Microaneurysm count as a predictor of long-term progression in diabetic retinopathy in young patients with type 1 diabetes: the Danish Cohort of Pediatric Diabetes 1987 (DCPD1987).

PURPOSE: To investigate microaneurysm (MA) count as a predictor of long-term progression of diabetic retinopathy (DR) in young patients with type 1 diabetes mellitus (T1DM). METHODS: We examined 185 patients with T1DM at baseline (1995) and at follow-up (2011). At baseline, mean age and duration of diabetes were 20.6 and 12.9 years, respectively. Two-field (1995) and seven-field (2011) fundus photographs were taken in accordance with the European Diabetes Study Group (EURODIAB) and the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, respectively. DR was graded in accordance to the ETDRS protocol, allowing for non-standard photography at baseline. Baseline MAs were counted; patients without DR and those with MAs only were included. Multivariable logistic regressions were performed to investigate MA-count as a predictor of two-step progression, progression to proliferative DR (PDR), and incident diabetic macula edema (DME). RESULTS: We included 138 patients (138 eyes). Of these, 58 had no retinopathy and 80 had MAs only. At follow-up, rates of two-step progression of DR, progression to PDR and incident DME were 52.9, 21.7, and 10.1 %, respectively. In logistic regression models, MA count was able to predict progression to PDR (OR: 1.51 per MA; 95 % CI: [1.04-2.20]) and DME (OR: 1.69 per MA; 95 % CI: [1.05-2.77]), but not two-step progression (OR 0.91 per MA, 95 % CI: [0.64-1.31]). CONCLUSIONS: In younger patients with T1DM, MA count predicts long-term incidence of PDR and DME. This demonstrates that early DR is a warning sign of late retinopathy complications and that the number of MAs is an important factor for long-term outcome.

Outcome, revision rate and indication for revision following resurfacing hemiarthroplasty for osteoarthritis of the shoulder: 837 operations reported to the Danish Shoulder Arthroplasty Registry.

In this study, we evaluated patient-reported outcomes, the rate of revision and the indications for revision following resurfacing hemiarthroplasty of the shoulder in patients with osteoarthritis. All patients with osteoarthritis who underwent primary resurfacing hemiarthroplasty and reported to the Danish Shoulder Arthroplasty Registry (DSR), between January 2006 and December 2010 were included. There were 772 patients (837 arthroplasties) in the study. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index was used to evaluate patient-reported outcome 12 months (10 to 14) post-operatively. The rates of revision were calculated from the revisions reported to the DSR up to December 2011 and by checking deaths with the Danish National Register of Persons. A complete questionnaire was returned by 688 patients (82.2%). The mean WOOS was 67 (0 to 100). A total of 63 hemiarthroplasties (7.5%) required revision; the cumulative five-year rate of revision was 9.9%. Patients aged < 55 years had a statistically significant inferior WOOS score, which exceeded the minimal clinically important difference, compared with older patients (mean difference 14.2 (8.8; 95% CI 19.6; p < 0.001), but with no increased risk of revision. There was no significant difference in the mean WOOS or the risk of revision between designs of resurfacing hemiarthroplasty.

The clinical outcomes of mosaicplasty in the treatment of osteochondritis dissecans of the distal humeral capitellum of young athletes.

BACKGROUND: The purpose of this study was to evaluate the clinical outcomes of mosaicplasty in the treatment of osteochondritis dissecans of the distal humeral capitellum. MATERIALS AND METHODS: Between 2003 and 2007, 10 patients (6 female and 4 male patients), with a mean age at surgery of 18 years (range, 13 to 27 years), with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. The surgical technique involves transplanting small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyle at the level of the patellofemoral joint to the defect of the capitellum. At a mean follow-up of 30 months, all elbows were assessed with the Mayo Elbow Performance Score and a modified functional elbow score (Constant). RESULTS: Postoperative radiographs and control magnetic resonance imaging/computed tomography images showed incorporation of the subchondral cortex in all patients. All but 2 patients were completely pain free after surgery. Of the patients, 8 (80%) had no reduction in range of motion. By use of the Mayo Elbow Performance Score, the injured elbow had a preoperative mean score of 71 points (range, 55 to 85 points) and increased significantly to a mean score of 93.5 points (range, 85 to 100 points) postoperatively (P = .0005, paired t test). The nonoperative elbows had a mean score of 100 points, whereas the operated elbows had a mean score of 93.5 points. The functional elbow score showed a mean difference of 7.5 points between the operated and nonoperative elbows. No infection or neurologic deficit developed after surgery in any case. CONCLUSIONS: Autologous osteochondral mosaicplasty for advanced lesions of capitellar osteochondritis dissecans can provide satisfactory clinical and radiographic results.

