Jason J. Scalise

The influence of three-dimensional computed tomography images of the shoulder in preoperative planning for total shoulder arthroplasty.

BACKGROUND Arthritic changes to glenoid morphology can be difficult to fully characterize on both plain radiographs and conventional two-dimensional computer tomography images. We tested the hypothesis that three-dimensional imaging of the shoulder would increase inter-rater agreement for assessing the extent and location of glenoid bone loss and also would improve surgical planning for total shoulder arthroplasty. METHODS Four shoulder surgeons independently and retrospectively reviewed the preoperative computed tomography scans of twenty-four arthritic shoulders. The blinded images were evaluated with conventional two-dimensional imaging software and then later with novel three-dimensional imaging software. Measurements and preoperative judgments were made for each shoulder with use of each imaging modality and then were compared. The glenoid measurements were glenoid version and bone loss. The judgments were the zone of maximum glenoid bone loss, glenoid implant fit within the glenoid vault, and how to surgically address abnormal glenoid version and bone loss. Agreement between observers was evaluated with use of intraclass correlation coefficients and the weighted kappa coefficient (kappa), and we determined if surgical decisions changed with use of the three-dimensional data. RESULTS The average glenoid version (and standard deviation) measured -17 degrees +/- 2.2 degrees on the two-dimensional images and -19 degrees +/- 2.4 degrees on the three-dimensional images (p < 0.05). The average posterior glenoid bone loss measured 9 +/- 2.3 mm on the two-dimensional images and 7 +/- 2 mm on the three-dimensional images (p < 0.05). The average anterior bone loss measured 1 mm on both the two-dimensional and the three-dimensional images. However, the intraclass correlation coefficients for anterior bone loss increased significantly with use of the three-dimensional data (from 0.36 to 0.70; p < 0.05). Observers were more likely to locate mid-anterior glenoid bone loss on the basis of the three-dimensional data (p < 0.05). The use of three-dimensional data provided greater agreement among observers with regard to the zone of glenoid bone loss, glenoid prosthetic fit, and surgical decision-making. Also, when the judgment of implant fit changed, observers more often determined that it would violate the vault walls on the basis of the three-dimensional data (p < 0.05). CONCLUSIONS The use of three-dimensional imaging can increase inter-rater agreement for the analysis of glenoid morphology and preoperative planning. Important considerations such as the extent and location of glenoid bone loss and the likelihood of implant fit were influenced by the three-dimensional data.

Clinical, Radiographic, and Ultrasonographic Comparison of Subscapularis Tenotomy and Lesser Tuberosity Osteotomy for Total Shoulder Arthroplasty

BACKGROUND Recently, a lesser tuberosity osteotomy has been promoted as an alternative to tenotomy for release of the subscapularis during shoulder arthroplasty. To our knowledge, no direct comparison of the clinical results of the two techniques has been presented. METHODS Thirty-five shoulders in thirty-four consecutive patients with osteoarthritis who had a primary total shoulder arthroplasty, performed with use of a standard subscapularis tenotomy (Group 1) or lesser tuberosity osteotomy (Group 2) to release the subscapularis, were evaluated retrospectively at an average of thirty-three months. Group 1 consisted of fifteen shoulders in fourteen patients (seven in males and eight in females, with an average age of sixty-seven years). Group 2 consisted of twenty shoulders in twenty patients (fourteen males and six females, with an average age of sixty-nine years). Assessment included a physical examination, clinical outcome questionnaires, conventional radiography, ultrasound examination of the subscapularis, and measurement of internal rotation strength. RESULTS The postoperative total Penn Shoulder Scores improved significantly from the preoperative levels in both groups (mean and standard deviation, 29 +/- 15 points to 81 +/- 20 points [p < 0.00001] in Group 1 and 29 +/- 16 points to 92 +/- 11 points [p < 0.00001] in Group 2). However, the postoperative mean total Penn Shoulder Score was higher in Group 2 (92 +/- 11 points) than in Group 1 (81 +/- 20 points) (p = 0.04). At one year, an abnormal subscapularis on ultrasound was associated with a lower mean Penn Shoulder Score in Group 1 (73 +/- 19 points compared with 92 +/- 3 points; p = 0.01). However, at a minimum two-year follow-up, this difference was not significant (mean, 74 +/- 24 points and 86 +/- 15 points, respectively; p = 0.25). There were more abnormal subscapularis tendons in Group 1 (six attenuated tendons and one full-thickness tear) than in Group 2 (two attenuated tendons). Internal rotation strength did not differ between the groups when controlled for sex (mean, 117 +/- 8 N and 127 +/- 21 N for males in Group 1 and Group 2, respectively [p = 0.22] and 77 +/- 27 N and 101 +/- 26 N, respectively, for females [p = 0.1]). CONCLUSIONS Both techniques resulted in improved clinical outcome scores. The lesser tuberosity osteotomy resulted in higher clinical outcome scores, a lower rate of subscapularis tendon tears, and universal healing of the osteotomy. This technique offers a means by which the rate of postoperative subscapularis tears may be reduced in patients undergoing total shoulder arthroplasty.

