The relationship of shoulder elevation strength to patient-reported outcome after anatomic total shoulder arthroplasty.

BACKGROUND: Most patient-reported outcome measures (PROMs) used to assess outcomes after anatomic total shoulder arthroplasty (aTSA) focus on pain and function. Although strength is considered an important component of function, only the Constant-Murley score (CMS) includes an objective measurement of shoulder strength. The purpose of this study was to evaluate the relationship between shoulder elevation strength (SES) and PROMs after aTSA for the treatment of primary glenohumeral osteoarthritis (GHOA). METHODS: This was a retrospective analysis of 605 patients enrolled in a multicenter clinical database who underwent aTSA to treat primary GHOA. Patients were evaluated preoperatively and at 24 months after surgery. Outcome was assessed with the CMS, American Shoulder and Elbow Surgeons score, Western Ontario Osteoarthritis of the Shoulder score, Single Assessment Numeric Evaluation score, and patient satisfaction. Relationships between SES and outcomes were investigated. RESULTS: The correlations between SES and the PROMs before and after treatment were very weak and weak, respectively (r ≤ 0.262 for all). The strength of the correlations between the absolute and adjusted CMS and the other PROMs varied from weak to moderate (r = 0.180 to r = 0.455), and the strength of the correlations was greater postoperatively. With the strength component removed from the CMS, the correlations between the CMS and other PROMs were stronger (r = 0.194 to r = 0.495). CONCLUSIONS: Although measurement of SES provides objective information about shoulder function and outcome related to the treatment of primary GHOA with aTSA, the actual relevance to patients is unclear as the correlations between SES and PROMs were weak. Furthermore, the variable correlations between the CMS and PROMs call into question the exclusive use of the CMS and support the use of other PROMs that may more accurately reflect patient perception of outcome.

One and two-year clinical outcomes for a polyethylene glenoid with a fluted peg: one thousand two hundred seventy individual patients from eleven centers.

PURPOSE: Clinical shoulder science lacks a benchmark against which the early clinical value of new glenoid components can be compared; such a benchmark may be derived from a multicenter study of patients receiving an established, internationally used design of glenoid component. METHODS: We obtained data from 11 centers on 1270 patients having total shoulder arthroplasty using an all-polyethylene component with a fluted central peg. We analyzed individual patient outcomes at 1 and 2 years after surgery. We compared the improvement for each patient to the minimal clinically important difference (MCID) and calculated each patient's improvement as a percent of maximal possible improvement (MPI). RESULTS: The preoperative scores improved from SST 3 ± 2, ASES 37 ± 15, Constant score 36 ± 16, and Penn score 30 ± 19 to SST 10 ± 2, ASES 90 ± 12, Constant 76 ± 13, and Penn 80 ± 24 (p < 0.001 for each). A high percentage of patients improved by more than the MCID (SST 96%, ASES 98%, Constant 94%, Penn 93%) and obtained improvement of at least 30% of the MPI (SST 95%, ASES 98%, Constant 91%, Penn 87%). The clinical outcomes realized with this glenoid design were not worse for the 41% of shoulders with preoperative type B glenoids or for the 30% of shoulders with more than 15 degrees of glenoid retroversion. CONCLUSIONS: Individual patients from 11 international practices having total shoulder arthroplasty using a basic glenoid component design obtained highly significant clinical outcomes, providing a benchmark against which the early outcomes of new designs can be compared to determine whether they provide increased clinical value.

Glenoid Bone Loss in Reverse Shoulder Arthroplasty Treated with Bone Graft Techniques.

The reverse shoulder arthroplasty facilitates surgical treatment of primary and revision shoulder with rotator cuff and bone deficiencies. Wear pattern classifications and a logical treatment approach for glenoid bone loss enable the surgeon to address a difficult series of problems in the reconstructions where the glenoid might not otherwise be able to support the implants. Bone grafting using the native humeral head in primary cases, and in revision cases, iliac crest are the most reliable sources for structural grafts for the worn or deficient glenoid vault.