Laxity of the elbow after experimental excision of the radial head and division of the medial collateral ligament. Efficacy of ligament repair and radial head prosthetic replacement: a cadaver study.

We studied the stabilising effect of prosthetic replacement of the radial head and repair of the medial collateral ligament (MCL) after excision of the radial head and section of the MCL in five cadaver elbows. Division of the MCL increased valgus angulation (mean 3.9 +/- 1.5 degrees) and internal rotatory laxity (mean 5.3 +/- 2.0 degrees). Subsequent excision of the radial head allowed additional valgus (mean 11.1 +/- 7.3 degrees) and internal rotatory laxity (mean 5.7 +/- 3.9 degrees). Isolated replacement of the radial head reduced valgus laxity to the level before excision of the head, while internal rotatory laxity was still greater (2.8 +/- 2.1 degrees). Isolated repair of the MCL corrected internal rotatory laxity, but a slight increase in valgus laxity remained (mean 0.7 +/- 0.6 degrees). Combined replacement of the head and repair of the MCL restored stability completely. We conclude that the radial head is a constraint secondary to the MCL for both valgus displacement and internal rotation. Isolated repair of the ligament is superior to isolated prosthetic replacement and may be sufficient to restore valgus and internal rotatory stability after excision of the radial head in MCL-deficient elbows.

The treatment of recurrent posterolateral instability of the elbow.

This study describes the surgical technique used for reconstruction and reinforcement of the lateral collateral ligament complex in patients with posterolateral instability of the elbow and the results. A triceps tendon graft from the ipsilateral elbow which was inserted through bone tunnels and fixed with bone anchors augmented the reconstruction. The operation was performed on 18 consecutive patients with instability after an acute traumatic dislocation. The mean follow-up was 44 months (14 to 88). There were no recurrent dislocations. The elbow was stable in 14 patients; three had some minor limitation of movement. Thirteen had no or only occasional slight pain, 15 returned to their normal level of activity and 17 were satisfied with the outcome. There was only one failure.

Nucleotide sequence and infectious cDNA clone of the L1 isolate of Pea seed-borne mosaic potyvirus.

The complete nucleotide sequence of Pea seed-borne mosaic potyvirus isolate L1 has been determined from cloned virus cDNA. The PSbMV L1 genome is 9895 nucleotides in length excluding the poly(A) tail. Computer analysis of the sequence revealed a single long open reading frame (ORF) of 9594 nucleotides. The ORF potentially encodes a polyprotein of 3198 amino acids with a deduced Mr of 363537. Nine putative proteolytic cleavage sites were identified by analogy to consensus sequences and genome arrangement in other potyviruses. Two full-length cDNA clones, p35S-L1-4 and p35S-L1-5, were assembled under control of an enhanced 35S promoter and nopaline synthase terminator. Clone p35S-L1-4 was constructed with four introns and p35S-L1-5 with five introns inserted in the cDNA. Clone p35S-L1-4 was unstable in Escherichia coli often resulting in amplification of plasmids with deletions. Clone p35S-L1-5 was stable and apparently less toxic to Escherichia coli resulting in larger bacterial colonies and higher plasmid yield. Both clones were infectious upon mechanical inoculation of plasmid DNA on susceptible pea cultivars Fjord, Scout, and Brutus. Eight pea genotypes resistant to L1 virus were also resistant to the cDNA derived L1 virus. Both native PSbMV L1 and the cDNA derived virus infected Chenopodium quinoa systemically giving rise to characteristic necrotic lesions on uninoculated leaves.

Functional and magnetic resonance imaging evaluation after single-tendon rotator cuff reconstruction.

