Inclination but not anatomical reconstruction is related with higher cobalt levels in MoM hip arthroplasty

Metal on Metal total hip arthroplasty is associated with elevated serum cobalt levels. In this study we investigate if there is a relation between the inclination and anteversion angle of the cup and the anatomical reconstruction of the hip on the serum cobalt level. Postoperative cobalt serum levels were measured in 250 patients with the M2a-38 cup and Taperloc stem combination. On standardized radiographs inclination and anteversion angle, lower limb length, lateral offset and center of rotation distance were evaluated. A difference of more than 5 millimeter compared to the preoperative situation was considered as a non-anatomical reconstruction. For every 10 degrees increase in inclination the cobalt level increased 14% (p = 0.036). Women with the same cup inclination angle showed 34% higher cobalt levels than men (p = 0.013). No relation was found between the anteversion angle, anatomical reconstruction and the serum cobalt levels. A higher inclination of the cup leads to higher serum cobalt levels, but a non-anatomical reconstruction has no influence on serum cobalt levels.

Teres major tendon transfer in the treatment of irreparable posterosuperior rotator cuff tears: long-term improvement of shoulder function and pain reduction at eight to 12 years’ follow-up

Aims

Since long-term outcome of teres major tendon transfer surgery for irreparable posterosuperior rotator cuff (RC) tears is largely unknown, the primary aim of this study was to evaluate the long-term outcome of the teres major transfer. We also aimed to report on the results of a cohort of patients with a similar indication for surgery that underwent a latissimus dorsi tendon transfer.

Patients and Methods

Patients and Methods In this prospective cohort study, we reported on the long-term results of 20 consecutive patients with a teres major tendon transfer for irreparable massive posterosuperior RC tears. Additionally, we reported on the results of the latissimus dorsi tendon transfer (n = 19). The mean age was 60 years (47 to 77). Outcomes included the Constant score (CS), and pain at rest and during movement using the Visual Analogue Scale (VAS).

Results

At a mean of ten years (8 to 12) following teres major transfer, the CS was still 23 points (95% confidence interval (CI) 14.6 to 30.9, p < 0.001) higher than preoperatively. VAS for pain at rest (21 mm, 95% CI 4.0 to 38.9, p = 0.016) and movement (31 mm, 95% CI 16.0 to 45.1, p < 0.001) were lower than preoperatively. We also found an increase in CS (32 points, 95% CI 23.4 to 40.2, p < 0.001) and reduction of pain (26 mm, 95% CI 9.9 to 41.8, p = 0.001) six years after latissimus dorsi transfer.

Conclusion

Teres major tendon transfer is a treatment option to gain shoulder function and reduce pain in patients with an irreparable posterosuperior RC tear at a mean follow-up of ten years. The teres major tendon might be a valuable alternative to the commonly performed latissimus dorsi tendon transfer in the treatment of irreparable posterosuperior RC tears. Cite this article: Bone Joint J 2018;100-B:309-17.

Three-dimensional shoulder motion after teres major or latissimus dorsi tendon transfer for posterosuperior rotator cuff tears

BACKGROUND

Teres major (TM) transfer and latissimus dorsi (LD) transfer are essential treatment options in patients with posterosuperior rotator cuff (RC) tears. The purpose of this study was to quantify shoulder kinematics before and after TM transfer and LD transfer in posterosuperior RC tear patients.

METHODS

In this prospective cohort study, we quantitatively measured shoulder movements using an electromagnetic tracking device (Flock of Birds) preoperatively and 1 year after either TM (n = 13) or LD (n = 9) tendon transfer. Additional outcome measures included the Constant score (CS), patient-reported pain, and quantitative range of motion. Scapular kinematics were evaluated during arm abduction.

RESULTS

By use of a quantitative assessment, forward flexion (from 87° to 106°, P = .007), abduction (from 86° to 106°, P = .010), and external rotation in abduction (from 52° to 70°, P = .019) improved. Both transfers reduced pain (from 50 to 10 mm, P < .001), and the CS improved (from 37 to 62 points, P < .001). No significant differences in postoperative improvement in pain and function were found between TM and LD tendon transfers. The TM transfer group showed increased scapular lateral rotation compared with the LD transfer group (13°; 95% confidence interval [CI], 4.8° to 21.7°; P = .003). We were unable to detect differences between TM transfer and LD transfer in the change in protraction (3.2°; 95% CI, -6.3° to 12.8°; P = .489) and posterior tilt (3.5°; 95% CI, -3.5° to 10.5°; P = .313).

CONCLUSION

Tendon transfer surgery resulted in an overall improvement in CS, pain relief, and quantitative range of motion in the treatment of an irreparable posterosuperior RC tear. Scapular lateral rotation gradually increased after TM transfer, reminiscent of RC function, whereas such an increase was not observed after LD transfer.