Radiographic changes and clinical outcomes associated with an adjustable diaphyseal press-fit humeral stem in primary reverse shoulder arthroplasty.

BACKGROUND: Press-fit humeral fixation in reverse shoulder arthroplasty (RSA) has become increasingly popular; however, radiographic analysis of these stems is limited. We aimed to evaluate the radiographic and clinical outcomes of an adjustable diaphyseal press-fit humeral stem in primary RSA. METHODS: We conducted a retrospective review of 232 primary RSAs in 219 patients performed by a single surgeon using this system. Radiographic outcomes were evaluated in patients with at least 2 years of radiographic follow-up. Standardized postoperative digital radiographs were analyzed for loosening, osteolysis, and stress shielding. Clinical outcomes in patients who also had complete clinical data sets were evaluated at the most recent follow-up. RESULTS: Radiographic evidence of loosening was identified in 1 RSA (0.4%) associated with deep infection. Aseptic loosening was not observed. No stems were identified as being at high risk for loosening. Internal stress shielding was observed proximal to the coated diaphyseal component in 226 shoulders (97.4%). This finding was often visible at 3 months (92.7%) and predictably progressed on subsequent radiographs. Progression beyond the 2-year period was rarely seen (4.4%). No external stress shielding or osteolysis was observed. Thirty-six complications occurred in 33 patients (15.1%). At an average follow-up of 36.6 months, significant improvements were identified in all measured clinical outcomes (P < .001). CONCLUSION: Predictable fixation is achieved using an adjustable diaphyseal press-fit humeral system in primary RSA. Internal stress shielding is commonly observed but does not appear to compromise quality of fixation or clinical outcomes.

Radiographic evaluation of short-stem press-fit total shoulder arthroplasty: short-term follow-up.

BACKGROUND: Humeral loosening is an uncommon etiology for revision shoulder arthroplasty. We aimed to evaluate the radiographic and clinical outcomes of a short-stem press-fit humeral component after primary total shoulder arthroplasty. METHODS: We reviewed our patient database, from January 2008 to December 2011, for primary total shoulder arthroplasties performed with a short-stem press-fit humeral component. Radiographs and clinical outcomes were evaluated in the immediate postoperative period and at the most recent follow-up, with at least 24 months of data for all patients. RESULTS: There were 73 shoulders that met our inclusion criteria, but 4 underwent revision before 2 years' follow-up. Only 1 of these 4 was revised for aseptic humeral loosening. Sixty-nine shoulders had at least 24 months of radiographic follow-up, and 62 had radiographic and clinical follow-up. Of the 69 shoulders, 5 underwent revision for humeral loosening: 1 for aseptic loosening and 4 for infection. Two other shoulders with humeral loosening were asymptomatic, and the patients refused revision surgery. The overall revision rate for humeral loosening was 8.2% (6 of 73 shoulders). Radiolucent zones of any size were seen in 71.0%, with 8.7% of these shoulders identified as having humeral stems at risk of future loosening. Significant improvements were made in most of the measured clinical outcomes. CONCLUSIONS: A high percentage of radiolucency was seen around the short-stem press-fit humeral components evaluated in this study at short-term follow-up. The overall rates of loosening and revision for the humeral implant examined in this study are higher than those noted in other recent studies evaluating press-fit stems. The cause of radiolucency and humeral loosening for this implant is not fully understood.

Analysis of severely fractured glenoid components: clinical consequences of biomechanics, design, and materials selection on implant performance.

