mean analogue pain score of two points. Conclusion: The HemiCAP-Arthrosurface^® system for shoulder surgery for a specific group of patients is a technique that preserves the bone stock with good functional and antalgic results.

Measurement of migration of a humeral head resurfacing prosthesis using radiostereometry without implant marking: an experimental study

INTRODUCTION

Standard radiostereometric analysis of prosthetic migration requires that tantalum beads are inserted into the implant. For manufacturing reasons, this is not possible for humeral head resurfacing implants. We therefore used marker-free radiostereometry, developed for metal-backed acetabular cups, on a dummy model to validate the method for a humeral head resurfacing prosthesis.

MATERIAL AND METHODS

3 hemispherical resurfacing prostheses of different sizes were marked with tantalum beads and mounted in a sawbone. Standard and marker-free radiostereometry was then done repeatedly with gradual shifts of position of the prosthesis between each analysis. The marker-free algorithm was then compared to the standard to determine the accuracy.

RESULTS

The accuracy for marker-free radiostereometry was 0.22-0.47 mm for translations and 0.92-1.56 degrees for rotations.

INTERPRETATION

Based on our results, marker-free radiostereometry can be used to measure migration of humeral head resurfacing prostheses. This indicates that implant marking is not required when doing radiostereometry on humeral head resurfacing in clinical trials.

Shoulder hemi arthroplasty radiological and clinical outcomes at more than two years follow-up

INTRODUCTION

Humeral head replacement is used for glenohumeral osteoarthritis in young or active patients, for conditions sparing glenoid cartilage or when glenoid implantation does not appear feasible. These surgical procedures usually give satisfactory results but there is a risk of glenoid erosion and a possible deterioration of long-term outcomes.

HYPOTHESIS

There is a risk of glenoid erosion after humeral head replacement which can be radiographically measured. The importance and progression of this erosion should be evaluated to determine its clinical relevance.

PATIENT AND METHODS

This is a retrospective study in 15 patients (19 shoulders) who underwent humeral head replacement between 1999 and 2006. There were 11 women and four men with an average age of 54.5 years. Etiologies were avascular necrosis (11 cases) and glenohumeral osteoarthritis (eight cases). All patients were reviewed in 2008 with more than two years follow-up. Clinical evaluation included measurements of range of motion and determination of the Constant and Murley score. In addition, the patients were asked to provide a subjective evaluation of their shoulder. Radiographic analysis included computer-assisted measurements.

RESULTS

The average follow-up was 45.8 months (26-108). At one year postoperative and at the final follow-up, clinical parameters such as the Constant and Murley score (37.4/100 preoperative to 64.4/100 at final follow-up) were significantly increased. During the first year, the rate of glenoid wear was 1.03 mm/year in case of avascular necrosis and 0.27 mm/year in case of osteoarthritis (p<0.001). Glenoid depth at the final follow-up was 6.97 mm for osteoarthritis compared to 4.59 mm for avascular necrosis (p<0.01). We did not find any correlation between glenoid erosion severity and clinical results.

DISCUSSION

Isolated humeral head replacement may result in glenoid erosion. The rate of progression of this erosion is clearly influenced by the etiology and therefore by the preexisting condition of the glenoid cartilage. At the average follow-up, the radiological glenoid deterioration is not correlated with pain or deterioration of clinical results.

LEVEL OF EVIDENCE

Level IV. Therapeutic study.

Shoulder resurfacing

Resurfacing is a type of shoulder arthroplasty that involves replacing the humeral joint surface with a metal covering, or cap, thus preserving the bone of the proximal part of the humerus. If the glenoid is also replaced, a current conventional polyethylene glenoid replacement prosthesis or an interposed soft-tissue graft is used. The potential advantages of humeral resurfacing, as compared with conventional shoulder arthroplasty, are: (1) no osteotomy is performed (and thus the head-shaft angle does not have to be addressed); (2) minimal bone resection; (3) a short operative time; (4) a low prevalence of humeral periprosthetic fractures; and (5) ease of revision to a conventional total shoulder replacement, if needed. Outcomes of surface replacement arthroplasty have been comparable with those of arthroplasties with a stemmed prosthesis in numerous short and mid-term follow-up studies. Future studies are required to assess the long-term outcomes of humeral resurfacing and to evaluate alternative surface bearing materials, especially on the glenoid side. Resurfacing appears to be a viable option for shoulder replacement, especially in young patients.

