Does the degree of osteoarthritis influence the clinical outcome after anatomic total shoulder arthroplasty?

BACKGROUND: The degree of preoperative osteoarthritis has been shown to influence the postoperative outcome and the patients' satisfaction rate in hip and knee joint replacement surgery. However, no corresponding information is available for total shoulder arthroplasty (TSA). We therefore set out to evaluate the influence of preoperatively measured end-stage osteoarthritis on the postoperative clinical outcome of TSA. METHODS: A retrospective analysis of 103 anatomic total shoulder replacements (96 patients) was performed. Patients were evaluated radiologically with X-rays in two planes and clinically using the Constant and Murley score (CS) and the self-reported satisfaction with the result. The degree of osteoarthritis was radiographically analyzed with the aid of the classifications according to Kellgren/Lawrence, Gerber, Guyette, and Allain and according to whether complete narrowing of the glenohumeral joint was present or not [bone-on-bone contact (BOB) or no bone-on-bone contact (No BOB)]. RESULTS: The clinical results of TSA did not differ significantly among the various stages of osteoarthritis in any of the classifications (p > 0.05). The CS was significantly higher postoperatively for both the BOB and the No BOB group (p < 0.0001). Patients with BOB had a significantly lower CS preoperatively than patients with No BOB (p = 0.0172). In addition, the preoperative pain level was significantly higher in patients with BOB (p = 0.014). Postoperatively, no significant difference in CS (p = 0.6738) was found between the BOB group and the No BOB group. The mean improvement in CS was not statistically significant (p = 0.2218). CONCLUSION: In contrast to hip and knee joint replacement procedures, a milder grade of osteoarthritis does not adversely influence the functional result or subjective satisfaction rate after TSA. The degree of osteoarthritis on conventional X-rays has no bearing on the postoperative clinical outcome. Therefore, the decision on when to carry out anatomic total shoulder arthroplasty should depend on the patient's pain level and loss of quality of life.

The subchondral bone layer and glenoid implant design are relevant for primary stability in glenoid arthroplasty.

BACKGROUND: Clinical studies suggest that reaming of the subchondral bone layer to achieve good implant seating is a risk factor for glenoid loosening. This study aims to evaluate (1) the importance of the subchondral bone layer and (2) the influence of the design of the glenoid component. METHODS: Different techniques for preparation of an A1 glenoid were compared: (1) preserving the subchondral bone layer; (2) removal of the subchondral bone layer; (3) implantation of a glenoid component that does not adapt to the native anatomy. Artificial glenoid bones (n = 5 each) were used with a highly standardized preparation and implantation protocol. Biomechanical testing was performed during simulated physiological shoulder motion. Using a high-resolution optical system, the micromotions between implant and bone were measured up to 10,000 motion cycles. RESULTS: At the 10,000 cycle measuring point, significantly more micromotions were found in the subchondral layer removed group than in the subchondral layer preserved group (p = 0.0427). The number of micromotions in the nonadapted group was significantly higher than in the subchondral layer preserved group (p = 0.0003) or the subchondral layer removed group (p = 0.0207). CONCLUSION: Conservative reaming proved important to diminish the micromotions of the glenoid component. Implantation of a glenoid component that matches with the bony underlying glenoid can help to preserve the subchondral bone layer without sacrificing proper implant seating.

Replacement options for the B2 glenoid in osteoarthritis of the shoulder: a biomechanical study.

BACKGROUND: Glenoid replacement in cases of severe glenoid retroversion (RV) or eccentric wear is challenging. The aim of this study was to evaluate different treatment methods under standardized conditions to assist surgeons in the decision-making process. METHODS: Three treatment options for severe glenoid RV (15°) were compared: (1) no RV correction; (2) complete RV correction; (3) no RV correction and implantation of a posterior augmented glenoid (PAG). A highly standardized implantation protocol using artificial glenoid bones (five per group) was chosen, and a physiologic shoulder movement was applied in a biomechanical setting. Micromotions (MM) between glenoid components and bone were quantified using an optical 3D measuring system. RESULTS: In the uncorrected retroversion group, three instances of subluxation of the prosthetic head occurred between 2000 and 4000 cycles. At 2000 cycles, significantly more MM were observed in the uncorrected RV group than in the corrected RV group (p < 0.0001) or to the augmented group (p < 0.0001). At 10|000 cycles, more MM were observed in the posterior augmented group than in the corrected RV group (p < 0.0001). CONCLUSION: If sufficient bone stock is available, retroversion correction should be favored. Posterior augmented glenoids seem to be a suitable treatment option if complete correction of the retroversion is not possible without compromising the glenoid vault. Without correction of the retroversion, high failure rates were observed.