BACKGROUND: The longevity of total shoulder replacement is primarily limited by the performance of the ultrahigh-molecular-weight polyethylene (UHMWPE) glenoid component in vivo. Variations in glenoid design (conformity, thickness), biomechanics (joint kinematics), and UHMWPE material selection (sterilization, cross-linking) distinguish total shoulder replacements from hip and knee arthroplasty devices. These variables can lead to severe mechanical failures, including gross fracture. METHODS: Sixteen retrieved glenoids with severe fracture were analyzed. The explant cohort included 3 material groups (gamma-sterilized Hylamer; gamma-sterilized UHMWPE; and gas plasma-sterilized, remelted, highly cross-linked UHMWPE [HXL]) and a range of conformities (0- to 10-mm radial mismatch). Analysis included fractography (optical and scanning electron microscopy) and Fourier transform infrared spectroscopy for oxidative analysis. RESULTS: Fracture primarily occurred along the exterior rim for all 16 explants. Fourier transform infrared analysis and fractography revealed significant oxidative embrittlement for all gamma-sterilized glenoids. Fatigue striations and internal flaws were evident on the fracture surface of the HXL glenoid, with little oxidation detected. CONCLUSIONS: Fracture initiated at the external rim of all devices. Elevated oxidation levels and visible material distortion for representative gamma-sterilized conventional and Hylamer devices suggest oxidative embrittlement as a driving force for crack inception and subsequent fracture. Brittle fracture of theHXL glenoid resulted from a combination of elevated contact stress due to a nonconforming surface, an internal flaw, and reduced resistance to fatigue crack growth. This demonstrates that glenoid fracture associated with oxidation has not been eliminated with the advent of modern materials (HXL) in the shoulder domain. LEVEL OF EVIDENCE: Basic Science Study; Implant Retrieval Study.

Radiographic and clinical outcomes of total shoulder arthroplasty with an all-polyethylene pegged bone ingrowth glenoid component: prospective short- to medium-term follow-up.

BACKGROUND: Glenoid components often cause total shoulder arthroplasty failure. This study examines short-term to midterm radiographic and clinical results of a hybrid glenoid component with 3 cemented peripheral pegs and a central peg, which allows biologic fixation with use of native humeral head autograft. METHODS: In 4 years, 80 glenoid components were implanted during primary total shoulder arthroplasty with at least 2-year follow-up data. Within 12 months, 4 shoulders were revised and excluded from final analyses. Seven patients did not complete their questionnaires. Outcomes data included the American Shoulder and Elbow Surgeons (ASES) questionnaire, Constant score, and satisfaction score. A shoulder and elbow fellowship-trained surgeon, not involved in the care of these patients, analyzed radiographs for radiolucent lines, glenoid seating, and radiodensity in between the flanges of the central peg. RESULTS: Only 1 of 80 shoulders was revised for aseptic glenoid loosening. At final follow-up, 81.6% had a radiolucency grade of 0 or 1. Nearly 90% had a glenoid seating grade of A or B. Grade 2 or 3 bone around the central peg was seen in 88.2%. No statistical association existed between Walch glenoid types and radiolucency grades, bone grades around the central peg, perfect radiolucency grade, seating grade, and grade 3 bone around the central peg. There was significant improvement in mean ASES score, adjusted ASES pain score, Constant score, and satisfaction score as well as in forward flexion, abduction, and external rotation. CONCLUSIONS: The hybrid glenoid can produce stable radiographic and clinical outcomes at short- to medium-term follow-up.

Clinical results of revision shoulder arthroplasty using the reverse prosthesis.