Quantitative Dixon MRI sequences to relate muscle atrophy and fatty degeneration with range of motion and muscle force in brachial plexus injury

BACKGROUND

Assessment of muscle atrophy and fatty degeneration in brachial plexus injury (BPI) could yield valuable insight into pathophysiology and could be used to predict clinical outcome. The objective of this study was to quantify and relate fat percentage and cross-sectional area (CSA) of the biceps to range of motion and muscle force of traumatic brachial plexus injury (BPI) patients.

METHODS

T1-weighted TSE sequence and three-point Dixon images of the affected and non-affected biceps brachii were acquired on a 3 Tesla magnetic resonance scanner to determine the fat percentage, total and contractile CSA of 20 adult BPI patients. Regions of interest were drawn by two independent investigators to determine the inter-observer reliability. Paired Students' t-test and multivariate analysis were used to relate fat percentage, total and contractile CSA to active flexion and biceps muscle force.

RESULTS

The mean fat percentage 12±5.1% of affected biceps was higher than 6±1.0% of the non-affected biceps (p<0.001). The mean contractile CSA 8.1±5.1cm² of the affected biceps was lower than 19.4±4.9cm² of the non-affected biceps (p<0.001). The inter-observer reliability was excellent (ICC 0.82 to 0.96). The contractile CSA contributed most to the reduction in active flexion and muscle force.

CONCLUSION

Quantitative measurement of fat percentage, total and contractile CSA using three-point Dixon sequences provides an excellent reliability and relates with active flexion and muscle force in BPI.

Subacromial anaesthetics increase asymmetry of scapular kinematics in patients with subacromial pain syndrome

BACKGROUND

Subacromial pain syndrome (SAPS) and scapular dyskinesis are closely associated, but the role of pain is unknown. We hypothesized that pain results in asymmetrical scapular kinematics, and we expected more symmetrical kinematics after infiltration of subacromial anaesthetics.

OBJECTIVE

To investigate the effect of subacromial anaesthetics on scapular kinematics in patients with SAPS.

DESIGN

Observational cohort study.

METHODS

We evaluated shoulder kinematics in 34 patients clinically and radiologically (magnetic resonance arthrography) identified with unilateral SAPS using three-dimensional electromagnetic motion analysis (Flock of Birds). Scapular internal rotation, upward rotation and posterior tilt of the affected shoulder were compared with the kinematics of the unaffected shoulder and following subacromial anaesthetics. Additionally, the association of pain (Visual Analogue Scale, VAS) and scapular rotation was analysed.

RESULTS

Compared with the contralateral healthy shoulder, 5° more (95% CI 0.4-9.7, p = 0.034) scapular internal rotation was observed in the affected shoulder at 110-120° of abduction. Following subacromial anaesthetics in the affected shoulder, internal rotation increased (2°, 95% CI 0.5-3.9, p = 0.045) and posterior tilt decreased (3°, 95% CI 1.5-5.0, p = 0.001) at 110-120° of abduction. Less scapular upward rotation was significantly associated with higher pain scores before infiltration (R = 0.45, p = 0.013).

CONCLUSIONS

More scapular internal rotation was observed in affected shoulders of patients with SAPS compared with unaffected shoulders. Subacromial infiltration did not restore kinematics toward symmetrical scapular motion. These findings suggest that subacromial anaesthesia is not an effective means to instantly restore symmetry of shoulder motion.

The minimal detectable change of the Constant score in impingement, full-thickness tears, and massive rotator cuff tears

HYPOTHESIS

The purpose of this study was to determine the minimal detectable change (MDC) for the Constant score in patients with impingement, a supraspinatus tear, or a massive rotator cuff (RC) tear as observed changes smaller than the MDC might be the result of measurement error.

METHODS

The Constant score was recorded in a total of 180 patients, including 34 patients with impingement, 105 with supraspinatus tears, and 41 with massive RC tears. We assessed the MDC in the 3 subgroups and total group using the samples standard deviation (SD), internal consistency (Cronbach α), and standard error of the measurement. Floor and ceiling effects were also reported.

RESULTS

The absolute mean Constant score was 72 (SD, 11.2) in the impingement group, 44 (SD, 14.7) in the supraspinatus tear group, and 46 (SD, 18.9) in the massive RC tear group. There were no floor and ceiling effects for the absolute Constant score. In the total group, the internal consistency was 0.8 and the standard error of the measurement was 8. The MDC was 23 points on the Constant score in the total group and 17, 18, and 23 points on the Constant score for impingement, RC tears, and massive RC tears, respectively.

CONCLUSION

This study demonstrates that the MDCs of the Constant score are different in patients with impingement, supraspinatus tears, and massive RC tears. Studies reporting the Constant score should be interpreted by use of the population-specific MDC and minimal clinical important change.

Use of sutures as Kirschner wire and tension-band wire for olecranon fractures: a technical note

Open reduction and internal fixation using tension-band wires for displaced olecranon fractures enables restoration of extensor function. We report on 3 elderly patients with a displaced olecranon fracture who underwent open reduction and internal fixation using sutures as the Kirschner wire and tension-band wire and achieved good outcome.