The three-dimensional glenoid vault model can estimate normal glenoid version in osteoarthritis.

Glenohumeral arthroplasty can involve correcting pathologic glenoid tilt or version. Predicting the physiologic glenoid version for a particular individual can be difficult. We propose using a previously validated, 3-dimensional, glenoid vault model as a template to predict normal glenoid version. Computed tomography scans of both shoulders were obtained in 14 subjects with unilateral glenohumeral osteoarthritis. Custom-developed graphic software was used to create a 3-D reconstruction of each scapula. Within the software, the vault model was placed in a best-fit orientation into each glenoid vault independently by 3 observers who were blinded to the contralateral scapula. Measurement differences between the glenoid and vault model were analyzed by repeated-measures analysis of variance. Standard errors of measurement (SEM) were calculated. Interobserver and intraobserver reliabilities were assessed. The healthy glenoid version averaged -7.0 degrees (SEM, 0.7 degrees ; range, 0 degrees to -14 degrees ). The arthritic glenoid version averaged -15.6 degrees (SEM, 0.7 degrees ; range, 1 degrees to -33 degrees ; P < .0001). The version of the implanted vault model measured -7.1 degrees (SEM, 0.7 degrees ; range, -1 degrees to -15 degrees ) on the healthy side and -7.2 degrees (SEM, 0.7 degrees ; range -2 degrees to -11 degrees ) on the arthritic side. Measurements between observers were not significantly different (P = .98). Interobserver and intraobserver correlation coefficients were 0.79 (P < .001) and 0.80 (P < .001). In the arthritic glenoid, the vault model reproducibly closely approximated the version of the normal contralateral glenoid, -7.2 degrees vs -7.0 degrees (P = .99) and is a novel and accurate method of estimating the normal glenoid version. This technique may be valuable in correcting pathologic glenoid version due to arthritis.

Quantitative analysis of glenoid bone loss in osteoarthritis using three-dimensional computed tomography scans

The 3-dimensional (3D) shape of the glenoid vault has been defined previously and shown to be a complex, yet consistent, shape in individuals without glenoid pathology. We proposed assessing whether this conserved shape could be used as a template to measure glenoid bone loss in subjects with glenohumeral osteoarthritis. Computed tomography (CT) scans of both shoulders were obtained from 12 subjects with unilateral glenohumeral osteoarthritis. The paired scapulae were reconstructed 3-dimensionally, using a previously developed graphic software package. Two methods of estimating glenoid bone loss were performed. First, using the software, a stereolithography model of the standardized vault shape was implanted into each glenoid and measurements made of the volume of the implant not contained within each vault. Second, direct measurements of the paired glenoid vault volumes were performed. The volume of the nonarthritic glenoid was used as a subject-specific template for normal glenoid vault volume for each pair. The glenoid bone volumes measured by each method were compared and Pearsons correlation coefficient determined. The average measurement of glenoid bone loss using the vault implant was within 0.8% (SD +/- 1.5%) of the measurement made using the contralateral, normal glenoid. For all patients, Pearsons correlation coefficient was .99, indicating a very high correlation between the two methods of measuring bone loss (P < .0001). The intricate, yet consistent 3D shape of the glenoid vault can be used as an accurate and reliable template to measure glenoid bone loss in glenohumeral osteoarthritis.