BACKGROUND: Success of revision shoulder arthroplasty using an unconstrained prosthesis depends on an intact rotator cuff and satisfactory bone quantity. However, the reverse shoulder arthroplasty can stabilize a glenohumeral joint even in patients with rotator cuff deficiency and bone deficits, resulting in improved outcomes. MATERIALS AND METHODS: Thirty shoulders in 28 patients with a failed arthroplasty were investigated consecutively between 2005 and 2008. All shoulders had significant rotator cuff deficiency without glenoid bone loss. Revision arthroplasty using the reverse prosthesis was performed with a minimum of 2 years of follow-up. Concomitant glenoid reconstructions with tricortical iliac crest bone grafting were necessary in 12 shoulders. RESULTS: The average adjusted Constant score improved from 24% to 65% and the American Shoulder and Elbow Surgeons (ASES) score improved from 55 to 72 (P < .0001). Average active forward flexion increased from 42° to 106° (P < .0001). The average ASES pain score improved from 6.6 to 1.6 (P < .0001). The overall complication rate was 50%, and 7 patients (23%) required reoperation. Overall, 24 of 30 shoulders (80%) were very satisfied or satisfied. CONCLUSION: Reverse shoulder arthroplasty can be an efficacious salvage procedure in the management of failed arthroplasty due to rotator cuff-related instability or bone defects, or both. Structural bone grafting on the glenoid side is successful at managing large defects, producing similar or better clinical outcomes compared with patients without bone loss. Although the operation is associated with a considerable complication rate, 80% of patients were satisfied with the results of the procedure, and 29 of 30 shoulders had a stable prosthesis.

Optimizing glenosphere position and fixation in reverse shoulder arthroplasty, Part One: The twelve-mm rule.

The Aequalis Reversed Shoulder Prosthesis (Tornier, Inc., Edina, MN) is a successful treatment option for older, low-demand patients with rotator cuff arthropathy. Scapular notching is the most common radiographic complication and is associated with poorer intermediate-term clinical outcomes. Aligning the lower border of the glenosphere baseplate with the inferior glenoid rim has been recommended to reduce this complication, but guidelines for achieving this positioning are currently lacking. The purpose of this study is to develop a rule of thumb that will facilitate proper glenosphere component positioning intraoperatively. Utilizing a computed tomography-templating protocol, we found that the ideal location of the drill hole for the baseplate post was 11.5 +/- 1.0 mm above the inferior glenoid rim. On the basis of measurements from 10 implanted cadaveric specimens, we concluded that drilling the baseplate posthole 12 mm above the inferior glenoid rim-the 12-mm rule-will result in excellent glenosphere position in most cases.

Optimizing glenosphere position and fixation in reverse shoulder arthroplasty, Part Two: The three-column concept.

Scapular geometry is complex, and a screw-placement technique for optimizing glenoid component fixation with an Aequalis Reversed Shoulder Prosthesis (Tornier, Inc., Edina, MN) has not yet been described. Ten cadaveric human scapulae were implanted with 2 types of reverse arthroplasty baseplates, 1 with fixed-angle locking screw holes and 1 with multidirectional locking screw holes. Optimal screw placement was defined as that which maximized screw length, accomplished far cortical fixation, and attained screw purchase in good bone stock. An anterior cruciate ligament drill guide was used to find the ideal trajectory for each screw. Trajectory angles of the screws relative to the face of the baseplate are presented for what we believe is best possible fixation. Awareness of the 3 major columns of scapular bone (the base of coracoid, the spine, and the pillar) and utilization of a baseplate with variable-angle locking screws will allow optimal initial fixation of the glenosphere.

Treatment of glenoid loosening and bone loss due to osteolysis with glenoid bone grafting.

Twenty-four patients underwent conversion of a total shoulder replacement to a humeral head replacement with glenoid bone grafting for glenoid loosening due to osteolysis. Of the 24 patients, 18 (75%) had satisfactory pain relief at a mean follow-up of 33.4 months (range, 24-63 months). Four had good pain relief with conversion back to total shoulder replacement at a mean of 11 months (range, 9-15 months) after the index procedure, thus bringing the rate of overall satisfactory pain relief to 92%. Two patients continued to report significant pain and were not satisfied with the procedure. Significant functional motion improvements were not seen (P > .05). Graft subsidence was seen in 10 of 20 cases (50%). Bone grafting of glenoid defects in revision arthroplasty provides satisfactory improvement in terms of pain relief and, by improving bone stock, allows for placement of a glenoid component at a later date if there is persistent pain. However, high rates of graft subsidence are concerning.