The aim of this study was to investigate tendon integrity after surgical repair of single-tendon rotator cuff lesions. In 31 patients, 31 single-tendon repairs were evaluated. Thirty-one patients were available for clinical assessment and magnetic resonance imaging (MRI) at follow-up. A standard series of MR images was obtained for each. The results of functional assessment were scored according to the system of Constant. According to MRI evaluation, 21 (68%) patients had an intact or thinned rotator cuff and 10 (32%) had recurrence of a full-thickness cuff defect at follow-up. Patients with an intact or thinned rotator cuff had a median Constant score of 75.5 points; patients with a full-thickness cuff defect had a median score of 62 points. There was no correlation between tendon integrity on postoperative MR images and functional outcome. Patients with intact or thinned cuffs did not have significantly better functional results than patients with retorn cuffs. Because of the presence of metal artifacts and the difficulty in distinguishing postoperative scar tissue from partial tears or thinning, MRI is of minor diagnostic value in assessing the shoulder after cuff repair. However, full-thickness tears are readily diagnosed after operation with MRI.

Elbow joint kinematics after excision of the radial head.

The contribution of the radial head to elbow joint kinematics was studied in 7 osteoligamentous elbow preparations. During unloaded flexion and extension, radial head excision induced a maximum varus displacement of 1.6 degrees with 20 degrees of joint flexion and a maximum external rotation of 3.2 degrees at 110 degrees of flexion. With application of a 0.75-Nm load, radial head excision induced a maximum laxity of 3.3 degrees at 20 degrees of flexion in forced varus and a maximum laxity of 8.9 degrees at 10 degrees of flexion in forced external rotation. No laxity was observed in forced valgus or internal rotation. The results were independent of the rotation of the forearm. This study indicates that the radial head acts as stabilizer to the elbow joint in forced varus and in forced external rotation. The results suggest that fractures of the radial head cannot be treated by simple excision without altering the basic kinematics of the elbow joint.

Kinematics of partial and total ruptures of the medial collateral ligament of the elbow.

In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral ligament and was maximum between 70 degrees to 90 degrees of flexion. No radial head movement was seen after partial or total transection of the anterior bundle of the medial collateral ligament was performed. In conclusion, this study indicates that valgus or internal rotatory elbow instability should be evaluated at 70 degrees to 90 degrees of flexion. Detection of partial ruptures in the anterior bundle of the medial collateral ligament based on medial joint opening and increased valgus movement is impossible.

The medial collateral ligament of the elbow joint: anatomy and kinematics.

Eighteen osteoligamentous elbow joint specimens were included in a study of the medial collateral ligament complex (MCL). The morphologic characteristics of the MCL were examined, and three-dimensional kinematic measurements were taken after selective ligament dissections were performed. On morphologic evaluation the MCL is divided into the anterior bundle and the posterior bundle. The anterior bundle can be divided into anterior and posterior bands. The maximum valgus and internal rotatory instability after transection of the anterior band, 11.7 degrees and 11.2 degrees, respectively, were found at elbow flexions of 30 degrees and 40 degrees. Severance of the entire anterior bundle produced major valgus and internal rotatory laxity through the complete flexion arc of maximal 14.2 degrees and 18.5 degrees, respectively, at 70 degrees and 60 degrees of elbow flexion. Cutting both the posterior band and the posterior bundle resulted in only internal rotatory laxity of maximal 7.2 degrees at 130 degrees of elbow flexion. This study defines the anterior band as the primary constraint to valgus and internal rotatory forces, the posterior band as the secondary, and the posterior bundle as the tertiary constraint. The MCL was observed to be a complex of ligamentous fibers rather than individual bands that stabilizes the joint against valgus and internal rotatory forces.

Hyperextension of the elbow joint: pathoanatomy and kinematics of ligament injuries.

According to an epidemiologic study (Scand J Med Sci 1996/ 6: 297-302) the mechanism of "handball goalie's elbow" may be forced hyperextension. The pathomechanics of hyperextension were studied in nine macroscopically normal male cadaver elbow joints. The mean age of the donors was 43.2 years (range 25 to 61 years). Kinematic tests were performed with an experimental three-dimensional kinematic loading apparatus. Hyperextension loads induced joint laxity during flexion of less than 50 degrees. The kinematic changes were significant in joint flexion during forced valgus and external and internal axial rotation, but were not significant in flexion during forced varus. No instability was found with flexion beyond 90 degrees. The hyperextension loads produced four lesions: (1) anterior capsule rupture; (2) L-shaped rupture of the pronator/flexor origin with elongation of the anterior part of the medial collateral ligament; (3) occasional incomplete rupture of the lateral collateral ligament; and (4) small fragments of cartilage near the posterior edge of the ulna in one of the specimens. One or more of these lesions may be responsible for the symptoms in "handball goalie's elbow."