Functional results of hemi- and total shoulder arthroplasty according to diagnosis and patient age at surgery.

Background and purpose - There is a lack of information on any associations between the functional outcome and age and diagnosis in patients who have undergone shoulder arthroplasty. We therefore evaluated the functional outcome in "young" and "old" patients treated with either hemiarthroplasty (HA) or total shoulder arthroplasty (TSA) with diverse diagnoses. Patients and methods - The functional results of 496 primary shoulder arthroplasties were analyzed using the Constant score (age- and sex-adjusted) and subjective satisfaction. Patients ≤55 years of age at surgery were defined as "young. Diagnoses were primary osteoarthritis (n = 339), posttraumatic osteoarthritis (n = 78), cuff tear arthropathy (n = 36), avascular necrosis (n = 30), and rheumatoid arthritis (n = 13). Mean length of follow-up was 4 (2-14) years. Results - 70% of the TSA patients were very satisfied with the postoperative result, as compared to 39% after HA. The Constant score and patient satisfaction were similar in the "young" and "old" groups. Pain relief was better in the "old" group. The mean improvement in the Constant score after cuff tear arthropathy (22 points) was inferior to that for primary osteoarthritis (36 points), avascular necrosis (34 points), and rheumatoid arthritis (37 points). Inferior mean Constant scores were also seen for posttraumatic osteoarthritis (29 points) compared to primary osteoarthritis (36 points). 63% of patients with primary osteoarthritis were very satisfied, as compared to only 36% of the patients with posttraumatic osteoarthritis. Interpretation - Shoulder arthroplasty is successful in the medium term for different glenohumeral diseases, irrespective of patient age at surgery. However, the appropriate treatment method for cuff tear and posttraumatic conditions of the shoulder remains to be found, particularly in young patients.

Activity levels after reverse shoulder arthroplasty.

BACKGROUND: Aim of this study was to analyze whether patients undergoing reverse shoulder arthroplasty (RSA) surgery are able to successfully return to sports and afterwards. METHODS: Thirty-eight patients treated with RSA for Cuff Tear Arthropathy (CTA) were included. Two sub-groups were built: Patients who have participated in sports activities within the last 5 years prior surgery [Group A: n = 21 (55 %)] and patients who have never participated in sports [Group B: n = 17 (45 %)]. Evaluation was based on a questionnaire asking types of sports, frequency, and time to return to sports. RESULTS: Mean age in Group A at the time of surgery was 76.2 (65-85) years and 78.4 (68-92) years in Group B. Most patients were women [n = 35 (92 %)]. Mean follow-up was 4.8 years (2.4-9.4) years. Fifteen (71 %) patients in Group A participated in sports at the time prior to surgery. Fourteen (67 %) patients returned to sports after surgery. The returning rate was 93 %. Six (29 %) patients of Group A stated that one reason they underwent shoulder replacement surgery was to continue to participate in sports. All active patients performed swimming at final follow up. CONCLUSIONS: Most patients being active prior to reverse shoulder arthroplasty surgery are successfully able to return to their activity afterwards.

Results of cementless humeral head resurfacing with cemented glenoid components.