Treatment of osteonecrosis of the humeral head with cementless surface replacement arthroplasty

BACKGROUND

Osteonecrosis of the humeral head is a disabling condition that can lead to joint destruction with persistent pain and dysfunction. The aim of the present study was to examine cementless humeral surface replacement arthroplasty as a treatment option for posttraumatic and nontraumatic osteonecrosis.

METHODS

Between 2002 and 2005, seventeen shoulders with posttraumatic (n = 8) or nontraumatic (n = 9) osteonecrosis of the humeral head were treated with cementless humeral replacement arthroplasty. The mean proportion of the humeral head that was occupied by necrotic bone was 18.6% (range, 8.9% to 30.9%). The mean duration of follow-up was three years. Constant scores, patient satisfaction, and complications were recorded. Volumetric measurements of the necrotic areas and signs of implant loosening were analyzed with use of standardized radiographs.

RESULTS

The mean Constant score for the entire cohort improved significantly from 31 to 62 points (34% to 75% when adjusted by age and sex) (p < 0.0001). There were also significant improvements in mean shoulder flexion (from 87 degrees to 139 degrees), abduction (from 64 degrees to 120 degrees), and external rotation (from 2 degrees to 27 degrees). The final values for the Constant score, abduction, and power were significantly higher for the nontraumatic group than for the posttraumatic group. Fourteen patients (fifteen shoulders) were very satisfied (eleven shoulders) or satisfied (four shoulders), and two patients (two shoulders) were somewhat disappointed with the postoperative result. Signs of implant loosening were not observed. One patient had a wound infection that required surgical débridement and antibiotic therapy. To date, no implant revisions have been necessary.

CONCLUSIONS

Cementless humeral surface replacement arthroplasty is a potentially bone-preserving option for patients with posttraumatic and nontraumatic osteonecrosis of the humeral head. Even in the presence of bone loss of as much as 31% of the humeral head, implant loosening was not observed. Good functional results and relief of pain in combination with a low complication rate can be achieved in the short term.

The DUROM cup humeral surface replacement in patients with rheumatoid arthritis. Surgical technique

BACKGROUND

Rheumatoid arthritis often leads to severe destruction of the glenohumeral joint, including synovitis and inflammation-induced alterations of the rotator cuff. Cup arthroplasty, or surface replacement of the shoulder, was introduced in the 1980s. The aim of this study was to evaluate the midterm results of the DUROM cup surface replacement for patients with rheumatoid arthritis affecting the glenohumeral joint.

METHODS

From 1997 to 2000, forty-two DUROM cup hemiprostheses were implanted in a cohort of thirty-five patients (forty-two shoulders), who were evaluated preoperatively and again at three, twelve, and more than sixty months postoperatively. Six patients (seven shoulders) were lost to follow-up. Thirty-five shoulders in twenty-nine patients (twenty-one women and eight men with an average age of 61.4 years) could be evaluated prospectively after an average follow-up period of 73.1 months. Patients were evaluated clinically with the use of the Constant score, and a detailed radiographic analysis was performed to determine the presence of endoprosthetic loosening, glenohumeral subluxation, and glenoid bone loss.

RESULTS

The mean Constant score for the thirty-five shoulders increased from 20.8 points preoperatively to 64.3 points at a mean of 73.1 months postoperatively. There were three revisions: one to replace an implant that was too large, another to treat glenoid erosion, and a third due to loosening of the implant. No additional cases of loosening of the prosthesis or changes in cup position were observed radiographically. Over the five-year follow-up period, proximal migration of the cup increased in 63% of the shoulders, and glenoid depth increased in 31%. With the numbers studied, no differences in clinical outcome were identified between patients with a massive rotator cuff tear and those with a smaller or no tear.

