The aim of our study was to assess, for the first time in a large study, whether there are radiological features of the acromioclavicular joint (ACJ) which vary with age or between genders and side. Clinical experience suggested that there was no clear correlation between the radiological features and symptoms arising from the ACJ. Therefore we also aimed to test the null hypothesis that there are no consistent radiological features which correspond with the need for surgical excision of the ACJ. We analysed 240 shoulder radiographs, divided into male and female, left and right shoulders, and decades from 20 to 80 years inclusive. At the ACJ the presence of sclerosis, osteophytes, cysts and lysis were recorded, and the width of the joint measured. These same parameters were assessed on the pre-operative radiographs for a group of 100 patients by a blinded observer. Fifty had undergone ASD (arthroscopic subacromial decompression), and 50 ASD with ACJ excision. These two groups were age matched. Statistical analyses were performed. There was no statistical difference between any of the parameters for gender or side however with increasing age there was a significantly increased incidence of joint space narrowing and increased features of osteoarthrosis. When comparing the matched ASD and the ACJ excision groups it was found that the presence of medial sclerosis (p = 0.016) and superior clavicular osteophytes (p = 0.016) were more common in the ACJ excision group. We concluded that there is a change in the radiological features of the ACJ with increasing age but not between sides or gender. The null hypothesis is upheld. Only 2 parameters, namely medial acromial sclerosis and superior clavicular osteophytes, are radiological features which correlate with a symptomatic acromioclavicular joint. These have poor sensitivity and specificity and therefore should not be used as a test.
The aim of our study was to assess, for the first time in a large study, whether there are radiological features of the acromioclavicular joint (ACJ) which vary with age or between genders and side. Clinical experience suggested that there was no clear correlation between the radiological features and symptoms arising from the ACJ. Therefore we also aimed to test the null hypothesis that there are no consistent radiological features which correspond with the need for surgical excision of the ACJ. We analysed 240 shoulder radiographs, divided into male and female, left and right shoulders, and decades from 20 to 80 years inclusive. At the ACJ the presence of sclerosis, osteophytes and cysts were recorded, and the width and angle of the joint measured. These same parameters were assessed on the preoperative radiographs for a group of 100 patients by a blinded observer. Fifty had undergone ASD (arthroscopic subacromial decompression), and 50 ASD with ACJ excision. These two groups were age matched. Statistical analyses were performed. There was no statistical difference between any of the parameters for gender or side however with increasing age there was a significantly increased incidence of acromial sclerosis and joint space narrowing. When comparing the matched ASD and the ACJ excision groups it was found that the presence of medial sclerosis of the acromium (p = 0.016) and superior clavicular osteophytes (p = 0.016) were more common in the ACJ excision group. We concluded that there is a change in the radiological features of the ACJ with increasing age but not between sides or gender. The null hypothesis has been rejected. The presence of either medial sclerosis of the acromium, and superior clavicular osteophytes, are radiological features which correlate with a symptomatic acromioclavicular joint.
The purpose of this study was to test the null hypothesis that patients with partial thickness rotator cuff tears do not suffer more pain or stiffness than those with full thickness tears. A power study determined that 68 partial thickness tears were required in the study in order to prove a clinically important difference (± = 0.05 and 2 = 0.2). Consecutive patients undergoing arthroscopy and bursoscopy for rotator cuff related problems were assessed using a pain analogue scale and their shoulder movements were measured. Information was gained both pre- and intra-operatively about possibly relevant confounders including age, site size and thickness of tears, and endocrine disorders. Exclusion criteria included glenohumeral arthropathy, frozen shoulder, instability and major traumatic injuries, as well as the inability to understand the pain score. 439 shoulders (428 patients) were included in the study; 216 shoulders had no cuff tear, 95 had partial thickness tears (75 joint side, 1 intrasubstance, 19 bursal side), and 128 shoulders had full thickness tears. There was no significant difference (p<
0.05) in the pain scores or range of movement between full and partial thickness tears. Age was the only independent variable to have an effect on pain score. The null hypothesis has been upheld. This study contradicts the findings of previous research and challenges commonly held assertions on this topic. Neither pain nor stiffness can be used clinically as discriminators between partial and full thickness rotator cuff tears.
The coraco-acromial ligament (CAL) is partially resected during a subacromial decompression. Clinical studies have reported the regeneration of a structure which appears to be a new CAL. Histological studies of regenerated CAL have demonstrated an abundance of relatively acellular collagen fibrils orientated in the line of a ligament and mechanical testing of the regenerated tissue has properties similar to those of normal CAL. However it is still not clear whether this structure represents scar tissue or truly reformed ligament. Defining the major collagen constituent of this regenerated tissue would allow the distinction between ligament and scar tissue. Therefore the aim of this study was to examine the level of expression of types I and III collagen in regenerated coraco-acromial ligaments (CAL) in humans. Samples of regenerated CAL were obtained during open surgery for repair of small rotator cuff tears at an average of 24 months (range 14 to 52) after arthroscopic subacromial decompression from 4 men and 3 women with an average age of 58 years (range 44 to 68). A standard protocol radio-active in-situ immunolocalisation technique was used to quantify the ratios of mRNA collagen I to collagen III in the samples. The results demonstrated that the average ratio of collagen I to collagen III was 6.5. This ratio is similar to the value for normal hip capsule (5–6:1) and human posterior cruciate ligament (8:1). We conclude that the reformed CALs are ligamentous structures, not scar tissue, and therefore represent truly regenerated ligaments.