Teres major tendon transfer for patients with massive irreparable posterosuperior rotator cuff tears: Short-term clinical results

Surgical repair of posterosuperior rotator cuff tears has a poorer outcome and a higher rate of failure compared with repairs of supraspinatus tears. In this prospective cohort study 28 consecutive patients with an irreparable posterosuperior rotator cuff tear after failed conservative or surgical treatment underwent teres major tendon transfer. Their mean age was 60 years (48 to 71) and the mean follow-up was 25 months (12 to 80). The mean active abduction improved from 79° (0° to 150°) pre-operatively to 105° (20° to 180°) post-operatively (p = 0.011). The mean active external rotation in 90° abduction improved from 25° (0° to 70°) pre-operatively to 55° (0° to 90°) post-operatively (p < 0.001). The mean Constant score improved from 43 (18 to 78) pre-operatively to 65 (30 to 86) post-operatively (p < 0.001). The median post-operative VAS (0 to 100) for pain decreased from 63 (0 to 96) pre-operatively to 5 (0 to 56) post-operatively (p < 0.001). In conclusion, teres major transfer effectively restores function and relieves pain in patients with irreparable posterosuperior rotator cuff tears and leads to an overall clinical improvement in a relatively young and active patient group with limited treatment options.

Cranial translation of the humeral head on radiographs in rotator cuff tear patients: the modified active abduction view

Cranial translation of the humeral head is related to massive rotator cuff tears; however, it may be unapparent in early-stage tears. The goal of this study was to investigate whether active abduction leads to increased active cranial humeral translation in early-stage tears. We assessed 20 consecutive patients (9 full-thickness supraspinatus tears, 11 posterosuperior tears) using the newly introduced modified active abduction view: acromiohumeral (AH) distance was measured on radiographs acquired during rest and active isometric abduction and adduction tasks with the arm alongside the body. Rest AH was 7.5 mm (SD = 1.53); during abduction and adduction, it decreased to 2.1 mm (95 % CI 1.28-3.01, p < 0.001) and 1.1 mm (95 % CI 0.46-1.65, p = 0.001), respectively. Cranial translation during abduction was more severe in shoulders with posterosuperior cuff tears (∆AH = 3 mm, SD = 1.5) compared to supraspinatus tears (∆AH = 1 mm, SD = 1.6), with a mean difference of 2 mm (95 % CI 0.64-3.58, p = 0.007). Both active isometric abduction and adduction leads to active cranial translation in cuff tear patients. Cranial translation is largest during active abduction. Furthermore, there is significant more cranial translation in posterosuperior cuff tear patients compared to supraspinatus cuff tear patients. Possibly, radiographs combined with active tasks offer new possibilities in diagnosing early-stage rotator cuff tears.

The Western Ontario rotator cuff index in rotator cuff disease patients: a comprehensive reliability and responsiveness validation study

BACKGROUND

The Western Ontario rotator cuff index (WORC) is an increasingly applied condition-specific outcome measure for rotator cuff (RC) conditions. However, in most WORC validation studies, only a limited number of psychometric properties are studied in indistinct patient groups.

PURPOSE

To assess psychometric properties of the WORC according to the Scientific Advisory Committee quality criteria for health questionnaires in 3 patient groups with distinct RC conditions.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

The WORC (range, 0-100; 21 items, 5 domains) was administered twice (T1, T2) in 92 patients (35 RC tears, 35 calcific tendinitis, 22 impingement). Additionally, the Constant score (CS) and the Disabilities of the Arm, Shoulder and Hand score (DASH) were recorded. Calcific tendinitis patients were reassessed 6 weeks after treatment with needling and lavage or a subacromial injection with corticosteroids (T3). We assessed floor and ceiling effects, internal consistency, test-retest reliability, precision, construct validity, minimally detectable change, and responsiveness in the diagnostic subgroups and the total group.

RESULTS

Mean age was 55.0 ± 8.7 years, and 49 of 92 (53%) patients were female. Mean baseline WORC was 46.8 ± 20.4, CS was 63.9 ± 15.4, and DASH was 40.9 ± 18.6. Significant differences were found for the CS and DASH between RC tear patients (severe symptoms) and the other patients, but not for the WORC. There were no floor and ceiling effects. Internal consistency was high: the Cronbach alpha coefficient was .95. The intraclass correlation coefficient of .89 and standard error of measurement of 6.9 indicated high reproducibility. Pearson correlations of the WORC with the CS and DASH were .56 and -.65, respectively (both P < .001). At T3, total WORC improved significantly (mean change, 18.8; 95% confidence interval, 11.3-26.2). Correlations of the WORC change scores with CS and DASH changes were .61 and -.84, respectively (both P < .001). Effect size was 0.96, with a standardized response mean of 0.91, indicating good responsiveness.

CONCLUSION

Applied to a variety of RC patients, the WORC had high internal consistency, moderate to good construct validity, high test-retest reliability, and good responsiveness. These findings support the use of the WORC as a condition-specific self-reported outcome measure in RC patients, but its validity in patients with severe symptoms needs further investigation.