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1.  A CT scan protocol for the detection of radiographic loosening of the glenoid component after total shoulder arthroplasty 
Acta Orthopaedica  2014;85(1):91-96.
Background and purpose
It is difficult to evaluate glenoid component periprosthetic radiolucencies in total shoulder arthroplasties (TSAs) using plain radiographs. This study was performed to evaluate whether computed tomography (CT) using a specific patient position in the CT scanner provides a better method for assessing radiolucencies in TSA.
Following TSA, 11 patients were CT scanned in a lateral decubitus position with maximum forward flexion, which aligns the glenoid orientation with the axis of the CT scanner. Follow-up CT scanning is part of our routine patient care. Glenoid component periprosthetic lucency was assessed according to the Molé score and it was compared to routine plain radiographs by 5 observers.
The protocol almost completely eliminated metal artifacts in the CT images and allowed accurate assessment of periprosthetic lucency of the glenoid fixation. Positioning of the patient within the CT scanner as described was possible for all 11 patients. A radiolucent line was identified in 54 of the 55 observed CT scans and osteolysis was identified in 25 observations. The average radiolucent line Molé score was 3.4 (SD 2.7) points with plain radiographs and 9.5 (SD 0.8) points with CT scans
(p = 0.001). The mean intra-observer variance was lower in the CT scan group than in the plain radiograph group (p = 0.001).
The CT scan protocol we used is of clinical value in routine assessment of glenoid periprosthetic lucency after TSA. The technique improves the ability to detect and monitor radiolucent lines and, therefore, possibly implant loosening also.
PMCID: PMC3940998  PMID: 24286563
2.  Accuracy of Glenoid Component Placement in Total Shoulder Arthroplasty and Its Effect on Clinical and Radiological Outcome in a Retrospective, Longitudinal, Monocentric Open Study 
PLoS ONE  2013;8(10):e75791.
The success of Total Shoulder Arthroplasty (TSA) is believed to depend on the restoration of the natural anatomy of the joint and a key development has been the introduction of modular humeral components to more accurately restore the patient’s anatomy. However, there are no peer-reviewed studies that have reported the degree of glenoid component mal-position achieved in clinical practice and the clinical outcome of such mal-position. The main purpose of this study was to assess the accuracy of glenoid implant positioning during TSA and to relate it to the radiological (occurrence of radiolucent lines and osteolysis on CT) and clinical outcomes.
68 TSAs were assessed with a mean follow-up of 38+/−27 months. The clinical evaluation consisted of measuring the mobility as well as of the Constant Score. The radiological evaluation was performed on CT-scans in which metal artefacts had been eliminated. From the CT-scans radiolucent lines and osteolysis were assessed. The positions of the glenoid and humeral components were also measured from the CT scans.
Four position glenoid component parameters were calculated The posterior version (6°±12°; mean ± SD), the superior tilt (12°±17°), the rotation of the implant relative to the scapular plane (3°±14°) and the off-set distance of the centre of the glenoid implant from the scapular plane (6±4 mm). An inferiorly inclined implant was found to be associated with higher levels of radiolucent lines while retroversion and non-neutral rotation were associated with a reduced range of motion.
this study demonstrates that glenoid implants of anatomic TSA are poorly positioned and that this malposition has a direct effect on the clinical and radiological outcome. Thus, further developments in glenoid implantation techniques are required to enable the surgeon to achieve a desired implant position and outcome.
PMCID: PMC3793002  PMID: 24116075
3.  Does Open Repair of Anterosuperior Rotator Cuff Tear Prevent Muscular Atrophy and Fatty Infiltration? 
Repair of cuff tears involving rotator interval reportedly improves function. However, it is unclear whether successful repair prevents shoulder degenerative changes.
Therefore, we (1) documented the minimal 4-year function of patients who underwent open surgical repair for rotator interval tears; (2) evaluated repaired tendon healing with postoperative MRI; and (3) sought to determine the influence of tendon healing on muscular and glenohumeral joint changes.