CONCLUSIONS

The midterm results of the cemented DUROM cup surface replacement for patients with advanced rheumatoid arthritis of the shoulder are very encouraging, even for patients with a massive tear of the rotator cuff. The advantage of this cup arthroplasty is the less complex bone-sparing surgery. In the event of failure of the implant, other reliable salvage options remain available.

The fulcrum axis: a new method for determining glenoid version

Previously applied methods for the evaluation of glenoid version did not use body-surface landmarks; therefore, it is not possible to get information about glenoid version from the outside. The tip of the coracoid and the posterolateral corner of the acromion can easily be found on the body surface. These 2 landmarks were connected by a line called the fulcrum axis. After using an experimental x-ray technique in 143 human cadaver scapulae, 5 independent observers identified the fulcrum axis and the glenoid fossa twice. The resulting overall angle between the fulcrum axis and the glenoid fossa was 1.8 degrees (SD 4.5). The fulcrum axis may be used for the preoperative planning and the intraoperative evaluation of glenoid version while performing total shoulder arthroplasties. As the fulcrum axis and the plane of the glenoid fossa are approximately parallel, the fulcrum axis can be used to position patients for performing a true antero-posterior x-ray.

Comparison of the short-term functional results after surface replacement and total shoulder arthroplasty for osteoarthritis of the shoulder: a matched-pair analysis

INTRODUCTION AND PURPOSE

The purpose of this clinical study with a matched-pair design was to compare the functional short-term results obtained in patients with primary osteoarthritis of the shoulder treated with cementless surface replacement of the humeral head (CUP) with those obtained after total shoulder replacement (TSR).

MATERIALS AND METHODS

Twenty-two patients (average age 61.4 years; 11 men, 11 women) with primary osteoarthritis who obtained surface replacement of the humeral head were matched to a control group of 22 patients (average age 61.1 years, 11 men, 11 women) with the same in- and exclusion criteria that were treated with a total shoulder arthroplasty. Preoperative status, perioperative results and postoperative status (Constant score and subcategories, subjective status, range of motion, radiographic evaluation) were compared in all patients and controls. Non-parametric analyses were used to compare the results in both groups.

RESULTS

Patients in the CUP group showed significantly better perioperative results (time of surgery, blood loss, days of inpatient treatment) compared to the patients in the TSR group. Results at 6 and 12 months revealed significant improvement of clinical function, significant pain reduction, and high subjective satisfaction rates in both groups. Concerning the absolute values, there were tendencially better results obtained in the TSR group compared to the CUP group at 12 months follow-up (Constant score 67.23 +/- 11.71 vs. 59.25 +/- 14.53), but only the criteria "mobility" and "abduction" revealed statistical significance. Regarding the relative improvement at 12 months compared to the baseline status, patients treated with TSR showed a significant better benefit in the total Constant score (+41.32 +/- 0.04 vs. +26.16 +/- 8.82) and in range of motion. Regarding the subjective assessment, there was no statistically significant difference in patients with TSR (mean value 1,5 (+/-0.55)) and patients with CUP (mean value 2,3 (+/-0.92)). Two CUP implants had to be removed during the follow-up period owing to secondary glenoidal erosion.

CONCLUSIONS

At short-term follow-up, surface replacement as a technically less demanding technique provided only slightly inferior results to TSR. We therefore believe that CUP arthroplasty is a therapeutic option and can be recommended in patients with primary osteoarthritis when limited to strictly defined indications.