Posterolateral elbow joint instability: the basic kinematics.

Thirty-five osteoligamentous elbows were included in a study on the kinematics of posterolateral elbow joint instability during the pivot shift test (PST) before and after separate ligament cuttings in the lateral collateral ligament complex (LCLC). Division of the annular ligament or the lateral ulnar collateral ligament caused no laxity during the PST. Division of the lateral collateral ligament caused maximal laxity of 4 degrees and 23 degrees during forced PST in valgus and external rotation (supination), respectively. Cutting of the LCLC at the ulnar or the humeral insertion was necessary for any PST stressed elbow joint laxity to occur. Total division of the LCLC induced a maximal laxity of 7.9 degrees and 37 degrees during forced PST in valgus and external rotation (supination), respectively. This study suggests the lateral collateral ligament to be the primary soft tissue constraint to PST stress and the annular ligament and the lateral ulnar collateral ligament to be only secondary constraints. This study indicates that the integrity of the medial collateral elbow ligaments should be evaluated during forced valgus in pronation or neutral forearm rotation. Furthermore an isometric lateral collateral ligament reconstruction was shown to correct the joint laxity introduced by total LCLC transection.

Combined hyperextension and supination of the elbow joint induces lateral ligament lesions. An experimental study of the pathoanatomy and kinematics in elbow ligament injuries.

An epidemiological study suggested that the injury mechanism of 'handball goalie's elbow' may be hyperextension. The pathomechanics of hyperextension combined with supination was studied in ten macroscopically normal, male, cadaveric elbow joint specimens. The age of the donors was 28.8 years (range 18-45 years). Extension loading of the elbow was performed in an experimental three-dimensional (3D)-kinematic loading apparatus. The degree of extension increased by 16.7 degrees +/- 8.7 degrees after loading. Hyperextension loads induced significant joint laxity in joint flexion (< 50 degrees) during forced valgus, external and internal rotation, respectively, but not during forced varus. The hyperextension trauma produced three lesions: (1) anterior capsule rupture, (2) avulsion of the proximal insertion of both the medial and the lateral collateral ligaments, and (3) occasional single rupture of the lateral collateral ligament. The lesions indicate that combined hyperextension and supination represent a possible mechanism leading to 'handball goalie's elbow'.

Humeral head size in shoulder arthroplasty: a kinematic study.

Changes in kinematics after hemiarthroplasty of the glenohumeral joint were investigated in nine cadaveric specimens. During experiments the influence of the humeral head size on glenohumeral kinematics was evaluated. A modular prosthesis with five different head sizes and press-fit stems was used. Three-dimensional kinematic measurements during abduction and adduction from 0 degree to 70 degrees showed increased external rotation with increasing head size. Small prosthetic heads translated inferiorly and large prosthetic heads superiorly compared with the intact humeral head. During forced anterior and posterior translation the mobility is restricted with increasing head size. This study found that when a press-fit prosthesis is used, it takes 1.25 times the volume of the intact humeral head to reconstruct the kinematics of the glenohumeral joint.

Kinematics of the lateral ligamentous constraints of the elbow joint.

Thirty osteoligamentous elbow joint specimens were included in a study of the lateral collateral ligament complex (LCLC). The morphologic characteristics of the LCLC were examined, and then three-dimensional kinematic measurements were undertaken after selective ligament dissections were performed. Isolated sectioning of the annular ligament (AL) or the lateral ulnar collateral ligament (LUCL) induced only minor laxity to the elbow joint with a maximum of 2.2 degrees and 4.4 degrees during forced varus and external rotation (supination), respectively. Transsection of the lateral collateral ligament (LCL) caused a maximal laxity of 15.4 degrees and 22.8 degrees during forced varus and external rotation (supination), respectively. Combined ligament dissections showed that total transection of the LCLC at the ulnar or the humeral insertion was important for joint laxity. Total transection of the LCLC at the humeral or the ulnar insertion induced a maximal laxity of 24.5 degrees and 37 degrees during forced varus and external rotation (supination), respectively. This study suggests the AL and the LUCL are of minor importance as constraints when cut separately, whereas the LCL is a significant preventer of elbow joint laxity. The LCLC was observed to be a complex structure of ligamentous fibers rather than discreet bands. The LCLC forms a ligamentous constraint between the lateral humeral epicondyle and the ulna, stabilizing the elbow joint and forming a base for radial head stability and rotation.