Use of shoulder manipulation in the treatment of frozen shoulder (FS) remains controversial. One of the purported risks associated with the procedure is the development of a rotator cuff tear. However the incidence of iatrogenic rotator cuff tears has not been reported. The purpose of the study was to assess the effect of manipulation of the shoulder on the integrity of the rotator cuff. In a prospective study 20 consecutive patients (21 shoulders) with FS underwent manipulation of the shoulder under anaesthesia (MUA). The average duration of symptoms was 7.3 months (4–18 months). Patients were assessed pre and post manipulation using the Constant score. An ultrasound scan of the rotator cuff was performed before and at 3 weeks after manipulation. In all patients, pre and post manipulation ultrasound scans showed the rotator cuff to be intact. At 12 weeks after manipulation all patients indicated that they had none or only occasional pain. The mean improvement in motion was 83 degrees (range, 20 – 100°) for flexion, 95 degrees (range, 20 – 120°) for abduction, 58 degrees (range, 0 – 80°) for external rotation and 3 levels of internal rotation (range 3–5 levels). These gains in motion were all significant (p <
0.01). No fractures, dislocations or nerve palsies were observed. In conclusion manipulation under anaesthesia for treatment of frozen shoulder resulted in significant improvements in shoulder function and pain relief as early as 3 weeks after surgery and was not associated with rotator cuff tears. When performed carefully this procedure is safe and leads to early improvements in pain relief, range of movement and shoulder function.
Atrophic non-unions are usually attributed to impaired blood supply but the events that lead to atrophic non-union remain poorly understood. Recent studies Twenty eight adult female Wistar rats underwent application of a novel circular frame external fixator to the right tibia under general anaesthesia. The fixator construct was standardised, with eight needles that were drilled through the skin into the proximal and distal metaphyses of the tibia. An osteotomy was performed with a 1mm burr under irrigation. The periosteum was removed on 14 of the 28 animals using a scalpel and the intramedullary canal was curetted. Both insults were performed proximally and distally for a distance equivalent to 1 diameter of the tibia. A 1mm gap was introduced at the osteotomy site and the wound was closed. Once the animal had recovered it was allowed unrestricted weight bearing. Anteroposterior X rays were performed every 2 weeks. Animals were killed at 1, 3, 8 and 16 weeks. Callus areas were measured from X rays using an image analysis system. The average callus area was calculated for each rat every 2 weeks as an indicator of callus production. Specimens were fixed, decalcified, embedded in paraffin wax and 6 ìm sections were stained with H&
E. Vascularity was assessed immunohistochemically with monoclonal antibody against smooth muscle actin. The total number of blood vessels in the interfragmentary gap was counted. At 8 and 16 weeks post-osteotomy all animals where stripping and curetting had been performed went on to an atrophic non-union. All animals where this was not performed went on to unite successfully. Histological observations support these radiological findings. Significantly less callus formed in the non-unions than in those that united. There were significantly fewer vessels in the non-unions at week 1 compared to the controls but, by 8 weeks the blood vessel density in the established atrophic non-unions had reached the same level as the vessel density during normal healing. An atrophic non-union model that closely resembles the clinical situation has been developed and validated in rats. The results support the hypothesis that the number of vessels in atrophic non-unions reaches the same level as in those that unite but at a later time point. It is concluded that diminished vessel density within the first 3 weeks may prevent fractures from uniting.
During fracture repair, a number of growth factors and cytokines are present at elevated levels at the fracture site such as Transforming Growth Factor Beta (TGF-), Fibroblast Growth Factor (FGF) and Platelet Derived Growth Factor (PDGF). The aim of the study was to investigate the presence of these growth factors in healing fractures and fracture non-unions, in order to test the hypothesis that atrophic non-unions express a lower level of growth factors than hypertrophic non-unions and healing fractures. Biopsies were taken from the fracture site of 23 patients (mean age 46) with uninfected non-unions, 12 patients with hypertrophic (mean 13.8 months after fracture) and 11 patients with atrophic (mean 16.5 months after fracture). A comparison group of biopsies from early fracture callus (one to four weeks after fracture) in five patients with healing fractures was also included. Five-micron paraffin sections were immunohistochemically stained for TGF-, FGF-II and PDGF. Growth factors were then assessed in six different cell types. Fibroblasts, endothelial cells and macrophages were found to express TGF-, FGF-II and PDGF in all three-fracture groups. Osteoblasts, osteoclasts and chondrocytes were not present in the healing fracture group. The growth factor expression in osteoblasts, osteoclasts and chondrocytes in the non-union groups were found to be variable, however, the expression of these growth factors appeared to be less in the atrophic non-unions than hypertrophic non-unions. The expression of these growth factors was found to be less in the atrophic non-union group than the hypertrophic non-union group in osteoblasts, osteoclasts and chondrocytes. These results may have relevance for new therapies that can be aimed at delivering growth factors to treat fracture non-unions. By further investigation of the differential expression of these growth factors it may be possible to determine which factors are likely to stimulate fracture healing.