Grade 3 Giant Cell Tumour of the Distal Humeral Epiphysis Treated with Intralesional Curettage, High Speed Burring and Bone Grafting: A Case Report.

Giant cell tumours of bone are benign but locally aggressive neoplasms involving the epi- and metaphysis of long bones. Tumours of the distal humeral epiphysis with cortical disruption and invasion into the joint and the soft tissues are rare and generally treated with wide resection and joint reconstruction. We present the case of a 19-year-old woman in whom such a tumour was successfully treated with intralesional curettage, high speed burring and autologous bone grafting. The patient underwent regular clinical and radiological follow-up. Ten years after the procedure she had no signs of tumour recurrence or degenerative changes, and she was pain free and had a normal elbow function.

Mid-term results of a stemless ceramic on polyethylene shoulder prosthesis - A prospective multicentre study.

INTRODUCTION: Early reports of stemless shoulder arthroplasty have shown promising clinical and radiological outcomes. The purpose of this study was to report on the mid-term results of an implant that utilises a ceramic humeral head. METHODS: A prospective, consecutive, multicentre study of stemless shoulder prosthesis with a minimum of four years of follow-up was conducted between August 2009 and May 2012. The adjusted Constant-Murley Score (CMS), revision rate and presence of radiolucent lines were recorded at intervals. RESULTS: A total of 207 patients were eligible for study inclusion; 62.8% were female and mean age was 64.8 years (range 30-86). Mean follow-up was 70.7 months (range 48-100), 73% underwent TSA and 27% hemiarthroplasty. The mean CMS improvement was 42.6 (p < 0.0001) at 48 months. Radiolucencies were present in 2.7% of humeral zones and 14% of glenoid zones at 48-month follow-up. The revision rate was 6.3% with rotator cuff failure (2.9%) the most common indication. CONCLUSIONS: Mid-term results demonstrate that the studied stemless implant with a ceramic humeral head had clinical and radiological outcomes that are comparable to other reported studies.

Duocentric® reversed shoulder prosthesis and Personal Fit® templates: innovative strategies to optimize prosthesis positioning and prevent scapular notching.

We describe our experience with a new system of patient-specific template called Personal Fit(®), which is unique in shoulder surgery and used in combination with Duocentric(®) prosthesis. The reverse prosthesis's concept is the invention of Paul Grammont, developed with Grammont's team of Dijon University as from 1981, which led to the first reversed total shoulder prosthesis called Trumpet in 1985. The Duocentric(®) prosthesis developed in 2001 is the third-generation prosthesis, coming from the Trumpet and the second-generation prosthesis Delta(®) (DePuy). This prosthesis provides a novel solution to the notching problem with an inferior overhang integrated onto the glenoid baseplate. Personal Fit(®) system is based on reconstructing the shoulder joint bones in three dimensions using CT scan data, placing a landmark on the scapula and locating points on the glenoid and humerus. That will be used as a reference for the patient-specific templates. We study the glenoid position planned with Personal Fit(®) software relative to native glenoid position in 30 cases. On average, the difference between the planned retroversion (or anteversion in one case) and native retroversion was 8.6°.

Analysis of a retrieved delta III total shoulder prosthesis.

A reversed Delta III total shoulder prosthesis was retrieved post-mortem, eight months after implantation. A significant notch was evident at the inferior pole of the scapular neck which extended beyond the inferior fixation screw. This bone loss was associated with a corresponding, erosive defect of the polyethylene cup. Histological examination revealed a chronic foreign-body reaction in the joint capsule. There were, however, no histological signs of loosening of the glenoid base plate and the stability of the prosthetic articulation was only slightly reduced by the eroded rim of the cup.

In vivo tendon force measurement of 2-week duration in sheep.

Tendon tension in vivo may be determined indirectly by measuring intratendinous pressure, by using a buckle transducer or by measuring the tendon strain. All of these methods require appropriate calibration, which is highly dependent on various variables. To measure the tendon load in vivo during a period of 2 weeks in sheep, a measurement technique has been developed using a force sensor interposed serially between the humeral head and the tendon end. Within a supporting frame, a flexion-sensitive force transducer is subjected to three-point bending stress. The load is transmitted by sutures from the tendon end through a hole in the sensor frame, orthogonal to the force transducer. In this configuration, the sensor measures the tensile force acting on the tendon, largely independent of the loading direction. The sensor was screwed to the humeral head and connected to the tendon end which was previously released from its insertion site along with a bone chip, using sutures. Connecting wires passed subcutaneously to a skin outlet about 30 cm away from the transducer. The sensor output was linear to the measured load up to 300 N, with maximum hysteresis of 18% full scale. All sensors worked in vivo without drift over a period of up to 14 days with no change in the calibration data. Forces up to 310 N have been recorded in vivo with daily tension measurements. This study shows that serial tendon tension measurement is feasible and allows for reliable, repeatable recording of the absolute tendon tension at the expense of tendon integrity.