Glenohumeral Arthrodesis After Failed Prosthetic Shoulder Arthroplasty

BACKGROUND While there have been numerous reports concerning glenohumeral arthrodesis for many indications, there is little available information specific to glenohumeral arthrodesis performed after failed prosthetic shoulder arthroplasty. The purpose of this study was to report the outcomes of glenohumeral arthrodesis in the setting of severe glenohumeral bone loss and deltoid muscle and rotator cuff insufficiency following failed prosthetic shoulder arthroplasty. METHODS We retrospectively reviewed clinical and radiographic data on seven consecutive patients treated with glenohumeral arthrodesis following a failed prosthetic shoulder arthroplasty between 1997 and 2004. The average duration of clinical follow-up was four years (range, 1.5 to eight years). RESULTS Five of the seven patients demonstrated an intact fusion at the time of the latest follow-up. Four of the seven patients had undergone additional bone-grafting procedures in an effort to obtain union. Two of these patients ultimately had a persistent nonunion despite the additional procedures for bone-grafting and revision of the fixation hardware. Overall, the average subjective clinical outcome score (Penn Shoulder Score) improved significantly from 17 points (range, 8 to 33 points) to 58 points (range, 31 to 77 points) (p = 0.008). The most common complication was delayed union requiring additional procedures for bone-grafting and revision of the fixation hardware. CONCLUSIONS Treatment of a failed prosthetic shoulder arthroplasty with concomitant extensive glenohumeral bone loss and soft-tissue deficiencies is extremely challenging. The results of this study suggest that glenohumeral arthrodesis can yield satisfactory clinical outcomes. However, both the patient and the surgeon should be aware of the complex nature of this surgery and the frequent need for additional surgical procedures to obtain fusion.

Inter-rater reliability of an arthritic glenoid morphology classification system

To our knowledge, no independent analysis of the inter-rater agreement of the widely used Walch classification for osteoarthritic glenoid morphology has been performed. The computed tomography scans of 24 shoulders with primary osteoarthritis were used by 4 experienced shoulder surgeons to classify the glenoids independently according to Walch et al. The weighted kappa statistic was calculated to determine the inter-rater and intrarater agreement among observers. The overall inter-rater agreement for the Walch classification was fair (kappa = 0.37) when classified into the 5 types (A1, A2, B1, B2, and C). Agreement for the various subclassifications was as follows: A1, kappa = 0.22; A2, kappa = 0.33; B1, kappa = 0.17; B2, kappa = 0.32; and C, kappa = 0.86. When the classification system was simplified to just the 3 major types (A, B, and C), overall agreement was moderate (kappa = 0.44). Agreement for each type was moderate for A (kappa = 0.59) and B (kappa = 0.59) and almost perfect for C (kappa = 0.89). Overall intrarater agreement was fair (kappa = 0.37). We conclude that only fair agreement was found among experienced shoulder surgeons when classifying arthritic shoulders using the classification system of Walch et al. A glenoid classification scheme that relies more upon glenoid morphology and less upon humeral head position may demonstrate greater observer agreement and, therefore, may offer greater value.

Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study

BACKGROUND This study compared ultrasound and magnetic resonance imaging (MRI) evaluation of the repaired rotator cuff to determine concordance between these imaging studies. METHODS We performed a concordance study using the data from a prospective nonrandomized multicenter study at 13 centers. A suture bridge technique was used to repair 113 rotator cuff tears that were between 1 and 4 cm wide. Repairs were evaluated with MRI and ultrasound at multiple time points after surgery. The MRI scans were read by a central radiologist and the surgeon, and the ultrasounds were read by a local radiologist or the surgeon who performed the ultrasound. RESULTS The concordance between the central radiologists MRI reading and the investigators MRI readings at all time points was 89%, with a κ coefficient of 0.60. The concordance between the central radiologists MRI and ultrasound readings at all time points was 85%, with a κ coefficient of 0.40. The concordance between the investigators MRI and ultrasound readings was 92%, with a κ coefficient of 0.70. CONCLUSIONS In the community setting, ultrasound may be used to evaluate the integrity of a repaired rotator cuff tendon and constitutes a comparable alternative to MRI when evaluating the integrity of a rotator cuff repair. Clinical investigators should compare their postoperative ultrasound results with their postoperative MRI results for a certain time period to establish the accuracy of ultrasound before relying solely on ultrasound imaging to evaluate the integrity of their rotator cuff repairs.

Glenohumeral Arthrodesis After Failed Prosthetic Shoulder Arthroplasty: Surgical Technique

BACKGROUND While there have been numerous reports concerning glenohumeral arthrodesis for many indications, there is little available information specific to glenohumeral arthrodesis performed after failed prosthetic shoulder arthroplasty. The purpose of this study was to report the outcomes of glenohumeral arthrodesis in the setting of severe glenohumeral bone loss and deltoid muscle and rotator cuff insufficiency following failed prosthetic shoulder arthroplasty. METHODS We retrospectively reviewed clinical and radiographic data on seven consecutive patients treated with glenohumeral arthrodesis following a failed prosthetic shoulder arthroplasty between 1997 and 2004. The average duration of clinical follow-up was four years (range, 1.5 to eight years). RESULTS Five of the seven patients demonstrated an intact fusion at the time of the latest follow-up. Four of the seven patients had undergone additional bone-grafting procedures in an effort to obtain union. Two of these patients ultimately had a persistent nonunion despite the additional procedures for bone-grafting and revision of the fixation hardware. Overall, the average subjective clinical outcome score (Penn Shoulder Score) improved significantly from 17 points (range, 8 to 33 points) to 58 points (range, 31 to 77 points) (p = 0.008). The most common complication was delayed union requiring additional procedures for bone-grafting and revision of the fixation hardware. CONCLUSIONS Treatment of a failed prosthetic shoulder arthroplasty with concomitant extensive glenohumeral bone loss and soft-tissue deficiencies is extremely challenging. The results of this study suggest that glenohumeral arthrodesis can yield satisfactory clinical outcomes. However, both the patient and the surgeon should be aware of the complex nature of this surgery and the frequent need for additional surgical procedures to obtain fusion.

Resurfacing arthroplasty of the humerus: Indications, surgical technique, and clinical results

Resurfacing arthroplasty of the shoulder is not a new concept in orthopedic surgery. Although only a few reports describe the indications, technique, and results, experience with these devices continues to grow. A specific advantage of resurfacing arthroplasty, the concept of a bone-preserving procedure, may prove to be particularly important in younger patients who require prosthetic arthroplasty surgery. The indications and surgical technique are illustrated in this review. Our early clinical results with 2 humeral resurfacing prostheses reflect those of other published reports; namely, favorable clinical outcomes can be expected.

The glenoid in total shoulder arthroplasty: current concepts

Total shoulder arthroplasty is an accepted treatment for glenohumeral arthritis. In appropriately selected patients, total shoulder arthroplasty decreases pain and improves function. One of the most common causes for failure is glenoid loosening, which leads to postoperative pain, limitation of function, and the possibility of revision surgery. The current literature has devoted considerable attention to the attributes of the glenoid in total shoulder arthroplasty. This article reviews the current state of knowledge about the glenoid, examining specifically the options for younger patients, for revision surgery, for glenoid erosion, and for maximizing implant longevity. The literature was searched for studies within the last 2 years regarding the glenoid in total shoulder arthroplasty, and relevant articles were selected for review. As the incidence of total shoulder arthroplasty increases, accurate and durable management of the glenoid will help minimize complications and promote better clinical outcomes. Clearly, further research is warranted on the optimal indications for the various techniques and strategies for treating the glenoid.