Indications for prosthetic replacement in proximal humeral fractures.

Prosthetic replacement is a good treatment option in osteoporotic patients with four-part fractures, fracture-dislocations, head-split fractures with more than 40% articular surface involvement, anatomic neck fractures, dislocations present for longer than 6 months, and selected three-part fractures. Early prosthetic replacement of proximal humeral fractures has a better outcome than late reconstructive prosthetic management. Prosthetic design features specific forfracture care have led to a reduction in complications. Techniques will continue to improve as prosthetic design features specific for fractures evolve.

Influence of preoperative factors on outcome of shoulder arthroplasty for glenohumeral osteoarthritis.

BACKGROUND: The results of shoulder arthroplasty for osteoarthritis have been reported to be excellent or good for the majority of patients, but the value of using a glenoid component and the anatomic factors that affect outcome are still debated. The purpose of this study was to evaluate the influence of an operatively confirmed full-thickness tear of the rotator cuff, the severity of preoperative erosion of glenoid bone, preoperative radiographic evidence of subluxation of the humeral head, and the severity of preoperative loss of the passive range of motion on the outcome of total shoulder arthroplasty and hemiarthroplasty. METHODS: In a multicenter clinical outcome study, we evaluated 128 shoulders in 118 patients with primary osteoarthritis who had been followed for a mean of forty-six months (range, twenty-four to eighty-seven months). RESULTS: Patients with <10 degrees of passive external rotation preoperatively had significantly less improvement in external rotation after hemiarthroplasty (p = 0.006). Thirteen (10%) of the 128 shoulders had a repairable full-thickness tear of the supraspinatus tendon, but these tears did not affect the overall American Shoulder and Elbow Surgeons score, the decrease in pain, or patient satisfaction. Severe or moderate eccentric glenoid erosion was seen in twenty-nine (23%) of the 128 shoulders, and total shoulder arthroplasty resulted in significantly better passive total elevation and active external rotation as well as a trend toward significantly better active forward flexion than did hemiarthroplasty in these shoulders. The humeral head was subluxated posteriorly in twenty-three shoulders (18%), and when they were compared with the other shoulders in the study, these shoulders were found to have lower final American Shoulder and Elbow Surgeons scores, more pain, and decreased active external rotation following either total shoulder arthroplasty or hemiarthroplasty. CONCLUSIONS: On the basis of our data, we recommend the use of a glenoid component in shoulders with glenoid erosion. Humeral head subluxation was associated with a less favorable result regardless of the type of shoulder arthroplasty and must be considered in preoperative planning and counseling. Severe loss of the passive range of motion preoperatively was associated with a decreased passive range of motion postoperatively. A repairable tear of the supraspinatus tendon is not a contraindication to the use of a glenoid component. .

Decision making in glenohumeral arthroplasty.

Prosthetic replacement arthroplasty for glenohumeral arthritis is a well-developed and well-described technique with good and excellent results. The surgeon is faced with many decisions to make, however, regarding choice of implant, implant fixation, soft tissue management, and options for glenoid resurfacing. In general, when the precise cause of the arthritic condition is identified, the choices become more straightforward. For advanced osteoarthritis of the shoulder joint in an older patient with asymmetric posterior erosion of the glenoid, a total shoulder arthroplasty renders the best relief of pain and improvement in motion. Similarly, for advanced rheumatoid arthritis in patients with an intact rotator cuff, a total shoulder arthroplasty results in the best pain relief. If the rotator cuff is deficient and irreparable, an anatomically sized humeral head replacement is appropriate, taking care to preserve the coracoacromial arch. Acute, nonreducible fractures of the proximal humerus are treated best with a humeral head replacement. Post-traumatic arthropathy of the shoulder joint is treated with arthroplasty, and the decision to resurface the glenoid should take into account the age of the patient and the wear and concentricity of the glenoid. Many options exist for the choice of an implant; biomechanical and anatomic studies suggest that a better technical result can be achieved with a third-generation implant design that has the ability to recreate accurately the proximal anatomy of the humerus.