„Resurfacing“ des Humeruskopfes

Surface replacement arthroplasty of the shoulder offers the ability to restore anatomy and biomechanics of the glenohumeral joint, if sufficient humeral bone stock of at least 60% of the humeral head is preserved and no severe deformity is present. The implantation following the individual anatomy helps to avoid complications such as prosthetic malpositioning and periprosthetic fractures. While the use of a glenoid component is technically demanding, revision to a stem prosthesis is relatively easy because of bone stock preservation. Indications for humeral head resurfacing are osteoarthritis (OA), rheumatoid arthritis (RA), avascular necrosis stages 2-4, and stable forms of cuff tear arthropathy (CTA). Published results for OA and RA are comparable to those obtained with modern modular stem prostheses; the use in CTA appears promising under "limited goals criteria."

The DUROM cup humeral surface replacement in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis often leads to severe destruction of the glenohumeral joint, including synovitis and inflammation-induced alterations of the rotator cuff. Cup arthroplasty, or surface replacement of the shoulder, was introduced in the 1980s. The aim of this study was to evaluate the midterm results of the DUROM cup surface replacement for patients with rheumatoid arthritis affecting the glenohumeral joint.

METHODS

From 1997 to 2000, forty-two DUROM cup hemiprostheses were implanted in a cohort of thirty-five patients (forty-two shoulders), who were evaluated preoperatively and again at three, twelve, and more than sixty months postoperatively. Six patients (seven shoulders) were lost to follow-up. Thirty-five shoulders in twenty-nine patients (twenty-one women and eight men with an average age of 61.4 years) could be evaluated prospectively after an average follow-up period of 73.1 months. Patients were evaluated clinically with the use of the Constant score, and a detailed radiographic analysis was performed to determine the presence of endoprosthetic loosening, glenohumeral subluxation, and glenoid bone loss.

RESULTS

The mean Constant score for the thirty-five shoulders increased from 20.8 points preoperatively to 64.3 points at a mean of 73.1 months postoperatively. There were three revisions: one to replace an implant that was too large, another to treat glenoid erosion, and a third due to loosening of the implant. No additional cases of loosening of the prosthesis or changes in cup position were observed radiographically. Over the five-year follow-up period, proximal migration of the cup increased in 63% of the shoulders, and the glenoid depth increased in 31%. With the numbers studied, no differences in clinical outcome were identified between patients with a massive rotator cuff tear and those with a smaller or no tear.

CONCLUSIONS

The midterm results of the cemented DUROM cup surface replacement for patients with advanced rheumatoid arthritis of the shoulder are very encouraging, even for patients with a massive tear of the rotator cuff. The advantage of this cup arthroplasty is the less complex bone-sparing surgery. In the event of failure of the implant, other reliable salvage options remain.

[Clinical and radiological evaluation in hemiarthroplasty of the shoulder]

OBJECTIVE

To determine the medium-term functional and radiological results in patients with hemiarthroplasty of the shoulder.

MATERIAL AND METHODS

A descriptive cross-sectional study was performed in 25 patients with glenohumeral osteoarthritis of any etiology, age, sex and occupation who underwent hemiarthroplasty of the shoulder using a deltopectoral approach with placement of a cemented modular hemiprosthesis; between November 2000 and December 2002. Functional evaluation (Constant 0-100 points) and radiological assessment were performed to determine the "radiological risk" of prosthetic clinical loosening. Descriptive and inferential statistics for the study variables were performed.

RESULTS

The prevalence of surgical disease was 0.4% of all first-time orthopedic consultations. The mean age was 61.7±12.49 (range 32-85 years); men accounted for 8.6% and women for 91.4%. The most frequent etiology was degenerative (45.8%). The most frequently affected side was the left (54.3%). With a mean follow-up of 19±8.6 months, functional evaluation was 60±12 points; radiological evaluation showed that 20.8% of the patients presented "radiological risk" for prosthetic clinical loosening whereas only 4.2% showed no line of radiolucency. Postoperative pain was significantly lower than preoperative pain (p<0.05); mean satisfaction was 72%. Complications occurred in 8.3%.

CONCLUSION

The functionality of the operated shoulder was good and radiological evaluation showed satisfactory medium-term results in patients with hemiarthroplasty of the shoulder.

