Judie Walton

Restore Orthobiologic Implant: Not Recommended for Augmentation of Rotator Cuff Repairs

BACKGROUND Following repairs of large-to-massive tears of the rotator cuff, the rates of tendon retears are high and often involve tissue deficiency. Animal studies of the Restore Orthobiologic Implant, a collagen-based material derived from the small intestine mucosa of pigs, have indicated that it might be used to help overcome such problems. We carried out a study to determine whether patients who received this xenograft to augment a rotator cuff repair exhibited greater shoulder strength, shoulder function, and/or resistance to retearing. METHODS We compared data from a group of patients who had undergone conventional rotator cuff repair with xenograft augmentation (the xenograft group) with data from a group in whom a repair had been done by the same surgeon without augmentation (the controls). The groups were matched for gender, mean age, and mean size of the rotator cuff tear. All subjects completed a pain and function questionnaire and were given a systematic clinical shoulder examination preoperatively and at three, six, and twenty-four months postoperatively. The twenty-four-month visit included magnetic resonance imaging to determine whether a retear had occurred. RESULTS Four patients who had received a xenograft had a severe postoperative reaction requiring surgical treatment. At two years after the surgery, six of the ten tendons repaired with a xenograft and seven of the twelve control tendons had retorn, as documented by magnetic resonance imaging. The patients with a xenograft had significantly less lift-off strength, as measured with a dynamometer, and significantly less strength in internal rotation and adduction than the controls at two years after the surgery (all p < 0.05). Also, the xenograft group had significantly more impingement in external rotation, a slower rate of resolution of pain during activities, more difficulty with hand-behind-the-back activities, and less sports participation (all p < 0.05). CONCLUSIONS Two years after surgical repair of a large rotator cuff defect supplemented with a xenograft, patients had several persisting deficits and no recognizable benefit as compared with the results in a control group. In view of these findings, together with the unsatisfactorily high proportion of patients with a severe inflammatory reaction to the xenograft, we do not recommend use of the Restore Orthobiologic Implant in its present form. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Diagnosis of rotator cuff tears

Rotator cuff tears account for almost 50% of major shoulder injuries but are sometimes difficult to diagnose. To aid diagnosis, we did a prospective study, comparing results of 23 clinical tests from 400 patients with and without rotator cuff tears. Three simple tests were predictive for rotator cuff tear: supraspinatus weakness, weakness in external rotation, and impingement. When all three were positive, or if two tests were positive and the patient was aged 60 or older, the individual had a 98% chance of having a rotator cuff tear; combined absence of these features excluded this diagnosis.

Diagnostic values of tests for acromioclavicular joint pain.

BACKGROUND This prospective study was performed to determine which clinical and imaging tests were most helpful for diagnosing acromioclavicular joint pain. METHODS Of 1037 patients with shoulder pain, 113 who mapped pain within an area bounded by the midpart of the clavicle and the deltoid insertion were eligible for inclusion in the study. Forty-two subjects agreed to participate, and four of them were lost to follow-up. Twenty clinical tests, radiography, bone-scanning, magnetic resonance imaging, and an acromioclavicular joint injection test were performed on all patients. The patients were divided into two groups according to whether they had a > or =50% decrease in pain following the acromioclavicular joint injection. Statistical analysis, including multivariate regression analysis, was performed in order to evaluate the diagnostic effectiveness of the various tests. RESULTS Acromioclavicular joint pain was confirmed in twenty-eight of the thirty-eight patients. The most sensitive tests were examination for acromioclavicular tenderness (96% sensitivity), the Paxinos test (79%), magnetic resonance imaging (85%), and bone-scanning (82%), but these studies had low specificity. In the stepwise regression model, with the response to the injection used as the dependent variable, bone-scanning and the Paxinos test were the only independent variables retained. Patients with a positive Paxinos test as well as a positive bone scan had high post-test odds (55:1) and a 99% post-test probability of having pain due to pathological changes in the acromioclavicular joint. The likelihood ratio for patients with one negative test and one positive test was indeterminate (0.4:1). Patients with both a negative Paxinos test and a negative bone scan had a likelihood ratio of 0.03:1 for having acromioclavicular joint pain, which basically rules out the disorder. CONCLUSIONS The highly sensitive tests had low specificity, and the highly specific tests had low sensitivity. However, the combination of a positive Paxinos test and a positive bone scan predicted damage to the acromioclavicular joint as the cause of shoulder pain with a high degree of confidence.