PURPOSE: The aim of this study was to analyse the short- and medium-term clinical and radiographic results of cementless humeral head resurfacing in combination with a cemented glenoid component. METHODS: Thirty-five patients with a mean age of 65 years (range 42-84) and a mean follow-up of three years (two to six) were followed up. The Constant score with its subgroups as well as shoulder motions and complications were recorded. Radiographs in two planes were analysed for loosening of the components. RESULTS: Mean Constant score improved from 29 points (6-63) to 70 points (41-89; p < 0.001). Mean shoulder flexion increased from 89° (20-170) to 158° (100-180) and mean external rotation from 10° (-10-30) to 39° (10-80). Satisfaction rate was 94 % at final follow-up. None of the components was found to be loose. There were three neurological complications, probably related to increased forces on the humeral head retractor during glenoid preparation. Two of them resolved completely; in one patient hyposensitivity remained. CONCLUSION: Cementless humeral surface replacement arthroplasty in combination with a cemented glenoid component leads to an overall satisfactory clinical outcome. However, the high rate of neurological complications found in this study, probably related to difficult glenoid exposure, led us to discontinue this implant configuration.

Mid- to long-term follow-up of total shoulder arthroplasty using a keeled glenoid in young adults with primary glenohumeral arthritis.

BACKGROUND: The purpose of this study was to examine the mid- to long-term functional outcome and implant survival of total shoulder arthroplasty (TSA) in adults aged 55 years or younger with primary glenohumeral arthritis. The hypothesis was that TSA would lead to improvement in functional outcome but that implant survival would decline between 5 years and 10 years postoperatively. MATERIALS AND METHODS: Between 1992 and 2004, 52 TSAs were implanted in 8 centers for primary glenohumeral arthritis in patients aged 55 years or younger. Minimum follow-up of 5 years was available in 50 patients at a mean of 115.5 months postoperatively. Kaplan-Meier survivorship analysis was performed, and clinical outcome was assessed. RESULTS: After TSA, adjusted Constant scores improved from 37.0% to 73.4% and forward flexion improved from 97° to 128° (P < .001). The adjusted Constant score was 80.0 in patients free of revision of the glenoid compared with 43.6 in the group requiring revision of the glenoid (P < .001). Survivorship of the glenoid component with revision surgery for glenoid loosening as the endpoint was 98% (95% confidence interval, 89.4%-100%) at 5 years and 62.5% (95% confidence interval, 40.6%-81.2%) at 10 years. Factors associated with survival of the glenoid included anatomic humeral component positioning and a compaction glenoid preparation technique. CONCLUSIONS: At 5 years' follow-up, TSA leads to improvement in functional outcome and a satisfactory implant survival rate of 98% in young adults with primary glenohumeral arthritis. However, the 10-year survival rate of TSA was only 62.5% in patients aged 55 years or younger at the time of surgery.

Bone cement penetration pattern and primary stability testing in keeled and pegged glenoid components.

BACKGROUND: It has been proposed that bone mineral density has an influence on cement penetration in hip and knee arthroplasty. The hypotheses of this study were that: 1) there is a negative correlation between bone mineral density (BMD) and cement penetration in cemented glenoid components; and 2) that implant design has an influence on cement penetration into the glenoid bone. METHODS: BMD of 10 pairs of fresh frozen scapulas was measured. Micro-computed tomography (micro-CT) scans in 3 different sections were analyzed after implantation of keeled and pegged glenoid components using a 3(rd)-generation cementing technique with a vacuum mixing system. Cement penetration was analyzed and correlated with BMD. Pull-out strength testing was performed to analyze primary stability. RESULTS: The overall peak BMD was 0.6 [g/cm(2)] (range, 0.33-0.98). A strong negative correlation between BMD and mean cement penetration was found for the peg (R(2) = -.83; P < .003) and for the keel group (R(2) = -.81; P < .005). Mean cement penetration was 78.4 mm(2) (range, 60.6-94.2) in the keel and 113.9 mm(2) (range, 78.2-143.4) in the peg group (P < .0001). In all cases, the components were pulled out of the cement mantle, whereas the bone-cement interfaces remained intact. The mean pull-out strength was 1093N (764-1343N) for keeled and 884N (650-1264N) for pegged components (P < .05). CONCLUSION: A modern cementing technique, leading to a deep bonding between bone and cement, is crucial to prevent loosening of glenoid components. The findings of this study might help us to better understand the results of follow-up studies of cemented glenoid implants. Our results could be helpful for the choice of implants in patients with poor bone quality like osteoporosis or rheumatoid arthritis.

Promising results after hemi-shoulder arthroplasty using pyrolytic carbon heads in young and middle-aged patients.