Copeland surface replacement arthroplasty of the shoulder in rheumatoid arthritis

BACKGROUND

Shoulder arthroplasty with a stemmed prosthesis is a recognized treatment for rheumatoid arthritis of the shoulder. The humeral component of the Copeland cementless surface replacement arthroplasty consists of a cup for surface replacement with a short central peg for primary fixation to the bone. We hypothesized that surface replacement may offer some advantages over stemmed prostheses.

METHODS

Between 1986 and 1998, seventy-five shoulders underwent surface replacement arthroplasty (thirty-three hemiarthroplasties and forty-two total shoulder arthroplasties) for the treatment of rheumatoid arthritis. The results of these procedures were reviewed after an average duration of follow-up of 6.5 years. Patients were assessed with use of the Constant score, a patient satisfaction score, and radiographs.

RESULTS

The average Constant score was 47.9 points (age and sex-adjusted score, 71%) in the hemiarthroplasty group and 53.4 points (age and sex-adjusted score, 76%) in the total shoulder replacement group. The mean range of active flexion improved from 50 degrees in the hemiarthroplasty group and 47 degrees in the total shoulder replacement group to 101 degrees and 104 degrees, respectively. Seventy-two of the seventy-five shoulders were considered by the patients to be much better or better at the time of the review. Of the sixty-eight humeral implants that were evaluated radiographically, fifty-six (82%) showed no lucencies, eleven (16%) showed localized lucencies of <1 mm in width, and one was definitely loose. Of the thirty-nine glenoid implants that were evaluated radiographically, nineteen (49%) showed no lucencies, nineteen showed localized lucencies of <1 mm, and one was definitely loose. No lucencies were observed adjacent to the hydroxyapatite-coated implants. Thirty-nine (57%) of the sixty-eight shoulders showed some degree of superior subluxation. Three patients required a major reoperation: two required a revision because of loosening of both components, and one patient with pain at the site of a hemiarthroplasty had a revision to a total shoulder arthroplasty to provide relief.

CONCLUSIONS

The indications for this surface replacement are the same as those for the conventional stemmed prostheses, but the surface replacement has the advantage of bone preservation as well as avoidance of the potential complications associated with a long humeral stem in rheumatoid bone. This procedure is not suitable for severely damaged joints in which the humeral head is insufficient or too soft.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Resection interposition arthroplasty of the shoulder affected by inflammatory arthritis

To determine the therapeutic value of resection-interposition arthroplasty (RIAP) of shoulders in rheumatoid or other inflammatory arthritis, 53 patients were reviewed clinically and radiographically after a mean follow-up period of 8.2 +/- 4.3 years (3.5 to 17.5 years). The Constant Score averaged 42.33 +/- 16.2 (12 to 76). Patients with a follow-up period of more than 10 years performed significantly worse than those with shorter follow-up periods. In most cases, radiographs showed a progressive medial displacement and loss of size of the humeral head as well as a decrease of the joint space with time. Abduction proved to be highly dependent on the degree of medial displacement of the humeral head, whereas the Constant Scores correlated with the width of the joint space. Despite initially acceptable postoperative results, outcome at longer follow-up periods worsened as the result of wear of the glenoidal cartilage and osseous resorption of the humeral head, resulting in a progressive medialization of the center of rotation.

Outcome after cup hemiarthroplasty in the rheumatoid shoulder: a retrospective evaluation of 39 patients followed for 2-6 years

33 rheumatoid patients, treated with hemispherical cup resurfacing hemiarthroplasty of the shoulder without medullary fixation (6 bilaterally), were reviewed after mean 4.4 (2-6) years. The median Constant score was 30 (15-79), mean proximal migration of the humerus 55 (SD 5.2) mm and mean glenoid erosion 2.6 (SD 1.7) mm. Proximal migration and glenoid erosion did not correlate with shoulder function or pain. Radiographic signs of loosening (changes in cup inclination combined with changes in cup distance above the greater tuberosity) occurred in one quarter of the shoulders. At follow-up, 26 patients were satisfied with the procedure, despite poor shoulder function and radiographic deterioration.