We retrospectively analyzed 22 patients (23 shoulders) treated by open transosseous reinsertion of supraspinatus and subscapularis tendons. The mean age of the patients was 53 years (range, 37–64 years). The tear was traumatic in four cases. Repair healing and muscular changes were assessed using MRI. The minimum followup was 46 months (mean, 75 months; range, 46–103 months).
We observed an improvement in the absolute Constant-Murley score from 63 points preoperatively to 76 points postoperatively. With the last followup MRI, the supraspinatus tendon repair had failed in two of the 23 shoulders, whereas the subscapularis tendon repair had healed in all cases. Once healing of the repaired tendon occurred, supraspinatus muscle atrophy never worsened. However, on MRI fatty infiltration of the rotator cuff muscles increased despite successful tendon repair. Glenohumeral arthritis remained stable. Postoperative abduction and internal rotation strengths were better when the standardized supraspinatus muscle area was greater than 0.5 at the final evaluation.
Durable functional improvement and limited degenerative articular and muscular changes can be expected in most patients 4 to 10 years after open repair of anterosuperior cuff tears provided that healing of the cuff is obtained.
Level of Evidence
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
PMCID: PMC3441980  PMID: 22733186
4.  Total shoulder arthroplasty does not correct the orientation of the eroded glenoid 
Acta Orthopaedica  2012;83(5):529-535.
Background and purpose
Alignment of the glenoid component with the scapula during total shoulder arthroplasty (TSA) is challenging due to glenoid erosion and lack of both bone stock and guiding landmarks. We determined the extent to which the implant position is governed by the preoperative erosion of the glenoid. Also, we investigated whether excessive erosion of the glenoid is associated with perforation of the glenoid vault.
We used preoperative and postoperative CT scans of 29 TSAs to assess version, inclination, rotation, and offset of the glenoid relative to the scapula plane. The position of the implant keel within the glenoid vault was classified into three types: centrally positioned, component touching vault cortex, and perforation of the cortex.
Preoperative glenoid erosion was statistically significantly linked to the postoperative placement of the implant regarding all position parameters. Retroversion of the eroded glenoid was on average 10° (SD10) and retroversion of the implant after surgery was 7° (SD11). The implant keel was centered within the vault in 7 of 29 patients and the glenoid vault was perforated in 5 patients. Anterior cortex perforation was most frequent and was associated with severe preoperative posterior erosion, causing implant retroversion.
The position of the glenoid component reflected the preoperative erosion and “correction” was not a characteristic of the reconstructive surgery. Severe erosion appears to be linked to vault perforation. If malalignment and perforation are associated with loosening, our results suggest reorientation of the implant relative to the eroded surface.
PMCID: PMC3488182  PMID: 23083436
5.  Measurement of femoral head penetration in polyethylene using a 3-dimensional CT-scan technique 
Acta Orthopaedica  2010;81(5):563-569.
Current techniques for measuring in vivo polyethylene wear suffer from a range of problems, resulting in an unacceptable lack of repeatability and/or insufficient accuracy when they are used to measure the low wear rates associated with new, highly crosslinked polyethylene. We describe an improved CT method for measurement of 3D femoral head penetration in PE acetabular cups that has sufficient accuracy and repeatability to allow assessment of the wear potential of modern implants.
The accuracy and repeatability of the CT-scan method was determined by blindly repeating measurements on a precisely calibrated 28-mm prosthetic head and by comparing them with direct metrological measurements on 10 acetabular specimens with in vitro wear from machining, and on 8 explanted acetabular specimens with in vivo wear.
The intra- and interobserver errors in femoral head diameter were 0.036 mm (SD 0.044) and 0.050 mm (SD 0.022), respectively. CT estimated femoral head penetration in both all-poly and metal-backed acetabular components with accuracy ranging from 0.009 to 0.245 mm (mean 0.080; SD 0.067).