Functional outcome after shoulder arthroplasty for primary osteoarthritis: a multicenter study.

Shoulder arthroplasty outcomes have been reported in many case series. Typically, these series have followed either a single prosthesis used to treat a variety of arthritic disorders of the shoulder or experience in a single institution. In contrast, this report of a prospective study summarizes the experience of several surgeons with a single prosthetic design for treatment of primary osteoarthritis of the shoulder. A prospective, multicenter clinical outcome study evaluated 176 shoulders in 160 patients with primary osteoarthritis. This study evaluated a single prosthetic design (Global Shoulder) used by 19 contributing surgeons. Enrollment included 133 total shoulder replacements and 43 humeral head replacements (hemiarthroplasty) in 98 men and 62 women. Neither age nor sex affected whether hemiarthroplasty or total shoulder arthroplasty was performed. Patients with full-thickness cuff tears preferentially had hemiarthroplasty. The decision to perform total shoulder arthroplasty or hemiarthroplasty was based on the surgeon's preference. There were significant improvements (P <.001) in all evaluated and self-assessed outcome parameters from the preoperative baseline for both total shoulder arthroplasty and hemiarthroplasty. The results confirm that prosthetic arthroplasty leads to dramatic improvement in pain, function, and patient satisfaction. Intraoperative complications occurred in 5.4% of cases, and postoperative complications occurred in 7.8%. The most common intraoperative complications were intraoperative fractures, occurring in 9 cases. The most common postoperative complications were glenoid component loosening and humeral head subluxation. Almost all cases of humeral head instability were associated with rotator cuff tears or glenoid component loosening (or both). Seven shoulders underwent 9 additional surgeries during the 5-year study period. Thirteen shoulders in 11 patients were lost as a result of death unrelated to the procedure; 2 shoulders in 1 patient were lost within 3 days/3 months after the bilateral replacements as a result of death from pulmonary embolism. Nine percent of the shoulders (16/176) had full-thickness rotator cuff tears. Eight of the 16 shoulders with full-thickness supraspinatus cuff tears had hemiarthroplasty. All of these tears were isolated to the supraspinatus tendon, and all were repairable. There were no differences in postoperative pain, function, American Shoulder and Elbow Surgeons scores, or range of motion. There were no differences between total shoulder arthroplasty and hemiarthroplasty in those patients with a reparable rotator cuff tear. Total shoulder arthroplasty and hemiarthroplasty for treatment of primary osteoarthritis result in good or excellent pain relief, improvement in function, and patient satisfaction in 95% of cases. Avoiding intraoperative humeral shaft fractures through use of an uncemented, canal-filling prosthetic stem requires careful attention to reaming and component sizing. Postoperative humeral head subluxation is often associated with other factors including rotator cuff tears or glenoid component loosening.

Retrieved glenoid components: a classification system for surface damage analysis.

There have been many reports describing modes of damage in retrieved total hip and total knee arthroplasty components. The most common mechanism in total hip arthroplasties has been shown to be surface wear. Fatigue failure shown as pitting and delamination are observed more often in total knee components. There has been no previous analysis of retrieved polyethylene glenoid components. This study evaluated the wear mechanisms contributing to failure of total shoulder glenoid components. Polyethylene glenoid components from 10 consecutive total shoulder arthroplasties have been retrieved and analyzed. Wear mechanisms were analyzed under low-power magnification, and a classification system was designed for total shoulder arthroplasties. This classification system is an adaptation of previous models of hip and knee surface damage. The severity of each damage mode was graded in 4 separate quadrants. The most prevalent damage modes were abrasion, pitting, and delamination. These data show a combination of abrasive wear and fatigue in retrieved total shoulder specimens. Surface wear and subsurface fatigue failure mechanisms both contribute to glenoid implant failure.