Influence of peg design and cement mantle thickness on pull-out strength of glenoid component pegs.

Fixation of the glenoid component is critical to the outcome of total shoulder arthroplasty. In an in vitro study, we analysed the effect of surface design and thickness of the cement mantle on the pull-out strength of the polyethylene pegs which are considered essential for fixation of cemented glenoid components. The macrostructure and surface of the pegs and the thickness of the cement mantle were studied in human glenoid bone. The lowest pull-out forces, 20 +/- 5 N, were for cylindrical pegs with a smooth surface fixed in the glenoid with a thin cement mantle. The highest values, 425 +/- 7 N, were for threaded pegs fixed with a thicker cement mantle. Increasing the diameter of the hole into which the peg is inserted from 5.2 to 6.2 mm thereby increasing the thickness of the cement mantle, improved the mean pull-out force for the pegs tested.

Effect of selective capsulorrhaphy on the passive range of motion of the glenohumeral joint.

BACKGROUND: Capsulorrhaphy of the glenohumeral joint is a common surgical procedure for the treatment of instability caused by increased capsular laxity. The effect of capsulorrhaphy on the range of motion of the shoulder is poorly understood. METHODS: We simulated localized capsular contractures by selective capsular plications in eight human cadaveric shoulders and studied the effect of such plications on the passive range of glenohumeral abduction, flexion, and external and internal rotation in different degrees of abduction. A 0.5 or 1-N-m torque was applied to the humerus, and the range of glenohumeral motion was measured with electronic goniometers in three planes and compared with those of the intact shoulder. RESULTS: Anterosuperior capsular plication most markedly affected external rotation of the adducted arm, decreasing it by a mean of 30.1 degrees (p < 0.0001). Anteroinferior plication significantly reduced abduction by a mean of 19.4 degrees (p < 0.0001) and external rotation by a mean of 20.6 degrees (p = 0.0046). Posterosuperior plication mostly limited internal rotation of the adducted arm (mean decrease, 16.1 degrees, p = 0.0045). On the average, total anterior and total posterior plication each limited flexion by approximately 20 degrees (p = 0.005) and abduction by >or=15 degrees (p < 0.005), whereas total anterior plication limited external rotation by >30 degrees (p 20 degrees (p < 0.0001). Total inferior capsular plication restricted abduction (by a mean of 27.7 degrees, p = 0.0001), flexion, and rotation. Total superior plication restricted external rotation and flexion. CONCLUSIONS AND CLINICAL RELEVANCE: Localized plications of the glenohumeral joint capsule lead to predictable patterns of loss of glenohumeral mobility. If plication is planned, losses of movement can be anticipated. The findings of this study may assist surgeons in identifying the parts of the capsule that are contracted and that may need lengthening.

Loosening performance of cemented glenoid prosthesis design pairs.

OBJECTIVE: The purpose of this pilot study (n=3) was to compare the loosening performance of glenoid prosthesis design pairs where only one design variable differed. DESIGN: Glenoids were subjected to dynamic edge loading in a biaxial test setup. BACKGROUND: Glenoid component loosening is the primary concern in total shoulder arthroplasty. METHODS: After the humeral head was cycled 100,000 times to the superior and inferior edges of the glenoid, the tensile edge displacements were measured under superior and inferior off-center loading. RESULTS AND CONCLUSIONS: Based on this study, a rough-backed design had dramatically better loosening performance than a smooth-backed; curved-backed was superior to flat-backed; a less-constrained articular surface was better than a more-constrained articular surface; pegs outperformed a keel; threaded pegs were marginally preferable to cylindrical pegs; and an all-polyethylene design rocked slightly less than a metal-mesh-backed design. RELEVANCE: A comparison of the laboratory loosening behavior of glenoid prostheses may lead to improved designs, subsequently leading to a reduction in the incidence of clinical loosening.

Posterior glenoid rim deficiency in recurrent (atraumatic) posterior shoulder instability.

OBJECTIVE: To assess the shape of the posterior glenoid rim in patients with recurrent (atraumatic) posterior instability. DESIGN AND PATIENTS: CT examinations of 15 shoulders with recurrent (atraumatic) posterior instability were reviewed in masked fashion with regard to abnormalities of the glenoid shape, specifically of its posterior rim. The glenoid version was also assessed. The findings were compared with the findings in 15 shoulders with recurrent anterior shoulder instability and 15 shoulders without instability. For all patients, surgical correlation was available. RESULTS: Fourteen of the 15 (93%) shoulders with recurrent (atraumatic) posterior shoulder instability had a deficiency of the posteroinferior glenoid rim. In patients with recurrent anterior instability or stable shoulders such deficiencies were less common (60% and 73%, respectively). The craniocaudal length of the deficiencies was largest in patients with posterior instability. When a posteroinferior deficiency with a craniocaudal length of 12 mm or more was defined as abnormal, sensitivity and specificity for diagnosing recurrent (atraumatic) posterior instability were 86.7% and 83.3%, respectively. There was a statistically significant difference in glenoid version between shoulders with posterior instability and stable shoulders (P=0.01). CONCLUSION: Recurrent (atraumatic) posterior shoulder instability should be considered in patients with a bony deficiency of the posteroinferior glenoid rim with a craniocaudal length of more than 12 mm.

