Bo Sanderhoff Olsen

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.

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.

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.

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.

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.

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.

Benefits and harms of locking plate osteosynthesis in intraarticular (OTA Type C) fractures of the proximal humerus: A systematic review

INTRODUCTION Locking plate osteosynthesis of proximal humeral fractures are widely recommended and used, even in complex intraarticular fracture patterns such as AO/OTA Type C fractures. We systematically reviewed clinical studies assessing the benefits and harms of osteosynthesis with angle stable plates in AO/OTA Type C fractures of the proximal humerus. METHODS We conducted an iterative search in PubMed, Embase, Cochrane Library, Web of Science, Cinahl, and PEDro in all languages from 1999 to November 2010. Eligible studies should study the outcome for Type C fractures after primary osteosynthesis with locking plate within two weeks of injury, and a follow-up period of six months or more. Patients should be evaluated with the Constant-Murley Score (CS). Two observers extracted data independently. RESULTS Twelve studies and 282 Type C fractures were included. Results were categorised according to study type and synthesised qualitatively. No randomised clinical trials were identified. Two comparative, observational studies reported a mean CS of 71 (relative to contralateral shoulder) and 75 (non-adjusted Constant Score) for Type C fractures. For all studies mean non-adjusted CS ranged from 53 to 75. Mean age- and sex-adjusted CS ranged from 60 to 88. Mean CS relative to the contralateral shoulder ranged from 71 to 85. The most common complications were avascular necrosis (range, 4-33%), screw perforations (range, 5-20%), loss of fixation (range, 3-16%), impingement (range, 7-11%) and infections range 4-19%. Reoperation rate ranged from 6 to 44%. CONCLUSIONS Insufficient study designs and unclear reporting preclude safe treatment recommendations. Complication and reoperation rates were unexpected high. Based on the studies included we cannot routinely recommend the use of locking plates in AO/OTA Type C fractures.

The Danish Shoulder Arthroplasty Registry: clinical outcome and short-term survival of 2,137 primary shoulder replacements.

The Danish Shoulder Arthroplasty Registry (DSR) was established in 2004. Data are reported electronically by the surgeons. Patient-reported outcome is collected 10–14 months postoperatively using the Western Ontario osteoarthritis of the shoulder index (WOOS). 2,137 primary shoulder arthroplasties (70% women) were reported to the registry between January 2006 and December 2008. Mean age at surgery was 69 years (SD 12). The most common indications were a displaced proximal humeral fracture (54%) or osteoarthritis (30%). 61% were stemmed hemiarthroplasties, 28% resurfacing hemiarthroplasties, 8% reverse shoulder arthroplasties, and 3% total arthroplasties. Median WOOS was 59% (IQR: 37–82). 5% had been revised by the end of June 2010. The most frequent indications for revision were dislocation or glenoid attrition.

A review of national shoulder and elbow joint replacement registries.

BACKGROUND The aim was to review the funding, organization, data handling, outcome measurements, and findings from existing national shoulder and elbow joint replacement registries; to consider the possibility of pooling data between registries; and to consider wether a pan european registry might be feasible. MATERIALS AND METHODS Web sites, annual reports, and publications from ongoing national registries were searched using Google, PubMed, and links from other registries. Representatives from each registry were contacted. RESULTS Between 1994 and 2004, 6 shoulder registries and 5 elbow registries were established, and by the end of 2009, the shoulder registries included between 2498 and 7113 replacements and the elbow registries between 267 and 1457 replacements. The registries were initiated by orthopedic societies and funded by the government or by levies on implant manufacturers. In some countries, data reporting and patient consent are required. Completeness is assessed by comparing data with the national health authority. All registries use implant survival as the primary outcome. Some registries use patient-reported outcomes as a secondary outcome. CONCLUSIONS A registry offers many advantages; however, adequate long-term funding and completeness remain a challenge. It is unlikely that large-scale international registries can be implemented, but more countries should be encouraged to establish registries and, by adopting compatible processes, data could be pooled between national registries, adding considerably to their power and usefulness.