Shoulder Pain in Elite Swimmers: Primarily Due to Swim-volume-induced Supraspinatus Tendinopathy

Background/hypothesis Shoulder pain in elite swimmers is common, and its pathogenesis is uncertain. Hypothesis/study design The authors used a crosssectional study design to test Jobe’s hypothesis that repetitive forceful swimming leads to shoulder laxity, which in turn leads to impingement pain. Methods Eighty young elite swimmers (13–25 years of age) completed questionnaires on their swimming training, pain and shoulder function. They were given a standardised clinical shoulder examination, and tested for glenohumeral joint laxity using a non-invasive electronic laxometer. 52/80 swimmers also attended for shoulder MRI. Results 73/80 (91%) swimmers reported shoulder pain. Most (84%) had a positive impingement sign, and 69% of those examined with MRI had supraspinatus tendinopathy. The impingement sign and MRIdetermined supraspinatus tendinopathy correlated strongly (rs=0.49, p<0.00001). Increased tendon thickness correlated with supraspinatus tendinopathy (rs=0.37, p<0.01). Laxity correlated weakly with impingement pain (rs=0.23, p<0.05) and was not associated with supraspinatus tendinopathy (rs=0.14, p=0.32). The number of hours swum/week (rs=0.39, p<0.005) and weekly mileage (rs=0.34, p=0.01) both correlated significantly with supraspinatus tendinopathy. Swimming stroke preference did not. Conclusions These data indicate: (1) supraspinatus tendinopathy is the major cause of shoulder pain in elite swimmers; (2) this tendinopathy is induced by large amounts of swimming training; and (3) shoulder laxity per se has only a minimal association with shoulder impingement in elite swimmers. These findings are consistent with animal and tissue culture findings which support an alternate hypothesis: the intensity and duration of load to tendon fibres and cells cause tendinopathy, impingement and shoulder pain.

APP expression, distribution and accumulation are altered by aluminum in a rodent model for Alzheimer's disease.

Up-regulated expression of amyloid precursor protein (APP) occurs early in the cascade of events that leads to amyloid plaque formation in the human brain. APP gene up-regulation, mediated by activated NF-kappaB, is a response to stress from nM concentrations of aluminum ions, aluminum-disregulated iron ions, reactive-oxygen species, cytokines, and physical trauma. We examined in vivo effects of aluminum on APP in aged rats, obtained from previously-reported longitudinal studies, that chronically ingested aluminum in amounts equivalent to total dietary aluminum levels that Americans routinely ingest. These rats exhibited two outcomes: one group remained cognitively-intact, scoring as well on a memory-discrimination task in old age as in middle age. The other developed cognitive deterioration, obtaining significantly lower mean performance scores in old age than in middle age and exhibiting abnormal behaviors associated with dementia. We compared the expression, distribution and accumulation of APP in hippocampal and cortical tissue of these two rat groups. Compared to results from cognitively-intact rats, hippocampal and cortical tissue from the cognitively-deteriorated rats showed elevated APP gene expression, significantly more dense APP deposits in cytoplasm of neural cells, and APP-immunoreactive neurites that were swollen and varicose. This study shows aluminum routinely derived from chronic oral ingestion, that gradually accumulates in brain regions important for memory-processing, is sufficient to increase APP levels in neural cells of those regions. Aluminum may thus launch the cascade that results in the formation of amyloid plaques in human brain.

Matrix-induced autologous chondrocyte implantation of talus articular defects.

Background: Osteochondral injury of the talus can be challenging to treat because the damaged articular cartilage has a poor intrinsic reparative capability. Autologous Chondrocyte Implantation has become an effective means for treating persistent cartilage lesions that fail to respond to routine ankle arthroscopy. The purpose of this study was to assess the results of Matrix-induced autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the talar dome using a technique which does not require an osteotomy of the tibia or fibula. Materials and Methods: A prospective investigation of MACI was performed on ten patients with full-thickness lesions of the talus. The patients had a documented talus lesion on MRI, failure of conservative treatment and arthroscopic debridement/curettage, persistent ankle pain and swelling, the absence of tibiotalar arthritis and a stable ankle. Five males and five females, with an average of 1.7 previous procedures prior to Matrix-induced autologous implantation, were included in this study. All patients were available for followup at 1 and 2 years. Lesions were graded during the harvesting procedure using the Cheng-Ferkel grading system, the Outerbridge classification, and the International Cartilage Repair Society system. Clinical and functional evaluation was done preoperatively, and at 1 and 2 years postoperatively using the AOFAS hindfoot evaluation and the SF-36 Health Survey. Results: Preoperative AOFAS hindfoot scores were 61.2 (range, 42 to 76) which improved 1 year postoperatively to 74.7 (range, 46 to 87) (p < 0.05) and 2 years postoperatively to 73.3 (range, 42 to 90) (p = 0.151). At both 1 and 2 years postoperatively, the results of the SF36 evaluation demonstrated a significant improvement in the Physical Functioning (p = 0.002) and Bodily Pain (p < 0.001) components. Subjectively, all ten patients believed this procedure helped them. Conclusion: The results of this study suggest that MACI may be an effective way to treat full-thickness lesions of the talus using harvested chondrocytes from the talus without malleolar osteotomy. We recommend it for patients who do not respond to initial curettage and microfracture. Level of Evidence: IV, Retrospective Case Series