We found that the CT method is rapid, is accurate, and has repeatability and ease of availability. Using a slice thickness of 0.0625 mm, this method can detect wear—and also the threshold for the wear rate that causes osteolysis—much earlier than previous methods.
PMCID: PMC3214744  PMID: 20860445
6.  Long-term Clinical and MRI Results of Open Repair of the Supraspinatus Tendon 
Open repair of full-thickness tears of the rotator cuff generally improves function, although anatomic failures are not uncommon. We asked whether the presence or absence of an anatomic repair influenced outcomes. We retrospectively analyzed 47 patients (49 shoulders) treated by open proximalized reinsertion of the supraspinatus tendon for chronic retracted detachment. The mean age of the patients at the time of surgery was 59 years. At a minimum 60-month followup (mean, 87 months; range, 60–133 months), we observed an improvement in the age- and gender-adjusted Constant-Murley score from 67% preoperatively to 95% postoperatively and in the pain score. With the last followup MRI, the supraspinatus tendon had reruptured in five patients (12%); the presence of a rerupture did not negatively influence the functional result. Once healing of the repaired tendons was achieved, supraspinatus muscle atrophy never worsened. However, on MRI, fatty infiltration of the supraspinatus, infraspinatus, and subscapularis muscles increased postoperatively despite tendon healing. Radiographic centering of the humeral head was preserved and glenohumeral arthritis remained stable. Functional results were better when the standardized supraspinatus muscle area was greater than 0.5 at the final evaluation.
Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
PMCID: PMC2745467  PMID: 19499278
7.  Massive tears of the rotator cuff treated with a deltoid flap 
International Orthopaedics  2004;28(4):226-230.
We retrospectively reviewed the charts of 29 patients younger than 65 years at surgery treated with deltoid flap reconstruction for massive postero-superior rotator cuff tears. All tears involved supraspinatus and infraspinatus tendons and were associated with tendon stump retraction to the glenoid rim, a preservable long biceps tendon, and an intact subscapularis tendon. Mean follow-up was 10.5 years. Patient satisfaction rate was 89%. Mean global Constant score improved from 43 to 71.5 points, mean pain score from 6.3 to 13.2, mean anterior flexion from 100 to 157°, and force in elevation from 2.3 to 3 kg. Two thirds of patients had no humeral head migration. Of the 18 patients whose flap was examined by magnetic resonance imaging, 15 had no tear and 12 had a flap signal of muscle intensity; mean flap thickness was 5 mm. Pre-operative factors associated with poorer outcomes were upwards humeral head migration with a subacromial space smaller than 6 mm, presence of glenohumeral osteoarthritis, and supraspinatus amyotrophy greater than 40%. Deltoid flap reconstruction is a valid option in this patient population.
PMCID: PMC3456937  PMID: 15168082
8.  The effect of tourniquet use in total knee arthroplasty 
International Orthopaedics  2002;26(5):306-309.
We conducted a prospective, randomised study on primary total knee replacements to evaluate the effects of tourniquet use on total calculated blood loss using Gross formula, post-operative measured blood loss, operating time, need for blood transfusion, post-operative pain, analgesia requirement and knee flexion. Forty patients were operated on with the use of an arterial tourniquet with pressure of 350 mmHg (group A), and 40 patients without the use of a tourniquet (group B). Total calculated blood loss was significantly increased (P=0.0165) without the use of a tourniquet. There was no significant difference in measured blood loss or operating time. The median units of blood given were similar in both groups. In spite of autologous transfusions 14% of patients received additional homologous transfusions. At 6 h post-operatively pain was significantly less (P=0.0458) in group B but was similar at 24 and 48 h. There was no significant difference in analgesia requirement. The mean change in total flexion in group B was significantly better (P<0.001) at 5 days than in group A, but knee flexion was similar at 10 days and 3 months. Knee arthroplasty operations without the use of a tourniquet cause a greater blood loss but have only small benefits in the early post-operative period.
PMCID: PMC3621001  PMID: 12378360

Results 1-8 (8)