Experimental rotator cuff repair. A preliminary study.

BACKGROUND: The repair of chronic, massive rotator cuff tears is associated with a high rate of failure. Prospective studies comparing different repair techniques are difficult to design and carry out because of the many factors that influence structural and clinical outcomes. The objective of this study was to develop a suitable animal model for evaluation of the efficacy of different repair techniques for massive rotator cuff tears and to use this model to compare a new repair technique, tested in vitro, with the conventional technique. METHODS: We compared two techniques of rotator cuff repair in vivo using the left shoulders of forty-seven sheep. With the conventional technique, simple stitches were used and both suture ends were passed transosseously and tied over the greater tuberosity of the humerus. With the other technique, the modified Mason-Allen stitch was used and both suture ends were passed transosseously and tied over a cortical-bone-augmentation device. This device consisted of a poly(L/D-lactide) plate that was fifteen millimeters long, ten millimeters wide, and two millimeters thick. Number-3 braided polyester suture material was used in all of the experiments. RESULTS: In pilot studies (without prevention of full weight-bearing), most repairs failed regardless of the technique that was used. The simple stitch always failed by the suture pulling through the tendon or the bone; the suture material did not break or tear. The modified Mason-Allen stitch failed in only two of seventeen shoulders. In ten shoulders, the suture material failed even though the stitches were intact. Thus, we concluded that the modified Mason-Allen stitch is a more secure method of achieving suture purchase in the tendon. In eight of sixteen shoulders, the nonaugmented double transosseous bone-fixation technique failed by the suture pulling through the bone. The cortical-bone-augmentation technique never failed. In definite studies, prevention of full weight-bearing was achieved by fixation of a ten-centimeter-diameter ball under the hoof of the sheep. This led to healing in eight of ten shoulders repaired with the modified Mason-Allen stitch and cortical-bone augmentation. On histological analysis, both the simple-stitch and the modified Mason-Allen technique caused similar degrees of transient localized tissue damage. Mechanical pullout tests of repairs with the new technique showed a failure strength that was approximately 30 percent of that of an intact infraspinatus tendon at six weeks, 52 percent of that of an intact tendon at three months, and 81 percent of that of an intact tendon at six months. CONCLUSIONS: The repair technique with a modified Mason-Allen stitch with number-3 braided polyester suture material and cortical-bone augmentation was superior to the conventional repair technique. Use of the modified Mason-Allen stitch and the cortical-bone-augmentation device transferred the weakest point of the repair to the suture material rather than to the bone or the tendon. Failure to protect the rotator cuff post-operatively was associated with an exceedingly high rate of failure, even if optimum repair technique was used. CLINICAL RELEVANCE: Different techniques for rotator cuff repair substantially influence the rate of failure. A modified Mason-Allen stitch does not cause tendon necrosis, and use of this stitch with cortical-bone augmentation yields a repair that is biologically well tolerated and stronger in vivo than a repair with the conventional technique. Unprotected repairs, however, have an exceedingly high rate of failure even if optimum repair technique is used. Postoperative protection from tension overload, such as with an abduction splint, may be necessary for successful healing of massive rotator cuff tears.

Structural changes of the rotator cuff caused by experimental subacromial impingement in the rat.

Subacromial impingement of the infraspinatus tendon was experimentally created in 28 young adult rats by thickening the undersurface of the acromion with either one or two platelike bony transplants of the ipsilateral scapular spine. Nine nonoperated and eight shoulders that had undergone a sham operation served as control groups. The rats were killed after 2 days and after 1, 2, 4, 8, 16, and 32 weeks for histologic evaluation. All rats with experimental subacromial impingement showed an infraspinatus tear on the bursal side of the tendon. An isolated tear on the articular side or within the tendon was not seen. Two plates caused larger tears than one (P = .04), and more long-standing impingement was associated with larger lesions (P = .002). Multiple chondrocytes were observed within the tendon adjacent to the bony transplants. No calcium deposits were found. In the subacromial space rapid thickening of the bursa was observed. The undersurfaces of the bony transplants showed no evidence of abrasion or remodeling caused by the tendon. The shoulders of the control groups were found intact without any alteration. Experimental subacromial impingement in the rat caused bursal side rotator cuff tears. The type of partial tears that are most frequently observed in clinical practice, that is, intratendinous and articular side tears, were not seen in this experimental model.