INTRODUCTION: The objective of this prospective cohort study was the assessment of short-term outcome results of shoulder hemiarthroplasty (HA) using pyrolytic carbon (PC) heads. PC has been introduced as a new material to avoid surgical revision due to glenoid erosion after HA. Glenoid erosion due to the use of metallic heads is known to reduce durability. HYPOTHESIS: HA using PC heads shows comparable or better radiographic and clinical outcome compared to the conventional HA using metallic heads in the short-term. PATIENTS AND METHODS: This study was conducted as a single center prospective cohort follow-up study including a total number of 16 consecutive HA with PC heads. Inclusion criteria were indication for HA, an intact rotator cuff, no proximal humeral fractures in patient's history and age>18years. Mean age at the time of arthroplasty was 52.8±10.8years. The mean follow-up was 24.3±8.1months. Baseline and follow-up Numeric Rating Scale (NRS), Constant Scores (CS), Range of Motion (ROM) and radiographs were assessed. RESULTS: At a mean follow-up of 24.3months the mean CS (p<0.001), mean NRS (p<0.001) and mean ROM (p<0.05) improved statistically significant. Subgroup analysis revealed no differences between subgroups (sex, age, diagnosis, and handedness). Survival rate was high (94.1%). One periprosthetic fracture occurred as the only complication during follow-up. Radiographs showed glenoid erosion in one case and subacromial space reduction in two cases. DISCUSSION: PC heads in HA show satisfying short-term results at a mean follow-up of two years, which are comparable to those of conventional HA. The clinical improvements were highly significant with good implant survival. However, long-term follow-up results are necessary, especially compared to conventional HA. LEVEL OF EVIDENCE: IV; observational therapeutic cohort study.

Muscle Activity of the Latissimus Dorsi after Tendon Transfer in Patients with Rotator Cuff Tears.

Background: Massive irreparable posterosuperior rotator cuff tears may result in the loss of external rotation. Most of the patients with posterosuperior rotator cuff tears suffer from a restriction in their daily life actions. Latissimus dorsi tendon transfer (LDTT) is a method to restore abduction and external rotation in these patients. However, the behavior of the LD after the transfer is not clear yet. Few studies have analyzed the activity of the LD after transfer. The goal of this study was to examine the function of the LD postoperatively in follow-up examinations during activities of daily life (ADLs) and during different movements evaluated by measuring the range of motion (ROM). Methods: We examined 12 patients 4.3 years (1-9 years) after LDTT, using simultaneous 3D motion analysis and surface Electromyography (sEMG) of 12 muscle parts; the opposite, nonaffected side was assessed as a control. The measurement protocol included two standardized movements (exorotation with an adducted arm and exorotation with 90° abduction) as well as two ADLs (combing hair and perineal care). Results: An average of 4.3 years (1-9 years) after LDTT, 9 of the 12 subjects showed EMG activity in the transferred LD during glenohumeral external rotation. During the endorotation phase, either little activity was registered or only the pectoralis major was active. During the ADLs, 6 out of 12 subjects showed EMG activity in the transferred LD while "combing hair", whereas all subjects showed EMG activity during perineal care. Conclusion: The LD showed partial activity in its new role as an exorotator, but no clear difference was observed between some of the movements as well as in comparison with the healthy shoulder. Further studies will need to be conducted to better differentiate voluntary contractions and co-contractions as well as tension and extension in the muscle.

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.

How does reverse shoulder replacement change proprioception in patients with cuff tear arthropathy? A prospective optical 3D motion analysis study.

BACKGROUND: Reverse total shoulder arthroplasty (RSA) can improve function in cuff tear arthropathy (CTA) shoulders, but limited data are available on the effect of RSA on proprioception. The purpose of this study was the evaluation of the proprioception after RSA. METHOD: This study included fifteen consecutive patients (n = 15) who received an RSA. We measured an active angle reproduction (AAR) by a novel 3D motion analysis using the Heidelberg upper extremity model (HUX). RESULTS: The overall proprioception didn't change significantly from 6.2° preoperatively to 6.2° postoperatively. CONCLUSION: We conclude that, the overall proprioception remained the same or deteriorated for different movements.