Lateral collateral ligament of the elbow joint: anatomy and kinematics.

The structure and kinematics of the lateral collateral ligament of the elbow joint were investigated in 10 cadaveric specimens. The lateral collateral ligament was observed to be a distinct part of the lateral collateral ligament complex. It contains posterior fibers that pass through the annular ligament and insert on the ulna. Three-dimensional kinematic measurements in different forearm rotations showed that joint puncture induced a 1 degree joint laxity significant in forced varus from 30 degrees to 80 degrees of flexion and in forced external rotation from 30 degrees to 120 degrees of flexion. Division of the posterolateral capsule caused no further laxity. Cutting the lateral collateral ligament induced a maximum laxity of 11.8 degrees at 110 degrees of flexion in forced varus and a maximum laxity of 20.6 degrees at 110 degrees of flexion in forced external rotation. The corresponding maximal posterior radial head translation was observed at 80 degrees to 100 degrees of flexion and was 5.7 mm in forced varus and 8.1 mm in forced external rotation. This study suggests the lateral collateral ligament to be an important stabilizer of the humeroulnar joint and the radial head in forced varus and external rotation. The humeroulnar stability is independent of forearm rotation.

Total shoulder replacement in rheumatoid arthritis: proximal migration and loosening.

A prospective study of 62 Neer mark II total shoulder arthroplasties performed during the period from 1981 to 1990 on 51 patients with rheumatoid arthritis was undertaken to evaluate factors associated with component loosening and proximal humeral migration. Thirty-two (51%) showed proximal migration of the humerus before surgery was performed. The mean follow-up time was 92 months (range 52 to 139 months). The results revealed proximal migration in 55% of the patients (34 shoulders), and 40% (25 shoulders) showed progressive radiographic loosening of the glenoid component. Five of 12 press-fit humeral components demonstrated progressive radiographic loosening, whereas no signs of loosening were found in 50 cemented humeral components. In spite of progressive component loosening and progressive migration, this study demonstrated good pain relief in 89% of the patients (55 shoulders) and also a significant improvement in range of movement and function. The presence of proximal humeral migration did not significantly influence the average results-neither pain relief, range of movement, abduction force, nor function. Also, component loosening did not significantly influence the average pain relief, range of movement, abduction force, or function. The risk of clinical asymptomatic loosening is a relatively late complication that is eventually followed by pronounced bone destruction related to the loose component. Long-term radiographic control of total shoulders with rheumatoid arthritis is recommended. Hemiarthroplasty with a cemented humeral prosthesis may be a better treatment in the end stage of rheumatoid arthritis of the shoulder.

Treatment of midshaft clavicular nonunion with plate fixation and autologous bone grafting.

We studied the results of 16 consecutive midshaft clavicular nonunions operated on at the Shoulder and Elbow Clinic during the period from 1990 to 1993. All patients were treated with rigid 3.5 mm plate fixation and autologous cancellous bone grafting. Union of the fractures was achieved in all except one case, with a reconstruction ratio (restoration of bone length) of 0.96 (range 0.88 to 1.03). At follow-up 12 of 16 patients had returned to their preinjury activity level and according to the Constant score had obtained an excellent result. Two patients were graded as good, one as fair, and one had a failure. Thirteen of 16 patients were satisfied with the cosmetic outcome, assessing their cosmetic result as either good or excellent. Rigid plate fixation and restoration of clavicular length with autologous cancellous bone graft is recommended for the treatment of symptomatic clavicular midshaft nonunions.

Elbow joint instability: A kinematic model.

The effect of simultaneous ulnar and radial collateral ligament division on the kinematics of the elbow joint is studied in a cadaveric model. Severance of the anterior part of the ulnar collateral ligament and the annular ligament led to significant elbow joint instability in valgus and varus stress and in forced external and internal rotation. The mean maximum laxity in valgus stress and forced external rotation were 5.7° and 13.2°. The forearms of the elbow joint specimens were transfixed in maximum pronation. During valgus and varus stress the corresponding spontaneous ulnar rotation of the specimens was recorded. The reproducibility of the instability pattern suggests that this model is suitable for evaluating stabilizing procedures aimed at correction of elbow joint instability before these procedures are introduced into patient care.