The Unstable Shoulder in the Adolescent Athlete

Shoulder dislocation and subluxation occur frequently in athletes, with peaks in the second and sixth decades. The majority of traumatic dislocations are in the anterior direction. The most frequent complication of shoulder dislocation is recurrence—a complication that occurs much more often in the adolescent population. The dynamic (muscular) and static (predominantly capsuloligamentous and labral) restraints to shoulder instability are now well defined. Recent surgical procedures for shoulder instability have become less interventional and have focused on restoring disrupted static restraints. The aim of rehabilitation is to enhance the dynamic muscular and proprioceptive restraints to shoulder instability.

A randomised clinical trial evaluating the efficacy of physiotherapy after rotator cuff repair

The optimal form of rehabilitation after rotator cuff repair has yet to be determined. A randomised clinical trial was undertaken to compare outcomes for two forms of rehabilitation for this condition: individualised supervised physiotherapy treatment, and a standardised unsupervised home exercise regime. Fifty-eight volunteers with all sizes of operatively repaired rotator cuff tears were allocated randomly to one of the two treatment groups. All subjects received a standardised home exercise regime. Subjects who were randomised to the physiotherapy group received additional individualised treatment. Independent, blinded assessments of range of motion, muscle force and functional outcome measures were performed pre-operatively, and at six, 12 and 24 weeks postoperation. At six, 12 and 24 weeks post-operation, comparable outcomes were demonstrated for both rehabilitation groups. By 24 weeks post-operation, most subjects demonstrated outcomes that were consistent with a favourable recovery, regardless of rehabilitation mode. On the basis of these results, outcomes for subjects allocated to individualised physiotherapy treatment after rotator cuff repair are no better than for subjects allocated to a standardised home exercise regime.

Effects of dietary restriction on radial-arm maze performance and flavor memory in aged rats

Two groups of aged rats, a dietary restricted group fed approximately 10 g per day from 6 weeks of age and a group fed ad lib throughout their life span, were compared with a young adult group on an 8-arm radial maze and a flavor memory task. The young adult displayed efficient performance on the radial-arm maze within the 15 day test period. In contrast, both aged groups exhibited significantly poorer performance in the maze in comparison with the young adult group neither aged group differed from chance at the end of the 15 days. The flavor memory task required the animals to consume a novel flavor. Their loss of neophobia, as indexed by their subsequent consumption, was then taken as an indication of the extent to which they remembered the novel flavor and its effects. The young adult group lost their neophobia more rapidly than either of the aged groups, which did not appear to differ from each other. Taken together, this pattern of results indicates that dietary restriction does not protect animals from the memory loss observed in aged animals.

Functional impairment in aged rats chronically exposed to human range dietary aluminum equivalents

Aluminum salts are ubiquitous in modern life. Yet, their possible adverse effects on human health remain to be determined. A longitudinal study was conducted in rats to assess whether chronic aluminum exposure at human-relevant dietary levels can alter performance on a hippocampal-dependent continuous alternation spatial memory discrimination T-maze task. From age 12 months onwards, three groups of rats trained to perform this task were chronically exposed to 0, 2, and 20ppm of aluminum in drinking water. When combined with the aluminum in their feed, these regimens resulted in approximately 0.4, 0.5 and 1.7mg aluminum (kg bodyweight day), designated as low, intermediate and higher aluminum doses. These levels are within the urban American dietary aluminum range. The rats were tested weekly during middle age (>or=12 to <24 months) and old age (>or=24 months) or until their terminal condition became apparent. Of the 30 rats that survived to at least 28 months, 0/10 on the lowest aluminum dose, 2/10 on the intermediate dose, and 7/10 on the higher dose attained significantly lower performance in old age than in middle age. Compared with rats whose T-maze performance remained intact, the rats with impaired performance had significantly higher serum aluminum levels (p<0.01) and cell counts indicating a larger percentage of aluminum-loaded pyramidal cells in their entorhinal cortex (p<0.05). Moreover, their percentage of aluminum-loaded entorhinal cortex cells correlated inversely with the decrease in their T-maze performance scores between middle age and old age (r=0.76, p<0.0005). The functionally-impaired rats also displayed aberrant behaviors including inability to focus attention on their task, perseverative activity, and incontinence while in the T-maze. Hence, in this longitudinal study, ingestion of 0.5mg aluminum/(kg bodyweight day) or more, consumed throughout most of adult life led, in old age, to a slowly-progressing condition that impaired cognitive function in susceptible rats.